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am3358——GPMC——参考网上驱动

發布時間：2023/12/20 编程问答 26 豆豆

生活随笔收集整理的這篇文章主要介紹了 am3358——GPMC——参考网上驱动小編覺得挺不錯的,現在分享給大家,幫大家做個參考.

作者：chenzhufly QQ：36886052 ( 轉載請注明出處)

轉自：?http://bbs.eeworld.com.cn/thread-333652-1-1.html

1.?參考資料

《AM335x ARM? Cortex?-A8 Microprocessors Technical Reference Manual》
《BeagleBone_revA3_SCH.pdf》
《BeagleBone_revA3_SRM.pdf》
《BeagleBone_revA3_BOM.xls》

2.?測試的硬件環境: Beaglebone + EE_FPGA

3. 硬件連接圖：用的是GPMC to 16-Bit Nonmultiplexed Memory

4. 設計思路

初始化GPMC相關引腳
完成GPMC驅動設計
完成GPMC應用設計

5.?初始化相關代碼，主要修改并編譯

/linux-3.1.0-psp04.06.00.03.sdk/arch/arm/mach-omap2/board-am335xevm.c

配置相關引腳

/* Pin mux for fpga module */
static struct pinmux_config fpga_pin_mux[] = {
{"gpmc_ad0.gpmc_ad0", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad1.gpmc_ad1", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad2.gpmc_ad2", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad3.gpmc_ad3", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad4.gpmc_ad4", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad5.gpmc_ad5", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad6.gpmc_ad6", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad7.gpmc_ad7", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad8.gpmc_ad8", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad9.gpmc_ad9", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad10.gpmc_ad10", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad11.gpmc_ad11", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad12.gpmc_ad12", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad13.gpmc_ad13", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad14.gpmc_ad14", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad15.gpmc_ad15", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},

{"lcd_data0.gpmc_a0", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_data1.gpmc_a1", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_data2.gpmc_a2", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_data3.gpmc_a3", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_data4.gpmc_a4", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_data5.gpmc_a5", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_data6.gpmc_a6", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_data7.gpmc_a7", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_vsync.gpmc_a8", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_hsync.gpmc_a9", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_pclk.gpmc_a10", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_ac_bias_en.gpmc_a11", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_data8.gpmc_a12", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_data9.gpmc_a13", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_data10.gpmc_a14", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"lcd_data11.gpmc_a15", OMAP_MUX_MODE1 | AM33XX_PIN_OUTPUT?
| AM33XX_PULL_DISA},?
{"gpmc_advn_ale.gpmc_advn_ale", OMAP_MUX_MODE0 | AM33XX_PULL_DISA},
{"gpmc_oen_ren.gpmc_oen_ren", OMAP_MUX_MODE0 | AM33XX_PULL_DISA},
{"gpmc_wen.gpmc_wen", OMAP_MUX_MODE0 | AM33XX_PULL_DISA},
{"gpmc_ben0_cle.gpmc_ben0_cle", OMAP_MUX_MODE0 | AM33XX_PULL_DISA},
{"gpmc_csn1.gpmc_csn1", OMAP_MUX_MODE0 | AM33XX_PULL_DISA},
{"gpmc_clk.gpmc_clk", OMAP_MUX_MODE0 | AM33XX_PULL_DISA},
{NULL, 0},
};

復制代碼

static void evm_fpga_init(int evm_id, int profile)
{
setup_pin_mux(fpga_pin_mux);
}

復制代碼

/* Beaglebone Rev A3 and after */
static struct evm_dev_cfg beaglebone_dev_cfg[] = {
{mii1_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{usb0_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{usb1_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{mmc0_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{evm_fpga_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{NULL, 0, 0},

復制代碼

6.?GPMC驅動設計

/*
Char device driver fpga.
Do a global replace of 'fpga' with your driver name.
*/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <asm/uaccess.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/slab.h>

#include <plat/gpmc.h>
#include "plat/gpio.h"
#include "plat/dma.h"

#include "asm/uaccess.h"
#include "asm/io.h"
#include "asm/atomic.h"


#define USER_BUFF_SIZE 128


struct fpga_dev {
dev_t devt;
struct cdev cdev;
struct semaphore sem;
struct class *class;
char *user_buff;
};

static struct fpga_dev fpga_dev;

unsigned long mem_base;
static void __iomem *fpga_base;
static void __iomem *gpmc_base;

/* GPMC register offsets */
#define GPMC_REVISION 0x00
#define GPMC_SYSCONFIG 0x10
#define GPMC_SYSSTATUS 0x14
#define GPMC_IRQSTATUS 0x18
#define GPMC_IRQENABLE 0x1c
#define GPMC_TIMEOUT_CONTROL 0x40
#define GPMC_ERR_ADDRESS 0x44
#define GPMC_ERR_TYPE 0x48
#define GPMC_CONFIG 0x50
#define GPMC_STATUS 0x54
#define GPMC_PREFETCH_CONFIG1 0x1e0
#define GPMC_PREFETCH_CONFIG2 0x1e4
#define GPMC_PREFETCH_CONTROL 0x1ec
#define GPMC_PREFETCH_STATUS 0x1f0
#define GPMC_ECC_CONFIG 0x1f4
#define GPMC_ECC_CONTROL 0x1f8
#define GPMC_ECC_SIZE_CONFIG 0x1fc
#define GPMC_ECC1_RESULT 0x200
#define GPMC_ECC_BCH_RESULT_0 0x240

#define GPMC_BASE_ADDR 0x50000000
#define GPMC_CS 1
#define GPMC_CS0 0x60
#define GPMC_CS_SIZE 0x30
#define STNOR_GPMC_CONFIG1 0x28601000
#define STNOR_GPMC_CONFIG2 0x00011001
#define STNOR_GPMC_CONFIG3 0x00020201
#define STNOR_GPMC_CONFIG4 0x08031003
#define STNOR_GPMC_CONFIG5 0x000f1111
#define STNOR_GPMC_CONFIG6 0x0f030080
static const u32 gpmc_nor[7] = {
STNOR_GPMC_CONFIG1,
STNOR_GPMC_CONFIG2,
STNOR_GPMC_CONFIG3,
STNOR_GPMC_CONFIG4,
STNOR_GPMC_CONFIG5,
STNOR_GPMC_CONFIG6, 0
};

static ssize_t fpga_write(struct file *filp, const char __user *buff,
size_t count, loff_t *f_pos)
{
ssize_t status;
size_t len = USER_BUFF_SIZE - 1;
int i,tmp;

if (count == 0)
return 0;

if (down_interruptible(&fpga_dev.sem))
return -ERESTARTSYS;

if (len > count)
len = count;

memset(fpga_dev.user_buff, 0, USER_BUFF_SIZE);

if (copy_from_user(fpga_dev.user_buff, buff, len)) {
status = -EFAULT;
goto fpga_write_done;
}

/* do something with the user data */

printk("fpga_write \n");
for (i = 0; i < len; i=i+2) {
tmp = fpga_dev.user_buff?| fpga_dev.user_buff[i+1] << 8;?
writew(tmp,fpga_base+i);
}

for (i = 0; i < len; i++) {
printk("0x%x ",fpga_dev.user_buff);?
}

printk("\n");

fpga_write_done:

up(&fpga_dev.sem);

return status;
}

static ssize_t fpga_read(struct file *filp, char __user *buff,?
size_t count, loff_t *offp)
{
ssize_t status;
size_t len;
// int i,tmp;

/*?
Generic user progs like cat will continue calling until we?
return zero. So if *offp != 0, we know this is at least the
second call.
*/
if (*offp > 0)
return 0;

if (down_interruptible(&fpga_dev.sem))?
return -ERESTARTSYS;

strcpy(fpga_dev.user_buff, "fpga driver data goes here\n");

len = strlen(fpga_dev.user_buff);

if (len > count)
len = count;

if (copy_to_user(buff, fpga_dev.user_buff, len)) {
status = -EFAULT;
goto fpga_read_done;
}

fpga_read_done:

up(&fpga_dev.sem);

return status; 
}

static int fpga_open(struct inode *inode, struct file *filp)
{ 
int status = 0;

if (down_interruptible(&fpga_dev.sem))?
return -ERESTARTSYS;

if (!fpga_dev.user_buff) {
fpga_dev.user_buff = kmalloc(USER_BUFF_SIZE, GFP_KERNEL);

if (!fpga_dev.user_buff) {
printk(KERN_ALERT "fpga_open: user_buff alloc failed\n");
status = -ENOMEM;
}
}

up(&fpga_dev.sem);

return status;
}

static const struct file_operations fpga_fops = {
.owner = THIS_MODULE,
.open = fpga_open, 
.read = fpga_read,
.write = fpga_write,
};

static int __init fpga_init_cdev(void)
{
int error;
u32 val;

fpga_dev.devt = MKDEV(0, 0);

error = alloc_chrdev_region(&fpga_dev.devt, 0, 1, "fpga");
if (error) {
printk(KERN_ALERT "alloc_chrdev_region() failed: %d\n", error);
return error;
}

cdev_init(&fpga_dev.cdev, &fpga_fops);
fpga_dev.cdev.owner = THIS_MODULE;

error = cdev_add(&fpga_dev.cdev, fpga_dev.devt, 1);
if (error) {
printk(KERN_ALERT "cdev_add() failed: %d\n", error);
unregister_chrdev_region(fpga_dev.devt, 1);
return error;
}

printk("Getting Chip Select\n");

// val = 0xf64;
// gpmc_cs_write_reg(GPMC_CS, GPMC_CS_CONFIG7, val);
//gpmc_base = ioremap(GPMC_BASE_ADDR, SZ_4K);
val = gpmc_read_reg(GPMC_REVISION);
printk("GPMC revision %d.%d\n", (val >> 4) & 0x0f, val & 0x0f);


gpmc_write_reg(GPMC_IRQENABLE, 0);
gpmc_write_reg(GPMC_TIMEOUT_CONTROL, 0);


gpmc_cs_write_reg(GPMC_CS, GPMC_CS_CONFIG1, gpmc_nor[0]);
gpmc_cs_write_reg(GPMC_CS, GPMC_CS_CONFIG2, gpmc_nor[1]);
gpmc_cs_write_reg(GPMC_CS, GPMC_CS_CONFIG3, gpmc_nor[2]);
gpmc_cs_write_reg(GPMC_CS, GPMC_CS_CONFIG4, gpmc_nor[3]);
gpmc_cs_write_reg(GPMC_CS, GPMC_CS_CONFIG5, gpmc_nor[4]);
gpmc_cs_write_reg(GPMC_CS, GPMC_CS_CONFIG6, gpmc_nor[5]);

val = gpmc_cs_read_reg(GPMC_CS, GPMC_CS_CONFIG7);
printk("GPMC_CS_CONFIG7 value 0x%x\n", val);

if (gpmc_cs_request(GPMC_CS, SZ_2K, (unsigned long *)&mem_base) < 0)?{
printk(KERN_ERR "Failed request for GPMC mem for usrp_e\n");
return -1;
}
printk("Got CS0, address = %lx\n", mem_base);

if (!request_mem_region(mem_base, SZ_2K, "mem_fpga"))?{
printk(KERN_ERR "Request_mem_region failed.\n");
gpmc_cs_free(GPMC_CS);
return -1;
}

fpga_base = ioremap(mem_base, SZ_2K); 




return 0;
}

static int __init fpga_init_class(void)
{
struct device *device;

fpga_dev.class = class_create(THIS_MODULE, "fpga");

if (IS_ERR(fpga_dev.class)) {
printk(KERN_ALERT "class_create(fpga) failed\n");
return PTR_ERR(fpga_dev.class);
}

device = device_create(fpga_dev.class, NULL, fpga_dev.devt, NULL,?
"fpga");

if (IS_ERR(device)) {
class_destroy(fpga_dev.class);
return PTR_ERR(device);
}

return 0;
}

static int __init fpga_init(void)
{
printk(KERN_INFO "fpga_init()\n");

memset(&fpga_dev, 0, sizeof(struct fpga_dev));

sema_init(&fpga_dev.sem, 1);

if (fpga_init_cdev())
goto init_fail_1;

if (fpga_init_class())
goto init_fail_2;

return 0;

init_fail_2:
cdev_del(&fpga_dev.cdev);
unregister_chrdev_region(fpga_dev.devt, 1);

init_fail_1:

return -1;
}
module_init(fpga_init);

static void __exit fpga_exit(void)
{
printk(KERN_INFO "fpga_exit()\n");

device_destroy(fpga_dev.class, fpga_dev.devt);
class_destroy(fpga_dev.class);

cdev_del(&fpga_dev.cdev);
unregister_chrdev_region(fpga_dev.devt, 1);

release_mem_region(mem_base, SZ_2K);
gpmc_cs_free(GPMC_CS);
iounmap(fpga_base);

if (fpga_dev.user_buff)
kfree(fpga_dev.user_buff);
}
module_exit(fpga_exit);


MODULE_AUTHOR("chenzhufly");
MODULE_DESCRIPTION("fpga driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_VERSION("0.1");

復制代碼

7. GPMC應用程序設計，目前只實現了beaglebone向FPGA寫的流程

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>

#define FPGA_DEV "/dev/fpga"
#define PAGE_SIZE 10


int main(void)
{
int fd,i,res;
unsigned char buf[PAGE_SIZE];

printf("GPMC Test version 1.0-BeagleBone Build on %s %s\n\r",__DATE__,__TIME__);?
fd=open(FPGA_DEV,O_RDWR);
if(fd<0)
{
printf("Can't Open %s !!!\n\r",FPGA_DEV);
return -1;
}


for(i=0;i<sizeof(buf);i++)
{
buf?= i;
}

write(fd,&buf,PAGE_SIZE);

close(fd);
return 0;

}

復制代碼

8. FPGA相關設計

ARM和FPGA的管腳分配如下圖所示?
FPGA簡要代碼如下所示：

module interface_test
(
input clk, 
input ebgcs,?
input eboe,?
input ebwe,?
input [11:0]ebaddr,

input [15:0]ebdata,

output led,
output led1

);


wire [15:0] ram_q;
wire ram_wren;
wire ram_rden;

assign ram_wren = ((ebgcs == 1'b0) && (ebwe == 1'b0)) ? 1'b1 : 1'b0;
assign ram_rden = ((ebgcs == 1'b0) && (eboe == 1'b0)) ? 1'b1 : 1'b0;

TestRam testram_inst (
.clock ( clk),
.data ( ebdata[15:0] ),
.rdaddress ( ebaddr[11:1] ),
.rden ( ram_rden ),
.wraddress ( ebaddr[11:1] ),
.wren ( ram_wren ),
.q ( ram_q[15:0] )
);

wire ARM_READ_REG_EN;
assign ARM_READ_REG_EN = ((ebgcs == 1'b0) && (eboe == 1'b0) && (ebaddr[11:1] == 11'b111_1111_1111)) ? 1'b1 : 1'b0;
assign led1 = ARM_READ_REG_EN ? 1'b1 :
ram_rden ? ram_q[0] : 1'bz;

endmodule

復制代碼

FPGA管腳分配如下所示：

set_location_assignment PIN_89 -to ebaddr[0]
set_location_assignment PIN_90 -to ebaddr[1]
set_location_assignment PIN_87 -to ebaddr[2]
set_location_assignment PIN_88 -to ebaddr[3]
set_location_assignment PIN_84 -to ebaddr[4]
set_location_assignment PIN_86 -to ebaddr[5]
set_location_assignment PIN_81 -to ebaddr[6]
set_location_assignment PIN_82 -to ebaddr[7]
set_location_assignment PIN_63 -to ebaddr[8]
set_location_assignment PIN_67 -to ebaddr[9]
set_location_assignment PIN_64 -to ebaddr[10]
set_location_assignment PIN_68 -to ebaddr[11]


set_location_assignment PIN_60 -to ebdata[0]
set_location_assignment PIN_59 -to ebdata[1]
set_location_assignment PIN_28 -to ebdata[2]
set_location_assignment PIN_30 -to ebdata[3]
set_location_assignment PIN_58 -to ebdata[4]
set_location_assignment PIN_57 -to ebdata[5]
set_location_assignment PIN_24 -to ebdata[6]
set_location_assignment PIN_27 -to ebdata[7]
set_location_assignment PIN_47 -to ebdata[8]
set_location_assignment PIN_40 -to ebdata[9]
set_location_assignment PIN_41 -to ebdata[10]
set_location_assignment PIN_45 -to ebdata[11]
set_location_assignment PIN_39 -to ebdata[12]
set_location_assignment PIN_37 -to ebdata[13]
set_location_assignment PIN_44 -to ebdata[14]
set_location_assignment PIN_43 -to ebdata[15]

set_location_assignment PIN_61 -to ebgcs
set_location_assignment PIN_33 -to eboe
set_location_assignment PIN_35 -to ebwe


set_location_assignment PIN_23 -to clk
set_location_assignment PIN_31 -to led
set_location_assignment PIN_34 -to led1

復制代碼

9. 測試結果BeagleBone向EE_FPGA寫0，1，2，3，4，5，6，7，8，9；通過signaltap抓的結果。?

備注：實際項目中只使用了其初始化，應用程序只操作內存就好。GPMC其實很簡單，就是只要向相應的GPMC_CS所申請的內存中丟數據，GPMC相應的片選會自動拉低。

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