target/linux/bcm27xx/patches-5.10/950-0481-gpio-fsm-Show-state-info-in-sys-class-gpio-fsm.patch

   1 From 1e50027d42006cbc42957b5053caf96ee52c7f8c Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Sat, 17 Oct 2020 15:42:54 +0100
   4 Subject: [PATCH] gpio-fsm: Show state info in /sys/class/gpio-fsm
   5
   6 Add gpio-fsm sysfs entries under /sys/class/gpio-fsm. For each state
   7 machine show the current state, which state (if any) will be entered
   8 after a delay, and the current value of that delay.
   9
  10 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  11 ---
  12  drivers/gpio/gpio-fsm.c | 112 ++++++++++++++++++++++++++++++++++++++--
  13  1 file changed, 108 insertions(+), 4 deletions(-)
  14
  15 --- a/drivers/gpio/gpio-fsm.c
  16 +++ b/drivers/gpio/gpio-fsm.c
  17 @@ -20,6 +20,7 @@
  18  #include <linux/interrupt.h>
  19  #include <linux/module.h>
  20  #include <linux/platform_device.h>
  21 +#include <linux/sysfs.h>
  22
  23  #include <dt-bindings/gpio/gpio-fsm.h>
  24
  25 @@ -120,6 +121,7 @@ struct gpio_fsm {
  26         struct fsm_state *current_state;
  27         struct fsm_state *next_state;
  28         struct fsm_state *delay_target_state;
  29 +       unsigned int delay_jiffies;
  30         int delay_ms;
  31         unsigned int debug;
  32         bool shutting_down;
  33 @@ -364,9 +366,10 @@ static void gpio_fsm_enter_state(struct
  34                         jiffies + msecs_to_jiffies(state->shutdown_ms);
  35
  36                 if (gf->shutting_down) {
  37 +                       gf->delay_jiffies = gf->shutdown_jiffies;
  38                         gf->delay_target_state = state->shutdown_target;
  39                         gf->delay_ms = state->shutdown_ms;
  40 -                       mod_timer(&gf->timer, gf->shutdown_jiffies);
  41 +                       mod_timer(&gf->timer, gf->delay_jiffies);
  42                 }
  43         }
  44
  45 @@ -421,9 +424,10 @@ static void gpio_fsm_enter_state(struct
  46         // 6. Schedule a timer callback if delay_target
  47         if (state->delay_target) {
  48                 gf->delay_target_state = state->delay_target;
  49 +               gf->delay_jiffies = jiffies +
  50 +                       msecs_to_jiffies(state->delay_ms);
  51                 gf->delay_ms = state->delay_ms;
  52 -               mod_timer(&gf->timer,
  53 -                         jiffies + msecs_to_jiffies(state->delay_ms));
  54 +               mod_timer(&gf->timer, gf->delay_jiffies);
  55         }
  56  }
  57
  58 @@ -847,10 +851,81 @@ static int resolve_sym_to_state(struct g
  59         return 0;
  60  }
  61
  62 +
  63 +/*
  64 + * /sys/class/gpio-fsm/<fsm-name>/
  65 + *   /state ... the current state
  66 + */
  67 +
  68 +static ssize_t state_show(struct device *dev,
  69 +                         struct device_attribute *attr, char *buf)
  70 +{
  71 +       const struct gpio_fsm *gf = dev_get_drvdata(dev);
  72 +
  73 +       return sprintf(buf, "%s\n", gf->current_state->name);
  74 +}
  75 +static DEVICE_ATTR_RO(state);
  76 +
  77 +static ssize_t delay_state_show(struct device *dev,
  78 +                         struct device_attribute *attr, char *buf)
  79 +{
  80 +       const struct gpio_fsm *gf = dev_get_drvdata(dev);
  81 +
  82 +       return sprintf(buf, "%s\n",
  83 +                      gf->delay_target_state ? gf->delay_target_state->name :
  84 +                      "-");
  85 +}
  86 +
  87 +static DEVICE_ATTR_RO(delay_state);
  88 +
  89 +static ssize_t delay_ms_show(struct device *dev,
  90 +                            struct device_attribute *attr, char *buf)
  91 +{
  92 +       const struct gpio_fsm *gf = dev_get_drvdata(dev);
  93 +       int jiffies_left;
  94 +
  95 +       jiffies_left = gf->delay_jiffies - jiffies;
  96 +       return sprintf(buf,
  97 +                      gf->delay_target_state ? "%u\n" : "-\n",
  98 +                      jiffies_to_msecs(jiffies_left));
  99 +}
 100 +static DEVICE_ATTR_RO(delay_ms);
 101 +
 102 +static struct attribute *gpio_fsm_attrs[] = {
 103 +       &dev_attr_state.attr,
 104 +       &dev_attr_delay_state.attr,
 105 +       &dev_attr_delay_ms.attr,
 106 +       NULL,
 107 +};
 108 +
 109 +static const struct attribute_group gpio_fsm_group = {
 110 +       .attrs = gpio_fsm_attrs,
 111 +       //.is_visible = gpio_is_visible,
 112 +};
 113 +
 114 +static const struct attribute_group *gpio_fsm_groups[] = {
 115 +       &gpio_fsm_group,
 116 +       NULL
 117 +};
 118 +
 119 +static struct attribute *gpio_fsm_class_attrs[] = {
 120 +       // There are no top-level attributes
 121 +       NULL,
 122 +};
 123 +ATTRIBUTE_GROUPS(gpio_fsm_class);
 124 +
 125 +static struct class gpio_fsm_class = {
 126 +       .name =         MODULE_NAME,
 127 +       .owner =        THIS_MODULE,
 128 +
 129 +       .class_groups = gpio_fsm_class_groups,
 130 +};
 131 +
 132  static int gpio_fsm_probe(struct platform_device *pdev)
 133  {
 134         struct input_gpio_state *inp_state;
 135         struct device *dev = &pdev->dev;
 136 +       struct device *sysfs_dev;
 137         struct device_node *np = dev->of_node;
 138         struct device_node *cp;
 139         struct gpio_fsm *gf;
 140 @@ -1029,6 +1104,13 @@ static int gpio_fsm_probe(struct platfor
 141
 142         platform_set_drvdata(pdev, gf);
 143
 144 +       sysfs_dev = device_create_with_groups(&gpio_fsm_class, dev,
 145 +                                             MKDEV(0, 0), gf,
 146 +                                             gpio_fsm_groups,
 147 +                                             "%s", np->name);
 148 +       if (IS_ERR(sysfs_dev))
 149 +               dev_err(gf->dev, "Error creating sysfs entry\n");
 150 +
 151         if (gf->debug)
 152                 dev_info(gf->dev, "Start -> %s\n", gf->start_state->name);
 153
 154 @@ -1097,7 +1179,29 @@ static struct platform_driver gpio_fsm_d
 155         .remove = gpio_fsm_remove,
 156         .shutdown = gpio_fsm_shutdown,
 157  };
 158 -module_platform_driver(gpio_fsm_driver);
 159 +
 160 +static int gpio_fsm_init(void)
 161 +{
 162 +       int ret;
 163 +
 164 +       ret = class_register(&gpio_fsm_class);
 165 +       if (ret)
 166 +               return ret;
 167 +
 168 +       ret = platform_driver_register(&gpio_fsm_driver);
 169 +       if (ret)
 170 +               class_unregister(&gpio_fsm_class);
 171 +
 172 +       return ret;
 173 +}
 174 +module_init(gpio_fsm_init);
 175 +
 176 +static void gpio_fsm_exit(void)
 177 +{
 178 +       platform_driver_unregister(&gpio_fsm_driver);
 179 +       class_unregister(&gpio_fsm_class);
 180 +}
 181 +module_exit(gpio_fsm_exit);
 182
 183  MODULE_LICENSE("GPL");
 184  MODULE_AUTHOR("Phil Elwell <phil@raspberrypi.com>");