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器件型号：AM625 工具与软件：
尊敬的支持部门：
我正在 am62上的定制电路板上评估 LCD (DPI、RGB888)。
如何将数据输出的时钟极性更改为上升沿驱动？
以下情况得到确认：
1.在 panel-simple.c 中的结构 panel_desc 中将"drm_BUS_FLAG_PIXDATA_DRIVE_POSedge"设置为".bus_FLAGS"
结果：IPC 寄存器被确认为"0"、但 DPI0_CLK_CTRL_DATA_CLK_INVDIS 为"0"。
是否应该将 DPI0_CLK_CTRL_DATA_CLK_INVDIS 设置为1？
从 Linux 中读取寄存器值。
root@am62xx-custom:~# devmem2 0x3020B04C w /dev/mem opened. Memory mapped at address 0xffffafc72000. Read at address 0x3020B04C (0xffffafc7204c): 0x00063000 root@am62xx-custom:~# devmem2 0x00108300 w /dev/mem opened. Memory mapped at address 0xffffa1837000. Read at address 0x00108300 (0xffffa1837300): 0x00000000
波形如下： (CH1：CLK、CH2：DATA)
数据在时钟的下降沿输出。 实际上、数据应该在时钟的上升沿输出。
2.将 "drm_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE"设置为 panel-simple.c 上结构体 panel desc 中的".bus_FLAGS"
结果：IPC 寄存器被确认为"1"、但 DPI0_CLK_CTRL_DATA_CLK_INVDIS 为"0"。
从 Linux 中读取寄存器值
root@am62xx-custom:~# devmem2 0x3020B04C w /dev/mem opened. Memory mapped at address 0xffff9f4a3000. Read at address 0x3020B04C (0xffff9f4a304c): 0x00067000 root@am62xx-custom:~# devmem2 0x00108300 w /dev/mem opened. Memory mapped at address 0xffff84d14000. Read at address 0x00108300 (0xffff84d14300): 0x00000000
波形如下：
数据在时钟的下降沿输出。 (CH1：CLK、CH2：DATA)
[参考]
SoC：AM6251
电路板：定制电路板
SDK：SDK-AM62X PROCESSOR-SDK-LINUX-RT (版本09.02.01.10)
液晶屏：P0700WVN1MB00 (天马)
设备驱动程序：Panel-simple.c ("CONFIG_DRM_Panel_SIMPLE)
# For LCD timing, add the following to panel-simple.c
@@ -4027,6 +4036,36 @@ static const struct panel_desc yes_optoelectronics_ytc700tlag_05_201c = {
.connector_type = DRM_MODE_CONNECTOR_LVDS,
};
+static const struct drm_display_mode tianma_P0700WVN1MB00_mode = {
+ .clock = 33300,
+ .hdisplay = 800,
+ .hsync_start = 800 + 210,
+ .hsync_end = 800 + 210 + 20,
+ .htotal = 800 + 210 + 20 + 26,
+ .vdisplay = 480,
+ .vsync_start = 480 + 22,
+ .vsync_end = 272 + 22 + 3,
+ .vtotal = 272 + 22 + 3 + 20,
+ .flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
+};
+
+static const struct panel_desc tianma_P0700WVN1MB00 = {
+ .modes = &tianma_P0700WVN1MB00_mode,
+ .num_modes = 1,
+ .bpc = 8,
+ .size = {
+ .width = 154,
+ .height = 86,
+ },
+ .delay = {
+ .prepare = 25,
+ .enable = 100,
+ },
+ .bus_format = MEDIA_BUS_FMT_RGB888_1X24,
+ .bus_flags = DRM_BUS_FLAG_DE_LOW,
+ .connector_type = DRM_MODE_CONNECTOR_DPI,
+};
+
@@ -4456,6 +4495,9 @@ static const struct of_device_id platform_of_match[] = {
}, {
.compatible = "yes-optoelectronics,ytc700tlag-05-201c",
.data = &yes_optoelectronics_ytc700tlag_05_201c,
+ }, {
+ .compatible = "tianma,P0700WVN1MB00",
+ .data = &tianma_P0700WVN1MB00,
}, {
/* Must be the last entry */
.compatible = "panel-dpi",
此致、
最终目的
