aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/lantiq/patches-3.2/0001-GPIO-add-bindings-for-managed-devices.patch
blob: 765d3c633233b2bea6c9092522b661e2afeb13c3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
From 282f1ca84b35f3be68abc4fd8b52e229f3cb6bb7 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Thu, 8 Mar 2012 13:23:53 +0100
Subject: [PATCH 01/70] GPIO: add bindings for managed devices

This patch adds 2 functions that allow managed devices to request GPIOs.
These GPIOs will then be managed by drivers/base/devres.c.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---
 drivers/gpio/Makefile      |    2 +-
 drivers/gpio/devres.c      |   90 ++++++++++++++++++++++++++++++++++++++++++++
 include/asm-generic/gpio.h |    4 ++
 3 files changed, 95 insertions(+), 1 deletions(-)
 create mode 100644 drivers/gpio/devres.c

--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -2,7 +2,7 @@
 
 ccflags-$(CONFIG_DEBUG_GPIO)	+= -DDEBUG
 
-obj-$(CONFIG_GPIOLIB)		+= gpiolib.o
+obj-$(CONFIG_GPIOLIB)		+= gpiolib.o devres.o
 
 # Device drivers. Generally keep list sorted alphabetically
 obj-$(CONFIG_GPIO_GENERIC)	+= gpio-generic.o
--- /dev/null
+++ b/drivers/gpio/devres.c
@@ -0,0 +1,90 @@
+/*
+ * drivers/gpio/devres.c - managed gpio resources
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * This file is based on kernel/irq/devres.c
+ *
+ * Copyright (c) 2011 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/device.h>
+#include <linux/gfp.h>
+
+static void devm_gpio_release(struct device *dev, void *res)
+{
+	unsigned *gpio = res;
+
+	gpio_free(*gpio);
+}
+
+static int devm_gpio_match(struct device *dev, void *res, void *data)
+{
+	unsigned *this = res, *gpio = data;
+
+	return *this == *gpio;
+}
+
+/**
+ *      devm_gpio_request - request a gpio for a managed device
+ *      @dev: device to request the gpio for
+ *      @gpio: gpio to allocate
+ *      @label: the name of the requested gpio
+ *
+ *      Except for the extra @dev argument, this function takes the
+ *      same arguments and performs the same function as
+ *      gpio_request().  GPIOs requested with this function will be
+ *      automatically freed on driver detach.
+ *
+ *      If an GPIO allocated with this function needs to be freed
+ *      separately, devm_gpio_free() must be used.
+ */
+
+int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
+{
+	unsigned *dr;
+	int rc;
+
+	dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	rc = gpio_request(gpio, label);
+	if (rc) {
+		devres_free(dr);
+		return rc;
+	}
+
+	*dr = gpio;
+	devres_add(dev, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL(devm_gpio_request);
+
+/**
+ *      devm_gpio_free - free an interrupt
+ *      @dev: device to free gpio for
+ *      @gpio: gpio to free
+ *
+ *      Except for the extra @dev argument, this function takes the
+ *      same arguments and performs the same function as gpio_free().
+ *      This function instead of gpio_free() should be used to manually
+ *      free GPIOs allocated with devm_gpio_request().
+ */
+void devm_gpio_free(struct device *dev, unsigned int gpio)
+{
+
+	WARN_ON(devres_destroy(dev, devm_gpio_release, devm_gpio_match,
+		&gpio));
+	gpio_free(gpio);
+}
+EXPORT_SYMBOL(devm_gpio_free);
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -175,6 +175,10 @@ extern int gpio_request_one(unsigned gpi
 extern int gpio_request_array(const struct gpio *array, size_t num);
 extern void gpio_free_array(const struct gpio *array, size_t num);
 
+/* bindings for managed devices that want to request gpios */
+int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
+void devm_gpio_free(struct device *dev, unsigned int gpio);
+
 #ifdef CONFIG_GPIO_SYSFS
 
 /*