intel/int3472/discrete.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /* Author: Dan Scally <djrscally@gmail.com> */
0003
0004 #include <linux/acpi.h>
0005 #include <linux/clkdev.h>
0006 #include <linux/clk-provider.h>
0007 #include <linux/device.h>
0008 #include <linux/gpio/consumer.h>
0009 #include <linux/gpio/machine.h>
0010 #include <linux/i2c.h>
0011 #include <linux/kernel.h>
0012 #include <linux/module.h>
0013 #include <linux/overflow.h>
0014 #include <linux/platform_device.h>
0015 #include <linux/uuid.h>
0016
0017 #include "common.h"
0018
0019 /*
0020  * 79234640-9e10-4fea-a5c1-b5aa8b19756f
0021  * This _DSM GUID returns information about the GPIO lines mapped to a
0022  * discrete INT3472 device. Function number 1 returns a count of the GPIO
0023  * lines that are mapped. Subsequent functions return 32 bit ints encoding
0024  * information about the GPIO line, including its purpose.
0025  */
0026 static const guid_t int3472_gpio_guid =
0027     GUID_INIT(0x79234640, 0x9e10, 0x4fea,
0028           0xa5, 0xc1, 0xb5, 0xaa, 0x8b, 0x19, 0x75, 0x6f);
0029
0030 /*
0031  * 822ace8f-2814-4174-a56b-5f029fe079ee
0032  * This _DSM GUID returns a string from the sensor device, which acts as a
0033  * module identifier.
0034  */
0035 static const guid_t cio2_sensor_module_guid =
0036     GUID_INIT(0x822ace8f, 0x2814, 0x4174,
0037           0xa5, 0x6b, 0x5f, 0x02, 0x9f, 0xe0, 0x79, 0xee);
0038
0039 /*
0040  * Here follows platform specific mapping information that we can pass to
0041  * the functions mapping resources to the sensors. Where the sensors have
0042  * a power enable pin defined in DSDT we need to provide a supply name so
0043  * the sensor drivers can find the regulator. The device name will be derived
0044  * from the sensor's ACPI device within the code. Optionally, we can provide a
0045  * NULL terminated array of function name mappings to deal with any platform
0046  * specific deviations from the documented behaviour of GPIOs.
0047  *
0048  * Map a GPIO function name to NULL to prevent the driver from mapping that
0049  * GPIO at all.
0050  */
0051
0052 static const struct int3472_gpio_function_remap ov2680_gpio_function_remaps[] = {
0053     { "reset", NULL },
0054     { "powerdown", "reset" },
0055     { }
0056 };
0057
0058 static const struct int3472_sensor_config int3472_sensor_configs[] = {
0059     /* Lenovo Miix 510-12ISK - OV2680, Front */
0060     { "GNDF140809R", { 0 }, ov2680_gpio_function_remaps },
0061     /* Lenovo Miix 510-12ISK - OV5648, Rear */
0062     { "GEFF150023R", REGULATOR_SUPPLY("avdd", NULL), NULL },
0063     /* Surface Go 1&2 - OV5693, Front */
0064     { "YHCU", REGULATOR_SUPPLY("avdd", NULL), NULL },
0065 };
0066
0067 static const struct int3472_sensor_config *
0068 skl_int3472_get_sensor_module_config(struct int3472_discrete_device *int3472)
0069 {
0070     union acpi_object *obj;
0071     unsigned int i;
0072
0073     obj = acpi_evaluate_dsm_typed(int3472->sensor->handle,
0074                       &cio2_sensor_module_guid, 0x00,
0075                       0x01, NULL, ACPI_TYPE_STRING);
0076
0077     if (!obj) {
0078         dev_err(int3472->dev,
0079             "Failed to get sensor module string from _DSM\n");
0080         return ERR_PTR(-ENODEV);
0081     }
0082
0083     if (obj->string.type != ACPI_TYPE_STRING) {
0084         dev_err(int3472->dev,
0085             "Sensor _DSM returned a non-string value\n");
0086
0087         ACPI_FREE(obj);
0088         return ERR_PTR(-EINVAL);
0089     }
0090
0091     for (i = 0; i < ARRAY_SIZE(int3472_sensor_configs); i++) {
0092         if (!strcmp(int3472_sensor_configs[i].sensor_module_name,
0093                 obj->string.pointer))
0094             break;
0095     }
0096
0097     ACPI_FREE(obj);
0098
0099     if (i >= ARRAY_SIZE(int3472_sensor_configs))
0100         return ERR_PTR(-EINVAL);
0101
0102     return &int3472_sensor_configs[i];
0103 }
0104
0105 static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
0106                       struct acpi_resource_gpio *agpio,
0107                       const char *func, u32 polarity)
0108 {
0109     const struct int3472_sensor_config *sensor_config;
0110     char *path = agpio->resource_source.string_ptr;
0111     struct gpiod_lookup *table_entry;
0112     struct acpi_device *adev;
0113     acpi_handle handle;
0114     acpi_status status;
0115
0116     if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
0117         dev_warn(int3472->dev, "Too many GPIOs mapped\n");
0118         return -EINVAL;
0119     }
0120
0121     sensor_config = int3472->sensor_config;
0122     if (!IS_ERR(sensor_config) && sensor_config->function_maps) {
0123         const struct int3472_gpio_function_remap *remap;
0124
0125         for (remap = sensor_config->function_maps; remap->documented; remap++) {
0126             if (!strcmp(func, remap->documented)) {
0127                 func = remap->actual;
0128                 break;
0129             }
0130         }
0131     }
0132
0133     /* Functions mapped to NULL should not be mapped to the sensor */
0134     if (!func)
0135         return 0;
0136
0137     status = acpi_get_handle(NULL, path, &handle);
0138     if (ACPI_FAILURE(status))
0139         return -EINVAL;
0140
0141     adev = acpi_fetch_acpi_dev(handle);
0142     if (!adev)
0143         return -ENODEV;
0144
0145     table_entry = &int3472->gpios.table[int3472->n_sensor_gpios];
0146     table_entry->key = acpi_dev_name(adev);
0147     table_entry->chip_hwnum = agpio->pin_table[0];
0148     table_entry->con_id = func;
0149     table_entry->idx = 0;
0150     table_entry->flags = polarity;
0151
0152     int3472->n_sensor_gpios++;
0153
0154     return 0;
0155 }
0156
0157 static int skl_int3472_map_gpio_to_clk(struct int3472_discrete_device *int3472,
0158                        struct acpi_resource_gpio *agpio, u8 type)
0159 {
0160     char *path = agpio->resource_source.string_ptr;
0161     u16 pin = agpio->pin_table[0];
0162     struct gpio_desc *gpio;
0163
0164     switch (type) {
0165     case INT3472_GPIO_TYPE_CLK_ENABLE:
0166         gpio = acpi_get_and_request_gpiod(path, pin, "int3472,clk-enable");
0167         if (IS_ERR(gpio))
0168             return (PTR_ERR(gpio));
0169
0170         int3472->clock.ena_gpio = gpio;
0171         break;
0172     case INT3472_GPIO_TYPE_PRIVACY_LED:
0173         gpio = acpi_get_and_request_gpiod(path, pin, "int3472,privacy-led");
0174         if (IS_ERR(gpio))
0175             return (PTR_ERR(gpio));
0176
0177         int3472->clock.led_gpio = gpio;
0178         break;
0179     default:
0180         dev_err(int3472->dev, "Invalid GPIO type 0x%02x for clock\n", type);
0181         break;
0182     }
0183
0184     return 0;
0185 }
0186
0187 /**
0188  * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
0189  * @ares: A pointer to a &struct acpi_resource
0190  * @data: A pointer to a &struct int3472_discrete_device
0191  *
0192  * This function handles GPIO resources that are against an INT3472
0193  * ACPI device, by checking the value of the corresponding _DSM entry.
0194  * This will return a 32bit int, where the lowest byte represents the
0195  * function of the GPIO pin:
0196  *
0197  * 0x00 Reset
0198  * 0x01 Power down
0199  * 0x0b Power enable
0200  * 0x0c Clock enable
0201  * 0x0d Privacy LED
0202  *
0203  * There are some known platform specific quirks where that does not quite
0204  * hold up; for example where a pin with type 0x01 (Power down) is mapped to
0205  * a sensor pin that performs a reset function or entries in _CRS and _DSM that
0206  * do not actually correspond to a physical connection. These will be handled
0207  * by the mapping sub-functions.
0208  *
0209  * GPIOs will either be mapped directly to the sensor device or else used
0210  * to create clocks and regulators via the usual frameworks.
0211  *
0212  * Return:
0213  * * 1      - To continue the loop
0214  * * 0      - When all resources found are handled properly.
0215  * * -EINVAL    - If the resource is not a GPIO IO resource
0216  * * -ENODEV    - If the resource has no corresponding _DSM entry
0217  * * -Other - Errors propagated from one of the sub-functions.
0218  */
0219 static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
0220                          void *data)
0221 {
0222     struct int3472_discrete_device *int3472 = data;
0223     struct acpi_resource_gpio *agpio;
0224     union acpi_object *obj;
0225     const char *err_msg;
0226     int ret;
0227     u8 type;
0228
0229     if (!acpi_gpio_get_io_resource(ares, &agpio))
0230         return 1;
0231
0232     /*
0233      * ngpios + 2 because the index of this _DSM function is 1-based and
0234      * the first function is just a count.
0235      */
0236     obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
0237                       &int3472_gpio_guid, 0x00,
0238                       int3472->ngpios + 2,
0239                       NULL, ACPI_TYPE_INTEGER);
0240
0241     if (!obj) {
0242         dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
0243              agpio->pin_table[0]);
0244         return 1;
0245     }
0246
0247     type = obj->integer.value & 0xff;
0248
0249     switch (type) {
0250     case INT3472_GPIO_TYPE_RESET:
0251         ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "reset",
0252                              GPIO_ACTIVE_LOW);
0253         if (ret)
0254             err_msg = "Failed to map reset pin to sensor\n";
0255
0256         break;
0257     case INT3472_GPIO_TYPE_POWERDOWN:
0258         ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, "powerdown",
0259                              GPIO_ACTIVE_LOW);
0260         if (ret)
0261             err_msg = "Failed to map powerdown pin to sensor\n";
0262
0263         break;
0264     case INT3472_GPIO_TYPE_CLK_ENABLE:
0265     case INT3472_GPIO_TYPE_PRIVACY_LED:
0266         ret = skl_int3472_map_gpio_to_clk(int3472, agpio, type);
0267         if (ret)
0268             err_msg = "Failed to map GPIO to clock\n";
0269
0270         break;
0271     case INT3472_GPIO_TYPE_POWER_ENABLE:
0272         ret = skl_int3472_register_regulator(int3472, agpio);
0273         if (ret)
0274             err_msg = "Failed to map regulator to sensor\n";
0275
0276         break;
0277     default:
0278         dev_warn(int3472->dev,
0279              "GPIO type 0x%02x unknown; the sensor may not work\n",
0280              type);
0281         ret = 1;
0282         break;
0283     }
0284
0285     int3472->ngpios++;
0286     ACPI_FREE(obj);
0287
0288     if (ret < 0)
0289         return dev_err_probe(int3472->dev, ret, err_msg);
0290
0291     return ret;
0292 }
0293
0294 static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
0295 {
0296     LIST_HEAD(resource_list);
0297     int ret;
0298
0299     /*
0300      * No error check, because not having a sensor config is not necessarily
0301      * a failure mode.
0302      */
0303     int3472->sensor_config = skl_int3472_get_sensor_module_config(int3472);
0304
0305     ret = acpi_dev_get_resources(int3472->adev, &resource_list,
0306                      skl_int3472_handle_gpio_resources,
0307                      int3472);
0308     if (ret < 0)
0309         return ret;
0310
0311     acpi_dev_free_resource_list(&resource_list);
0312
0313     /*
0314      * If we find no clock enable GPIO pin then the privacy LED won't work.
0315      * We've never seen that situation, but it's possible. Warn the user so
0316      * it's clear what's happened.
0317      */
0318     if (int3472->clock.ena_gpio) {
0319         ret = skl_int3472_register_clock(int3472);
0320         if (ret)
0321             return ret;
0322     } else {
0323         if (int3472->clock.led_gpio)
0324             dev_warn(int3472->dev,
0325                  "No clk GPIO. The privacy LED won't work\n");
0326     }
0327
0328     int3472->gpios.dev_id = int3472->sensor_name;
0329     gpiod_add_lookup_table(&int3472->gpios);
0330
0331     return 0;
0332 }
0333
0334 static int skl_int3472_discrete_remove(struct platform_device *pdev);
0335
0336 static int skl_int3472_discrete_probe(struct platform_device *pdev)
0337 {
0338     struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
0339     struct int3472_discrete_device *int3472;
0340     struct int3472_cldb cldb;
0341     int ret;
0342
0343     ret = skl_int3472_fill_cldb(adev, &cldb);
0344     if (ret) {
0345         dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
0346         return ret;
0347     }
0348
0349     if (cldb.control_logic_type != 1) {
0350         dev_err(&pdev->dev, "Unsupported control logic type %u\n",
0351             cldb.control_logic_type);
0352         return -EINVAL;
0353     }
0354
0355     /* Max num GPIOs we've seen plus a terminator */
0356     int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
0357                    INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
0358     if (!int3472)
0359         return -ENOMEM;
0360
0361     int3472->adev = adev;
0362     int3472->dev = &pdev->dev;
0363     platform_set_drvdata(pdev, int3472);
0364
0365     ret = skl_int3472_get_sensor_adev_and_name(&pdev->dev, &int3472->sensor,
0366                            &int3472->sensor_name);
0367     if (ret)
0368         return ret;
0369
0370     /*
0371      * Initialising this list means we can call gpiod_remove_lookup_table()
0372      * in failure paths without issue.
0373      */
0374     INIT_LIST_HEAD(&int3472->gpios.list);
0375
0376     ret = skl_int3472_parse_crs(int3472);
0377     if (ret) {
0378         skl_int3472_discrete_remove(pdev);
0379         return ret;
0380     }
0381
0382     acpi_dev_clear_dependencies(adev);
0383     return 0;
0384 }
0385
0386 static int skl_int3472_discrete_remove(struct platform_device *pdev)
0387 {
0388     struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
0389
0390     gpiod_remove_lookup_table(&int3472->gpios);
0391
0392     if (int3472->clock.cl)
0393         skl_int3472_unregister_clock(int3472);
0394
0395     gpiod_put(int3472->clock.ena_gpio);
0396     gpiod_put(int3472->clock.led_gpio);
0397
0398     skl_int3472_unregister_regulator(int3472);
0399
0400     return 0;
0401 }
0402
0403 static const struct acpi_device_id int3472_device_id[] = {
0404     { "INT3472", 0 },
0405     { }
0406 };
0407 MODULE_DEVICE_TABLE(acpi, int3472_device_id);
0408
0409 static struct platform_driver int3472_discrete = {
0410     .driver = {
0411         .name = "int3472-discrete",
0412         .acpi_match_table = int3472_device_id,
0413     },
0414     .probe = skl_int3472_discrete_probe,
0415     .remove = skl_int3472_discrete_remove,
0416 };
0417 module_platform_driver(int3472_discrete);
0418
0419 MODULE_DESCRIPTION("Intel SkyLake INT3472 ACPI Discrete Device Driver");
0420 MODULE_AUTHOR("Daniel Scally <djrscally@gmail.com>");
0421 MODULE_LICENSE("GPL v2");