Exynos5420: Fix up the i2c driver for use with the TPM driver

The TPM driver expects to call i2c_read with zero address length. The i2c
driver wasn't prepared to handle that particularly in the case of reads
because it expected to send an address before switching over to read mode for
the data. This change also fixes up the read and write calls to consistently
be read32 and write32 instead of readl and writel.

Change-Id: I33dee89b83d4cd9d3e1b90e84b40e761bb8d4de4
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/175966
Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
Tested-by: Stefan Reinauer <reinauer@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit cf686269424ea938d6f953d0f76103182eb71297)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6857
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

1 files changed, 15 insertions, 13 deletions

diff --git a/src/soc/samsung/exynos5420/i2c.c b/src/soc/samsung/exynos5420/i2c.c
index 226862802a..6ca0087e5b 100644
--- a/src/soc/samsung/exynos5420/i2c.c
+++ b/src/soc/samsung/exynos5420/i2c.c
@@ -210,7 +210,7 @@ static int WaitForXfer(struct s3c24x0_i2c *i2c)
 
 static void ReadWriteByte(struct s3c24x0_i2c *i2c)
 {
-	writel(read32(&i2c->iiccon) & ~I2CCON_IRPND, &i2c->iiccon);
+	write32(read32(&i2c->iiccon) & ~I2CCON_IRPND, &i2c->iiccon);
 }
 
 static void i2c_ch_init(struct s3c24x0_i2c_bus *bus, int speed, int slaveadd)
@@ -318,7 +318,7 @@ static void hsi2c_ch_init(struct s3c24x0_i2c_bus *i2c_bus,
 	write32(HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN, &hsregs->usi_fifo_ctl);
 
 	/* i2c_conf configure */
-	write32(readl(&hsregs->usi_conf) | HSI2C_AUTO_MODE, &hsregs->usi_conf);
+	write32(read32(&hsregs->usi_conf) | HSI2C_AUTO_MODE, &hsregs->usi_conf);
 }
 
 /* SW reset for the high speed bus */
@@ -484,17 +484,19 @@ static int hsi2c_read(struct exynos5_hsi2c *i2c,
 	/* chip address */
 	write32(HSI2C_SLV_ADDR_MAS(chip), &i2c->i2c_addr);
 
-	/* usi_ctl enable i2c func, master write configure */
-	write32((HSI2C_TXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER),
-							&i2c->usi_ctl);
+	if (alen) {
+		/* usi_ctl enable i2c func, master write configure */
+		write32(HSI2C_TXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER,
+			&i2c->usi_ctl);
 
-	/* auto_conf */
-	write32(alen | HSI2C_MASTER_RUN | HSI2C_STOP_AFTER_TRANS,
-		&i2c->usi_auto_conf);
+		/* auto_conf */
+		write32(alen | HSI2C_MASTER_RUN | HSI2C_STOP_AFTER_TRANS,
+			&i2c->usi_auto_conf);
 
-	if (hsi2c_senddata(i2c, addr, alen) ||
-	    hsi2c_wait_for_transfer(i2c) != 1) {
-		return -1;
+		if (hsi2c_senddata(i2c, addr, alen) ||
+		    hsi2c_wait_for_transfer(i2c) != 1) {
+			return -1;
+		}
 	}
 
 	/* usi_ctl enable i2c func, master WRITE configure */
@@ -542,7 +544,7 @@ static int i2c_transfer(struct s3c24x0_i2c *i2c,
 	timer_monotonic_get(&current);
 	end = current;
 	mono_time_add_usecs(&end, I2C_TIMEOUT_MS * 1000);
-	while (readl(&i2c->iicstat) & I2CSTAT_BSY) {
+	while (read32(&i2c->iicstat) & I2CSTAT_BSY) {
 		if (!mono_time_before(&current, &end)){
 			printk(BIOS_ERR, "%s timed out\n", __func__);
 			return I2C_NOK_TOUT;
@@ -607,7 +609,7 @@ static int i2c_transfer(struct s3c24x0_i2c *i2c,
 		while ((i < data_len) && (result == I2C_OK)) {
 			/* disable ACK for final READ */
 			if (i == data_len - 1)
-				write32(readl(&i2c->iiccon)
+				write32(read32(&i2c->iiccon)
 				       & ~I2CCON_ACKGEN,
 				       &i2c->iiccon);
 			ReadWriteByte(i2c);