新路程------imx6的uart小结(1)

本文主要是介绍新路程------imx6的uart小结(1)，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

imx6用的是RS485，今天看看这个接口是怎么初始化的。

首先在./arch/arm/mach-mx6/board-mx6q_sabresd.c里找uart的相关信息

在static void __init mx6_sabresd_board_init(void)肯定会有初始化的相关信息

        gpio_request(SABRESD_EPDC_PWRSTAT, "uart2_en"); 申请gpio
gpio_direction_output(SABRESD_EPDC_PWRSTAT, 1);  设置输入输出gpio_set_value(SABRESD_EPDC_PWRSTAT, 1);  设置初始电平gpio_request(SABRESD_EPDC_PWRCTRL0, "uart2_rts");gpio_direction_output(SABRESD_EPDC_PWRCTRL0, 1);gpio_set_value(SABRESD_EPDC_PWRCTRL0, 1);gpio_request(SABRESD_EPDC_PWRCTRL1, "uart3_en");gpio_direction_output(SABRESD_EPDC_PWRCTRL1, 1);gpio_set_value(SABRESD_EPDC_PWRCTRL1, 1);mx6q_sabresd_init_uart();

这里找到了之后，看看mx6q_sabresd_init_uart()

static const struct imxuart_platform_data mx6q_sd_uart3_data __initconst = {
	.flags      = IMXUART_HAVE_RTSCTS,
	.dma_req_rx = MX6Q_DMA_REQ_UART3_RX,
	.dma_req_tx = MX6Q_DMA_REQ_UART3_TX,
};

static inline void mx6q_sabresd_init_uart(void)
{//imx6q_add_imx_uart(2, NULL);imx6q_add_imx_uart(0, NULL);imx6q_add_imx_uart(1, NULL);imx6q_add_imx_uart(2, &mx6q_sd_uart3_data);imx6q_add_imx_uart(3, NULL);imx6q_add_imx_uart(4, NULL);
}

再看看#define imx6q_add_imx_uart(id, pdata) \
imx_add_imx_uart_1irq(&imx6q_imx_uart_data[id], pdata)
接下来是

struct platform_device *__init imx_add_imx_uart_1irq(const struct imx_imx_uart_1irq_data *data,const struct imxuart_platform_data *pdata)
{struct resource res[] = {{.start = data->iobase,.end = data->iobase + data->iosize - 1,.flags = IORESOURCE_MEM,}, {.start = data->irq,.end = data->irq,.flags = IORESOURCE_IRQ,},};return imx_add_platform_device("imx-uart", data->id, res, ARRAY_SIZE(res),pdata, sizeof(*pdata));
}

之前只有uart2有pdata，所以也只有2有用
这个

#ifdef CONFIG_SOC_IMX6Q
const struct imx_imx_uart_1irq_data imx6q_imx_uart_data[] __initconst = {
#define imx6q_imx_uart_data_entry(_id, _hwid) \
imx_imx_uart_1irq_data_entry(MX6Q, _id, _hwid, SZ_4K)
imx6q_imx_uart_data_entry(0, 1),
imx6q_imx_uart_data_entry(1, 2),
imx6q_imx_uart_data_entry(2, 3),
imx6q_imx_uart_data_entry(3, 4),
imx6q_imx_uart_data_entry(4, 5),
};

#define imx_imx_uart_1irq_data_entry(soc, _id, _hwid, _size) \
[_id] = { \
.id = _id, \
.iobase = soc ## _UART ## _hwid ## _BASE_ADDR, \
.iosize = _size, \
.irq = soc ## _INT_UART ## _hwid, \
}