Steve Twiss | 608567a | 2017-03-28 15:43:33 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Thermal device driver for DA9062 and DA9061 |
| 3 | * Copyright (C) 2017 Dialog Semiconductor |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License |
| 7 | * as published by the Free Software Foundation; either version 2 |
| 8 | * of the License, or (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | */ |
| 15 | |
| 16 | /* When over-temperature is reached, an interrupt from the device will be |
| 17 | * triggered. Following this event the interrupt will be disabled and |
| 18 | * periodic transmission of uevents (HOT trip point) should define the |
| 19 | * first level of temperature supervision. It is expected that any final |
| 20 | * implementation of the thermal driver will include a .notify() function |
| 21 | * to implement these uevents to userspace. |
| 22 | * |
| 23 | * These uevents are intended to indicate non-invasive temperature control |
| 24 | * of the system, where the necessary measures for cooling are the |
| 25 | * responsibility of the host software. Once the temperature falls again, |
| 26 | * the IRQ is re-enabled so the start of a new over-temperature event can |
| 27 | * be detected without constant software monitoring. |
| 28 | */ |
| 29 | |
| 30 | #include <linux/errno.h> |
| 31 | #include <linux/interrupt.h> |
| 32 | #include <linux/module.h> |
| 33 | #include <linux/of.h> |
| 34 | #include <linux/platform_device.h> |
| 35 | #include <linux/regmap.h> |
| 36 | #include <linux/thermal.h> |
| 37 | #include <linux/workqueue.h> |
| 38 | |
| 39 | #include <linux/mfd/da9062/core.h> |
| 40 | #include <linux/mfd/da9062/registers.h> |
| 41 | |
| 42 | /* Minimum, maximum and default polling millisecond periods are provided |
| 43 | * here as an example. It is expected that any final implementation to also |
| 44 | * include a modification of these settings to match the required |
| 45 | * application. |
| 46 | */ |
| 47 | #define DA9062_DEFAULT_POLLING_MS_PERIOD 3000 |
| 48 | #define DA9062_MAX_POLLING_MS_PERIOD 10000 |
| 49 | #define DA9062_MIN_POLLING_MS_PERIOD 1000 |
| 50 | |
| 51 | #define DA9062_MILLI_CELSIUS(t) ((t) * 1000) |
| 52 | |
| 53 | struct da9062_thermal_config { |
| 54 | const char *name; |
| 55 | }; |
| 56 | |
| 57 | struct da9062_thermal { |
| 58 | struct da9062 *hw; |
| 59 | struct delayed_work work; |
| 60 | struct thermal_zone_device *zone; |
| 61 | enum thermal_device_mode mode; |
| 62 | struct mutex lock; /* protection for da9062_thermal temperature */ |
| 63 | int temperature; |
| 64 | int irq; |
| 65 | const struct da9062_thermal_config *config; |
| 66 | struct device *dev; |
| 67 | }; |
| 68 | |
| 69 | static void da9062_thermal_poll_on(struct work_struct *work) |
| 70 | { |
| 71 | struct da9062_thermal *thermal = container_of(work, |
| 72 | struct da9062_thermal, |
| 73 | work.work); |
| 74 | unsigned long delay; |
| 75 | unsigned int val; |
| 76 | int ret; |
| 77 | |
| 78 | /* clear E_TEMP */ |
| 79 | ret = regmap_write(thermal->hw->regmap, |
| 80 | DA9062AA_EVENT_B, |
| 81 | DA9062AA_E_TEMP_MASK); |
| 82 | if (ret < 0) { |
| 83 | dev_err(thermal->dev, |
| 84 | "Cannot clear the TJUNC temperature status\n"); |
| 85 | goto err_enable_irq; |
| 86 | } |
| 87 | |
| 88 | /* Now read E_TEMP again: it is acting like a status bit. |
| 89 | * If over-temperature, then this status will be true. |
| 90 | * If not over-temperature, this status will be false. |
| 91 | */ |
| 92 | ret = regmap_read(thermal->hw->regmap, |
| 93 | DA9062AA_EVENT_B, |
| 94 | &val); |
| 95 | if (ret < 0) { |
| 96 | dev_err(thermal->dev, |
| 97 | "Cannot check the TJUNC temperature status\n"); |
| 98 | goto err_enable_irq; |
| 99 | } |
| 100 | |
| 101 | if (val & DA9062AA_E_TEMP_MASK) { |
| 102 | mutex_lock(&thermal->lock); |
| 103 | thermal->temperature = DA9062_MILLI_CELSIUS(125); |
| 104 | mutex_unlock(&thermal->lock); |
| 105 | thermal_zone_device_update(thermal->zone, |
| 106 | THERMAL_EVENT_UNSPECIFIED); |
| 107 | |
| 108 | delay = msecs_to_jiffies(thermal->zone->passive_delay); |
Geert Uytterhoeven | 0a76f5c | 2018-10-12 09:20:17 +0200 | [diff] [blame] | 109 | queue_delayed_work(system_freezable_wq, &thermal->work, delay); |
Steve Twiss | 608567a | 2017-03-28 15:43:33 +0100 | [diff] [blame] | 110 | return; |
| 111 | } |
| 112 | |
| 113 | mutex_lock(&thermal->lock); |
| 114 | thermal->temperature = DA9062_MILLI_CELSIUS(0); |
| 115 | mutex_unlock(&thermal->lock); |
| 116 | thermal_zone_device_update(thermal->zone, |
| 117 | THERMAL_EVENT_UNSPECIFIED); |
| 118 | |
| 119 | err_enable_irq: |
| 120 | enable_irq(thermal->irq); |
| 121 | } |
| 122 | |
| 123 | static irqreturn_t da9062_thermal_irq_handler(int irq, void *data) |
| 124 | { |
| 125 | struct da9062_thermal *thermal = data; |
| 126 | |
| 127 | disable_irq_nosync(thermal->irq); |
Geert Uytterhoeven | 0a76f5c | 2018-10-12 09:20:17 +0200 | [diff] [blame] | 128 | queue_delayed_work(system_freezable_wq, &thermal->work, 0); |
Steve Twiss | 608567a | 2017-03-28 15:43:33 +0100 | [diff] [blame] | 129 | |
| 130 | return IRQ_HANDLED; |
| 131 | } |
| 132 | |
| 133 | static int da9062_thermal_get_mode(struct thermal_zone_device *z, |
| 134 | enum thermal_device_mode *mode) |
| 135 | { |
| 136 | struct da9062_thermal *thermal = z->devdata; |
| 137 | *mode = thermal->mode; |
| 138 | return 0; |
| 139 | } |
| 140 | |
| 141 | static int da9062_thermal_get_trip_type(struct thermal_zone_device *z, |
| 142 | int trip, |
| 143 | enum thermal_trip_type *type) |
| 144 | { |
| 145 | struct da9062_thermal *thermal = z->devdata; |
| 146 | |
| 147 | switch (trip) { |
| 148 | case 0: |
| 149 | *type = THERMAL_TRIP_HOT; |
| 150 | break; |
| 151 | default: |
| 152 | dev_err(thermal->dev, |
| 153 | "Driver does not support more than 1 trip-wire\n"); |
| 154 | return -EINVAL; |
| 155 | } |
| 156 | |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z, |
| 161 | int trip, |
| 162 | int *temp) |
| 163 | { |
| 164 | struct da9062_thermal *thermal = z->devdata; |
| 165 | |
| 166 | switch (trip) { |
| 167 | case 0: |
| 168 | *temp = DA9062_MILLI_CELSIUS(125); |
| 169 | break; |
| 170 | default: |
| 171 | dev_err(thermal->dev, |
| 172 | "Driver does not support more than 1 trip-wire\n"); |
| 173 | return -EINVAL; |
| 174 | } |
| 175 | |
| 176 | return 0; |
| 177 | } |
| 178 | |
| 179 | static int da9062_thermal_get_temp(struct thermal_zone_device *z, |
| 180 | int *temp) |
| 181 | { |
| 182 | struct da9062_thermal *thermal = z->devdata; |
| 183 | |
| 184 | mutex_lock(&thermal->lock); |
| 185 | *temp = thermal->temperature; |
| 186 | mutex_unlock(&thermal->lock); |
| 187 | |
| 188 | return 0; |
| 189 | } |
| 190 | |
| 191 | static struct thermal_zone_device_ops da9062_thermal_ops = { |
| 192 | .get_temp = da9062_thermal_get_temp, |
| 193 | .get_mode = da9062_thermal_get_mode, |
| 194 | .get_trip_type = da9062_thermal_get_trip_type, |
| 195 | .get_trip_temp = da9062_thermal_get_trip_temp, |
| 196 | }; |
| 197 | |
| 198 | static const struct da9062_thermal_config da9062_config = { |
| 199 | .name = "da9062-thermal", |
| 200 | }; |
| 201 | |
| 202 | static const struct of_device_id da9062_compatible_reg_id_table[] = { |
| 203 | { .compatible = "dlg,da9062-thermal", .data = &da9062_config }, |
| 204 | { }, |
| 205 | }; |
| 206 | |
| 207 | MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table); |
| 208 | |
| 209 | static int da9062_thermal_probe(struct platform_device *pdev) |
| 210 | { |
| 211 | struct da9062 *chip = dev_get_drvdata(pdev->dev.parent); |
| 212 | struct da9062_thermal *thermal; |
| 213 | unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD; |
| 214 | const struct of_device_id *match; |
| 215 | int ret = 0; |
| 216 | |
| 217 | match = of_match_node(da9062_compatible_reg_id_table, |
| 218 | pdev->dev.of_node); |
| 219 | if (!match) |
| 220 | return -ENXIO; |
| 221 | |
| 222 | if (pdev->dev.of_node) { |
| 223 | if (!of_property_read_u32(pdev->dev.of_node, |
| 224 | "polling-delay-passive", |
| 225 | &pp_tmp)) { |
| 226 | if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD || |
| 227 | pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) { |
| 228 | dev_warn(&pdev->dev, |
| 229 | "Out-of-range polling period %d ms\n", |
| 230 | pp_tmp); |
| 231 | pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD; |
| 232 | } |
| 233 | } |
| 234 | } |
| 235 | |
| 236 | thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal), |
| 237 | GFP_KERNEL); |
| 238 | if (!thermal) { |
| 239 | ret = -ENOMEM; |
| 240 | goto err; |
| 241 | } |
| 242 | |
| 243 | thermal->config = match->data; |
| 244 | thermal->hw = chip; |
| 245 | thermal->mode = THERMAL_DEVICE_ENABLED; |
| 246 | thermal->dev = &pdev->dev; |
| 247 | |
| 248 | INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on); |
| 249 | mutex_init(&thermal->lock); |
| 250 | |
| 251 | thermal->zone = thermal_zone_device_register(thermal->config->name, |
| 252 | 1, 0, thermal, |
| 253 | &da9062_thermal_ops, NULL, pp_tmp, |
| 254 | 0); |
| 255 | if (IS_ERR(thermal->zone)) { |
| 256 | dev_err(&pdev->dev, "Cannot register thermal zone device\n"); |
| 257 | ret = PTR_ERR(thermal->zone); |
| 258 | goto err; |
| 259 | } |
| 260 | |
| 261 | dev_dbg(&pdev->dev, |
| 262 | "TJUNC temperature polling period set at %d ms\n", |
| 263 | thermal->zone->passive_delay); |
| 264 | |
| 265 | ret = platform_get_irq_byname(pdev, "THERMAL"); |
| 266 | if (ret < 0) { |
| 267 | dev_err(&pdev->dev, "Failed to get platform IRQ.\n"); |
| 268 | goto err_zone; |
| 269 | } |
| 270 | thermal->irq = ret; |
| 271 | |
| 272 | ret = request_threaded_irq(thermal->irq, NULL, |
| 273 | da9062_thermal_irq_handler, |
| 274 | IRQF_TRIGGER_LOW | IRQF_ONESHOT, |
| 275 | "THERMAL", thermal); |
| 276 | if (ret) { |
| 277 | dev_err(&pdev->dev, |
| 278 | "Failed to request thermal device IRQ.\n"); |
| 279 | goto err_zone; |
| 280 | } |
| 281 | |
| 282 | platform_set_drvdata(pdev, thermal); |
| 283 | return 0; |
| 284 | |
| 285 | err_zone: |
| 286 | thermal_zone_device_unregister(thermal->zone); |
| 287 | err: |
| 288 | return ret; |
| 289 | } |
| 290 | |
| 291 | static int da9062_thermal_remove(struct platform_device *pdev) |
| 292 | { |
| 293 | struct da9062_thermal *thermal = platform_get_drvdata(pdev); |
| 294 | |
| 295 | free_irq(thermal->irq, thermal); |
| 296 | cancel_delayed_work_sync(&thermal->work); |
| 297 | thermal_zone_device_unregister(thermal->zone); |
| 298 | return 0; |
| 299 | } |
| 300 | |
| 301 | static struct platform_driver da9062_thermal_driver = { |
| 302 | .probe = da9062_thermal_probe, |
| 303 | .remove = da9062_thermal_remove, |
| 304 | .driver = { |
| 305 | .name = "da9062-thermal", |
| 306 | .of_match_table = da9062_compatible_reg_id_table, |
| 307 | }, |
| 308 | }; |
| 309 | |
| 310 | module_platform_driver(da9062_thermal_driver); |
| 311 | |
| 312 | MODULE_AUTHOR("Steve Twiss"); |
| 313 | MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061"); |
| 314 | MODULE_LICENSE("GPL"); |
| 315 | MODULE_ALIAS("platform:da9062-thermal"); |