[PATCH v4] powerpc/5200: Rework GPT driver to also be an IRQ controller
Wolfram Sang
w.sang at pengutronix.de
Thu Feb 5 06:55:06 EST 2009
Hello Grant,
On Wed, Feb 04, 2009 at 11:23:05AM -0700, Grant Likely wrote:
> From: Grant Likely <grant.likely at secretlab.ca>
>
> 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.
>
> v4 changes:
> - Fix compile error when GPIOLIB is not enabled.
> v3 changes:
> - Use set/clbits() for manipulating registers
> - Fix incorrect comments
> - Other minor tidying
> v2 changes:
> - Removed magic numbers
> - Only set to GPIO mode if it has the gpio-controller property. Otherwise
> leave the configuration alone. Firmware may have already configured it.
I have been told to move such a changelog below the dashed lines,
because it is not so important for the git-history.
>
> Signed-off-by: Grant Likely <grant.likely at secretlab.ca>
> ---
>
> Here is what I hope to be the last version of this patch. This version fixes
> a compile error when GPIO support is not compiled into the kernel. I've
> pushed this out to my -next tree. I'll be asking Ben to pull it tomorrow.
Sorry, but it still has issues. This review in a hurry leaves me with a
bit uneasy feelings, still, if the remaining issues get resolved, you
may add my
Reviewed-by: Wolfram Sang <w.sang at pengutronix.de>
>
> g.
>
> arch/powerpc/platforms/52xx/Makefile | 2
> arch/powerpc/platforms/52xx/mpc52xx_gpio.c | 85 -----
> arch/powerpc/platforms/52xx/mpc52xx_gpt.c | 435 ++++++++++++++++++++++++++++
> 3 files changed, 436 insertions(+), 86 deletions(-)
> create mode 100644 arch/powerpc/platforms/52xx/mpc52xx_gpt.c
>
>
> diff --git a/arch/powerpc/platforms/52xx/Makefile b/arch/powerpc/platforms/52xx/Makefile
> index 9dfbde2..bfd4f52 100644
> --- a/arch/powerpc/platforms/52xx/Makefile
> +++ b/arch/powerpc/platforms/52xx/Makefile
> @@ -1,7 +1,7 @@
> #
> # 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
> diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpio.c b/arch/powerpc/platforms/52xx/mpc52xx_gpio.c
> index 07f89ae..2b8d8ef 100644
> --- a/arch/powerpc/platforms/52xx/mpc52xx_gpio.c
> +++ b/arch/powerpc/platforms/52xx/mpc52xx_gpio.c
> @@ -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(®s->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(®s->mode, 0x34);
> - else
> - out_be32(®s->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(®s->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;
> }
>
> diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
> new file mode 100644
> index 0000000..1a834e1
> --- /dev/null
> +++ b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
> @@ -0,0 +1,435 @@
> +/*
> + * MPC5200 General Purpose Timer device driver
> + *
> + * Copyright (c) 2009 Secret Lab Technologies Ltd.
> + * Copyright (c) 2008 Sascha Hauer <s.hauer at 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;
Like I mentioned in my first review, the following if-clause is always
true. You probably mean "& 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);
Space after ','. As it is now, this is a checkpatch-error. Lines over 80
chars are a warning.
> +}
> +
> +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) */
Hmmm, I still have problems with this sysfs-entry. If you say that this
is good for debugging, then please make it #DEBUG at least. Imagine
every driver doing such things, this adds bloat. I'd still rather
suggest using
~ memedit /dev/mem
-> map <MBAR> 0x4000
-> md 0x600
which does the same and even allows for more (writing for example).
> +
> +/* ---------------------------------------------------------------------
> + * 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);
>
Regards,
Wolfram
--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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