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 typedef int (*rsmu_rw_device)(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u8 bytes);
36
37 static const struct regmap_range_cfg rsmu_sabre_range_cfg[] = {
38 {
39 .range_min = 0,
40 .range_max = 0x400,
41 .selector_reg = RSMU_SABRE_PAGE_ADDR,
42 .selector_mask = 0xFF,
43 .selector_shift = 0,
44 .window_start = 0,
45 .window_len = RSMU_SABRE_PAGE_WINDOW,
46 }
47 };
48
rsmu_sabre_volatile_reg(struct device * dev,unsigned int reg)49 static bool rsmu_sabre_volatile_reg(struct device *dev, unsigned int reg)
50 {
51 switch (reg) {
52 case RSMU_SABRE_PAGE_ADDR:
53 return false;
54 default:
55 return true;
56 }
57 }
58
rsmu_smbus_i2c_write_device(struct rsmu_ddata * rsmu,u8 reg,u8 * buf,u8 bytes)59 static int rsmu_smbus_i2c_write_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u8 bytes)
60 {
61 struct i2c_client *client = to_i2c_client(rsmu->dev);
62
63 return i2c_smbus_write_i2c_block_data(client, reg, bytes, buf);
64 }
65
rsmu_smbus_i2c_read_device(struct rsmu_ddata * rsmu,u8 reg,u8 * buf,u8 bytes)66 static int rsmu_smbus_i2c_read_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u8 bytes)
67 {
68 struct i2c_client *client = to_i2c_client(rsmu->dev);
69 int ret;
70
71 ret = i2c_smbus_read_i2c_block_data(client, reg, bytes, buf);
72 if (ret == bytes)
73 return 0;
74 else if (ret < 0)
75 return ret;
76 else
77 return -EIO;
78 }
79
rsmu_i2c_read_device(struct rsmu_ddata * rsmu,u8 reg,u8 * buf,u8 bytes)80 static int rsmu_i2c_read_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u8 bytes)
81 {
82 struct i2c_client *client = to_i2c_client(rsmu->dev);
83 struct i2c_msg msg[2];
84 int cnt;
85
86 msg[0].addr = client->addr;
87 msg[0].flags = 0;
88 msg[0].len = 1;
89 msg[0].buf = ®
90
91 msg[1].addr = client->addr;
92 msg[1].flags = I2C_M_RD;
93 msg[1].len = bytes;
94 msg[1].buf = buf;
95
96 cnt = i2c_transfer(client->adapter, msg, 2);
97
98 if (cnt < 0) {
99 dev_err(rsmu->dev, "i2c_transfer failed at addr: %04x!", reg);
100 return cnt;
101 } else if (cnt != 2) {
102 dev_err(rsmu->dev,
103 "i2c_transfer sent only %d of 2 messages", cnt);
104 return -EIO;
105 }
106
107 return 0;
108 }
109
rsmu_i2c_write_device(struct rsmu_ddata * rsmu,u8 reg,u8 * buf,u8 bytes)110 static int rsmu_i2c_write_device(struct rsmu_ddata *rsmu, u8 reg, u8 *buf, u8 bytes)
111 {
112 struct i2c_client *client = to_i2c_client(rsmu->dev);
113 /* we add 1 byte for device register */
114 u8 msg[RSMU_MAX_WRITE_COUNT + 1];
115 int cnt;
116
117 if (bytes > RSMU_MAX_WRITE_COUNT)
118 return -EINVAL;
119
120 msg[0] = reg;
121 memcpy(&msg[1], buf, bytes);
122
123 cnt = i2c_master_send(client, msg, bytes + 1);
124
125 if (cnt < 0) {
126 dev_err(&client->dev,
127 "i2c_master_send failed at addr: %04x!", reg);
128 return cnt;
129 }
130
131 return 0;
132 }
133
rsmu_write_page_register(struct rsmu_ddata * rsmu,u32 reg,rsmu_rw_device rsmu_write_device)134 static int rsmu_write_page_register(struct rsmu_ddata *rsmu, u32 reg,
135 rsmu_rw_device rsmu_write_device)
136 {
137 u32 page = reg & RSMU_CM_PAGE_MASK;
138 u8 buf[4];
139 int err;
140
141 /* Do not modify offset register for none-scsr registers */
142 if (reg < RSMU_CM_SCSR_BASE)
143 return 0;
144
145 /* Simply return if we are on the same page */
146 if (rsmu->page == page)
147 return 0;
148
149 buf[0] = 0x0;
150 buf[1] = (u8)((page >> 8) & 0xFF);
151 buf[2] = (u8)((page >> 16) & 0xFF);
152 buf[3] = (u8)((page >> 24) & 0xFF);
153
154 err = rsmu_write_device(rsmu, RSMU_CM_PAGE_ADDR, buf, sizeof(buf));
155 if (err)
156 dev_err(rsmu->dev, "Failed to set page offset 0x%x\n", page);
157 else
158 /* Remember the last page */
159 rsmu->page = page;
160
161 return err;
162 }
163
rsmu_i2c_reg_read(void * context,unsigned int reg,unsigned int * val)164 static int rsmu_i2c_reg_read(void *context, unsigned int reg, unsigned int *val)
165 {
166 struct rsmu_ddata *rsmu = i2c_get_clientdata((struct i2c_client *)context);
167 u8 addr = (u8)(reg & RSMU_CM_ADDRESS_MASK);
168 int err;
169
170 err = rsmu_write_page_register(rsmu, reg, rsmu_i2c_write_device);
171 if (err)
172 return err;
173
174 err = rsmu_i2c_read_device(rsmu, addr, (u8 *)val, 1);
175 if (err)
176 dev_err(rsmu->dev, "Failed to read offset address 0x%x\n", addr);
177
178 return err;
179 }
180
rsmu_i2c_reg_write(void * context,unsigned int reg,unsigned int val)181 static int rsmu_i2c_reg_write(void *context, unsigned int reg, unsigned int val)
182 {
183 struct rsmu_ddata *rsmu = i2c_get_clientdata((struct i2c_client *)context);
184 u8 addr = (u8)(reg & RSMU_CM_ADDRESS_MASK);
185 u8 data = (u8)val;
186 int err;
187
188 err = rsmu_write_page_register(rsmu, reg, rsmu_i2c_write_device);
189 if (err)
190 return err;
191
192 err = rsmu_i2c_write_device(rsmu, addr, &data, 1);
193 if (err)
194 dev_err(rsmu->dev,
195 "Failed to write offset address 0x%x\n", addr);
196
197 return err;
198 }
199
rsmu_smbus_i2c_reg_read(void * context,unsigned int reg,unsigned int * val)200 static int rsmu_smbus_i2c_reg_read(void *context, unsigned int reg, unsigned int *val)
201 {
202 struct rsmu_ddata *rsmu = i2c_get_clientdata((struct i2c_client *)context);
203 u8 addr = (u8)(reg & RSMU_CM_ADDRESS_MASK);
204 int err;
205
206 err = rsmu_write_page_register(rsmu, reg, rsmu_smbus_i2c_write_device);
207 if (err)
208 return err;
209
210 err = rsmu_smbus_i2c_read_device(rsmu, addr, (u8 *)val, 1);
211 if (err)
212 dev_err(rsmu->dev, "Failed to read offset address 0x%x\n", addr);
213
214 return err;
215 }
216
rsmu_smbus_i2c_reg_write(void * context,unsigned int reg,unsigned int val)217 static int rsmu_smbus_i2c_reg_write(void *context, unsigned int reg, unsigned int val)
218 {
219 struct rsmu_ddata *rsmu = i2c_get_clientdata((struct i2c_client *)context);
220 u8 addr = (u8)(reg & RSMU_CM_ADDRESS_MASK);
221 u8 data = (u8)val;
222 int err;
223
224 err = rsmu_write_page_register(rsmu, reg, rsmu_smbus_i2c_write_device);
225 if (err)
226 return err;
227
228 err = rsmu_smbus_i2c_write_device(rsmu, addr, &data, 1);
229 if (err)
230 dev_err(rsmu->dev,
231 "Failed to write offset address 0x%x\n", addr);
232
233 return err;
234 }
235
236 static const struct regmap_config rsmu_i2c_cm_regmap_config = {
237 .reg_bits = 32,
238 .val_bits = 8,
239 .max_register = 0x20120000,
240 .reg_read = rsmu_i2c_reg_read,
241 .reg_write = rsmu_i2c_reg_write,
242 .cache_type = REGCACHE_NONE,
243 };
244
245 static const struct regmap_config rsmu_smbus_i2c_cm_regmap_config = {
246 .reg_bits = 32,
247 .val_bits = 8,
248 .max_register = 0x20120000,
249 .reg_read = rsmu_smbus_i2c_reg_read,
250 .reg_write = rsmu_smbus_i2c_reg_write,
251 .cache_type = REGCACHE_NONE,
252 };
253
254 static const struct regmap_config rsmu_sabre_regmap_config = {
255 .reg_bits = 8,
256 .val_bits = 8,
257 .max_register = 0x400,
258 .ranges = rsmu_sabre_range_cfg,
259 .num_ranges = ARRAY_SIZE(rsmu_sabre_range_cfg),
260 .volatile_reg = rsmu_sabre_volatile_reg,
261 .cache_type = REGCACHE_MAPLE,
262 .can_multi_write = true,
263 };
264
265 static const struct regmap_config rsmu_sl_regmap_config = {
266 .reg_bits = 16,
267 .val_bits = 8,
268 .reg_format_endian = REGMAP_ENDIAN_BIG,
269 .max_register = 0x340,
270 .cache_type = REGCACHE_NONE,
271 .can_multi_write = true,
272 };
273
rsmu_i2c_probe(struct i2c_client * client)274 static int rsmu_i2c_probe(struct i2c_client *client)
275 {
276 const struct i2c_device_id *id = i2c_client_get_device_id(client);
277 const struct regmap_config *cfg;
278 struct rsmu_ddata *rsmu;
279 int ret;
280
281 rsmu = devm_kzalloc(&client->dev, sizeof(*rsmu), GFP_KERNEL);
282 if (!rsmu)
283 return -ENOMEM;
284
285 i2c_set_clientdata(client, rsmu);
286
287 rsmu->dev = &client->dev;
288 rsmu->type = (enum rsmu_type)id->driver_data;
289
290 switch (rsmu->type) {
291 case RSMU_CM:
292 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
293 cfg = &rsmu_i2c_cm_regmap_config;
294 } else if (i2c_check_functionality(client->adapter,
295 I2C_FUNC_SMBUS_I2C_BLOCK)) {
296 cfg = &rsmu_smbus_i2c_cm_regmap_config;
297 } else {
298 dev_err(rsmu->dev, "Unsupported i2c adapter\n");
299 return -ENOTSUPP;
300 }
301 break;
302 case RSMU_SABRE:
303 cfg = &rsmu_sabre_regmap_config;
304 break;
305 case RSMU_SL:
306 cfg = &rsmu_sl_regmap_config;
307 break;
308 default:
309 dev_err(rsmu->dev, "Unsupported RSMU device type: %d\n", rsmu->type);
310 return -ENODEV;
311 }
312
313 if (rsmu->type == RSMU_CM)
314 rsmu->regmap = devm_regmap_init(&client->dev, NULL, client, cfg);
315 else
316 rsmu->regmap = devm_regmap_init_i2c(client, cfg);
317
318 if (IS_ERR(rsmu->regmap)) {
319 ret = PTR_ERR(rsmu->regmap);
320 dev_err(rsmu->dev, "Failed to allocate register map: %d\n", ret);
321 return ret;
322 }
323
324 return rsmu_core_init(rsmu);
325 }
326
rsmu_i2c_remove(struct i2c_client * client)327 static void rsmu_i2c_remove(struct i2c_client *client)
328 {
329 struct rsmu_ddata *rsmu = i2c_get_clientdata(client);
330
331 rsmu_core_exit(rsmu);
332 }
333
334 static const struct i2c_device_id rsmu_i2c_id[] = {
335 { "8a34000", RSMU_CM },
336 { "8a34001", RSMU_CM },
337 { "82p33810", RSMU_SABRE },
338 { "82p33811", RSMU_SABRE },
339 { "8v19n850", RSMU_SL },
340 { "8v19n851", RSMU_SL },
341 {}
342 };
343 MODULE_DEVICE_TABLE(i2c, rsmu_i2c_id);
344
345 static const struct of_device_id rsmu_i2c_of_match[] = {
346 { .compatible = "idt,8a34000", .data = (void *)RSMU_CM },
347 { .compatible = "idt,8a34001", .data = (void *)RSMU_CM },
348 { .compatible = "idt,82p33810", .data = (void *)RSMU_SABRE },
349 { .compatible = "idt,82p33811", .data = (void *)RSMU_SABRE },
350 { .compatible = "idt,8v19n850", .data = (void *)RSMU_SL },
351 { .compatible = "idt,8v19n851", .data = (void *)RSMU_SL },
352 {}
353 };
354 MODULE_DEVICE_TABLE(of, rsmu_i2c_of_match);
355
356 static struct i2c_driver rsmu_i2c_driver = {
357 .driver = {
358 .name = "rsmu-i2c",
359 .of_match_table = rsmu_i2c_of_match,
360 },
361 .probe = rsmu_i2c_probe,
362 .remove = rsmu_i2c_remove,
363 .id_table = rsmu_i2c_id,
364 };
365
rsmu_i2c_init(void)366 static int __init rsmu_i2c_init(void)
367 {
368 return i2c_add_driver(&rsmu_i2c_driver);
369 }
370 subsys_initcall(rsmu_i2c_init);
371
rsmu_i2c_exit(void)372 static void __exit rsmu_i2c_exit(void)
373 {
374 i2c_del_driver(&rsmu_i2c_driver);
375 }
376 module_exit(rsmu_i2c_exit);
377
378 MODULE_DESCRIPTION("Renesas SMU I2C driver");
379 MODULE_LICENSE("GPL");
380