Merge branch 'master' of git://git.denx.de/u-boot-arm

[platform/kernel/u-boot.git] / drivers / spi / mxc_spi.c

diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
index 4c19e0b..9c68d7d 100644 (file)
--- a/drivers/spi/mxc_spi.c
+++ b/drivers/spi/mxc_spi.c
@@ -128,8 +128,8 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
                unsigned int max_hz, unsigned int mode)
 {
        u32 clk_src = mxc_get_clock(MXC_CSPI_CLK);
-       s32 pre_div = 0, post_div = 0, i, reg_ctrl, reg_config;
-       u32 ss_pol = 0, sclkpol = 0, sclkpha = 0;
+       s32 reg_ctrl, reg_config;
+       u32 ss_pol = 0, sclkpol = 0, sclkpha = 0, pre_div = 0, post_div = 0;
        struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
 
        if (max_hz == 0) {
@@ -137,32 +137,30 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
                return -1;
        }
 
-       /* Reset spi */
-       reg_write(&regs->ctrl, 0);
-       reg_write(&regs->ctrl, MXC_CSPICTRL_EN);
-
-       reg_ctrl = reg_read(&regs->ctrl);
-
        /*
-        * The following computation is taken directly from Freescale's code.
+        * Reset SPI and set all CSs to master mode, if toggling
+        * between slave and master mode we might see a glitch
+        * on the clock line
         */
+       reg_ctrl = MXC_CSPICTRL_MODE_MASK;
+       reg_write(&regs->ctrl, reg_ctrl);
+       reg_ctrl |=  MXC_CSPICTRL_EN;
+       reg_write(&regs->ctrl, reg_ctrl);
+
        if (clk_src > max_hz) {
-               pre_div = DIV_ROUND_UP(clk_src, max_hz);
-               if (pre_div > 16) {
-                       post_div = pre_div / 16;
-                       pre_div = 15;
-               }
-               if (post_div != 0) {
-                       for (i = 0; i < 16; i++) {
-                               if ((1 << i) >= post_div)
-                                       break;
-                       }
-                       if (i == 16) {
+               pre_div = (clk_src - 1) / max_hz;
+               /* fls(1) = 1, fls(0x80000000) = 32, fls(16) = 5 */
+               post_div = fls(pre_div);
+               if (post_div > 4) {
+                       post_div -= 4;
+                       if (post_div >= 16) {
                                printf("Error: no divider for the freq: %d\n",
                                        max_hz);
                                return -1;
                        }
-                       post_div = i;
+                       pre_div >>= post_div;
+               } else {
+                       post_div = 0;
                }
        }
 
@@ -174,9 +172,6 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
        reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_POSTDIV(0x0F)) |
                MXC_CSPICTRL_POSTDIV(post_div);
 
-       /* always set to master mode */
-       reg_ctrl |= 1 << (cs + 4);
-
        /* We need to disable SPI before changing registers */
        reg_ctrl &= ~MXC_CSPICTRL_EN;
 
@@ -223,7 +218,7 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen,
        const u8 *dout, u8 *din, unsigned long flags)
 {
        struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
-       int nbytes = (bitlen + 7) / 8;
+       int nbytes = DIV_ROUND_UP(bitlen, 8);
        u32 data, cnt, i;
        struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
 
@@ -293,7 +288,7 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen,
        /* Transfer completed, clear any pending request */
        reg_write(&regs->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF);
 
-       nbytes = (bitlen + 7) / 8;
+       nbytes = DIV_ROUND_UP(bitlen, 8);
 
        cnt = nbytes % 32;
 
@@ -329,7 +324,7 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen,
 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
                void *din, unsigned long flags)
 {
-       int n_bytes = (bitlen + 7) / 8;
+       int n_bytes = DIV_ROUND_UP(bitlen, 8);
        int n_bits;
        int ret;
        u32 blk_size;
@@ -408,7 +403,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
        if (bus >= ARRAY_SIZE(spi_bases))
                return NULL;
 
-       mxcs = calloc(sizeof(struct mxc_spi_slave), 1);
+       mxcs = spi_alloc_slave(struct mxc_spi_slave, bus, cs);
        if (!mxcs) {
                puts("mxc_spi: SPI Slave not allocated !\n");
                return NULL;
@@ -424,8 +419,6 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 
        cs = ret;
 
-       mxcs->slave.bus = bus;
-       mxcs->slave.cs = cs;
        mxcs->base = spi_bases[bus];
 
        ret = spi_cfg_mxc(mxcs, cs, max_hz, mode);