Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / mtd / nand / gpmi-nand / gpmi-nand.c
diff --git a/kernel/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/kernel/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
new file mode 100644 (file)
index 0000000..1b8f350
--- /dev/null
@@ -0,0 +1,2051 @@
+/*
+ * Freescale GPMI NAND Flash Driver
+ *
+ * Copyright (C) 2010-2011 Freescale Semiconductor, Inc.
+ * Copyright (C) 2008 Embedded Alley Solutions, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_mtd.h>
+#include "gpmi-nand.h"
+#include "bch-regs.h"
+
+/* Resource names for the GPMI NAND driver. */
+#define GPMI_NAND_GPMI_REGS_ADDR_RES_NAME  "gpmi-nand"
+#define GPMI_NAND_BCH_REGS_ADDR_RES_NAME   "bch"
+#define GPMI_NAND_BCH_INTERRUPT_RES_NAME   "bch"
+
+/* add our owner bbt descriptor */
+static uint8_t scan_ff_pattern[] = { 0xff };
+static struct nand_bbt_descr gpmi_bbt_descr = {
+       .options        = 0,
+       .offs           = 0,
+       .len            = 1,
+       .pattern        = scan_ff_pattern
+};
+
+/*
+ * We may change the layout if we can get the ECC info from the datasheet,
+ * else we will use all the (page + OOB).
+ */
+static struct nand_ecclayout gpmi_hw_ecclayout = {
+       .eccbytes = 0,
+       .eccpos = { 0, },
+       .oobfree = { {.offset = 0, .length = 0} }
+};
+
+static const struct gpmi_devdata gpmi_devdata_imx23 = {
+       .type = IS_MX23,
+       .bch_max_ecc_strength = 20,
+       .max_chain_delay = 16,
+};
+
+static const struct gpmi_devdata gpmi_devdata_imx28 = {
+       .type = IS_MX28,
+       .bch_max_ecc_strength = 20,
+       .max_chain_delay = 16,
+};
+
+static const struct gpmi_devdata gpmi_devdata_imx6q = {
+       .type = IS_MX6Q,
+       .bch_max_ecc_strength = 40,
+       .max_chain_delay = 12,
+};
+
+static const struct gpmi_devdata gpmi_devdata_imx6sx = {
+       .type = IS_MX6SX,
+       .bch_max_ecc_strength = 62,
+       .max_chain_delay = 12,
+};
+
+static irqreturn_t bch_irq(int irq, void *cookie)
+{
+       struct gpmi_nand_data *this = cookie;
+
+       gpmi_clear_bch(this);
+       complete(&this->bch_done);
+       return IRQ_HANDLED;
+}
+
+/*
+ *  Calculate the ECC strength by hand:
+ *     E : The ECC strength.
+ *     G : the length of Galois Field.
+ *     N : The chunk count of per page.
+ *     O : the oobsize of the NAND chip.
+ *     M : the metasize of per page.
+ *
+ *     The formula is :
+ *             E * G * N
+ *           ------------ <= (O - M)
+ *                  8
+ *
+ *      So, we get E by:
+ *                    (O - M) * 8
+ *              E <= -------------
+ *                       G * N
+ */
+static inline int get_ecc_strength(struct gpmi_nand_data *this)
+{
+       struct bch_geometry *geo = &this->bch_geometry;
+       struct mtd_info *mtd = &this->mtd;
+       int ecc_strength;
+
+       ecc_strength = ((mtd->oobsize - geo->metadata_size) * 8)
+                       / (geo->gf_len * geo->ecc_chunk_count);
+
+       /* We need the minor even number. */
+       return round_down(ecc_strength, 2);
+}
+
+static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
+{
+       struct bch_geometry *geo = &this->bch_geometry;
+
+       /* Do the sanity check. */
+       if (GPMI_IS_MX23(this) || GPMI_IS_MX28(this)) {
+               /* The mx23/mx28 only support the GF13. */
+               if (geo->gf_len == 14)
+                       return false;
+       }
+       return geo->ecc_strength <= this->devdata->bch_max_ecc_strength;
+}
+
+/*
+ * If we can get the ECC information from the nand chip, we do not
+ * need to calculate them ourselves.
+ *
+ * We may have available oob space in this case.
+ */
+static bool set_geometry_by_ecc_info(struct gpmi_nand_data *this)
+{
+       struct bch_geometry *geo = &this->bch_geometry;
+       struct mtd_info *mtd = &this->mtd;
+       struct nand_chip *chip = mtd->priv;
+       struct nand_oobfree *of = gpmi_hw_ecclayout.oobfree;
+       unsigned int block_mark_bit_offset;
+
+       if (!(chip->ecc_strength_ds > 0 && chip->ecc_step_ds > 0))
+               return false;
+
+       switch (chip->ecc_step_ds) {
+       case SZ_512:
+               geo->gf_len = 13;
+               break;
+       case SZ_1K:
+               geo->gf_len = 14;
+               break;
+       default:
+               dev_err(this->dev,
+                       "unsupported nand chip. ecc bits : %d, ecc size : %d\n",
+                       chip->ecc_strength_ds, chip->ecc_step_ds);
+               return false;
+       }
+       geo->ecc_chunk_size = chip->ecc_step_ds;
+       geo->ecc_strength = round_up(chip->ecc_strength_ds, 2);
+       if (!gpmi_check_ecc(this))
+               return false;
+
+       /* Keep the C >= O */
+       if (geo->ecc_chunk_size < mtd->oobsize) {
+               dev_err(this->dev,
+                       "unsupported nand chip. ecc size: %d, oob size : %d\n",
+                       chip->ecc_step_ds, mtd->oobsize);
+               return false;
+       }
+
+       /* The default value, see comment in the legacy_set_geometry(). */
+       geo->metadata_size = 10;
+
+       geo->ecc_chunk_count = mtd->writesize / geo->ecc_chunk_size;
+
+       /*
+        * Now, the NAND chip with 2K page(data chunk is 512byte) shows below:
+        *
+        *    |                          P                            |
+        *    |<----------------------------------------------------->|
+        *    |                                                       |
+        *    |                                        (Block Mark)   |
+        *    |                      P'                      |      | |     |
+        *    |<-------------------------------------------->|  D   | |  O' |
+        *    |                                              |<---->| |<--->|
+        *    V                                              V      V V     V
+        *    +---+----------+-+----------+-+----------+-+----------+-+-----+
+        *    | M |   data   |E|   data   |E|   data   |E|   data   |E|     |
+        *    +---+----------+-+----------+-+----------+-+----------+-+-----+
+        *                                                   ^              ^
+        *                                                   |      O       |
+        *                                                   |<------------>|
+        *                                                   |              |
+        *
+        *      P : the page size for BCH module.
+        *      E : The ECC strength.
+        *      G : the length of Galois Field.
+        *      N : The chunk count of per page.
+        *      M : the metasize of per page.
+        *      C : the ecc chunk size, aka the "data" above.
+        *      P': the nand chip's page size.
+        *      O : the nand chip's oob size.
+        *      O': the free oob.
+        *
+        *      The formula for P is :
+        *
+        *                  E * G * N
+        *             P = ------------ + P' + M
+        *                      8
+        *
+        * The position of block mark moves forward in the ECC-based view
+        * of page, and the delta is:
+        *
+        *                   E * G * (N - 1)
+        *             D = (---------------- + M)
+        *                          8
+        *
+        * Please see the comment in legacy_set_geometry().
+        * With the condition C >= O , we still can get same result.
+        * So the bit position of the physical block mark within the ECC-based
+        * view of the page is :
+        *             (P' - D) * 8
+        */
+       geo->page_size = mtd->writesize + geo->metadata_size +
+               (geo->gf_len * geo->ecc_strength * geo->ecc_chunk_count) / 8;
+
+       /* The available oob size we have. */
+       if (geo->page_size < mtd->writesize + mtd->oobsize) {
+               of->offset = geo->page_size - mtd->writesize;
+               of->length = mtd->oobsize - of->offset;
+       }
+
+       geo->payload_size = mtd->writesize;
+
+       geo->auxiliary_status_offset = ALIGN(geo->metadata_size, 4);
+       geo->auxiliary_size = ALIGN(geo->metadata_size, 4)
+                               + ALIGN(geo->ecc_chunk_count, 4);
+
+       if (!this->swap_block_mark)
+               return true;
+
+       /* For bit swap. */
+       block_mark_bit_offset = mtd->writesize * 8 -
+               (geo->ecc_strength * geo->gf_len * (geo->ecc_chunk_count - 1)
+                               + geo->metadata_size * 8);
+
+       geo->block_mark_byte_offset = block_mark_bit_offset / 8;
+       geo->block_mark_bit_offset  = block_mark_bit_offset % 8;
+       return true;
+}
+
+static int legacy_set_geometry(struct gpmi_nand_data *this)
+{
+       struct bch_geometry *geo = &this->bch_geometry;
+       struct mtd_info *mtd = &this->mtd;
+       unsigned int metadata_size;
+       unsigned int status_size;
+       unsigned int block_mark_bit_offset;
+
+       /*
+        * The size of the metadata can be changed, though we set it to 10
+        * bytes now. But it can't be too large, because we have to save
+        * enough space for BCH.
+        */
+       geo->metadata_size = 10;
+
+       /* The default for the length of Galois Field. */
+       geo->gf_len = 13;
+
+       /* The default for chunk size. */
+       geo->ecc_chunk_size = 512;
+       while (geo->ecc_chunk_size < mtd->oobsize) {
+               geo->ecc_chunk_size *= 2; /* keep C >= O */
+               geo->gf_len = 14;
+       }
+
+       geo->ecc_chunk_count = mtd->writesize / geo->ecc_chunk_size;
+
+       /* We use the same ECC strength for all chunks. */
+       geo->ecc_strength = get_ecc_strength(this);
+       if (!gpmi_check_ecc(this)) {
+               dev_err(this->dev,
+                       "required ecc strength of the NAND chip: %d is not supported by the GPMI controller (%d)\n",
+                       geo->ecc_strength,
+                       this->devdata->bch_max_ecc_strength);
+               return -EINVAL;
+       }
+
+       geo->page_size = mtd->writesize + mtd->oobsize;
+       geo->payload_size = mtd->writesize;
+
+       /*
+        * The auxiliary buffer contains the metadata and the ECC status. The
+        * metadata is padded to the nearest 32-bit boundary. The ECC status
+        * contains one byte for every ECC chunk, and is also padded to the
+        * nearest 32-bit boundary.
+        */
+       metadata_size = ALIGN(geo->metadata_size, 4);
+       status_size   = ALIGN(geo->ecc_chunk_count, 4);
+
+       geo->auxiliary_size = metadata_size + status_size;
+       geo->auxiliary_status_offset = metadata_size;
+
+       if (!this->swap_block_mark)
+               return 0;
+
+       /*
+        * We need to compute the byte and bit offsets of
+        * the physical block mark within the ECC-based view of the page.
+        *
+        * NAND chip with 2K page shows below:
+        *                                             (Block Mark)
+        *                                                   |      |
+        *                                                   |  D   |
+        *                                                   |<---->|
+        *                                                   V      V
+        *    +---+----------+-+----------+-+----------+-+----------+-+
+        *    | M |   data   |E|   data   |E|   data   |E|   data   |E|
+        *    +---+----------+-+----------+-+----------+-+----------+-+
+        *
+        * The position of block mark moves forward in the ECC-based view
+        * of page, and the delta is:
+        *
+        *                   E * G * (N - 1)
+        *             D = (---------------- + M)
+        *                          8
+        *
+        * With the formula to compute the ECC strength, and the condition
+        *       : C >= O         (C is the ecc chunk size)
+        *
+        * It's easy to deduce to the following result:
+        *
+        *         E * G       (O - M)      C - M         C - M
+        *      ----------- <= ------- <=  --------  <  ---------
+        *           8            N           N          (N - 1)
+        *
+        *  So, we get:
+        *
+        *                   E * G * (N - 1)
+        *             D = (---------------- + M) < C
+        *                          8
+        *
+        *  The above inequality means the position of block mark
+        *  within the ECC-based view of the page is still in the data chunk,
+        *  and it's NOT in the ECC bits of the chunk.
+        *
+        *  Use the following to compute the bit position of the
+        *  physical block mark within the ECC-based view of the page:
+        *          (page_size - D) * 8
+        *
+        *  --Huang Shijie
+        */
+       block_mark_bit_offset = mtd->writesize * 8 -
+               (geo->ecc_strength * geo->gf_len * (geo->ecc_chunk_count - 1)
+                               + geo->metadata_size * 8);
+
+       geo->block_mark_byte_offset = block_mark_bit_offset / 8;
+       geo->block_mark_bit_offset  = block_mark_bit_offset % 8;
+       return 0;
+}
+
+int common_nfc_set_geometry(struct gpmi_nand_data *this)
+{
+       if (of_property_read_bool(this->dev->of_node, "fsl,use-minimum-ecc")
+               && set_geometry_by_ecc_info(this))
+               return 0;
+       return legacy_set_geometry(this);
+}
+
+struct dma_chan *get_dma_chan(struct gpmi_nand_data *this)
+{
+       /* We use the DMA channel 0 to access all the nand chips. */
+       return this->dma_chans[0];
+}
+
+/* Can we use the upper's buffer directly for DMA? */
+void prepare_data_dma(struct gpmi_nand_data *this, enum dma_data_direction dr)
+{
+       struct scatterlist *sgl = &this->data_sgl;
+       int ret;
+
+       /* first try to map the upper buffer directly */
+       if (virt_addr_valid(this->upper_buf) &&
+               !object_is_on_stack(this->upper_buf)) {
+               sg_init_one(sgl, this->upper_buf, this->upper_len);
+               ret = dma_map_sg(this->dev, sgl, 1, dr);
+               if (ret == 0)
+                       goto map_fail;
+
+               this->direct_dma_map_ok = true;
+               return;
+       }
+
+map_fail:
+       /* We have to use our own DMA buffer. */
+       sg_init_one(sgl, this->data_buffer_dma, this->upper_len);
+
+       if (dr == DMA_TO_DEVICE)
+               memcpy(this->data_buffer_dma, this->upper_buf, this->upper_len);
+
+       dma_map_sg(this->dev, sgl, 1, dr);
+
+       this->direct_dma_map_ok = false;
+}
+
+/* This will be called after the DMA operation is finished. */
+static void dma_irq_callback(void *param)
+{
+       struct gpmi_nand_data *this = param;
+       struct completion *dma_c = &this->dma_done;
+
+       switch (this->dma_type) {
+       case DMA_FOR_COMMAND:
+               dma_unmap_sg(this->dev, &this->cmd_sgl, 1, DMA_TO_DEVICE);
+               break;
+
+       case DMA_FOR_READ_DATA:
+               dma_unmap_sg(this->dev, &this->data_sgl, 1, DMA_FROM_DEVICE);
+               if (this->direct_dma_map_ok == false)
+                       memcpy(this->upper_buf, this->data_buffer_dma,
+                               this->upper_len);
+               break;
+
+       case DMA_FOR_WRITE_DATA:
+               dma_unmap_sg(this->dev, &this->data_sgl, 1, DMA_TO_DEVICE);
+               break;
+
+       case DMA_FOR_READ_ECC_PAGE:
+       case DMA_FOR_WRITE_ECC_PAGE:
+               /* We have to wait the BCH interrupt to finish. */
+               break;
+
+       default:
+               dev_err(this->dev, "in wrong DMA operation.\n");
+       }
+
+       complete(dma_c);
+}
+
+int start_dma_without_bch_irq(struct gpmi_nand_data *this,
+                               struct dma_async_tx_descriptor *desc)
+{
+       struct completion *dma_c = &this->dma_done;
+       unsigned long timeout;
+
+       init_completion(dma_c);
+
+       desc->callback          = dma_irq_callback;
+       desc->callback_param    = this;
+       dmaengine_submit(desc);
+       dma_async_issue_pending(get_dma_chan(this));
+
+       /* Wait for the interrupt from the DMA block. */
+       timeout = wait_for_completion_timeout(dma_c, msecs_to_jiffies(1000));
+       if (!timeout) {
+               dev_err(this->dev, "DMA timeout, last DMA :%d\n",
+                       this->last_dma_type);
+               gpmi_dump_info(this);
+               return -ETIMEDOUT;
+       }
+       return 0;
+}
+
+/*
+ * This function is used in BCH reading or BCH writing pages.
+ * It will wait for the BCH interrupt as long as ONE second.
+ * Actually, we must wait for two interrupts :
+ *     [1] firstly the DMA interrupt and
+ *     [2] secondly the BCH interrupt.
+ */
+int start_dma_with_bch_irq(struct gpmi_nand_data *this,
+                       struct dma_async_tx_descriptor *desc)
+{
+       struct completion *bch_c = &this->bch_done;
+       unsigned long timeout;
+
+       /* Prepare to receive an interrupt from the BCH block. */
+       init_completion(bch_c);
+
+       /* start the DMA */
+       start_dma_without_bch_irq(this, desc);
+
+       /* Wait for the interrupt from the BCH block. */
+       timeout = wait_for_completion_timeout(bch_c, msecs_to_jiffies(1000));
+       if (!timeout) {
+               dev_err(this->dev, "BCH timeout, last DMA :%d\n",
+                       this->last_dma_type);
+               gpmi_dump_info(this);
+               return -ETIMEDOUT;
+       }
+       return 0;
+}
+
+static int acquire_register_block(struct gpmi_nand_data *this,
+                                 const char *res_name)
+{
+       struct platform_device *pdev = this->pdev;
+       struct resources *res = &this->resources;
+       struct resource *r;
+       void __iomem *p;
+
+       r = platform_get_resource_byname(pdev, IORESOURCE_MEM, res_name);
+       p = devm_ioremap_resource(&pdev->dev, r);
+       if (IS_ERR(p))
+               return PTR_ERR(p);
+
+       if (!strcmp(res_name, GPMI_NAND_GPMI_REGS_ADDR_RES_NAME))
+               res->gpmi_regs = p;
+       else if (!strcmp(res_name, GPMI_NAND_BCH_REGS_ADDR_RES_NAME))
+               res->bch_regs = p;
+       else
+               dev_err(this->dev, "unknown resource name : %s\n", res_name);
+
+       return 0;
+}
+
+static int acquire_bch_irq(struct gpmi_nand_data *this, irq_handler_t irq_h)
+{
+       struct platform_device *pdev = this->pdev;
+       const char *res_name = GPMI_NAND_BCH_INTERRUPT_RES_NAME;
+       struct resource *r;
+       int err;
+
+       r = platform_get_resource_byname(pdev, IORESOURCE_IRQ, res_name);
+       if (!r) {
+               dev_err(this->dev, "Can't get resource for %s\n", res_name);
+               return -ENODEV;
+       }
+
+       err = devm_request_irq(this->dev, r->start, irq_h, 0, res_name, this);
+       if (err)
+               dev_err(this->dev, "error requesting BCH IRQ\n");
+
+       return err;
+}
+
+static void release_dma_channels(struct gpmi_nand_data *this)
+{
+       unsigned int i;
+       for (i = 0; i < DMA_CHANS; i++)
+               if (this->dma_chans[i]) {
+                       dma_release_channel(this->dma_chans[i]);
+                       this->dma_chans[i] = NULL;
+               }
+}
+
+static int acquire_dma_channels(struct gpmi_nand_data *this)
+{
+       struct platform_device *pdev = this->pdev;
+       struct dma_chan *dma_chan;
+
+       /* request dma channel */
+       dma_chan = dma_request_slave_channel(&pdev->dev, "rx-tx");
+       if (!dma_chan) {
+               dev_err(this->dev, "Failed to request DMA channel.\n");
+               goto acquire_err;
+       }
+
+       this->dma_chans[0] = dma_chan;
+       return 0;
+
+acquire_err:
+       release_dma_channels(this);
+       return -EINVAL;
+}
+
+static char *extra_clks_for_mx6q[GPMI_CLK_MAX] = {
+       "gpmi_apb", "gpmi_bch", "gpmi_bch_apb", "per1_bch",
+};
+
+static int gpmi_get_clks(struct gpmi_nand_data *this)
+{
+       struct resources *r = &this->resources;
+       char **extra_clks = NULL;
+       struct clk *clk;
+       int err, i;
+
+       /* The main clock is stored in the first. */
+       r->clock[0] = devm_clk_get(this->dev, "gpmi_io");
+       if (IS_ERR(r->clock[0])) {
+               err = PTR_ERR(r->clock[0]);
+               goto err_clock;
+       }
+
+       /* Get extra clocks */
+       if (GPMI_IS_MX6(this))
+               extra_clks = extra_clks_for_mx6q;
+       if (!extra_clks)
+               return 0;
+
+       for (i = 1; i < GPMI_CLK_MAX; i++) {
+               if (extra_clks[i - 1] == NULL)
+                       break;
+
+               clk = devm_clk_get(this->dev, extra_clks[i - 1]);
+               if (IS_ERR(clk)) {
+                       err = PTR_ERR(clk);
+                       goto err_clock;
+               }
+
+               r->clock[i] = clk;
+       }
+
+       if (GPMI_IS_MX6(this))
+               /*
+                * Set the default value for the gpmi clock.
+                *
+                * If you want to use the ONFI nand which is in the
+                * Synchronous Mode, you should change the clock as you need.
+                */
+               clk_set_rate(r->clock[0], 22000000);
+
+       return 0;
+
+err_clock:
+       dev_dbg(this->dev, "failed in finding the clocks.\n");
+       return err;
+}
+
+static int acquire_resources(struct gpmi_nand_data *this)
+{
+       int ret;
+
+       ret = acquire_register_block(this, GPMI_NAND_GPMI_REGS_ADDR_RES_NAME);
+       if (ret)
+               goto exit_regs;
+
+       ret = acquire_register_block(this, GPMI_NAND_BCH_REGS_ADDR_RES_NAME);
+       if (ret)
+               goto exit_regs;
+
+       ret = acquire_bch_irq(this, bch_irq);
+       if (ret)
+               goto exit_regs;
+
+       ret = acquire_dma_channels(this);
+       if (ret)
+               goto exit_regs;
+
+       ret = gpmi_get_clks(this);
+       if (ret)
+               goto exit_clock;
+       return 0;
+
+exit_clock:
+       release_dma_channels(this);
+exit_regs:
+       return ret;
+}
+
+static void release_resources(struct gpmi_nand_data *this)
+{
+       release_dma_channels(this);
+}
+
+static int init_hardware(struct gpmi_nand_data *this)
+{
+       int ret;
+
+       /*
+        * This structure contains the "safe" GPMI timing that should succeed
+        * with any NAND Flash device
+        * (although, with less-than-optimal performance).
+        */
+       struct nand_timing  safe_timing = {
+               .data_setup_in_ns        = 80,
+               .data_hold_in_ns         = 60,
+               .address_setup_in_ns     = 25,
+               .gpmi_sample_delay_in_ns =  6,
+               .tREA_in_ns              = -1,
+               .tRLOH_in_ns             = -1,
+               .tRHOH_in_ns             = -1,
+       };
+
+       /* Initialize the hardwares. */
+       ret = gpmi_init(this);
+       if (ret)
+               return ret;
+
+       this->timing = safe_timing;
+       return 0;
+}
+
+static int read_page_prepare(struct gpmi_nand_data *this,
+                       void *destination, unsigned length,
+                       void *alt_virt, dma_addr_t alt_phys, unsigned alt_size,
+                       void **use_virt, dma_addr_t *use_phys)
+{
+       struct device *dev = this->dev;
+
+       if (virt_addr_valid(destination)) {
+               dma_addr_t dest_phys;
+
+               dest_phys = dma_map_single(dev, destination,
+                                               length, DMA_FROM_DEVICE);
+               if (dma_mapping_error(dev, dest_phys)) {
+                       if (alt_size < length) {
+                               dev_err(dev, "Alternate buffer is too small\n");
+                               return -ENOMEM;
+                       }
+                       goto map_failed;
+               }
+               *use_virt = destination;
+               *use_phys = dest_phys;
+               this->direct_dma_map_ok = true;
+               return 0;
+       }
+
+map_failed:
+       *use_virt = alt_virt;
+       *use_phys = alt_phys;
+       this->direct_dma_map_ok = false;
+       return 0;
+}
+
+static inline void read_page_end(struct gpmi_nand_data *this,
+                       void *destination, unsigned length,
+                       void *alt_virt, dma_addr_t alt_phys, unsigned alt_size,
+                       void *used_virt, dma_addr_t used_phys)
+{
+       if (this->direct_dma_map_ok)
+               dma_unmap_single(this->dev, used_phys, length, DMA_FROM_DEVICE);
+}
+
+static inline void read_page_swap_end(struct gpmi_nand_data *this,
+                       void *destination, unsigned length,
+                       void *alt_virt, dma_addr_t alt_phys, unsigned alt_size,
+                       void *used_virt, dma_addr_t used_phys)
+{
+       if (!this->direct_dma_map_ok)
+               memcpy(destination, alt_virt, length);
+}
+
+static int send_page_prepare(struct gpmi_nand_data *this,
+                       const void *source, unsigned length,
+                       void *alt_virt, dma_addr_t alt_phys, unsigned alt_size,
+                       const void **use_virt, dma_addr_t *use_phys)
+{
+       struct device *dev = this->dev;
+
+       if (virt_addr_valid(source)) {
+               dma_addr_t source_phys;
+
+               source_phys = dma_map_single(dev, (void *)source, length,
+                                               DMA_TO_DEVICE);
+               if (dma_mapping_error(dev, source_phys)) {
+                       if (alt_size < length) {
+                               dev_err(dev, "Alternate buffer is too small\n");
+                               return -ENOMEM;
+                       }
+                       goto map_failed;
+               }
+               *use_virt = source;
+               *use_phys = source_phys;
+               return 0;
+       }
+map_failed:
+       /*
+        * Copy the content of the source buffer into the alternate
+        * buffer and set up the return values accordingly.
+        */
+       memcpy(alt_virt, source, length);
+
+       *use_virt = alt_virt;
+       *use_phys = alt_phys;
+       return 0;
+}
+
+static void send_page_end(struct gpmi_nand_data *this,
+                       const void *source, unsigned length,
+                       void *alt_virt, dma_addr_t alt_phys, unsigned alt_size,
+                       const void *used_virt, dma_addr_t used_phys)
+{
+       struct device *dev = this->dev;
+       if (used_virt == source)
+               dma_unmap_single(dev, used_phys, length, DMA_TO_DEVICE);
+}
+
+static void gpmi_free_dma_buffer(struct gpmi_nand_data *this)
+{
+       struct device *dev = this->dev;
+
+       if (this->page_buffer_virt && virt_addr_valid(this->page_buffer_virt))
+               dma_free_coherent(dev, this->page_buffer_size,
+                                       this->page_buffer_virt,
+                                       this->page_buffer_phys);
+       kfree(this->cmd_buffer);
+       kfree(this->data_buffer_dma);
+       kfree(this->raw_buffer);
+
+       this->cmd_buffer        = NULL;
+       this->data_buffer_dma   = NULL;
+       this->page_buffer_virt  = NULL;
+       this->page_buffer_size  =  0;
+}
+
+/* Allocate the DMA buffers */
+static int gpmi_alloc_dma_buffer(struct gpmi_nand_data *this)
+{
+       struct bch_geometry *geo = &this->bch_geometry;
+       struct device *dev = this->dev;
+       struct mtd_info *mtd = &this->mtd;
+
+       /* [1] Allocate a command buffer. PAGE_SIZE is enough. */
+       this->cmd_buffer = kzalloc(PAGE_SIZE, GFP_DMA | GFP_KERNEL);
+       if (this->cmd_buffer == NULL)
+               goto error_alloc;
+
+       /*
+        * [2] Allocate a read/write data buffer.
+        *     The gpmi_alloc_dma_buffer can be called twice.
+        *     We allocate a PAGE_SIZE length buffer if gpmi_alloc_dma_buffer
+        *     is called before the nand_scan_ident; and we allocate a buffer
+        *     of the real NAND page size when the gpmi_alloc_dma_buffer is
+        *     called after the nand_scan_ident.
+        */
+       this->data_buffer_dma = kzalloc(mtd->writesize ?: PAGE_SIZE,
+                                       GFP_DMA | GFP_KERNEL);
+       if (this->data_buffer_dma == NULL)
+               goto error_alloc;
+
+       /*
+        * [3] Allocate the page buffer.
+        *
+        * Both the payload buffer and the auxiliary buffer must appear on
+        * 32-bit boundaries. We presume the size of the payload buffer is a
+        * power of two and is much larger than four, which guarantees the
+        * auxiliary buffer will appear on a 32-bit boundary.
+        */
+       this->page_buffer_size = geo->payload_size + geo->auxiliary_size;
+       this->page_buffer_virt = dma_alloc_coherent(dev, this->page_buffer_size,
+                                       &this->page_buffer_phys, GFP_DMA);
+       if (!this->page_buffer_virt)
+               goto error_alloc;
+
+       this->raw_buffer = kzalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL);
+       if (!this->raw_buffer)
+               goto error_alloc;
+
+       /* Slice up the page buffer. */
+       this->payload_virt = this->page_buffer_virt;
+       this->payload_phys = this->page_buffer_phys;
+       this->auxiliary_virt = this->payload_virt + geo->payload_size;
+       this->auxiliary_phys = this->payload_phys + geo->payload_size;
+       return 0;
+
+error_alloc:
+       gpmi_free_dma_buffer(this);
+       return -ENOMEM;
+}
+
+static void gpmi_cmd_ctrl(struct mtd_info *mtd, int data, unsigned int ctrl)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct gpmi_nand_data *this = chip->priv;
+       int ret;
+
+       /*
+        * Every operation begins with a command byte and a series of zero or
+        * more address bytes. These are distinguished by either the Address
+        * Latch Enable (ALE) or Command Latch Enable (CLE) signals being
+        * asserted. When MTD is ready to execute the command, it will deassert
+        * both latch enables.
+        *
+        * Rather than run a separate DMA operation for every single byte, we
+        * queue them up and run a single DMA operation for the entire series
+        * of command and data bytes. NAND_CMD_NONE means the END of the queue.
+        */
+       if ((ctrl & (NAND_ALE | NAND_CLE))) {
+               if (data != NAND_CMD_NONE)
+                       this->cmd_buffer[this->command_length++] = data;
+               return;
+       }
+
+       if (!this->command_length)
+               return;
+
+       ret = gpmi_send_command(this);
+       if (ret)
+               dev_err(this->dev, "Chip: %u, Error %d\n",
+                       this->current_chip, ret);
+
+       this->command_length = 0;
+}
+
+static int gpmi_dev_ready(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct gpmi_nand_data *this = chip->priv;
+
+       return gpmi_is_ready(this, this->current_chip);
+}
+
+static void gpmi_select_chip(struct mtd_info *mtd, int chipnr)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct gpmi_nand_data *this = chip->priv;
+
+       if ((this->current_chip < 0) && (chipnr >= 0))
+               gpmi_begin(this);
+       else if ((this->current_chip >= 0) && (chipnr < 0))
+               gpmi_end(this);
+
+       this->current_chip = chipnr;
+}
+
+static void gpmi_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct gpmi_nand_data *this = chip->priv;
+
+       dev_dbg(this->dev, "len is %d\n", len);
+       this->upper_buf = buf;
+       this->upper_len = len;
+
+       gpmi_read_data(this);
+}
+
+static void gpmi_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct gpmi_nand_data *this = chip->priv;
+
+       dev_dbg(this->dev, "len is %d\n", len);
+       this->upper_buf = (uint8_t *)buf;
+       this->upper_len = len;
+
+       gpmi_send_data(this);
+}
+
+static uint8_t gpmi_read_byte(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct gpmi_nand_data *this = chip->priv;
+       uint8_t *buf = this->data_buffer_dma;
+
+       gpmi_read_buf(mtd, buf, 1);
+       return buf[0];
+}
+
+/*
+ * Handles block mark swapping.
+ * It can be called in swapping the block mark, or swapping it back,
+ * because the the operations are the same.
+ */
+static void block_mark_swapping(struct gpmi_nand_data *this,
+                               void *payload, void *auxiliary)
+{
+       struct bch_geometry *nfc_geo = &this->bch_geometry;
+       unsigned char *p;
+       unsigned char *a;
+       unsigned int  bit;
+       unsigned char mask;
+       unsigned char from_data;
+       unsigned char from_oob;
+
+       if (!this->swap_block_mark)
+               return;
+
+       /*
+        * If control arrives here, we're swapping. Make some convenience
+        * variables.
+        */
+       bit = nfc_geo->block_mark_bit_offset;
+       p   = payload + nfc_geo->block_mark_byte_offset;
+       a   = auxiliary;
+
+       /*
+        * Get the byte from the data area that overlays the block mark. Since
+        * the ECC engine applies its own view to the bits in the page, the
+        * physical block mark won't (in general) appear on a byte boundary in
+        * the data.
+        */
+       from_data = (p[0] >> bit) | (p[1] << (8 - bit));
+
+       /* Get the byte from the OOB. */
+       from_oob = a[0];
+
+       /* Swap them. */
+       a[0] = from_data;
+
+       mask = (0x1 << bit) - 1;
+       p[0] = (p[0] & mask) | (from_oob << bit);
+
+       mask = ~0 << bit;
+       p[1] = (p[1] & mask) | (from_oob >> (8 - bit));
+}
+
+static int gpmi_ecc_read_page(struct mtd_info *mtd, struct nand_chip *chip,
+                               uint8_t *buf, int oob_required, int page)
+{
+       struct gpmi_nand_data *this = chip->priv;
+       struct bch_geometry *nfc_geo = &this->bch_geometry;
+       void          *payload_virt;
+       dma_addr_t    payload_phys;
+       void          *auxiliary_virt;
+       dma_addr_t    auxiliary_phys;
+       unsigned int  i;
+       unsigned char *status;
+       unsigned int  max_bitflips = 0;
+       int           ret;
+
+       dev_dbg(this->dev, "page number is : %d\n", page);
+       ret = read_page_prepare(this, buf, nfc_geo->payload_size,
+                                       this->payload_virt, this->payload_phys,
+                                       nfc_geo->payload_size,
+                                       &payload_virt, &payload_phys);
+       if (ret) {
+               dev_err(this->dev, "Inadequate DMA buffer\n");
+               ret = -ENOMEM;
+               return ret;
+       }
+       auxiliary_virt = this->auxiliary_virt;
+       auxiliary_phys = this->auxiliary_phys;
+
+       /* go! */
+       ret = gpmi_read_page(this, payload_phys, auxiliary_phys);
+       read_page_end(this, buf, nfc_geo->payload_size,
+                       this->payload_virt, this->payload_phys,
+                       nfc_geo->payload_size,
+                       payload_virt, payload_phys);
+       if (ret) {
+               dev_err(this->dev, "Error in ECC-based read: %d\n", ret);
+               return ret;
+       }
+
+       /* handle the block mark swapping */
+       block_mark_swapping(this, payload_virt, auxiliary_virt);
+
+       /* Loop over status bytes, accumulating ECC status. */
+       status = auxiliary_virt + nfc_geo->auxiliary_status_offset;
+
+       for (i = 0; i < nfc_geo->ecc_chunk_count; i++, status++) {
+               if ((*status == STATUS_GOOD) || (*status == STATUS_ERASED))
+                       continue;
+
+               if (*status == STATUS_UNCORRECTABLE) {
+                       mtd->ecc_stats.failed++;
+                       continue;
+               }
+               mtd->ecc_stats.corrected += *status;
+               max_bitflips = max_t(unsigned int, max_bitflips, *status);
+       }
+
+       if (oob_required) {
+               /*
+                * It's time to deliver the OOB bytes. See gpmi_ecc_read_oob()
+                * for details about our policy for delivering the OOB.
+                *
+                * We fill the caller's buffer with set bits, and then copy the
+                * block mark to th caller's buffer. Note that, if block mark
+                * swapping was necessary, it has already been done, so we can
+                * rely on the first byte of the auxiliary buffer to contain
+                * the block mark.
+                */
+               memset(chip->oob_poi, ~0, mtd->oobsize);
+               chip->oob_poi[0] = ((uint8_t *) auxiliary_virt)[0];
+       }
+
+       read_page_swap_end(this, buf, nfc_geo->payload_size,
+                       this->payload_virt, this->payload_phys,
+                       nfc_geo->payload_size,
+                       payload_virt, payload_phys);
+
+       return max_bitflips;
+}
+
+/* Fake a virtual small page for the subpage read */
+static int gpmi_ecc_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
+                       uint32_t offs, uint32_t len, uint8_t *buf, int page)
+{
+       struct gpmi_nand_data *this = chip->priv;
+       void __iomem *bch_regs = this->resources.bch_regs;
+       struct bch_geometry old_geo = this->bch_geometry;
+       struct bch_geometry *geo = &this->bch_geometry;
+       int size = chip->ecc.size; /* ECC chunk size */
+       int meta, n, page_size;
+       u32 r1_old, r2_old, r1_new, r2_new;
+       unsigned int max_bitflips;
+       int first, last, marker_pos;
+       int ecc_parity_size;
+       int col = 0;
+       int old_swap_block_mark = this->swap_block_mark;
+
+       /* The size of ECC parity */
+       ecc_parity_size = geo->gf_len * geo->ecc_strength / 8;
+
+       /* Align it with the chunk size */
+       first = offs / size;
+       last = (offs + len - 1) / size;
+
+       if (this->swap_block_mark) {
+               /*
+                * Find the chunk which contains the Block Marker.
+                * If this chunk is in the range of [first, last],
+                * we have to read out the whole page.
+                * Why? since we had swapped the data at the position of Block
+                * Marker to the metadata which is bound with the chunk 0.
+                */
+               marker_pos = geo->block_mark_byte_offset / size;
+               if (last >= marker_pos && first <= marker_pos) {
+                       dev_dbg(this->dev,
+                               "page:%d, first:%d, last:%d, marker at:%d\n",
+                               page, first, last, marker_pos);
+                       return gpmi_ecc_read_page(mtd, chip, buf, 0, page);
+               }
+       }
+
+       meta = geo->metadata_size;
+       if (first) {
+               col = meta + (size + ecc_parity_size) * first;
+               chip->cmdfunc(mtd, NAND_CMD_RNDOUT, col, -1);
+
+               meta = 0;
+               buf = buf + first * size;
+       }
+
+       /* Save the old environment */
+       r1_old = r1_new = readl(bch_regs + HW_BCH_FLASH0LAYOUT0);
+       r2_old = r2_new = readl(bch_regs + HW_BCH_FLASH0LAYOUT1);
+
+       /* change the BCH registers and bch_geometry{} */
+       n = last - first + 1;
+       page_size = meta + (size + ecc_parity_size) * n;
+
+       r1_new &= ~(BM_BCH_FLASH0LAYOUT0_NBLOCKS |
+                       BM_BCH_FLASH0LAYOUT0_META_SIZE);
+       r1_new |= BF_BCH_FLASH0LAYOUT0_NBLOCKS(n - 1)
+                       | BF_BCH_FLASH0LAYOUT0_META_SIZE(meta);
+       writel(r1_new, bch_regs + HW_BCH_FLASH0LAYOUT0);
+
+       r2_new &= ~BM_BCH_FLASH0LAYOUT1_PAGE_SIZE;
+       r2_new |= BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(page_size);
+       writel(r2_new, bch_regs + HW_BCH_FLASH0LAYOUT1);
+
+       geo->ecc_chunk_count = n;
+       geo->payload_size = n * size;
+       geo->page_size = page_size;
+       geo->auxiliary_status_offset = ALIGN(meta, 4);
+
+       dev_dbg(this->dev, "page:%d(%d:%d)%d, chunk:(%d:%d), BCH PG size:%d\n",
+               page, offs, len, col, first, n, page_size);
+
+       /* Read the subpage now */
+       this->swap_block_mark = false;
+       max_bitflips = gpmi_ecc_read_page(mtd, chip, buf, 0, page);
+
+       /* Restore */
+       writel(r1_old, bch_regs + HW_BCH_FLASH0LAYOUT0);
+       writel(r2_old, bch_regs + HW_BCH_FLASH0LAYOUT1);
+       this->bch_geometry = old_geo;
+       this->swap_block_mark = old_swap_block_mark;
+
+       return max_bitflips;
+}
+
+static int gpmi_ecc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+                               const uint8_t *buf, int oob_required)
+{
+       struct gpmi_nand_data *this = chip->priv;
+       struct bch_geometry *nfc_geo = &this->bch_geometry;
+       const void *payload_virt;
+       dma_addr_t payload_phys;
+       const void *auxiliary_virt;
+       dma_addr_t auxiliary_phys;
+       int        ret;
+
+       dev_dbg(this->dev, "ecc write page.\n");
+       if (this->swap_block_mark) {
+               /*
+                * If control arrives here, we're doing block mark swapping.
+                * Since we can't modify the caller's buffers, we must copy them
+                * into our own.
+                */
+               memcpy(this->payload_virt, buf, mtd->writesize);
+               payload_virt = this->payload_virt;
+               payload_phys = this->payload_phys;
+
+               memcpy(this->auxiliary_virt, chip->oob_poi,
+                               nfc_geo->auxiliary_size);
+               auxiliary_virt = this->auxiliary_virt;
+               auxiliary_phys = this->auxiliary_phys;
+
+               /* Handle block mark swapping. */
+               block_mark_swapping(this,
+                               (void *)payload_virt, (void *)auxiliary_virt);
+       } else {
+               /*
+                * If control arrives here, we're not doing block mark swapping,
+                * so we can to try and use the caller's buffers.
+                */
+               ret = send_page_prepare(this,
+                               buf, mtd->writesize,
+                               this->payload_virt, this->payload_phys,
+                               nfc_geo->payload_size,
+                               &payload_virt, &payload_phys);
+               if (ret) {
+                       dev_err(this->dev, "Inadequate payload DMA buffer\n");
+                       return 0;
+               }
+
+               ret = send_page_prepare(this,
+                               chip->oob_poi, mtd->oobsize,
+                               this->auxiliary_virt, this->auxiliary_phys,
+                               nfc_geo->auxiliary_size,
+                               &auxiliary_virt, &auxiliary_phys);
+               if (ret) {
+                       dev_err(this->dev, "Inadequate auxiliary DMA buffer\n");
+                       goto exit_auxiliary;
+               }
+       }
+
+       /* Ask the NFC. */
+       ret = gpmi_send_page(this, payload_phys, auxiliary_phys);
+       if (ret)
+               dev_err(this->dev, "Error in ECC-based write: %d\n", ret);
+
+       if (!this->swap_block_mark) {
+               send_page_end(this, chip->oob_poi, mtd->oobsize,
+                               this->auxiliary_virt, this->auxiliary_phys,
+                               nfc_geo->auxiliary_size,
+                               auxiliary_virt, auxiliary_phys);
+exit_auxiliary:
+               send_page_end(this, buf, mtd->writesize,
+                               this->payload_virt, this->payload_phys,
+                               nfc_geo->payload_size,
+                               payload_virt, payload_phys);
+       }
+
+       return 0;
+}
+
+/*
+ * There are several places in this driver where we have to handle the OOB and
+ * block marks. This is the function where things are the most complicated, so
+ * this is where we try to explain it all. All the other places refer back to
+ * here.
+ *
+ * These are the rules, in order of decreasing importance:
+ *
+ * 1) Nothing the caller does can be allowed to imperil the block mark.
+ *
+ * 2) In read operations, the first byte of the OOB we return must reflect the
+ *    true state of the block mark, no matter where that block mark appears in
+ *    the physical page.
+ *
+ * 3) ECC-based read operations return an OOB full of set bits (since we never
+ *    allow ECC-based writes to the OOB, it doesn't matter what ECC-based reads
+ *    return).
+ *
+ * 4) "Raw" read operations return a direct view of the physical bytes in the
+ *    page, using the conventional definition of which bytes are data and which
+ *    are OOB. This gives the caller a way to see the actual, physical bytes
+ *    in the page, without the distortions applied by our ECC engine.
+ *
+ *
+ * What we do for this specific read operation depends on two questions:
+ *
+ * 1) Are we doing a "raw" read, or an ECC-based read?
+ *
+ * 2) Are we using block mark swapping or transcription?
+ *
+ * There are four cases, illustrated by the following Karnaugh map:
+ *
+ *                    |           Raw           |         ECC-based       |
+ *       -------------+-------------------------+-------------------------+
+ *                    | Read the conventional   |                         |
+ *                    | OOB at the end of the   |                         |
+ *       Swapping     | page and return it. It  |                         |
+ *                    | contains exactly what   |                         |
+ *                    | we want.                | Read the block mark and |
+ *       -------------+-------------------------+ return it in a buffer   |
+ *                    | Read the conventional   | full of set bits.       |
+ *                    | OOB at the end of the   |                         |
+ *                    | page and also the block |                         |
+ *       Transcribing | mark in the metadata.   |                         |
+ *                    | Copy the block mark     |                         |
+ *                    | into the first byte of  |                         |
+ *                    | the OOB.                |                         |
+ *       -------------+-------------------------+-------------------------+
+ *
+ * Note that we break rule #4 in the Transcribing/Raw case because we're not
+ * giving an accurate view of the actual, physical bytes in the page (we're
+ * overwriting the block mark). That's OK because it's more important to follow
+ * rule #2.
+ *
+ * It turns out that knowing whether we want an "ECC-based" or "raw" read is not
+ * easy. When reading a page, for example, the NAND Flash MTD code calls our
+ * ecc.read_page or ecc.read_page_raw function. Thus, the fact that MTD wants an
+ * ECC-based or raw view of the page is implicit in which function it calls
+ * (there is a similar pair of ECC-based/raw functions for writing).
+ */
+static int gpmi_ecc_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
+                               int page)
+{
+       struct gpmi_nand_data *this = chip->priv;
+
+       dev_dbg(this->dev, "page number is %d\n", page);
+       /* clear the OOB buffer */
+       memset(chip->oob_poi, ~0, mtd->oobsize);
+
+       /* Read out the conventional OOB. */
+       chip->cmdfunc(mtd, NAND_CMD_READ0, mtd->writesize, page);
+       chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+
+       /*
+        * Now, we want to make sure the block mark is correct. In the
+        * non-transcribing case (!GPMI_IS_MX23()), we already have it.
+        * Otherwise, we need to explicitly read it.
+        */
+       if (GPMI_IS_MX23(this)) {
+               /* Read the block mark into the first byte of the OOB buffer. */
+               chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
+               chip->oob_poi[0] = chip->read_byte(mtd);
+       }
+
+       return 0;
+}
+
+static int
+gpmi_ecc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, int page)
+{
+       struct nand_oobfree *of = mtd->ecclayout->oobfree;
+       int status = 0;
+
+       /* Do we have available oob area? */
+       if (!of->length)
+               return -EPERM;
+
+       if (!nand_is_slc(chip))
+               return -EPERM;
+
+       chip->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize + of->offset, page);
+       chip->write_buf(mtd, chip->oob_poi + of->offset, of->length);
+       chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+
+       status = chip->waitfunc(mtd, chip);
+       return status & NAND_STATUS_FAIL ? -EIO : 0;
+}
+
+/*
+ * This function reads a NAND page without involving the ECC engine (no HW
+ * ECC correction).
+ * The tricky part in the GPMI/BCH controller is that it stores ECC bits
+ * inline (interleaved with payload DATA), and do not align data chunk on
+ * byte boundaries.
+ * We thus need to take care moving the payload data and ECC bits stored in the
+ * page into the provided buffers, which is why we're using gpmi_copy_bits.
+ *
+ * See set_geometry_by_ecc_info inline comments to have a full description
+ * of the layout used by the GPMI controller.
+ */
+static int gpmi_ecc_read_page_raw(struct mtd_info *mtd,
+                                 struct nand_chip *chip, uint8_t *buf,
+                                 int oob_required, int page)
+{
+       struct gpmi_nand_data *this = chip->priv;
+       struct bch_geometry *nfc_geo = &this->bch_geometry;
+       int eccsize = nfc_geo->ecc_chunk_size;
+       int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len;
+       u8 *tmp_buf = this->raw_buffer;
+       size_t src_bit_off;
+       size_t oob_bit_off;
+       size_t oob_byte_off;
+       uint8_t *oob = chip->oob_poi;
+       int step;
+
+       chip->read_buf(mtd, tmp_buf,
+                      mtd->writesize + mtd->oobsize);
+
+       /*
+        * If required, swap the bad block marker and the data stored in the
+        * metadata section, so that we don't wrongly consider a block as bad.
+        *
+        * See the layout description for a detailed explanation on why this
+        * is needed.
+        */
+       if (this->swap_block_mark) {
+               u8 swap = tmp_buf[0];
+
+               tmp_buf[0] = tmp_buf[mtd->writesize];
+               tmp_buf[mtd->writesize] = swap;
+       }
+
+       /*
+        * Copy the metadata section into the oob buffer (this section is
+        * guaranteed to be aligned on a byte boundary).
+        */
+       if (oob_required)
+               memcpy(oob, tmp_buf, nfc_geo->metadata_size);
+
+       oob_bit_off = nfc_geo->metadata_size * 8;
+       src_bit_off = oob_bit_off;
+
+       /* Extract interleaved payload data and ECC bits */
+       for (step = 0; step < nfc_geo->ecc_chunk_count; step++) {
+               if (buf)
+                       gpmi_copy_bits(buf, step * eccsize * 8,
+                                      tmp_buf, src_bit_off,
+                                      eccsize * 8);
+               src_bit_off += eccsize * 8;
+
+               /* Align last ECC block to align a byte boundary */
+               if (step == nfc_geo->ecc_chunk_count - 1 &&
+                   (oob_bit_off + eccbits) % 8)
+                       eccbits += 8 - ((oob_bit_off + eccbits) % 8);
+
+               if (oob_required)
+                       gpmi_copy_bits(oob, oob_bit_off,
+                                      tmp_buf, src_bit_off,
+                                      eccbits);
+
+               src_bit_off += eccbits;
+               oob_bit_off += eccbits;
+       }
+
+       if (oob_required) {
+               oob_byte_off = oob_bit_off / 8;
+
+               if (oob_byte_off < mtd->oobsize)
+                       memcpy(oob + oob_byte_off,
+                              tmp_buf + mtd->writesize + oob_byte_off,
+                              mtd->oobsize - oob_byte_off);
+       }
+
+       return 0;
+}
+
+/*
+ * This function writes a NAND page without involving the ECC engine (no HW
+ * ECC generation).
+ * The tricky part in the GPMI/BCH controller is that it stores ECC bits
+ * inline (interleaved with payload DATA), and do not align data chunk on
+ * byte boundaries.
+ * We thus need to take care moving the OOB area at the right place in the
+ * final page, which is why we're using gpmi_copy_bits.
+ *
+ * See set_geometry_by_ecc_info inline comments to have a full description
+ * of the layout used by the GPMI controller.
+ */
+static int gpmi_ecc_write_page_raw(struct mtd_info *mtd,
+                                  struct nand_chip *chip,
+                                  const uint8_t *buf,
+                                  int oob_required)
+{
+       struct gpmi_nand_data *this = chip->priv;
+       struct bch_geometry *nfc_geo = &this->bch_geometry;
+       int eccsize = nfc_geo->ecc_chunk_size;
+       int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len;
+       u8 *tmp_buf = this->raw_buffer;
+       uint8_t *oob = chip->oob_poi;
+       size_t dst_bit_off;
+       size_t oob_bit_off;
+       size_t oob_byte_off;
+       int step;
+
+       /*
+        * Initialize all bits to 1 in case we don't have a buffer for the
+        * payload or oob data in order to leave unspecified bits of data
+        * to their initial state.
+        */
+       if (!buf || !oob_required)
+               memset(tmp_buf, 0xff, mtd->writesize + mtd->oobsize);
+
+       /*
+        * First copy the metadata section (stored in oob buffer) at the
+        * beginning of the page, as imposed by the GPMI layout.
+        */
+       memcpy(tmp_buf, oob, nfc_geo->metadata_size);
+       oob_bit_off = nfc_geo->metadata_size * 8;
+       dst_bit_off = oob_bit_off;
+
+       /* Interleave payload data and ECC bits */
+       for (step = 0; step < nfc_geo->ecc_chunk_count; step++) {
+               if (buf)
+                       gpmi_copy_bits(tmp_buf, dst_bit_off,
+                                      buf, step * eccsize * 8, eccsize * 8);
+               dst_bit_off += eccsize * 8;
+
+               /* Align last ECC block to align a byte boundary */
+               if (step == nfc_geo->ecc_chunk_count - 1 &&
+                   (oob_bit_off + eccbits) % 8)
+                       eccbits += 8 - ((oob_bit_off + eccbits) % 8);
+
+               if (oob_required)
+                       gpmi_copy_bits(tmp_buf, dst_bit_off,
+                                      oob, oob_bit_off, eccbits);
+
+               dst_bit_off += eccbits;
+               oob_bit_off += eccbits;
+       }
+
+       oob_byte_off = oob_bit_off / 8;
+
+       if (oob_required && oob_byte_off < mtd->oobsize)
+               memcpy(tmp_buf + mtd->writesize + oob_byte_off,
+                      oob + oob_byte_off, mtd->oobsize - oob_byte_off);
+
+       /*
+        * If required, swap the bad block marker and the first byte of the
+        * metadata section, so that we don't modify the bad block marker.
+        *
+        * See the layout description for a detailed explanation on why this
+        * is needed.
+        */
+       if (this->swap_block_mark) {
+               u8 swap = tmp_buf[0];
+
+               tmp_buf[0] = tmp_buf[mtd->writesize];
+               tmp_buf[mtd->writesize] = swap;
+       }
+
+       chip->write_buf(mtd, tmp_buf, mtd->writesize + mtd->oobsize);
+
+       return 0;
+}
+
+static int gpmi_ecc_read_oob_raw(struct mtd_info *mtd, struct nand_chip *chip,
+                                int page)
+{
+       chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
+
+       return gpmi_ecc_read_page_raw(mtd, chip, NULL, 1, page);
+}
+
+static int gpmi_ecc_write_oob_raw(struct mtd_info *mtd, struct nand_chip *chip,
+                                int page)
+{
+       chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0, page);
+
+       return gpmi_ecc_write_page_raw(mtd, chip, NULL, 1);
+}
+
+static int gpmi_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+       struct nand_chip *chip = mtd->priv;
+       struct gpmi_nand_data *this = chip->priv;
+       int ret = 0;
+       uint8_t *block_mark;
+       int column, page, status, chipnr;
+
+       chipnr = (int)(ofs >> chip->chip_shift);
+       chip->select_chip(mtd, chipnr);
+
+       column = !GPMI_IS_MX23(this) ? mtd->writesize : 0;
+
+       /* Write the block mark. */
+       block_mark = this->data_buffer_dma;
+       block_mark[0] = 0; /* bad block marker */
+
+       /* Shift to get page */
+       page = (int)(ofs >> chip->page_shift);
+
+       chip->cmdfunc(mtd, NAND_CMD_SEQIN, column, page);
+       chip->write_buf(mtd, block_mark, 1);
+       chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+
+       status = chip->waitfunc(mtd, chip);
+       if (status & NAND_STATUS_FAIL)
+               ret = -EIO;
+
+       chip->select_chip(mtd, -1);
+
+       return ret;
+}
+
+static int nand_boot_set_geometry(struct gpmi_nand_data *this)
+{
+       struct boot_rom_geometry *geometry = &this->rom_geometry;
+
+       /*
+        * Set the boot block stride size.
+        *
+        * In principle, we should be reading this from the OTP bits, since
+        * that's where the ROM is going to get it. In fact, we don't have any
+        * way to read the OTP bits, so we go with the default and hope for the
+        * best.
+        */
+       geometry->stride_size_in_pages = 64;
+
+       /*
+        * Set the search area stride exponent.
+        *
+        * In principle, we should be reading this from the OTP bits, since
+        * that's where the ROM is going to get it. In fact, we don't have any
+        * way to read the OTP bits, so we go with the default and hope for the
+        * best.
+        */
+       geometry->search_area_stride_exponent = 2;
+       return 0;
+}
+
+static const char  *fingerprint = "STMP";
+static int mx23_check_transcription_stamp(struct gpmi_nand_data *this)
+{
+       struct boot_rom_geometry *rom_geo = &this->rom_geometry;
+       struct device *dev = this->dev;
+       struct mtd_info *mtd = &this->mtd;
+       struct nand_chip *chip = &this->nand;
+       unsigned int search_area_size_in_strides;
+       unsigned int stride;
+       unsigned int page;
+       uint8_t *buffer = chip->buffers->databuf;
+       int saved_chip_number;
+       int found_an_ncb_fingerprint = false;
+
+       /* Compute the number of strides in a search area. */
+       search_area_size_in_strides = 1 << rom_geo->search_area_stride_exponent;
+
+       saved_chip_number = this->current_chip;
+       chip->select_chip(mtd, 0);
+
+       /*
+        * Loop through the first search area, looking for the NCB fingerprint.
+        */
+       dev_dbg(dev, "Scanning for an NCB fingerprint...\n");
+
+       for (stride = 0; stride < search_area_size_in_strides; stride++) {
+               /* Compute the page addresses. */
+               page = stride * rom_geo->stride_size_in_pages;
+
+               dev_dbg(dev, "Looking for a fingerprint in page 0x%x\n", page);
+
+               /*
+                * Read the NCB fingerprint. The fingerprint is four bytes long
+                * and starts in the 12th byte of the page.
+                */
+               chip->cmdfunc(mtd, NAND_CMD_READ0, 12, page);
+               chip->read_buf(mtd, buffer, strlen(fingerprint));
+
+               /* Look for the fingerprint. */
+               if (!memcmp(buffer, fingerprint, strlen(fingerprint))) {
+                       found_an_ncb_fingerprint = true;
+                       break;
+               }
+
+       }
+
+       chip->select_chip(mtd, saved_chip_number);
+
+       if (found_an_ncb_fingerprint)
+               dev_dbg(dev, "\tFound a fingerprint\n");
+       else
+               dev_dbg(dev, "\tNo fingerprint found\n");
+       return found_an_ncb_fingerprint;
+}
+
+/* Writes a transcription stamp. */
+static int mx23_write_transcription_stamp(struct gpmi_nand_data *this)
+{
+       struct device *dev = this->dev;
+       struct boot_rom_geometry *rom_geo = &this->rom_geometry;
+       struct mtd_info *mtd = &this->mtd;
+       struct nand_chip *chip = &this->nand;
+       unsigned int block_size_in_pages;
+       unsigned int search_area_size_in_strides;
+       unsigned int search_area_size_in_pages;
+       unsigned int search_area_size_in_blocks;
+       unsigned int block;
+       unsigned int stride;
+       unsigned int page;
+       uint8_t      *buffer = chip->buffers->databuf;
+       int saved_chip_number;
+       int status;
+
+       /* Compute the search area geometry. */
+       block_size_in_pages = mtd->erasesize / mtd->writesize;
+       search_area_size_in_strides = 1 << rom_geo->search_area_stride_exponent;
+       search_area_size_in_pages = search_area_size_in_strides *
+                                       rom_geo->stride_size_in_pages;
+       search_area_size_in_blocks =
+                 (search_area_size_in_pages + (block_size_in_pages - 1)) /
+                                   block_size_in_pages;
+
+       dev_dbg(dev, "Search Area Geometry :\n");
+       dev_dbg(dev, "\tin Blocks : %u\n", search_area_size_in_blocks);
+       dev_dbg(dev, "\tin Strides: %u\n", search_area_size_in_strides);
+       dev_dbg(dev, "\tin Pages  : %u\n", search_area_size_in_pages);
+
+       /* Select chip 0. */
+       saved_chip_number = this->current_chip;
+       chip->select_chip(mtd, 0);
+
+       /* Loop over blocks in the first search area, erasing them. */
+       dev_dbg(dev, "Erasing the search area...\n");
+
+       for (block = 0; block < search_area_size_in_blocks; block++) {
+               /* Compute the page address. */
+               page = block * block_size_in_pages;
+
+               /* Erase this block. */
+               dev_dbg(dev, "\tErasing block 0x%x\n", block);
+               chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
+               chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
+
+               /* Wait for the erase to finish. */
+               status = chip->waitfunc(mtd, chip);
+               if (status & NAND_STATUS_FAIL)
+                       dev_err(dev, "[%s] Erase failed.\n", __func__);
+       }
+
+       /* Write the NCB fingerprint into the page buffer. */
+       memset(buffer, ~0, mtd->writesize);
+       memcpy(buffer + 12, fingerprint, strlen(fingerprint));
+
+       /* Loop through the first search area, writing NCB fingerprints. */
+       dev_dbg(dev, "Writing NCB fingerprints...\n");
+       for (stride = 0; stride < search_area_size_in_strides; stride++) {
+               /* Compute the page addresses. */
+               page = stride * rom_geo->stride_size_in_pages;
+
+               /* Write the first page of the current stride. */
+               dev_dbg(dev, "Writing an NCB fingerprint in page 0x%x\n", page);
+               chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
+               chip->ecc.write_page_raw(mtd, chip, buffer, 0);
+               chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+
+               /* Wait for the write to finish. */
+               status = chip->waitfunc(mtd, chip);
+               if (status & NAND_STATUS_FAIL)
+                       dev_err(dev, "[%s] Write failed.\n", __func__);
+       }
+
+       /* Deselect chip 0. */
+       chip->select_chip(mtd, saved_chip_number);
+       return 0;
+}
+
+static int mx23_boot_init(struct gpmi_nand_data  *this)
+{
+       struct device *dev = this->dev;
+       struct nand_chip *chip = &this->nand;
+       struct mtd_info *mtd = &this->mtd;
+       unsigned int block_count;
+       unsigned int block;
+       int     chipnr;
+       int     page;
+       loff_t  byte;
+       uint8_t block_mark;
+       int     ret = 0;
+
+       /*
+        * If control arrives here, we can't use block mark swapping, which
+        * means we're forced to use transcription. First, scan for the
+        * transcription stamp. If we find it, then we don't have to do
+        * anything -- the block marks are already transcribed.
+        */
+       if (mx23_check_transcription_stamp(this))
+               return 0;
+
+       /*
+        * If control arrives here, we couldn't find a transcription stamp, so
+        * so we presume the block marks are in the conventional location.
+        */
+       dev_dbg(dev, "Transcribing bad block marks...\n");
+
+       /* Compute the number of blocks in the entire medium. */
+       block_count = chip->chipsize >> chip->phys_erase_shift;
+
+       /*
+        * Loop over all the blocks in the medium, transcribing block marks as
+        * we go.
+        */
+       for (block = 0; block < block_count; block++) {
+               /*
+                * Compute the chip, page and byte addresses for this block's
+                * conventional mark.
+                */
+               chipnr = block >> (chip->chip_shift - chip->phys_erase_shift);
+               page = block << (chip->phys_erase_shift - chip->page_shift);
+               byte = block <<  chip->phys_erase_shift;
+
+               /* Send the command to read the conventional block mark. */
+               chip->select_chip(mtd, chipnr);
+               chip->cmdfunc(mtd, NAND_CMD_READ0, mtd->writesize, page);
+               block_mark = chip->read_byte(mtd);
+               chip->select_chip(mtd, -1);
+
+               /*
+                * Check if the block is marked bad. If so, we need to mark it
+                * again, but this time the result will be a mark in the
+                * location where we transcribe block marks.
+                */
+               if (block_mark != 0xff) {
+                       dev_dbg(dev, "Transcribing mark in block %u\n", block);
+                       ret = chip->block_markbad(mtd, byte);
+                       if (ret)
+                               dev_err(dev,
+                                       "Failed to mark block bad with ret %d\n",
+                                       ret);
+               }
+       }
+
+       /* Write the stamp that indicates we've transcribed the block marks. */
+       mx23_write_transcription_stamp(this);
+       return 0;
+}
+
+static int nand_boot_init(struct gpmi_nand_data  *this)
+{
+       nand_boot_set_geometry(this);
+
+       /* This is ROM arch-specific initilization before the BBT scanning. */
+       if (GPMI_IS_MX23(this))
+               return mx23_boot_init(this);
+       return 0;
+}
+
+static int gpmi_set_geometry(struct gpmi_nand_data *this)
+{
+       int ret;
+
+       /* Free the temporary DMA memory for reading ID. */
+       gpmi_free_dma_buffer(this);
+
+       /* Set up the NFC geometry which is used by BCH. */
+       ret = bch_set_geometry(this);
+       if (ret) {
+               dev_err(this->dev, "Error setting BCH geometry : %d\n", ret);
+               return ret;
+       }
+
+       /* Alloc the new DMA buffers according to the pagesize and oobsize */
+       return gpmi_alloc_dma_buffer(this);
+}
+
+static void gpmi_nand_exit(struct gpmi_nand_data *this)
+{
+       nand_release(&this->mtd);
+       gpmi_free_dma_buffer(this);
+}
+
+static int gpmi_init_last(struct gpmi_nand_data *this)
+{
+       struct mtd_info *mtd = &this->mtd;
+       struct nand_chip *chip = mtd->priv;
+       struct nand_ecc_ctrl *ecc = &chip->ecc;
+       struct bch_geometry *bch_geo = &this->bch_geometry;
+       int ret;
+
+       /* Set up the medium geometry */
+       ret = gpmi_set_geometry(this);
+       if (ret)
+               return ret;
+
+       /* Init the nand_ecc_ctrl{} */
+       ecc->read_page  = gpmi_ecc_read_page;
+       ecc->write_page = gpmi_ecc_write_page;
+       ecc->read_oob   = gpmi_ecc_read_oob;
+       ecc->write_oob  = gpmi_ecc_write_oob;
+       ecc->read_page_raw = gpmi_ecc_read_page_raw;
+       ecc->write_page_raw = gpmi_ecc_write_page_raw;
+       ecc->read_oob_raw = gpmi_ecc_read_oob_raw;
+       ecc->write_oob_raw = gpmi_ecc_write_oob_raw;
+       ecc->mode       = NAND_ECC_HW;
+       ecc->size       = bch_geo->ecc_chunk_size;
+       ecc->strength   = bch_geo->ecc_strength;
+       ecc->layout     = &gpmi_hw_ecclayout;
+
+       /*
+        * We only enable the subpage read when:
+        *  (1) the chip is imx6, and
+        *  (2) the size of the ECC parity is byte aligned.
+        */
+       if (GPMI_IS_MX6(this) &&
+               ((bch_geo->gf_len * bch_geo->ecc_strength) % 8) == 0) {
+               ecc->read_subpage = gpmi_ecc_read_subpage;
+               chip->options |= NAND_SUBPAGE_READ;
+       }
+
+       /*
+        * Can we enable the extra features? such as EDO or Sync mode.
+        *
+        * We do not check the return value now. That's means if we fail in
+        * enable the extra features, we still can run in the normal way.
+        */
+       gpmi_extra_init(this);
+
+       return 0;
+}
+
+static int gpmi_nand_init(struct gpmi_nand_data *this)
+{
+       struct mtd_info  *mtd = &this->mtd;
+       struct nand_chip *chip = &this->nand;
+       struct mtd_part_parser_data ppdata = {};
+       int ret;
+
+       /* init current chip */
+       this->current_chip      = -1;
+
+       /* init the MTD data structures */
+       mtd->priv               = chip;
+       mtd->name               = "gpmi-nand";
+       mtd->owner              = THIS_MODULE;
+
+       /* init the nand_chip{}, we don't support a 16-bit NAND Flash bus. */
+       chip->priv              = this;
+       chip->select_chip       = gpmi_select_chip;
+       chip->cmd_ctrl          = gpmi_cmd_ctrl;
+       chip->dev_ready         = gpmi_dev_ready;
+       chip->read_byte         = gpmi_read_byte;
+       chip->read_buf          = gpmi_read_buf;
+       chip->write_buf         = gpmi_write_buf;
+       chip->badblock_pattern  = &gpmi_bbt_descr;
+       chip->block_markbad     = gpmi_block_markbad;
+       chip->options           |= NAND_NO_SUBPAGE_WRITE;
+
+       /* Set up swap_block_mark, must be set before the gpmi_set_geometry() */
+       this->swap_block_mark = !GPMI_IS_MX23(this);
+
+       if (of_get_nand_on_flash_bbt(this->dev->of_node)) {
+               chip->bbt_options |= NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
+
+               if (of_property_read_bool(this->dev->of_node,
+                                               "fsl,no-blockmark-swap"))
+                       this->swap_block_mark = false;
+       }
+       dev_dbg(this->dev, "Blockmark swapping %sabled\n",
+               this->swap_block_mark ? "en" : "dis");
+
+       /*
+        * Allocate a temporary DMA buffer for reading ID in the
+        * nand_scan_ident().
+        */
+       this->bch_geometry.payload_size = 1024;
+       this->bch_geometry.auxiliary_size = 128;
+       ret = gpmi_alloc_dma_buffer(this);
+       if (ret)
+               goto err_out;
+
+       ret = nand_scan_ident(mtd, GPMI_IS_MX6(this) ? 2 : 1, NULL);
+       if (ret)
+               goto err_out;
+
+       ret = gpmi_init_last(this);
+       if (ret)
+               goto err_out;
+
+       chip->options |= NAND_SKIP_BBTSCAN;
+       ret = nand_scan_tail(mtd);
+       if (ret)
+               goto err_out;
+
+       ret = nand_boot_init(this);
+       if (ret)
+               goto err_out;
+       ret = chip->scan_bbt(mtd);
+       if (ret)
+               goto err_out;
+
+       ppdata.of_node = this->pdev->dev.of_node;
+       ret = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
+       if (ret)
+               goto err_out;
+       return 0;
+
+err_out:
+       gpmi_nand_exit(this);
+       return ret;
+}
+
+static const struct of_device_id gpmi_nand_id_table[] = {
+       {
+               .compatible = "fsl,imx23-gpmi-nand",
+               .data = &gpmi_devdata_imx23,
+       }, {
+               .compatible = "fsl,imx28-gpmi-nand",
+               .data = &gpmi_devdata_imx28,
+       }, {
+               .compatible = "fsl,imx6q-gpmi-nand",
+               .data = &gpmi_devdata_imx6q,
+       }, {
+               .compatible = "fsl,imx6sx-gpmi-nand",
+               .data = &gpmi_devdata_imx6sx,
+       }, {}
+};
+MODULE_DEVICE_TABLE(of, gpmi_nand_id_table);
+
+static int gpmi_nand_probe(struct platform_device *pdev)
+{
+       struct gpmi_nand_data *this;
+       const struct of_device_id *of_id;
+       int ret;
+
+       this = devm_kzalloc(&pdev->dev, sizeof(*this), GFP_KERNEL);
+       if (!this)
+               return -ENOMEM;
+
+       of_id = of_match_device(gpmi_nand_id_table, &pdev->dev);
+       if (of_id) {
+               this->devdata = of_id->data;
+       } else {
+               dev_err(&pdev->dev, "Failed to find the right device id.\n");
+               return -ENODEV;
+       }
+
+       platform_set_drvdata(pdev, this);
+       this->pdev  = pdev;
+       this->dev   = &pdev->dev;
+
+       ret = acquire_resources(this);
+       if (ret)
+               goto exit_acquire_resources;
+
+       ret = init_hardware(this);
+       if (ret)
+               goto exit_nfc_init;
+
+       ret = gpmi_nand_init(this);
+       if (ret)
+               goto exit_nfc_init;
+
+       dev_info(this->dev, "driver registered.\n");
+
+       return 0;
+
+exit_nfc_init:
+       release_resources(this);
+exit_acquire_resources:
+
+       return ret;
+}
+
+static int gpmi_nand_remove(struct platform_device *pdev)
+{
+       struct gpmi_nand_data *this = platform_get_drvdata(pdev);
+
+       gpmi_nand_exit(this);
+       release_resources(this);
+       return 0;
+}
+
+static struct platform_driver gpmi_nand_driver = {
+       .driver = {
+               .name = "gpmi-nand",
+               .of_match_table = gpmi_nand_id_table,
+       },
+       .probe   = gpmi_nand_probe,
+       .remove  = gpmi_nand_remove,
+};
+module_platform_driver(gpmi_nand_driver);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("i.MX GPMI NAND Flash Controller Driver");
+MODULE_LICENSE("GPL");