drivers/platform/x86/intel/int3472/discrete.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Author: Dan Scally <djrscally@gmail.com> */
   3
   4 #include <linux/acpi.h>
   5 #include <linux/bitfield.h>
   6 #include <linux/device.h>
   7 #include <linux/gpio/consumer.h>
   8 #include <linux/gpio/machine.h>
   9 #include <linux/i2c.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/overflow.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/string_choices.h>
  15 #include <linux/uuid.h>
  16
  17 #include "common.h"
  18
  19 /*
  20  * 79234640-9e10-4fea-a5c1-b5aa8b19756f
  21  * This _DSM GUID returns information about the GPIO lines mapped to a
  22  * discrete INT3472 device. Function number 1 returns a count of the GPIO
  23  * lines that are mapped. Subsequent functions return 32 bit ints encoding
  24  * information about the GPIO line, including its purpose.
  25  */
  26 static const guid_t int3472_gpio_guid =
  27         GUID_INIT(0x79234640, 0x9e10, 0x4fea,
  28                   0xa5, 0xc1, 0xb5, 0xaa, 0x8b, 0x19, 0x75, 0x6f);
  29
  30 #define INT3472_GPIO_DSM_TYPE                           GENMASK(7, 0)
  31 #define INT3472_GPIO_DSM_PIN                            GENMASK(15, 8)
  32 #define INT3472_GPIO_DSM_SENSOR_ON_VAL                  GENMASK(31, 24)
  33
  34 /*
  35  * 822ace8f-2814-4174-a56b-5f029fe079ee
  36  * This _DSM GUID returns a string from the sensor device, which acts as a
  37  * module identifier.
  38  */
  39 static const guid_t cio2_sensor_module_guid =
  40         GUID_INIT(0x822ace8f, 0x2814, 0x4174,
  41                   0xa5, 0x6b, 0x5f, 0x02, 0x9f, 0xe0, 0x79, 0xee);
  42
  43 static void skl_int3472_log_sensor_module_name(struct int3472_discrete_device *int3472)
  44 {
  45         union acpi_object *obj;
  46
  47         obj = acpi_evaluate_dsm_typed(int3472->sensor->handle,
  48                                       &cio2_sensor_module_guid, 0x00,
  49                                       0x01, NULL, ACPI_TYPE_STRING);
  50         if (obj) {
  51                 dev_dbg(int3472->dev, "Sensor module id: '%s'\n", obj->string.pointer);
  52                 ACPI_FREE(obj);
  53         }
  54 }
  55
  56 static int skl_int3472_fill_gpiod_lookup(struct gpiod_lookup *table_entry,
  57                                          struct acpi_resource_gpio *agpio,
  58                                          const char *func, u32 polarity)
  59 {
  60         char *path = agpio->resource_source.string_ptr;
  61         struct acpi_device *adev;
  62         acpi_handle handle;
  63         acpi_status status;
  64
  65         status = acpi_get_handle(NULL, path, &handle);
  66         if (ACPI_FAILURE(status))
  67                 return -EINVAL;
  68
  69         adev = acpi_fetch_acpi_dev(handle);
  70         if (!adev)
  71                 return -ENODEV;
  72
  73         *table_entry = GPIO_LOOKUP(acpi_dev_name(adev), agpio->pin_table[0], func, polarity);
  74
  75         return 0;
  76 }
  77
  78 static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
  79                                           struct acpi_resource_gpio *agpio,
  80                                           const char *func, u32 polarity)
  81 {
  82         int ret;
  83
  84         if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
  85                 dev_warn(int3472->dev, "Too many GPIOs mapped\n");
  86                 return -EINVAL;
  87         }
  88
  89         ret = skl_int3472_fill_gpiod_lookup(&int3472->gpios.table[int3472->n_sensor_gpios],
  90                                             agpio, func, polarity);
  91         if (ret)
  92                 return ret;
  93
  94         int3472->n_sensor_gpios++;
  95
  96         return 0;
  97 }
  98
  99 /* This should *really* only be used when there's no other way... */
 100 static struct gpio_desc *
 101 skl_int3472_gpiod_get_from_temp_lookup(struct int3472_discrete_device *int3472,
 102                                        struct acpi_resource_gpio *agpio,
 103                                        const char *func, u32 polarity)
 104 {
 105         struct gpio_desc *desc;
 106         int ret;
 107
 108         struct gpiod_lookup_table *lookup __free(kfree) =
 109                         kzalloc(struct_size(lookup, table, 2), GFP_KERNEL);
 110         if (!lookup)
 111                 return ERR_PTR(-ENOMEM);
 112
 113         lookup->dev_id = dev_name(int3472->dev);
 114         ret = skl_int3472_fill_gpiod_lookup(&lookup->table[0], agpio, func, polarity);
 115         if (ret)
 116                 return ERR_PTR(ret);
 117
 118         gpiod_add_lookup_table(lookup);
 119         desc = devm_gpiod_get(int3472->dev, func, GPIOD_OUT_LOW);
 120         gpiod_remove_lookup_table(lookup);
 121
 122         return desc;
 123 }
 124
 125 static void int3472_get_func_and_polarity(u8 type, const char **func, u32 *polarity)
 126 {
 127         switch (type) {
 128         case INT3472_GPIO_TYPE_RESET:
 129                 *func = "reset";
 130                 *polarity = GPIO_ACTIVE_LOW;
 131                 break;
 132         case INT3472_GPIO_TYPE_POWERDOWN:
 133                 *func = "powerdown";
 134                 *polarity = GPIO_ACTIVE_LOW;
 135                 break;
 136         case INT3472_GPIO_TYPE_CLK_ENABLE:
 137                 *func = "clk-enable";
 138                 *polarity = GPIO_ACTIVE_HIGH;
 139                 break;
 140         case INT3472_GPIO_TYPE_PRIVACY_LED:
 141                 *func = "privacy-led";
 142                 *polarity = GPIO_ACTIVE_HIGH;
 143                 break;
 144         case INT3472_GPIO_TYPE_POWER_ENABLE:
 145                 *func = "power-enable";
 146                 *polarity = GPIO_ACTIVE_HIGH;
 147                 break;
 148         default:
 149                 *func = "unknown";
 150                 *polarity = GPIO_ACTIVE_HIGH;
 151                 break;
 152         }
 153 }
 154
 155 /**
 156  * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
 157  * @ares: A pointer to a &struct acpi_resource
 158  * @data: A pointer to a &struct int3472_discrete_device
 159  *
 160  * This function handles GPIO resources that are against an INT3472
 161  * ACPI device, by checking the value of the corresponding _DSM entry.
 162  * This will return a 32bit int, where the lowest byte represents the
 163  * function of the GPIO pin:
 164  *
 165  * 0x00 Reset
 166  * 0x01 Power down
 167  * 0x0b Power enable
 168  * 0x0c Clock enable
 169  * 0x0d Privacy LED
 170  *
 171  * There are some known platform specific quirks where that does not quite
 172  * hold up; for example where a pin with type 0x01 (Power down) is mapped to
 173  * a sensor pin that performs a reset function or entries in _CRS and _DSM that
 174  * do not actually correspond to a physical connection. These will be handled
 175  * by the mapping sub-functions.
 176  *
 177  * GPIOs will either be mapped directly to the sensor device or else used
 178  * to create clocks and regulators via the usual frameworks.
 179  *
 180  * Return:
 181  * * 1          - To continue the loop
 182  * * 0          - When all resources found are handled properly.
 183  * * -EINVAL    - If the resource is not a GPIO IO resource
 184  * * -ENODEV    - If the resource has no corresponding _DSM entry
 185  * * -Other     - Errors propagated from one of the sub-functions.
 186  */
 187 static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
 188                                              void *data)
 189 {
 190         struct int3472_discrete_device *int3472 = data;
 191         struct acpi_resource_gpio *agpio;
 192         u8 active_value, pin, type;
 193         union acpi_object *obj;
 194         struct gpio_desc *gpio;
 195         const char *err_msg;
 196         const char *func;
 197         u32 polarity;
 198         int ret;
 199
 200         if (!acpi_gpio_get_io_resource(ares, &agpio))
 201                 return 1;
 202
 203         /*
 204          * ngpios + 2 because the index of this _DSM function is 1-based and
 205          * the first function is just a count.
 206          */
 207         obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
 208                                       &int3472_gpio_guid, 0x00,
 209                                       int3472->ngpios + 2,
 210                                       NULL, ACPI_TYPE_INTEGER);
 211
 212         if (!obj) {
 213                 dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
 214                          agpio->pin_table[0]);
 215                 return 1;
 216         }
 217
 218         type = FIELD_GET(INT3472_GPIO_DSM_TYPE, obj->integer.value);
 219
 220         int3472_get_func_and_polarity(type, &func, &polarity);
 221
 222         pin = FIELD_GET(INT3472_GPIO_DSM_PIN, obj->integer.value);
 223         if (pin != agpio->pin_table[0])
 224                 dev_warn(int3472->dev, "%s %s pin number mismatch _DSM %d resource %d\n",
 225                          func, agpio->resource_source.string_ptr, pin,
 226                          agpio->pin_table[0]);
 227
 228         active_value = FIELD_GET(INT3472_GPIO_DSM_SENSOR_ON_VAL, obj->integer.value);
 229         if (!active_value)
 230                 polarity ^= GPIO_ACTIVE_LOW;
 231
 232         dev_dbg(int3472->dev, "%s %s pin %d active-%s\n", func,
 233                 agpio->resource_source.string_ptr, agpio->pin_table[0],
 234                 str_high_low(polarity == GPIO_ACTIVE_HIGH));
 235
 236         switch (type) {
 237         case INT3472_GPIO_TYPE_RESET:
 238         case INT3472_GPIO_TYPE_POWERDOWN:
 239                 ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, func, polarity);
 240                 if (ret)
 241                         err_msg = "Failed to map GPIO pin to sensor\n";
 242
 243                 break;
 244         case INT3472_GPIO_TYPE_CLK_ENABLE:
 245         case INT3472_GPIO_TYPE_PRIVACY_LED:
 246         case INT3472_GPIO_TYPE_POWER_ENABLE:
 247                 gpio = skl_int3472_gpiod_get_from_temp_lookup(int3472, agpio, func, polarity);
 248                 if (IS_ERR(gpio)) {
 249                         ret = PTR_ERR(gpio);
 250                         err_msg = "Failed to get GPIO\n";
 251                         break;
 252                 }
 253
 254                 switch (type) {
 255                 case INT3472_GPIO_TYPE_CLK_ENABLE:
 256                         ret = skl_int3472_register_gpio_clock(int3472, gpio);
 257                         if (ret)
 258                                 err_msg = "Failed to register clock\n";
 259
 260                         break;
 261                 case INT3472_GPIO_TYPE_PRIVACY_LED:
 262                         ret = skl_int3472_register_pled(int3472, gpio);
 263                         if (ret)
 264                                 err_msg = "Failed to register LED\n";
 265
 266                         break;
 267                 case INT3472_GPIO_TYPE_POWER_ENABLE:
 268                         ret = skl_int3472_register_regulator(int3472, gpio);
 269                         if (ret)
 270                                 err_msg = "Failed to map regulator to sensor\n";
 271
 272                         break;
 273                 default: /* Never reached */
 274                         ret = -EINVAL;
 275                         break;
 276                 }
 277                 break;
 278         default:
 279                 dev_warn(int3472->dev,
 280                          "GPIO type 0x%02x unknown; the sensor may not work\n",
 281                          type);
 282                 ret = 1;
 283                 break;
 284         }
 285
 286         int3472->ngpios++;
 287         ACPI_FREE(obj);
 288
 289         if (ret < 0)
 290                 return dev_err_probe(int3472->dev, ret, err_msg);
 291
 292         return ret;
 293 }
 294
 295 static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
 296 {
 297         LIST_HEAD(resource_list);
 298         int ret;
 299
 300         skl_int3472_log_sensor_module_name(int3472);
 301
 302         ret = acpi_dev_get_resources(int3472->adev, &resource_list,
 303                                      skl_int3472_handle_gpio_resources,
 304                                      int3472);
 305         if (ret < 0)
 306                 return ret;
 307
 308         acpi_dev_free_resource_list(&resource_list);
 309
 310         /* Register _DSM based clock (no-op if a GPIO clock was already registered) */
 311         ret = skl_int3472_register_dsm_clock(int3472);
 312         if (ret < 0)
 313                 return ret;
 314
 315         int3472->gpios.dev_id = int3472->sensor_name;
 316         gpiod_add_lookup_table(&int3472->gpios);
 317
 318         return 0;
 319 }
 320
 321 static void skl_int3472_discrete_remove(struct platform_device *pdev)
 322 {
 323         struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
 324
 325         gpiod_remove_lookup_table(&int3472->gpios);
 326
 327         skl_int3472_unregister_clock(int3472);
 328         skl_int3472_unregister_pled(int3472);
 329         skl_int3472_unregister_regulator(int3472);
 330 }
 331
 332 static int skl_int3472_discrete_probe(struct platform_device *pdev)
 333 {
 334         struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
 335         struct int3472_discrete_device *int3472;
 336         struct int3472_cldb cldb;
 337         int ret;
 338
 339         ret = skl_int3472_fill_cldb(adev, &cldb);
 340         if (ret) {
 341                 dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
 342                 return ret;
 343         }
 344
 345         if (cldb.control_logic_type != 1) {
 346                 dev_err(&pdev->dev, "Unsupported control logic type %u\n",
 347                         cldb.control_logic_type);
 348                 return -EINVAL;
 349         }
 350
 351         /* Max num GPIOs we've seen plus a terminator */
 352         int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
 353                                INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
 354         if (!int3472)
 355                 return -ENOMEM;
 356
 357         int3472->adev = adev;
 358         int3472->dev = &pdev->dev;
 359         platform_set_drvdata(pdev, int3472);
 360         int3472->clock.imgclk_index = cldb.clock_source;
 361
 362         ret = skl_int3472_get_sensor_adev_and_name(&pdev->dev, &int3472->sensor,
 363                                                    &int3472->sensor_name);
 364         if (ret)
 365                 return ret;
 366
 367         /*
 368          * Initialising this list means we can call gpiod_remove_lookup_table()
 369          * in failure paths without issue.
 370          */
 371         INIT_LIST_HEAD(&int3472->gpios.list);
 372
 373         ret = skl_int3472_parse_crs(int3472);
 374         if (ret) {
 375                 skl_int3472_discrete_remove(pdev);
 376                 return ret;
 377         }
 378
 379         acpi_dev_clear_dependencies(adev);
 380         return 0;
 381 }
 382
 383 static const struct acpi_device_id int3472_device_id[] = {
 384         { "INT3472", 0 },
 385         { }
 386 };
 387 MODULE_DEVICE_TABLE(acpi, int3472_device_id);
 388
 389 static struct platform_driver int3472_discrete = {
 390         .driver = {
 391                 .name = "int3472-discrete",
 392                 .acpi_match_table = int3472_device_id,
 393         },
 394         .probe = skl_int3472_discrete_probe,
 395         .remove = skl_int3472_discrete_remove,
 396 };
 397 module_platform_driver(int3472_discrete);
 398
 399 MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
 400 MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
 401 MODULE_LICENSE("GPL v2");