target/linux/bcm63xx/patches-5.10/143-gpio-fix-device-tree-gpio-hogs-on-dual-role-gpio-pin.patch

   1 From e058fa1969019c2f6705c53c4130e364a877d4e6 Mon Sep 17 00:00:00 2001
   2 From: Jonas Gorski <jonas.gorski@gmail.com>
   3 Date: Sun, 26 Nov 2017 12:07:31 +0100
   4 Subject: [PATCH] gpio: fix device tree gpio hogs on dual role gpio/pincontrol
   5  controllers
   6
   7 For dual role gpio and pincontrol controller, the device registration
   8 path is often:
   9
  10   pinctrl_register(...);
  11   gpiochip_add_data(...);
  12   gpiochip_add_pin_range(...);
  13
  14 If the device tree node has any gpio-hogs, the code will try to apply them
  15 in the gpiochip_add_data step, but fail as they cannot be requested, as the
  16 ranges are missing. But we also cannot first add the pinranges, as the
  17 appropriate data structures are only initialized in gpiochip_add_data.
  18
  19 To fix this, defer gpio-hogs to the time pin ranges get added instead of
  20 directly at chip request time, if the gpio-chip has a request method.
  21
  22 Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
  23 ---
  24
  25  drivers/gpio/gpiolib-of.c | 20 +++++++++++++++-----
  26  drivers/gpio/gpiolib.c    |  5 +++--
  27  drivers/gpio/gpiolib.h    |  8 ++++++++
  28  3 files changed, 26 insertions(+), 7 deletions(-)
  29
  30 --- a/drivers/gpio/gpiolib-of.c
  31 +++ b/drivers/gpio/gpiolib-of.c
  32 @@ -644,23 +644,30 @@ static struct gpio_desc *of_parse_own_gp
  33   * of_gpiochip_add_hog - Add all hogs in a hog device node
  34   * @chip:      gpio chip to act on
  35   * @hog:       device node describing the hogs
  36 + * @start:     first gpio to check
  37 + * @num:       number of gpios to check
  38   *
  39   * Returns error if it fails otherwise 0 on success.
  40   */
  41 -static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog)
  42 +static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog,
  43 +                              unsigned int start, unsigned int num)
  44  {
  45         enum gpiod_flags dflags;
  46         struct gpio_desc *desc;
  47         unsigned long lflags;
  48         const char *name;
  49         unsigned int i;
  50 -       int ret;
  51 +       int ret, hwgpio;
  52
  53         for (i = 0;; i++) {
  54                 desc = of_parse_own_gpio(hog, chip, i, &name, &lflags, &dflags);
  55                 if (IS_ERR(desc))
  56                         break;
  57
  58 +               hwgpio = gpio_chip_hwgpio(desc);
  59 +               if (hwgpio < start || hwgpio >= (start + num))
  60 +                       continue;
  61 +
  62                 ret = gpiod_hog(desc, name, lflags, dflags);
  63                 if (ret < 0)
  64                         return ret;
  65 @@ -676,12 +683,15 @@ static int of_gpiochip_add_hog(struct gp
  66  /**
  67   * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
  68   * @chip:      gpio chip to act on
  69 + * @start:     first gpio to check
  70 + * @num:       number of gpios to check
  71   *
  72 - * This is only used by of_gpiochip_add to request/set GPIO initial
  73 - * configuration.
  74 + * This is used by of_gpiochip_add, gpiochip_add_pingroup_range and
  75 + * gpiochip_add_pin_range to request/set GPIO initial configuration.
  76   * It returns error if it fails otherwise 0 on success.
  77   */
  78 -static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
  79 +int of_gpiochip_scan_gpios(struct gpio_chip *chip, unsigned int start,
  80 +                          unsigned int num)
  81  {
  82         struct device_node *np;
  83         int ret;
  84 @@ -690,7 +700,7 @@ static int of_gpiochip_scan_gpios(struct
  85                 if (!of_property_read_bool(np, "gpio-hog"))
  86                         continue;
  87
  88 -               ret = of_gpiochip_add_hog(chip, np);
  89 +               ret = of_gpiochip_add_hog(chip, np, start, num);
  90                 if (ret < 0) {
  91                         of_node_put(np);
  92                         return ret;
  93 @@ -756,7 +766,7 @@ static int of_gpio_notify(struct notifie
  94                 if (chip == NULL)
  95                         return NOTIFY_OK;       /* not for us */
  96
  97 -               ret = of_gpiochip_add_hog(chip, rd->dn);
  98 +               ret = of_gpiochip_add_hog(chip, rd->dn, 0, chip->ngpio);
  99                 if (ret < 0) {
 100                         pr_err("%s: failed to add hogs for %pOF\n", __func__,
 101                                rd->dn);
 102 @@ -1028,9 +1038,11 @@ int of_gpiochip_add(struct gpio_chip *ch
 103
 104         of_node_get(chip->of_node);
 105
 106 -       ret = of_gpiochip_scan_gpios(chip);
 107 -       if (ret)
 108 -               of_node_put(chip->of_node);
 109 +       if (!chip->request) {
 110 +               ret = of_gpiochip_scan_gpios(chip, 0, chip->ngpio);
 111 +               if (ret)
 112 +                       of_node_put(chip->of_node);
 113 +       }
 114
 115         return ret;
 116  }
 117 --- a/drivers/gpio/gpiolib.c
 118 +++ b/drivers/gpio/gpiolib.c
 119 @@ -1890,7 +1890,8 @@ int gpiochip_add_pingroup_range(struct g
 120
 121         list_add_tail(&pin_range->node, &gdev->pin_ranges);
 122
 123 -       return 0;
 124 +       return of_gpiochip_scan_gpios(gc, gpio_offset,
 125 +                                     pin_range->range.npins);
 126  }
 127  EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
 128
 129 @@ -1947,7 +1948,7 @@ int gpiochip_add_pin_range(struct gpio_c
 130
 131         list_add_tail(&pin_range->node, &gdev->pin_ranges);
 132
 133 -       return 0;
 134 +       return of_gpiochip_scan_gpios(gc, gpio_offset, npins);
 135  }
 136  EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
 137
 138 --- a/drivers/gpio/gpiolib-of.h
 139 +++ b/drivers/gpio/gpiolib-of.h
 140 @@ -13,6 +13,8 @@ struct gpio_desc *of_find_gpio(struct de
 141                                unsigned long *lookupflags);
 142  int of_gpiochip_add(struct gpio_chip *gc);
 143  void of_gpiochip_remove(struct gpio_chip *gc);
 144 +int of_gpiochip_scan_gpios(struct gpio_chip *chip, unsigned int start,
 145 +                          unsigned int num);
 146  int of_gpio_get_count(struct device *dev, const char *con_id);
 147  bool of_gpio_need_valid_mask(const struct gpio_chip *gc);
 148  #else
 149 @@ -25,6 +27,12 @@ static inline struct gpio_desc *of_find_
 150  }
 151  static inline int of_gpiochip_add(struct gpio_chip *gc) { return 0; }
 152  static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
 153 +static inline int of_gpiochip_scan_gpios(struct gpio_chip *chip,
 154 +                                        unsigned int start,
 155 +                                        unsigned int num)
 156 +{
 157 +       return 0;
 158 +}
 159  static inline int of_gpio_get_count(struct device *dev, const char *con_id)
 160  {
 161         return 0;