diff mbox

[v2,4/6,media] rc: pwm-ir-tx: add new driver

Message ID ae8550faaabeb0d1c9f3b65f29ea32bd8c259146.1499419624.git.sean@mess.org (mailing list archive)
State New, archived
Headers show

Commit Message

Sean Young July 7, 2017, 9:52 a.m. UTC 
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 <sean@mess.org>
---
 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

Comments

Pavel Machek July 7, 2017, 4:48 p.m. UTC | #1 
On Fri 2017-07-07 10:52:02, Sean Young wrote:
> 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 <sean@mess.org>
> ---
>  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

nothing apparently wrong.

Reviewed-by: Pavel Machek <pavel@ucw.cz>
Matthias Reichl July 21, 2017, 9:12 p.m. UTC | #2 
Hi Sean,

sorry for double-post, forgot to CC the list and others.

On Fri, Jul 07, 2017 at 10:52:02AM +0100, Sean Young wrote:
> 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 <sean@mess.org>

Tested-by: Matthias Reichl <hias@horus.com>

Tested on RPi2, with downstream RPi kernel 4.13-rc1, using
ir-ctl to send RC-5 codes, against another RPi with gpio-ir-recv.
Also verified signal polarity and frequency on scope.

so long & thanks a lot,

Hias

> ---
>  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 8a37c2f..446a528 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -10449,6 +10449,12 @@ 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 <sean@mess.org>
> +L:	linux-media@vger.kernel.org
> +S:	Maintained
> +F:	drivers/media/rc/pwm-ir-tx.c
> +
>  PWM SUBSYSTEM
>  M:	Thierry Reding <thierry.reding@gmail.com>
>  L:	linux-pwm@vger.kernel.org
> diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
> index ef767d1..bca77f0 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 3e64a4e..466c402 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 0000000..27d0f58
> --- /dev/null
> +++ b/drivers/media/rc/pwm-ir-tx.c
> @@ -0,0 +1,138 @@
> +/*
> + * 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/pwm.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	"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 <sean@mess.org>");
> +MODULE_LICENSE("GPL");
> -- 
> 2.9.4
>
diff mbox

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 8a37c2f..446a528 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10449,6 +10449,12 @@  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 <sean@mess.org>
+L:	linux-media@vger.kernel.org
+S:	Maintained
+F:	drivers/media/rc/pwm-ir-tx.c
+
 PWM SUBSYSTEM
 M:	Thierry Reding <thierry.reding@gmail.com>
 L:	linux-pwm@vger.kernel.org
diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
index ef767d1..bca77f0 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 3e64a4e..466c402 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 0000000..27d0f58
--- /dev/null
+++ b/drivers/media/rc/pwm-ir-tx.c
@@ -0,0 +1,138 @@ 
+/*
+ * 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/pwm.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	"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 <sean@mess.org>");
+MODULE_LICENSE("GPL");