diff options
author | Jamie Iles <jamie@jamieiles.com> | 2011-05-20 00:40:19 -0600 |
---|---|---|
committer | Grant Likely <grant.likely@secretlab.ca> | 2011-05-20 00:40:19 -0600 |
commit | 280df6b3c3ad777a91f1011cd98d50df891bfef8 (patch) | |
tree | 31a03f7c9a8b2e1f4abf26f8fcf46e90c09ccb88 /drivers | |
parent | e849dc044af0939135c822833092bc9baf480222 (diff) | |
download | op-kernel-dev-280df6b3c3ad777a91f1011cd98d50df891bfef8.zip op-kernel-dev-280df6b3c3ad777a91f1011cd98d50df891bfef8.tar.gz |
basic_mmio_gpio: split into a gpio library and platform device
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
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/gpio/Kconfig | 6 | ||||
-rw-r--r-- | drivers/gpio/Makefile | 1 | ||||
-rw-r--r-- | drivers/gpio/basic_mmio_gpio.c | 317 |
3 files changed, 176 insertions, 148 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 44235bd..b57ec09 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 7b2bdce..d92ce3a 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..8152e9f5 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>"); |