am335x 内核源码分析2 LCD移植

来源：互联网发布：网络盒子加密软件编辑：程序博客网时间：2024/05/16 11:16

1、/arch/arm/mach-omap2/board-am335xevm.c/lcdc_init(){得到LCD硬件参数struct da8xx_lcdc_platform_data} -> am33xx_register_lcdc() -> omap_device_build() -> omap_device_build_ss() -> platform_device_add_data(){pdev->dev.platform_data = d}

2、platform_device端注册过程：

omap_device_build_ss(){pdev = platform_device_alloc(pdev_name, pdev_id);} -> omap_device_register() -> platform_device_add()

3、platform_device设备名确定过程：

am33xx_register_lcdc(){char *dev_name = “da8xx_lcdc”;} -> omap_device_build() -> omap_device_build_ss(){pdev = platform_device_alloc(pdev_name, pdev_id);}

4、通过设备名搜索找到设备驱动文件: drivers/video/da8xx-fb.c

5、board-am335xevm.c记录的屏的类型有：

.type = “TFC_S9700RTWV35TR_01B“,

.type = “NHD-4.3-ATXI#-T-1”,

da8xx-fb.c记录的屏的类型有：

.name = “Sharp_LCD035Q3DG01”,

.name = “Sharp_LK043T1DG01”,

.name = “TFC_S9700RTWV35TR_01B“,

.name = “NHD-4.3-ATXI#-T-1”,

6、配置驱动程序进入fb_probe()获取LCD硬件参数用于配置struct da8xx_lcdc_platform_data：

struct da8xx_lcdc_platform_data *fb_pdata = device->dev.platform_data;

7、匹配合适的屏，并输出屏的类型(通过dmesg查看匹配信息是否正确)，否则退出驱动:

{

if (i == ARRAY_SIZE(known_lcd_panels)) {

dev_err(&device->dev, “GLCD: No valid panel found\n”);

ret = -ENODEV;

goto err_pm_runtime_disable;

} else

dev_info(&device->dev, “GLCD: Found %s panel\n”,

fb_pdata->type);

}

8、fb_probe()接下来复位LCD并配置硬件参数，最后申请fb_info注册framebuffer设备

9、硬件资源设置：

am33xx_register_lcdc(){oh = omap_hwmod_lookup(oh_name);} -> omap_device_build(…struct omap_hwmod *oh,…){struct omap_hwmod *ohs[] = { oh };} -> omap_device_build_ss(…struct omap_hwmod **ohs,…) -> omap_device_alloc(…struct omap_hwmod **ohs,…){od->hwmods = hwmods(来至于参数ohs);} -> omap_device_fill_resources(od, res){omap_hwmod_fill_resources(od->hwmods[i], res){填充 struct resource}} -> platform_device_add_resources(){pdev->resource = r;}

10、资源来源omap_hwmod：

omap_hwmod_lookup(oh_name) -> _lookup(name) -> 遍历链表omap_hwmod_list并返回struct omap_hwmod

11、被返回的返回struct omap_hwmod来至于：

MACHINE_START -> am33xx_init_early() -> am33xx_hwmod_init() -> omap_hwmod_register(){将am33xx_lcdc_hwmod添加到omap_hwmod_list链表当中}

static struct omap_hwmod am33xx_lcdc_hwmod = {

……

.slaves = am33xx_lcdc_slaves,//记录了物理起始地址

……

};

12、总结：两个数据结构共同决定LCD控制寄存器的配置参数：

static struct lcd_ctrl_config lcd_cfg = {

&disp_panel,

.ac_bias = 255,

.ac_bias_intrpt = 0,

.dma_burst_sz = 16,

.bpp = 32,

.fdd = 0x80,

.tft_alt_mode = 0,

.stn_565_mode = 0,

.mono_8bit_mode = 0,

.invert_line_clock = 1,

.invert_frm_clock = 1,

.sync_edge = 0,

.sync_ctrl = 1,

.raster_order = 0,

};

static struct da8xx_panel known_lcd_panels[] = {

[2] = {

.name = “TFC_S9700RTWV35TR_01B”,

.width = 800,

.height = 480,

.hfp = 39,

.hbp = 39,

.hsw = 47,

.vfp = 13,

.vbp = 29,

.vsw = 2,

.pxl_clk = 30000000,

.invert_pxl_clk = 0,

}

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