drivers/mfd/rn5t618.c

   1 /*
   2  * MFD core driver for Ricoh RN5T618 PMIC
   3  *
   4  * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
   5  * Copyright (C) 2016 Toradex AG
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  13  */
  14
  15 #include <linux/delay.h>
  16 #include <linux/i2c.h>
  17 #include <linux/mfd/core.h>
  18 #include <linux/mfd/rn5t618.h>
  19 #include <linux/module.h>
  20 #include <linux/of_device.h>
  21 #include <linux/reboot.h>
  22 #include <linux/regmap.h>
  23
  24 static const struct mfd_cell rn5t618_cells[] = {
  25         { .name = "rn5t618-regulator" },
  26         { .name = "rn5t618-wdt" },
  27 };
  28
  29 static bool rn5t618_volatile_reg(struct device *dev, unsigned int reg)
  30 {
  31         switch (reg) {
  32         case RN5T618_WATCHDOGCNT:
  33         case RN5T618_DCIRQ:
  34         case RN5T618_ILIMDATAH ... RN5T618_AIN0DATAL:
  35         case RN5T618_ADCCNT3:
  36         case RN5T618_IR_ADC1 ... RN5T618_IR_ADC3:
  37         case RN5T618_IR_GPR:
  38         case RN5T618_IR_GPF:
  39         case RN5T618_MON_IOIN:
  40         case RN5T618_INTMON:
  41                 return true;
  42         default:
  43                 return false;
  44         }
  45 }
  46
  47 static const struct regmap_config rn5t618_regmap_config = {
  48         .reg_bits       = 8,
  49         .val_bits       = 8,
  50         .volatile_reg   = rn5t618_volatile_reg,
  51         .max_register   = RN5T618_MAX_REG,
  52         .cache_type     = REGCACHE_RBTREE,
  53 };
  54
  55 static struct rn5t618 *rn5t618_pm_power_off;
  56 static struct notifier_block rn5t618_restart_handler;
  57
  58 static void rn5t618_trigger_poweroff_sequence(bool repower)
  59 {
  60         /* disable automatic repower-on */
  61         regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_REPCNT,
  62                            RN5T618_REPCNT_REPWRON,
  63                            repower ? RN5T618_REPCNT_REPWRON : 0);
  64         /* start power-off sequence */
  65         regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_SLPCNT,
  66                            RN5T618_SLPCNT_SWPWROFF, RN5T618_SLPCNT_SWPWROFF);
  67 }
  68
  69 static void rn5t618_power_off(void)
  70 {
  71         rn5t618_trigger_poweroff_sequence(false);
  72 }
  73
  74 static int rn5t618_restart(struct notifier_block *this,
  75                             unsigned long mode, void *cmd)
  76 {
  77         rn5t618_trigger_poweroff_sequence(true);
  78
  79         /*
  80          * Re-power factor detection on PMIC side is not instant. 1ms
  81          * proved to be enough time until reset takes effect.
  82          */
  83         mdelay(1);
  84
  85         return NOTIFY_DONE;
  86 }
  87
  88 static const struct of_device_id rn5t618_of_match[] = {
  89         { .compatible = "ricoh,rn5t567", .data = (void *)RN5T567 },
  90         { .compatible = "ricoh,rn5t618", .data = (void *)RN5T618 },
  91         { .compatible = "ricoh,rc5t619", .data = (void *)RC5T619 },
  92         { }
  93 };
  94 MODULE_DEVICE_TABLE(of, rn5t618_of_match);
  95
  96 static int rn5t618_i2c_probe(struct i2c_client *i2c,
  97                              const struct i2c_device_id *id)
  98 {
  99         const struct of_device_id *of_id;
 100         struct rn5t618 *priv;
 101         int ret;
 102
 103         of_id = of_match_device(rn5t618_of_match, &i2c->dev);
 104         if (!of_id) {
 105                 dev_err(&i2c->dev, "Failed to find matching DT ID\n");
 106                 return -EINVAL;
 107         }
 108
 109         priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
 110         if (!priv)
 111                 return -ENOMEM;
 112
 113         i2c_set_clientdata(i2c, priv);
 114         priv->variant = (long)of_id->data;
 115
 116         priv->regmap = devm_regmap_init_i2c(i2c, &rn5t618_regmap_config);
 117         if (IS_ERR(priv->regmap)) {
 118                 ret = PTR_ERR(priv->regmap);
 119                 dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
 120                 return ret;
 121         }
 122
 123         ret = devm_mfd_add_devices(&i2c->dev, -1, rn5t618_cells,
 124                                    ARRAY_SIZE(rn5t618_cells), NULL, 0, NULL);
 125         if (ret) {
 126                 dev_err(&i2c->dev, "failed to add sub-devices: %d\n", ret);
 127                 return ret;
 128         }
 129
 130         rn5t618_pm_power_off = priv;
 131         if (of_device_is_system_power_controller(i2c->dev.of_node)) {
 132                 if (!pm_power_off)
 133                         pm_power_off = rn5t618_power_off;
 134                 else
 135                         dev_warn(&i2c->dev, "Poweroff callback already assigned\n");
 136         }
 137
 138         rn5t618_restart_handler.notifier_call = rn5t618_restart;
 139         rn5t618_restart_handler.priority = 192;
 140
 141         ret = register_restart_handler(&rn5t618_restart_handler);
 142         if (ret) {
 143                 dev_err(&i2c->dev, "cannot register restart handler, %d\n", ret);
 144                 return ret;
 145         }
 146
 147         return 0;
 148 }
 149
 150 static int rn5t618_i2c_remove(struct i2c_client *i2c)
 151 {
 152         struct rn5t618 *priv = i2c_get_clientdata(i2c);
 153
 154         if (priv == rn5t618_pm_power_off) {
 155                 rn5t618_pm_power_off = NULL;
 156                 pm_power_off = NULL;
 157         }
 158
 159         unregister_restart_handler(&rn5t618_restart_handler);
 160
 161         return 0;
 162 }
 163
 164 static const struct i2c_device_id rn5t618_i2c_id[] = {
 165         { }
 166 };
 167 MODULE_DEVICE_TABLE(i2c, rn5t618_i2c_id);
 168
 169 static struct i2c_driver rn5t618_i2c_driver = {
 170         .driver = {
 171                 .name = "rn5t618",
 172                 .of_match_table = of_match_ptr(rn5t618_of_match),
 173         },
 174         .probe = rn5t618_i2c_probe,
 175         .remove = rn5t618_i2c_remove,
 176         .id_table = rn5t618_i2c_id,
 177 };
 178
 179 module_i2c_driver(rn5t618_i2c_driver);
 180
 181 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
 182 MODULE_DESCRIPTION("Ricoh RN5T567/618 MFD driver");
 183 MODULE_LICENSE("GPL v2");