Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / spi / spi-imx.c
diff --git a/kernel/drivers/spi/spi-imx.c b/kernel/drivers/spi/spi-imx.c
new file mode 100644 (file)
index 0000000..f08e812
--- /dev/null
@@ -0,0 +1,1249 @@
+/*
+ * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright (C) 2008 Juergen Beisert
+ *
+ * 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
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/types.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+
+#include <linux/platform_data/dma-imx.h>
+#include <linux/platform_data/spi-imx.h>
+
+#define DRIVER_NAME "spi_imx"
+
+#define MXC_CSPIRXDATA         0x00
+#define MXC_CSPITXDATA         0x04
+#define MXC_CSPICTRL           0x08
+#define MXC_CSPIINT            0x0c
+#define MXC_RESET              0x1c
+
+/* generic defines to abstract from the different register layouts */
+#define MXC_INT_RR     (1 << 0) /* Receive data ready interrupt */
+#define MXC_INT_TE     (1 << 1) /* Transmit FIFO empty interrupt */
+
+/* The maximum  bytes that a sdma BD can transfer.*/
+#define MAX_SDMA_BD_BYTES  (1 << 15)
+#define IMX_DMA_TIMEOUT (msecs_to_jiffies(3000))
+struct spi_imx_config {
+       unsigned int speed_hz;
+       unsigned int bpw;
+       unsigned int mode;
+       u8 cs;
+};
+
+enum spi_imx_devtype {
+       IMX1_CSPI,
+       IMX21_CSPI,
+       IMX27_CSPI,
+       IMX31_CSPI,
+       IMX35_CSPI,     /* CSPI on all i.mx except above */
+       IMX51_ECSPI,    /* ECSPI on i.mx51 and later */
+};
+
+struct spi_imx_data;
+
+struct spi_imx_devtype_data {
+       void (*intctrl)(struct spi_imx_data *, int);
+       int (*config)(struct spi_imx_data *, struct spi_imx_config *);
+       void (*trigger)(struct spi_imx_data *);
+       int (*rx_available)(struct spi_imx_data *);
+       void (*reset)(struct spi_imx_data *);
+       enum spi_imx_devtype devtype;
+};
+
+struct spi_imx_data {
+       struct spi_bitbang bitbang;
+
+       struct completion xfer_done;
+       void __iomem *base;
+       struct clk *clk_per;
+       struct clk *clk_ipg;
+       unsigned long spi_clk;
+
+       unsigned int count;
+       void (*tx)(struct spi_imx_data *);
+       void (*rx)(struct spi_imx_data *);
+       void *rx_buf;
+       const void *tx_buf;
+       unsigned int txfifo; /* number of words pushed in tx FIFO */
+
+       /* DMA */
+       unsigned int dma_is_inited;
+       unsigned int dma_finished;
+       bool usedma;
+       u32 rx_wml;
+       u32 tx_wml;
+       u32 rxt_wml;
+       struct completion dma_rx_completion;
+       struct completion dma_tx_completion;
+
+       const struct spi_imx_devtype_data *devtype_data;
+       int chipselect[0];
+};
+
+static inline int is_imx27_cspi(struct spi_imx_data *d)
+{
+       return d->devtype_data->devtype == IMX27_CSPI;
+}
+
+static inline int is_imx35_cspi(struct spi_imx_data *d)
+{
+       return d->devtype_data->devtype == IMX35_CSPI;
+}
+
+static inline unsigned spi_imx_get_fifosize(struct spi_imx_data *d)
+{
+       return (d->devtype_data->devtype == IMX51_ECSPI) ? 64 : 8;
+}
+
+#define MXC_SPI_BUF_RX(type)                                           \
+static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx)                \
+{                                                                      \
+       unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA);       \
+                                                                       \
+       if (spi_imx->rx_buf) {                                          \
+               *(type *)spi_imx->rx_buf = val;                         \
+               spi_imx->rx_buf += sizeof(type);                        \
+       }                                                               \
+}
+
+#define MXC_SPI_BUF_TX(type)                                           \
+static void spi_imx_buf_tx_##type(struct spi_imx_data *spi_imx)                \
+{                                                                      \
+       type val = 0;                                                   \
+                                                                       \
+       if (spi_imx->tx_buf) {                                          \
+               val = *(type *)spi_imx->tx_buf;                         \
+               spi_imx->tx_buf += sizeof(type);                        \
+       }                                                               \
+                                                                       \
+       spi_imx->count -= sizeof(type);                                 \
+                                                                       \
+       writel(val, spi_imx->base + MXC_CSPITXDATA);                    \
+}
+
+MXC_SPI_BUF_RX(u8)
+MXC_SPI_BUF_TX(u8)
+MXC_SPI_BUF_RX(u16)
+MXC_SPI_BUF_TX(u16)
+MXC_SPI_BUF_RX(u32)
+MXC_SPI_BUF_TX(u32)
+
+/* First entry is reserved, second entry is valid only if SDHC_SPIEN is set
+ * (which is currently not the case in this driver)
+ */
+static int mxc_clkdivs[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
+       256, 384, 512, 768, 1024};
+
+/* MX21, MX27 */
+static unsigned int spi_imx_clkdiv_1(unsigned int fin,
+               unsigned int fspi, unsigned int max)
+{
+       int i;
+
+       for (i = 2; i < max; i++)
+               if (fspi * mxc_clkdivs[i] >= fin)
+                       return i;
+
+       return max;
+}
+
+/* MX1, MX31, MX35, MX51 CSPI */
+static unsigned int spi_imx_clkdiv_2(unsigned int fin,
+               unsigned int fspi)
+{
+       int i, div = 4;
+
+       for (i = 0; i < 7; i++) {
+               if (fspi * div >= fin)
+                       return i;
+               div <<= 1;
+       }
+
+       return 7;
+}
+
+static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
+                        struct spi_transfer *transfer)
+{
+       struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+
+       if (spi_imx->dma_is_inited && (transfer->len > spi_imx->rx_wml)
+           && (transfer->len > spi_imx->tx_wml))
+               return true;
+       return false;
+}
+
+#define MX51_ECSPI_CTRL                0x08
+#define MX51_ECSPI_CTRL_ENABLE         (1 <<  0)
+#define MX51_ECSPI_CTRL_XCH            (1 <<  2)
+#define MX51_ECSPI_CTRL_SMC            (1 << 3)
+#define MX51_ECSPI_CTRL_MODE_MASK      (0xf << 4)
+#define MX51_ECSPI_CTRL_POSTDIV_OFFSET 8
+#define MX51_ECSPI_CTRL_PREDIV_OFFSET  12
+#define MX51_ECSPI_CTRL_CS(cs)         ((cs) << 18)
+#define MX51_ECSPI_CTRL_BL_OFFSET      20
+
+#define MX51_ECSPI_CONFIG      0x0c
+#define MX51_ECSPI_CONFIG_SCLKPHA(cs)  (1 << ((cs) +  0))
+#define MX51_ECSPI_CONFIG_SCLKPOL(cs)  (1 << ((cs) +  4))
+#define MX51_ECSPI_CONFIG_SBBCTRL(cs)  (1 << ((cs) +  8))
+#define MX51_ECSPI_CONFIG_SSBPOL(cs)   (1 << ((cs) + 12))
+#define MX51_ECSPI_CONFIG_SCLKCTL(cs)  (1 << ((cs) + 20))
+
+#define MX51_ECSPI_INT         0x10
+#define MX51_ECSPI_INT_TEEN            (1 <<  0)
+#define MX51_ECSPI_INT_RREN            (1 <<  3)
+
+#define MX51_ECSPI_DMA      0x14
+#define MX51_ECSPI_DMA_TX_WML_OFFSET   0
+#define MX51_ECSPI_DMA_TX_WML_MASK     0x3F
+#define MX51_ECSPI_DMA_RX_WML_OFFSET   16
+#define MX51_ECSPI_DMA_RX_WML_MASK     (0x3F << 16)
+#define MX51_ECSPI_DMA_RXT_WML_OFFSET  24
+#define MX51_ECSPI_DMA_RXT_WML_MASK    (0x3F << 24)
+
+#define MX51_ECSPI_DMA_TEDEN_OFFSET    7
+#define MX51_ECSPI_DMA_RXDEN_OFFSET    23
+#define MX51_ECSPI_DMA_RXTDEN_OFFSET   31
+
+#define MX51_ECSPI_STAT                0x18
+#define MX51_ECSPI_STAT_RR             (1 <<  3)
+
+/* MX51 eCSPI */
+static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi,
+                                     unsigned int *fres)
+{
+       /*
+        * there are two 4-bit dividers, the pre-divider divides by
+        * $pre, the post-divider by 2^$post
+        */
+       unsigned int pre, post;
+
+       if (unlikely(fspi > fin))
+               return 0;
+
+       post = fls(fin) - fls(fspi);
+       if (fin > fspi << post)
+               post++;
+
+       /* now we have: (fin <= fspi << post) with post being minimal */
+
+       post = max(4U, post) - 4;
+       if (unlikely(post > 0xf)) {
+               pr_err("%s: cannot set clock freq: %u (base freq: %u)\n",
+                               __func__, fspi, fin);
+               return 0xff;
+       }
+
+       pre = DIV_ROUND_UP(fin, fspi << post) - 1;
+
+       pr_debug("%s: fin: %u, fspi: %u, post: %u, pre: %u\n",
+                       __func__, fin, fspi, post, pre);
+
+       /* Resulting frequency for the SCLK line. */
+       *fres = (fin / (pre + 1)) >> post;
+
+       return (pre << MX51_ECSPI_CTRL_PREDIV_OFFSET) |
+               (post << MX51_ECSPI_CTRL_POSTDIV_OFFSET);
+}
+
+static void __maybe_unused mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int enable)
+{
+       unsigned val = 0;
+
+       if (enable & MXC_INT_TE)
+               val |= MX51_ECSPI_INT_TEEN;
+
+       if (enable & MXC_INT_RR)
+               val |= MX51_ECSPI_INT_RREN;
+
+       writel(val, spi_imx->base + MX51_ECSPI_INT);
+}
+
+static void __maybe_unused mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
+{
+       u32 reg = readl(spi_imx->base + MX51_ECSPI_CTRL);
+
+       if (!spi_imx->usedma)
+               reg |= MX51_ECSPI_CTRL_XCH;
+       else if (!spi_imx->dma_finished)
+               reg |= MX51_ECSPI_CTRL_SMC;
+       else
+               reg &= ~MX51_ECSPI_CTRL_SMC;
+       writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
+}
+
+static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
+               struct spi_imx_config *config)
+{
+       u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0;
+       u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg;
+       u32 clk = config->speed_hz, delay;
+
+       /*
+        * The hardware seems to have a race condition when changing modes. The
+        * current assumption is that the selection of the channel arrives
+        * earlier in the hardware than the mode bits when they are written at
+        * the same time.
+        * So set master mode for all channels as we do not support slave mode.
+        */
+       ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
+
+       /* set clock speed */
+       ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz, &clk);
+
+       /* set chip select to use */
+       ctrl |= MX51_ECSPI_CTRL_CS(config->cs);
+
+       ctrl |= (config->bpw - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
+
+       cfg |= MX51_ECSPI_CONFIG_SBBCTRL(config->cs);
+
+       if (config->mode & SPI_CPHA)
+               cfg |= MX51_ECSPI_CONFIG_SCLKPHA(config->cs);
+
+       if (config->mode & SPI_CPOL) {
+               cfg |= MX51_ECSPI_CONFIG_SCLKPOL(config->cs);
+               cfg |= MX51_ECSPI_CONFIG_SCLKCTL(config->cs);
+       }
+       if (config->mode & SPI_CS_HIGH)
+               cfg |= MX51_ECSPI_CONFIG_SSBPOL(config->cs);
+
+       writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
+       writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
+
+       /*
+        * Wait until the changes in the configuration register CONFIGREG
+        * propagate into the hardware. It takes exactly one tick of the
+        * SCLK clock, but we will wait two SCLK clock just to be sure. The
+        * effect of the delay it takes for the hardware to apply changes
+        * is noticable if the SCLK clock run very slow. In such a case, if
+        * the polarity of SCLK should be inverted, the GPIO ChipSelect might
+        * be asserted before the SCLK polarity changes, which would disrupt
+        * the SPI communication as the device on the other end would consider
+        * the change of SCLK polarity as a clock tick already.
+        */
+       delay = (2 * 1000000) / clk;
+       if (likely(delay < 10)) /* SCLK is faster than 100 kHz */
+               udelay(delay);
+       else                    /* SCLK is _very_ slow */
+               usleep_range(delay, delay + 10);
+
+       /*
+        * Configure the DMA register: setup the watermark
+        * and enable DMA request.
+        */
+       if (spi_imx->dma_is_inited) {
+               dma = readl(spi_imx->base + MX51_ECSPI_DMA);
+
+               spi_imx->rxt_wml = spi_imx_get_fifosize(spi_imx) / 2;
+               rx_wml_cfg = spi_imx->rx_wml << MX51_ECSPI_DMA_RX_WML_OFFSET;
+               tx_wml_cfg = spi_imx->tx_wml << MX51_ECSPI_DMA_TX_WML_OFFSET;
+               rxt_wml_cfg = spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET;
+               dma = (dma & ~MX51_ECSPI_DMA_TX_WML_MASK
+                          & ~MX51_ECSPI_DMA_RX_WML_MASK
+                          & ~MX51_ECSPI_DMA_RXT_WML_MASK)
+                          | rx_wml_cfg | tx_wml_cfg | rxt_wml_cfg
+                          |(1 << MX51_ECSPI_DMA_TEDEN_OFFSET)
+                          |(1 << MX51_ECSPI_DMA_RXDEN_OFFSET)
+                          |(1 << MX51_ECSPI_DMA_RXTDEN_OFFSET);
+
+               writel(dma, spi_imx->base + MX51_ECSPI_DMA);
+       }
+
+       return 0;
+}
+
+static int __maybe_unused mx51_ecspi_rx_available(struct spi_imx_data *spi_imx)
+{
+       return readl(spi_imx->base + MX51_ECSPI_STAT) & MX51_ECSPI_STAT_RR;
+}
+
+static void __maybe_unused mx51_ecspi_reset(struct spi_imx_data *spi_imx)
+{
+       /* drain receive buffer */
+       while (mx51_ecspi_rx_available(spi_imx))
+               readl(spi_imx->base + MXC_CSPIRXDATA);
+}
+
+#define MX31_INTREG_TEEN       (1 << 0)
+#define MX31_INTREG_RREN       (1 << 3)
+
+#define MX31_CSPICTRL_ENABLE   (1 << 0)
+#define MX31_CSPICTRL_MASTER   (1 << 1)
+#define MX31_CSPICTRL_XCH      (1 << 2)
+#define MX31_CSPICTRL_POL      (1 << 4)
+#define MX31_CSPICTRL_PHA      (1 << 5)
+#define MX31_CSPICTRL_SSCTL    (1 << 6)
+#define MX31_CSPICTRL_SSPOL    (1 << 7)
+#define MX31_CSPICTRL_BC_SHIFT 8
+#define MX35_CSPICTRL_BL_SHIFT 20
+#define MX31_CSPICTRL_CS_SHIFT 24
+#define MX35_CSPICTRL_CS_SHIFT 12
+#define MX31_CSPICTRL_DR_SHIFT 16
+
+#define MX31_CSPISTATUS                0x14
+#define MX31_STATUS_RR         (1 << 3)
+
+/* These functions also work for the i.MX35, but be aware that
+ * the i.MX35 has a slightly different register layout for bits
+ * we do not use here.
+ */
+static void __maybe_unused mx31_intctrl(struct spi_imx_data *spi_imx, int enable)
+{
+       unsigned int val = 0;
+
+       if (enable & MXC_INT_TE)
+               val |= MX31_INTREG_TEEN;
+       if (enable & MXC_INT_RR)
+               val |= MX31_INTREG_RREN;
+
+       writel(val, spi_imx->base + MXC_CSPIINT);
+}
+
+static void __maybe_unused mx31_trigger(struct spi_imx_data *spi_imx)
+{
+       unsigned int reg;
+
+       reg = readl(spi_imx->base + MXC_CSPICTRL);
+       reg |= MX31_CSPICTRL_XCH;
+       writel(reg, spi_imx->base + MXC_CSPICTRL);
+}
+
+static int __maybe_unused mx31_config(struct spi_imx_data *spi_imx,
+               struct spi_imx_config *config)
+{
+       unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER;
+       int cs = spi_imx->chipselect[config->cs];
+
+       reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
+               MX31_CSPICTRL_DR_SHIFT;
+
+       if (is_imx35_cspi(spi_imx)) {
+               reg |= (config->bpw - 1) << MX35_CSPICTRL_BL_SHIFT;
+               reg |= MX31_CSPICTRL_SSCTL;
+       } else {
+               reg |= (config->bpw - 1) << MX31_CSPICTRL_BC_SHIFT;
+       }
+
+       if (config->mode & SPI_CPHA)
+               reg |= MX31_CSPICTRL_PHA;
+       if (config->mode & SPI_CPOL)
+               reg |= MX31_CSPICTRL_POL;
+       if (config->mode & SPI_CS_HIGH)
+               reg |= MX31_CSPICTRL_SSPOL;
+       if (cs < 0)
+               reg |= (cs + 32) <<
+                       (is_imx35_cspi(spi_imx) ? MX35_CSPICTRL_CS_SHIFT :
+                                                 MX31_CSPICTRL_CS_SHIFT);
+
+       writel(reg, spi_imx->base + MXC_CSPICTRL);
+
+       return 0;
+}
+
+static int __maybe_unused mx31_rx_available(struct spi_imx_data *spi_imx)
+{
+       return readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR;
+}
+
+static void __maybe_unused mx31_reset(struct spi_imx_data *spi_imx)
+{
+       /* drain receive buffer */
+       while (readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR)
+               readl(spi_imx->base + MXC_CSPIRXDATA);
+}
+
+#define MX21_INTREG_RR         (1 << 4)
+#define MX21_INTREG_TEEN       (1 << 9)
+#define MX21_INTREG_RREN       (1 << 13)
+
+#define MX21_CSPICTRL_POL      (1 << 5)
+#define MX21_CSPICTRL_PHA      (1 << 6)
+#define MX21_CSPICTRL_SSPOL    (1 << 8)
+#define MX21_CSPICTRL_XCH      (1 << 9)
+#define MX21_CSPICTRL_ENABLE   (1 << 10)
+#define MX21_CSPICTRL_MASTER   (1 << 11)
+#define MX21_CSPICTRL_DR_SHIFT 14
+#define MX21_CSPICTRL_CS_SHIFT 19
+
+static void __maybe_unused mx21_intctrl(struct spi_imx_data *spi_imx, int enable)
+{
+       unsigned int val = 0;
+
+       if (enable & MXC_INT_TE)
+               val |= MX21_INTREG_TEEN;
+       if (enable & MXC_INT_RR)
+               val |= MX21_INTREG_RREN;
+
+       writel(val, spi_imx->base + MXC_CSPIINT);
+}
+
+static void __maybe_unused mx21_trigger(struct spi_imx_data *spi_imx)
+{
+       unsigned int reg;
+
+       reg = readl(spi_imx->base + MXC_CSPICTRL);
+       reg |= MX21_CSPICTRL_XCH;
+       writel(reg, spi_imx->base + MXC_CSPICTRL);
+}
+
+static int __maybe_unused mx21_config(struct spi_imx_data *spi_imx,
+               struct spi_imx_config *config)
+{
+       unsigned int reg = MX21_CSPICTRL_ENABLE | MX21_CSPICTRL_MASTER;
+       int cs = spi_imx->chipselect[config->cs];
+       unsigned int max = is_imx27_cspi(spi_imx) ? 16 : 18;
+
+       reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, config->speed_hz, max) <<
+               MX21_CSPICTRL_DR_SHIFT;
+       reg |= config->bpw - 1;
+
+       if (config->mode & SPI_CPHA)
+               reg |= MX21_CSPICTRL_PHA;
+       if (config->mode & SPI_CPOL)
+               reg |= MX21_CSPICTRL_POL;
+       if (config->mode & SPI_CS_HIGH)
+               reg |= MX21_CSPICTRL_SSPOL;
+       if (cs < 0)
+               reg |= (cs + 32) << MX21_CSPICTRL_CS_SHIFT;
+
+       writel(reg, spi_imx->base + MXC_CSPICTRL);
+
+       return 0;
+}
+
+static int __maybe_unused mx21_rx_available(struct spi_imx_data *spi_imx)
+{
+       return readl(spi_imx->base + MXC_CSPIINT) & MX21_INTREG_RR;
+}
+
+static void __maybe_unused mx21_reset(struct spi_imx_data *spi_imx)
+{
+       writel(1, spi_imx->base + MXC_RESET);
+}
+
+#define MX1_INTREG_RR          (1 << 3)
+#define MX1_INTREG_TEEN                (1 << 8)
+#define MX1_INTREG_RREN                (1 << 11)
+
+#define MX1_CSPICTRL_POL       (1 << 4)
+#define MX1_CSPICTRL_PHA       (1 << 5)
+#define MX1_CSPICTRL_XCH       (1 << 8)
+#define MX1_CSPICTRL_ENABLE    (1 << 9)
+#define MX1_CSPICTRL_MASTER    (1 << 10)
+#define MX1_CSPICTRL_DR_SHIFT  13
+
+static void __maybe_unused mx1_intctrl(struct spi_imx_data *spi_imx, int enable)
+{
+       unsigned int val = 0;
+
+       if (enable & MXC_INT_TE)
+               val |= MX1_INTREG_TEEN;
+       if (enable & MXC_INT_RR)
+               val |= MX1_INTREG_RREN;
+
+       writel(val, spi_imx->base + MXC_CSPIINT);
+}
+
+static void __maybe_unused mx1_trigger(struct spi_imx_data *spi_imx)
+{
+       unsigned int reg;
+
+       reg = readl(spi_imx->base + MXC_CSPICTRL);
+       reg |= MX1_CSPICTRL_XCH;
+       writel(reg, spi_imx->base + MXC_CSPICTRL);
+}
+
+static int __maybe_unused mx1_config(struct spi_imx_data *spi_imx,
+               struct spi_imx_config *config)
+{
+       unsigned int reg = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_MASTER;
+
+       reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
+               MX1_CSPICTRL_DR_SHIFT;
+       reg |= config->bpw - 1;
+
+       if (config->mode & SPI_CPHA)
+               reg |= MX1_CSPICTRL_PHA;
+       if (config->mode & SPI_CPOL)
+               reg |= MX1_CSPICTRL_POL;
+
+       writel(reg, spi_imx->base + MXC_CSPICTRL);
+
+       return 0;
+}
+
+static int __maybe_unused mx1_rx_available(struct spi_imx_data *spi_imx)
+{
+       return readl(spi_imx->base + MXC_CSPIINT) & MX1_INTREG_RR;
+}
+
+static void __maybe_unused mx1_reset(struct spi_imx_data *spi_imx)
+{
+       writel(1, spi_imx->base + MXC_RESET);
+}
+
+static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
+       .intctrl = mx1_intctrl,
+       .config = mx1_config,
+       .trigger = mx1_trigger,
+       .rx_available = mx1_rx_available,
+       .reset = mx1_reset,
+       .devtype = IMX1_CSPI,
+};
+
+static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
+       .intctrl = mx21_intctrl,
+       .config = mx21_config,
+       .trigger = mx21_trigger,
+       .rx_available = mx21_rx_available,
+       .reset = mx21_reset,
+       .devtype = IMX21_CSPI,
+};
+
+static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
+       /* i.mx27 cspi shares the functions with i.mx21 one */
+       .intctrl = mx21_intctrl,
+       .config = mx21_config,
+       .trigger = mx21_trigger,
+       .rx_available = mx21_rx_available,
+       .reset = mx21_reset,
+       .devtype = IMX27_CSPI,
+};
+
+static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
+       .intctrl = mx31_intctrl,
+       .config = mx31_config,
+       .trigger = mx31_trigger,
+       .rx_available = mx31_rx_available,
+       .reset = mx31_reset,
+       .devtype = IMX31_CSPI,
+};
+
+static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
+       /* i.mx35 and later cspi shares the functions with i.mx31 one */
+       .intctrl = mx31_intctrl,
+       .config = mx31_config,
+       .trigger = mx31_trigger,
+       .rx_available = mx31_rx_available,
+       .reset = mx31_reset,
+       .devtype = IMX35_CSPI,
+};
+
+static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
+       .intctrl = mx51_ecspi_intctrl,
+       .config = mx51_ecspi_config,
+       .trigger = mx51_ecspi_trigger,
+       .rx_available = mx51_ecspi_rx_available,
+       .reset = mx51_ecspi_reset,
+       .devtype = IMX51_ECSPI,
+};
+
+static struct platform_device_id spi_imx_devtype[] = {
+       {
+               .name = "imx1-cspi",
+               .driver_data = (kernel_ulong_t) &imx1_cspi_devtype_data,
+       }, {
+               .name = "imx21-cspi",
+               .driver_data = (kernel_ulong_t) &imx21_cspi_devtype_data,
+       }, {
+               .name = "imx27-cspi",
+               .driver_data = (kernel_ulong_t) &imx27_cspi_devtype_data,
+       }, {
+               .name = "imx31-cspi",
+               .driver_data = (kernel_ulong_t) &imx31_cspi_devtype_data,
+       }, {
+               .name = "imx35-cspi",
+               .driver_data = (kernel_ulong_t) &imx35_cspi_devtype_data,
+       }, {
+               .name = "imx51-ecspi",
+               .driver_data = (kernel_ulong_t) &imx51_ecspi_devtype_data,
+       }, {
+               /* sentinel */
+       }
+};
+
+static const struct of_device_id spi_imx_dt_ids[] = {
+       { .compatible = "fsl,imx1-cspi", .data = &imx1_cspi_devtype_data, },
+       { .compatible = "fsl,imx21-cspi", .data = &imx21_cspi_devtype_data, },
+       { .compatible = "fsl,imx27-cspi", .data = &imx27_cspi_devtype_data, },
+       { .compatible = "fsl,imx31-cspi", .data = &imx31_cspi_devtype_data, },
+       { .compatible = "fsl,imx35-cspi", .data = &imx35_cspi_devtype_data, },
+       { .compatible = "fsl,imx51-ecspi", .data = &imx51_ecspi_devtype_data, },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, spi_imx_dt_ids);
+
+static void spi_imx_chipselect(struct spi_device *spi, int is_active)
+{
+       struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+       int gpio = spi_imx->chipselect[spi->chip_select];
+       int active = is_active != BITBANG_CS_INACTIVE;
+       int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH);
+
+       if (!gpio_is_valid(gpio))
+               return;
+
+       gpio_set_value(gpio, dev_is_lowactive ^ active);
+}
+
+static void spi_imx_push(struct spi_imx_data *spi_imx)
+{
+       while (spi_imx->txfifo < spi_imx_get_fifosize(spi_imx)) {
+               if (!spi_imx->count)
+                       break;
+               spi_imx->tx(spi_imx);
+               spi_imx->txfifo++;
+       }
+
+       spi_imx->devtype_data->trigger(spi_imx);
+}
+
+static irqreturn_t spi_imx_isr(int irq, void *dev_id)
+{
+       struct spi_imx_data *spi_imx = dev_id;
+
+       while (spi_imx->devtype_data->rx_available(spi_imx)) {
+               spi_imx->rx(spi_imx);
+               spi_imx->txfifo--;
+       }
+
+       if (spi_imx->count) {
+               spi_imx_push(spi_imx);
+               return IRQ_HANDLED;
+       }
+
+       if (spi_imx->txfifo) {
+               /* No data left to push, but still waiting for rx data,
+                * enable receive data available interrupt.
+                */
+               spi_imx->devtype_data->intctrl(
+                               spi_imx, MXC_INT_RR);
+               return IRQ_HANDLED;
+       }
+
+       spi_imx->devtype_data->intctrl(spi_imx, 0);
+       complete(&spi_imx->xfer_done);
+
+       return IRQ_HANDLED;
+}
+
+static int spi_imx_setupxfer(struct spi_device *spi,
+                                struct spi_transfer *t)
+{
+       struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+       struct spi_imx_config config;
+
+       config.bpw = t ? t->bits_per_word : spi->bits_per_word;
+       config.speed_hz  = t ? t->speed_hz : spi->max_speed_hz;
+       config.mode = spi->mode;
+       config.cs = spi->chip_select;
+
+       if (!config.speed_hz)
+               config.speed_hz = spi->max_speed_hz;
+       if (!config.bpw)
+               config.bpw = spi->bits_per_word;
+
+       /* Initialize the functions for transfer */
+       if (config.bpw <= 8) {
+               spi_imx->rx = spi_imx_buf_rx_u8;
+               spi_imx->tx = spi_imx_buf_tx_u8;
+       } else if (config.bpw <= 16) {
+               spi_imx->rx = spi_imx_buf_rx_u16;
+               spi_imx->tx = spi_imx_buf_tx_u16;
+       } else {
+               spi_imx->rx = spi_imx_buf_rx_u32;
+               spi_imx->tx = spi_imx_buf_tx_u32;
+       }
+
+       spi_imx->devtype_data->config(spi_imx, &config);
+
+       return 0;
+}
+
+static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx)
+{
+       struct spi_master *master = spi_imx->bitbang.master;
+
+       if (master->dma_rx) {
+               dma_release_channel(master->dma_rx);
+               master->dma_rx = NULL;
+       }
+
+       if (master->dma_tx) {
+               dma_release_channel(master->dma_tx);
+               master->dma_tx = NULL;
+       }
+
+       spi_imx->dma_is_inited = 0;
+}
+
+static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
+                            struct spi_master *master,
+                            const struct resource *res)
+{
+       struct dma_slave_config slave_config = {};
+       int ret;
+
+       /* use pio mode for i.mx6dl chip TKT238285 */
+       if (of_machine_is_compatible("fsl,imx6dl"))
+               return 0;
+
+       /* Prepare for TX DMA: */
+       master->dma_tx = dma_request_slave_channel(dev, "tx");
+       if (!master->dma_tx) {
+               dev_err(dev, "cannot get the TX DMA channel!\n");
+               ret = -EINVAL;
+               goto err;
+       }
+
+       slave_config.direction = DMA_MEM_TO_DEV;
+       slave_config.dst_addr = res->start + MXC_CSPITXDATA;
+       slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+       slave_config.dst_maxburst = spi_imx_get_fifosize(spi_imx) / 2;
+       ret = dmaengine_slave_config(master->dma_tx, &slave_config);
+       if (ret) {
+               dev_err(dev, "error in TX dma configuration.\n");
+               goto err;
+       }
+
+       /* Prepare for RX : */
+       master->dma_rx = dma_request_slave_channel(dev, "rx");
+       if (!master->dma_rx) {
+               dev_dbg(dev, "cannot get the DMA channel.\n");
+               ret = -EINVAL;
+               goto err;
+       }
+
+       slave_config.direction = DMA_DEV_TO_MEM;
+       slave_config.src_addr = res->start + MXC_CSPIRXDATA;
+       slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+       slave_config.src_maxburst = spi_imx_get_fifosize(spi_imx) / 2;
+       ret = dmaengine_slave_config(master->dma_rx, &slave_config);
+       if (ret) {
+               dev_err(dev, "error in RX dma configuration.\n");
+               goto err;
+       }
+
+       init_completion(&spi_imx->dma_rx_completion);
+       init_completion(&spi_imx->dma_tx_completion);
+       master->can_dma = spi_imx_can_dma;
+       master->max_dma_len = MAX_SDMA_BD_BYTES;
+       spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX |
+                                        SPI_MASTER_MUST_TX;
+       spi_imx->tx_wml = spi_imx_get_fifosize(spi_imx) / 2;
+       spi_imx->rx_wml = spi_imx_get_fifosize(spi_imx) / 2;
+       spi_imx->dma_is_inited = 1;
+
+       return 0;
+err:
+       spi_imx_sdma_exit(spi_imx);
+       return ret;
+}
+
+static void spi_imx_dma_rx_callback(void *cookie)
+{
+       struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
+
+       complete(&spi_imx->dma_rx_completion);
+}
+
+static void spi_imx_dma_tx_callback(void *cookie)
+{
+       struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
+
+       complete(&spi_imx->dma_tx_completion);
+}
+
+static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
+                               struct spi_transfer *transfer)
+{
+       struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
+       int ret;
+       unsigned long timeout;
+       u32 dma;
+       int left;
+       struct spi_master *master = spi_imx->bitbang.master;
+       struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg;
+
+       if (tx) {
+               desc_tx = dmaengine_prep_slave_sg(master->dma_tx,
+                                       tx->sgl, tx->nents, DMA_MEM_TO_DEV,
+                                       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+               if (!desc_tx)
+                       goto no_dma;
+
+               desc_tx->callback = spi_imx_dma_tx_callback;
+               desc_tx->callback_param = (void *)spi_imx;
+               dmaengine_submit(desc_tx);
+       }
+
+       if (rx) {
+               desc_rx = dmaengine_prep_slave_sg(master->dma_rx,
+                                       rx->sgl, rx->nents, DMA_DEV_TO_MEM,
+                                       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+               if (!desc_rx)
+                       goto no_dma;
+
+               desc_rx->callback = spi_imx_dma_rx_callback;
+               desc_rx->callback_param = (void *)spi_imx;
+               dmaengine_submit(desc_rx);
+       }
+
+       reinit_completion(&spi_imx->dma_rx_completion);
+       reinit_completion(&spi_imx->dma_tx_completion);
+
+       /* Trigger the cspi module. */
+       spi_imx->dma_finished = 0;
+
+       dma = readl(spi_imx->base + MX51_ECSPI_DMA);
+       dma = dma & (~MX51_ECSPI_DMA_RXT_WML_MASK);
+       /* Change RX_DMA_LENGTH trigger dma fetch tail data */
+       left = transfer->len % spi_imx->rxt_wml;
+       if (left)
+               writel(dma | (left << MX51_ECSPI_DMA_RXT_WML_OFFSET),
+                               spi_imx->base + MX51_ECSPI_DMA);
+       spi_imx->devtype_data->trigger(spi_imx);
+
+       dma_async_issue_pending(master->dma_tx);
+       dma_async_issue_pending(master->dma_rx);
+       /* Wait SDMA to finish the data transfer.*/
+       timeout = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
+                                               IMX_DMA_TIMEOUT);
+       if (!timeout) {
+               pr_warn("%s %s: I/O Error in DMA TX\n",
+                       dev_driver_string(&master->dev),
+                       dev_name(&master->dev));
+               dmaengine_terminate_all(master->dma_tx);
+       } else {
+               timeout = wait_for_completion_timeout(
+                               &spi_imx->dma_rx_completion, IMX_DMA_TIMEOUT);
+               if (!timeout) {
+                       pr_warn("%s %s: I/O Error in DMA RX\n",
+                               dev_driver_string(&master->dev),
+                               dev_name(&master->dev));
+                       spi_imx->devtype_data->reset(spi_imx);
+                       dmaengine_terminate_all(master->dma_rx);
+               }
+               writel(dma |
+                      spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET,
+                      spi_imx->base + MX51_ECSPI_DMA);
+       }
+
+       spi_imx->dma_finished = 1;
+       spi_imx->devtype_data->trigger(spi_imx);
+
+       if (!timeout)
+               ret = -ETIMEDOUT;
+       else
+               ret = transfer->len;
+
+       return ret;
+
+no_dma:
+       pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
+                    dev_driver_string(&master->dev),
+                    dev_name(&master->dev));
+       return -EAGAIN;
+}
+
+static int spi_imx_pio_transfer(struct spi_device *spi,
+                               struct spi_transfer *transfer)
+{
+       struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+
+       spi_imx->tx_buf = transfer->tx_buf;
+       spi_imx->rx_buf = transfer->rx_buf;
+       spi_imx->count = transfer->len;
+       spi_imx->txfifo = 0;
+
+       reinit_completion(&spi_imx->xfer_done);
+
+       spi_imx_push(spi_imx);
+
+       spi_imx->devtype_data->intctrl(spi_imx, MXC_INT_TE);
+
+       wait_for_completion(&spi_imx->xfer_done);
+
+       return transfer->len;
+}
+
+static int spi_imx_transfer(struct spi_device *spi,
+                               struct spi_transfer *transfer)
+{
+       int ret;
+       struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+
+       if (spi_imx->bitbang.master->can_dma &&
+           spi_imx_can_dma(spi_imx->bitbang.master, spi, transfer)) {
+               spi_imx->usedma = true;
+               ret = spi_imx_dma_transfer(spi_imx, transfer);
+               if (ret != -EAGAIN)
+                       return ret;
+       }
+       spi_imx->usedma = false;
+
+       return spi_imx_pio_transfer(spi, transfer);
+}
+
+static int spi_imx_setup(struct spi_device *spi)
+{
+       struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+       int gpio = spi_imx->chipselect[spi->chip_select];
+
+       dev_dbg(&spi->dev, "%s: mode %d, %u bpw, %d hz\n", __func__,
+                spi->mode, spi->bits_per_word, spi->max_speed_hz);
+
+       if (gpio_is_valid(gpio))
+               gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
+
+       spi_imx_chipselect(spi, BITBANG_CS_INACTIVE);
+
+       return 0;
+}
+
+static void spi_imx_cleanup(struct spi_device *spi)
+{
+}
+
+static int
+spi_imx_prepare_message(struct spi_master *master, struct spi_message *msg)
+{
+       struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+       int ret;
+
+       ret = clk_enable(spi_imx->clk_per);
+       if (ret)
+               return ret;
+
+       ret = clk_enable(spi_imx->clk_ipg);
+       if (ret) {
+               clk_disable(spi_imx->clk_per);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int
+spi_imx_unprepare_message(struct spi_master *master, struct spi_message *msg)
+{
+       struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+
+       clk_disable(spi_imx->clk_ipg);
+       clk_disable(spi_imx->clk_per);
+       return 0;
+}
+
+static int spi_imx_probe(struct platform_device *pdev)
+{
+       struct device_node *np = pdev->dev.of_node;
+       const struct of_device_id *of_id =
+                       of_match_device(spi_imx_dt_ids, &pdev->dev);
+       struct spi_imx_master *mxc_platform_info =
+                       dev_get_platdata(&pdev->dev);
+       struct spi_master *master;
+       struct spi_imx_data *spi_imx;
+       struct resource *res;
+       int i, ret, num_cs, irq;
+
+       if (!np && !mxc_platform_info) {
+               dev_err(&pdev->dev, "can't get the platform data\n");
+               return -EINVAL;
+       }
+
+       ret = of_property_read_u32(np, "fsl,spi-num-chipselects", &num_cs);
+       if (ret < 0) {
+               if (mxc_platform_info)
+                       num_cs = mxc_platform_info->num_chipselect;
+               else
+                       return ret;
+       }
+
+       master = spi_alloc_master(&pdev->dev,
+                       sizeof(struct spi_imx_data) + sizeof(int) * num_cs);
+       if (!master)
+               return -ENOMEM;
+
+       platform_set_drvdata(pdev, master);
+
+       master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
+       master->bus_num = pdev->id;
+       master->num_chipselect = num_cs;
+
+       spi_imx = spi_master_get_devdata(master);
+       spi_imx->bitbang.master = master;
+
+       for (i = 0; i < master->num_chipselect; i++) {
+               int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
+               if (!gpio_is_valid(cs_gpio) && mxc_platform_info)
+                       cs_gpio = mxc_platform_info->chipselect[i];
+
+               spi_imx->chipselect[i] = cs_gpio;
+               if (!gpio_is_valid(cs_gpio))
+                       continue;
+
+               ret = devm_gpio_request(&pdev->dev, spi_imx->chipselect[i],
+                                       DRIVER_NAME);
+               if (ret) {
+                       dev_err(&pdev->dev, "can't get cs gpios\n");
+                       goto out_master_put;
+               }
+       }
+
+       spi_imx->bitbang.chipselect = spi_imx_chipselect;
+       spi_imx->bitbang.setup_transfer = spi_imx_setupxfer;
+       spi_imx->bitbang.txrx_bufs = spi_imx_transfer;
+       spi_imx->bitbang.master->setup = spi_imx_setup;
+       spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
+       spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
+       spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
+       spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
+       init_completion(&spi_imx->xfer_done);
+
+       spi_imx->devtype_data = of_id ? of_id->data :
+               (struct spi_imx_devtype_data *) pdev->id_entry->driver_data;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       spi_imx->base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(spi_imx->base)) {
+               ret = PTR_ERR(spi_imx->base);
+               goto out_master_put;
+       }
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               ret = irq;
+               goto out_master_put;
+       }
+
+       ret = devm_request_irq(&pdev->dev, irq, spi_imx_isr, 0,
+                              dev_name(&pdev->dev), spi_imx);
+       if (ret) {
+               dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret);
+               goto out_master_put;
+       }
+
+       spi_imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+       if (IS_ERR(spi_imx->clk_ipg)) {
+               ret = PTR_ERR(spi_imx->clk_ipg);
+               goto out_master_put;
+       }
+
+       spi_imx->clk_per = devm_clk_get(&pdev->dev, "per");
+       if (IS_ERR(spi_imx->clk_per)) {
+               ret = PTR_ERR(spi_imx->clk_per);
+               goto out_master_put;
+       }
+
+       ret = clk_prepare_enable(spi_imx->clk_per);
+       if (ret)
+               goto out_master_put;
+
+       ret = clk_prepare_enable(spi_imx->clk_ipg);
+       if (ret)
+               goto out_put_per;
+
+       spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per);
+       /*
+        * Only validated on i.mx6 now, can remove the constrain if validated on
+        * other chips.
+        */
+       if (spi_imx->devtype_data == &imx51_ecspi_devtype_data
+           && spi_imx_sdma_init(&pdev->dev, spi_imx, master, res))
+               dev_err(&pdev->dev, "dma setup error,use pio instead\n");
+
+       spi_imx->devtype_data->reset(spi_imx);
+
+       spi_imx->devtype_data->intctrl(spi_imx, 0);
+
+       master->dev.of_node = pdev->dev.of_node;
+       ret = spi_bitbang_start(&spi_imx->bitbang);
+       if (ret) {
+               dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
+               goto out_clk_put;
+       }
+
+       dev_info(&pdev->dev, "probed\n");
+
+       clk_disable(spi_imx->clk_ipg);
+       clk_disable(spi_imx->clk_per);
+       return ret;
+
+out_clk_put:
+       clk_disable_unprepare(spi_imx->clk_ipg);
+out_put_per:
+       clk_disable_unprepare(spi_imx->clk_per);
+out_master_put:
+       spi_master_put(master);
+
+       return ret;
+}
+
+static int spi_imx_remove(struct platform_device *pdev)
+{
+       struct spi_master *master = platform_get_drvdata(pdev);
+       struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+
+       spi_bitbang_stop(&spi_imx->bitbang);
+
+       writel(0, spi_imx->base + MXC_CSPICTRL);
+       clk_unprepare(spi_imx->clk_ipg);
+       clk_unprepare(spi_imx->clk_per);
+       spi_imx_sdma_exit(spi_imx);
+       spi_master_put(master);
+
+       return 0;
+}
+
+static struct platform_driver spi_imx_driver = {
+       .driver = {
+                  .name = DRIVER_NAME,
+                  .of_match_table = spi_imx_dt_ids,
+                  },
+       .id_table = spi_imx_devtype,
+       .probe = spi_imx_probe,
+       .remove = spi_imx_remove,
+};
+module_platform_driver(spi_imx_driver);
+
+MODULE_DESCRIPTION("SPI Master Controller driver");
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);