2 * Watchdog driver for Conexant Digicolor
4 * Copyright (C) 2015 Paradox Innovation Ltd.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
12 #include <linux/types.h>
13 #include <linux/module.h>
15 #include <linux/delay.h>
16 #include <linux/clk.h>
17 #include <linux/watchdog.h>
18 #include <linux/platform_device.h>
19 #include <linux/of_address.h>
21 #define TIMER_A_CONTROL 0
22 #define TIMER_A_COUNT 4
24 #define TIMER_A_ENABLE_COUNT BIT(0)
25 #define TIMER_A_ENABLE_WATCHDOG BIT(1)
33 static unsigned timeout
;
34 module_param(timeout
, uint
, 0);
35 MODULE_PARM_DESC(timeout
, "Watchdog timeout in seconds");
37 static void dc_wdt_set(struct dc_wdt
*wdt
, u32 ticks
)
41 spin_lock_irqsave(&wdt
->lock
, flags
);
43 writel_relaxed(0, wdt
->base
+ TIMER_A_CONTROL
);
44 writel_relaxed(ticks
, wdt
->base
+ TIMER_A_COUNT
);
45 writel_relaxed(TIMER_A_ENABLE_COUNT
| TIMER_A_ENABLE_WATCHDOG
,
46 wdt
->base
+ TIMER_A_CONTROL
);
48 spin_unlock_irqrestore(&wdt
->lock
, flags
);
51 static int dc_wdt_restart(struct watchdog_device
*wdog
)
53 struct dc_wdt
*wdt
= watchdog_get_drvdata(wdog
);
56 /* wait for reset to assert... */
62 static int dc_wdt_start(struct watchdog_device
*wdog
)
64 struct dc_wdt
*wdt
= watchdog_get_drvdata(wdog
);
66 dc_wdt_set(wdt
, wdog
->timeout
* clk_get_rate(wdt
->clk
));
71 static int dc_wdt_stop(struct watchdog_device
*wdog
)
73 struct dc_wdt
*wdt
= watchdog_get_drvdata(wdog
);
75 writel_relaxed(0, wdt
->base
+ TIMER_A_CONTROL
);
80 static int dc_wdt_set_timeout(struct watchdog_device
*wdog
, unsigned int t
)
82 struct dc_wdt
*wdt
= watchdog_get_drvdata(wdog
);
84 dc_wdt_set(wdt
, t
* clk_get_rate(wdt
->clk
));
90 static unsigned int dc_wdt_get_timeleft(struct watchdog_device
*wdog
)
92 struct dc_wdt
*wdt
= watchdog_get_drvdata(wdog
);
93 uint32_t count
= readl_relaxed(wdt
->base
+ TIMER_A_COUNT
);
95 return count
/ clk_get_rate(wdt
->clk
);
98 static struct watchdog_ops dc_wdt_ops
= {
100 .start
= dc_wdt_start
,
102 .set_timeout
= dc_wdt_set_timeout
,
103 .get_timeleft
= dc_wdt_get_timeleft
,
104 .restart
= dc_wdt_restart
,
107 static struct watchdog_info dc_wdt_info
= {
108 .options
= WDIOF_SETTIMEOUT
| WDIOF_MAGICCLOSE
109 | WDIOF_KEEPALIVEPING
,
110 .identity
= "Conexant Digicolor Watchdog",
113 static struct watchdog_device dc_wdt_wdd
= {
114 .info
= &dc_wdt_info
,
119 static int dc_wdt_probe(struct platform_device
*pdev
)
121 struct device
*dev
= &pdev
->dev
;
122 struct device_node
*np
= dev
->of_node
;
126 wdt
= devm_kzalloc(dev
, sizeof(struct dc_wdt
), GFP_KERNEL
);
129 platform_set_drvdata(pdev
, wdt
);
131 wdt
->base
= of_iomap(np
, 0);
133 dev_err(dev
, "Failed to remap watchdog regs");
137 wdt
->clk
= devm_clk_get(&pdev
->dev
, NULL
);
138 if (IS_ERR(wdt
->clk
)) {
139 ret
= PTR_ERR(wdt
->clk
);
142 dc_wdt_wdd
.max_timeout
= U32_MAX
/ clk_get_rate(wdt
->clk
);
143 dc_wdt_wdd
.timeout
= dc_wdt_wdd
.max_timeout
;
144 dc_wdt_wdd
.parent
= &pdev
->dev
;
146 spin_lock_init(&wdt
->lock
);
148 watchdog_set_drvdata(&dc_wdt_wdd
, wdt
);
149 watchdog_set_restart_priority(&dc_wdt_wdd
, 128);
150 watchdog_init_timeout(&dc_wdt_wdd
, timeout
, dev
);
151 ret
= watchdog_register_device(&dc_wdt_wdd
);
153 dev_err(dev
, "Failed to register watchdog device");
164 static int dc_wdt_remove(struct platform_device
*pdev
)
166 struct dc_wdt
*wdt
= platform_get_drvdata(pdev
);
168 watchdog_unregister_device(&dc_wdt_wdd
);
174 static void dc_wdt_shutdown(struct platform_device
*pdev
)
176 dc_wdt_stop(&dc_wdt_wdd
);
179 static const struct of_device_id dc_wdt_of_match
[] = {
180 { .compatible
= "cnxt,cx92755-wdt", },
183 MODULE_DEVICE_TABLE(of
, dc_wdt_of_match
);
185 static struct platform_driver dc_wdt_driver
= {
186 .probe
= dc_wdt_probe
,
187 .remove
= dc_wdt_remove
,
188 .shutdown
= dc_wdt_shutdown
,
190 .name
= "digicolor-wdt",
191 .of_match_table
= dc_wdt_of_match
,
194 module_platform_driver(dc_wdt_driver
);
196 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
197 MODULE_DESCRIPTION("Driver for Conexant Digicolor watchdog timer");
198 MODULE_LICENSE("GPL");