Neil Armstrong | 683fa50 | 2016-07-10 11:11:04 +0200 | [diff] [blame] | 1 | /* |
| 2 | * This file is provided under a dual BSD/GPLv2 license. When using or |
| 3 | * redistributing this file, you may do so under either license. |
| 4 | * |
| 5 | * GPL LICENSE SUMMARY |
| 6 | * |
| 7 | * Copyright (c) 2016 BayLibre, SAS. |
| 8 | * Author: Neil Armstrong <narmstrong@baylibre.com> |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of version 2 of the GNU General Public License as |
| 12 | * published by the Free Software Foundation. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, but |
| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 17 | * General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License |
| 20 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
| 21 | * The full GNU General Public License is included in this distribution |
| 22 | * in the file called COPYING. |
| 23 | * |
| 24 | * BSD LICENSE |
| 25 | * |
| 26 | * Copyright (c) 2016 BayLibre, SAS. |
| 27 | * Author: Neil Armstrong <narmstrong@baylibre.com> |
| 28 | * |
| 29 | * Redistribution and use in source and binary forms, with or without |
| 30 | * modification, are permitted provided that the following conditions |
| 31 | * are met: |
| 32 | * |
| 33 | * * Redistributions of source code must retain the above copyright |
| 34 | * notice, this list of conditions and the following disclaimer. |
| 35 | * * Redistributions in binary form must reproduce the above copyright |
| 36 | * notice, this list of conditions and the following disclaimer in |
| 37 | * the documentation and/or other materials provided with the |
| 38 | * distribution. |
| 39 | * * Neither the name of Intel Corporation nor the names of its |
| 40 | * contributors may be used to endorse or promote products derived |
| 41 | * from this software without specific prior written permission. |
| 42 | * |
| 43 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 44 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 45 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 46 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 47 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 48 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 49 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 50 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 51 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 52 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 53 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 54 | */ |
| 55 | #include <linux/clk.h> |
| 56 | #include <linux/err.h> |
| 57 | #include <linux/io.h> |
| 58 | #include <linux/module.h> |
| 59 | #include <linux/of.h> |
| 60 | #include <linux/platform_device.h> |
| 61 | #include <linux/slab.h> |
| 62 | #include <linux/types.h> |
| 63 | #include <linux/watchdog.h> |
| 64 | |
| 65 | #define DEFAULT_TIMEOUT 30 /* seconds */ |
| 66 | |
| 67 | #define GXBB_WDT_CTRL_REG 0x0 |
| 68 | #define GXBB_WDT_TCNT_REG 0x8 |
| 69 | #define GXBB_WDT_RSET_REG 0xc |
| 70 | |
| 71 | #define GXBB_WDT_CTRL_CLKDIV_EN BIT(25) |
| 72 | #define GXBB_WDT_CTRL_CLK_EN BIT(24) |
| 73 | #define GXBB_WDT_CTRL_EE_RESET BIT(21) |
| 74 | #define GXBB_WDT_CTRL_EN BIT(18) |
| 75 | #define GXBB_WDT_CTRL_DIV_MASK (BIT(18) - 1) |
| 76 | |
| 77 | #define GXBB_WDT_TCNT_SETUP_MASK (BIT(16) - 1) |
| 78 | #define GXBB_WDT_TCNT_CNT_SHIFT 16 |
| 79 | |
| 80 | struct meson_gxbb_wdt { |
| 81 | void __iomem *reg_base; |
| 82 | struct watchdog_device wdt_dev; |
| 83 | struct clk *clk; |
| 84 | }; |
| 85 | |
| 86 | static int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev) |
| 87 | { |
| 88 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| 89 | |
| 90 | writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN, |
| 91 | data->reg_base + GXBB_WDT_CTRL_REG); |
| 92 | |
| 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | static int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev) |
| 97 | { |
| 98 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| 99 | |
| 100 | writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN, |
| 101 | data->reg_base + GXBB_WDT_CTRL_REG); |
| 102 | |
| 103 | return 0; |
| 104 | } |
| 105 | |
| 106 | static int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev) |
| 107 | { |
| 108 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| 109 | |
| 110 | writel(0, data->reg_base + GXBB_WDT_RSET_REG); |
| 111 | |
| 112 | return 0; |
| 113 | } |
| 114 | |
| 115 | static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev, |
| 116 | unsigned int timeout) |
| 117 | { |
| 118 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| 119 | unsigned long tcnt = timeout * 1000; |
| 120 | |
| 121 | if (tcnt > GXBB_WDT_TCNT_SETUP_MASK) |
| 122 | tcnt = GXBB_WDT_TCNT_SETUP_MASK; |
| 123 | |
| 124 | wdt_dev->timeout = timeout; |
| 125 | |
| 126 | meson_gxbb_wdt_ping(wdt_dev); |
| 127 | |
| 128 | writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG); |
| 129 | |
| 130 | return 0; |
| 131 | } |
| 132 | |
| 133 | static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev) |
| 134 | { |
| 135 | struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev); |
| 136 | unsigned long reg; |
| 137 | |
| 138 | reg = readl(data->reg_base + GXBB_WDT_TCNT_REG); |
| 139 | |
| 140 | return ((reg >> GXBB_WDT_TCNT_CNT_SHIFT) - |
| 141 | (reg & GXBB_WDT_TCNT_SETUP_MASK)) / 1000; |
| 142 | } |
| 143 | |
| 144 | static const struct watchdog_ops meson_gxbb_wdt_ops = { |
| 145 | .start = meson_gxbb_wdt_start, |
| 146 | .stop = meson_gxbb_wdt_stop, |
| 147 | .ping = meson_gxbb_wdt_ping, |
| 148 | .set_timeout = meson_gxbb_wdt_set_timeout, |
| 149 | .get_timeleft = meson_gxbb_wdt_get_timeleft, |
| 150 | }; |
| 151 | |
| 152 | static const struct watchdog_info meson_gxbb_wdt_info = { |
| 153 | .identity = "Meson GXBB Watchdog", |
| 154 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
| 155 | }; |
| 156 | |
| 157 | static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev) |
| 158 | { |
| 159 | struct meson_gxbb_wdt *data = dev_get_drvdata(dev); |
| 160 | |
| 161 | if (watchdog_active(&data->wdt_dev)) |
| 162 | meson_gxbb_wdt_start(&data->wdt_dev); |
| 163 | |
| 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev) |
| 168 | { |
| 169 | struct meson_gxbb_wdt *data = dev_get_drvdata(dev); |
| 170 | |
| 171 | if (watchdog_active(&data->wdt_dev)) |
| 172 | meson_gxbb_wdt_stop(&data->wdt_dev); |
| 173 | |
| 174 | return 0; |
| 175 | } |
| 176 | |
| 177 | static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = { |
| 178 | SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume) |
| 179 | }; |
| 180 | |
| 181 | static const struct of_device_id meson_gxbb_wdt_dt_ids[] = { |
| 182 | { .compatible = "amlogic,meson-gxbb-wdt", }, |
| 183 | { /* sentinel */ }, |
| 184 | }; |
| 185 | MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids); |
| 186 | |
| 187 | static int meson_gxbb_wdt_probe(struct platform_device *pdev) |
| 188 | { |
| 189 | struct meson_gxbb_wdt *data; |
| 190 | struct resource *res; |
| 191 | int ret; |
| 192 | |
| 193 | data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); |
| 194 | if (!data) |
| 195 | return -ENOMEM; |
| 196 | |
| 197 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 198 | data->reg_base = devm_ioremap_resource(&pdev->dev, res); |
| 199 | if (IS_ERR(data->reg_base)) |
| 200 | return PTR_ERR(data->reg_base); |
| 201 | |
| 202 | data->clk = devm_clk_get(&pdev->dev, NULL); |
| 203 | if (IS_ERR(data->clk)) |
| 204 | return PTR_ERR(data->clk); |
| 205 | |
| 206 | clk_prepare_enable(data->clk); |
| 207 | |
| 208 | platform_set_drvdata(pdev, data); |
| 209 | |
| 210 | data->wdt_dev.parent = &pdev->dev; |
| 211 | data->wdt_dev.info = &meson_gxbb_wdt_info; |
| 212 | data->wdt_dev.ops = &meson_gxbb_wdt_ops; |
| 213 | data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK; |
| 214 | data->wdt_dev.min_timeout = 1; |
| 215 | data->wdt_dev.timeout = DEFAULT_TIMEOUT; |
| 216 | watchdog_set_drvdata(&data->wdt_dev, data); |
| 217 | |
| 218 | /* Setup with 1ms timebase */ |
| 219 | writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) | |
| 220 | GXBB_WDT_CTRL_EE_RESET | |
| 221 | GXBB_WDT_CTRL_CLK_EN | |
| 222 | GXBB_WDT_CTRL_CLKDIV_EN, |
| 223 | data->reg_base + GXBB_WDT_CTRL_REG); |
| 224 | |
| 225 | meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout); |
| 226 | |
| 227 | ret = watchdog_register_device(&data->wdt_dev); |
| 228 | if (ret) { |
| 229 | clk_disable_unprepare(data->clk); |
| 230 | return ret; |
| 231 | } |
| 232 | |
| 233 | return 0; |
| 234 | } |
| 235 | |
| 236 | static int meson_gxbb_wdt_remove(struct platform_device *pdev) |
| 237 | { |
| 238 | struct meson_gxbb_wdt *data = platform_get_drvdata(pdev); |
| 239 | |
| 240 | watchdog_unregister_device(&data->wdt_dev); |
| 241 | |
| 242 | clk_disable_unprepare(data->clk); |
| 243 | |
| 244 | return 0; |
| 245 | } |
| 246 | |
| 247 | static void meson_gxbb_wdt_shutdown(struct platform_device *pdev) |
| 248 | { |
| 249 | struct meson_gxbb_wdt *data = platform_get_drvdata(pdev); |
| 250 | |
| 251 | meson_gxbb_wdt_stop(&data->wdt_dev); |
| 252 | } |
| 253 | |
| 254 | static struct platform_driver meson_gxbb_wdt_driver = { |
| 255 | .probe = meson_gxbb_wdt_probe, |
| 256 | .remove = meson_gxbb_wdt_remove, |
| 257 | .shutdown = meson_gxbb_wdt_shutdown, |
| 258 | .driver = { |
| 259 | .name = "meson-gxbb-wdt", |
| 260 | .pm = &meson_gxbb_wdt_pm_ops, |
| 261 | .of_match_table = meson_gxbb_wdt_dt_ids, |
| 262 | }, |
| 263 | }; |
| 264 | |
| 265 | module_platform_driver(meson_gxbb_wdt_driver); |
| 266 | |
| 267 | MODULE_ALIAS("platform:meson-gxbb-wdt"); |
| 268 | MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>"); |
| 269 | MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver"); |
| 270 | MODULE_LICENSE("Dual BSD/GPL"); |