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i2c: designware: Get right data length

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IC_DATA_CMD[11] indicates the first data byte received after the address
phase for receive transfer in Master receiver or Slave receiver mode,
this bit was set in some transfer flow. IC_DATA_CMD[7:0] contains the
data to be transmitted or received on the I2C bus, so we should use the
lower 8 bits to get the real data length.

Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
This commit is contained in:
Liguang Zhang 2021-02-25 22:26:31 +08:00 committed by Wolfram Sang
parent a1858ce0cf
commit f53f15ba5a
2 changed files with 3 additions and 1 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

2
drivers/i2c/busses/i2c-designware-core.h
View file

@ -38,6 +38,8 @@
#define DW_IC_CON_TX_EMPTY_CTRL BIT(8) #define DW_IC_CON_TX_EMPTY_CTRL BIT(8)
#define DW_IC_CON_RX_FIFO_FULL_HLD_CTRL BIT(9) #define DW_IC_CON_RX_FIFO_FULL_HLD_CTRL BIT(9)
#define DW_IC_DATA_CMD_DAT GENMASK(7, 0)
/* /*
* Registers offset * Registers offset
*/ */

2
drivers/i2c/busses/i2c-designware-master.c
View file

@ -432,7 +432,7 @@ i2c_dw_read(struct dw_i2c_dev *dev)
regmap_read(dev->map, DW_IC_DATA_CMD, &tmp); regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
/* Ensure length byte is a valid value */ /* Ensure length byte is a valid value */
if (flags & I2C_M_RECV_LEN && if (flags & I2C_M_RECV_LEN &&
tmp <= I2C_SMBUS_BLOCK_MAX && tmp > 0) { (tmp & DW_IC_DATA_CMD_DAT) <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
len = i2c_dw_recv_len(dev, tmp); len = i2c_dw_recv_len(dev, tmp);
} }
*buf++ = tmp; *buf++ = tmp;