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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/watchdog/imx2_wdt.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/watchdog/imx2_wdt.c')
-rw-r--r--drivers/watchdog/imx2_wdt.c441
1 files changed, 441 insertions, 0 deletions
diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
new file mode 100644
index 000000000..d0c5d47dd
--- /dev/null
+++ b/drivers/watchdog/imx2_wdt.c
@@ -0,0 +1,441 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Watchdog driver for IMX2 and later processors
+ *
+ * Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <kernel@pengutronix.de>
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ *
+ * some parts adapted by similar drivers from Darius Augulis and Vladimir
+ * Zapolskiy, additional improvements by Wim Van Sebroeck.
+ *
+ * NOTE: MX1 has a slightly different Watchdog than MX2 and later:
+ *
+ * MX1: MX2+:
+ * ---- -----
+ * Registers: 32-bit 16-bit
+ * Stopable timer: Yes No
+ * Need to enable clk: No Yes
+ * Halt on suspend: Manual Can be automatic
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/watchdog.h>
+
+#define DRIVER_NAME "imx2-wdt"
+
+#define IMX2_WDT_WCR 0x00 /* Control Register */
+#define IMX2_WDT_WCR_WT (0xFF << 8) /* -> Watchdog Timeout Field */
+#define IMX2_WDT_WCR_WDA BIT(5) /* -> External Reset WDOG_B */
+#define IMX2_WDT_WCR_SRS BIT(4) /* -> Software Reset Signal */
+#define IMX2_WDT_WCR_WRE BIT(3) /* -> WDOG Reset Enable */
+#define IMX2_WDT_WCR_WDE BIT(2) /* -> Watchdog Enable */
+#define IMX2_WDT_WCR_WDZST BIT(0) /* -> Watchdog timer Suspend */
+
+#define IMX2_WDT_WSR 0x02 /* Service Register */
+#define IMX2_WDT_SEQ1 0x5555 /* -> service sequence 1 */
+#define IMX2_WDT_SEQ2 0xAAAA /* -> service sequence 2 */
+
+#define IMX2_WDT_WRSR 0x04 /* Reset Status Register */
+#define IMX2_WDT_WRSR_TOUT BIT(1) /* -> Reset due to Timeout */
+
+#define IMX2_WDT_WICR 0x06 /* Interrupt Control Register */
+#define IMX2_WDT_WICR_WIE BIT(15) /* -> Interrupt Enable */
+#define IMX2_WDT_WICR_WTIS BIT(14) /* -> Interrupt Status */
+#define IMX2_WDT_WICR_WICT 0xFF /* -> Interrupt Count Timeout */
+
+#define IMX2_WDT_WMCR 0x08 /* Misc Register */
+
+#define IMX2_WDT_MAX_TIME 128U
+#define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */
+
+#define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8)
+
+struct imx2_wdt_device {
+ struct clk *clk;
+ struct regmap *regmap;
+ struct watchdog_device wdog;
+ bool ext_reset;
+ bool clk_is_on;
+ bool no_ping;
+};
+
+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) ")");
+
+static unsigned timeout;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
+ __MODULE_STRING(IMX2_WDT_DEFAULT_TIME) ")");
+
+static const struct watchdog_info imx2_wdt_info = {
+ .identity = "imx2+ watchdog",
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_info imx2_wdt_pretimeout_info = {
+ .identity = "imx2+ watchdog",
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE |
+ WDIOF_PRETIMEOUT,
+};
+
+static int imx2_wdt_restart(struct watchdog_device *wdog, unsigned long action,
+ void *data)
+{
+ struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+ unsigned int wcr_enable = IMX2_WDT_WCR_WDE;
+
+ /* Use internal reset or external - not both */
+ if (wdev->ext_reset)
+ wcr_enable |= IMX2_WDT_WCR_SRS; /* do not assert int reset */
+ else
+ wcr_enable |= IMX2_WDT_WCR_WDA; /* do not assert ext-reset */
+
+ /* Assert SRS signal */
+ regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable);
+ /*
+ * Due to imx6q errata ERR004346 (WDOG: WDOG SRS bit requires to be
+ * written twice), we add another two writes to ensure there must be at
+ * least two writes happen in the same one 32kHz clock period. We save
+ * the target check here, since the writes shouldn't be a huge burden
+ * for other platforms.
+ */
+ regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable);
+ regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable);
+
+ /* wait for reset to assert... */
+ mdelay(500);
+
+ return 0;
+}
+
+static inline void imx2_wdt_setup(struct watchdog_device *wdog)
+{
+ struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+ u32 val;
+
+ regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);
+
+ /* Suspend timer in low power mode, write once-only */
+ val |= IMX2_WDT_WCR_WDZST;
+ /* Strip the old watchdog Time-Out value */
+ val &= ~IMX2_WDT_WCR_WT;
+ /* Generate internal chip-level reset if WDOG times out */
+ if (!wdev->ext_reset)
+ val &= ~IMX2_WDT_WCR_WRE;
+ /* Or if external-reset assert WDOG_B reset only on time-out */
+ else
+ val |= IMX2_WDT_WCR_WRE;
+ /* Keep Watchdog Disabled */
+ val &= ~IMX2_WDT_WCR_WDE;
+ /* Set the watchdog's Time-Out value */
+ val |= WDOG_SEC_TO_COUNT(wdog->timeout);
+
+ regmap_write(wdev->regmap, IMX2_WDT_WCR, val);
+
+ /* enable the watchdog */
+ val |= IMX2_WDT_WCR_WDE;
+ regmap_write(wdev->regmap, IMX2_WDT_WCR, val);
+}
+
+static inline bool imx2_wdt_is_running(struct imx2_wdt_device *wdev)
+{
+ u32 val;
+
+ regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);
+
+ return val & IMX2_WDT_WCR_WDE;
+}
+
+static int imx2_wdt_ping(struct watchdog_device *wdog)
+{
+ struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ if (!wdev->clk_is_on)
+ return 0;
+
+ regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1);
+ regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2);
+ return 0;
+}
+
+static void __imx2_wdt_set_timeout(struct watchdog_device *wdog,
+ unsigned int new_timeout)
+{
+ struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ regmap_update_bits(wdev->regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT,
+ WDOG_SEC_TO_COUNT(new_timeout));
+}
+
+static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
+ unsigned int new_timeout)
+{
+ unsigned int actual;
+
+ actual = min(new_timeout, IMX2_WDT_MAX_TIME);
+ __imx2_wdt_set_timeout(wdog, actual);
+ wdog->timeout = new_timeout;
+ return 0;
+}
+
+static int imx2_wdt_set_pretimeout(struct watchdog_device *wdog,
+ unsigned int new_pretimeout)
+{
+ struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ if (new_pretimeout >= IMX2_WDT_MAX_TIME)
+ return -EINVAL;
+
+ wdog->pretimeout = new_pretimeout;
+
+ regmap_update_bits(wdev->regmap, IMX2_WDT_WICR,
+ IMX2_WDT_WICR_WIE | IMX2_WDT_WICR_WICT,
+ IMX2_WDT_WICR_WIE | (new_pretimeout << 1));
+ return 0;
+}
+
+static irqreturn_t imx2_wdt_isr(int irq, void *wdog_arg)
+{
+ struct watchdog_device *wdog = wdog_arg;
+ struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ regmap_write_bits(wdev->regmap, IMX2_WDT_WICR,
+ IMX2_WDT_WICR_WTIS, IMX2_WDT_WICR_WTIS);
+
+ watchdog_notify_pretimeout(wdog);
+
+ return IRQ_HANDLED;
+}
+
+static int imx2_wdt_start(struct watchdog_device *wdog)
+{
+ struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ if (imx2_wdt_is_running(wdev))
+ imx2_wdt_set_timeout(wdog, wdog->timeout);
+ else
+ imx2_wdt_setup(wdog);
+
+ set_bit(WDOG_HW_RUNNING, &wdog->status);
+
+ return imx2_wdt_ping(wdog);
+}
+
+static const struct watchdog_ops imx2_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = imx2_wdt_start,
+ .ping = imx2_wdt_ping,
+ .set_timeout = imx2_wdt_set_timeout,
+ .set_pretimeout = imx2_wdt_set_pretimeout,
+ .restart = imx2_wdt_restart,
+};
+
+static const struct regmap_config imx2_wdt_regmap_config = {
+ .reg_bits = 16,
+ .reg_stride = 2,
+ .val_bits = 16,
+ .max_register = 0x8,
+};
+
+static void imx2_wdt_action(void *data)
+{
+ clk_disable_unprepare(data);
+}
+
+static int __init imx2_wdt_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct imx2_wdt_device *wdev;
+ struct watchdog_device *wdog;
+ void __iomem *base;
+ int ret;
+ u32 val;
+
+ wdev = devm_kzalloc(dev, sizeof(*wdev), GFP_KERNEL);
+ if (!wdev)
+ return -ENOMEM;
+
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ wdev->regmap = devm_regmap_init_mmio_clk(dev, NULL, base,
+ &imx2_wdt_regmap_config);
+ if (IS_ERR(wdev->regmap)) {
+ dev_err(dev, "regmap init failed\n");
+ return PTR_ERR(wdev->regmap);
+ }
+
+ wdev->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(wdev->clk)) {
+ dev_err(dev, "can't get Watchdog clock\n");
+ return PTR_ERR(wdev->clk);
+ }
+
+ wdog = &wdev->wdog;
+ wdog->info = &imx2_wdt_info;
+ wdog->ops = &imx2_wdt_ops;
+ wdog->min_timeout = 1;
+ wdog->timeout = IMX2_WDT_DEFAULT_TIME;
+ wdog->max_hw_heartbeat_ms = IMX2_WDT_MAX_TIME * 1000;
+ wdog->parent = dev;
+
+ ret = platform_get_irq(pdev, 0);
+ if (ret > 0)
+ if (!devm_request_irq(dev, ret, imx2_wdt_isr, 0,
+ dev_name(dev), wdog))
+ wdog->info = &imx2_wdt_pretimeout_info;
+
+ ret = clk_prepare_enable(wdev->clk);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(dev, imx2_wdt_action, wdev->clk);
+ if (ret)
+ return ret;
+
+ wdev->clk_is_on = true;
+
+ regmap_read(wdev->regmap, IMX2_WDT_WRSR, &val);
+ wdog->bootstatus = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
+
+ wdev->ext_reset = of_property_read_bool(dev->of_node,
+ "fsl,ext-reset-output");
+ /*
+ * The i.MX7D doesn't support low power mode, so we need to ping the watchdog
+ * during suspend.
+ */
+ wdev->no_ping = !of_device_is_compatible(dev->of_node, "fsl,imx7d-wdt");
+ platform_set_drvdata(pdev, wdog);
+ watchdog_set_drvdata(wdog, wdev);
+ watchdog_set_nowayout(wdog, nowayout);
+ watchdog_set_restart_priority(wdog, 128);
+ watchdog_init_timeout(wdog, timeout, dev);
+ if (wdev->no_ping)
+ watchdog_stop_ping_on_suspend(wdog);
+
+ if (imx2_wdt_is_running(wdev)) {
+ imx2_wdt_set_timeout(wdog, wdog->timeout);
+ set_bit(WDOG_HW_RUNNING, &wdog->status);
+ }
+
+ /*
+ * Disable the watchdog power down counter at boot. Otherwise the power
+ * down counter will pull down the #WDOG interrupt line for one clock
+ * cycle.
+ */
+ regmap_write(wdev->regmap, IMX2_WDT_WMCR, 0);
+
+ return devm_watchdog_register_device(dev, wdog);
+}
+
+static void imx2_wdt_shutdown(struct platform_device *pdev)
+{
+ struct watchdog_device *wdog = platform_get_drvdata(pdev);
+ struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ if (imx2_wdt_is_running(wdev)) {
+ /*
+ * We are running, configure max timeout before reboot
+ * will take place.
+ */
+ imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
+ imx2_wdt_ping(wdog);
+ dev_crit(&pdev->dev, "Device shutdown: Expect reboot!\n");
+ }
+}
+
+/* Disable watchdog if it is active or non-active but still running */
+static int __maybe_unused imx2_wdt_suspend(struct device *dev)
+{
+ struct watchdog_device *wdog = dev_get_drvdata(dev);
+ struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+ /* The watchdog IP block is running */
+ if (imx2_wdt_is_running(wdev)) {
+ /*
+ * Don't update wdog->timeout, we'll restore the current value
+ * during resume.
+ */
+ __imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
+ imx2_wdt_ping(wdog);
+ }
+
+ if (wdev->no_ping) {
+ clk_disable_unprepare(wdev->clk);
+
+ wdev->clk_is_on = false;
+ }
+
+ return 0;
+}
+
+/* Enable watchdog and configure it if necessary */
+static int __maybe_unused imx2_wdt_resume(struct device *dev)
+{
+ struct watchdog_device *wdog = dev_get_drvdata(dev);
+ struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+ int ret;
+
+ if (wdev->no_ping) {
+ ret = clk_prepare_enable(wdev->clk);
+
+ if (ret)
+ return ret;
+
+ wdev->clk_is_on = true;
+ }
+
+ if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) {
+ /*
+ * If the watchdog is still active and resumes
+ * from deep sleep state, need to restart the
+ * watchdog again.
+ */
+ imx2_wdt_setup(wdog);
+ }
+ if (imx2_wdt_is_running(wdev)) {
+ imx2_wdt_set_timeout(wdog, wdog->timeout);
+ imx2_wdt_ping(wdog);
+ }
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend,
+ imx2_wdt_resume);
+
+static const struct of_device_id imx2_wdt_dt_ids[] = {
+ { .compatible = "fsl,imx21-wdt", },
+ { .compatible = "fsl,imx7d-wdt", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx2_wdt_dt_ids);
+
+static struct platform_driver imx2_wdt_driver = {
+ .shutdown = imx2_wdt_shutdown,
+ .driver = {
+ .name = DRIVER_NAME,
+ .pm = &imx2_wdt_pm_ops,
+ .of_match_table = imx2_wdt_dt_ids,
+ },
+};
+
+module_platform_driver_probe(imx2_wdt_driver, imx2_wdt_probe);
+
+MODULE_AUTHOR("Wolfram Sang");
+MODULE_DESCRIPTION("Watchdog driver for IMX2 and later");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);