target/linux/cns3xxx/patches-4.14/020-watchdog_support.patch

   1 Add a watchdog driver for ARM MPcore processors.
   2
   3 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   4 --- a/drivers/watchdog/Kconfig
   5 +++ b/drivers/watchdog/Kconfig
   6 @@ -355,6 +355,13 @@ config KS8695_WATCHDOG
   7           Watchdog timer embedded into KS8695 processor. This will reboot your
   8           system when the timeout is reached.
   9
  10 +config MPCORE_WATCHDOG
  11 +       tristate "MPcore watchdog"
  12 +       depends on HAVE_ARM_TWD
  13 +       select WATCHDOG_CORE
  14 +       help
  15 +         Watchdog timer embedded into the MPcore system
  16 +
  17  config HAVE_S3C2410_WATCHDOG
  18         bool
  19         help
  20 --- a/drivers/watchdog/Makefile
  21 +++ b/drivers/watchdog/Makefile
  22 @@ -49,6 +49,7 @@ obj-$(CONFIG_977_WATCHDOG) += wdt977.o
  23  obj-$(CONFIG_GEMINI_WATCHDOG) += gemini_wdt.o
  24  obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
  25  obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o
  26 +obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o
  27  obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o
  28  obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o
  29  obj-$(CONFIG_SAMA5D4_WATCHDOG) += sama5d4_wdt.o
  30 --- /dev/null
  31 +++ b/drivers/watchdog/mpcore_wdt.c
  32 @@ -0,0 +1,118 @@
  33 +/*
  34 + * Watchdog driver for ARM MPcore
  35 + *
  36 + * Copyright (C) 2017 Felix Fietkau <nbd@nbd.name>
  37 + */
  38 +
  39 +#include <linux/export.h>
  40 +#include <linux/module.h>
  41 +#include <linux/kernel.h>
  42 +#include <linux/watchdog.h>
  43 +#include <linux/platform_device.h>
  44 +#include <linux/io.h>
  45 +#include <asm/smp_twd.h>
  46 +
  47 +static void __iomem *wdt_base;
  48 +static int wdt_timeout = 60;
  49 +
  50 +static int mpcore_wdt_keepalive(struct watchdog_device *wdd)
  51 +{
  52 +       static int perturb;
  53 +       u32 count;
  54 +
  55 +       count = (twd_timer_get_rate() / 256) * wdt_timeout;
  56 +
  57 +       /* Reload register needs a different value on each refresh */
  58 +       count += perturb;
  59 +       perturb = !perturb;
  60 +
  61 +       iowrite32(count, wdt_base + TWD_WDOG_LOAD);
  62 +
  63 +       return 0;
  64 +}
  65 +
  66 +static int mpcore_wdt_start(struct watchdog_device *wdd)
  67 +{
  68 +       mpcore_wdt_keepalive(wdd);
  69 +
  70 +       /* prescale = 256, mode = 1, enable = 1 */
  71 +       iowrite32(0x0000FF09, wdt_base + TWD_WDOG_CONTROL);
  72 +
  73 +       return 0;
  74 +}
  75 +
  76 +static int mpcore_wdt_stop(struct watchdog_device *wdd)
  77 +{
  78 +       iowrite32(0x12345678, wdt_base + TWD_WDOG_DISABLE);
  79 +       iowrite32(0x87654321, wdt_base + TWD_WDOG_DISABLE);
  80 +       iowrite32(0x0, wdt_base + TWD_WDOG_CONTROL);
  81 +
  82 +       return 0;
  83 +}
  84 +
  85 +static int mpcore_wdt_set_timeout(struct watchdog_device *wdd,
  86 +                                unsigned int timeout)
  87 +{
  88 +       mpcore_wdt_stop(wdd);
  89 +       wdt_timeout = timeout;
  90 +       mpcore_wdt_start(wdd);
  91 +
  92 +       return 0;
  93 +}
  94 +
  95 +static const struct watchdog_info mpcore_wdt_info = {
  96 +       .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
  97 +       .identity = "MPcore Watchdog",
  98 +};
  99 +
 100 +static const struct watchdog_ops mpcore_wdt_ops = {
 101 +       .owner = THIS_MODULE,
 102 +       .start = mpcore_wdt_start,
 103 +       .stop  = mpcore_wdt_stop,
 104 +       .ping  = mpcore_wdt_keepalive,
 105 +       .set_timeout = mpcore_wdt_set_timeout,
 106 +};
 107 +
 108 +static struct watchdog_device mpcore_wdt = {
 109 +       .info = &mpcore_wdt_info,
 110 +       .ops = &mpcore_wdt_ops,
 111 +       .min_timeout = 1,
 112 +       .max_timeout = 65535,
 113 +};
 114 +
 115 +static int mpcore_wdt_probe(struct platform_device *pdev)
 116 +{
 117 +       struct resource *res;
 118 +       unsigned long rate = twd_timer_get_rate();
 119 +
 120 +       pr_info("MPCore WD init. clockrate: %u prescaler: %u countrate: %u timeout: %us\n", rate, 256, rate / 256, wdt_timeout);
 121 +
 122 +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 123 +       if (!res)
 124 +               return -ENODEV;
 125 +
 126 +       wdt_base = devm_ioremap_resource(&pdev->dev, res);
 127 +       if (IS_ERR(wdt_base))
 128 +               return PTR_ERR(wdt_base);
 129 +
 130 +       watchdog_register_device(&mpcore_wdt);
 131 +       return 0;
 132 +}
 133 +
 134 +static int mpcore_wdt_remove(struct platform_device *dev)
 135 +{
 136 +       watchdog_unregister_device(&mpcore_wdt);
 137 +       return 0;
 138 +}
 139 +
 140 +static struct platform_driver mpcore_wdt_driver = {
 141 +       .probe          = mpcore_wdt_probe,
 142 +       .remove         = mpcore_wdt_remove,
 143 +       .driver         = {
 144 +               .name   = "mpcore_wdt",
 145 +       },
 146 +};
 147 +
 148 +module_platform_driver(mpcore_wdt_driver);
 149 +MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
 150 +MODULE_LICENSE("GPL");
 151 --- a/arch/arm/include/asm/smp_twd.h
 152 +++ b/arch/arm/include/asm/smp_twd.h
 153 @@ -34,5 +34,6 @@ struct twd_local_timer name __initdata =
 154  };
 155
 156  int twd_local_timer_register(struct twd_local_timer *);
 157 +unsigned long twd_timer_get_rate(void);
 158
 159  #endif
 160 --- a/arch/arm/kernel/smp_twd.c
 161 +++ b/arch/arm/kernel/smp_twd.c
 162 @@ -15,6 +15,7 @@
 163  #include <linux/delay.h>
 164  #include <linux/device.h>
 165  #include <linux/err.h>
 166 +#include <linux/export.h>
 167  #include <linux/smp.h>
 168  #include <linux/jiffies.h>
 169  #include <linux/clockchips.h>
 170 @@ -380,6 +381,14 @@ int __init twd_local_timer_register(stru
 171         return twd_local_timer_common_register(NULL);
 172  }
 173
 174 +/* Needed by mpcore_wdt */
 175 +unsigned long twd_timer_get_rate(void)
 176 +{
 177 +       return twd_timer_rate;
 178 +}
 179 +EXPORT_SYMBOL_GPL(twd_timer_get_rate);
 180 +
 181 +
 182  #ifdef CONFIG_OF
 183  static int __init twd_local_timer_of_register(struct device_node *np)
 184  {