From: Naveen Krishna Chatradhi <ch.nav...@samsung.com>
Adding NACK logic for i2c write.
Verified by reading and writing to device with address 9 on i2c-0.
Signed-off-by: Naveen Krishna Chatradhi <ch.nav...@samsung.com>
Signed-off-by: Akshay Saraswat <aksha...@samsung.com>
---
drivers/i2c/s3c24x0_i2c.c | 111 +++++++++++++++++++++++-----------------------
1 file changed, 56 insertions(+), 55 deletions(-)
diff --git a/drivers/i2c/s3c24x0_i2c.c b/drivers/i2c/s3c24x0_i2c.c
index 769a2ba..d2b4eb0 100644
--- a/drivers/i2c/s3c24x0_i2c.c
+++ b/drivers/i2c/s3c24x0_i2c.c
@@ -201,6 +201,35 @@ unsigned int i2c_get_bus_num(void)
}
#endif
+/*
+ * Verify the whether I2C ACK was received or not
+ *
+ * @param i2c pointer to I2C register base
+ * @param buf array of data
+ * @param len length of data
+ * return I2C_OK when transmission done
+ * I2C_NACK otherwise
+ */
+static int i2c_send_verify(struct s3c24x0_i2c *i2c, unsigned char buf[],
+ unsigned char len)
+{
+ int i, result = I2C_OK;
+
+ if (IsACK(i2c)) {
+ for (i = 0; (i < len) && (result == I2C_OK); i++) {
+ writel(buf[i], &i2c->iicds);
+ ReadWriteByte(i2c);
+ result = WaitForXfer(i2c);
+ if (!IsACK(i2c))
+ result = I2C_NACK;
+ }
+ } else {
+ result = I2C_NACK;
+ }
+
+ return result;
+}
+
void i2c_init(int speed, int slaveadd)
{
struct s3c24x0_i2c *i2c;
@@ -302,41 +331,30 @@ static int i2c_transfer(struct s3c24x0_i2c *i2c,
return I2C_NOK_TOUT;
writel(readl(&i2c->iiccon) | I2CCON_ACKGEN, &i2c->iiccon);
- result = I2C_OK;
+
+ if (addr && addr_len) {
+ writel(chip, &i2c->iicds);
+ /* send START */
+ writel(I2C_MODE_MT | I2C_TXRX_ENA | I2C_START_STOP,
+ &i2c->iicstat);
+ if (WaitForXfer(i2c) == I2C_OK)
+ result = i2c_send_verify(i2c, addr, addr_len);
+ else
+ result = I2C_NACK;
+ } else
+ result = I2C_NACK;
switch (cmd_type) {
case I2C_WRITE:
- if (addr && addr_len) {
- writel(chip, &i2c->iicds);
- /* send START */
- writel(I2C_MODE_MT | I2C_TXRX_ENA | I2C_START_STOP,
- &i2c->iicstat);
- i = 0;
- while ((i < addr_len) && (result == I2C_OK)) {
- result = WaitForXfer(i2c);
- writel(addr[i], &i2c->iicds);
- ReadWriteByte(i2c);
- i++;
- }
- i = 0;
- while ((i < data_len) && (result == I2C_OK)) {
- result = WaitForXfer(i2c);
- writel(data[i], &i2c->iicds);
- ReadWriteByte(i2c);
- i++;
- }
- } else {
+ if (result == I2C_OK)
+ result = i2c_send_verify(i2c, data, data_len);
+ else {
writel(chip, &i2c->iicds);
/* send START */
writel(I2C_MODE_MT | I2C_TXRX_ENA | I2C_START_STOP,
- &i2c->iicstat);
- i = 0;
- while ((i < data_len) && (result = I2C_OK)) {
- result = WaitForXfer(i2c);
- writel(data[i], &i2c->iicds);
- ReadWriteByte(i2c);
- i++;
- }
+ &i2c->iicstat);
+ if (WaitForXfer(i2c) == I2C_OK)
+ result = i2c_send_verify(i2c, data, data_len);
}
if (result == I2C_OK)
@@ -348,42 +366,25 @@ static int i2c_transfer(struct s3c24x0_i2c *i2c,
break;
case I2C_READ:
- if (addr && addr_len) {
- writel(I2C_MODE_MT | I2C_TXRX_ENA, &i2c->iicstat);
+ if (result == I2C_OK) {
+ writel(I2C_MODE_MR | I2C_TXRX_ENA, &i2c->iicstat);
writel(chip, &i2c->iicds);
/* send START */
writel(readl(&i2c->iicstat) | I2C_START_STOP,
&i2c->iicstat);
- result = WaitForXfer(i2c);
- if (IsACK(i2c)) {
- i = 0;
- while ((i < addr_len) && (result == I2C_OK)) {
- writel(addr[i], &i2c->iicds);
- ReadWriteByte(i2c);
- result = WaitForXfer(i2c);
- i++;
- }
-
- writel(chip, &i2c->iicds);
- /* resend START */
- writel(I2C_MODE_MR | I2C_TXRX_ENA |
- I2C_START_STOP, &i2c->iicstat);
ReadWriteByte(i2c);
result = WaitForXfer(i2c);
- i = 0;
- while ((i < data_len) && (result == I2C_OK)) {
- /* disable ACK for final READ */
- if (i == data_len - 1)
- writel(readl(&i2c->iiccon)
+ i = 0;
+ while ((i < data_len) && (result == I2C_OK)) {
+ /* disable ACK for final READ */
+ if (i == data_len - 1)
+ writel(readl(&i2c->iiccon)
& ~I2CCON_ACKGEN,
&i2c->iiccon);
ReadWriteByte(i2c);
result = WaitForXfer(i2c);
- data[i] = readl(&i2c->iicds);
- i++;
- }
- } else {
- result = I2C_NACK;
+ data[i] = readl(&i2c->iicds);
+ i++;
}
} else {
--
1.8.0
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
