diff options
| author | Bastian Stender <bst@pengutronix.de> | 2017-08-16 12:16:44 +0200 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2017-11-17 10:33:51 +0100 |
| commit | b4947c6c05719a77f95062d18aa5be7fd14474b9 (patch) | |
| tree | 515d7cae018b2a29f1c441a0a24592f586e2fbd1 /drivers/i2c | |
| parent | 3f2df4e92a8b68760e8e4f3c481cce88bd0bd082 (diff) | |
| download | barebox-b4947c6c05719a77f95062d18aa5be7fd14474b9.tar.gz barebox-b4947c6c05719a77f95062d18aa5be7fd14474b9.tar.xz | |
i2c: mv64xxx: add timeout waiting for bus ready
This prevents barebox hanging e.g. in case the i2c clock is accidentally
connected to GND.
Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-mv64xxx.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c index fd1665bebb..f54d81608f 100644 --- a/drivers/i2c/busses/i2c-mv64xxx.c +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -37,6 +37,8 @@ #define REG_CONTROL_TWSIEN 0x00000040 #define REG_CONTROL_INTEN 0x00000080 +#define MV46XXX_I2C_TIMEOUT (100 * MSECOND) /* transfer timeout */ + /* Ctlr status values */ #define STATUS_MAST_START 0x08 #define STATUS_MAST_REPEAT_START 0x10 @@ -421,10 +423,11 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) * ***************************************************************************** */ -static void +static int mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data) { u32 status; + uint64_t start = get_time_ns(); do { if (mv64xxx_read(drv_data, drv_data->reg_offsets.control) & REG_CONTROL_IFLG) { @@ -432,6 +435,11 @@ mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data) drv_data->reg_offsets.status); mv64xxx_i2c_fsm(drv_data, status); mv64xxx_i2c_do_action(drv_data); + } else { + if (is_timeout(start, MV46XXX_I2C_TIMEOUT)) { + dev_warn(&drv_data->adapter.dev, "timeout waiting for bus ready\n"); + return -ETIMEDOUT; + } } if (drv_data->rc) { drv_data->state = STATE_IDLE; @@ -440,6 +448,8 @@ mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data) drv_data->block = false; } } while (drv_data->block); + + return 0; } /* @@ -453,7 +463,7 @@ static int mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) { struct mv64xxx_i2c_data *drv_data = container_of(adap, struct mv64xxx_i2c_data, adapter); - int ret = num; + int ret; BUG_ON(drv_data->msgs != NULL); @@ -463,15 +473,15 @@ mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) drv_data->send_stop = (num == 1); drv_data->block = true; mv64xxx_i2c_send_start(drv_data); - mv64xxx_i2c_wait_for_completion(drv_data); + ret = mv64xxx_i2c_wait_for_completion(drv_data); - if (drv_data->rc < 0) + if (!ret && drv_data->rc < 0) ret = drv_data->rc; drv_data->num_msgs = 0; drv_data->msgs = NULL; - return ret; + return (ret < 0) ? ret : num; } /* |