diff options
| author | Akhil R <akhilrajeev@nvidia.com> | 2022-02-10 21:06:03 +0530 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2022-03-01 20:34:00 +0100 |
| commit | d7583c8a57485da19feb6dd85573763a8c5ec1d1 (patch) | |
| tree | edf57fb682d554339e0a0e216311967e388aa34a /drivers/i2c | |
| parent | 80704a84a9f8276337a83c0c3ce641af3b27c79c (diff) | |
| download | linux-d7583c8a57485da19feb6dd85573763a8c5ec1d1.tar.bz2 | |
i2c: tegra: Add SMBus block read function
Emulate SMBus block read using ContinueXfer to read the length byte
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-tegra.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 03cea102ab76..2941e42aa6a0 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -1233,6 +1233,11 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, return err; i2c_dev->msg_buf = msg->buf; + + /* The condition true implies smbus block read and len is already read */ + if (msg->flags & I2C_M_RECV_LEN && end_state != MSG_END_CONTINUE) + i2c_dev->msg_buf = msg->buf + 1; + i2c_dev->msg_buf_remaining = msg->len; i2c_dev->msg_err = I2C_ERR_NONE; i2c_dev->msg_read = !!(msg->flags & I2C_M_RD); @@ -1389,6 +1394,15 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], else end_type = MSG_END_REPEAT_START; } + /* If M_RECV_LEN use ContinueXfer to read the first byte */ + if (msgs[i].flags & I2C_M_RECV_LEN) { + ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], MSG_END_CONTINUE); + if (ret) + break; + /* Set the read byte as msg len */ + msgs[i].len = msgs[i].buf[0]; + dev_dbg(i2c_dev->dev, "reading %d bytes\n", msgs[i].len); + } ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type); if (ret) break; @@ -1416,10 +1430,10 @@ static u32 tegra_i2c_func(struct i2c_adapter *adap) { struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap); u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) | - I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING; + I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING; if (i2c_dev->hw->has_continue_xfer_support) - ret |= I2C_FUNC_NOSTART; + ret |= I2C_FUNC_NOSTART | I2C_FUNC_SMBUS_READ_BLOCK_DATA; return ret; } |