The power light has anything with the touch screen on IMX53 Tablet WinCE7

[holyyuan]

Hi, all.
Now ,I  find a problem of the iMX53 tablet PC, while I have a long press the  power button until the Windows CE7  system is off and the power light is off. Then, Restart the Tablet is good . But I have a press the power button until the system is off ,but the power light is nont off. then the system has some problem,that is when restart the board , the touch screen function is useless. You have to restart tiwce  to make sure the touch function is good.

Does it has something with the power management chips DA9053? THIS problem now even drive me crazy.

so , how can I get over this problem? Could any one  tell me or analyze the problem for me ?

Thank s alot

Best Regards.

Holy

[jamesbone]

I believe  this issue is caused by the  BSP does not handle the backlight enable signal - DCDC5V_BB_EN while power on or power down the system.

If you smd is revD, please remove R554 and apply below patch. If your board is Rev B just apply the patch.

diff --git a/arch/arm/mach-mx5/mx53_smd.c b/arch/arm/mach-mx5/mx53_smd.c

old mode 100644

new mode 100755

index 97ec0fb..6e6b550

--- a/arch/arm/mach-mx5/mx53_smd.c

+++ b/arch/arm/mach-mx5/mx53_smd.c

@@ -1225,8 +1225,16 @@ static void __init mx53_smd_io_init(void)

  /* mag3110 magnetometer sensor */

  gpio_request(MX53_SMD_eCOMPASS_INT, "ecompass int");

  gpio_direction_input(MX53_SMD_eCOMPASS_INT);

+

+ gpio_request(MX53_SMD_SYS_ON_OFF_CTL, "sys-on-off");

+ gpio_direction_output(MX53_SMD_SYS_ON_OFF_CTL, 1);

}

+void smd_power_off()

+{

+ gpio_direction_output(MX53_SMD_SYS_ON_OFF_CTL, 0);

+ da9053_power_off();

+}

/*!

  * Board specific initialization.

  */

@@ -1251,7 +1259,8 @@ static void __init mxc_board_init(void)

  mx53_smd_io_init();

  /* power off by sending shutdown command to da9053*/

- pm_power_off = da9053_power_off;

+ //pm_power_off = da9053_power_off;

+ pm_power_off = smd_power_off;

  mxc_register_device(&mxc_dma_device, NULL);

  mxc_register_device(&mxc_wdt_device, NULL);

  mxc_register_device(&mxcspi1_device, &mxcspi1_data);