drivers/mfd/lochnagar-i2c.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Lochnagar I2C bus interface
   4  *
   5  * Copyright (c) 2012-2018 Cirrus Logic, Inc. and
   6  *                         Cirrus Logic International Semiconductor Ltd.
   7  *
   8  * Author: Charles Keepax <ckeepax@opensource.cirrus.com>
   9  */
  10
  11 #include <linux/delay.h>
  12 #include <linux/device.h>
  13 #include <linux/err.h>
  14 #include <linux/gpio/consumer.h>
  15 #include <linux/i2c.h>
  16 #include <linux/lockdep.h>
  17 #include <linux/mfd/core.h>
  18 #include <linux/mutex.h>
  19 #include <linux/of.h>
  20 #include <linux/of_platform.h>
  21 #include <linux/regmap.h>
  22
  23 #include <linux/mfd/lochnagar.h>
  24 #include <linux/mfd/lochnagar1_regs.h>
  25 #include <linux/mfd/lochnagar2_regs.h>
  26
  27 #define LOCHNAGAR_BOOT_RETRIES          10
  28 #define LOCHNAGAR_BOOT_DELAY_MS         350
  29
  30 #define LOCHNAGAR_CONFIG_POLL_US        10000
  31
  32 static bool lochnagar1_readable_register(struct device *dev, unsigned int reg)
  33 {
  34         switch (reg) {
  35         case LOCHNAGAR_SOFTWARE_RESET:
  36         case LOCHNAGAR_FIRMWARE_ID1...LOCHNAGAR_FIRMWARE_ID2:
  37         case LOCHNAGAR1_CDC_AIF1_SEL...LOCHNAGAR1_CDC_AIF3_SEL:
  38         case LOCHNAGAR1_CDC_MCLK1_SEL...LOCHNAGAR1_CDC_MCLK2_SEL:
  39         case LOCHNAGAR1_CDC_AIF_CTRL1...LOCHNAGAR1_CDC_AIF_CTRL2:
  40         case LOCHNAGAR1_EXT_AIF_CTRL:
  41         case LOCHNAGAR1_DSP_AIF1_SEL...LOCHNAGAR1_DSP_AIF2_SEL:
  42         case LOCHNAGAR1_DSP_CLKIN_SEL:
  43         case LOCHNAGAR1_DSP_AIF:
  44         case LOCHNAGAR1_GF_AIF1...LOCHNAGAR1_GF_AIF2:
  45         case LOCHNAGAR1_PSIA_AIF:
  46         case LOCHNAGAR1_PSIA1_SEL...LOCHNAGAR1_PSIA2_SEL:
  47         case LOCHNAGAR1_SPDIF_AIF_SEL:
  48         case LOCHNAGAR1_GF_AIF3_SEL...LOCHNAGAR1_GF_AIF4_SEL:
  49         case LOCHNAGAR1_GF_CLKOUT1_SEL:
  50         case LOCHNAGAR1_GF_AIF1_SEL...LOCHNAGAR1_GF_AIF2_SEL:
  51         case LOCHNAGAR1_GF_GPIO2...LOCHNAGAR1_GF_GPIO7:
  52         case LOCHNAGAR1_RST:
  53         case LOCHNAGAR1_LED1...LOCHNAGAR1_LED2:
  54         case LOCHNAGAR1_I2C_CTRL:
  55                 return true;
  56         default:
  57                 return false;
  58         }
  59 }
  60
  61 static const struct regmap_config lochnagar1_i2c_regmap = {
  62         .reg_bits = 8,
  63         .val_bits = 8,
  64         .reg_format_endian = REGMAP_ENDIAN_BIG,
  65         .val_format_endian = REGMAP_ENDIAN_BIG,
  66
  67         .max_register = 0x50,
  68         .readable_reg = lochnagar1_readable_register,
  69
  70         .use_single_read = true,
  71         .use_single_write = true,
  72
  73         .cache_type = REGCACHE_RBTREE,
  74 };
  75
  76 static const struct reg_sequence lochnagar1_patch[] = {
  77         { 0x40, 0x0083 },
  78         { 0x47, 0x0018 },
  79         { 0x50, 0x0000 },
  80 };
  81
  82 static bool lochnagar2_readable_register(struct device *dev, unsigned int reg)
  83 {
  84         switch (reg) {
  85         case LOCHNAGAR_SOFTWARE_RESET:
  86         case LOCHNAGAR_FIRMWARE_ID1...LOCHNAGAR_FIRMWARE_ID2:
  87         case LOCHNAGAR2_CDC_AIF1_CTRL...LOCHNAGAR2_CDC_AIF3_CTRL:
  88         case LOCHNAGAR2_DSP_AIF1_CTRL...LOCHNAGAR2_DSP_AIF2_CTRL:
  89         case LOCHNAGAR2_PSIA1_CTRL...LOCHNAGAR2_PSIA2_CTRL:
  90         case LOCHNAGAR2_GF_AIF3_CTRL...LOCHNAGAR2_GF_AIF4_CTRL:
  91         case LOCHNAGAR2_GF_AIF1_CTRL...LOCHNAGAR2_GF_AIF2_CTRL:
  92         case LOCHNAGAR2_SPDIF_AIF_CTRL:
  93         case LOCHNAGAR2_USB_AIF1_CTRL...LOCHNAGAR2_USB_AIF2_CTRL:
  94         case LOCHNAGAR2_ADAT_AIF_CTRL:
  95         case LOCHNAGAR2_CDC_MCLK1_CTRL...LOCHNAGAR2_CDC_MCLK2_CTRL:
  96         case LOCHNAGAR2_DSP_CLKIN_CTRL:
  97         case LOCHNAGAR2_PSIA1_MCLK_CTRL...LOCHNAGAR2_PSIA2_MCLK_CTRL:
  98         case LOCHNAGAR2_SPDIF_MCLK_CTRL:
  99         case LOCHNAGAR2_GF_CLKOUT1_CTRL...LOCHNAGAR2_GF_CLKOUT2_CTRL:
 100         case LOCHNAGAR2_ADAT_MCLK_CTRL:
 101         case LOCHNAGAR2_SOUNDCARD_MCLK_CTRL:
 102         case LOCHNAGAR2_GPIO_FPGA_GPIO1...LOCHNAGAR2_GPIO_FPGA_GPIO6:
 103         case LOCHNAGAR2_GPIO_CDC_GPIO1...LOCHNAGAR2_GPIO_CDC_GPIO8:
 104         case LOCHNAGAR2_GPIO_DSP_GPIO1...LOCHNAGAR2_GPIO_DSP_GPIO6:
 105         case LOCHNAGAR2_GPIO_GF_GPIO2...LOCHNAGAR2_GPIO_GF_GPIO7:
 106         case LOCHNAGAR2_GPIO_CDC_AIF1_BCLK...LOCHNAGAR2_GPIO_CDC_AIF3_TXDAT:
 107         case LOCHNAGAR2_GPIO_DSP_AIF1_BCLK...LOCHNAGAR2_GPIO_DSP_AIF2_TXDAT:
 108         case LOCHNAGAR2_GPIO_PSIA1_BCLK...LOCHNAGAR2_GPIO_PSIA2_TXDAT:
 109         case LOCHNAGAR2_GPIO_GF_AIF3_BCLK...LOCHNAGAR2_GPIO_GF_AIF4_TXDAT:
 110         case LOCHNAGAR2_GPIO_GF_AIF1_BCLK...LOCHNAGAR2_GPIO_GF_AIF2_TXDAT:
 111         case LOCHNAGAR2_GPIO_DSP_UART1_RX...LOCHNAGAR2_GPIO_DSP_UART2_TX:
 112         case LOCHNAGAR2_GPIO_GF_UART2_RX...LOCHNAGAR2_GPIO_GF_UART2_TX:
 113         case LOCHNAGAR2_GPIO_USB_UART_RX:
 114         case LOCHNAGAR2_GPIO_CDC_PDMCLK1...LOCHNAGAR2_GPIO_CDC_PDMDAT2:
 115         case LOCHNAGAR2_GPIO_CDC_DMICCLK1...LOCHNAGAR2_GPIO_CDC_DMICDAT4:
 116         case LOCHNAGAR2_GPIO_DSP_DMICCLK1...LOCHNAGAR2_GPIO_DSP_DMICDAT2:
 117         case LOCHNAGAR2_GPIO_I2C2_SCL...LOCHNAGAR2_GPIO_I2C4_SDA:
 118         case LOCHNAGAR2_GPIO_DSP_STANDBY:
 119         case LOCHNAGAR2_GPIO_CDC_MCLK1...LOCHNAGAR2_GPIO_CDC_MCLK2:
 120         case LOCHNAGAR2_GPIO_DSP_CLKIN:
 121         case LOCHNAGAR2_GPIO_PSIA1_MCLK...LOCHNAGAR2_GPIO_PSIA2_MCLK:
 122         case LOCHNAGAR2_GPIO_GF_GPIO1...LOCHNAGAR2_GPIO_GF_GPIO5:
 123         case LOCHNAGAR2_GPIO_DSP_GPIO20:
 124         case LOCHNAGAR2_GPIO_CHANNEL1...LOCHNAGAR2_GPIO_CHANNEL16:
 125         case LOCHNAGAR2_MINICARD_RESETS:
 126         case LOCHNAGAR2_ANALOGUE_PATH_CTRL1...LOCHNAGAR2_ANALOGUE_PATH_CTRL2:
 127         case LOCHNAGAR2_COMMS_CTRL4:
 128         case LOCHNAGAR2_SPDIF_CTRL:
 129         case LOCHNAGAR2_IMON_CTRL1...LOCHNAGAR2_IMON_CTRL4:
 130         case LOCHNAGAR2_IMON_DATA1...LOCHNAGAR2_IMON_DATA2:
 131         case LOCHNAGAR2_POWER_CTRL:
 132         case LOCHNAGAR2_MICVDD_CTRL1:
 133         case LOCHNAGAR2_MICVDD_CTRL2:
 134         case LOCHNAGAR2_VDDCORE_CDC_CTRL1:
 135         case LOCHNAGAR2_VDDCORE_CDC_CTRL2:
 136         case LOCHNAGAR2_SOUNDCARD_AIF_CTRL:
 137                 return true;
 138         default:
 139                 return false;
 140         }
 141 }
 142
 143 static bool lochnagar2_volatile_register(struct device *dev, unsigned int reg)
 144 {
 145         switch (reg) {
 146         case LOCHNAGAR2_GPIO_CHANNEL1...LOCHNAGAR2_GPIO_CHANNEL16:
 147         case LOCHNAGAR2_ANALOGUE_PATH_CTRL1:
 148         case LOCHNAGAR2_IMON_CTRL3...LOCHNAGAR2_IMON_CTRL4:
 149         case LOCHNAGAR2_IMON_DATA1...LOCHNAGAR2_IMON_DATA2:
 150                 return true;
 151         default:
 152                 return false;
 153         }
 154 }
 155
 156 static const struct regmap_config lochnagar2_i2c_regmap = {
 157         .reg_bits = 16,
 158         .val_bits = 16,
 159         .reg_format_endian = REGMAP_ENDIAN_BIG,
 160         .val_format_endian = REGMAP_ENDIAN_BIG,
 161
 162         .max_register = 0x1F1F,
 163         .readable_reg = lochnagar2_readable_register,
 164         .volatile_reg = lochnagar2_volatile_register,
 165
 166         .cache_type = REGCACHE_RBTREE,
 167 };
 168
 169 static const struct reg_sequence lochnagar2_patch[] = {
 170         { 0x00EE, 0x0000 },
 171 };
 172
 173 struct lochnagar_config {
 174         int id;
 175         const char * const name;
 176         enum lochnagar_type type;
 177         const struct regmap_config *regmap;
 178         const struct reg_sequence *patch;
 179         int npatch;
 180 };
 181
 182 static struct lochnagar_config lochnagar_configs[] = {
 183         {
 184                 .id = 0x50,
 185                 .name = "lochnagar1",
 186                 .type = LOCHNAGAR1,
 187                 .regmap = &lochnagar1_i2c_regmap,
 188                 .patch = lochnagar1_patch,
 189                 .npatch = ARRAY_SIZE(lochnagar1_patch),
 190         },
 191         {
 192                 .id = 0xCB58,
 193                 .name = "lochnagar2",
 194                 .type = LOCHNAGAR2,
 195                 .regmap = &lochnagar2_i2c_regmap,
 196                 .patch = lochnagar2_patch,
 197                 .npatch = ARRAY_SIZE(lochnagar2_patch),
 198         },
 199 };
 200
 201 static const struct of_device_id lochnagar_of_match[] = {
 202         { .compatible = "cirrus,lochnagar1", .data = &lochnagar_configs[0] },
 203         { .compatible = "cirrus,lochnagar2", .data = &lochnagar_configs[1] },
 204         {},
 205 };
 206
 207 static int lochnagar_wait_for_boot(struct regmap *regmap, unsigned int *id)
 208 {
 209         int i, ret;
 210
 211         for (i = 0; i < LOCHNAGAR_BOOT_RETRIES; ++i) {
 212                 msleep(LOCHNAGAR_BOOT_DELAY_MS);
 213
 214                 /* The reset register will return the device ID when read */
 215                 ret = regmap_read(regmap, LOCHNAGAR_SOFTWARE_RESET, id);
 216                 if (!ret)
 217                         return ret;
 218         }
 219
 220         return -ETIMEDOUT;
 221 }
 222
 223 /**
 224  * lochnagar_update_config - Synchronise the boards analogue configuration to
 225  *                           the hardware.
 226  *
 227  * @lochnagar: A pointer to the primary core data structure.
 228  *
 229  * Return: Zero on success or an appropriate negative error code on failure.
 230  */
 231 int lochnagar_update_config(struct lochnagar *lochnagar)
 232 {
 233         struct regmap *regmap = lochnagar->regmap;
 234         unsigned int done = LOCHNAGAR2_ANALOGUE_PATH_UPDATE_STS_MASK;
 235         int timeout_ms = LOCHNAGAR_BOOT_DELAY_MS * LOCHNAGAR_BOOT_RETRIES;
 236         unsigned int val = 0;
 237         int ret;
 238
 239         lockdep_assert_held(&lochnagar->analogue_config_lock);
 240
 241         if (lochnagar->type != LOCHNAGAR2)
 242                 return 0;
 243
 244         /*
 245          * Toggle the ANALOGUE_PATH_UPDATE bit and wait for the device to
 246          * acknowledge that any outstanding changes to the analogue
 247          * configuration have been applied.
 248          */
 249         ret = regmap_write(regmap, LOCHNAGAR2_ANALOGUE_PATH_CTRL1, 0);
 250         if (ret < 0)
 251                 return ret;
 252
 253         ret = regmap_write(regmap, LOCHNAGAR2_ANALOGUE_PATH_CTRL1,
 254                            LOCHNAGAR2_ANALOGUE_PATH_UPDATE_MASK);
 255         if (ret < 0)
 256                 return ret;
 257
 258         ret = regmap_read_poll_timeout(regmap,
 259                                        LOCHNAGAR2_ANALOGUE_PATH_CTRL1, val,
 260                                        (val & done), LOCHNAGAR_CONFIG_POLL_US,
 261                                        timeout_ms * 1000);
 262         if (ret < 0)
 263                 return ret;
 264
 265         return 0;
 266 }
 267 EXPORT_SYMBOL_GPL(lochnagar_update_config);
 268
 269 static int lochnagar_i2c_probe(struct i2c_client *i2c)
 270 {
 271         struct device *dev = &i2c->dev;
 272         const struct lochnagar_config *config = NULL;
 273         const struct of_device_id *of_id;
 274         struct lochnagar *lochnagar;
 275         struct gpio_desc *reset, *present;
 276         unsigned int val;
 277         unsigned int firmwareid;
 278         unsigned int devid, rev;
 279         int ret;
 280
 281         lochnagar = devm_kzalloc(dev, sizeof(*lochnagar), GFP_KERNEL);
 282         if (!lochnagar)
 283                 return -ENOMEM;
 284
 285         of_id = of_match_device(lochnagar_of_match, dev);
 286         if (!of_id)
 287                 return -EINVAL;
 288
 289         config = of_id->data;
 290
 291         lochnagar->dev = dev;
 292         mutex_init(&lochnagar->analogue_config_lock);
 293
 294         dev_set_drvdata(dev, lochnagar);
 295
 296         reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
 297         if (IS_ERR(reset)) {
 298                 ret = PTR_ERR(reset);
 299                 dev_err(dev, "Failed to get reset GPIO: %d\n", ret);
 300                 return ret;
 301         }
 302
 303         present = devm_gpiod_get_optional(dev, "present", GPIOD_OUT_HIGH);
 304         if (IS_ERR(present)) {
 305                 ret = PTR_ERR(present);
 306                 dev_err(dev, "Failed to get present GPIO: %d\n", ret);
 307                 return ret;
 308         }
 309
 310         /* Leave the Lochnagar in reset for a reasonable amount of time */
 311         msleep(20);
 312
 313         /* Bring Lochnagar out of reset */
 314         gpiod_set_value_cansleep(reset, 1);
 315
 316         /* Identify Lochnagar */
 317         lochnagar->type = config->type;
 318
 319         lochnagar->regmap = devm_regmap_init_i2c(i2c, config->regmap);
 320         if (IS_ERR(lochnagar->regmap)) {
 321                 ret = PTR_ERR(lochnagar->regmap);
 322                 dev_err(dev, "Failed to allocate register map: %d\n", ret);
 323                 return ret;
 324         }
 325
 326         /* Wait for Lochnagar to boot */
 327         ret = lochnagar_wait_for_boot(lochnagar->regmap, &val);
 328         if (ret < 0) {
 329                 dev_err(dev, "Failed to read device ID: %d\n", ret);
 330                 return ret;
 331         }
 332
 333         devid = val & LOCHNAGAR_DEVICE_ID_MASK;
 334         rev = val & LOCHNAGAR_REV_ID_MASK;
 335
 336         if (devid != config->id) {
 337                 dev_err(dev,
 338                         "ID does not match %s (expected 0x%x got 0x%x)\n",
 339                         config->name, config->id, devid);
 340                 return -ENODEV;
 341         }
 342
 343         /* Identify firmware */
 344         ret = regmap_read(lochnagar->regmap, LOCHNAGAR_FIRMWARE_ID1, &val);
 345         if (ret < 0) {
 346                 dev_err(dev, "Failed to read firmware id 1: %d\n", ret);
 347                 return ret;
 348         }
 349
 350         firmwareid = val;
 351
 352         ret = regmap_read(lochnagar->regmap, LOCHNAGAR_FIRMWARE_ID2, &val);
 353         if (ret < 0) {
 354                 dev_err(dev, "Failed to read firmware id 2: %d\n", ret);
 355                 return ret;
 356         }
 357
 358         firmwareid |= (val << config->regmap->val_bits);
 359
 360         dev_info(dev, "Found %s (0x%x) revision %u firmware 0x%.6x\n",
 361                  config->name, devid, rev + 1, firmwareid);
 362
 363         ret = regmap_register_patch(lochnagar->regmap, config->patch,
 364                                     config->npatch);
 365         if (ret < 0) {
 366                 dev_err(dev, "Failed to register patch: %d\n", ret);
 367                 return ret;
 368         }
 369
 370         ret = devm_of_platform_populate(dev);
 371         if (ret < 0) {
 372                 dev_err(dev, "Failed to populate child nodes: %d\n", ret);
 373                 return ret;
 374         }
 375
 376         return ret;
 377 }
 378
 379 static struct i2c_driver lochnagar_i2c_driver = {
 380         .driver = {
 381                 .name = "lochnagar",
 382                 .of_match_table = of_match_ptr(lochnagar_of_match),
 383                 .suppress_bind_attrs = true,
 384         },
 385         .probe_new = lochnagar_i2c_probe,
 386 };
 387
 388 static int __init lochnagar_i2c_init(void)
 389 {
 390         int ret;
 391
 392         ret = i2c_add_driver(&lochnagar_i2c_driver);
 393         if (ret)
 394                 pr_err("Failed to register Lochnagar driver: %d\n", ret);
 395
 396         return ret;
 397 }
 398 subsys_initcall(lochnagar_i2c_init);