diff options
Diffstat (limited to 'drivers/pwm/pwm-axi-pwmgen.c')
| -rw-r--r-- | drivers/pwm/pwm-axi-pwmgen.c | 37 |
1 files changed, 27 insertions, 10 deletions
diff --git a/drivers/pwm/pwm-axi-pwmgen.c b/drivers/pwm/pwm-axi-pwmgen.c index 39d184417c7c..4259a0db9ff4 100644 --- a/drivers/pwm/pwm-axi-pwmgen.c +++ b/drivers/pwm/pwm-axi-pwmgen.c @@ -9,7 +9,7 @@ * * Limitations: * - The writes to registers for period and duty are shadowed until - * LOAD_CONFIG is written to AXI_PWMGEN_REG_CONFIG, at which point + * LOAD_CONFIG is written to AXI_PWMGEN_REG_RSTN, at which point * they take effect. * - Writing LOAD_CONFIG also has the effect of re-synchronizing all * enabled channels, which could cause glitching on other channels. It @@ -33,14 +33,16 @@ #define AXI_PWMGEN_REG_ID 0x04 #define AXI_PWMGEN_REG_SCRATCHPAD 0x08 #define AXI_PWMGEN_REG_CORE_MAGIC 0x0C -#define AXI_PWMGEN_REG_CONFIG 0x10 +#define AXI_PWMGEN_REG_RSTN 0x10 +#define AXI_PWMGEN_REG_RSTN_LOAD_CONFIG BIT(1) +#define AXI_PWMGEN_REG_RSTN_RESET BIT(0) #define AXI_PWMGEN_REG_NPWM 0x14 +#define AXI_PWMGEN_REG_CONFIG 0x18 +#define AXI_PWMGEN_REG_CONFIG_FORCE_ALIGN BIT(1) #define AXI_PWMGEN_CHX_PERIOD(ch) (0x40 + (4 * (ch))) #define AXI_PWMGEN_CHX_DUTY(ch) (0x80 + (4 * (ch))) #define AXI_PWMGEN_CHX_OFFSET(ch) (0xC0 + (4 * (ch))) #define AXI_PWMGEN_REG_CORE_MAGIC_VAL 0x601A3471 /* Identification number to test during setup */ -#define AXI_PWMGEN_LOAD_CONFIG BIT(1) -#define AXI_PWMGEN_REG_CONFIG_RESET BIT(0) struct axi_pwmgen_ddata { struct regmap *regmap; @@ -61,13 +63,18 @@ struct axi_pwmgen_waveform { u32 duty_offset_cnt; }; +static struct axi_pwmgen_ddata *axi_pwmgen_ddata_from_chip(struct pwm_chip *chip) +{ + return pwmchip_get_drvdata(chip); +} + static int axi_pwmgen_round_waveform_tohw(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_waveform *wf, void *_wfhw) { struct axi_pwmgen_waveform *wfhw = _wfhw; - struct axi_pwmgen_ddata *ddata = pwmchip_get_drvdata(chip); + struct axi_pwmgen_ddata *ddata = axi_pwmgen_ddata_from_chip(chip); if (wf->period_length_ns == 0) { *wfhw = (struct axi_pwmgen_waveform){ @@ -111,7 +118,7 @@ static int axi_pwmgen_round_waveform_fromhw(struct pwm_chip *chip, struct pwm_de const void *_wfhw, struct pwm_waveform *wf) { const struct axi_pwmgen_waveform *wfhw = _wfhw; - struct axi_pwmgen_ddata *ddata = pwmchip_get_drvdata(chip); + struct axi_pwmgen_ddata *ddata = axi_pwmgen_ddata_from_chip(chip); wf->period_length_ns = DIV64_U64_ROUND_UP((u64)wfhw->period_cnt * NSEC_PER_SEC, ddata->clk_rate_hz); @@ -130,7 +137,7 @@ static int axi_pwmgen_write_waveform(struct pwm_chip *chip, const void *_wfhw) { const struct axi_pwmgen_waveform *wfhw = _wfhw; - struct axi_pwmgen_ddata *ddata = pwmchip_get_drvdata(chip); + struct axi_pwmgen_ddata *ddata = axi_pwmgen_ddata_from_chip(chip); struct regmap *regmap = ddata->regmap; unsigned int ch = pwm->hwpwm; int ret; @@ -147,7 +154,7 @@ static int axi_pwmgen_write_waveform(struct pwm_chip *chip, if (ret) return ret; - return regmap_write(regmap, AXI_PWMGEN_REG_CONFIG, AXI_PWMGEN_LOAD_CONFIG); + return regmap_write(regmap, AXI_PWMGEN_REG_RSTN, AXI_PWMGEN_REG_RSTN_LOAD_CONFIG); } static int axi_pwmgen_read_waveform(struct pwm_chip *chip, @@ -155,7 +162,7 @@ static int axi_pwmgen_read_waveform(struct pwm_chip *chip, void *_wfhw) { struct axi_pwmgen_waveform *wfhw = _wfhw; - struct axi_pwmgen_ddata *ddata = pwmchip_get_drvdata(chip); + struct axi_pwmgen_ddata *ddata = axi_pwmgen_ddata_from_chip(chip); struct regmap *regmap = ddata->regmap; unsigned int ch = pwm->hwpwm; int ret; @@ -218,7 +225,17 @@ static int axi_pwmgen_setup(struct regmap *regmap, struct device *dev) } /* Enable the core */ - ret = regmap_clear_bits(regmap, AXI_PWMGEN_REG_CONFIG, AXI_PWMGEN_REG_CONFIG_RESET); + ret = regmap_clear_bits(regmap, AXI_PWMGEN_REG_RSTN, AXI_PWMGEN_REG_RSTN_RESET); + if (ret) + return ret; + + /* + * Enable force align so that changes to PWM period and duty cycle take + * effect immediately. Otherwise, the effect of the change is delayed + * until the period of all channels run out, which can be long after the + * apply function returns. + */ + ret = regmap_set_bits(regmap, AXI_PWMGEN_REG_CONFIG, AXI_PWMGEN_REG_CONFIG_FORCE_ALIGN); if (ret) return ret; |