fsl_pmic: add I2C interface support

This patch add I2C interface for fsl_pmic driver support

Signed-off-by: Jason Liu <r64343@freescale.com>
diff --git a/drivers/misc/fsl_pmic.c b/drivers/misc/fsl_pmic.c
index 5ee1de1..ef80ad9 100644
--- a/drivers/misc/fsl_pmic.c
+++ b/drivers/misc/fsl_pmic.c
@@ -22,11 +22,48 @@
 
 #include <config.h>
 #include <common.h>
-#include <spi.h>
 #include <asm/errno.h>
 #include <linux/types.h>
 #include <fsl_pmic.h>
 
+static int check_param(u32 reg, u32 write)
+{
+	if (reg > 63 || write > 1) {
+		printf("<reg num> = %d is invalid. Should be less then 63\n",
+			reg);
+		return -1;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_FSL_PMIC_I2C
+#include <i2c.h>
+
+u32 pmic_reg(u32 reg, u32 val, u32 write)
+{
+	unsigned char buf[4] = { 0 };
+	u32 ret_val = 0;
+
+	if (check_param(reg, write))
+		return -1;
+
+	if (write) {
+		buf[0] = (val >> 16) & 0xff;
+		buf[1] = (val >> 8) & 0xff;
+		buf[2] = (val) & 0xff;
+		if (i2c_write(CONFIG_SYS_FSL_PMIC_I2C_ADDR, reg, 1, buf, 3))
+			return -1;
+	} else {
+		if (i2c_read(CONFIG_SYS_FSL_PMIC_I2C_ADDR, reg, 1, buf, 3))
+			return -1;
+		ret_val = buf[0] << 16 | buf[1] << 8 | buf[2];
+	}
+
+	return ret_val;
+}
+#else /* SPI interface */
+#include <spi.h>
 static struct spi_slave *slave;
 
 struct spi_slave *pmic_spi_probe(void)
@@ -55,11 +92,8 @@
 			return -1;
 	}
 
-	if (reg > 63 || write > 1) {
-		printf("<reg num> = %d is invalid. Should be less then 63\n",
-			reg);
+	if (check_param(reg, write))
 		return -1;
-	}
 
 	if (spi_claim_bus(slave))
 		return -1;
@@ -87,6 +121,7 @@
 	spi_release_bus(slave);
 	return cpu_to_be32(pmic_rx);
 }
+#endif
 
 void pmic_reg_write(u32 reg, u32 value)
 {