lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

gpiolib: provide provision to register pin ranges

Browse Source 
pinctrl subsystem needs gpio chip base to prepare set of gpio
pin ranges, which a given pinctrl driver can handle. This is
important to handle pinctrl gpio request calls in order to
program a given pin properly for gpio operation.

As gpio base is allocated dynamically during gpiochip
registration, presently there exists no clean way to pass this
information to the pinctrl subsystem.

After few discussions from [1], it was concluded that may be
gpio controller reporting the pin range it supports, is a
better way than pinctrl subsystem directly registering it.

[1] http://comments.gmane.org/gmane.linux.ports.arm.kernel/184816

Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
[Edited documentation a bit]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Shiraz Hashim
2012-10-27 15:21:36 +05:30
committed by Linus Walleij
parent 7e10ee68f8
commit f23f1516b6
10 changed files with 251 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
include/asm-generic/gpio.h
View File

@@ -5,6 +5,7 @@
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/of.h>
#include <linux/pinctrl/pinctrl.h>
#ifdef CONFIG_GPIOLIB
@@ -47,6 +48,21 @@ struct seq_file;
struct module;
struct device_node;
#ifdef CONFIG_PINCTRL
/**
* struct gpio_pin_range - pin range controlled by a gpio chip
* @head: list for maintaining set of pin ranges, used internally
* @pctldev: pinctrl device which handles corresponding pins
* @range: actual range of pins controlled by a gpio controller
*/
struct gpio_pin_range {
struct list_head node;
struct pinctrl_dev *pctldev;
struct pinctrl_gpio_range range;
};
#endif
/**
* struct gpio_chip - abstract a GPIO controller
* @label: for diagnostics
@@ -134,6 +150,15 @@ struct gpio_chip {
int (*of_xlate)(struct gpio_chip *gc,
const struct of_phandle_args *gpiospec, u32 *flags);
#endif
#ifdef CONFIG_PINCTRL
/*
* If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
* describe the actual pin range which they serve in an SoC. This
* information would be used by pinctrl subsystem to configure
* corresponding pins for gpio usage.
*/
struct list_head pin_ranges;
#endif
};
extern const char *gpiochip_is_requested(struct gpio_chip *chip,