Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net> |
| 3 | * JZ4740 Watchdog driver |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License as published by the |
| 7 | * Free Software Foundation; either version 2 of the License, or (at your |
| 8 | * option) any later version. |
| 9 | * |
| 10 | * You should have received a copy of the GNU General Public License along |
| 11 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 12 | * 675 Mass Ave, Cambridge, MA 02139, USA. |
| 13 | * |
| 14 | */ |
| 15 | |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/moduleparam.h> |
| 18 | #include <linux/types.h> |
| 19 | #include <linux/kernel.h> |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 20 | #include <linux/miscdevice.h> |
| 21 | #include <linux/watchdog.h> |
| 22 | #include <linux/init.h> |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 23 | #include <linux/platform_device.h> |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 24 | #include <linux/io.h> |
| 25 | #include <linux/device.h> |
| 26 | #include <linux/clk.h> |
| 27 | #include <linux/slab.h> |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 28 | #include <linux/err.h> |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 29 | |
| 30 | #include <asm/mach-jz4740/timer.h> |
| 31 | |
| 32 | #define JZ_REG_WDT_TIMER_DATA 0x0 |
| 33 | #define JZ_REG_WDT_COUNTER_ENABLE 0x4 |
| 34 | #define JZ_REG_WDT_TIMER_COUNTER 0x8 |
| 35 | #define JZ_REG_WDT_TIMER_CONTROL 0xC |
| 36 | |
| 37 | #define JZ_WDT_CLOCK_PCLK 0x1 |
| 38 | #define JZ_WDT_CLOCK_RTC 0x2 |
| 39 | #define JZ_WDT_CLOCK_EXT 0x4 |
| 40 | |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 41 | #define JZ_WDT_CLOCK_DIV_SHIFT 3 |
| 42 | |
| 43 | #define JZ_WDT_CLOCK_DIV_1 (0 << JZ_WDT_CLOCK_DIV_SHIFT) |
| 44 | #define JZ_WDT_CLOCK_DIV_4 (1 << JZ_WDT_CLOCK_DIV_SHIFT) |
| 45 | #define JZ_WDT_CLOCK_DIV_16 (2 << JZ_WDT_CLOCK_DIV_SHIFT) |
| 46 | #define JZ_WDT_CLOCK_DIV_64 (3 << JZ_WDT_CLOCK_DIV_SHIFT) |
| 47 | #define JZ_WDT_CLOCK_DIV_256 (4 << JZ_WDT_CLOCK_DIV_SHIFT) |
| 48 | #define JZ_WDT_CLOCK_DIV_1024 (5 << JZ_WDT_CLOCK_DIV_SHIFT) |
| 49 | |
| 50 | #define DEFAULT_HEARTBEAT 5 |
| 51 | #define MAX_HEARTBEAT 2048 |
| 52 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 53 | static bool nowayout = WATCHDOG_NOWAYOUT; |
| 54 | module_param(nowayout, bool, 0); |
| 55 | MODULE_PARM_DESC(nowayout, |
| 56 | "Watchdog cannot be stopped once started (default=" |
| 57 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
| 58 | |
| 59 | static unsigned int heartbeat = DEFAULT_HEARTBEAT; |
| 60 | module_param(heartbeat, uint, 0); |
| 61 | MODULE_PARM_DESC(heartbeat, |
| 62 | "Watchdog heartbeat period in seconds from 1 to " |
| 63 | __MODULE_STRING(MAX_HEARTBEAT) ", default " |
| 64 | __MODULE_STRING(DEFAULT_HEARTBEAT)); |
| 65 | |
| 66 | struct jz4740_wdt_drvdata { |
| 67 | struct watchdog_device wdt; |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 68 | void __iomem *base; |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 69 | struct clk *rtc_clk; |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 70 | }; |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 71 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 72 | static int jz4740_wdt_ping(struct watchdog_device *wdt_dev) |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 73 | { |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 74 | struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); |
| 75 | |
| 76 | writew(0x0, drvdata->base + JZ_REG_WDT_TIMER_COUNTER); |
| 77 | return 0; |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 78 | } |
| 79 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 80 | static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, |
| 81 | unsigned int new_timeout) |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 82 | { |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 83 | struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 84 | unsigned int rtc_clk_rate; |
| 85 | unsigned int timeout_value; |
| 86 | unsigned short clock_div = JZ_WDT_CLOCK_DIV_1; |
| 87 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 88 | rtc_clk_rate = clk_get_rate(drvdata->rtc_clk); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 89 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 90 | timeout_value = rtc_clk_rate * new_timeout; |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 91 | while (timeout_value > 0xffff) { |
| 92 | if (clock_div == JZ_WDT_CLOCK_DIV_1024) { |
| 93 | /* Requested timeout too high; |
| 94 | * use highest possible value. */ |
| 95 | timeout_value = 0xffff; |
| 96 | break; |
| 97 | } |
| 98 | timeout_value >>= 2; |
| 99 | clock_div += (1 << JZ_WDT_CLOCK_DIV_SHIFT); |
| 100 | } |
| 101 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 102 | writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE); |
| 103 | writew(clock_div, drvdata->base + JZ_REG_WDT_TIMER_CONTROL); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 104 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 105 | writew((u16)timeout_value, drvdata->base + JZ_REG_WDT_TIMER_DATA); |
| 106 | writew(0x0, drvdata->base + JZ_REG_WDT_TIMER_COUNTER); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 107 | writew(clock_div | JZ_WDT_CLOCK_RTC, |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 108 | drvdata->base + JZ_REG_WDT_TIMER_CONTROL); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 109 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 110 | writeb(0x1, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 111 | |
Wim Van Sebroeck | 0197c1c | 2012-02-29 20:20:58 +0100 | [diff] [blame] | 112 | wdt_dev->timeout = new_timeout; |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 113 | return 0; |
| 114 | } |
| 115 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 116 | static int jz4740_wdt_start(struct watchdog_device *wdt_dev) |
| 117 | { |
| 118 | jz4740_timer_enable_watchdog(); |
| 119 | jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout); |
| 120 | |
| 121 | return 0; |
| 122 | } |
| 123 | |
| 124 | static int jz4740_wdt_stop(struct watchdog_device *wdt_dev) |
| 125 | { |
| 126 | struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); |
| 127 | |
| 128 | jz4740_timer_disable_watchdog(); |
| 129 | writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE); |
| 130 | |
| 131 | return 0; |
| 132 | } |
| 133 | |
| 134 | static const struct watchdog_info jz4740_wdt_info = { |
| 135 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
| 136 | .identity = "jz4740 Watchdog", |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 137 | }; |
| 138 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 139 | static const struct watchdog_ops jz4740_wdt_ops = { |
| 140 | .owner = THIS_MODULE, |
| 141 | .start = jz4740_wdt_start, |
| 142 | .stop = jz4740_wdt_stop, |
| 143 | .ping = jz4740_wdt_ping, |
| 144 | .set_timeout = jz4740_wdt_set_timeout, |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 145 | }; |
| 146 | |
Bill Pemberton | 2d991a1 | 2012-11-19 13:21:41 -0500 | [diff] [blame] | 147 | static int jz4740_wdt_probe(struct platform_device *pdev) |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 148 | { |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 149 | struct jz4740_wdt_drvdata *drvdata; |
| 150 | struct watchdog_device *jz4740_wdt; |
| 151 | struct resource *res; |
| 152 | int ret; |
| 153 | |
| 154 | drvdata = devm_kzalloc(&pdev->dev, sizeof(struct jz4740_wdt_drvdata), |
| 155 | GFP_KERNEL); |
| 156 | if (!drvdata) { |
| 157 | dev_err(&pdev->dev, "Unable to alloacate watchdog device\n"); |
| 158 | return -ENOMEM; |
| 159 | } |
| 160 | |
| 161 | if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT) |
| 162 | heartbeat = DEFAULT_HEARTBEAT; |
| 163 | |
| 164 | jz4740_wdt = &drvdata->wdt; |
| 165 | jz4740_wdt->info = &jz4740_wdt_info; |
| 166 | jz4740_wdt->ops = &jz4740_wdt_ops; |
| 167 | jz4740_wdt->timeout = heartbeat; |
| 168 | jz4740_wdt->min_timeout = 1; |
| 169 | jz4740_wdt->max_timeout = MAX_HEARTBEAT; |
| 170 | watchdog_set_nowayout(jz4740_wdt, nowayout); |
| 171 | watchdog_set_drvdata(jz4740_wdt, drvdata); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 172 | |
| 173 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
Thierry Reding | 4c271bb | 2013-01-21 11:09:25 +0100 | [diff] [blame] | 174 | drvdata->base = devm_ioremap_resource(&pdev->dev, res); |
| 175 | if (IS_ERR(drvdata->base)) { |
| 176 | ret = PTR_ERR(drvdata->base); |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 177 | goto err_out; |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 178 | } |
| 179 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 180 | drvdata->rtc_clk = clk_get(NULL, "rtc"); |
| 181 | if (IS_ERR(drvdata->rtc_clk)) { |
| 182 | dev_err(&pdev->dev, "cannot find RTC clock\n"); |
| 183 | ret = PTR_ERR(drvdata->rtc_clk); |
| 184 | goto err_out; |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 185 | } |
| 186 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 187 | ret = watchdog_register_device(&drvdata->wdt); |
| 188 | if (ret < 0) |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 189 | goto err_disable_clk; |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 190 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 191 | platform_set_drvdata(pdev, drvdata); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 192 | return 0; |
| 193 | |
| 194 | err_disable_clk: |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 195 | clk_put(drvdata->rtc_clk); |
| 196 | err_out: |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 197 | return ret; |
| 198 | } |
| 199 | |
Bill Pemberton | 4b12b89 | 2012-11-19 13:26:24 -0500 | [diff] [blame] | 200 | static int jz4740_wdt_remove(struct platform_device *pdev) |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 201 | { |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 202 | struct jz4740_wdt_drvdata *drvdata = platform_get_drvdata(pdev); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 203 | |
Axel Lin | 85f6df1 | 2012-01-26 18:10:45 +0800 | [diff] [blame] | 204 | jz4740_wdt_stop(&drvdata->wdt); |
| 205 | watchdog_unregister_device(&drvdata->wdt); |
| 206 | clk_put(drvdata->rtc_clk); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 207 | |
| 208 | return 0; |
| 209 | } |
| 210 | |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 211 | static struct platform_driver jz4740_wdt_driver = { |
| 212 | .probe = jz4740_wdt_probe, |
Bill Pemberton | 8226871 | 2012-11-19 13:21:12 -0500 | [diff] [blame] | 213 | .remove = jz4740_wdt_remove, |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 214 | .driver = { |
| 215 | .name = "jz4740-wdt", |
| 216 | .owner = THIS_MODULE, |
| 217 | }, |
| 218 | }; |
| 219 | |
Axel Lin | b8ec611 | 2011-11-29 13:56:27 +0800 | [diff] [blame] | 220 | module_platform_driver(jz4740_wdt_driver); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 221 | |
| 222 | MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>"); |
| 223 | MODULE_DESCRIPTION("jz4740 Watchdog Driver"); |
Paul Cercueil | f865c35 | 2010-12-05 21:08:22 +0100 | [diff] [blame] | 224 | MODULE_LICENSE("GPL"); |
| 225 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
| 226 | MODULE_ALIAS("platform:jz4740-wdt"); |