Re: [PATCH] gpio-ep93xx: convert to platform_driver and usebasic_mmio_gpio library

From: Grant Likely
Date: Wed Jun 08 2011 - 18:08:11 EST

On Wed, Jun 08, 2011 at 02:35:33PM -0700, H Hartley Sweeten wrote:
> This converts the gpio-ep93xx driver into a platform_driver and uses
> the basic_mmio_gpio library.
>
> Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
> Cc: Ryan Mallon <ryan@xxxxxxxxxxxxxxxx>
> Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>

Merged, thanks.

g.

>
> ---
>
> diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c
> index cc9f1d4..1280046 100644
> --- a/arch/arm/mach-ep93xx/core.c
> +++ b/arch/arm/mach-ep93xx/core.c
> @@ -174,14 +174,10 @@ struct sys_timer ep93xx_timer = {
> /*************************************************************************
> * EP93xx IRQ handling
> *************************************************************************/
> -extern void ep93xx_gpio_init_irq(void);
> -
> void __init ep93xx_init_irq(void)
> {
> vic_init(EP93XX_VIC1_BASE, 0, EP93XX_VIC1_VALID_IRQ_MASK, 0);
> vic_init(EP93XX_VIC2_BASE, 32, EP93XX_VIC2_VALID_IRQ_MASK, 0);
> -
> - ep93xx_gpio_init_irq();
> }
>
>
> @@ -241,6 +237,24 @@ unsigned int ep93xx_chip_revision(void)
> }
>
> /*************************************************************************
> + * EP93xx GPIO
> + *************************************************************************/
> +static struct resource ep93xx_gpio_resource[] = {
> + {
> + .start = EP93XX_GPIO_PHYS_BASE,
> + .end = EP93XX_GPIO_PHYS_BASE + 0xcc - 1,
> + .flags = IORESOURCE_MEM,
> + },
> +};
> +
> +static struct platform_device ep93xx_gpio_device = {
> + .name = "gpio-ep93xx",
> + .id = -1,
> + .num_resources = ARRAY_SIZE(ep93xx_gpio_resource),
> + .resource = ep93xx_gpio_resource,
> +};
> +
> +/*************************************************************************
> * EP93xx peripheral handling
> *************************************************************************/
> #define EP93XX_UART_MCR_OFFSET (0x0100)
> @@ -870,14 +884,13 @@ void __init ep93xx_register_ac97(void)
> platform_device_register(&ep93xx_pcm_device);
> }
>
> -extern void ep93xx_gpio_init(void);
> -
> void __init ep93xx_init_devices(void)
> {
> /* Disallow access to MaverickCrunch initially */
> ep93xx_devcfg_clear_bits(EP93XX_SYSCON_DEVCFG_CPENA);
>
> - ep93xx_gpio_init();
> + /* Get the GPIO working early, other devices need it */
> + platform_device_register(&ep93xx_gpio_device);
>
> amba_device_register(&uart1_device, &iomem_resource);
> amba_device_register(&uart2_device, &iomem_resource);
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index b84666a..9f06e63 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -87,6 +87,7 @@ config GPIO_IT8761E
> config GPIO_EP93XX
> def_bool y
> depends on ARCH_EP93XX
> + select GPIO_GENERIC
>
> config GPIO_EXYNOS4
> def_bool y
> diff --git a/drivers/gpio/gpio-ep93xx.c b/drivers/gpio/gpio-ep93xx.c
> index 3d427b9..22ffa1d 100644
> --- a/drivers/gpio/gpio-ep93xx.c
> +++ b/drivers/gpio/gpio-ep93xx.c
> @@ -2,6 +2,7 @@
> * Generic EP93xx GPIO handling
> *
> * Copyright (c) 2008 Ryan Mallon <ryan@xxxxxxxxxxxxxxxx>
> + * Copyright (c) 2011 H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
> *
> * Based on code originally from:
> * linux/arch/arm/mach-ep93xx/core.c
> @@ -14,14 +15,20 @@
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>
> #include <linux/init.h>
> -#include <linux/module.h>
> -#include <linux/seq_file.h>
> +#include <linux/platform_device.h>
> #include <linux/io.h>
> #include <linux/gpio.h>
> #include <linux/irq.h>
> +#include <linux/slab.h>
> +#include <linux/basic_mmio_gpio.h>
>
> #include <mach/hardware.h>
>
> +struct ep93xx_gpio {
> + void __iomem *mmio_base;
> + struct bgpio_chip bgc[8];
> +};
> +
> /*************************************************************************
> * Interrupt handling for EP93xx on-chip GPIOs
> *************************************************************************/
> @@ -223,7 +230,7 @@ static struct irq_chip ep93xx_gpio_irq_chip = {
> .irq_set_type = ep93xx_gpio_irq_type,
> };
>
> -void __init ep93xx_gpio_init_irq(void)
> +static void ep93xx_gpio_init_irq(void)
> {
> int gpio_irq;
>
> @@ -258,151 +265,142 @@ void __init ep93xx_gpio_init_irq(void)
> /*************************************************************************
> * gpiolib interface for EP93xx on-chip GPIOs
> *************************************************************************/
> -struct ep93xx_gpio_chip {
> - struct gpio_chip chip;
> -
> - void __iomem *data_reg;
> - void __iomem *data_dir_reg;
> +struct ep93xx_gpio_bank {
> + const char *label;
> + int data;
> + int dir;
> + int base;
> + bool has_debounce;
> };
>
> -#define to_ep93xx_gpio_chip(c) container_of(c, struct ep93xx_gpio_chip, chip)
> +#define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _debounce) \
> + { \
> + .label = _label, \
> + .data = _data, \
> + .dir = _dir, \
> + .base = _base, \
> + .has_debounce = _debounce, \
> + }
>
> -static int ep93xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
> +static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
> + EP93XX_GPIO_BANK("A", 0x00, 0x10, 0, true),
> + EP93XX_GPIO_BANK("B", 0x04, 0x14, 8, true),
> + EP93XX_GPIO_BANK("C", 0x08, 0x18, 40, false),
> + EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24, false),
> + EP93XX_GPIO_BANK("E", 0x20, 0x24, 32, false),
> + EP93XX_GPIO_BANK("F", 0x30, 0x34, 16, true),
> + EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48, false),
> + EP93XX_GPIO_BANK("H", 0x40, 0x44, 56, false),
> +};
> +
> +static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
> + unsigned offset, unsigned debounce)
> {
> - struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
> - unsigned long flags;
> - u8 v;
> + int gpio = chip->base + offset;
> + int irq = gpio_to_irq(gpio);
>
> - local_irq_save(flags);
> - v = __raw_readb(ep93xx_chip->data_dir_reg);
> - v &= ~(1 << offset);
> - __raw_writeb(v, ep93xx_chip->data_dir_reg);
> - local_irq_restore(flags);
> + if (irq < 0)
> + return -EINVAL;
> +
> + ep93xx_gpio_int_debounce(irq, debounce ? true : false);
>
> return 0;
> }
>
> -static int ep93xx_gpio_direction_output(struct gpio_chip *chip,
> - unsigned offset, int val)
> +static int ep93xx_gpio_add_bank(struct bgpio_chip *bgc, struct device *dev,
> + void __iomem *mmio_base, struct ep93xx_gpio_bank *bank)
> {
> - struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
> - unsigned long flags;
> - int line;
> - u8 v;
> -
> - local_irq_save(flags);
> + void __iomem *data = mmio_base + bank->data;
> + void __iomem *dir = mmio_base + bank->dir;
> + int err;
>
> - /* Set the value */
> - v = __raw_readb(ep93xx_chip->data_reg);
> - if (val)
> - v |= (1 << offset);
> - else
> - v &= ~(1 << offset);
> - __raw_writeb(v, ep93xx_chip->data_reg);
> -
> - /* Drive as an output */
> - line = chip->base + offset;
> - if (line <= EP93XX_GPIO_LINE_MAX_IRQ) {
> - /* Ports A/B/F */
> - ep93xx_gpio_int_mask(line);
> - ep93xx_gpio_update_int_params(line >> 3);
> - }
> + err = bgpio_init(bgc, dev, 1, data, NULL, NULL, dir, NULL, false);
> + if (err)
> + return err;
>
> - v = __raw_readb(ep93xx_chip->data_dir_reg);
> - v |= (1 << offset);
> - __raw_writeb(v, ep93xx_chip->data_dir_reg);
> + bgc->gc.label = bank->label;
> + bgc->gc.base = bank->base;
>
> - local_irq_restore(flags);
> + if (bank->has_debounce)
> + bgc->gc.set_debounce = ep93xx_gpio_set_debounce;
>
> - return 0;
> + return gpiochip_add(&bgc->gc);
> }
>
> -static int ep93xx_gpio_get(struct gpio_chip *chip, unsigned offset)
> +static int __devinit ep93xx_gpio_probe(struct platform_device *pdev)
> {
> - struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
> + struct ep93xx_gpio *ep93xx_gpio;
> + struct resource *res;
> + void __iomem *mmio;
> + int i;
> + int ret;
>
> - return !!(__raw_readb(ep93xx_chip->data_reg) & (1 << offset));
> -}
> + ep93xx_gpio = kzalloc(sizeof(*ep93xx_gpio), GFP_KERNEL);
> + if (!ep93xx_gpio)
> + return -ENOMEM;
>
> -static void ep93xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
> -{
> - struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
> - unsigned long flags;
> - u8 v;
> -
> - local_irq_save(flags);
> - v = __raw_readb(ep93xx_chip->data_reg);
> - if (val)
> - v |= (1 << offset);
> - else
> - v &= ~(1 << offset);
> - __raw_writeb(v, ep93xx_chip->data_reg);
> - local_irq_restore(flags);
> -}
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + ret = -ENXIO;
> + goto exit_free;
> + }
>
> -static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
> - unsigned offset, unsigned debounce)
> -{
> - int gpio = chip->base + offset;
> - int irq = gpio_to_irq(gpio);
> + if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
> + ret = -EBUSY;
> + goto exit_free;
> + }
>
> - if (irq < 0)
> - return -EINVAL;
> + mmio = ioremap(res->start, resource_size(res));
> + if (!mmio) {
> + ret = -ENXIO;
> + goto exit_release;
> + }
> + ep93xx_gpio->mmio_base = mmio;
>
> - ep93xx_gpio_int_debounce(irq, debounce ? true : false);
> + /* Default all ports to GPIO */
> + ep93xx_devcfg_set_bits(EP93XX_SYSCON_DEVCFG_KEYS |
> + EP93XX_SYSCON_DEVCFG_GONK |
> + EP93XX_SYSCON_DEVCFG_EONIDE |
> + EP93XX_SYSCON_DEVCFG_GONIDE |
> + EP93XX_SYSCON_DEVCFG_HONIDE);
>
> - return 0;
> -}
> + for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
> + struct bgpio_chip *bgc = &ep93xx_gpio->bgc[i];
> + struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];
>
> -#define EP93XX_GPIO_BANK(name, dr, ddr, base_gpio) \
> - { \
> - .chip = { \
> - .label = name, \
> - .direction_input = ep93xx_gpio_direction_input, \
> - .direction_output = ep93xx_gpio_direction_output, \
> - .get = ep93xx_gpio_get, \
> - .set = ep93xx_gpio_set, \
> - .base = base_gpio, \
> - .ngpio = 8, \
> - }, \
> - .data_reg = EP93XX_GPIO_REG(dr), \
> - .data_dir_reg = EP93XX_GPIO_REG(ddr), \
> + if (ep93xx_gpio_add_bank(bgc, &pdev->dev, mmio, bank))
> + dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
> + bank->label);
> }
>
> -static struct ep93xx_gpio_chip ep93xx_gpio_banks[] = {
> - EP93XX_GPIO_BANK("A", 0x00, 0x10, 0),
> - EP93XX_GPIO_BANK("B", 0x04, 0x14, 8),
> - EP93XX_GPIO_BANK("C", 0x08, 0x18, 40),
> - EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24),
> - EP93XX_GPIO_BANK("E", 0x20, 0x24, 32),
> - EP93XX_GPIO_BANK("F", 0x30, 0x34, 16),
> - EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48),
> - EP93XX_GPIO_BANK("H", 0x40, 0x44, 56),
> -};
> + ep93xx_gpio_init_irq();
>
> -void __init ep93xx_gpio_init(void)
> -{
> - int i;
> + return 0;
>
> - /* Set Ports C, D, E, G, and H for GPIO use */
> - ep93xx_devcfg_set_bits(EP93XX_SYSCON_DEVCFG_KEYS |
> - EP93XX_SYSCON_DEVCFG_GONK |
> - EP93XX_SYSCON_DEVCFG_EONIDE |
> - EP93XX_SYSCON_DEVCFG_GONIDE |
> - EP93XX_SYSCON_DEVCFG_HONIDE);
> +exit_release:
> + release_mem_region(res->start, resource_size(res));
> +exit_free:
> + kfree(ep93xx_gpio);
> + dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, ret);
> + return ret;
> +}
>
> - for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
> - struct gpio_chip *chip = &ep93xx_gpio_banks[i].chip;
> -
> - /*
> - * Ports A, B, and F support input debouncing when
> - * used as interrupts.
> - */
> - if (!strcmp(chip->label, "A") ||
> - !strcmp(chip->label, "B") ||
> - !strcmp(chip->label, "F"))
> - chip->set_debounce = ep93xx_gpio_set_debounce;
> -
> - gpiochip_add(chip);
> - }
> +static struct platform_driver ep93xx_gpio_driver = {
> + .driver = {
> + .name = "gpio-ep93xx",
> + .owner = THIS_MODULE,
> + },
> + .probe = ep93xx_gpio_probe,
> +};
> +
> +static int __init ep93xx_gpio_init(void)
> +{
> + pr_info("%s\n", __func__);
> + return platform_driver_register(&ep93xx_gpio_driver);
> }
> +postcore_initcall(ep93xx_gpio_init);
> +
> +MODULE_AUTHOR("Ryan Mallon <ryan@xxxxxxxxxxxxxxxx> "
> + "H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("EP93XX GPIO driver");
> +MODULE_LICENSE("GPL");
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