From patchwork Sun Jul 2 11:06:11 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Young X-Patchwork-Id: 783175 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3x0nht5GgXz9sNw for ; Sun, 2 Jul 2017 21:14:22 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752178AbdGBLOU (ORCPT ); Sun, 2 Jul 2017 07:14:20 -0400 Received: from gofer.mess.org ([88.97.38.141]:43317 "EHLO gofer.mess.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751973AbdGBLOU (ORCPT ); Sun, 2 Jul 2017 07:14:20 -0400 X-Greylist: delayed 488 seconds by postgrey-1.27 at vger.kernel.org; Sun, 02 Jul 2017 07:14:20 EDT Received: by gofer.mess.org (Postfix, from userid 1000) id 8D22560301; Sun, 2 Jul 2017 12:06:11 +0100 (BST) From: Sean Young To: linux-media@vger.kernel.org, devicetree@vger.kernel.org, Rob Herring Subject: [PATCH 3/4] [media] rc: gpio-ir-tx: add new driver Date: Sun, 2 Jul 2017 12:06:11 +0100 Message-Id: <616e336df6badc96ced14d14956ed7c080b39781.1498992850.git.sean@mess.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: References: Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org This is a simple bit-banging GPIO IR TX driver. Signed-off-by: Sean Young --- .../devicetree/bindings/leds/irled/gpio-ir-tx.txt | 11 ++ drivers/media/rc/Kconfig | 11 ++ drivers/media/rc/Makefile | 1 + drivers/media/rc/gpio-ir-tx.c | 189 +++++++++++++++++++++ 4 files changed, 212 insertions(+) create mode 100644 Documentation/devicetree/bindings/leds/irled/gpio-ir-tx.txt create mode 100644 drivers/media/rc/gpio-ir-tx.c diff --git a/Documentation/devicetree/bindings/leds/irled/gpio-ir-tx.txt b/Documentation/devicetree/bindings/leds/irled/gpio-ir-tx.txt new file mode 100644 index 0000000..bf4d4fb --- /dev/null +++ b/Documentation/devicetree/bindings/leds/irled/gpio-ir-tx.txt @@ -0,0 +1,11 @@ +Device tree bindings for IR LED connected through gpio pin which is used as +IR transmitter. + +Required properties: + - compatible: should be "gpio-ir-tx". + +Example: + irled@0 { + compatible = "gpio-ir-tx"; + gpios = <&gpio1 2 GPIO_ACTIVE_HIGH>; + }; diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig index 5e83b76..ad54011 100644 --- a/drivers/media/rc/Kconfig +++ b/drivers/media/rc/Kconfig @@ -388,6 +388,17 @@ config IR_GPIO_CIR To compile this driver as a module, choose M here: the module will be called gpio-ir-recv. +config IR_GPIO_TX + tristate "GPIO IR bit banging transmitter" + depends on RC_CORE + depends on LIRC + ---help--- + Say Y if you want to a GPIO based IR transmitter. This is a + bit banging driver. + + To compile this driver as a module, choose M here: the module will + be called gpio-ir-tx. + config RC_ST tristate "ST remote control receiver" depends on RC_CORE diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile index 245e2c2..3e64a4e 100644 --- a/drivers/media/rc/Makefile +++ b/drivers/media/rc/Makefile @@ -32,6 +32,7 @@ obj-$(CONFIG_IR_STREAMZAP) += streamzap.o obj-$(CONFIG_IR_WINBOND_CIR) += winbond-cir.o obj-$(CONFIG_RC_LOOPBACK) += rc-loopback.o obj-$(CONFIG_IR_GPIO_CIR) += gpio-ir-recv.o +obj-$(CONFIG_IR_GPIO_TX) += gpio-ir-tx.o obj-$(CONFIG_IR_IGORPLUGUSB) += igorplugusb.o obj-$(CONFIG_IR_IGUANA) += iguanair.o obj-$(CONFIG_IR_TTUSBIR) += ttusbir.o diff --git a/drivers/media/rc/gpio-ir-tx.c b/drivers/media/rc/gpio-ir-tx.c new file mode 100644 index 0000000..c2ea002 --- /dev/null +++ b/drivers/media/rc/gpio-ir-tx.c @@ -0,0 +1,189 @@ +/* + * Copyright (C) 2017 Sean Young + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRIVER_NAME "gpio-ir-tx" +#define DEVICE_NAME "GPIO IR Bit Banging Transmitter" + +struct gpio_rc_dev { + int gpio_nr; + unsigned int carrier; + unsigned int duty_cycle; + bool active_low; + /* we need a spinlock to hold the cpu while transmitting */ + spinlock_t lock; +}; + +static const struct of_device_id gpio_ir_tx_of_match[] = { + { .compatible = "gpio-ir-tx", }, + { }, +}; +MODULE_DEVICE_TABLE(of, gpio_ir_tx_of_match); + +static int gpio_ir_tx_set_duty_cycle(struct rc_dev *dev, u32 duty_cycle) +{ + struct gpio_rc_dev *gpio_dev = dev->priv; + + gpio_dev->duty_cycle = duty_cycle; + + return 0; +} + +static int gpio_ir_tx_set_carrier(struct rc_dev *dev, u32 carrier) +{ + struct gpio_rc_dev *gpio_dev = dev->priv; + + if (!carrier) + return -EINVAL; + + gpio_dev->carrier = carrier; + + return 0; +} + +static int gpio_ir_tx(struct rc_dev *dev, unsigned int *txbuf, + unsigned int count) +{ + struct gpio_rc_dev *gpio_dev = dev->priv; + unsigned long flags; + ktime_t edge; + s64 delta; + int i; + unsigned int pulse, space; + + /* Ensure the dividend fits into 32 bit */ + pulse = DIV_ROUND_CLOSEST(gpio_dev->duty_cycle * (NSEC_PER_SEC / 100), + gpio_dev->carrier); + space = DIV_ROUND_CLOSEST((100l - gpio_dev->duty_cycle) * + (NSEC_PER_SEC / 100), gpio_dev->carrier); + + spin_lock_irqsave(&gpio_dev->lock, flags); + + edge = ktime_get(); + + for (i = 0; i < count; i++) { + if (i % 2) { + // space + edge = ktime_add_us(edge, txbuf[i]); + delta = ktime_us_delta(edge, ktime_get()); + if (delta > 10) { + spin_unlock_irqrestore(&gpio_dev->lock, flags); + usleep_range(delta - 10, delta + 10); + spin_lock_irqsave(&gpio_dev->lock, flags); + } else if (delta > 0) { + udelay(delta); + } + } else { + // pulse + ktime_t last = ktime_add_us(edge, txbuf[i]); + + while (ktime_get() < last) { + gpio_set_value(gpio_dev->gpio_nr, + gpio_dev->active_low); + edge += pulse; + delta = ktime_sub(edge, ktime_get()); + if (delta > 0) + ndelay(delta); + gpio_set_value(gpio_dev->gpio_nr, + !gpio_dev->active_low); + edge += space; + delta = ktime_sub(edge, ktime_get()); + if (delta > 0) + ndelay(delta); + } + + edge = last; + } + } + + spin_unlock_irqrestore(&gpio_dev->lock, flags); + + return count; +} + +static int gpio_ir_tx_probe(struct platform_device *pdev) +{ + struct gpio_rc_dev *gpio_dev; + struct rc_dev *rcdev; + enum of_gpio_flags flags; + int rc, gpio; + + gpio = of_get_gpio_flags(pdev->dev.of_node, 0, &flags); + if (gpio < 0) { + if (gpio != -EPROBE_DEFER) + dev_err(&pdev->dev, "Failed to get gpio flags (%d)\n", + gpio); + return -EINVAL; + } + + gpio_dev = devm_kzalloc(&pdev->dev, sizeof(*gpio_dev), GFP_KERNEL); + if (!gpio_dev) + return -ENOMEM; + + rcdev = devm_rc_allocate_device(&pdev->dev, RC_DRIVER_IR_RAW_TX); + if (!rcdev) + return -ENOMEM; + + rcdev->priv = gpio_dev; + rcdev->driver_name = DRIVER_NAME; + rcdev->device_name = DEVICE_NAME; + rcdev->tx_ir = gpio_ir_tx; + rcdev->s_tx_duty_cycle = gpio_ir_tx_set_duty_cycle; + rcdev->s_tx_carrier = gpio_ir_tx_set_carrier; + + gpio_dev->gpio_nr = gpio; + gpio_dev->active_low = (flags & OF_GPIO_ACTIVE_LOW) != 0; + spin_lock_init(&gpio_dev->lock); + gpio_dev->carrier = 38000; + gpio_dev->duty_cycle = 50; + + rc = devm_gpio_request(&pdev->dev, gpio, "gpio-ir-tx"); + if (rc < 0) + return rc; + + rc = gpio_direction_output(gpio, !gpio_dev->active_low); + if (rc < 0) + return rc; + + rc = devm_rc_register_device(&pdev->dev, rcdev); + if (rc < 0) { + dev_err(&pdev->dev, "failed to register rc device\n"); + return rc; + } + + platform_set_drvdata(pdev, gpio_dev); + + return 0; +} + +static struct platform_driver gpio_ir_tx_driver = { + .probe = gpio_ir_tx_probe, + .driver = { + .name = DRIVER_NAME, + .of_match_table = of_match_ptr(gpio_ir_tx_of_match), + }, +}; +module_platform_driver(gpio_ir_tx_driver); + +MODULE_DESCRIPTION("GPIO IR Bit Banging Transmitter"); +MODULE_AUTHOR("Sean Young "); +MODULE_LICENSE("GPL");