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 void 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 } 234 235 static const struct acpi_device_id ni903x_device_ids[] = { 236 {"NIC775C", 0}, 237 {"", 0}, 238 }; 239 MODULE_DEVICE_TABLE(acpi, ni903x_device_ids); 240 241 static struct acpi_driver ni903x_acpi_driver = { 242 .name = NIWD_NAME, 243 .ids = ni903x_device_ids, 244 .ops = { 245 .add = ni903x_acpi_add, 246 .remove = ni903x_acpi_remove, 247 }, 248 }; 249 250 module_acpi_driver(ni903x_acpi_driver); 251 252 MODULE_DESCRIPTION("NI 903x Watchdog"); 253 MODULE_AUTHOR("Jeff Westfahl <jeff.westfahl@ni.com>"); 254 MODULE_AUTHOR("Kyle Roeschley <kyle.roeschley@ni.com>"); 255 MODULE_LICENSE("GPL"); 256