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@xxxxxxxx>
---
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@xxxxxxxx>
+L: linux-media@xxxxxxxxxxxxxxx
+S: Maintained
+F: drivers/media/rc/pwm-ir-tx.c
+
PWM SUBSYSTEM
M: Thierry Reding <thierry.reding@xxxxxxxxx>
L: linux-pwm@xxxxxxxxxxxxxxx
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@xxxxxxxx>
+ *
+ * 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@xxxxxxxx>");
+MODULE_LICENSE("GPL");
--
2.9.4
