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cpu/allwinner/a10/twi.c: Refactor I²C handler to use i2c_seg API 

The coreboot I²C API was completely reworked in commit
* cdb61a6 i2c: Replace the i2c API.

For the allwinner I²C driver, wrappers to the old API were provided
on a "best guess" basis. Replace these wrappers with proper
transaction handling based on the i2c_seg API.

Change-Id: Ibdda3b022ce4876deb2906e17a5a0ca9e939aada
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/8431
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
This commit is contained in:
Alexandru Gagniuc 2015-02-13 16:30:30 -06:00
parent 1959abd790
commit e5ccbfd290
1 changed files with 26 additions and 59 deletions
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85
src/cpu/allwinner/a10/twi.c
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@ -109,29 +109,11 @@ static void i2c_send_stop(struct a1x_twi *twi)
write32(reg32, &twi->ctl);
}
static int i2c_read(unsigned bus, unsigned chip, unsigned addr,
uint8_t *buf, unsigned len)
static int i2c_read(struct a1x_twi *twi, uint8_t chip,
uint8_t *buf, size_t len)
{
unsigned count = len;
enum twi_status expected_status;
struct a1x_twi *twi = (void *)TWI_BASE(bus);
if (wait_until_idle(twi) != CB_SUCCESS)
return CB_ERR;
i2c_send_start(twi);
if (wait_for_status(twi) != TWI_STAT_TX_START)
return CB_ERR;
/* Send chip address */
i2c_send_data(twi, chip << 1);
if (wait_for_status(twi) != TWI_STAT_TX_AW_ACK)
return CB_ERR;
/* Send data address */
i2c_send_data(twi, addr);
if (wait_for_status(twi) != TWI_STAT_TXD_ACK)
return CB_ERR;
/* Send restart for read */
i2c_send_start(twi);
@ -164,19 +146,13 @@ static int i2c_read(unsigned bus, unsigned chip, unsigned addr,
count--;
}
i2c_send_stop(twi);
return len;
}
static int i2c_write(unsigned bus, unsigned chip, unsigned addr,
const uint8_t *buf, unsigned len)
static int i2c_write(struct a1x_twi *twi, uint8_t chip,
const uint8_t *buf, size_t len)
{
unsigned count = len;
struct a1x_twi *twi = (void *)TWI_BASE(bus);
if (wait_until_idle(twi) != CB_SUCCESS)
return CB_ERR;
size_t count = len;
i2c_send_start(twi);
if (wait_for_status(twi) != TWI_STAT_TX_START)
@ -187,11 +163,6 @@ static int i2c_write(unsigned bus, unsigned chip, unsigned addr,
if (wait_for_status(twi) != TWI_STAT_TX_AW_ACK)
return CB_ERR;
/* Send data address */
i2c_send_data(twi, addr);
if (wait_for_status(twi) != TWI_STAT_TXD_ACK)
return CB_ERR;
/* Send data */
while (count > 0) {
i2c_send_data(twi, *buf++);
@ -200,39 +171,35 @@ static int i2c_write(unsigned bus, unsigned chip, unsigned addr,
count--;
}
i2c_send_stop(twi);
return len;
}
/*
* This transfer function is not complete or correct, but it provides
* the basic support that the above read and write functions previously
* provided directly. It is extremely limited and not useful for
* advanced drivers like TPM.
*
* TODO: Rewite the i2c_transfer and supporting functions
*
*/
int platform_i2c_transfer(unsigned bus, struct i2c_seg *segments, int count)
{
int i, ret = CB_SUCCESS;
struct i2c_seg *seg = segments;
struct a1x_twi *twi = (void *)TWI_BASE(bus);
if (seg->read) {
/* Read has one buf for the addr and one for the data */
if (count != 2)
return -1;
if(i2c_read(bus, seg->chip, *seg->buf, seg[1].buf, seg[1].len) < 0)
return -1;
} else {
/* Write buf has adder and data. */
if (count != 1)
return -1;
if (wait_until_idle(twi) != CB_SUCCESS)
return CB_ERR;
if(i2c_write(bus, seg->chip, *seg->buf, seg->buf+1, seg->len-1) < 0)
return -1;
for (i = 0; i < count; i++) {
seg = segments + i;
if (seg->read) {
ret = i2c_read(twi, seg->chip, seg->buf, seg->len);
if (ret < 0)
break;
} else {
ret = i2c_write(twi, seg->chip, seg->buf, seg->len);
if (ret < 0)
break;
}
}
return 0;
/* Don't worry about the status. STOP is on a best-effort basis */
i2c_send_stop(twi);
return ret;
}