Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 310 insertions, 0 deletions

diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c
new file mode 100644
index 000000000..922b60374
--- /dev/null
+++ b/drivers/watchdog/imx7ulp_wdt.c
@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/watchdog.h>
+
+#define WDOG_CS			0x0
+#define WDOG_CS_CMD32EN		BIT(13)
+#define WDOG_CS_ULK		BIT(11)
+#define WDOG_CS_RCS		BIT(10)
+#define LPO_CLK			0x1
+#define LPO_CLK_SHIFT		8
+#define WDOG_CS_CLK		(LPO_CLK << LPO_CLK_SHIFT)
+#define WDOG_CS_EN		BIT(7)
+#define WDOG_CS_UPDATE		BIT(5)
+#define WDOG_CS_WAIT		BIT(1)
+#define WDOG_CS_STOP		BIT(0)
+
+#define WDOG_CNT	0x4
+#define WDOG_TOVAL	0x8
+
+#define REFRESH_SEQ0	0xA602
+#define REFRESH_SEQ1	0xB480
+#define REFRESH		((REFRESH_SEQ1 << 16) | REFRESH_SEQ0)
+
+#define UNLOCK_SEQ0	0xC520
+#define UNLOCK_SEQ1	0xD928
+#define UNLOCK		((UNLOCK_SEQ1 << 16) | UNLOCK_SEQ0)
+
+#define DEFAULT_TIMEOUT	60
+#define MAX_TIMEOUT	128
+#define WDOG_CLOCK_RATE	1000
+#define WDOG_WAIT_TIMEOUT	20
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0000);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct imx7ulp_wdt_device {
+	struct watchdog_device wdd;
+	void __iomem *base;
+	struct clk *clk;
+};
+
+static int imx7ulp_wdt_wait(void __iomem *base, u32 mask)
+{
+	u32 val = readl(base + WDOG_CS);
+
+	if (!(val & mask) && readl_poll_timeout_atomic(base + WDOG_CS, val,
+						       val & mask, 0,
+						       WDOG_WAIT_TIMEOUT))
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable)
+{
+	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
+
+	u32 val = readl(wdt->base + WDOG_CS);
+	int ret;
+
+	local_irq_disable();
+	writel(UNLOCK, wdt->base + WDOG_CNT);
+	ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK);
+	if (ret)
+		goto enable_out;
+	if (enable)
+		writel(val | WDOG_CS_EN, wdt->base + WDOG_CS);
+	else
+		writel(val & ~WDOG_CS_EN, wdt->base + WDOG_CS);
+	imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS);
+
+enable_out:
+	local_irq_enable();
+
+	return ret;
+}
+
+static bool imx7ulp_wdt_is_enabled(void __iomem *base)
+{
+	u32 val = readl(base + WDOG_CS);
+
+	return val & WDOG_CS_EN;
+}
+
+static int imx7ulp_wdt_ping(struct watchdog_device *wdog)
+{
+	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
+
+	writel(REFRESH, wdt->base + WDOG_CNT);
+
+	return 0;
+}
+
+static int imx7ulp_wdt_start(struct watchdog_device *wdog)
+{
+	return imx7ulp_wdt_enable(wdog, true);
+}
+
+static int imx7ulp_wdt_stop(struct watchdog_device *wdog)
+{
+	return imx7ulp_wdt_enable(wdog, false);
+}
+
+static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog,
+				   unsigned int timeout)
+{
+	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
+	u32 val = WDOG_CLOCK_RATE * timeout;
+	int ret;
+
+	local_irq_disable();
+	writel(UNLOCK, wdt->base + WDOG_CNT);
+	ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK);
+	if (ret)
+		goto timeout_out;
+	writel(val, wdt->base + WDOG_TOVAL);
+	imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS);
+
+	wdog->timeout = timeout;
+
+timeout_out:
+	local_irq_enable();
+
+	return ret;
+}
+
+static int imx7ulp_wdt_restart(struct watchdog_device *wdog,
+			       unsigned long action, void *data)
+{
+	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
+	int ret;
+
+	ret = imx7ulp_wdt_enable(wdog, true);
+	if (ret)
+		return ret;
+
+	ret = imx7ulp_wdt_set_timeout(&wdt->wdd, 1);
+	if (ret)
+		return ret;
+
+	/* wait for wdog to fire */
+	while (true)
+		;
+
+	return NOTIFY_DONE;
+}
+
+static const struct watchdog_ops imx7ulp_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = imx7ulp_wdt_start,
+	.stop  = imx7ulp_wdt_stop,
+	.ping  = imx7ulp_wdt_ping,
+	.set_timeout = imx7ulp_wdt_set_timeout,
+	.restart = imx7ulp_wdt_restart,
+};
+
+static const struct watchdog_info imx7ulp_wdt_info = {
+	.identity = "i.MX7ULP watchdog timer",
+	.options  = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
+		    WDIOF_MAGICCLOSE,
+};
+
+static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
+{
+	u32 val;
+	int ret;
+
+	local_irq_disable();
+	/* unlock the wdog for reconfiguration */
+	writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
+	writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);
+	ret = imx7ulp_wdt_wait(base, WDOG_CS_ULK);
+	if (ret)
+		goto init_out;
+
+	/* set an initial timeout value in TOVAL */
+	writel(timeout, base + WDOG_TOVAL);
+	/* enable 32bit command sequence and reconfigure */
+	val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE |
+	      WDOG_CS_WAIT | WDOG_CS_STOP;
+	writel(val, base + WDOG_CS);
+	imx7ulp_wdt_wait(base, WDOG_CS_RCS);
+
+init_out:
+	local_irq_enable();
+
+	return ret;
+}
+
+static void imx7ulp_wdt_action(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int imx7ulp_wdt_probe(struct platform_device *pdev)
+{
+	struct imx7ulp_wdt_device *imx7ulp_wdt;
+	struct device *dev = &pdev->dev;
+	struct watchdog_device *wdog;
+	int ret;
+
+	imx7ulp_wdt = devm_kzalloc(dev, sizeof(*imx7ulp_wdt), GFP_KERNEL);
+	if (!imx7ulp_wdt)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, imx7ulp_wdt);
+
+	imx7ulp_wdt->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(imx7ulp_wdt->base))
+		return PTR_ERR(imx7ulp_wdt->base);
+
+	imx7ulp_wdt->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(imx7ulp_wdt->clk)) {
+		dev_err(dev, "Failed to get watchdog clock\n");
+		return PTR_ERR(imx7ulp_wdt->clk);
+	}
+
+	ret = clk_prepare_enable(imx7ulp_wdt->clk);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, imx7ulp_wdt_action, imx7ulp_wdt->clk);
+	if (ret)
+		return ret;
+
+	wdog = &imx7ulp_wdt->wdd;
+	wdog->info = &imx7ulp_wdt_info;
+	wdog->ops = &imx7ulp_wdt_ops;
+	wdog->min_timeout = 1;
+	wdog->max_timeout = MAX_TIMEOUT;
+	wdog->parent = dev;
+	wdog->timeout = DEFAULT_TIMEOUT;
+
+	watchdog_init_timeout(wdog, 0, dev);
+	watchdog_stop_on_reboot(wdog);
+	watchdog_stop_on_unregister(wdog);
+	watchdog_set_drvdata(wdog, imx7ulp_wdt);
+	ret = imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE);
+	if (ret)
+		return ret;
+
+	return devm_watchdog_register_device(dev, wdog);
+}
+
+static int __maybe_unused imx7ulp_wdt_suspend(struct device *dev)
+{
+	struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev);
+
+	if (watchdog_active(&imx7ulp_wdt->wdd))
+		imx7ulp_wdt_stop(&imx7ulp_wdt->wdd);
+
+	clk_disable_unprepare(imx7ulp_wdt->clk);
+
+	return 0;
+}
+
+static int __maybe_unused imx7ulp_wdt_resume(struct device *dev)
+{
+	struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev);
+	u32 timeout = imx7ulp_wdt->wdd.timeout * WDOG_CLOCK_RATE;
+	int ret;
+
+	ret = clk_prepare_enable(imx7ulp_wdt->clk);
+	if (ret)
+		return ret;
+
+	if (imx7ulp_wdt_is_enabled(imx7ulp_wdt->base))
+		imx7ulp_wdt_init(imx7ulp_wdt->base, timeout);
+
+	if (watchdog_active(&imx7ulp_wdt->wdd))
+		imx7ulp_wdt_start(&imx7ulp_wdt->wdd);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(imx7ulp_wdt_pm_ops, imx7ulp_wdt_suspend,
+			 imx7ulp_wdt_resume);
+
+static const struct of_device_id imx7ulp_wdt_dt_ids[] = {
+	{ .compatible = "fsl,imx7ulp-wdt", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx7ulp_wdt_dt_ids);
+
+static struct platform_driver imx7ulp_wdt_driver = {
+	.probe		= imx7ulp_wdt_probe,
+	.driver		= {
+		.name	= "imx7ulp-wdt",
+		.pm	= &imx7ulp_wdt_pm_ops,
+		.of_match_table = imx7ulp_wdt_dt_ids,
+	},
+};
+module_platform_driver(imx7ulp_wdt_driver);
+
+MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
+MODULE_DESCRIPTION("Freescale i.MX7ULP watchdog driver");
+MODULE_LICENSE("GPL v2");