kernel/linux.git/drivers/input/touchscreen/silead.c, branch v4.9.307

Input: silead - add workaround for x86 BIOS-es which bring the chip up in a stuck state

2021-05-22T08:40:34+00:00

[ Upstream commit e479187748a8f151a85116a7091c599b121fdea5 ] Some buggy BIOS-es bring up the touchscreen-controller in a stuck state where it blocks the I2C bus. Specifically this happens on the Jumper EZpad 7 tablet model. After much poking at this problem I have found that the following steps are necessary to unstuck the chip / bus: 1. Turn off the Silead chip. 2. Try to do an I2C transfer with the chip, this will fail in response to which the I2C-bus-driver will call: i2c_recover_bus() which will unstuck the I2C-bus. Note the unstuck-ing of the I2C bus only works if we first drop the chip of the bus by turning it off. 3. Turn the chip back on. On the x86/ACPI systems were this problem is seen, step 1. and 3. require making ACPI calls and dealing with ACPI Power Resources. This commit adds a workaround which runtime-suspends the chip to turn it off, leaving it up to the ACPI subsystem to deal with all the ACPI specific details. There is no good way to detect this bug, so the workaround gets activated by a new "silead,stuck-controller-bug" boolean device-property. Since this is only used on x86/ACPI, this will be set by model specific device-props set by drivers/platform/x86/touchscreen_dmi.c. Therefor this new device-property is not documented in the DT-bindings. Dmesg will contain the following messages on systems where the workaround is activated: [ 54.309029] silead_ts i2c-MSSL1680:00: [Firmware Bug]: Stuck I2C bus: please ignore the next 'controller timed out' error [ 55.373593] i2c_designware 808622C1:04: controller timed out [ 55.582186] silead_ts i2c-MSSL1680:00: Silead chip ID: 0x80360000 Signed-off-by: Hans de Goede Link: https://lore.kernel.org/r/20210405202745.16777-1-hdegoede@redhat.com Signed-off-by: Dmitry Torokhov Signed-off-by: Sasha Levin

Input: silead - try firmware reload after unsuccessful resume

2019-11-25T08:53:37+00:00

[ Upstream commit dde27443211062e841806feaf690674b7c3a599f ] A certain silead controller (Chip ID: 0x56810000) loses its firmware after suspend, causing the resume to fail. This patch tries to load the firmware, should a resume error occur and retries the resuming. Signed-off-by: Julian Sax Acked-by: Hans de Goede Signed-off-by: Dmitry Torokhov Signed-off-by: Sasha Levin

Input: silead_gsl1680 - use "silead/" prefix for firmware loading

2016-09-10T17:49:15+00:00

The silead touch-controller ICs use a different firmware per digitizer / tablet model. So there are going to be quite a few of then and they really should be under a separate subdir. This commit prefixes the default firmware names with "silead/" just like we are already doing for devicetree specified firmware names. Signed-off-by: Hans de Goede Signed-off-by: Dmitry Torokhov

Input: silead_gsl1680 - document firmware-name, fix implementation

2016-09-10T17:49:12+00:00

The driver has supported touchscreen-fw-name to specify the firmware to load since it has been merged, but this was omitted from the dt-binding documentation. During review of adding touchscreen-fw-name to the binding documentation it was brought up that there is a standard property name called "firmware-name" for this, which should be used. Since there are no users of touchscreen-fw-name yet, this commit adds documentation of "firmware-name" to the dt-binding documentation and switches the driver over to use this. This commit also makes the driver add a "silead/" prefix to the firmware name from dt before calling request_firmware. That the firmware files are stored under /lib/firmware/silead under Linux is an implementation detail and does not belong in devicetree. Signed-off-by: Hans de Goede Acked-by: Rob Herring Signed-off-by: Dmitry Torokhov

Input: silead - use devm_gpiod_get

2016-08-22T21:14:15+00:00

The silead code is using devm_foo for everything (and does not free any resources). Except that it is using gpiod_get instead of devm_gpiod_get (but is not freeing the gpio_desc), change this to use devm_gpiod_get so that the gpio will be properly released. Signed-off-by: Hans de Goede Signed-off-by: Dmitry Torokhov

Input: silead - remove some dead code

2016-08-04T15:28:11+00:00

buf[0] is an unsigned char. touch_nr is an int. The test for negative here doesn't make sense so I have removed it. Signed-off-by: Dan Carpenter Signed-off-by: Dmitry Torokhov

Input: add driver for Silead touchscreens

2016-08-03T06:37:49+00:00

This driver adds support for Silead touchscreens. It has been tested with GSL1680 and GSL3680 touch panels. It supports ACPI and device tree enumeration. Screen resolution, the maximum number of fingers supported and firmware name are configurable. Signed-off-by: Robert Dolca Signed-off-by: Daniel Jansen Signed-off-by: Hans de Goede Signed-off-by: Dmitry Torokhov