drivers/gpio/gpiolib.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Internal GPIO functions.
   4  *
   5  * Copyright (C) 2013, Intel Corporation
   6  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
   7  */
   8
   9 #ifndef GPIOLIB_H
  10 #define GPIOLIB_H
  11
  12 #include <linux/cdev.h>
  13 #include <linux/device.h>
  14 #include <linux/err.h>
  15 #include <linux/gpio/consumer.h> /* for enum gpiod_flags */
  16 #include <linux/gpio/driver.h>
  17 #include <linux/module.h>
  18 #include <linux/notifier.h>
  19 #include <linux/srcu.h>
  20 #include <linux/workqueue.h>
  21
  22 #define GPIOCHIP_NAME   "gpiochip"
  23
  24 /**
  25  * struct gpio_device - internal state container for GPIO devices
  26  * @dev: the GPIO device struct
  27  * @chrdev: character device for the GPIO device
  28  * @id: numerical ID number for the GPIO chip
  29  * @mockdev: class device used by the deprecated sysfs interface (may be
  30  * NULL)
  31  * @owner: helps prevent removal of modules exporting active GPIOs
  32  * @chip: pointer to the corresponding gpiochip, holding static
  33  * data for this device
  34  * @descs: array of ngpio descriptors.
  35  * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users
  36  * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
  37  * of the @descs array.
  38  * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep
  39  * implying that they cannot be used from atomic context
  40  * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
  41  * at device creation time.
  42  * @label: a descriptive name for the GPIO device, such as the part number
  43  * or name of the IP component in a System on Chip.
  44  * @data: per-instance data assigned by the driver
  45  * @list: links gpio_device:s together for traversal
  46  * @line_state_notifier: used to notify subscribers about lines being
  47  *                       requested, released or reconfigured
  48  * @line_state_wq: used to emit line state events from a separate thread in
  49  *                 process context
  50  * @device_notifier: used to notify character device wait queues about the GPIO
  51  *                   device being unregistered
  52  * @srcu: protects the pointer to the underlying GPIO chip
  53  * @pin_ranges: range of pins served by the GPIO driver
  54  *
  55  * This state container holds most of the runtime variable data
  56  * for a GPIO device and can hold references and live on after the
  57  * GPIO chip has been removed, if it is still being used from
  58  * userspace.
  59  */
  60 struct gpio_device {
  61         struct device           dev;
  62         struct cdev             chrdev;
  63         int                     id;
  64         struct device           *mockdev;
  65         struct module           *owner;
  66         struct gpio_chip __rcu  *chip;
  67         struct gpio_desc        *descs;
  68         struct srcu_struct      desc_srcu;
  69         unsigned int            base;
  70         u16                     ngpio;
  71         bool                    can_sleep;
  72         const char              *label;
  73         void                    *data;
  74         struct list_head        list;
  75         struct atomic_notifier_head line_state_notifier;
  76         struct workqueue_struct *line_state_wq;
  77         struct blocking_notifier_head device_notifier;
  78         struct srcu_struct      srcu;
  79
  80 #ifdef CONFIG_PINCTRL
  81         /*
  82          * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
  83          * describe the actual pin range which they serve in an SoC. This
  84          * information would be used by pinctrl subsystem to configure
  85          * corresponding pins for gpio usage.
  86          */
  87         struct list_head pin_ranges;
  88 #endif
  89 };
  90
  91 static inline struct gpio_device *to_gpio_device(struct device *dev)
  92 {
  93         return container_of(dev, struct gpio_device, dev);
  94 }
  95
  96 /* GPIO suffixes used for ACPI and device tree lookup */
  97 extern const char *const gpio_suffixes[];
  98
  99 #define for_each_gpio_property_name(propname, con_id)                                   \
 100         for (const char * const *__suffixes = gpio_suffixes;                            \
 101              *__suffixes && ({                                                          \
 102                 const char *__gs = *__suffixes;                                         \
 103                                                                                         \
 104                 if (con_id)                                                             \
 105                         snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs);    \
 106                 else                                                                    \
 107                         snprintf(propname, sizeof(propname), "%s", __gs);               \
 108                 1;                                                                      \
 109              });                                                                        \
 110              __suffixes++)
 111
 112 /**
 113  * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes
 114  *
 115  * @desc:               Array of pointers to the GPIO descriptors
 116  * @size:               Number of elements in desc
 117  * @chip:               Parent GPIO chip
 118  * @get_mask:           Get mask used in fastpath
 119  * @set_mask:           Set mask used in fastpath
 120  * @invert_mask:        Invert mask used in fastpath
 121  *
 122  * This structure is attached to struct gpiod_descs obtained from
 123  * gpiod_get_array() and can be passed back to get/set array functions in order
 124  * to activate fast processing path if applicable.
 125  */
 126 struct gpio_array {
 127         struct gpio_desc        **desc;
 128         unsigned int            size;
 129         struct gpio_chip        *chip;
 130         unsigned long           *get_mask;
 131         unsigned long           *set_mask;
 132         unsigned long           invert_mask[];
 133 };
 134
 135 #define for_each_gpio_desc(gc, desc)                                    \
 136         for (unsigned int __i = 0;                                      \
 137              __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i));    \
 138              __i++)                                                     \
 139
 140 #define for_each_gpio_desc_with_flag(gc, desc, flag)                    \
 141         for_each_gpio_desc(gc, desc)                                    \
 142                 if (!test_bit(flag, &desc->flags)) {} else
 143
 144 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
 145                                   unsigned int array_size,
 146                                   struct gpio_desc **desc_array,
 147                                   struct gpio_array *array_info,
 148                                   unsigned long *value_bitmap);
 149 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
 150                                   unsigned int array_size,
 151                                   struct gpio_desc **desc_array,
 152                                   struct gpio_array *array_info,
 153                                   unsigned long *value_bitmap);
 154
 155 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory);
 156
 157 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
 158 int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value);
 159 int gpiod_direction_input_nonotify(struct gpio_desc *desc);
 160
 161 struct gpio_desc_label {
 162         struct rcu_head rh;
 163         char str[];
 164 };
 165
 166 /**
 167  * struct gpio_desc - Opaque descriptor for a GPIO
 168  *
 169  * @gdev:               Pointer to the parent GPIO device
 170  * @flags:              Binary descriptor flags
 171  * @label:              Name of the consumer
 172  * @name:               Line name
 173  * @hog:                Pointer to the device node that hogs this line (if any)
 174  * @debounce_period_us: Debounce period in microseconds
 175  *
 176  * These are obtained using gpiod_get() and are preferable to the old
 177  * integer-based handles.
 178  *
 179  * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be
 180  * valid until the GPIO is released.
 181  */
 182 struct gpio_desc {
 183         struct gpio_device      *gdev;
 184         unsigned long           flags;
 185 /* flag symbols are bit numbers */
 186 #define FLAG_REQUESTED  0
 187 #define FLAG_IS_OUT     1
 188 #define FLAG_EXPORT     2       /* protected by sysfs_lock */
 189 #define FLAG_SYSFS      3       /* exported via /sys/class/gpio/control */
 190 #define FLAG_ACTIVE_LOW 6       /* value has active low */
 191 #define FLAG_OPEN_DRAIN 7       /* Gpio is open drain type */
 192 #define FLAG_OPEN_SOURCE 8      /* Gpio is open source type */
 193 #define FLAG_USED_AS_IRQ 9      /* GPIO is connected to an IRQ */
 194 #define FLAG_IRQ_IS_ENABLED 10  /* GPIO is connected to an enabled IRQ */
 195 #define FLAG_IS_HOGGED  11      /* GPIO is hogged */
 196 #define FLAG_TRANSITORY 12      /* GPIO may lose value in sleep or reset */
 197 #define FLAG_PULL_UP    13      /* GPIO has pull up enabled */
 198 #define FLAG_PULL_DOWN  14      /* GPIO has pull down enabled */
 199 #define FLAG_BIAS_DISABLE    15 /* GPIO has pull disabled */
 200 #define FLAG_EDGE_RISING     16 /* GPIO CDEV detects rising edge events */
 201 #define FLAG_EDGE_FALLING    17 /* GPIO CDEV detects falling edge events */
 202 #define FLAG_EVENT_CLOCK_REALTIME       18 /* GPIO CDEV reports REALTIME timestamps in events */
 203 #define FLAG_EVENT_CLOCK_HTE            19 /* GPIO CDEV reports hardware timestamps in events */
 204
 205         /* Connection label */
 206         struct gpio_desc_label __rcu *label;
 207         /* Name of the GPIO */
 208         const char              *name;
 209 #ifdef CONFIG_OF_DYNAMIC
 210         struct device_node      *hog;
 211 #endif
 212 #ifdef CONFIG_GPIO_CDEV
 213         /* debounce period in microseconds */
 214         unsigned int            debounce_period_us;
 215 #endif
 216 };
 217
 218 #define gpiod_not_found(desc)           (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
 219
 220 struct gpio_chip_guard {
 221         struct gpio_device *gdev;
 222         struct gpio_chip *gc;
 223         int idx;
 224 };
 225
 226 DEFINE_CLASS(gpio_chip_guard,
 227              struct gpio_chip_guard,
 228              srcu_read_unlock(&_T.gdev->srcu, _T.idx),
 229              ({
 230                 struct gpio_chip_guard _guard;
 231
 232                 _guard.gdev = desc->gdev;
 233                 _guard.idx = srcu_read_lock(&_guard.gdev->srcu);
 234                 _guard.gc = srcu_dereference(_guard.gdev->chip,
 235                                              &_guard.gdev->srcu);
 236
 237                 _guard;
 238              }),
 239              struct gpio_desc *desc)
 240
 241 int gpiod_request(struct gpio_desc *desc, const char *label);
 242 void gpiod_free(struct gpio_desc *desc);
 243
 244 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)
 245 {
 246         int ret;
 247
 248         ret = gpiod_request(desc, label);
 249         if (ret == -EPROBE_DEFER)
 250                 ret = -ENODEV;
 251
 252         return ret;
 253 }
 254
 255 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
 256                                          struct fwnode_handle *fwnode,
 257                                          const char *con_id,
 258                                          unsigned int idx,
 259                                          enum gpiod_flags flags,
 260                                          const char *label,
 261                                          bool platform_lookup_allowed);
 262
 263 int gpio_do_set_config(struct gpio_desc *desc, unsigned long config);
 264 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
 265                 unsigned long lflags, enum gpiod_flags dflags);
 266 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
 267 int gpiod_hog(struct gpio_desc *desc, const char *name,
 268                 unsigned long lflags, enum gpiod_flags dflags);
 269 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);
 270 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);
 271 const char *gpiod_get_label(struct gpio_desc *desc);
 272
 273 /*
 274  * Return the GPIO number of the passed descriptor relative to its chip
 275  */
 276 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)
 277 {
 278         return desc - &desc->gdev->descs[0];
 279 }
 280
 281 /* With descriptor prefix */
 282
 283 #define gpiod_err(desc, fmt, ...) \
 284 do { \
 285         scoped_guard(srcu, &desc->gdev->desc_srcu) { \
 286                 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
 287                        gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
 288         } \
 289 } while (0)
 290
 291 #define gpiod_warn(desc, fmt, ...) \
 292 do { \
 293         scoped_guard(srcu, &desc->gdev->desc_srcu) { \
 294                 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
 295                         gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
 296         } \
 297 } while (0)
 298
 299 #define gpiod_dbg(desc, fmt, ...) \
 300 do { \
 301         scoped_guard(srcu, &desc->gdev->desc_srcu) { \
 302                 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \
 303                          gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \
 304         } \
 305 } while (0)
 306
 307 /* With chip prefix */
 308
 309 #define chip_err(gc, fmt, ...)                                  \
 310         dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
 311 #define chip_warn(gc, fmt, ...)                                 \
 312         dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
 313 #define chip_info(gc, fmt, ...)                                 \
 314         dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
 315 #define chip_dbg(gc, fmt, ...)                                  \
 316         dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)
 317
 318 #endif /* GPIOLIB_H */