diff options
| -rw-r--r-- | MAINTAINERS | 6 | ||||
| -rw-r--r-- | drivers/media/rc/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/media/rc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/media/rc/gpio-ir-tx.c | 174 |
4 files changed, 192 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 55d756712baf..a4736049d1f1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5769,6 +5769,12 @@ S: Maintained F: Documentation/acpi/gpio-properties.txt F: drivers/gpio/gpiolib-acpi.c +GPIO IR Transmitter +M: Sean Young <sean@mess.org> +L: linux-media@vger.kernel.org +S: Maintained +F: drivers/media/rc/gpio-ir-tx.c + GPIO MOCKUP DRIVER M: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> L: linux-gpio@vger.kernel.org diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig index b6433c57a024..06179d37a7c7 100644 --- a/drivers/media/rc/Kconfig +++ b/drivers/media/rc/Kconfig @@ -399,6 +399,17 @@ 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 245e2c2d0b22..3e64a4e4b312 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 000000000000..0b83408a2e18 --- /dev/null +++ b/drivers/media/rc/gpio-ir-tx.c @@ -0,0 +1,174 @@ +/* + * Copyright (C) 2017 Sean Young <sean@mess.org> + * + * 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 <linux/kernel.h> +#include <linux/module.h> +#include <linux/gpio/consumer.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <media/rc-core.h> + +#define DRIVER_NAME "gpio-ir-tx" +#define DEVICE_NAME "GPIO IR Bit Banging Transmitter" + +struct gpio_ir { + struct gpio_desc *gpio; + unsigned int carrier; + unsigned int duty_cycle; + /* 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_ir *gpio_ir = dev->priv; + + gpio_ir->duty_cycle = duty_cycle; + + return 0; +} + +static int gpio_ir_tx_set_carrier(struct rc_dev *dev, u32 carrier) +{ + struct gpio_ir *gpio_ir = dev->priv; + + if (!carrier) + return -EINVAL; + + gpio_ir->carrier = carrier; + + return 0; +} + +static int gpio_ir_tx(struct rc_dev *dev, unsigned int *txbuf, + unsigned int count) +{ + struct gpio_ir *gpio_ir = dev->priv; + unsigned long flags; + ktime_t edge; + /* + * delta should never exceed 0.5 seconds (IR_MAX_DURATION) and on + * m68k ndelay(s64) does not compile; so use s32 rather than s64. + */ + s32 delta; + int i; + unsigned int pulse, space; + + /* Ensure the dividend fits into 32 bit */ + pulse = DIV_ROUND_CLOSEST(gpio_ir->duty_cycle * (NSEC_PER_SEC / 100), + gpio_ir->carrier); + space = DIV_ROUND_CLOSEST((100 - gpio_ir->duty_cycle) * + (NSEC_PER_SEC / 100), gpio_ir->carrier); + + spin_lock_irqsave(&gpio_ir->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_ir->lock, flags); + usleep_range(delta, delta + 10); + spin_lock_irqsave(&gpio_ir->lock, flags); + } else if (delta > 0) { + udelay(delta); + } + } else { + // pulse + ktime_t last = ktime_add_us(edge, txbuf[i]); + + while (ktime_get() < last) { + gpiod_set_value(gpio_ir->gpio, 1); + edge += pulse; + delta = edge - ktime_get(); + if (delta > 0) + ndelay(delta); + gpiod_set_value(gpio_ir->gpio, 0); + edge += space; + delta = edge - ktime_get(); + if (delta > 0) + ndelay(delta); + } + + edge = last; + } + } + + spin_unlock_irqrestore(&gpio_ir->lock, flags); + + return count; +} + +static int gpio_ir_tx_probe(struct platform_device *pdev) +{ + struct gpio_ir *gpio_ir; + struct rc_dev *rcdev; + int rc; + + gpio_ir = devm_kmalloc(&pdev->dev, sizeof(*gpio_ir), GFP_KERNEL); + if (!gpio_ir) + return -ENOMEM; + + rcdev = devm_rc_allocate_device(&pdev->dev, RC_DRIVER_IR_RAW_TX); + if (!rcdev) + return -ENOMEM; + + gpio_ir->gpio = devm_gpiod_get(&pdev->dev, NULL, GPIOD_OUT_LOW); + if (IS_ERR(gpio_ir->gpio)) { + if (PTR_ERR(gpio_ir->gpio) != -EPROBE_DEFER) + dev_err(&pdev->dev, "Failed to get gpio (%ld)\n", + PTR_ERR(gpio_ir->gpio)); + return PTR_ERR(gpio_ir->gpio); + } + + rcdev->priv = gpio_ir; + 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_ir->carrier = 38000; + gpio_ir->duty_cycle = 50; + spin_lock_init(&gpio_ir->lock); + + rc = devm_rc_register_device(&pdev->dev, rcdev); + if (rc < 0) + dev_err(&pdev->dev, "failed to register rc device\n"); + + return rc; +} + +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 <sean@mess.org>"); +MODULE_LICENSE("GPL"); |