drivers/watchdog/pm8916_wdt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/bitops.h>
   3 #include <linux/interrupt.h>
   4 #include <linux/kernel.h>
   5 #include <linux/module.h>
   6 #include <linux/of.h>
   7 #include <linux/property.h>
   8 #include <linux/platform_device.h>
   9 #include <linux/regmap.h>
  10 #include <linux/watchdog.h>
  11
  12 #define PON_POFF_REASON1                0x0c
  13 #define PON_POFF_REASON1_PMIC_WD        BIT(2)
  14 #define PON_POFF_REASON2                0x0d
  15 #define PON_POFF_REASON2_UVLO           BIT(5)
  16 #define PON_POFF_REASON2_OTST3          BIT(6)
  17
  18 #define PON_INT_RT_STS                  0x10
  19 #define PMIC_WD_BARK_STS_BIT            BIT(6)
  20
  21 #define PON_PMIC_WD_RESET_S1_TIMER      0x54
  22 #define PON_PMIC_WD_RESET_S2_TIMER      0x55
  23
  24 #define PON_PMIC_WD_RESET_S2_CTL        0x56
  25 #define RESET_TYPE_WARM                 0x01
  26 #define RESET_TYPE_SHUTDOWN             0x04
  27 #define RESET_TYPE_HARD                 0x07
  28
  29 #define PON_PMIC_WD_RESET_S2_CTL2       0x57
  30 #define S2_RESET_EN_BIT                 BIT(7)
  31
  32 #define PON_PMIC_WD_RESET_PET           0x58
  33 #define WATCHDOG_PET_BIT                BIT(0)
  34
  35 #define PM8916_WDT_DEFAULT_TIMEOUT      32
  36 #define PM8916_WDT_MIN_TIMEOUT          1
  37 #define PM8916_WDT_MAX_TIMEOUT          127
  38
  39 struct pm8916_wdt {
  40         struct regmap *regmap;
  41         struct watchdog_device wdev;
  42         u32 baseaddr;
  43 };
  44
  45 static int pm8916_wdt_start(struct watchdog_device *wdev)
  46 {
  47         struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
  48
  49         return regmap_update_bits(wdt->regmap,
  50                                   wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL2,
  51                                   S2_RESET_EN_BIT, S2_RESET_EN_BIT);
  52 }
  53
  54 static int pm8916_wdt_stop(struct watchdog_device *wdev)
  55 {
  56         struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
  57
  58         return regmap_update_bits(wdt->regmap,
  59                                   wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL2,
  60                                   S2_RESET_EN_BIT, 0);
  61 }
  62
  63 static int pm8916_wdt_ping(struct watchdog_device *wdev)
  64 {
  65         struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
  66
  67         return regmap_write(wdt->regmap, wdt->baseaddr + PON_PMIC_WD_RESET_PET,
  68                             WATCHDOG_PET_BIT);
  69 }
  70
  71 static int pm8916_wdt_configure_timers(struct watchdog_device *wdev)
  72 {
  73         struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
  74         int err;
  75
  76         err = regmap_write(wdt->regmap,
  77                            wdt->baseaddr + PON_PMIC_WD_RESET_S1_TIMER,
  78                            wdev->timeout - wdev->pretimeout);
  79         if (err)
  80                 return err;
  81
  82         return regmap_write(wdt->regmap,
  83                             wdt->baseaddr + PON_PMIC_WD_RESET_S2_TIMER,
  84                             wdev->pretimeout);
  85 }
  86
  87 static int pm8916_wdt_set_timeout(struct watchdog_device *wdev,
  88                                   unsigned int timeout)
  89 {
  90         wdev->timeout = timeout;
  91
  92         return pm8916_wdt_configure_timers(wdev);
  93 }
  94
  95 static int pm8916_wdt_set_pretimeout(struct watchdog_device *wdev,
  96                                      unsigned int pretimeout)
  97 {
  98         wdev->pretimeout = pretimeout;
  99
 100         return pm8916_wdt_configure_timers(wdev);
 101 }
 102
 103 static irqreturn_t pm8916_wdt_isr(int irq, void *arg)
 104 {
 105         struct pm8916_wdt *wdt = arg;
 106         int err, sts;
 107
 108         err = regmap_read(wdt->regmap, wdt->baseaddr + PON_INT_RT_STS, &sts);
 109         if (err)
 110                 return IRQ_HANDLED;
 111
 112         if (sts & PMIC_WD_BARK_STS_BIT)
 113                 watchdog_notify_pretimeout(&wdt->wdev);
 114
 115         return IRQ_HANDLED;
 116 }
 117
 118 static const struct watchdog_info pm8916_wdt_ident = {
 119         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE |
 120                    WDIOF_OVERHEAT | WDIOF_CARDRESET | WDIOF_POWERUNDER,
 121         .identity = "QCOM PM8916 PON WDT",
 122 };
 123
 124 static const struct watchdog_info pm8916_wdt_pt_ident = {
 125         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE |
 126                    WDIOF_OVERHEAT | WDIOF_CARDRESET | WDIOF_POWERUNDER |
 127                    WDIOF_PRETIMEOUT,
 128         .identity = "QCOM PM8916 PON WDT",
 129 };
 130
 131 static const struct watchdog_ops pm8916_wdt_ops = {
 132         .owner = THIS_MODULE,
 133         .start = pm8916_wdt_start,
 134         .stop = pm8916_wdt_stop,
 135         .ping = pm8916_wdt_ping,
 136         .set_timeout = pm8916_wdt_set_timeout,
 137         .set_pretimeout = pm8916_wdt_set_pretimeout,
 138 };
 139
 140 static int pm8916_wdt_probe(struct platform_device *pdev)
 141 {
 142         struct device *dev = &pdev->dev;
 143         struct pm8916_wdt *wdt;
 144         struct device *parent;
 145         unsigned int val;
 146         int err, irq;
 147         u8 poff[2];
 148
 149         wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
 150         if (!wdt)
 151                 return -ENOMEM;
 152
 153         parent = dev->parent;
 154
 155         /*
 156          * The pm8916-pon-wdt is a child of the pon device, which is a child
 157          * of the pm8916 mfd device. We want access to the pm8916 registers.
 158          * Retrieve regmap from pm8916 (parent->parent) and base address
 159          * from pm8916-pon (pon).
 160          */
 161         wdt->regmap = dev_get_regmap(parent->parent, NULL);
 162         if (!wdt->regmap) {
 163                 dev_err(dev, "failed to locate regmap\n");
 164                 return -ENODEV;
 165         }
 166
 167         err = device_property_read_u32(parent, "reg", &wdt->baseaddr);
 168         if (err) {
 169                 dev_err(dev, "failed to get pm8916-pon address\n");
 170                 return err;
 171         }
 172
 173         irq = platform_get_irq(pdev, 0);
 174         if (irq > 0) {
 175                 err = devm_request_irq(dev, irq, pm8916_wdt_isr, 0,
 176                                        "pm8916_wdt", wdt);
 177                 if (err)
 178                         return err;
 179
 180                 wdt->wdev.info = &pm8916_wdt_pt_ident;
 181         } else {
 182                 if (irq == -EPROBE_DEFER)
 183                         return -EPROBE_DEFER;
 184
 185                 wdt->wdev.info = &pm8916_wdt_ident;
 186         }
 187
 188         err = regmap_bulk_read(wdt->regmap, wdt->baseaddr + PON_POFF_REASON1,
 189                                &poff, ARRAY_SIZE(poff));
 190         if (err) {
 191                 dev_err(dev, "failed to read POFF reason: %d\n", err);
 192                 return err;
 193         }
 194
 195         dev_dbg(dev, "POFF reason: %#x %#x\n", poff[0], poff[1]);
 196         if (poff[0] & PON_POFF_REASON1_PMIC_WD)
 197                 wdt->wdev.bootstatus |= WDIOF_CARDRESET;
 198         if (poff[1] & PON_POFF_REASON2_UVLO)
 199                 wdt->wdev.bootstatus |= WDIOF_POWERUNDER;
 200         if (poff[1] & PON_POFF_REASON2_OTST3)
 201                 wdt->wdev.bootstatus |= WDIOF_OVERHEAT;
 202
 203         err = regmap_read(wdt->regmap, wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL2,
 204                           &val);
 205         if (err)  {
 206                 dev_err(dev, "failed to check if watchdog is active: %d\n", err);
 207                 return err;
 208         }
 209         if (val & S2_RESET_EN_BIT)
 210                 set_bit(WDOG_HW_RUNNING, &wdt->wdev.status);
 211
 212         /* Configure watchdog to hard-reset mode */
 213         err = regmap_write(wdt->regmap,
 214                            wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL,
 215                            RESET_TYPE_HARD);
 216         if (err) {
 217                 dev_err(dev, "failed configure watchdog\n");
 218                 return err;
 219         }
 220
 221         wdt->wdev.ops = &pm8916_wdt_ops,
 222         wdt->wdev.parent = dev;
 223         wdt->wdev.min_timeout = PM8916_WDT_MIN_TIMEOUT;
 224         wdt->wdev.max_timeout = PM8916_WDT_MAX_TIMEOUT;
 225         wdt->wdev.timeout = PM8916_WDT_DEFAULT_TIMEOUT;
 226         wdt->wdev.pretimeout = 0;
 227         watchdog_set_drvdata(&wdt->wdev, wdt);
 228         platform_set_drvdata(pdev, wdt);
 229
 230         watchdog_init_timeout(&wdt->wdev, 0, dev);
 231         pm8916_wdt_configure_timers(&wdt->wdev);
 232
 233         return devm_watchdog_register_device(dev, &wdt->wdev);
 234 }
 235
 236 static int __maybe_unused pm8916_wdt_suspend(struct device *dev)
 237 {
 238         struct pm8916_wdt *wdt = dev_get_drvdata(dev);
 239
 240         if (watchdog_active(&wdt->wdev))
 241                 return pm8916_wdt_stop(&wdt->wdev);
 242
 243         return 0;
 244 }
 245
 246 static int __maybe_unused pm8916_wdt_resume(struct device *dev)
 247 {
 248         struct pm8916_wdt *wdt = dev_get_drvdata(dev);
 249
 250         if (watchdog_active(&wdt->wdev))
 251                 return pm8916_wdt_start(&wdt->wdev);
 252
 253         return 0;
 254 }
 255
 256 static SIMPLE_DEV_PM_OPS(pm8916_wdt_pm_ops, pm8916_wdt_suspend,
 257                          pm8916_wdt_resume);
 258
 259 static const struct of_device_id pm8916_wdt_id_table[] = {
 260         { .compatible = "qcom,pm8916-wdt" },
 261         { }
 262 };
 263 MODULE_DEVICE_TABLE(of, pm8916_wdt_id_table);
 264
 265 static struct platform_driver pm8916_wdt_driver = {
 266         .probe = pm8916_wdt_probe,
 267         .driver = {
 268                 .name = "pm8916-wdt",
 269                 .of_match_table = pm8916_wdt_id_table,
 270                 .pm = &pm8916_wdt_pm_ops,
 271         },
 272 };
 273 module_platform_driver(pm8916_wdt_driver);
 274
 275 MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>");
 276 MODULE_DESCRIPTION("Qualcomm pm8916 watchdog driver");
 277 MODULE_LICENSE("GPL v2");