drivers/watchdog/ni903x_wdt.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2016 National Instruments Corp.
   4  */
   5
   6 #include <linux/acpi.h>
   7 #include <linux/device.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/io.h>
  10 #include <linux/module.h>
  11 #include <linux/watchdog.h>
  12
  13 #define NIWD_CONTROL    0x01
  14 #define NIWD_COUNTER2   0x02
  15 #define NIWD_COUNTER1   0x03
  16 #define NIWD_COUNTER0   0x04
  17 #define NIWD_SEED2      0x05
  18 #define NIWD_SEED1      0x06
  19 #define NIWD_SEED0      0x07
  20
  21 #define NIWD_IO_SIZE    0x08
  22
  23 #define NIWD_CONTROL_MODE               0x80
  24 #define NIWD_CONTROL_PROC_RESET         0x20
  25 #define NIWD_CONTROL_PET                0x10
  26 #define NIWD_CONTROL_RUNNING            0x08
  27 #define NIWD_CONTROL_CAPTURECOUNTER     0x04
  28 #define NIWD_CONTROL_RESET              0x02
  29 #define NIWD_CONTROL_ALARM              0x01
  30
  31 #define NIWD_PERIOD_NS          30720
  32 #define NIWD_MIN_TIMEOUT        1
  33 #define NIWD_MAX_TIMEOUT        515
  34 #define NIWD_DEFAULT_TIMEOUT    60
  35
  36 #define NIWD_NAME               "ni903x_wdt"
  37
  38 struct ni903x_wdt {
  39         struct device *dev;
  40         u16 io_base;
  41         struct watchdog_device wdd;
  42 };
  43
  44 static unsigned int timeout;
  45 module_param(timeout, uint, 0);
  46 MODULE_PARM_DESC(timeout,
  47                  "Watchdog timeout in seconds. (default="
  48                  __MODULE_STRING(NIWD_DEFAULT_TIMEOUT) ")");
  49
  50 static int nowayout = WATCHDOG_NOWAYOUT;
  51 module_param(nowayout, int, S_IRUGO);
  52 MODULE_PARM_DESC(nowayout,
  53                  "Watchdog cannot be stopped once started (default="
  54                  __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  55
  56 static void ni903x_start(struct ni903x_wdt *wdt)
  57 {
  58         u8 control = inb(wdt->io_base + NIWD_CONTROL);
  59
  60         outb(control | NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL);
  61         outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL);
  62 }
  63
  64 static int ni903x_wdd_set_timeout(struct watchdog_device *wdd,
  65                                   unsigned int timeout)
  66 {
  67         struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
  68         u32 counter = timeout * (1000000000 / NIWD_PERIOD_NS);
  69
  70         outb(((0x00FF0000 & counter) >> 16), wdt->io_base + NIWD_SEED2);
  71         outb(((0x0000FF00 & counter) >> 8), wdt->io_base + NIWD_SEED1);
  72         outb((0x000000FF & counter), wdt->io_base + NIWD_SEED0);
  73
  74         wdd->timeout = timeout;
  75
  76         return 0;
  77 }
  78
  79 static unsigned int ni903x_wdd_get_timeleft(struct watchdog_device *wdd)
  80 {
  81         struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
  82         u8 control, counter0, counter1, counter2;
  83         u32 counter;
  84
  85         control = inb(wdt->io_base + NIWD_CONTROL);
  86         control |= NIWD_CONTROL_CAPTURECOUNTER;
  87         outb(control, wdt->io_base + NIWD_CONTROL);
  88
  89         counter2 = inb(wdt->io_base + NIWD_COUNTER2);
  90         counter1 = inb(wdt->io_base + NIWD_COUNTER1);
  91         counter0 = inb(wdt->io_base + NIWD_COUNTER0);
  92
  93         counter = (counter2 << 16) | (counter1 << 8) | counter0;
  94
  95         return counter / (1000000000 / NIWD_PERIOD_NS);
  96 }
  97
  98 static int ni903x_wdd_ping(struct watchdog_device *wdd)
  99 {
 100         struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
 101         u8 control;
 102
 103         control = inb(wdt->io_base + NIWD_CONTROL);
 104         outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL);
 105
 106         return 0;
 107 }
 108
 109 static int ni903x_wdd_start(struct watchdog_device *wdd)
 110 {
 111         struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
 112
 113         outb(NIWD_CONTROL_RESET | NIWD_CONTROL_PROC_RESET,
 114              wdt->io_base + NIWD_CONTROL);
 115
 116         ni903x_wdd_set_timeout(wdd, wdd->timeout);
 117         ni903x_start(wdt);
 118
 119         return 0;
 120 }
 121
 122 static int ni903x_wdd_stop(struct watchdog_device *wdd)
 123 {
 124         struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
 125
 126         outb(NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL);
 127
 128         return 0;
 129 }
 130
 131 static acpi_status ni903x_resources(struct acpi_resource *res, void *data)
 132 {
 133         struct ni903x_wdt *wdt = data;
 134         u16 io_size;
 135
 136         switch (res->type) {
 137         case ACPI_RESOURCE_TYPE_IO:
 138                 if (wdt->io_base != 0) {
 139                         dev_err(wdt->dev, "too many IO resources\n");
 140                         return AE_ERROR;
 141                 }
 142
 143                 wdt->io_base = res->data.io.minimum;
 144                 io_size = res->data.io.address_length;
 145
 146                 if (io_size < NIWD_IO_SIZE) {
 147                         dev_err(wdt->dev, "memory region too small\n");
 148                         return AE_ERROR;
 149                 }
 150
 151                 if (!devm_request_region(wdt->dev, wdt->io_base, io_size,
 152                                          NIWD_NAME)) {
 153                         dev_err(wdt->dev, "failed to get memory region\n");
 154                         return AE_ERROR;
 155                 }
 156
 157                 return AE_OK;
 158
 159         case ACPI_RESOURCE_TYPE_END_TAG:
 160         default:
 161                 /* Ignore unsupported resources, e.g. IRQ */
 162                 return AE_OK;
 163         }
 164 }
 165
 166 static const struct watchdog_info ni903x_wdd_info = {
 167         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
 168         .identity = "NI Watchdog",
 169 };
 170
 171 static const struct watchdog_ops ni903x_wdd_ops = {
 172         .owner = THIS_MODULE,
 173         .start = ni903x_wdd_start,
 174         .stop = ni903x_wdd_stop,
 175         .ping = ni903x_wdd_ping,
 176         .set_timeout = ni903x_wdd_set_timeout,
 177         .get_timeleft = ni903x_wdd_get_timeleft,
 178 };
 179
 180 static int ni903x_acpi_add(struct acpi_device *device)
 181 {
 182         struct device *dev = &device->dev;
 183         struct watchdog_device *wdd;
 184         struct ni903x_wdt *wdt;
 185         acpi_status status;
 186         int ret;
 187
 188         wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
 189         if (!wdt)
 190                 return -ENOMEM;
 191
 192         device->driver_data = wdt;
 193         wdt->dev = dev;
 194
 195         status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 196                                      ni903x_resources, wdt);
 197         if (ACPI_FAILURE(status) || wdt->io_base == 0) {
 198                 dev_err(dev, "failed to get resources\n");
 199                 return -ENODEV;
 200         }
 201
 202         wdd = &wdt->wdd;
 203         wdd->info = &ni903x_wdd_info;
 204         wdd->ops = &ni903x_wdd_ops;
 205         wdd->min_timeout = NIWD_MIN_TIMEOUT;
 206         wdd->max_timeout = NIWD_MAX_TIMEOUT;
 207         wdd->timeout = NIWD_DEFAULT_TIMEOUT;
 208         wdd->parent = dev;
 209         watchdog_set_drvdata(wdd, wdt);
 210         watchdog_set_nowayout(wdd, nowayout);
 211         watchdog_init_timeout(wdd, timeout, dev);
 212
 213         ret = watchdog_register_device(wdd);
 214         if (ret)
 215                 return ret;
 216
 217         /* Switch from boot mode to user mode */
 218         outb(NIWD_CONTROL_RESET | NIWD_CONTROL_MODE,
 219              wdt->io_base + NIWD_CONTROL);
 220
 221         dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
 222                 wdt->io_base, timeout, nowayout);
 223
 224         return 0;
 225 }
 226
 227 static int ni903x_acpi_remove(struct acpi_device *device)
 228 {
 229         struct ni903x_wdt *wdt = acpi_driver_data(device);
 230
 231         ni903x_wdd_stop(&wdt->wdd);
 232         watchdog_unregister_device(&wdt->wdd);
 233
 234         return 0;
 235 }
 236
 237 static const struct acpi_device_id ni903x_device_ids[] = {
 238         {"NIC775C", 0},
 239         {"", 0},
 240 };
 241 MODULE_DEVICE_TABLE(acpi, ni903x_device_ids);
 242
 243 static struct acpi_driver ni903x_acpi_driver = {
 244         .name = NIWD_NAME,
 245         .ids = ni903x_device_ids,
 246         .ops = {
 247                 .add = ni903x_acpi_add,
 248                 .remove = ni903x_acpi_remove,
 249         },
 250 };
 251
 252 module_acpi_driver(ni903x_acpi_driver);
 253
 254 MODULE_DESCRIPTION("NI 903x Watchdog");
 255 MODULE_AUTHOR("Jeff Westfahl <jeff.westfahl@ni.com>");
 256 MODULE_AUTHOR("Kyle Roeschley <kyle.roeschley@ni.com>");
 257 MODULE_LICENSE("GPL");