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Groups > linux.kernel > #1618731 > unrolled thread

[PATCH 1/2] mfd: arizona: Add GPIO maintain state flag

Started byCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
First post2017-04-07 14:40 +0200
Last post2017-04-08 05:50 +0200
Articles 3 — 2 participants

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  [PATCH 1/2] mfd: arizona: Add GPIO maintain state flag Charles Keepax <ckeepax@opensource.wolfsonmicro.com> - 2017-04-07 14:40 +0200
    [PATCH 2/2] gpio: arizona: Add support for GPIOs that need to be maintained Charles Keepax <ckeepax@opensource.wolfsonmicro.com> - 2017-04-07 14:40 +0200
      Re: [PATCH 2/2] gpio: arizona: Add support for GPIOs that need to be  maintained kbuild test robot <lkp@intel.com> - 2017-04-08 05:50 +0200

#1618731 — [PATCH 1/2] mfd: arizona: Add GPIO maintain state flag

FromCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Date2017-04-07 14:40 +0200
Subject[PATCH 1/2] mfd: arizona: Add GPIO maintain state flag
Message-ID<ttBlf-746-15@gated-at.bofh.it>
The Arizona devices only maintain the state of output GPIOs whilst the
CODEC is active, this can cause issues if the CODEC suspends whilst
something is relying on the state of one of its GPIOs. However, in
many systems the CODEC GPIOs are used for audio related features
and thus the state of the GPIOs is unimportant whilst the CODEC is
suspended. Often keeping the CODEC resumed in such a system would
incur a power impact that is unacceptable.

Add a flag through the second cell of the GPIO specifier in device
tree, to allow the user to select whether a GPIO being configured as
an output should keep the CODEC resumed.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---
 Documentation/devicetree/bindings/mfd/arizona.txt | 5 ++++-
 include/dt-bindings/mfd/arizona.h                 | 3 +++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mfd/arizona.txt b/Documentation/devicetree/bindings/mfd/arizona.txt
index 8f2e282..6af0d82 100644
--- a/Documentation/devicetree/bindings/mfd/arizona.txt
+++ b/Documentation/devicetree/bindings/mfd/arizona.txt
@@ -30,7 +30,10 @@ Required properties:
 
   - gpio-controller : Indicates this device is a GPIO controller.
   - #gpio-cells : Must be 2. The first cell is the pin number and the
-    second cell is used to specify optional parameters (currently unused).
+    second cell is used to specify optional parameters, the following flags
+    are supported:
+      "ARIZONA_GP_MAINTAIN" the output of the GPIO must be maintained, this
+      prevents the CODEC going into low power mode.
 
   - AVDD-supply, DBVDD1-supply, CPVDD-supply : Power supplies for the device,
     as covered in Documentation/devicetree/bindings/regulator/regulator.txt
diff --git a/include/dt-bindings/mfd/arizona.h b/include/dt-bindings/mfd/arizona.h
index dedf46f..68f3782 100644
--- a/include/dt-bindings/mfd/arizona.h
+++ b/include/dt-bindings/mfd/arizona.h
@@ -77,6 +77,9 @@
 #define ARIZONA_GP_INPUT               (ARIZONA_GP_FN_GPIO | \
 					ARIZONA_GPN_DIR)
 
+/* Flags for the GPIO driver properties */
+#define ARIZONA_GP_MAINTAIN 0x80000000
+
 #define ARIZONA_32KZ_MCLK1 1
 #define ARIZONA_32KZ_MCLK2 2
 #define ARIZONA_32KZ_NONE  3
-- 
2.1.4

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#1618736 — [PATCH 2/2] gpio: arizona: Add support for GPIOs that need to be maintained

FromCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Date2017-04-07 14:40 +0200
Subject[PATCH 2/2] gpio: arizona: Add support for GPIOs that need to be maintained
Message-ID<ttBlg-746-27@gated-at.bofh.it>
In reply to#1618731
The Arizona devices only maintain the state of output GPIOs whilst the
CODEC is active, this can cause issues if the CODEC suspends whilst
something is relying on the state of one of its GPIOs. However, in
many systems the CODEC GPIOs are used for audio related features
and thus the state of the GPIOs is unimportant whilst the CODEC is
suspended. Often keeping the CODEC resumed in such a system would
incur a power impact that is unacceptable.

Allow the user to select whether a GPIO output should keep the
CODEC resumed, by adding a flag through the second cell of the GPIO
specifier in device tree. The default behaviour remains the same with
the GPIO not forcing the CODEC to remain active and losing state, so
as to not cause power regressions on existing systems.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---
 drivers/gpio/gpio-arizona.c | 52 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/drivers/gpio/gpio-arizona.c b/drivers/gpio/gpio-arizona.c
index 60b3102..027a70a 100644
--- a/drivers/gpio/gpio-arizona.c
+++ b/drivers/gpio/gpio-arizona.c
@@ -24,15 +24,27 @@
 #include <linux/mfd/arizona/pdata.h>
 #include <linux/mfd/arizona/registers.h>
 
+#define ARIZONA_GP_STATE_OUTPUT   0x00000001
+
 struct arizona_gpio {
 	struct arizona *arizona;
 	struct gpio_chip gpio_chip;
+	int status[ARIZONA_MAX_GPIO];
 };
 
 static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
 {
 	struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
 	struct arizona *arizona = arizona_gpio->arizona;
+	int status = arizona_gpio->status[offset];
+
+	status &= (ARIZONA_GP_MAINTAIN | ARIZONA_GP_STATE_OUTPUT);
+	if (status == (ARIZONA_GP_MAINTAIN | ARIZONA_GP_STATE_OUTPUT)) {
+		arizona_gpio->status[offset] &= ~ARIZONA_GP_STATE_OUTPUT;
+
+		pm_runtime_mark_last_busy(chip->parent);
+		pm_runtime_put_autosuspend(chip->parent);
+	}
 
 	return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
 				  ARIZONA_GPN_DIR, ARIZONA_GPN_DIR);
@@ -85,6 +97,19 @@ static int arizona_gpio_direction_out(struct gpio_chip *chip,
 {
 	struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
 	struct arizona *arizona = arizona_gpio->arizona;
+	int status = arizona_gpio->status[offset];
+	int ret;
+
+	status &= (ARIZONA_GP_MAINTAIN | ARIZONA_GP_STATE_OUTPUT);
+	if (status == ARIZONA_GP_MAINTAIN) {
+		arizona_gpio->status[offset] |= ARIZONA_GP_STATE_OUTPUT;
+
+		ret = pm_runtime_get_sync(chip->parent);
+		if (ret < 0) {
+			dev_err(chip->parent, "Failed to resume: %d\n", ret);
+			return ret;
+		}
+	}
 
 	if (value)
 		value = ARIZONA_GPN_LVL;
@@ -105,6 +130,29 @@ static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 			   ARIZONA_GPN_LVL, value);
 }
 
+static int arizona_gpio_of_xlate(struct gpio_chip *chip,
+				 const struct of_phandle_args *gpiospec,
+				 u32 *flags)
+{
+	struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
+	u32 offset = gpiospec->args[0];
+	u32 bits = gpiospec->args[1];
+
+	if (gpiospec->args_count < chip->of_gpio_n_cells)
+		return -EINVAL;
+
+	if (offset >= chip->ngpio)
+		return -EINVAL;
+
+	if (flags)
+		*flags = bits & ~ARIZONA_GP_MAINTAIN;
+
+	if (bits & ARIZONA_GP_MAINTAIN)
+		arizona_gpio->status[offset] |= ARIZONA_GP_MAINTAIN;
+
+	return offset;
+}
+
 static const struct gpio_chip template_chip = {
 	.label			= "arizona",
 	.owner			= THIS_MODULE,
@@ -113,6 +161,8 @@ static const struct gpio_chip template_chip = {
 	.direction_output	= arizona_gpio_direction_out,
 	.set			= arizona_gpio_set,
 	.can_sleep		= true,
+	.of_xlate		= arizona_gpio_of_xlate,
+	.of_gpio_n_cells	= 2,
 };
 
 static int arizona_gpio_probe(struct platform_device *pdev)
@@ -158,6 +208,8 @@ static int arizona_gpio_probe(struct platform_device *pdev)
 	else
 		arizona_gpio->gpio_chip.base = -1;
 
+	pm_runtime_enable(&pdev->dev);
+
 	ret = devm_gpiochip_add_data(&pdev->dev, &arizona_gpio->gpio_chip,
 				     arizona_gpio);
 	if (ret < 0) {
-- 
2.1.4

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#1619217 — Re: [PATCH 2/2] gpio: arizona: Add support for GPIOs that need to be maintained

Fromkbuild test robot <lkp@intel.com>
Date2017-04-08 05:50 +0200
SubjectRe: [PATCH 2/2] gpio: arizona: Add support for GPIOs that need to be maintained
Message-ID<ttPxT-8ty-1@gated-at.bofh.it>
In reply to#1618736

[Multipart message — attachments visible in raw view] — view raw

Hi Charles,

[auto build test ERROR on gpio/for-next]
[also build test ERROR on v4.11-rc5 next-20170407]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Charles-Keepax/mfd-arizona-Add-GPIO-maintain-state-flag/20170408-111119
base:   https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git for-next
config: x86_64-randconfig-x003-201714 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All error/warnings (new ones prefixed by >>):

   drivers//gpio/gpio-arizona.c: In function 'arizona_gpio_direction_in':
   drivers//gpio/gpio-arizona.c:44:3: error: implicit declaration of function 'pm_runtime_mark_last_busy' [-Werror=implicit-function-declaration]
      pm_runtime_mark_last_busy(chip->parent);
      ^~~~~~~~~~~~~~~~~~~~~~~~~
   drivers//gpio/gpio-arizona.c:45:3: error: implicit declaration of function 'pm_runtime_put_autosuspend' [-Werror=implicit-function-declaration]
      pm_runtime_put_autosuspend(chip->parent);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers//gpio/gpio-arizona.c: In function 'arizona_gpio_set':
   drivers//gpio/gpio-arizona.c:93:9: error: implicit declaration of function 'pm_runtime_get_sync' [-Werror=implicit-function-declaration]
      ret = pm_runtime_get_sync(chip->parent);
            ^~~~~~~~~~~~~~~~~~~
   drivers//gpio/gpio-arizona.c:96:11: warning: 'return' with a value, in function returning void
       return ret;
              ^~~
   drivers//gpio/gpio-arizona.c:82:13: note: declared here
    static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
                ^~~~~~~~~~~~~~~~
   In file included from include/linux/linkage.h:4:0,
                    from include/linux/kernel.h:6,
                    from drivers//gpio/gpio-arizona.c:15:
   drivers//gpio/gpio-arizona.c: In function 'arizona_gpio_of_xlate':
>> drivers//gpio/gpio-arizona.c:115:33: error: 'struct gpio_chip' has no member named 'of_gpio_n_cells'
     if (gpiospec->args_count < chip->of_gpio_n_cells)
                                    ^
   include/linux/compiler.h:160:30: note: in definition of macro '__trace_if'
     if (__builtin_constant_p(!!(cond)) ? !!(cond) :   \
                                 ^~~~
>> drivers//gpio/gpio-arizona.c:115:2: note: in expansion of macro 'if'
     if (gpiospec->args_count < chip->of_gpio_n_cells)
     ^~
>> drivers//gpio/gpio-arizona.c:115:33: error: 'struct gpio_chip' has no member named 'of_gpio_n_cells'
     if (gpiospec->args_count < chip->of_gpio_n_cells)
                                    ^
   include/linux/compiler.h:160:42: note: in definition of macro '__trace_if'
     if (__builtin_constant_p(!!(cond)) ? !!(cond) :   \
                                             ^~~~
>> drivers//gpio/gpio-arizona.c:115:2: note: in expansion of macro 'if'
     if (gpiospec->args_count < chip->of_gpio_n_cells)
     ^~
>> drivers//gpio/gpio-arizona.c:115:33: error: 'struct gpio_chip' has no member named 'of_gpio_n_cells'
     if (gpiospec->args_count < chip->of_gpio_n_cells)
                                    ^
   include/linux/compiler.h:171:16: note: in definition of macro '__trace_if'
      ______r = !!(cond);     \
                   ^~~~
>> drivers//gpio/gpio-arizona.c:115:2: note: in expansion of macro 'if'
     if (gpiospec->args_count < chip->of_gpio_n_cells)
     ^~
   drivers//gpio/gpio-arizona.c: At top level:
>> drivers//gpio/gpio-arizona.c:138:2: error: unknown field 'of_xlate' specified in initializer
     .of_xlate  = arizona_gpio_of_xlate,
     ^
>> drivers//gpio/gpio-arizona.c:138:15: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
     .of_xlate  = arizona_gpio_of_xlate,
                  ^~~~~~~~~~~~~~~~~~~~~
   drivers//gpio/gpio-arizona.c:138:15: note: (near initialization for 'template_chip.read_reg')
>> drivers//gpio/gpio-arizona.c:139:2: error: unknown field 'of_gpio_n_cells' specified in initializer
     .of_gpio_n_cells = 2,
     ^
>> drivers//gpio/gpio-arizona.c:139:21: warning: initialization makes pointer from integer without a cast [-Wint-conversion]
     .of_gpio_n_cells = 2,
                        ^
   drivers//gpio/gpio-arizona.c:139:21: note: (near initialization for 'template_chip.write_reg')
   drivers//gpio/gpio-arizona.c: In function 'arizona_gpio_probe':
   drivers//gpio/gpio-arizona.c:185:2: error: implicit declaration of function 'pm_runtime_enable' [-Werror=implicit-function-declaration]
     pm_runtime_enable(&pdev->dev);
     ^~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +115 drivers//gpio/gpio-arizona.c

     9	 *  under  the terms of  the GNU General  Public License as published by the
    10	 *  Free Software Foundation;  either version 2 of the  License, or (at your
    11	 *  option) any later version.
    12	 *
    13	 */
    14	
  > 15	#include <linux/kernel.h>
    16	#include <linux/slab.h>
    17	#include <linux/module.h>
    18	#include <linux/gpio.h>
    19	#include <linux/platform_device.h>
    20	#include <linux/seq_file.h>
    21	
    22	#include <linux/mfd/arizona/core.h>
    23	#include <linux/mfd/arizona/pdata.h>
    24	#include <linux/mfd/arizona/registers.h>
    25	
    26	#define ARIZONA_GP_STATE_OUTPUT   0x00000001
    27	
    28	struct arizona_gpio {
    29		struct arizona *arizona;
    30		struct gpio_chip gpio_chip;
    31		int status[ARIZONA_MAX_GPIO];
    32	};
    33	
    34	static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
    35	{
    36		struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
    37		struct arizona *arizona = arizona_gpio->arizona;
    38		int status = arizona_gpio->status[offset];
    39	
    40		status &= (ARIZONA_GP_MAINTAIN | ARIZONA_GP_STATE_OUTPUT);
    41		if (status == (ARIZONA_GP_MAINTAIN | ARIZONA_GP_STATE_OUTPUT)) {
    42			arizona_gpio->status[offset] &= ~ARIZONA_GP_STATE_OUTPUT;
    43	
    44			pm_runtime_mark_last_busy(chip->parent);
    45			pm_runtime_put_autosuspend(chip->parent);
    46		}
    47	
    48		return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
    49					  ARIZONA_GPN_DIR, ARIZONA_GPN_DIR);
    50	}
    51	
    52	static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
    53	{
    54		struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
    55		struct arizona *arizona = arizona_gpio->arizona;
    56		unsigned int val;
    57		int ret;
    58	
    59		ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val);
    60		if (ret < 0)
    61			return ret;
    62	
    63		if (val & ARIZONA_GPN_LVL)
    64			return 1;
    65		else
    66			return 0;
    67	}
    68	
    69	static int arizona_gpio_direction_out(struct gpio_chip *chip,
    70					     unsigned offset, int value)
    71	{
    72		struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
    73		struct arizona *arizona = arizona_gpio->arizona;
    74	
    75		if (value)
    76			value = ARIZONA_GPN_LVL;
    77	
    78		return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
    79					  ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value);
    80	}
    81	
  > 82	static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
    83	{
    84		struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
    85		struct arizona *arizona = arizona_gpio->arizona;
    86		int status = arizona_gpio->status[offset];
    87		int ret;
    88	
    89		status &= (ARIZONA_GP_MAINTAIN | ARIZONA_GP_STATE_OUTPUT);
    90		if (status == ARIZONA_GP_MAINTAIN) {
    91			arizona_gpio->status[offset] |= ARIZONA_GP_STATE_OUTPUT;
    92	
    93			ret = pm_runtime_get_sync(chip->parent);
    94			if (ret < 0) {
    95				dev_err(chip->parent, "Failed to resume: %d\n", ret);
    96				return ret;
    97			}
    98		}
    99	
   100		if (value)
   101			value = ARIZONA_GPN_LVL;
   102	
   103		regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
   104				   ARIZONA_GPN_LVL, value);
   105	}
   106	
   107	static int arizona_gpio_of_xlate(struct gpio_chip *chip,
   108					 const struct of_phandle_args *gpiospec,
   109					 u32 *flags)
   110	{
   111		struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
   112		u32 offset = gpiospec->args[0];
   113		u32 bits = gpiospec->args[1];
   114	
 > 115		if (gpiospec->args_count < chip->of_gpio_n_cells)
   116			return -EINVAL;
   117	
   118		if (offset >= chip->ngpio)
   119			return -EINVAL;
   120	
   121		if (flags)
   122			*flags = bits & ~ARIZONA_GP_MAINTAIN;
   123	
   124		if (bits & ARIZONA_GP_MAINTAIN)
   125			arizona_gpio->status[offset] |= ARIZONA_GP_MAINTAIN;
   126	
   127		return offset;
   128	}
   129	
   130	static const struct gpio_chip template_chip = {
   131		.label			= "arizona",
   132		.owner			= THIS_MODULE,
   133		.direction_input	= arizona_gpio_direction_in,
   134		.get			= arizona_gpio_get,
   135		.direction_output	= arizona_gpio_direction_out,
   136		.set			= arizona_gpio_set,
   137		.can_sleep		= true,
 > 138		.of_xlate		= arizona_gpio_of_xlate,
 > 139		.of_gpio_n_cells	= 2,
   140	};
   141	
   142	static int arizona_gpio_probe(struct platform_device *pdev)

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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