[PATCH 0/8] ARM: davinci: complete the conversion to using the reset framework

[PATCH 0/8] ARM: davinci: complete the conversion to using the reset framework

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

This series converts the only user of the handcoded, mach-specific reset
routines in the davinci platform to using the reset framework.

Patch 1 modifies the way lookup entries are registered with the reset
framework.

Patches 2-4 add necessary lookups/DT-properties.

Patches 5-7 convert the davinci-rproc driver to the reset framework.

Patch 8 removes now dead code.

Philipp: it turned out that it's indeed better to use the reset
controller's device name for the entry lookup.

Tested both in DT and legacy modes by booting the examples from
ti-ipc-rtos recipe in meta-ti.

This series applies on top of David Lechner's common-clk-v9 branch[1]
with Philipp Zabel's reset/next branch[2] pulled in.

It can be found in my github tree as well[3].

[1] git://github.com/dlech/ev3dev-kernel.git common-clk-v9
[2] git://git.pengutronix.de/git/pza/linux reset/next
[3] git@github.com:brgl/linux.git topic/davinci-reset

Bartosz Golaszewski (8):
  reset: modify the way reset lookup works for board files
  ARM: davinci: dts: make psc0 a reset provider
  ARM: davinci: dts: add a reset control to the dsp node
  clk: davinci: add a reset lookup table for psc0
  remoteproc: da8xx: add the missing checke for clk_enable()
  remoteproc: da8xx: prepare and unprepare the clock where needed
  remoteproc: da8xx: use the reset framework
  clk: davinci: kill davinci_clk_reset_assert/deassert()

 arch/arm/boot/dts/da850.dtsi               |  2 ++
 arch/arm/mach-davinci/include/mach/clock.h | 21 ----------------
 drivers/clk/davinci/psc-da850.c            |  8 ++++++
 drivers/clk/davinci/psc.c                  | 19 +-------------
 drivers/remoteproc/da8xx_remoteproc.c      | 40 ++++++++++++++++++++++++------
 drivers/reset/core.c                       | 33 +++++++++++++++++++++---
 include/linux/reset-controller.h           |  8 +++---
 7 files changed, 78 insertions(+), 53 deletions(-)
 delete mode 100644 arch/arm/mach-davinci/include/mach/clock.h

-- 
2.16.1

[PATCH 1/8] reset: modify the way reset lookup works for board files

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Commit 7af1bb19f1d7 ("reset: add support for non-DT systems")
introduced reset control lookup mechanism for boards that still use
board files.

The routine used to register lookup entries takes the corresponding
reset_controlled_dev structure as argument.

It's been determined however that for the first user of this new
interface - davinci psc driver - it will be easier to register the
lookup entries using the reset controller device name.

This patch changes the way lookup entries are added.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/reset/core.c             | 33 +++++++++++++++++++++++++++++----
 include/linux/reset-controller.h |  8 +++++---
 2 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 06fa4907afc4..f37048e55336 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -153,11 +153,11 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
 
 /**
  * reset_controller_add_lookup - register a set of lookup entries
- * @rcdev: initialized reset controller device owning the reset line
+ * @provider: name of the reset controller provider
  * @lookup: array of reset lookup entries
  * @num_entries: number of entries in the lookup array
  */
-void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
+void reset_controller_add_lookup(const char *provider,
 				 struct reset_control_lookup *lookup,
 				 unsigned int num_entries)
 {
@@ -174,7 +174,7 @@ void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
 			continue;
 		}
 
-		entry->rcdev = rcdev;
+		entry->provider = provider;
 		list_add_tail(&entry->list, &reset_lookup_list);
 	}
 	mutex_unlock(&reset_lookup_mutex);
@@ -526,11 +526,30 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
 }
 EXPORT_SYMBOL_GPL(__of_reset_control_get);
 
+static struct reset_controller_dev *
+__reset_controller_by_name(const char *name)
+{
+	struct reset_controller_dev *rcdev;
+
+	lockdep_assert_held(&reset_list_mutex);
+
+	list_for_each_entry(rcdev, &reset_controller_list, list) {
+		if (!rcdev->dev)
+			continue;
+
+		if (!strcmp(name, dev_name(rcdev->dev)))
+			return rcdev;
+	}
+
+	return NULL;
+}
+
 static struct reset_control *
 __reset_control_get_from_lookup(struct device *dev, const char *con_id,
 				bool shared, bool optional)
 {
 	const struct reset_control_lookup *lookup;
+	struct reset_controller_dev *rcdev;
 	const char *dev_id = dev_name(dev);
 	struct reset_control *rstc = NULL;
 
@@ -547,7 +566,13 @@ __reset_control_get_from_lookup(struct device *dev, const char *con_id,
 		    ((con_id && lookup->con_id) &&
 		     !strcmp(con_id, lookup->con_id))) {
 			mutex_lock(&reset_list_mutex);
-			rstc = __reset_control_get_internal(lookup->rcdev,
+			rcdev = __reset_controller_by_name(lookup->provider);
+			if (!rcdev) {
+				mutex_unlock(&reset_list_mutex);
+				continue;
+			}
+
+			rstc = __reset_control_get_internal(rcdev,
 							    lookup->index,
 							    shared);
 			mutex_unlock(&reset_list_mutex);
diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h
index 25698f6c1fae..1a6c25d825d3 100644
--- a/include/linux/reset-controller.h
+++ b/include/linux/reset-controller.h
@@ -30,14 +30,14 @@ struct of_phandle_args;
  * struct reset_control_lookup - represents a single lookup entry
  *
  * @list: internal list of all reset lookup entries
- * @rcdev: reset controller device controlling this reset line
+ * @provider: name of the reset controller device controlling this reset line
  * @index: ID of the reset controller in the reset controller device
  * @dev_id: name of the device associated with this reset line
  * @con_id name of the reset line (can be NULL)
  */
 struct reset_control_lookup {
 	struct list_head list;
-	struct reset_controller_dev *rcdev;
+	const char *provider;
 	unsigned int index;
 	const char *dev_id;
 	const char *con_id;
@@ -57,6 +57,7 @@ struct reset_control_lookup {
  * @owner: kernel module of the reset controller driver
  * @list: internal list of reset controller devices
  * @reset_control_head: head of internal list of requested reset controls
+ * @dev: corresponding driver model device struct
  * @of_node: corresponding device tree node as phandle target
  * @of_reset_n_cells: number of cells in reset line specifiers
  * @of_xlate: translation function to translate from specifier as found in the
@@ -68,6 +69,7 @@ struct reset_controller_dev {
 	struct module *owner;
 	struct list_head list;
 	struct list_head reset_control_head;
+	struct device *dev;
 	struct device_node *of_node;
 	int of_reset_n_cells;
 	int (*of_xlate)(struct reset_controller_dev *rcdev,
@@ -82,7 +84,7 @@ struct device;
 int devm_reset_controller_register(struct device *dev,
 				   struct reset_controller_dev *rcdev);
 
-void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
+void reset_controller_add_lookup(const char *provider,
 				 struct reset_control_lookup *lookup,
 				 unsigned int num_entries);
 
-- 
2.16.1

[PATCH 2/8] ARM: davinci: dts: make psc0 a reset provider

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The psc driver registers with the reset framework as a provider. Add
the #reset-cells property to the psc0 node.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
index a3b9a99b43ca..89af749c5b6f 100644
--- a/arch/arm/boot/dts/da850.dtsi
+++ b/arch/arm/boot/dts/da850.dtsi
@@ -109,6 +109,7 @@
 		interrupt-parent = <&intc>;
 		interrupts = <28>;
 		clocks = <&psc0 15>;
+		resets = <&psc0 15>;
 		status = "disabled";
 	};
 	soc@1c00000 {
-- 
2.16.1

[PATCH 3/8] ARM: davinci: dts: add a reset control to the dsp node

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The davinci-rproc driver will soon use the reset framework. Add the
resets property to the dsp node in da850.dtsi.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/boot/dts/da850.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
index 89af749c5b6f..5b485e44b83e 100644
--- a/arch/arm/boot/dts/da850.dtsi
+++ b/arch/arm/boot/dts/da850.dtsi
@@ -124,6 +124,7 @@
 			compatible = "ti,da850-psc0";
 			reg = <0x10000 0x1000>;
 			#clock-cells = <1>;
+			#reset-cells = <1>;
 			#power-domain-cells = <1>;
 			clocks = <&pll0_sysclk 1>, <&pll0_sysclk 2>,
 				 <&pll0_sysclk 4>, <&pll0_sysclk 6>,
-- 
2.16.1

Re: [PATCH 3/8] ARM: davinci: dts: add a reset control to the dsp node

[Bartosz Golaszewski]

2018-03-21 13:08 GMT+01:00 Bartosz Golaszewski <brgl@bgdev.pl>:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>
> The davinci-rproc driver will soon use the reset framework. Add the
> resets property to the dsp node in da850.dtsi.
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  arch/arm/boot/dts/da850.dtsi | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
> index 89af749c5b6f..5b485e44b83e 100644
> --- a/arch/arm/boot/dts/da850.dtsi
> +++ b/arch/arm/boot/dts/da850.dtsi
> @@ -124,6 +124,7 @@
>                         compatible = "ti,da850-psc0";
>                         reg = <0x10000 0x1000>;
>                         #clock-cells = <1>;
> +                       #reset-cells = <1>;
>                         #power-domain-cells = <1>;
>                         clocks = <&pll0_sysclk 1>, <&pll0_sysclk 2>,
>                                  <&pll0_sysclk 4>, <&pll0_sysclk 6>,
> --
> 2.16.1
>

I noticed I mixed up the descriptions in patches 2/8 and 3/8. It'll
need a v2, but I'll wait for some reviews first.

Bart

Re: [PATCH 3/8] ARM: davinci: dts: add a reset control to the dsp node

[David Lechner]

On 03/21/2018 09:04 AM, Bartosz Golaszewski wrote:
> 2018-03-21 13:08 GMT+01:00 Bartosz Golaszewski <brgl@bgdev.pl>:
>> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>
>> The davinci-rproc driver will soon use the reset framework. Add the
>> resets property to the dsp node in da850.dtsi.
>>
>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>> ---
>>   arch/arm/boot/dts/da850.dtsi | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
>> index 89af749c5b6f..5b485e44b83e 100644
>> --- a/arch/arm/boot/dts/da850.dtsi
>> +++ b/arch/arm/boot/dts/da850.dtsi
>> @@ -124,6 +124,7 @@
>>                          compatible = "ti,da850-psc0";
>>                          reg = <0x10000 0x1000>;
>>                          #clock-cells = <1>;
>> +                       #reset-cells = <1>;
>>                          #power-domain-cells = <1>;
>>                          clocks = <&pll0_sysclk 1>, <&pll0_sysclk 2>,
>>                                   <&pll0_sysclk 4>, <&pll0_sysclk 6>,
>> --
>> 2.16.1
>>
> 
> I noticed I mixed up the descriptions in patches 2/8 and 3/8. It'll
> need a v2, but I'll wait for some reviews first.
> 
> Bart
> 

Yes, and this patch should be first to avoid a possible compiler warning.

[PATCH 4/8] clk: davinci: add a reset lookup table for psc0

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

In order to be able to use the reset framework in legacy boot mode as
well, add the reset lookup table to the psc driver for da850 variant.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/clk/davinci/psc-da850.c | 8 ++++++++
 drivers/clk/davinci/psc.c       | 1 +
 2 files changed, 9 insertions(+)

diff --git a/drivers/clk/davinci/psc-da850.c b/drivers/clk/davinci/psc-da850.c
index ccc7eb17bf3a..395db4b2c0ee 100644
--- a/drivers/clk/davinci/psc-da850.c
+++ b/drivers/clk/davinci/psc-da850.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/clk-provider.h>
+#include <linux/reset-controller.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
 #include <linux/init.h>
@@ -66,8 +67,15 @@ LPSC_CLKDEV3(ecap_clkdev,	"fck",	"ecap.0",
 				"fck",	"ecap.1",
 				"fck",	"ecap.2");
 
+static struct reset_control_lookup da850_psc0_reset_lookup_table[] = {
+	RESET_LOOKUP("davinci-rproc.0", NULL, 15),
+};
+
 static int da850_psc0_init(struct device *dev, void __iomem *base)
 {
+	reset_controller_add_lookup("da850-psc0",
+				    da850_psc0_reset_lookup_table,
+				    ARRAY_SIZE(da850_psc0_reset_lookup_table));
 	return davinci_psc_register_clocks(dev, da850_psc0_info, 16, base);
 }
 
diff --git a/drivers/clk/davinci/psc.c b/drivers/clk/davinci/psc.c
index 3b0e59dfbdd7..063df62381ea 100644
--- a/drivers/clk/davinci/psc.c
+++ b/drivers/clk/davinci/psc.c
@@ -425,6 +425,7 @@ __davinci_psc_register_clocks(struct device *dev,
 
 	psc->rcdev.ops = &davinci_psc_reset_ops;
 	psc->rcdev.owner = THIS_MODULE;
+	psc->rcdev.dev = dev;
 	psc->rcdev.of_node = dev->of_node;
 	psc->rcdev.of_reset_n_cells = 1;
 	psc->rcdev.of_xlate = davinci_psc_reset_of_xlate;
-- 
2.16.1

Re: [PATCH 4/8] clk: davinci: add a reset lookup table for psc0

[David Lechner]

On 03/21/2018 07:08 AM, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> In order to be able to use the reset framework in legacy boot mode as
> well, add the reset lookup table to the psc driver for da850 variant.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>   drivers/clk/davinci/psc-da850.c | 8 ++++++++
>   drivers/clk/davinci/psc.c       | 1 +
>   2 files changed, 9 insertions(+)
> 
> diff --git a/drivers/clk/davinci/psc-da850.c b/drivers/clk/davinci/psc-da850.c
> index ccc7eb17bf3a..395db4b2c0ee 100644
> --- a/drivers/clk/davinci/psc-da850.c
> +++ b/drivers/clk/davinci/psc-da850.c
> @@ -6,6 +6,7 @@
>    */
>   
>   #include <linux/clk-provider.h>
> +#include <linux/reset-controller.h>
>   #include <linux/clk.h>
>   #include <linux/clkdev.h>
>   #include <linux/init.h>
> @@ -66,8 +67,15 @@ LPSC_CLKDEV3(ecap_clkdev,	"fck",	"ecap.0",
>   				"fck",	"ecap.1",
>   				"fck",	"ecap.2");
>   
> +static struct reset_control_lookup da850_psc0_reset_lookup_table[] = {
> +	RESET_LOOKUP("davinci-rproc.0", NULL, 15),
> +};
> +
>   static int da850_psc0_init(struct device *dev, void __iomem *base)
>   {
> +	reset_controller_add_lookup("da850-psc0",
> +				    da850_psc0_reset_lookup_table,
> +				    ARRAY_SIZE(da850_psc0_reset_lookup_table));

Could there be a race condition here since you are adding the lookup *before*
you are adding the actual provider? It seems like reset_controller_add_lookup()
should be after davinci_psc_register_clocks().

>   	return davinci_psc_register_clocks(dev, da850_psc0_info, 16, base);
>   }
>   
> diff --git a/drivers/clk/davinci/psc.c b/drivers/clk/davinci/psc.c
> index 3b0e59dfbdd7..063df62381ea 100644
> --- a/drivers/clk/davinci/psc.c
> +++ b/drivers/clk/davinci/psc.c
> @@ -425,6 +425,7 @@ __davinci_psc_register_clocks(struct device *dev,
>   
>   	psc->rcdev.ops = &davinci_psc_reset_ops;
>   	psc->rcdev.owner = THIS_MODULE;
> +	psc->rcdev.dev = dev;
>   	psc->rcdev.of_node = dev->of_node;
>   	psc->rcdev.of_reset_n_cells = 1;
>   	psc->rcdev.of_xlate = davinci_psc_reset_of_xlate;
> 

Re: [PATCH 4/8] clk: davinci: add a reset lookup table for psc0

[Bartosz Golaszewski]

2018-03-21 17:01 GMT+01:00 David Lechner <david@lechnology.com>:
> On 03/21/2018 07:08 AM, Bartosz Golaszewski wrote:
>>
>> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>
>> In order to be able to use the reset framework in legacy boot mode as
>> well, add the reset lookup table to the psc driver for da850 variant.
>>
>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>> ---
>>   drivers/clk/davinci/psc-da850.c | 8 ++++++++
>>   drivers/clk/davinci/psc.c       | 1 +
>>   2 files changed, 9 insertions(+)
>>
>> diff --git a/drivers/clk/davinci/psc-da850.c
>> b/drivers/clk/davinci/psc-da850.c
>> index ccc7eb17bf3a..395db4b2c0ee 100644
>> --- a/drivers/clk/davinci/psc-da850.c
>> +++ b/drivers/clk/davinci/psc-da850.c
>> @@ -6,6 +6,7 @@
>>    */
>>     #include <linux/clk-provider.h>
>> +#include <linux/reset-controller.h>
>>   #include <linux/clk.h>
>>   #include <linux/clkdev.h>
>>   #include <linux/init.h>
>> @@ -66,8 +67,15 @@ LPSC_CLKDEV3(ecap_clkdev,    "fck",  "ecap.0",
>>                                 "fck",  "ecap.1",
>>                                 "fck",  "ecap.2");
>>   +static struct reset_control_lookup da850_psc0_reset_lookup_table[] = {
>> +       RESET_LOOKUP("davinci-rproc.0", NULL, 15),
>> +};
>> +
>>   static int da850_psc0_init(struct device *dev, void __iomem *base)
>>   {
>> +       reset_controller_add_lookup("da850-psc0",
>> +                                   da850_psc0_reset_lookup_table,
>> +
>> ARRAY_SIZE(da850_psc0_reset_lookup_table));
>
>
> Could there be a race condition here since you are adding the lookup
> *before*
> you are adding the actual provider? It seems like
> reset_controller_add_lookup()
> should be after davinci_psc_register_clocks().
>

I don't think so, because reset_controller_add_lookup() only adds the
lookup structure to the list in reset/core.c. The actual reset
controller struct is only located and used when reset_control_get_*()
is called, so after probing the user. And it's all protected with
mutexes.

This made me think though - maybe if we can't locate the controller,
we should return -EPROBE_DEFER from probe in davinci-rproc?

Bart

Re: [PATCH 4/8] clk: davinci: add a reset lookup table for psc0

[David Lechner]

On 03/21/2018 11:08 AM, Bartosz Golaszewski wrote:
> 2018-03-21 17:01 GMT+01:00 David Lechner <david@lechnology.com>:
>> On 03/21/2018 07:08 AM, Bartosz Golaszewski wrote:
>>>
>>> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>>
>>> In order to be able to use the reset framework in legacy boot mode as
>>> well, add the reset lookup table to the psc driver for da850 variant.
>>>
>>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>> ---
>>>    drivers/clk/davinci/psc-da850.c | 8 ++++++++
>>>    drivers/clk/davinci/psc.c       | 1 +
>>>    2 files changed, 9 insertions(+)
>>>
>>> diff --git a/drivers/clk/davinci/psc-da850.c
>>> b/drivers/clk/davinci/psc-da850.c
>>> index ccc7eb17bf3a..395db4b2c0ee 100644
>>> --- a/drivers/clk/davinci/psc-da850.c
>>> +++ b/drivers/clk/davinci/psc-da850.c
>>> @@ -6,6 +6,7 @@
>>>     */
>>>      #include <linux/clk-provider.h>
>>> +#include <linux/reset-controller.h>
>>>    #include <linux/clk.h>
>>>    #include <linux/clkdev.h>
>>>    #include <linux/init.h>
>>> @@ -66,8 +67,15 @@ LPSC_CLKDEV3(ecap_clkdev,    "fck",  "ecap.0",
>>>                                  "fck",  "ecap.1",
>>>                                  "fck",  "ecap.2");
>>>    +static struct reset_control_lookup da850_psc0_reset_lookup_table[] = {
>>> +       RESET_LOOKUP("davinci-rproc.0", NULL, 15),
>>> +};
>>> +
>>>    static int da850_psc0_init(struct device *dev, void __iomem *base)
>>>    {
>>> +       reset_controller_add_lookup("da850-psc0",
>>> +                                   da850_psc0_reset_lookup_table,
>>> +
>>> ARRAY_SIZE(da850_psc0_reset_lookup_table));
>>
>>
>> Could there be a race condition here since you are adding the lookup
>> *before*
>> you are adding the actual provider? It seems like
>> reset_controller_add_lookup()
>> should be after davinci_psc_register_clocks().
>>
> 
> I don't think so, because reset_controller_add_lookup() only adds the
> lookup structure to the list in reset/core.c. The actual reset
> controller struct is only located and used when reset_control_get_*()
> is called, so after probing the user. And it's all protected with
> mutexes.
> 
> This made me think though - maybe if we can't locate the controller,
> we should return -EPROBE_DEFER from probe in davinci-rproc?
> 
> Bart
> 

Yes, especially since we know that the PSC driver itself does get
deferred already.

Re: [PATCH 4/8] clk: davinci: add a reset lookup table for psc0

[Bartosz Golaszewski]

2018-03-21 17:17 GMT+01:00 David Lechner <david@lechnology.com>:
> On 03/21/2018 11:08 AM, Bartosz Golaszewski wrote:
>>
>> 2018-03-21 17:01 GMT+01:00 David Lechner <david@lechnology.com>:
>>>
>>> On 03/21/2018 07:08 AM, Bartosz Golaszewski wrote:
>>>>
>>>>
>>>> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>>>
>>>> In order to be able to use the reset framework in legacy boot mode as
>>>> well, add the reset lookup table to the psc driver for da850 variant.
>>>>
>>>> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
>>>> ---
>>>>    drivers/clk/davinci/psc-da850.c | 8 ++++++++
>>>>    drivers/clk/davinci/psc.c       | 1 +
>>>>    2 files changed, 9 insertions(+)
>>>>
>>>> diff --git a/drivers/clk/davinci/psc-da850.c
>>>> b/drivers/clk/davinci/psc-da850.c
>>>> index ccc7eb17bf3a..395db4b2c0ee 100644
>>>> --- a/drivers/clk/davinci/psc-da850.c
>>>> +++ b/drivers/clk/davinci/psc-da850.c
>>>> @@ -6,6 +6,7 @@
>>>>     */
>>>>      #include <linux/clk-provider.h>
>>>> +#include <linux/reset-controller.h>
>>>>    #include <linux/clk.h>
>>>>    #include <linux/clkdev.h>
>>>>    #include <linux/init.h>
>>>> @@ -66,8 +67,15 @@ LPSC_CLKDEV3(ecap_clkdev,    "fck",  "ecap.0",
>>>>                                  "fck",  "ecap.1",
>>>>                                  "fck",  "ecap.2");
>>>>    +static struct reset_control_lookup da850_psc0_reset_lookup_table[] =
>>>> {
>>>> +       RESET_LOOKUP("davinci-rproc.0", NULL, 15),
>>>> +};
>>>> +
>>>>    static int da850_psc0_init(struct device *dev, void __iomem *base)
>>>>    {
>>>> +       reset_controller_add_lookup("da850-psc0",
>>>> +                                   da850_psc0_reset_lookup_table,
>>>> +
>>>> ARRAY_SIZE(da850_psc0_reset_lookup_table));
>>>
>>>
>>>
>>> Could there be a race condition here since you are adding the lookup
>>> *before*
>>> you are adding the actual provider? It seems like
>>> reset_controller_add_lookup()
>>> should be after davinci_psc_register_clocks().
>>>
>>
>> I don't think so, because reset_controller_add_lookup() only adds the
>> lookup structure to the list in reset/core.c. The actual reset
>> controller struct is only located and used when reset_control_get_*()
>> is called, so after probing the user. And it's all protected with
>> mutexes.
>>
>> This made me think though - maybe if we can't locate the controller,
>> we should return -EPROBE_DEFER from probe in davinci-rproc?
>>
>> Bart
>>
>
> Yes, especially since we know that the PSC driver itself does get
> deferred already.

On the other hand if clk_get() succeeded, than the psc driver is
already initialized and the subsequent call to reset_control_get()
must succeed. But this is probably too machine-specific for a driver.

Bart

[PATCH 5/8] remoteproc: da8xx: add the missing checke for clk_enable()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The davinci platform is being switched to using the common clock
framework, where clk_enable() can fail. Add the return value check.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/remoteproc/da8xx_remoteproc.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/da8xx_remoteproc.c b/drivers/remoteproc/da8xx_remoteproc.c
index bf3b9034c319..592bf0fc52e8 100644
--- a/drivers/remoteproc/da8xx_remoteproc.c
+++ b/drivers/remoteproc/da8xx_remoteproc.c
@@ -138,6 +138,7 @@ static int da8xx_rproc_start(struct rproc *rproc)
 	struct device *dev = rproc->dev.parent;
 	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
 	struct clk *dsp_clk = drproc->dsp_clk;
+	int rv;
 
 	/* hw requires the start (boot) address be on 1KB boundary */
 	if (rproc->bootaddr & 0x3ff) {
@@ -148,7 +149,12 @@ static int da8xx_rproc_start(struct rproc *rproc)
 
 	writel(rproc->bootaddr, drproc->bootreg);
 
-	clk_enable(dsp_clk);
+	rv = clk_enable(dsp_clk);
+	if (rv) {
+		dev_err(dev, "clk_enable() failed: %d\n", rv);
+		return rv;
+	}
+
 	davinci_clk_reset_deassert(dsp_clk);
 
 	return 0;
-- 
2.16.1

Re: [PATCH 5/8] remoteproc: da8xx: add the missing checke for clk_enable()

[David Lechner]

On 03/21/2018 07:08 AM, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> The davinci platform is being switched to using the common clock
> framework, where clk_enable() can fail. Add the return value check.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>   drivers/remoteproc/da8xx_remoteproc.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/remoteproc/da8xx_remoteproc.c b/drivers/remoteproc/da8xx_remoteproc.c
> index bf3b9034c319..592bf0fc52e8 100644
> --- a/drivers/remoteproc/da8xx_remoteproc.c
> +++ b/drivers/remoteproc/da8xx_remoteproc.c
> @@ -138,6 +138,7 @@ static int da8xx_rproc_start(struct rproc *rproc)
>   	struct device *dev = rproc->dev.parent;
>   	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
>   	struct clk *dsp_clk = drproc->dsp_clk;
> +	int rv;

For style points, you could use ret instead of rv to be consistent with
the rest of this driver.

>   
>   	/* hw requires the start (boot) address be on 1KB boundary */
>   	if (rproc->bootaddr & 0x3ff) {
> @@ -148,7 +149,12 @@ static int da8xx_rproc_start(struct rproc *rproc)
>   
>   	writel(rproc->bootaddr, drproc->bootreg);
>   
> -	clk_enable(dsp_clk);
> +	rv = clk_enable(dsp_clk);
> +	if (rv) {
> +		dev_err(dev, "clk_enable() failed: %d\n", rv);
> +		return rv;
> +	}
> +
>   	davinci_clk_reset_deassert(dsp_clk);
>   
>   	return 0;
> 

[PATCH 6/8] remoteproc: da8xx: prepare and unprepare the clock where needed

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

We're currently switching the platform to using the common clock
framework. We need to explicitly prepare and unprepare the rproc
clock.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/remoteproc/da8xx_remoteproc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/remoteproc/da8xx_remoteproc.c b/drivers/remoteproc/da8xx_remoteproc.c
index 592bf0fc52e8..83f2d66ad3a9 100644
--- a/drivers/remoteproc/da8xx_remoteproc.c
+++ b/drivers/remoteproc/da8xx_remoteproc.c
@@ -149,9 +149,9 @@ static int da8xx_rproc_start(struct rproc *rproc)
 
 	writel(rproc->bootaddr, drproc->bootreg);
 
-	rv = clk_enable(dsp_clk);
+	rv = clk_prepare_enable(dsp_clk);
 	if (rv) {
-		dev_err(dev, "clk_enable() failed: %d\n", rv);
+		dev_err(dev, "clk_prepare_enable() failed: %d\n", rv);
 		return rv;
 	}
 
@@ -165,7 +165,7 @@ static int da8xx_rproc_stop(struct rproc *rproc)
 	struct da8xx_rproc *drproc = rproc->priv;
 
 	davinci_clk_reset_assert(drproc->dsp_clk);
-	clk_disable(drproc->dsp_clk);
+	clk_disable_unprepare(drproc->dsp_clk);
 
 	return 0;
 }
-- 
2.16.1

[PATCH 7/8] remoteproc: da8xx: use the reset framework

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Switch to using the reset framework instead of handcoded reset routines
we used so far.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/remoteproc/da8xx_remoteproc.c | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/drivers/remoteproc/da8xx_remoteproc.c b/drivers/remoteproc/da8xx_remoteproc.c
index 83f2d66ad3a9..fc29b78d0f77 100644
--- a/drivers/remoteproc/da8xx_remoteproc.c
+++ b/drivers/remoteproc/da8xx_remoteproc.c
@@ -10,6 +10,7 @@
 
 #include <linux/bitops.h>
 #include <linux/clk.h>
+#include <linux/reset.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -20,8 +21,6 @@
 #include <linux/platform_device.h>
 #include <linux/remoteproc.h>
 
-#include <mach/clock.h>   /* for davinci_clk_reset_assert/deassert() */
-
 #include "remoteproc_internal.h"
 
 static char *da8xx_fw_name;
@@ -72,6 +71,7 @@ struct da8xx_rproc {
 	struct da8xx_rproc_mem *mem;
 	int num_mems;
 	struct clk *dsp_clk;
+	struct reset_control *dsp_reset;
 	void (*ack_fxn)(struct irq_data *data);
 	struct irq_data *irq_data;
 	void __iomem *chipsig;
@@ -138,6 +138,7 @@ static int da8xx_rproc_start(struct rproc *rproc)
 	struct device *dev = rproc->dev.parent;
 	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
 	struct clk *dsp_clk = drproc->dsp_clk;
+	struct reset_control *dsp_reset = drproc->dsp_reset;
 	int rv;
 
 	/* hw requires the start (boot) address be on 1KB boundary */
@@ -155,7 +156,11 @@ static int da8xx_rproc_start(struct rproc *rproc)
 		return rv;
 	}
 
-	davinci_clk_reset_deassert(dsp_clk);
+	rv = reset_control_deassert(dsp_reset);
+	if (rv) {
+		dev_err(dev, "reset_control_deassert() failed: %d\n", rv);
+		return rv;
+	}
 
 	return 0;
 }
@@ -163,8 +168,15 @@ static int da8xx_rproc_start(struct rproc *rproc)
 static int da8xx_rproc_stop(struct rproc *rproc)
 {
 	struct da8xx_rproc *drproc = rproc->priv;
+	int rv;
+
+	rv = reset_control_assert(drproc->dsp_reset);
+	if (rv) {
+		dev_err(rproc->dev.parent,
+			"reset_control_assert() failed: %d\n", rv);
+		return rv;
+	}
 
-	davinci_clk_reset_assert(drproc->dsp_clk);
 	clk_disable_unprepare(drproc->dsp_clk);
 
 	return 0;
@@ -232,6 +244,7 @@ static int da8xx_rproc_probe(struct platform_device *pdev)
 	struct resource *bootreg_res;
 	struct resource *chipsig_res;
 	struct clk *dsp_clk;
+	struct reset_control *dsp_reset;
 	void __iomem *chipsig;
 	void __iomem *bootreg;
 	int irq;
@@ -268,6 +281,13 @@ static int da8xx_rproc_probe(struct platform_device *pdev)
 		return PTR_ERR(dsp_clk);
 	}
 
+	dsp_reset = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(dsp_reset)) {
+		dev_err(dev, "unable to get reset control: %ld\n",
+			PTR_ERR(dsp_reset));
+		return PTR_ERR(dsp_reset);
+	}
+
 	if (dev->of_node) {
 		ret = of_reserved_mem_device_init(dev);
 		if (ret) {
@@ -309,7 +329,7 @@ static int da8xx_rproc_probe(struct platform_device *pdev)
 	 * *not* in reset, but da8xx_rproc_start() needs the DSP to be
 	 * held in reset at the time it is called.
 	 */
-	ret = davinci_clk_reset_assert(drproc->dsp_clk);
+	ret = reset_control_assert(dsp_reset);
 	if (ret)
 		goto free_rproc;
 
-- 
2.16.1

[PATCH 8/8] clk: davinci: kill davinci_clk_reset_assert/deassert()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

This code is no longer used. Remove it.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 arch/arm/mach-davinci/include/mach/clock.h | 21 ---------------------
 drivers/clk/davinci/psc.c                  | 18 ------------------
 2 files changed, 39 deletions(-)
 delete mode 100644 arch/arm/mach-davinci/include/mach/clock.h

diff --git a/arch/arm/mach-davinci/include/mach/clock.h b/arch/arm/mach-davinci/include/mach/clock.h
deleted file mode 100644
index 42ed4f2f5ce4..000000000000
--- a/arch/arm/mach-davinci/include/mach/clock.h
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * arch/arm/mach-davinci/include/mach/clock.h
- *
- * Clock control driver for DaVinci - header file
- *
- * Authors: Vladimir Barinov <source@mvista.com>
- *
- * 2007 (c) MontaVista Software, Inc. This file is licensed under
- * the terms of the GNU General Public License version 2. This program
- * is licensed "as is" without any warranty of any kind, whether express
- * or implied.
- */
-#ifndef __ASM_ARCH_DAVINCI_CLOCK_H
-#define __ASM_ARCH_DAVINCI_CLOCK_H
-
-struct clk;
-
-int davinci_clk_reset_assert(struct clk *c);
-int davinci_clk_reset_deassert(struct clk *c);
-
-#endif
diff --git a/drivers/clk/davinci/psc.c b/drivers/clk/davinci/psc.c
index 063df62381ea..75c4bc6f23e3 100644
--- a/drivers/clk/davinci/psc.c
+++ b/drivers/clk/davinci/psc.c
@@ -295,24 +295,6 @@ static int davinci_lpsc_clk_reset(struct clk *clk, bool reset)
 	return 0;
 }
 
-/*
- * REVISIT: These exported functions can be removed after a non-DT lookup is
- * added to the reset controller framework and the davinci-rproc driver is
- * updated to use the generic reset controller framework.
- */
-
-int davinci_clk_reset_assert(struct clk *clk)
-{
-	return davinci_lpsc_clk_reset(clk, true);
-}
-EXPORT_SYMBOL(davinci_clk_reset_assert);
-
-int davinci_clk_reset_deassert(struct clk *clk)
-{
-	return davinci_lpsc_clk_reset(clk, false);
-}
-EXPORT_SYMBOL(davinci_clk_reset_deassert);
-
 static int davinci_psc_reset_assert(struct reset_controller_dev *rcdev,
 				    unsigned long id)
 {
-- 
2.16.1

Re: [PATCH 8/8] clk: davinci: kill davinci_clk_reset_assert/deassert()

[David Lechner]

On 03/21/2018 07:08 AM, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> This code is no longer used. Remove it.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---

Reviewed-by: David Lechner <david@lechnology.com>