Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / spi / spi-omap2-mcspi.c
diff --git a/kernel/drivers/spi/spi-omap2-mcspi.c b/kernel/drivers/spi/spi-omap2-mcspi.c
new file mode 100644 (file)
index 0000000..d1a5b9f
--- /dev/null
@@ -0,0 +1,1535 @@
+/*
+ * OMAP2 McSPI controller driver
+ *
+ * Copyright (C) 2005, 2006 Nokia Corporation
+ * Author:     Samuel Ortiz <samuel.ortiz@nokia.com> and
+ *             Juha Yrj�l� <juha.yrjola@nokia.com>
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/omap-dma.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/gcd.h>
+
+#include <linux/spi/spi.h>
+
+#include <linux/platform_data/spi-omap2-mcspi.h>
+
+#define OMAP2_MCSPI_MAX_FREQ           48000000
+#define OMAP2_MCSPI_MAX_DIVIDER                4096
+#define OMAP2_MCSPI_MAX_FIFODEPTH      64
+#define OMAP2_MCSPI_MAX_FIFOWCNT       0xFFFF
+#define SPI_AUTOSUSPEND_TIMEOUT                2000
+
+#define OMAP2_MCSPI_REVISION           0x00
+#define OMAP2_MCSPI_SYSSTATUS          0x14
+#define OMAP2_MCSPI_IRQSTATUS          0x18
+#define OMAP2_MCSPI_IRQENABLE          0x1c
+#define OMAP2_MCSPI_WAKEUPENABLE       0x20
+#define OMAP2_MCSPI_SYST               0x24
+#define OMAP2_MCSPI_MODULCTRL          0x28
+#define OMAP2_MCSPI_XFERLEVEL          0x7c
+
+/* per-channel banks, 0x14 bytes each, first is: */
+#define OMAP2_MCSPI_CHCONF0            0x2c
+#define OMAP2_MCSPI_CHSTAT0            0x30
+#define OMAP2_MCSPI_CHCTRL0            0x34
+#define OMAP2_MCSPI_TX0                        0x38
+#define OMAP2_MCSPI_RX0                        0x3c
+
+/* per-register bitmasks: */
+#define OMAP2_MCSPI_IRQSTATUS_EOW      BIT(17)
+
+#define OMAP2_MCSPI_MODULCTRL_SINGLE   BIT(0)
+#define OMAP2_MCSPI_MODULCTRL_MS       BIT(2)
+#define OMAP2_MCSPI_MODULCTRL_STEST    BIT(3)
+
+#define OMAP2_MCSPI_CHCONF_PHA         BIT(0)
+#define OMAP2_MCSPI_CHCONF_POL         BIT(1)
+#define OMAP2_MCSPI_CHCONF_CLKD_MASK   (0x0f << 2)
+#define OMAP2_MCSPI_CHCONF_EPOL                BIT(6)
+#define OMAP2_MCSPI_CHCONF_WL_MASK     (0x1f << 7)
+#define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY BIT(12)
+#define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY BIT(13)
+#define OMAP2_MCSPI_CHCONF_TRM_MASK    (0x03 << 12)
+#define OMAP2_MCSPI_CHCONF_DMAW                BIT(14)
+#define OMAP2_MCSPI_CHCONF_DMAR                BIT(15)
+#define OMAP2_MCSPI_CHCONF_DPE0                BIT(16)
+#define OMAP2_MCSPI_CHCONF_DPE1                BIT(17)
+#define OMAP2_MCSPI_CHCONF_IS          BIT(18)
+#define OMAP2_MCSPI_CHCONF_TURBO       BIT(19)
+#define OMAP2_MCSPI_CHCONF_FORCE       BIT(20)
+#define OMAP2_MCSPI_CHCONF_FFET                BIT(27)
+#define OMAP2_MCSPI_CHCONF_FFER                BIT(28)
+#define OMAP2_MCSPI_CHCONF_CLKG                BIT(29)
+
+#define OMAP2_MCSPI_CHSTAT_RXS         BIT(0)
+#define OMAP2_MCSPI_CHSTAT_TXS         BIT(1)
+#define OMAP2_MCSPI_CHSTAT_EOT         BIT(2)
+#define OMAP2_MCSPI_CHSTAT_TXFFE       BIT(3)
+
+#define OMAP2_MCSPI_CHCTRL_EN          BIT(0)
+#define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK (0xff << 8)
+
+#define OMAP2_MCSPI_WAKEUPENABLE_WKEN  BIT(0)
+
+/* We have 2 DMA channels per CS, one for RX and one for TX */
+struct omap2_mcspi_dma {
+       struct dma_chan *dma_tx;
+       struct dma_chan *dma_rx;
+
+       int dma_tx_sync_dev;
+       int dma_rx_sync_dev;
+
+       struct completion dma_tx_completion;
+       struct completion dma_rx_completion;
+
+       char dma_rx_ch_name[14];
+       char dma_tx_ch_name[14];
+};
+
+/* use PIO for small transfers, avoiding DMA setup/teardown overhead and
+ * cache operations; better heuristics consider wordsize and bitrate.
+ */
+#define DMA_MIN_BYTES                  160
+
+
+/*
+ * Used for context save and restore, structure members to be updated whenever
+ * corresponding registers are modified.
+ */
+struct omap2_mcspi_regs {
+       u32 modulctrl;
+       u32 wakeupenable;
+       struct list_head cs;
+};
+
+struct omap2_mcspi {
+       struct spi_master       *master;
+       /* Virtual base address of the controller */
+       void __iomem            *base;
+       unsigned long           phys;
+       /* SPI1 has 4 channels, while SPI2 has 2 */
+       struct omap2_mcspi_dma  *dma_channels;
+       struct device           *dev;
+       struct omap2_mcspi_regs ctx;
+       int                     fifo_depth;
+       unsigned int            pin_dir:1;
+};
+
+struct omap2_mcspi_cs {
+       void __iomem            *base;
+       unsigned long           phys;
+       int                     word_len;
+       u16                     mode;
+       struct list_head        node;
+       /* Context save and restore shadow register */
+       u32                     chconf0, chctrl0;
+};
+
+static inline void mcspi_write_reg(struct spi_master *master,
+               int idx, u32 val)
+{
+       struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
+
+       writel_relaxed(val, mcspi->base + idx);
+}
+
+static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
+{
+       struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
+
+       return readl_relaxed(mcspi->base + idx);
+}
+
+static inline void mcspi_write_cs_reg(const struct spi_device *spi,
+               int idx, u32 val)
+{
+       struct omap2_mcspi_cs   *cs = spi->controller_state;
+
+       writel_relaxed(val, cs->base +  idx);
+}
+
+static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
+{
+       struct omap2_mcspi_cs   *cs = spi->controller_state;
+
+       return readl_relaxed(cs->base + idx);
+}
+
+static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
+{
+       struct omap2_mcspi_cs *cs = spi->controller_state;
+
+       return cs->chconf0;
+}
+
+static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
+{
+       struct omap2_mcspi_cs *cs = spi->controller_state;
+
+       cs->chconf0 = val;
+       mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
+       mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
+}
+
+static inline int mcspi_bytes_per_word(int word_len)
+{
+       if (word_len <= 8)
+               return 1;
+       else if (word_len <= 16)
+               return 2;
+       else /* word_len <= 32 */
+               return 4;
+}
+
+static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
+               int is_read, int enable)
+{
+       u32 l, rw;
+
+       l = mcspi_cached_chconf0(spi);
+
+       if (is_read) /* 1 is read, 0 write */
+               rw = OMAP2_MCSPI_CHCONF_DMAR;
+       else
+               rw = OMAP2_MCSPI_CHCONF_DMAW;
+
+       if (enable)
+               l |= rw;
+       else
+               l &= ~rw;
+
+       mcspi_write_chconf0(spi, l);
+}
+
+static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
+{
+       struct omap2_mcspi_cs *cs = spi->controller_state;
+       u32 l;
+
+       l = cs->chctrl0;
+       if (enable)
+               l |= OMAP2_MCSPI_CHCTRL_EN;
+       else
+               l &= ~OMAP2_MCSPI_CHCTRL_EN;
+       cs->chctrl0 = l;
+       mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
+       /* Flash post-writes */
+       mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
+}
+
+static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
+{
+       u32 l;
+
+       l = mcspi_cached_chconf0(spi);
+       if (cs_active)
+               l |= OMAP2_MCSPI_CHCONF_FORCE;
+       else
+               l &= ~OMAP2_MCSPI_CHCONF_FORCE;
+
+       mcspi_write_chconf0(spi, l);
+}
+
+static void omap2_mcspi_set_master_mode(struct spi_master *master)
+{
+       struct omap2_mcspi      *mcspi = spi_master_get_devdata(master);
+       struct omap2_mcspi_regs *ctx = &mcspi->ctx;
+       u32 l;
+
+       /*
+        * Setup when switching from (reset default) slave mode
+        * to single-channel master mode
+        */
+       l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
+       l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS);
+       l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
+       mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
+
+       ctx->modulctrl = l;
+}
+
+static void omap2_mcspi_set_fifo(const struct spi_device *spi,
+                               struct spi_transfer *t, int enable)
+{
+       struct spi_master *master = spi->master;
+       struct omap2_mcspi_cs *cs = spi->controller_state;
+       struct omap2_mcspi *mcspi;
+       unsigned int wcnt;
+       int max_fifo_depth, fifo_depth, bytes_per_word;
+       u32 chconf, xferlevel;
+
+       mcspi = spi_master_get_devdata(master);
+
+       chconf = mcspi_cached_chconf0(spi);
+       if (enable) {
+               bytes_per_word = mcspi_bytes_per_word(cs->word_len);
+               if (t->len % bytes_per_word != 0)
+                       goto disable_fifo;
+
+               if (t->rx_buf != NULL && t->tx_buf != NULL)
+                       max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
+               else
+                       max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
+
+               fifo_depth = gcd(t->len, max_fifo_depth);
+               if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0)
+                       goto disable_fifo;
+
+               wcnt = t->len / bytes_per_word;
+               if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
+                       goto disable_fifo;
+
+               xferlevel = wcnt << 16;
+               if (t->rx_buf != NULL) {
+                       chconf |= OMAP2_MCSPI_CHCONF_FFER;
+                       xferlevel |= (fifo_depth - 1) << 8;
+               }
+               if (t->tx_buf != NULL) {
+                       chconf |= OMAP2_MCSPI_CHCONF_FFET;
+                       xferlevel |= fifo_depth - 1;
+               }
+
+               mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel);
+               mcspi_write_chconf0(spi, chconf);
+               mcspi->fifo_depth = fifo_depth;
+
+               return;
+       }
+
+disable_fifo:
+       if (t->rx_buf != NULL)
+               chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
+
+       if (t->tx_buf != NULL)
+               chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
+
+       mcspi_write_chconf0(spi, chconf);
+       mcspi->fifo_depth = 0;
+}
+
+static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
+{
+       struct spi_master       *spi_cntrl = mcspi->master;
+       struct omap2_mcspi_regs *ctx = &mcspi->ctx;
+       struct omap2_mcspi_cs   *cs;
+
+       /* McSPI: context restore */
+       mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
+       mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
+
+       list_for_each_entry(cs, &ctx->cs, node)
+               writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
+}
+
+static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
+{
+       unsigned long timeout;
+
+       timeout = jiffies + msecs_to_jiffies(1000);
+       while (!(readl_relaxed(reg) & bit)) {
+               if (time_after(jiffies, timeout)) {
+                       if (!(readl_relaxed(reg) & bit))
+                               return -ETIMEDOUT;
+                       else
+                               return 0;
+               }
+               cpu_relax();
+       }
+       return 0;
+}
+
+static void omap2_mcspi_rx_callback(void *data)
+{
+       struct spi_device *spi = data;
+       struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
+       struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+
+       /* We must disable the DMA RX request */
+       omap2_mcspi_set_dma_req(spi, 1, 0);
+
+       complete(&mcspi_dma->dma_rx_completion);
+}
+
+static void omap2_mcspi_tx_callback(void *data)
+{
+       struct spi_device *spi = data;
+       struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
+       struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+
+       /* We must disable the DMA TX request */
+       omap2_mcspi_set_dma_req(spi, 0, 0);
+
+       complete(&mcspi_dma->dma_tx_completion);
+}
+
+static void omap2_mcspi_tx_dma(struct spi_device *spi,
+                               struct spi_transfer *xfer,
+                               struct dma_slave_config cfg)
+{
+       struct omap2_mcspi      *mcspi;
+       struct omap2_mcspi_dma  *mcspi_dma;
+       unsigned int            count;
+
+       mcspi = spi_master_get_devdata(spi->master);
+       mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+       count = xfer->len;
+
+       if (mcspi_dma->dma_tx) {
+               struct dma_async_tx_descriptor *tx;
+               struct scatterlist sg;
+
+               dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
+
+               sg_init_table(&sg, 1);
+               sg_dma_address(&sg) = xfer->tx_dma;
+               sg_dma_len(&sg) = xfer->len;
+
+               tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
+               DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+               if (tx) {
+                       tx->callback = omap2_mcspi_tx_callback;
+                       tx->callback_param = spi;
+                       dmaengine_submit(tx);
+               } else {
+                       /* FIXME: fall back to PIO? */
+               }
+       }
+       dma_async_issue_pending(mcspi_dma->dma_tx);
+       omap2_mcspi_set_dma_req(spi, 0, 1);
+
+}
+
+static unsigned
+omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
+                               struct dma_slave_config cfg,
+                               unsigned es)
+{
+       struct omap2_mcspi      *mcspi;
+       struct omap2_mcspi_dma  *mcspi_dma;
+       unsigned int            count, dma_count;
+       u32                     l;
+       int                     elements = 0;
+       int                     word_len, element_count;
+       struct omap2_mcspi_cs   *cs = spi->controller_state;
+       mcspi = spi_master_get_devdata(spi->master);
+       mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+       count = xfer->len;
+       dma_count = xfer->len;
+
+       if (mcspi->fifo_depth == 0)
+               dma_count -= es;
+
+       word_len = cs->word_len;
+       l = mcspi_cached_chconf0(spi);
+
+       if (word_len <= 8)
+               element_count = count;
+       else if (word_len <= 16)
+               element_count = count >> 1;
+       else /* word_len <= 32 */
+               element_count = count >> 2;
+
+       if (mcspi_dma->dma_rx) {
+               struct dma_async_tx_descriptor *tx;
+               struct scatterlist sg;
+
+               dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
+
+               if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
+                       dma_count -= es;
+
+               sg_init_table(&sg, 1);
+               sg_dma_address(&sg) = xfer->rx_dma;
+               sg_dma_len(&sg) = dma_count;
+
+               tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
+                               DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
+                               DMA_CTRL_ACK);
+               if (tx) {
+                       tx->callback = omap2_mcspi_rx_callback;
+                       tx->callback_param = spi;
+                       dmaengine_submit(tx);
+               } else {
+                               /* FIXME: fall back to PIO? */
+               }
+       }
+
+       dma_async_issue_pending(mcspi_dma->dma_rx);
+       omap2_mcspi_set_dma_req(spi, 1, 1);
+
+       wait_for_completion(&mcspi_dma->dma_rx_completion);
+       dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
+                        DMA_FROM_DEVICE);
+
+       if (mcspi->fifo_depth > 0)
+               return count;
+
+       omap2_mcspi_set_enable(spi, 0);
+
+       elements = element_count - 1;
+
+       if (l & OMAP2_MCSPI_CHCONF_TURBO) {
+               elements--;
+
+               if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
+                                  & OMAP2_MCSPI_CHSTAT_RXS)) {
+                       u32 w;
+
+                       w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
+                       if (word_len <= 8)
+                               ((u8 *)xfer->rx_buf)[elements++] = w;
+                       else if (word_len <= 16)
+                               ((u16 *)xfer->rx_buf)[elements++] = w;
+                       else /* word_len <= 32 */
+                               ((u32 *)xfer->rx_buf)[elements++] = w;
+               } else {
+                       int bytes_per_word = mcspi_bytes_per_word(word_len);
+                       dev_err(&spi->dev, "DMA RX penultimate word empty\n");
+                       count -= (bytes_per_word << 1);
+                       omap2_mcspi_set_enable(spi, 1);
+                       return count;
+               }
+       }
+       if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
+                               & OMAP2_MCSPI_CHSTAT_RXS)) {
+               u32 w;
+
+               w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
+               if (word_len <= 8)
+                       ((u8 *)xfer->rx_buf)[elements] = w;
+               else if (word_len <= 16)
+                       ((u16 *)xfer->rx_buf)[elements] = w;
+               else /* word_len <= 32 */
+                       ((u32 *)xfer->rx_buf)[elements] = w;
+       } else {
+               dev_err(&spi->dev, "DMA RX last word empty\n");
+               count -= mcspi_bytes_per_word(word_len);
+       }
+       omap2_mcspi_set_enable(spi, 1);
+       return count;
+}
+
+static unsigned
+omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
+{
+       struct omap2_mcspi      *mcspi;
+       struct omap2_mcspi_cs   *cs = spi->controller_state;
+       struct omap2_mcspi_dma  *mcspi_dma;
+       unsigned int            count;
+       u32                     l;
+       u8                      *rx;
+       const u8                *tx;
+       struct dma_slave_config cfg;
+       enum dma_slave_buswidth width;
+       unsigned es;
+       u32                     burst;
+       void __iomem            *chstat_reg;
+       void __iomem            *irqstat_reg;
+       int                     wait_res;
+
+       mcspi = spi_master_get_devdata(spi->master);
+       mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+       l = mcspi_cached_chconf0(spi);
+
+
+       if (cs->word_len <= 8) {
+               width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+               es = 1;
+       } else if (cs->word_len <= 16) {
+               width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+               es = 2;
+       } else {
+               width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+               es = 4;
+       }
+
+       count = xfer->len;
+       burst = 1;
+
+       if (mcspi->fifo_depth > 0) {
+               if (count > mcspi->fifo_depth)
+                       burst = mcspi->fifo_depth / es;
+               else
+                       burst = count / es;
+       }
+
+       memset(&cfg, 0, sizeof(cfg));
+       cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
+       cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
+       cfg.src_addr_width = width;
+       cfg.dst_addr_width = width;
+       cfg.src_maxburst = burst;
+       cfg.dst_maxburst = burst;
+
+       rx = xfer->rx_buf;
+       tx = xfer->tx_buf;
+
+       if (tx != NULL)
+               omap2_mcspi_tx_dma(spi, xfer, cfg);
+
+       if (rx != NULL)
+               count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
+
+       if (tx != NULL) {
+               wait_for_completion(&mcspi_dma->dma_tx_completion);
+               dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
+                                DMA_TO_DEVICE);
+
+               if (mcspi->fifo_depth > 0) {
+                       irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
+
+                       if (mcspi_wait_for_reg_bit(irqstat_reg,
+                                               OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
+                               dev_err(&spi->dev, "EOW timed out\n");
+
+                       mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
+                                       OMAP2_MCSPI_IRQSTATUS_EOW);
+               }
+
+               /* for TX_ONLY mode, be sure all words have shifted out */
+               if (rx == NULL) {
+                       chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
+                       if (mcspi->fifo_depth > 0) {
+                               wait_res = mcspi_wait_for_reg_bit(chstat_reg,
+                                               OMAP2_MCSPI_CHSTAT_TXFFE);
+                               if (wait_res < 0)
+                                       dev_err(&spi->dev, "TXFFE timed out\n");
+                       } else {
+                               wait_res = mcspi_wait_for_reg_bit(chstat_reg,
+                                               OMAP2_MCSPI_CHSTAT_TXS);
+                               if (wait_res < 0)
+                                       dev_err(&spi->dev, "TXS timed out\n");
+                       }
+                       if (wait_res >= 0 &&
+                               (mcspi_wait_for_reg_bit(chstat_reg,
+                                       OMAP2_MCSPI_CHSTAT_EOT) < 0))
+                               dev_err(&spi->dev, "EOT timed out\n");
+               }
+       }
+       return count;
+}
+
+static unsigned
+omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
+{
+       struct omap2_mcspi      *mcspi;
+       struct omap2_mcspi_cs   *cs = spi->controller_state;
+       unsigned int            count, c;
+       u32                     l;
+       void __iomem            *base = cs->base;
+       void __iomem            *tx_reg;
+       void __iomem            *rx_reg;
+       void __iomem            *chstat_reg;
+       int                     word_len;
+
+       mcspi = spi_master_get_devdata(spi->master);
+       count = xfer->len;
+       c = count;
+       word_len = cs->word_len;
+
+       l = mcspi_cached_chconf0(spi);
+
+       /* We store the pre-calculated register addresses on stack to speed
+        * up the transfer loop. */
+       tx_reg          = base + OMAP2_MCSPI_TX0;
+       rx_reg          = base + OMAP2_MCSPI_RX0;
+       chstat_reg      = base + OMAP2_MCSPI_CHSTAT0;
+
+       if (c < (word_len>>3))
+               return 0;
+
+       if (word_len <= 8) {
+               u8              *rx;
+               const u8        *tx;
+
+               rx = xfer->rx_buf;
+               tx = xfer->tx_buf;
+
+               do {
+                       c -= 1;
+                       if (tx != NULL) {
+                               if (mcspi_wait_for_reg_bit(chstat_reg,
+                                               OMAP2_MCSPI_CHSTAT_TXS) < 0) {
+                                       dev_err(&spi->dev, "TXS timed out\n");
+                                       goto out;
+                               }
+                               dev_vdbg(&spi->dev, "write-%d %02x\n",
+                                               word_len, *tx);
+                               writel_relaxed(*tx++, tx_reg);
+                       }
+                       if (rx != NULL) {
+                               if (mcspi_wait_for_reg_bit(chstat_reg,
+                                               OMAP2_MCSPI_CHSTAT_RXS) < 0) {
+                                       dev_err(&spi->dev, "RXS timed out\n");
+                                       goto out;
+                               }
+
+                               if (c == 1 && tx == NULL &&
+                                   (l & OMAP2_MCSPI_CHCONF_TURBO)) {
+                                       omap2_mcspi_set_enable(spi, 0);
+                                       *rx++ = readl_relaxed(rx_reg);
+                                       dev_vdbg(&spi->dev, "read-%d %02x\n",
+                                                   word_len, *(rx - 1));
+                                       if (mcspi_wait_for_reg_bit(chstat_reg,
+                                               OMAP2_MCSPI_CHSTAT_RXS) < 0) {
+                                               dev_err(&spi->dev,
+                                                       "RXS timed out\n");
+                                               goto out;
+                                       }
+                                       c = 0;
+                               } else if (c == 0 && tx == NULL) {
+                                       omap2_mcspi_set_enable(spi, 0);
+                               }
+
+                               *rx++ = readl_relaxed(rx_reg);
+                               dev_vdbg(&spi->dev, "read-%d %02x\n",
+                                               word_len, *(rx - 1));
+                       }
+               } while (c);
+       } else if (word_len <= 16) {
+               u16             *rx;
+               const u16       *tx;
+
+               rx = xfer->rx_buf;
+               tx = xfer->tx_buf;
+               do {
+                       c -= 2;
+                       if (tx != NULL) {
+                               if (mcspi_wait_for_reg_bit(chstat_reg,
+                                               OMAP2_MCSPI_CHSTAT_TXS) < 0) {
+                                       dev_err(&spi->dev, "TXS timed out\n");
+                                       goto out;
+                               }
+                               dev_vdbg(&spi->dev, "write-%d %04x\n",
+                                               word_len, *tx);
+                               writel_relaxed(*tx++, tx_reg);
+                       }
+                       if (rx != NULL) {
+                               if (mcspi_wait_for_reg_bit(chstat_reg,
+                                               OMAP2_MCSPI_CHSTAT_RXS) < 0) {
+                                       dev_err(&spi->dev, "RXS timed out\n");
+                                       goto out;
+                               }
+
+                               if (c == 2 && tx == NULL &&
+                                   (l & OMAP2_MCSPI_CHCONF_TURBO)) {
+                                       omap2_mcspi_set_enable(spi, 0);
+                                       *rx++ = readl_relaxed(rx_reg);
+                                       dev_vdbg(&spi->dev, "read-%d %04x\n",
+                                                   word_len, *(rx - 1));
+                                       if (mcspi_wait_for_reg_bit(chstat_reg,
+                                               OMAP2_MCSPI_CHSTAT_RXS) < 0) {
+                                               dev_err(&spi->dev,
+                                                       "RXS timed out\n");
+                                               goto out;
+                                       }
+                                       c = 0;
+                               } else if (c == 0 && tx == NULL) {
+                                       omap2_mcspi_set_enable(spi, 0);
+                               }
+
+                               *rx++ = readl_relaxed(rx_reg);
+                               dev_vdbg(&spi->dev, "read-%d %04x\n",
+                                               word_len, *(rx - 1));
+                       }
+               } while (c >= 2);
+       } else if (word_len <= 32) {
+               u32             *rx;
+               const u32       *tx;
+
+               rx = xfer->rx_buf;
+               tx = xfer->tx_buf;
+               do {
+                       c -= 4;
+                       if (tx != NULL) {
+                               if (mcspi_wait_for_reg_bit(chstat_reg,
+                                               OMAP2_MCSPI_CHSTAT_TXS) < 0) {
+                                       dev_err(&spi->dev, "TXS timed out\n");
+                                       goto out;
+                               }
+                               dev_vdbg(&spi->dev, "write-%d %08x\n",
+                                               word_len, *tx);
+                               writel_relaxed(*tx++, tx_reg);
+                       }
+                       if (rx != NULL) {
+                               if (mcspi_wait_for_reg_bit(chstat_reg,
+                                               OMAP2_MCSPI_CHSTAT_RXS) < 0) {
+                                       dev_err(&spi->dev, "RXS timed out\n");
+                                       goto out;
+                               }
+
+                               if (c == 4 && tx == NULL &&
+                                   (l & OMAP2_MCSPI_CHCONF_TURBO)) {
+                                       omap2_mcspi_set_enable(spi, 0);
+                                       *rx++ = readl_relaxed(rx_reg);
+                                       dev_vdbg(&spi->dev, "read-%d %08x\n",
+                                                   word_len, *(rx - 1));
+                                       if (mcspi_wait_for_reg_bit(chstat_reg,
+                                               OMAP2_MCSPI_CHSTAT_RXS) < 0) {
+                                               dev_err(&spi->dev,
+                                                       "RXS timed out\n");
+                                               goto out;
+                                       }
+                                       c = 0;
+                               } else if (c == 0 && tx == NULL) {
+                                       omap2_mcspi_set_enable(spi, 0);
+                               }
+
+                               *rx++ = readl_relaxed(rx_reg);
+                               dev_vdbg(&spi->dev, "read-%d %08x\n",
+                                               word_len, *(rx - 1));
+                       }
+               } while (c >= 4);
+       }
+
+       /* for TX_ONLY mode, be sure all words have shifted out */
+       if (xfer->rx_buf == NULL) {
+               if (mcspi_wait_for_reg_bit(chstat_reg,
+                               OMAP2_MCSPI_CHSTAT_TXS) < 0) {
+                       dev_err(&spi->dev, "TXS timed out\n");
+               } else if (mcspi_wait_for_reg_bit(chstat_reg,
+                               OMAP2_MCSPI_CHSTAT_EOT) < 0)
+                       dev_err(&spi->dev, "EOT timed out\n");
+
+               /* disable chan to purge rx datas received in TX_ONLY transfer,
+                * otherwise these rx datas will affect the direct following
+                * RX_ONLY transfer.
+                */
+               omap2_mcspi_set_enable(spi, 0);
+       }
+out:
+       omap2_mcspi_set_enable(spi, 1);
+       return count - c;
+}
+
+static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
+{
+       u32 div;
+
+       for (div = 0; div < 15; div++)
+               if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
+                       return div;
+
+       return 15;
+}
+
+/* called only when no transfer is active to this device */
+static int omap2_mcspi_setup_transfer(struct spi_device *spi,
+               struct spi_transfer *t)
+{
+       struct omap2_mcspi_cs *cs = spi->controller_state;
+       struct omap2_mcspi *mcspi;
+       struct spi_master *spi_cntrl;
+       u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
+       u8 word_len = spi->bits_per_word;
+       u32 speed_hz = spi->max_speed_hz;
+
+       mcspi = spi_master_get_devdata(spi->master);
+       spi_cntrl = mcspi->master;
+
+       if (t != NULL && t->bits_per_word)
+               word_len = t->bits_per_word;
+
+       cs->word_len = word_len;
+
+       if (t && t->speed_hz)
+               speed_hz = t->speed_hz;
+
+       speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
+       if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
+               clkd = omap2_mcspi_calc_divisor(speed_hz);
+               speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
+               clkg = 0;
+       } else {
+               div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
+               speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
+               clkd = (div - 1) & 0xf;
+               extclk = (div - 1) >> 4;
+               clkg = OMAP2_MCSPI_CHCONF_CLKG;
+       }
+
+       l = mcspi_cached_chconf0(spi);
+
+       /* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
+        * REVISIT: this controller could support SPI_3WIRE mode.
+        */
+       if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
+               l &= ~OMAP2_MCSPI_CHCONF_IS;
+               l &= ~OMAP2_MCSPI_CHCONF_DPE1;
+               l |= OMAP2_MCSPI_CHCONF_DPE0;
+       } else {
+               l |= OMAP2_MCSPI_CHCONF_IS;
+               l |= OMAP2_MCSPI_CHCONF_DPE1;
+               l &= ~OMAP2_MCSPI_CHCONF_DPE0;
+       }
+
+       /* wordlength */
+       l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
+       l |= (word_len - 1) << 7;
+
+       /* set chipselect polarity; manage with FORCE */
+       if (!(spi->mode & SPI_CS_HIGH))
+               l |= OMAP2_MCSPI_CHCONF_EPOL;   /* active-low; normal */
+       else
+               l &= ~OMAP2_MCSPI_CHCONF_EPOL;
+
+       /* set clock divisor */
+       l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
+       l |= clkd << 2;
+
+       /* set clock granularity */
+       l &= ~OMAP2_MCSPI_CHCONF_CLKG;
+       l |= clkg;
+       if (clkg) {
+               cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
+               cs->chctrl0 |= extclk << 8;
+               mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
+       }
+
+       /* set SPI mode 0..3 */
+       if (spi->mode & SPI_CPOL)
+               l |= OMAP2_MCSPI_CHCONF_POL;
+       else
+               l &= ~OMAP2_MCSPI_CHCONF_POL;
+       if (spi->mode & SPI_CPHA)
+               l |= OMAP2_MCSPI_CHCONF_PHA;
+       else
+               l &= ~OMAP2_MCSPI_CHCONF_PHA;
+
+       mcspi_write_chconf0(spi, l);
+
+       cs->mode = spi->mode;
+
+       dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
+                       speed_hz,
+                       (spi->mode & SPI_CPHA) ? "trailing" : "leading",
+                       (spi->mode & SPI_CPOL) ? "inverted" : "normal");
+
+       return 0;
+}
+
+/*
+ * Note that we currently allow DMA only if we get a channel
+ * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
+ */
+static int omap2_mcspi_request_dma(struct spi_device *spi)
+{
+       struct spi_master       *master = spi->master;
+       struct omap2_mcspi      *mcspi;
+       struct omap2_mcspi_dma  *mcspi_dma;
+       dma_cap_mask_t mask;
+       unsigned sig;
+
+       mcspi = spi_master_get_devdata(master);
+       mcspi_dma = mcspi->dma_channels + spi->chip_select;
+
+       init_completion(&mcspi_dma->dma_rx_completion);
+       init_completion(&mcspi_dma->dma_tx_completion);
+
+       dma_cap_zero(mask);
+       dma_cap_set(DMA_SLAVE, mask);
+       sig = mcspi_dma->dma_rx_sync_dev;
+
+       mcspi_dma->dma_rx =
+               dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
+                                                &sig, &master->dev,
+                                                mcspi_dma->dma_rx_ch_name);
+       if (!mcspi_dma->dma_rx)
+               goto no_dma;
+
+       sig = mcspi_dma->dma_tx_sync_dev;
+       mcspi_dma->dma_tx =
+               dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
+                                                &sig, &master->dev,
+                                                mcspi_dma->dma_tx_ch_name);
+
+       if (!mcspi_dma->dma_tx) {
+               dma_release_channel(mcspi_dma->dma_rx);
+               mcspi_dma->dma_rx = NULL;
+               goto no_dma;
+       }
+
+       return 0;
+
+no_dma:
+       dev_warn(&spi->dev, "not using DMA for McSPI\n");
+       return -EAGAIN;
+}
+
+static int omap2_mcspi_setup(struct spi_device *spi)
+{
+       int                     ret;
+       struct omap2_mcspi      *mcspi = spi_master_get_devdata(spi->master);
+       struct omap2_mcspi_regs *ctx = &mcspi->ctx;
+       struct omap2_mcspi_dma  *mcspi_dma;
+       struct omap2_mcspi_cs   *cs = spi->controller_state;
+
+       mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+
+       if (!cs) {
+               cs = kzalloc(sizeof *cs, GFP_KERNEL);
+               if (!cs)
+                       return -ENOMEM;
+               cs->base = mcspi->base + spi->chip_select * 0x14;
+               cs->phys = mcspi->phys + spi->chip_select * 0x14;
+               cs->mode = 0;
+               cs->chconf0 = 0;
+               cs->chctrl0 = 0;
+               spi->controller_state = cs;
+               /* Link this to context save list */
+               list_add_tail(&cs->node, &ctx->cs);
+       }
+
+       if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
+               ret = omap2_mcspi_request_dma(spi);
+               if (ret < 0 && ret != -EAGAIN)
+                       return ret;
+       }
+
+       ret = pm_runtime_get_sync(mcspi->dev);
+       if (ret < 0)
+               return ret;
+
+       ret = omap2_mcspi_setup_transfer(spi, NULL);
+       pm_runtime_mark_last_busy(mcspi->dev);
+       pm_runtime_put_autosuspend(mcspi->dev);
+
+       return ret;
+}
+
+static void omap2_mcspi_cleanup(struct spi_device *spi)
+{
+       struct omap2_mcspi      *mcspi;
+       struct omap2_mcspi_dma  *mcspi_dma;
+       struct omap2_mcspi_cs   *cs;
+
+       mcspi = spi_master_get_devdata(spi->master);
+
+       if (spi->controller_state) {
+               /* Unlink controller state from context save list */
+               cs = spi->controller_state;
+               list_del(&cs->node);
+
+               kfree(cs);
+       }
+
+       if (spi->chip_select < spi->master->num_chipselect) {
+               mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+
+               if (mcspi_dma->dma_rx) {
+                       dma_release_channel(mcspi_dma->dma_rx);
+                       mcspi_dma->dma_rx = NULL;
+               }
+               if (mcspi_dma->dma_tx) {
+                       dma_release_channel(mcspi_dma->dma_tx);
+                       mcspi_dma->dma_tx = NULL;
+               }
+       }
+}
+
+static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m)
+{
+
+       /* We only enable one channel at a time -- the one whose message is
+        * -- although this controller would gladly
+        * arbitrate among multiple channels.  This corresponds to "single
+        * channel" master mode.  As a side effect, we need to manage the
+        * chipselect with the FORCE bit ... CS != channel enable.
+        */
+
+       struct spi_device               *spi;
+       struct spi_transfer             *t = NULL;
+       struct spi_master               *master;
+       struct omap2_mcspi_dma          *mcspi_dma;
+       int                             cs_active = 0;
+       struct omap2_mcspi_cs           *cs;
+       struct omap2_mcspi_device_config *cd;
+       int                             par_override = 0;
+       int                             status = 0;
+       u32                             chconf;
+
+       spi = m->spi;
+       master = spi->master;
+       mcspi_dma = mcspi->dma_channels + spi->chip_select;
+       cs = spi->controller_state;
+       cd = spi->controller_data;
+
+       /*
+        * The slave driver could have changed spi->mode in which case
+        * it will be different from cs->mode (the current hardware setup).
+        * If so, set par_override (even though its not a parity issue) so
+        * omap2_mcspi_setup_transfer will be called to configure the hardware
+        * with the correct mode on the first iteration of the loop below.
+        */
+       if (spi->mode != cs->mode)
+               par_override = 1;
+
+       omap2_mcspi_set_enable(spi, 0);
+       list_for_each_entry(t, &m->transfers, transfer_list) {
+               if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
+                       status = -EINVAL;
+                       break;
+               }
+               if (par_override ||
+                   (t->speed_hz != spi->max_speed_hz) ||
+                   (t->bits_per_word != spi->bits_per_word)) {
+                       par_override = 1;
+                       status = omap2_mcspi_setup_transfer(spi, t);
+                       if (status < 0)
+                               break;
+                       if (t->speed_hz == spi->max_speed_hz &&
+                           t->bits_per_word == spi->bits_per_word)
+                               par_override = 0;
+               }
+               if (cd && cd->cs_per_word) {
+                       chconf = mcspi->ctx.modulctrl;
+                       chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
+                       mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
+                       mcspi->ctx.modulctrl =
+                               mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
+               }
+
+
+               if (!cs_active) {
+                       omap2_mcspi_force_cs(spi, 1);
+                       cs_active = 1;
+               }
+
+               chconf = mcspi_cached_chconf0(spi);
+               chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
+               chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
+
+               if (t->tx_buf == NULL)
+                       chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
+               else if (t->rx_buf == NULL)
+                       chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
+
+               if (cd && cd->turbo_mode && t->tx_buf == NULL) {
+                       /* Turbo mode is for more than one word */
+                       if (t->len > ((cs->word_len + 7) >> 3))
+                               chconf |= OMAP2_MCSPI_CHCONF_TURBO;
+               }
+
+               mcspi_write_chconf0(spi, chconf);
+
+               if (t->len) {
+                       unsigned        count;
+
+                       if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
+                           (m->is_dma_mapped || t->len >= DMA_MIN_BYTES))
+                               omap2_mcspi_set_fifo(spi, t, 1);
+
+                       omap2_mcspi_set_enable(spi, 1);
+
+                       /* RX_ONLY mode needs dummy data in TX reg */
+                       if (t->tx_buf == NULL)
+                               writel_relaxed(0, cs->base
+                                               + OMAP2_MCSPI_TX0);
+
+                       if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
+                           (m->is_dma_mapped || t->len >= DMA_MIN_BYTES))
+                               count = omap2_mcspi_txrx_dma(spi, t);
+                       else
+                               count = omap2_mcspi_txrx_pio(spi, t);
+                       m->actual_length += count;
+
+                       if (count != t->len) {
+                               status = -EIO;
+                               break;
+                       }
+               }
+
+               if (t->delay_usecs)
+                       udelay(t->delay_usecs);
+
+               /* ignore the "leave it on after last xfer" hint */
+               if (t->cs_change) {
+                       omap2_mcspi_force_cs(spi, 0);
+                       cs_active = 0;
+               }
+
+               omap2_mcspi_set_enable(spi, 0);
+
+               if (mcspi->fifo_depth > 0)
+                       omap2_mcspi_set_fifo(spi, t, 0);
+       }
+       /* Restore defaults if they were overriden */
+       if (par_override) {
+               par_override = 0;
+               status = omap2_mcspi_setup_transfer(spi, NULL);
+       }
+
+       if (cs_active)
+               omap2_mcspi_force_cs(spi, 0);
+
+       if (cd && cd->cs_per_word) {
+               chconf = mcspi->ctx.modulctrl;
+               chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
+               mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
+               mcspi->ctx.modulctrl =
+                       mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
+       }
+
+       omap2_mcspi_set_enable(spi, 0);
+
+       if (mcspi->fifo_depth > 0 && t)
+               omap2_mcspi_set_fifo(spi, t, 0);
+
+       m->status = status;
+}
+
+static int omap2_mcspi_transfer_one_message(struct spi_master *master,
+               struct spi_message *m)
+{
+       struct spi_device       *spi;
+       struct omap2_mcspi      *mcspi;
+       struct omap2_mcspi_dma  *mcspi_dma;
+       struct spi_transfer     *t;
+       int status;
+
+       spi = m->spi;
+       mcspi = spi_master_get_devdata(master);
+       mcspi_dma = mcspi->dma_channels + spi->chip_select;
+       m->actual_length = 0;
+       m->status = 0;
+
+       list_for_each_entry(t, &m->transfers, transfer_list) {
+               const void      *tx_buf = t->tx_buf;
+               void            *rx_buf = t->rx_buf;
+               unsigned        len = t->len;
+
+               if ((len && !(rx_buf || tx_buf))) {
+                       dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
+                                       t->speed_hz,
+                                       len,
+                                       tx_buf ? "tx" : "",
+                                       rx_buf ? "rx" : "",
+                                       t->bits_per_word);
+                       status = -EINVAL;
+                       goto out;
+               }
+
+               if (m->is_dma_mapped || len < DMA_MIN_BYTES)
+                       continue;
+
+               if (mcspi_dma->dma_tx && tx_buf != NULL) {
+                       t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf,
+                                       len, DMA_TO_DEVICE);
+                       if (dma_mapping_error(mcspi->dev, t->tx_dma)) {
+                               dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
+                                               'T', len);
+                               status = -EINVAL;
+                               goto out;
+                       }
+               }
+               if (mcspi_dma->dma_rx && rx_buf != NULL) {
+                       t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len,
+                                       DMA_FROM_DEVICE);
+                       if (dma_mapping_error(mcspi->dev, t->rx_dma)) {
+                               dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
+                                               'R', len);
+                               if (tx_buf != NULL)
+                                       dma_unmap_single(mcspi->dev, t->tx_dma,
+                                                       len, DMA_TO_DEVICE);
+                               status = -EINVAL;
+                               goto out;
+                       }
+               }
+       }
+
+       omap2_mcspi_work(mcspi, m);
+       /* spi_finalize_current_message() changes the status inside the
+        * spi_message, save the status here. */
+       status = m->status;
+out:
+       spi_finalize_current_message(master);
+       return status;
+}
+
+static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
+{
+       struct spi_master       *master = mcspi->master;
+       struct omap2_mcspi_regs *ctx = &mcspi->ctx;
+       int                     ret = 0;
+
+       ret = pm_runtime_get_sync(mcspi->dev);
+       if (ret < 0)
+               return ret;
+
+       mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
+                       OMAP2_MCSPI_WAKEUPENABLE_WKEN);
+       ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
+
+       omap2_mcspi_set_master_mode(master);
+       pm_runtime_mark_last_busy(mcspi->dev);
+       pm_runtime_put_autosuspend(mcspi->dev);
+       return 0;
+}
+
+static int omap_mcspi_runtime_resume(struct device *dev)
+{
+       struct omap2_mcspi      *mcspi;
+       struct spi_master       *master;
+
+       master = dev_get_drvdata(dev);
+       mcspi = spi_master_get_devdata(master);
+       omap2_mcspi_restore_ctx(mcspi);
+
+       return 0;
+}
+
+static struct omap2_mcspi_platform_config omap2_pdata = {
+       .regs_offset = 0,
+};
+
+static struct omap2_mcspi_platform_config omap4_pdata = {
+       .regs_offset = OMAP4_MCSPI_REG_OFFSET,
+};
+
+static const struct of_device_id omap_mcspi_of_match[] = {
+       {
+               .compatible = "ti,omap2-mcspi",
+               .data = &omap2_pdata,
+       },
+       {
+               .compatible = "ti,omap4-mcspi",
+               .data = &omap4_pdata,
+       },
+       { },
+};
+MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
+
+static int omap2_mcspi_probe(struct platform_device *pdev)
+{
+       struct spi_master       *master;
+       const struct omap2_mcspi_platform_config *pdata;
+       struct omap2_mcspi      *mcspi;
+       struct resource         *r;
+       int                     status = 0, i;
+       u32                     regs_offset = 0;
+       static int              bus_num = 1;
+       struct device_node      *node = pdev->dev.of_node;
+       const struct of_device_id *match;
+
+       master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
+       if (master == NULL) {
+               dev_dbg(&pdev->dev, "master allocation failed\n");
+               return -ENOMEM;
+       }
+
+       /* the spi->mode bits understood by this driver: */
+       master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+       master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
+       master->setup = omap2_mcspi_setup;
+       master->auto_runtime_pm = true;
+       master->transfer_one_message = omap2_mcspi_transfer_one_message;
+       master->cleanup = omap2_mcspi_cleanup;
+       master->dev.of_node = node;
+       master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
+       master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
+
+       platform_set_drvdata(pdev, master);
+
+       mcspi = spi_master_get_devdata(master);
+       mcspi->master = master;
+
+       match = of_match_device(omap_mcspi_of_match, &pdev->dev);
+       if (match) {
+               u32 num_cs = 1; /* default number of chipselect */
+               pdata = match->data;
+
+               of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
+               master->num_chipselect = num_cs;
+               master->bus_num = bus_num++;
+               if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
+                       mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
+       } else {
+               pdata = dev_get_platdata(&pdev->dev);
+               master->num_chipselect = pdata->num_cs;
+               if (pdev->id != -1)
+                       master->bus_num = pdev->id;
+               mcspi->pin_dir = pdata->pin_dir;
+       }
+       regs_offset = pdata->regs_offset;
+
+       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (r == NULL) {
+               status = -ENODEV;
+               goto free_master;
+       }
+
+       r->start += regs_offset;
+       r->end += regs_offset;
+       mcspi->phys = r->start;
+
+       mcspi->base = devm_ioremap_resource(&pdev->dev, r);
+       if (IS_ERR(mcspi->base)) {
+               status = PTR_ERR(mcspi->base);
+               goto free_master;
+       }
+
+       mcspi->dev = &pdev->dev;
+
+       INIT_LIST_HEAD(&mcspi->ctx.cs);
+
+       mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
+                                          sizeof(struct omap2_mcspi_dma),
+                                          GFP_KERNEL);
+       if (mcspi->dma_channels == NULL) {
+               status = -ENOMEM;
+               goto free_master;
+       }
+
+       for (i = 0; i < master->num_chipselect; i++) {
+               char *dma_rx_ch_name = mcspi->dma_channels[i].dma_rx_ch_name;
+               char *dma_tx_ch_name = mcspi->dma_channels[i].dma_tx_ch_name;
+               struct resource *dma_res;
+
+               sprintf(dma_rx_ch_name, "rx%d", i);
+               if (!pdev->dev.of_node) {
+                       dma_res =
+                               platform_get_resource_byname(pdev,
+                                                            IORESOURCE_DMA,
+                                                            dma_rx_ch_name);
+                       if (!dma_res) {
+                               dev_dbg(&pdev->dev,
+                                       "cannot get DMA RX channel\n");
+                               status = -ENODEV;
+                               break;
+                       }
+
+                       mcspi->dma_channels[i].dma_rx_sync_dev =
+                               dma_res->start;
+               }
+               sprintf(dma_tx_ch_name, "tx%d", i);
+               if (!pdev->dev.of_node) {
+                       dma_res =
+                               platform_get_resource_byname(pdev,
+                                                            IORESOURCE_DMA,
+                                                            dma_tx_ch_name);
+                       if (!dma_res) {
+                               dev_dbg(&pdev->dev,
+                                       "cannot get DMA TX channel\n");
+                               status = -ENODEV;
+                               break;
+                       }
+
+                       mcspi->dma_channels[i].dma_tx_sync_dev =
+                               dma_res->start;
+               }
+       }
+
+       if (status < 0)
+               goto free_master;
+
+       pm_runtime_use_autosuspend(&pdev->dev);
+       pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
+       pm_runtime_enable(&pdev->dev);
+
+       status = omap2_mcspi_master_setup(mcspi);
+       if (status < 0)
+               goto disable_pm;
+
+       status = devm_spi_register_master(&pdev->dev, master);
+       if (status < 0)
+               goto disable_pm;
+
+       return status;
+
+disable_pm:
+       pm_runtime_disable(&pdev->dev);
+free_master:
+       spi_master_put(master);
+       return status;
+}
+
+static int omap2_mcspi_remove(struct platform_device *pdev)
+{
+       struct spi_master *master = platform_get_drvdata(pdev);
+       struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
+
+       pm_runtime_put_sync(mcspi->dev);
+       pm_runtime_disable(&pdev->dev);
+
+       return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:omap2_mcspi");
+
+#ifdef CONFIG_SUSPEND
+/*
+ * When SPI wake up from off-mode, CS is in activate state. If it was in
+ * unactive state when driver was suspend, then force it to unactive state at
+ * wake up.
+ */
+static int omap2_mcspi_resume(struct device *dev)
+{
+       struct spi_master       *master = dev_get_drvdata(dev);
+       struct omap2_mcspi      *mcspi = spi_master_get_devdata(master);
+       struct omap2_mcspi_regs *ctx = &mcspi->ctx;
+       struct omap2_mcspi_cs   *cs;
+
+       pm_runtime_get_sync(mcspi->dev);
+       list_for_each_entry(cs, &ctx->cs, node) {
+               if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
+                       /*
+                        * We need to toggle CS state for OMAP take this
+                        * change in account.
+                        */
+                       cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
+                       writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
+                       cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
+                       writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
+               }
+       }
+       pm_runtime_mark_last_busy(mcspi->dev);
+       pm_runtime_put_autosuspend(mcspi->dev);
+       return 0;
+}
+#else
+#define        omap2_mcspi_resume      NULL
+#endif
+
+static const struct dev_pm_ops omap2_mcspi_pm_ops = {
+       .resume = omap2_mcspi_resume,
+       .runtime_resume = omap_mcspi_runtime_resume,
+};
+
+static struct platform_driver omap2_mcspi_driver = {
+       .driver = {
+               .name =         "omap2_mcspi",
+               .pm =           &omap2_mcspi_pm_ops,
+               .of_match_table = omap_mcspi_of_match,
+       },
+       .probe =        omap2_mcspi_probe,
+       .remove =       omap2_mcspi_remove,
+};
+
+module_platform_driver(omap2_mcspi_driver);
+MODULE_LICENSE("GPL");