2 * OF helpers for the GPIO API
4 * Copyright (c) 2007-2008 MontaVista Software, Inc.
6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
14 #include <linux/device.h>
15 #include <linux/err.h>
16 #include <linux/errno.h>
17 #include <linux/module.h>
19 #include <linux/gpio/consumer.h>
21 #include <linux/of_address.h>
22 #include <linux/of_gpio.h>
23 #include <linux/pinctrl/pinctrl.h>
24 #include <linux/slab.h>
28 /* Private data structure for of_gpiochip_find_and_xlate */
30 enum of_gpio_flags
*flags
;
31 struct of_phandle_args gpiospec
;
33 struct gpio_desc
*out_gpio
;
36 /* Private function for resolving node pointer to gpio_chip */
37 static int of_gpiochip_find_and_xlate(struct gpio_chip
*gc
, void *data
)
39 struct gg_data
*gg_data
= data
;
42 if ((gc
->of_node
!= gg_data
->gpiospec
.np
) ||
43 (gc
->of_gpio_n_cells
!= gg_data
->gpiospec
.args_count
) ||
47 ret
= gc
->of_xlate(gc
, &gg_data
->gpiospec
, gg_data
->flags
);
49 /* We've found the gpio chip, but the translation failed.
50 * Return true to stop looking and return the translation
53 gg_data
->out_gpio
= ERR_PTR(ret
);
57 gg_data
->out_gpio
= gpiochip_get_desc(gc
, ret
);
62 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
63 * @np: device node to get GPIO from
64 * @propname: property name containing gpio specifier(s)
65 * @index: index of the GPIO
66 * @flags: a flags pointer to fill in
68 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
69 * value on the error condition. If @flags is not NULL the function also fills
70 * in flags for the GPIO.
72 struct gpio_desc
*of_get_named_gpiod_flags(struct device_node
*np
,
73 const char *propname
, int index
, enum of_gpio_flags
*flags
)
75 /* Return -EPROBE_DEFER to support probe() functions to be called
76 * later when the GPIO actually becomes available
78 struct gg_data gg_data
= {
80 .out_gpio
= ERR_PTR(-EPROBE_DEFER
)
84 /* .of_xlate might decide to not fill in the flags, so clear it. */
88 ret
= of_parse_phandle_with_args(np
, propname
, "#gpio-cells", index
,
91 pr_debug("%s: can't parse '%s' property of node '%s[%d]'\n",
92 __func__
, propname
, np
->full_name
, index
);
96 gpiochip_find(&gg_data
, of_gpiochip_find_and_xlate
);
98 of_node_put(gg_data
.gpiospec
.np
);
99 pr_debug("%s: parsed '%s' property of node '%s[%d]' - status (%d)\n",
100 __func__
, propname
, np
->full_name
, index
,
101 PTR_ERR_OR_ZERO(gg_data
.out_gpio
));
102 return gg_data
.out_gpio
;
105 int of_get_named_gpio_flags(struct device_node
*np
, const char *list_name
,
106 int index
, enum of_gpio_flags
*flags
)
108 struct gpio_desc
*desc
;
110 desc
= of_get_named_gpiod_flags(np
, list_name
, index
, flags
);
113 return PTR_ERR(desc
);
115 return desc_to_gpio(desc
);
117 EXPORT_SYMBOL(of_get_named_gpio_flags
);
120 * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
121 * @gc: pointer to the gpio_chip structure
122 * @np: device node of the GPIO chip
123 * @gpio_spec: gpio specifier as found in the device tree
124 * @flags: a flags pointer to fill in
126 * This is simple translation function, suitable for the most 1:1 mapped
127 * gpio chips. This function performs only one sanity check: whether gpio
128 * is less than ngpios (that is specified in the gpio_chip).
130 int of_gpio_simple_xlate(struct gpio_chip
*gc
,
131 const struct of_phandle_args
*gpiospec
, u32
*flags
)
134 * We're discouraging gpio_cells < 2, since that way you'll have to
135 * write your own xlate function (that will have to retrive the GPIO
136 * number and the flags from a single gpio cell -- this is possible,
137 * but not recommended).
139 if (gc
->of_gpio_n_cells
< 2) {
144 if (WARN_ON(gpiospec
->args_count
< gc
->of_gpio_n_cells
))
147 if (gpiospec
->args
[0] >= gc
->ngpio
)
151 *flags
= gpiospec
->args
[1];
153 return gpiospec
->args
[0];
155 EXPORT_SYMBOL(of_gpio_simple_xlate
);
158 * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank)
159 * @np: device node of the GPIO chip
160 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
162 * To use this function you should allocate and fill mm_gc with:
164 * 1) In the gpio_chip structure:
165 * - all the callbacks
167 * - of_xlate callback (optional)
169 * 3) In the of_mm_gpio_chip structure:
170 * - save_regs callback (optional)
172 * If succeeded, this function will map bank's memory and will
173 * do all necessary work for you. Then you'll able to use .regs
174 * to manage GPIOs from the callbacks.
176 int of_mm_gpiochip_add(struct device_node
*np
,
177 struct of_mm_gpio_chip
*mm_gc
)
180 struct gpio_chip
*gc
= &mm_gc
->gc
;
182 gc
->label
= kstrdup(np
->full_name
, GFP_KERNEL
);
186 mm_gc
->regs
= of_iomap(np
, 0);
192 if (mm_gc
->save_regs
)
193 mm_gc
->save_regs(mm_gc
);
195 mm_gc
->gc
.of_node
= np
;
197 ret
= gpiochip_add(gc
);
203 iounmap(mm_gc
->regs
);
207 pr_err("%s: GPIO chip registration failed with status %d\n",
211 EXPORT_SYMBOL(of_mm_gpiochip_add
);
214 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
215 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure
217 void of_mm_gpiochip_remove(struct of_mm_gpio_chip
*mm_gc
)
219 struct gpio_chip
*gc
= &mm_gc
->gc
;
225 iounmap(mm_gc
->regs
);
228 EXPORT_SYMBOL(of_mm_gpiochip_remove
);
230 #ifdef CONFIG_PINCTRL
231 static void of_gpiochip_add_pin_range(struct gpio_chip
*chip
)
233 struct device_node
*np
= chip
->of_node
;
234 struct of_phandle_args pinspec
;
235 struct pinctrl_dev
*pctldev
;
238 static const char group_names_propname
[] = "gpio-ranges-group-names";
239 struct property
*group_names
;
244 group_names
= of_find_property(np
, group_names_propname
, NULL
);
247 ret
= of_parse_phandle_with_fixed_args(np
, "gpio-ranges", 3,
252 pctldev
= of_pinctrl_get(pinspec
.np
);
256 if (pinspec
.args
[2]) {
258 ret
= of_property_read_string_index(np
,
259 group_names_propname
,
262 pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
267 /* npins != 0: linear range */
268 ret
= gpiochip_add_pin_range(chip
,
269 pinctrl_dev_get_devname(pctldev
),
276 /* npins == 0: special range */
277 if (pinspec
.args
[1]) {
278 pr_err("%s: Illegal gpio-range format.\n",
284 pr_err("%s: GPIO group range requested but no %s property.\n",
285 np
->full_name
, group_names_propname
);
289 ret
= of_property_read_string_index(np
,
290 group_names_propname
,
296 pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
301 ret
= gpiochip_add_pingroup_range(chip
, pctldev
,
302 pinspec
.args
[0], name
);
310 static void of_gpiochip_add_pin_range(struct gpio_chip
*chip
) {}
313 void of_gpiochip_add(struct gpio_chip
*chip
)
315 if ((!chip
->of_node
) && (chip
->dev
))
316 chip
->of_node
= chip
->dev
->of_node
;
321 if (!chip
->of_xlate
) {
322 chip
->of_gpio_n_cells
= 2;
323 chip
->of_xlate
= of_gpio_simple_xlate
;
326 of_gpiochip_add_pin_range(chip
);
327 of_node_get(chip
->of_node
);
330 void of_gpiochip_remove(struct gpio_chip
*chip
)
332 gpiochip_remove_pin_ranges(chip
);
333 of_node_put(chip
->of_node
);