i2c: mxs: Abstract out the MXS I2C speed setup

This patch pulls out the I2C speed setup from the i2c_init() call
and implements the bus configuration lookup table with register
values that needs to be programmed into the I2C IP to run at
particular speed.

This patch is a first step towards implementing run-time I2C bus
speed configuration for the MXS I2C IP.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>

diff --git a/drivers/i2c/mxs_i2c.c b/drivers/i2c/mxs_i2c.c
index 2a193c2..98f6e8c 100644 (file)
--- a/drivers/i2c/mxs_i2c.c
+++ b/drivers/i2c/mxs_i2c.c
@@ -210,34 +210,51 @@ int i2c_probe(uchar chip)
        return ret;
 }
 
+static struct mxs_i2c_speed_table {
+       uint32_t        speed;
+       uint32_t        timing0;
+       uint32_t        timing1;
+} mxs_i2c_tbl[] = {
+       {
+               100000,
+               (0x0078 << I2C_TIMING0_HIGH_COUNT_OFFSET) |
+               (0x0030 << I2C_TIMING0_RCV_COUNT_OFFSET),
+               (0x0080 << I2C_TIMING1_LOW_COUNT_OFFSET) |
+               (0x0030 << I2C_TIMING1_XMIT_COUNT_OFFSET)
+       },
+       {
+               400000,
+               (0x000f << I2C_TIMING0_HIGH_COUNT_OFFSET) |
+               (0x0007 << I2C_TIMING0_RCV_COUNT_OFFSET),
+               (0x001f << I2C_TIMING1_LOW_COUNT_OFFSET) |
+               (0x000f << I2C_TIMING1_XMIT_COUNT_OFFSET),
+       }
+};
+
+static struct mxs_i2c_speed_table *mxs_i2c_speed_to_cfg(uint32_t speed)
+{
+       int i;
+       for (i = 0; i < ARRAY_SIZE(mxs_i2c_tbl); i++)
+               if (mxs_i2c_tbl[i].speed == speed)
+                       return &mxs_i2c_tbl[i];
+       return NULL;
+}
+
 void i2c_init(int speed, int slaveadd)
 {
        struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
+       struct mxs_i2c_speed_table *spd = mxs_i2c_speed_to_cfg(speed);
 
-       mxs_i2c_reset();
-
-       switch (speed) {
-       case 100000:
-               writel((0x0078 << I2C_TIMING0_HIGH_COUNT_OFFSET) |
-                       (0x0030 << I2C_TIMING0_RCV_COUNT_OFFSET),
-                       &i2c_regs->hw_i2c_timing0);
-               writel((0x0080 << I2C_TIMING1_LOW_COUNT_OFFSET) |
-                       (0x0030 << I2C_TIMING1_XMIT_COUNT_OFFSET),
-                       &i2c_regs->hw_i2c_timing1);
-               break;
-       case 400000:
-               writel((0x000f << I2C_TIMING0_HIGH_COUNT_OFFSET) |
-                       (0x0007 << I2C_TIMING0_RCV_COUNT_OFFSET),
-                       &i2c_regs->hw_i2c_timing0);
-               writel((0x001f << I2C_TIMING1_LOW_COUNT_OFFSET) |
-                       (0x000f << I2C_TIMING1_XMIT_COUNT_OFFSET),
-                       &i2c_regs->hw_i2c_timing1);
-               break;
-       default:
+       if (!spd) {
                printf("MXS I2C: Invalid speed selected (%d Hz)\n", speed);
                return;
        }
 
+       mxs_i2c_reset();
+
+       writel(spd->timing0, &i2c_regs->hw_i2c_timing0);
+       writel(spd->timing1, &i2c_regs->hw_i2c_timing1);
+
        writel((0x0015 << I2C_TIMING2_BUS_FREE_OFFSET) |
                (0x000d << I2C_TIMING2_LEADIN_COUNT_OFFSET),
                &i2c_regs->hw_i2c_timing2);