1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * MPC5200 General Purpose Timer device driver
5 * Copyright (c) 2009 Secret Lab Technologies Ltd.
6 * Copyright (c) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
8 * This file is a driver for the the General Purpose Timer (gpt) devices
9 * found on the MPC5200 SoC. Each timer has an IO pin which can be used
10 * for GPIO or can be used to raise interrupts. The timer function can
11 * be used independently from the IO pin, or it can be used to control
12 * output signals or measure input signals.
14 * This driver supports the GPIO and IRQ controller functions of the GPT
15 * device. Timer functions are not yet supported.
17 * The timer gpt0 can be used as watchdog (wdt). If the wdt mode is used,
18 * this prevents the use of any gpt0 gpt function (i.e. they will fail with
19 * -EBUSY). Thus, the safety wdt function always has precedence over the gpt
20 * function. If the kernel has been compiled with CONFIG_WATCHDOG_NOWAYOUT,
21 * this means that gpt0 is locked in wdt mode until the next reboot - this
22 * may be a requirement in safety applications.
24 * To use the GPIO function, the following two properties must be added
25 * to the device tree node for the gpt device (typically in the .dts file
28 * #gpio-cells = < 2 >;
29 * This driver will register the GPIO pin if it finds the gpio-controller
30 * property in the device tree.
32 * To use the IRQ controller function, the following two properties must
33 * be added to the device tree node for the gpt device:
34 * interrupt-controller;
35 * #interrupt-cells = < 1 >;
36 * The IRQ controller binding only uses one cell to specify the interrupt,
37 * and the IRQ flags are encoded in the cell. A cell is not used to encode
38 * the IRQ number because the GPT only has a single IRQ source. For flags,
39 * a value of '1' means rising edge sensitive and '2' means falling edge.
41 * The GPIO and the IRQ controller functions can be used at the same time,
42 * but in this use case the IO line will only work as an input. Trying to
43 * use it as a GPIO output will not work.
45 * When using the GPIO line as an output, it can either be driven as normal
46 * IO, or it can be an Open Collector (OC) output. At the moment it is the
47 * responsibility of either the bootloader or the platform setup code to set
48 * the output mode. This driver does not change the output mode setting.
51 #include <linux/device.h>
52 #include <linux/irq.h>
53 #include <linux/interrupt.h>
55 #include <linux/list.h>
56 #include <linux/mutex.h>
58 #include <linux/of_platform.h>
59 #include <linux/of_gpio.h>
60 #include <linux/kernel.h>
61 #include <linux/slab.h>
63 #include <linux/watchdog.h>
64 #include <linux/miscdevice.h>
65 #include <linux/uaccess.h>
66 #include <linux/module.h>
67 #include <asm/div64.h>
68 #include <asm/mpc52xx.h>
70 MODULE_DESCRIPTION("Freescale MPC52xx gpt driver");
71 MODULE_AUTHOR("Sascha Hauer, Grant Likely, Albrecht Dreß");
72 MODULE_LICENSE("GPL");
75 * struct mpc52xx_gpt - Private data structure for MPC52xx GPT driver
76 * @dev: pointer to device structure
77 * @regs: virtual address of GPT registers
78 * @lock: spinlock to coordinate between different functions.
79 * @gc: gpio_chip instance structure; used when GPIO is enabled
80 * @irqhost: Pointer to irq_domain instance; used when IRQ mode is supported
81 * @wdt_mode: only relevant for gpt0: bit 0 (MPC52xx_GPT_CAN_WDT) indicates
82 * if the gpt may be used as wdt, bit 1 (MPC52xx_GPT_IS_WDT) indicates
83 * if the timer is actively used as wdt which blocks gpt functions
85 struct mpc52xx_gpt_priv {
86 struct list_head list; /* List of all GPT devices */
88 struct mpc52xx_gpt __iomem *regs;
90 struct irq_domain *irqhost;
94 #if defined(CONFIG_GPIOLIB)
99 LIST_HEAD(mpc52xx_gpt_list);
100 DEFINE_MUTEX(mpc52xx_gpt_list_mutex);
102 #define MPC52xx_GPT_MODE_MS_MASK (0x07)
103 #define MPC52xx_GPT_MODE_MS_IC (0x01)
104 #define MPC52xx_GPT_MODE_MS_OC (0x02)
105 #define MPC52xx_GPT_MODE_MS_PWM (0x03)
106 #define MPC52xx_GPT_MODE_MS_GPIO (0x04)
108 #define MPC52xx_GPT_MODE_GPIO_MASK (0x30)
109 #define MPC52xx_GPT_MODE_GPIO_OUT_LOW (0x20)
110 #define MPC52xx_GPT_MODE_GPIO_OUT_HIGH (0x30)
112 #define MPC52xx_GPT_MODE_COUNTER_ENABLE (0x1000)
113 #define MPC52xx_GPT_MODE_CONTINUOUS (0x0400)
114 #define MPC52xx_GPT_MODE_OPEN_DRAIN (0x0200)
115 #define MPC52xx_GPT_MODE_IRQ_EN (0x0100)
116 #define MPC52xx_GPT_MODE_WDT_EN (0x8000)
118 #define MPC52xx_GPT_MODE_ICT_MASK (0x030000)
119 #define MPC52xx_GPT_MODE_ICT_RISING (0x010000)
120 #define MPC52xx_GPT_MODE_ICT_FALLING (0x020000)
121 #define MPC52xx_GPT_MODE_ICT_TOGGLE (0x030000)
123 #define MPC52xx_GPT_MODE_WDT_PING (0xa5)
125 #define MPC52xx_GPT_STATUS_IRQMASK (0x000f)
127 #define MPC52xx_GPT_CAN_WDT (1 << 0)
128 #define MPC52xx_GPT_IS_WDT (1 << 1)
131 /* ---------------------------------------------------------------------
132 * Cascaded interrupt controller hooks
135 static void mpc52xx_gpt_irq_unmask(struct irq_data *d)
137 struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d);
140 raw_spin_lock_irqsave(&gpt->lock, flags);
141 setbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_IRQ_EN);
142 raw_spin_unlock_irqrestore(&gpt->lock, flags);
145 static void mpc52xx_gpt_irq_mask(struct irq_data *d)
147 struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d);
150 raw_spin_lock_irqsave(&gpt->lock, flags);
151 clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_IRQ_EN);
152 raw_spin_unlock_irqrestore(&gpt->lock, flags);
155 static void mpc52xx_gpt_irq_ack(struct irq_data *d)
157 struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d);
159 out_be32(&gpt->regs->status, MPC52xx_GPT_STATUS_IRQMASK);
162 static int mpc52xx_gpt_irq_set_type(struct irq_data *d, unsigned int flow_type)
164 struct mpc52xx_gpt_priv *gpt = irq_data_get_irq_chip_data(d);
168 dev_dbg(gpt->dev, "%s: virq=%i type=%x\n", __func__, d->irq, flow_type);
170 raw_spin_lock_irqsave(&gpt->lock, flags);
171 reg = in_be32(&gpt->regs->mode) & ~MPC52xx_GPT_MODE_ICT_MASK;
172 if (flow_type & IRQF_TRIGGER_RISING)
173 reg |= MPC52xx_GPT_MODE_ICT_RISING;
174 if (flow_type & IRQF_TRIGGER_FALLING)
175 reg |= MPC52xx_GPT_MODE_ICT_FALLING;
176 out_be32(&gpt->regs->mode, reg);
177 raw_spin_unlock_irqrestore(&gpt->lock, flags);
182 static struct irq_chip mpc52xx_gpt_irq_chip = {
183 .name = "MPC52xx GPT",
184 .irq_unmask = mpc52xx_gpt_irq_unmask,
185 .irq_mask = mpc52xx_gpt_irq_mask,
186 .irq_ack = mpc52xx_gpt_irq_ack,
187 .irq_set_type = mpc52xx_gpt_irq_set_type,
190 static void mpc52xx_gpt_irq_cascade(struct irq_desc *desc)
192 struct mpc52xx_gpt_priv *gpt = irq_desc_get_handler_data(desc);
196 status = in_be32(&gpt->regs->status) & MPC52xx_GPT_STATUS_IRQMASK;
198 sub_virq = irq_linear_revmap(gpt->irqhost, 0);
199 generic_handle_irq(sub_virq);
203 static int mpc52xx_gpt_irq_map(struct irq_domain *h, unsigned int virq,
206 struct mpc52xx_gpt_priv *gpt = h->host_data;
208 dev_dbg(gpt->dev, "%s: h=%p, virq=%i\n", __func__, h, virq);
209 irq_set_chip_data(virq, gpt);
210 irq_set_chip_and_handler(virq, &mpc52xx_gpt_irq_chip, handle_edge_irq);
215 static int mpc52xx_gpt_irq_xlate(struct irq_domain *h, struct device_node *ct,
216 const u32 *intspec, unsigned int intsize,
217 irq_hw_number_t *out_hwirq,
218 unsigned int *out_flags)
220 struct mpc52xx_gpt_priv *gpt = h->host_data;
222 dev_dbg(gpt->dev, "%s: flags=%i\n", __func__, intspec[0]);
224 if ((intsize < 1) || (intspec[0] > 3)) {
225 dev_err(gpt->dev, "bad irq specifier in %pOF\n", ct);
229 *out_hwirq = 0; /* The GPT only has 1 IRQ line */
230 *out_flags = intspec[0];
235 static const struct irq_domain_ops mpc52xx_gpt_irq_ops = {
236 .map = mpc52xx_gpt_irq_map,
237 .xlate = mpc52xx_gpt_irq_xlate,
241 mpc52xx_gpt_irq_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
247 cascade_virq = irq_of_parse_and_map(node, 0);
251 gpt->irqhost = irq_domain_add_linear(node, 1, &mpc52xx_gpt_irq_ops, gpt);
253 dev_err(gpt->dev, "irq_domain_add_linear() failed\n");
257 irq_set_handler_data(cascade_virq, gpt);
258 irq_set_chained_handler(cascade_virq, mpc52xx_gpt_irq_cascade);
260 /* If the GPT is currently disabled, then change it to be in Input
261 * Capture mode. If the mode is non-zero, then the pin could be
262 * already in use for something. */
263 raw_spin_lock_irqsave(&gpt->lock, flags);
264 mode = in_be32(&gpt->regs->mode);
265 if ((mode & MPC52xx_GPT_MODE_MS_MASK) == 0)
266 out_be32(&gpt->regs->mode, mode | MPC52xx_GPT_MODE_MS_IC);
267 raw_spin_unlock_irqrestore(&gpt->lock, flags);
269 dev_dbg(gpt->dev, "%s() complete. virq=%i\n", __func__, cascade_virq);
273 /* ---------------------------------------------------------------------
276 #if defined(CONFIG_GPIOLIB)
277 static int mpc52xx_gpt_gpio_get(struct gpio_chip *gc, unsigned int gpio)
279 struct mpc52xx_gpt_priv *gpt = gpiochip_get_data(gc);
281 return (in_be32(&gpt->regs->status) >> 8) & 1;
285 mpc52xx_gpt_gpio_set(struct gpio_chip *gc, unsigned int gpio, int v)
287 struct mpc52xx_gpt_priv *gpt = gpiochip_get_data(gc);
291 dev_dbg(gpt->dev, "%s: gpio:%d v:%d\n", __func__, gpio, v);
292 r = v ? MPC52xx_GPT_MODE_GPIO_OUT_HIGH : MPC52xx_GPT_MODE_GPIO_OUT_LOW;
294 raw_spin_lock_irqsave(&gpt->lock, flags);
295 clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_GPIO_MASK, r);
296 raw_spin_unlock_irqrestore(&gpt->lock, flags);
299 static int mpc52xx_gpt_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
301 struct mpc52xx_gpt_priv *gpt = gpiochip_get_data(gc);
304 dev_dbg(gpt->dev, "%s: gpio:%d\n", __func__, gpio);
306 raw_spin_lock_irqsave(&gpt->lock, flags);
307 clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_GPIO_MASK);
308 raw_spin_unlock_irqrestore(&gpt->lock, flags);
314 mpc52xx_gpt_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
316 mpc52xx_gpt_gpio_set(gc, gpio, val);
321 mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *gpt, struct device_node *node)
325 /* Only setup GPIO if the device tree claims the GPT is
326 * a GPIO controller */
327 if (!of_find_property(node, "gpio-controller", NULL))
330 gpt->gc.label = kasprintf(GFP_KERNEL, "%pOF", node);
331 if (!gpt->gc.label) {
332 dev_err(gpt->dev, "out of memory\n");
337 gpt->gc.direction_input = mpc52xx_gpt_gpio_dir_in;
338 gpt->gc.direction_output = mpc52xx_gpt_gpio_dir_out;
339 gpt->gc.get = mpc52xx_gpt_gpio_get;
340 gpt->gc.set = mpc52xx_gpt_gpio_set;
342 gpt->gc.of_node = node;
344 /* Setup external pin in GPIO mode */
345 clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_MS_MASK,
346 MPC52xx_GPT_MODE_MS_GPIO);
348 rc = gpiochip_add_data(&gpt->gc, gpt);
350 dev_err(gpt->dev, "gpiochip_add_data() failed; rc=%i\n", rc);
352 dev_dbg(gpt->dev, "%s() complete.\n", __func__);
354 #else /* defined(CONFIG_GPIOLIB) */
356 mpc52xx_gpt_gpio_setup(struct mpc52xx_gpt_priv *p, struct device_node *np) { }
357 #endif /* defined(CONFIG_GPIOLIB) */
359 /***********************************************************************
364 * mpc52xx_gpt_from_irq - Return the GPT device associated with an IRQ number
365 * @irq: irq of timer.
367 struct mpc52xx_gpt_priv *mpc52xx_gpt_from_irq(int irq)
369 struct mpc52xx_gpt_priv *gpt;
370 struct list_head *pos;
372 /* Iterate over the list of timers looking for a matching device */
373 mutex_lock(&mpc52xx_gpt_list_mutex);
374 list_for_each(pos, &mpc52xx_gpt_list) {
375 gpt = container_of(pos, struct mpc52xx_gpt_priv, list);
376 if (gpt->irqhost && irq == irq_linear_revmap(gpt->irqhost, 0)) {
377 mutex_unlock(&mpc52xx_gpt_list_mutex);
381 mutex_unlock(&mpc52xx_gpt_list_mutex);
385 EXPORT_SYMBOL(mpc52xx_gpt_from_irq);
387 static int mpc52xx_gpt_do_start(struct mpc52xx_gpt_priv *gpt, u64 period,
388 int continuous, int as_wdt)
395 clear = MPC52xx_GPT_MODE_MS_MASK | MPC52xx_GPT_MODE_CONTINUOUS;
396 set = MPC52xx_GPT_MODE_MS_GPIO | MPC52xx_GPT_MODE_COUNTER_ENABLE;
398 clear |= MPC52xx_GPT_MODE_IRQ_EN;
399 set |= MPC52xx_GPT_MODE_WDT_EN;
400 } else if (continuous)
401 set |= MPC52xx_GPT_MODE_CONTINUOUS;
403 /* Determine the number of clocks in the requested period. 64 bit
404 * arithmatic is done here to preserve the precision until the value
405 * is scaled back down into the u32 range. Period is in 'ns', bus
406 * frequency is in Hz. */
407 clocks = period * (u64)gpt->ipb_freq;
408 do_div(clocks, 1000000000); /* Scale it down to ns range */
410 /* This device cannot handle a clock count greater than 32 bits */
411 if (clocks > 0xffffffff)
414 /* Calculate the prescaler and count values from the clocks value.
415 * 'clocks' is the number of clock ticks in the period. The timer
416 * has 16 bit precision and a 16 bit prescaler. Prescaler is
417 * calculated by integer dividing the clocks by 0x10000 (shifting
418 * down 16 bits) to obtain the smallest possible divisor for clocks
419 * to get a 16 bit count value.
421 * Note: the prescale register is '1' based, not '0' based. ie. a
422 * value of '1' means divide the clock by one. 0xffff divides the
423 * clock by 0xffff. '0x0000' does not divide by zero, but wraps
424 * around and divides by 0x10000. That is why prescale must be
425 * a u32 variable, not a u16, for this calculation. */
426 prescale = (clocks >> 16) + 1;
427 do_div(clocks, prescale);
428 if (clocks > 0xffff) {
429 pr_err("calculation error; prescale:%x clocks:%llx\n",
434 /* Set and enable the timer, reject an attempt to use a wdt as gpt */
435 raw_spin_lock_irqsave(&gpt->lock, flags);
437 gpt->wdt_mode |= MPC52xx_GPT_IS_WDT;
438 else if ((gpt->wdt_mode & MPC52xx_GPT_IS_WDT) != 0) {
439 raw_spin_unlock_irqrestore(&gpt->lock, flags);
442 out_be32(&gpt->regs->count, prescale << 16 | clocks);
443 clrsetbits_be32(&gpt->regs->mode, clear, set);
444 raw_spin_unlock_irqrestore(&gpt->lock, flags);
450 * mpc52xx_gpt_start_timer - Set and enable the GPT timer
451 * @gpt: Pointer to gpt private data structure
452 * @period: period of timer in ns; max. ~130s @ 33MHz IPB clock
453 * @continuous: set to 1 to make timer continuous free running
455 * An interrupt will be generated every time the timer fires
457 int mpc52xx_gpt_start_timer(struct mpc52xx_gpt_priv *gpt, u64 period,
460 return mpc52xx_gpt_do_start(gpt, period, continuous, 0);
462 EXPORT_SYMBOL(mpc52xx_gpt_start_timer);
465 * mpc52xx_gpt_stop_timer - Stop a gpt
466 * @gpt: Pointer to gpt private data structure
468 * Returns an error if attempting to stop a wdt
470 int mpc52xx_gpt_stop_timer(struct mpc52xx_gpt_priv *gpt)
474 /* reject the operation if the timer is used as watchdog (gpt 0 only) */
475 raw_spin_lock_irqsave(&gpt->lock, flags);
476 if ((gpt->wdt_mode & MPC52xx_GPT_IS_WDT) != 0) {
477 raw_spin_unlock_irqrestore(&gpt->lock, flags);
481 clrbits32(&gpt->regs->mode, MPC52xx_GPT_MODE_COUNTER_ENABLE);
482 raw_spin_unlock_irqrestore(&gpt->lock, flags);
485 EXPORT_SYMBOL(mpc52xx_gpt_stop_timer);
488 * mpc52xx_gpt_timer_period - Read the timer period
489 * @gpt: Pointer to gpt private data structure
491 * Returns the timer period in ns
493 u64 mpc52xx_gpt_timer_period(struct mpc52xx_gpt_priv *gpt)
499 raw_spin_lock_irqsave(&gpt->lock, flags);
500 period = in_be32(&gpt->regs->count);
501 raw_spin_unlock_irqrestore(&gpt->lock, flags);
503 prescale = period >> 16;
507 period = period * prescale * 1000000000ULL;
508 do_div(period, (u64)gpt->ipb_freq);
511 EXPORT_SYMBOL(mpc52xx_gpt_timer_period);
513 #if defined(CONFIG_MPC5200_WDT)
514 /***********************************************************************
515 * Watchdog API for gpt0
518 #define WDT_IDENTITY "mpc52xx watchdog on GPT0"
520 /* wdt_is_active stores whether or not the /dev/watchdog device is opened */
521 static unsigned long wdt_is_active;
523 /* wdt-capable gpt */
524 static struct mpc52xx_gpt_priv *mpc52xx_gpt_wdt;
526 /* low-level wdt functions */
527 static inline void mpc52xx_gpt_wdt_ping(struct mpc52xx_gpt_priv *gpt_wdt)
531 raw_spin_lock_irqsave(&gpt_wdt->lock, flags);
532 out_8((u8 *) &gpt_wdt->regs->mode, MPC52xx_GPT_MODE_WDT_PING);
533 raw_spin_unlock_irqrestore(&gpt_wdt->lock, flags);
536 /* wdt misc device api */
537 static ssize_t mpc52xx_wdt_write(struct file *file, const char __user *data,
538 size_t len, loff_t *ppos)
540 struct mpc52xx_gpt_priv *gpt_wdt = file->private_data;
541 mpc52xx_gpt_wdt_ping(gpt_wdt);
545 static const struct watchdog_info mpc5200_wdt_info = {
546 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
547 .identity = WDT_IDENTITY,
550 static long mpc52xx_wdt_ioctl(struct file *file, unsigned int cmd,
553 struct mpc52xx_gpt_priv *gpt_wdt = file->private_data;
554 int __user *data = (int __user *)arg;
560 case WDIOC_GETSUPPORT:
561 ret = copy_to_user(data, &mpc5200_wdt_info,
562 sizeof(mpc5200_wdt_info));
567 case WDIOC_GETSTATUS:
568 case WDIOC_GETBOOTSTATUS:
569 ret = put_user(0, data);
572 case WDIOC_KEEPALIVE:
573 mpc52xx_gpt_wdt_ping(gpt_wdt);
576 case WDIOC_SETTIMEOUT:
577 ret = get_user(timeout, data);
580 real_timeout = (u64) timeout * 1000000000ULL;
581 ret = mpc52xx_gpt_do_start(gpt_wdt, real_timeout, 0, 1);
584 /* fall through and return the timeout */
587 case WDIOC_GETTIMEOUT:
588 /* we need to round here as to avoid e.g. the following
590 * - timeout requested is 1 second;
591 * - real timeout @33MHz is 999997090ns
592 * - the int divide by 10^9 will return 0.
595 mpc52xx_gpt_timer_period(gpt_wdt) + 500000000ULL;
596 do_div(real_timeout, 1000000000ULL);
597 timeout = (int) real_timeout;
598 ret = put_user(timeout, data);
607 static int mpc52xx_wdt_open(struct inode *inode, struct file *file)
612 if (!mpc52xx_gpt_wdt)
615 /* /dev/watchdog can only be opened once */
616 if (test_and_set_bit(0, &wdt_is_active))
619 /* Set and activate the watchdog with 30 seconds timeout */
620 ret = mpc52xx_gpt_do_start(mpc52xx_gpt_wdt, 30ULL * 1000000000ULL,
623 clear_bit(0, &wdt_is_active);
627 file->private_data = mpc52xx_gpt_wdt;
628 return stream_open(inode, file);
631 static int mpc52xx_wdt_release(struct inode *inode, struct file *file)
633 /* note: releasing the wdt in NOWAYOUT-mode does not stop it */
634 #if !defined(CONFIG_WATCHDOG_NOWAYOUT)
635 struct mpc52xx_gpt_priv *gpt_wdt = file->private_data;
638 raw_spin_lock_irqsave(&gpt_wdt->lock, flags);
639 clrbits32(&gpt_wdt->regs->mode,
640 MPC52xx_GPT_MODE_COUNTER_ENABLE | MPC52xx_GPT_MODE_WDT_EN);
641 gpt_wdt->wdt_mode &= ~MPC52xx_GPT_IS_WDT;
642 raw_spin_unlock_irqrestore(&gpt_wdt->lock, flags);
644 clear_bit(0, &wdt_is_active);
649 static const struct file_operations mpc52xx_wdt_fops = {
650 .owner = THIS_MODULE,
652 .write = mpc52xx_wdt_write,
653 .unlocked_ioctl = mpc52xx_wdt_ioctl,
654 .compat_ioctl = compat_ptr_ioctl,
655 .open = mpc52xx_wdt_open,
656 .release = mpc52xx_wdt_release,
659 static struct miscdevice mpc52xx_wdt_miscdev = {
660 .minor = WATCHDOG_MINOR,
662 .fops = &mpc52xx_wdt_fops,
665 static int mpc52xx_gpt_wdt_init(void)
669 /* try to register the watchdog misc device */
670 err = misc_register(&mpc52xx_wdt_miscdev);
672 pr_err("%s: cannot register watchdog device\n", WDT_IDENTITY);
674 pr_info("%s: watchdog device registered\n", WDT_IDENTITY);
678 static int mpc52xx_gpt_wdt_setup(struct mpc52xx_gpt_priv *gpt,
683 /* remember the gpt for the wdt operation */
684 mpc52xx_gpt_wdt = gpt;
686 /* configure the wdt if the device tree contained a timeout */
687 if (!period || *period == 0)
690 real_timeout = (u64) *period * 1000000000ULL;
691 if (mpc52xx_gpt_do_start(gpt, real_timeout, 0, 1))
692 dev_warn(gpt->dev, "starting as wdt failed\n");
694 dev_info(gpt->dev, "watchdog set to %us timeout\n", *period);
700 static int mpc52xx_gpt_wdt_init(void)
705 static inline int mpc52xx_gpt_wdt_setup(struct mpc52xx_gpt_priv *gpt,
711 #endif /* CONFIG_MPC5200_WDT */
713 /* ---------------------------------------------------------------------
714 * of_platform bus binding code
716 static int mpc52xx_gpt_probe(struct platform_device *ofdev)
718 struct mpc52xx_gpt_priv *gpt;
720 gpt = devm_kzalloc(&ofdev->dev, sizeof *gpt, GFP_KERNEL);
724 raw_spin_lock_init(&gpt->lock);
725 gpt->dev = &ofdev->dev;
726 gpt->ipb_freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
727 gpt->regs = of_iomap(ofdev->dev.of_node, 0);
731 dev_set_drvdata(&ofdev->dev, gpt);
733 mpc52xx_gpt_gpio_setup(gpt, ofdev->dev.of_node);
734 mpc52xx_gpt_irq_setup(gpt, ofdev->dev.of_node);
736 mutex_lock(&mpc52xx_gpt_list_mutex);
737 list_add(&gpt->list, &mpc52xx_gpt_list);
738 mutex_unlock(&mpc52xx_gpt_list_mutex);
740 /* check if this device could be a watchdog */
741 if (of_get_property(ofdev->dev.of_node, "fsl,has-wdt", NULL) ||
742 of_get_property(ofdev->dev.of_node, "has-wdt", NULL)) {
743 const u32 *on_boot_wdt;
745 gpt->wdt_mode = MPC52xx_GPT_CAN_WDT;
746 on_boot_wdt = of_get_property(ofdev->dev.of_node,
747 "fsl,wdt-on-boot", NULL);
749 dev_info(gpt->dev, "used as watchdog\n");
750 gpt->wdt_mode |= MPC52xx_GPT_IS_WDT;
752 dev_info(gpt->dev, "can function as watchdog\n");
753 mpc52xx_gpt_wdt_setup(gpt, on_boot_wdt);
759 static int mpc52xx_gpt_remove(struct platform_device *ofdev)
764 static const struct of_device_id mpc52xx_gpt_match[] = {
765 { .compatible = "fsl,mpc5200-gpt", },
767 /* Depreciated compatible values; don't use for new dts files */
768 { .compatible = "fsl,mpc5200-gpt-gpio", },
769 { .compatible = "mpc5200-gpt", },
773 static struct platform_driver mpc52xx_gpt_driver = {
775 .name = "mpc52xx-gpt",
776 .of_match_table = mpc52xx_gpt_match,
778 .probe = mpc52xx_gpt_probe,
779 .remove = mpc52xx_gpt_remove,
782 static int __init mpc52xx_gpt_init(void)
784 return platform_driver_register(&mpc52xx_gpt_driver);
787 /* Make sure GPIOs and IRQs get set up before anyone tries to use them */
788 subsys_initcall(mpc52xx_gpt_init);
789 device_initcall(mpc52xx_gpt_wdt_init);