am335x 内核源码分析2 LCD移植

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,

       },

}