Re: [PATCH] platform/chrome: chromeos_laptop - do not probe devices on Pixel 1

From: Benson Leung
Date: Thu Apr 09 2015 - 17:57:31 EST

On Thu, Apr 9, 2015 at 1:39 PM, Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
> Atmel MXT devices use different i2c addresses, depending on the current
> mode of operation (bootloader or application). The Atmel MXT driver
> expects i2c client's address contain the application address of the
> chip, and calculates the expected bootloader address form the
> application address. Unfortunately chrome_laptop does probe the devices


> and if touchpad (or touchscreen, or both) comes up in bootloader mode
> the i2c device gets instantiated with the bootloader address, instead of
> application address, which confuses the driver.
> Given that hardware on Pixel is set and is not going to change let's not
> try to probe devices to see if they are present or not, but rather
> instantiate them always at expected addresses.
> Since all devices are now probed and/or instantiated at given address,
> we no longer need to support probing multiple addresses for the same
> device.
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> ---

Also, since we no longer probe for the bootloader addresses, you
should remove the following two unused defines too :
#define ATMEL_TP_I2C_BL_ADDR 0x25
#define ATMEL_TS_I2C_BL_ADDR 0x26

Otherwise :
Reviewed-by: Benson Leung <bleung@xxxxxxxxxxxx>

Benson Leung
Software Engineer, Chrom* OS
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