drivers/platform/x86/intel/int1092/intel_sar.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2021, Intel Corporation.
   4  */
   5
   6 #include <linux/acpi.h>
   7 #include <linux/kobject.h>
   8 #include <linux/platform_device.h>
   9 #include <linux/sysfs.h>
  10 #include "intel_sar.h"
  11
  12 /**
  13  * get_int_value: Retrieve integer values from ACPI Object
  14  * @obj: acpi_object pointer which has the integer value
  15  * @out: output pointer will get integer value
  16  *
  17  * Function is used to retrieve integer value from acpi object.
  18  *
  19  * Return:
  20  * * 0 on success
  21  * * -EIO if there is an issue in acpi_object passed.
  22  */
  23 static int get_int_value(union acpi_object *obj, int *out)
  24 {
  25         if (!obj || obj->type != ACPI_TYPE_INTEGER)
  26                 return -EIO;
  27         *out = (int)obj->integer.value;
  28         return 0;
  29 }
  30
  31 /**
  32  * update_sar_data: sar data is updated based on regulatory mode
  33  * @context: pointer to driver context structure
  34  *
  35  * sar_data is updated based on regulatory value
  36  * context->reg_value will never exceed MAX_REGULATORY
  37  */
  38 static void update_sar_data(struct wwan_sar_context *context)
  39 {
  40         struct wwan_device_mode_configuration *config =
  41                 &context->config_data[context->reg_value];
  42
  43         if (config->device_mode_info &&
  44             context->sar_data.device_mode < config->total_dev_mode) {
  45                 int itr = 0;
  46
  47                 for (itr = 0; itr < config->total_dev_mode; itr++) {
  48                         if (context->sar_data.device_mode ==
  49                                 config->device_mode_info[itr].device_mode) {
  50                                 struct wwan_device_mode_info *dev_mode =
  51                                 &config->device_mode_info[itr];
  52
  53                                 context->sar_data.antennatable_index = dev_mode->antennatable_index;
  54                                 context->sar_data.bandtable_index = dev_mode->bandtable_index;
  55                                 context->sar_data.sartable_index = dev_mode->sartable_index;
  56                                 break;
  57                         }
  58                 }
  59         }
  60 }
  61
  62 /**
  63  * parse_package: parse acpi package for retrieving SAR information
  64  * @context: pointer to driver context structure
  65  * @item : acpi_object pointer
  66  *
  67  * Given acpi_object is iterated to retrieve information for each device mode.
  68  * If a given package corresponding to a specific device mode is faulty, it is
  69  * skipped and the specific entry in context structure will have the default value
  70  * of zero. Decoding of subsequent device modes is realized by having "continue"
  71  * statements in the for loop on encountering error in parsing given device mode.
  72  *
  73  * Return:
  74  * AE_OK if success
  75  * AE_ERROR on error
  76  */
  77 static acpi_status parse_package(struct wwan_sar_context *context, union acpi_object *item)
  78 {
  79         struct wwan_device_mode_configuration *data;
  80         int value, itr, reg;
  81         union acpi_object *num;
  82
  83         num = &item->package.elements[0];
  84         if (get_int_value(num, &value) || value < 0 || value >= MAX_REGULATORY)
  85                 return AE_ERROR;
  86
  87         reg = value;
  88
  89         data = &context->config_data[reg];
  90         if (data->total_dev_mode > MAX_DEV_MODES ||     data->total_dev_mode == 0 ||
  91             item->package.count <= data->total_dev_mode)
  92                 return AE_ERROR;
  93
  94         data->device_mode_info = kmalloc_array(data->total_dev_mode,
  95                                                sizeof(struct wwan_device_mode_info), GFP_KERNEL);
  96         if (!data->device_mode_info)
  97                 return AE_ERROR;
  98
  99         for (itr = 0; itr < data->total_dev_mode; itr++) {
 100                 struct wwan_device_mode_info temp = { 0 };
 101
 102                 num = &item->package.elements[itr + 1];
 103                 if (num->type != ACPI_TYPE_PACKAGE || num->package.count < TOTAL_DATA)
 104                         continue;
 105                 if (get_int_value(&num->package.elements[0], &temp.device_mode))
 106                         continue;
 107                 if (get_int_value(&num->package.elements[1], &temp.bandtable_index))
 108                         continue;
 109                 if (get_int_value(&num->package.elements[2], &temp.antennatable_index))
 110                         continue;
 111                 if (get_int_value(&num->package.elements[3], &temp.sartable_index))
 112                         continue;
 113                 data->device_mode_info[itr] = temp;
 114         }
 115         return AE_OK;
 116 }
 117
 118 /**
 119  * sar_get_device_mode: Extraction of information from BIOS via DSM calls
 120  * @device: ACPI device for which to retrieve the data
 121  *
 122  * Retrieve the current device mode information from the BIOS.
 123  *
 124  * Return:
 125  * AE_OK on success
 126  * AE_ERROR on error
 127  */
 128 static acpi_status sar_get_device_mode(struct platform_device *device)
 129 {
 130         struct wwan_sar_context *context = dev_get_drvdata(&device->dev);
 131         acpi_status status = AE_OK;
 132         union acpi_object *out;
 133         u32 rev = 0;
 134
 135         out = acpi_evaluate_dsm_typed(context->handle, &context->guid, rev,
 136                                       COMMAND_ID_DEV_MODE, NULL, ACPI_TYPE_INTEGER);
 137         if (!out) {
 138                 dev_err(&device->dev, "DSM cmd:%d Failed to retrieve value\n", COMMAND_ID_DEV_MODE);
 139                 status = AE_ERROR;
 140                 goto dev_mode_error;
 141         }
 142         context->sar_data.device_mode = out->integer.value;
 143         update_sar_data(context);
 144         sysfs_notify(&device->dev.kobj, NULL, SYSFS_DATANAME);
 145
 146 dev_mode_error:
 147         ACPI_FREE(out);
 148         return status;
 149 }
 150
 151 static const struct acpi_device_id sar_device_ids[] = {
 152         { "INTC1092", 0},
 153         {}
 154 };
 155 MODULE_DEVICE_TABLE(acpi, sar_device_ids);
 156
 157 static ssize_t intc_data_show(struct device *dev, struct device_attribute *attr, char *buf)
 158 {
 159         struct wwan_sar_context *context = dev_get_drvdata(dev);
 160
 161         return sysfs_emit(buf, "%d %d %d %d\n", context->sar_data.device_mode,
 162                       context->sar_data.bandtable_index,
 163                       context->sar_data.antennatable_index,
 164                       context->sar_data.sartable_index);
 165 }
 166 static DEVICE_ATTR_RO(intc_data);
 167
 168 static ssize_t intc_reg_show(struct device *dev, struct device_attribute *attr, char *buf)
 169 {
 170         struct wwan_sar_context *context = dev_get_drvdata(dev);
 171
 172         return sysfs_emit(buf, "%d\n", context->reg_value);
 173 }
 174
 175 static ssize_t intc_reg_store(struct device *dev, struct device_attribute *attr,
 176                               const char *buf, size_t count)
 177 {
 178         struct wwan_sar_context *context = dev_get_drvdata(dev);
 179         unsigned int value;
 180         int read;
 181
 182         if (!count)
 183                 return -EINVAL;
 184         read = kstrtouint(buf, 10, &value);
 185         if (read < 0)
 186                 return read;
 187         if (value >= MAX_REGULATORY)
 188                 return -EOVERFLOW;
 189         context->reg_value = value;
 190         update_sar_data(context);
 191         sysfs_notify(&dev->kobj, NULL, SYSFS_DATANAME);
 192         return count;
 193 }
 194 static DEVICE_ATTR_RW(intc_reg);
 195
 196 static struct attribute *intcsar_attrs[] = {
 197         &dev_attr_intc_data.attr,
 198         &dev_attr_intc_reg.attr,
 199         NULL
 200 };
 201
 202 static struct attribute_group intcsar_group = {
 203         .attrs = intcsar_attrs,
 204 };
 205
 206 static void sar_notify(acpi_handle handle, u32 event, void *data)
 207 {
 208         struct platform_device *device = data;
 209
 210         if (event == SAR_EVENT) {
 211                 if (sar_get_device_mode(device) != AE_OK)
 212                         dev_err(&device->dev, "sar_get_device_mode error");
 213         }
 214 }
 215
 216 static void sar_get_data(int reg, struct wwan_sar_context *context)
 217 {
 218         union acpi_object *out, req;
 219         u32 rev = 0;
 220
 221         req.type = ACPI_TYPE_INTEGER;
 222         req.integer.value = reg;
 223         out = acpi_evaluate_dsm_typed(context->handle, &context->guid, rev,
 224                                       COMMAND_ID_CONFIG_TABLE, &req, ACPI_TYPE_PACKAGE);
 225         if (!out)
 226                 return;
 227         if (out->package.count >= 3 &&
 228             out->package.elements[0].type == ACPI_TYPE_INTEGER &&
 229             out->package.elements[1].type == ACPI_TYPE_INTEGER &&
 230             out->package.elements[2].type == ACPI_TYPE_PACKAGE &&
 231             out->package.elements[2].package.count > 0) {
 232                 context->config_data[reg].version = out->package.elements[0].integer.value;
 233                 context->config_data[reg].total_dev_mode =
 234                         out->package.elements[1].integer.value;
 235                 if (context->config_data[reg].total_dev_mode <= 0 ||
 236                     context->config_data[reg].total_dev_mode > MAX_DEV_MODES) {
 237                         ACPI_FREE(out);
 238                         return;
 239                 }
 240                 parse_package(context, &out->package.elements[2]);
 241         }
 242         ACPI_FREE(out);
 243 }
 244
 245 static int sar_probe(struct platform_device *device)
 246 {
 247         struct wwan_sar_context *context;
 248         int reg;
 249         int result;
 250
 251         context = kzalloc(sizeof(*context), GFP_KERNEL);
 252         if (!context)
 253                 return -ENOMEM;
 254
 255         context->sar_device = device;
 256         context->handle = ACPI_HANDLE(&device->dev);
 257         dev_set_drvdata(&device->dev, context);
 258
 259         result = guid_parse(SAR_DSM_UUID, &context->guid);
 260         if (result) {
 261                 dev_err(&device->dev, "SAR UUID parse error: %d\n", result);
 262                 goto r_free;
 263         }
 264
 265         for (reg = 0; reg < MAX_REGULATORY; reg++)
 266                 sar_get_data(reg, context);
 267
 268         if (sar_get_device_mode(device) != AE_OK) {
 269                 dev_err(&device->dev, "Failed to get device mode\n");
 270                 result = -EIO;
 271                 goto r_free;
 272         }
 273
 274         result = sysfs_create_group(&device->dev.kobj, &intcsar_group);
 275         if (result) {
 276                 dev_err(&device->dev, "sysfs creation failed\n");
 277                 goto r_free;
 278         }
 279
 280         if (acpi_install_notify_handler(ACPI_HANDLE(&device->dev), ACPI_DEVICE_NOTIFY,
 281                                         sar_notify, (void *)device) != AE_OK) {
 282                 dev_err(&device->dev, "Failed acpi_install_notify_handler\n");
 283                 result = -EIO;
 284                 goto r_sys;
 285         }
 286         return 0;
 287
 288 r_sys:
 289         sysfs_remove_group(&device->dev.kobj, &intcsar_group);
 290 r_free:
 291         kfree(context);
 292         return result;
 293 }
 294
 295 static void sar_remove(struct platform_device *device)
 296 {
 297         struct wwan_sar_context *context = dev_get_drvdata(&device->dev);
 298         int reg;
 299
 300         acpi_remove_notify_handler(ACPI_HANDLE(&device->dev),
 301                                    ACPI_DEVICE_NOTIFY, sar_notify);
 302         sysfs_remove_group(&device->dev.kobj, &intcsar_group);
 303         for (reg = 0; reg < MAX_REGULATORY; reg++)
 304                 kfree(context->config_data[reg].device_mode_info);
 305
 306         kfree(context);
 307 }
 308
 309 static struct platform_driver sar_driver = {
 310         .probe = sar_probe,
 311         .remove = sar_remove,
 312         .driver = {
 313                 .name = DRVNAME,
 314                 .acpi_match_table = ACPI_PTR(sar_device_ids)
 315         }
 316 };
 317 module_platform_driver(sar_driver);
 318
 319 MODULE_LICENSE("GPL v2");
 320 MODULE_DESCRIPTION("Platform device driver for INTEL MODEM BIOS SAR");
 321 MODULE_AUTHOR("Shravan Sudhakar <s.shravan@intel.com>");