tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
33struct pm8916_wdt {
34 struct regmap *regmap;
35 struct watchdog_device wdev;
36 u32 baseaddr;
37};
38
39static 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
48static 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
57static 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
66static 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
82static 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
90static 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
98static 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
113static const struct watchdog_info pm8916_wdt_ident = {
114 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
115 .identity = "QCOM PM8916 PON WDT",
116};
117
118static 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
124static 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
133static 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 if (devm_request_irq(dev, irq, pm8916_wdt_isr, 0, "pm8916_wdt",
167 wdt))
168 irq = 0;
169 }
170
171 /* Configure watchdog to hard-reset mode */
172 err = regmap_write(wdt->regmap,
173 wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL,
174 RESET_TYPE_HARD);
175 if (err) {
176 dev_err(dev, "failed configure watchdog\n");
177 return err;
178 }
179
180 wdt->wdev.info = (irq > 0) ? &pm8916_wdt_pt_ident : &pm8916_wdt_ident,
181 wdt->wdev.ops = &pm8916_wdt_ops,
182 wdt->wdev.parent = dev;
183 wdt->wdev.min_timeout = PM8916_WDT_MIN_TIMEOUT;
184 wdt->wdev.max_timeout = PM8916_WDT_MAX_TIMEOUT;
185 wdt->wdev.timeout = PM8916_WDT_DEFAULT_TIMEOUT;
186 wdt->wdev.pretimeout = 0;
187 watchdog_set_drvdata(&wdt->wdev, wdt);
188
189 watchdog_init_timeout(&wdt->wdev, 0, dev);
190 pm8916_wdt_configure_timers(&wdt->wdev);
191
192 return devm_watchdog_register_device(dev, &wdt->wdev);
193}
194
195static const struct of_device_id pm8916_wdt_id_table[] = {
196 { .compatible = "qcom,pm8916-wdt" },
197 { }
198};
199MODULE_DEVICE_TABLE(of, pm8916_wdt_id_table);
200
201static struct platform_driver pm8916_wdt_driver = {
202 .probe = pm8916_wdt_probe,
203 .driver = {
204 .name = "pm8916-wdt",
205 .of_match_table = of_match_ptr(pm8916_wdt_id_table),
206 },
207};
208module_platform_driver(pm8916_wdt_driver);
209
210MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>");
211MODULE_DESCRIPTION("Qualcomm pm8916 watchdog driver");
212MODULE_LICENSE("GPL v2");