/* * This file is provided under a dual BSD/GPLv2 license. When using or * redistributing this file, you may do so under either license. * * GPL LICENSE SUMMARY * * Copyright (c) 2016 BayLibre, SAS. * Author: Neil Armstrong * * This program is free software; you can redistribute it and/or modify * it under the terms of version 2 of the GNU General Public License as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * The full GNU General Public License is included in this distribution * in the file called COPYING. * * BSD LICENSE * * Copyright (c) 2016 BayLibre, SAS. * Author: Neil Armstrong * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * Neither the name of Intel Corporation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #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 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_CNT_SHIFT) - (reg & GXBB_WDT_TCNT_SETUP_MASK)) / 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 int meson_gxbb_wdt_probe(struct platform_device *pdev) { struct meson_gxbb_wdt *data; struct resource *res; int ret; data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); data->reg_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(data->reg_base)) return PTR_ERR(data->reg_base); data->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(data->clk)) return PTR_ERR(data->clk); ret = clk_prepare_enable(data->clk); if (ret) return ret; platform_set_drvdata(pdev, data); data->wdt_dev.parent = &pdev->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_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); ret = watchdog_register_device(&data->wdt_dev); if (ret) { clk_disable_unprepare(data->clk); return ret; } return 0; } static int meson_gxbb_wdt_remove(struct platform_device *pdev) { struct meson_gxbb_wdt *data = platform_get_drvdata(pdev); watchdog_unregister_device(&data->wdt_dev); clk_disable_unprepare(data->clk); return 0; } static void meson_gxbb_wdt_shutdown(struct platform_device *pdev) { struct meson_gxbb_wdt *data = platform_get_drvdata(pdev); meson_gxbb_wdt_stop(&data->wdt_dev); } static struct platform_driver meson_gxbb_wdt_driver = { .probe = meson_gxbb_wdt_probe, .remove = meson_gxbb_wdt_remove, .shutdown = meson_gxbb_wdt_shutdown, .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 "); MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver"); MODULE_LICENSE("Dual BSD/GPL");