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_MAPLE,
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{
89 struct device *dev = &client->dev;
90 struct khadas_mcu *ddata;
91 int ret;
92
93 ddata = devm_kzalloc(dev, size: sizeof(*ddata), GFP_KERNEL);
94 if (!ddata)
95 return -ENOMEM;
96
97 i2c_set_clientdata(client, data: ddata);
98
99 ddata->dev = dev;
100
101 ddata->regmap = devm_regmap_init_i2c(client, &khadas_mcu_regmap_config);
102 if (IS_ERR(ptr: ddata->regmap)) {
103 ret = PTR_ERR(ptr: ddata->regmap);
104 dev_err(dev, "Failed to allocate register map: %d\n", ret);
105 return ret;
106 }
107
108 ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
109 cells: khadas_mcu_cells,
110 ARRAY_SIZE(khadas_mcu_cells),
111 NULL, irq_base: 0, NULL);
112 if (ret)
113 return ret;
114
115 if (of_property_present(np: dev->of_node, propname: "#cooling-cells"))
116 return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
117 cells: khadas_mcu_fan_cells,
118 ARRAY_SIZE(khadas_mcu_fan_cells),
119 NULL, irq_base: 0, NULL);
120
121 return 0;
122}
123
124#ifdef CONFIG_OF
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#endif
131
132static struct i2c_driver khadas_mcu_driver = {
133 .driver = {
134 .name = "khadas-mcu-core",
135 .of_match_table = of_match_ptr(khadas_mcu_of_match),
136 },
137 .probe = khadas_mcu_probe,
138};
139module_i2c_driver(khadas_mcu_driver);
140
141MODULE_DESCRIPTION("Khadas MCU core driver");
142MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
143MODULE_LICENSE("GPL v2");
144

source code of linux/drivers/mfd/khadas-mcu.c