From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vignesh R Subject: Re: [PATCH 3/5] mfd: ti_am335x_tscadc: Remove unwanted reg_se_cache save Date: Mon, 10 Nov 2014 16:14:53 +0530 Message-ID: <54609725.9080608@ti.com> References: <1415339350-17679-1-git-send-email-vigneshr@ti.com> <1415339350-17679-4-git-send-email-vigneshr@ti.com> <20141110091527.GD21424@x1> <20141110092645.GE21424@x1> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20141110092645.GE21424@x1> Sender: linux-input-owner@vger.kernel.org To: Lee Jones Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Benoit Cousson , Tony Lindgren , Russell King , Jonathan Cameron , Hartmut Knaack , Dmitry Torokhov , Sebastian Andrzej Siewior , Lars-Peter Clausen , Peter Meerwald , Samuel Ortiz , Felipe Balbi , Brad Griffis , Sanjeev Sharma , Paul Gortmaker , Jan Kardell , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel List-Id: devicetree@vger.kernel.org On Monday 10 November 2014 02:56 PM, Lee Jones wrote: > On Mon, 10 Nov 2014, Lee Jones wrote: > >> On Fri, 07 Nov 2014, Vignesh R wrote: >> >>> 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. >>> Also, when ADC wakes up Sequencer should not be busy executing any of the >>> config steps except for the charge step. Previously charge step was 1 ADC >>> clock cycle and hence it was ignored. >>> >>> Signed-off-by: Vignesh R >>> --- >>> drivers/mfd/ti_am335x_tscadc.c | 7 +++++-- >>> include/linux/mfd/ti_am335x_tscadc.h | 1 + >>> 2 files changed, 6 insertions(+), 2 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)); >> >> This is almost certainly not correct. >> >> Please take another look at the logic. >> >> I'm _assuming_ you mean (reg & SEQ_STATUS && !CHARGE_STEP). > > So I just saw that CHARGE_STEP is actually the new macro below. > > So you're currently ANDing these together. > > xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx reg > 00000000 00000000 00000000 00100000 #define SEQ_STATUS BIT(5) > 00000000 00000000 00000000 00010001 #define CHARGE_STEP 0x11 > > ... which will always equate to 0. > Oops.. Sorry.. I meant ((reg & SEQ_STATUS) && !(reg & CHARGE_STEP)). I will fix this. >>> 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; > > Didn't you add this line a little over 1 month ago? > > Why the change of heart? > Previously, TSC did not reliably re-enable its steps as the TSC irq handler received false pen up events. Hence, in order to use TSC after ADC operation, it was necessary to save and re-enable TSC steps (basically, to keep TSC steps enabled always). The change was more of a workaround to overcome limitation of TSC irq handler. With this series of patches, TSC irq handler is very reliable and the workaround is no longer required. >>> am335x_tscadc_need_adc(tsadc); >>> >>> tscadc_writel(tsadc, REG_SE, val); >>> diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h >>> index c99be5dc0f5c..fcce182e4a35 100644 >>> --- a/include/linux/mfd/ti_am335x_tscadc.h >>> +++ b/include/linux/mfd/ti_am335x_tscadc.h >>> @@ -128,6 +128,7 @@ >>> >>> /* Sequencer Status */ >>> #define SEQ_STATUS BIT(5) >>> +#define CHARGE_STEP 0x11 >>> >>> #define ADC_CLK 3000000 >>> #define TOTAL_STEPS 16 >> >