mxc_i2c: prep work for multiple busses support

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>

diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c
index 44a04b57d649307dc4d8dc3dd6d00828d2986df5..ead6e209b25441d9d2422c68d14a3aa64f03f89a 100644 (file)
--- a/drivers/i2c/mxc_i2c.c
+++ b/drivers/i2c/mxc_i2c.c
@@ -59,9 +59,7 @@ struct mxc_i2c_regs {
 #define I2SR_IIF       (1 << 1)
 #define I2SR_RX_NO_AK  (1 << 0)
 
-#ifdef CONFIG_SYS_I2C_BASE
-#define I2C_BASE       CONFIG_SYS_I2C_BASE
-#else
+#if defined(CONFIG_HARD_I2C) && !defined(CONFIG_SYS_I2C_BASE)
 #error "define CONFIG_SYS_I2C_BASE to use the mxc_i2c driver"
 #endif
 
@@ -115,11 +113,11 @@ static uint8_t i2c_imx_get_clk(unsigned int rate)
 }
 
 /*
- * Init I2C Bus
+ * Set I2C Bus speed
  */
-void i2c_init(int speed, int unused)
+int bus_i2c_set_bus_speed(void *base, int speed)
 {
-       struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
+       struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
        u8 clk_idx = i2c_imx_get_clk(speed);
        u8 idx = i2c_clk_div[clk_idx][1];
 
@@ -129,23 +127,15 @@ void i2c_init(int speed, int unused)
        /* Reset module */
        writeb(0, &i2c_regs->i2cr);
        writeb(0, &i2c_regs->i2sr);
-}
-
-/*
- * Set I2C Speed
- */
-int i2c_set_bus_speed(unsigned int speed)
-{
-       i2c_init(speed, 0);
        return 0;
 }
 
 /*
  * Get I2C Speed
  */
-unsigned int i2c_get_bus_speed(void)
+unsigned int bus_i2c_get_bus_speed(void *base)
 {
-       struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
+       struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
        u8 clk_idx = readb(&i2c_regs->ifdr);
        u8 clk_div;
 
@@ -287,12 +277,13 @@ static int i2c_init_transfer(struct mxc_i2c_regs *i2c_regs,
 /*
  * Read data from I2C device
  */
-int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
+int bus_i2c_read(void *base, uchar chip, uint addr, int alen, uchar *buf,
+               int len)
 {
-       struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
        int ret;
        unsigned int temp;
        int i;
+       struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
 
        ret = i2c_init_transfer(i2c_regs, chip, addr, alen);
        if (ret < 0)
@@ -346,11 +337,12 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
 /*
  * Write data to I2C device
  */
-int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
+int bus_i2c_write(void *base, uchar chip, uint addr, int alen,
+               const uchar *buf, int len)
 {
-       struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
        int ret;
        int i;
+       struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
 
        ret = i2c_init_transfer(i2c_regs, chip, addr, alen);
        if (ret < 0)
@@ -365,10 +357,101 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
        return ret;
 }
 
+struct i2c_parms {
+       void *base;
+       void *idle_bus_data;
+       int (*idle_bus_fn)(void *p);
+};
+
+struct sram_data {
+       unsigned curr_i2c_bus;
+       struct i2c_parms i2c_data[3];
+};
+
+/*
+ * For SPL boot some boards need i2c before SDRAM is initialized so force
+ * variables to live in SRAM
+ */
+static struct sram_data __attribute__((section(".data"))) srdata;
+
+void *get_base(void)
+{
+#ifdef CONFIG_SYS_I2C_BASE
+#ifdef CONFIG_I2C_MULTI_BUS
+       void *ret = srdata.i2c_data[srdata.curr_i2c_bus].base;
+       if (ret)
+               return ret;
+#endif
+       return (void *)CONFIG_SYS_I2C_BASE;
+#elif defined(CONFIG_I2C_MULTI_BUS)
+       return srdata.i2c_data[srdata.curr_i2c_bus].base;
+#else
+       return srdata.i2c_data[0].base;
+#endif
+}
+
+int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
+{
+       return bus_i2c_read(get_base(), chip, addr, alen, buf, len);
+}
+
+int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
+{
+       return bus_i2c_write(get_base(), chip, addr, alen, buf, len);
+}
+
 /*
  * Test if a chip at a given address responds (probe the chip)
  */
 int i2c_probe(uchar chip)
 {
-       return i2c_write(chip, 0, 0, NULL, 0);
+       return bus_i2c_write(get_base(), chip, 0, 0, NULL, 0);
+}
+
+void bus_i2c_init(void *base, int speed, int unused,
+               int (*idle_bus_fn)(void *p), void *idle_bus_data)
+{
+       int i = 0;
+       struct i2c_parms *p = srdata.i2c_data;
+       if (!base)
+               return;
+       for (;;) {
+               if (!p->base || (p->base == base)) {
+                       p->base = base;
+                       if (idle_bus_fn) {
+                               p->idle_bus_fn = idle_bus_fn;
+                               p->idle_bus_data = idle_bus_data;
+                       }
+                       break;
+               }
+               p++;
+               i++;
+               if (i >= ARRAY_SIZE(srdata.i2c_data))
+                       return;
+       }
+       bus_i2c_set_bus_speed(base, speed);
+}
+
+/*
+ * Init I2C Bus
+ */
+void i2c_init(int speed, int unused)
+{
+       bus_i2c_init(get_base(), speed, unused, NULL, NULL);
+}
+
+/*
+ * Set I2C Speed
+ */
+int i2c_set_bus_speed(unsigned int speed)
+{
+       return bus_i2c_set_bus_speed(get_base(), speed);
+}
+
+/*
+ * Get I2C Speed
+ */
+unsigned int i2c_get_bus_speed(void)
+{
+       return bus_i2c_get_bus_speed(get_base());
 }