- 根目录:
- arch
- powerpc
- platforms
- 52xx
- mpc52xx_gpt.c
/*
* MPC5200 General Purpose Timer device driver
*
* Copyright (c) 2009 Secret Lab Technologies Ltd.
* Copyright (c) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This file is a driver for the the General Purpose Timer (gpt) devices
* found on the MPC5200 SoC. Each timer has an IO pin which can be used
* for GPIO or can be used to raise interrupts. The timer function can
* be used independently from the IO pin, or it can be used to control
* output signals or measure input signals.
*
* This driver supports the GPIO and IRQ controller functions of the GPT
* device. Timer functions are not yet supported.
*
* The timer gpt0 can be used as watchdog (wdt). If the wdt mode is used,
* this prevents the use of any gpt0 gpt function (i.e. they will fail with
* -EBUSY). Thus, the safety wdt function always has precedence over the gpt
* function. If the kernel has been compiled with CONFIG_WATCHDOG_NOWAYOUT,
* this means that gpt0 is locked in wdt mode until the next reboot - this
* may be a requirement in safety applications.
*
* To use the GPIO function, the following two properties must be added
* to the device tree node for the gpt device (typically in the .dts file
* for the board):
* gpio-controller;
* #gpio-cells = < 2 >;
* This driver will register the GPIO pin if it finds the gpio-controller
* property in the device tree.
*
* To use the IRQ controller function, the following two properties must
* be added to the device tree node for the gpt device:
* interrupt-controller;
* #interrupt-cells = < 1 >;
* The IRQ controller binding only uses one cell to specify the interrupt,
* and the IRQ flags are encoded in the cell. A cell is not used to encode
* the IRQ number because the GPT only has a single IRQ source. For flags,
* a value of '1' means rising edge sensitive and '2' means falling edge.
*
* The GPIO and the IRQ controller functions can be used at the same time,
* but in this use case the IO line will only work as an input. Trying to
* use it as a GPIO output will not work.
*
* When using the GPIO line as an output, it can either be driven as normal
* IO, or it can be an Open Collector (OC) output. At the moment it is the
* responsibility of either the bootloader or the platform setup code to set
* the output mode. This driver does not change the output mode setting.
*/
#include <linux/device.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/watchdog.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <asm/div64.h>
#include <asm/mpc52xx.h>
MODULE_DESCRIPTION("Freescale MPC52xx gpt driver");
MODULE_AUTHOR("Sascha Hauer, Grant Likely, Albrecht Dreß");
MODULE_LICENSE("GPL");
/**
* struct mpc52xx_gpt - Private data structure for MPC52xx GPT driver
* @dev: pointer to device structure
* @regs: virtual address of GPT registers
* @lock: spinlock to coordinate between different functions.
* @gc: gpio_chip instance structure; used when GPIO is enabled
* @irqhost: Pointer to irq_domain instance; used when IRQ mode is supported
* @wdt_mode: only relevant for gpt0: bit 0 (MPC52xx_GPT_CAN_WDT) indicates
* if the gpt may be used as wdt, bit 1 (MPC52xx_GPT_IS_WDT) indicates
* if the timer is actively used as wdt which blocks gpt functions
*/
struct mpc52xx_gpt_priv {
struct list_head list; /* List of all GPT devices */
struct device *dev;
struct mpc52xx_gpt __iomem *regs;
spinlock_t lock;
struct irq_domain *irqhost;
u32 ipb_freq;
u8 wdt_mode;
#if defined(CONFIG_GPIOLIB)
struct gpio_chip gc;
#endif
};
LIST_HEAD(mpc52xx_gpt_list);
DEFINE_MUTEX(mpc52xx_gpt_list_mutex);
#define MPC52xx_GPT_MODE_MS_MASK (0x07)
#define MPC52xx_GPT_MODE_MS_IC (0x01)
#define MPC52xx_GPT_MODE_MS_OC (0x02)
#define MPC52xx_GPT_MODE_MS_PWM (0x03)
#define MPC52xx_GPT_MODE_MS_GPIO (0x04)
#define MPC52xx_GPT_MODE_GPIO_MASK (0x30)
#define MPC52xx_GPT_MODE_GPIO_OUT_LOW (0x20)
#define MPC52xx_GPT_MODE_GPIO_OUT_HIGH (0x30)
#define MPC52xx_GPT_MODE_COUNTER_ENABLE (0x1000)
#define MPC52xx_GPT_MODE_CONTINUOUS (0x0400)
#define MPC52xx_GPT_MODE_OPEN_DRAIN (0x0200)
#define MPC52xx_GPT_MODE_IRQ_EN (0x0100)
#define MPC52xx_GPT_MODE_WDT_EN (0x8000)
#define MPC52xx_GPT_MODE_ICT_MASK (0x030000)
#define MPC52xx_GPT_MODE_ICT_RISING (0x010000)
#define MPC52xx_GPT_MODE_ICT_FALLING (0x020000)
#define MPC52xx_GPT_MODE_ICT_TOGGLE (0x030000)
#define MPC52xx_GPT_MODE_WDT_PING (0xa5)
#define MPC52xx_GPT_STATUS_IRQMASK (0x000f)
#define MPC52xx_GPT_CAN_WDT (1 << 0)
#define MPC52xx_GPT_IS_WDT (1 << 1)
/* ---------------------------------------------------------------------
* Cascaded interrupt controller hooks
*/
static void mpc52xx_gpt_irq_unmask(struct irq_data *d)
{
struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d);
unsigned long flags;
spin_lock_irqsave(&gpt->lock, flags);
setbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_IRQ_EN);
spin_unlock_irqrestore(&gpt->lock, flags);
}
static void mpc52xx_gpt_irq_mask(struct irq_data *d)
{
struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d);
unsigned long flags;
spin_lock_irqsave(&gpt->lock, flags);
clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_IRQ_EN);
spin_unlock_irqrestore(&gpt->lock, flags);
}
static void mpc52xx_gpt_irq_ack(struct irq_data *d)
{
struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d);
out_be32(&gpt->regs->status, MPC52xx_GPT_STATUS_IRQMASK);
}
static int mpc52xx_gpt_irq_set_type(struct irq_data *d, unsigned int flow_type)
{
struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d);
unsigned long flags;
u32 reg;
dev_dbg(gpt->dev, "%s: virq=%i type=%x\n", __func__, d->irq, flow_type);
spin_lock_irqsave(&gpt->lock, flags);
reg = in_be32(&gpt->regs->mode) & ~MPC52xx_GPT_MODE_ICT_MASK;
if (flow_type & IRQF_TRIGGER_RISING)
reg |= MPC52xx_GPT_MODE_ICT_RISING;
if (flow_type & IRQF_TRIGGER_FALLING)
reg |= MPC52xx_GPT_MODE_ICT_FALLING;
out_be32(&gpt->regs->mode, reg);
spin_unlock_irqrestore(&gpt->lock, flags);
return 0;
}
static struct irq_chip mpc52xx_gpt_irq_chip = {
.name = "MPC52xx GPT",
.irq_unmask = mpc52xx_gpt_irq_unmask,
.irq_mask = mpc52xx_gpt_irq_mask,
.irq_ack = mpc52xx_gpt_irq_ack,
.irq_set_type = mpc52xx_gpt_irq_set_type,
};
void mpc52xx_gpt_irq_cascade(unsigned int virq, struct irq_desc *desc)
{
struct mpc52xx_gpt_priv *gpt = irq_get_handler_data(virq);
int sub_virq;
u32 status;
status = in_be32(&gpt->regs->status) & MPC52xx_GPT_STATUS_IRQMASK;
if (status) {
sub_virq = irq_linear_revmap(gpt->irqhost, 0);
generic_handle_irq(sub_virq);
}
}
static int mpc52xx_gpt_irq_map(struct irq_domain *h, unsigned int virq,
irq_hw_number_t hw)
{
struct mpc52xx_gpt_priv *gpt = h->host_data;
dev_dbg(gpt->dev, "%s: h=%p, virq=%i\n", __func__, h, virq);
irq_set_chip_data(virq, gpt);
irq_set_chip_and_handler(virq, &mpc52xx_gpt_irq_chip, handle_edge_irq);
return 0;
}
static int mpc52xx_gpt_irq_xlate(struct irq_domain *h, struct device_node *ct,
const u32 *intspec, unsigned int intsize,
irq_hw_number_t *out_hwirq,
unsigned int *out_flags)
{
struct mpc52xx_gpt_priv *gpt = h->host_data;
dev_dbg(gpt->dev, "%s: flags=%i\n", __func__, intspec[0]);
if ((intsize < 1) || (intspec[0] > 3)) {
dev_err(gpt->dev, "bad irq specifier in %s\n", ct->full_name);
return -EINVAL;
}
*out_hwirq = 0; /* The GPT only has 1 IRQ line */
*out_flags = intspec[0];
return 0;
}
static const struct irq_domain_ops mpc52xx_gpt_irq_ops = {
.map = mpc52xx_gpt_irq_map,
.xlate = mpc52xx_gpt_irq_xlate,
};
static void
mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
{
int cascade_virq;
unsigned long flags;
u32 mode;
cascade_virq = irq_of_parse_and_map(node, 0);
if (!cascade_virq)
return;
gpt->irqhost = irq_domain_add_linear(node, 1, &mpc52xx_gpt_irq_ops, gpt);
if (!gpt->irqhost) {
dev_err(gpt->dev, "irq_domain_add_linear() failed\n");
return;
}
irq_set_handler_data(cascade_virq, gpt);
irq_set_chained_handler(cascade_virq, mpc52xx_gpt_irq_cascade);
/* If the GPT is currently disabled, then change it to be in Input
* Capture mode. If the mode is non-zero, then the pin could be
* already in use for something. */
spin_lock_irqsave(&gpt->lock, flags);
mode = in_be32(&gpt->regs->mode);
if ((mode & MPC52xx_GPT_MODE_MS_MASK) == 0)
out_be32(&gpt->regs->mode, mode | MPC52xx_GPT_MODE_MS_IC);
spin_unlock_irqrestore(&gpt->lock, flags);
dev_dbg(gpt->dev, "%s() complete. virq=%i\n", __func__, cascade_virq);
}
/* ---------------------------------------------------------------------
* GPIOLIB hooks
*/
#if defined(CONFIG_GPIOLIB)
static inline struct mpc52xx_gpt_priv *gc_to_mpc52xx_gpt(struct gpio_chip *gc)
{
return container_of(gc, struct mpc52xx_gpt_priv, gc);
}
static int mpc52xx_gpt_gpio_get(struct gpio_chip *gc, unsigned int gpio)
{
struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc);
return (in_be32(&gpt->regs->status) >> 8) & 1;
}
static void
mpc52xx_gpt_gpio_set(struct gpio_chip *gc, unsigned int gpio, int v)
{
struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc);
unsigned long flags;
u32 r;
dev_dbg(gpt->dev, "%s: gpio:%d v:%d\n", __func__, gpio, v);
r = v ? MPC52xx_GPT_MODE_GPIO_OUT_HIGH : MPC52xx_GPT_MODE_GPIO_OUT_LOW;
spin_lock_irqsave(&gpt->lock, flags);
clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_GPIO_MASK, r);
spin_unlock_irqrestore(&gpt->lock, flags);
}
static int mpc52xx_gpt_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
{
struct mpc52xx_gpt_priv *gpt = gc_to_mpc52xx_gpt(gc);
unsigned long flags;
dev_dbg(gpt->dev, "%s: gpio:%d\n", __func__, gpio);
spin_lock_irqsave(&gpt->lock, flags);
clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_GPIO_MASK);
spin_unlock_irqrestore(&gpt->lock, flags);
return 0;
}
static int
mpc52xx_gpt_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
{
mpc52xx_gpt_gpio_set(gc, gpio, val);
return 0;
}
static void
mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
{
int rc;
/* Only setup GPIO if the device tree claims the GPT is
* a GPIO controller */
if (!of_find_property(node, "gpio-controller", NULL))
return;
gpt->gc.label = kstrdup(node->full_name, GFP_KERNEL);
if (!gpt->gc.label) {
dev_err(gpt->dev, "out of memory\n");
return;
}
gpt->gc.ngpio = 1;
gpt->gc.direction_input = mpc52xx_gpt_gpio_dir_in;
gpt->gc.direction_output = mpc52xx_gpt_gpio_dir_out;
gpt->gc.get = mpc52xx_gpt_gpio_get;
gpt->gc.set = mpc52xx_gpt_gpio_set;
gpt->gc.base = -1;
gpt->gc.of_node = node;
/* Setup external pin in GPIO mode */
clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_MS_MASK,
MPC52xx_GPT_MODE_MS_GPIO);
rc = gpiochip_add(&gpt->gc);
if (rc)
dev_err(gpt->dev, "gpiochip_add() failed; rc=%i\n", rc);
dev_dbg(gpt->dev, "%s() complete.\n", __func__);
}
#else /* defined(CONFIG_GPIOLIB) */
static void
mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *p, struct device_node *np) { }
#endif /* defined(CONFIG_GPIOLIB) */
/***********************************************************************
* Timer API
*/
/**
* mpc52xx_gpt_from_irq - Return the GPT device associated with an IRQ number
* @irq: irq of timer.
*/
struct mpc52xx_gpt_priv *mpc52xx_gpt_from_irq(int irq)
{
struct mpc52xx_gpt_priv *gpt;
struct list_head *pos;
/* Iterate over the list of timers looking for a matching device */
mutex_lock(&mpc52xx_gpt_list_mutex);
list_for_each(pos, &mpc52xx_gpt_list) {
gpt = container_of(pos, struct mpc52xx_gpt_priv, list);
if (gpt->irqhost && irq == irq_linear_revmap(gpt->irqhost, 0)) {
mutex_unlock(&mpc52xx_gpt_list_mutex);
return gpt;
}
}
mutex_unlock(&mpc52xx_gpt_list_mutex);
return NULL;
}
EXPORT_SYMBOL(mpc52xx_gpt_from_irq);
static int mpc52xx_gpt_do_start(struct mpc52xx_gpt_priv *gpt, u64 period,
int continuous, int as_wdt)
{
u32 clear, set;
u64 clocks;
u32 prescale;
unsigned long flags;
clear = MPC52xx_GPT_MODE_MS_MASK | MPC52xx_GPT_MODE_CONTINUOUS;
set = MPC52xx_GPT_MODE_MS_GPIO | MPC52xx_GPT_MODE_COUNTER_ENABLE;
if (as_wdt) {
clear |= MPC52xx_GPT_MODE_IRQ_EN;
set |= MPC52xx_GPT_MODE_WDT_EN;
} else if (continuous)
set |= MPC52xx_GPT_MODE_CONTINUOUS;
/* Determine the number of clocks in the requested period. 64 bit
* arithmatic is done here to preserve the precision until the value
* is scaled back down into the u32 range. Period is in 'ns', bus
* frequency is in Hz. */
clocks = period * (u64)gpt->ipb_freq;
do_div(clocks, 1000000000); /* Scale it down to ns range */
/* This device cannot handle a clock count greater than 32 bits */
if (clocks > 0xffffffff)
return -EINVAL;
/* Calculate the prescaler and count values from the clocks value.
* 'clocks' is the number of clock ticks in the period. The timer
* has 16 bit precision and a 16 bit prescaler. Prescaler is
* calculated by integer dividing the clocks by 0x10000 (shifting
* down 16 bits) to obtain the smallest possible divisor for clocks
* to get a 16 bit count value.
*
* Note: the prescale register is '1' based, not '0' based. ie. a
* value of '1' means divide the clock by one. 0xffff divides the
* clock by 0xffff. '0x0000' does not divide by zero, but wraps
* around and divides by 0x10000. That is why prescale must be
* a u32 variable, not a u16, for this calculation. */
prescale = (clocks >> 16) + 1;
do_div(clocks, prescale);
if (clocks > 0xffff) {
pr_err("calculation error; prescale:%x clocks:%llx\n",
prescale, clocks);
return -EINVAL;
}
/* Set and enable the timer, reject an attempt to use a wdt as gpt */
spin_lock_irqsave(&gpt->lock, flags);
if (as_wdt)
gpt->wdt_mode |= MPC52xx_GPT_IS_WDT;
else if ((gpt->wdt_mode & MPC52xx_GPT_IS_WDT) != 0) {
spin_unlock_irqrestore(&gpt->lock, flags);
return -EBUSY;
}
out_be32(&gpt->regs->count, prescale << 16 | clocks);
clrsetbits_be32(&gpt->regs->mode, clear, set);
spin_unlock_irqrestore(&gpt->lock, flags);
return 0;
}
/**
* mpc52xx_gpt_start_timer - Set and enable the GPT timer
* @gpt: Pointer to gpt private data structure
* @period: period of timer in ns; max. ~130s @ 33MHz IPB clock
* @continuous: set to 1 to make timer continuous free running
*
* An interrupt will be generated every time the timer fires
*/
int mpc52xx_gpt_start_timer(struct mpc52xx_gpt_priv *gpt, u64 period,
int continuous)
{
return mpc52xx_gpt_do_start(gpt, period, continuous, 0);
}
EXPORT_SYMBOL(mpc52xx_gpt_start_timer);
/**
* mpc52xx_gpt_stop_timer - Stop a gpt
* @gpt: Pointer to gpt private data structure
*
* Returns an error if attempting to stop a wdt
*/
int mpc52xx_gpt_stop_timer(struct mpc52xx_gpt_priv *gpt)
{
unsigned long flags;
/* reject the operation if the timer is used as watchdog (gpt 0 only) */
spin_lock_irqsave(&gpt->lock, flags);
if ((gpt->wdt_mode & MPC52xx_GPT_IS_WDT) != 0) {
spin_unlock_irqrestore(&gpt->lock, flags);
return -EBUSY;
}
clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_COUNTER_ENABLE);
spin_unlock_irqrestore(&gpt->lock, flags);
return 0;
}
EXPORT_SYMBOL(mpc52xx_gpt_stop_timer);
/**
* mpc52xx_gpt_timer_period - Read the timer period
* @gpt: Pointer to gpt private data structure
*
* Returns the timer period in ns
*/
u64 mpc52xx_gpt_timer_period(struct mpc52xx_gpt_priv *gpt)
{
u64 period;
u64 prescale;
unsigned long flags;
spin_lock_irqsave(&gpt->lock, flags);
period = in_be32(&gpt->regs->count);
spin_unlock_irqrestore(&gpt->lock, flags);
prescale = period >> 16;
period &= 0xffff;
if (prescale == 0)
prescale = 0x10000;
period = period * prescale * 1000000000ULL;
do_div(period, (u64)gpt->ipb_freq);
return period;
}
EXPORT_SYMBOL(mpc52xx_gpt_timer_period);
#if defined(CONFIG_MPC5200_WDT)
/***********************************************************************
* Watchdog API for gpt0
*/
#define WDT_IDENTITY "mpc52xx watchdog on GPT0"
/* wdt_is_active stores whether or not the /dev/watchdog device is opened */
static unsigned long wdt_is_active;
/* wdt-capable gpt */
static struct mpc52xx_gpt_priv *mpc52xx_gpt_wdt;
/* low-level wdt functions */
static inline void mpc52xx_gpt_wdt_ping(struct mpc52xx_gpt_priv *gpt_wdt)
{
unsigned long flags;
spin_lock_irqsave(&gpt_wdt->lock, flags);
out_8((u8 *) &gpt_wdt->regs->mode, MPC52xx_GPT_MODE_WDT_PING);
spin_unlock_irqrestore(&gpt_wdt->lock, flags);
}
/* wdt misc device api */
static ssize_t mpc52xx_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
struct mpc52xx_gpt_priv *gpt_wdt = file->private_data;
mpc52xx_gpt_wdt_ping(gpt_wdt);
return 0;
}
static const struct watchdog_info mpc5200_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = WDT_IDENTITY,
};
static long mpc52xx_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct mpc52xx_gpt_priv *gpt_wdt = file->private_data;
int __user *data = (int __user *)arg;
int timeout;
u64 real_timeout;
int ret = 0;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user(data, &mpc5200_wdt_info,
sizeof(mpc5200_wdt_info));
if (ret)
ret = -EFAULT;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, data);
break;
case WDIOC_KEEPALIVE:
mpc52xx_gpt_wdt_ping(gpt_wdt);
break;
case WDIOC_SETTIMEOUT:
ret = get_user(timeout, data);
if (ret)
break;
real_timeout = (u64) timeout * 1000000000ULL;
ret = mpc52xx_gpt_do_start(gpt_wdt, real_timeout, 0, 1);
if (ret)
break;
/* fall through and return the timeout */
case WDIOC_GETTIMEOUT:
/* we need to round here as to avoid e.g. the following
* situation:
* - timeout requested is 1 second;
* - real timeout @33MHz is 999997090ns
* - the int divide by 10^9 will return 0.
*/
real_timeout =
mpc52xx_gpt_timer_period(gpt_wdt) + 500000000ULL;
do_div(real_timeout, 1000000000ULL);
timeout = (int) real_timeout;
ret = put_user(timeout, data);
break;
default:
ret = -ENOTTY;
}
return ret;
}
static int mpc52xx_wdt_open(struct inode *inode, struct file *file)
{
int ret;
/* sanity check */
if (!mpc52xx_gpt_wdt)
return -ENODEV;
/* /dev/watchdog can only be opened once */
if (test_and_set_bit(0, &wdt_is_active))
return -EBUSY;
/* Set and activate the watchdog with 30 seconds timeout */
ret = mpc52xx_gpt_do_start(mpc52xx_gpt_wdt, 30ULL * 1000000000ULL,
0, 1);
if (ret) {
clear_bit(0, &wdt_is_active);
return ret;
}
file->private_data = mpc52xx_gpt_wdt;
return nonseekable_open(inode, file);
}
static int mpc52xx_wdt_release(struct inode *inode, struct file *file)
{
/* note: releasing the wdt in NOWAYOUT-mode does not stop it */
#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
struct mpc52xx_gpt_priv *gpt_wdt = file->private_data;
unsigned long flags;
spin_lock_irqsave(&gpt_wdt->lock, flags);
clrbits32(&gpt_wdt->regs->mode,
MPC52xx_GPT_MODE_COUNTER_ENABLE | MPC52xx_GPT_MODE_WDT_EN);
gpt_wdt->wdt_mode &= ~MPC52xx_GPT_IS_WDT;
spin_unlock_irqrestore(&gpt_wdt->lock, flags);
#endif
clear_bit(0, &wdt_is_active);
return 0;
}
static const struct file_operations mpc52xx_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = mpc52xx_wdt_write,
.unlocked_ioctl = mpc52xx_wdt_ioctl,
.open = mpc52xx_wdt_open,
.release = mpc52xx_wdt_release,
};
static struct miscdevice mpc52xx_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &mpc52xx_wdt_fops,
};
static int mpc52xx_gpt_wdt_init(void)
{
int err;
/* try to register the watchdog misc device */
err = misc_register(&mpc52xx_wdt_miscdev);
if (err)
pr_err("%s: cannot register watchdog device\n", WDT_IDENTITY);
else
pr_info("%s: watchdog device registered\n", WDT_IDENTITY);
return err;
}
static int mpc52xx_gpt_wdt_setup(struct mpc52xx_gpt_priv *gpt,
const u32 *period)
{
u64 real_timeout;
/* remember the gpt for the wdt operation */
mpc52xx_gpt_wdt = gpt;
/* configure the wdt if the device tree contained a timeout */
if (!period || *period == 0)
return 0;
real_timeout = (u64) *period * 1000000000ULL;
if (mpc52xx_gpt_do_start(gpt, real_timeout, 0, 1))
dev_warn(gpt->dev, "starting as wdt failed\n");
else
dev_info(gpt->dev, "watchdog set to %us timeout\n", *period);
return 0;
}
#else
static int mpc52xx_gpt_wdt_init(void)
{
return 0;
}
static inline int mpc52xx_gpt_wdt_setup(struct mpc52xx_gpt_priv *gpt,
const u32 *period)
{
return 0;
}
#endif /* CONFIG_MPC5200_WDT */
/* ---------------------------------------------------------------------
* of_platform bus binding code
*/
static int mpc52xx_gpt_probe(struct platform_device *ofdev)
{
struct mpc52xx_gpt_priv *gpt;
gpt = kzalloc(sizeof *gpt, GFP_KERNEL);
if (!gpt)
return -ENOMEM;
spin_lock_init(&gpt->lock);
gpt->dev = &ofdev->dev;
gpt->ipb_freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
gpt->regs = of_iomap(ofdev->dev.of_node, 0);
if (!gpt->regs) {
kfree(gpt);
return -ENOMEM;
}
dev_set_drvdata(&ofdev->dev, gpt);
mpc52xx_gpt_gpio_setup(gpt, ofdev->dev.of_node);
mpc52xx_gpt_irq_setup(gpt, ofdev->dev.of_node);
mutex_lock(&mpc52xx_gpt_list_mutex);
list_add(&gpt->list, &mpc52xx_gpt_list);
mutex_unlock(&mpc52xx_gpt_list_mutex);
/* check if this device could be a watchdog */
if (of_get_property(ofdev->dev.of_node, "fsl,has-wdt", NULL) ||
of_get_property(ofdev->dev.of_node, "has-wdt", NULL)) {
const u32 *on_boot_wdt;
gpt->wdt_mode = MPC52xx_GPT_CAN_WDT;
on_boot_wdt = of_get_property(ofdev->dev.of_node,
"fsl,wdt-on-boot", NULL);
if (on_boot_wdt) {
dev_info(gpt->dev, "used as watchdog\n");
gpt->wdt_mode |= MPC52xx_GPT_IS_WDT;
} else
dev_info(gpt->dev, "can function as watchdog\n");
mpc52xx_gpt_wdt_setup(gpt, on_boot_wdt);
}
return 0;
}
static int mpc52xx_gpt_remove(struct platform_device *ofdev)
{
return -EBUSY;
}
static const struct of_device_id mpc52xx_gpt_match[] = {
{ .compatible = "fsl,mpc5200-gpt", },
/* Depreciated compatible values; don't use for new dts files */
{ .compatible = "fsl,mpc5200-gpt-gpio", },
{ .compatible = "mpc5200-gpt", },
{}
};
static struct platform_driver mpc52xx_gpt_driver = {
.driver = {
.name = "mpc52xx-gpt",
.owner = THIS_MODULE,
.of_match_table = mpc52xx_gpt_match,
},
.probe = mpc52xx_gpt_probe,
.remove = mpc52xx_gpt_remove,
};
static int __init mpc52xx_gpt_init(void)
{
return platform_driver_register(&mpc52xx_gpt_driver);
}
/* Make sure GPIOs and IRQs get set up before anyone tries to use them */
subsys_initcall(mpc52xx_gpt_init);
device_initcall(mpc52xx_gpt_wdt_init);