Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Naidu Tellapati | 1054 | 86.32% | 1 | 7.69% |
Guenter Roeck | 64 | 5.24% | 2 | 15.38% |
Andrew Bresticker | 49 | 4.01% | 3 | 23.08% |
Damien Riegel | 25 | 2.05% | 2 | 15.38% |
Ezequiel García | 21 | 1.72% | 1 | 7.69% |
Eric Miao | 3 | 0.25% | 1 | 7.69% |
James Hogan | 2 | 0.16% | 1 | 7.69% |
Thomas Gleixner | 2 | 0.16% | 1 | 7.69% |
Bhumika Goyal | 1 | 0.08% | 1 | 7.69% |
Total | 1221 | 13 |
// SPDX-License-Identifier: GPL-2.0-only /* * Imagination Technologies PowerDown Controller Watchdog Timer. * * Copyright (c) 2014 Imagination Technologies Ltd. * * Based on drivers/watchdog/sunxi_wdt.c Copyright (c) 2013 Carlo Caione * 2012 Henrik Nordstrom * * Notes * ----- * The timeout value is rounded to the next power of two clock cycles. * This is configured using the PDC_WDT_CONFIG register, according to this * formula: * * timeout = 2^(delay + 1) clock cycles * * Where 'delay' is the value written in PDC_WDT_CONFIG register. * * Therefore, the hardware only allows to program watchdog timeouts, expressed * as a power of two number of watchdog clock cycles. The current implementation * guarantees that the actual watchdog timeout will be _at least_ the value * programmed in the imgpdg_wdt driver. * * The following table shows how the user-configured timeout relates * to the actual hardware timeout (watchdog clock @ 40000 Hz): * * input timeout | WD_DELAY | actual timeout * ----------------------------------- * 10 | 18 | 13 seconds * 20 | 19 | 26 seconds * 30 | 20 | 52 seconds * 60 | 21 | 104 seconds * * Albeit coarse, this granularity would suffice most watchdog uses. * If the platform allows it, the user should be able to change the watchdog * clock rate and achieve a finer timeout granularity. */ #include <linux/clk.h> #include <linux/io.h> #include <linux/log2.h> #include <linux/module.h> #include <linux/mod_devicetable.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/watchdog.h> /* registers */ #define PDC_WDT_SOFT_RESET 0x00 #define PDC_WDT_CONFIG 0x04 #define PDC_WDT_CONFIG_ENABLE BIT(31) #define PDC_WDT_CONFIG_DELAY_MASK 0x1f #define PDC_WDT_TICKLE1 0x08 #define PDC_WDT_TICKLE1_MAGIC 0xabcd1234 #define PDC_WDT_TICKLE2 0x0c #define PDC_WDT_TICKLE2_MAGIC 0x4321dcba #define PDC_WDT_TICKLE_STATUS_MASK 0x7 #define PDC_WDT_TICKLE_STATUS_SHIFT 0 #define PDC_WDT_TICKLE_STATUS_HRESET 0x0 /* Hard reset */ #define PDC_WDT_TICKLE_STATUS_TIMEOUT 0x1 /* Timeout */ #define PDC_WDT_TICKLE_STATUS_TICKLE 0x2 /* Tickled incorrectly */ #define PDC_WDT_TICKLE_STATUS_SRESET 0x3 /* Soft reset */ #define PDC_WDT_TICKLE_STATUS_USER 0x4 /* User reset */ /* Timeout values are in seconds */ #define PDC_WDT_MIN_TIMEOUT 1 #define PDC_WDT_DEF_TIMEOUT 64 static int heartbeat; module_param(heartbeat, int, 0); MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds " "(default=" __MODULE_STRING(PDC_WDT_DEF_TIMEOUT) ")"); static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); struct pdc_wdt_dev { struct watchdog_device wdt_dev; struct clk *wdt_clk; struct clk *sys_clk; void __iomem *base; }; static int pdc_wdt_keepalive(struct watchdog_device *wdt_dev) { struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev); writel(PDC_WDT_TICKLE1_MAGIC, wdt->base + PDC_WDT_TICKLE1); writel(PDC_WDT_TICKLE2_MAGIC, wdt->base + PDC_WDT_TICKLE2); return 0; } static int pdc_wdt_stop(struct watchdog_device *wdt_dev) { unsigned int val; struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev); val = readl(wdt->base + PDC_WDT_CONFIG); val &= ~PDC_WDT_CONFIG_ENABLE; writel(val, wdt->base + PDC_WDT_CONFIG); /* Must tickle to finish the stop */ pdc_wdt_keepalive(wdt_dev); return 0; } static void __pdc_wdt_set_timeout(struct pdc_wdt_dev *wdt) { unsigned long clk_rate = clk_get_rate(wdt->wdt_clk); unsigned int val; val = readl(wdt->base + PDC_WDT_CONFIG) & ~PDC_WDT_CONFIG_DELAY_MASK; val |= order_base_2(wdt->wdt_dev.timeout * clk_rate) - 1; writel(val, wdt->base + PDC_WDT_CONFIG); } static int pdc_wdt_set_timeout(struct watchdog_device *wdt_dev, unsigned int new_timeout) { struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev); wdt->wdt_dev.timeout = new_timeout; __pdc_wdt_set_timeout(wdt); return 0; } /* Start the watchdog timer (delay should already be set) */ static int pdc_wdt_start(struct watchdog_device *wdt_dev) { unsigned int val; struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev); __pdc_wdt_set_timeout(wdt); val = readl(wdt->base + PDC_WDT_CONFIG); val |= PDC_WDT_CONFIG_ENABLE; writel(val, wdt->base + PDC_WDT_CONFIG); return 0; } static int pdc_wdt_restart(struct watchdog_device *wdt_dev, unsigned long action, void *data) { struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev); /* Assert SOFT_RESET */ writel(0x1, wdt->base + PDC_WDT_SOFT_RESET); return 0; } static const struct watchdog_info pdc_wdt_info = { .identity = "IMG PDC Watchdog", .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, }; static const struct watchdog_ops pdc_wdt_ops = { .owner = THIS_MODULE, .start = pdc_wdt_start, .stop = pdc_wdt_stop, .ping = pdc_wdt_keepalive, .set_timeout = pdc_wdt_set_timeout, .restart = pdc_wdt_restart, }; static void pdc_clk_disable_unprepare(void *data) { clk_disable_unprepare(data); } static int pdc_wdt_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; u64 div; int ret, val; unsigned long clk_rate; struct pdc_wdt_dev *pdc_wdt; pdc_wdt = devm_kzalloc(dev, sizeof(*pdc_wdt), GFP_KERNEL); if (!pdc_wdt) return -ENOMEM; pdc_wdt->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(pdc_wdt->base)) return PTR_ERR(pdc_wdt->base); pdc_wdt->sys_clk = devm_clk_get(dev, "sys"); if (IS_ERR(pdc_wdt->sys_clk)) { dev_err(dev, "failed to get the sys clock\n"); return PTR_ERR(pdc_wdt->sys_clk); } pdc_wdt->wdt_clk = devm_clk_get(dev, "wdt"); if (IS_ERR(pdc_wdt->wdt_clk)) { dev_err(dev, "failed to get the wdt clock\n"); return PTR_ERR(pdc_wdt->wdt_clk); } ret = clk_prepare_enable(pdc_wdt->sys_clk); if (ret) { dev_err(dev, "could not prepare or enable sys clock\n"); return ret; } ret = devm_add_action_or_reset(dev, pdc_clk_disable_unprepare, pdc_wdt->sys_clk); if (ret) return ret; ret = clk_prepare_enable(pdc_wdt->wdt_clk); if (ret) { dev_err(dev, "could not prepare or enable wdt clock\n"); return ret; } ret = devm_add_action_or_reset(dev, pdc_clk_disable_unprepare, pdc_wdt->wdt_clk); if (ret) return ret; /* We use the clock rate to calculate the max timeout */ clk_rate = clk_get_rate(pdc_wdt->wdt_clk); if (clk_rate == 0) { dev_err(dev, "failed to get clock rate\n"); return -EINVAL; } if (order_base_2(clk_rate) > PDC_WDT_CONFIG_DELAY_MASK + 1) { dev_err(dev, "invalid clock rate\n"); return -EINVAL; } if (order_base_2(clk_rate) == 0) pdc_wdt->wdt_dev.min_timeout = PDC_WDT_MIN_TIMEOUT + 1; else pdc_wdt->wdt_dev.min_timeout = PDC_WDT_MIN_TIMEOUT; pdc_wdt->wdt_dev.info = &pdc_wdt_info; pdc_wdt->wdt_dev.ops = &pdc_wdt_ops; div = 1ULL << (PDC_WDT_CONFIG_DELAY_MASK + 1); do_div(div, clk_rate); pdc_wdt->wdt_dev.max_timeout = div; pdc_wdt->wdt_dev.timeout = PDC_WDT_DEF_TIMEOUT; pdc_wdt->wdt_dev.parent = dev; watchdog_set_drvdata(&pdc_wdt->wdt_dev, pdc_wdt); watchdog_init_timeout(&pdc_wdt->wdt_dev, heartbeat, dev); pdc_wdt_stop(&pdc_wdt->wdt_dev); /* Find what caused the last reset */ val = readl(pdc_wdt->base + PDC_WDT_TICKLE1); val = (val & PDC_WDT_TICKLE_STATUS_MASK) >> PDC_WDT_TICKLE_STATUS_SHIFT; switch (val) { case PDC_WDT_TICKLE_STATUS_TICKLE: case PDC_WDT_TICKLE_STATUS_TIMEOUT: pdc_wdt->wdt_dev.bootstatus |= WDIOF_CARDRESET; dev_info(dev, "watchdog module last reset due to timeout\n"); break; case PDC_WDT_TICKLE_STATUS_HRESET: dev_info(dev, "watchdog module last reset due to hard reset\n"); break; case PDC_WDT_TICKLE_STATUS_SRESET: dev_info(dev, "watchdog module last reset due to soft reset\n"); break; case PDC_WDT_TICKLE_STATUS_USER: dev_info(dev, "watchdog module last reset due to user reset\n"); break; default: dev_info(dev, "contains an illegal status code (%08x)\n", val); break; } watchdog_set_nowayout(&pdc_wdt->wdt_dev, nowayout); watchdog_set_restart_priority(&pdc_wdt->wdt_dev, 128); platform_set_drvdata(pdev, pdc_wdt); watchdog_stop_on_reboot(&pdc_wdt->wdt_dev); watchdog_stop_on_unregister(&pdc_wdt->wdt_dev); return devm_watchdog_register_device(dev, &pdc_wdt->wdt_dev); } static const struct of_device_id pdc_wdt_match[] = { { .compatible = "img,pdc-wdt" }, {} }; MODULE_DEVICE_TABLE(of, pdc_wdt_match); static struct platform_driver pdc_wdt_driver = { .driver = { .name = "imgpdc-wdt", .of_match_table = pdc_wdt_match, }, .probe = pdc_wdt_probe, }; module_platform_driver(pdc_wdt_driver); MODULE_AUTHOR("Jude Abraham <Jude.Abraham@imgtec.com>"); MODULE_AUTHOR("Naidu Tellapati <Naidu.Tellapati@imgtec.com>"); MODULE_DESCRIPTION("Imagination Technologies PDC Watchdog Timer Driver"); MODULE_LICENSE("GPL v2");
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