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Message-ID: <20220818232040.GA3505561@roeck-us.net>
Date: Thu, 18 Aug 2022 16:20:40 -0700
From: Guenter Roeck <linux@...ck-us.net>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: Uwe Kleine-König
<u.kleine-koenig@...gutronix.de>, linux-doc@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-pwm@...r.kernel.org,
linux-hwmon@...r.kernel.org, Jonathan Corbet <corbet@....net>,
Thierry Reding <thierry.reding@...il.com>,
Jean Delvare <jdelvare@...e.com>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
Subject: Re: [PATCH v1 1/3] hwmon: (pwm-fan) Make use of device properties
On Sat, Aug 06, 2022 at 06:25:15PM +0300, Andy Shevchenko wrote:
> Convert the module to be property provider agnostic and allow
> it to be used on non-OF platforms.
>
> Add mod_devicetable.h include.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> Acked-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
I had another look at this patch. A substantial part of the changes
is because device properties don't support of_property_read_u32_index(),
reworking the code to use device_property_read_u32_array() instead.
Sorry, I don't like it, it results in a substantial number of unnecessary
changes. Device properties should support the equivalent of
of_property_read_u32_index() instead to simplify conversions.
Guenter
> ---
> drivers/hwmon/Kconfig | 2 +-
> drivers/hwmon/pwm-fan.c | 50 +++++++++++++++++++++--------------------
> 2 files changed, 27 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index e70d9614bec2..58912a5c5de8 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1613,7 +1613,7 @@ source "drivers/hwmon/pmbus/Kconfig"
>
> config SENSORS_PWM_FAN
> tristate "PWM fan"
> - depends on (PWM && OF) || COMPILE_TEST
> + depends on PWM || COMPILE_TEST
> depends on THERMAL || THERMAL=n
> help
> If you say yes here you get support for fans connected to PWM lines.
> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
> index 6c08551d8d14..9ce9f2543861 100644
> --- a/drivers/hwmon/pwm-fan.c
> +++ b/drivers/hwmon/pwm-fan.c
> @@ -9,10 +9,11 @@
>
> #include <linux/hwmon.h>
> #include <linux/interrupt.h>
> +#include <linux/mod_devicetable.h>
> #include <linux/module.h>
> #include <linux/mutex.h>
> -#include <linux/of.h>
> #include <linux/platform_device.h>
> +#include <linux/property.h>
> #include <linux/pwm.h>
> #include <linux/regulator/consumer.h>
> #include <linux/sysfs.h>
> @@ -25,7 +26,6 @@ struct pwm_fan_tach {
> int irq;
> atomic_t pulses;
> unsigned int rpm;
> - u8 pulses_per_revolution;
> };
>
> struct pwm_fan_ctx {
> @@ -36,6 +36,7 @@ struct pwm_fan_ctx {
>
> int tach_count;
> struct pwm_fan_tach *tachs;
> + u32 *pulses_per_revolution;
> ktime_t sample_start;
> struct timer_list rpm_timer;
>
> @@ -73,7 +74,7 @@ static void sample_timer(struct timer_list *t)
> pulses = atomic_read(&tach->pulses);
> atomic_sub(pulses, &tach->pulses);
> tach->rpm = (unsigned int)(pulses * 1000 * 60) /
> - (tach->pulses_per_revolution * delta);
> + (ctx->pulses_per_revolution[i] * delta);
> }
>
> ctx->sample_start = ktime_get();
> @@ -229,16 +230,14 @@ static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
> .set_cur_state = pwm_fan_set_cur_state,
> };
>
> -static int pwm_fan_of_get_cooling_data(struct device *dev,
> - struct pwm_fan_ctx *ctx)
> +static int pwm_fan_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx)
> {
> - struct device_node *np = dev->of_node;
> int num, i, ret;
>
> - if (!of_find_property(np, "cooling-levels", NULL))
> + if (!device_property_present(dev, "cooling-levels"))
> return 0;
>
> - ret = of_property_count_u32_elems(np, "cooling-levels");
> + ret = device_property_count_u32(dev, "cooling-levels");
> if (ret <= 0) {
> dev_err(dev, "Wrong data!\n");
> return ret ? : -EINVAL;
> @@ -250,8 +249,8 @@ static int pwm_fan_of_get_cooling_data(struct device *dev,
> if (!ctx->pwm_fan_cooling_levels)
> return -ENOMEM;
>
> - ret = of_property_read_u32_array(np, "cooling-levels",
> - ctx->pwm_fan_cooling_levels, num);
> + ret = device_property_read_u32_array(dev, "cooling-levels",
> + ctx->pwm_fan_cooling_levels, num);
> if (ret) {
> dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
> return ret;
> @@ -302,7 +301,7 @@ static int pwm_fan_probe(struct platform_device *pdev)
>
> mutex_init(&ctx->lock);
>
> - ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL);
> + ctx->pwm = devm_pwm_get(dev, NULL);
> if (IS_ERR(ctx->pwm))
> return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");
>
> @@ -370,6 +369,20 @@ static int pwm_fan_probe(struct platform_device *pdev)
> if (!fan_channel_config)
> return -ENOMEM;
> ctx->fan_channel.config = fan_channel_config;
> +
> + ctx->pulses_per_revolution = devm_kmalloc_array(dev,
> + ctx->tach_count,
> + sizeof(*ctx->pulses_per_revolution),
> + GFP_KERNEL);
> + if (!ctx->pulses_per_revolution)
> + return -ENOMEM;
> +
> + /* Setup default pulses per revolution */
> + memset32(ctx->pulses_per_revolution, 2, ctx->tach_count);
> +
> + device_property_read_u32_array(dev, "pulses-per-revolution",
> + ctx->pulses_per_revolution,
> + ctx->tach_count);
> }
>
> channels = devm_kcalloc(dev, channel_count + 1,
> @@ -381,7 +394,6 @@ static int pwm_fan_probe(struct platform_device *pdev)
>
> for (i = 0; i < ctx->tach_count; i++) {
> struct pwm_fan_tach *tach = &ctx->tachs[i];
> - u32 ppr = 2;
>
> tach->irq = platform_get_irq(pdev, i);
> if (tach->irq == -EPROBE_DEFER)
> @@ -397,20 +409,10 @@ static int pwm_fan_probe(struct platform_device *pdev)
> }
> }
>
> - 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;
> - }
> -
> 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);
> + i, tach->irq, ctx->pulses_per_revolution[i]);
> }
>
> if (ctx->tach_count > 0) {
> @@ -430,7 +432,7 @@ static int pwm_fan_probe(struct platform_device *pdev)
> return PTR_ERR(hwmon);
> }
>
> - ret = pwm_fan_of_get_cooling_data(dev, ctx);
> + ret = pwm_fan_get_cooling_data(dev, ctx);
> if (ret)
> return ret;
>
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