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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2015 Broadcom Corporation
4 *
5 */
6
7#include <linux/clk.h>
8#include <linux/init.h>
9#include <linux/io.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/platform_data/bcm7038_wdt.h>
14#include <linux/pm.h>
15#include <linux/watchdog.h>
16
17#define WDT_START_1 0xff00
18#define WDT_START_2 0x00ff
19#define WDT_STOP_1 0xee00
20#define WDT_STOP_2 0x00ee
21
22#define WDT_TIMEOUT_REG 0x0
23#define WDT_CMD_REG 0x4
24
25#define WDT_MIN_TIMEOUT 1 /* seconds */
26#define WDT_DEFAULT_TIMEOUT 30 /* seconds */
27#define WDT_DEFAULT_RATE 27000000
28
29struct bcm7038_watchdog {
30 void __iomem *base;
31 struct watchdog_device wdd;
32 u32 rate;
33 struct clk *clk;
34};
35
36static bool nowayout = WATCHDOG_NOWAYOUT;
37
38static inline void bcm7038_wdt_write(u32 value, void __iomem *addr)
39{
40 /* MIPS chips strapped for BE will automagically configure the
41 * peripheral registers for CPU-native byte order.
42 */
43 if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
44 __raw_writel(value, addr);
45 else
46 writel_relaxed(value, addr);
47}
48
49static inline u32 bcm7038_wdt_read(void __iomem *addr)
50{
51 if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
52 return __raw_readl(addr);
53 else
54 return readl_relaxed(addr);
55}
56
57static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog)
58{
59 struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
60 u32 timeout;
61
62 timeout = wdt->rate * wdog->timeout;
63
64 bcm7038_wdt_write(timeout, wdt->base + WDT_TIMEOUT_REG);
65}
66
67static int bcm7038_wdt_ping(struct watchdog_device *wdog)
68{
69 struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
70
71 bcm7038_wdt_write(WDT_START_1, wdt->base + WDT_CMD_REG);
72 bcm7038_wdt_write(WDT_START_2, wdt->base + WDT_CMD_REG);
73
74 return 0;
75}
76
77static int bcm7038_wdt_start(struct watchdog_device *wdog)
78{
79 bcm7038_wdt_set_timeout_reg(wdog);
80 bcm7038_wdt_ping(wdog);
81
82 return 0;
83}
84
85static int bcm7038_wdt_stop(struct watchdog_device *wdog)
86{
87 struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
88
89 bcm7038_wdt_write(WDT_STOP_1, wdt->base + WDT_CMD_REG);
90 bcm7038_wdt_write(WDT_STOP_2, wdt->base + WDT_CMD_REG);
91
92 return 0;
93}
94
95static int bcm7038_wdt_set_timeout(struct watchdog_device *wdog,
96 unsigned int t)
97{
98 /* Can't modify timeout value if watchdog timer is running */
99 bcm7038_wdt_stop(wdog);
100 wdog->timeout = t;
101 bcm7038_wdt_start(wdog);
102
103 return 0;
104}
105
106static unsigned int bcm7038_wdt_get_timeleft(struct watchdog_device *wdog)
107{
108 struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
109 u32 time_left;
110
111 time_left = bcm7038_wdt_read(wdt->base + WDT_CMD_REG);
112
113 return time_left / wdt->rate;
114}
115
116static const struct watchdog_info bcm7038_wdt_info = {
117 .identity = "Broadcom BCM7038 Watchdog Timer",
118 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
119 WDIOF_MAGICCLOSE
120};
121
122static const struct watchdog_ops bcm7038_wdt_ops = {
123 .owner = THIS_MODULE,
124 .start = bcm7038_wdt_start,
125 .stop = bcm7038_wdt_stop,
126 .set_timeout = bcm7038_wdt_set_timeout,
127 .get_timeleft = bcm7038_wdt_get_timeleft,
128};
129
130static void bcm7038_clk_disable_unprepare(void *data)
131{
132 clk_disable_unprepare(data);
133}
134
135static int bcm7038_wdt_probe(struct platform_device *pdev)
136{
137 struct bcm7038_wdt_platform_data *pdata = pdev->dev.platform_data;
138 struct device *dev = &pdev->dev;
139 struct bcm7038_watchdog *wdt;
140 const char *clk_name = NULL;
141 int err;
142
143 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
144 if (!wdt)
145 return -ENOMEM;
146
147 platform_set_drvdata(pdev, wdt);
148
149 wdt->base = devm_platform_ioremap_resource(pdev, 0);
150 if (IS_ERR(wdt->base))
151 return PTR_ERR(wdt->base);
152
153 if (pdata && pdata->clk_name)
154 clk_name = pdata->clk_name;
155
156 wdt->clk = devm_clk_get(dev, clk_name);
157 /* If unable to get clock, use default frequency */
158 if (!IS_ERR(wdt->clk)) {
159 err = clk_prepare_enable(wdt->clk);
160 if (err)
161 return err;
162 err = devm_add_action_or_reset(dev,
163 bcm7038_clk_disable_unprepare,
164 wdt->clk);
165 if (err)
166 return err;
167 wdt->rate = clk_get_rate(wdt->clk);
168 /* Prevent divide-by-zero exception */
169 if (!wdt->rate)
170 wdt->rate = WDT_DEFAULT_RATE;
171 } else {
172 wdt->rate = WDT_DEFAULT_RATE;
173 wdt->clk = NULL;
174 }
175
176 wdt->wdd.info = &bcm7038_wdt_info;
177 wdt->wdd.ops = &bcm7038_wdt_ops;
178 wdt->wdd.min_timeout = WDT_MIN_TIMEOUT;
179 wdt->wdd.timeout = WDT_DEFAULT_TIMEOUT;
180 wdt->wdd.max_timeout = 0xffffffff / wdt->rate;
181 wdt->wdd.parent = dev;
182 watchdog_set_drvdata(&wdt->wdd, wdt);
183
184 watchdog_stop_on_reboot(&wdt->wdd);
185 watchdog_stop_on_unregister(&wdt->wdd);
186 err = devm_watchdog_register_device(dev, &wdt->wdd);
187 if (err)
188 return err;
189
190 dev_info(dev, "Registered BCM7038 Watchdog\n");
191
192 return 0;
193}
194
195static int bcm7038_wdt_suspend(struct device *dev)
196{
197 struct bcm7038_watchdog *wdt = dev_get_drvdata(dev);
198
199 if (watchdog_active(&wdt->wdd))
200 return bcm7038_wdt_stop(&wdt->wdd);
201
202 return 0;
203}
204
205static int bcm7038_wdt_resume(struct device *dev)
206{
207 struct bcm7038_watchdog *wdt = dev_get_drvdata(dev);
208
209 if (watchdog_active(&wdt->wdd))
210 return bcm7038_wdt_start(&wdt->wdd);
211
212 return 0;
213}
214
215static DEFINE_SIMPLE_DEV_PM_OPS(bcm7038_wdt_pm_ops,
216 bcm7038_wdt_suspend, bcm7038_wdt_resume);
217
218static const struct of_device_id bcm7038_wdt_match[] = {
219 { .compatible = "brcm,bcm6345-wdt" },
220 { .compatible = "brcm,bcm7038-wdt" },
221 {},
222};
223MODULE_DEVICE_TABLE(of, bcm7038_wdt_match);
224
225static const struct platform_device_id bcm7038_wdt_devtype[] = {
226 { .name = "bcm63xx-wdt" },
227 { /* sentinel */ },
228};
229MODULE_DEVICE_TABLE(platform, bcm7038_wdt_devtype);
230
231static struct platform_driver bcm7038_wdt_driver = {
232 .probe = bcm7038_wdt_probe,
233 .id_table = bcm7038_wdt_devtype,
234 .driver = {
235 .name = "bcm7038-wdt",
236 .of_match_table = bcm7038_wdt_match,
237 .pm = pm_sleep_ptr(&bcm7038_wdt_pm_ops),
238 }
239};
240module_platform_driver(bcm7038_wdt_driver);
241
242module_param(nowayout, bool, 0);
243MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
244 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
245MODULE_LICENSE("GPL");
246MODULE_DESCRIPTION("Driver for Broadcom 7038 SoCs Watchdog");
247MODULE_AUTHOR("Justin Chen");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2015 Broadcom Corporation
4 *
5 */
6
7#include <linux/clk.h>
8#include <linux/init.h>
9#include <linux/io.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/pm.h>
14#include <linux/watchdog.h>
15
16#define WDT_START_1 0xff00
17#define WDT_START_2 0x00ff
18#define WDT_STOP_1 0xee00
19#define WDT_STOP_2 0x00ee
20
21#define WDT_TIMEOUT_REG 0x0
22#define WDT_CMD_REG 0x4
23
24#define WDT_MIN_TIMEOUT 1 /* seconds */
25#define WDT_DEFAULT_TIMEOUT 30 /* seconds */
26#define WDT_DEFAULT_RATE 27000000
27
28struct bcm7038_watchdog {
29 void __iomem *base;
30 struct watchdog_device wdd;
31 u32 rate;
32 struct clk *clk;
33};
34
35static bool nowayout = WATCHDOG_NOWAYOUT;
36
37static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog)
38{
39 struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
40 u32 timeout;
41
42 timeout = wdt->rate * wdog->timeout;
43
44 writel(timeout, wdt->base + WDT_TIMEOUT_REG);
45}
46
47static int bcm7038_wdt_ping(struct watchdog_device *wdog)
48{
49 struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
50
51 writel(WDT_START_1, wdt->base + WDT_CMD_REG);
52 writel(WDT_START_2, wdt->base + WDT_CMD_REG);
53
54 return 0;
55}
56
57static int bcm7038_wdt_start(struct watchdog_device *wdog)
58{
59 bcm7038_wdt_set_timeout_reg(wdog);
60 bcm7038_wdt_ping(wdog);
61
62 return 0;
63}
64
65static int bcm7038_wdt_stop(struct watchdog_device *wdog)
66{
67 struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
68
69 writel(WDT_STOP_1, wdt->base + WDT_CMD_REG);
70 writel(WDT_STOP_2, wdt->base + WDT_CMD_REG);
71
72 return 0;
73}
74
75static int bcm7038_wdt_set_timeout(struct watchdog_device *wdog,
76 unsigned int t)
77{
78 /* Can't modify timeout value if watchdog timer is running */
79 bcm7038_wdt_stop(wdog);
80 wdog->timeout = t;
81 bcm7038_wdt_start(wdog);
82
83 return 0;
84}
85
86static unsigned int bcm7038_wdt_get_timeleft(struct watchdog_device *wdog)
87{
88 struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog);
89 u32 time_left;
90
91 time_left = readl(wdt->base + WDT_CMD_REG);
92
93 return time_left / wdt->rate;
94}
95
96static const struct watchdog_info bcm7038_wdt_info = {
97 .identity = "Broadcom BCM7038 Watchdog Timer",
98 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
99 WDIOF_MAGICCLOSE
100};
101
102static const struct watchdog_ops bcm7038_wdt_ops = {
103 .owner = THIS_MODULE,
104 .start = bcm7038_wdt_start,
105 .stop = bcm7038_wdt_stop,
106 .set_timeout = bcm7038_wdt_set_timeout,
107 .get_timeleft = bcm7038_wdt_get_timeleft,
108};
109
110static void bcm7038_clk_disable_unprepare(void *data)
111{
112 clk_disable_unprepare(data);
113}
114
115static int bcm7038_wdt_probe(struct platform_device *pdev)
116{
117 struct device *dev = &pdev->dev;
118 struct bcm7038_watchdog *wdt;
119 int err;
120
121 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
122 if (!wdt)
123 return -ENOMEM;
124
125 platform_set_drvdata(pdev, wdt);
126
127 wdt->base = devm_platform_ioremap_resource(pdev, 0);
128 if (IS_ERR(wdt->base))
129 return PTR_ERR(wdt->base);
130
131 wdt->clk = devm_clk_get(dev, NULL);
132 /* If unable to get clock, use default frequency */
133 if (!IS_ERR(wdt->clk)) {
134 err = clk_prepare_enable(wdt->clk);
135 if (err)
136 return err;
137 err = devm_add_action_or_reset(dev,
138 bcm7038_clk_disable_unprepare,
139 wdt->clk);
140 if (err)
141 return err;
142 wdt->rate = clk_get_rate(wdt->clk);
143 /* Prevent divide-by-zero exception */
144 if (!wdt->rate)
145 wdt->rate = WDT_DEFAULT_RATE;
146 } else {
147 wdt->rate = WDT_DEFAULT_RATE;
148 wdt->clk = NULL;
149 }
150
151 wdt->wdd.info = &bcm7038_wdt_info;
152 wdt->wdd.ops = &bcm7038_wdt_ops;
153 wdt->wdd.min_timeout = WDT_MIN_TIMEOUT;
154 wdt->wdd.timeout = WDT_DEFAULT_TIMEOUT;
155 wdt->wdd.max_timeout = 0xffffffff / wdt->rate;
156 wdt->wdd.parent = dev;
157 watchdog_set_drvdata(&wdt->wdd, wdt);
158
159 watchdog_stop_on_reboot(&wdt->wdd);
160 watchdog_stop_on_unregister(&wdt->wdd);
161 err = devm_watchdog_register_device(dev, &wdt->wdd);
162 if (err)
163 return err;
164
165 dev_info(dev, "Registered BCM7038 Watchdog\n");
166
167 return 0;
168}
169
170#ifdef CONFIG_PM_SLEEP
171static int bcm7038_wdt_suspend(struct device *dev)
172{
173 struct bcm7038_watchdog *wdt = dev_get_drvdata(dev);
174
175 if (watchdog_active(&wdt->wdd))
176 return bcm7038_wdt_stop(&wdt->wdd);
177
178 return 0;
179}
180
181static int bcm7038_wdt_resume(struct device *dev)
182{
183 struct bcm7038_watchdog *wdt = dev_get_drvdata(dev);
184
185 if (watchdog_active(&wdt->wdd))
186 return bcm7038_wdt_start(&wdt->wdd);
187
188 return 0;
189}
190#endif
191
192static SIMPLE_DEV_PM_OPS(bcm7038_wdt_pm_ops, bcm7038_wdt_suspend,
193 bcm7038_wdt_resume);
194
195static const struct of_device_id bcm7038_wdt_match[] = {
196 { .compatible = "brcm,bcm7038-wdt" },
197 {},
198};
199MODULE_DEVICE_TABLE(of, bcm7038_wdt_match);
200
201static struct platform_driver bcm7038_wdt_driver = {
202 .probe = bcm7038_wdt_probe,
203 .driver = {
204 .name = "bcm7038-wdt",
205 .of_match_table = bcm7038_wdt_match,
206 .pm = &bcm7038_wdt_pm_ops,
207 }
208};
209module_platform_driver(bcm7038_wdt_driver);
210
211module_param(nowayout, bool, 0);
212MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
213 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
214MODULE_LICENSE("GPL");
215MODULE_DESCRIPTION("Driver for Broadcom 7038 SoCs Watchdog");
216MODULE_AUTHOR("Justin Chen");