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2e62c498 | 1 | // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause |
683fa50f | 2 | /* |
683fa50f NA |
3 | * Copyright (c) 2016 BayLibre, SAS. |
4 | * Author: Neil Armstrong <narmstrong@baylibre.com> | |
5 | * | |
683fa50f NA |
6 | */ |
7 | #include <linux/clk.h> | |
8 | #include <linux/err.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/slab.h> | |
14 | #include <linux/types.h> | |
15 | #include <linux/watchdog.h> | |
16 | ||
17 | #define DEFAULT_TIMEOUT 30 /* seconds */ | |
18 | ||
19 | #define GXBB_WDT_CTRL_REG 0x0 | |
20 | #define GXBB_WDT_TCNT_REG 0x8 | |
21 | #define GXBB_WDT_RSET_REG 0xc | |
22 | ||
23 | #define GXBB_WDT_CTRL_CLKDIV_EN BIT(25) | |
24 | #define GXBB_WDT_CTRL_CLK_EN BIT(24) | |
25 | #define GXBB_WDT_CTRL_EE_RESET BIT(21) | |
26 | #define GXBB_WDT_CTRL_EN BIT(18) | |
27 | #define GXBB_WDT_CTRL_DIV_MASK (BIT(18) - 1) | |
28 | ||
29 | #define GXBB_WDT_TCNT_SETUP_MASK (BIT(16) - 1) | |
30 | #define GXBB_WDT_TCNT_CNT_SHIFT 16 | |
31 | ||
32 | struct meson_gxbb_wdt { | |
33 | void __iomem *reg_base; | |
34 | struct watchdog_device wdt_dev; | |
35 | struct clk *clk; | |
36 | }; | |
37 | ||
38 | static int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev) | |
39 | { | |
40 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); | |
41 | ||
42 | writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN, | |
43 | data->reg_base + GXBB_WDT_CTRL_REG); | |
44 | ||
45 | return 0; | |
46 | } | |
47 | ||
48 | static int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev) | |
49 | { | |
50 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); | |
51 | ||
52 | writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN, | |
53 | data->reg_base + GXBB_WDT_CTRL_REG); | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | static int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev) | |
59 | { | |
60 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); | |
61 | ||
62 | writel(0, data->reg_base + GXBB_WDT_RSET_REG); | |
63 | ||
64 | return 0; | |
65 | } | |
66 | ||
67 | static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev, | |
68 | unsigned int timeout) | |
69 | { | |
70 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); | |
71 | unsigned long tcnt = timeout * 1000; | |
72 | ||
73 | if (tcnt > GXBB_WDT_TCNT_SETUP_MASK) | |
74 | tcnt = GXBB_WDT_TCNT_SETUP_MASK; | |
75 | ||
76 | wdt_dev->timeout = timeout; | |
77 | ||
78 | meson_gxbb_wdt_ping(wdt_dev); | |
79 | ||
80 | writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG); | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
85 | static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev) | |
86 | { | |
87 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); | |
88 | unsigned long reg; | |
89 | ||
90 | reg = readl(data->reg_base + GXBB_WDT_TCNT_REG); | |
91 | ||
92 | return ((reg >> GXBB_WDT_TCNT_CNT_SHIFT) - | |
93 | (reg & GXBB_WDT_TCNT_SETUP_MASK)) / 1000; | |
94 | } | |
95 | ||
96 | static const struct watchdog_ops meson_gxbb_wdt_ops = { | |
97 | .start = meson_gxbb_wdt_start, | |
98 | .stop = meson_gxbb_wdt_stop, | |
99 | .ping = meson_gxbb_wdt_ping, | |
100 | .set_timeout = meson_gxbb_wdt_set_timeout, | |
101 | .get_timeleft = meson_gxbb_wdt_get_timeleft, | |
102 | }; | |
103 | ||
104 | static const struct watchdog_info meson_gxbb_wdt_info = { | |
105 | .identity = "Meson GXBB Watchdog", | |
106 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
107 | }; | |
108 | ||
109 | static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev) | |
110 | { | |
111 | struct meson_gxbb_wdt *data = dev_get_drvdata(dev); | |
112 | ||
113 | if (watchdog_active(&data->wdt_dev)) | |
114 | meson_gxbb_wdt_start(&data->wdt_dev); | |
115 | ||
116 | return 0; | |
117 | } | |
118 | ||
119 | static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev) | |
120 | { | |
121 | struct meson_gxbb_wdt *data = dev_get_drvdata(dev); | |
122 | ||
123 | if (watchdog_active(&data->wdt_dev)) | |
124 | meson_gxbb_wdt_stop(&data->wdt_dev); | |
125 | ||
126 | return 0; | |
127 | } | |
128 | ||
129 | static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = { | |
130 | SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume) | |
131 | }; | |
132 | ||
133 | static const struct of_device_id meson_gxbb_wdt_dt_ids[] = { | |
134 | { .compatible = "amlogic,meson-gxbb-wdt", }, | |
135 | { /* sentinel */ }, | |
136 | }; | |
137 | MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids); | |
138 | ||
139 | static int meson_gxbb_wdt_probe(struct platform_device *pdev) | |
140 | { | |
141 | struct meson_gxbb_wdt *data; | |
683fa50f NA |
142 | int ret; |
143 | ||
144 | data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); | |
145 | if (!data) | |
146 | return -ENOMEM; | |
147 | ||
0f0a6a28 | 148 | data->reg_base = devm_platform_ioremap_resource(pdev, 0); |
683fa50f NA |
149 | if (IS_ERR(data->reg_base)) |
150 | return PTR_ERR(data->reg_base); | |
151 | ||
152 | data->clk = devm_clk_get(&pdev->dev, NULL); | |
153 | if (IS_ERR(data->clk)) | |
154 | return PTR_ERR(data->clk); | |
155 | ||
65360944 AY |
156 | ret = clk_prepare_enable(data->clk); |
157 | if (ret) | |
158 | return ret; | |
683fa50f NA |
159 | |
160 | platform_set_drvdata(pdev, data); | |
161 | ||
162 | data->wdt_dev.parent = &pdev->dev; | |
163 | data->wdt_dev.info = &meson_gxbb_wdt_info; | |
164 | data->wdt_dev.ops = &meson_gxbb_wdt_ops; | |
165 | data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK; | |
166 | data->wdt_dev.min_timeout = 1; | |
167 | data->wdt_dev.timeout = DEFAULT_TIMEOUT; | |
168 | watchdog_set_drvdata(&data->wdt_dev, data); | |
169 | ||
170 | /* Setup with 1ms timebase */ | |
171 | writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) | | |
172 | GXBB_WDT_CTRL_EE_RESET | | |
173 | GXBB_WDT_CTRL_CLK_EN | | |
174 | GXBB_WDT_CTRL_CLKDIV_EN, | |
175 | data->reg_base + GXBB_WDT_CTRL_REG); | |
176 | ||
177 | meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout); | |
178 | ||
179 | ret = watchdog_register_device(&data->wdt_dev); | |
180 | if (ret) { | |
181 | clk_disable_unprepare(data->clk); | |
182 | return ret; | |
183 | } | |
184 | ||
185 | return 0; | |
186 | } | |
187 | ||
188 | static int meson_gxbb_wdt_remove(struct platform_device *pdev) | |
189 | { | |
190 | struct meson_gxbb_wdt *data = platform_get_drvdata(pdev); | |
191 | ||
192 | watchdog_unregister_device(&data->wdt_dev); | |
193 | ||
194 | clk_disable_unprepare(data->clk); | |
195 | ||
196 | return 0; | |
197 | } | |
198 | ||
199 | static void meson_gxbb_wdt_shutdown(struct platform_device *pdev) | |
200 | { | |
201 | struct meson_gxbb_wdt *data = platform_get_drvdata(pdev); | |
202 | ||
203 | meson_gxbb_wdt_stop(&data->wdt_dev); | |
204 | } | |
205 | ||
206 | static struct platform_driver meson_gxbb_wdt_driver = { | |
207 | .probe = meson_gxbb_wdt_probe, | |
208 | .remove = meson_gxbb_wdt_remove, | |
209 | .shutdown = meson_gxbb_wdt_shutdown, | |
210 | .driver = { | |
211 | .name = "meson-gxbb-wdt", | |
212 | .pm = &meson_gxbb_wdt_pm_ops, | |
213 | .of_match_table = meson_gxbb_wdt_dt_ids, | |
214 | }, | |
215 | }; | |
216 | ||
217 | module_platform_driver(meson_gxbb_wdt_driver); | |
218 | ||
683fa50f NA |
219 | MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>"); |
220 | MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver"); | |
221 | MODULE_LICENSE("Dual BSD/GPL"); |