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 * 32-bit register address: the lower 8 bits of the register address come
22 * from the offset addr byte and the upper 24 bits come from the page register.
23 */
24 #define RSMU_CM_PAGE_ADDR 0xFC
25 #define RSMU_CM_PAGE_MASK 0xFFFFFF00
26 #define RSMU_CM_ADDRESS_MASK 0x000000FF
27
28 /*
29 * 15-bit register address: the lower 7 bits of the register address come
30 * from the offset addr byte and the upper 8 bits come from the page register.
31 */
32 #define RSMU_SABRE_PAGE_ADDR 0x7F
33 #define RSMU_SABRE_PAGE_WINDOW 128
34
35 static const struct regmap_range_cfg rsmu_sabre_range_cfg[] = {
36 {
37 .range_min = 0,
38 .range_max = 0x400,
39 .selector_reg = RSMU_SABRE_PAGE_ADDR,
40 .selector_mask = 0xFF,
41 .selector_shift = 0,
42 .window_start = 0,
43 .window_len = RSMU_SABRE_PAGE_WINDOW,
44 }
45 };
46
rsmu_sabre_volatile_reg(struct device * dev,unsigned int reg)47 static bool rsmu_sabre_volatile_reg(struct device *dev, unsigned int reg)
48 {
49 switch (reg) {
50 case RSMU_SABRE_PAGE_ADDR:
51 return false;
52 default:
53 return true;
54 }
55 }
56
rsmu_read_device(struct rsmu_ddata * rsmu,u8 reg,u8 * buf,u16 bytes)57 static int rsmu_read_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes)
58 {
59 struct i2c_client *client = to_i2c_client(rsmu->dev);
60 struct i2c_msg msg[2];
61 int cnt;
62
63 msg[0].addr = client->addr;
64 msg[0].flags = 0;
65 msg[0].len = 1;
66 msg[0].buf = ®
67
68 msg[1].addr = client->addr;
69 msg[1].flags = I2C_M_RD;
70 msg[1].len = bytes;
71 msg[1].buf = buf;
72
73 cnt = i2c_transfer(client->adapter, msg, 2);
74
75 if (cnt < 0) {
76 dev_err(rsmu->dev, "i2c_transfer failed at addr: %04x!", reg);
77 return cnt;
78 } else if (cnt != 2) {
79 dev_err(rsmu->dev,
80 "i2c_transfer sent only %d of 2 messages", cnt);
81 return -EIO;
82 }
83
84 return 0;
85 }
86
rsmu_write_device(struct rsmu_ddata * rsmu,u8 reg,u8 * buf,u16 bytes)87 static int rsmu_write_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u16 bytes)
88 {
89 struct i2c_client *client = to_i2c_client(rsmu->dev);
90 u8 msg[RSMU_MAX_WRITE_COUNT + 1]; /* 1 Byte added for the device register */
91 int cnt;
92
93 if (bytes > RSMU_MAX_WRITE_COUNT)
94 return -EINVAL;
95
96 msg[0] = reg;
97 memcpy(&msg[1], buf, bytes);
98
99 cnt = i2c_master_send(client, msg, bytes + 1);
100
101 if (cnt < 0) {
102 dev_err(&client->dev,
103 "i2c_master_send failed at addr: %04x!", reg);
104 return cnt;
105 }
106
107 return 0;
108 }
109
rsmu_write_page_register(struct rsmu_ddata * rsmu,u32 reg)110 static int rsmu_write_page_register(struct rsmu_ddata *rsmu, u32 reg)
111 {
112 u32 page = reg & RSMU_CM_PAGE_MASK;
113 u8 buf[4];
114 int err;
115
116 /* Do not modify offset register for none-scsr registers */
117 if (reg < RSMU_CM_SCSR_BASE)
118 return 0;
119
120 /* Simply return if we are on the same page */
121 if (rsmu->page == page)
122 return 0;
123
124 buf[0] = 0x0;
125 buf[1] = (u8)((page >> 8) & 0xFF);
126 buf[2] = (u8)((page >> 16) & 0xFF);
127 buf[3] = (u8)((page >> 24) & 0xFF);
128
129 err = rsmu_write_device(rsmu, RSMU_CM_PAGE_ADDR, buf, sizeof(buf));
130 if (err)
131 dev_err(rsmu->dev, "Failed to set page offset 0x%x\n", page);
132 else
133 /* Remember the last page */
134 rsmu->page = page;
135
136 return err;
137 }
138
rsmu_reg_read(void * context,unsigned int reg,unsigned int * val)139 static int rsmu_reg_read(void *context, unsigned int reg, unsigned int *val)
140 {
141 struct rsmu_ddata *rsmu = i2c_get_clientdata((struct i2c_client *)context);
142 u8 addr = (u8)(reg & RSMU_CM_ADDRESS_MASK);
143 int err;
144
145 err = rsmu_write_page_register(rsmu, reg);
146 if (err)
147 return err;
148
149 err = rsmu_read_device(rsmu, addr, (u8 *)val, 1);
150 if (err)
151 dev_err(rsmu->dev, "Failed to read offset address 0x%x\n", addr);
152
153 return err;
154 }
155
rsmu_reg_write(void * context,unsigned int reg,unsigned int val)156 static int rsmu_reg_write(void *context, unsigned int reg, unsigned int val)
157 {
158 struct rsmu_ddata *rsmu = i2c_get_clientdata((struct i2c_client *)context);
159 u8 addr = (u8)(reg & RSMU_CM_ADDRESS_MASK);
160 u8 data = (u8)val;
161 int err;
162
163 err = rsmu_write_page_register(rsmu, reg);
164 if (err)
165 return err;
166
167 err = rsmu_write_device(rsmu, addr, &data, 1);
168 if (err)
169 dev_err(rsmu->dev,
170 "Failed to write offset address 0x%x\n", addr);
171
172 return err;
173 }
174
175 static const struct regmap_config rsmu_cm_regmap_config = {
176 .reg_bits = 32,
177 .val_bits = 8,
178 .max_register = 0x20120000,
179 .reg_read = rsmu_reg_read,
180 .reg_write = rsmu_reg_write,
181 .cache_type = REGCACHE_NONE,
182 };
183
184 static const struct regmap_config rsmu_sabre_regmap_config = {
185 .reg_bits = 8,
186 .val_bits = 8,
187 .max_register = 0x400,
188 .ranges = rsmu_sabre_range_cfg,
189 .num_ranges = ARRAY_SIZE(rsmu_sabre_range_cfg),
190 .volatile_reg = rsmu_sabre_volatile_reg,
191 .cache_type = REGCACHE_RBTREE,
192 .can_multi_write = true,
193 };
194
195 static const struct regmap_config rsmu_sl_regmap_config = {
196 .reg_bits = 16,
197 .val_bits = 8,
198 .reg_format_endian = REGMAP_ENDIAN_BIG,
199 .max_register = 0x340,
200 .cache_type = REGCACHE_NONE,
201 .can_multi_write = true,
202 };
203
rsmu_i2c_probe(struct i2c_client * client)204 static int rsmu_i2c_probe(struct i2c_client *client)
205 {
206 const struct i2c_device_id *id = i2c_client_get_device_id(client);
207 const struct regmap_config *cfg;
208 struct rsmu_ddata *rsmu;
209 int ret;
210
211 rsmu = devm_kzalloc(&client->dev, sizeof(*rsmu), GFP_KERNEL);
212 if (!rsmu)
213 return -ENOMEM;
214
215 i2c_set_clientdata(client, rsmu);
216
217 rsmu->dev = &client->dev;
218 rsmu->type = (enum rsmu_type)id->driver_data;
219
220 switch (rsmu->type) {
221 case RSMU_CM:
222 cfg = &rsmu_cm_regmap_config;
223 break;
224 case RSMU_SABRE:
225 cfg = &rsmu_sabre_regmap_config;
226 break;
227 case RSMU_SL:
228 cfg = &rsmu_sl_regmap_config;
229 break;
230 default:
231 dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);
232 return -ENODEV;
233 }
234
235 if (rsmu->type == RSMU_CM)
236 rsmu->regmap = devm_regmap_init(&client->dev, NULL, client, cfg);
237 else
238 rsmu->regmap = devm_regmap_init_i2c(client, cfg);
239 if (IS_ERR(rsmu->regmap)) {
240 ret = PTR_ERR(rsmu->regmap);
241 dev_err(rsmu->dev, "Failed to allocate register map: %d\n", ret);
242 return ret;
243 }
244
245 return rsmu_core_init(rsmu);
246 }
247
rsmu_i2c_remove(struct i2c_client * client)248 static void rsmu_i2c_remove(struct i2c_client *client)
249 {
250 struct rsmu_ddata *rsmu = i2c_get_clientdata(client);
251
252 rsmu_core_exit(rsmu);
253 }
254
255 static const struct i2c_device_id rsmu_i2c_id[] = {
256 { "8a34000", RSMU_CM },
257 { "8a34001", RSMU_CM },
258 { "82p33810", RSMU_SABRE },
259 { "82p33811", RSMU_SABRE },
260 { "8v19n850", RSMU_SL },
261 { "8v19n851", RSMU_SL },
262 {}
263 };
264 MODULE_DEVICE_TABLE(i2c, rsmu_i2c_id);
265
266 static const struct of_device_id rsmu_i2c_of_match[] = {
267 { .compatible = "idt,8a34000", .data = (void *)RSMU_CM },
268 { .compatible = "idt,8a34001", .data = (void *)RSMU_CM },
269 { .compatible = "idt,82p33810", .data = (void *)RSMU_SABRE },
270 { .compatible = "idt,82p33811", .data = (void *)RSMU_SABRE },
271 { .compatible = "idt,8v19n850", .data = (void *)RSMU_SL },
272 { .compatible = "idt,8v19n851", .data = (void *)RSMU_SL },
273 {}
274 };
275 MODULE_DEVICE_TABLE(of, rsmu_i2c_of_match);
276
277 static struct i2c_driver rsmu_i2c_driver = {
278 .driver = {
279 .name = "rsmu-i2c",
280 .of_match_table = rsmu_i2c_of_match,
281 },
282 .probe = rsmu_i2c_probe,
283 .remove = rsmu_i2c_remove,
284 .id_table = rsmu_i2c_id,
285 };
286
rsmu_i2c_init(void)287 static int __init rsmu_i2c_init(void)
288 {
289 return i2c_add_driver(&rsmu_i2c_driver);
290 }
291 subsys_initcall(rsmu_i2c_init);
292
rsmu_i2c_exit(void)293 static void __exit rsmu_i2c_exit(void)
294 {
295 i2c_del_driver(&rsmu_i2c_driver);
296 }
297 module_exit(rsmu_i2c_exit);
298
299 MODULE_DESCRIPTION("Renesas SMU I2C driver");
300 MODULE_LICENSE("GPL");
301