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SubjectRe: [PATCHv2] basic_mmio_gpio: split into a gpio library and platform device
On Sat, May 14, 2011 at 03:39:15PM +0100, Jamie Iles wrote:
> Allow GPIO_BASIC_MMIO_CORE to be used to provide an accessor library
> for implementing GPIO drivers whilst abstracting the register access
> detail. Based on a patch from Anton Vorontsov[1] and adapted to allow
> bgpio_chip to be embedded in another structure.
>
> Changes since v1:
> - Register the gpio_chip in the platform device probe
>
> 1. https://lkml.org/lkml/2011/4/19/401
>
> Cc: Grant Likely <grant.likely@secretlab.ca>
> Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
> Signed-off-by: Jamie Iles <jamie@jamieiles.com>

Merged, thanks.

g.

> ---
> drivers/gpio/Kconfig | 6 +
> drivers/gpio/Makefile | 1 +
> drivers/gpio/basic_mmio_gpio.c | 317 +++++++++++++++++++++------------------
> include/linux/basic_mmio_gpio.h | 55 +++++++
> 4 files changed, 231 insertions(+), 148 deletions(-)
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index b7fac15..ca16a30 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -70,8 +70,14 @@ config GPIO_MAX730X
>
> comment "Memory mapped GPIO drivers:"
>
> +config GPIO_BASIC_MMIO_CORE
> + tristate
> + help
> + Provides core functionality for basic memory-mapped GPIO controllers.
> +
> config GPIO_BASIC_MMIO
> tristate "Basic memory-mapped GPIO controllers support"
> + select GPIO_BASIC_MMIO_CORE
> help
> Say yes here to support basic memory-mapped GPIO controllers.
>
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index cfbdef1..91a295d 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -6,6 +6,7 @@ obj-$(CONFIG_GPIOLIB) += gpiolib.o
>
> obj-$(CONFIG_GPIO_ADP5520) += adp5520-gpio.o
> obj-$(CONFIG_GPIO_ADP5588) += adp5588-gpio.o
> +obj-$(CONFIG_GPIO_BASIC_MMIO_CORE) += basic_mmio_gpio.o
> obj-$(CONFIG_GPIO_BASIC_MMIO) += basic_mmio_gpio.o
> obj-$(CONFIG_GPIO_LANGWELL) += langwell_gpio.o
> obj-$(CONFIG_GPIO_MAX730X) += max730x.o
> diff --git a/drivers/gpio/basic_mmio_gpio.c b/drivers/gpio/basic_mmio_gpio.c
> index b2ec45f..8152e9f 100644
> --- a/drivers/gpio/basic_mmio_gpio.c
> +++ b/drivers/gpio/basic_mmio_gpio.c
> @@ -45,6 +45,7 @@ o ` ~~~~\___/~~~~ ` controller in FPGA is ,.`
> */
>
> #include <linux/init.h>
> +#include <linux/err.h>
> #include <linux/bug.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> @@ -61,44 +62,6 @@ o ` ~~~~\___/~~~~ ` controller in FPGA is ,.`
> #include <linux/mod_devicetable.h>
> #include <linux/basic_mmio_gpio.h>
>
> -struct bgpio_chip {
> - struct gpio_chip gc;
> -
> - unsigned long (*read_reg)(void __iomem *reg);
> - void (*write_reg)(void __iomem *reg, unsigned long data);
> -
> - void __iomem *reg_dat;
> - void __iomem *reg_set;
> - void __iomem *reg_clr;
> - void __iomem *reg_dir;
> -
> - /* Number of bits (GPIOs): <register width> * 8. */
> - int bits;
> -
> - /*
> - * Some GPIO controllers work with the big-endian bits notation,
> - * e.g. in a 8-bits register, GPIO7 is the least significant bit.
> - */
> - unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);
> -
> - /*
> - * Used to lock bgpio_chip->data. Also, this is needed to keep
> - * shadowed and real data registers writes together.
> - */
> - spinlock_t lock;
> -
> - /* Shadowed data register to clear/set bits safely. */
> - unsigned long data;
> -
> - /* Shadowed direction registers to clear/set direction safely. */
> - unsigned long dir;
> -};
> -
> -static struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)
> -{
> - return container_of(gc, struct bgpio_chip, gc);
> -}
> -
> static void bgpio_write8(void __iomem *reg, unsigned long data)
> {
> writeb(data, reg);
> @@ -284,20 +247,10 @@ static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val)
> return 0;
> }
>
> -static void __iomem *bgpio_request_and_map(struct device *dev,
> - struct resource *res)
> -{
> - if (!devm_request_mem_region(dev, res->start, resource_size(res),
> - res->name ?: "mmio_gpio"))
> - return NULL;
> -
> - return devm_ioremap(dev, res->start, resource_size(res));
> -}
> -
> -static int bgpio_setup_accessors(struct platform_device *pdev,
> - struct bgpio_chip *bgc)
> +static int bgpio_setup_accessors(struct device *dev,
> + struct bgpio_chip *bgc,
> + bool be)
> {
> - const struct platform_device_id *platid = platform_get_device_id(pdev);
>
> switch (bgc->bits) {
> case 8:
> @@ -319,13 +272,11 @@ static int bgpio_setup_accessors(struct platform_device *pdev,
> break;
> #endif /* BITS_PER_LONG >= 64 */
> default:
> - dev_err(&pdev->dev, "unsupported data width %u bits\n",
> - bgc->bits);
> + dev_err(dev, "unsupported data width %u bits\n", bgc->bits);
> return -EINVAL;
> }
>
> - bgc->pin2mask = strcmp(platid->name, "basic-mmio-gpio-be") ?
> - bgpio_pin2mask : bgpio_pin2mask_be;
> + bgc->pin2mask = be ? bgpio_pin2mask_be : bgpio_pin2mask;
>
> return 0;
> }
> @@ -352,51 +303,22 @@ static int bgpio_setup_accessors(struct platform_device *pdev,
> * - an input direction register (named "dirin") where a 1 bit indicates
> * the GPIO is an input.
> */
> -static int bgpio_setup_io(struct platform_device *pdev,
> - struct bgpio_chip *bgc)
> +static int bgpio_setup_io(struct bgpio_chip *bgc,
> + void __iomem *dat,
> + void __iomem *set,
> + void __iomem *clr)
> {
> - struct resource *res_set;
> - struct resource *res_clr;
> - struct resource *res_dat;
> - resource_size_t dat_sz;
>
> - res_dat = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
> - if (!res_dat)
> - return -EINVAL;
> -
> - dat_sz = resource_size(res_dat);
> - if (!is_power_of_2(dat_sz))
> - return -EINVAL;
> -
> - bgc->bits = dat_sz * 8;
> - if (bgc->bits > BITS_PER_LONG)
> - return -EINVAL;
> -
> - bgc->reg_dat = bgpio_request_and_map(&pdev->dev, res_dat);
> + bgc->reg_dat = dat;
> if (!bgc->reg_dat)
> - return -ENOMEM;
> -
> - res_set = platform_get_resource_byname(pdev, IORESOURCE_MEM, "set");
> - res_clr = platform_get_resource_byname(pdev, IORESOURCE_MEM, "clr");
> - if (res_set && res_clr) {
> - if (resource_size(res_set) != resource_size(res_clr) ||
> - resource_size(res_set) != resource_size(res_dat))
> - return -EINVAL;
> -
> - bgc->reg_set = bgpio_request_and_map(&pdev->dev, res_set);
> - bgc->reg_clr = bgpio_request_and_map(&pdev->dev, res_clr);
> - if (!bgc->reg_set || !bgc->reg_clr)
> - return -ENOMEM;
> + return -EINVAL;
>
> + if (set && clr) {
> + bgc->reg_set = set;
> + bgc->reg_clr = clr;
> bgc->gc.set = bgpio_set_with_clear;
> - } else if (res_set && !res_clr) {
> - if (resource_size(res_set) != resource_size(res_dat))
> - return -EINVAL;
> -
> - bgc->reg_set = bgpio_request_and_map(&pdev->dev, res_set);
> - if (!bgc->reg_set)
> - return -ENOMEM;
> -
> + } else if (set && !clr) {
> + bgc->reg_set = set;
> bgc->gc.set = bgpio_set_set;
> } else {
> bgc->gc.set = bgpio_set;
> @@ -407,27 +329,18 @@ static int bgpio_setup_io(struct platform_device *pdev,
> return 0;
> }
>
> -static int bgpio_setup_direction(struct platform_device *pdev,
> - struct bgpio_chip *bgc)
> +static int bgpio_setup_direction(struct bgpio_chip *bgc,
> + void __iomem *dirout,
> + void __iomem *dirin)
> {
> - struct resource *res_dirout;
> - struct resource *res_dirin;
> -
> - res_dirout = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> - "dirout");
> - res_dirin = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dirin");
> - if (res_dirout && res_dirin) {
> + if (dirout && dirin) {
> return -EINVAL;
> - } else if (res_dirout) {
> - bgc->reg_dir = bgpio_request_and_map(&pdev->dev, res_dirout);
> - if (!bgc->reg_dir)
> - return -ENOMEM;
> + } else if (dirout) {
> + bgc->reg_dir = dirout;
> bgc->gc.direction_output = bgpio_dir_out;
> bgc->gc.direction_input = bgpio_dir_in;
> - } else if (res_dirin) {
> - bgc->reg_dir = bgpio_request_and_map(&pdev->dev, res_dirin);
> - if (!bgc->reg_dir)
> - return -ENOMEM;
> + } else if (dirin) {
> + bgc->reg_dir = dirin;
> bgc->gc.direction_output = bgpio_dir_out_inv;
> bgc->gc.direction_input = bgpio_dir_in_inv;
> } else {
> @@ -438,60 +351,166 @@ static int bgpio_setup_direction(struct platform_device *pdev,
> return 0;
> }
>
> -static int __devinit bgpio_probe(struct platform_device *pdev)
> +int __devexit bgpio_remove(struct bgpio_chip *bgc)
> +{
> + int err = gpiochip_remove(&bgc->gc);
> +
> + kfree(bgc);
> +
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(bgpio_remove);
> +
> +int __devinit bgpio_init(struct bgpio_chip *bgc,
> + struct device *dev,
> + unsigned long sz,
> + void __iomem *dat,
> + void __iomem *set,
> + void __iomem *clr,
> + void __iomem *dirout,
> + void __iomem *dirin,
> + bool big_endian)
> {
> - struct device *dev = &pdev->dev;
> - struct bgpio_pdata *pdata = dev_get_platdata(dev);
> - struct bgpio_chip *bgc;
> int ret;
> - int ngpio;
>
> - bgc = devm_kzalloc(dev, sizeof(*bgc), GFP_KERNEL);
> - if (!bgc)
> - return -ENOMEM;
> + if (!is_power_of_2(sz))
> + return -EINVAL;
>
> - ret = bgpio_setup_io(pdev, bgc);
> + bgc->bits = sz * 8;
> + if (bgc->bits > BITS_PER_LONG)
> + return -EINVAL;
> +
> + spin_lock_init(&bgc->lock);
> + bgc->gc.dev = dev;
> + bgc->gc.label = dev_name(dev);
> + bgc->gc.base = -1;
> + bgc->gc.ngpio = bgc->bits;
> +
> + ret = bgpio_setup_io(bgc, dat, set, clr);
> if (ret)
> return ret;
>
> - ngpio = bgc->bits;
> - if (pdata) {
> - bgc->gc.base = pdata->base;
> - if (pdata->ngpio > 0)
> - ngpio = pdata->ngpio;
> - } else {
> - bgc->gc.base = -1;
> - }
> -
> - ret = bgpio_setup_accessors(pdev, bgc);
> + ret = bgpio_setup_accessors(dev, bgc, big_endian);
> if (ret)
> return ret;
>
> - spin_lock_init(&bgc->lock);
> - ret = bgpio_setup_direction(pdev, bgc);
> + ret = bgpio_setup_direction(bgc, dirout, dirin);
> if (ret)
> return ret;
>
> bgc->data = bgc->read_reg(bgc->reg_dat);
>
> - bgc->gc.ngpio = ngpio;
> - bgc->gc.dev = dev;
> - bgc->gc.label = dev_name(dev);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(bgpio_init);
>
> - platform_set_drvdata(pdev, bgc);
> +#ifdef CONFIG_GPIO_BASIC_MMIO
>
> - ret = gpiochip_add(&bgc->gc);
> - if (ret)
> - dev_err(dev, "gpiochip_add() failed: %d\n", ret);
> +static void __iomem *bgpio_map(struct platform_device *pdev,
> + const char *name,
> + resource_size_t sane_sz,
> + int *err)
> +{
> + struct device *dev = &pdev->dev;
> + struct resource *r;
> + resource_size_t start;
> + resource_size_t sz;
> + void __iomem *ret;
> +
> + *err = 0;
> +
> + r = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
> + if (!r)
> + return NULL;
> +
> + sz = resource_size(r);
> + if (sz != sane_sz) {
> + *err = -EINVAL;
> + return NULL;
> + }
> +
> + start = r->start;
> + if (!devm_request_mem_region(dev, start, sz, r->name)) {
> + *err = -EBUSY;
> + return NULL;
> + }
> +
> + ret = devm_ioremap(dev, start, sz);
> + if (!ret) {
> + *err = -ENOMEM;
> + return NULL;
> + }
>
> return ret;
> }
>
> -static int __devexit bgpio_remove(struct platform_device *pdev)
> +static int __devinit bgpio_pdev_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct resource *r;
> + void __iomem *dat;
> + void __iomem *set;
> + void __iomem *clr;
> + void __iomem *dirout;
> + void __iomem *dirin;
> + unsigned long sz;
> + bool be;
> + int err;
> + struct bgpio_chip *bgc;
> + struct bgpio_pdata *pdata = dev_get_platdata(dev);
> +
> + r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
> + if (!r)
> + return -EINVAL;
> +
> + sz = resource_size(r);
> +
> + dat = bgpio_map(pdev, "dat", sz, &err);
> + if (!dat)
> + return err ? err : -EINVAL;
> +
> + set = bgpio_map(pdev, "set", sz, &err);
> + if (err)
> + return err;
> +
> + clr = bgpio_map(pdev, "clr", sz, &err);
> + if (err)
> + return err;
> +
> + dirout = bgpio_map(pdev, "dirout", sz, &err);
> + if (err)
> + return err;
> +
> + dirin = bgpio_map(pdev, "dirin", sz, &err);
> + if (err)
> + return err;
> +
> + be = !strcmp(platform_get_device_id(pdev)->name, "basic-mmio-gpio-be");
> +
> + bgc = devm_kzalloc(&pdev->dev, sizeof(*bgc), GFP_KERNEL);
> + if (!bgc)
> + return -ENOMEM;
> +
> + err = bgpio_init(bgc, dev, sz, dat, set, clr, dirout, dirin, be);
> + if (err)
> + return err;
> +
> + if (pdata) {
> + bgc->gc.base = pdata->base;
> + if (pdata->ngpio > 0)
> + bgc->gc.ngpio = pdata->ngpio;
> + }
> +
> + platform_set_drvdata(pdev, bgc);
> +
> + return gpiochip_add(&bgc->gc);
> +}
> +
> +static int __devexit bgpio_pdev_remove(struct platform_device *pdev)
> {
> struct bgpio_chip *bgc = platform_get_drvdata(pdev);
>
> - return gpiochip_remove(&bgc->gc);
> + return bgpio_remove(bgc);
> }
>
> static const struct platform_device_id bgpio_id_table[] = {
> @@ -506,21 +525,23 @@ static struct platform_driver bgpio_driver = {
> .name = "basic-mmio-gpio",
> },
> .id_table = bgpio_id_table,
> - .probe = bgpio_probe,
> - .remove = __devexit_p(bgpio_remove),
> + .probe = bgpio_pdev_probe,
> + .remove = __devexit_p(bgpio_pdev_remove),
> };
>
> -static int __init bgpio_init(void)
> +static int __init bgpio_platform_init(void)
> {
> return platform_driver_register(&bgpio_driver);
> }
> -module_init(bgpio_init);
> +module_init(bgpio_platform_init);
>
> -static void __exit bgpio_exit(void)
> +static void __exit bgpio_platform_exit(void)
> {
> platform_driver_unregister(&bgpio_driver);
> }
> -module_exit(bgpio_exit);
> +module_exit(bgpio_platform_exit);
> +
> +#endif /* CONFIG_GPIO_BASIC_MMIO */
>
> MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers");
> MODULE_AUTHOR("Anton Vorontsov <cbouatmailru@gmail.com>");
> diff --git a/include/linux/basic_mmio_gpio.h b/include/linux/basic_mmio_gpio.h
> index f23ec73..1ae1271 100644
> --- a/include/linux/basic_mmio_gpio.h
> +++ b/include/linux/basic_mmio_gpio.h
> @@ -13,9 +13,64 @@
> #ifndef __BASIC_MMIO_GPIO_H
> #define __BASIC_MMIO_GPIO_H
>
> +#include <linux/gpio.h>
> +#include <linux/types.h>
> +#include <linux/compiler.h>
> +
> struct bgpio_pdata {
> int base;
> int ngpio;
> };
>
> +struct device;
> +
> +struct bgpio_chip {
> + struct gpio_chip gc;
> +
> + unsigned long (*read_reg)(void __iomem *reg);
> + void (*write_reg)(void __iomem *reg, unsigned long data);
> +
> + void __iomem *reg_dat;
> + void __iomem *reg_set;
> + void __iomem *reg_clr;
> + void __iomem *reg_dir;
> +
> + /* Number of bits (GPIOs): <register width> * 8. */
> + int bits;
> +
> + /*
> + * Some GPIO controllers work with the big-endian bits notation,
> + * e.g. in a 8-bits register, GPIO7 is the least significant bit.
> + */
> + unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);
> +
> + /*
> + * Used to lock bgpio_chip->data. Also, this is needed to keep
> + * shadowed and real data registers writes together.
> + */
> + spinlock_t lock;
> +
> + /* Shadowed data register to clear/set bits safely. */
> + unsigned long data;
> +
> + /* Shadowed direction registers to clear/set direction safely. */
> + unsigned long dir;
> +};
> +
> +static inline struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)
> +{
> + return container_of(gc, struct bgpio_chip, gc);
> +}
> +
> +int __devexit bgpio_remove(struct bgpio_chip *bgc);
> +int __devinit bgpio_init(struct bgpio_chip *bgc,
> + struct device *dev,
> + unsigned long sz,
> + void __iomem *dat,
> + void __iomem *set,
> + void __iomem *clr,
> + void __iomem *dirout,
> + void __iomem *dirin,
> + bool big_endian);
> +
> #endif /* __BASIC_MMIO_GPIO_H */
> --
> 1.7.4.4
>


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