gpio: split gpiod board registration into machine header
[linux-2.6-block.git] / include / linux / gpio / driver.h
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1#ifndef __LINUX_GPIO_DRIVER_H
2#define __LINUX_GPIO_DRIVER_H
3
4#include <linux/types.h>
c9a9972b 5#include <linux/module.h>
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6#include <linux/irq.h>
7#include <linux/irqchip/chained_irq.h>
8#include <linux/irqdomain.h>
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9
10struct device;
11struct gpio_desc;
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12struct of_phandle_args;
13struct device_node;
f3ed0b66 14struct seq_file;
79a9becd 15
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16#ifdef CONFIG_GPIOLIB
17
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18/**
19 * struct gpio_chip - abstract a GPIO controller
20 * @label: for diagnostics
21 * @dev: optional device providing the GPIOs
22 * @owner: helps prevent removal of modules exporting active GPIOs
23 * @list: links gpio_chips together for traversal
24 * @request: optional hook for chip-specific activation, such as
25 * enabling module power and clock; may sleep
26 * @free: optional hook for chip-specific deactivation, such as
27 * disabling module power and clock; may sleep
28 * @get_direction: returns direction for signal "offset", 0=out, 1=in,
29 * (same as GPIOF_DIR_XXX), or negative error
30 * @direction_input: configures signal "offset" as input, or returns error
31 * @direction_output: configures signal "offset" as output, or returns error
32 * @get: returns value for signal "offset"; for output signals this
33 * returns either the value actually sensed, or zero
34 * @set: assigns output value for signal "offset"
35 * @set_debounce: optional hook for setting debounce time for specified gpio in
36 * interrupt triggered gpio chips
37 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
38 * implementation may not sleep
39 * @dbg_show: optional routine to show contents in debugfs; default code
40 * will be used when this is omitted, but custom code can show extra
41 * state (such as pullup/pulldown configuration).
42 * @base: identifies the first GPIO number handled by this chip; or, if
43 * negative during registration, requests dynamic ID allocation.
44 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
45 * handled is (base + ngpio - 1).
46 * @desc: array of ngpio descriptors. Private.
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47 * @names: if set, must be an array of strings to use as alternative
48 * names for the GPIOs in this chip. Any entry in the array
49 * may be NULL if there is no alias for the GPIO, however the
50 * array must be @ngpio entries long. A name can include a single printk
51 * format specifier for an unsigned int. It is substituted by the actual
52 * number of the gpio.
9fb1f39e 53 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
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54 * must while accessing GPIO expander chips over I2C or SPI. This
55 * implies that if the chip supports IRQs, these IRQs need to be threaded
56 * as the chip access may sleep when e.g. reading out the IRQ status
57 * registers.
9fb1f39e 58 * @exported: flags if the gpiochip is exported for use from sysfs. Private.
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59 *
60 * A gpio_chip can help platforms abstract various sources of GPIOs so
61 * they can all be accessed through a common programing interface.
62 * Example sources would be SOC controllers, FPGAs, multifunction
63 * chips, dedicated GPIO expanders, and so on.
64 *
65 * Each chip controls a number of signals, identified in method calls
66 * by "offset" values in the range 0..(@ngpio - 1). When those signals
67 * are referenced through calls like gpio_get_value(gpio), the offset
68 * is calculated by subtracting @base from the gpio number.
69 */
70struct gpio_chip {
71 const char *label;
72 struct device *dev;
73 struct module *owner;
74 struct list_head list;
75
76 int (*request)(struct gpio_chip *chip,
77 unsigned offset);
78 void (*free)(struct gpio_chip *chip,
79 unsigned offset);
80 int (*get_direction)(struct gpio_chip *chip,
81 unsigned offset);
82 int (*direction_input)(struct gpio_chip *chip,
83 unsigned offset);
84 int (*direction_output)(struct gpio_chip *chip,
85 unsigned offset, int value);
86 int (*get)(struct gpio_chip *chip,
87 unsigned offset);
88 void (*set)(struct gpio_chip *chip,
89 unsigned offset, int value);
90 int (*set_debounce)(struct gpio_chip *chip,
91 unsigned offset,
92 unsigned debounce);
93
94 int (*to_irq)(struct gpio_chip *chip,
95 unsigned offset);
96
97 void (*dbg_show)(struct seq_file *s,
98 struct gpio_chip *chip);
99 int base;
100 u16 ngpio;
101 struct gpio_desc *desc;
102 const char *const *names;
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103 bool can_sleep;
104 bool exported;
79a9becd 105
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106#ifdef CONFIG_GPIOLIB_IRQCHIP
107 /*
108 * With CONFIG_GPIO_IRQCHIP we get an irqchip inside the gpiolib
109 * to handle IRQs for most practical cases.
110 */
111 struct irq_chip *irqchip;
112 struct irq_domain *irqdomain;
c3626fde 113 unsigned int irq_base;
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114 irq_flow_handler_t irq_handler;
115 unsigned int irq_default_type;
116#endif
117
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118#if defined(CONFIG_OF_GPIO)
119 /*
120 * If CONFIG_OF is enabled, then all GPIO controllers described in the
121 * device tree automatically may have an OF translation
122 */
123 struct device_node *of_node;
124 int of_gpio_n_cells;
125 int (*of_xlate)(struct gpio_chip *gc,
126 const struct of_phandle_args *gpiospec, u32 *flags);
127#endif
128#ifdef CONFIG_PINCTRL
129 /*
130 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
131 * describe the actual pin range which they serve in an SoC. This
132 * information would be used by pinctrl subsystem to configure
133 * corresponding pins for gpio usage.
134 */
135 struct list_head pin_ranges;
136#endif
137};
138
139extern const char *gpiochip_is_requested(struct gpio_chip *chip,
140 unsigned offset);
141
142/* add/remove chips */
143extern int gpiochip_add(struct gpio_chip *chip);
14c8a620 144extern int gpiochip_remove(struct gpio_chip *chip);
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145extern struct gpio_chip *gpiochip_find(void *data,
146 int (*match)(struct gpio_chip *chip, void *data));
147
148/* lock/unlock as IRQ */
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149int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
150void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
79a9becd 151
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152struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
153
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154#ifdef CONFIG_GPIOLIB_IRQCHIP
155
156void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
157 struct irq_chip *irqchip,
158 int parent_irq,
159 irq_flow_handler_t parent_handler);
160
161int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
162 struct irq_chip *irqchip,
163 unsigned int first_irq,
164 irq_flow_handler_t handler,
165 unsigned int type);
166
167#endif /* CONFIG_GPIO_IRQCHIP */
168
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169int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label);
170void gpiochip_free_own_desc(struct gpio_desc *desc);
171
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172#else /* CONFIG_GPIOLIB */
173
174static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
175{
176 /* GPIO can never have been requested */
177 WARN_ON(1);
178 return ERR_PTR(-ENODEV);
179}
180
181#endif /* CONFIG_GPIOLIB */
182
79a9becd 183#endif