target/linux/brcm63xx/patches-4.9/143-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 @@ -274,19 +274,22 @@ static void of_gpiochip_set_names(struct
  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 retures 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         const char *name;
  52         enum gpio_lookup_flags lflags;
  53         enum gpiod_flags dflags;
  54 -       int ret;
  55 +       int ret, hwgpio;
  56
  57         for_each_available_child_of_node(chip->of_node, np) {
  58                 if (!of_property_read_bool(np, "gpio-hog"))
  59 @@ -296,6 +299,10 @@ static int of_gpiochip_scan_gpios(struct
  60                 if (IS_ERR(desc))
  61                         continue;
  62
  63 +               hwgpio = gpio_chip_hwgpio(desc);
  64 +               if (hwgpio < start || hwgpio >= (start + num))
  65 +                       continue;
  66 +
  67                 ret = gpiod_hog(desc, name, lflags, dflags);
  68                 if (ret < 0)
  69                         return ret;
  70 @@ -531,7 +538,10 @@ int of_gpiochip_add(struct gpio_chip *ch
  71
  72         of_node_get(chip->of_node);
  73
  74 -       return of_gpiochip_scan_gpios(chip);
  75 +       if (!chip->request)
  76 +               status = of_gpiochip_scan_gpios(chip, 0, chip->ngpio);
  77 +
  78 +       return status;
  79  }
  80
  81  void of_gpiochip_remove(struct gpio_chip *chip)
  82 --- a/drivers/gpio/gpiolib.c
  83 +++ b/drivers/gpio/gpiolib.c
  84 @@ -1884,7 +1884,8 @@ int gpiochip_add_pingroup_range(struct g
  85
  86         list_add_tail(&pin_range->node, &gdev->pin_ranges);
  87
  88 -       return 0;
  89 +       return of_gpiochip_scan_gpios(chip, gpio_offset,
  90 +                                     pin_range->range.npins);
  91  }
  92  EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
  93
  94 @@ -1933,7 +1934,7 @@ int gpiochip_add_pin_range(struct gpio_c
  95
  96         list_add_tail(&pin_range->node, &gdev->pin_ranges);
  97
  98 -       return 0;
  99 +       return of_gpiochip_scan_gpios(chip, gpio_offset, npins);
 100  }
 101  EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
 102
 103 --- a/drivers/gpio/gpiolib.h
 104 +++ b/drivers/gpio/gpiolib.h
 105 @@ -96,6 +96,8 @@ struct gpio_desc *of_get_named_gpiod_fla
 106                    const char *list_name, int index, enum of_gpio_flags *flags);
 107  int of_gpiochip_add(struct gpio_chip *gc);
 108  void of_gpiochip_remove(struct gpio_chip *gc);
 109 +int of_gpiochip_scan_gpios(struct gpio_chip *chip, unsigned int start,
 110 +                          unsigned int num);
 111  #else
 112  static inline struct gpio_desc *of_find_gpio(struct device *dev,
 113                                              const char *con_id,
 114 @@ -111,6 +113,12 @@ static inline struct gpio_desc *of_get_n
 115  }
 116  static inline int of_gpiochip_add(struct gpio_chip *gc) { return 0; }
 117  static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
 118 +static inline int of_gpiochip_scan_gpios(struct gpio_chip *chip,
 119 +                                        unsigned int start,
 120 +                                        unsigned int num)
 121 +{
 122 +       return 0;
 123 +}
 124  #endif /* CONFIG_OF_GPIO */
 125
 126  #ifdef CONFIG_ACPI