diff options
| author | Brad Griffis <bgriffis@ti.com> | 2015-02-03 11:44:12 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2015-02-03 11:50:38 -0800 |
| commit | 344d635b9a41b19837ccf8083a99ea688027019c (patch) | |
| tree | f1b09497f07b3d825a66ba14f793d41605eedfdd /include/linux/mfd | |
| parent | 3a59684ccc5d529e7e9ce8b068889dbaa4c34e9b (diff) | |
Input: ti_am335x_tsc - remove udelay in interrupt handler
TSC interrupt handler had udelay to avoid reporting of false pen-up
interrupt to user space. This patch implements workaround suggesting in
Advisory 1.0.31 of silicon errata for am335x, thus eliminating udelay and
touchscreen lag. This also improves performance of touchscreen and
eliminates sudden jump of cursor at touch release.
IDLECONFIG and CHARGECONFIG registers are to be configured with same values
in order to eliminate false pen-up events. This workaround may result in
false pen-down to be detected, hence considerable charge step delay needs
to be added. The charge delay is set to 0xB000 (in terms of ADC clock
cycles) by default.
TSC steps are disabled at the end of every sampling cycle and EOS bit is
set. Once the EOS bit is set, the TSC steps need to be re-enabled to begin
next sampling cycle.
Signed-off-by: Brad Griffis <bgriffis@ti.com>
[vigneshr@ti.com: Ported the patch from v3.12 to v3.19rc1]
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'include/linux/mfd')
| -rw-r--r-- | include/linux/mfd/ti_am335x_tscadc.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h index e2e70053470e..3f4e994ace2b 100644 --- a/include/linux/mfd/ti_am335x_tscadc.h +++ b/include/linux/mfd/ti_am335x_tscadc.h @@ -52,6 +52,7 @@ /* IRQ enable */ #define IRQENB_HW_PEN BIT(0) +#define IRQENB_EOS BIT(1) #define IRQENB_FIFO0THRES BIT(2) #define IRQENB_FIFO0OVRRUN BIT(3) #define IRQENB_FIFO0UNDRFLW BIT(4) @@ -107,7 +108,7 @@ /* Charge delay */ #define CHARGEDLY_OPEN_MASK (0x3FFFF << 0) #define CHARGEDLY_OPEN(val) ((val) << 0) -#define CHARGEDLY_OPENDLY CHARGEDLY_OPEN(1) +#define CHARGEDLY_OPENDLY CHARGEDLY_OPEN(0x400) /* Control register */ #define CNTRLREG_TSCSSENB BIT(0) |