WhyCan Forum(哇酷开发者社区)

我有一份应用层屏驱可以点亮屏幕，它点屏只需要两步：
第一步：复位
         这是复位代码：       void lcd_st77916_reset(void)
                                   {
                                             system("echo PD8 1 > /sys/kernel/debug/sunxi_pinctrl/function");
                                             system("echo PD8 0 > /sys/kernel/debug/sunxi_pinctrl/data");
                                             usleep(10);
                                             system("echo PD8 1 > /sys/kernel/debug/sunxi_pinctrl/data");
                                    }

第二步：屏幕初始化
         前提条件：fd = open(“/dev/spidev1.0”, O_RDWR);
                     struct   qspi_lcd_cmd {
                                           uint8_t a ;
                                           uint8_t b ;
                                           uint8_t cmd;
                                           uint8_t c ;
                                           uint8_t param[16];
                             };
                   struct   qspi_lcd_cmd   cmd_tbl[] = {
                                                {0x02,0x00,0xf0,0x00,{0x08}},
                                                {0x02,0x00,0xf2,0x00,{0x08}},
                                                {0x02,0x00,0x9B,0x00,{0x51，0x33,0x44,0x55}},
                                                 .
                                                 .
                                                 .
                             };
         执行代码：for (int i = 0; i < sizeof(cmd_tbl) / sizeof(struct qspi_lcd_cmd); i++) 
                      _transfer(fd, cmd_tbl[i],  NULL, strlen(cmd_tbl[i]))
                      (就是把初始化命令和数据，一次发一行)
         这是部分代码：  static int _transfer(int fd, uint8_t const *tx, uint8_t const *rx, size_t len)
                              {
                                   int ret;
                                   int out_fd;
                                   struct spi_ioc_transfer tr = {
                                                .tx_buf = (unsigned long)tx,
                                                .rx_buf = (unsigned long)rx,
                                                .len = len,
                                                .delay_usecs = 0,
                                                .speed_hz = SPI_SPEED,
                                                .bits_per_word = 8,
                                                .tx_nbits = 1,
                                                .rx_nbits = 1 
                                              };

                                     ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);（这个不懂，我猜它是发送的函数，在其他地方看过一次）
                                     if (ret < 1)
                                       {
                                                 pabort("can't send spi message");
                                                 return -EIO;
                                      }
                        .
                        .
                        .
                      }

现在在fbtft的屏驱：
static int init_display(struct fbtft_par *par)
{
    printk(KERN_INFO "屏幕初始化 started.\n");
    mdelay(10);
    write_reg(par,0xF0,0x08);（这是最初这样的）
    write_reg(par,0xF2,0x08);（这是最初这样的）
    ....
    write_reg(par,0x02,0x00,0xF0,0x00,0x08);（这是我根据最初和我的情况改的）
    write_reg(par,0x02,0x00,0xF2,0x00,0x08);
    ...
}（write_reg有3个参数，par，sizeof（0x02,0x00,0xF0,0x00,0x08）/u8 , (0x02,0x00,0xF0,0x00,0x08) 这里经过宏定义，可变变量，变成了两个参数）
static int set_var(struct fbtft_par *par)
{
	u8 madctl_par = 0;
	if (par->bgr)
		madctl_par |= MADCTL_BGR;
	switch (par->info->var.rotate) {
	case 0:
		break;
	case 90:
		madctl_par |= (MADCTL_MV | MADCTL_MY);
		break;
	case 180:
		madctl_par |= (MADCTL_MX | MADCTL_MY);
		break;
	case 270:
		madctl_par |= (MADCTL_MV | MADCTL_MX);
		break;
	default:
		return -EINVAL;
	}
	write_reg(par, MIPI_DCS_SET_ADDRESS_MODE, madctl_par);
	return 0;
}
static int set_gamma(struct fbtft_par *par, unsigned long *curves)
{
	int i;
	int j;
	int c; /* curve index offset */
	const u8 gamma_par_mask[] = {
		0xFF, /* V63[3:0], V0[3:0]*/
		0x3F, /* V1[5:0] */
		0x3F, /* V2[5:0] */
		0x1F, /* V4[4:0] */
		0x1F, /* V6[4:0] */
		0x3F, /* J0[1:0], V13[3:0] */
		0x7F, /* V20[6:0] */
		0x77, /* V36[2:0], V27[2:0] */
		0x7F, /* V43[6:0] */
		0x3F, /* J1[1:0], V50[3:0] */
		0x1F, /* V57[4:0] */
		0x1F, /* V59[4:0] */
		0x3F, /* V61[5:0] */
		0x3F, /* V62[5:0] */
	};

	for (i = 0; i < par->gamma.num_curves; i++) {
		c = i * par->gamma.num_values;
		for (j = 0; j < par->gamma.num_values; j++)
			curves[c + j] &= gamma_par_mask[j];
		write_reg(
			par, PVGAMCTRL + i,
			curves[c + 0], curves[c + 1], curves[c + 2],
			curves[c + 3], curves[c + 4], curves[c + 5],
			curves[c + 6], curves[c + 7], curves[c + 8],
			curves[c + 9], curves[c + 10], curves[c + 11],
			curves[c + 12], curves[c + 13]);
	}
	return 0;
}

static int blank(struct fbtft_par *par, bool on)
{
	if (on)
		write_reg(par, MIPI_DCS_SET_DISPLAY_OFF);
	else
		write_reg(par, MIPI_DCS_SET_DISPLAY_ON);
	return 0;
}

static struct fbtft_display display = {
	.regwidth = 4,
	.width = 360,
	.height = 360,
	.gamma_num = 2,
	.gamma_len = 14,
	.gamma = DEFAULT_GAMMA,
	.fbtftops = {
		.init_display = init_display,
		.set_var = set_var,
		.set_gamma = set_gamma,
		.blank = blank,
	},
};

FBTFT_REGISTER_DRIVER(DRVNAME, "sitronix,st77916", &display);

MODULE_ALIAS("spi:" DRVNAME);
MODULE_ALIAS("platform:" DRVNAME);
MODULE_ALIAS("spi:st77916");
MODULE_ALIAS("platform:st77916");

MODULE_DESCRIPTION("FB driver for the st77916 LCD Controller");
MODULE_AUTHOR("Dennis Menschel");
MODULE_LICENSE("GPL");

fbtft-core.c文件

static int fbtft_request_one_gpio(struct fbtft_par *par,
				  const char *name, int index, int *gpiop)
{
	struct device *dev = par->info->device;
	struct device_node *node = dev->of_node;
	int gpio, flags, ret = 0;
	enum of_gpio_flags of_flags;

	if (of_find_property(node, name, NULL)) {
		printk(KERN_INFO "of_find_property  11111111111  over.\n");
		gpio = of_get_named_gpio_flags(node, name, index, &of_flags);
		printk(KERN_INFO "of_get_named_gpio_flags  11111111111  over.\n");
		if (gpio == -ENOENT)
			return 0;
		if (gpio == -EPROBE_DEFER)
			return gpio;
		if (gpio < 0) {
			dev_err(dev,
				"failed to get '%s' from DT\n", name);
			return gpio;
		}
.
.
.
.
.
}