diff mbox series

[4/8] soc: ti: omap-prm: add support for denying idle for reset clockdomain

Message ID 1565164139-21886-5-git-send-email-t-kristo@ti.com (mailing list archive)
State New, archived
Headers show
Series soc: ti: Add OMAP PRM driver | expand

Commit Message

Tero Kristo Aug. 7, 2019, 7:48 a.m. UTC 
TI SoCs hardware reset signals require the parent clockdomain to be
in force wakeup mode while de-asserting the reset, otherwise it may
never complete. To support this, add pdata hooks to control the
clockdomain directly.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
---
 drivers/soc/ti/omap_prm.c            | 32 ++++++++++++++++++++++++++++----
 include/linux/platform_data/ti-prm.h | 21 +++++++++++++++++++++
 2 files changed, 49 insertions(+), 4 deletions(-)
 create mode 100644 include/linux/platform_data/ti-prm.h

Comments

Suman Anna Aug. 19, 2019, 11:16 p.m. UTC | #1 
Hi Tero,

On 8/7/19 2:48 AM, Tero Kristo wrote:
> TI SoCs hardware reset signals require the parent clockdomain to be
> in force wakeup mode while de-asserting the reset, otherwise it may
> never complete. To support this, add pdata hooks to control the
> clockdomain directly.
> 
> Signed-off-by: Tero Kristo <t-kristo@ti.com>
> ---
>  drivers/soc/ti/omap_prm.c            | 32 ++++++++++++++++++++++++++++----
>  include/linux/platform_data/ti-prm.h | 21 +++++++++++++++++++++
>  2 files changed, 49 insertions(+), 4 deletions(-)
>  create mode 100644 include/linux/platform_data/ti-prm.h
> 
> diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c
> index d412af3..870515e3 100644
> --- a/drivers/soc/ti/omap_prm.c
> +++ b/drivers/soc/ti/omap_prm.c
> @@ -16,6 +16,8 @@
>  #include <linux/reset-controller.h>
>  #include <linux/delay.h>
>  
> +#include <linux/platform_data/ti-prm.h>
> +
>  struct omap_rst_map {
>  	s8 rst;
>  	s8 st;
> @@ -24,6 +26,7 @@ struct omap_rst_map {
>  struct omap_prm_data {
>  	u32 base;
>  	const char *name;
> +	const char *clkdm_name;
>  	u16 pwstctrl;
>  	u16 pwstst;
>  	u16 rstctl;
> @@ -40,6 +43,8 @@ struct omap_prm {
>  struct omap_reset_data {
>  	struct reset_controller_dev rcdev;
>  	struct omap_prm *prm;
> +	struct clockdomain *clkdm;
> +	struct device *dev;
>  };
>  
>  #define to_omap_reset_data(p) container_of((p), struct omap_reset_data, rcdev)
> @@ -108,6 +113,8 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
>  	int st_bit = id;
>  	bool has_rstst;
>  	int timeout = 0;
> +	struct ti_prm_platform_data *pdata = dev_get_platdata(reset->dev);
> +	int ret = 0;
>  
>  	/* check the current status to avoid de-asserting the line twice */
>  	v = readl_relaxed(reset->prm->base + reset->prm->data->rstctl);
> @@ -125,13 +132,16 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
>  		writel_relaxed(v, reset->prm->base + reset->prm->data->rstst);
>  	}
>  
> +	if (pdata->clkdm_deny_idle && reset->clkdm)
> +		pdata->clkdm_deny_idle(reset->clkdm);
> +
>  	/* de-assert the reset control line */
>  	v = readl_relaxed(reset->prm->base + reset->prm->data->rstctl);
>  	v &= ~(1 << id);
>  	writel_relaxed(v, reset->prm->base + reset->prm->data->rstctl);
>  
>  	if (!has_rstst)
> -		return 0;
> +		goto exit;
>  
>  	/* wait for the status to be set */
>  	while (1) {
> @@ -140,13 +150,19 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
>  		if (v)
>  			break;
>  		timeout++;
> -		if (timeout > OMAP_RESET_MAX_WAIT)
> -			return -EBUSY;
> +		if (timeout > OMAP_RESET_MAX_WAIT) {
> +			ret = -EBUSY;
> +			goto exit;
> +		}
>  
>  		udelay(1);
>  	}
>  
> -	return 0;
> +exit:
> +	if (pdata->clkdm_allow_idle && reset->clkdm)
> +		pdata->clkdm_allow_idle(reset->clkdm);
> +
> +	return ret;
>  }
>  
>  static const struct reset_control_ops omap_reset_ops = {
> @@ -159,6 +175,8 @@ static int omap_prm_reset_probe(struct platform_device *pdev,
>  				struct omap_prm *prm)
>  {
>  	struct omap_reset_data *reset;
> +	struct ti_prm_platform_data *pdata = dev_get_platdata(&pdev->dev);

Please add checks for NULL callbacks. I don't think these are optional
right, so better to check in init rather than during runtime. Granted
you will probably not run into this after patch 8, but would be good to
check and print an error in case pdata quirks is missed out.

> +	char buf[32];
>  
>  	/*
>  	 * Check if we have resets. If either rstctl or rstst is
> @@ -177,9 +195,15 @@ static int omap_prm_reset_probe(struct platform_device *pdev,
>  	reset->rcdev.ops = &omap_reset_ops;
>  	reset->rcdev.of_node = pdev->dev.of_node;
>  	reset->rcdev.nr_resets = OMAP_MAX_RESETS;
> +	reset->dev = &pdev->dev;
>  
>  	reset->prm = prm;
>  
> +	sprintf(buf, "%s_clkdm", prm->data->clkdm_name ? prm->data->clkdm_name :
> +		prm->data->name);
> +
> +	reset->clkdm = pdata->clkdm_lookup(buf);

Not checking return status?

regards
Suman

> +
>  	return devm_reset_controller_register(&pdev->dev, &reset->rcdev);
>  }
>  
> diff --git a/include/linux/platform_data/ti-prm.h b/include/linux/platform_data/ti-prm.h
> new file mode 100644
> index 0000000..28154c3
> --- /dev/null
> +++ b/include/linux/platform_data/ti-prm.h
> @@ -0,0 +1,21 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * TI PRM (Power & Reset Manager) platform data
> + *
> + * Copyright (C) 2019 Texas Instruments, Inc.
> + *
> + * Tero Kristo <t-kristo@ti.com>
> + */
> +
> +#ifndef _LINUX_PLATFORM_DATA_TI_PRM_H
> +#define _LINUX_PLATFORM_DATA_TI_PRM_H
> +
> +struct clockdomain;
> +
> +struct ti_prm_platform_data {
> +	void (*clkdm_deny_idle)(struct clockdomain *clkdm);
> +	void (*clkdm_allow_idle)(struct clockdomain *clkdm);
> +	struct clockdomain * (*clkdm_lookup)(const char *name);
> +};
> +
> +#endif /* _LINUX_PLATFORM_DATA_TI_PRM_H */
>
Tero Kristo Aug. 20, 2019, 7:51 a.m. UTC | #2 
On 20.8.2019 2.16, Suman Anna wrote:
> Hi Tero,
> 
> On 8/7/19 2:48 AM, Tero Kristo wrote:
>> TI SoCs hardware reset signals require the parent clockdomain to be
>> in force wakeup mode while de-asserting the reset, otherwise it may
>> never complete. To support this, add pdata hooks to control the
>> clockdomain directly.
>>
>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>> ---
>>   drivers/soc/ti/omap_prm.c            | 32 ++++++++++++++++++++++++++++----
>>   include/linux/platform_data/ti-prm.h | 21 +++++++++++++++++++++
>>   2 files changed, 49 insertions(+), 4 deletions(-)
>>   create mode 100644 include/linux/platform_data/ti-prm.h
>>
>> diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c
>> index d412af3..870515e3 100644
>> --- a/drivers/soc/ti/omap_prm.c
>> +++ b/drivers/soc/ti/omap_prm.c
>> @@ -16,6 +16,8 @@
>>   #include <linux/reset-controller.h>
>>   #include <linux/delay.h>
>>   
>> +#include <linux/platform_data/ti-prm.h>
>> +
>>   struct omap_rst_map {
>>   	s8 rst;
>>   	s8 st;
>> @@ -24,6 +26,7 @@ struct omap_rst_map {
>>   struct omap_prm_data {
>>   	u32 base;
>>   	const char *name;
>> +	const char *clkdm_name;
>>   	u16 pwstctrl;
>>   	u16 pwstst;
>>   	u16 rstctl;
>> @@ -40,6 +43,8 @@ struct omap_prm {
>>   struct omap_reset_data {
>>   	struct reset_controller_dev rcdev;
>>   	struct omap_prm *prm;
>> +	struct clockdomain *clkdm;
>> +	struct device *dev;
>>   };
>>   
>>   #define to_omap_reset_data(p) container_of((p), struct omap_reset_data, rcdev)
>> @@ -108,6 +113,8 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
>>   	int st_bit = id;
>>   	bool has_rstst;
>>   	int timeout = 0;
>> +	struct ti_prm_platform_data *pdata = dev_get_platdata(reset->dev);
>> +	int ret = 0;
>>   
>>   	/* check the current status to avoid de-asserting the line twice */
>>   	v = readl_relaxed(reset->prm->base + reset->prm->data->rstctl);
>> @@ -125,13 +132,16 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
>>   		writel_relaxed(v, reset->prm->base + reset->prm->data->rstst);
>>   	}
>>   
>> +	if (pdata->clkdm_deny_idle && reset->clkdm)
>> +		pdata->clkdm_deny_idle(reset->clkdm);
>> +
>>   	/* de-assert the reset control line */
>>   	v = readl_relaxed(reset->prm->base + reset->prm->data->rstctl);
>>   	v &= ~(1 << id);
>>   	writel_relaxed(v, reset->prm->base + reset->prm->data->rstctl);
>>   
>>   	if (!has_rstst)
>> -		return 0;
>> +		goto exit;
>>   
>>   	/* wait for the status to be set */
>>   	while (1) {
>> @@ -140,13 +150,19 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
>>   		if (v)
>>   			break;
>>   		timeout++;
>> -		if (timeout > OMAP_RESET_MAX_WAIT)
>> -			return -EBUSY;
>> +		if (timeout > OMAP_RESET_MAX_WAIT) {
>> +			ret = -EBUSY;
>> +			goto exit;
>> +		}
>>   
>>   		udelay(1);
>>   	}
>>   
>> -	return 0;
>> +exit:
>> +	if (pdata->clkdm_allow_idle && reset->clkdm)
>> +		pdata->clkdm_allow_idle(reset->clkdm);
>> +
>> +	return ret;
>>   }
>>   
>>   static const struct reset_control_ops omap_reset_ops = {
>> @@ -159,6 +175,8 @@ static int omap_prm_reset_probe(struct platform_device *pdev,
>>   				struct omap_prm *prm)
>>   {
>>   	struct omap_reset_data *reset;
>> +	struct ti_prm_platform_data *pdata = dev_get_platdata(&pdev->dev);
> 
> Please add checks for NULL callbacks. I don't think these are optional
> right, so better to check in init rather than during runtime. Granted
> you will probably not run into this after patch 8, but would be good to
> check and print an error in case pdata quirks is missed out.

Hmm ok, this would get rid of the runtime checks which would be slightly 
cleaner.

> 
>> +	char buf[32];
>>   
>>   	/*
>>   	 * Check if we have resets. If either rstctl or rstst is
>> @@ -177,9 +195,15 @@ static int omap_prm_reset_probe(struct platform_device *pdev,
>>   	reset->rcdev.ops = &omap_reset_ops;
>>   	reset->rcdev.of_node = pdev->dev.of_node;
>>   	reset->rcdev.nr_resets = OMAP_MAX_RESETS;
>> +	reset->dev = &pdev->dev;
>>   
>>   	reset->prm = prm;
>>   
>> +	sprintf(buf, "%s_clkdm", prm->data->clkdm_name ? prm->data->clkdm_name :
>> +		prm->data->name);
>> +
>> +	reset->clkdm = pdata->clkdm_lookup(buf);
> 
> Not checking return status?

clkdm will just end up being NULL in failure, which is fine for rest of 
the code. I don't think it can be ever NULL though, so I can add a check 
here for sanity.

-Tero

> 
> regards
> Suman
> 
>> +
>>   	return devm_reset_controller_register(&pdev->dev, &reset->rcdev);
>>   }
>>   
>> diff --git a/include/linux/platform_data/ti-prm.h b/include/linux/platform_data/ti-prm.h
>> new file mode 100644
>> index 0000000..28154c3
>> --- /dev/null
>> +++ b/include/linux/platform_data/ti-prm.h
>> @@ -0,0 +1,21 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * TI PRM (Power & Reset Manager) platform data
>> + *
>> + * Copyright (C) 2019 Texas Instruments, Inc.
>> + *
>> + * Tero Kristo <t-kristo@ti.com>
>> + */
>> +
>> +#ifndef _LINUX_PLATFORM_DATA_TI_PRM_H
>> +#define _LINUX_PLATFORM_DATA_TI_PRM_H
>> +
>> +struct clockdomain;
>> +
>> +struct ti_prm_platform_data {
>> +	void (*clkdm_deny_idle)(struct clockdomain *clkdm);
>> +	void (*clkdm_allow_idle)(struct clockdomain *clkdm);
>> +	struct clockdomain * (*clkdm_lookup)(const char *name);
>> +};
>> +
>> +#endif /* _LINUX_PLATFORM_DATA_TI_PRM_H */
>>
> 

--
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diff mbox series

Patch

diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c
index d412af3..870515e3 100644
--- a/drivers/soc/ti/omap_prm.c
+++ b/drivers/soc/ti/omap_prm.c
@@ -16,6 +16,8 @@ 
 #include <linux/reset-controller.h>
 #include <linux/delay.h>
 
+#include <linux/platform_data/ti-prm.h>
+
 struct omap_rst_map {
 	s8 rst;
 	s8 st;
@@ -24,6 +26,7 @@  struct omap_rst_map {
 struct omap_prm_data {
 	u32 base;
 	const char *name;
+	const char *clkdm_name;
 	u16 pwstctrl;
 	u16 pwstst;
 	u16 rstctl;
@@ -40,6 +43,8 @@  struct omap_prm {
 struct omap_reset_data {
 	struct reset_controller_dev rcdev;
 	struct omap_prm *prm;
+	struct clockdomain *clkdm;
+	struct device *dev;
 };
 
 #define to_omap_reset_data(p) container_of((p), struct omap_reset_data, rcdev)
@@ -108,6 +113,8 @@  static int omap_reset_deassert(struct reset_controller_dev *rcdev,
 	int st_bit = id;
 	bool has_rstst;
 	int timeout = 0;
+	struct ti_prm_platform_data *pdata = dev_get_platdata(reset->dev);
+	int ret = 0;
 
 	/* check the current status to avoid de-asserting the line twice */
 	v = readl_relaxed(reset->prm->base + reset->prm->data->rstctl);
@@ -125,13 +132,16 @@  static int omap_reset_deassert(struct reset_controller_dev *rcdev,
 		writel_relaxed(v, reset->prm->base + reset->prm->data->rstst);
 	}
 
+	if (pdata->clkdm_deny_idle && reset->clkdm)
+		pdata->clkdm_deny_idle(reset->clkdm);
+
 	/* de-assert the reset control line */
 	v = readl_relaxed(reset->prm->base + reset->prm->data->rstctl);
 	v &= ~(1 << id);
 	writel_relaxed(v, reset->prm->base + reset->prm->data->rstctl);
 
 	if (!has_rstst)
-		return 0;
+		goto exit;
 
 	/* wait for the status to be set */
 	while (1) {
@@ -140,13 +150,19 @@  static int omap_reset_deassert(struct reset_controller_dev *rcdev,
 		if (v)
 			break;
 		timeout++;
-		if (timeout > OMAP_RESET_MAX_WAIT)
-			return -EBUSY;
+		if (timeout > OMAP_RESET_MAX_WAIT) {
+			ret = -EBUSY;
+			goto exit;
+		}
 
 		udelay(1);
 	}
 
-	return 0;
+exit:
+	if (pdata->clkdm_allow_idle && reset->clkdm)
+		pdata->clkdm_allow_idle(reset->clkdm);
+
+	return ret;
 }
 
 static const struct reset_control_ops omap_reset_ops = {
@@ -159,6 +175,8 @@  static int omap_prm_reset_probe(struct platform_device *pdev,
 				struct omap_prm *prm)
 {
 	struct omap_reset_data *reset;
+	struct ti_prm_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	char buf[32];
 
 	/*
 	 * Check if we have resets. If either rstctl or rstst is
@@ -177,9 +195,15 @@  static int omap_prm_reset_probe(struct platform_device *pdev,
 	reset->rcdev.ops = &omap_reset_ops;
 	reset->rcdev.of_node = pdev->dev.of_node;
 	reset->rcdev.nr_resets = OMAP_MAX_RESETS;
+	reset->dev = &pdev->dev;
 
 	reset->prm = prm;
 
+	sprintf(buf, "%s_clkdm", prm->data->clkdm_name ? prm->data->clkdm_name :
+		prm->data->name);
+
+	reset->clkdm = pdata->clkdm_lookup(buf);
+
 	return devm_reset_controller_register(&pdev->dev, &reset->rcdev);
 }
 
diff --git a/include/linux/platform_data/ti-prm.h b/include/linux/platform_data/ti-prm.h
new file mode 100644
index 0000000..28154c3
--- /dev/null
+++ b/include/linux/platform_data/ti-prm.h
@@ -0,0 +1,21 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * TI PRM (Power & Reset Manager) platform data
+ *
+ * Copyright (C) 2019 Texas Instruments, Inc.
+ *
+ * Tero Kristo <t-kristo@ti.com>
+ */
+
+#ifndef _LINUX_PLATFORM_DATA_TI_PRM_H
+#define _LINUX_PLATFORM_DATA_TI_PRM_H
+
+struct clockdomain;
+
+struct ti_prm_platform_data {
+	void (*clkdm_deny_idle)(struct clockdomain *clkdm);
+	void (*clkdm_allow_idle)(struct clockdomain *clkdm);
+	struct clockdomain * (*clkdm_lookup)(const char *name);
+};
+
+#endif /* _LINUX_PLATFORM_DATA_TI_PRM_H */