--- /dev/null
+/*
+ * drivers/char/watchdog/pnx4008_wdt.c
+ *
+ * Watchdog driver for PNX4008 board
+ *
+ * Authors: Dmitry Chigirev <source@mvista.com>,
+ * Vitaly Wool <vitalywool@gmail.com>
+ * Based on sa1100 driver,
+ * Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
+ *
+ * 2005-2006 (c) MontaVista Software, Inc.
+ *
+ * (C) 2012 Wolfram Sang, Pengutronix
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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/clk.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <mach/hardware.h>
+
+/* WatchDog Timer - Chapter 23 Page 207 */
+
+#define DEFAULT_HEARTBEAT 19
+#define MAX_HEARTBEAT 60
+
+/* Watchdog timer register set definition */
+#define WDTIM_INT(p) ((p) + 0x0)
+#define WDTIM_CTRL(p) ((p) + 0x4)
+#define WDTIM_COUNTER(p) ((p) + 0x8)
+#define WDTIM_MCTRL(p) ((p) + 0xC)
+#define WDTIM_MATCH0(p) ((p) + 0x10)
+#define WDTIM_EMR(p) ((p) + 0x14)
+#define WDTIM_PULSE(p) ((p) + 0x18)
+#define WDTIM_RES(p) ((p) + 0x1C)
+
+/* WDTIM_INT bit definitions */
+#define MATCH_INT 1
+
+/* WDTIM_CTRL bit definitions */
+#define COUNT_ENAB 1
+#define RESET_COUNT (1 << 1)
+#define DEBUG_EN (1 << 2)
+
+/* WDTIM_MCTRL bit definitions */
+#define MR0_INT 1
+#undef RESET_COUNT0
+#define RESET_COUNT0 (1 << 2)
+#define STOP_COUNT0 (1 << 2)
+#define M_RES1 (1 << 3)
+#define M_RES2 (1 << 4)
+#define RESFRC1 (1 << 5)
+#define RESFRC2 (1 << 6)
+
+/* WDTIM_EMR bit definitions */
+#define EXT_MATCH0 1
+#define MATCH_OUTPUT_HIGH (2 << 4) /*a MATCH_CTRL setting */
+
+/* WDTIM_RES bit definitions */
+#define WDOG_RESET 1 /* read only */
+
+#define WDOG_COUNTER_RATE 13000000 /*the counter clock is 13 MHz fixed */
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int heartbeat = DEFAULT_HEARTBEAT;
+
+static DEFINE_SPINLOCK(io_lock);
+static void __iomem *wdt_base;
+struct clk *wdt_clk;
+
+static int pnx4008_wdt_start(struct watchdog_device *wdd)
+{
+ spin_lock(&io_lock);
+
+ /* stop counter, initiate counter reset */
+ writel(RESET_COUNT, WDTIM_CTRL(wdt_base));
+ /*wait for reset to complete. 100% guarantee event */
+ while (readl(WDTIM_COUNTER(wdt_base)))
+ cpu_relax();
+ /* internal and external reset, stop after that */
+ writel(M_RES2 | STOP_COUNT0 | RESET_COUNT0, WDTIM_MCTRL(wdt_base));
+ /* configure match output */
+ writel(MATCH_OUTPUT_HIGH, WDTIM_EMR(wdt_base));
+ /* clear interrupt, just in case */
+ writel(MATCH_INT, WDTIM_INT(wdt_base));
+ /* the longest pulse period 65541/(13*10^6) seconds ~ 5 ms. */
+ writel(0xFFFF, WDTIM_PULSE(wdt_base));
+ writel(wdd->timeout * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
+ /*enable counter, stop when debugger active */
+ writel(COUNT_ENAB | DEBUG_EN, WDTIM_CTRL(wdt_base));
+
+ spin_unlock(&io_lock);
+ return 0;
+}
+
+static int pnx4008_wdt_stop(struct watchdog_device *wdd)
+{
+ spin_lock(&io_lock);
+
+ writel(0, WDTIM_CTRL(wdt_base)); /*stop counter */
+
+ spin_unlock(&io_lock);
+ return 0;
+}
+
+static int pnx4008_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int new_timeout)
+{
+ wdd->timeout = new_timeout;
+ return 0;
+}
+
+static const struct watchdog_info pnx4008_wdt_ident = {
+ .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
+ WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+ .identity = "PNX4008 Watchdog",
+};
+
+static const struct watchdog_ops pnx4008_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = pnx4008_wdt_start,
+ .stop = pnx4008_wdt_stop,
+ .set_timeout = pnx4008_wdt_set_timeout,
+};
+
+static struct watchdog_device pnx4008_wdd = {
+ .info = &pnx4008_wdt_ident,
+ .ops = &pnx4008_wdt_ops,
+ .timeout = DEFAULT_HEARTBEAT,
+ .min_timeout = 1,
+ .max_timeout = MAX_HEARTBEAT,
+};
+
+static int pnx4008_wdt_probe(struct platform_device *pdev)
+{
+ struct resource *r;
+ int ret = 0;
+
+ watchdog_init_timeout(&pnx4008_wdd, heartbeat, &pdev->dev);
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ wdt_base = devm_ioremap_resource(&pdev->dev, r);
+ if (IS_ERR(wdt_base))
+ return PTR_ERR(wdt_base);
+
+ wdt_clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(wdt_clk))
+ return PTR_ERR(wdt_clk);
+
+ ret = clk_enable(wdt_clk);
+ if (ret)
+ return ret;
+
+ pnx4008_wdd.bootstatus = (readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ?
+ WDIOF_CARDRESET : 0;
+ watchdog_set_nowayout(&pnx4008_wdd, nowayout);
+
+ pnx4008_wdt_stop(&pnx4008_wdd); /* disable for now */
+
+ ret = watchdog_register_device(&pnx4008_wdd);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "cannot register watchdog device\n");
+ goto disable_clk;
+ }
+
+ dev_info(&pdev->dev, "PNX4008 Watchdog Timer: heartbeat %d sec\n",
+ pnx4008_wdd.timeout);
+
+ return 0;
+
+disable_clk:
+ clk_disable(wdt_clk);
+ return ret;
+}
+
+static int pnx4008_wdt_remove(struct platform_device *pdev)
+{
+ watchdog_unregister_device(&pnx4008_wdd);
+
+ clk_disable(wdt_clk);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id pnx4008_wdt_match[] = {
+ { .compatible = "nxp,pnx4008-wdt" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, pnx4008_wdt_match);
+#endif
+
+static struct platform_driver platform_wdt_driver = {
+ .driver = {
+ .name = "pnx4008-watchdog",
+ .of_match_table = of_match_ptr(pnx4008_wdt_match),
+ },
+ .probe = pnx4008_wdt_probe,
+ .remove = pnx4008_wdt_remove,
+};
+
+module_platform_driver(platform_wdt_driver);
+
+MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
+MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
+MODULE_DESCRIPTION("PNX4008 Watchdog Driver");
+
+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));
+
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Set to 1 to keep watchdog running after device release");
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pnx4008-watchdog");
Code Review / kvmfornfv.git / blobdiff