Re: [PATCH 3/4] devfreq: exynos4: Add ppmu's clock control and code clean about regulator control

[Chanwoo Choi <cw00.choi@samsung.com>]

Hi Batlomiej,

On 03/13/2014 12:17 AM, Bartlomiej Zolnierkiewicz wrote:
> 
> Hi,
> 
> On Wednesday, March 12, 2014 08:48:01 PM Chanwoo Choi wrote:
>> There are not the clock controller of ppmudmc0/1. This patch control the clock
>> of ppmudmc0/1 which is used for monitoring memory bus utilization.
>>
>> Also, this patch code clean about regulator control and free resource
>> when calling exit/remove function.
>>
>> For example,
>> busfreq@106A0000 {
>> 	compatible = "samsung,exynos4x12-busfreq";
>>
>> 	/* Clock for PPMUDMC0/1 */
>> 	clocks = <&clock CLK_PPMUDMC0>, <&clock CLK_PPMUDMC1>;
>> 	clock-names = "ppmudmc0", "ppmudmc1";
>>
>> 	/* Regulator for MIF/INT block */
>> 	vdd_mif-supply = <&buck1_reg>;
>> 	vdd_int-supply = <&buck3_reg>;
>> };
> 
> This should be in Documentation/devicetree/bindings/ documentation.

OK, I will add documentation about it.

> 
>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
>> ---
>>  drivers/devfreq/exynos/exynos4_bus.c | 107 ++++++++++++++++++++++++++++++-----
>>  1 file changed, 93 insertions(+), 14 deletions(-)
>>
>> diff --git a/drivers/devfreq/exynos/exynos4_bus.c b/drivers/devfreq/exynos/exynos4_bus.c
>> index 16fb3cb..0c5b99e 100644
>> --- a/drivers/devfreq/exynos/exynos4_bus.c
>> +++ b/drivers/devfreq/exynos/exynos4_bus.c
>> @@ -62,6 +62,11 @@ enum exynos_ppmu_idx {
>>  	PPMU_END,
>>  };
>>  
>> +static const char *exynos_ppmu_clk_name[] = {
>> +	[PPMU_DMC0]	= "ppmudmc0",
>> +	[PPMU_DMC1]	= "ppmudmc1",
>> +};
>> +
>>  #define EX4210_LV_MAX	LV_2
>>  #define EX4x12_LV_MAX	LV_4
>>  #define EX4210_LV_NUM	(LV_2 + 1)
>> @@ -86,6 +91,7 @@ struct busfreq_data {
>>  	struct regulator *vdd_mif; /* Exynos4412/4212 only */
>>  	struct busfreq_opp_info curr_oppinfo;
>>  	struct exynos_ppmu ppmu[PPMU_END];
>> +	struct clk *clk_ppmu[PPMU_END];
>>  
>>  	struct notifier_block pm_notifier;
>>  	struct mutex lock;
>> @@ -722,8 +728,26 @@ static int exynos4_bus_get_dev_status(struct device *dev,
>>  static void exynos4_bus_exit(struct device *dev)
>>  {
>>  	struct busfreq_data *data = dev_get_drvdata(dev);
>> +	int i;
>>  
>> -	devfreq_unregister_opp_notifier(dev, data->devfreq);
>> +	/*
>> +	 * Un-map memory man and disable regulator/clocks
>> +	 * to prevent power leakage.
>> +	 */
>> +	regulator_disable(data->vdd_int);
>> +	if (data->type == TYPE_BUSF_EXYNOS4x12)
>> +		regulator_disable(data->vdd_mif);
>> +
>> +	for (i = 0; i < PPMU_END; i++) {
>> +		if (data->clk_ppmu[i])
>> +			clk_disable_unprepare(data->clk_ppmu[i]);
>> +	}
>> +
>> +	for (i = 0; i < PPMU_END; i++) {
>> +		if (data->ppmu[i].hw_base)
>> +			iounmap(data->ppmu[i].hw_base);
>> +
>> +	}
>>  }
>>  
>>  static struct devfreq_dev_profile exynos4_devfreq_profile = {
>> @@ -987,6 +1011,7 @@ static int exynos4_busfreq_parse_dt(struct busfreq_data *data)
>>  {
>>  	struct device *dev = data->dev;
>>  	struct device_node *np = dev->of_node;
>> +	const char **clk_name = exynos_ppmu_clk_name;
>>  	int i, ret;
>>  
>>  	if (!np) {
>> @@ -1005,8 +1030,67 @@ static int exynos4_busfreq_parse_dt(struct busfreq_data *data)
>>  		}
>>  	}
>>  
>> +	/*
>> +	 * Get PPMU's clocks to control them. But, if PPMU's clocks
>> +	 * is default 'pass' state, this driver don't need control
>> +	 * PPMU's clock.
>> +	 */
>> +	for (i = 0; i < PPMU_END; i++) {
>> +		data->clk_ppmu[i] = devm_clk_get(dev, clk_name[i]);
>> +		if (IS_ERR_OR_NULL(data->clk_ppmu[i])) {
>> +			dev_warn(dev, "Cannot get %s clock\n", clk_name[i]);
>> +			data->clk_ppmu[i] = NULL;
>> +		}
>> +
>> +		ret = clk_prepare_enable(data->clk_ppmu[i]);
>> +		if (ret < 0) {
>> +			dev_warn(dev, "Cannot enable %s clock\n", clk_name[i]);
>> +			data->clk_ppmu[i] = NULL;
>> +			goto err_clocks;
>> +		}
>> +	}
>> +
>> +
>> +	/* Get regulators to control voltage of int/mif block */
>> +	data->vdd_int = devm_regulator_get(dev, "vdd_int");
>> +	if (IS_ERR(data->vdd_int)) {
>> +		dev_err(dev, "Failed to get the regulator of vdd_int\n");
>> +		ret = PTR_ERR(data->vdd_int);
>> +		goto err_clocks;
>> +	}
>> +	ret = regulator_enable(data->vdd_int);
>> +	if (ret < 0) {
>> +		dev_err(dev, "Failed to enable regulator of vdd_int\n");
>> +		goto err_clocks;
>> +	}
>> +
>> +	switch (data->type) {
>> +	case TYPE_BUSF_EXYNOS4x12:
>> +		data->vdd_mif = devm_regulator_get(dev, "vdd_mif");
>> +		if (IS_ERR(data->vdd_mif)) {
>> +			dev_err(dev, "Failed to get the regulator vdd_mif\n");
>> +			ret = PTR_ERR(data->vdd_mif);
>> +			goto err_clocks;
> 
> This won't disable vdd_int regulator.

I don't understand. This patch contro/enable always vdd_int regualor as following:
	>> +	data->vdd_int = devm_regulator_get(dev, "vdd_int");
	>> +	ret = regulator_enable(data->vdd_int);
You can check this code on this patch. upper

> 
>> +		}
>> +		ret = regulator_enable(data->vdd_mif);
>> +		if (ret < 0) {
>> +			dev_err(dev, "Failed to enable regulator of vdd_mif\n");
>> +			goto err_clocks;
> 
> ditto

> 
>> +		}
>> +		break;
>> +	case TYPE_BUSF_EXYNOS4210:
>> +	default:
>> +		dev_err(data->dev, "Unknown device type\n");
>> +		return -EINVAL;
> 
> This looks very wrong for Exynos4210.

What is wrong for Exynos4210?
Always, exynos4210/exynos4x12 control vdd_int regulator uppper this patch.

> 
>> +	};
>> +
>>  	return 0;
>>  
>> +err_clocks:
>> +	for (i = 0; i < PPMU_END; i++) {
>> +		if (data->clk_ppmu[i])
>> +			clk_disable_unprepare(data->clk_ppmu[i]);
>> +	}
>>  err_iomap:
>>  	for (i = 0; i < PPMU_END; i++) {
>>  		if (data->ppmu[i].hw_base)
>> @@ -1068,19 +1152,6 @@ static int exynos4_busfreq_probe(struct platform_device *pdev)
>>  	if (err)
>>  		return err;
>>  
>> -	data->vdd_int = devm_regulator_get(dev, "vdd_int");
>> -	if (IS_ERR(data->vdd_int)) {
>> -		dev_err(dev, "Cannot get the regulator \"vdd_int\"\n");
>> -		return PTR_ERR(data->vdd_int);
>> -	}
>> -	if (data->type == TYPE_BUSF_EXYNOS4x12) {
>> -		data->vdd_mif = devm_regulator_get(dev, "vdd_mif");
>> -		if (IS_ERR(data->vdd_mif)) {
>> -			dev_err(dev, "Cannot get the regulator \"vdd_mif\"\n");
>> -			return PTR_ERR(data->vdd_mif);
>> -		}
>> -	}
>> -
>>  	rcu_read_lock();
>>  	opp = dev_pm_opp_find_freq_floor(dev,
>>  					 &exynos4_devfreq_profile.initial_freq);
>> @@ -1133,6 +1204,11 @@ err_notifier_opp:
>>  	devfreq_remove_device(data->devfreq);
>>  err_opp:
> 
> Disabling of regulators on failure is missing here.

OK, I'll control regulator.

Best Regard,
Chanwoo Choi