ARMV7: Modify i2c driver for more reliable operation on OMAP4

[oweals/u-boot.git] / drivers / i2c / omap24xx_i2c.c

diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
index ff18991f0e49d9bdf536f9703af33ad1cfe09feb..7c98f150d74f3d27d0035077ca6f00952b133600 100644 (file)
--- a/drivers/i2c/omap24xx_i2c.c
+++ b/drivers/i2c/omap24xx_i2c.c
@@ -25,6 +25,10 @@
 #include <asm/arch/i2c.h>
 #include <asm/io.h>
 
+#include "omap24xx_i2c.h"
+
+#define I2C_TIMEOUT    10
+
 static void wait_for_bb (void);
 static u16 wait_for_pin (void);
 static void flush_fifo(void);
@@ -39,6 +43,7 @@ void i2c_init (int speed, int slaveadd)
        int psc, fsscll, fssclh;
        int hsscll = 0, hssclh = 0;
        u32 scll, sclh;
+       int timeout = I2C_TIMEOUT;
 
        /* Only handle standard, fast and high speeds */
        if ((speed != OMAP_I2C_STANDARD) &&
@@ -100,15 +105,24 @@ void i2c_init (int speed, int slaveadd)
                sclh = (unsigned int)fssclh;
        }
 
-       writew(0x2, &i2c_base->sysc); /* for ES2 after soft reset */
-       udelay(1000);
-       writew(0x0, &i2c_base->sysc); /* will probably self clear but */
-
        if (readw (&i2c_base->con) & I2C_CON_EN) {
                writew (0, &i2c_base->con);
                udelay (50000);
        }
 
+       writew(0x2, &i2c_base->sysc); /* for ES2 after soft reset */
+       udelay(1000);
+
+       writew(I2C_CON_EN, &i2c_base->con);
+       while (!(readw(&i2c_base->syss) & I2C_SYSS_RDONE) && timeout--) {
+               if (timeout <= 0) {
+                       printf("ERROR: Timeout in soft-reset\n");
+                       return;
+               }
+               udelay(1000);
+       }
+
+       writew(0, &i2c_base->con);
        writew(psc, &i2c_base->psc);
        writew(scll, &i2c_base->scll);
        writew(sclh, &i2c_base->sclh);
@@ -157,15 +171,14 @@ static int i2c_read_byte (u8 devaddr, u8 regoffset, u8 * value)
        }
 
        if (!i2c_error) {
-               /* free bus, otherwise we can't use a combined transction */
-               writew (0, &i2c_base->con);
-               while (readw (&i2c_base->stat) || (readw (&i2c_base->con) & I2C_CON_MST)) {
+               writew (I2C_CON_EN, &i2c_base->con);
+               while (readw(&i2c_base->stat) &
+                       (I2C_STAT_XRDY | I2C_STAT_ARDY)) {
                        udelay (10000);
                        /* Have to clear pending interrupt to clear I2C_STAT */
                        writew (0xFFFF, &i2c_base->stat);
                }
 
-               wait_for_bb ();
                /* set slave address */
                writew (devaddr, &i2c_base->sa);
                /* read one byte from slave */
@@ -176,7 +189,8 @@ static int i2c_read_byte (u8 devaddr, u8 regoffset, u8 * value)
 
                status = wait_for_pin ();
                if (status & I2C_STAT_RRDY) {
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
+    defined(CONFIG_OMAP44XX)
                        *value = readb (&i2c_base->data);
 #else
                        *value = readw (&i2c_base->data);
@@ -188,8 +202,8 @@ static int i2c_read_byte (u8 devaddr, u8 regoffset, u8 * value)
 
                if (!i2c_error) {
                        writew (I2C_CON_EN, &i2c_base->con);
-                       while (readw (&i2c_base->stat)
-                              || (readw (&i2c_base->con) & I2C_CON_MST)) {
+                       while (readw (&i2c_base->stat) &
+                               (I2C_STAT_RRDY | I2C_STAT_ARDY)) {
                                udelay (10000);
                                writew (0xFFFF, &i2c_base->stat);
                        }
@@ -221,7 +235,8 @@ static int i2c_write_byte (u8 devaddr, u8 regoffset, u8 value)
        status = wait_for_pin ();
 
        if (status & I2C_STAT_XRDY) {
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
+    defined(CONFIG_OMAP44XX)
                /* send out 1 byte */
                writeb (regoffset, &i2c_base->data);
                writew (I2C_STAT_XRDY, &i2c_base->stat);
@@ -274,7 +289,8 @@ static void flush_fifo(void)
        while(1){
                stat = readw(&i2c_base->stat);
                if(stat == I2C_STAT_RRDY){
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
+    defined(CONFIG_OMAP44XX)
                        readb(&i2c_base->data);
 #else
                        readw(&i2c_base->data);
@@ -435,3 +451,9 @@ int i2c_set_bus_num(unsigned int bus)
 
        return 0;
 }
+
+int i2c_get_bus_num(void)
+{
+       return (int) current_bus;
+}
+