| // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause |
| /* |
| * Copyright (c) 2016 BayLibre, SAS. |
| * Author: Neil Armstrong <narmstrong@baylibre.com> |
| * |
| */ |
| #include <linux/clk.h> |
| #include <linux/err.h> |
| #include <linux/io.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/platform_device.h> |
| #include <linux/slab.h> |
| #include <linux/types.h> |
| #include <linux/watchdog.h> |
| |
| #define DEFAULT_TIMEOUT 30 /* seconds */ |
| |
| #define GXBB_WDT_CTRL_REG 0x0 |
| #define GXBB_WDT_TCNT_REG 0x8 |
| #define GXBB_WDT_RSET_REG 0xc |
| |
| #define GXBB_WDT_CTRL_CLKDIV_EN BIT(25) |
| #define GXBB_WDT_CTRL_CLK_EN BIT(24) |
| #define GXBB_WDT_CTRL_EE_RESET BIT(21) |
| #define GXBB_WDT_CTRL_EN BIT(18) |
| #define GXBB_WDT_CTRL_DIV_MASK (BIT(18) - 1) |
| |
| #define GXBB_WDT_TCNT_SETUP_MASK (BIT(16) - 1) |
| #define GXBB_WDT_TCNT_CNT_SHIFT 16 |
| |
| 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 meson_gxbb_wdt { |
| void __iomem *reg_base; |
| struct watchdog_device wdt_dev; |
| struct clk *clk; |
| }; |
| |
| static int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev) |
| { |
| struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| |
| writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN, |
| data->reg_base + GXBB_WDT_CTRL_REG); |
| |
| return 0; |
| } |
| |
| static int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev) |
| { |
| struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| |
| writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN, |
| data->reg_base + GXBB_WDT_CTRL_REG); |
| |
| return 0; |
| } |
| |
| static int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev) |
| { |
| struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| |
| writel(0, data->reg_base + GXBB_WDT_RSET_REG); |
| |
| return 0; |
| } |
| |
| static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev, |
| unsigned int timeout) |
| { |
| struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| unsigned long tcnt = timeout * 1000; |
| |
| if (tcnt > GXBB_WDT_TCNT_SETUP_MASK) |
| tcnt = GXBB_WDT_TCNT_SETUP_MASK; |
| |
| wdt_dev->timeout = timeout; |
| |
| meson_gxbb_wdt_ping(wdt_dev); |
| |
| writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG); |
| |
| return 0; |
| } |
| |
| static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev) |
| { |
| struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| unsigned long reg; |
| |
| reg = readl(data->reg_base + GXBB_WDT_TCNT_REG); |
| |
| return ((reg & GXBB_WDT_TCNT_SETUP_MASK) - |
| (reg >> GXBB_WDT_TCNT_CNT_SHIFT)) / 1000; |
| } |
| |
| static const struct watchdog_ops meson_gxbb_wdt_ops = { |
| .start = meson_gxbb_wdt_start, |
| .stop = meson_gxbb_wdt_stop, |
| .ping = meson_gxbb_wdt_ping, |
| .set_timeout = meson_gxbb_wdt_set_timeout, |
| .get_timeleft = meson_gxbb_wdt_get_timeleft, |
| }; |
| |
| static const struct watchdog_info meson_gxbb_wdt_info = { |
| .identity = "Meson GXBB Watchdog", |
| .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
| }; |
| |
| static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev) |
| { |
| struct meson_gxbb_wdt *data = dev_get_drvdata(dev); |
| |
| if (watchdog_active(&data->wdt_dev)) |
| meson_gxbb_wdt_start(&data->wdt_dev); |
| |
| return 0; |
| } |
| |
| static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev) |
| { |
| struct meson_gxbb_wdt *data = dev_get_drvdata(dev); |
| |
| if (watchdog_active(&data->wdt_dev)) |
| meson_gxbb_wdt_stop(&data->wdt_dev); |
| |
| return 0; |
| } |
| |
| static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = { |
| SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume) |
| }; |
| |
| static const struct of_device_id meson_gxbb_wdt_dt_ids[] = { |
| { .compatible = "amlogic,meson-gxbb-wdt", }, |
| { /* sentinel */ }, |
| }; |
| MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids); |
| |
| static void meson_clk_disable_unprepare(void *data) |
| { |
| clk_disable_unprepare(data); |
| } |
| |
| static int meson_gxbb_wdt_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct meson_gxbb_wdt *data; |
| int ret; |
| |
| data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); |
| if (!data) |
| return -ENOMEM; |
| |
| data->reg_base = devm_platform_ioremap_resource(pdev, 0); |
| if (IS_ERR(data->reg_base)) |
| return PTR_ERR(data->reg_base); |
| |
| data->clk = devm_clk_get(dev, NULL); |
| if (IS_ERR(data->clk)) |
| return PTR_ERR(data->clk); |
| |
| ret = clk_prepare_enable(data->clk); |
| if (ret) |
| return ret; |
| ret = devm_add_action_or_reset(dev, meson_clk_disable_unprepare, |
| data->clk); |
| if (ret) |
| return ret; |
| |
| platform_set_drvdata(pdev, data); |
| |
| data->wdt_dev.parent = dev; |
| data->wdt_dev.info = &meson_gxbb_wdt_info; |
| data->wdt_dev.ops = &meson_gxbb_wdt_ops; |
| data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK; |
| data->wdt_dev.min_timeout = 1; |
| data->wdt_dev.timeout = DEFAULT_TIMEOUT; |
| watchdog_set_nowayout(&data->wdt_dev, nowayout); |
| watchdog_set_drvdata(&data->wdt_dev, data); |
| |
| /* Setup with 1ms timebase */ |
| writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) | |
| GXBB_WDT_CTRL_EE_RESET | |
| GXBB_WDT_CTRL_CLK_EN | |
| GXBB_WDT_CTRL_CLKDIV_EN, |
| data->reg_base + GXBB_WDT_CTRL_REG); |
| |
| meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout); |
| |
| watchdog_stop_on_reboot(&data->wdt_dev); |
| return devm_watchdog_register_device(dev, &data->wdt_dev); |
| } |
| |
| static struct platform_driver meson_gxbb_wdt_driver = { |
| .probe = meson_gxbb_wdt_probe, |
| .driver = { |
| .name = "meson-gxbb-wdt", |
| .pm = &meson_gxbb_wdt_pm_ops, |
| .of_match_table = meson_gxbb_wdt_dt_ids, |
| }, |
| }; |
| |
| module_platform_driver(meson_gxbb_wdt_driver); |
| |
| MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>"); |
| MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver"); |
| MODULE_LICENSE("Dual BSD/GPL"); |