| Message ID | 2c54a25eecc6f4745861568c49b98ca5b34a2f73.1720435656.git.u.kleine-koenig@baylibre.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | pwm: New abstraction and userspace API | expand |
On 2024-07-08 6:52 a.m., Uwe Kleine-König wrote: > Convert the axi-pwmgen driver to use the new callbacks for hardware > programming. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Tested-by: Trevor Gamblin <tgamblin@baylibre.com> > --- > drivers/pwm/pwm-axi-pwmgen.c | 148 ++++++++++++++++++++++++----------- > 1 file changed, 102 insertions(+), 46 deletions(-) > > diff --git a/drivers/pwm/pwm-axi-pwmgen.c b/drivers/pwm/pwm-axi-pwmgen.c > index aac4f395497b..757ae037d5d6 100644 > --- a/drivers/pwm/pwm-axi-pwmgen.c > +++ b/drivers/pwm/pwm-axi-pwmgen.c > @@ -23,6 +23,7 @@ > #include <linux/err.h> > #include <linux/fpga/adi-axi-common.h> > #include <linux/io.h> > +#include <linux/minmax.h> > #include <linux/module.h> > #include <linux/platform_device.h> > #include <linux/pwm.h> > @@ -53,81 +54,136 @@ static const struct regmap_config axi_pwmgen_regmap_config = { > .val_bits = 32, > }; > > -static int axi_pwmgen_apply(struct pwm_chip *chip, struct pwm_device *pwm, > - const struct pwm_state *state) > +/* This represents a hardware configuration for one channel */ > +struct axi_pwmgen_waveform { > + u32 period_cnt; > + u32 duty_cycle_cnt; > + u32 duty_offset_cnt; > +}; > + > +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); > + > + if (wf->period_length == 0) { > + *wfhw = (struct axi_pwmgen_waveform){ > + .period_cnt = 0, > + .duty_cycle_cnt = 0, > + .duty_offset_cnt = 0, > + }; > + } else { > + /* With ddata->clk_rate_hz < NSEC_PER_SEC this won't overflow. */ > + wfhw->period_cnt = min_t(u64, mul_u64_u32_div(wf->period_length, ddata->clk_rate_hz, NSEC_PER_SEC), U32_MAX); > + > + if (wfhw->period_cnt == 0) { > + /* > + * The specified period is too short for the hardware. > + * Let's round .duty_cycle down to 0 to get a (somewhat) > + * valid result. > + */ > + wfhw->period_cnt = 1; > + wfhw->duty_cycle_cnt = 0; > + wfhw->duty_offset_cnt = 0; > + } else { > + wfhw->duty_cycle_cnt = min_t(u64, mul_u64_u32_div(wf->duty_length, ddata->clk_rate_hz, NSEC_PER_SEC), U32_MAX); > + wfhw->duty_offset_cnt = min_t(u64, mul_u64_u32_div(wf->duty_offset, ddata->clk_rate_hz, NSEC_PER_SEC), U32_MAX); > + } > + } > + > + dev_dbg(&chip->dev, "pwm#%u: %lld/%lld [+%lld] @%lu -> PERIOD: %08x, DUTY: %08x, OFFSET: %08x\n", > + pwm->hwpwm, wf->duty_length, wf->period_length, wf->duty_offset, > + ddata->clk_rate_hz, wfhw->period_cnt, wfhw->duty_cycle_cnt, wfhw->duty_offset_cnt); > + > + return 0; > +} > + > +static int axi_pwmgen_round_waveform_fromhw(struct pwm_chip *chip, struct pwm_device *pwm, > + const void *_wfhw, struct pwm_waveform *wf) > +{ > + const struct axi_pwmgen_waveform *wfhw = _wfhw; > + struct axi_pwmgen_ddata *ddata = pwmchip_get_drvdata(chip); > + > + wf->period_length = DIV64_U64_ROUND_UP((u64)wfhw->period_cnt * NSEC_PER_SEC, > + ddata->clk_rate_hz); > + > + wf->duty_length = DIV64_U64_ROUND_UP((u64)wfhw->duty_cycle_cnt * NSEC_PER_SEC, > + ddata->clk_rate_hz); > + > + wf->duty_offset = DIV64_U64_ROUND_UP((u64)wfhw->duty_offset_cnt * NSEC_PER_SEC, > + ddata->clk_rate_hz); > + > + return 0; > +} > + > +static int axi_pwmgen_write_waveform(struct pwm_chip *chip, > + struct pwm_device *pwm, > + const void *_wfhw) > +{ > + const struct axi_pwmgen_waveform *wfhw = _wfhw; > struct axi_pwmgen_ddata *ddata = pwmchip_get_drvdata(chip); > - unsigned int ch = pwm->hwpwm; > struct regmap *regmap = ddata->regmap; > - u64 period_cnt, duty_cnt; > + unsigned int ch = pwm->hwpwm; > int ret; > > - if (state->polarity != PWM_POLARITY_NORMAL) > - return -EINVAL; > + ret = regmap_write(regmap, AXI_PWMGEN_CHX_PERIOD(ch), wfhw->period_cnt); > + if (ret) > + return ret; > > - if (state->enabled) { > - period_cnt = mul_u64_u64_div_u64(state->period, ddata->clk_rate_hz, NSEC_PER_SEC); > - if (period_cnt > UINT_MAX) > - period_cnt = UINT_MAX; > + ret = regmap_write(regmap, AXI_PWMGEN_CHX_DUTY(ch), wfhw->duty_cycle_cnt); > + if (ret) > + return ret; > > - if (period_cnt == 0) > - return -EINVAL; > - > - ret = regmap_write(regmap, AXI_PWMGEN_CHX_PERIOD(ch), period_cnt); > - if (ret) > - return ret; > - > - duty_cnt = mul_u64_u64_div_u64(state->duty_cycle, ddata->clk_rate_hz, NSEC_PER_SEC); > - if (duty_cnt > UINT_MAX) > - duty_cnt = UINT_MAX; > - > - ret = regmap_write(regmap, AXI_PWMGEN_CHX_DUTY(ch), duty_cnt); > - if (ret) > - return ret; > - } else { > - ret = regmap_write(regmap, AXI_PWMGEN_CHX_PERIOD(ch), 0); > - if (ret) > - return ret; > - > - ret = regmap_write(regmap, AXI_PWMGEN_CHX_DUTY(ch), 0); > - if (ret) > - return ret; > - } > + ret = regmap_write(regmap, AXI_PWMGEN_CHX_OFFSET(ch), wfhw->duty_offset_cnt); > + if (ret) > + return ret; > > return regmap_write(regmap, AXI_PWMGEN_REG_CONFIG, AXI_PWMGEN_LOAD_CONFIG); > } > > -static int axi_pwmgen_get_state(struct pwm_chip *chip, struct pwm_device *pwm, > - struct pwm_state *state) > +static int axi_pwmgen_read_waveform(struct pwm_chip *chip, > + struct pwm_device *pwm, > + void *_wfhw) > { > + struct axi_pwmgen_waveform *wfhw = _wfhw; > struct axi_pwmgen_ddata *ddata = pwmchip_get_drvdata(chip); > struct regmap *regmap = ddata->regmap; > unsigned int ch = pwm->hwpwm; > - u32 cnt; > int ret; > > - ret = regmap_read(regmap, AXI_PWMGEN_CHX_PERIOD(ch), &cnt); > + ret = regmap_read(regmap, AXI_PWMGEN_CHX_PERIOD(ch), &wfhw->period_cnt); > if (ret) > return ret; > > - state->enabled = cnt != 0; > - > - state->period = DIV_ROUND_UP_ULL((u64)cnt * NSEC_PER_SEC, ddata->clk_rate_hz); > - > - ret = regmap_read(regmap, AXI_PWMGEN_CHX_DUTY(ch), &cnt); > + ret = regmap_read(regmap, AXI_PWMGEN_CHX_DUTY(ch), &wfhw->duty_cycle_cnt); > if (ret) > return ret; > > - state->duty_cycle = DIV_ROUND_UP_ULL((u64)cnt * NSEC_PER_SEC, ddata->clk_rate_hz); > + ret = regmap_read(regmap, AXI_PWMGEN_CHX_OFFSET(ch), &wfhw->duty_offset_cnt); > + if (ret) > + return ret; > > - state->polarity = PWM_POLARITY_NORMAL; > + if (wfhw->duty_cycle_cnt > wfhw->period_cnt) > + wfhw->duty_cycle_cnt = wfhw->period_cnt; > + > + /* XXX: is this the actual behaviour of the hardware? */ > + if (wfhw->duty_offset_cnt >= wfhw->period_cnt) { > + wfhw->duty_cycle_cnt = 0; > + wfhw->duty_offset_cnt = 0; > + } > > return 0; > } > > static const struct pwm_ops axi_pwmgen_pwm_ops = { > - .apply = axi_pwmgen_apply, > - .get_state = axi_pwmgen_get_state, > + .sizeof_wfhw = sizeof(struct axi_pwmgen_waveform), > + .round_waveform_tohw = axi_pwmgen_round_waveform_tohw, > + .round_waveform_fromhw = axi_pwmgen_round_waveform_fromhw, > + .read_waveform = axi_pwmgen_read_waveform, > + .write_waveform = axi_pwmgen_write_waveform, > }; > > static int axi_pwmgen_setup(struct regmap *regmap, struct device *dev)
diff --git a/drivers/pwm/pwm-axi-pwmgen.c b/drivers/pwm/pwm-axi-pwmgen.c index aac4f395497b..757ae037d5d6 100644 --- a/drivers/pwm/pwm-axi-pwmgen.c +++ b/drivers/pwm/pwm-axi-pwmgen.c @@ -23,6 +23,7 @@ #include <linux/err.h> #include <linux/fpga/adi-axi-common.h> #include <linux/io.h> +#include <linux/minmax.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/pwm.h> @@ -53,81 +54,136 @@ static const struct regmap_config axi_pwmgen_regmap_config = { .val_bits = 32, }; -static int axi_pwmgen_apply(struct pwm_chip *chip, struct pwm_device *pwm, - const struct pwm_state *state) +/* This represents a hardware configuration for one channel */ +struct axi_pwmgen_waveform { + u32 period_cnt; + u32 duty_cycle_cnt; + u32 duty_offset_cnt; +}; + +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); + + if (wf->period_length == 0) { + *wfhw = (struct axi_pwmgen_waveform){ + .period_cnt = 0, + .duty_cycle_cnt = 0, + .duty_offset_cnt = 0, + }; + } else { + /* With ddata->clk_rate_hz < NSEC_PER_SEC this won't overflow. */ + wfhw->period_cnt = min_t(u64, mul_u64_u32_div(wf->period_length, ddata->clk_rate_hz, NSEC_PER_SEC), U32_MAX); + + if (wfhw->period_cnt == 0) { + /* + * The specified period is too short for the hardware. + * Let's round .duty_cycle down to 0 to get a (somewhat) + * valid result. + */ + wfhw->period_cnt = 1; + wfhw->duty_cycle_cnt = 0; + wfhw->duty_offset_cnt = 0; + } else { + wfhw->duty_cycle_cnt = min_t(u64, mul_u64_u32_div(wf->duty_length, ddata->clk_rate_hz, NSEC_PER_SEC), U32_MAX); + wfhw->duty_offset_cnt = min_t(u64, mul_u64_u32_div(wf->duty_offset, ddata->clk_rate_hz, NSEC_PER_SEC), U32_MAX); + } + } + + dev_dbg(&chip->dev, "pwm#%u: %lld/%lld [+%lld] @%lu -> PERIOD: %08x, DUTY: %08x, OFFSET: %08x\n", + pwm->hwpwm, wf->duty_length, wf->period_length, wf->duty_offset, + ddata->clk_rate_hz, wfhw->period_cnt, wfhw->duty_cycle_cnt, wfhw->duty_offset_cnt); + + return 0; +} + +static int axi_pwmgen_round_waveform_fromhw(struct pwm_chip *chip, struct pwm_device *pwm, + const void *_wfhw, struct pwm_waveform *wf) +{ + const struct axi_pwmgen_waveform *wfhw = _wfhw; + struct axi_pwmgen_ddata *ddata = pwmchip_get_drvdata(chip); + + wf->period_length = DIV64_U64_ROUND_UP((u64)wfhw->period_cnt * NSEC_PER_SEC, + ddata->clk_rate_hz); + + wf->duty_length = DIV64_U64_ROUND_UP((u64)wfhw->duty_cycle_cnt * NSEC_PER_SEC, + ddata->clk_rate_hz); + + wf->duty_offset = DIV64_U64_ROUND_UP((u64)wfhw->duty_offset_cnt * NSEC_PER_SEC, + ddata->clk_rate_hz); + + return 0; +} + +static int axi_pwmgen_write_waveform(struct pwm_chip *chip, + struct pwm_device *pwm, + const void *_wfhw) +{ + const struct axi_pwmgen_waveform *wfhw = _wfhw; struct axi_pwmgen_ddata *ddata = pwmchip_get_drvdata(chip); - unsigned int ch = pwm->hwpwm; struct regmap *regmap = ddata->regmap; - u64 period_cnt, duty_cnt; + unsigned int ch = pwm->hwpwm; int ret; - if (state->polarity != PWM_POLARITY_NORMAL) - return -EINVAL; + ret = regmap_write(regmap, AXI_PWMGEN_CHX_PERIOD(ch), wfhw->period_cnt); + if (ret) + return ret; - if (state->enabled) { - period_cnt = mul_u64_u64_div_u64(state->period, ddata->clk_rate_hz, NSEC_PER_SEC); - if (period_cnt > UINT_MAX) - period_cnt = UINT_MAX; + ret = regmap_write(regmap, AXI_PWMGEN_CHX_DUTY(ch), wfhw->duty_cycle_cnt); + if (ret) + return ret; - if (period_cnt == 0) - return -EINVAL; - - ret = regmap_write(regmap, AXI_PWMGEN_CHX_PERIOD(ch), period_cnt); - if (ret) - return ret; - - duty_cnt = mul_u64_u64_div_u64(state->duty_cycle, ddata->clk_rate_hz, NSEC_PER_SEC); - if (duty_cnt > UINT_MAX) - duty_cnt = UINT_MAX; - - ret = regmap_write(regmap, AXI_PWMGEN_CHX_DUTY(ch), duty_cnt); - if (ret) - return ret; - } else { - ret = regmap_write(regmap, AXI_PWMGEN_CHX_PERIOD(ch), 0); - if (ret) - return ret; - - ret = regmap_write(regmap, AXI_PWMGEN_CHX_DUTY(ch), 0); - if (ret) - return ret; - } + ret = regmap_write(regmap, AXI_PWMGEN_CHX_OFFSET(ch), wfhw->duty_offset_cnt); + if (ret) + return ret; return regmap_write(regmap, AXI_PWMGEN_REG_CONFIG, AXI_PWMGEN_LOAD_CONFIG); } -static int axi_pwmgen_get_state(struct pwm_chip *chip, struct pwm_device *pwm, - struct pwm_state *state) +static int axi_pwmgen_read_waveform(struct pwm_chip *chip, + struct pwm_device *pwm, + void *_wfhw) { + struct axi_pwmgen_waveform *wfhw = _wfhw; struct axi_pwmgen_ddata *ddata = pwmchip_get_drvdata(chip); struct regmap *regmap = ddata->regmap; unsigned int ch = pwm->hwpwm; - u32 cnt; int ret; - ret = regmap_read(regmap, AXI_PWMGEN_CHX_PERIOD(ch), &cnt); + ret = regmap_read(regmap, AXI_PWMGEN_CHX_PERIOD(ch), &wfhw->period_cnt); if (ret) return ret; - state->enabled = cnt != 0; - - state->period = DIV_ROUND_UP_ULL((u64)cnt * NSEC_PER_SEC, ddata->clk_rate_hz); - - ret = regmap_read(regmap, AXI_PWMGEN_CHX_DUTY(ch), &cnt); + ret = regmap_read(regmap, AXI_PWMGEN_CHX_DUTY(ch), &wfhw->duty_cycle_cnt); if (ret) return ret; - state->duty_cycle = DIV_ROUND_UP_ULL((u64)cnt * NSEC_PER_SEC, ddata->clk_rate_hz); + ret = regmap_read(regmap, AXI_PWMGEN_CHX_OFFSET(ch), &wfhw->duty_offset_cnt); + if (ret) + return ret; - state->polarity = PWM_POLARITY_NORMAL; + if (wfhw->duty_cycle_cnt > wfhw->period_cnt) + wfhw->duty_cycle_cnt = wfhw->period_cnt; + + /* XXX: is this the actual behaviour of the hardware? */ + if (wfhw->duty_offset_cnt >= wfhw->period_cnt) { + wfhw->duty_cycle_cnt = 0; + wfhw->duty_offset_cnt = 0; + } return 0; } static const struct pwm_ops axi_pwmgen_pwm_ops = { - .apply = axi_pwmgen_apply, - .get_state = axi_pwmgen_get_state, + .sizeof_wfhw = sizeof(struct axi_pwmgen_waveform), + .round_waveform_tohw = axi_pwmgen_round_waveform_tohw, + .round_waveform_fromhw = axi_pwmgen_round_waveform_fromhw, + .read_waveform = axi_pwmgen_read_waveform, + .write_waveform = axi_pwmgen_write_waveform, }; static int axi_pwmgen_setup(struct regmap *regmap, struct device *dev)
Convert the axi-pwmgen driver to use the new callbacks for hardware programming. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> --- drivers/pwm/pwm-axi-pwmgen.c | 148 ++++++++++++++++++++++++----------- 1 file changed, 102 insertions(+), 46 deletions(-)