From patchwork Thu May 19 09:04:00 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vignesh Raghavendra X-Patchwork-Id: 9125131 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 20F499F30C for ; Thu, 19 May 2016 09:06:41 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DFF1D2021B for ; Thu, 19 May 2016 09:06:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 894EC20219 for ; Thu, 19 May 2016 09:06:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754131AbcESJFy (ORCPT ); Thu, 19 May 2016 05:05:54 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:50130 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753979AbcESJFu (ORCPT ); Thu, 19 May 2016 05:05:50 -0400 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id u4J94iXe005379; Thu, 19 May 2016 04:04:44 -0500 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id u4J94ivT013164; Thu, 19 May 2016 04:04:44 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.3.294.0; Thu, 19 May 2016 04:04:43 -0500 Received: from uda0132425.india.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id u4J94Su3016295; Thu, 19 May 2016 04:04:37 -0500 From: Vignesh R To: Dmitry Torokhov , Rob Herring , Tony Lindgren CC: Jonathan Corbet , Johan Hovold , Sylvain Rochet , Vignesh R , Masanari Iida , Ezequiel Garcia , S Twiss , Krzysztof Kozlowski , Moritz Fischer , Arnd Bergmann , Geert Uytterhoeven , Timo Teras , Guido Martinez , Clifton Barnes , Uwe Kleine-Konig , , , , , , Subject: [RFC PATCH 1/2] Input: rotary-encoder- Add support for absolute encoder Date: Thu, 19 May 2016 14:34:00 +0530 Message-ID: <1463648641-6931-2-git-send-email-vigneshr@ti.com> X-Mailer: git-send-email 2.8.2 In-Reply-To: <1463648641-6931-1-git-send-email-vigneshr@ti.com> References: <1463648641-6931-1-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=-8.3 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 There are rotary-encoders where GPIO lines reflect the actual position of the rotary encoder dial. For example, if dial points to 9, then four GPIO lines connected to the rotary encoder will read HLLH(1001b = 9). Add support for such rotary-encoder. The driver relies on rotary-encoder,absolute-encoder DT property to detect such encoders. Since, GPIO IRQs are not necessary to work with such encoders, optional polling mode support is added using input_poll_dev skeleton. This is can be used by enabling CONFIG_INPUT_GPIO_ROTARY_ENCODER_POLL_MODE_SUPPORT. Signed-off-by: Vignesh R --- .../devicetree/bindings/input/rotary-encoder.txt | 4 + Documentation/input/rotary-encoder.txt | 9 ++ drivers/input/misc/Kconfig | 11 ++ drivers/input/misc/rotary_encoder.c | 165 ++++++++++++++++----- 4 files changed, 155 insertions(+), 34 deletions(-) diff --git a/Documentation/devicetree/bindings/input/rotary-encoder.txt b/Documentation/devicetree/bindings/input/rotary-encoder.txt index 6c9f0c8a846c..9c928dbd1500 100644 --- a/Documentation/devicetree/bindings/input/rotary-encoder.txt +++ b/Documentation/devicetree/bindings/input/rotary-encoder.txt @@ -12,6 +12,10 @@ Optional properties: - rotary-encoder,relative-axis: register a relative axis rather than an absolute one. Relative axis will only generate +1/-1 events on the input device, hence no steps need to be passed. +- rotary-encoder,absolute-encoder: support encoders where GPIO lines + reflect the actual position of the rotary encoder dial. For example, + if dial points to 9, then four GPIO lines read HLLH(1001b = 9). + In this case, rotary-encoder,steps-per-period needed not be defined. - rotary-encoder,rollover: Automatic rollove when the rotary value becomes greater than the specified steps or smaller than 0. For absolute axis only. - rotary-encoder,steps-per-period: Number of steps (stable states) per period. diff --git a/Documentation/input/rotary-encoder.txt b/Documentation/input/rotary-encoder.txt index 46a74f0c551a..dc76092f5618 100644 --- a/Documentation/input/rotary-encoder.txt +++ b/Documentation/input/rotary-encoder.txt @@ -36,6 +36,15 @@ The phase diagram of these two outputs look like this: |<>| one step (quarter-period mode) + +In some encoders, the value pointed by rotary encoders switch is directly +reflected by status of the GPIOs connecting rotary encoder to CPU. For +example, if rotary encoder dial points to 9, then the four GPIOs +conncting rotary encoder will read HLLH(1001b = 9). Such encoders are +supported by defining devictree binding "rotary-encoder,absolute-encoder". +These encoders are also supported without need for event(IRQ) generation +using Input subsytem's polling mode support. + For more information, please see https://en.wikipedia.org/wiki/Rotary_encoder diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig index 1f2337abcf2f..81805f9a534c 100644 --- a/drivers/input/misc/Kconfig +++ b/drivers/input/misc/Kconfig @@ -566,6 +566,17 @@ config INPUT_GPIO_ROTARY_ENCODER To compile this driver as a module, choose M here: the module will be called rotary_encoder. +config INPUT_GPIO_ROTARY_ENCODER_POLL_MODE_SUPPORT + bool "Polling mode support for rotary encoder" + depends on INPUT_GPIO_ROTARY_ENCODER + select INPUT_POLLDEV + help + Say Y here to enable polling mode support for rotary encoders + connected to GPIO lines that do have interrupt capability and + report rotary encoder position as absolute value over GPIO + lines. Check file: Documentation/input/rotary-encoder.txt for + more information. + config INPUT_RB532_BUTTON tristate "Mikrotik Routerboard 532 button interface" depends on MIKROTIK_RB532 diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index c7fc8d4fb080..8f60289fb6cd 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c @@ -25,24 +25,29 @@ #include #include #include +#include #define DRV_NAME "rotary-encoder" struct rotary_encoder { struct input_dev *input; - +#ifdef CONFIG_INPUT_GPIO_ROTARY_ENCODER_POLL_MODE_SUPPORT + struct input_polled_dev *poll_dev; +#endif struct mutex access_mutex; u32 steps; u32 axis; bool relative_axis; bool rollover; + bool absolute_encoder; unsigned int pos; struct gpio_descs *gpios; + struct device *dev; - unsigned int *irq; + int *irq; bool armed; signed char dir; /* 1 - clockwise, -1 - CCW */ @@ -67,6 +72,21 @@ static unsigned int rotary_encoder_get_state(struct rotary_encoder *encoder) return ret & 3; } +static unsigned int rotary_encoder_get_gpios_state(struct rotary_encoder + *encoder) +{ + int i; + unsigned int ret = 0; + + for (i = 0; i < encoder->gpios->ndescs; ++i) { + int val = gpiod_get_value_cansleep(encoder->gpios->desc[i]); + + ret = ret << 1 | val; + } + + return ret; +} + static void rotary_encoder_report_event(struct rotary_encoder *encoder) { if (encoder->relative_axis) { @@ -178,6 +198,72 @@ out: return IRQ_HANDLED; } +static void rotary_encoder_setup_input_params(struct rotary_encoder *encoder) +{ + struct input_dev *input = encoder->input; + struct platform_device *pdev = to_platform_device(encoder->dev); + + input->name = pdev->name; + input->id.bustype = BUS_HOST; + input->dev.parent = encoder->dev; + + if (encoder->relative_axis) + input_set_capability(input, EV_REL, encoder->axis); + else + input_set_abs_params(input, + encoder->axis, 0, encoder->steps, 0, 1); +} + +static irqreturn_t rotary_absolute_encoder_irq(int irq, void *dev_id) +{ + struct rotary_encoder *encoder = dev_id; + unsigned int state; + + mutex_lock(&encoder->access_mutex); + + state = rotary_encoder_get_gpios_state(encoder); + if (state != encoder->last_stable) { + input_report_abs(encoder->input, encoder->axis, state); + input_sync(encoder->input); + encoder->last_stable = state; + } + + mutex_lock(&encoder->access_mutex); + + return IRQ_HANDLED; +} + +#ifdef CONFIG_INPUT_GPIO_ROTARY_ENCODER_POLL_MODE_SUPPORT +static void rotary_encoder_poll_gpios(struct input_polled_dev *poll_dev) +{ + struct rotary_encoder *encoder = poll_dev->private; + unsigned int state = rotary_encoder_get_gpios_state(encoder); + + if (state != encoder->last_stable) { + input_report_abs(encoder->input, encoder->axis, state); + input_sync(encoder->input); + encoder->last_stable = state; + } +} + +static int rotary_encoder_register_poll_device(struct rotary_encoder + *encoder) +{ + struct input_polled_dev *poll_dev = + devm_input_allocate_polled_device(encoder->dev); + + if (!poll_dev) + return -ENOMEM; + poll_dev->private = encoder; + poll_dev->poll = rotary_encoder_poll_gpios; + encoder->input = poll_dev->input; + rotary_encoder_setup_input_params(encoder); + encoder->poll_dev = poll_dev; + + return input_register_polled_device(poll_dev); +} +#endif + static int rotary_encoder_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -227,38 +313,32 @@ static int rotary_encoder_probe(struct platform_device *pdev) return -EINVAL; } - input = devm_input_allocate_device(dev); - if (!input) - return -ENOMEM; - - encoder->input = input; - - input->name = pdev->name; - input->id.bustype = BUS_HOST; - input->dev.parent = dev; - - if (encoder->relative_axis) - input_set_capability(input, EV_REL, encoder->axis); - else - input_set_abs_params(input, - encoder->axis, 0, encoder->steps, 0, 1); - - switch (steps_per_period >> (encoder->gpios->ndescs - 2)) { - case 4: - handler = &rotary_encoder_quarter_period_irq; - encoder->last_stable = rotary_encoder_get_state(encoder); - break; - case 2: - handler = &rotary_encoder_half_period_irq; - encoder->last_stable = rotary_encoder_get_state(encoder); - break; - case 1: - handler = &rotary_encoder_irq; - break; - default: - dev_err(dev, "'%d' is not a valid steps-per-period value\n", - steps_per_period); - return -EINVAL; + encoder->dev = dev; + encoder->absolute_encoder = + device_property_read_bool(dev, + "rotary-encoder,absolute-encoder"); + if (encoder->absolute_encoder) { + handler = rotary_absolute_encoder_irq; + } else { + switch (steps_per_period >> (encoder->gpios->ndescs - 2)) { + case 4: + handler = &rotary_encoder_quarter_period_irq; + encoder->last_stable = + rotary_encoder_get_state(encoder); + break; + case 2: + handler = &rotary_encoder_half_period_irq; + encoder->last_stable = + rotary_encoder_get_state(encoder); + break; + case 1: + handler = &rotary_encoder_irq; + break; + default: + dev_err(dev, "'%d' is not a valid steps-per-period value\n", + steps_per_period); + return -EINVAL; + } } encoder->irq = @@ -271,6 +351,18 @@ static int rotary_encoder_probe(struct platform_device *pdev) for (i = 0; i < encoder->gpios->ndescs; ++i) { encoder->irq[i] = gpiod_to_irq(encoder->gpios->desc[i]); +#ifdef CONFIG_INPUT_GPIO_ROTARY_ENCODER_POLL_MODE_SUPPORT + if (encoder->irq[i] < 0 && encoder->absolute_encoder) { + dev_info(dev, "Using poll mode\n"); + err = rotary_encoder_register_poll_device(encoder); + if (err) { + dev_err(dev, "failed to register poll dev\n"); + return err; + } + platform_set_drvdata(pdev, encoder); + return 0; + } +#endif err = devm_request_threaded_irq(dev, encoder->irq[i], NULL, handler, IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | @@ -283,6 +375,11 @@ static int rotary_encoder_probe(struct platform_device *pdev) } } + input = devm_input_allocate_device(dev); + if (!input) + return -ENOMEM; + encoder->input = input; + rotary_encoder_setup_input_params(encoder); err = input_register_device(input); if (err) { dev_err(dev, "failed to register input device\n");