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2bdf6acb AF |
1 | /* |
2 | * Realtek RTD129x watchdog | |
3 | * | |
4 | * Copyright (c) 2017 Andreas Färber | |
5 | * | |
6 | * SPDX-License-Identifier: GPL-2.0+ | |
7 | */ | |
8 | ||
9 | #include <linux/bitops.h> | |
10 | #include <linux/clk.h> | |
11 | #include <linux/io.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/of.h> | |
14 | #include <linux/of_address.h> | |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/watchdog.h> | |
17 | ||
18 | #define RTD119X_TCWCR 0x0 | |
19 | #define RTD119X_TCWTR 0x4 | |
20 | #define RTD119X_TCWOV 0xc | |
21 | ||
22 | #define RTD119X_TCWCR_WDEN_DISABLED 0xa5 | |
23 | #define RTD119X_TCWCR_WDEN_ENABLED 0xff | |
24 | #define RTD119X_TCWCR_WDEN_MASK 0xff | |
25 | ||
26 | #define RTD119X_TCWTR_WDCLR BIT(0) | |
27 | ||
28 | struct rtd119x_watchdog_device { | |
29 | struct watchdog_device wdt_dev; | |
30 | void __iomem *base; | |
31 | struct clk *clk; | |
32 | }; | |
33 | ||
34 | static int rtd119x_wdt_start(struct watchdog_device *wdev) | |
35 | { | |
36 | struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev); | |
37 | u32 val; | |
38 | ||
39 | val = readl_relaxed(data->base + RTD119X_TCWCR); | |
40 | val &= ~RTD119X_TCWCR_WDEN_MASK; | |
41 | val |= RTD119X_TCWCR_WDEN_ENABLED; | |
42 | writel(val, data->base + RTD119X_TCWCR); | |
43 | ||
44 | return 0; | |
45 | } | |
46 | ||
47 | static int rtd119x_wdt_stop(struct watchdog_device *wdev) | |
48 | { | |
49 | struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev); | |
50 | u32 val; | |
51 | ||
52 | val = readl_relaxed(data->base + RTD119X_TCWCR); | |
53 | val &= ~RTD119X_TCWCR_WDEN_MASK; | |
54 | val |= RTD119X_TCWCR_WDEN_DISABLED; | |
55 | writel(val, data->base + RTD119X_TCWCR); | |
56 | ||
57 | return 0; | |
58 | } | |
59 | ||
60 | static int rtd119x_wdt_ping(struct watchdog_device *wdev) | |
61 | { | |
62 | struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev); | |
63 | ||
64 | writel_relaxed(RTD119X_TCWTR_WDCLR, data->base + RTD119X_TCWTR); | |
65 | ||
66 | return rtd119x_wdt_start(wdev); | |
67 | } | |
68 | ||
69 | static int rtd119x_wdt_set_timeout(struct watchdog_device *wdev, unsigned int val) | |
70 | { | |
71 | struct rtd119x_watchdog_device *data = watchdog_get_drvdata(wdev); | |
72 | ||
73 | writel(val * clk_get_rate(data->clk), data->base + RTD119X_TCWOV); | |
74 | ||
75 | data->wdt_dev.timeout = val; | |
76 | ||
77 | return 0; | |
78 | } | |
79 | ||
80 | static const struct watchdog_ops rtd119x_wdt_ops = { | |
81 | .owner = THIS_MODULE, | |
82 | .start = rtd119x_wdt_start, | |
83 | .stop = rtd119x_wdt_stop, | |
84 | .ping = rtd119x_wdt_ping, | |
85 | .set_timeout = rtd119x_wdt_set_timeout, | |
86 | }; | |
87 | ||
88 | static const struct watchdog_info rtd119x_wdt_info = { | |
89 | .identity = "rtd119x-wdt", | |
90 | .options = 0, | |
91 | }; | |
92 | ||
93 | static const struct of_device_id rtd119x_wdt_dt_ids[] = { | |
94 | { .compatible = "realtek,rtd1295-watchdog" }, | |
95 | { } | |
96 | }; | |
97 | ||
98 | static int rtd119x_wdt_probe(struct platform_device *pdev) | |
99 | { | |
100 | struct rtd119x_watchdog_device *data; | |
101 | struct resource *res; | |
102 | int ret; | |
103 | ||
104 | data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); | |
105 | if (!data) | |
106 | return -ENOMEM; | |
107 | ||
108 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
109 | data->base = devm_ioremap_resource(&pdev->dev, res); | |
110 | if (IS_ERR(data->base)) | |
111 | return PTR_ERR(data->base); | |
112 | ||
113 | data->clk = of_clk_get(pdev->dev.of_node, 0); | |
114 | if (IS_ERR(data->clk)) | |
115 | return PTR_ERR(data->clk); | |
116 | ||
117 | ret = clk_prepare_enable(data->clk); | |
118 | if (ret) { | |
119 | clk_put(data->clk); | |
120 | return ret; | |
121 | } | |
122 | ||
123 | data->wdt_dev.info = &rtd119x_wdt_info; | |
124 | data->wdt_dev.ops = &rtd119x_wdt_ops; | |
125 | data->wdt_dev.timeout = 120; | |
126 | data->wdt_dev.max_timeout = 0xffffffff / clk_get_rate(data->clk); | |
127 | data->wdt_dev.min_timeout = 1; | |
128 | data->wdt_dev.parent = &pdev->dev; | |
129 | ||
130 | watchdog_stop_on_reboot(&data->wdt_dev); | |
131 | watchdog_set_drvdata(&data->wdt_dev, data); | |
132 | platform_set_drvdata(pdev, data); | |
133 | ||
134 | writel_relaxed(RTD119X_TCWTR_WDCLR, data->base + RTD119X_TCWTR); | |
135 | rtd119x_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout); | |
136 | rtd119x_wdt_stop(&data->wdt_dev); | |
137 | ||
138 | ret = devm_watchdog_register_device(&pdev->dev, &data->wdt_dev); | |
139 | if (ret) { | |
140 | clk_disable_unprepare(data->clk); | |
141 | clk_put(data->clk); | |
142 | return ret; | |
143 | } | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | static int rtd119x_wdt_remove(struct platform_device *pdev) | |
149 | { | |
150 | struct rtd119x_watchdog_device *data = platform_get_drvdata(pdev); | |
151 | ||
152 | watchdog_unregister_device(&data->wdt_dev); | |
153 | ||
154 | clk_disable_unprepare(data->clk); | |
155 | clk_put(data->clk); | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
160 | static struct platform_driver rtd119x_wdt_driver = { | |
161 | .probe = rtd119x_wdt_probe, | |
162 | .remove = rtd119x_wdt_remove, | |
163 | .driver = { | |
164 | .name = "rtd1295-watchdog", | |
165 | .of_match_table = rtd119x_wdt_dt_ids, | |
166 | }, | |
167 | }; | |
168 | builtin_platform_driver(rtd119x_wdt_driver); |