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gpio.c

/*
 *  Miscellaneous functions for IDT EB434 board
 *
 *  Copyright 2004 IDT Inc. (rischelp@idt.com)
 *  Copyright 2006 Phil Sutter <n0-1@freewrt.org>
 *  Copyright 2007 Florian Fainelli <florian@openwrt.org>
 *
 *  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.
 *
 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  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.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>

#include <asm/mach-rc32434/rb.h>
#include <asm/mach-rc32434/gpio.h>

struct rb532_gpio_chip {
      struct gpio_chip chip;
      void __iomem       *regbase;
};

struct mpmc_device dev3;

static struct resource rb532_gpio_reg0_res[] = {
      {
            .name       = "gpio_reg0",
            .start      = REGBASE + GPIOBASE,
            .end  = REGBASE + GPIOBASE + sizeof(struct rb532_gpio_reg) - 1,
            .flags      = IORESOURCE_MEM,
      }
};

static struct resource rb532_dev3_ctl_res[] = {
      {
            .name = "dev3_ctl",
            .start      = REGBASE + DEV3BASE,
            .end  = REGBASE + DEV3BASE + sizeof(struct dev_reg) - 1,
            .flags      = IORESOURCE_MEM,
      }
};

void set_434_reg(unsigned reg_offs, unsigned bit, unsigned len, unsigned val)
{
      unsigned long flags;
      unsigned data;
      unsigned i = 0;

      spin_lock_irqsave(&dev3.lock, flags);

      data = readl(IDT434_REG_BASE + reg_offs);
      for (i = 0; i != len; ++i) {
            if (val & (1 << i))
                  data |= (1 << (i + bit));
            else
                  data &= ~(1 << (i + bit));
      }
      writel(data, (IDT434_REG_BASE + reg_offs));

      spin_unlock_irqrestore(&dev3.lock, flags);
}
EXPORT_SYMBOL(set_434_reg);

unsigned get_434_reg(unsigned reg_offs)
{
      return readl(IDT434_REG_BASE + reg_offs);
}
EXPORT_SYMBOL(get_434_reg);

void set_latch_u5(unsigned char or_mask, unsigned char nand_mask)
{
      unsigned long flags;

      spin_lock_irqsave(&dev3.lock, flags);

      dev3.state = (dev3.state | or_mask) & ~nand_mask;
      writel(dev3.state, &dev3.base);

      spin_unlock_irqrestore(&dev3.lock, flags);
}
EXPORT_SYMBOL(set_latch_u5);

unsigned char get_latch_u5(void)
{
      return dev3.state;
}
EXPORT_SYMBOL(get_latch_u5);

/* rb532_set_bit - sanely set a bit
 *
 * bitval: new value for the bit
 * offset: bit index in the 4 byte address range
 * ioaddr: 4 byte aligned address being altered
 */
static inline void rb532_set_bit(unsigned bitval,
            unsigned offset, void __iomem *ioaddr)
{
      unsigned long flags;
      u32 val;

      bitval = !!bitval;              /* map parameter to {0,1} */

      local_irq_save(flags);

      val = readl(ioaddr);
      val &= ~( ~bitval << offset );   /* unset bit if bitval == 0 */
      val |=  (  bitval << offset );   /* set bit if bitval == 1 */
      writel(val, ioaddr);

      local_irq_restore(flags);
}

/* rb532_get_bit - read a bit
 *
 * returns the boolean state of the bit, which may be > 1
 */
static inline int rb532_get_bit(unsigned offset, void __iomem *ioaddr)
{
      return (readl(ioaddr) & (1 << offset));
}

/*
 * Return GPIO level */
static int rb532_gpio_get(struct gpio_chip *chip, unsigned offset)
{
      struct rb532_gpio_chip  *gpch;

      gpch = container_of(chip, struct rb532_gpio_chip, chip);
      return rb532_get_bit(offset, gpch->regbase + GPIOD);
}

/*
 * Set output GPIO level
 */
static void rb532_gpio_set(struct gpio_chip *chip,
                        unsigned offset, int value)
{
      struct rb532_gpio_chip  *gpch;

      gpch = container_of(chip, struct rb532_gpio_chip, chip);
      rb532_set_bit(value, offset, gpch->regbase + GPIOD);
}

/*
 * Set GPIO direction to input
 */
static int rb532_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
      struct rb532_gpio_chip  *gpch;

      gpch = container_of(chip, struct rb532_gpio_chip, chip);

      if (rb532_get_bit(offset, gpch->regbase + GPIOFUNC))
            return 1;   /* alternate function, GPIOCFG is ignored */

      rb532_set_bit(0, offset, gpch->regbase + GPIOCFG);
      return 0;
}

/*
 * Set GPIO direction to output
 */
static int rb532_gpio_direction_output(struct gpio_chip *chip,
                              unsigned offset, int value)
{
      struct rb532_gpio_chip  *gpch;

      gpch = container_of(chip, struct rb532_gpio_chip, chip);

      if (rb532_get_bit(offset, gpch->regbase + GPIOFUNC))
            return 1;   /* alternate function, GPIOCFG is ignored */

      /* set the initial output value */
      rb532_set_bit(value, offset, gpch->regbase + GPIOD);

      rb532_set_bit(1, offset, gpch->regbase + GPIOCFG);
      return 0;
}

static struct rb532_gpio_chip rb532_gpio_chip[] = {
      [0] = {
            .chip = {
                  .label                  = "gpio0",
                  .direction_input  = rb532_gpio_direction_input,
                  .direction_output = rb532_gpio_direction_output,
                  .get              = rb532_gpio_get,
                  .set              = rb532_gpio_set,
                  .base             = 0,
                  .ngpio                  = 32,
            },
      },
};

/*
 * Set GPIO interrupt level
 */
void rb532_gpio_set_ilevel(int bit, unsigned gpio)
{
      rb532_set_bit(bit, gpio, rb532_gpio_chip->regbase + GPIOILEVEL);
}
EXPORT_SYMBOL(rb532_gpio_set_ilevel);

/*
 * Set GPIO interrupt status
 */
void rb532_gpio_set_istat(int bit, unsigned gpio)
{
      rb532_set_bit(bit, gpio, rb532_gpio_chip->regbase + GPIOISTAT);
}
EXPORT_SYMBOL(rb532_gpio_set_istat);

/*
 * Configure GPIO alternate function
 */
static void rb532_gpio_set_func(int bit, unsigned gpio)
{
       rb532_set_bit(bit, gpio, rb532_gpio_chip->regbase + GPIOFUNC);
}

int __init rb532_gpio_init(void)
{
      struct resource *r;

      r = rb532_gpio_reg0_res;
      rb532_gpio_chip->regbase = ioremap_nocache(r->start, r->end - r->start);

      if (!rb532_gpio_chip->regbase) {
            printk(KERN_ERR "rb532: cannot remap GPIO register 0\n");
            return -ENXIO;
      }

      /* Register our GPIO chip */
      gpiochip_add(&rb532_gpio_chip->chip);

      r = rb532_dev3_ctl_res;
      dev3.base = ioremap_nocache(r->start, r->end - r->start);

      if (!dev3.base) {
            printk(KERN_ERR "rb532: cannot remap device controller 3\n");
            return -ENXIO;
      }

      /* configure CF_GPIO_NUM as CFRDY IRQ source */
      rb532_gpio_set_func(0, CF_GPIO_NUM);
      rb532_gpio_direction_input(&rb532_gpio_chip->chip, CF_GPIO_NUM);
      rb532_gpio_set_ilevel(1, CF_GPIO_NUM);
      rb532_gpio_set_istat(0, CF_GPIO_NUM);

      return 0;
}
arch_initcall(rb532_gpio_init);

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