Hello,
On Thu, Jul 23, 2020 at 03:44:18PM +0800, Rahul Tanwar wrote:
> +static int lgm_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> + const struct pwm_state *state)
> +{
> + struct lgm_pwm_chip *pc = to_lgm_pwm_chip(chip);
> + u32 duty_cycle, val;
> + int ret;
> +
> + if (!state->enabled) {
> + ret = lgm_pwm_enable(chip, 0);
> + return ret;
> + }
> +
> + /*
> + * HW only supports NORMAL polarity
> + * HW supports fixed period which can not be changed/configured by user
> + */
> + if (state->polarity != PWM_POLARITY_NORMAL ||
> + state->period != pc->period)
> + return -EINVAL;
At least for state->polarity you have to check before state->enabled, as
the expectation on
.enabled = false
.polarity = PWM_POLARITY_INVERSED
is that the output becomes constant high. Also as confirmed at the end
of v4, state->period < pc->period was the right check to do.
> + duty_cycle = min_t(u64, state->duty_cycle, state->period);
> + /* reg_value = duty_ns * LGM_PWM_MAX_DUTY_CYCLE(0xff) / period_ns */
> + val = duty_cycle * LGM_PWM_MAX_DUTY_CYCLE / state->period;
The comment adds only little compared to the code line below. Please
drop it.
Dividing by state->period is wrong. I think you need pc->period here.
> + ret = regmap_update_bits(pc->regmap, LGM_PWM_FAN_CON0, LGM_PWM_FAN_DC_MSK,
> + FIELD_PREP(LGM_PWM_FAN_DC_MSK, val));
> + if (ret)
> + return ret;
> +
> + if (state->enabled)
> + ret = lgm_pwm_enable(chip, 1);
> +
> + return ret;
> +}
> +
> +static void lgm_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
> + struct pwm_state *state)
> +{
> + struct lgm_pwm_chip *pc = to_lgm_pwm_chip(chip);
> + u32 duty, val;
> +
> + state->enabled = regmap_test_bits(pc->regmap, LGM_PWM_FAN_CON0,
> + LGM_PWM_FAN_EN_EN);
> + state->polarity = PWM_POLARITY_NORMAL;
> + state->period = pc->period; /* fixed period */
> +
> + regmap_read(pc->regmap, LGM_PWM_FAN_CON0, &val);
> + duty = FIELD_GET(LGM_PWM_FAN_DC_MSK, val);
> + state->duty_cycle = DIV_ROUND_UP(duty * pc->period,
> + LGM_PWM_MAX_DUTY_CYCLE);
> +}
> +
> +static const struct pwm_ops lgm_pwm_ops = {
> + .get_state = lgm_pwm_get_state,
> + .apply = lgm_pwm_apply,
> + .owner = THIS_MODULE,
> +};
> +
> +static void lgm_pwm_init(struct lgm_pwm_chip *pc)
> +{
> + struct device *dev = pc->chip.dev;
> + struct regmap *regmap = pc->regmap;
> + u32 max_rpm, fan_wire, con0_val, con0_mask;
> +
> + if (device_property_read_u32(dev, "intel,fan-wire", &fan_wire))
> + fan_wire = 2; /* default is 2 wire mode */
> +
> + con0_mask = LGM_PWM_FAN_MODE_MSK;
> +
> + switch (fan_wire) {
> + case 4:
> + con0_val = FIELD_PREP(LGM_PWM_FAN_MODE_MSK, LGM_PWM_FAN_MODE_4WIRE);
> + pc->period = LGM_PWM_PERIOD_4WIRE_NSECS;
> + break;
> + default:
> + /* default is 2wire mode */
> + con0_val = FIELD_PREP(LGM_PWM_FAN_MODE_MSK, LGM_PWM_FAN_MODE_2WIRE);
> + pc->period = LGM_PWM_PERIOD_2WIRE_NSECS;
> + break;
> + }
> +
> + if (device_property_read_u32(dev, "intel,max-rpm", &max_rpm))
> + max_rpm = LGM_PWM_DEFAULT_RPM;
This property isn't in the binding!?
> + max_rpm = min_t(u32, max_rpm, LGM_PWM_MAX_RPM);
> + if (max_rpm == 0)
> + max_rpm = LGM_PWM_DEFAULT_RPM;
> +
> + regmap_update_bits(regmap, LGM_PWM_FAN_CON1, LGM_PWM_FAN_MAX_RPM_MSK, max_rpm);
> + regmap_update_bits(regmap, LGM_PWM_FAN_CON0, con0_mask, con0_val);
> +}
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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