linux/drivers/mfd/rn5t618.c
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   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
  24static const struct mfd_cell rn5t618_cells[] = {
  25        { .name = "rn5t618-regulator" },
  26        { .name = "rn5t618-wdt" },
  27};
  28
  29static 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
  46static 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
  54static struct rn5t618 *rn5t618_pm_power_off;
  55static struct notifier_block rn5t618_restart_handler;
  56
  57static 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
  68static void rn5t618_power_off(void)
  69{
  70        rn5t618_trigger_poweroff_sequence(false);
  71}
  72
  73static 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
  87static const struct of_device_id rn5t618_of_match[] = {
  88        { .compatible = "ricoh,rn5t567", .data = (void *)RN5T567 },
  89        { .compatible = "ricoh,rn5t618", .data = (void *)RN5T618 },
  90        { .compatible = "ricoh,rc5t619", .data = (void *)RC5T619 },
  91        { }
  92};
  93MODULE_DEVICE_TABLE(of, rn5t618_of_match);
  94
  95static int rn5t618_i2c_probe(struct i2c_client *i2c,
  96                             const struct i2c_device_id *id)
  97{
  98        const struct of_device_id *of_id;
  99        struct rn5t618 *priv;
 100        int ret;
 101
 102        of_id = of_match_device(rn5t618_of_match, &i2c->dev);
 103        if (!of_id) {
 104                dev_err(&i2c->dev, "Failed to find matching DT ID\n");
 105                return -EINVAL;
 106        }
 107
 108        priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
 109        if (!priv)
 110                return -ENOMEM;
 111
 112        i2c_set_clientdata(i2c, priv);
 113        priv->variant = (long)of_id->data;
 114
 115        priv->regmap = devm_regmap_init_i2c(i2c, &rn5t618_regmap_config);
 116        if (IS_ERR(priv->regmap)) {
 117                ret = PTR_ERR(priv->regmap);
 118                dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
 119                return ret;
 120        }
 121
 122        ret = devm_mfd_add_devices(&i2c->dev, -1, rn5t618_cells,
 123                                   ARRAY_SIZE(rn5t618_cells), NULL, 0, NULL);
 124        if (ret) {
 125                dev_err(&i2c->dev, "failed to add sub-devices: %d\n", ret);
 126                return ret;
 127        }
 128
 129        rn5t618_pm_power_off = priv;
 130        if (of_device_is_system_power_controller(i2c->dev.of_node)) {
 131                if (!pm_power_off)
 132                        pm_power_off = rn5t618_power_off;
 133                else
 134                        dev_warn(&i2c->dev, "Poweroff callback already assigned\n");
 135        }
 136
 137        rn5t618_restart_handler.notifier_call = rn5t618_restart;
 138        rn5t618_restart_handler.priority = 192;
 139
 140        ret = register_restart_handler(&rn5t618_restart_handler);
 141        if (ret) {
 142                dev_err(&i2c->dev, "cannot register restart handler, %d\n", ret);
 143                return ret;
 144        }
 145
 146        return 0;
 147}
 148
 149static int rn5t618_i2c_remove(struct i2c_client *i2c)
 150{
 151        struct rn5t618 *priv = i2c_get_clientdata(i2c);
 152
 153        if (priv == rn5t618_pm_power_off) {
 154                rn5t618_pm_power_off = NULL;
 155                pm_power_off = NULL;
 156        }
 157
 158        unregister_restart_handler(&rn5t618_restart_handler);
 159
 160        return 0;
 161}
 162
 163static const struct i2c_device_id rn5t618_i2c_id[] = {
 164        { }
 165};
 166MODULE_DEVICE_TABLE(i2c, rn5t618_i2c_id);
 167
 168static struct i2c_driver rn5t618_i2c_driver = {
 169        .driver = {
 170                .name = "rn5t618",
 171                .of_match_table = of_match_ptr(rn5t618_of_match),
 172        },
 173        .probe = rn5t618_i2c_probe,
 174        .remove = rn5t618_i2c_remove,
 175        .id_table = rn5t618_i2c_id,
 176};
 177
 178module_i2c_driver(rn5t618_i2c_driver);
 179
 180MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
 181MODULE_DESCRIPTION("Ricoh RN5T567/618 MFD driver");
 182MODULE_LICENSE("GPL v2");
 183