1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * I2C driver for Renesas Synchronization Management Unit (SMU) devices.
4  *
5  * Copyright (C) 2021 Integrated Device Technology, Inc., a Renesas Company.
6  */
7 
8 #include <linux/i2c.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/mfd/core.h>
12 #include <linux/mfd/rsmu.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/regmap.h>
16 #include <linux/slab.h>
17 
18 #include "rsmu.h"
19 
20 /*
21  * 16-bit register address: the lower 8 bits of the register address come
22  * from the offset addr byte and the upper 8 bits come from the page register.
23  */
24 #define	RSMU_CM_PAGE_ADDR		0xFD
25 #define	RSMU_CM_PAGE_WINDOW		256
26 
27 /*
28  * 15-bit register address: the lower 7 bits of the register address come
29  * from the offset addr byte and the upper 8 bits come from the page register.
30  */
31 #define	RSMU_SABRE_PAGE_ADDR		0x7F
32 #define	RSMU_SABRE_PAGE_WINDOW		128
33 
34 static const struct regmap_range_cfg rsmu_cm_range_cfg[] = {
35 	{
36 		.range_min = 0,
37 		.range_max = 0xD000,
38 		.selector_reg = RSMU_CM_PAGE_ADDR,
39 		.selector_mask = 0xFF,
40 		.selector_shift = 0,
41 		.window_start = 0,
42 		.window_len = RSMU_CM_PAGE_WINDOW,
43 	}
44 };
45 
46 static const struct regmap_range_cfg rsmu_sabre_range_cfg[] = {
47 	{
48 		.range_min = 0,
49 		.range_max = 0x400,
50 		.selector_reg = RSMU_SABRE_PAGE_ADDR,
51 		.selector_mask = 0xFF,
52 		.selector_shift = 0,
53 		.window_start = 0,
54 		.window_len = RSMU_SABRE_PAGE_WINDOW,
55 	}
56 };
57 
rsmu_cm_volatile_reg(struct device * dev,unsigned int reg)58 static bool rsmu_cm_volatile_reg(struct device *dev, unsigned int reg)
59 {
60 	switch (reg) {
61 	case RSMU_CM_PAGE_ADDR:
62 		return false;
63 	default:
64 		return true;
65 	}
66 }
67 
rsmu_sabre_volatile_reg(struct device * dev,unsigned int reg)68 static bool rsmu_sabre_volatile_reg(struct device *dev, unsigned int reg)
69 {
70 	switch (reg) {
71 	case RSMU_SABRE_PAGE_ADDR:
72 		return false;
73 	default:
74 		return true;
75 	}
76 }
77 
78 static const struct regmap_config rsmu_cm_regmap_config = {
79 	.reg_bits = 8,
80 	.val_bits = 8,
81 	.max_register = 0xD000,
82 	.ranges = rsmu_cm_range_cfg,
83 	.num_ranges = ARRAY_SIZE(rsmu_cm_range_cfg),
84 	.volatile_reg = rsmu_cm_volatile_reg,
85 	.cache_type = REGCACHE_RBTREE,
86 	.can_multi_write = true,
87 };
88 
89 static const struct regmap_config rsmu_sabre_regmap_config = {
90 	.reg_bits = 8,
91 	.val_bits = 8,
92 	.max_register = 0x400,
93 	.ranges = rsmu_sabre_range_cfg,
94 	.num_ranges = ARRAY_SIZE(rsmu_sabre_range_cfg),
95 	.volatile_reg = rsmu_sabre_volatile_reg,
96 	.cache_type = REGCACHE_RBTREE,
97 	.can_multi_write = true,
98 };
99 
100 static const struct regmap_config rsmu_sl_regmap_config = {
101 	.reg_bits = 16,
102 	.val_bits = 8,
103 	.reg_format_endian = REGMAP_ENDIAN_BIG,
104 	.max_register = 0x339,
105 	.cache_type = REGCACHE_NONE,
106 	.can_multi_write = true,
107 };
108 
rsmu_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)109 static int rsmu_i2c_probe(struct i2c_client *client,
110 			  const struct i2c_device_id *id)
111 {
112 	const struct regmap_config *cfg;
113 	struct rsmu_ddata *rsmu;
114 	int ret;
115 
116 	rsmu = devm_kzalloc(&client->dev, sizeof(*rsmu), GFP_KERNEL);
117 	if (!rsmu)
118 		return -ENOMEM;
119 
120 	i2c_set_clientdata(client, rsmu);
121 
122 	rsmu->dev = &client->dev;
123 	rsmu->type = (enum rsmu_type)id->driver_data;
124 
125 	switch (rsmu->type) {
126 	case RSMU_CM:
127 		cfg = &rsmu_cm_regmap_config;
128 		break;
129 	case RSMU_SABRE:
130 		cfg = &rsmu_sabre_regmap_config;
131 		break;
132 	case RSMU_SL:
133 		cfg = &rsmu_sl_regmap_config;
134 		break;
135 	default:
136 		dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);
137 		return -ENODEV;
138 	}
139 	rsmu->regmap = devm_regmap_init_i2c(client, cfg);
140 	if (IS_ERR(rsmu->regmap)) {
141 		ret = PTR_ERR(rsmu->regmap);
142 		dev_err(rsmu->dev, "Failed to allocate register map: %d\n", ret);
143 		return ret;
144 	}
145 
146 	return rsmu_core_init(rsmu);
147 }
148 
rsmu_i2c_remove(struct i2c_client * client)149 static int rsmu_i2c_remove(struct i2c_client *client)
150 {
151 	struct rsmu_ddata *rsmu = i2c_get_clientdata(client);
152 
153 	rsmu_core_exit(rsmu);
154 
155 	return 0;
156 }
157 
158 static const struct i2c_device_id rsmu_i2c_id[] = {
159 	{ "8a34000",  RSMU_CM },
160 	{ "8a34001",  RSMU_CM },
161 	{ "82p33810", RSMU_SABRE },
162 	{ "82p33811", RSMU_SABRE },
163 	{ "8v19n850", RSMU_SL },
164 	{ "8v19n851", RSMU_SL },
165 	{}
166 };
167 MODULE_DEVICE_TABLE(i2c, rsmu_i2c_id);
168 
169 static const struct of_device_id rsmu_i2c_of_match[] = {
170 	{ .compatible = "idt,8a34000",  .data = (void *)RSMU_CM },
171 	{ .compatible = "idt,8a34001",  .data = (void *)RSMU_CM },
172 	{ .compatible = "idt,82p33810", .data = (void *)RSMU_SABRE },
173 	{ .compatible = "idt,82p33811", .data = (void *)RSMU_SABRE },
174 	{ .compatible = "idt,8v19n850", .data = (void *)RSMU_SL },
175 	{ .compatible = "idt,8v19n851", .data = (void *)RSMU_SL },
176 	{}
177 };
178 MODULE_DEVICE_TABLE(of, rsmu_i2c_of_match);
179 
180 static struct i2c_driver rsmu_i2c_driver = {
181 	.driver = {
182 		.name = "rsmu-i2c",
183 		.of_match_table = of_match_ptr(rsmu_i2c_of_match),
184 	},
185 	.probe = rsmu_i2c_probe,
186 	.remove	= rsmu_i2c_remove,
187 	.id_table = rsmu_i2c_id,
188 };
189 
rsmu_i2c_init(void)190 static int __init rsmu_i2c_init(void)
191 {
192 	return i2c_add_driver(&rsmu_i2c_driver);
193 }
194 subsys_initcall(rsmu_i2c_init);
195 
rsmu_i2c_exit(void)196 static void __exit rsmu_i2c_exit(void)
197 {
198 	i2c_del_driver(&rsmu_i2c_driver);
199 }
200 module_exit(rsmu_i2c_exit);
201 
202 MODULE_DESCRIPTION("Renesas SMU I2C driver");
203 MODULE_LICENSE("GPL");
204