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From: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
To: matti.vaittinen@fi.rohmeurope.com, mazziesaccount@gmail.com
Cc: Lee Jones <lee.jones@linaro.org>,
	Jacek Anaszewski <jacek.anaszewski@gmail.com>,
	Pavel Machek <pavel@ucw.cz>, Dan Murphy <dmurphy@ti.com>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
	Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	Alessandro Zummo <a.zummo@towertech.it>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
	Jeff Kirsher <jeffrey.t.kirsher@intel.com>,
	Wolfram Sang <wsa+renesas@sang-engineering.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Nicholas Mc Guire <hofrat@osadl.org>,
	Phil Edworthy <phil.edworthy@renesas.com>,
	linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org,
	linux-rtc@vger.kernel.org
Subject: [PATCH v5 10/16] gpio: devres: Add devm_gpiod_get_parent_array
Date: Mon, 18 Nov 2019 08:58:30 +0200
Message-ID: <8dd9dad2765d47fd6c6fec20566326d00e48a696.1574059625.git.matti.vaittinen@fi.rohmeurope.com> (raw)
In-Reply-To: <cover.1574059625.git.matti.vaittinen@fi.rohmeurope.com>

Bunch of MFD sub-devices which are instantiated by MFD do not have
own device-tree nodes but have (for example) the GPIO consumer
information in parent device's DT node. Add resource managed
devm_gpiod_get_array() for such devices so that they can get the
consumer information from parent DT while still binding the GPIO
reservation life-time to this sub-device life time.

If devm_gpiod_get_array is used as such - then unloading and then
re-loading the child device fails as the GPIOs reserved during first
load are not freed when driver for sub-device is unload (if parent
stays there).

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
---

No changes from v4

 .../driver-api/driver-model/devres.rst        |  1 +
 drivers/gpio/gpiolib-devres.c                 | 65 ++++++++++++++-----
 include/linux/gpio/consumer.h                 |  5 ++
 3 files changed, 56 insertions(+), 15 deletions(-)

diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index a100bef54952..1b8302ba405b 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -270,6 +270,7 @@ GPIO
   devm_gpiod_get_index()
   devm_gpiod_get_index_optional()
   devm_gpiod_get_optional()
+  devm_gpiod_get_parent_array()
   devm_gpiod_put()
   devm_gpiod_unhinge()
   devm_gpiochip_add_data()
diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c
index 98e3c20d9730..584fa6edfd20 100644
--- a/drivers/gpio/gpiolib-devres.c
+++ b/drivers/gpio/gpiolib-devres.c
@@ -270,19 +270,11 @@ struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_gpiod_get_index_optional);
 
-/**
- * devm_gpiod_get_array - Resource-managed gpiod_get_array()
- * @dev:	GPIO consumer
- * @con_id:	function within the GPIO consumer
- * @flags:	optional GPIO initialization flags
- *
- * Managed gpiod_get_array(). GPIO descriptors returned from this function are
- * automatically disposed on driver detach. See gpiod_get_array() for detailed
- * information about behavior and return values.
- */
-struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
-						     const char *con_id,
-						     enum gpiod_flags flags)
+static struct gpio_descs *__must_check
+__devm_gpiod_get_array(struct device *gpiodev,
+		       struct device *managed,
+		       const char *con_id,
+		       enum gpiod_flags flags)
 {
 	struct gpio_descs **dr;
 	struct gpio_descs *descs;
@@ -292,19 +284,62 @@ struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
 	if (!dr)
 		return ERR_PTR(-ENOMEM);
 
-	descs = gpiod_get_array(dev, con_id, flags);
+	descs = gpiod_get_array(gpiodev, con_id, flags);
 	if (IS_ERR(descs)) {
 		devres_free(dr);
 		return descs;
 	}
 
 	*dr = descs;
-	devres_add(dev, dr);
+	if (managed)
+		devres_add(managed, dr);
+	else
+		devres_add(gpiodev, dr);
 
 	return descs;
 }
+
+/**
+ * devm_gpiod_get_array - Resource-managed gpiod_get_array()
+ * @dev:	GPIO consumer
+ * @con_id:	function within the GPIO consumer
+ * @flags:	optional GPIO initialization flags
+ *
+ * Managed gpiod_get_array(). GPIO descriptors returned from this function are
+ * automatically disposed on driver detach. See gpiod_get_array() for detailed
+ * information about behavior and return values.
+ */
+struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
+						     const char *con_id,
+						     enum gpiod_flags flags)
+{
+	return __devm_gpiod_get_array(dev, NULL, con_id, flags);
+}
 EXPORT_SYMBOL_GPL(devm_gpiod_get_array);
 
+/**
+ * devm_gpiod_get_parent_array - Resource-managed gpiod_get_array for subdevices
+ * @dev:	Managed device whose parent is the GPIO consumer
+ * @con_id:	function within the GPIO consumer
+ * @flags:	optional GPIO initialization flags
+ *
+ * Managed gpiod_get_array() for subdevices. This function is intended to be
+ * used by MFD sub-devices whose GPIO bindings are in parent (MFD) device but
+ * whose GPIO reservation should last only for the dub-device life time.
+ * Returns EINVAL if no parent device is found. Rest of the behaviour and
+ * return values are as documented for gpiod_get_array()
+ */
+struct gpio_descs *__must_check
+devm_gpiod_get_parent_array(struct device *dev,
+			    const char *con_id,
+			    enum gpiod_flags flags)
+{
+	if (!dev | !dev->parent)
+		return ERR_PTR(-EINVAL);
+	return __devm_gpiod_get_array(dev->parent, dev, con_id, flags);
+}
+EXPORT_SYMBOL_GPL(devm_gpiod_get_parent_array);
+
 /**
  * devm_gpiod_get_array_optional - Resource-managed gpiod_get_array_optional()
  * @dev:	GPIO consumer
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index b70af921c614..01a82b1c6828 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -103,6 +103,11 @@ struct gpio_descs *__must_check devm_gpiod_get_array(struct device *dev,
 struct gpio_descs *__must_check
 devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
 			      enum gpiod_flags flags);
+struct gpio_descs *__must_check
+devm_gpiod_get_parent_array(struct device *dev,
+			    const char *con_id,
+			    enum gpiod_flags flags);
+
 void devm_gpiod_put(struct device *dev, struct gpio_desc *desc);
 void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc);
 void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs);
-- 
2.21.0


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =] 

  parent reply index

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-18  6:53 [PATCH v5 00/16] Support ROHM BD71828 PMIC Matti Vaittinen
2019-11-18  6:53 ` [PATCH v5 01/16] dt-bindings: regulator: Document ROHM BD71282 regulator bindings Matti Vaittinen
2019-11-18 16:25   ` Mark Brown
2019-11-18 18:03     ` Vaittinen, Matti
2019-11-19 18:13       ` Mark Brown
2019-11-19 18:51         ` Vaittinen, Matti
2019-11-19 19:36           ` Mark Brown
2019-11-29  7:48             ` Vaittinen, Matti
2019-11-29 12:09               ` Mark Brown
2019-12-02  7:57                 ` Vaittinen, Matti
2019-12-02 13:11                   ` Mark Brown
2019-12-02 14:02                     ` Vaittinen, Matti
2019-12-04 12:47                       ` Mark Brown
2019-12-04 13:13                         ` Vaittinen, Matti
2019-12-04 14:14                           ` Mark Brown
2019-12-10 10:39                             ` Vaittinen, Matti
2019-12-10 11:14                 ` Vaittinen, Matti
2019-12-10 12:11                   ` Mark Brown
2019-12-10 12:41                     ` Vaittinen, Matti
2019-12-10 12:45                       ` Mark Brown
2019-12-10 13:07                         ` Vaittinen, Matti
2019-11-22 22:48   ` Rob Herring
2019-11-18  6:54 ` [PATCH v5 02/16] dt-bindings: leds: ROHM BD71282 PMIC LED driver Matti Vaittinen
2019-11-22 23:00   ` Rob Herring
2019-11-18  6:54 ` [PATCH v5 03/16] dt-bindings: mfd: Document ROHM BD71828 bindings Matti Vaittinen
2019-11-22 23:05   ` Rob Herring
2019-11-18  6:55 ` [PATCH v5 04/16] mfd: rohm PMICs - use platform_device_id to match MFD sub-devices Matti Vaittinen
2019-11-18  6:55 ` [PATCH v5 05/16] mfd: bd71828: Support ROHM BD71828 PMIC - core Matti Vaittinen
2019-11-18  6:56 ` [PATCH v5 06/16] mfd: input: bd71828: Add power-key support Matti Vaittinen
2019-11-18  6:56 ` [PATCH v5 07/16] clk: bd718x7: Support ROHM BD71828 clk block Matti Vaittinen
2019-11-18  6:57 ` [PATCH v5 08/16] regulator: bd718x7: Split driver to common and bd718x7 specific parts Matti Vaittinen
2019-11-18  6:57 ` [PATCH v5 09/16] regulator: bd71828: Basic support for ROHM bd71828 PMIC regulators Matti Vaittinen
2019-11-18 16:20   ` Mark Brown
2019-11-19  9:12     ` Vaittinen, Matti
2019-11-18  6:58 ` Matti Vaittinen [this message]
2019-11-19 14:43   ` [PATCH v5 10/16] gpio: devres: Add devm_gpiod_get_parent_array Linus Walleij
2019-11-19 17:54     ` Vaittinen, Matti
2019-11-21 14:13       ` Linus Walleij
2019-11-18  6:59 ` [PATCH v5 11/16] docs: driver-model: Add missing managed GPIO array get functions Matti Vaittinen
2019-11-18  6:59 ` [PATCH v5 12/16] regulator: bd71828: Add GPIO based run-level control for regulators Matti Vaittinen
2019-11-18  7:00 ` [PATCH v5 13/16] rtc: bd70528 add BD71828 support Matti Vaittinen
2019-12-10 13:24   ` Alexandre Belloni
2019-11-18  7:01 ` [PATCH v5 14/16] gpio: bd71828: Initial support for ROHM BD71828 PMIC GPIOs Matti Vaittinen
2019-11-18  9:22   ` Bartosz Golaszewski
2019-11-18  7:03 ` [PATCH v5 15/16] leds: Add common LED binding parsing support to LED class/core Matti Vaittinen
2019-11-18 21:55   ` Jacek Anaszewski
2019-11-19  7:21     ` Vaittinen, Matti
2019-11-19 19:30       ` Jacek Anaszewski
2019-11-20  7:31         ` Vaittinen, Matti
2019-11-19 14:23   ` Vaittinen, Matti
2019-11-18  7:03 ` [PATCH v5 16/16] led: bd71828: Support LED outputs on ROHM BD71828 PMIC Matti Vaittinen

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