Date:	Thu, 11 Apr 2013 15:33:46 -0400
From:	Eduardo Valentin <eduardo.valentin@...com>
To:	Amit Daniel Kachhap <amit.daniel@...sung.com>
CC:	<linux-pm@...r.kernel.org>,
	Thomas Abraham <thomas.abraham@...aro.org>,
	Zhang Rui <rui.zhang@...el.com>,
	<linux-samsung-soc@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <amit.kachhap@...il.com>,
	Kukjin Kim <kgene.kim@...sung.com>, <eduardo.valentin@...com>
Subject: Re: [1/9] thermal: exynos: Adapt to temperature emulation core thermal
 framework

Hello Amit,

Couple of comments inline.

On 26-03-2013 07:33, Amit Daniel Kachhap wrote:
> This removes the driver specific sysfs support of the temperature
> emulation and uses the newly added core thermal framework for thermal
> emulation. An exynos platform specific handler is added to support this.
>
> In this patch, the exynos senor(tmu) related code and exynos framework
> related (thermal zone, cooling devices) code are intentionally kept separate.
> So an emulated function pointer is passed from sensor to framework. This is
> beneficial in adding more sensor support using the same framework code
> which is an ongoing work. The goal is to finally split them totally. Even
> the existing read_temperature also follows the same execution method.
>
> Acked-by: Kukjin Kim <kgene.kim@...sung.com>
> Signed-off-by: Amit Daniel Kachhap <amit.daniel@...sung.com>
>
> ---
> Documentation/thermal/exynos_thermal_emulation |    8 +-
>   drivers/thermal/Kconfig                        |    9 --
>   drivers/thermal/exynos_thermal.c               |  158 ++++++++++--------------
>   3 files changed, 67 insertions(+), 108 deletions(-)
>
> diff --git a/Documentation/thermal/exynos_thermal_emulation b/Documentation/thermal/exynos_thermal_emulation
> index b73bbfb..36a3e79 100644
> --- a/Documentation/thermal/exynos_thermal_emulation
> +++ b/Documentation/thermal/exynos_thermal_emulation
> @@ -13,11 +13,11 @@ Thermal emulation mode supports software debug for TMU's operation. User can set
>   manually with software code and TMU will read current temperature from user value not from
>   sensor's value.
>
> -Enabling CONFIG_EXYNOS_THERMAL_EMUL option will make this support in available.
> -When it's enabled, sysfs node will be created under
> -/sys/bus/platform/devices/'exynos device name'/ with name of 'emulation'.
> +Enabling CONFIG_THERMAL_EMULATION option will make this support available.
> +When it's enabled, sysfs node will be created as
> +/sys/devices/virtual/thermal/thermal_zone'zone id'/emul_temp.
>
> -The sysfs node, 'emulation', will contain value 0 for the initial state. When you input any
> +The sysfs node, 'emul_node', will contain value 0 for the initial state. When you input any
>   temperature you want to update to sysfs node, it automatically enable emulation mode and
>   current temperature will be changed into it.
>   (Exynos also supports user changable delay time which would be used to delay of

not part of this patch but:
s/changable/changeable

> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index a764f16..da4c19e 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -117,15 +117,6 @@ config EXYNOS_THERMAL
>   	  If you say yes here you get support for TMU (Thermal Management
>   	  Unit) on SAMSUNG EXYNOS series of SoC.
>
> -config EXYNOS_THERMAL_EMUL
> -	bool "EXYNOS TMU emulation mode support"
> -	depends on EXYNOS_THERMAL
> -	help
> -	  Exynos 4412 and 4414 and 5 series has emulation mode on TMU.
> -	  Enable this option will be make sysfs node in exynos thermal platform
> -	  device directory to support emulation mode. With emulation mode sysfs
> -	  node, you can manually input temperature to TMU for simulation purpose.
> -
>   config DOVE_THERMAL
>   	tristate "Temperature sensor on Marvell Dove SoCs"
>   	depends on ARCH_DOVE
> diff --git a/drivers/thermal/exynos_thermal.c b/drivers/thermal/exynos_thermal.c
> index 46568c0..1cd7837 100644
> --- a/drivers/thermal/exynos_thermal.c
> +++ b/drivers/thermal/exynos_thermal.c
> @@ -100,13 +100,13 @@
>   #define IDLE_INTERVAL 10000
>   #define MCELSIUS	1000
>
> -#ifdef CONFIG_EXYNOS_THERMAL_EMUL
> +#ifdef CONFIG_THERMAL_EMULATION
>   #define EXYNOS_EMUL_TIME	0x57F0
>   #define EXYNOS_EMUL_TIME_SHIFT	16
>   #define EXYNOS_EMUL_DATA_SHIFT	8
>   #define EXYNOS_EMUL_DATA_MASK	0xFF
>   #define EXYNOS_EMUL_ENABLE	0x1
> -#endif /* CONFIG_EXYNOS_THERMAL_EMUL */
> +#endif /* CONFIG_THERMAL_EMULATION */
>

As the above is only used in one single function, I suggest moving it to 
same ifdef where the function belongs below. It reduces your ifdefery 
and also makes your code cleaner.


>   /* CPU Zone information */
>   #define PANIC_ZONE      4
> @@ -145,6 +145,7 @@ struct	thermal_cooling_conf {
>   struct thermal_sensor_conf {
>   	char name[SENSOR_NAME_LEN];
>   	int (*read_temperature)(void *data);
> +	int (*write_emul_temp)(void *drv_data, unsigned long temp);

I dont get why you  need a private callback to do this, assuming you 
have only one sensor_conf for exynos.

>   	struct thermal_trip_point_conf trip_data;
>   	struct thermal_cooling_conf cooling_data;
>   	void *private_data;
> @@ -369,6 +370,23 @@ static int exynos_get_temp(struct thermal_zone_device *thermal,
>   	return 0;
>   }
>
> +/* Get temperature callback functions for thermal zone */
> +static int exynos_set_emul_temp(struct thermal_zone_device *thermal,
> +						unsigned long temp)
> +{
> +	void *data;
> +	int ret = -EINVAL;

In case you still want to keep your private callback, Id say -ENOTSUPP 
is better for the case you dont have the callback.

> +
> +	if (!th_zone->sensor_conf) {
> +		pr_info("Temperature sensor not initialised\n");
> +		return -EINVAL;
> +	}
> +	data = th_zone->sensor_conf->private_data;
> +	if (th_zone->sensor_conf->write_emul_temp)
> +		ret = th_zone->sensor_conf->write_emul_temp(data, temp);

nip: a blank line.

> +	return ret;
> +}
> +
>   /* Get the temperature trend */
>   static int exynos_get_trend(struct thermal_zone_device *thermal,
>   			int trip, enum thermal_trend *trend)
> @@ -392,6 +410,7 @@ static struct thermal_zone_device_ops const exynos_dev_ops = {
>   	.bind = exynos_bind,
>   	.unbind = exynos_unbind,
>   	.get_temp = exynos_get_temp,
> +	.set_emul_temp = exynos_set_emul_temp,
>   	.get_trend = exynos_get_trend,
>   	.get_mode = exynos_get_mode,
>   	.set_mode = exynos_set_mode,
> @@ -714,6 +733,47 @@ static int exynos_tmu_read(struct exynos_tmu_data *data)
>   	return temp;
>   }
>
> +#ifdef CONFIG_THERMAL_EMULATION
>

I think your code looks cleaner if you move the defines at the beginning 
of your patch to this point.

+static int exynos_tmu_set_emulation(void *drv_data, unsigned long temp)
> +{
> +	struct exynos_tmu_data *data = drv_data;
> +	unsigned int reg;
> +	int ret = -EINVAL;
> +
> +	if (data->soc == SOC_ARCH_EXYNOS4210)
> +		goto out;
> +

Can you resolve this by not defining this callback for the 
SOC_ARCH_EXYNOS4210 thermal zone ops?


> +	if (temp && temp < MCELSIUS)
> +		goto out;
> +
> +	mutex_lock(&data->lock);
> +	clk_enable(data->clk);
> +
> +	reg = readl(data->base + EXYNOS_EMUL_CON);
> +
> +	if (temp) {
> +		temp /= MCELSIUS;
> +
> +		reg = (EXYNOS_EMUL_TIME << EXYNOS_EMUL_TIME_SHIFT) |
> +			(temp_to_code(data, temp)
> +			 << EXYNOS_EMUL_DATA_SHIFT) | EXYNOS_EMUL_ENABLE;
> +	} else {
> +		reg &= ~EXYNOS_EMUL_ENABLE;
> +	}
> +
> +	writel(reg, data->base + EXYNOS_EMUL_CON);
> +
> +	clk_disable(data->clk);
> +	mutex_unlock(&data->lock);

nip: blank line.

> +	return 0;
> +out:
> +	return ret;
> +}
> +#else
> +static int exynos_tmu_set_emulation(void *drv_data,	unsigned long temp)
unnecessary space                                     |

> +	{ return -EINVAL; }

I believe if you do a static inline function return 0, the compiler 
should translate it into a nope.

> +#endif/*CONFIG_THERMAL_EMULATION*/
> +
>   static void exynos_tmu_work(struct work_struct *work)
>   {
>   	struct exynos_tmu_data *data = container_of(work,
> @@ -747,6 +807,7 @@ static irqreturn_t exynos_tmu_irq(int irq, void *id)
>   static struct thermal_sensor_conf exynos_sensor_conf = {
>   	.name			= "exynos-therm",
>   	.read_temperature	= (int (*)(void *))exynos_tmu_read,
> +	.write_emul_temp	= exynos_tmu_set_emulation,
>   };
>
>   #if defined(CONFIG_CPU_EXYNOS4210)
> @@ -853,93 +914,6 @@ static inline struct  exynos_tmu_platform_data *exynos_get_driver_data(
>   			platform_get_device_id(pdev)->driver_data;
>   }
>
> -#ifdef CONFIG_EXYNOS_THERMAL_EMUL
> -static ssize_t exynos_tmu_emulation_show(struct device *dev,
> -					 struct device_attribute *attr,
> -					 char *buf)
> -{
> -	struct platform_device *pdev = container_of(dev,
> -					struct platform_device, dev);
> -	struct exynos_tmu_data *data = platform_get_drvdata(pdev);
> -	unsigned int reg;
> -	u8 temp_code;
> -	int temp = 0;
> -
> -	if (data->soc == SOC_ARCH_EXYNOS4210)
> -		goto out;
> -
> -	mutex_lock(&data->lock);
> -	clk_enable(data->clk);
> -	reg = readl(data->base + EXYNOS_EMUL_CON);
> -	clk_disable(data->clk);
> -	mutex_unlock(&data->lock);
> -
> -	if (reg & EXYNOS_EMUL_ENABLE) {
> -		reg >>= EXYNOS_EMUL_DATA_SHIFT;
> -		temp_code = reg & EXYNOS_EMUL_DATA_MASK;
> -		temp = code_to_temp(data, temp_code);
> -	}
> -out:
> -	return sprintf(buf, "%d\n", temp * MCELSIUS);
> -}
> -
> -static ssize_t exynos_tmu_emulation_store(struct device *dev,
> -					struct device_attribute *attr,
> -					const char *buf, size_t count)
> -{
> -	struct platform_device *pdev = container_of(dev,
> -					struct platform_device, dev);
> -	struct exynos_tmu_data *data = platform_get_drvdata(pdev);
> -	unsigned int reg;
> -	int temp;
> -
> -	if (data->soc == SOC_ARCH_EXYNOS4210)
> -		goto out;
> -
> -	if (!sscanf(buf, "%d\n", &temp) || temp < 0)
> -		return -EINVAL;
> -
> -	mutex_lock(&data->lock);
> -	clk_enable(data->clk);
> -
> -	reg = readl(data->base + EXYNOS_EMUL_CON);
> -
> -	if (temp) {
> -		/* Both CELSIUS and MCELSIUS type are available for input */
> -		if (temp > MCELSIUS)
> -			temp /= MCELSIUS;
> -
> -		reg = (EXYNOS_EMUL_TIME << EXYNOS_EMUL_TIME_SHIFT) |
> -			(temp_to_code(data, (temp / MCELSIUS))
> -			 << EXYNOS_EMUL_DATA_SHIFT) | EXYNOS_EMUL_ENABLE;
> -	} else {
> -		reg &= ~EXYNOS_EMUL_ENABLE;
> -	}
> -
> -	writel(reg, data->base + EXYNOS_EMUL_CON);
> -
> -	clk_disable(data->clk);
> -	mutex_unlock(&data->lock);
> -
> -out:
> -	return count;
> -}
> -
> -static DEVICE_ATTR(emulation, 0644, exynos_tmu_emulation_show,
> -					exynos_tmu_emulation_store);
> -static int create_emulation_sysfs(struct device *dev)
> -{
> -	return device_create_file(dev, &dev_attr_emulation);
> -}
> -static void remove_emulation_sysfs(struct device *dev)
> -{
> -	device_remove_file(dev, &dev_attr_emulation);
> -}
> -#else
> -static inline int create_emulation_sysfs(struct device *dev) { return 0; }
> -static inline void remove_emulation_sysfs(struct device *dev) {}
> -#endif
> -
>   static int exynos_tmu_probe(struct platform_device *pdev)
>   {
>   	struct exynos_tmu_data *data;
> @@ -1039,10 +1013,6 @@ static int exynos_tmu_probe(struct platform_device *pdev)
>   		goto err_clk;
>   	}
>
> -	ret = create_emulation_sysfs(&pdev->dev);
> -	if (ret)
> -		dev_err(&pdev->dev, "Failed to create emulation mode sysfs node\n");
> -
>   	return 0;
>   err_clk:
>   	platform_set_drvdata(pdev, NULL);
> @@ -1054,8 +1024,6 @@ static int exynos_tmu_remove(struct platform_device *pdev)
>   {
>   	struct exynos_tmu_data *data = platform_get_drvdata(pdev);
>
> -	remove_emulation_sysfs(&pdev->dev);
> -
>   	exynos_tmu_control(pdev, false);
>
>   	exynos_unregister_thermal();
>

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