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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/media/rc/gpio-ir-tx.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/media/rc/gpio-ir-tx.c')
-rw-r--r--drivers/media/rc/gpio-ir-tx.c209
1 files changed, 209 insertions, 0 deletions
diff --git a/drivers/media/rc/gpio-ir-tx.c b/drivers/media/rc/gpio-ir-tx.c
new file mode 100644
index 0000000000..1a8fea357f
--- /dev/null
+++ b/drivers/media/rc/gpio-ir-tx.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2017 Sean Young <sean@mess.org>
+ */
+
+#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;
+};
+
+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 > 500000)
+ return -EINVAL;
+
+ gpio_ir->carrier = carrier;
+
+ return 0;
+}
+
+static void delay_until(ktime_t until)
+{
+ /*
+ * 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;
+
+ while (true) {
+ delta = ktime_us_delta(until, ktime_get());
+ if (delta <= 0)
+ return;
+
+ /* udelay more than 1ms may not work */
+ if (delta >= 1000) {
+ mdelay(delta / 1000);
+ continue;
+ }
+
+ udelay(delta);
+ break;
+ }
+}
+
+static void gpio_ir_tx_unmodulated(struct gpio_ir *gpio_ir, uint *txbuf,
+ uint count)
+{
+ ktime_t edge;
+ int i;
+
+ local_irq_disable();
+
+ edge = ktime_get();
+
+ for (i = 0; i < count; i++) {
+ gpiod_set_value(gpio_ir->gpio, !(i % 2));
+
+ edge = ktime_add_us(edge, txbuf[i]);
+ delay_until(edge);
+ }
+
+ gpiod_set_value(gpio_ir->gpio, 0);
+}
+
+static void gpio_ir_tx_modulated(struct gpio_ir *gpio_ir, uint *txbuf,
+ uint count)
+{
+ 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);
+
+ local_irq_disable();
+
+ edge = ktime_get();
+
+ for (i = 0; i < count; i++) {
+ if (i % 2) {
+ // space
+ edge = ktime_add_us(edge, txbuf[i]);
+ delay_until(edge);
+ } else {
+ // pulse
+ ktime_t last = ktime_add_us(edge, txbuf[i]);
+
+ while (ktime_before(ktime_get(), last)) {
+ gpiod_set_value(gpio_ir->gpio, 1);
+ edge = ktime_add_ns(edge, pulse);
+ delta = ktime_to_ns(ktime_sub(edge,
+ ktime_get()));
+ if (delta > 0)
+ ndelay(delta);
+ gpiod_set_value(gpio_ir->gpio, 0);
+ edge = ktime_add_ns(edge, space);
+ delta = ktime_to_ns(ktime_sub(edge,
+ ktime_get()));
+ if (delta > 0)
+ ndelay(delta);
+ }
+
+ edge = last;
+ }
+ }
+}
+
+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;
+
+ local_irq_save(flags);
+ if (gpio_ir->carrier)
+ gpio_ir_tx_modulated(gpio_ir, txbuf, count);
+ else
+ gpio_ir_tx_unmodulated(gpio_ir, txbuf, count);
+ local_irq_restore(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))
+ return dev_err_probe(&pdev->dev, PTR_ERR(gpio_ir->gpio),
+ "Failed to get gpio\n");
+
+ 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;
+
+ 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 = 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");