Marcus Folkesson | 2e62c49 | 2018-03-16 16:14:11 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 2 | /* |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 3 | * Copyright (c) 2016 BayLibre, SAS. |
| 4 | * Author: Neil Armstrong <narmstrong@baylibre.com> |
| 5 | * |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 6 | */ |
| 7 | #include <linux/clk.h> |
| 8 | #include <linux/err.h> |
| 9 | #include <linux/io.h> |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/of.h> |
| 12 | #include <linux/platform_device.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/types.h> |
| 15 | #include <linux/watchdog.h> |
| 16 | |
| 17 | #define DEFAULT_TIMEOUT 30 /* seconds */ |
| 18 | |
| 19 | #define GXBB_WDT_CTRL_REG 0x0 |
| 20 | #define GXBB_WDT_TCNT_REG 0x8 |
| 21 | #define GXBB_WDT_RSET_REG 0xc |
| 22 | |
| 23 | #define GXBB_WDT_CTRL_CLKDIV_EN BIT(25) |
| 24 | #define GXBB_WDT_CTRL_CLK_EN BIT(24) |
| 25 | #define GXBB_WDT_CTRL_EE_RESET BIT(21) |
| 26 | #define GXBB_WDT_CTRL_EN BIT(18) |
| 27 | #define GXBB_WDT_CTRL_DIV_MASK (BIT(18) - 1) |
| 28 | |
| 29 | #define GXBB_WDT_TCNT_SETUP_MASK (BIT(16) - 1) |
| 30 | #define GXBB_WDT_TCNT_CNT_SHIFT 16 |
| 31 | |
Artem Lapkin | bb6d772 | 2021-07-30 12:13:53 +0800 | [diff] [blame] | 32 | static bool nowayout = WATCHDOG_NOWAYOUT; |
| 33 | module_param(nowayout, bool, 0); |
| 34 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started default=" |
| 35 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
| 36 | |
Artem Lapkin | f01f0717 | 2021-07-30 12:13:54 +0800 | [diff] [blame] | 37 | static unsigned int timeout; |
| 38 | module_param(timeout, uint, 0); |
| 39 | MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds=" |
| 40 | __MODULE_STRING(DEFAULT_TIMEOUT) ")"); |
| 41 | |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 42 | struct meson_gxbb_wdt { |
| 43 | void __iomem *reg_base; |
| 44 | struct watchdog_device wdt_dev; |
| 45 | struct clk *clk; |
| 46 | }; |
| 47 | |
| 48 | static int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev) |
| 49 | { |
| 50 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| 51 | |
| 52 | writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN, |
| 53 | data->reg_base + GXBB_WDT_CTRL_REG); |
| 54 | |
| 55 | return 0; |
| 56 | } |
| 57 | |
| 58 | static int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev) |
| 59 | { |
| 60 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| 61 | |
| 62 | writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN, |
| 63 | data->reg_base + GXBB_WDT_CTRL_REG); |
| 64 | |
| 65 | return 0; |
| 66 | } |
| 67 | |
| 68 | static int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev) |
| 69 | { |
| 70 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| 71 | |
| 72 | writel(0, data->reg_base + GXBB_WDT_RSET_REG); |
| 73 | |
| 74 | return 0; |
| 75 | } |
| 76 | |
| 77 | static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev, |
| 78 | unsigned int timeout) |
| 79 | { |
| 80 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| 81 | unsigned long tcnt = timeout * 1000; |
| 82 | |
| 83 | if (tcnt > GXBB_WDT_TCNT_SETUP_MASK) |
| 84 | tcnt = GXBB_WDT_TCNT_SETUP_MASK; |
| 85 | |
| 86 | wdt_dev->timeout = timeout; |
| 87 | |
| 88 | meson_gxbb_wdt_ping(wdt_dev); |
| 89 | |
| 90 | writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG); |
| 91 | |
| 92 | return 0; |
| 93 | } |
| 94 | |
| 95 | static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev) |
| 96 | { |
| 97 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| 98 | unsigned long reg; |
| 99 | |
| 100 | reg = readl(data->reg_base + GXBB_WDT_TCNT_REG); |
| 101 | |
Xingyu Chen | 2c77734 | 2019-09-29 18:53:49 +0800 | [diff] [blame] | 102 | return ((reg & GXBB_WDT_TCNT_SETUP_MASK) - |
| 103 | (reg >> GXBB_WDT_TCNT_CNT_SHIFT)) / 1000; |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 104 | } |
| 105 | |
| 106 | static const struct watchdog_ops meson_gxbb_wdt_ops = { |
| 107 | .start = meson_gxbb_wdt_start, |
| 108 | .stop = meson_gxbb_wdt_stop, |
| 109 | .ping = meson_gxbb_wdt_ping, |
| 110 | .set_timeout = meson_gxbb_wdt_set_timeout, |
| 111 | .get_timeleft = meson_gxbb_wdt_get_timeleft, |
| 112 | }; |
| 113 | |
| 114 | static const struct watchdog_info meson_gxbb_wdt_info = { |
| 115 | .identity = "Meson GXBB Watchdog", |
| 116 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
| 117 | }; |
| 118 | |
| 119 | static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev) |
| 120 | { |
| 121 | struct meson_gxbb_wdt *data = dev_get_drvdata(dev); |
| 122 | |
| 123 | if (watchdog_active(&data->wdt_dev)) |
| 124 | meson_gxbb_wdt_start(&data->wdt_dev); |
| 125 | |
| 126 | return 0; |
| 127 | } |
| 128 | |
| 129 | static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev) |
| 130 | { |
| 131 | struct meson_gxbb_wdt *data = dev_get_drvdata(dev); |
| 132 | |
| 133 | if (watchdog_active(&data->wdt_dev)) |
| 134 | meson_gxbb_wdt_stop(&data->wdt_dev); |
| 135 | |
| 136 | return 0; |
| 137 | } |
| 138 | |
| 139 | static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = { |
| 140 | SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume) |
| 141 | }; |
| 142 | |
| 143 | static const struct of_device_id meson_gxbb_wdt_dt_ids[] = { |
| 144 | { .compatible = "amlogic,meson-gxbb-wdt", }, |
| 145 | { /* sentinel */ }, |
| 146 | }; |
| 147 | MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids); |
| 148 | |
| 149 | static int meson_gxbb_wdt_probe(struct platform_device *pdev) |
| 150 | { |
Guenter Roeck | 1678f83 | 2019-04-09 10:23:42 -0700 | [diff] [blame] | 151 | struct device *dev = &pdev->dev; |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 152 | struct meson_gxbb_wdt *data; |
Philippe Boos | 6adbfba | 2022-08-01 11:21:50 +0200 | [diff] [blame] | 153 | u32 ctrl_reg; |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 154 | |
Guenter Roeck | 1678f83 | 2019-04-09 10:23:42 -0700 | [diff] [blame] | 155 | data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 156 | if (!data) |
| 157 | return -ENOMEM; |
| 158 | |
Guenter Roeck | 0f0a6a2 | 2019-04-02 12:01:53 -0700 | [diff] [blame] | 159 | data->reg_base = devm_platform_ioremap_resource(pdev, 0); |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 160 | if (IS_ERR(data->reg_base)) |
| 161 | return PTR_ERR(data->reg_base); |
| 162 | |
Christophe JAILLET | 2cf46c6 | 2022-12-31 13:34:44 +0100 | [diff] [blame] | 163 | data->clk = devm_clk_get_enabled(dev, NULL); |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 164 | if (IS_ERR(data->clk)) |
| 165 | return PTR_ERR(data->clk); |
| 166 | |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 167 | platform_set_drvdata(pdev, data); |
| 168 | |
Guenter Roeck | 1678f83 | 2019-04-09 10:23:42 -0700 | [diff] [blame] | 169 | data->wdt_dev.parent = dev; |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 170 | data->wdt_dev.info = &meson_gxbb_wdt_info; |
| 171 | data->wdt_dev.ops = &meson_gxbb_wdt_ops; |
| 172 | data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK; |
| 173 | data->wdt_dev.min_timeout = 1; |
| 174 | data->wdt_dev.timeout = DEFAULT_TIMEOUT; |
Artem Lapkin | f01f0717 | 2021-07-30 12:13:54 +0800 | [diff] [blame] | 175 | watchdog_init_timeout(&data->wdt_dev, timeout, dev); |
Artem Lapkin | bb6d772 | 2021-07-30 12:13:53 +0800 | [diff] [blame] | 176 | watchdog_set_nowayout(&data->wdt_dev, nowayout); |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 177 | watchdog_set_drvdata(&data->wdt_dev, data); |
| 178 | |
Philippe Boos | 6adbfba | 2022-08-01 11:21:50 +0200 | [diff] [blame] | 179 | ctrl_reg = readl(data->reg_base + GXBB_WDT_CTRL_REG) & |
| 180 | GXBB_WDT_CTRL_EN; |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 181 | |
Philippe Boos | 6adbfba | 2022-08-01 11:21:50 +0200 | [diff] [blame] | 182 | if (ctrl_reg) { |
| 183 | /* Watchdog is running - keep it running but extend timeout |
| 184 | * to the maximum while setting the timebase |
| 185 | */ |
| 186 | set_bit(WDOG_HW_RUNNING, &data->wdt_dev.status); |
| 187 | meson_gxbb_wdt_set_timeout(&data->wdt_dev, |
| 188 | GXBB_WDT_TCNT_SETUP_MASK / 1000); |
| 189 | } |
| 190 | |
| 191 | /* Setup with 1ms timebase */ |
| 192 | ctrl_reg |= ((clk_get_rate(data->clk) / 1000) & |
| 193 | GXBB_WDT_CTRL_DIV_MASK) | |
| 194 | GXBB_WDT_CTRL_EE_RESET | |
| 195 | GXBB_WDT_CTRL_CLK_EN | |
| 196 | GXBB_WDT_CTRL_CLKDIV_EN; |
| 197 | |
| 198 | writel(ctrl_reg, data->reg_base + GXBB_WDT_CTRL_REG); |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 199 | meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout); |
| 200 | |
Guenter Roeck | 1678f83 | 2019-04-09 10:23:42 -0700 | [diff] [blame] | 201 | return devm_watchdog_register_device(dev, &data->wdt_dev); |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 202 | } |
| 203 | |
| 204 | static struct platform_driver meson_gxbb_wdt_driver = { |
| 205 | .probe = meson_gxbb_wdt_probe, |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 206 | .driver = { |
| 207 | .name = "meson-gxbb-wdt", |
| 208 | .pm = &meson_gxbb_wdt_pm_ops, |
| 209 | .of_match_table = meson_gxbb_wdt_dt_ids, |
| 210 | }, |
| 211 | }; |
| 212 | |
| 213 | module_platform_driver(meson_gxbb_wdt_driver); |
| 214 | |
Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 215 | MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>"); |
| 216 | MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver"); |
| 217 | MODULE_LICENSE("Dual BSD/GPL"); |