summaryrefslogtreecommitdiffstats
path: root/drivers/watchdog/jz4740_wdt.c
diff options
context:
space:
mode:
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/jz4740_wdt.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.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/jz4740_wdt.c')
-rw-r--r--drivers/watchdog/jz4740_wdt.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c
new file mode 100644
index 000000000..395bde79e
--- /dev/null
+++ b/drivers/watchdog/jz4740_wdt.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net>
+ * JZ4740 Watchdog driver
+ */
+
+#include <linux/mfd/ingenic-tcu.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/device.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+#define DEFAULT_HEARTBEAT 5
+#define MAX_HEARTBEAT 2048
+
+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 int heartbeat = DEFAULT_HEARTBEAT;
+module_param(heartbeat, uint, 0);
+MODULE_PARM_DESC(heartbeat,
+ "Watchdog heartbeat period in seconds from 1 to "
+ __MODULE_STRING(MAX_HEARTBEAT) ", default "
+ __MODULE_STRING(DEFAULT_HEARTBEAT));
+
+struct jz4740_wdt_drvdata {
+ struct watchdog_device wdt;
+ struct regmap *map;
+ struct clk *clk;
+ unsigned long clk_rate;
+};
+
+static int jz4740_wdt_ping(struct watchdog_device *wdt_dev)
+{
+ struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
+
+ regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0);
+
+ return 0;
+}
+
+static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev,
+ unsigned int new_timeout)
+{
+ struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
+ u16 timeout_value = (u16)(drvdata->clk_rate * new_timeout);
+ unsigned int tcer;
+
+ regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer);
+ regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0);
+
+ regmap_write(drvdata->map, TCU_REG_WDT_TDR, timeout_value);
+ regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0);
+
+ if (tcer & TCU_WDT_TCER_TCEN)
+ regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN);
+
+ wdt_dev->timeout = new_timeout;
+ return 0;
+}
+
+static int jz4740_wdt_start(struct watchdog_device *wdt_dev)
+{
+ struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
+ unsigned int tcer;
+ int ret;
+
+ ret = clk_prepare_enable(drvdata->clk);
+ if (ret)
+ return ret;
+
+ regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer);
+
+ jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
+
+ /* Start watchdog if it wasn't started already */
+ if (!(tcer & TCU_WDT_TCER_TCEN))
+ regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN);
+
+ return 0;
+}
+
+static int jz4740_wdt_stop(struct watchdog_device *wdt_dev)
+{
+ struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
+
+ regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0);
+ clk_disable_unprepare(drvdata->clk);
+
+ return 0;
+}
+
+static int jz4740_wdt_restart(struct watchdog_device *wdt_dev,
+ unsigned long action, void *data)
+{
+ wdt_dev->timeout = 0;
+ jz4740_wdt_start(wdt_dev);
+ return 0;
+}
+
+static const struct watchdog_info jz4740_wdt_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+ .identity = "jz4740 Watchdog",
+};
+
+static const struct watchdog_ops jz4740_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = jz4740_wdt_start,
+ .stop = jz4740_wdt_stop,
+ .ping = jz4740_wdt_ping,
+ .set_timeout = jz4740_wdt_set_timeout,
+ .restart = jz4740_wdt_restart,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id jz4740_wdt_of_matches[] = {
+ { .compatible = "ingenic,jz4740-watchdog", },
+ { .compatible = "ingenic,jz4780-watchdog", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, jz4740_wdt_of_matches);
+#endif
+
+static int jz4740_wdt_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct jz4740_wdt_drvdata *drvdata;
+ struct watchdog_device *jz4740_wdt;
+ long rate;
+ int ret;
+
+ drvdata = devm_kzalloc(dev, sizeof(struct jz4740_wdt_drvdata),
+ GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
+
+ drvdata->clk = devm_clk_get(&pdev->dev, "wdt");
+ if (IS_ERR(drvdata->clk)) {
+ dev_err(&pdev->dev, "cannot find WDT clock\n");
+ return PTR_ERR(drvdata->clk);
+ }
+
+ /* Set smallest clock possible */
+ rate = clk_round_rate(drvdata->clk, 1);
+ if (rate < 0)
+ return rate;
+
+ ret = clk_set_rate(drvdata->clk, rate);
+ if (ret)
+ return ret;
+
+ drvdata->clk_rate = rate;
+ jz4740_wdt = &drvdata->wdt;
+ jz4740_wdt->info = &jz4740_wdt_info;
+ jz4740_wdt->ops = &jz4740_wdt_ops;
+ jz4740_wdt->min_timeout = 1;
+ jz4740_wdt->max_timeout = 0xffff / rate;
+ jz4740_wdt->timeout = clamp(heartbeat,
+ jz4740_wdt->min_timeout,
+ jz4740_wdt->max_timeout);
+ jz4740_wdt->parent = dev;
+ watchdog_set_nowayout(jz4740_wdt, nowayout);
+ watchdog_set_drvdata(jz4740_wdt, drvdata);
+
+ drvdata->map = device_node_to_regmap(dev->parent->of_node);
+ if (IS_ERR(drvdata->map)) {
+ dev_err(dev, "regmap not found\n");
+ return PTR_ERR(drvdata->map);
+ }
+
+ return devm_watchdog_register_device(dev, &drvdata->wdt);
+}
+
+static struct platform_driver jz4740_wdt_driver = {
+ .probe = jz4740_wdt_probe,
+ .driver = {
+ .name = "jz4740-wdt",
+ .of_match_table = of_match_ptr(jz4740_wdt_of_matches),
+ },
+};
+
+module_platform_driver(jz4740_wdt_driver);
+
+MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
+MODULE_DESCRIPTION("jz4740 Watchdog Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:jz4740-wdt");