From patchwork Thu Dec 19 15:28:29 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 3382251 Return-Path: X-Original-To: patchwork-linux-input@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id DCB6B9F39F for ; Thu, 19 Dec 2013 15:30:56 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1F8C420671 for ; Thu, 19 Dec 2013 15:30:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C132120142 for ; Thu, 19 Dec 2013 15:30:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754015Ab3LSP2t (ORCPT ); Thu, 19 Dec 2013 10:28:49 -0500 Received: from www.linutronix.de ([62.245.132.108]:53647 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753866Ab3LSP2r (ORCPT ); Thu, 19 Dec 2013 10:28:47 -0500 Received: from localhost ([127.0.0.1] helo=bazinga.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.72) (envelope-from ) id 1VtfWj-0002ZL-Ab; Thu, 19 Dec 2013 16:28:41 +0100 From: Sebastian Andrzej Siewior To: Lee Jones , Samuel Ortiz Cc: Jonathan Cameron , Dmitry Torokhov , Zubair Lutfullah , Felipe Balbi , linux-iio@vger.kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Sebastian Andrzej Siewior Subject: [PATCH 3/5] mfd: ti_am335x_tscadc: Don't read back REG_SE Date: Thu, 19 Dec 2013 16:28:29 +0100 Message-Id: <1387466911-3732-4-git-send-email-bigeasy@linutronix.de> X-Mailer: git-send-email 1.8.5.1 In-Reply-To: <1387466911-3732-1-git-send-email-bigeasy@linutronix.de> References: <1387466911-3732-1-git-send-email-bigeasy@linutronix.de> MIME-Version: 1.0 X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1, SHORTCIRCUIT=-0.0001, URIBL_BLOCKED=0.001 Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Signed-off-by: Sebastian Andrzej Siewior Acked-by: Jonathan Cameron Acked-by: Dmitry Torokhov --- 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