drivers/mfd/rn5t618.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * MFD core driver for Ricoh RN5T618 PMIC
   4  *
   5  * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
   6  * Copyright (C) 2016 Toradex AG
   7  */
   8
   9 #include <linux/delay.h>
  10 #include <linux/i2c.h>
  11 #include <linux/mfd/core.h>
  12 #include <linux/mfd/rn5t618.h>
  13 #include <linux/module.h>
  14 #include <linux/of_device.h>
  15 #include <linux/reboot.h>
  16 #include <linux/regmap.h>
  17
  18 static const struct mfd_cell rn5t618_cells[] = {
  19         { .name = "rn5t618-regulator" },
  20         { .name = "rn5t618-wdt" },
  21 };
  22
  23 static bool rn5t618_volatile_reg(struct device *dev, unsigned int reg)
  24 {
  25         switch (reg) {
  26         case RN5T618_WATCHDOGCNT:
  27         case RN5T618_DCIRQ:
  28         case RN5T618_ILIMDATAH ... RN5T618_AIN0DATAL:
  29         case RN5T618_IR_ADC1 ... RN5T618_IR_ADC3:
  30         case RN5T618_IR_GPR:
  31         case RN5T618_IR_GPF:
  32         case RN5T618_MON_IOIN:
  33         case RN5T618_INTMON:
  34                 return true;
  35         default:
  36                 return false;
  37         }
  38 }
  39
  40 static const struct regmap_config rn5t618_regmap_config = {
  41         .reg_bits       = 8,
  42         .val_bits       = 8,
  43         .volatile_reg   = rn5t618_volatile_reg,
  44         .max_register   = RN5T618_MAX_REG,
  45         .cache_type     = REGCACHE_RBTREE,
  46 };
  47
  48 static struct rn5t618 *rn5t618_pm_power_off;
  49 static struct notifier_block rn5t618_restart_handler;
  50
  51 static void rn5t618_trigger_poweroff_sequence(bool repower)
  52 {
  53         /* disable automatic repower-on */
  54         regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_REPCNT,
  55                            RN5T618_REPCNT_REPWRON,
  56                            repower ? RN5T618_REPCNT_REPWRON : 0);
  57         /* start power-off sequence */
  58         regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_SLPCNT,
  59                            RN5T618_SLPCNT_SWPWROFF, RN5T618_SLPCNT_SWPWROFF);
  60 }
  61
  62 static void rn5t618_power_off(void)
  63 {
  64         rn5t618_trigger_poweroff_sequence(false);
  65 }
  66
  67 static int rn5t618_restart(struct notifier_block *this,
  68                             unsigned long mode, void *cmd)
  69 {
  70         rn5t618_trigger_poweroff_sequence(true);
  71
  72         /*
  73          * Re-power factor detection on PMIC side is not instant. 1ms
  74          * proved to be enough time until reset takes effect.
  75          */
  76         mdelay(1);
  77
  78         return NOTIFY_DONE;
  79 }
  80
  81 static const struct of_device_id rn5t618_of_match[] = {
  82         { .compatible = "ricoh,rn5t567", .data = (void *)RN5T567 },
  83         { .compatible = "ricoh,rn5t618", .data = (void *)RN5T618 },
  84         { .compatible = "ricoh,rc5t619", .data = (void *)RC5T619 },
  85         { }
  86 };
  87 MODULE_DEVICE_TABLE(of, rn5t618_of_match);
  88
  89 static int rn5t618_i2c_probe(struct i2c_client *i2c,
  90                              const struct i2c_device_id *id)
  91 {
  92         const struct of_device_id *of_id;
  93         struct rn5t618 *priv;
  94         int ret;
  95
  96         of_id = of_match_device(rn5t618_of_match, &i2c->dev);
  97         if (!of_id) {
  98                 dev_err(&i2c->dev, "Failed to find matching DT ID\n");
  99                 return -EINVAL;
 100         }
 101
 102         priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
 103         if (!priv)
 104                 return -ENOMEM;
 105
 106         i2c_set_clientdata(i2c, priv);
 107         priv->variant = (long)of_id->data;
 108
 109         priv->regmap = devm_regmap_init_i2c(i2c, &rn5t618_regmap_config);
 110         if (IS_ERR(priv->regmap)) {
 111                 ret = PTR_ERR(priv->regmap);
 112                 dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
 113                 return ret;
 114         }
 115
 116         ret = devm_mfd_add_devices(&i2c->dev, -1, rn5t618_cells,
 117                                    ARRAY_SIZE(rn5t618_cells), NULL, 0, NULL);
 118         if (ret) {
 119                 dev_err(&i2c->dev, "failed to add sub-devices: %d\n", ret);
 120                 return ret;
 121         }
 122
 123         rn5t618_pm_power_off = priv;
 124         if (of_device_is_system_power_controller(i2c->dev.of_node)) {
 125                 if (!pm_power_off)
 126                         pm_power_off = rn5t618_power_off;
 127                 else
 128                         dev_warn(&i2c->dev, "Poweroff callback already assigned\n");
 129         }
 130
 131         rn5t618_restart_handler.notifier_call = rn5t618_restart;
 132         rn5t618_restart_handler.priority = 192;
 133
 134         ret = register_restart_handler(&rn5t618_restart_handler);
 135         if (ret) {
 136                 dev_err(&i2c->dev, "cannot register restart handler, %d\n", ret);
 137                 return ret;
 138         }
 139
 140         return 0;
 141 }
 142
 143 static int rn5t618_i2c_remove(struct i2c_client *i2c)
 144 {
 145         struct rn5t618 *priv = i2c_get_clientdata(i2c);
 146
 147         if (priv == rn5t618_pm_power_off) {
 148                 rn5t618_pm_power_off = NULL;
 149                 pm_power_off = NULL;
 150         }
 151
 152         unregister_restart_handler(&rn5t618_restart_handler);
 153
 154         return 0;
 155 }
 156
 157 static const struct i2c_device_id rn5t618_i2c_id[] = {
 158         { }
 159 };
 160 MODULE_DEVICE_TABLE(i2c, rn5t618_i2c_id);
 161
 162 static struct i2c_driver rn5t618_i2c_driver = {
 163         .driver = {
 164                 .name = "rn5t618",
 165                 .of_match_table = of_match_ptr(rn5t618_of_match),
 166         },
 167         .probe = rn5t618_i2c_probe,
 168         .remove = rn5t618_i2c_remove,
 169         .id_table = rn5t618_i2c_id,
 170 };
 171
 172 module_i2c_driver(rn5t618_i2c_driver);
 173
 174 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
 175 MODULE_DESCRIPTION("Ricoh RN5T567/618 MFD driver");
 176 MODULE_LICENSE("GPL v2");