From patchwork Fri Nov 7 05:49:07 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vignesh Raghavendra X-Patchwork-Id: 5250141 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id D87A9C11AC for ; Fri, 7 Nov 2014 05:55:15 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DAA8C2011E for ; Fri, 7 Nov 2014 05:55:14 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E7933200DF for ; Fri, 7 Nov 2014 05:55:13 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XmcTB-0002Un-Qt; Fri, 07 Nov 2014 05:52:25 +0000 Received: from arroyo.ext.ti.com ([192.94.94.40]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XmcRe-0001YL-Kx for linux-arm-kernel@lists.infradead.org; Fri, 07 Nov 2014 05:50:52 +0000 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id sA75o1xn012106; Thu, 6 Nov 2014 23:50:01 -0600 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id sA75o1iw011288; Thu, 6 Nov 2014 23:50:01 -0600 Received: from dlep33.itg.ti.com (157.170.170.75) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.174.1; Thu, 6 Nov 2014 23:50:01 -0600 Received: from uda0132425.apr.dhcp.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep33.itg.ti.com (8.14.3/8.13.8) with ESMTP id sA75nbng031339; Thu, 6 Nov 2014 23:49:54 -0600 From: Vignesh R To: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Benoit Cousson , Tony Lindgren , Russell King , Jonathan Cameron , Hartmut Knaack , Dmitry Torokhov , Lee Jones , Sebastian Andrzej Siewior Subject: [PATCH 2/5] input: touchscreen: ti_am335x_tsc: Remove udelay in interrupt handler Date: Fri, 7 Nov 2014 11:19:07 +0530 Message-ID: <1415339350-17679-3-git-send-email-vigneshr@ti.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1415339350-17679-1-git-send-email-vigneshr@ti.com> References: <1415339350-17679-1-git-send-email-vigneshr@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141106_215050_821825_784B5038 X-CRM114-Status: GOOD ( 15.77 ) X-Spam-Score: -5.6 (-----) Cc: devicetree@vger.kernel.org, linux-iio@vger.kernel.org, Lars-Peter Clausen , Brad Griffis , Jan Kardell , Vignesh R , linux-kernel@vger.kernel.org, Felipe Balbi , Paul Gortmaker , Peter Meerwald , linux-input@vger.kernel.org, Sanjeev Sharma , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Samuel Ortiz X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, 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 From: Brad Griffis 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. Signed-off-by: Brad Griffis [vigneshr@ti.com: Ported the patch from v3.12 to v3.18rc2] Signed-off-by: Vignesh R Acked-by: Lee Jones --- drivers/input/touchscreen/ti_am335x_tsc.c | 56 ++++++++++++------------------- include/linux/mfd/ti_am335x_tscadc.h | 3 +- 2 files changed, 24 insertions(+), 35 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/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h index e2e70053470e..c99be5dc0f5c 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 (0x3FFFF << 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)