drivers/thermal/broadcom/brcmstb_thermal.c

   1 /*
   2  * Broadcom STB AVS TMON thermal sensor driver
   3  *
   4  * Copyright (c) 2015-2017 Broadcom
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   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
  17 #define DRV_NAME        "brcmstb_thermal"
  18
  19 #define pr_fmt(fmt)     DRV_NAME ": " fmt
  20
  21 #include <linux/bitops.h>
  22 #include <linux/device.h>
  23 #include <linux/err.h>
  24 #include <linux/io.h>
  25 #include <linux/irqreturn.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/of_device.h>
  31 #include <linux/thermal.h>
  32
  33 #define AVS_TMON_STATUS                 0x00
  34  #define AVS_TMON_STATUS_valid_msk      BIT(11)
  35  #define AVS_TMON_STATUS_data_msk       GENMASK(10, 1)
  36  #define AVS_TMON_STATUS_data_shift     1
  37
  38 #define AVS_TMON_EN_OVERTEMP_RESET      0x04
  39  #define AVS_TMON_EN_OVERTEMP_RESET_msk BIT(0)
  40
  41 #define AVS_TMON_RESET_THRESH           0x08
  42  #define AVS_TMON_RESET_THRESH_msk      GENMASK(10, 1)
  43  #define AVS_TMON_RESET_THRESH_shift    1
  44
  45 #define AVS_TMON_INT_IDLE_TIME          0x10
  46
  47 #define AVS_TMON_EN_TEMP_INT_SRCS       0x14
  48  #define AVS_TMON_EN_TEMP_INT_SRCS_high BIT(1)
  49  #define AVS_TMON_EN_TEMP_INT_SRCS_low  BIT(0)
  50
  51 #define AVS_TMON_INT_THRESH             0x18
  52  #define AVS_TMON_INT_THRESH_high_msk   GENMASK(26, 17)
  53  #define AVS_TMON_INT_THRESH_high_shift 17
  54  #define AVS_TMON_INT_THRESH_low_msk    GENMASK(10, 1)
  55  #define AVS_TMON_INT_THRESH_low_shift  1
  56
  57 #define AVS_TMON_TEMP_INT_CODE          0x1c
  58 #define AVS_TMON_TP_TEST_ENABLE         0x20
  59
  60 /* Default coefficients */
  61 #define AVS_TMON_TEMP_SLOPE             -487
  62 #define AVS_TMON_TEMP_OFFSET            410040
  63
  64 /* HW related temperature constants */
  65 #define AVS_TMON_TEMP_MAX               0x3ff
  66 #define AVS_TMON_TEMP_MIN               -88161
  67 #define AVS_TMON_TEMP_MASK              AVS_TMON_TEMP_MAX
  68
  69 enum avs_tmon_trip_type {
  70         TMON_TRIP_TYPE_LOW = 0,
  71         TMON_TRIP_TYPE_HIGH,
  72         TMON_TRIP_TYPE_RESET,
  73         TMON_TRIP_TYPE_MAX,
  74 };
  75
  76 struct avs_tmon_trip {
  77         /* HW bit to enable the trip */
  78         u32 enable_offs;
  79         u32 enable_mask;
  80
  81         /* HW field to read the trip temperature */
  82         u32 reg_offs;
  83         u32 reg_msk;
  84         int reg_shift;
  85 };
  86
  87 static struct avs_tmon_trip avs_tmon_trips[] = {
  88         /* Trips when temperature is below threshold */
  89         [TMON_TRIP_TYPE_LOW] = {
  90                 .enable_offs    = AVS_TMON_EN_TEMP_INT_SRCS,
  91                 .enable_mask    = AVS_TMON_EN_TEMP_INT_SRCS_low,
  92                 .reg_offs       = AVS_TMON_INT_THRESH,
  93                 .reg_msk        = AVS_TMON_INT_THRESH_low_msk,
  94                 .reg_shift      = AVS_TMON_INT_THRESH_low_shift,
  95         },
  96         /* Trips when temperature is above threshold */
  97         [TMON_TRIP_TYPE_HIGH] = {
  98                 .enable_offs    = AVS_TMON_EN_TEMP_INT_SRCS,
  99                 .enable_mask    = AVS_TMON_EN_TEMP_INT_SRCS_high,
 100                 .reg_offs       = AVS_TMON_INT_THRESH,
 101                 .reg_msk        = AVS_TMON_INT_THRESH_high_msk,
 102                 .reg_shift      = AVS_TMON_INT_THRESH_high_shift,
 103         },
 104         /* Automatically resets chip when above threshold */
 105         [TMON_TRIP_TYPE_RESET] = {
 106                 .enable_offs    = AVS_TMON_EN_OVERTEMP_RESET,
 107                 .enable_mask    = AVS_TMON_EN_OVERTEMP_RESET_msk,
 108                 .reg_offs       = AVS_TMON_RESET_THRESH,
 109                 .reg_msk        = AVS_TMON_RESET_THRESH_msk,
 110                 .reg_shift      = AVS_TMON_RESET_THRESH_shift,
 111         },
 112 };
 113
 114 struct brcmstb_thermal_priv {
 115         void __iomem *tmon_base;
 116         struct device *dev;
 117         struct thermal_zone_device *thermal;
 118 };
 119
 120 static void avs_tmon_get_coeffs(struct thermal_zone_device *tz, int *slope,
 121                                 int *offset)
 122 {
 123         *slope = thermal_zone_get_slope(tz);
 124         *offset = thermal_zone_get_offset(tz);
 125 }
 126
 127 /* Convert a HW code to a temperature reading (millidegree celsius) */
 128 static inline int avs_tmon_code_to_temp(struct thermal_zone_device *tz,
 129                                         u32 code)
 130 {
 131         const int val = code & AVS_TMON_TEMP_MASK;
 132         int slope, offset;
 133
 134         avs_tmon_get_coeffs(tz, &slope, &offset);
 135
 136         return slope * val + offset;
 137 }
 138
 139 /*
 140  * Convert a temperature value (millidegree celsius) to a HW code
 141  *
 142  * @temp: temperature to convert
 143  * @low: if true, round toward the low side
 144  */
 145 static inline u32 avs_tmon_temp_to_code(struct thermal_zone_device *tz,
 146                                         int temp, bool low)
 147 {
 148         int slope, offset;
 149
 150         if (temp < AVS_TMON_TEMP_MIN)
 151                 return AVS_TMON_TEMP_MAX; /* Maximum code value */
 152
 153         avs_tmon_get_coeffs(tz, &slope, &offset);
 154
 155         if (temp >= offset)
 156                 return 0;       /* Minimum code value */
 157
 158         if (low)
 159                 return (u32)(DIV_ROUND_UP(offset - temp, abs(slope)));
 160         else
 161                 return (u32)((offset - temp) / abs(slope));
 162 }
 163
 164 static int brcmstb_get_temp(void *data, int *temp)
 165 {
 166         struct brcmstb_thermal_priv *priv = data;
 167         u32 val;
 168         long t;
 169
 170         val = __raw_readl(priv->tmon_base + AVS_TMON_STATUS);
 171
 172         if (!(val & AVS_TMON_STATUS_valid_msk)) {
 173                 dev_err(priv->dev, "reading not valid\n");
 174                 return -EIO;
 175         }
 176
 177         val = (val & AVS_TMON_STATUS_data_msk) >> AVS_TMON_STATUS_data_shift;
 178
 179         t = avs_tmon_code_to_temp(priv->thermal, val);
 180         if (t < 0)
 181                 *temp = 0;
 182         else
 183                 *temp = t;
 184
 185         return 0;
 186 }
 187
 188 static void avs_tmon_trip_enable(struct brcmstb_thermal_priv *priv,
 189                                  enum avs_tmon_trip_type type, int en)
 190 {
 191         struct avs_tmon_trip *trip = &avs_tmon_trips[type];
 192         u32 val = __raw_readl(priv->tmon_base + trip->enable_offs);
 193
 194         dev_dbg(priv->dev, "%sable trip, type %d\n", en ? "en" : "dis", type);
 195
 196         if (en)
 197                 val |= trip->enable_mask;
 198         else
 199                 val &= ~trip->enable_mask;
 200
 201         __raw_writel(val, priv->tmon_base + trip->enable_offs);
 202 }
 203
 204 static int avs_tmon_get_trip_temp(struct brcmstb_thermal_priv *priv,
 205                                   enum avs_tmon_trip_type type)
 206 {
 207         struct avs_tmon_trip *trip = &avs_tmon_trips[type];
 208         u32 val = __raw_readl(priv->tmon_base + trip->reg_offs);
 209
 210         val &= trip->reg_msk;
 211         val >>= trip->reg_shift;
 212
 213         return avs_tmon_code_to_temp(priv->thermal, val);
 214 }
 215
 216 static void avs_tmon_set_trip_temp(struct brcmstb_thermal_priv *priv,
 217                                    enum avs_tmon_trip_type type,
 218                                    int temp)
 219 {
 220         struct avs_tmon_trip *trip = &avs_tmon_trips[type];
 221         u32 val, orig;
 222
 223         dev_dbg(priv->dev, "set temp %d to %d\n", type, temp);
 224
 225         /* round toward low temp for the low interrupt */
 226         val = avs_tmon_temp_to_code(priv->thermal, temp,
 227                                     type == TMON_TRIP_TYPE_LOW);
 228
 229         val <<= trip->reg_shift;
 230         val &= trip->reg_msk;
 231
 232         orig = __raw_readl(priv->tmon_base + trip->reg_offs);
 233         orig &= ~trip->reg_msk;
 234         orig |= val;
 235         __raw_writel(orig, priv->tmon_base + trip->reg_offs);
 236 }
 237
 238 static int avs_tmon_get_intr_temp(struct brcmstb_thermal_priv *priv)
 239 {
 240         u32 val;
 241
 242         val = __raw_readl(priv->tmon_base + AVS_TMON_TEMP_INT_CODE);
 243         return avs_tmon_code_to_temp(priv->thermal, val);
 244 }
 245
 246 static irqreturn_t brcmstb_tmon_irq_thread(int irq, void *data)
 247 {
 248         struct brcmstb_thermal_priv *priv = data;
 249         int low, high, intr;
 250
 251         low = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_LOW);
 252         high = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_HIGH);
 253         intr = avs_tmon_get_intr_temp(priv);
 254
 255         dev_dbg(priv->dev, "low/intr/high: %d/%d/%d\n",
 256                         low, intr, high);
 257
 258         /* Disable high-temp until next threshold shift */
 259         if (intr >= high)
 260                 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
 261         /* Disable low-temp until next threshold shift */
 262         if (intr <= low)
 263                 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
 264
 265         /*
 266          * Notify using the interrupt temperature, in case the temperature
 267          * changes before it can next be read out
 268          */
 269         thermal_zone_device_update(priv->thermal, intr);
 270
 271         return IRQ_HANDLED;
 272 }
 273
 274 static int brcmstb_set_trips(void *data, int low, int high)
 275 {
 276         struct brcmstb_thermal_priv *priv = data;
 277
 278         dev_dbg(priv->dev, "set trips %d <--> %d\n", low, high);
 279
 280         /*
 281          * Disable low-temp if "low" is too small. As per thermal framework
 282          * API, we use -INT_MAX rather than INT_MIN.
 283          */
 284         if (low <= -INT_MAX) {
 285                 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
 286         } else {
 287                 avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_LOW, low);
 288                 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 1);
 289         }
 290
 291         /* Disable high-temp if "high" is too big. */
 292         if (high == INT_MAX) {
 293                 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
 294         } else {
 295                 avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_HIGH, high);
 296                 avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 1);
 297         }
 298
 299         return 0;
 300 }
 301
 302 static struct thermal_zone_of_device_ops of_ops = {
 303         .get_temp       = brcmstb_get_temp,
 304         .set_trips      = brcmstb_set_trips,
 305 };
 306
 307 static const struct of_device_id brcmstb_thermal_id_table[] = {
 308         { .compatible = "brcm,avs-tmon" },
 309         {},
 310 };
 311 MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);
 312
 313 static int brcmstb_thermal_probe(struct platform_device *pdev)
 314 {
 315         struct thermal_zone_device *thermal;
 316         struct brcmstb_thermal_priv *priv;
 317         struct resource *res;
 318         int irq, ret;
 319
 320         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 321         if (!priv)
 322                 return -ENOMEM;
 323
 324         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 325         priv->tmon_base = devm_ioremap_resource(&pdev->dev, res);
 326         if (IS_ERR(priv->tmon_base))
 327                 return PTR_ERR(priv->tmon_base);
 328
 329         priv->dev = &pdev->dev;
 330         platform_set_drvdata(pdev, priv);
 331
 332         thermal = thermal_zone_of_sensor_register(&pdev->dev, 0, priv, &of_ops);
 333         if (IS_ERR(thermal)) {
 334                 ret = PTR_ERR(thermal);
 335                 dev_err(&pdev->dev, "could not register sensor: %d\n", ret);
 336                 return ret;
 337         }
 338
 339         priv->thermal = thermal;
 340
 341         irq = platform_get_irq(pdev, 0);
 342         if (irq < 0) {
 343                 dev_err(&pdev->dev, "could not get IRQ\n");
 344                 ret = irq;
 345                 goto err;
 346         }
 347         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 348                                         brcmstb_tmon_irq_thread, IRQF_ONESHOT,
 349                                         DRV_NAME, priv);
 350         if (ret < 0) {
 351                 dev_err(&pdev->dev, "could not request IRQ: %d\n", ret);
 352                 goto err;
 353         }
 354
 355         dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");
 356
 357         return 0;
 358
 359 err:
 360         thermal_zone_of_sensor_unregister(&pdev->dev, thermal);
 361         return ret;
 362 }
 363
 364 static int brcmstb_thermal_exit(struct platform_device *pdev)
 365 {
 366         struct brcmstb_thermal_priv *priv = platform_get_drvdata(pdev);
 367         struct thermal_zone_device *thermal = priv->thermal;
 368
 369         if (thermal)
 370                 thermal_zone_of_sensor_unregister(&pdev->dev, priv->thermal);
 371
 372         return 0;
 373 }
 374
 375 static struct platform_driver brcmstb_thermal_driver = {
 376         .probe = brcmstb_thermal_probe,
 377         .remove = brcmstb_thermal_exit,
 378         .driver = {
 379                 .name = DRV_NAME,
 380                 .of_match_table = brcmstb_thermal_id_table,
 381         },
 382 };
 383 module_platform_driver(brcmstb_thermal_driver);
 384
 385 MODULE_LICENSE("GPL v2");
 386 MODULE_AUTHOR("Brian Norris");
 387 MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");