Re: [PATCH] touchscreen: stmpe-ts: enable module autoload

Am 22.05.2015 um 22:17 schrieb Dmitry Torokhov:

On Fri, May 22, 2015 at 09:01:50PM +0200, Heiner Kallweit wrote:

quoted

Am 22.05.2015 um 20:29 schrieb Dmitry Torokhov:

quoted

On Fri, May 22, 2015 at 07:34:43AM +0200, Heiner Kallweit wrote:

quoted

Am 22.05.2015 um 01:06 schrieb Dmitry Torokhov:

quoted

Hi Heiner,

On Thu, May 21, 2015 at 11:19:52PM +0200, Heiner Kallweit wrote:

quoted

Even with poper DT config the module didn't autoload.
That's fixed by this additional alias.

Tested successfully with a STMPE610-based Adafruit PITFT Plus 3.5"
on RPI2 under Arch Linux ARM (kernel 3.18.13).

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/input/touchscreen/stmpe-ts.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c
index e4c3125..1940e3c 100644
--- a/drivers/input/touchscreen/stmpe-ts.c
+++ b/drivers/input/touchscreen/stmpe-ts.c

@@ -393,4 +393,5 @@ module_platform_driver(stmpe_ts_driver);
 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
 MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
 MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:" STMPE_TS_NAME);
 MODULE_ALIAS("platform:" STMPE_TS_NAME);

Bit this is not an SPI driver, it is a platform driver for a MFD cell.
Why does adding SPI alias help?

Thanks.

The STMPE610 in my case is used on a small touchscreen for the Raspberry Pi
and touchscreen controller as well as display controller are connected via
SPI + a few GPIOs to the RPI.

The display controller is supported by the fbtft driver and the drivers
for the respective display controllers have similar aliases.
see e.g. drivers/staging/fbtft/fb_hx8353d.c

MODULE_ALIAS("spi:hx8353d");
MODULE_ALIAS("platform:hx8353d");

I understand why both platform and spi aliases are needed for
fb_hx8353d: FBTFT_REGISTER_DRIVER macro does register 2 separate
drivers, one SPI and another platform, and so needs both aliases. You
still have not explained why we need SPI alias for stmpe-ts which is MFD
cell represented by a platform device/driver no matter what bus is used
to connect stmpe itself, I2C or SPI.

What is the modalias on the stmpe-ts device in sysfs?

Thanks.

These are the stmpe-related entries under /sys/devices:

./soc/3f204000.spi/spi_master/spi0/spi0.1/stmpe-gpio
./soc/3f204000.spi/spi_master/spi0/spi0.1/stmpe-ts

stmpe-ts/modalias is:
of:Nstmpe_touchscreenT<NULL>Cst,stmpe-ts

OK, that explains it. Does the patch below help?

Thanks.

Yes, with your patch autoloading works. Thanks.