| Message ID | 1387466911-3732-4-git-send-email-bigeasy@linutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 12/19/13 15:28, Sebastian Andrzej Siewior wrote: > The purpose of reg_se_cache has been defeated. It should avoid the > read-back of the register to avoid the latency and the fact that the > bits are reset to 0 after the individual conversation took place. > > The reason why this is required like this to work, is that read-back of > the register removes the bits of the ADC so they do not start another > conversation after the register is re-written from the TSC side for the > update. > To avoid the not required read-back I introduce a "set once" variant which > does not update the cache mask. After the conversation completes, the > bit is removed from the SE register anyway and we don't plan a new > conversation "any time soon". The current set function is renamed to > set_cache to distinguish the two operations. > This is a small preparation for a larger sync-rework. > > Acked-by: Lee Jones <lee.jones@linaro.org> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Jonathan Cameron <jic23@kernel.org> > --- > drivers/iio/adc/ti_am335x_adc.c | 4 ++-- > drivers/input/touchscreen/ti_am335x_tsc.c | 4 ++-- > drivers/mfd/ti_am335x_tscadc.c | 16 ++++++++++++---- > include/linux/mfd/ti_am335x_tscadc.h | 3 ++- > 4 files changed, 18 insertions(+), 9 deletions(-) > > diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c > index e948454..b5197a0 100644 > --- a/drivers/iio/adc/ti_am335x_adc.c > +++ b/drivers/iio/adc/ti_am335x_adc.c > @@ -181,7 +181,7 @@ static int tiadc_buffer_postenable(struct iio_dev *indio_dev) > enb |= (get_adc_step_bit(adc_dev, bit) << 1); > adc_dev->buffer_en_ch_steps = enb; > > - am335x_tsc_se_set(adc_dev->mfd_tscadc, enb); > + am335x_tsc_se_set_cache(adc_dev->mfd_tscadc, enb); > > tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES > | IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW); > @@ -335,7 +335,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev, > return -EBUSY; > > step_en = get_adc_step_mask(adc_dev); > - am335x_tsc_se_set(adc_dev->mfd_tscadc, step_en); > + am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en); > > /* Wait for ADC sequencer to complete sampling */ > while (tiadc_readl(adc_dev, REG_ADCFSM) & SEQ_STATUS) { > diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c > index 68beada..2ca5a7b 100644 > --- a/drivers/input/touchscreen/ti_am335x_tsc.c > +++ b/drivers/input/touchscreen/ti_am335x_tsc.c > @@ -198,7 +198,7 @@ static void titsc_step_config(struct titsc *ts_dev) > /* The steps1 … end and bit 0 for TS_Charge */ > stepenable = (1 << (end_step + 2)) - 1; > ts_dev->step_mask = stepenable; > - am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask); > + am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask); > } > > static void titsc_read_coordinates(struct titsc *ts_dev, > @@ -322,7 +322,7 @@ static irqreturn_t titsc_irq(int irq, void *dev) > > if (irqclr) { > titsc_writel(ts_dev, REG_IRQSTATUS, irqclr); > - am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask); > + am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask); > return IRQ_HANDLED; > } > return IRQ_NONE; > diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c > index 67d0eb4..cb0c211 100644 > --- a/drivers/mfd/ti_am335x_tscadc.c > +++ b/drivers/mfd/ti_am335x_tscadc.c > @@ -53,24 +53,32 @@ static void am335x_tsc_se_update(struct ti_tscadc_dev *tsadc) > tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache); > } > > -void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val) > +void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val) > { > unsigned long flags; > > spin_lock_irqsave(&tsadc->reg_lock, flags); > - tsadc->reg_se_cache = tscadc_readl(tsadc, REG_SE); > tsadc->reg_se_cache |= val; > am335x_tsc_se_update(tsadc); > spin_unlock_irqrestore(&tsadc->reg_lock, flags); > } > -EXPORT_SYMBOL_GPL(am335x_tsc_se_set); > +EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache); > + > +void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val) > +{ > + unsigned long flags; > + > + spin_lock_irqsave(&tsadc->reg_lock, flags); > + tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache | val); > + spin_unlock_irqrestore(&tsadc->reg_lock, flags); > +} > +EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once); > > void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val) > { > unsigned long flags; > > spin_lock_irqsave(&tsadc->reg_lock, flags); > - tsadc->reg_se_cache = tscadc_readl(tsadc, REG_SE); > tsadc->reg_se_cache &= ~val; > am335x_tsc_se_update(tsadc); > spin_unlock_irqrestore(&tsadc->reg_lock, flags); > diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h > index 1fe7219..2fa9c06 100644 > --- a/include/linux/mfd/ti_am335x_tscadc.h > +++ b/include/linux/mfd/ti_am335x_tscadc.h > @@ -176,7 +176,8 @@ static inline struct ti_tscadc_dev *ti_tscadc_dev_get(struct platform_device *p) > return *tscadc_dev; > } > > -void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val); > +void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val); > +void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val); > void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val); > > #endif > -- 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 Thu, 19 Dec 2013, Sebastian Andrzej Siewior wrote: > The purpose of reg_se_cache has been defeated. It should avoid the > read-back of the register to avoid the latency and the fact that the > bits are reset to 0 after the individual conversation took place. > > The reason why this is required like this to work, is that read-back of > the register removes the bits of the ADC so they do not start another > conversation after the register is re-written from the TSC side for the > update. > To avoid the not required read-back I introduce a "set once" variant which > does not update the cache mask. After the conversation completes, the > bit is removed from the SE register anyway and we don't plan a new > conversation "any time soon". The current set function is renamed to > set_cache to distinguish the two operations. > This is a small preparation for a larger sync-rework. > > Acked-by: Lee Jones <lee.jones@linaro.org> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > --- > drivers/iio/adc/ti_am335x_adc.c | 4 ++-- > drivers/input/touchscreen/ti_am335x_tsc.c | 4 ++-- Just need Dmitry's Ack now.
On Mon, Jan 06, 2014 at 09:35:25AM +0000, Lee Jones wrote: > On Thu, 19 Dec 2013, Sebastian Andrzej Siewior wrote: > > > The purpose of reg_se_cache has been defeated. It should avoid the > > read-back of the register to avoid the latency and the fact that the > > bits are reset to 0 after the individual conversation took place. > > > > The reason why this is required like this to work, is that read-back of > > the register removes the bits of the ADC so they do not start another > > conversation after the register is re-written from the TSC side for the > > update. > > To avoid the not required read-back I introduce a "set once" variant which > > does not update the cache mask. After the conversation completes, the > > bit is removed from the SE register anyway and we don't plan a new > > conversation "any time soon". The current set function is renamed to > > set_cache to distinguish the two operations. > > This is a small preparation for a larger sync-rework. > > > > Acked-by: Lee Jones <lee.jones@linaro.org> > > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > > --- > > drivers/iio/adc/ti_am335x_adc.c | 4 ++-- > > drivers/input/touchscreen/ti_am335x_tsc.c | 4 ++-- > > Just need Dmitry's Ack now. Well, that has nothing to do with input per se but rather inner workings of the device. But yes, FWIW: Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Thanks.
diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c index e948454..b5197a0 100644 --- a/drivers/iio/adc/ti_am335x_adc.c +++ b/drivers/iio/adc/ti_am335x_adc.c @@ -181,7 +181,7 @@ static int tiadc_buffer_postenable(struct iio_dev *indio_dev) enb |= (get_adc_step_bit(adc_dev, bit) << 1); adc_dev->buffer_en_ch_steps = enb; - am335x_tsc_se_set(adc_dev->mfd_tscadc, enb); + am335x_tsc_se_set_cache(adc_dev->mfd_tscadc, enb); tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES | IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW); @@ -335,7 +335,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev, return -EBUSY; step_en = get_adc_step_mask(adc_dev); - am335x_tsc_se_set(adc_dev->mfd_tscadc, step_en); + am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en); /* Wait for ADC sequencer to complete sampling */ while (tiadc_readl(adc_dev, REG_ADCFSM) & SEQ_STATUS) { diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c index 68beada..2ca5a7b 100644 --- a/drivers/input/touchscreen/ti_am335x_tsc.c +++ b/drivers/input/touchscreen/ti_am335x_tsc.c @@ -198,7 +198,7 @@ static void titsc_step_config(struct titsc *ts_dev) /* The steps1 … end and bit 0 for TS_Charge */ stepenable = (1 << (end_step + 2)) - 1; ts_dev->step_mask = stepenable; - am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask); + am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask); } static void titsc_read_coordinates(struct titsc *ts_dev, @@ -322,7 +322,7 @@ static irqreturn_t titsc_irq(int irq, void *dev) if (irqclr) { titsc_writel(ts_dev, REG_IRQSTATUS, irqclr); - am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask); + am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask); return IRQ_HANDLED; } return IRQ_NONE; diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c index 67d0eb4..cb0c211 100644 --- a/drivers/mfd/ti_am335x_tscadc.c +++ b/drivers/mfd/ti_am335x_tscadc.c @@ -53,24 +53,32 @@ static void am335x_tsc_se_update(struct ti_tscadc_dev *tsadc) tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache); } -void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val) +void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val) { unsigned long flags; spin_lock_irqsave(&tsadc->reg_lock, flags); - tsadc->reg_se_cache = tscadc_readl(tsadc, REG_SE); tsadc->reg_se_cache |= val; am335x_tsc_se_update(tsadc); spin_unlock_irqrestore(&tsadc->reg_lock, flags); } -EXPORT_SYMBOL_GPL(am335x_tsc_se_set); +EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache); + +void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val) +{ + unsigned long flags; + + spin_lock_irqsave(&tsadc->reg_lock, flags); + tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache | val); + spin_unlock_irqrestore(&tsadc->reg_lock, flags); +} +EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once); void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val) { unsigned long flags; spin_lock_irqsave(&tsadc->reg_lock, flags); - tsadc->reg_se_cache = tscadc_readl(tsadc, REG_SE); tsadc->reg_se_cache &= ~val; am335x_tsc_se_update(tsadc); spin_unlock_irqrestore(&tsadc->reg_lock, flags); diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h index 1fe7219..2fa9c06 100644 --- a/include/linux/mfd/ti_am335x_tscadc.h +++ b/include/linux/mfd/ti_am335x_tscadc.h @@ -176,7 +176,8 @@ static inline struct ti_tscadc_dev *ti_tscadc_dev_get(struct platform_device *p) return *tscadc_dev; } -void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val); +void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val); +void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val); void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val); #endif