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cros_ec: i2c: Group i2c write / read into single transaction 

Replace dm_i2c_write() / dm_i2c_read() with transaction using
struct i2c_msg[2] in order to allow for i2c controller to detect
write/read cycle to emit a repeated start condition.

Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: u-boot@lists.denx.de
Acked-by: Simon Glass <sjg@chromium.org>
Tested on snow:
Tested-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Moritz Fischer 2017-01-12 09:47:30 -08:00 committed by Simon Glass
parent 136026f18e
commit e9b25f2ea1
1 changed files with 15 additions and 11 deletions
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26
drivers/misc/cros_ec_i2c.c
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@ -29,6 +29,8 @@ static int cros_ec_i2c_command(struct udevice *udev, uint8_t cmd,
int dout_len, uint8_t **dinp, int din_len)
{
struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
struct dm_i2c_chip *chip = dev_get_parent_platdata(udev);
struct i2c_msg i2c_msg[2];
/* version8, cmd8, arglen8, out8[dout_len], csum8 */
int out_bytes = dout_len + 4;
/* response8, arglen8, in8[din_len], checksum8 */
@ -53,6 +55,11 @@ static int cros_ec_i2c_command(struct udevice *udev, uint8_t cmd,
assert(dout_len >= 0);
assert(dinp);
i2c_msg[0].addr = chip->chip_addr;
i2c_msg[0].len = out_bytes;
i2c_msg[0].buf = dev->dout;
i2c_msg[0].flags = 0;
/*
* Copy command and data into output buffer so we can do a single I2C
* burst transaction.
@ -85,24 +92,21 @@ static int cros_ec_i2c_command(struct udevice *udev, uint8_t cmd,
*ptr++ = (uint8_t)
cros_ec_calc_checksum(dev->dout, dout_len + 3);
i2c_msg[1].addr = chip->chip_addr;
i2c_msg[1].len = in_bytes;
i2c_msg[1].buf = in_ptr;
i2c_msg[1].flags = I2C_M_RD;
/* Send output data */
cros_ec_dump_data("out", -1, dev->dout, out_bytes);
ret = dm_i2c_write(udev, 0, dev->dout, out_bytes);
ret = dm_i2c_xfer(udev, &i2c_msg[0], 2);
if (ret) {
debug("%s: Cannot complete I2C write to %s\n", __func__,
debug("%s: Could not execute transfer to %s\n", __func__,
udev->name);
ret = -1;
}
if (!ret) {
ret = dm_i2c_read(udev, 0, in_ptr, in_bytes);
if (ret) {
debug("%s: Cannot complete I2C read from %s\n",
__func__, udev->name);
ret = -1;
}
}
if (*in_ptr != EC_RES_SUCCESS) {
debug("%s: Received bad result code %d\n", __func__, *in_ptr);
return -(int)*in_ptr;