Re: [PATCH 2/4] input: touchscreen: ti_am335x_tsc: Remove udelay in interrupt handler

2014-11-06 Thread Vignesh R 


On Monday 03 November 2014 08:35 PM, Lee Jones wrote:
 On Mon, 27 Oct 2014, Vignesh R wrote:
 From: Brad Griffis bgrif...@ti.com

 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.

 In one shot mode, sequencer automatically disables all enabled steps at
 the end of each cycle. (both ADC steps and TSC steps) Hence these steps
 need not be saved in reg_se_cache for clearing these steps at a later
 stage.

 Signed-off-by: Brad Griffis bgrif...@ti.com
 [vigne...@ti.com: Ported patch from v3.12 to v3.18rc2]
 Signed-off-by: Vignesh R vigne...@ti.com
 ---
  drivers/input/touchscreen/ti_am335x_tsc.c | 56 
 ---
  drivers/mfd/ti_am335x_tscadc.c|  7 ++--
  include/linux/mfd/ti_am335x_tscadc.h  |  4 ++-
  3 files changed, 30 insertions(+), 37 deletions(-)
 
 [...]
 
 diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
 index d877e777cce6..94ef8992f46b 100644
 --- a/drivers/mfd/ti_am335x_tscadc.c
 +++ b/drivers/mfd/ti_am335x_tscadc.c
 @@ -86,8 +86,12 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev 
 *tsadc)
  spin_lock_irq(tsadc-reg_lock);
  finish_wait(tsadc-reg_se_wait, wait);
  
 +/*
 + * Sequencer should either be idle or
 + * busy applying the charge step.
 + */
  reg = tscadc_readl(tsadc, REG_ADCFSM);
 -WARN_ON(reg  SEQ_STATUS);
 +WARN_ON(reg  SEQ_STATUS  (!CHARGE_STEP));
  tsadc-adc_waiting = false;
  }
  tsadc-adc_in_use = true;
 @@ -96,7 +100,6 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev 
 *tsadc)
  void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
  {
  spin_lock_irq(tsadc-reg_lock);
 -tsadc-reg_se_cache |= val;
  am335x_tscadc_need_adc(tsadc);
  
  tscadc_writel(tsadc, REG_SE, val);
 
 I believe all of these changes can, and therefor should live in a
 separate patch.

I will split this patch accordingly.

 
 diff --git a/include/linux/mfd/ti_am335x_tscadc.h 
 b/include/linux/mfd/ti_am335x_tscadc.h
 index e2e70053470e..fcce182e4a35 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 (0x3  0)
  #define CHARGEDLY_OPEN(val) ((val)  0)
 -#define CHARGEDLY_OPENDLY   CHARGEDLY_OPEN(1)
 +#define CHARGEDLY_OPENDLY   CHARGEDLY_OPEN(0xB000)
  
  /* Control register */
  #define CNTRLREG_TSCSSENB   BIT(0)
 @@ -127,6 +128,7 @@
  
  /* Sequencer Status */
  #define SEQ_STATUS BIT(5)
 +#define CHARGE_STEP 0x11
  
  #define ADC_CLK 300
  #define TOTAL_STEPS 16
 
 The header changes should be split between the two Input and MFD
 patches.
 
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Re: [PATCH 2/4] input: touchscreen: ti_am335x_tsc: Remove udelay in interrupt handler

2014-11-03 Thread Lee Jones 
On Mon, 27 Oct 2014, Vignesh R wrote:
 From: Brad Griffis bgrif...@ti.com
 
 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.
 
 In one shot mode, sequencer automatically disables all enabled steps at
 the end of each cycle. (both ADC steps and TSC steps) Hence these steps
 need not be saved in reg_se_cache for clearing these steps at a later
 stage.
 
 Signed-off-by: Brad Griffis bgrif...@ti.com
 [vigne...@ti.com: Ported patch from v3.12 to v3.18rc2]
 Signed-off-by: Vignesh R vigne...@ti.com
 ---
  drivers/input/touchscreen/ti_am335x_tsc.c | 56 
 ---
  drivers/mfd/ti_am335x_tscadc.c|  7 ++--
  include/linux/mfd/ti_am335x_tscadc.h  |  4 ++-
  3 files changed, 30 insertions(+), 37 deletions(-)

[...]

 diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
 index d877e777cce6..94ef8992f46b 100644
 --- a/drivers/mfd/ti_am335x_tscadc.c
 +++ b/drivers/mfd/ti_am335x_tscadc.c
 @@ -86,8 +86,12 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev 
 *tsadc)
   spin_lock_irq(tsadc-reg_lock);
   finish_wait(tsadc-reg_se_wait, wait);
  
 + /*
 +  * Sequencer should either be idle or
 +  * busy applying the charge step.
 +  */
   reg = tscadc_readl(tsadc, REG_ADCFSM);
 - WARN_ON(reg  SEQ_STATUS);
 + WARN_ON(reg  SEQ_STATUS  (!CHARGE_STEP));
   tsadc-adc_waiting = false;
   }
   tsadc-adc_in_use = true;
 @@ -96,7 +100,6 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev 
 *tsadc)
  void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
  {
   spin_lock_irq(tsadc-reg_lock);
 - tsadc-reg_se_cache |= val;
   am335x_tscadc_need_adc(tsadc);
  
   tscadc_writel(tsadc, REG_SE, val);

I believe all of these changes can, and therefor should live in a
separate patch.

 diff --git a/include/linux/mfd/ti_am335x_tscadc.h 
 b/include/linux/mfd/ti_am335x_tscadc.h
 index e2e70053470e..fcce182e4a35 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_PENBIT(0)
 +#define IRQENB_EOS   BIT(1)
  #define IRQENB_FIFO0THRESBIT(2)
  #define IRQENB_FIFO0OVRRUN   BIT(3)
  #define IRQENB_FIFO0UNDRFLW  BIT(4)
 @@ -107,7 +108,7 @@
  /* Charge delay */
  #define CHARGEDLY_OPEN_MASK  (0x3  0)
  #define CHARGEDLY_OPEN(val)  ((val)  0)
 -#define CHARGEDLY_OPENDLYCHARGEDLY_OPEN(1)
 +#define CHARGEDLY_OPENDLYCHARGEDLY_OPEN(0xB000)
  
  /* Control register */
  #define CNTRLREG_TSCSSENBBIT(0)
 @@ -127,6 +128,7 @@
  
  /* Sequencer Status */
  #define SEQ_STATUS BIT(5)
 +#define CHARGE_STEP  0x11
  
  #define ADC_CLK  300
  #define TOTAL_STEPS  16

The header changes should be split between the two Input and MFD
patches.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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[PATCH 2/4] input: touchscreen: ti_am335x_tsc: Remove udelay in interrupt handler

2014-10-27 Thread Vignesh R 
From: Brad Griffis bgrif...@ti.com

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.

In one shot mode, sequencer automatically disables all enabled steps at
the end of each cycle. (both ADC steps and TSC steps) Hence these steps
need not be saved in reg_se_cache for clearing these steps at a later
stage.

Signed-off-by: Brad Griffis bgrif...@ti.com
[vigne...@ti.com: Ported patch from v3.12 to v3.18rc2]
Signed-off-by: Vignesh R vigne...@ti.com
---
 drivers/input/touchscreen/ti_am335x_tsc.c | 56 ---
 drivers/mfd/ti_am335x_tscadc.c|  7 ++--
 include/linux/mfd/ti_am335x_tscadc.h  |  4 ++-
 3 files changed, 30 insertions(+), 37 deletions(-)

diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c 
b/drivers/input/touchscreen/ti_am335x_tsc.c
index 1aeac9675fe7..483fd97c0e0c 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -173,11 +173,9 @@ static void titsc_step_config(struct titsc *ts_dev)
titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
}
 
-   /* Charge step configuration */
-   config = ts_dev-bit_xp | ts_dev-bit_yn |
-   STEPCHARGE_RFP_XPUL | STEPCHARGE_RFM_XNUR |
-   STEPCHARGE_INM_AN1 | STEPCHARGE_INP(ts_dev-inp_yp);
+   /* Make CHARGECONFIG same as IDLECONFIG */
 
+   config = titsc_readl(ts_dev, REG_IDLECONFIG);
titsc_writel(ts_dev, REG_CHARGECONFIG, config);
titsc_writel(ts_dev, REG_CHARGEDELAY, CHARGEDLY_OPENDLY);
 
@@ -264,9 +262,26 @@ static irqreturn_t titsc_irq(int irq, void *dev)
unsigned int status, irqclr = 0;
unsigned int x = 0, y = 0;
unsigned int z1, z2, z;
-   unsigned int fsm;
 
-   status = titsc_readl(ts_dev, REG_IRQSTATUS);
+   status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
+   if (status  IRQENB_HW_PEN) {
+   ts_dev-pen_down = true;
+   titsc_writel(ts_dev, REG_IRQWAKEUP, 0x00);
+   titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
+   irqclr |= IRQENB_HW_PEN;
+   }
+
+   if (status  IRQENB_PENUP) {
+   ts_dev-pen_down = false;
+   input_report_key(input_dev, BTN_TOUCH, 0);
+   input_report_abs(input_dev, ABS_PRESSURE, 0);
+   input_sync(input_dev);
+   irqclr |= IRQENB_PENUP;
+   }
+
+   if (status  IRQENB_EOS)
+   irqclr |= IRQENB_EOS;
+
/*
 * ADC and touchscreen share the IRQ line.
 * FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
@@ -297,34 +312,6 @@ static irqreturn_t titsc_irq(int irq, void *dev)
}
irqclr |= IRQENB_FIFO0THRES;
}
-
-   /*
-* Time for sequencer to settle, to read
-* correct state of the sequencer.
-*/
-   udelay(SEQ_SETTLE);
-
-   status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
-   if (status  IRQENB_PENUP) {
-   /* Pen up event */
-   fsm = titsc_readl(ts_dev, REG_ADCFSM);
-   if (fsm == ADCFSM_STEPID) {
-   ts_dev-pen_down = false;
-   input_report_key(input_dev, BTN_TOUCH, 0);
-   input_report_abs(input_dev, ABS_PRESSURE, 0);
-   input_sync(input_dev);
-   } else {
-   ts_dev-pen_down = true;
-   }
-   irqclr |= IRQENB_PENUP;
-   }
-
-   if (status  IRQENB_HW_PEN) {
-
-   titsc_writel(ts_dev, REG_IRQWAKEUP, 0x00);
-   titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
-   }
-
if (irqclr) {
titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
am335x_tsc_se_set_cache(ts_dev-mfd_tscadc, ts_dev-step_mask);
@@ -417,6 +404,7 @@ static int titsc_probe(struct platform_device *pdev)
}
 
titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
+   titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_EOS);
err = titsc_config_wires(ts_dev);
if (err) {
dev_err(pdev-dev, wrong i/p wire configuration\n);
diff --git a/drivers/mfd/ti_am335x_tscadc.c