drivers/hwmon/sfctemp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk>
   4  * Copyright (C) 2021 Samin Guo <samin.guo@starfivetech.com>
   5  */
   6 #include <linux/clk.h>
   7 #include <linux/completion.h>
   8 #include <linux/delay.h>
   9 #include <linux/hwmon.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/io.h>
  12 #include <linux/module.h>
  13 #include <linux/mutex.h>
  14 #include <linux/of.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/reset.h>
  17 #include <linux/pm_runtime.h>
  18
  19 /*
  20  * TempSensor reset. The RSTN can be de-asserted once the analog core has
  21  * powered up. Trst(min 100ns)
  22  * 0:reset  1:de-assert
  23  */
  24 #define SFCTEMP_RSTN    BIT(0)
  25
  26 /*
  27  * TempSensor analog core power down. The analog core will be powered up
  28  * Tpu(min 50us) after PD is de-asserted. RSTN should be held low until the
  29  * analog core is powered up.
  30  * 0:power up  1:power down
  31  */
  32 #define SFCTEMP_PD      BIT(1)
  33
  34 /*
  35  * TempSensor start conversion enable.
  36  * 0:disable  1:enable
  37  */
  38 #define SFCTEMP_RUN     BIT(2)
  39
  40 /*
  41  * TempSensor conversion value output.
  42  * Temp(C)=DOUT*Y/4094 - K
  43  */
  44 #define SFCTEMP_DOUT_POS        16
  45 #define SFCTEMP_DOUT_MSK        GENMASK(27, 16)
  46
  47 /* DOUT to Celcius conversion constants */
  48 #define SFCTEMP_Y1000   237500L
  49 #define SFCTEMP_Z       4094L
  50 #define SFCTEMP_K1000   81100L
  51
  52 struct sfctemp {
  53         /* serialize access to hardware register and enabled below */
  54         struct mutex lock;
  55         struct completion conversion_done;
  56         void __iomem *regs;
  57         struct clk *clk_sense;
  58         struct clk *clk_bus;
  59         struct reset_control *rst_sense;
  60         struct reset_control *rst_bus;
  61         bool enabled;
  62 };
  63
  64 static irqreturn_t sfctemp_isr(int irq, void *data)
  65 {
  66         struct sfctemp *sfctemp = data;
  67
  68         complete(&sfctemp->conversion_done);
  69         return IRQ_HANDLED;
  70 }
  71
  72 static void sfctemp_power_up(struct sfctemp *sfctemp)
  73 {
  74         /* make sure we're powered down first */
  75         writel(SFCTEMP_PD, sfctemp->regs);
  76         udelay(1);
  77
  78         writel(0, sfctemp->regs);
  79         /* wait t_pu(50us) + t_rst(100ns) */
  80         usleep_range(60, 200);
  81
  82         /* de-assert reset */
  83         writel(SFCTEMP_RSTN, sfctemp->regs);
  84         udelay(1); /* wait t_su(500ps) */
  85 }
  86
  87 static void sfctemp_power_down(struct sfctemp *sfctemp)
  88 {
  89         writel(SFCTEMP_PD, sfctemp->regs);
  90 }
  91
  92 static void sfctemp_run_single(struct sfctemp *sfctemp)
  93 {
  94         writel(SFCTEMP_RSTN | SFCTEMP_RUN, sfctemp->regs);
  95         udelay(1);
  96         writel(SFCTEMP_RSTN, sfctemp->regs);
  97 }
  98
  99 static int sfctemp_enable(struct sfctemp *sfctemp)
 100 {
 101         int ret = 0;
 102
 103         mutex_lock(&sfctemp->lock);
 104         if (sfctemp->enabled)
 105                 goto done;
 106
 107         ret = clk_prepare_enable(sfctemp->clk_bus);
 108         if (ret)
 109                 goto err;
 110         ret = reset_control_deassert(sfctemp->rst_bus);
 111         if (ret)
 112                 goto err_disable_bus;
 113
 114         ret = clk_prepare_enable(sfctemp->clk_sense);
 115         if (ret)
 116                 goto err_assert_bus;
 117         ret = reset_control_deassert(sfctemp->rst_sense);
 118         if (ret)
 119                 goto err_disable_sense;
 120
 121         sfctemp_power_up(sfctemp);
 122         sfctemp->enabled = true;
 123 done:
 124         mutex_unlock(&sfctemp->lock);
 125         return ret;
 126
 127 err_disable_sense:
 128         clk_disable_unprepare(sfctemp->clk_sense);
 129 err_assert_bus:
 130         reset_control_assert(sfctemp->rst_bus);
 131 err_disable_bus:
 132         clk_disable_unprepare(sfctemp->clk_bus);
 133 err:
 134         mutex_unlock(&sfctemp->lock);
 135         return ret;
 136 }
 137
 138 static int sfctemp_disable(struct sfctemp *sfctemp)
 139 {
 140         mutex_lock(&sfctemp->lock);
 141         if (!sfctemp->enabled)
 142                 goto done;
 143
 144         sfctemp_power_down(sfctemp);
 145         reset_control_assert(sfctemp->rst_sense);
 146         clk_disable_unprepare(sfctemp->clk_sense);
 147         reset_control_assert(sfctemp->rst_bus);
 148         clk_disable_unprepare(sfctemp->clk_bus);
 149         sfctemp->enabled = false;
 150 done:
 151         mutex_unlock(&sfctemp->lock);
 152         return 0;
 153 }
 154
 155 static void sfctemp_disable_action(void *data)
 156 {
 157         sfctemp_disable(data);
 158 }
 159
 160 static int sfctemp_convert(struct sfctemp *sfctemp, long *val)
 161 {
 162         int ret;
 163
 164         mutex_lock(&sfctemp->lock);
 165         if (!sfctemp->enabled) {
 166                 ret = -ENODATA;
 167                 goto out;
 168         }
 169
 170         sfctemp_run_single(sfctemp);
 171
 172         ret = wait_for_completion_interruptible_timeout(&sfctemp->conversion_done,
 173                                                         msecs_to_jiffies(10));
 174         if (ret <= 0) {
 175                 if (ret == 0)
 176                         ret = -ETIMEDOUT;
 177                 goto out;
 178         }
 179
 180         /* calculate temperature in milli Celcius */
 181         *val = (long)((readl(sfctemp->regs) & SFCTEMP_DOUT_MSK) >> SFCTEMP_DOUT_POS)
 182                 * SFCTEMP_Y1000 / SFCTEMP_Z - SFCTEMP_K1000;
 183
 184         ret = 0;
 185 out:
 186         mutex_unlock(&sfctemp->lock);
 187         return ret;
 188 }
 189
 190 static umode_t sfctemp_is_visible(const void *data, enum hwmon_sensor_types type,
 191                                   u32 attr, int channel)
 192 {
 193         switch (type) {
 194         case hwmon_temp:
 195                 switch (attr) {
 196                 case hwmon_temp_enable:
 197                         return 0644;
 198                 case hwmon_temp_input:
 199                         return 0444;
 200                 }
 201                 return 0;
 202         default:
 203                 return 0;
 204         }
 205 }
 206
 207 static int sfctemp_read(struct device *dev, enum hwmon_sensor_types type,
 208                         u32 attr, int channel, long *val)
 209 {
 210         struct sfctemp *sfctemp = dev_get_drvdata(dev);
 211         int ret;
 212
 213         ret = pm_runtime_get_sync(dev);
 214
 215         switch (type) {
 216         case hwmon_temp:
 217                 switch (attr) {
 218                 case hwmon_temp_enable:
 219                         *val = sfctemp->enabled;
 220                         pm_runtime_put(dev);
 221                         return 0;
 222                 case hwmon_temp_input:
 223                         ret = sfctemp_convert(sfctemp, val);
 224                         pm_runtime_put(dev);
 225                         return ret;
 226                 }
 227                 pm_runtime_put(dev);
 228                 return -EINVAL;
 229         default:
 230                 pm_runtime_put(dev);
 231                 return -EINVAL;
 232         }
 233 }
 234
 235 static int sfctemp_write(struct device *dev, enum hwmon_sensor_types type,
 236                          u32 attr, int channel, long val)
 237 {
 238         struct sfctemp *sfctemp = dev_get_drvdata(dev);
 239
 240         switch (type) {
 241         case hwmon_temp:
 242                 switch (attr) {
 243                 case hwmon_temp_enable:
 244                         if (val == 0)
 245                                 return sfctemp_disable(sfctemp);
 246                         if (val == 1)
 247                                 return sfctemp_enable(sfctemp);
 248                         break;
 249                 }
 250                 return -EINVAL;
 251         default:
 252                 return -EINVAL;
 253         }
 254 }
 255
 256 static const struct hwmon_channel_info *sfctemp_info[] = {
 257         HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
 258         HWMON_CHANNEL_INFO(temp, HWMON_T_ENABLE | HWMON_T_INPUT),
 259         NULL
 260 };
 261
 262 static const struct hwmon_ops sfctemp_hwmon_ops = {
 263         .is_visible = sfctemp_is_visible,
 264         .read = sfctemp_read,
 265         .write = sfctemp_write,
 266 };
 267
 268 static const struct hwmon_chip_info sfctemp_chip_info = {
 269         .ops = &sfctemp_hwmon_ops,
 270         .info = sfctemp_info,
 271 };
 272
 273 static int sfctemp_probe(struct platform_device *pdev)
 274 {
 275         struct device *dev = &pdev->dev;
 276         struct device *hwmon_dev;
 277         struct sfctemp *sfctemp;
 278         int ret;
 279
 280         sfctemp = devm_kzalloc(dev, sizeof(*sfctemp), GFP_KERNEL);
 281         if (!sfctemp)
 282                 return -ENOMEM;
 283
 284         dev_set_drvdata(dev, sfctemp);
 285         mutex_init(&sfctemp->lock);
 286         init_completion(&sfctemp->conversion_done);
 287
 288         sfctemp->regs = devm_platform_ioremap_resource(pdev, 0);
 289         if (IS_ERR(sfctemp->regs))
 290                 return PTR_ERR(sfctemp->regs);
 291
 292         sfctemp->clk_sense = devm_clk_get(dev, "sense");
 293         if (IS_ERR(sfctemp->clk_sense))
 294                 return dev_err_probe(dev, PTR_ERR(sfctemp->clk_sense),
 295                                      "error getting sense clock\n");
 296
 297         sfctemp->clk_bus = devm_clk_get(dev, "bus");
 298         if (IS_ERR(sfctemp->clk_bus))
 299                 return dev_err_probe(dev, PTR_ERR(sfctemp->clk_bus),
 300                                      "error getting bus clock\n");
 301
 302         sfctemp->rst_sense = devm_reset_control_get_exclusive(dev, "sense");
 303         if (IS_ERR(sfctemp->rst_sense))
 304                 return dev_err_probe(dev, PTR_ERR(sfctemp->rst_sense),
 305                                      "error getting sense reset\n");
 306
 307         sfctemp->rst_bus = devm_reset_control_get_exclusive(dev, "bus");
 308         if (IS_ERR(sfctemp->rst_bus))
 309                 return dev_err_probe(dev, PTR_ERR(sfctemp->rst_bus),
 310                                      "error getting busreset\n");
 311
 312         ret = reset_control_assert(sfctemp->rst_sense);
 313         if (ret)
 314                 return dev_err_probe(dev, ret, "error asserting sense reset\n");
 315
 316         ret = reset_control_assert(sfctemp->rst_bus);
 317         if (ret)
 318                 return dev_err_probe(dev, ret, "error asserting bus reset\n");
 319
 320         ret = platform_get_irq(pdev, 0);
 321         if (ret < 0)
 322                 return ret;
 323
 324         ret = devm_request_irq(dev, ret, sfctemp_isr, 0, pdev->name, sfctemp);
 325         if (ret)
 326                 return dev_err_probe(dev, ret, "error requesting irq\n");
 327
 328         ret = devm_add_action(dev, sfctemp_disable_action, sfctemp);
 329         if (ret)
 330                 return ret;
 331
 332         ret = sfctemp_enable(sfctemp);
 333         if (ret)
 334                 return dev_err_probe(dev, ret, "error enabling temperature sensor: %d\n", ret);
 335
 336         hwmon_dev = devm_hwmon_device_register_with_info(dev, pdev->name, sfctemp,
 337                                                          &sfctemp_chip_info, NULL);
 338
 339         pm_runtime_enable(hwmon_dev);
 340         pm_runtime_enable(dev);
 341
 342         sfctemp_disable(sfctemp);
 343
 344         return PTR_ERR_OR_ZERO(hwmon_dev);
 345 }
 346
 347 #ifdef CONFIG_PM
 348
 349 static int starfive_temp_suspend(struct device *dev)
 350 {
 351         struct sfctemp *sfctemp = dev_get_drvdata(dev);
 352
 353         dev_dbg(dev, "starfive temp runtime suspend");
 354
 355         return sfctemp_disable(sfctemp);
 356 }
 357
 358 static int starfive_temp_resume(struct device *dev)
 359 {
 360         struct sfctemp *sfctemp = dev_get_drvdata(dev);
 361
 362         dev_dbg(dev, "starfive temp runtime resume");
 363
 364         return sfctemp_enable(sfctemp);
 365 }
 366 #endif /* CONFIG_PM */
 367
 368 static const struct dev_pm_ops sfctemp_dev_pm_ops = {
 369         SET_RUNTIME_PM_OPS(starfive_temp_suspend, starfive_temp_resume, NULL)
 370         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
 371 };
 372
 373 static const struct of_device_id sfctemp_of_match[] = {
 374         { .compatible = "starfive,jh7100-temp" },
 375         { .compatible = "starfive,jh7110-temp" },
 376         { /* sentinel */ }
 377 };
 378 MODULE_DEVICE_TABLE(of, sfctemp_of_match);
 379
 380 static struct platform_driver sfctemp_driver = {
 381         .probe  = sfctemp_probe,
 382         .driver = {
 383                 .name = "sfctemp",
 384                 .of_match_table = sfctemp_of_match,
 385                 .pm   = &sfctemp_dev_pm_ops,
 386         },
 387 };
 388 module_platform_driver(sfctemp_driver);
 389
 390 MODULE_AUTHOR("Emil Renner Berthing");
 391 MODULE_DESCRIPTION("StarFive JH7100 temperature sensor driver");
 392 MODULE_LICENSE("GPL");