122 lines
4.4 KiB
Diff
122 lines
4.4 KiB
Diff
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From b08ea35a3296ee25c4cb53a977b752266dafa2c2 Mon Sep 17 00:00:00 2001
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From: Linus Walleij <linus.walleij@linaro.org>
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Date: Thu, 3 Dec 2015 15:14:13 +0100
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Subject: [PATCH] gpio: add a data pointer to gpio_chip
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This adds a void * pointer to gpio_chip so that driver can
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assign and retrieve some states. This is done to get rid of
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container_of() calls for gpio_chips embedded inside state
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containers, so we can remove the need to have the gpio_chip
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or later (planned) struct gpio_device be dynamically allocated
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at registration time, so that its struct device can be properly
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reference counted and not bound to its parent device (e.g.
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a platform_device) but instead live on after unregistration
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if it is opened by e.g. a char device or sysfs.
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The data is added with the new function gpiochip_add_data()
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and for compatibility we add static inline wrapper function
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gpiochip_add() that will call gpiochip_add_data() with
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NULL as argument. The latter will be removed once we have
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exorcised gpiochip_add() from the kernel.
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gpiochip_get_data() is added as a static inline accessor
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for drivers to quickly get their data out.
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Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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---
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drivers/gpio/gpiolib.c | 10 ++++++----
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include/linux/gpio/driver.h | 14 +++++++++++++-
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2 files changed, 19 insertions(+), 5 deletions(-)
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--- a/drivers/gpio/gpiolib.c
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+++ b/drivers/gpio/gpiolib.c
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@@ -280,7 +280,7 @@ static int gpiochip_set_desc_names(struc
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}
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/**
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- * gpiochip_add() - register a gpio_chip
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+ * gpiochip_add_data() - register a gpio_chip
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* @chip: the chip to register, with chip->base initialized
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* Context: potentially before irqs will work
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*
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@@ -288,7 +288,7 @@ static int gpiochip_set_desc_names(struc
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* because the chip->base is invalid or already associated with a
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* different chip. Otherwise it returns zero as a success code.
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*
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- * When gpiochip_add() is called very early during boot, so that GPIOs
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+ * When gpiochip_add_data() is called very early during boot, so that GPIOs
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* can be freely used, the chip->dev device must be registered before
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* the gpio framework's arch_initcall(). Otherwise sysfs initialization
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* for GPIOs will fail rudely.
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@@ -296,7 +296,7 @@ static int gpiochip_set_desc_names(struc
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* If chip->base is negative, this requests dynamic assignment of
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* a range of valid GPIOs.
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*/
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-int gpiochip_add(struct gpio_chip *chip)
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+int gpiochip_add_data(struct gpio_chip *chip, void *data)
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{
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unsigned long flags;
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int status = 0;
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@@ -308,6 +308,8 @@ int gpiochip_add(struct gpio_chip *chip)
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if (!descs)
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return -ENOMEM;
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+ chip->data = data;
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+
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spin_lock_irqsave(&gpio_lock, flags);
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if (base < 0) {
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@@ -389,7 +391,7 @@ err_free_descs:
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chip->label ? : "generic");
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return status;
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}
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-EXPORT_SYMBOL_GPL(gpiochip_add);
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+EXPORT_SYMBOL_GPL(gpiochip_add_data);
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/**
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* gpiochip_remove() - unregister a gpio_chip
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--- a/include/linux/gpio/driver.h
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+++ b/include/linux/gpio/driver.h
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@@ -23,6 +23,7 @@ struct seq_file;
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* @dev: optional device providing the GPIOs
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* @cdev: class device used by sysfs interface (may be NULL)
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* @owner: helps prevent removal of modules exporting active GPIOs
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+ * @data: per-instance data assigned by the driver
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* @list: links gpio_chips together for traversal
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* @request: optional hook for chip-specific activation, such as
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* enabling module power and clock; may sleep
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@@ -92,6 +93,7 @@ struct gpio_chip {
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struct device *dev;
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struct device *cdev;
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struct module *owner;
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+ void *data;
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struct list_head list;
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int (*request)(struct gpio_chip *chip,
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@@ -166,7 +168,11 @@ extern const char *gpiochip_is_requested
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unsigned offset);
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/* add/remove chips */
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-extern int gpiochip_add(struct gpio_chip *chip);
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+extern int gpiochip_add_data(struct gpio_chip *chip, void *data);
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+static inline int gpiochip_add(struct gpio_chip *chip)
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+{
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+ return gpiochip_add_data(chip, NULL);
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+}
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extern void gpiochip_remove(struct gpio_chip *chip);
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extern struct gpio_chip *gpiochip_find(void *data,
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int (*match)(struct gpio_chip *chip, void *data));
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@@ -175,6 +181,12 @@ extern struct gpio_chip *gpiochip_find(v
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int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
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void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
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+/* get driver data */
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+static inline void *gpiochip_get_data(struct gpio_chip *chip)
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+{
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+ return chip->data;
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+}
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+
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struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
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#ifdef CONFIG_GPIOLIB_IRQCHIP
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