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path: root/include/linux/spi/ads7846.h
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2008-09-17Input: ads7846 - introduce .gpio_pendown to get pendown stateEric Miao
The GPIO connected to ADS7846 nPENIRQ signal is usually used to get the pendown state as well. Introduce a .gpio_pendown, and use this to decide the pendown state if .get_pendown_state is NULL. Signed-off-by: Eric Miao <eric.miao@marvell.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2008-04-02Input: ads7846 - simplify support of external vREF (and ads7843)David Brownell
This updates the ads7846 driver to handle external vREF (required on boards using ads7843 chips) without module parameters, and also removes a needless variable with its associated bogus gcc warning. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2007-07-18Input: ads7846 - re-check pendown status before reporting eventsSemih Hazar
Pendown status from the PENIRQ pin is currently read only at the beginning of a sample set. If the pen is lifted just after sampling has began then sampled values become wrong. This patch adds an optional platform penirq_recheck_delay attribute. If non-zero, samples are only reported to the input subsystem if PENIRQ is still active that long after the samples taken. Signed-off-by: Semih Hazar <semih.hazar@indefia.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2007-07-18Input: ads7846 - introduce sample settling delaySemih Hazar
The ads7846 driver has support for filtering, but when the chip gets deselected between samples this causes noise. This patch adds support for an optional settling delay time, so that two consecutive samples will be taken with the specified delay time apart. This ensures that the chip won't be deselected, so the noise won't appear. Filtering can still be done, but will have less work to do since each time a new sample is taken the same delay applies. Signed-off-by: Semih Hazar <semih.hazar@indefia.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2007-01-18Input: ads7846 - optionally leave Vref on during differential measurementsImre Deak
On some LCDs leaving the Vref on provides much better readings. Signed-off-by: Jarkko Oikarinen <jarkko.oikarinen@nokia.com> Signed-off-by: Imre Deak <imre.deak@solidboot.com> Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2007-01-18Input: ads7846 - pluggable filtering logicImre Deak
Some LCDs like the LS041Y3 require a customized filtering logic for reliable readings, so make the filtering function replacable through platform specific hooks. Signed-off-by: Imre Deak <imre.deak@solidboot.com> Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2006-04-26Input: ads7846 - improve filtering for thumb press accuracyImre Deak
Providing more accurate coordinates for thumb press requires additional steps in the filtering logic: - Ignore samples found invalid by the debouncing logic, or the ones that have out of bound pressure value. - Add a parameter to repeat debouncing, so that more then two consecutive good readings are required for a valid sample. Signed-off-by: Imre Deak <imre.deak@nokia.com> Acked-by: Juha Yrjola <juha.yrjola@nokia.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2006-04-11Input: ads7846 - handle IRQs that were latched during disabled IRQsImre Deak
The pen down IRQ will toggle during each X,Y,Z measurement cycle. Even though the IRQ is disabled it will be latched and delivered when after enable_irq. Thus in the IRQ handler we must avoid starting a new measurement cycle when such an "unwanted" IRQ happens. Add a get_pendown_state platform function, which will probably determine this by reading the current GPIO level of the pen IRQ pin. Move the IRQ reenabling from the SPI RX function to the timer. After the last power down message the pen IRQ pin is still active for a while and get_pendown_state would report incorrectly a pen down state. When suspending we should check the ts->pending flag instead of ts->pendown, since the timer can be pending regardless of ts->pendown. Also if ts->pending is set we can be sure that the timer is running, so no need to rearm it. Similarly if ts->pending is not set we can be sure that the IRQ is enabled (and the timer is not). Signed-off-by: Imre Deak <imre.deak@nokia.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2006-04-11Input: ads7846 - debouncing and rudimentary sample filteringImre Deak
Some touchscreens seem to oscillate heavily for a while after touching the screen.  Implement support for sampling the screen until we get two consecutive values that are close enough. Signed-off-by: Imre Deak <imre.deak@nokia.com> Signed-off-by: Juha Yrjola <juha.yrjola@nokia.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2006-01-13[PATCH] spi: ads7836 uses spi_driverDavid Brownell
This updates the ads7864 driver to use the new "spi_driver" struct, and includes some minor unrelated cleanup. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13[PATCH] spi: ads7846 driverDavid Brownell
This is a driver for the ADS7846 touchscreen sensor, derived from the corgi_ts and omap_ts drivers. Key differences from those two: - Uses the new SPI framework (minimalist version) - <linux/spi/ads7846.h> abstracts board-specific touchscreen info - Sysfs attributes for the temperature and voltage sensors - Uses fewer ARM-specific IRQ primitives The temperature and voltage sensors show up in sysfs like this: $ pwd /sys/devices/platform/omap-uwire/spi2.0 $ ls bus@ input:event0@ power/ temp1 vbatt driver@ modalias temp0 vaux $ cat modalias ads7846 $ cat temp0 991 $ cat temp1 1177 $ So far only basic testing has been done. There's a fair amount of hardware that uses this sensor, and which also runs Linux, which should eventually be able to use this driver. One portability note may be of special interest. It turns out that not all SPI controllers are happy issuing requests that do things like "write 8 bit command, read 12 bit response". Most of them seem happy to handle various word sizes, so the issue isn't "12 bit response" but rather "different rx and tx write sizes", despite that being a common MicroWire convention. So this version of the driver no longer reads 12 bit native-endian words; it reads 16-bit big-endian responses, then byteswaps them and shifts the results to discard the noise. Signed-off-by: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>