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AM335X GPMC 編程問題

jiew
Expert 2272 points


請問

我依照下列流程在驅動源程序 config GPMC ,並透過應用程序控制

但寫資料時,實際量測波形,gpmc_ad0,ad1...動作都正確

但gpmc_csn1 卻無反應

請問是遺漏了什麼???

=================================== board-am335xevm.c

/*pin mux for FIFO writing*/
static struct pinmux_config fifo_pin_mux[] =
{
{"gpmc_ad0.gpmc_ad0", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad1.gpmc_ad1", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad2.gpmc_ad2", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad3.gpmc_ad3", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad4.gpmc_ad4", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad5.gpmc_ad5", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad6.gpmc_ad6", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad7.gpmc_ad7", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad8.gpmc_ad8", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad9.gpmc_ad9", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad10.gpmc_ad10", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad11.gpmc_ad11", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad12.gpmc_ad12", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad13.gpmc_ad13", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad14.gpmc_ad14", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},
{"gpmc_ad15.gpmc_ad15", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},

{"gpmc_csn1.gpio1_30", OMAP_MUX_MODE7 | AM33XX_PIN_OUTPUT},
{"gpmc_csn2.gpio1_31", OMAP_MUX_MODE7 | AM33XX_PIN_INPUT},
{"gpmc_csn3.gpio2_0", OMAP_MUX_MODE7 | AM33XX_PIN_INPUT},
{"gpmc_clk.gpio2_1", OMAP_MUX_MODE7 | AM33XX_PIN_OUTPUT},
{"lcd_vsync.gpio2_22", OMAP_MUX_MODE7 | AM33XX_PIN_OUTPUT},
{"lcd_pclk.gpio2_24", OMAP_MUX_MODE7 | AM33XX_PIN_OUTPUT},
{"gpmc_wen.gpmc_wen", OMAP_MUX_MODE0 | AM33XX_PULL_DISA},
{"gpmc_ben1.gpmc_dir", OMAP_MUX_MODE4 | AM33XX_PULL_DISA},

{NULL, 0},
};

...

===================================  gpmc driver

#define GPMC_CS 1

...


//配置GPMC 寄存器
val = gpmc_cs_read_reg(GPMC_CS, GPMC_CS_CONFIG7);
val &= ~GPMC_CONFIG7_CSVALID; /*disable chip-select*/
gpmc_cs_write_reg(GPMC_CS, GPMC_CS_CONFIG7, val);

gpmc_cs_configure(GPMC_CS, GPMC_SET_IRQ_STATUS, 0); /*set irq status*/
gpmc_cs_configure(GPMC_CS, GPMC_ENABLE_IRQ, 0); /*disable irqs*/

gpmc_cs_write_reg(GPMC_CS,GPMC_CS_CONFIG1, GPMC_CONFIG1_READTYPE_ASYNC | /*set read type Asynchronous*/
GPMC_CONFIG1_WRITETYPE_ASYNC | /*set write type Asynchronous*/
GPMC_CONFIG1_DEVICESIZE_16 | /*set device size 16bit*/
GPMC_CONFIG1_DEVICETYPE_NOR | /*set device type NOR*/
GPMC_CONFIG1_FCLK_DIV3); /*GPMC_CLK frequency=GPMC_FCLK frequency/3*/
val = gpmc_cs_read_reg(GPMC_CS, GPMC_CS_CONFIG1);
val &= NONE_MUXADDATA; /*Non-multiplexed attached device*/
gpmc_cs_write_reg(GPMC_CS, GPMC_CS_CONFIG1, val);

ret = gpmc_cs_set_timings(GPMC_CS, &fifo_timings); /*set timing parameters*/


// 申請gpmc 片選空間並用ioremap 函數映射為內核虛擬地址
/*********** 為FIFO 申請GPMC chip-select 空間**********/
if (gpmc_cs_request(GPMC_CS, FIFO_SIZE, &mem_base)<0)
{
printk(KERN_ERR "gpmc_cs_request failed.\n");
return -1;
}
/*********** 為FIFO 申請虛擬內存空間**********/
if (!request_mem_region(mem_base, FIFO_SIZE, GPMC_DRIVER_NAME))
{
printk(KERN_ERR "request_mem_region failed.\n");
return -1;
}
/****** 物理地址映射為虛擬地址*****/
fifo_base = ioremap (mem_base, FIFO_SIZE);

  • 0
    Mastermind 9486 points

    val = gpmc_cs_read_reg(GPMC_CS, GPMC_CS_CONFIG7);
    val &= ~GPMC_CONFIG7_CSVALID; /*disable chip-select*/
    gpmc_cs_write_reg(GPMC_CS, GPMC_CS_CONFIG7, val);

  • 0 回复 leo chen
    Expert 2272 points

    Dear Leo

    TRM有提到

    在設定 GPMC相關Reg時,須將Chip select 關閉

    Chip-select configuration (base and mask address or any protocol and timing settings) must be performed
    while the associated chip-select is disabled through the GPMC_CONFIG7_i[6] CSVALID bit. In addition, a
    chip-select configuration can only be disabled if there is no ongoing access to that chip-select. This
    requires activity monitoring of the prefetch or write-posting engine if the engine is active on the chip-select.
    Also, the write buffer state must be monitored to wait for any posted write completion to the chip-select.

    我也有試過後完成設定 GPMC相關Reg後將Chip select打開

    val = gpmc_cs_read_reg(GPMC_CS, GPMC_CS_CONFIG7);
    val |= GPMC_CONFIG7_CSVALID; /*disable chip-select*/
    gpmc_cs_write_reg(GPMC_CS, GPMC_CS_CONFIG7, val);

    但是insmod時卻產生一堆錯誤!!

    請問正確流程是要在何時將cs打開呢?

    感謝...

  • 0 回复 jiew
    Mastermind 9486 points

    把配置GPMC_CS_CONFIG7去掉试试

    这个好像在gpmc_cs_request中使能的

  • 0
    Prodigy 150 points

    我也遇到同样的问题了，CS没有反映，我注意到GPMC_CONFIG7_i Field Descriptions有这么一说，当片选为0到3时，片选的精度为16M，是不是说这个3个片选的首地址要从16M处开始，而我的外设不需要那么宽，是不是应该选择其他片选（CS > 3)。所以虽然地址有动作，但是并不在片选的范围内，所以CS没有动作。

    5-0            BASEADDRESS             0-3Fh        Chip-select base address.     CSi base address where i = 0 to 3 (16 Mbytes minimum granularity). Bits [5-0] corresponds  to A29, A28, A27, A26, A25, and A24.

    但是我把gpmc_cs_request(3,SZ_16M,(unsigned long *)&phy_base)，改为 gpmc_cs_request(6,SZ_16M,(unsigned long *)&phy_base)得到phy_base一样都是0x1000000。

  • 0 回复 leo chen
    Expert 2272 points

    Dear Leo

    去掉後,CS 一樣無法出來

    另外再請教

    我使用BB Black測試

    我GPMC時序設定如下,除GPMC外其餘都未修改

    static struct gpmc_timings fifo_timings =
    {
    /*GPMC timing configurations*/
    .sync_clk = 0,

    .cs_on = 0, /* Assertion time */
    .cs_rd_off = 82, /* Read deassertion time */
    .cs_wr_off = 82, /* Write deassertion time */

    .we_on = 40, /* WE assertion time */
    .we_off = 40, /* WE deassertion time */

    .oe_on = 40, /* OE assertion time */
    .oe_off = 40, /* OE deassertion time */
    .access = 50, /* Start-cycle to first data valid delay */
    .rd_cycle = 82, /* Total read cycle time */
    .wr_cycle = 82, /* Total write cycle time */
    };

    為什麼出來的gpmc_wen 訊號 low    |_|   寬度為52ns????

  • 0 回复 jiew
    Prodigy 150 points

    片选跟你读写的地址有关系，你应该看下你片选的mem_base物理地址是好多，还有片选大小，也就是config7，你可以打印出来看下这个值是多少，然后对照读写的地址看是否在这个区间。

    http://blog.csdn.net/qq405180763/article/details/7616941 我的不知道为什么申请的片选基地址都是从0x1000000开始，于是我把GPMC_A8复用为GPMC_A24，然后我在驱动中循环对一个地址写操作，用示波器就能看到CS动作了。

  • 0 回复 liu yang2
    Expert 2272 points

    經由您的提醒,我後發現是我pinmux_config弄錯了

    修改後就可以送出gpmc_times結構所定義的時序了(但cs有點誤差)

  • 0 回复 jiew
    Mastermind 9486 points

    解决了没？

  • 0 回复 leo chen
    Expert 2272 points

    Dear Leo

    解決了~~~^^

  • 0 回复 jiew
    Intellectual 534 points

    我调用gpmc_cs_request(GPMC_CS, SZ_4M, (unsigned long *)&mem_base命令，得到基地址为0x1000000大小为16M。之前我没有设置过GPMC_CONFIG1_7,是SDK的默认配置吗，在哪里可以修改，求详解。

  • 0 回复 liu yang2
    Prodigy 71 points

    GPMC_A8复用为GPMC_A24


    请问一下，这个复用的时候，寄存器的值是如何设置的呢？

  • 0 回复 jiew
    Prodigy 71 points

    请问一下，是哪个管脚的复用出问题了？正确的配置应该是怎么样的呢？

  • 0 回复 sktor
    Mastermind 9486 points

    类似于这样的设置，自己找一些呗

    {"gpmc_ad6.gpmc_ad6", OMAP_MUX_MODE0 | AM33XX_PIN_OUTPUT},

  • 0
    Intellectual 330 points

    请问下你的这个配置是用来和FPGA通信吗？如果是，我想请教下你，你的硬件上怎么和FPGA连接的？