diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-master.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-master.c | 74 |
1 files changed, 65 insertions, 9 deletions
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c index c7e56002809a..e8ac9a7bf0b3 100644 --- a/drivers/i2c/busses/i2c-designware-master.c +++ b/drivers/i2c/busses/i2c-designware-master.c @@ -22,6 +22,8 @@ #include <linux/regmap.h> #include <linux/reset.h> +#define DEFAULT_SYMBOL_NAMESPACE I2C_DW + #include "i2c-designware-core.h" #define AMD_TIMEOUT_MIN_US 25 @@ -64,13 +66,17 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev) if (!dev->ss_hcnt || !dev->ss_lcnt) { ic_clk = i2c_dw_clk_rate(dev); dev->ss_hcnt = - i2c_dw_scl_hcnt(ic_clk, + i2c_dw_scl_hcnt(dev, + DW_IC_SS_SCL_HCNT, + ic_clk, 4000, /* tHD;STA = tHIGH = 4.0 us */ sda_falling_time, 0, /* 0: DW default, 1: Ideal */ 0); /* No offset */ dev->ss_lcnt = - i2c_dw_scl_lcnt(ic_clk, + i2c_dw_scl_lcnt(dev, + DW_IC_SS_SCL_LCNT, + ic_clk, 4700, /* tLOW = 4.7 us */ scl_falling_time, 0); /* No offset */ @@ -94,13 +100,17 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev) } else { ic_clk = i2c_dw_clk_rate(dev); dev->fs_hcnt = - i2c_dw_scl_hcnt(ic_clk, + i2c_dw_scl_hcnt(dev, + DW_IC_FS_SCL_HCNT, + ic_clk, 260, /* tHIGH = 260 ns */ sda_falling_time, 0, /* DW default */ 0); /* No offset */ dev->fs_lcnt = - i2c_dw_scl_lcnt(ic_clk, + i2c_dw_scl_lcnt(dev, + DW_IC_FS_SCL_LCNT, + ic_clk, 500, /* tLOW = 500 ns */ scl_falling_time, 0); /* No offset */ @@ -114,13 +124,17 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev) if (!dev->fs_hcnt || !dev->fs_lcnt) { ic_clk = i2c_dw_clk_rate(dev); dev->fs_hcnt = - i2c_dw_scl_hcnt(ic_clk, + i2c_dw_scl_hcnt(dev, + DW_IC_FS_SCL_HCNT, + ic_clk, 600, /* tHD;STA = tHIGH = 0.6 us */ sda_falling_time, 0, /* 0: DW default, 1: Ideal */ 0); /* No offset */ dev->fs_lcnt = - i2c_dw_scl_lcnt(ic_clk, + i2c_dw_scl_lcnt(dev, + DW_IC_FS_SCL_LCNT, + ic_clk, 1300, /* tLOW = 1.3 us */ scl_falling_time, 0); /* No offset */ @@ -142,13 +156,17 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev) } else if (!dev->hs_hcnt || !dev->hs_lcnt) { ic_clk = i2c_dw_clk_rate(dev); dev->hs_hcnt = - i2c_dw_scl_hcnt(ic_clk, + i2c_dw_scl_hcnt(dev, + DW_IC_HS_SCL_HCNT, + ic_clk, 160, /* tHIGH = 160 ns */ sda_falling_time, 0, /* DW default */ 0); /* No offset */ dev->hs_lcnt = - i2c_dw_scl_lcnt(ic_clk, + i2c_dw_scl_lcnt(dev, + DW_IC_HS_SCL_LCNT, + ic_clk, 320, /* tLOW = 320 ns */ scl_falling_time, 0); /* No offset */ @@ -253,6 +271,34 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) __i2c_dw_write_intr_mask(dev, DW_IC_INTR_MASTER_MASK); } +/* + * This function waits for the controller to be idle before disabling I2C + * When the controller is not in the IDLE state, the MST_ACTIVITY bit + * (IC_STATUS[5]) is set. + * + * Values: + * 0x1 (ACTIVE): Controller not idle + * 0x0 (IDLE): Controller is idle + * + * The function is called after completing the current transfer. + * + * Returns: + * False when the controller is in the IDLE state. + * True when the controller is in the ACTIVE state. + */ +static bool i2c_dw_is_controller_active(struct dw_i2c_dev *dev) +{ + u32 status; + + regmap_read(dev->map, DW_IC_STATUS, &status); + if (!(status & DW_IC_STATUS_MASTER_ACTIVITY)) + return false; + + return regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status, + !(status & DW_IC_STATUS_MASTER_ACTIVITY), + 1100, 20000) != 0; +} + static int i2c_dw_check_stopbit(struct dw_i2c_dev *dev) { u32 val; @@ -789,6 +835,16 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) } /* + * This happens rarely (~1:500) and is hard to reproduce. Debug trace + * showed that IC_STATUS had value of 0x23 when STOP_DET occurred, + * if disable IC_ENABLE.ENABLE immediately that can result in + * IC_RAW_INTR_STAT.MASTER_ON_HOLD holding SCL low. Check if + * controller is still ACTIVE before disabling I2C. + */ + if (i2c_dw_is_controller_active(dev)) + dev_err(dev->dev, "controller active\n"); + + /* * We must disable the adapter before returning and signaling the end * of the current transfer. Otherwise the hardware might continue * generating interrupts which in turn causes a race condition with @@ -931,7 +987,6 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev) init_completion(&dev->cmd_complete); dev->init = i2c_dw_init_master; - dev->disable = i2c_dw_disable; ret = i2c_dw_init_regmap(dev); if (ret) @@ -1021,3 +1076,4 @@ EXPORT_SYMBOL_GPL(i2c_dw_probe_master); MODULE_DESCRIPTION("Synopsys DesignWare I2C bus master adapter"); MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(I2C_DW_COMMON); |