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Commit 5496eab2 authored by Grant Likely's avatar Grant Likely
Browse files

powerpc/5200: Rework GPT driver to also be an IRQ controller 



This patch adds IRQ controller support to the MPC5200 General
Purpose Timer (GPT) device driver.  With this patch the mpc5200-gpt
driver supports both GPIO and IRQ functions.

The GPT driver was contained within the mpc52xx_gpio.c file, but this
patch moves it out into a new file (mpc52xx_gpt.c) since it has more
than just GPIO functionality now and it was only grouped with the
mpc52xx-gpio drivers as a matter of convenience before.  Also, this
driver will most likely get extended again to also provide support
for the timer function.

Implementation note: Alternately, I could have tried to implement
the IRQ support as a separate driver and left the GPIO portion alone.
However, multiple functions of this device (ie. GPIO input+interrupt
controller, or timer+GPIO) can be active at the same time and the
registers are shared so it is safer to contain all functionality
within a single driver.

Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
Reviewed-by: default avatarWolfram Sang <w.sang@pengutronix.de>
parent 8f2558de

arch/powerpc/platforms/52xx/Makefile

+1 −1
Original line number Diff line number Diff line 
#

# Makefile for 52xx based boards

#

obj-y				+= mpc52xx_pic.o mpc52xx_common.o

obj-y				+= mpc52xx_pic.o mpc52xx_common.o mpc52xx_gpt.o

obj-$(CONFIG_PCI)		+= mpc52xx_pci.o



obj-$(CONFIG_PPC_MPC5200_SIMPLE) += mpc5200_simple.o

arch/powerpc/platforms/52xx/mpc52xx_gpio.c

+0 −85
Original line number Diff line number Diff line
@@ -354,88 +354,6 @@ static struct of_platform_driver mpc52xx_simple_gpiochip_driver = { 
	.remove = mpc52xx_gpiochip_remove,

};



/*

 * GPIO LIB API implementation for gpt GPIOs.

 *

 * Each gpt only has a single GPIO.

 */

static int mpc52xx_gpt_gpio_get(struct gpio_chip *gc, unsigned int gpio)

{

	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);

	struct mpc52xx_gpt __iomem *regs = mm_gc->regs;



	return (in_be32(&regs->status) & (1 << (31 - 23))) ? 1 : 0;

}



static void

mpc52xx_gpt_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)

{

	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);

	struct mpc52xx_gpt __iomem *regs = mm_gc->regs;



	if (val)

		out_be32(&regs->mode, 0x34);

	else

		out_be32(&regs->mode, 0x24);



	pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);

}



static int mpc52xx_gpt_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)

{

	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);

	struct mpc52xx_gpt __iomem *regs = mm_gc->regs;



	out_be32(&regs->mode, 0x04);



	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);

	pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);



	return 0;

}



static int __devinit mpc52xx_gpt_gpiochip_probe(struct of_device *ofdev,

					const struct of_device_id *match)

{

	struct of_mm_gpio_chip *mmchip;

	struct of_gpio_chip *chip;



	mmchip = kzalloc(sizeof(*mmchip), GFP_KERNEL);

	if (!mmchip)

		return -ENOMEM;



	chip = &mmchip->of_gc;



	chip->gpio_cells          = 2;

	chip->gc.ngpio            = 1;

	chip->gc.direction_input  = mpc52xx_gpt_gpio_dir_in;

	chip->gc.direction_output = mpc52xx_gpt_gpio_dir_out;

	chip->gc.get              = mpc52xx_gpt_gpio_get;

	chip->gc.set              = mpc52xx_gpt_gpio_set;



	return of_mm_gpiochip_add(ofdev->node, mmchip);

}



static const struct of_device_id mpc52xx_gpt_gpiochip_match[] = {

	{

		.compatible = "fsl,mpc5200-gpt-gpio",

	},

	{}

};



static struct of_platform_driver mpc52xx_gpt_gpiochip_driver = {

	.name = "gpio_gpt",

	.match_table = mpc52xx_gpt_gpiochip_match,

	.probe = mpc52xx_gpt_gpiochip_probe,

	.remove = mpc52xx_gpiochip_remove,

};



static int __init mpc52xx_gpio_init(void)

{

	if (of_register_platform_driver(&mpc52xx_wkup_gpiochip_driver))
@@ -444,9 +362,6 @@ static int __init mpc52xx_gpio_init(void) 
	if (of_register_platform_driver(&mpc52xx_simple_gpiochip_driver))

		printk(KERN_ERR "Unable to register simple GPIO driver\n");



	if (of_register_platform_driver(&mpc52xx_gpt_gpiochip_driver))

		printk(KERN_ERR "Unable to register gpt GPIO driver\n");



	return 0;

}

arch/powerpc/platforms/52xx/mpc52xx_gpt.c

0 → 100644
+435 −0
Original line number Diff line number Diff line 
/*

 * 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, nor is the watchdog

 * timer.

 *

 * 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/irq.h>

#include <linux/interrupt.h>

#include <linux/io.h>

#include <linux/of.h>

#include <linux/of_platform.h>

#include <linux/of_gpio.h>

#include <linux/kernel.h>

#include <asm/mpc52xx.h>



MODULE_DESCRIPTION("Freescale MPC52xx gpt driver");

MODULE_AUTHOR("Sascha Hauer, Grant Likely");

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.

 * @of_gc: of_gpio_chip instance structure; used when GPIO is enabled

 * @irqhost: Pointer to irq_host instance; used when IRQ mode is supported

 */

struct mpc52xx_gpt_priv {

	struct device *dev;

	struct mpc52xx_gpt __iomem *regs;

	spinlock_t lock;

	struct irq_host *irqhost;



#if defined(CONFIG_GPIOLIB)

	struct of_gpio_chip of_gc;

#endif

};



#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_IRQ_EN		(0x0100)



#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_STATUS_IRQMASK	(0x000f)



/* ---------------------------------------------------------------------

 * Cascaded interrupt controller hooks

 */



static void mpc52xx_gpt_irq_unmask(unsigned int virq)

{

	struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);

	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(unsigned int virq)

{

	struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);

	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(unsigned int virq)

{

	struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);



	out_be32(&gpt->regs->status, MPC52xx_GPT_STATUS_IRQMASK);

}



static int mpc52xx_gpt_irq_set_type(unsigned int virq, unsigned int flow_type)

{

	struct mpc52xx_gpt_priv *gpt = get_irq_chip_data(virq);

	unsigned long flags;

	u32 reg;



	dev_dbg(gpt->dev, "%s: virq=%i type=%x\n", __func__, virq, 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 = {

	.typename = "MPC52xx GPT",

	.unmask = mpc52xx_gpt_irq_unmask,

	.mask = mpc52xx_gpt_irq_mask,

	.ack = mpc52xx_gpt_irq_ack,

	.set_type = mpc52xx_gpt_irq_set_type,

};



void mpc52xx_gpt_irq_cascade(unsigned int virq, struct irq_desc *desc)

{

	struct mpc52xx_gpt_priv *gpt = get_irq_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_host *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);

	set_irq_chip_data(virq, gpt);

	set_irq_chip_and_handler(virq, &mpc52xx_gpt_irq_chip, handle_edge_irq);



	return 0;

}



static int mpc52xx_gpt_irq_xlate(struct irq_host *h, struct device_node *ct,

				 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] < 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 struct irq_host_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;



	/* Only setup cascaded IRQ if device tree claims the GPT is

	 * an interrupt controller */

	if (!of_find_property(node, "interrupt-controller", NULL))

		return;



	cascade_virq = irq_of_parse_and_map(node, 0);



	gpt->irqhost = irq_alloc_host(node, IRQ_HOST_MAP_LINEAR, 1,

				      &mpc52xx_gpt_irq_ops, -1);

	if (!gpt->irqhost) {

		dev_err(gpt->dev, "irq_alloc_host() failed\n");

		return;

	}



	gpt->irqhost->host_data = gpt;



	set_irq_data(cascade_virq, gpt);

	set_irq_chained_handler(cascade_virq, mpc52xx_gpt_irq_cascade);



	/* Set to Input Capture mode */

	spin_lock_irqsave(&gpt->lock, flags);

	clrsetbits_be32(&gpt->regs->mode, MPC52xx_GPT_MODE_MS_MASK,

			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(to_of_gpio_chip(gc), struct mpc52xx_gpt_priv,of_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->of_gc.gc.label = kstrdup(node->full_name, GFP_KERNEL);

	if (!gpt->of_gc.gc.label) {

		dev_err(gpt->dev, "out of memory\n");

		return;

	}



	gpt->of_gc.gpio_cells = 2;

	gpt->of_gc.gc.ngpio = 1;

	gpt->of_gc.gc.direction_input  = mpc52xx_gpt_gpio_dir_in;

	gpt->of_gc.gc.direction_output = mpc52xx_gpt_gpio_dir_out;

	gpt->of_gc.gc.get = mpc52xx_gpt_gpio_get;

	gpt->of_gc.gc.set = mpc52xx_gpt_gpio_set;

	gpt->of_gc.gc.base = -1;

	gpt->of_gc.xlate = of_gpio_simple_xlate;

	node->data = &gpt->of_gc;

	of_node_get(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->of_gc.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) */



/***********************************************************************

 * SYSFS attributes

 */

#if defined(CONFIG_SYSFS)

static ssize_t mpc52xx_gpt_show_regs(struct device *dev,

				     struct device_attribute *attr, char *buf)

{

	struct mpc52xx_gpt_priv *gpt = dev_get_drvdata(dev);

	int i, len = 0;

	u32 __iomem *regs = (void __iomem *) gpt->regs;



	for (i = 0; i < 4; i++)

		len += sprintf(buf + len, "%.8x ", in_be32(regs + i));

	len += sprintf(buf + len, "\n");



	return len;

}



static struct device_attribute mpc52xx_gpt_attrib[] = {

	__ATTR(regs, S_IRUGO | S_IWUSR, mpc52xx_gpt_show_regs, NULL),

};



static void mpc52xx_gpt_create_attribs(struct mpc52xx_gpt_priv *gpt)

{

	int i, err = 0;



	for (i = 0; i < ARRAY_SIZE(mpc52xx_gpt_attrib); i++) {

		err = device_create_file(gpt->dev, &mpc52xx_gpt_attrib[i]);

		if (err)

			dev_err(gpt->dev, "error creating attribute %i\n", i);

	}



}



#else /* defined(CONFIG_SYSFS) */

static void mpc52xx_gpt_create_attribs(struct mpc52xx_gpt_priv *) { return 0; }

#endif /* defined(CONFIG_SYSFS) */



/* ---------------------------------------------------------------------

 * of_platform bus binding code

 */

static int __devinit mpc52xx_gpt_probe(struct of_device *ofdev,

				       const struct of_device_id *match)

{

	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->regs = of_iomap(ofdev->node, 0);

	if (!gpt->regs) {

		kfree(gpt);

		return -ENOMEM;

	}



	dev_set_drvdata(&ofdev->dev, gpt);



	mpc52xx_gpt_create_attribs(gpt);

	mpc52xx_gpt_gpio_setup(gpt, ofdev->node);

	mpc52xx_gpt_irq_setup(gpt, ofdev->node);



	return 0;

}



static int mpc52xx_gpt_remove(struct of_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 of_platform_driver mpc52xx_gpt_driver = {

	.name = "mpc52xx-gpt",

	.match_table = mpc52xx_gpt_match,

	.probe = mpc52xx_gpt_probe,

	.remove = mpc52xx_gpt_remove,

};



static int __init mpc52xx_gpt_init(void)

{

	if (of_register_platform_driver(&mpc52xx_gpt_driver))

		pr_err("error registering MPC52xx GPT driver\n");



	return 0;

}



/* Make sure GPIOs and IRQs get set up before anyone tries to use them */

subsys_initcall(mpc52xx_gpt_init);