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
}