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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Author: Dan Scally <djrscally@gmail.com> */
   3
   4 #include <linux/acpi.h>
   5 #include <linux/clkdev.h>
   6 #include <linux/clk-provider.h>
   7 #include <linux/device.h>
   8 #include <linux/dmi.h>
   9 #include <linux/gpio/consumer.h>
  10 #include <linux/regulator/driver.h>
  11 #include <linux/slab.h>
  12
  13 #include "common.h"
  14
  15 /*
  16  * 82c0d13a-78c5-4244-9bb1-eb8b539a8d11
  17  * This _DSM GUID allows controlling the sensor clk when it is not controlled
  18  * through a GPIO.
  19  */
  20 static const guid_t img_clk_guid =
  21         GUID_INIT(0x82c0d13a, 0x78c5, 0x4244,
  22                   0x9b, 0xb1, 0xeb, 0x8b, 0x53, 0x9a, 0x8d, 0x11);
  23
  24 static void skl_int3472_enable_clk(struct int3472_clock *clk, int enable)
  25 {
  26         struct int3472_discrete_device *int3472 = to_int3472_device(clk);
  27         union acpi_object args[3];
  28         union acpi_object argv4;
  29
  30         if (clk->ena_gpio) {
  31                 gpiod_set_value_cansleep(clk->ena_gpio, enable);
  32                 return;
  33         }
  34
  35         args[0].integer.type = ACPI_TYPE_INTEGER;
  36         args[0].integer.value = clk->imgclk_index;
  37         args[1].integer.type = ACPI_TYPE_INTEGER;
  38         args[1].integer.value = enable;
  39         args[2].integer.type = ACPI_TYPE_INTEGER;
  40         args[2].integer.value = 1;
  41
  42         argv4.type = ACPI_TYPE_PACKAGE;
  43         argv4.package.count = 3;
  44         argv4.package.elements = args;
  45
  46         acpi_evaluate_dsm(acpi_device_handle(int3472->adev), &img_clk_guid,
  47                           0, 1, &argv4);
  48 }
  49
  50 /*
  51  * The regulators have to have .ops to be valid, but the only ops we actually
  52  * support are .enable and .disable which are handled via .ena_gpiod. Pass an
  53  * empty struct to clear the check without lying about capabilities.
  54  */
  55 static const struct regulator_ops int3472_gpio_regulator_ops;
  56
  57 static int skl_int3472_clk_prepare(struct clk_hw *hw)
  58 {
  59         skl_int3472_enable_clk(to_int3472_clk(hw), 1);
  60         return 0;
  61 }
  62
  63 static void skl_int3472_clk_unprepare(struct clk_hw *hw)
  64 {
  65         skl_int3472_enable_clk(to_int3472_clk(hw), 0);
  66 }
  67
  68 static int skl_int3472_clk_enable(struct clk_hw *hw)
  69 {
  70         /*
  71          * We're just turning a GPIO on to enable the clock, which operation
  72          * has the potential to sleep. Given .enable() cannot sleep, but
  73          * .prepare() can, we toggle the GPIO in .prepare() instead. Thus,
  74          * nothing to do here.
  75          */
  76         return 0;
  77 }
  78
  79 static void skl_int3472_clk_disable(struct clk_hw *hw)
  80 {
  81         /* Likewise, nothing to do here... */
  82 }
  83
  84 static unsigned int skl_int3472_get_clk_frequency(struct int3472_discrete_device *int3472)
  85 {
  86         union acpi_object *obj;
  87         unsigned int freq;
  88
  89         obj = skl_int3472_get_acpi_buffer(int3472->sensor, "SSDB");
  90         if (IS_ERR(obj))
  91                 return 0; /* report rate as 0 on error */
  92
  93         if (obj->buffer.length < CIO2_SENSOR_SSDB_MCLKSPEED_OFFSET + sizeof(u32)) {
  94                 dev_err(int3472->dev, "The buffer is too small\n");
  95                 kfree(obj);
  96                 return 0;
  97         }
  98
  99         freq = *(u32 *)(obj->buffer.pointer + CIO2_SENSOR_SSDB_MCLKSPEED_OFFSET);
 100
 101         kfree(obj);
 102         return freq;
 103 }
 104
 105 static unsigned long skl_int3472_clk_recalc_rate(struct clk_hw *hw,
 106                                                  unsigned long parent_rate)
 107 {
 108         struct int3472_clock *clk = to_int3472_clk(hw);
 109
 110         return clk->frequency;
 111 }
 112
 113 static const struct clk_ops skl_int3472_clock_ops = {
 114         .prepare = skl_int3472_clk_prepare,
 115         .unprepare = skl_int3472_clk_unprepare,
 116         .enable = skl_int3472_clk_enable,
 117         .disable = skl_int3472_clk_disable,
 118         .recalc_rate = skl_int3472_clk_recalc_rate,
 119 };
 120
 121 int skl_int3472_register_dsm_clock(struct int3472_discrete_device *int3472)
 122 {
 123         struct acpi_device *adev = int3472->adev;
 124         struct clk_init_data init = {
 125                 .ops = &skl_int3472_clock_ops,
 126                 .flags = CLK_GET_RATE_NOCACHE,
 127         };
 128         int ret;
 129
 130         if (int3472->clock.cl)
 131                 return 0; /* A GPIO controlled clk has already been registered */
 132
 133         if (!acpi_check_dsm(adev->handle, &img_clk_guid, 0, BIT(1)))
 134                 return 0; /* DSM clock control is not available */
 135
 136         init.name = kasprintf(GFP_KERNEL, "%s-clk", acpi_dev_name(adev));
 137         if (!init.name)
 138                 return -ENOMEM;
 139
 140         int3472->clock.frequency = skl_int3472_get_clk_frequency(int3472);
 141         int3472->clock.clk_hw.init = &init;
 142         int3472->clock.clk = clk_register(&adev->dev, &int3472->clock.clk_hw);
 143         if (IS_ERR(int3472->clock.clk)) {
 144                 ret = PTR_ERR(int3472->clock.clk);
 145                 goto out_free_init_name;
 146         }
 147
 148         int3472->clock.cl = clkdev_create(int3472->clock.clk, NULL, int3472->sensor_name);
 149         if (!int3472->clock.cl) {
 150                 ret = -ENOMEM;
 151                 goto err_unregister_clk;
 152         }
 153
 154         kfree(init.name);
 155         return 0;
 156
 157 err_unregister_clk:
 158         clk_unregister(int3472->clock.clk);
 159 out_free_init_name:
 160         kfree(init.name);
 161         return ret;
 162 }
 163
 164 int skl_int3472_register_gpio_clock(struct int3472_discrete_device *int3472,
 165                                     struct gpio_desc *gpio)
 166 {
 167         struct clk_init_data init = {
 168                 .ops = &skl_int3472_clock_ops,
 169                 .flags = CLK_GET_RATE_NOCACHE,
 170         };
 171         int ret;
 172
 173         if (int3472->clock.cl)
 174                 return -EBUSY;
 175
 176         int3472->clock.ena_gpio = gpio;
 177
 178         init.name = kasprintf(GFP_KERNEL, "%s-clk",
 179                               acpi_dev_name(int3472->adev));
 180         if (!init.name)
 181                 return -ENOMEM;
 182
 183         int3472->clock.frequency = skl_int3472_get_clk_frequency(int3472);
 184
 185         int3472->clock.clk_hw.init = &init;
 186         int3472->clock.clk = clk_register(&int3472->adev->dev,
 187                                           &int3472->clock.clk_hw);
 188         if (IS_ERR(int3472->clock.clk)) {
 189                 ret = PTR_ERR(int3472->clock.clk);
 190                 goto out_free_init_name;
 191         }
 192
 193         int3472->clock.cl = clkdev_create(int3472->clock.clk, NULL,
 194                                           int3472->sensor_name);
 195         if (!int3472->clock.cl) {
 196                 ret = -ENOMEM;
 197                 goto err_unregister_clk;
 198         }
 199
 200         kfree(init.name);
 201         return 0;
 202
 203 err_unregister_clk:
 204         clk_unregister(int3472->clock.clk);
 205 out_free_init_name:
 206         kfree(init.name);
 207
 208         return ret;
 209 }
 210
 211 void skl_int3472_unregister_clock(struct int3472_discrete_device *int3472)
 212 {
 213         if (!int3472->clock.cl)
 214                 return;
 215
 216         clkdev_drop(int3472->clock.cl);
 217         clk_unregister(int3472->clock.clk);
 218 }
 219
 220 /*
 221  * The INT3472 device is going to be the only supplier of a regulator for
 222  * the sensor device. But unlike the clk framework the regulator framework
 223  * does not allow matching by consumer-device-name only.
 224  *
 225  * Ideally all sensor drivers would use "avdd" as supply-id. But for drivers
 226  * where this cannot be changed because another supply-id is already used in
 227  * e.g. DeviceTree files an alias for the other supply-id can be added here.
 228  *
 229  * Do not forget to update GPIO_REGULATOR_SUPPLY_MAP_COUNT when changing this.
 230  */
 231 static const char * const skl_int3472_regulator_map_supplies[] = {
 232         "avdd",
 233         "AVDD",
 234 };
 235
 236 static_assert(ARRAY_SIZE(skl_int3472_regulator_map_supplies) ==
 237               GPIO_REGULATOR_SUPPLY_MAP_COUNT);
 238
 239 /*
 240  * On some models there is a single GPIO regulator which is shared between
 241  * sensors and only listed in the ACPI resources of one sensor.
 242  * This DMI table contains the name of the second sensor. This is used to add
 243  * entries for the second sensor to the supply_map.
 244  */
 245 static const struct dmi_system_id skl_int3472_regulator_second_sensor[] = {
 246         {
 247                 /* Lenovo Miix 510-12IKB */
 248                 .matches = {
 249                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 250                         DMI_MATCH(DMI_PRODUCT_VERSION, "MIIX 510-12IKB"),
 251                 },
 252                 .driver_data = "i2c-OVTI2680:00",
 253         },
 254         { }
 255 };
 256
 257 int skl_int3472_register_regulator(struct int3472_discrete_device *int3472,
 258                                    struct gpio_desc *gpio)
 259 {
 260         struct regulator_init_data init_data = { };
 261         struct regulator_config cfg = { };
 262         const char *second_sensor = NULL;
 263         const struct dmi_system_id *id;
 264         int i, j;
 265
 266         id = dmi_first_match(skl_int3472_regulator_second_sensor);
 267         if (id)
 268                 second_sensor = id->driver_data;
 269
 270         for (i = 0, j = 0; i < ARRAY_SIZE(skl_int3472_regulator_map_supplies); i++) {
 271                 int3472->regulator.supply_map[j].supply = skl_int3472_regulator_map_supplies[i];
 272                 int3472->regulator.supply_map[j].dev_name = int3472->sensor_name;
 273                 j++;
 274
 275                 if (second_sensor) {
 276                         int3472->regulator.supply_map[j].supply =
 277                                 skl_int3472_regulator_map_supplies[i];
 278                         int3472->regulator.supply_map[j].dev_name = second_sensor;
 279                         j++;
 280                 }
 281         }
 282
 283         init_data.constraints.valid_ops_mask = REGULATOR_CHANGE_STATUS;
 284         init_data.consumer_supplies = int3472->regulator.supply_map;
 285         init_data.num_consumer_supplies = j;
 286
 287         snprintf(int3472->regulator.regulator_name,
 288                  sizeof(int3472->regulator.regulator_name), "%s-regulator",
 289                  acpi_dev_name(int3472->adev));
 290         snprintf(int3472->regulator.supply_name,
 291                  GPIO_REGULATOR_SUPPLY_NAME_LENGTH, "supply-0");
 292
 293         int3472->regulator.rdesc = INT3472_REGULATOR(
 294                                                 int3472->regulator.regulator_name,
 295                                                 int3472->regulator.supply_name,
 296                                                 &int3472_gpio_regulator_ops);
 297
 298         int3472->regulator.gpio = gpio;
 299
 300         cfg.dev = &int3472->adev->dev;
 301         cfg.init_data = &init_data;
 302         cfg.ena_gpiod = int3472->regulator.gpio;
 303
 304         int3472->regulator.rdev = regulator_register(int3472->dev,
 305                                                      &int3472->regulator.rdesc,
 306                                                      &cfg);
 307
 308         return PTR_ERR_OR_ZERO(int3472->regulator.rdev);
 309 }
 310
 311 void skl_int3472_unregister_regulator(struct int3472_discrete_device *int3472)
 312 {
 313         regulator_unregister(int3472->regulator.rdev);
 314 }