1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Driver for Khadas System control Microcontroller
  4 *
  5 * Copyright (C) 2020 BayLibre SAS
  6 *
  7 * Author(s): Neil Armstrong <narmstrong@baylibre.com>
  8 */
  9#include <linux/bitfield.h>
 10#include <linux/i2c.h>
 11#include <linux/mfd/core.h>
 12#include <linux/mfd/khadas-mcu.h>
 13#include <linux/module.h>
 14#include <linux/regmap.h>
 15
 16static bool khadas_mcu_reg_volatile(struct device *dev, unsigned int reg)
 17{
 18	if (reg >= KHADAS_MCU_USER_DATA_0_REG &&
 19	    reg < KHADAS_MCU_PWR_OFF_CMD_REG)
 20		return true;
 21
 22	switch (reg) {
 23	case KHADAS_MCU_PWR_OFF_CMD_REG:
 24	case KHADAS_MCU_PASSWD_START_REG:
 25	case KHADAS_MCU_CHECK_VEN_PASSWD_REG:
 26	case KHADAS_MCU_CHECK_USER_PASSWD_REG:
 27	case KHADAS_MCU_WOL_INIT_START_REG:
 28	case KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG:
 29		return true;
 30	default:
 31		return false;
 32	}
 33}
 34
 35static bool khadas_mcu_reg_writeable(struct device *dev, unsigned int reg)
 36{
 37	switch (reg) {
 38	case KHADAS_MCU_PASSWD_VEN_0_REG:
 39	case KHADAS_MCU_PASSWD_VEN_1_REG:
 40	case KHADAS_MCU_PASSWD_VEN_2_REG:
 41	case KHADAS_MCU_PASSWD_VEN_3_REG:
 42	case KHADAS_MCU_PASSWD_VEN_4_REG:
 43	case KHADAS_MCU_PASSWD_VEN_5_REG:
 44	case KHADAS_MCU_MAC_0_REG:
 45	case KHADAS_MCU_MAC_1_REG:
 46	case KHADAS_MCU_MAC_2_REG:
 47	case KHADAS_MCU_MAC_3_REG:
 48	case KHADAS_MCU_MAC_4_REG:
 49	case KHADAS_MCU_MAC_5_REG:
 50	case KHADAS_MCU_USID_0_REG:
 51	case KHADAS_MCU_USID_1_REG:
 52	case KHADAS_MCU_USID_2_REG:
 53	case KHADAS_MCU_USID_3_REG:
 54	case KHADAS_MCU_USID_4_REG:
 55	case KHADAS_MCU_USID_5_REG:
 56	case KHADAS_MCU_VERSION_0_REG:
 57	case KHADAS_MCU_VERSION_1_REG:
 58	case KHADAS_MCU_DEVICE_NO_0_REG:
 59	case KHADAS_MCU_DEVICE_NO_1_REG:
 60	case KHADAS_MCU_FACTORY_TEST_REG:
 61	case KHADAS_MCU_SHUTDOWN_NORMAL_STATUS_REG:
 62		return false;
 63	default:
 64		return true;
 65	}
 66}
 67
 68static const struct regmap_config khadas_mcu_regmap_config = {
 69	.reg_bits	= 8,
 70	.reg_stride	= 1,
 71	.val_bits	= 8,
 72	.max_register	= KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
 73	.volatile_reg	= khadas_mcu_reg_volatile,
 74	.writeable_reg	= khadas_mcu_reg_writeable,
 75	.cache_type	= REGCACHE_RBTREE,
 76};
 77
 78static struct mfd_cell khadas_mcu_fan_cells[] = {
 79	/* VIM1/2 Rev13+ and VIM3 only */
 80	{ .name = "khadas-mcu-fan-ctrl", },
 81};
 82
 83static struct mfd_cell khadas_mcu_cells[] = {
 84	{ .name = "khadas-mcu-user-mem", },
 85};
 86
 87static int khadas_mcu_probe(struct i2c_client *client,
 88		       const struct i2c_device_id *id)
 89{
 90	struct device *dev = &client->dev;
 91	struct khadas_mcu *ddata;
 92	int ret;
 93
 94	ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
 95	if (!ddata)
 96		return -ENOMEM;
 97
 98	i2c_set_clientdata(client, ddata);
 99
100	ddata->dev = dev;
101
102	ddata->regmap = devm_regmap_init_i2c(client, &khadas_mcu_regmap_config);
103	if (IS_ERR(ddata->regmap)) {
104		ret = PTR_ERR(ddata->regmap);
105		dev_err(dev, "Failed to allocate register map: %d\n", ret);
106		return ret;
107	}
108
109	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
110				   khadas_mcu_cells,
111				   ARRAY_SIZE(khadas_mcu_cells),
112				   NULL, 0, NULL);
113	if (ret)
114		return ret;
115
116	if (of_find_property(dev->of_node, "#cooling-cells", NULL))
117		return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
118					    khadas_mcu_fan_cells,
119					    ARRAY_SIZE(khadas_mcu_fan_cells),
120					    NULL, 0, NULL);
121
122	return 0;
123}
124
125static const struct of_device_id khadas_mcu_of_match[] = {
126	{ .compatible = "khadas,mcu", },
127	{},
128};
129MODULE_DEVICE_TABLE(of, khadas_mcu_of_match);
130
131static struct i2c_driver khadas_mcu_driver = {
132	.driver = {
133		.name = "khadas-mcu-core",
134		.of_match_table = of_match_ptr(khadas_mcu_of_match),
135	},
136	.probe = khadas_mcu_probe,
137};
138module_i2c_driver(khadas_mcu_driver);
139
140MODULE_DESCRIPTION("Khadas MCU core driver");
141MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
142MODULE_LICENSE("GPL v2");