1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright 2018-2019 NXP. 4 */ 5 6 #include <linux/arm-smccc.h> 7 #include <linux/firmware/imx/sci.h> 8 #include <linux/io.h> 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/moduleparam.h> 12 #include <linux/of.h> 13 #include <linux/platform_device.h> 14 #include <linux/watchdog.h> 15 16 #define DEFAULT_TIMEOUT 60 17 /* 18 * Software timer tick implemented in scfw side, support 10ms to 0xffffffff ms 19 * in theory, but for normal case, 1s~128s is enough, you can change this max 20 * value in case it's not enough. 21 */ 22 #define MAX_TIMEOUT 128 23 24 #define IMX_SIP_TIMER 0xC2000002 25 #define IMX_SIP_TIMER_START_WDOG 0x01 26 #define IMX_SIP_TIMER_STOP_WDOG 0x02 27 #define IMX_SIP_TIMER_SET_WDOG_ACT 0x03 28 #define IMX_SIP_TIMER_PING_WDOG 0x04 29 #define IMX_SIP_TIMER_SET_TIMEOUT_WDOG 0x05 30 #define IMX_SIP_TIMER_GET_WDOG_STAT 0x06 31 #define IMX_SIP_TIMER_SET_PRETIME_WDOG 0x07 32 33 #define SC_TIMER_WDOG_ACTION_PARTITION 0 34 35 #define SC_IRQ_WDOG 1 36 #define SC_IRQ_GROUP_WDOG 1 37 38 static bool nowayout = WATCHDOG_NOWAYOUT; 39 module_param(nowayout, bool, 0000); 40 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" 41 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 42 43 struct imx_sc_wdt_device { 44 struct watchdog_device wdd; 45 struct notifier_block wdt_notifier; 46 }; 47 48 static int imx_sc_wdt_ping(struct watchdog_device *wdog) 49 { 50 struct arm_smccc_res res; 51 52 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG, 53 0, 0, 0, 0, 0, 0, &res); 54 55 return 0; 56 } 57 58 static int imx_sc_wdt_start(struct watchdog_device *wdog) 59 { 60 struct arm_smccc_res res; 61 62 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG, 63 0, 0, 0, 0, 0, 0, &res); 64 if (res.a0) 65 return -EACCES; 66 67 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT, 68 SC_TIMER_WDOG_ACTION_PARTITION, 69 0, 0, 0, 0, 0, &res); 70 return res.a0 ? -EACCES : 0; 71 } 72 73 static int imx_sc_wdt_stop(struct watchdog_device *wdog) 74 { 75 struct arm_smccc_res res; 76 77 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG, 78 0, 0, 0, 0, 0, 0, &res); 79 80 return res.a0 ? -EACCES : 0; 81 } 82 83 static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog, 84 unsigned int timeout) 85 { 86 struct arm_smccc_res res; 87 88 wdog->timeout = timeout; 89 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_TIMEOUT_WDOG, 90 timeout * 1000, 0, 0, 0, 0, 0, &res); 91 92 return res.a0 ? -EACCES : 0; 93 } 94 95 static int imx_sc_wdt_set_pretimeout(struct watchdog_device *wdog, 96 unsigned int pretimeout) 97 { 98 struct arm_smccc_res res; 99 100 /* 101 * SCU firmware calculates pretimeout based on current time 102 * stamp instead of watchdog timeout stamp, need to convert 103 * the pretimeout to SCU firmware's timeout value. 104 */ 105 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_PRETIME_WDOG, 106 (wdog->timeout - pretimeout) * 1000, 0, 0, 0, 107 0, 0, &res); 108 if (res.a0) 109 return -EACCES; 110 111 wdog->pretimeout = pretimeout; 112 113 return 0; 114 } 115 116 static int imx_sc_wdt_notify(struct notifier_block *nb, 117 unsigned long event, void *group) 118 { 119 struct imx_sc_wdt_device *imx_sc_wdd = 120 container_of(nb, 121 struct imx_sc_wdt_device, 122 wdt_notifier); 123 124 if (event & SC_IRQ_WDOG && 125 *(u8 *)group == SC_IRQ_GROUP_WDOG) 126 watchdog_notify_pretimeout(&imx_sc_wdd->wdd); 127 128 return 0; 129 } 130 131 static void imx_sc_wdt_action(void *data) 132 { 133 struct notifier_block *wdt_notifier = data; 134 135 imx_scu_irq_unregister_notifier(wdt_notifier); 136 imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, 137 SC_IRQ_WDOG, 138 false); 139 } 140 141 static const struct watchdog_ops imx_sc_wdt_ops = { 142 .owner = THIS_MODULE, 143 .start = imx_sc_wdt_start, 144 .stop = imx_sc_wdt_stop, 145 .ping = imx_sc_wdt_ping, 146 .set_timeout = imx_sc_wdt_set_timeout, 147 .set_pretimeout = imx_sc_wdt_set_pretimeout, 148 }; 149 150 static struct watchdog_info imx_sc_wdt_info = { 151 .identity = "i.MX SC watchdog timer", 152 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | 153 WDIOF_MAGICCLOSE, 154 }; 155 156 static int imx_sc_wdt_probe(struct platform_device *pdev) 157 { 158 struct imx_sc_wdt_device *imx_sc_wdd; 159 struct watchdog_device *wdog; 160 struct device *dev = &pdev->dev; 161 int ret; 162 163 imx_sc_wdd = devm_kzalloc(dev, sizeof(*imx_sc_wdd), GFP_KERNEL); 164 if (!imx_sc_wdd) 165 return -ENOMEM; 166 167 platform_set_drvdata(pdev, imx_sc_wdd); 168 169 wdog = &imx_sc_wdd->wdd; 170 wdog->info = &imx_sc_wdt_info; 171 wdog->ops = &imx_sc_wdt_ops; 172 wdog->min_timeout = 1; 173 wdog->max_timeout = MAX_TIMEOUT; 174 wdog->parent = dev; 175 wdog->timeout = DEFAULT_TIMEOUT; 176 177 watchdog_init_timeout(wdog, 0, dev); 178 179 ret = imx_sc_wdt_set_timeout(wdog, wdog->timeout); 180 if (ret) 181 return ret; 182 183 watchdog_stop_on_reboot(wdog); 184 watchdog_stop_on_unregister(wdog); 185 186 ret = imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, 187 SC_IRQ_WDOG, 188 true); 189 if (ret) { 190 dev_warn(dev, "Enable irq failed, pretimeout NOT supported\n"); 191 goto register_device; 192 } 193 194 imx_sc_wdd->wdt_notifier.notifier_call = imx_sc_wdt_notify; 195 ret = imx_scu_irq_register_notifier(&imx_sc_wdd->wdt_notifier); 196 if (ret) { 197 imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, 198 SC_IRQ_WDOG, 199 false); 200 dev_warn(dev, 201 "Register irq notifier failed, pretimeout NOT supported\n"); 202 goto register_device; 203 } 204 205 ret = devm_add_action_or_reset(dev, imx_sc_wdt_action, 206 &imx_sc_wdd->wdt_notifier); 207 if (!ret) 208 imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT; 209 else 210 dev_warn(dev, "Add action failed, pretimeout NOT supported\n"); 211 212 register_device: 213 return devm_watchdog_register_device(dev, wdog); 214 } 215 216 static const struct of_device_id imx_sc_wdt_dt_ids[] = { 217 { .compatible = "fsl,imx-sc-wdt", }, 218 { /* sentinel */ } 219 }; 220 MODULE_DEVICE_TABLE(of, imx_sc_wdt_dt_ids); 221 222 static struct platform_driver imx_sc_wdt_driver = { 223 .probe = imx_sc_wdt_probe, 224 .driver = { 225 .name = "imx-sc-wdt", 226 .of_match_table = imx_sc_wdt_dt_ids, 227 }, 228 }; 229 module_platform_driver(imx_sc_wdt_driver); 230 231 MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>"); 232 MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver"); 233 MODULE_LICENSE("GPL v2"); 234