diff mbox series

[v6,2/3] reset-controller: ti: introduce a new reset handler

Message ID 20200930022159.5559-3-crystal.guo@mediatek.com (mailing list archive)
State New, archived
Headers show
Series introduce TI reset controller for MT8192 SoC | expand

Commit Message

Crystal Guo Sept. 30, 2020, 2:21 a.m. UTC
Introduce ti_syscon_reset() to integrate assert and deassert together.
If some modules need do serialized assert and deassert operations
to reset itself, reset_control_reset can be called for convenience.

Such as reset-qcom-aoss.c, it integrates assert and deassert together
by 'reset' method. MTK Socs also need this method to perform reset.

Signed-off-by: Crystal Guo <crystal.guo@mediatek.com>
---
 drivers/reset/reset-ti-syscon.c | 40 ++++++++++++++++++++++++++++++++-
 1 file changed, 39 insertions(+), 1 deletion(-)

Comments

Ikjoon Jang Nov. 30, 2020, 10:35 a.m. UTC | #1
On Wed, Sep 30, 2020 at 10:21:58AM +0800, Crystal Guo wrote:
> Introduce ti_syscon_reset() to integrate assert and deassert together.
> If some modules need do serialized assert and deassert operations
> to reset itself, reset_control_reset can be called for convenience.
> 
> Such as reset-qcom-aoss.c, it integrates assert and deassert together
> by 'reset' method. MTK Socs also need this method to perform reset.
> 
> Signed-off-by: Crystal Guo <crystal.guo@mediatek.com>

Reviewed-by: Ikjoon Jang <ikjn@chromium.org>

> ---
>  drivers/reset/reset-ti-syscon.c | 40 ++++++++++++++++++++++++++++++++-
>  1 file changed, 39 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/reset/reset-ti-syscon.c b/drivers/reset/reset-ti-syscon.c
> index a2635c21db7f..5d1f8306cd4f 100644
> --- a/drivers/reset/reset-ti-syscon.c
> +++ b/drivers/reset/reset-ti-syscon.c
> @@ -15,15 +15,22 @@
>   * GNU General Public License for more details.
>   */
>  
> +#include <linux/delay.h>
>  #include <linux/mfd/syscon.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/of_device.h>
>  #include <linux/platform_device.h>
>  #include <linux/regmap.h>
>  #include <linux/reset-controller.h>
>  
>  #include <dt-bindings/reset/ti-syscon.h>
>  
> +struct mediatek_reset_data {
> +	unsigned char *reset_bits;
> +	unsigned int reset_duration_us;
> +};
> +
>  /**
>   * struct ti_syscon_reset_control - reset control structure
>   * @assert_offset: reset assert control register offset from syscon base
> @@ -56,6 +63,7 @@ struct ti_syscon_reset_data {
>  	struct regmap *regmap;
>  	struct ti_syscon_reset_control *controls;
>  	unsigned int nr_controls;
> +	const struct mediatek_reset_data *reset_data;
>  };
>  
>  #define to_ti_syscon_reset_data(rcdev)	\
> @@ -158,9 +166,29 @@ static int ti_syscon_reset_status(struct reset_controller_dev *rcdev,
>  		!(control->flags & STATUS_SET);
>  }
>  
> +static int ti_syscon_reset(struct reset_controller_dev *rcdev,
> +				  unsigned long id)
> +{
> +	struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
> +	int ret;
> +
> +	if (data->reset_data) {
> +		ret = ti_syscon_reset_assert(rcdev, id);
> +		if (ret)
> +			return ret;
> +		usleep_range(data->reset_data->reset_duration_us,
> +			data->reset_data->reset_duration_us * 2);
> +

There are many users using assert() and deassert() seperately
without any delay between them.

If there's a timing requirement between assertion and deassertion,
shouldn't there be a same amount of delay in assert?

> +		return ti_syscon_reset_deassert(rcdev, id);
> +	} else {
> +		return -ENOTSUPP;
> +	}
> +}
> +
>  static const struct reset_control_ops ti_syscon_reset_ops = {
>  	.assert		= ti_syscon_reset_assert,
>  	.deassert	= ti_syscon_reset_deassert,
> +	.reset		= ti_syscon_reset,
>  	.status		= ti_syscon_reset_status,
>  };
>  
> @@ -182,7 +210,11 @@ static int ti_syscon_reset_probe(struct platform_device *pdev)
>  	if (IS_ERR(regmap))
>  		return PTR_ERR(regmap);
>  
> -	list = of_get_property(np, "ti,reset-bits", &size);
> +	data->reset_data = of_device_get_match_data(&pdev->dev);
> +	if (data->reset_data)
> +		list = of_get_property(np, data->reset_data->reset_bits, &size);
> +	else
> +		list = of_get_property(np, "ti,reset-bits", &size);
>  	if (!list || (size / sizeof(*list)) % 7 != 0) {
>  		dev_err(dev, "invalid DT reset description\n");
>  		return -EINVAL;
> @@ -217,8 +249,14 @@ static int ti_syscon_reset_probe(struct platform_device *pdev)
>  	return devm_reset_controller_register(dev, &data->rcdev);
>  }
>  
> +static const struct mediatek_reset_data mtk_reset_data = {
> +	.reset_bits = "mediatek,reset-bits",
> +	.reset_duration_us = 10,
> +};
> +
>  static const struct of_device_id ti_syscon_reset_of_match[] = {
>  	{ .compatible = "ti,syscon-reset", },
> +	{ .compatible = "mediatek,syscon-reset", .data = &mtk_reset_data},
>  	{ /* sentinel */ },
>  };
>  MODULE_DEVICE_TABLE(of, ti_syscon_reset_of_match);
Crystal Guo Dec. 4, 2020, 2:34 a.m. UTC | #2
On Mon, 2020-11-30 at 18:35 +0800, Ikjoon Jang wrote:
> On Wed, Sep 30, 2020 at 10:21:58AM +0800, Crystal Guo wrote:
> > Introduce ti_syscon_reset() to integrate assert and deassert together.
> > If some modules need do serialized assert and deassert operations
> > to reset itself, reset_control_reset can be called for convenience.
> > 
> > Such as reset-qcom-aoss.c, it integrates assert and deassert together
> > by 'reset' method. MTK Socs also need this method to perform reset.
> > 
> > Signed-off-by: Crystal Guo <crystal.guo@mediatek.com>
> 
> Reviewed-by: Ikjoon Jang <ikjn@chromium.org>
> 
> > ---
> >  drivers/reset/reset-ti-syscon.c | 40 ++++++++++++++++++++++++++++++++-
> >  1 file changed, 39 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/reset/reset-ti-syscon.c b/drivers/reset/reset-ti-syscon.c
> > index a2635c21db7f..5d1f8306cd4f 100644
> > --- a/drivers/reset/reset-ti-syscon.c
> > +++ b/drivers/reset/reset-ti-syscon.c
> > @@ -15,15 +15,22 @@
> >   * GNU General Public License for more details.
> >   */
> >  
> > +#include <linux/delay.h>
> >  #include <linux/mfd/syscon.h>
> >  #include <linux/module.h>
> >  #include <linux/of.h>
> > +#include <linux/of_device.h>
> >  #include <linux/platform_device.h>
> >  #include <linux/regmap.h>
> >  #include <linux/reset-controller.h>
> >  
> >  #include <dt-bindings/reset/ti-syscon.h>
> >  
> > +struct mediatek_reset_data {
> > +	unsigned char *reset_bits;
> > +	unsigned int reset_duration_us;
> > +};
> > +
> >  /**
> >   * struct ti_syscon_reset_control - reset control structure
> >   * @assert_offset: reset assert control register offset from syscon base
> > @@ -56,6 +63,7 @@ struct ti_syscon_reset_data {
> >  	struct regmap *regmap;
> >  	struct ti_syscon_reset_control *controls;
> >  	unsigned int nr_controls;
> > +	const struct mediatek_reset_data *reset_data;
> >  };
> >  
> >  #define to_ti_syscon_reset_data(rcdev)	\
> > @@ -158,9 +166,29 @@ static int ti_syscon_reset_status(struct reset_controller_dev *rcdev,
> >  		!(control->flags & STATUS_SET);
> >  }
> >  
> > +static int ti_syscon_reset(struct reset_controller_dev *rcdev,
> > +				  unsigned long id)
> > +{
> > +	struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
> > +	int ret;
> > +
> > +	if (data->reset_data) {
> > +		ret = ti_syscon_reset_assert(rcdev, id);
> > +		if (ret)
> > +			return ret;
> > +		usleep_range(data->reset_data->reset_duration_us,
> > +			data->reset_data->reset_duration_us * 2);
> > +
> 
> There are many users using assert() and deassert() seperately
> without any delay between them.
> 
> If there's a timing requirement between assertion and deassertion,
> shouldn't there be a same amount of delay in assert?

The "reset_duration_us" is an optional configuration to make the reset
operation more generic, which was added based on Philipp's comment in
[v2,4/6].

Thanks,
Crystal
> 
> > +		return ti_syscon_reset_deassert(rcdev, id);
> > +	} else {
> > +		return -ENOTSUPP;
> > +	}
> > +}
> > +
> >  static const struct reset_control_ops ti_syscon_reset_ops = {
> >  	.assert		= ti_syscon_reset_assert,
> >  	.deassert	= ti_syscon_reset_deassert,
> > +	.reset		= ti_syscon_reset,
> >  	.status		= ti_syscon_reset_status,
> >  };
> >  
> > @@ -182,7 +210,11 @@ static int ti_syscon_reset_probe(struct platform_device *pdev)
> >  	if (IS_ERR(regmap))
> >  		return PTR_ERR(regmap);
> >  
> > -	list = of_get_property(np, "ti,reset-bits", &size);
> > +	data->reset_data = of_device_get_match_data(&pdev->dev);
> > +	if (data->reset_data)
> > +		list = of_get_property(np, data->reset_data->reset_bits, &size);
> > +	else
> > +		list = of_get_property(np, "ti,reset-bits", &size);
> >  	if (!list || (size / sizeof(*list)) % 7 != 0) {
> >  		dev_err(dev, "invalid DT reset description\n");
> >  		return -EINVAL;
> > @@ -217,8 +249,14 @@ static int ti_syscon_reset_probe(struct platform_device *pdev)
> >  	return devm_reset_controller_register(dev, &data->rcdev);
> >  }
> >  
> > +static const struct mediatek_reset_data mtk_reset_data = {
> > +	.reset_bits = "mediatek,reset-bits",
> > +	.reset_duration_us = 10,
> > +};
> > +
> >  static const struct of_device_id ti_syscon_reset_of_match[] = {
> >  	{ .compatible = "ti,syscon-reset", },
> > +	{ .compatible = "mediatek,syscon-reset", .data = &mtk_reset_data},
> >  	{ /* sentinel */ },
> >  };
> >  MODULE_DEVICE_TABLE(of, ti_syscon_reset_of_match);
diff mbox series

Patch

diff --git a/drivers/reset/reset-ti-syscon.c b/drivers/reset/reset-ti-syscon.c
index a2635c21db7f..5d1f8306cd4f 100644
--- a/drivers/reset/reset-ti-syscon.c
+++ b/drivers/reset/reset-ti-syscon.c
@@ -15,15 +15,22 @@ 
  * GNU General Public License for more details.
  */
 
+#include <linux/delay.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/reset-controller.h>
 
 #include <dt-bindings/reset/ti-syscon.h>
 
+struct mediatek_reset_data {
+	unsigned char *reset_bits;
+	unsigned int reset_duration_us;
+};
+
 /**
  * struct ti_syscon_reset_control - reset control structure
  * @assert_offset: reset assert control register offset from syscon base
@@ -56,6 +63,7 @@  struct ti_syscon_reset_data {
 	struct regmap *regmap;
 	struct ti_syscon_reset_control *controls;
 	unsigned int nr_controls;
+	const struct mediatek_reset_data *reset_data;
 };
 
 #define to_ti_syscon_reset_data(rcdev)	\
@@ -158,9 +166,29 @@  static int ti_syscon_reset_status(struct reset_controller_dev *rcdev,
 		!(control->flags & STATUS_SET);
 }
 
+static int ti_syscon_reset(struct reset_controller_dev *rcdev,
+				  unsigned long id)
+{
+	struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
+	int ret;
+
+	if (data->reset_data) {
+		ret = ti_syscon_reset_assert(rcdev, id);
+		if (ret)
+			return ret;
+		usleep_range(data->reset_data->reset_duration_us,
+			data->reset_data->reset_duration_us * 2);
+
+		return ti_syscon_reset_deassert(rcdev, id);
+	} else {
+		return -ENOTSUPP;
+	}
+}
+
 static const struct reset_control_ops ti_syscon_reset_ops = {
 	.assert		= ti_syscon_reset_assert,
 	.deassert	= ti_syscon_reset_deassert,
+	.reset		= ti_syscon_reset,
 	.status		= ti_syscon_reset_status,
 };
 
@@ -182,7 +210,11 @@  static int ti_syscon_reset_probe(struct platform_device *pdev)
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);
 
-	list = of_get_property(np, "ti,reset-bits", &size);
+	data->reset_data = of_device_get_match_data(&pdev->dev);
+	if (data->reset_data)
+		list = of_get_property(np, data->reset_data->reset_bits, &size);
+	else
+		list = of_get_property(np, "ti,reset-bits", &size);
 	if (!list || (size / sizeof(*list)) % 7 != 0) {
 		dev_err(dev, "invalid DT reset description\n");
 		return -EINVAL;
@@ -217,8 +249,14 @@  static int ti_syscon_reset_probe(struct platform_device *pdev)
 	return devm_reset_controller_register(dev, &data->rcdev);
 }
 
+static const struct mediatek_reset_data mtk_reset_data = {
+	.reset_bits = "mediatek,reset-bits",
+	.reset_duration_us = 10,
+};
+
 static const struct of_device_id ti_syscon_reset_of_match[] = {
 	{ .compatible = "ti,syscon-reset", },
+	{ .compatible = "mediatek,syscon-reset", .data = &mtk_reset_data},
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, ti_syscon_reset_of_match);