| Message ID | 1376412499-21007-2-git-send-email-zubair.lutfullah@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
* Zubair Lutfullah | 2013-08-13 17:48:16 [+0100]: >diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c >index e1c5300..e165fcb 100644 >--- a/drivers/input/touchscreen/ti_am335x_tsc.c >+++ b/drivers/input/touchscreen/ti_am335x_tsc.c >@@ -52,6 +52,7 @@ struct titsc { > u32 config_inp[4]; > u32 bit_xp, bit_xn, bit_yp, bit_yn; > u32 inp_xp, inp_xn, inp_yp, inp_yn; >+ u32 step_mask; > }; > > static unsigned int titsc_readl(struct titsc *ts, unsigned int reg) >@@ -196,7 +197,8 @@ static void titsc_step_config(struct titsc *ts_dev) > > /* The steps1 … end and bit 0 for TS_Charge */ > stepenable = (1 << (end_step + 2)) - 1; >- am335x_tsc_se_set(ts_dev->mfd_tscadc, stepenable); >+ ts_dev->step_mask = stepenable; >+ am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask); > } > > static void titsc_read_coordinates(struct titsc *ts_dev, >@@ -316,7 +318,7 @@ static irqreturn_t titsc_irq(int irq, void *dev) > > if (irqclr) { > titsc_writel(ts_dev, REG_IRQSTATUS, irqclr); >- am335x_tsc_se_update(ts_dev->mfd_tscadc); >+ am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask); > return IRQ_HANDLED; > } > return IRQ_NONE; titsc_step_config() computes the mask once since it does not change. It is then assigned via am335x_tsc_se_set() to ->reg_se_cache() and later always udpated via am335x_tsc_se_update(). This should ensure that ADC's and TSC's bits are in sync and clear each other out. Now you call am335x_tsc_se_set() in every irq which adds the TSC's mask to ->reg_se_cache but why? It was never removed. Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Aug 16, 2013 at 10:53:50AM +0200, Sebastian Andrzej Siewior wrote: > * Zubair Lutfullah | 2013-08-13 17:48:16 [+0100]: > > >@@ -316,7 +318,7 @@ static irqreturn_t titsc_irq(int irq, void *dev) > > > > if (irqclr) { > > titsc_writel(ts_dev, REG_IRQSTATUS, irqclr); > >- am335x_tsc_se_update(ts_dev->mfd_tscadc); > >+ am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask); > > return IRQ_HANDLED; > > } > > return IRQ_NONE; > > titsc_step_config() computes the mask once since it does not change. It > is then assigned via am335x_tsc_se_set() to ->reg_se_cache() and later > always udpated via am335x_tsc_se_update(). This should ensure that ADC's > and TSC's bits are in sync and clear each other out. > Now you call am335x_tsc_se_set() in every irq which adds the TSC's mask > to ->reg_se_cache but why? It was never removed. > > Sebastian The problem is when ADC/TSC are used together. reg_se_cache would get updated with masks in the se_set function in MFD core. From TSC driver, the TSC steps would be set in the reg_se_cache variable. From ADC driver, the ADC steps would be set in the reg_se_cache variable. But the ADC masks weren't being cleared from the reg_se_cache variable anywhere. After a while of using ADC/TSC together, the reg_se_cache variable would have FFFF always. Resulting in redundant sampling and data in ADC FIFO0. MFD has received fixes to update the reg_se_cache upon every call to the se_set functions. Thus, the step_mask must be set every time to ensure that it is updated correctly every time. Hope that clears the confusion. This TSC/ADC sharing can be pretty confusing. Thanks Zubair -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c index e1c5300..e165fcb 100644 --- a/drivers/input/touchscreen/ti_am335x_tsc.c +++ b/drivers/input/touchscreen/ti_am335x_tsc.c @@ -52,6 +52,7 @@ struct titsc { u32 config_inp[4]; u32 bit_xp, bit_xn, bit_yp, bit_yn; u32 inp_xp, inp_xn, inp_yp, inp_yn; + u32 step_mask; }; static unsigned int titsc_readl(struct titsc *ts, unsigned int reg) @@ -196,7 +197,8 @@ static void titsc_step_config(struct titsc *ts_dev) /* The steps1 … end and bit 0 for TS_Charge */ stepenable = (1 << (end_step + 2)) - 1; - am335x_tsc_se_set(ts_dev->mfd_tscadc, stepenable); + ts_dev->step_mask = stepenable; + am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask); } static void titsc_read_coordinates(struct titsc *ts_dev, @@ -316,7 +318,7 @@ static irqreturn_t titsc_irq(int irq, void *dev) if (irqclr) { titsc_writel(ts_dev, REG_IRQSTATUS, irqclr); - am335x_tsc_se_update(ts_dev->mfd_tscadc); + am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask); return IRQ_HANDLED; } return IRQ_NONE;
TSC steps should be enabled again after IRQ routine. This fix ensures they are updated correctly every time. Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com> --- drivers/input/touchscreen/ti_am335x_tsc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)