drivers/mfd/rsmu_i2c.c

   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
  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
  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
  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
  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 = &reg;
  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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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");