On Sat, Dec 12, 2020 at 07:50:08PM +0000, Paul Barker wrote:
> The pwm-fan driver is extended to support multiple fan tachometer
> signals connected to GPIO inputs. This is intended to support the case
> where a single PWM output signal is routed to multiple fans, each of
> which have a tachometer output connected back to a GPIO pin.
>
> The number of fan tachometer inputs is determined by the number of
> interrupt sources configured for the pwm-fan device. The number of
> pulses-per-revolution entries should match the number of interrupt
> sources so that each input has a value assigned.
>
> The fan tachometer measurements are exposed as sysfs files fan1_input,
> fan2_input, etc up to the number of configured inputs.
>
> Signed-off-by: Paul Barker <pbarker@xxxxxxxxxxxx>
Applied.
Thanks,
Guenter
> ---
> drivers/hwmon/pwm-fan.c | 91 ++++++++++++++++++++++++-----------------
> 1 file changed, 53 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
> index 4a7f0e87b08f..cc64bae0ffa8 100644
> --- a/drivers/hwmon/pwm-fan.c
> +++ b/drivers/hwmon/pwm-fan.c
> @@ -33,7 +33,8 @@ struct pwm_fan_ctx {
> struct pwm_device *pwm;
> struct regulator *reg_en;
>
> - struct pwm_fan_tach *tach;
> + int tach_count;
> + struct pwm_fan_tach *tachs;
> ktime_t sample_start;
> struct timer_list rpm_timer;
>
> @@ -44,6 +45,7 @@ struct pwm_fan_ctx {
> struct thermal_cooling_device *cdev;
>
> struct hwmon_chip_info info;
> + struct hwmon_channel_info fan_channel;
> };
>
> static const u32 pwm_fan_channel_config_pwm[] = {
> @@ -56,16 +58,6 @@ static const struct hwmon_channel_info pwm_fan_channel_pwm = {
> .config = pwm_fan_channel_config_pwm,
> };
>
> -static const u32 pwm_fan_channel_config_fan[] = {
> - HWMON_F_INPUT,
> - 0
> -};
> -
> -static const struct hwmon_channel_info pwm_fan_channel_fan = {
> - .type = hwmon_fan,
> - .config = pwm_fan_channel_config_fan,
> -};
> -
> /* This handler assumes self resetting edge triggered interrupt. */
> static irqreturn_t pulse_handler(int irq, void *dev_id)
> {
> @@ -79,15 +71,19 @@ static irqreturn_t pulse_handler(int irq, void *dev_id)
> static void sample_timer(struct timer_list *t)
> {
> struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer);
> - struct pwm_fan_tach *tach = ctx->tach;
> unsigned int delta = ktime_ms_delta(ktime_get(), ctx->sample_start);
> - int pulses;
> + int i;
>
> if (delta) {
> - pulses = atomic_read(&tach->pulses);
> - atomic_sub(pulses, &tach->pulses);
> - tach->rpm = (unsigned int)(pulses * 1000 * 60) /
> - (tach->pulses_per_revolution * delta);
> + for (i = 0; i < ctx->tach_count; i++) {
> + struct pwm_fan_tach *tach = &ctx->tachs[i];
> + int pulses;
> +
> + pulses = atomic_read(&tach->pulses);
> + atomic_sub(pulses, &tach->pulses);
> + tach->rpm = (unsigned int)(pulses * 1000 * 60) /
> + (tach->pulses_per_revolution * delta);
> + }
>
> ctx->sample_start = ktime_get();
> }
> @@ -157,7 +153,7 @@ static int pwm_fan_read(struct device *dev, enum hwmon_sensor_types type,
> return 0;
>
> case hwmon_fan:
> - *val = ctx->tach->rpm;
> + *val = ctx->tachs[channel].rpm;
> return 0;
>
> default:
> @@ -304,8 +300,10 @@ static int pwm_fan_probe(struct platform_device *pdev)
> struct device *hwmon;
> int ret;
> struct pwm_state state = { };
> - int tach_count;
> const struct hwmon_channel_info **channels;
> + u32 *fan_channel_config;
> + int channel_count = 1; /* We always have a PWM channel. */
> + int i;
>
> ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> if (!ctx)
> @@ -354,29 +352,41 @@ static int pwm_fan_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> - tach_count = platform_irq_count(pdev);
> - if (tach_count < 0)
> - return dev_err_probe(dev, tach_count,
> + ctx->tach_count = platform_irq_count(pdev);
> + if (ctx->tach_count < 0)
> + return dev_err_probe(dev, ctx->tach_count,
> "Could not get number of fan tachometer inputs\n");
> + dev_dbg(dev, "%d fan tachometer inputs\n", ctx->tach_count);
>
> - channels = devm_kcalloc(dev, tach_count + 2,
> + if (ctx->tach_count) {
> + channel_count++; /* We also have a FAN channel. */
> +
> + ctx->tachs = devm_kcalloc(dev, ctx->tach_count,
> + sizeof(struct pwm_fan_tach),
> + GFP_KERNEL);
> + if (!ctx->tachs)
> + return -ENOMEM;
> +
> + ctx->fan_channel.type = hwmon_fan;
> + fan_channel_config = devm_kcalloc(dev, ctx->tach_count + 1,
> + sizeof(u32), GFP_KERNEL);
> + if (!fan_channel_config)
> + return -ENOMEM;
> + ctx->fan_channel.config = fan_channel_config;
> + }
> +
> + channels = devm_kcalloc(dev, channel_count + 1,
> sizeof(struct hwmon_channel_info *), GFP_KERNEL);
> if (!channels)
> return -ENOMEM;
>
> channels[0] = &pwm_fan_channel_pwm;
>
> - if (tach_count > 0) {
> - struct pwm_fan_tach *tach;
> + for (i = 0; i < ctx->tach_count; i++) {
> + struct pwm_fan_tach *tach = &ctx->tachs[i];
> u32 ppr = 2;
>
> - tach = devm_kzalloc(dev, sizeof(struct pwm_fan_tach),
> - GFP_KERNEL);
> - if (!tach)
> - return -ENOMEM;
> - ctx->tach = tach;
> -
> - tach->irq = platform_get_irq(pdev, 0);
> + tach->irq = platform_get_irq(pdev, i);
> if (tach->irq == -EPROBE_DEFER)
> return tach->irq;
> if (tach->irq > 0) {
> @@ -390,22 +400,27 @@ static int pwm_fan_probe(struct platform_device *pdev)
> }
> }
>
> - of_property_read_u32(dev->of_node,
> - "pulses-per-revolution",
> - &ppr);
> + of_property_read_u32_index(dev->of_node,
> + "pulses-per-revolution",
> + i,
> + &ppr);
> tach->pulses_per_revolution = ppr;
> if (!tach->pulses_per_revolution) {
> dev_err(dev, "pulses-per-revolution can't be zero.\n");
> return -EINVAL;
> }
>
> - dev_dbg(dev, "tach: irq=%d, pulses_per_revolution=%d\n",
> - tach->irq, tach->pulses_per_revolution);
> + fan_channel_config[i] = HWMON_F_INPUT;
> +
> + dev_dbg(dev, "tach%d: irq=%d, pulses_per_revolution=%d\n",
> + i, tach->irq, tach->pulses_per_revolution);
> + }
>
> + if (ctx->tach_count > 0) {
> ctx->sample_start = ktime_get();
> mod_timer(&ctx->rpm_timer, jiffies + HZ);
>
> - channels[1] = &pwm_fan_channel_fan;
> + channels[1] = &ctx->fan_channel;
> }
>
> ctx->info.ops = &pwm_fan_hwmon_ops;
