target/linux/sunxi/patches-4.9/0038-pinctrl-sunxi-Add-support-for-fetching-pinconf-setti.patch

   1 From c5fda170e87a4bdaeb278f7e50f7a1f654e94eb5 Mon Sep 17 00:00:00 2001
   2 From: Chen-Yu Tsai <wens@csie.org>
   3 Date: Fri, 11 Nov 2016 17:50:35 +0800
   4 Subject: pinctrl: sunxi: Add support for fetching pinconf settings from
   5  hardware
   6
   7 The sunxi pinctrl driver only caches whatever pinconf setting was last
   8 set on a given pingroup. This is not particularly helpful, nor is it
   9 correct.
  10
  11 Fix this by actually reading the hardware registers and returning
  12 the correct results or error codes. Also filter out unsupported
  13 pinconf settings. Since this driver has a peculiar setup of 1 pin
  14 per group, we can support both pin and pingroup pinconf setting
  15 read back with the same code. The sunxi_pconf_reg helper and code
  16 structure is inspired by pinctrl-msm.
  17
  18 With this done we can also claim to support generic pinconf, by
  19 setting .is_generic = true in pinconf_ops.
  20
  21 Also remove the cached config value. The behavior of this was never
  22 correct, as it only cached 1 setting instead of all of them. Since
  23 we can now read back settings directly from the hardware, it is no
  24 longer required.
  25
  26 Signed-off-by: Chen-Yu Tsai <wens@csie.org>
  27 Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
  28 Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
  29 ---
  30  drivers/pinctrl/sunxi/pinctrl-sunxi.c | 86 +++++++++++++++++++++++++++++++++--
  31  drivers/pinctrl/sunxi/pinctrl-sunxi.h |  1 -
  32  2 files changed, 81 insertions(+), 6 deletions(-)
  33
  34 --- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
  35 +++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
  36 @@ -438,15 +438,91 @@ static const struct pinctrl_ops sunxi_pc
  37         .get_group_pins         = sunxi_pctrl_get_group_pins,
  38  };
  39
  40 +static int sunxi_pconf_reg(unsigned pin, enum pin_config_param param,
  41 +                          u32 *offset, u32 *shift, u32 *mask)
  42 +{
  43 +       switch (param) {
  44 +       case PIN_CONFIG_DRIVE_STRENGTH:
  45 +               *offset = sunxi_dlevel_reg(pin);
  46 +               *shift = sunxi_dlevel_offset(pin);
  47 +               *mask = DLEVEL_PINS_MASK;
  48 +               break;
  49 +
  50 +       case PIN_CONFIG_BIAS_PULL_UP:
  51 +       case PIN_CONFIG_BIAS_PULL_DOWN:
  52 +       case PIN_CONFIG_BIAS_DISABLE:
  53 +               *offset = sunxi_pull_reg(pin);
  54 +               *shift = sunxi_pull_offset(pin);
  55 +               *mask = PULL_PINS_MASK;
  56 +               break;
  57 +
  58 +       default:
  59 +               return -ENOTSUPP;
  60 +       }
  61 +
  62 +       return 0;
  63 +}
  64 +
  65 +static int sunxi_pconf_get(struct pinctrl_dev *pctldev, unsigned pin,
  66 +                          unsigned long *config)
  67 +{
  68 +       struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
  69 +       enum pin_config_param param = pinconf_to_config_param(*config);
  70 +       u32 offset, shift, mask, val;
  71 +       u16 arg;
  72 +       int ret;
  73 +
  74 +       pin -= pctl->desc->pin_base;
  75 +
  76 +       ret = sunxi_pconf_reg(pin, param, &offset, &shift, &mask);
  77 +       if (ret < 0)
  78 +               return ret;
  79 +
  80 +       val = (readl(pctl->membase + offset) >> shift) & mask;
  81 +
  82 +       switch (pinconf_to_config_param(*config)) {
  83 +       case PIN_CONFIG_DRIVE_STRENGTH:
  84 +               arg = (val + 1) * 10;
  85 +               break;
  86 +
  87 +       case PIN_CONFIG_BIAS_PULL_UP:
  88 +               if (val != SUN4I_PINCTRL_PULL_UP)
  89 +                       return -EINVAL;
  90 +               arg = 1; /* hardware is weak pull-up */
  91 +               break;
  92 +
  93 +       case PIN_CONFIG_BIAS_PULL_DOWN:
  94 +               if (val != SUN4I_PINCTRL_PULL_DOWN)
  95 +                       return -EINVAL;
  96 +               arg = 1; /* hardware is weak pull-down */
  97 +               break;
  98 +
  99 +       case PIN_CONFIG_BIAS_DISABLE:
 100 +               if (val != SUN4I_PINCTRL_NO_PULL)
 101 +                       return -EINVAL;
 102 +               arg = 0;
 103 +               break;
 104 +
 105 +       default:
 106 +               /* sunxi_pconf_reg should catch anything unsupported */
 107 +               WARN_ON(1);
 108 +               return -ENOTSUPP;
 109 +       }
 110 +
 111 +       *config = pinconf_to_config_packed(param, arg);
 112 +
 113 +       return 0;
 114 +}
 115 +
 116  static int sunxi_pconf_group_get(struct pinctrl_dev *pctldev,
 117                                  unsigned group,
 118                                  unsigned long *config)
 119  {
 120         struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
 121 +       struct sunxi_pinctrl_group *g = &pctl->groups[group];
 122
 123 -       *config = pctl->groups[group].config;
 124 -
 125 -       return 0;
 126 +       /* We only support 1 pin per group. Chain it to the pin callback */
 127 +       return sunxi_pconf_get(pctldev, g->pin, config);
 128  }
 129
 130  static int sunxi_pconf_group_set(struct pinctrl_dev *pctldev,
 131 @@ -508,8 +584,6 @@ static int sunxi_pconf_group_set(struct
 132                 default:
 133                         break;
 134                 }
 135 -               /* cache the config value */
 136 -               g->config = configs[i];
 137         } /* for each config */
 138
 139         spin_unlock_irqrestore(&pctl->lock, flags);
 140 @@ -518,6 +592,8 @@ static int sunxi_pconf_group_set(struct
 141  }
 142
 143  static const struct pinconf_ops sunxi_pconf_ops = {
 144 +       .is_generic             = true,
 145 +       .pin_config_get         = sunxi_pconf_get,
 146         .pin_config_group_get   = sunxi_pconf_group_get,
 147         .pin_config_group_set   = sunxi_pconf_group_set,
 148  };
 149 --- a/drivers/pinctrl/sunxi/pinctrl-sunxi.h
 150 +++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.h
 151 @@ -109,7 +109,6 @@ struct sunxi_pinctrl_function {
 152
 153  struct sunxi_pinctrl_group {
 154         const char      *name;
 155 -       unsigned long   config;
 156         unsigned        pin;
 157  };
 158