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 ---
   5 --- a/drivers/watchdog/Kconfig
   6 +++ b/drivers/watchdog/Kconfig
   7 @@ -355,6 +355,13 @@ config KS8695_WATCHDOG
   8           Watchdog timer embedded into KS8695 processor. This will reboot your
   9           system when the timeout is reached.
  10
  11 +config MPCORE_WATCHDOG
  12 +       tristate "MPcore watchdog"
  13 +       depends on HAVE_ARM_TWD
  14 +       select WATCHDOG_CORE
  15 +       help
  16 +         Watchdog timer embedded into the MPcore system
  17 +
  18  config HAVE_S3C2410_WATCHDOG
  19         bool
  20         help
  21 --- a/drivers/watchdog/Makefile
  22 +++ b/drivers/watchdog/Makefile
  23 @@ -49,6 +49,7 @@ obj-$(CONFIG_977_WATCHDOG) += wdt977.o
  24  obj-$(CONFIG_GEMINI_WATCHDOG) += gemini_wdt.o
  25  obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
  26  obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o
  27 +obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o
  28  obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o
  29  obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o
  30  obj-$(CONFIG_SAMA5D4_WATCHDOG) += sama5d4_wdt.o
  31 --- /dev/null
  32 +++ b/drivers/watchdog/mpcore_wdt.c
  33 @@ -0,0 +1,118 @@
  34 +/*
  35 + * Watchdog driver for ARM MPcore
  36 + *
  37 + * Copyright (C) 2017 Felix Fietkau <nbd@nbd.name>
  38 + */
  39 +
  40 +#include <linux/export.h>
  41 +#include <linux/module.h>
  42 +#include <linux/kernel.h>
  43 +#include <linux/watchdog.h>
  44 +#include <linux/platform_device.h>
  45 +#include <linux/io.h>
  46 +#include <asm/smp_twd.h>
  47 +
  48 +static void __iomem *wdt_base;
  49 +static int wdt_timeout = 60;
  50 +
  51 +static int mpcore_wdt_keepalive(struct watchdog_device *wdd)
  52 +{
  53 +       static int perturb;
  54 +       u32 count;
  55 +
  56 +       count = (twd_timer_get_rate() / 256) * wdt_timeout;
  57 +
  58 +       /* Reload register needs a different value on each refresh */
  59 +       count += perturb;
  60 +       perturb = !perturb;
  61 +
  62 +       iowrite32(count, wdt_base + TWD_WDOG_LOAD);
  63 +
  64 +       return 0;
  65 +}
  66 +
  67 +static int mpcore_wdt_start(struct watchdog_device *wdd)
  68 +{
  69 +       mpcore_wdt_keepalive(wdd);
  70 +
  71 +       /* prescale = 256, mode = 1, enable = 1 */
  72 +       iowrite32(0x0000FF09, wdt_base + TWD_WDOG_CONTROL);
  73 +
  74 +       return 0;
  75 +}
  76 +
  77 +static int mpcore_wdt_stop(struct watchdog_device *wdd)
  78 +{
  79 +       iowrite32(0x12345678, wdt_base + TWD_WDOG_DISABLE);
  80 +       iowrite32(0x87654321, wdt_base + TWD_WDOG_DISABLE);
  81 +       iowrite32(0x0, wdt_base + TWD_WDOG_CONTROL);
  82 +
  83 +       return 0;
  84 +}
  85 +
  86 +static int mpcore_wdt_set_timeout(struct watchdog_device *wdd,
  87 +                                unsigned int timeout)
  88 +{
  89 +       mpcore_wdt_stop(wdd);
  90 +       wdt_timeout = timeout;
  91 +       mpcore_wdt_start(wdd);
  92 +
  93 +       return 0;
  94 +}
  95 +
  96 +static const struct watchdog_info mpcore_wdt_info = {
  97 +       .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
  98 +       .identity = "MPcore Watchdog",
  99 +};
 100 +
 101 +static const struct watchdog_ops mpcore_wdt_ops = {
 102 +       .owner = THIS_MODULE,
 103 +       .start = mpcore_wdt_start,
 104 +       .stop  = mpcore_wdt_stop,
 105 +       .ping  = mpcore_wdt_keepalive,
 106 +       .set_timeout = mpcore_wdt_set_timeout,
 107 +};
 108 +
 109 +static struct watchdog_device mpcore_wdt = {
 110 +       .info = &mpcore_wdt_info,
 111 +       .ops = &mpcore_wdt_ops,
 112 +       .min_timeout = 1,
 113 +       .max_timeout = 65535,
 114 +};
 115 +
 116 +static int mpcore_wdt_probe(struct platform_device *pdev)
 117 +{
 118 +       struct resource *res;
 119 +       unsigned long rate = twd_timer_get_rate();
 120 +
 121 +       pr_info("MPCore WD init. clockrate: %u prescaler: %u countrate: %u timeout: %us\n", rate, 256, rate / 256, wdt_timeout);
 122 +
 123 +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 124 +       if (!res)
 125 +               return -ENODEV;
 126 +
 127 +       wdt_base = devm_ioremap_resource(&pdev->dev, res);
 128 +       if (IS_ERR(wdt_base))
 129 +               return PTR_ERR(wdt_base);
 130 +
 131 +       watchdog_register_device(&mpcore_wdt);
 132 +       return 0;
 133 +}
 134 +
 135 +static int mpcore_wdt_remove(struct platform_device *dev)
 136 +{
 137 +       watchdog_unregister_device(&mpcore_wdt);
 138 +       return 0;
 139 +}
 140 +
 141 +static struct platform_driver mpcore_wdt_driver = {
 142 +       .probe          = mpcore_wdt_probe,
 143 +       .remove         = mpcore_wdt_remove,
 144 +       .driver         = {
 145 +               .name   = "mpcore_wdt",
 146 +       },
 147 +};
 148 +
 149 +module_platform_driver(mpcore_wdt_driver);
 150 +MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
 151 +MODULE_LICENSE("GPL");
 152 --- a/arch/arm/include/asm/smp_twd.h
 153 +++ b/arch/arm/include/asm/smp_twd.h
 154 @@ -34,5 +34,6 @@ struct twd_local_timer name __initdata =
 155  };
 156
 157  int twd_local_timer_register(struct twd_local_timer *);
 158 +unsigned long twd_timer_get_rate(void);
 159
 160  #endif
 161 --- a/arch/arm/kernel/smp_twd.c
 162 +++ b/arch/arm/kernel/smp_twd.c
 163 @@ -15,6 +15,7 @@
 164  #include <linux/delay.h>
 165  #include <linux/device.h>
 166  #include <linux/err.h>
 167 +#include <linux/export.h>
 168  #include <linux/smp.h>
 169  #include <linux/jiffies.h>
 170  #include <linux/clockchips.h>
 171 @@ -380,6 +381,14 @@ int __init twd_local_timer_register(stru
 172         return twd_local_timer_common_register(NULL);
 173  }
 174
 175 +/* Needed by mpcore_wdt */
 176 +unsigned long twd_timer_get_rate(void)
 177 +{
 178 +       return twd_timer_rate;
 179 +}
 180 +EXPORT_SYMBOL_GPL(twd_timer_get_rate);
 181 +
 182 +
 183  #ifdef CONFIG_OF
 184  static int __init twd_local_timer_of_register(struct device_node *np)
 185  {