From mboxrd@z Thu Jan 1 00:00:00 1970 From: w.sang@pengutronix.de (Wolfram Sang) Date: Fri, 14 May 2010 04:49:15 +0200 Subject: [PATCH 1/6] Driver for the watchdog timer on Freescale IMX2 (and later) processors. In-Reply-To: <1272528202-24159-2-git-send-email-w.sang@pengutronix.de> References: <1272528202-24159-1-git-send-email-w.sang@pengutronix.de> <1272528202-24159-2-git-send-email-w.sang@pengutronix.de> Message-ID: <20100514024915.GE30794@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Apr 29, 2010 at 10:03:17AM +0200, Wolfram Sang wrote: > Signed-off-by: Wolfram Sang > Cc: Vladimir Zapolskiy > Cc: Sascha Hauer > Cc: Wim Van Sebroeck Ping. Wim, did you notice this one? Shall the driver go via your tree or via the imx-tree along with the resource updates (with your ack)? > --- > drivers/watchdog/Kconfig | 12 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/imx2_wdt.c | 279 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 292 insertions(+), 0 deletions(-) > create mode 100644 drivers/watchdog/imx2_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 0e8468f..b24baec 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -306,6 +306,18 @@ config MAX63XX_WATCHDOG > help > Support for memory mapped max63{69,70,71,72,73,74} watchdog timer. > > +config IMX2_WDT > + tristate "IMX2+ Watchdog" > + depends on ARCH_MX2 || ARCH_MX25 || ARCH_MX3 || ARCH_MX5 > + help > + This is the driver for the hardware watchdog > + on the Freescale IMX2 and later processors. > + If you have one of these processors and wish to have > + watchdog support enabled, say Y, otherwise say N. > + > + To compile this driver as a module, choose M here: the > + module will be called imx2_wdt. > + > # AVR32 Architecture > > config AT32AP700X_WDT > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 5e3cb95..72f3e20 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -47,6 +47,7 @@ obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o > obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o > obj-$(CONFIG_ADX_WATCHDOG) += adx_wdt.o > obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o > +obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o > > # AVR32 Architecture > obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o > diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c > new file mode 100644 > index 0000000..980aa2e > --- /dev/null > +++ b/drivers/watchdog/imx2_wdt.c > @@ -0,0 +1,279 @@ > +/* > + * Watchdog driver for IMX2 and later processors > + * > + * Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. > + * > + * some parts adapted by similar drivers from Darius Augulis and Vladimir > + * Zapolskiy. > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms of the GNU General Public License version 2 as published by > + * the Free Software Foundation. > + * > + * 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 > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define DRIVER_NAME "imx2-wdt" > + > +#define IMX2_WDT_WCR 0x00 /* Control reg */ > +#define IMX2_WDT_WCR_WDZST (1 << 0) > +#define IMX2_WDT_WCR_WDE (1 << 2) > +#define IMX2_WDT_WSR 0x02 /* Service reg */ > + > +#define IMX2_WDT_MAX_TIME 128 > +#define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */ > +#define IMX2_WDT_SEQ1 0x5555 > +#define IMX2_WDT_SEQ2 0xAAAA > + > +#define IMX2_WDT_STATUS_OPEN 0 > +#define IMX2_WDT_STATUS_STARTED 1 > + > +static struct { > + struct clk *clk; > + void __iomem *base; > + unsigned timeout; > + unsigned long status; > + struct timer_list timer; /* Pings the watchdog when closed */ > +} imx2_wdt; > + > +static struct miscdevice imx2_wdt_miscdev; > + > +static int nowayout = WATCHDOG_NOWAYOUT; > + > +static unsigned timeout = IMX2_WDT_DEFAULT_TIME; > +module_param(timeout, uint, 0); > +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds"); > + > +static const struct watchdog_info imx2_wdt_info = { > + .identity = "imx2+ watchdog", > + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, > +}; > + > +static void imx2_wdt_ping(void) > +{ > + __raw_writew(IMX2_WDT_SEQ1, imx2_wdt.base + IMX2_WDT_WSR); > + __raw_writew(IMX2_WDT_SEQ2, imx2_wdt.base + IMX2_WDT_WSR); > +} > + > +static void imx2_wdt_timer_ping(unsigned long arg) > +{ > + imx2_wdt_ping(); > + mod_timer(&imx2_wdt.timer, jiffies + imx2_wdt.timeout * HZ / 2); > +} > + > +static void imx2_wdt_setup(void) > +{ > + u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR); > + > + val = (val & 0x00ff) | ((imx2_wdt.timeout * 2 - 1) << 8); > + val |= IMX2_WDT_WCR_WDE; > + __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR); > + imx2_wdt_ping(); > +} > + > +static int imx2_wdt_open(struct inode *inode, struct file *file) > +{ > + if (test_and_set_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status)) > + return -EBUSY; > + > + clk_enable(imx2_wdt.clk); > + imx2_wdt_setup(); > + del_timer_sync(&imx2_wdt.timer); > + set_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status); > + return nonseekable_open(inode, file); > +} > + > +static int imx2_wdt_close(struct inode *inode, struct file *file) > +{ > + /* no clk_disable. it cannot be disabled once started */ > + clear_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status); > + if (nowayout) > + dev_crit(imx2_wdt_miscdev.parent, > + "Device closed: Expect reboot!\n"); > + else > + imx2_wdt_timer_ping(0); > + > + return 0; > +} > + > +static int imx2_wdt_ioctl(struct inode *inode, struct file *file, > + unsigned int cmd, unsigned long arg) > +{ > + void __user *argp = (void __user *)arg; > + int __user *p = argp; > + int new_value; > + > + switch (cmd) { > + case WDIOC_KEEPALIVE: > + imx2_wdt_ping(); > + return 0; > + > + case WDIOC_GETSUPPORT: > + return copy_to_user(argp, &imx2_wdt_info, > + sizeof(struct watchdog_info)) ? -EFAULT : 0; > + > + case WDIOC_SETTIMEOUT: > + if (get_user(new_value, p)) > + return -EFAULT; > + if ((new_value < 1) || (new_value > IMX2_WDT_MAX_TIME)) > + return -EINVAL; > + > + imx2_wdt.timeout = new_value; > + imx2_wdt_setup(); > + > + /* Fallthrough to return current value */ > + case WDIOC_GETTIMEOUT: > + return put_user(imx2_wdt.timeout, p); > + > + default: > + return -ENOTTY; > + } > +} > + > +static ssize_t imx2_wdt_write(struct file *file, const char *data, > + size_t len, loff_t *ppos) > +{ > + if (len) > + imx2_wdt_ping(); > + return len; > +} > + > +static const struct file_operations imx2_wdt_fops = { > + .owner = THIS_MODULE, > + .llseek = no_llseek, > + .ioctl = imx2_wdt_ioctl, > + .open = imx2_wdt_open, > + .release = imx2_wdt_close, > + .write = imx2_wdt_write, > +}; > + > +static struct miscdevice imx2_wdt_miscdev = { > + .minor = WATCHDOG_MINOR, > + .name = "watchdog", > + .fops = &imx2_wdt_fops, > +}; > + > +static void imx2_wdt_shutdown(struct platform_device *pdev) > +{ > + del_timer_sync(&imx2_wdt.timer); > + if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) > + dev_crit(imx2_wdt_miscdev.parent, > + "Device shutdown: Expect reboot!\n"); > +} > + > +static int __devinit imx2_wdt_probe(struct platform_device *pdev) > +{ > + int ret; > + int res_size; > + struct resource *res; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!res) { > + dev_err(&pdev->dev, "can't get device resources\n"); > + return -ENODEV; > + } > + > + res_size = resource_size(res); > + if (!devm_request_mem_region(&pdev->dev, res->start, res_size, > + res->name)) { > + dev_err(&pdev->dev, "can't allocate %d bytes at %d address\n", > + res_size, res->start); > + return -ENOMEM; > + } > + > + imx2_wdt.base = devm_ioremap_nocache(&pdev->dev, res->start, res_size); > + if (!imx2_wdt.base) { > + dev_err(&pdev->dev, "ioremap failed\n"); > + return -ENOMEM; > + } > + > + imx2_wdt.clk = clk_get_sys("imx-wdt.0", NULL); > + if (IS_ERR(imx2_wdt.clk)) { > + dev_err(&pdev->dev, "can't get Watchdog clock\n"); > + return PTR_ERR(imx2_wdt.clk); > + } > + > + imx2_wdt.timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME); > + if (imx2_wdt.timeout != timeout) > + dev_warn(&pdev->dev, "Initial timeout out of range! " > + "Clamped from %u to %u\n", timeout, imx2_wdt.timeout); > + > + imx2_wdt_miscdev.parent = &pdev->dev; > + ret = misc_register(&imx2_wdt_miscdev); > + if (ret) > + goto fail; > + > + setup_timer(&imx2_wdt.timer, imx2_wdt_timer_ping, 0); > + dev_info(&pdev->dev, "IMX2+ Watchdog Timer enabled\n"); > + return 0; > + > +fail: > + imx2_wdt_miscdev.parent = NULL; > + clk_put(imx2_wdt.clk); > + return ret; > +} > + > +static int __devexit imx2_wdt_remove(struct platform_device *pdev) > +{ > + del_timer_sync(&imx2_wdt.timer); > + misc_deregister(&imx2_wdt_miscdev); > + imx2_wdt_miscdev.parent = NULL; > + > + if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) > + dev_crit(imx2_wdt_miscdev.parent, > + "Device removed: Expect reboot!\n"); > + else > + clk_put(imx2_wdt.clk); > + > + return 0; > +} > + > +static struct platform_driver imx2_wdt_driver = { > + .probe = imx2_wdt_probe, > + .remove = __devexit_p(imx2_wdt_remove), > + .shutdown = imx2_wdt_shutdown, > + .driver = { > + .name = DRIVER_NAME, > + .owner = THIS_MODULE, > + }, > +}; > + > +static int __init imx2_wdt_init(void) > +{ > + return platform_driver_probe(&imx2_wdt_driver, imx2_wdt_probe); > +} > +module_init(imx2_wdt_init); > + > +static void __exit imx2_wdt_exit(void) > +{ > + platform_driver_unregister(&imx2_wdt_driver); > +} > +module_exit(imx2_wdt_exit); > + > +MODULE_AUTHOR("Wolfram Sang"); > +MODULE_DESCRIPTION("Watchdog driver for IMX2 and later"); > +MODULE_LICENSE("GPL v2"); > +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); > +MODULE_ALIAS("platform:" DRIVER_NAME); > -- > 1.7.0 > -- Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ | -------------- next part -------------- A non-text attachment was scrubbed... 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