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