From db3df8765e38db994d602435e578f6e1b41e7a87 Mon Sep 17 00:00:00 2001 From: Sean Young Date: Fri, 7 Jul 2017 05:52:02 -0400 Subject: [PATCH] media: rc: pwm-ir-tx: add new driver This is new driver which uses pwm, so it is more power-efficient than the bit banging gpio-ir-tx driver. Signed-off-by: Sean Young Reviewed-by: Pavel Machek Tested-by: Matthias Reichl Signed-off-by: Mauro Carvalho Chehab --- MAINTAINERS | 6 ++ drivers/media/rc/Kconfig | 12 +++ drivers/media/rc/Makefile | 1 + drivers/media/rc/pwm-ir-tx.c | 138 +++++++++++++++++++++++++++++++++++ 4 files changed, 157 insertions(+) create mode 100644 drivers/media/rc/pwm-ir-tx.c diff --git a/MAINTAINERS b/MAINTAINERS index a4736049d1f1..38471657e222 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10794,6 +10794,12 @@ F: Documentation/devicetree/bindings/hwmon/pwm-fan.txt F: Documentation/hwmon/pwm-fan F: drivers/hwmon/pwm-fan.c +PWM IR Transmitter +M: Sean Young +L: linux-media@vger.kernel.org +S: Maintained +F: drivers/media/rc/pwm-ir-tx.c + PWM SUBSYSTEM M: Thierry Reding L: linux-pwm@vger.kernel.org diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig index 06179d37a7c7..d27be2516974 100644 --- a/drivers/media/rc/Kconfig +++ b/drivers/media/rc/Kconfig @@ -410,6 +410,18 @@ config IR_GPIO_TX To compile this driver as a module, choose M here: the module will be called gpio-ir-tx. +config IR_PWM_TX + tristate "PWM IR transmitter" + depends on RC_CORE + depends on LIRC + depends on PWM + ---help--- + Say Y if you want to use a PWM based IR transmitter. This is + more power efficient than the bit banging gpio driver. + + To compile this driver as a module, choose M here: the module will + be called pwm-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 3e64a4e4b312..466c40216347 100644 --- a/drivers/media/rc/Makefile +++ b/drivers/media/rc/Makefile @@ -33,6 +33,7 @@ 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-$(CONFIG_IR_PWM_TX) += pwm-ir-tx.o obj-$(CONFIG_IR_IGORPLUGUSB) += igorplugusb.o obj-$(CONFIG_IR_IGUANA) += iguanair.o obj-$(CONFIG_IR_TTUSBIR) += ttusbir.o diff --git a/drivers/media/rc/pwm-ir-tx.c b/drivers/media/rc/pwm-ir-tx.c new file mode 100644 index 000000000000..27d0f5837a76 --- /dev/null +++ b/drivers/media/rc/pwm-ir-tx.c @@ -0,0 +1,138 @@ +/* + * 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 + +#define DRIVER_NAME "pwm-ir-tx" +#define DEVICE_NAME "PWM IR Transmitter" + +struct pwm_ir { + struct pwm_device *pwm; + unsigned int carrier; + unsigned int duty_cycle; +}; + +static const struct of_device_id pwm_ir_of_match[] = { + { .compatible = "pwm-ir-tx", }, + { }, +}; +MODULE_DEVICE_TABLE(of, pwm_ir_of_match); + +static int pwm_ir_set_duty_cycle(struct rc_dev *dev, u32 duty_cycle) +{ + struct pwm_ir *pwm_ir = dev->priv; + + pwm_ir->duty_cycle = duty_cycle; + + return 0; +} + +static int pwm_ir_set_carrier(struct rc_dev *dev, u32 carrier) +{ + struct pwm_ir *pwm_ir = dev->priv; + + if (!carrier) + return -EINVAL; + + pwm_ir->carrier = carrier; + + return 0; +} + +static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf, + unsigned int count) +{ + struct pwm_ir *pwm_ir = dev->priv; + struct pwm_device *pwm = pwm_ir->pwm; + int i, duty, period; + ktime_t edge; + long delta; + + period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, pwm_ir->carrier); + duty = DIV_ROUND_CLOSEST(pwm_ir->duty_cycle * period, 100); + + pwm_config(pwm, duty, period); + + edge = ktime_get(); + + for (i = 0; i < count; i++) { + if (i % 2) // space + pwm_disable(pwm); + else + pwm_enable(pwm); + + edge = ktime_add_us(edge, txbuf[i]); + delta = ktime_us_delta(edge, ktime_get()); + if (delta > 0) + usleep_range(delta, delta + 10); + } + + pwm_disable(pwm); + + return count; +} + +static int pwm_ir_probe(struct platform_device *pdev) +{ + struct pwm_ir *pwm_ir; + struct rc_dev *rcdev; + int rc; + + pwm_ir = devm_kmalloc(&pdev->dev, sizeof(*pwm_ir), GFP_KERNEL); + if (!pwm_ir) + return -ENOMEM; + + pwm_ir->pwm = devm_pwm_get(&pdev->dev, NULL); + if (IS_ERR(pwm_ir->pwm)) + return PTR_ERR(pwm_ir->pwm); + + pwm_ir->carrier = 38000; + pwm_ir->duty_cycle = 50; + + rcdev = devm_rc_allocate_device(&pdev->dev, RC_DRIVER_IR_RAW_TX); + if (!rcdev) + return -ENOMEM; + + rcdev->priv = pwm_ir; + rcdev->driver_name = DRIVER_NAME; + rcdev->device_name = DEVICE_NAME; + rcdev->tx_ir = pwm_ir_tx; + rcdev->s_tx_duty_cycle = pwm_ir_set_duty_cycle; + rcdev->s_tx_carrier = pwm_ir_set_carrier; + + 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 pwm_ir_driver = { + .probe = pwm_ir_probe, + .driver = { + .name = DRIVER_NAME, + .of_match_table = of_match_ptr(pwm_ir_of_match), + }, +}; +module_platform_driver(pwm_ir_driver); + +MODULE_DESCRIPTION("PWM IR Transmitter"); +MODULE_AUTHOR("Sean Young "); +MODULE_LICENSE("GPL"); -- 2.20.1