~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/asm-generic/gpio.h

Version: ~ [ linux-5.15-rc5 ] ~ [ linux-5.14.11 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.72 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.152 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.210 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.250 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.286 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.288 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 #ifndef _ASM_GENERIC_GPIO_H
  2 #define _ASM_GENERIC_GPIO_H
  3 
  4 #include <linux/kernel.h>
  5 #include <linux/types.h>
  6 #include <linux/errno.h>
  7 
  8 #ifdef CONFIG_GPIOLIB
  9 
 10 #include <linux/compiler.h>
 11 
 12 /* Platforms may implement their GPIO interface with library code,
 13  * at a small performance cost for non-inlined operations and some
 14  * extra memory (for code and for per-GPIO table entries).
 15  *
 16  * While the GPIO programming interface defines valid GPIO numbers
 17  * to be in the range 0..MAX_INT, this library restricts them to the
 18  * smaller range 0..ARCH_NR_GPIOS-1.
 19  */
 20 
 21 #ifndef ARCH_NR_GPIOS
 22 #define ARCH_NR_GPIOS           256
 23 #endif
 24 
 25 static inline int gpio_is_valid(int number)
 26 {
 27         /* only some non-negative numbers are valid */
 28         return ((unsigned)number) < ARCH_NR_GPIOS;
 29 }
 30 
 31 struct seq_file;
 32 struct module;
 33 
 34 /**
 35  * struct gpio_chip - abstract a GPIO controller
 36  * @label: for diagnostics
 37  * @dev: optional device providing the GPIOs
 38  * @owner: helps prevent removal of modules exporting active GPIOs
 39  * @request: optional hook for chip-specific activation, such as
 40  *      enabling module power and clock; may sleep
 41  * @free: optional hook for chip-specific deactivation, such as
 42  *      disabling module power and clock; may sleep
 43  * @direction_input: configures signal "offset" as input, or returns error
 44  * @get: returns value for signal "offset"; for output signals this
 45  *      returns either the value actually sensed, or zero
 46  * @direction_output: configures signal "offset" as output, or returns error
 47  * @set: assigns output value for signal "offset"
 48  * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
 49  *      implementation may not sleep
 50  * @dbg_show: optional routine to show contents in debugfs; default code
 51  *      will be used when this is omitted, but custom code can show extra
 52  *      state (such as pullup/pulldown configuration).
 53  * @base: identifies the first GPIO number handled by this chip; or, if
 54  *      negative during registration, requests dynamic ID allocation.
 55  * @ngpio: the number of GPIOs handled by this controller; the last GPIO
 56  *      handled is (base + ngpio - 1).
 57  * @can_sleep: flag must be set iff get()/set() methods sleep, as they
 58  *      must while accessing GPIO expander chips over I2C or SPI
 59  * @names: if set, must be an array of strings to use as alternative
 60  *      names for the GPIOs in this chip. Any entry in the array
 61  *      may be NULL if there is no alias for the GPIO, however the
 62  *      array must be @ngpio entries long.
 63  *
 64  * A gpio_chip can help platforms abstract various sources of GPIOs so
 65  * they can all be accessed through a common programing interface.
 66  * Example sources would be SOC controllers, FPGAs, multifunction
 67  * chips, dedicated GPIO expanders, and so on.
 68  *
 69  * Each chip controls a number of signals, identified in method calls
 70  * by "offset" values in the range 0..(@ngpio - 1).  When those signals
 71  * are referenced through calls like gpio_get_value(gpio), the offset
 72  * is calculated by subtracting @base from the gpio number.
 73  */
 74 struct gpio_chip {
 75         const char              *label;
 76         struct device           *dev;
 77         struct module           *owner;
 78 
 79         int                     (*request)(struct gpio_chip *chip,
 80                                                 unsigned offset);
 81         void                    (*free)(struct gpio_chip *chip,
 82                                                 unsigned offset);
 83 
 84         int                     (*direction_input)(struct gpio_chip *chip,
 85                                                 unsigned offset);
 86         int                     (*get)(struct gpio_chip *chip,
 87                                                 unsigned offset);
 88         int                     (*direction_output)(struct gpio_chip *chip,
 89                                                 unsigned offset, int value);
 90         void                    (*set)(struct gpio_chip *chip,
 91                                                 unsigned offset, int value);
 92 
 93         int                     (*to_irq)(struct gpio_chip *chip,
 94                                                 unsigned offset);
 95 
 96         void                    (*dbg_show)(struct seq_file *s,
 97                                                 struct gpio_chip *chip);
 98         int                     base;
 99         u16                     ngpio;
100         char                    **names;
101         unsigned                can_sleep:1;
102         unsigned                exported:1;
103 };
104 
105 extern const char *gpiochip_is_requested(struct gpio_chip *chip,
106                         unsigned offset);
107 extern int __must_check gpiochip_reserve(int start, int ngpio);
108 
109 /* add/remove chips */
110 extern int gpiochip_add(struct gpio_chip *chip);
111 extern int __must_check gpiochip_remove(struct gpio_chip *chip);
112 
113 
114 /* Always use the library code for GPIO management calls,
115  * or when sleeping may be involved.
116  */
117 extern int gpio_request(unsigned gpio, const char *label);
118 extern void gpio_free(unsigned gpio);
119 
120 extern int gpio_direction_input(unsigned gpio);
121 extern int gpio_direction_output(unsigned gpio, int value);
122 
123 extern int gpio_get_value_cansleep(unsigned gpio);
124 extern void gpio_set_value_cansleep(unsigned gpio, int value);
125 
126 
127 /* A platform's <asm/gpio.h> code may want to inline the I/O calls when
128  * the GPIO is constant and refers to some always-present controller,
129  * giving direct access to chip registers and tight bitbanging loops.
130  */
131 extern int __gpio_get_value(unsigned gpio);
132 extern void __gpio_set_value(unsigned gpio, int value);
133 
134 extern int __gpio_cansleep(unsigned gpio);
135 
136 extern int __gpio_to_irq(unsigned gpio);
137 
138 #ifdef CONFIG_GPIO_SYSFS
139 
140 /*
141  * A sysfs interface can be exported by individual drivers if they want,
142  * but more typically is configured entirely from userspace.
143  */
144 extern int gpio_export(unsigned gpio, bool direction_may_change);
145 extern int gpio_export_link(struct device *dev, const char *name,
146                         unsigned gpio);
147 extern void gpio_unexport(unsigned gpio);
148 
149 #endif  /* CONFIG_GPIO_SYSFS */
150 
151 #else   /* !CONFIG_HAVE_GPIO_LIB */
152 
153 static inline int gpio_is_valid(int number)
154 {
155         /* only non-negative numbers are valid */
156         return number >= 0;
157 }
158 
159 /* platforms that don't directly support access to GPIOs through I2C, SPI,
160  * or other blocking infrastructure can use these wrappers.
161  */
162 
163 static inline int gpio_cansleep(unsigned gpio)
164 {
165         return 0;
166 }
167 
168 static inline int gpio_get_value_cansleep(unsigned gpio)
169 {
170         might_sleep();
171         return gpio_get_value(gpio);
172 }
173 
174 static inline void gpio_set_value_cansleep(unsigned gpio, int value)
175 {
176         might_sleep();
177         gpio_set_value(gpio, value);
178 }
179 
180 #endif /* !CONFIG_HAVE_GPIO_LIB */
181 
182 #ifndef CONFIG_GPIO_SYSFS
183 
184 /* sysfs support is only available with gpiolib, where it's optional */
185 
186 static inline int gpio_export(unsigned gpio, bool direction_may_change)
187 {
188         return -ENOSYS;
189 }
190 
191 static inline int gpio_export_link(struct device *dev, const char *name,
192                                 unsigned gpio)
193 {
194         return -ENOSYS;
195 }
196 
197 static inline void gpio_unexport(unsigned gpio)
198 {
199 }
200 #endif  /* CONFIG_GPIO_SYSFS */
201 
202 #endif /* _ASM_GENERIC_GPIO_H */
203 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp