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