omap24xx_i2c: add 2-byte address support

Various devices like EEPROMs require 2-byte address support to
be properly accessed. This patch adds this support for OMAP2/3/4
I2C controller driver.
I've tested it with EEPROM (16 bit address) and TPS65217 chip
(8 bit address) on TI Beaglebone board.

Unfortunately I don't have access to any compatible hardware
with 16bit data register so I can't test if those #ifdef
clauses really work.

CC: Tom Rini <trini@ti.com>
Signed-off-by: Ilya Yanok <ilya.yanok@cogentembedded.com>

diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
index 81193b0..978507b 100644 (file)
--- a/drivers/i2c/omap24xx_i2c.c
+++ b/drivers/i2c/omap24xx_i2c.c
@@ -150,16 +150,19 @@ void i2c_init(int speed, int slaveadd)
                bus_initialized[current_bus] = 1;
 }
 
-static int i2c_read_byte(u8 devaddr, u8 regoffset, u8 *value)
+static int i2c_read_byte(u8 devaddr, u16 regoffset, u8 alen, u8 *value)
 {
        int i2c_error = 0;
        u16 status;
+       int i = 2 - alen;
+       u8 tmpbuf[2] = {(regoffset) >> 8, regoffset & 0xff};
+       u16 w;
 
        /* wait until bus not busy */
        wait_for_bb();
 
        /* one byte only */
-       writew(1, &i2c_base->cnt);
+       writew(alen, &i2c_base->cnt);
        /* set slave address */
        writew(devaddr, &i2c_base->sa);
        /* no stop bit needed here */
@@ -174,8 +177,12 @@ static int i2c_read_byte(u8 devaddr, u8 regoffset, u8 *value)
                        goto read_exit;
                }
                if (status & I2C_STAT_XRDY) {
-                       /* Important: have to use byte access */
-                       writeb(regoffset, &i2c_base->data);
+                       w = tmpbuf[i++];
+#if !(defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
+       defined(CONFIG_OMAP44XX) || defined(CONFIG_AM33XX))
+                       w |= tmpbuf[i++] << 8;
+#endif
+                       writew(w, &i2c_base->data);
                        writew(I2C_STAT_XRDY, &i2c_base->stat);
                }
                if (status & I2C_STAT_ARDY) {
@@ -303,18 +310,18 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 {
        int i;
 
-       if (alen > 1) {
+       if (alen > 2) {
                printf("I2C read: addr len %d not supported\n", alen);
                return 1;
        }
 
-       if (addr + len > 256) {
+       if (addr + len > (1 << 16)) {
                puts("I2C read: address out of range\n");
                return 1;
        }
 
        for (i = 0; i < len; i++) {
-               if (i2c_read_byte(chip, addr + i, &buffer[i])) {
+               if (i2c_read_byte(chip, addr + i, alen, &buffer[i])) {
                        puts("I2C read: I/O error\n");
                        i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
                        return 1;
@@ -329,13 +336,15 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
        int i;
        u16 status;
        int i2c_error = 0;
+       u16 w;
+       u8 tmpbuf[2] = {addr >> 8, addr & 0xff};
 
-       if (alen > 1) {
+       if (alen > 2) {
                printf("I2C write: addr len %d not supported\n", alen);
                return 1;
        }
 
-       if (addr + len > 256) {
+       if (addr + len > (1 << 16)) {
                printf("I2C write: address 0x%x + 0x%x out of range\n",
                                addr, len);
                return 1;
@@ -353,28 +362,8 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
        writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
                I2C_CON_STP, &i2c_base->con);
 
-       /* Send address byte */
-       status = wait_for_pin();
-
-       if (status == 0 || status & I2C_STAT_NACK) {
-               i2c_error = 1;
-               printf("error waiting for i2c address ACK (status=0x%x)\n",
-                     status);
-               goto write_exit;
-       }
-
-       if (status & I2C_STAT_XRDY) {
-               writeb(addr & 0xFF, &i2c_base->data);
-               writew(I2C_STAT_XRDY, &i2c_base->stat);
-       } else {
-               i2c_error = 1;
-               printf("i2c bus not ready for transmit (status=0x%x)\n",
-                     status);
-               goto write_exit;
-       }
-
-       /* address phase is over, now write data */
-       for (i = 0; i < len; i++) {
+       /* Send address and data */
+       for (i = -alen; i < len; i++) {
                status = wait_for_pin();
 
                if (status == 0 || status & I2C_STAT_NACK) {
@@ -385,7 +374,12 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
                }
 
                if (status & I2C_STAT_XRDY) {
-                       writeb(buffer[i], &i2c_base->data);
+                       w = (i < 0) ? tmpbuf[2+i] : buffer[i];
+#if !(defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
+       defined(CONFIG_OMAP44XX) || defined(CONFIG_AM33XX))
+                       w |= ((++i < 0) ? tmpbuf[2+i] : buffer[i]) << 8;
+#endif
+                       writew(w, &i2c_base->data);
                        writew(I2C_STAT_XRDY, &i2c_base->stat);
                } else {
                        i2c_error = 1;