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_IR_ADC1 ... RN5T618_IR_ADC3:
  36         case RN5T618_IR_GPR:
  37         case RN5T618_IR_GPF:
  38         case RN5T618_MON_IOIN:
  39         case RN5T618_INTMON:
  40                 return true;
  41         default:
  42                 return false;
  43         }
  44 }
  45
  46 static const struct regmap_config rn5t618_regmap_config = {
  47         .reg_bits       = 8,
  48         .val_bits       = 8,
  49         .volatile_reg   = rn5t618_volatile_reg,
  50         .max_register   = RN5T618_MAX_REG,
  51         .cache_type     = REGCACHE_RBTREE,
  52 };
  53
  54 static struct rn5t618 *rn5t618_pm_power_off;
  55 static struct notifier_block rn5t618_restart_handler;
  56
  57 static void rn5t618_trigger_poweroff_sequence(bool repower)
  58 {
  59         /* disable automatic repower-on */
  60         regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_REPCNT,
  61                            RN5T618_REPCNT_REPWRON,
  62                            repower ? RN5T618_REPCNT_REPWRON : 0);
  63         /* start power-off sequence */
  64         regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_SLPCNT,
  65                            RN5T618_SLPCNT_SWPWROFF, RN5T618_SLPCNT_SWPWROFF);
  66 }
  67
  68 static void rn5t618_power_off(void)
  69 {
  70         rn5t618_trigger_poweroff_sequence(false);
  71 }
  72
  73 static int rn5t618_restart(struct notifier_block *this,
  74                             unsigned long mode, void *cmd)
  75 {
  76         rn5t618_trigger_poweroff_sequence(true);
  77
  78         /*
  79          * Re-power factor detection on PMIC side is not instant. 1ms
  80          * proved to be enough time until reset takes effect.
  81          */
  82         mdelay(1);
  83
  84         return NOTIFY_DONE;
  85 }
  86
  87 static const struct of_device_id rn5t618_of_match[] = {
  88         { .compatible = "ricoh,rn5t567", .data = (void *)RN5T567 },
  89         { .compatible = "ricoh,rn5t618", .data = (void *)RN5T618 },
  90         { }
  91 };
  92 MODULE_DEVICE_TABLE(of, rn5t618_of_match);
  93
  94 static int rn5t618_i2c_probe(struct i2c_client *i2c,
  95                              const struct i2c_device_id *id)
  96 {
  97         const struct of_device_id *of_id;
  98         struct rn5t618 *priv;
  99         int ret;
 100
 101         of_id = of_match_device(rn5t618_of_match, &i2c->dev);
 102         if (!of_id) {
 103                 dev_err(&i2c->dev, "Failed to find matching DT ID\n");
 104                 return -EINVAL;
 105         }
 106
 107         priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
 108         if (!priv)
 109                 return -ENOMEM;
 110
 111         i2c_set_clientdata(i2c, priv);
 112         priv->variant = (long)of_id->data;
 113
 114         priv->regmap = devm_regmap_init_i2c(i2c, &rn5t618_regmap_config);
 115         if (IS_ERR(priv->regmap)) {
 116                 ret = PTR_ERR(priv->regmap);
 117                 dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
 118                 return ret;
 119         }
 120
 121         ret = devm_mfd_add_devices(&i2c->dev, -1, rn5t618_cells,
 122                                    ARRAY_SIZE(rn5t618_cells), NULL, 0, NULL);
 123         if (ret) {
 124                 dev_err(&i2c->dev, "failed to add sub-devices: %d\n", ret);
 125                 return ret;
 126         }
 127
 128         rn5t618_pm_power_off = priv;
 129         if (of_device_is_system_power_controller(i2c->dev.of_node)) {
 130                 if (!pm_power_off)
 131                         pm_power_off = rn5t618_power_off;
 132                 else
 133                         dev_warn(&i2c->dev, "Poweroff callback already assigned\n");
 134         }
 135
 136         rn5t618_restart_handler.notifier_call = rn5t618_restart;
 137         rn5t618_restart_handler.priority = 192;
 138
 139         ret = register_restart_handler(&rn5t618_restart_handler);
 140         if (ret) {
 141                 dev_err(&i2c->dev, "cannot register restart handler, %d\n", ret);
 142                 return ret;
 143         }
 144
 145         return 0;
 146 }
 147
 148 static int rn5t618_i2c_remove(struct i2c_client *i2c)
 149 {
 150         struct rn5t618 *priv = i2c_get_clientdata(i2c);
 151
 152         if (priv == rn5t618_pm_power_off) {
 153                 rn5t618_pm_power_off = NULL;
 154                 pm_power_off = NULL;
 155         }
 156
 157         return 0;
 158 }
 159
 160 static const struct i2c_device_id rn5t618_i2c_id[] = {
 161         { }
 162 };
 163 MODULE_DEVICE_TABLE(i2c, rn5t618_i2c_id);
 164
 165 static struct i2c_driver rn5t618_i2c_driver = {
 166         .driver = {
 167                 .name = "rn5t618",
 168                 .of_match_table = of_match_ptr(rn5t618_of_match),
 169         },
 170         .probe = rn5t618_i2c_probe,
 171         .remove = rn5t618_i2c_remove,
 172         .id_table = rn5t618_i2c_id,
 173 };
 174
 175 module_i2c_driver(rn5t618_i2c_driver);
 176
 177 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
 178 MODULE_DESCRIPTION("Ricoh RN5T567/618 MFD driver");
 179 MODULE_LICENSE("GPL v2");