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
 18static const struct mfd_cell rn5t618_cells[] = {
 19	{ .name = "rn5t618-regulator" },
 20	{ .name = "rn5t618-wdt" },
 21};
 22
 23static 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_IR_ADC1 ... RN5T618_IR_ADC3:
 30	case RN5T618_IR_GPR:
 31	case RN5T618_IR_GPF:
 32	case RN5T618_MON_IOIN:
 33	case RN5T618_INTMON:
 34		return true;
 35	default:
 36		return false;
 37	}
 38}
 39
 40static const struct regmap_config rn5t618_regmap_config = {
 41	.reg_bits	= 8,
 42	.val_bits	= 8,
 43	.volatile_reg	= rn5t618_volatile_reg,
 44	.max_register	= RN5T618_MAX_REG,
 45	.cache_type	= REGCACHE_RBTREE,
 46};
 47
 48static struct rn5t618 *rn5t618_pm_power_off;
 49static struct notifier_block rn5t618_restart_handler;
 50
 51static void rn5t618_trigger_poweroff_sequence(bool repower)
 52{
 53	/* disable automatic repower-on */
 54	regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_REPCNT,
 55			   RN5T618_REPCNT_REPWRON,
 56			   repower ? RN5T618_REPCNT_REPWRON : 0);
 57	/* start power-off sequence */
 58	regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_SLPCNT,
 59			   RN5T618_SLPCNT_SWPWROFF, RN5T618_SLPCNT_SWPWROFF);
 60}
 61
 62static void rn5t618_power_off(void)
 63{
 64	rn5t618_trigger_poweroff_sequence(false);
 65}
 66
 67static int rn5t618_restart(struct notifier_block *this,
 68			    unsigned long mode, void *cmd)
 69{
 70	rn5t618_trigger_poweroff_sequence(true);
 71
 72	/*
 73	 * Re-power factor detection on PMIC side is not instant. 1ms
 74	 * proved to be enough time until reset takes effect.
 75	 */
 76	mdelay(1);
 77
 78	return NOTIFY_DONE;
 79}
 80
 81static const struct of_device_id rn5t618_of_match[] = {
 82	{ .compatible = "ricoh,rn5t567", .data = (void *)RN5T567 },
 83	{ .compatible = "ricoh,rn5t618", .data = (void *)RN5T618 },
 84	{ .compatible = "ricoh,rc5t619", .data = (void *)RC5T619 },
 85	{ }
 86};
 87MODULE_DEVICE_TABLE(of, rn5t618_of_match);
 88
 89static int rn5t618_i2c_probe(struct i2c_client *i2c,
 90			     const struct i2c_device_id *id)
 91{
 92	const struct of_device_id *of_id;
 93	struct rn5t618 *priv;
 94	int ret;
 95
 96	of_id = of_match_device(rn5t618_of_match, &i2c->dev);
 97	if (!of_id) {
 98		dev_err(&i2c->dev, "Failed to find matching DT ID\n");
 99		return -EINVAL;
100	}
101
102	priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
103	if (!priv)
104		return -ENOMEM;
105
106	i2c_set_clientdata(i2c, priv);
107	priv->variant = (long)of_id->data;
108
109	priv->regmap = devm_regmap_init_i2c(i2c, &rn5t618_regmap_config);
110	if (IS_ERR(priv->regmap)) {
111		ret = PTR_ERR(priv->regmap);
112		dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
113		return ret;
114	}
115
116	ret = devm_mfd_add_devices(&i2c->dev, -1, rn5t618_cells,
117				   ARRAY_SIZE(rn5t618_cells), NULL, 0, NULL);
118	if (ret) {
119		dev_err(&i2c->dev, "failed to add sub-devices: %d\n", ret);
120		return ret;
121	}
122
123	rn5t618_pm_power_off = priv;
124	if (of_device_is_system_power_controller(i2c->dev.of_node)) {
125		if (!pm_power_off)
126			pm_power_off = rn5t618_power_off;
127		else
128			dev_warn(&i2c->dev, "Poweroff callback already assigned\n");
129	}
130
131	rn5t618_restart_handler.notifier_call = rn5t618_restart;
132	rn5t618_restart_handler.priority = 192;
133
134	ret = register_restart_handler(&rn5t618_restart_handler);
135	if (ret) {
136		dev_err(&i2c->dev, "cannot register restart handler, %d\n", ret);
137		return ret;
138	}
139
140	return 0;
141}
142
143static int rn5t618_i2c_remove(struct i2c_client *i2c)
144{
145	struct rn5t618 *priv = i2c_get_clientdata(i2c);
146
147	if (priv == rn5t618_pm_power_off) {
148		rn5t618_pm_power_off = NULL;
149		pm_power_off = NULL;
150	}
151
152	unregister_restart_handler(&rn5t618_restart_handler);
153
154	return 0;
155}
156
157static const struct i2c_device_id rn5t618_i2c_id[] = {
158	{ }
159};
160MODULE_DEVICE_TABLE(i2c, rn5t618_i2c_id);
161
162static struct i2c_driver rn5t618_i2c_driver = {
163	.driver = {
164		.name = "rn5t618",
165		.of_match_table = of_match_ptr(rn5t618_of_match),
166	},
167	.probe = rn5t618_i2c_probe,
168	.remove = rn5t618_i2c_remove,
169	.id_table = rn5t618_i2c_id,
170};
171
172module_i2c_driver(rn5t618_i2c_driver);
173
174MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
175MODULE_DESCRIPTION("Ricoh RN5T567/618 MFD driver");
176MODULE_LICENSE("GPL v2");