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
pm8916_wdt_start(struct watchdog_device * wdev)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
pm8916_wdt_stop(struct watchdog_device * wdev)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
pm8916_wdt_ping(struct watchdog_device * wdev)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
pm8916_wdt_configure_timers(struct watchdog_device * wdev)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
pm8916_wdt_set_timeout(struct watchdog_device * wdev,unsigned int timeout)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
pm8916_wdt_set_pretimeout(struct watchdog_device * wdev,unsigned int pretimeout)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
pm8916_wdt_isr(int irq,void * arg)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
pm8916_wdt_probe(struct platform_device * pdev)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
196 watchdog_init_timeout(&wdt->wdev, 0, dev);
197 pm8916_wdt_configure_timers(&wdt->wdev);
198
199 return devm_watchdog_register_device(dev, &wdt->wdev);
200 }
201
202 static const struct of_device_id pm8916_wdt_id_table[] = {
203 { .compatible = "qcom,pm8916-wdt" },
204 { }
205 };
206 MODULE_DEVICE_TABLE(of, pm8916_wdt_id_table);
207
208 static struct platform_driver pm8916_wdt_driver = {
209 .probe = pm8916_wdt_probe,
210 .driver = {
211 .name = "pm8916-wdt",
212 .of_match_table = of_match_ptr(pm8916_wdt_id_table),
213 },
214 };
215 module_platform_driver(pm8916_wdt_driver);
216
217 MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>");
218 MODULE_DESCRIPTION("Qualcomm pm8916 watchdog driver");
219 MODULE_LICENSE("GPL v2");
220