diff options
Diffstat (limited to 'drivers/gpio/basic_mmio_gpio.c')
| -rw-r--r-- | drivers/gpio/basic_mmio_gpio.c | 297 |
1 files changed, 0 insertions, 297 deletions
diff --git a/drivers/gpio/basic_mmio_gpio.c b/drivers/gpio/basic_mmio_gpio.c deleted file mode 100644 index 3addea65894..00000000000 --- a/drivers/gpio/basic_mmio_gpio.c +++ /dev/null @@ -1,297 +0,0 @@ -/* - * Driver for basic memory-mapped GPIO controllers. - * - * Copyright 2008 MontaVista Software, Inc. - * Copyright 2008,2010 Anton Vorontsov <cbouatmailru@gmail.com> - * - * 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. - * - * ....``.```~~~~````.`.`.`.`.```````'',,,.........`````......`....... - * ...`` ```````.. - * ..The simplest form of a GPIO controller that the driver supports is`` - * `.just a single "data" register, where GPIO state can be read and/or ` - * `,..written. ,,..``~~~~ .....``.`.`.~~.```.`.........``````.``````` - * ````````` - ___ -_/~~|___/~| . ```~~~~~~ ___/___\___ ,~.`.`.`.`````.~~...,,,,... -__________|~$@~~~ %~ /o*o*o*o*o*o\ .. Implementing such a GPIO . -o ` ~~~~\___/~~~~ ` controller in FPGA is ,.` - `....trivial..'~`.```.``` - * ``````` - * .```````~~~~`..`.``.``. - * . The driver supports `... ,..```.`~~~```````````````....````.``,, - * . big-endian notation, just`. .. A bit more sophisticated controllers , - * . register the device with -be`. .with a pair of set/clear-bit registers , - * `.. suffix. ```~~`````....`.` . affecting the data register and the .` - * ``.`.``...``` ```.. output pins are also supported.` - * ^^ `````.`````````.,``~``~``~~`````` - * . ^^ - * ,..`.`.`...````````````......`.`.`.`.`.`..`.`.`.. - * .. The expectation is that in at least some cases . ,-~~~-, - * .this will be used with roll-your-own ASIC/FPGA .` \ / - * .logic in Verilog or VHDL. ~~~`````````..`````~~` \ / - * ..````````......``````````` \o_ - * | - * ^^ / \ - * - * ...`````~~`.....``.`..........``````.`.``.```........``. - * ` 8, 16, 32 and 64 bits registers are supported, and``. - * . the number of GPIOs is determined by the width of ~ - * .. the registers. ,............```.`.`..`.`.~~~.`.`.`~ - * `.......````.``` - */ - -#include <linux/init.h> -#include <linux/bug.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/spinlock.h> -#include <linux/compiler.h> -#include <linux/types.h> -#include <linux/errno.h> -#include <linux/log2.h> -#include <linux/ioport.h> -#include <linux/io.h> -#include <linux/gpio.h> -#include <linux/slab.h> -#include <linux/platform_device.h> -#include <linux/mod_devicetable.h> -#include <linux/basic_mmio_gpio.h> - -struct bgpio_chip { - struct gpio_chip gc; - void __iomem *reg_dat; - void __iomem *reg_set; - void __iomem *reg_clr; - - /* 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. - */ - int big_endian_bits; - - /* - * 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; -}; - -static struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc) -{ - return container_of(gc, struct bgpio_chip, gc); -} - -static unsigned long bgpio_in(struct bgpio_chip *bgc) -{ - switch (bgc->bits) { - case 8: - return __raw_readb(bgc->reg_dat); - case 16: - return __raw_readw(bgc->reg_dat); - case 32: - return __raw_readl(bgc->reg_dat); -#if BITS_PER_LONG >= 64 - case 64: - return __raw_readq(bgc->reg_dat); -#endif - } - return -EINVAL; -} - -static void bgpio_out(struct bgpio_chip *bgc, void __iomem *reg, - unsigned long data) -{ - switch (bgc->bits) { - case 8: - __raw_writeb(data, reg); - return; - case 16: - __raw_writew(data, reg); - return; - case 32: - __raw_writel(data, reg); - return; -#if BITS_PER_LONG >= 64 - case 64: - __raw_writeq(data, reg); - return; -#endif - } -} - -static unsigned long bgpio_pin2mask(struct bgpio_chip *bgc, unsigned int pin) -{ - if (bgc->big_endian_bits) - return 1 << (bgc->bits - 1 - pin); - else - return 1 << pin; -} - -static int bgpio_get(struct gpio_chip *gc, unsigned int gpio) -{ - struct bgpio_chip *bgc = to_bgpio_chip(gc); - - return bgpio_in(bgc) & bgpio_pin2mask(bgc, gpio); -} - -static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val) -{ - struct bgpio_chip *bgc = to_bgpio_chip(gc); - unsigned long mask = bgpio_pin2mask(bgc, gpio); - unsigned long flags; - - if (bgc->reg_set) { - if (val) - bgpio_out(bgc, bgc->reg_set, mask); - else - bgpio_out(bgc, bgc->reg_clr, mask); - return; - } - - spin_lock_irqsave(&bgc->lock, flags); - - if (val) - bgc->data |= mask; - else - bgc->data &= ~mask; - - bgpio_out(bgc, bgc->reg_dat, bgc->data); - - spin_unlock_irqrestore(&bgc->lock, flags); -} - -static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio) -{ - return 0; -} - -static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) -{ - bgpio_set(gc, gpio, val); - return 0; -} - -static int __devinit bgpio_probe(struct platform_device *pdev) -{ - const struct platform_device_id *platid = platform_get_device_id(pdev); - struct device *dev = &pdev->dev; - struct bgpio_pdata *pdata = dev_get_platdata(dev); - struct bgpio_chip *bgc; - struct resource *res_dat; - struct resource *res_set; - struct resource *res_clr; - resource_size_t dat_sz; - int bits; - int ret; - - 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; - - bits = dat_sz * 8; - if (bits > BITS_PER_LONG) - return -EINVAL; - - bgc = devm_kzalloc(dev, sizeof(*bgc), GFP_KERNEL); - if (!bgc) - return -ENOMEM; - - bgc->reg_dat = devm_ioremap(dev, res_dat->start, dat_sz); - 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) != dat_sz) - return -EINVAL; - - bgc->reg_set = devm_ioremap(dev, res_set->start, dat_sz); - bgc->reg_clr = devm_ioremap(dev, res_clr->start, dat_sz); - if (!bgc->reg_set || !bgc->reg_clr) - return -ENOMEM; - } else if (res_set || res_clr) { - return -EINVAL; - } - - spin_lock_init(&bgc->lock); - - bgc->bits = bits; - bgc->big_endian_bits = !strcmp(platid->name, "basic-mmio-gpio-be"); - bgc->data = bgpio_in(bgc); - - bgc->gc.ngpio = bits; - bgc->gc.direction_input = bgpio_dir_in; - bgc->gc.direction_output = bgpio_dir_out; - bgc->gc.get = bgpio_get; - bgc->gc.set = bgpio_set; - bgc->gc.dev = dev; - bgc->gc.label = dev_name(dev); - - if (pdata) - bgc->gc.base = pdata->base; - else - bgc->gc.base = -1; - - dev_set_drvdata(dev, bgc); - - ret = gpiochip_add(&bgc->gc); - if (ret) - dev_err(dev, "gpiochip_add() failed: %d\n", ret); - - return ret; -} - -static int __devexit bgpio_remove(struct platform_device *pdev) -{ - struct bgpio_chip *bgc = dev_get_drvdata(&pdev->dev); - - return gpiochip_remove(&bgc->gc); -} - -static const struct platform_device_id bgpio_id_table[] = { - { "basic-mmio-gpio", }, - { "basic-mmio-gpio-be", }, - {}, -}; -MODULE_DEVICE_TABLE(platform, bgpio_id_table); - -static struct platform_driver bgpio_driver = { - .driver = { - .name = "basic-mmio-gpio", - }, - .id_table = bgpio_id_table, - .probe = bgpio_probe, - .remove = __devexit_p(bgpio_remove), -}; - -static int __init bgpio_init(void) -{ - return platform_driver_register(&bgpio_driver); -} -module_init(bgpio_init); - -static void __exit bgpio_exit(void) -{ - platform_driver_unregister(&bgpio_driver); -} -module_exit(bgpio_exit); - -MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers"); -MODULE_AUTHOR("Anton Vorontsov <cbouatmailru@gmail.com>"); -MODULE_LICENSE("GPL"); |