diff options
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.c | 80 |
1 files changed, 62 insertions, 18 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.c b/drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.c index 751ea2517c43..7d74d6204d8d 100644 --- a/drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.c +++ b/drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.c @@ -54,12 +54,48 @@ static void smu_v11_0_i2c_set_clock_gating(struct i2c_adapter *control, bool en) WREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT, reg); } +/* The T_I2C_POLL_US is defined as follows: + * + * "Define a timer interval (t_i2c_poll) equal to 10 times the + * signalling period for the highest I2C transfer speed used in the + * system and supported by DW_apb_i2c. For instance, if the highest + * I2C data transfer mode is 400 kb/s, then t_i2c_poll is 25 us." -- + * DesignWare DW_apb_i2c Databook, Version 1.21a, section 3.8.3.1, + * page 56, with grammar and syntax corrections. + * + * Vcc for our device is at 1.8V which puts it at 400 kHz, + * see Atmel AT24CM02 datasheet, section 8.3 DC Characteristics table, page 14. + * + * The procedure to disable the IP block is described in section + * 3.8.3 Disabling DW_apb_i2c on page 56. + */ +#define I2C_SPEED_MODE_FAST 2 +#define T_I2C_POLL_US 25 +#define I2C_MAX_T_POLL_COUNT 1000 -static void smu_v11_0_i2c_enable(struct i2c_adapter *control, bool enable) +static int smu_v11_0_i2c_enable(struct i2c_adapter *control, bool enable) { struct amdgpu_device *adev = to_amdgpu_device(control); WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, enable ? 1 : 0); + + if (!enable) { + int ii; + + for (ii = I2C_MAX_T_POLL_COUNT; ii > 0; ii--) { + u32 en_stat = RREG32_SOC15(SMUIO, + 0, + mmCKSVII2C_IC_ENABLE_STATUS); + if (REG_GET_FIELD(en_stat, CKSVII2C_IC_ENABLE_STATUS, IC_EN)) + udelay(T_I2C_POLL_US); + else + return I2C_OK; + } + + return I2C_ABORT; + } + + return I2C_OK; } static void smu_v11_0_i2c_clear_status(struct i2c_adapter *control) @@ -81,8 +117,13 @@ static void smu_v11_0_i2c_configure(struct i2c_adapter *control) reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_RESTART_EN, 1); reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_MASTER, 0); reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_SLAVE, 0); - /* Standard mode */ - reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MAX_SPEED_MODE, 2); + /* The values of IC_MAX_SPEED_MODE are, + * 1: standard mode, 0 - 100 Kb/s, + * 2: fast mode, <= 400 Kb/s, or fast mode plus, <= 1000 Kb/s, + * 3: high speed mode, <= 3.4 Mb/s. + */ + reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MAX_SPEED_MODE, + I2C_SPEED_MODE_FAST); reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MASTER_MODE, 1); WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CON, reg); @@ -404,7 +445,6 @@ static void smu_v11_0_i2c_abort(struct i2c_adapter *control) DRM_DEBUG_DRIVER("I2C_Abort() Done."); } - static bool smu_v11_0_i2c_activity_done(struct i2c_adapter *control) { struct amdgpu_device *adev = to_amdgpu_device(control); @@ -416,7 +456,6 @@ static bool smu_v11_0_i2c_activity_done(struct i2c_adapter *control) reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS); reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE); - if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) && (REG_GET_FIELD(reg_ic_enable_status, CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) { /* @@ -446,6 +485,8 @@ static bool smu_v11_0_i2c_activity_done(struct i2c_adapter *control) static void smu_v11_0_i2c_init(struct i2c_adapter *control) { + int res; + /* Disable clock gating */ smu_v11_0_i2c_set_clock_gating(control, false); @@ -453,7 +494,9 @@ static void smu_v11_0_i2c_init(struct i2c_adapter *control) DRM_WARN("I2C busy !"); /* Disable I2C */ - smu_v11_0_i2c_enable(control, false); + res = smu_v11_0_i2c_enable(control, false); + if (res != I2C_OK) + smu_v11_0_i2c_abort(control); /* Configure I2C to operate as master and in standard mode */ smu_v11_0_i2c_configure(control); @@ -466,21 +509,22 @@ static void smu_v11_0_i2c_init(struct i2c_adapter *control) static void smu_v11_0_i2c_fini(struct i2c_adapter *control) { struct amdgpu_device *adev = to_amdgpu_device(control); - uint32_t reg_ic_enable_status, reg_ic_enable; + u32 status, enable, en_stat; + int res; - smu_v11_0_i2c_enable(control, false); + res = smu_v11_0_i2c_enable(control, false); + if (res != I2C_OK) { + status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS); + enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE); + en_stat = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS); - /* Double check if disabled, else force abort */ - reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS); - reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE); - - if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) && - (REG_GET_FIELD(reg_ic_enable_status, - CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) { - /* - * Nobody is using I2C engine, but engine remains active because - * someone missed to send STOP + /* Nobody is using the I2C engine, yet it remains + * active, possibly because someone missed to send + * STOP. */ + DRM_DEBUG_DRIVER("Aborting from fini: status:0x%08x " + "enable:0x%08x enable_stat:0x%08x", + status, enable, en_stat); smu_v11_0_i2c_abort(control); } |