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_ADCCNT3:
  30         case RN5T618_IR_ADC1 ... RN5T618_IR_ADC3:
  31         case RN5T618_IR_GPR:
  32         case RN5T618_IR_GPF:
  33         case RN5T618_MON_IOIN:
  34         case RN5T618_INTMON:
  35                 return true;
  36         default:
  37                 return false;
  38         }
  39 }
  40
  41 static const struct regmap_config rn5t618_regmap_config = {
  42         .reg_bits       = 8,
  43         .val_bits       = 8,
  44         .volatile_reg   = rn5t618_volatile_reg,
  45         .max_register   = RN5T618_MAX_REG,
  46         .cache_type     = REGCACHE_RBTREE,
  47 };
  48
  49 static struct rn5t618 *rn5t618_pm_power_off;
  50 static struct notifier_block rn5t618_restart_handler;
  51
  52 static void rn5t618_trigger_poweroff_sequence(bool repower)
  53 {
  54         /* disable automatic repower-on */
  55         regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_REPCNT,
  56                            RN5T618_REPCNT_REPWRON,
  57                            repower ? RN5T618_REPCNT_REPWRON : 0);
  58         /* start power-off sequence */
  59         regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_SLPCNT,
  60                            RN5T618_SLPCNT_SWPWROFF, RN5T618_SLPCNT_SWPWROFF);
  61 }
  62
  63 static void rn5t618_power_off(void)
  64 {
  65         rn5t618_trigger_poweroff_sequence(false);
  66 }
  67
  68 static int rn5t618_restart(struct notifier_block *this,
  69                             unsigned long mode, void *cmd)
  70 {
  71         rn5t618_trigger_poweroff_sequence(true);
  72
  73         /*
  74          * Re-power factor detection on PMIC side is not instant. 1ms
  75          * proved to be enough time until reset takes effect.
  76          */
  77         mdelay(1);
  78
  79         return NOTIFY_DONE;
  80 }
  81
  82 static const struct of_device_id rn5t618_of_match[] = {
  83         { .compatible = "ricoh,rn5t567", .data = (void *)RN5T567 },
  84         { .compatible = "ricoh,rn5t618", .data = (void *)RN5T618 },
  85         { .compatible = "ricoh,rc5t619", .data = (void *)RC5T619 },
  86         { }
  87 };
  88 MODULE_DEVICE_TABLE(of, rn5t618_of_match);
  89
  90 static int rn5t618_i2c_probe(struct i2c_client *i2c,
  91                              const struct i2c_device_id *id)
  92 {
  93         const struct of_device_id *of_id;
  94         struct rn5t618 *priv;
  95         int ret;
  96
  97         of_id = of_match_device(rn5t618_of_match, &i2c->dev);
  98         if (!of_id) {
  99                 dev_err(&i2c->dev, "Failed to find matching DT ID\n");
 100                 return -EINVAL;
 101         }
 102
 103         priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
 104         if (!priv)
 105                 return -ENOMEM;
 106
 107         i2c_set_clientdata(i2c, priv);
 108         priv->variant = (long)of_id->data;
 109
 110         priv->regmap = devm_regmap_init_i2c(i2c, &rn5t618_regmap_config);
 111         if (IS_ERR(priv->regmap)) {
 112                 ret = PTR_ERR(priv->regmap);
 113                 dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
 114                 return ret;
 115         }
 116
 117         ret = devm_mfd_add_devices(&i2c->dev, -1, rn5t618_cells,
 118                                    ARRAY_SIZE(rn5t618_cells), NULL, 0, NULL);
 119         if (ret) {
 120                 dev_err(&i2c->dev, "failed to add sub-devices: %d\n", ret);
 121                 return ret;
 122         }
 123
 124         rn5t618_pm_power_off = priv;
 125         if (of_device_is_system_power_controller(i2c->dev.of_node)) {
 126                 if (!pm_power_off)
 127                         pm_power_off = rn5t618_power_off;
 128                 else
 129                         dev_warn(&i2c->dev, "Poweroff callback already assigned\n");
 130         }
 131
 132         rn5t618_restart_handler.notifier_call = rn5t618_restart;
 133         rn5t618_restart_handler.priority = 192;
 134
 135         ret = register_restart_handler(&rn5t618_restart_handler);
 136         if (ret) {
 137                 dev_err(&i2c->dev, "cannot register restart handler, %d\n", ret);
 138                 return ret;
 139         }
 140
 141         return 0;
 142 }
 143
 144 static int rn5t618_i2c_remove(struct i2c_client *i2c)
 145 {
 146         struct rn5t618 *priv = i2c_get_clientdata(i2c);
 147
 148         if (priv == rn5t618_pm_power_off) {
 149                 rn5t618_pm_power_off = NULL;
 150                 pm_power_off = NULL;
 151         }
 152
 153         unregister_restart_handler(&rn5t618_restart_handler);
 154
 155         return 0;
 156 }
 157
 158 static const struct i2c_device_id rn5t618_i2c_id[] = {
 159         { }
 160 };
 161 MODULE_DEVICE_TABLE(i2c, rn5t618_i2c_id);
 162
 163 static struct i2c_driver rn5t618_i2c_driver = {
 164         .driver = {
 165                 .name = "rn5t618",
 166                 .of_match_table = of_match_ptr(rn5t618_of_match),
 167         },
 168         .probe = rn5t618_i2c_probe,
 169         .remove = rn5t618_i2c_remove,
 170         .id_table = rn5t618_i2c_id,
 171 };
 172
 173 module_i2c_driver(rn5t618_i2c_driver);
 174
 175 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
 176 MODULE_DESCRIPTION("Ricoh RN5T567/618 MFD driver");
 177 MODULE_LICENSE("GPL v2");