From patchwork Wed Jan 7 05:49:37 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vignesh Raghavendra X-Patchwork-Id: 5582371 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 80485BF6C3 for ; Wed, 7 Jan 2015 05:53:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 93E2B20256 for ; Wed, 7 Jan 2015 05:53:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95B372024C for ; Wed, 7 Jan 2015 05:53:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755066AbbAGFx0 (ORCPT ); Wed, 7 Jan 2015 00:53:26 -0500 Received: from arroyo.ext.ti.com ([192.94.94.40]:50393 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754939AbbAGFw3 (ORCPT ); Wed, 7 Jan 2015 00:52:29 -0500 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id t075pSkD004624; Tue, 6 Jan 2015 23:51:28 -0600 Received: from DLEE71.ent.ti.com (dlee71.ent.ti.com [157.170.170.114]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id t075pS7p012172; Tue, 6 Jan 2015 23:51:28 -0600 Received: from dlep32.itg.ti.com (157.170.170.100) by DLEE71.ent.ti.com (157.170.170.114) with Microsoft SMTP Server id 14.3.174.1; Tue, 6 Jan 2015 23:51:28 -0600 Received: from uda0132425.apr.dhcp.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep32.itg.ti.com (8.14.3/8.13.8) with ESMTP id t075olTS006590; Tue, 6 Jan 2015 23:51:20 -0600 From: Vignesh R To: Jonathan Cameron , Hartmut Knaack , Dmitry Torokhov , Lee Jones , Sebastian Andrzej Siewior CC: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Benoit Cousson , Tony Lindgren , Russell King , Lars-Peter Clausen , Peter Meerwald , Samuel Ortiz , Brad Griffis , Paul Gortmaker , Sanjeev Sharma , Jan Kardell , Felipe Balbi , Wolfram Sang , , , , , , , Vignesh R Subject: [PATCH v6 4/6] input: touchscreen: ti_am335x_tsc: Read charge delay from DT Date: Wed, 7 Jan 2015 11:19:37 +0530 Message-ID: <1420609779-11156-5-git-send-email-vigneshr@ti.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1420609779-11156-1-git-send-email-vigneshr@ti.com> References: <1420609779-11156-1-git-send-email-vigneshr@ti.com> MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_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 This patch reads charge delay from tsc DT node and writes to REG_CHARGEDELAY register. If the charge delay is not specified in DT then default value of 0x400(CHARGEDLY_OPENDLY) is used. Signed-off-by: Vignesh R --- v6: - Move Documentation from DT patch to driver code. v5: - print out a warning when ti,charge-delay is not specified v4: - Set charge delay to 0x400 as default. Most devices function normally at this value .../devicetree/bindings/input/touchscreen/ti-tsc-adc.txt | 15 +++++++++++++++ drivers/input/touchscreen/ti_am335x_tsc.c | 14 +++++++++++++- 2 files changed, 28 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt index 878549ba814d..6c4fb34823d3 100644 --- a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt +++ b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt @@ -28,6 +28,20 @@ Required properties: ti,adc-channels: List of analog inputs available for ADC. AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7. +Optional properties: +- child "tsc" + ti,charge-delay: Length of touch screen charge delay step in terms of + ADC clock cycles. Charge delay value should be large + in order to avoid false pen-up events. This value + effects the overall sampling speed, hence need to be + kept as low as possible, while avoiding false pen-up + event. Start from a lower value, say 0x400, and + increase value until false pen-up events are avoided. + The pen-up detection happens immediately after the + charge step, so this does in fact function as a + hardware knob for adjusting the amount of "settling + time". + Example: tscadc: tscadc@44e0d000 { compatible = "ti,am3359-tscadc"; @@ -36,6 +50,7 @@ Example: ti,x-plate-resistance = <200>; ti,coordiante-readouts = <5>; ti,wire-config = <0x00 0x11 0x22 0x33>; + ti,charge-delay = <0x400>; }; adc { diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c index 0625c102a1d0..7c0f6b21559d 100644 --- a/drivers/input/touchscreen/ti_am335x_tsc.c +++ b/drivers/input/touchscreen/ti_am335x_tsc.c @@ -52,6 +52,7 @@ struct titsc { u32 bit_xp, bit_xn, bit_yp, bit_yn; u32 inp_xp, inp_xn, inp_yp, inp_yn; u32 step_mask; + u32 charge_delay; }; static unsigned int titsc_readl(struct titsc *ts, unsigned int reg) @@ -177,7 +178,7 @@ static void titsc_step_config(struct titsc *ts_dev) config = titsc_readl(ts_dev, REG_IDLECONFIG); titsc_writel(ts_dev, REG_CHARGECONFIG, config); - titsc_writel(ts_dev, REG_CHARGEDELAY, CHARGEDLY_OPENDLY); + titsc_writel(ts_dev, REG_CHARGEDELAY, ts_dev->charge_delay); /* coordinate_readouts + 1 ... coordinate_readouts + 2 is for Z */ config = STEPCONFIG_MODE_HWSYNC | @@ -368,6 +369,17 @@ static int titsc_parse_dt(struct platform_device *pdev, if (err < 0) return err; + err = of_property_read_u32(node, "ti,charge-delay", + &ts_dev->charge_delay); + /* + * If ti,charge-delay value is not specified, then use + * CHARGEDLY_OPENDLY as the default value. + */ + if (err < 0) { + ts_dev->charge_delay = CHARGEDLY_OPENDLY; + dev_warn(&pdev->dev, "ti,charge-delay not specified\n"); + } + return of_property_read_u32_array(node, "ti,wire-config", ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp)); }