+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * watchdog driver for ZTE's zx2967 family
- *
- * Copyright (C) 2017 ZTE Ltd.
- *
- * Author: Baoyou Xie <baoyou.xie@linaro.org>
- */
-
-#include <linux/clk.h>
-#include <linux/io.h>
-#include <linux/mfd/syscon.h>
-#include <linux/module.h>
-#include <linux/of_address.h>
-#include <linux/platform_device.h>
-#include <linux/regmap.h>
-#include <linux/reset.h>
-#include <linux/watchdog.h>
-
-#define ZX2967_WDT_CFG_REG 0x4
-#define ZX2967_WDT_LOAD_REG 0x8
-#define ZX2967_WDT_REFRESH_REG 0x18
-#define ZX2967_WDT_START_REG 0x1c
-
-#define ZX2967_WDT_REFRESH_MASK GENMASK(5, 0)
-
-#define ZX2967_WDT_CFG_DIV(n) ((((n) & 0xff) - 1) << 8)
-#define ZX2967_WDT_START_EN 0x1
-
-/*
- * Hardware magic number.
- * When watchdog reg is written, the lowest 16 bits are valid, but
- * the highest 16 bits should be always this number.
- */
-#define ZX2967_WDT_WRITEKEY (0x1234 << 16)
-#define ZX2967_WDT_VAL_MASK GENMASK(15, 0)
-
-#define ZX2967_WDT_DIV_DEFAULT 16
-#define ZX2967_WDT_DEFAULT_TIMEOUT 32
-#define ZX2967_WDT_MIN_TIMEOUT 1
-#define ZX2967_WDT_MAX_TIMEOUT 524
-#define ZX2967_WDT_MAX_COUNT 0xffff
-
-#define ZX2967_WDT_CLK_FREQ 0x8000
-
-#define ZX2967_WDT_FLAG_REBOOT_MON BIT(0)
-
-struct zx2967_wdt {
- struct watchdog_device wdt_device;
- void __iomem *reg_base;
- struct clk *clock;
-};
-
-static inline u32 zx2967_wdt_readl(struct zx2967_wdt *wdt, u16 reg)
-{
- return readl_relaxed(wdt->reg_base + reg);
-}
-
-static inline void zx2967_wdt_writel(struct zx2967_wdt *wdt, u16 reg, u32 val)
-{
- writel_relaxed(val | ZX2967_WDT_WRITEKEY, wdt->reg_base + reg);
-}
-
-static void zx2967_wdt_refresh(struct zx2967_wdt *wdt)
-{
- u32 val;
-
- val = zx2967_wdt_readl(wdt, ZX2967_WDT_REFRESH_REG);
- /*
- * Bit 4-5, 1 and 2: refresh config info
- * Bit 2-3, 1 and 2: refresh counter
- * Bit 0-1, 1 and 2: refresh int-value
- * we shift each group value between 1 and 2 to refresh all data.
- */
- val ^= ZX2967_WDT_REFRESH_MASK;
- zx2967_wdt_writel(wdt, ZX2967_WDT_REFRESH_REG,
- val & ZX2967_WDT_VAL_MASK);
-}
-
-static int
-zx2967_wdt_set_timeout(struct watchdog_device *wdd, unsigned int timeout)
-{
- struct zx2967_wdt *wdt = watchdog_get_drvdata(wdd);
- unsigned int divisor = ZX2967_WDT_DIV_DEFAULT;
- u32 count;
-
- count = timeout * ZX2967_WDT_CLK_FREQ;
- if (count > divisor * ZX2967_WDT_MAX_COUNT)
- divisor = DIV_ROUND_UP(count, ZX2967_WDT_MAX_COUNT);
- count = DIV_ROUND_UP(count, divisor);
- zx2967_wdt_writel(wdt, ZX2967_WDT_CFG_REG,
- ZX2967_WDT_CFG_DIV(divisor) & ZX2967_WDT_VAL_MASK);
- zx2967_wdt_writel(wdt, ZX2967_WDT_LOAD_REG,
- count & ZX2967_WDT_VAL_MASK);
- zx2967_wdt_refresh(wdt);
- wdd->timeout = (count * divisor) / ZX2967_WDT_CLK_FREQ;
-
- return 0;
-}
-
-static void __zx2967_wdt_start(struct zx2967_wdt *wdt)
-{
- u32 val;
-
- val = zx2967_wdt_readl(wdt, ZX2967_WDT_START_REG);
- val |= ZX2967_WDT_START_EN;
- zx2967_wdt_writel(wdt, ZX2967_WDT_START_REG,
- val & ZX2967_WDT_VAL_MASK);
-}
-
-static void __zx2967_wdt_stop(struct zx2967_wdt *wdt)
-{
- u32 val;
-
- val = zx2967_wdt_readl(wdt, ZX2967_WDT_START_REG);
- val &= ~ZX2967_WDT_START_EN;
- zx2967_wdt_writel(wdt, ZX2967_WDT_START_REG,
- val & ZX2967_WDT_VAL_MASK);
-}
-
-static int zx2967_wdt_start(struct watchdog_device *wdd)
-{
- struct zx2967_wdt *wdt = watchdog_get_drvdata(wdd);
-
- zx2967_wdt_set_timeout(wdd, wdd->timeout);
- __zx2967_wdt_start(wdt);
-
- return 0;
-}
-
-static int zx2967_wdt_stop(struct watchdog_device *wdd)
-{
- struct zx2967_wdt *wdt = watchdog_get_drvdata(wdd);
-
- __zx2967_wdt_stop(wdt);
-
- return 0;
-}
-
-static int zx2967_wdt_keepalive(struct watchdog_device *wdd)
-{
- struct zx2967_wdt *wdt = watchdog_get_drvdata(wdd);
-
- zx2967_wdt_refresh(wdt);
-
- return 0;
-}
-
-#define ZX2967_WDT_OPTIONS \
- (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
-static const struct watchdog_info zx2967_wdt_ident = {
- .options = ZX2967_WDT_OPTIONS,
- .identity = "zx2967 watchdog",
-};
-
-static const struct watchdog_ops zx2967_wdt_ops = {
- .owner = THIS_MODULE,
- .start = zx2967_wdt_start,
- .stop = zx2967_wdt_stop,
- .ping = zx2967_wdt_keepalive,
- .set_timeout = zx2967_wdt_set_timeout,
-};
-
-static void zx2967_wdt_reset_sysctrl(struct device *dev)
-{
- int ret;
- void __iomem *regmap;
- unsigned int offset, mask, config;
- struct of_phandle_args out_args;
-
- ret = of_parse_phandle_with_fixed_args(dev->of_node,
- "zte,wdt-reset-sysctrl", 3, 0, &out_args);
- if (ret)
- return;
-
- offset = out_args.args[0];
- config = out_args.args[1];
- mask = out_args.args[2];
-
- regmap = syscon_node_to_regmap(out_args.np);
- if (IS_ERR(regmap)) {
- of_node_put(out_args.np);
- return;
- }
-
- regmap_update_bits(regmap, offset, mask, config);
- of_node_put(out_args.np);
-}
-
-static void zx2967_clk_disable_unprepare(void *data)
-{
- clk_disable_unprepare(data);
-}
-
-static int zx2967_wdt_probe(struct platform_device *pdev)
-{
- struct device *dev = &pdev->dev;
- struct zx2967_wdt *wdt;
- int ret;
- struct reset_control *rstc;
-
- wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
- if (!wdt)
- return -ENOMEM;
-
- platform_set_drvdata(pdev, wdt);
-
- wdt->wdt_device.info = &zx2967_wdt_ident;
- wdt->wdt_device.ops = &zx2967_wdt_ops;
- wdt->wdt_device.timeout = ZX2967_WDT_DEFAULT_TIMEOUT;
- wdt->wdt_device.max_timeout = ZX2967_WDT_MAX_TIMEOUT;
- wdt->wdt_device.min_timeout = ZX2967_WDT_MIN_TIMEOUT;
- wdt->wdt_device.parent = dev;
-
- wdt->reg_base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(wdt->reg_base))
- return PTR_ERR(wdt->reg_base);
-
- zx2967_wdt_reset_sysctrl(dev);
-
- wdt->clock = devm_clk_get(dev, NULL);
- if (IS_ERR(wdt->clock)) {
- dev_err(dev, "failed to find watchdog clock source\n");
- return PTR_ERR(wdt->clock);
- }
-
- ret = clk_prepare_enable(wdt->clock);
- if (ret < 0) {
- dev_err(dev, "failed to enable clock\n");
- return ret;
- }
- ret = devm_add_action_or_reset(dev, zx2967_clk_disable_unprepare,
- wdt->clock);
- if (ret)
- return ret;
- clk_set_rate(wdt->clock, ZX2967_WDT_CLK_FREQ);
-
- rstc = devm_reset_control_get_exclusive(dev, NULL);
- if (IS_ERR(rstc)) {
- dev_err(dev, "failed to get rstc");
- return PTR_ERR(rstc);
- }
-
- reset_control_assert(rstc);
- reset_control_deassert(rstc);
-
- watchdog_set_drvdata(&wdt->wdt_device, wdt);
- watchdog_init_timeout(&wdt->wdt_device,
- ZX2967_WDT_DEFAULT_TIMEOUT, dev);
- watchdog_set_nowayout(&wdt->wdt_device, WATCHDOG_NOWAYOUT);
-
- ret = devm_watchdog_register_device(dev, &wdt->wdt_device);
- if (ret)
- return ret;
-
- dev_info(dev, "watchdog enabled (timeout=%d sec, nowayout=%d)",
- wdt->wdt_device.timeout, WATCHDOG_NOWAYOUT);
-
- return 0;
-}
-
-static const struct of_device_id zx2967_wdt_match[] = {
- { .compatible = "zte,zx296718-wdt", },
- {}
-};
-MODULE_DEVICE_TABLE(of, zx2967_wdt_match);
-
-static struct platform_driver zx2967_wdt_driver = {
- .probe = zx2967_wdt_probe,
- .driver = {
- .name = "zx2967-wdt",
- .of_match_table = of_match_ptr(zx2967_wdt_match),
- },
-};
-module_platform_driver(zx2967_wdt_driver);
-
-MODULE_AUTHOR("Baoyou Xie <baoyou.xie@linaro.org>");
-MODULE_DESCRIPTION("ZTE zx2967 Watchdog Device Driver");
-MODULE_LICENSE("GPL v2");
projects / platform / kernel / linux-rpi.git / commitdiff