target/linux/brcm63xx/patches-4.14/143-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 @@ -237,12 +237,15 @@ static struct gpio_desc *of_parse_own_gp
  33  /**
  34   * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
  35   * @chip:      gpio chip to act on
  36 + * @start:     first gpio to check
  37 + * @num:       number of gpios to check
  38   *
  39 - * This is only used by of_gpiochip_add to request/set GPIO initial
  40 - * configuration.
  41 + * This is used by of_gpiochip_add, gpiochip_add_pingroup_range and
  42 + * gpiochip_add_pin_range to request/set GPIO initial configuration.
  43   * It returns error if it fails otherwise 0 on success.
  44   */
  45 -static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
  46 +int of_gpiochip_scan_gpios(struct gpio_chip *chip, unsigned int start,
  47 +                          unsigned int num)
  48  {
  49         struct gpio_desc *desc = NULL;
  50         struct device_node *np;
  51 @@ -250,7 +253,7 @@ static int of_gpiochip_scan_gpios(struct
  52         enum gpio_lookup_flags lflags;
  53         enum gpiod_flags dflags;
  54         unsigned int i;
  55 -       int ret;
  56 +       int ret, hwgpio;
  57
  58         for_each_available_child_of_node(chip->of_node, np) {
  59                 if (!of_property_read_bool(np, "gpio-hog"))
  60 @@ -262,6 +265,10 @@ static int of_gpiochip_scan_gpios(struct
  61                         if (IS_ERR(desc))
  62                                 break;
  63
  64 +                       hwgpio = gpio_chip_hwgpio(desc);
  65 +                       if (hwgpio < start || hwgpio >= (start + num))
  66 +                               continue;
  67 +
  68                         ret = gpiod_hog(desc, name, lflags, dflags);
  69                         if (ret < 0) {
  70                                 of_node_put(np);
  71 @@ -499,12 +506,13 @@ int of_gpiochip_add(struct gpio_chip *ch
  72
  73         of_node_get(chip->of_node);
  74
  75 -       status = of_gpiochip_scan_gpios(chip);
  76 -       if (status) {
  77 -               of_node_put(chip->of_node);
  78 -               gpiochip_remove_pin_ranges(chip);
  79 +       if (!chip->request) {
  80 +               status = of_gpiochip_scan_gpios(chip, 0, chip->ngpio);
  81 +               if (status) {
  82 +                       of_node_put(chip->of_node);
  83 +                       gpiochip_remove_pin_ranges(chip);
  84 +               }
  85         }
  86 -
  87         return status;
  88  }
  89
  90 --- a/drivers/gpio/gpiolib.c
  91 +++ b/drivers/gpio/gpiolib.c
  92 @@ -1941,7 +1941,8 @@ int gpiochip_add_pingroup_range(struct g
  93
  94         list_add_tail(&pin_range->node, &gdev->pin_ranges);
  95
  96 -       return 0;
  97 +       return of_gpiochip_scan_gpios(chip, gpio_offset,
  98 +                                     pin_range->range.npins);
  99  }
 100  EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
 101
 102 @@ -1993,7 +1994,7 @@ int gpiochip_add_pin_range(struct gpio_c
 103
 104         list_add_tail(&pin_range->node, &gdev->pin_ranges);
 105
 106 -       return 0;
 107 +       return of_gpiochip_scan_gpios(chip, gpio_offset, npins);
 108  }
 109  EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
 110
 111 --- a/drivers/gpio/gpiolib.h
 112 +++ b/drivers/gpio/gpiolib.h
 113 @@ -99,6 +99,8 @@ struct gpio_desc *of_get_named_gpiod_fla
 114                    const char *list_name, int index, enum of_gpio_flags *flags);
 115  int of_gpiochip_add(struct gpio_chip *gc);
 116  void of_gpiochip_remove(struct gpio_chip *gc);
 117 +int of_gpiochip_scan_gpios(struct gpio_chip *chip, unsigned int start,
 118 +                          unsigned int num);
 119  #else
 120  static inline struct gpio_desc *of_find_gpio(struct device *dev,
 121                                              const char *con_id,
 122 @@ -114,6 +116,12 @@ static inline struct gpio_desc *of_get_n
 123  }
 124  static inline int of_gpiochip_add(struct gpio_chip *gc) { return 0; }
 125  static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
 126 +static inline int of_gpiochip_scan_gpios(struct gpio_chip *chip,
 127 +                                        unsigned int start,
 128 +                                        unsigned int num)
 129 +{
 130 +       return 0;
 131 +}
 132  #endif /* CONFIG_OF_GPIO */
 133
 134  #ifdef CONFIG_ACPI