lkml.org 
[lkml]   [2019]   [Feb]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] i2c: imx: add support for I2C_M_STOP flag
Date
Add support for the I2C_M_STOP flag to the i2c-imx driver.  This allows
devices requiring a stop between messages to work with this controller.

Signed-off-by: Mans Rullgard <mans@mansr.com>
---
drivers/i2c/busses/i2c-imx.c | 26 ++++++++++++++++++++++----
1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index c406700789e1..43b4d5bc2196 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -908,10 +908,17 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,

/* read/write data */
for (i = 0; i < num; i++) {
- if (i == num - 1)
- is_lastmsg = true;
+ if (is_lastmsg) {
+ /* previous message had I2C_M_STOP flag set */
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_MSTA;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ result = i2c_imx_bus_busy(i2c_imx, 1);
+ if (result)
+ goto fail0;
+ }

- if (i) {
+ if (i && !is_lastmsg) {
dev_dbg(&i2c_imx->adapter.dev,
"<%s> repeated start\n", __func__);
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
@@ -921,6 +928,10 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
if (result)
goto fail0;
}
+
+ if (i == num - 1 || (msgs[i].flags & I2C_M_STOP))
+ is_lastmsg = true;
+
dev_dbg(&i2c_imx->adapter.dev,
"<%s> transfer message: %d\n", __func__, i);
/* write/read data */
@@ -948,6 +959,13 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
result = i2c_imx_dma_write(i2c_imx, &msgs[i]);
else
result = i2c_imx_write(i2c_imx, &msgs[i]);
+
+ if (msgs[i].flags & I2C_M_STOP) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp &= ~I2CR_MSTA;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ i2c_imx_bus_busy(i2c_imx, 0);
+ }
}
if (result)
goto fail0;
@@ -1034,7 +1052,7 @@ static int i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx,

static u32 i2c_imx_func(struct i2c_adapter *adapter)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
+ return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_SMBUS_EMUL
| I2C_FUNC_SMBUS_READ_BLOCK_DATA;
}

--
2.20.1
\
 
 \ /
  Last update: 2019-02-27 19:22    [W:0.039 / U:5.904 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site