uboot下gpio驱动移植

芯片：freescale Mpc8308

当前uboot版本：u-boot-2009.11-rc1.2

由于当前uboot版本中没有mpc8308的gpio驱动，所以找了一下别的uboot版本，在uboot-2011-12中找到了
在/driver/gpio下找到mpc83xx_gpio.c，对比gpio的寄存器基地址和mpc8308的手册中gpio的地址 一致，说明驱动合适

说明一下，移植并不具有通用性，如果其他版本的uboot有相关芯片的定义也需要检查地址是否一致，如果没有可以仿照相关架构的芯片的驱动写一个

移植过程：

1.文件copy

将mpc8308xx_gpio.c copy到 u-boot-2009.11-rc1.2/drivers/gpio/下

并修改 Makefile

+COBJS-$(CONFIG_MPC83XX_GPIO) += mpc83xx_gpio.o

我将mpc8308xx_gpio.c贴在最后

2.将涉及到的相关头文件内容添加到u-boot-2009.11-rc1.2/include 下

/*
* 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 _MPC83XX_GPIO_H_
#define _MPC83XX_GPIO_H_

/*
* The MCP83xx's 1-2 GPIO controllers each with 32 bits.
*/
#if defined(CONFIG_MPC8313) || defined(CONFIG_MPC8308) || \
defined(CONFIG_MPC8315)
#define MPC83XX_GPIO_CTRLRS 1
#elif defined(CONFIG_MPC834x) || defined(CONFIG_MPC837x)
#define MPC83XX_GPIO_CTRLRS 2
#else
#define MPC83XX_GPIO_CTRLRS 0
#endif

#define MAX_NUM_GPIOS (32 * MPC83XX_GPIO_CTRLRS)

void mpc83xx_gpio_init_f(void);
void mpc83xx_gpio_init_r(void);

#endif	/* MPC83XX_GPIO_H_ */

3.添加gpio宏开关

在u-boot-2009.11-rc1.2/include/configs/MPC8308EDD.h 添加

+/*

+ *add 83xx gpio

+ */

+#define CONFIG_MPC83XX_GPIO

4.初始化

在/lib_ppc/board.c添加头文件

#include <gpio.h>

并在main_loop前添加初始化函数

mpc83xx_gpio_init_f();
mpc83xx_gpio_init_r();

mpc8308xx_gpio.c

/*
* Freescale MPC83xx GPIO handling.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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
*/

#include <common.h>
#include <mpc83xx.h>
#include <asm/gpio.h>
#include <asm/io.h>

#ifndef CONFIG_MPC83XX_GPIO_0_INIT_DIRECTION
#define CONFIG_MPC83XX_GPIO_0_INIT_DIRECTION 0
#endif
#ifndef CONFIG_MPC83XX_GPIO_1_INIT_DIRECTION
#define CONFIG_MPC83XX_GPIO_1_INIT_DIRECTION 0
#endif
#ifndef CONFIG_MPC83XX_GPIO_0_INIT_OPEN_DRAIN
#define CONFIG_MPC83XX_GPIO_0_INIT_OPEN_DRAIN 0
#endif
#ifndef CONFIG_MPC83XX_GPIO_1_INIT_OPEN_DRAIN
#define CONFIG_MPC83XX_GPIO_1_INIT_OPEN_DRAIN 0
#endif
#ifndef CONFIG_MPC83XX_GPIO_0_INIT_VALUE
#define CONFIG_MPC83XX_GPIO_0_INIT_VALUE 0
#endif
#ifndef CONFIG_MPC83XX_GPIO_1_INIT_VALUE
#define CONFIG_MPC83XX_GPIO_1_INIT_VALUE 0
#endif

static unsigned int gpio_output_value[MPC83XX_GPIO_CTRLRS];

/*
* Generic_GPIO primitives.
*/

int gpio_request(unsigned gpio, const char *label)
{
if (gpio >= MAX_NUM_GPIOS)
return -1;

return 0;
}

int gpio_free(unsigned gpio)
{
/* Do not set to input */
return 0;
}

/* set GPIO pin 'gpio' as an input */
int gpio_direction_input(unsigned gpio)
{
immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
unsigned int ctrlr;
unsigned int line;
unsigned int line_mask;

/* 32-bits per controller */
ctrlr = gpio >> 5;
line = gpio & (0x1F);

/* Big endian */
line_mask = 1 << (31 - line);

clrbits_be32(&im->gpio[ctrlr].dir, line_mask);

return 0;
}

/* set GPIO pin 'gpio' as an output, with polarity 'value' */
int gpio_direction_output(unsigned gpio, int value)
{
immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
unsigned int ctrlr;
unsigned int line;
unsigned int line_mask;

if (value != 0 && value != 1) {
printf("Error: Value parameter must be 0 or 1.\n");
return -1;
}

gpio_set_value(gpio, value);

/* 32-bits per controller */
ctrlr = gpio >> 5;
line = gpio & (0x1F);

/* Big endian */
line_mask = 1 << (31 - line);

/* Make the line output */
setbits_be32(&im->gpio[ctrlr].dir, line_mask);

return 0;
}

/* read GPIO IN value of pin 'gpio' */
int gpio_get_value(unsigned gpio)
{
immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
unsigned int ctrlr;
unsigned int line;
unsigned int line_mask;

/* 32-bits per controller */
ctrlr = gpio >> 5;
line = gpio & (0x1F);

/* Big endian */
line_mask = 1 << (31 - line);

/* Read the value and mask off the bit */
return (in_be32(&im->gpio[ctrlr].dat) & line_mask) != 0;
}

/* write GPIO OUT value to pin 'gpio' */
int gpio_set_value(unsigned gpio, int value)
{
immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
unsigned int ctrlr;
unsigned int line;
unsigned int line_mask;

if (value != 0 && value != 1) {
printf("Error: Value parameter must be 0 or 1.\n");
return -1;
}

/* 32-bits per controller */
ctrlr = gpio >> 5;
line = gpio & (0x1F);

/* Big endian */
line_mask = 1 << (31 - line);

/* Update the local output buffer soft copy */
gpio_output_value[ctrlr] =
(gpio_output_value[ctrlr] & ~line_mask) | \
(value ? line_mask : 0);

/* Write the output */
out_be32(&im->gpio[ctrlr].dat, gpio_output_value[ctrlr]);

return 0;
}

/* Configure GPIO registers early */
void mpc83xx_gpio_init_f()
{
immap_t *im = (immap_t *)CONFIG_SYS_IMMR;

#if MPC83XX_GPIO_CTRLRS >= 1
out_be32(&im->gpio[0].dir, CONFIG_MPC83XX_GPIO_0_INIT_DIRECTION);
out_be32(&im->gpio[0].odr, CONFIG_MPC83XX_GPIO_0_INIT_OPEN_DRAIN);
out_be32(&im->gpio[0].dat, CONFIG_MPC83XX_GPIO_0_INIT_VALUE);
out_be32(&im->gpio[0].ier, 0xFFFFFFFF); /* Clear all events */
out_be32(&im->gpio[0].imr, 0);
out_be32(&im->gpio[0].icr, 0);
#endif

#if MPC83XX_GPIO_CTRLRS >= 2
out_be32(&im->gpio[1].dir, CONFIG_MPC83XX_GPIO_1_INIT_DIRECTION);
out_be32(&im->gpio[1].odr, CONFIG_MPC83XX_GPIO_1_INIT_OPEN_DRAIN);
out_be32(&im->gpio[1].dat, CONFIG_MPC83XX_GPIO_1_INIT_VALUE);
out_be32(&im->gpio[1].ier, 0xFFFFFFFF); /* Clear all events */
out_be32(&im->gpio[1].imr, 0);
out_be32(&im->gpio[1].icr, 0);
#endif
}

/* Initialize GPIO soft-copies */
void mpc83xx_gpio_init_r()
{
#if MPC83XX_GPIO_CTRLRS >= 1
gpio_output_value[0] = CONFIG_MPC83XX_GPIO_0_INIT_VALUE;
#endif

#if MPC83XX_GPIO_CTRLRS >= 2
gpio_output_value[1] = CONFIG_MPC83XX_GPIO_1_INIT_VALUE;
#endif
}