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1 | /* |
2 | * This file is provided under a dual BSD/GPLv2 license. When using or | |
3 | * redistributing this file, you may do so under either license. | |
4 | * | |
5 | * GPL LICENSE SUMMARY | |
6 | * | |
7 | * Copyright (c) 2016 BayLibre, SAS. | |
8 | * Author: Neil Armstrong <narmstrong@baylibre.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of version 2 of the GNU General Public License as | |
12 | * published by the Free Software Foundation. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, but | |
15 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
21 | * The full GNU General Public License is included in this distribution | |
22 | * in the file called COPYING. | |
23 | * | |
24 | * BSD LICENSE | |
25 | * | |
26 | * Copyright (c) 2016 BayLibre, SAS. | |
27 | * Author: Neil Armstrong <narmstrong@baylibre.com> | |
28 | * | |
29 | * Redistribution and use in source and binary forms, with or without | |
30 | * modification, are permitted provided that the following conditions | |
31 | * are met: | |
32 | * | |
33 | * * Redistributions of source code must retain the above copyright | |
34 | * notice, this list of conditions and the following disclaimer. | |
35 | * * Redistributions in binary form must reproduce the above copyright | |
36 | * notice, this list of conditions and the following disclaimer in | |
37 | * the documentation and/or other materials provided with the | |
38 | * distribution. | |
39 | * * Neither the name of Intel Corporation nor the names of its | |
40 | * contributors may be used to endorse or promote products derived | |
41 | * from this software without specific prior written permission. | |
42 | * | |
43 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
44 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
45 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
46 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
47 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
48 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
49 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
50 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
51 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
52 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
53 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
54 | */ | |
55 | #include <linux/clk.h> | |
56 | #include <linux/err.h> | |
57 | #include <linux/io.h> | |
58 | #include <linux/module.h> | |
59 | #include <linux/of.h> | |
60 | #include <linux/platform_device.h> | |
61 | #include <linux/slab.h> | |
62 | #include <linux/types.h> | |
63 | #include <linux/watchdog.h> | |
64 | ||
65 | #define DEFAULT_TIMEOUT 30 /* seconds */ | |
66 | ||
67 | #define GXBB_WDT_CTRL_REG 0x0 | |
68 | #define GXBB_WDT_TCNT_REG 0x8 | |
69 | #define GXBB_WDT_RSET_REG 0xc | |
70 | ||
71 | #define GXBB_WDT_CTRL_CLKDIV_EN BIT(25) | |
72 | #define GXBB_WDT_CTRL_CLK_EN BIT(24) | |
73 | #define GXBB_WDT_CTRL_EE_RESET BIT(21) | |
74 | #define GXBB_WDT_CTRL_EN BIT(18) | |
75 | #define GXBB_WDT_CTRL_DIV_MASK (BIT(18) - 1) | |
76 | ||
77 | #define GXBB_WDT_TCNT_SETUP_MASK (BIT(16) - 1) | |
78 | #define GXBB_WDT_TCNT_CNT_SHIFT 16 | |
79 | ||
80 | struct meson_gxbb_wdt { | |
81 | void __iomem *reg_base; | |
82 | struct watchdog_device wdt_dev; | |
83 | struct clk *clk; | |
84 | }; | |
85 | ||
86 | static int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev) | |
87 | { | |
88 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); | |
89 | ||
90 | writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN, | |
91 | data->reg_base + GXBB_WDT_CTRL_REG); | |
92 | ||
93 | return 0; | |
94 | } | |
95 | ||
96 | static int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev) | |
97 | { | |
98 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); | |
99 | ||
100 | writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN, | |
101 | data->reg_base + GXBB_WDT_CTRL_REG); | |
102 | ||
103 | return 0; | |
104 | } | |
105 | ||
106 | static int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev) | |
107 | { | |
108 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); | |
109 | ||
110 | writel(0, data->reg_base + GXBB_WDT_RSET_REG); | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev, | |
116 | unsigned int timeout) | |
117 | { | |
118 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); | |
119 | unsigned long tcnt = timeout * 1000; | |
120 | ||
121 | if (tcnt > GXBB_WDT_TCNT_SETUP_MASK) | |
122 | tcnt = GXBB_WDT_TCNT_SETUP_MASK; | |
123 | ||
124 | wdt_dev->timeout = timeout; | |
125 | ||
126 | meson_gxbb_wdt_ping(wdt_dev); | |
127 | ||
128 | writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG); | |
129 | ||
130 | return 0; | |
131 | } | |
132 | ||
133 | static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev) | |
134 | { | |
135 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); | |
136 | unsigned long reg; | |
137 | ||
138 | reg = readl(data->reg_base + GXBB_WDT_TCNT_REG); | |
139 | ||
140 | return ((reg >> GXBB_WDT_TCNT_CNT_SHIFT) - | |
141 | (reg & GXBB_WDT_TCNT_SETUP_MASK)) / 1000; | |
142 | } | |
143 | ||
144 | static const struct watchdog_ops meson_gxbb_wdt_ops = { | |
145 | .start = meson_gxbb_wdt_start, | |
146 | .stop = meson_gxbb_wdt_stop, | |
147 | .ping = meson_gxbb_wdt_ping, | |
148 | .set_timeout = meson_gxbb_wdt_set_timeout, | |
149 | .get_timeleft = meson_gxbb_wdt_get_timeleft, | |
150 | }; | |
151 | ||
152 | static const struct watchdog_info meson_gxbb_wdt_info = { | |
153 | .identity = "Meson GXBB Watchdog", | |
154 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
155 | }; | |
156 | ||
157 | static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev) | |
158 | { | |
159 | struct meson_gxbb_wdt *data = dev_get_drvdata(dev); | |
160 | ||
161 | if (watchdog_active(&data->wdt_dev)) | |
162 | meson_gxbb_wdt_start(&data->wdt_dev); | |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
167 | static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev) | |
168 | { | |
169 | struct meson_gxbb_wdt *data = dev_get_drvdata(dev); | |
170 | ||
171 | if (watchdog_active(&data->wdt_dev)) | |
172 | meson_gxbb_wdt_stop(&data->wdt_dev); | |
173 | ||
174 | return 0; | |
175 | } | |
176 | ||
177 | static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = { | |
178 | SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume) | |
179 | }; | |
180 | ||
181 | static const struct of_device_id meson_gxbb_wdt_dt_ids[] = { | |
182 | { .compatible = "amlogic,meson-gxbb-wdt", }, | |
183 | { /* sentinel */ }, | |
184 | }; | |
185 | MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids); | |
186 | ||
187 | static int meson_gxbb_wdt_probe(struct platform_device *pdev) | |
188 | { | |
189 | struct meson_gxbb_wdt *data; | |
190 | struct resource *res; | |
191 | int ret; | |
192 | ||
193 | data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); | |
194 | if (!data) | |
195 | return -ENOMEM; | |
196 | ||
197 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
198 | data->reg_base = devm_ioremap_resource(&pdev->dev, res); | |
199 | if (IS_ERR(data->reg_base)) | |
200 | return PTR_ERR(data->reg_base); | |
201 | ||
202 | data->clk = devm_clk_get(&pdev->dev, NULL); | |
203 | if (IS_ERR(data->clk)) | |
204 | return PTR_ERR(data->clk); | |
205 | ||
65360944 AY |
206 | ret = clk_prepare_enable(data->clk); |
207 | if (ret) | |
208 | return ret; | |
683fa50f NA |
209 | |
210 | platform_set_drvdata(pdev, data); | |
211 | ||
212 | data->wdt_dev.parent = &pdev->dev; | |
213 | data->wdt_dev.info = &meson_gxbb_wdt_info; | |
214 | data->wdt_dev.ops = &meson_gxbb_wdt_ops; | |
215 | data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK; | |
216 | data->wdt_dev.min_timeout = 1; | |
217 | data->wdt_dev.timeout = DEFAULT_TIMEOUT; | |
218 | watchdog_set_drvdata(&data->wdt_dev, data); | |
219 | ||
220 | /* Setup with 1ms timebase */ | |
221 | writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) | | |
222 | GXBB_WDT_CTRL_EE_RESET | | |
223 | GXBB_WDT_CTRL_CLK_EN | | |
224 | GXBB_WDT_CTRL_CLKDIV_EN, | |
225 | data->reg_base + GXBB_WDT_CTRL_REG); | |
226 | ||
227 | meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout); | |
228 | ||
229 | ret = watchdog_register_device(&data->wdt_dev); | |
230 | if (ret) { | |
231 | clk_disable_unprepare(data->clk); | |
232 | return ret; | |
233 | } | |
234 | ||
235 | return 0; | |
236 | } | |
237 | ||
238 | static int meson_gxbb_wdt_remove(struct platform_device *pdev) | |
239 | { | |
240 | struct meson_gxbb_wdt *data = platform_get_drvdata(pdev); | |
241 | ||
242 | watchdog_unregister_device(&data->wdt_dev); | |
243 | ||
244 | clk_disable_unprepare(data->clk); | |
245 | ||
246 | return 0; | |
247 | } | |
248 | ||
249 | static void meson_gxbb_wdt_shutdown(struct platform_device *pdev) | |
250 | { | |
251 | struct meson_gxbb_wdt *data = platform_get_drvdata(pdev); | |
252 | ||
253 | meson_gxbb_wdt_stop(&data->wdt_dev); | |
254 | } | |
255 | ||
256 | static struct platform_driver meson_gxbb_wdt_driver = { | |
257 | .probe = meson_gxbb_wdt_probe, | |
258 | .remove = meson_gxbb_wdt_remove, | |
259 | .shutdown = meson_gxbb_wdt_shutdown, | |
260 | .driver = { | |
261 | .name = "meson-gxbb-wdt", | |
262 | .pm = &meson_gxbb_wdt_pm_ops, | |
263 | .of_match_table = meson_gxbb_wdt_dt_ids, | |
264 | }, | |
265 | }; | |
266 | ||
267 | module_platform_driver(meson_gxbb_wdt_driver); | |
268 | ||
683fa50f NA |
269 | MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>"); |
270 | MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver"); | |
271 | MODULE_LICENSE("Dual BSD/GPL"); |