mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-13 06:42:56 +00:00
710308ee18
To ease the implementation of other MPC85xx board ports, several common GPIO helpers are added to <asm/mpc85xx_gpio.h>. Since each of these compiles to no more than 4-5 instructions it would be very inefficient to call them out of line, therefore we put them entirely in the header file. The HWW-1U-1A board port which these were written for strongly prefers to set multiple GPIOs as a single batch operation, so the API is designed around that basis. To assist other board ports, a small set of wrappers are used which provides a standard gpio_request() interface around the MPC85xx-specific functions. This can be enabled with CONFIG_MPC85XX_GENERIC_GPIO Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com> Cc: Andy Fleming <afleming@gmail.com> Cc: Peter Tyser <ptyser@xes-inc.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
123 lines
3.2 KiB
C
123 lines
3.2 KiB
C
/*
|
|
* Copyright 2010 eXMeritus, A Boeing Company
|
|
*
|
|
* 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 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
|
|
*/
|
|
|
|
#ifndef POWERPC_ASM_MPC85XX_GPIO_H_
|
|
#define POWERPC_ASM_MPC85XX_GPIO_H_
|
|
|
|
# include <asm/immap_85xx.h>
|
|
|
|
/*
|
|
* The following internal functions are an MPC85XX-specific GPIO API which
|
|
* allows setting and querying multiple GPIOs in a single operation.
|
|
*
|
|
* All of these look relatively large, but the arguments are almost always
|
|
* constants, so they compile down to just a few instructions and a
|
|
* memory-mapped IO operation or two.
|
|
*/
|
|
static inline void mpc85xx_gpio_set(unsigned int mask,
|
|
unsigned int dir, unsigned int val)
|
|
{
|
|
ccsr_gpio_t *gpio = (void *)(CONFIG_SYS_MPC85xx_GPIO_ADDR + 0xc00);
|
|
|
|
/* First mask off the unwanted parts of "dir" and "val" */
|
|
dir &= mask;
|
|
val &= mask;
|
|
|
|
/* Now read in the values we're supposed to preserve */
|
|
dir |= (in_be32(&gpio->gpdir) & ~mask);
|
|
val |= (in_be32(&gpio->gpdat) & ~mask);
|
|
|
|
/*
|
|
* Poke the new output values first, then set the direction. This
|
|
* helps to avoid transient data when switching from input to output
|
|
* and vice versa.
|
|
*/
|
|
out_be32(&gpio->gpdat, val);
|
|
out_be32(&gpio->gpdir, dir);
|
|
}
|
|
|
|
static inline void mpc85xx_gpio_set_in(unsigned int gpios)
|
|
{
|
|
mpc85xx_gpio_set(gpios, 0x00000000, 0x00000000);
|
|
}
|
|
|
|
static inline void mpc85xx_gpio_set_low(unsigned int gpios)
|
|
{
|
|
mpc85xx_gpio_set(gpios, 0xFFFFFFFF, 0x00000000);
|
|
}
|
|
|
|
static inline void mpc85xx_gpio_set_high(unsigned int gpios)
|
|
{
|
|
mpc85xx_gpio_set(gpios, 0xFFFFFFFF, 0xFFFFFFFF);
|
|
}
|
|
|
|
static inline unsigned int mpc85xx_gpio_get(unsigned int mask)
|
|
{
|
|
ccsr_gpio_t *gpio = (void *)(CONFIG_SYS_MPC85xx_GPIO_ADDR + 0xc00);
|
|
|
|
/* Read the requested values */
|
|
return in_be32(&gpio->gpdat) & mask;
|
|
}
|
|
|
|
/*
|
|
* These implement the generic Linux GPIO API on top of the other functions
|
|
* in this header.
|
|
*/
|
|
static inline int gpio_request(unsigned gpio, const char *label)
|
|
{
|
|
/* Compatibility shim */
|
|
return 0;
|
|
}
|
|
|
|
static inline void gpio_free(unsigned gpio)
|
|
{
|
|
/* Compatibility shim */
|
|
}
|
|
|
|
static inline int gpio_direction_input(unsigned gpio)
|
|
{
|
|
mpc85xx_gpio_set_in(1U << gpio);
|
|
return 0;
|
|
}
|
|
|
|
static inline int gpio_direction_output(unsigned gpio, int value)
|
|
{
|
|
mpc85xx_gpio_set_low(1U << gpio);
|
|
return 0;
|
|
}
|
|
|
|
static inline int gpio_get_value(unsigned gpio)
|
|
{
|
|
return !!mpc85xx_gpio_get(1U << gpio);
|
|
}
|
|
|
|
static inline void gpio_set_value(unsigned gpio, int value)
|
|
{
|
|
if (value)
|
|
mpc85xx_gpio_set_high(1U << gpio);
|
|
else
|
|
mpc85xx_gpio_set_low(1U << gpio);
|
|
}
|
|
|
|
static inline int gpio_is_valid(int gpio)
|
|
{
|
|
return (gpio >= 0) && (gpio < 32);
|
|
}
|
|
|
|
#endif /* not POWERPC_ASM_MPC85XX_GPIO_H_ */
|