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	return 0;
159}
160
161static const struct i2c_device_id rn5t618_i2c_id[] = {
162	{ }
163};
164MODULE_DEVICE_TABLE(i2c, rn5t618_i2c_id);
165
166static struct i2c_driver rn5t618_i2c_driver = {
167	.driver = {
168		.name = "rn5t618",
169		.of_match_table = of_match_ptr(rn5t618_of_match),
170	},
171	.probe = rn5t618_i2c_probe,
172	.remove = rn5t618_i2c_remove,
173	.id_table = rn5t618_i2c_id,
174};
175
176module_i2c_driver(rn5t618_i2c_driver);
177
178MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
179MODULE_DESCRIPTION("Ricoh RN5T567/618 MFD driver");
180MODULE_LICENSE("GPL v2");