releases/4.9.52/pinctrl-amd-save-pin-registers-over-suspend-resume.patch

   1 From 79d2c8bede2c93f9432d7da0bc2f76a195c90fc0 Mon Sep 17 00:00:00 2001
   2 From: Daniel Drake <drake@endlessm.com>
   3 Date: Mon, 11 Sep 2017 14:11:56 +0800
   4 Subject: pinctrl/amd: save pin registers over suspend/resume
   5
   6 From: Daniel Drake <drake@endlessm.com>
   7
   8 commit 79d2c8bede2c93f9432d7da0bc2f76a195c90fc0 upstream.
   9
  10 The touchpad in the Asus laptop models X505BA/BP and X542BA/BP is
  11 unresponsive after suspend/resume. The following error appears during
  12 resume:
  13
  14   i2c_hid i2c-ELAN1300:00: failed to reset device.
  15
  16 The problem here is that i2c_hid does not notice the interrupt being
  17 generated at this point, because the GPIO is no longer configured
  18 for interrupts.
  19
  20 Fix this by saving pinctrl-amd pin registers during suspend and
  21 restoring them at resume time.
  22
  23 Based on code from pinctrl-intel.
  24
  25 Signed-off-by: Daniel Drake <drake@endlessm.com>
  26 Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
  27 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  28
  29 ---
  30  drivers/pinctrl/pinctrl-amd.c |   75 ++++++++++++++++++++++++++++++++++++++++++
  31  drivers/pinctrl/pinctrl-amd.h |    1
  32  2 files changed, 76 insertions(+)
  33
  34 --- a/drivers/pinctrl/pinctrl-amd.c
  35 +++ b/drivers/pinctrl/pinctrl-amd.c
  36 @@ -32,6 +32,7 @@
  37  #include <linux/pinctrl/pinconf.h>
  38  #include <linux/pinctrl/pinconf-generic.h>
  39
  40 +#include "core.h"
  41  #include "pinctrl-utils.h"
  42  #include "pinctrl-amd.h"
  43
  44 @@ -712,6 +713,69 @@ static const struct pinconf_ops amd_pinc
  45         .pin_config_group_set = amd_pinconf_group_set,
  46  };
  47
  48 +#ifdef CONFIG_PM_SLEEP
  49 +static bool amd_gpio_should_save(struct amd_gpio *gpio_dev, unsigned int pin)
  50 +{
  51 +       const struct pin_desc *pd = pin_desc_get(gpio_dev->pctrl, pin);
  52 +
  53 +       if (!pd)
  54 +               return false;
  55 +
  56 +       /*
  57 +        * Only restore the pin if it is actually in use by the kernel (or
  58 +        * by userspace).
  59 +        */
  60 +       if (pd->mux_owner || pd->gpio_owner ||
  61 +           gpiochip_line_is_irq(&gpio_dev->gc, pin))
  62 +               return true;
  63 +
  64 +       return false;
  65 +}
  66 +
  67 +int amd_gpio_suspend(struct device *dev)
  68 +{
  69 +       struct platform_device *pdev = to_platform_device(dev);
  70 +       struct amd_gpio *gpio_dev = platform_get_drvdata(pdev);
  71 +       struct pinctrl_desc *desc = gpio_dev->pctrl->desc;
  72 +       int i;
  73 +
  74 +       for (i = 0; i < desc->npins; i++) {
  75 +               int pin = desc->pins[i].number;
  76 +
  77 +               if (!amd_gpio_should_save(gpio_dev, pin))
  78 +                       continue;
  79 +
  80 +               gpio_dev->saved_regs[i] = readl(gpio_dev->base + pin*4);
  81 +       }
  82 +
  83 +       return 0;
  84 +}
  85 +
  86 +int amd_gpio_resume(struct device *dev)
  87 +{
  88 +       struct platform_device *pdev = to_platform_device(dev);
  89 +       struct amd_gpio *gpio_dev = platform_get_drvdata(pdev);
  90 +       struct pinctrl_desc *desc = gpio_dev->pctrl->desc;
  91 +       int i;
  92 +
  93 +       for (i = 0; i < desc->npins; i++) {
  94 +               int pin = desc->pins[i].number;
  95 +
  96 +               if (!amd_gpio_should_save(gpio_dev, pin))
  97 +                       continue;
  98 +
  99 +               writel(gpio_dev->saved_regs[i], gpio_dev->base + pin*4);
 100 +       }
 101 +
 102 +       return 0;
 103 +}
 104 +
 105 +static const struct dev_pm_ops amd_gpio_pm_ops = {
 106 +       SET_LATE_SYSTEM_SLEEP_PM_OPS(amd_gpio_suspend,
 107 +                                    amd_gpio_resume)
 108 +};
 109 +#endif
 110 +
 111  static struct pinctrl_desc amd_pinctrl_desc = {
 112         .pins   = kerncz_pins,
 113         .npins = ARRAY_SIZE(kerncz_pins),
 114 @@ -751,6 +815,14 @@ static int amd_gpio_probe(struct platfor
 115                 return -EINVAL;
 116         }
 117
 118 +#ifdef CONFIG_PM_SLEEP
 119 +       gpio_dev->saved_regs = devm_kcalloc(&pdev->dev, amd_pinctrl_desc.npins,
 120 +                                           sizeof(*gpio_dev->saved_regs),
 121 +                                           GFP_KERNEL);
 122 +       if (!gpio_dev->saved_regs)
 123 +               return -ENOMEM;
 124 +#endif
 125 +
 126         gpio_dev->pdev = pdev;
 127         gpio_dev->gc.direction_input    = amd_gpio_direction_input;
 128         gpio_dev->gc.direction_output   = amd_gpio_direction_output;
 129 @@ -839,6 +911,9 @@ static struct platform_driver amd_gpio_d
 130         .driver         = {
 131                 .name   = "amd_gpio",
 132                 .acpi_match_table = ACPI_PTR(amd_gpio_acpi_match),
 133 +#ifdef CONFIG_PM_SLEEP
 134 +               .pm     = &amd_gpio_pm_ops,
 135 +#endif
 136         },
 137         .probe          = amd_gpio_probe,
 138         .remove         = amd_gpio_remove,
 139 --- a/drivers/pinctrl/pinctrl-amd.h
 140 +++ b/drivers/pinctrl/pinctrl-amd.h
 141 @@ -95,6 +95,7 @@ struct amd_gpio {
 142         struct gpio_chip        gc;
 143         struct resource         *res;
 144         struct platform_device  *pdev;
 145 +       u32                     *saved_regs;
 146  };
 147
 148  /*  KERNCZ configuration*/