2 * System monitoring driver for DA9052 PMICs.
4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
6 * Author: Anthony Olech <Anthony.Olech@diasemi.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
15 #include <linux/module.h>
16 #include <linux/delay.h>
17 #include <linux/uaccess.h>
18 #include <linux/platform_device.h>
19 #include <linux/time.h>
20 #include <linux/watchdog.h>
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/jiffies.h>
24 #include <linux/delay.h>
26 #include <linux/mfd/da9052/reg.h>
27 #include <linux/mfd/da9052/da9052.h>
29 #define DA9052_DEF_TIMEOUT 4
30 #define DA9052_TWDMIN 256
32 struct da9052_wdt_data
{
33 struct watchdog_device wdt
;
34 struct da9052
*da9052
;
41 int time
; /* Seconds */
42 } da9052_wdt_maps
[] = {
48 { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */
50 { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */
55 static void da9052_wdt_release_resources(struct kref
*r
)
57 struct da9052_wdt_data
*driver_data
=
58 container_of(r
, struct da9052_wdt_data
, kref
);
63 static int da9052_wdt_set_timeout(struct watchdog_device
*wdt_dev
,
66 struct da9052_wdt_data
*driver_data
= watchdog_get_drvdata(wdt_dev
);
67 struct da9052
*da9052
= driver_data
->da9052
;
71 * Disable the Watchdog timer before setting
74 ret
= da9052_reg_update(da9052
, DA9052_CONTROL_D_REG
,
75 DA9052_CONTROLD_TWDSCALE
, 0);
77 dev_err(da9052
->dev
, "Failed to disable watchdog bit, %d\n",
83 * To change the timeout, da9052 needs to
84 * be disabled for at least 150 us.
88 /* Set the desired timeout */
89 for (i
= 0; i
< ARRAY_SIZE(da9052_wdt_maps
); i
++)
90 if (da9052_wdt_maps
[i
].time
== timeout
)
93 if (i
== ARRAY_SIZE(da9052_wdt_maps
))
96 ret
= da9052_reg_update(da9052
, DA9052_CONTROL_D_REG
,
97 DA9052_CONTROLD_TWDSCALE
,
98 da9052_wdt_maps
[i
].reg_val
);
101 "Failed to update timescale bit, %d\n", ret
);
105 wdt_dev
->timeout
= timeout
;
106 driver_data
->jpast
= jiffies
;
112 static void da9052_wdt_ref(struct watchdog_device
*wdt_dev
)
114 struct da9052_wdt_data
*driver_data
= watchdog_get_drvdata(wdt_dev
);
116 kref_get(&driver_data
->kref
);
119 static void da9052_wdt_unref(struct watchdog_device
*wdt_dev
)
121 struct da9052_wdt_data
*driver_data
= watchdog_get_drvdata(wdt_dev
);
123 kref_put(&driver_data
->kref
, da9052_wdt_release_resources
);
126 static int da9052_wdt_start(struct watchdog_device
*wdt_dev
)
128 return da9052_wdt_set_timeout(wdt_dev
, wdt_dev
->timeout
);
131 static int da9052_wdt_stop(struct watchdog_device
*wdt_dev
)
133 return da9052_wdt_set_timeout(wdt_dev
, 0);
136 static int da9052_wdt_ping(struct watchdog_device
*wdt_dev
)
138 struct da9052_wdt_data
*driver_data
= watchdog_get_drvdata(wdt_dev
);
139 struct da9052
*da9052
= driver_data
->da9052
;
140 unsigned long msec
, jnow
= jiffies
;
144 * We have a minimum time for watchdog window called TWDMIN. A write
145 * to the watchdog before this elapsed time should cause an error.
147 msec
= (jnow
- driver_data
->jpast
) * 1000/HZ
;
148 if (msec
< DA9052_TWDMIN
)
151 /* Reset the watchdog timer */
152 ret
= da9052_reg_update(da9052
, DA9052_CONTROL_D_REG
,
153 DA9052_CONTROLD_WATCHDOG
, 1 << 7);
158 * FIXME: Reset the watchdog core, in general PMIC
159 * is supposed to do this
161 ret
= da9052_reg_update(da9052
, DA9052_CONTROL_D_REG
,
162 DA9052_CONTROLD_WATCHDOG
, 0 << 7);
167 static struct watchdog_info da9052_wdt_info
= {
168 .options
= WDIOF_SETTIMEOUT
| WDIOF_KEEPALIVEPING
,
169 .identity
= "DA9052 Watchdog",
172 static const struct watchdog_ops da9052_wdt_ops
= {
173 .owner
= THIS_MODULE
,
174 .start
= da9052_wdt_start
,
175 .stop
= da9052_wdt_stop
,
176 .ping
= da9052_wdt_ping
,
177 .set_timeout
= da9052_wdt_set_timeout
,
178 .ref
= da9052_wdt_ref
,
179 .unref
= da9052_wdt_unref
,
183 static int __devinit
da9052_wdt_probe(struct platform_device
*pdev
)
185 struct da9052
*da9052
= dev_get_drvdata(pdev
->dev
.parent
);
186 struct da9052_wdt_data
*driver_data
;
187 struct watchdog_device
*da9052_wdt
;
190 driver_data
= devm_kzalloc(&pdev
->dev
, sizeof(*driver_data
),
193 dev_err(da9052
->dev
, "Unable to alloacate watchdog device\n");
197 driver_data
->da9052
= da9052
;
199 da9052_wdt
= &driver_data
->wdt
;
201 da9052_wdt
->timeout
= DA9052_DEF_TIMEOUT
;
202 da9052_wdt
->info
= &da9052_wdt_info
;
203 da9052_wdt
->ops
= &da9052_wdt_ops
;
204 watchdog_set_drvdata(da9052_wdt
, driver_data
);
206 kref_init(&driver_data
->kref
);
208 ret
= da9052_reg_update(da9052
, DA9052_CONTROL_D_REG
,
209 DA9052_CONTROLD_TWDSCALE
, 0);
211 dev_err(&pdev
->dev
, "Failed to disable watchdog bits, %d\n",
216 ret
= watchdog_register_device(&driver_data
->wdt
);
218 dev_err(da9052
->dev
, "watchdog_register_device() failed: %d\n",
223 dev_set_drvdata(&pdev
->dev
, driver_data
);
228 static int __devexit
da9052_wdt_remove(struct platform_device
*pdev
)
230 struct da9052_wdt_data
*driver_data
= dev_get_drvdata(&pdev
->dev
);
232 watchdog_unregister_device(&driver_data
->wdt
);
233 kref_put(&driver_data
->kref
, da9052_wdt_release_resources
);
238 static struct platform_driver da9052_wdt_driver
= {
239 .probe
= da9052_wdt_probe
,
240 .remove
= __devexit_p(da9052_wdt_remove
),
242 .name
= "da9052-watchdog",
246 module_platform_driver(da9052_wdt_driver
);
248 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
249 MODULE_DESCRIPTION("DA9052 SM Device Driver");
250 MODULE_LICENSE("GPL");
251 MODULE_ALIAS("platform:da9052-watchdog");