百问网 IMX6ULL-QEMU 的按键驱动程序(查询方式)

• 在 IMX6ULL QEMU 虚拟开发板上，我们为它设计了 2 个 按键
• 
• 只需修改框架的硬件相关代码 : board_100ask_imx6ull-qemu.c ```c /* 涉及的寄存器挺多，一个一个去执行 ioremap 效率太低。
  • 先定义结构体，然后对结构体指针进行 ioremap。
  • IOMUXC GPIO / struct iomux { volatile unsigned int unnames[23]; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_GPIO1_IO00; / offset 0x5c */ volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_GPIO1_IO01; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_GPIO1_IO02; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_GPIO1_IO03; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_GPIO1_IO04; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_GPIO1_IO05; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_GPIO1_IO06; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_GPIO1_IO07; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_GPIO1_IO08; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_GPIO1_IO09; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_UART1_TX_DATA; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_UART1_RX_DATA; volatile unsigned int IOMUXC_SW_MUX_CTL_PAD_UART1_CTS_B; };

struct imx6ull_gpio { volatile unsigned int dr; volatile unsigned int gdir; volatile unsigned int psr; volatile unsigned int icr1; volatile unsigned int icr2; volatile unsigned int imr; volatile unsigned int isr; volatile unsigned int edge_sel; };

/ enable GPIO1,GPIO5 / static volatile unsigned int *CCM_CCGR1;

/ set GPIO5_IO03 as GPIO / static volatile unsigned int *IOMUXC_SNVS_SW_MUX_CTL_PAD_SNVS_TAMPER1;

static struct iomux *iomux;

static struct imx6ull_gpio gpio1; static struct imx6ull_gpio gpio5;

static void board_imx6ull_button_init (int which) / 初始化button, which-哪个button /
{ if (!CCM_CCGR1) { CCM_CCGR1 = ioremap(0x20C406C, 4); IOMUXC_SNVS_SW_MUX_CTL_PAD_SNVS_TAMPER1 = ioremap(0x229000C, 4);

    iomux = ioremap(0x20e0000, sizeof(struct iomux));
    gpio1 = ioremap(0x209C000, sizeof(struct imx6ull_gpio));
    gpio5 = ioremap(0x20AC000, sizeof(struct imx6ull_gpio));
}
if (which == 0)
{
    /* 1. enable GPIO5 
     * CG15, b[31:30] = 0b11
     */
    *CCM_CCGR1 |= (3<<30);
    /* 2. set GPIO5_IO01 as GPIO 
     * MUX_MODE, b[3:0] = 0b101
     */
    *IOMUXC_SNVS_SW_MUX_CTL_PAD_SNVS_TAMPER1 = 5;
    /* 3. set GPIO5_IO01 as input 
     * GPIO5 GDIR, b[1] = 0b0
     */
    gpio5->gdir &= ~(1<<1);
}
else if(which == 1)
{
    /* 1. enable GPIO1 
     * CG13, b[27:26] = 0b11
     */
    *CCM_CCGR1 |= (3<<26);
    /* 2. set GPIO1_IO18 as GPIO 
     * MUX_MODE, b[3:0] = 0b101
     */
    iomux->IOMUXC_SW_MUX_CTL_PAD_UART1_CTS_B = 5;
    /* 3. set GPIO1_IO18 as input 
     * GPIO1 GDIR, b[18] = 0b0
     */
    gpio1->gdir &= ~(1<<18);
}

}

static int boardimx6ullbuttonread (int which) / 读button, which-哪个 / { //printk(“%s %s line %d, button %d, 0x%x\n”, FILE, _FUNCTION, __LINE, which, *GPIO1_DATAIN); if (which == 0) return (gpio5->psr & (1<<1)) ? 1 : 0; else return (gpio1->psr & (1<<18)) ? 1 : 0; }

static struct button_operations my_buttons_ops = { .count = 2, .init = board_imx6ull_button_init, .read = board_imx6ull_button_read, };

int board_imx6ull_button_drv_init(void) { register_button_operations(&my_buttons_ops); return 0; }

void board_imx6ull_button_drv_exit(void) { unregister_button_operations(); }

module_init(board_imx6ull_button_drv_init); module_exit(board_imx6ull_button_drv_exit);

MODULE_LICENSE(“GPL”); ```

• 先启动 IMX6ULL QEMU 模拟器，挂载 NFS 文件系统

运行 QEMU 时，
QEMU 内部为主机虚拟出一个网卡, IP 为 10.0.2.2，
IMX6ULL 有一个网卡, IP 为 10.0.2.15，
它连接到主机的虚拟网卡。
这样 IMX6ULL 就可以通过 10.0.2.2 去访问 Ubuntu 了。