diff mbox series

[v4,1/9] reset: amlogic: convert driver to regmap

Message ID 20240906-meson-rst-aux-v4-1-08824c3d108b@baylibre.com (mailing list archive)
State Superseded
Headers show
Series reset: amlogic: move audio reset drivers out of CCF | expand

Commit Message

Jerome Brunet Sept. 6, 2024, 1:34 p.m. UTC
To allow using the same driver for the main reset controller and the
auxiliary ones embedded in the clock controllers, convert the
the Amlogic reset driver to regmap.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/reset/reset-meson.c | 79 ++++++++++++++++++++++++---------------------
 1 file changed, 43 insertions(+), 36 deletions(-)

Comments

Philipp Zabel Sept. 6, 2024, 2:19 p.m. UTC | #1
On Fr, 2024-09-06 at 15:34 +0200, Jerome Brunet wrote:
> To allow using the same driver for the main reset controller and the
> auxiliary ones embedded in the clock controllers, convert the
> the Amlogic reset driver to regmap.
> 
> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
> ---
>  drivers/reset/reset-meson.c | 79 ++++++++++++++++++++++++---------------------

This patch should also make RESET_MESON select REGMAP.

>  1 file changed, 43 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/reset/reset-meson.c b/drivers/reset/reset-meson.c
> index 1e9fca3e30e8..9dd38cc209e2 100644
> --- a/drivers/reset/reset-meson.c
> +++ b/drivers/reset/reset-meson.c
> @@ -11,36 +11,43 @@
>  #include <linux/of.h>
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
> +#include <linux/regmap.h>
>  #include <linux/reset-controller.h>
>  #include <linux/slab.h>
>  #include <linux/types.h>
>  
> -#define BITS_PER_REG	32
> -
>  struct meson_reset_param {
>  	int reg_count;
>  	int level_offset;
>  };
>  
>  struct meson_reset {
> -	void __iomem *reg_base;
>  	const struct meson_reset_param *param;
>  	struct reset_controller_dev rcdev;
> -	spinlock_t lock;
> +	struct regmap *map;
>  };
>  
> +static void meson_reset_offset_and_bit(struct meson_reset *data,
> +				       unsigned long id,
> +				       unsigned int *offset,
> +				       unsigned int *bit)
> +{
> +	unsigned int stride = regmap_get_reg_stride(data->map);

You know this is always 4. Having a #define for this (that is also used
to initialize regmap_config.reg_stride, and for now nr_resets, below)
instead of going through an exported function would allow the compiler
to optimize this all away:

> +
> +	*offset = (id / (stride * BITS_PER_BYTE)) * stride;
> +	*bit = id % (stride * BITS_PER_BYTE);
> +}
> +
>  static int meson_reset_reset(struct reset_controller_dev *rcdev,
> -			      unsigned long id)
> +			     unsigned long id)
>  {
>  	struct meson_reset *data =
>  		container_of(rcdev, struct meson_reset, rcdev);
> -	unsigned int bank = id / BITS_PER_REG;
> -	unsigned int offset = id % BITS_PER_REG;
> -	void __iomem *reg_addr = data->reg_base + (bank << 2);
> +	unsigned int offset, bit;
>  
> -	writel(BIT(offset), reg_addr);
> +	meson_reset_offset_and_bit(data, id, &offset, &bit);
>  
> -	return 0;
> +	return regmap_write(data->map, offset, BIT(bit));
>  }
>  
>  static int meson_reset_level(struct reset_controller_dev *rcdev,
> @@ -48,25 +55,13 @@ static int meson_reset_level(struct reset_controller_dev *rcdev,
>  {
>  	struct meson_reset *data =
>  		container_of(rcdev, struct meson_reset, rcdev);
> -	unsigned int bank = id / BITS_PER_REG;
> -	unsigned int offset = id % BITS_PER_REG;
> -	void __iomem *reg_addr;
> -	unsigned long flags;
> -	u32 reg;
> +	unsigned int offset, bit;
>  
> -	reg_addr = data->reg_base + data->param->level_offset + (bank << 2);
> +	meson_reset_offset_and_bit(data, id, &offset, &bit);
> +	offset += data->param->level_offset;
>  
> -	spin_lock_irqsave(&data->lock, flags);
> -
> -	reg = readl(reg_addr);
> -	if (assert)
> -		writel(reg & ~BIT(offset), reg_addr);
> -	else
> -		writel(reg | BIT(offset), reg_addr);
> -
> -	spin_unlock_irqrestore(&data->lock, flags);
> -
> -	return 0;
> +	return regmap_update_bits(data->map, offset,
> +				  BIT(bit), assert ? 0 : BIT(bit));

Matter of taste, perhaps, but the BIT() could be moved into
meson_reset_offset_and_bit().

>  }
>  
>  static int meson_reset_assert(struct reset_controller_dev *rcdev,
> @@ -119,30 +114,42 @@ static const struct of_device_id meson_reset_dt_ids[] = {
>  };
>  MODULE_DEVICE_TABLE(of, meson_reset_dt_ids);
>  
> +static const struct regmap_config regmap_config = {
> +	.reg_bits   = 32,
> +	.val_bits   = 32,
> +	.reg_stride = 4,
> +};
> +
>  static int meson_reset_probe(struct platform_device *pdev)
>  {
> +	struct device *dev = &pdev->dev;
>  	struct meson_reset *data;
> +	void __iomem *base;
>  
> -	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>  	if (!data)
>  		return -ENOMEM;
>  
> -	data->reg_base = devm_platform_ioremap_resource(pdev, 0);
> -	if (IS_ERR(data->reg_base))
> -		return PTR_ERR(data->reg_base);
> +	base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(base))
> +		return PTR_ERR(base);
>  
> -	data->param = of_device_get_match_data(&pdev->dev);
> +	data->param = of_device_get_match_data(dev);
>  	if (!data->param)
>  		return -ENODEV;
>  
> -	spin_lock_init(&data->lock);
> +	data->map = devm_regmap_init_mmio(dev, base, &regmap_config);
> +	if (IS_ERR(data->map))
> +		return dev_err_probe(dev, PTR_ERR(data->map),
> +				     "can't init regmap mmio region\n");
>  
>  	data->rcdev.owner = THIS_MODULE;
> -	data->rcdev.nr_resets = data->param->reg_count * BITS_PER_REG;
> +	data->rcdev.nr_resets = data->param->reg_count * BITS_PER_BYTE
> +		* regmap_config.reg_stride;
>  	data->rcdev.ops = &meson_reset_ops;
> -	data->rcdev.of_node = pdev->dev.of_node;
> +	data->rcdev.of_node = dev->of_node;
>  
> -	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
> +	return devm_reset_controller_register(dev, &data->rcdev);
>  }
>  
>  static struct platform_driver meson_reset_driver = {

regards
Philipp
Jerome Brunet Sept. 6, 2024, 2:46 p.m. UTC | #2
On Fri 06 Sep 2024 at 16:19, Philipp Zabel <p.zabel@pengutronix.de> wrote:

> On Fr, 2024-09-06 at 15:34 +0200, Jerome Brunet wrote:
>> To allow using the same driver for the main reset controller and the
>> auxiliary ones embedded in the clock controllers, convert the
>> the Amlogic reset driver to regmap.
>> 
>> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
>> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
>> ---
>>  drivers/reset/reset-meson.c | 79 ++++++++++++++++++++++++---------------------
>
> This patch should also make RESET_MESON select REGMAP.

Indeed

>
>>  1 file changed, 43 insertions(+), 36 deletions(-)
>> 
>> diff --git a/drivers/reset/reset-meson.c b/drivers/reset/reset-meson.c
>> index 1e9fca3e30e8..9dd38cc209e2 100644
>> --- a/drivers/reset/reset-meson.c
>> +++ b/drivers/reset/reset-meson.c
>> @@ -11,36 +11,43 @@
>>  #include <linux/of.h>
>>  #include <linux/module.h>
>>  #include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>>  #include <linux/reset-controller.h>
>>  #include <linux/slab.h>
>>  #include <linux/types.h>
>>  
>> -#define BITS_PER_REG	32
>> -
>>  struct meson_reset_param {
>>  	int reg_count;
>>  	int level_offset;
>>  };
>>  
>>  struct meson_reset {
>> -	void __iomem *reg_base;
>>  	const struct meson_reset_param *param;
>>  	struct reset_controller_dev rcdev;
>> -	spinlock_t lock;
>> +	struct regmap *map;
>>  };
>>  
>> +static void meson_reset_offset_and_bit(struct meson_reset *data,
>> +				       unsigned long id,
>> +				       unsigned int *offset,
>> +				       unsigned int *bit)
>> +{
>> +	unsigned int stride = regmap_get_reg_stride(data->map);
>
> You know this is always 4. Having a #define for this (that is also used
> to initialize regmap_config.reg_stride, and for now nr_resets, below)
> instead of going through an exported function would allow the compiler
> to optimize this all away:

Yes, for now. However, with the auxiliary you may get a regmap with
different value. I've seen example with stride = 1. 

I'll admit is very unlikely but I does not really worth it considering
how often we'll get through this and how difficult it will be to debug
if stride ever get different.

>
>> +
>> +	*offset = (id / (stride * BITS_PER_BYTE)) * stride;
>> +	*bit = id % (stride * BITS_PER_BYTE);
>> +}
>> +
>>  static int meson_reset_reset(struct reset_controller_dev *rcdev,
>> -			      unsigned long id)
>> +			     unsigned long id)
>>  {
>>  	struct meson_reset *data =
>>  		container_of(rcdev, struct meson_reset, rcdev);
>> -	unsigned int bank = id / BITS_PER_REG;
>> -	unsigned int offset = id % BITS_PER_REG;
>> -	void __iomem *reg_addr = data->reg_base + (bank << 2);
>> +	unsigned int offset, bit;
>>  
>> -	writel(BIT(offset), reg_addr);
>> +	meson_reset_offset_and_bit(data, id, &offset, &bit);
>>  
>> -	return 0;
>> +	return regmap_write(data->map, offset, BIT(bit));
>>  }
>>  
>>  static int meson_reset_level(struct reset_controller_dev *rcdev,
>> @@ -48,25 +55,13 @@ static int meson_reset_level(struct reset_controller_dev *rcdev,
>>  {
>>  	struct meson_reset *data =
>>  		container_of(rcdev, struct meson_reset, rcdev);
>> -	unsigned int bank = id / BITS_PER_REG;
>> -	unsigned int offset = id % BITS_PER_REG;
>> -	void __iomem *reg_addr;
>> -	unsigned long flags;
>> -	u32 reg;
>> +	unsigned int offset, bit;
>>  
>> -	reg_addr = data->reg_base + data->param->level_offset + (bank << 2);
>> +	meson_reset_offset_and_bit(data, id, &offset, &bit);
>> +	offset += data->param->level_offset;
>>  
>> -	spin_lock_irqsave(&data->lock, flags);
>> -
>> -	reg = readl(reg_addr);
>> -	if (assert)
>> -		writel(reg & ~BIT(offset), reg_addr);
>> -	else
>> -		writel(reg | BIT(offset), reg_addr);
>> -
>> -	spin_unlock_irqrestore(&data->lock, flags);
>> -
>> -	return 0;
>> +	return regmap_update_bits(data->map, offset,
>> +				  BIT(bit), assert ? 0 : BIT(bit));
>
> Matter of taste, perhaps, but the BIT() could be moved into
> meson_reset_offset_and_bit().

It's not really related to this particular patch which is about moving
to regmap.

I can add it to another patch if you want

>
>>  }
>>  
>>  static int meson_reset_assert(struct reset_controller_dev *rcdev,
>> @@ -119,30 +114,42 @@ static const struct of_device_id meson_reset_dt_ids[] = {
>>  };
>>  MODULE_DEVICE_TABLE(of, meson_reset_dt_ids);
>>  
>> +static const struct regmap_config regmap_config = {
>> +	.reg_bits   = 32,
>> +	.val_bits   = 32,
>> +	.reg_stride = 4,
>> +};
>> +
>>  static int meson_reset_probe(struct platform_device *pdev)
>>  {
>> +	struct device *dev = &pdev->dev;
>>  	struct meson_reset *data;
>> +	void __iomem *base;
>>  
>> -	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
>> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>>  	if (!data)
>>  		return -ENOMEM;
>>  
>> -	data->reg_base = devm_platform_ioremap_resource(pdev, 0);
>> -	if (IS_ERR(data->reg_base))
>> -		return PTR_ERR(data->reg_base);
>> +	base = devm_platform_ioremap_resource(pdev, 0);
>> +	if (IS_ERR(base))
>> +		return PTR_ERR(base);
>>  
>> -	data->param = of_device_get_match_data(&pdev->dev);
>> +	data->param = of_device_get_match_data(dev);
>>  	if (!data->param)
>>  		return -ENODEV;
>>  
>> -	spin_lock_init(&data->lock);
>> +	data->map = devm_regmap_init_mmio(dev, base, &regmap_config);
>> +	if (IS_ERR(data->map))
>> +		return dev_err_probe(dev, PTR_ERR(data->map),
>> +				     "can't init regmap mmio region\n");
>>  
>>  	data->rcdev.owner = THIS_MODULE;
>> -	data->rcdev.nr_resets = data->param->reg_count * BITS_PER_REG;
>> +	data->rcdev.nr_resets = data->param->reg_count * BITS_PER_BYTE
>> +		* regmap_config.reg_stride;
>>  	data->rcdev.ops = &meson_reset_ops;
>> -	data->rcdev.of_node = pdev->dev.of_node;
>> +	data->rcdev.of_node = dev->of_node;
>>  
>> -	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
>> +	return devm_reset_controller_register(dev, &data->rcdev);
>>  }
>>  
>>  static struct platform_driver meson_reset_driver = {
>
> regards
> Philipp
Philipp Zabel Sept. 10, 2024, 8:20 a.m. UTC | #3
On Fr, 2024-09-06 at 16:46 +0200, Jerome Brunet wrote:
> On Fri 06 Sep 2024 at 16:19, Philipp Zabel <p.zabel@pengutronix.de> wrote:
> > On Fr, 2024-09-06 at 15:34 +0200, Jerome Brunet wrote:
[...]
> > > +static void meson_reset_offset_and_bit(struct meson_reset *data,
> > > +				       unsigned long id,
> > > +				       unsigned int *offset,
> > > +				       unsigned int *bit)
> > > +{
> > > +	unsigned int stride = regmap_get_reg_stride(data->map);
> > 
> > You know this is always 4. Having a #define for this (that is also used
> > to initialize regmap_config.reg_stride, and for now nr_resets, below)
> > instead of going through an exported function would allow the compiler
> > to optimize this all away:
> 
> Yes, for now. However, with the auxiliary you may get a regmap with
> different value. I've seen example with stride = 1. 
> 
> I'll admit is very unlikely but I does not really worth it considering
> how often we'll get through this and how difficult it will be to debug
> if stride ever get different.

Oh right, the aux regmap being passed in from the outside in a later
patch invalidates my point.

[...]
> > > @@ -48,25 +55,13 @@ static int meson_reset_level(struct reset_controller_dev *rcdev,
> > >  {
> > >  	struct meson_reset *data =
> > >  		container_of(rcdev, struct meson_reset, rcdev);
> > > -	unsigned int bank = id / BITS_PER_REG;
> > > -	unsigned int offset = id % BITS_PER_REG;
> > > -	void __iomem *reg_addr;
> > > -	unsigned long flags;
> > > -	u32 reg;
> > > +	unsigned int offset, bit;
> > >  
> > > -	reg_addr = data->reg_base + data->param->level_offset + (bank << 2);
> > > +	meson_reset_offset_and_bit(data, id, &offset, &bit);
> > > +	offset += data->param->level_offset;
> > >  
> > > -	spin_lock_irqsave(&data->lock, flags);
> > > -
> > > -	reg = readl(reg_addr);
> > > -	if (assert)
> > > -		writel(reg & ~BIT(offset), reg_addr);
> > > -	else
> > > -		writel(reg | BIT(offset), reg_addr);
> > > -
> > > -	spin_unlock_irqrestore(&data->lock, flags);
> > > -
> > > -	return 0;
> > > +	return regmap_update_bits(data->map, offset,
> > > +				  BIT(bit), assert ? 0 : BIT(bit));
> > 
> > Matter of taste, perhaps, but the BIT() could be moved into
> > meson_reset_offset_and_bit().
> 
> It's not really related to this particular patch which is about moving
> to regmap.
> 
> I can add it to another patch if you want

Either way is fine.


regards
Philipp
diff mbox series

Patch

diff --git a/drivers/reset/reset-meson.c b/drivers/reset/reset-meson.c
index 1e9fca3e30e8..9dd38cc209e2 100644
--- a/drivers/reset/reset-meson.c
+++ b/drivers/reset/reset-meson.c
@@ -11,36 +11,43 @@ 
 #include <linux/of.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/reset-controller.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 
-#define BITS_PER_REG	32
-
 struct meson_reset_param {
 	int reg_count;
 	int level_offset;
 };
 
 struct meson_reset {
-	void __iomem *reg_base;
 	const struct meson_reset_param *param;
 	struct reset_controller_dev rcdev;
-	spinlock_t lock;
+	struct regmap *map;
 };
 
+static void meson_reset_offset_and_bit(struct meson_reset *data,
+				       unsigned long id,
+				       unsigned int *offset,
+				       unsigned int *bit)
+{
+	unsigned int stride = regmap_get_reg_stride(data->map);
+
+	*offset = (id / (stride * BITS_PER_BYTE)) * stride;
+	*bit = id % (stride * BITS_PER_BYTE);
+}
+
 static int meson_reset_reset(struct reset_controller_dev *rcdev,
-			      unsigned long id)
+			     unsigned long id)
 {
 	struct meson_reset *data =
 		container_of(rcdev, struct meson_reset, rcdev);
-	unsigned int bank = id / BITS_PER_REG;
-	unsigned int offset = id % BITS_PER_REG;
-	void __iomem *reg_addr = data->reg_base + (bank << 2);
+	unsigned int offset, bit;
 
-	writel(BIT(offset), reg_addr);
+	meson_reset_offset_and_bit(data, id, &offset, &bit);
 
-	return 0;
+	return regmap_write(data->map, offset, BIT(bit));
 }
 
 static int meson_reset_level(struct reset_controller_dev *rcdev,
@@ -48,25 +55,13 @@  static int meson_reset_level(struct reset_controller_dev *rcdev,
 {
 	struct meson_reset *data =
 		container_of(rcdev, struct meson_reset, rcdev);
-	unsigned int bank = id / BITS_PER_REG;
-	unsigned int offset = id % BITS_PER_REG;
-	void __iomem *reg_addr;
-	unsigned long flags;
-	u32 reg;
+	unsigned int offset, bit;
 
-	reg_addr = data->reg_base + data->param->level_offset + (bank << 2);
+	meson_reset_offset_and_bit(data, id, &offset, &bit);
+	offset += data->param->level_offset;
 
-	spin_lock_irqsave(&data->lock, flags);
-
-	reg = readl(reg_addr);
-	if (assert)
-		writel(reg & ~BIT(offset), reg_addr);
-	else
-		writel(reg | BIT(offset), reg_addr);
-
-	spin_unlock_irqrestore(&data->lock, flags);
-
-	return 0;
+	return regmap_update_bits(data->map, offset,
+				  BIT(bit), assert ? 0 : BIT(bit));
 }
 
 static int meson_reset_assert(struct reset_controller_dev *rcdev,
@@ -119,30 +114,42 @@  static const struct of_device_id meson_reset_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, meson_reset_dt_ids);
 
+static const struct regmap_config regmap_config = {
+	.reg_bits   = 32,
+	.val_bits   = 32,
+	.reg_stride = 4,
+};
+
 static int meson_reset_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct meson_reset *data;
+	void __iomem *base;
 
-	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
-	data->reg_base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(data->reg_base))
-		return PTR_ERR(data->reg_base);
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
 
-	data->param = of_device_get_match_data(&pdev->dev);
+	data->param = of_device_get_match_data(dev);
 	if (!data->param)
 		return -ENODEV;
 
-	spin_lock_init(&data->lock);
+	data->map = devm_regmap_init_mmio(dev, base, &regmap_config);
+	if (IS_ERR(data->map))
+		return dev_err_probe(dev, PTR_ERR(data->map),
+				     "can't init regmap mmio region\n");
 
 	data->rcdev.owner = THIS_MODULE;
-	data->rcdev.nr_resets = data->param->reg_count * BITS_PER_REG;
+	data->rcdev.nr_resets = data->param->reg_count * BITS_PER_BYTE
+		* regmap_config.reg_stride;
 	data->rcdev.ops = &meson_reset_ops;
-	data->rcdev.of_node = pdev->dev.of_node;
+	data->rcdev.of_node = dev->of_node;
 
-	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
+	return devm_reset_controller_register(dev, &data->rcdev);
 }
 
 static struct platform_driver meson_reset_driver = {