diff options
Diffstat (limited to 'arch/powerpc/platforms/4xx/gpio.c')
| -rw-r--r-- | arch/powerpc/platforms/4xx/gpio.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/4xx/gpio.c b/arch/powerpc/platforms/4xx/gpio.c new file mode 100644 index 000000000000..2238e369cde4 --- /dev/null +++ b/arch/powerpc/platforms/4xx/gpio.c @@ -0,0 +1,207 @@ +/* + * PPC4xx gpio driver + * + * Copyright (c) 2008 Harris Corporation + * Copyright (c) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix + * Copyright (c) MontaVista Software, Inc. 2008. + * + * Author: Steve Falco <sfalco@harris.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_gpio.h> +#include <linux/gpio/driver.h> +#include <linux/types.h> +#include <linux/slab.h> + +#define GPIO_MASK(gpio) (0x80000000 >> (gpio)) +#define GPIO_MASK2(gpio) (0xc0000000 >> ((gpio) * 2)) + +/* Physical GPIO register layout */ +struct ppc4xx_gpio { + __be32 or; + __be32 tcr; + __be32 osrl; + __be32 osrh; + __be32 tsrl; + __be32 tsrh; + __be32 odr; + __be32 ir; + __be32 rr1; + __be32 rr2; + __be32 rr3; + __be32 reserved1; + __be32 isr1l; + __be32 isr1h; + __be32 isr2l; + __be32 isr2h; + __be32 isr3l; + __be32 isr3h; +}; + +struct ppc4xx_gpio_chip { + struct of_mm_gpio_chip mm_gc; + spinlock_t lock; +}; + +/* + * GPIO LIB API implementation for GPIOs + * + * There are a maximum of 32 gpios in each gpio controller. + */ + +static int ppc4xx_gpio_get(struct gpio_chip *gc, unsigned int gpio) +{ + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + struct ppc4xx_gpio __iomem *regs = mm_gc->regs; + + return !!(in_be32(®s->ir) & GPIO_MASK(gpio)); +} + +static inline void +__ppc4xx_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 ppc4xx_gpio __iomem *regs = mm_gc->regs; + + if (val) + setbits32(®s->or, GPIO_MASK(gpio)); + else + clrbits32(®s->or, GPIO_MASK(gpio)); +} + +static void +ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val) +{ + struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc); + unsigned long flags; + + spin_lock_irqsave(&chip->lock, flags); + + __ppc4xx_gpio_set(gc, gpio, val); + + spin_unlock_irqrestore(&chip->lock, flags); + + pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val); +} + +static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio) +{ + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc); + struct ppc4xx_gpio __iomem *regs = mm_gc->regs; + unsigned long flags; + + spin_lock_irqsave(&chip->lock, flags); + + /* Disable open-drain function */ + clrbits32(®s->odr, GPIO_MASK(gpio)); + + /* Float the pin */ + clrbits32(®s->tcr, GPIO_MASK(gpio)); + + /* Bits 0-15 use TSRL/OSRL, bits 16-31 use TSRH/OSRH */ + if (gpio < 16) { + clrbits32(®s->osrl, GPIO_MASK2(gpio)); + clrbits32(®s->tsrl, GPIO_MASK2(gpio)); + } else { + clrbits32(®s->osrh, GPIO_MASK2(gpio)); + clrbits32(®s->tsrh, GPIO_MASK2(gpio)); + } + + spin_unlock_irqrestore(&chip->lock, flags); + + return 0; +} + +static int +ppc4xx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) +{ + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc); + struct ppc4xx_gpio __iomem *regs = mm_gc->regs; + unsigned long flags; + + spin_lock_irqsave(&chip->lock, flags); + + /* First set initial value */ + __ppc4xx_gpio_set(gc, gpio, val); + + /* Disable open-drain function */ + clrbits32(®s->odr, GPIO_MASK(gpio)); + + /* Drive the pin */ + setbits32(®s->tcr, GPIO_MASK(gpio)); + + /* Bits 0-15 use TSRL, bits 16-31 use TSRH */ + if (gpio < 16) { + clrbits32(®s->osrl, GPIO_MASK2(gpio)); + clrbits32(®s->tsrl, GPIO_MASK2(gpio)); + } else { + clrbits32(®s->osrh, GPIO_MASK2(gpio)); + clrbits32(®s->tsrh, GPIO_MASK2(gpio)); + } + + spin_unlock_irqrestore(&chip->lock, flags); + + pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val); + + return 0; +} + +static int __init ppc4xx_add_gpiochips(void) +{ + struct device_node *np; + + for_each_compatible_node(np, NULL, "ibm,ppc4xx-gpio") { + int ret; + struct ppc4xx_gpio_chip *ppc4xx_gc; + struct of_mm_gpio_chip *mm_gc; + struct gpio_chip *gc; + + ppc4xx_gc = kzalloc(sizeof(*ppc4xx_gc), GFP_KERNEL); + if (!ppc4xx_gc) { + ret = -ENOMEM; + goto err; + } + + spin_lock_init(&ppc4xx_gc->lock); + + mm_gc = &ppc4xx_gc->mm_gc; + gc = &mm_gc->gc; + + gc->ngpio = 32; + gc->direction_input = ppc4xx_gpio_dir_in; + gc->direction_output = ppc4xx_gpio_dir_out; + gc->get = ppc4xx_gpio_get; + gc->set = ppc4xx_gpio_set; + + ret = of_mm_gpiochip_add_data(np, mm_gc, ppc4xx_gc); + if (ret) + goto err; + continue; +err: + pr_err("%pOF: registration failed with status %d\n", np, ret); + kfree(ppc4xx_gc); + /* try others anyway */ + } + return 0; +} +arch_initcall(ppc4xx_add_gpiochips); |