1 From 78046b68c1fc757162e32c83f59c3a94e794bf2e Mon Sep 17 00:00:00 2001
2 From: John Crispin <blogic@openwrt.org>
3 Date: Sun, 28 Jul 2013 13:51:58 +0200
4 Subject: [PATCH 04/25] watchdog: MIPS: add ralink watchdog driver
6 Add a driver for the watchdog timer found on Ralink SoC
8 Signed-off-by: John Crispin <blogic@openwrt.org>
9 Cc: linux-watchdog@vger.kernel.org
10 Cc: linux-mips@linux-mips.org
12 drivers/watchdog/Kconfig | 7 ++
13 drivers/watchdog/Makefile | 1 +
14 drivers/watchdog/rt2880_wdt.c | 208 +++++++++++++++++++++++++++++++++++++++++
15 3 files changed, 216 insertions(+)
16 create mode 100644 drivers/watchdog/rt2880_wdt.c
18 --- a/drivers/watchdog/Kconfig
19 +++ b/drivers/watchdog/Kconfig
20 @@ -1113,6 +1113,13 @@ config LANTIQ_WDT
22 Hardware driver for the Lantiq SoC Watchdog Timer.
25 + tristate "Ralink SoC watchdog"
26 + select WATCHDOG_CORE
29 + Hardware driver for the Ralink SoC Watchdog Timer.
33 # POWERPC Architecture
34 --- a/drivers/watchdog/Makefile
35 +++ b/drivers/watchdog/Makefile
36 @@ -135,6 +135,7 @@ obj-$(CONFIG_TXX9_WDT) += txx9wdt.o
37 obj-$(CONFIG_OCTEON_WDT) += octeon-wdt.o
38 octeon-wdt-y := octeon-wdt-main.o octeon-wdt-nmi.o
39 obj-$(CONFIG_LANTIQ_WDT) += lantiq_wdt.o
40 +obj-$(CONFIG_RALINK_WDT) += rt2880_wdt.o
45 +++ b/drivers/watchdog/rt2880_wdt.c
48 + * Ralink RT288x/RT3xxx/MT76xx built-in hardware watchdog timer
50 + * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
51 + * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
53 + * This driver was based on: drivers/watchdog/softdog.c
55 + * This program is free software; you can redistribute it and/or modify it
56 + * under the terms of the GNU General Public License version 2 as published
57 + * by the Free Software Foundation.
60 +#include <linux/clk.h>
61 +#include <linux/reset.h>
62 +#include <linux/module.h>
63 +#include <linux/kernel.h>
64 +#include <linux/watchdog.h>
65 +#include <linux/miscdevice.h>
66 +#include <linux/moduleparam.h>
67 +#include <linux/platform_device.h>
69 +#include <asm/mach-ralink/ralink_regs.h>
71 +#define SYSC_RSTSTAT 0x38
72 +#define WDT_RST_CAUSE BIT(1)
74 +#define RALINK_WDT_TIMEOUT 30
75 +#define RALINK_WDT_PRESCALE 65536
77 +#define TIMER_REG_TMR1LOAD 0x00
78 +#define TIMER_REG_TMR1CTL 0x08
80 +#define TMRSTAT_TMR1RST BIT(5)
82 +#define TMR1CTL_ENABLE BIT(7)
83 +#define TMR1CTL_MODE_SHIFT 4
84 +#define TMR1CTL_MODE_MASK 0x3
85 +#define TMR1CTL_MODE_FREE_RUNNING 0x0
86 +#define TMR1CTL_MODE_PERIODIC 0x1
87 +#define TMR1CTL_MODE_TIMEOUT 0x2
88 +#define TMR1CTL_MODE_WDT 0x3
89 +#define TMR1CTL_PRESCALE_MASK 0xf
90 +#define TMR1CTL_PRESCALE_65536 0xf
92 +static struct clk *rt288x_wdt_clk;
93 +static unsigned long rt288x_wdt_freq;
94 +static void __iomem *rt288x_wdt_base;
96 +static bool nowayout = WATCHDOG_NOWAYOUT;
97 +module_param(nowayout, bool, 0);
98 +MODULE_PARM_DESC(nowayout,
99 + "Watchdog cannot be stopped once started (default="
100 + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
102 +static inline void rt_wdt_w32(unsigned reg, u32 val)
104 + iowrite32(val, rt288x_wdt_base + reg);
107 +static inline u32 rt_wdt_r32(unsigned reg)
109 + return ioread32(rt288x_wdt_base + reg);
112 +static int rt288x_wdt_ping(struct watchdog_device *w)
114 + rt_wdt_w32(TIMER_REG_TMR1LOAD, w->timeout * rt288x_wdt_freq);
119 +static int rt288x_wdt_start(struct watchdog_device *w)
123 + t = rt_wdt_r32(TIMER_REG_TMR1CTL);
124 + t &= ~(TMR1CTL_MODE_MASK << TMR1CTL_MODE_SHIFT |
125 + TMR1CTL_PRESCALE_MASK);
126 + t |= (TMR1CTL_MODE_WDT << TMR1CTL_MODE_SHIFT |
127 + TMR1CTL_PRESCALE_65536);
128 + rt_wdt_w32(TIMER_REG_TMR1CTL, t);
130 + rt288x_wdt_ping(w);
132 + t = rt_wdt_r32(TIMER_REG_TMR1CTL);
133 + t |= TMR1CTL_ENABLE;
134 + rt_wdt_w32(TIMER_REG_TMR1CTL, t);
139 +static int rt288x_wdt_stop(struct watchdog_device *w)
143 + rt288x_wdt_ping(w);
145 + t = rt_wdt_r32(TIMER_REG_TMR1CTL);
146 + t &= ~TMR1CTL_ENABLE;
147 + rt_wdt_w32(TIMER_REG_TMR1CTL, t);
152 +static int rt288x_wdt_set_timeout(struct watchdog_device *w, unsigned int t)
155 + rt288x_wdt_ping(w);
160 +static int rt288x_wdt_bootcause(void)
162 + if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE)
163 + return WDIOF_CARDRESET;
168 +static struct watchdog_info rt288x_wdt_info = {
169 + .identity = "Ralink Watchdog",
170 + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
173 +static struct watchdog_ops rt288x_wdt_ops = {
174 + .owner = THIS_MODULE,
175 + .start = rt288x_wdt_start,
176 + .stop = rt288x_wdt_stop,
177 + .ping = rt288x_wdt_ping,
178 + .set_timeout = rt288x_wdt_set_timeout,
181 +static struct watchdog_device rt288x_wdt_dev = {
182 + .info = &rt288x_wdt_info,
183 + .ops = &rt288x_wdt_ops,
187 +static int rt288x_wdt_probe(struct platform_device *pdev)
189 + struct resource *res;
192 + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
193 + rt288x_wdt_base = devm_request_and_ioremap(&pdev->dev, res);
194 + if (IS_ERR(rt288x_wdt_base))
195 + return PTR_ERR(rt288x_wdt_base);
197 + rt288x_wdt_clk = devm_clk_get(&pdev->dev, NULL);
198 + if (IS_ERR(rt288x_wdt_clk))
199 + return PTR_ERR(rt288x_wdt_clk);
201 + device_reset(&pdev->dev);
203 + rt288x_wdt_freq = clk_get_rate(rt288x_wdt_clk) / RALINK_WDT_PRESCALE;
205 + rt288x_wdt_dev.dev = &pdev->dev;
206 + rt288x_wdt_dev.bootstatus = rt288x_wdt_bootcause();
208 + rt288x_wdt_dev.max_timeout = (0xfffful / rt288x_wdt_freq);
209 + rt288x_wdt_dev.timeout = rt288x_wdt_dev.max_timeout;
211 + watchdog_set_nowayout(&rt288x_wdt_dev, nowayout);
213 + ret = watchdog_register_device(&rt288x_wdt_dev);
215 + dev_info(&pdev->dev, "Initialized\n");
220 +static int rt288x_wdt_remove(struct platform_device *pdev)
222 + watchdog_unregister_device(&rt288x_wdt_dev);
227 +static void rt288x_wdt_shutdown(struct platform_device *pdev)
229 + rt288x_wdt_stop(&rt288x_wdt_dev);
232 +static const struct of_device_id rt288x_wdt_match[] = {
233 + { .compatible = "ralink,rt2880-wdt" },
236 +MODULE_DEVICE_TABLE(of, rt288x_wdt_match);
238 +static struct platform_driver rt288x_wdt_driver = {
239 + .probe = rt288x_wdt_probe,
240 + .remove = rt288x_wdt_remove,
241 + .shutdown = rt288x_wdt_shutdown,
243 + .name = KBUILD_MODNAME,
244 + .owner = THIS_MODULE,
245 + .of_match_table = rt288x_wdt_match,
249 +module_platform_driver(rt288x_wdt_driver);
251 +MODULE_DESCRIPTION("MediaTek/Ralink RT288x/RT3xxx hardware watchdog driver");
252 +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org");
253 +MODULE_LICENSE("GPL v2");
254 +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);