spi: imx: Revert "spi: imx: dynamic burst length adjust for PIO mode"

This reverts commits 8d4a6cad7adb3ddac32cd52635f20e11de11a658 and
179547e143e773f9f866ad3536275ab627711f3a.

Besides the problems already found with this patch it also modifies
the spi transfer tx_buf in spi_imx_u32_swap_u8() and spi_imx_u32_swap_u16().
This is hidden from the compiler with an explicit cast from const void*
to u32*, so no warning is issued.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 19b30cf7d2b737b15dc5161a8e4a32e5c25e164f..b402530a7a9a94d6ed4d7e836c3da67b8a645f3f 100644 (file)
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -56,11 +56,9 @@
 
 /* The maximum  bytes that a sdma BD can transfer.*/
 #define MAX_SDMA_BD_BYTES  (1 << 15)
-#define MX51_ECSPI_CTRL_MAX_BURST      512
 struct spi_imx_config {
        unsigned int speed_hz;
        unsigned int bpw;
-       unsigned int len;
 };
 
 enum spi_imx_devtype {
@@ -99,14 +97,12 @@ struct spi_imx_data {
        unsigned int bytes_per_word;
        unsigned int spi_drctl;
 
-       unsigned int count, count_index;
+       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 */
-       unsigned int dynamic_burst, bpw_rx;
-       unsigned int bpw_w;
 
        /* DMA */
        bool usedma;
@@ -256,7 +252,6 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 #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_CTRL_BL_MASK                (0xfff << 20)
 
 #define MX51_ECSPI_CONFIG      0x0c
 #define MX51_ECSPI_CONFIG_SCLKPHA(cs)  (1 << ((cs) +  0))
@@ -284,77 +279,6 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 #define MX51_ECSPI_TESTREG     0x20
 #define MX51_ECSPI_TESTREG_LBC BIT(31)
 
-static void spi_imx_u32_swap_u8(struct spi_transfer *transfer, u32 *buf)
-{
-       int i;
-
-       if (!buf)
-               return;
-
-       for (i = 0; i < transfer->len / 4; i++)
-               *(buf + i) = cpu_to_be32(*(buf + i));
-}
-
-static void spi_imx_u32_swap_u16(struct spi_transfer *transfer, u32 *buf)
-{
-       int i;
-
-       if (!buf)
-               return;
-
-       for (i = 0; i < transfer->len / 4; i++) {
-               u16 *temp = (u16 *)buf;
-
-               *(temp + i * 2) = cpu_to_be16(*(temp + i * 2));
-               *(temp + i * 2 + 1) = cpu_to_be16(*(temp + i * 2 + 1));
-
-               *(buf + i) = cpu_to_be32(*(buf + i));
-       }
-}
-
-static void spi_imx_buf_rx_swap(struct spi_imx_data *spi_imx)
-{
-       if (!spi_imx->bpw_rx) {
-               spi_imx_buf_rx_u32(spi_imx);
-               return;
-       }
-
-       if (spi_imx->bpw_w == 1)
-               spi_imx_buf_rx_u8(spi_imx);
-       else if (spi_imx->bpw_w == 2)
-               spi_imx_buf_rx_u16(spi_imx);
-}
-
-static void spi_imx_buf_tx_swap(struct spi_imx_data *spi_imx)
-{
-       u32 ctrl, val;
-
-       if (spi_imx->count == spi_imx->count_index) {
-               spi_imx->count_index = spi_imx->count > sizeof(u32) ?
-                                       spi_imx->count % sizeof(u32) : 0;
-               ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
-               ctrl &= ~MX51_ECSPI_CTRL_BL_MASK;
-               if (spi_imx->count >= sizeof(u32)) {
-                       val = spi_imx->count - spi_imx->count_index;
-               } else {
-                       val = spi_imx->bpw_w;
-                       spi_imx->bpw_rx = 1;
-               }
-               ctrl |= ((val * 8 - 1) << MX51_ECSPI_CTRL_BL_OFFSET);
-               writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
-       }
-
-       if (spi_imx->count >= sizeof(u32)) {
-               spi_imx_buf_tx_u32(spi_imx);
-               return;
-       }
-
-       if (spi_imx->bpw_w == 1)
-               spi_imx_buf_tx_u8(spi_imx);
-       else if (spi_imx->bpw_w == 2)
-               spi_imx_buf_tx_u16(spi_imx);
-}
-
 /* MX51 eCSPI */
 static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx,
                                      unsigned int fspi, unsigned int *fres)
@@ -446,15 +370,7 @@ static int mx51_ecspi_config(struct spi_device *spi,
        /* set chip select to use */
        ctrl |= MX51_ECSPI_CTRL_CS(spi->chip_select);
 
-       if (spi_imx->dynamic_burst) {
-               if (config->len > MX51_ECSPI_CTRL_MAX_BURST)
-                       ctrl |= MX51_ECSPI_CTRL_BL_MASK;
-               else
-                       ctrl |= (((config->len - config->len % 4) * 8 - 1) <<
-                               MX51_ECSPI_CTRL_BL_OFFSET);
-       } else {
-               ctrl |= (config->bpw - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
-       }
+       ctrl |= (config->bpw - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
 
        cfg |= MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
 
@@ -889,8 +805,6 @@ 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;
-               if (spi_imx->txfifo && (spi_imx->count == spi_imx->count_index))
-                       break;
                spi_imx->tx(spi_imx);
                spi_imx->txfifo++;
        }
@@ -981,12 +895,8 @@ static int spi_imx_setupxfer(struct spi_device *spi,
        struct spi_imx_config config;
        int ret;
 
-       spi_imx->dynamic_burst = 0;
-       spi_imx->bpw_rx = 0;
-
        config.bpw = t ? t->bits_per_word : spi->bits_per_word;
        config.speed_hz  = t ? t->speed_hz : spi->max_speed_hz;
-       config.len = t->len;
 
        if (!config.speed_hz)
                config.speed_hz = spi->max_speed_hz;
@@ -995,32 +905,14 @@ static int spi_imx_setupxfer(struct spi_device *spi,
 
        /* Initialize the functions for transfer */
        if (config.bpw <= 8) {
-               if (t->len >= sizeof(u32) && is_imx51_ecspi(spi_imx)) {
-                       spi_imx->dynamic_burst = 1;
-                       spi_imx->rx = spi_imx_buf_rx_swap;
-                       spi_imx->tx = spi_imx_buf_tx_swap;
-               } else {
-                       spi_imx->rx = spi_imx_buf_rx_u8;
-                       spi_imx->tx = spi_imx_buf_tx_u8;
-               }
+               spi_imx->rx = spi_imx_buf_rx_u8;
+               spi_imx->tx = spi_imx_buf_tx_u8;
        } else if (config.bpw <= 16) {
-               if (t->len >= sizeof(u32) && is_imx51_ecspi(spi_imx)) {
-                       spi_imx->dynamic_burst = 1;
-                       spi_imx->rx = spi_imx_buf_rx_swap;
-                       spi_imx->tx = spi_imx_buf_tx_swap;
-               } else {
-                       spi_imx->rx = spi_imx_buf_rx_u16;
-                       spi_imx->tx = spi_imx_buf_tx_u16;
-               }
+               spi_imx->rx = spi_imx_buf_rx_u16;
+               spi_imx->tx = spi_imx_buf_tx_u16;
        } else {
-               if (is_imx51_ecspi(spi_imx)) {
-                       spi_imx->dynamic_burst = 1;
-                       spi_imx->rx = spi_imx_buf_rx_swap;
-                       spi_imx->tx = spi_imx_buf_tx_swap;
-               } else {
-                       spi_imx->rx = spi_imx_buf_rx_u32;
-                       spi_imx->tx = spi_imx_buf_tx_u32;
-               }
+               spi_imx->rx = spi_imx_buf_rx_u32;
+               spi_imx->tx = spi_imx_buf_tx_u32;
        }
 
        if (spi_imx_can_dma(spi_imx->bitbang.master, spi, t))
@@ -1028,8 +920,6 @@ static int spi_imx_setupxfer(struct spi_device *spi,
        else
                spi_imx->usedma = 0;
 
-       spi_imx->bpw_w = DIV_ROUND_UP(config.bpw, 8);
-
        if (spi_imx->usedma) {
                ret = spi_imx_dma_configure(spi->master,
                                            spi_imx_bytes_per_word(config.bpw));
@@ -1204,27 +1094,6 @@ static int spi_imx_pio_transfer(struct spi_device *spi,
        spi_imx->count = transfer->len;
        spi_imx->txfifo = 0;
 
-       if (spi_imx->dynamic_burst) {
-               if (spi_imx->count > MX51_ECSPI_CTRL_MAX_BURST)
-                       spi_imx->count_index = spi_imx->count %
-                                              MX51_ECSPI_CTRL_MAX_BURST;
-               else
-                       spi_imx->count_index = spi_imx->count % sizeof(u32);
-
-               switch (spi_imx->bpw_w) {
-               case 1:
-                       spi_imx_u32_swap_u8(transfer,
-                                           (u32 *)transfer->tx_buf);
-                       break;
-               case 2:
-                       spi_imx_u32_swap_u16(transfer,
-                                            (u32 *)transfer->tx_buf);
-                       break;
-               default:
-                       break;
-               }
-       }
-
        reinit_completion(&spi_imx->xfer_done);
 
        spi_imx_push(spi_imx);
@@ -1241,22 +1110,6 @@ static int spi_imx_pio_transfer(struct spi_device *spi,
                return -ETIMEDOUT;
        }
 
-       if (spi_imx->dynamic_burst) {
-               switch (spi_imx->bpw_w) {
-               case 1:
-                       spi_imx_u32_swap_u8(transfer,
-                                           (u32 *)transfer->rx_buf);
-                       break;
-               case 2:
-                       spi_imx_u32_swap_u16(transfer,
-                                            (u32 *)transfer->rx_buf);
-                       break;
-               default:
-                       break;
-               }
-               spi_imx->dynamic_burst = 0;
-       }
-
        return transfer->len;
 }