target/linux/ramips/patches-3.10/0004-watchdog-MIPS-add-ralink-watchdog-driver.patch

   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
   5
   6 Add a driver for the watchdog timer found on Ralink SoC
   7
   8 Signed-off-by: John Crispin <blogic@openwrt.org>
   9 Cc: linux-watchdog@vger.kernel.org
  10 Cc: linux-mips@linux-mips.org
  11 ---
  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
  17
  18 --- a/drivers/watchdog/Kconfig
  19 +++ b/drivers/watchdog/Kconfig
  20 @@ -1113,6 +1113,13 @@ config LANTIQ_WDT
  21         help
  22           Hardware driver for the Lantiq SoC Watchdog Timer.
  23
  24 +config RALINK_WDT
  25 +       tristate "Ralink SoC watchdog"
  26 +       select WATCHDOG_CORE
  27 +       depends on RALINK
  28 +       help
  29 +         Hardware driver for the Ralink SoC Watchdog Timer.
  30 +
  31  # PARISC Architecture
  32
  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
  41
  42  # PARISC Architecture
  43
  44 --- /dev/null
  45 +++ b/drivers/watchdog/rt2880_wdt.c
  46 @@ -0,0 +1,208 @@
  47 +/*
  48 + * Ralink RT288x/RT3xxx/MT76xx built-in hardware watchdog timer
  49 + *
  50 + * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
  51 + * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
  52 + *
  53 + * This driver was based on: drivers/watchdog/softdog.c
  54 + *
  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.
  58 + */
  59 +
  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>
  68 +
  69 +#include <asm/mach-ralink/ralink_regs.h>
  70 +
  71 +#define SYSC_RSTSTAT                   0x38
  72 +#define WDT_RST_CAUSE                  BIT(1)
  73 +
  74 +#define RALINK_WDT_TIMEOUT             30
  75 +#define RALINK_WDT_PRESCALE            65536
  76 +
  77 +#define TIMER_REG_TMR1LOAD             0x00
  78 +#define TIMER_REG_TMR1CTL              0x08
  79 +
  80 +#define TMRSTAT_TMR1RST                        BIT(5)
  81 +
  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
  91 +
  92 +static struct clk *rt288x_wdt_clk;
  93 +static unsigned long rt288x_wdt_freq;
  94 +static void __iomem *rt288x_wdt_base;
  95 +
  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) ")");
 101 +
 102 +static inline void rt_wdt_w32(unsigned reg, u32 val)
 103 +{
 104 +       iowrite32(val, rt288x_wdt_base + reg);
 105 +}
 106 +
 107 +static inline u32 rt_wdt_r32(unsigned reg)
 108 +{
 109 +       return ioread32(rt288x_wdt_base + reg);
 110 +}
 111 +
 112 +static int rt288x_wdt_ping(struct watchdog_device *w)
 113 +{
 114 +       rt_wdt_w32(TIMER_REG_TMR1LOAD, w->timeout * rt288x_wdt_freq);
 115 +
 116 +       return 0;
 117 +}
 118 +
 119 +static int rt288x_wdt_start(struct watchdog_device *w)
 120 +{
 121 +       u32 t;
 122 +
 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);
 129 +
 130 +       rt288x_wdt_ping(w);
 131 +
 132 +       t = rt_wdt_r32(TIMER_REG_TMR1CTL);
 133 +       t |= TMR1CTL_ENABLE;
 134 +       rt_wdt_w32(TIMER_REG_TMR1CTL, t);
 135 +
 136 +       return 0;
 137 +}
 138 +
 139 +static int rt288x_wdt_stop(struct watchdog_device *w)
 140 +{
 141 +       u32 t;
 142 +
 143 +       rt288x_wdt_ping(w);
 144 +
 145 +       t = rt_wdt_r32(TIMER_REG_TMR1CTL);
 146 +       t &= ~TMR1CTL_ENABLE;
 147 +       rt_wdt_w32(TIMER_REG_TMR1CTL, t);
 148 +
 149 +       return 0;
 150 +}
 151 +
 152 +static int rt288x_wdt_set_timeout(struct watchdog_device *w, unsigned int t)
 153 +{
 154 +       w->timeout = t;
 155 +       rt288x_wdt_ping(w);
 156 +
 157 +       return 0;
 158 +}
 159 +
 160 +static int rt288x_wdt_bootcause(void)
 161 +{
 162 +       if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE)
 163 +               return WDIOF_CARDRESET;
 164 +
 165 +       return 0;
 166 +}
 167 +
 168 +static struct watchdog_info rt288x_wdt_info = {
 169 +       .identity = "Ralink Watchdog",
 170 +       .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
 171 +};
 172 +
 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,
 179 +};
 180 +
 181 +static struct watchdog_device rt288x_wdt_dev = {
 182 +       .info = &rt288x_wdt_info,
 183 +       .ops = &rt288x_wdt_ops,
 184 +       .min_timeout = 1,
 185 +};
 186 +
 187 +static int rt288x_wdt_probe(struct platform_device *pdev)
 188 +{
 189 +       struct resource *res;
 190 +       int ret;
 191 +
 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);
 196 +
 197 +       rt288x_wdt_clk = devm_clk_get(&pdev->dev, NULL);
 198 +       if (IS_ERR(rt288x_wdt_clk))
 199 +               return PTR_ERR(rt288x_wdt_clk);
 200 +
 201 +       device_reset(&pdev->dev);
 202 +
 203 +       rt288x_wdt_freq = clk_get_rate(rt288x_wdt_clk) / RALINK_WDT_PRESCALE;
 204 +
 205 +       rt288x_wdt_dev.dev = &pdev->dev;
 206 +       rt288x_wdt_dev.bootstatus = rt288x_wdt_bootcause();
 207 +
 208 +       rt288x_wdt_dev.max_timeout = (0xfffful / rt288x_wdt_freq);
 209 +       rt288x_wdt_dev.timeout = rt288x_wdt_dev.max_timeout;
 210 +
 211 +       watchdog_set_nowayout(&rt288x_wdt_dev, nowayout);
 212 +
 213 +       ret = watchdog_register_device(&rt288x_wdt_dev);
 214 +       if (!ret)
 215 +               dev_info(&pdev->dev, "Initialized\n");
 216 +
 217 +       return 0;
 218 +}
 219 +
 220 +static int rt288x_wdt_remove(struct platform_device *pdev)
 221 +{
 222 +       watchdog_unregister_device(&rt288x_wdt_dev);
 223 +
 224 +       return 0;
 225 +}
 226 +
 227 +static void rt288x_wdt_shutdown(struct platform_device *pdev)
 228 +{
 229 +       rt288x_wdt_stop(&rt288x_wdt_dev);
 230 +}
 231 +
 232 +static const struct of_device_id rt288x_wdt_match[] = {
 233 +       { .compatible = "ralink,rt2880-wdt" },
 234 +       {},
 235 +};
 236 +MODULE_DEVICE_TABLE(of, rt288x_wdt_match);
 237 +
 238 +static struct platform_driver rt288x_wdt_driver = {
 239 +       .probe          = rt288x_wdt_probe,
 240 +       .remove         = rt288x_wdt_remove,
 241 +       .shutdown       = rt288x_wdt_shutdown,
 242 +       .driver         = {
 243 +               .name           = KBUILD_MODNAME,
 244 +               .owner          = THIS_MODULE,
 245 +               .of_match_table = rt288x_wdt_match,
 246 +       },
 247 +};
 248 +
 249 +module_platform_driver(rt288x_wdt_driver);
 250 +
 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);