diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-core.h | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-master.c | 20 |
2 files changed, 21 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index 6bc2edec14f2..932395ddd42b 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -37,6 +37,7 @@ #define DW_IC_CON_STOP_DET_IFADDRESSED BIT(7) #define DW_IC_CON_TX_EMPTY_CTRL BIT(8) #define DW_IC_CON_RX_FIFO_FULL_HLD_CTRL BIT(9) +#define DW_IC_CON_BUS_CLEAR_CTRL BIT(11) #define DW_IC_DATA_CMD_DAT GENMASK(7, 0) diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c index 45f569155bfe..3be7581ee3fb 100644 --- a/drivers/i2c/busses/i2c-designware-master.c +++ b/drivers/i2c/busses/i2c-designware-master.c @@ -865,6 +865,7 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev) { struct i2c_adapter *adap = &dev->adapter; unsigned long irq_flags; + unsigned int ic_con; int ret; init_completion(&dev->cmd_complete); @@ -884,6 +885,25 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev) if (ret) return ret; + /* Lock the bus for accessing DW_IC_CON */ + ret = i2c_dw_acquire_lock(dev); + if (ret) + return ret; + + /* + * On AMD platforms BIOS advertises the bus clear feature + * and enables the SCL/SDA stuck low. SMU FW does the + * bus recovery process. Driver should not ignore this BIOS + * advertisement of bus clear feature. + */ + ret = regmap_read(dev->map, DW_IC_CON, &ic_con); + i2c_dw_release_lock(dev); + if (ret) + return ret; + + if (ic_con & DW_IC_CON_BUS_CLEAR_CTRL) + dev->master_cfg |= DW_IC_CON_BUS_CLEAR_CTRL; + ret = dev->init(dev); if (ret) return ret; |