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author | Paul Barker <pbarker@konsulko.com> | 2020-12-12 19:50:08 +0000 |
---|---|---|
committer | Guenter Roeck <linux@roeck-us.net> | 2021-01-27 17:44:18 -0800 |
commit | f0dc7cb6b4c9cd24a69f80423f6d7a03825b72e4 (patch) | |
tree | 529d810b651697e960408784d85221b9d2bba88f /drivers/hwmon/pwm-fan.c | |
parent | 01695410d4529e38fea6159fa9f1260c598290b0 (diff) | |
download | linux-stable-f0dc7cb6b4c9cd24a69f80423f6d7a03825b72e4.tar.gz linux-stable-f0dc7cb6b4c9cd24a69f80423f6d7a03825b72e4.tar.bz2 linux-stable-f0dc7cb6b4c9cd24a69f80423f6d7a03825b72e4.zip |
hwmon: (pwm-fan) Support multiple fan tachometers
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@konsulko.com>
Link: https://lore.kernel.org/r/20201212195008.6036-3-pbarker@konsulko.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon/pwm-fan.c')
-rw-r--r-- | drivers/hwmon/pwm-fan.c | 91 |
1 files changed, 53 insertions, 38 deletions
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index a7b7bcac1b40..b5204aeb8085 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) @@ -364,29 +362,41 @@ 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) { @@ -400,22 +410,27 @@ 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; |