On Fri, Nov 13, 2020 at 03:08:50PM +0000, Paul Barker wrote:
> Use platform_irq_count to determine the number of fan tachometer inputs
> configured in the device tree. At this stage we support either 0 or 1
> inputs.
>
> Once we have this information we only need to read the
> pulses-per-revolution value if a fan tachometer is actually configured
> via an IRQ value.
>
> Also add a debug print of the IRQ number and the pulses-per-revolution
> value to aid in investigating issues.
>
> Signed-off-by: Paul Barker <pbarker@xxxxxxxxxxxx>
For my reference:
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> drivers/hwmon/pwm-fan.c | 50 +++++++++++++++++++++++++++--------------
> 1 file changed, 33 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
> index 1f63807c0399..efe2764f42d3 100644
> --- a/drivers/hwmon/pwm-fan.c
> +++ b/drivers/hwmon/pwm-fan.c
> @@ -286,7 +286,7 @@ static int pwm_fan_probe(struct platform_device *pdev)
> struct device *hwmon;
> int ret;
> struct pwm_state state = { };
> - u32 ppr = 2;
> + int tach_count;
>
> ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> if (!ctx)
> @@ -300,10 +300,6 @@ static int pwm_fan_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, ctx);
>
> - ctx->irq = platform_get_irq_optional(pdev, 0);
> - if (ctx->irq == -EPROBE_DEFER)
> - return ctx->irq;
> -
> ctx->reg_en = devm_regulator_get_optional(dev, "fan");
> if (IS_ERR(ctx->reg_en)) {
> if (PTR_ERR(ctx->reg_en) != -ENODEV)
> @@ -339,20 +335,40 @@ static int pwm_fan_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> - of_property_read_u32(dev->of_node, "pulses-per-revolution", &ppr);
> - ctx->pulses_per_revolution = ppr;
> - if (!ctx->pulses_per_revolution) {
> - dev_err(dev, "pulses-per-revolution can't be zero.\n");
> - return -EINVAL;
> - }
> + tach_count = platform_irq_count(pdev);
> + if (tach_count < 0)
> + return dev_err_probe(dev, tach_count,
> + "Could not get number of fan tachometer inputs\n");
> +
> + if (tach_count > 0) {
> + u32 ppr = 2;
> +
> + ctx->irq = platform_get_irq(pdev, 0);
> + if (ctx->irq == -EPROBE_DEFER)
> + return ctx->irq;
> + if (ctx->irq > 0) {
> + ret = devm_request_irq(dev, ctx->irq, pulse_handler, 0,
> + pdev->name, ctx);
> + if (ret) {
> + dev_err(dev,
> + "Failed to request interrupt: %d\n",
> + ret);
> + return ret;
> + }
> + }
>
> - if (ctx->irq > 0) {
> - ret = devm_request_irq(dev, ctx->irq, pulse_handler, 0,
> - pdev->name, ctx);
> - if (ret) {
> - dev_err(dev, "Failed to request interrupt: %d\n", ret);
> - return ret;
> + of_property_read_u32(dev->of_node,
> + "pulses-per-revolution",
> + &ppr);
> + ctx->pulses_per_revolution = ppr;
> + if (!ctx->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",
> + ctx->irq, ctx->pulses_per_revolution);
> +
> ctx->sample_start = ktime_get();
> mod_timer(&ctx->rpm_timer, jiffies + HZ);
> }
> --
> 2.29.2
>
