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Diffstat (limited to 'drivers/media/rc/ir-spi.c')
-rw-r--r--drivers/media/rc/ir-spi.c173
1 files changed, 173 insertions, 0 deletions
diff --git a/drivers/media/rc/ir-spi.c b/drivers/media/rc/ir-spi.c
new file mode 100644
index 000000000..51aa55a84
--- /dev/null
+++ b/drivers/media/rc/ir-spi.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+// SPI driven IR LED device driver
+//
+// Copyright (c) 2016 Samsung Electronics Co., Ltd.
+// Copyright (c) Andi Shyti <andi@etezian.org>
+
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_gpio.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <media/rc-core.h>
+
+#define IR_SPI_DRIVER_NAME "ir-spi"
+
+#define IR_SPI_DEFAULT_FREQUENCY 38000
+#define IR_SPI_MAX_BUFSIZE 4096
+
+struct ir_spi_data {
+ u32 freq;
+ bool negated;
+
+ u16 tx_buf[IR_SPI_MAX_BUFSIZE];
+ u16 pulse;
+ u16 space;
+
+ struct rc_dev *rc;
+ struct spi_device *spi;
+ struct regulator *regulator;
+};
+
+static int ir_spi_tx(struct rc_dev *dev,
+ unsigned int *buffer, unsigned int count)
+{
+ int i;
+ int ret;
+ unsigned int len = 0;
+ struct ir_spi_data *idata = dev->priv;
+ struct spi_transfer xfer;
+
+ /* convert the pulse/space signal to raw binary signal */
+ for (i = 0; i < count; i++) {
+ unsigned int periods;
+ int j;
+ u16 val;
+
+ periods = DIV_ROUND_CLOSEST(buffer[i] * idata->freq, 1000000);
+
+ if (len + periods >= IR_SPI_MAX_BUFSIZE)
+ return -EINVAL;
+
+ /*
+ * the first value in buffer is a pulse, so that 0, 2, 4, ...
+ * contain a pulse duration. On the contrary, 1, 3, 5, ...
+ * contain a space duration.
+ */
+ val = (i % 2) ? idata->space : idata->pulse;
+ for (j = 0; j < periods; j++)
+ idata->tx_buf[len++] = val;
+ }
+
+ memset(&xfer, 0, sizeof(xfer));
+
+ xfer.speed_hz = idata->freq * 16;
+ xfer.len = len * sizeof(*idata->tx_buf);
+ xfer.tx_buf = idata->tx_buf;
+
+ ret = regulator_enable(idata->regulator);
+ if (ret)
+ return ret;
+
+ ret = spi_sync_transfer(idata->spi, &xfer, 1);
+ if (ret)
+ dev_err(&idata->spi->dev, "unable to deliver the signal\n");
+
+ regulator_disable(idata->regulator);
+
+ return ret ? ret : count;
+}
+
+static int ir_spi_set_tx_carrier(struct rc_dev *dev, u32 carrier)
+{
+ struct ir_spi_data *idata = dev->priv;
+
+ if (!carrier)
+ return -EINVAL;
+
+ idata->freq = carrier;
+
+ return 0;
+}
+
+static int ir_spi_set_duty_cycle(struct rc_dev *dev, u32 duty_cycle)
+{
+ struct ir_spi_data *idata = dev->priv;
+ int bits = (duty_cycle * 15) / 100;
+
+ idata->pulse = GENMASK(bits, 0);
+
+ if (idata->negated) {
+ idata->pulse = ~idata->pulse;
+ idata->space = 0xffff;
+ } else {
+ idata->space = 0;
+ }
+
+ return 0;
+}
+
+static int ir_spi_probe(struct spi_device *spi)
+{
+ int ret;
+ u8 dc;
+ struct ir_spi_data *idata;
+
+ idata = devm_kzalloc(&spi->dev, sizeof(*idata), GFP_KERNEL);
+ if (!idata)
+ return -ENOMEM;
+
+ idata->regulator = devm_regulator_get(&spi->dev, "irda_regulator");
+ if (IS_ERR(idata->regulator))
+ return PTR_ERR(idata->regulator);
+
+ idata->rc = devm_rc_allocate_device(&spi->dev, RC_DRIVER_IR_RAW_TX);
+ if (!idata->rc)
+ return -ENOMEM;
+
+ idata->rc->tx_ir = ir_spi_tx;
+ idata->rc->s_tx_carrier = ir_spi_set_tx_carrier;
+ idata->rc->s_tx_duty_cycle = ir_spi_set_duty_cycle;
+ idata->rc->device_name = "IR SPI";
+ idata->rc->driver_name = IR_SPI_DRIVER_NAME;
+ idata->rc->priv = idata;
+ idata->spi = spi;
+
+ idata->negated = of_property_read_bool(spi->dev.of_node,
+ "led-active-low");
+ ret = of_property_read_u8(spi->dev.of_node, "duty-cycle", &dc);
+ if (ret)
+ dc = 50;
+
+ /* ir_spi_set_duty_cycle cannot fail,
+ * it returns int to be compatible with the
+ * rc->s_tx_duty_cycle function
+ */
+ ir_spi_set_duty_cycle(idata->rc, dc);
+
+ idata->freq = IR_SPI_DEFAULT_FREQUENCY;
+
+ return devm_rc_register_device(&spi->dev, idata->rc);
+}
+
+static const struct of_device_id ir_spi_of_match[] = {
+ { .compatible = "ir-spi-led" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ir_spi_of_match);
+
+static struct spi_driver ir_spi_driver = {
+ .probe = ir_spi_probe,
+ .driver = {
+ .name = IR_SPI_DRIVER_NAME,
+ .of_match_table = ir_spi_of_match,
+ },
+};
+
+module_spi_driver(ir_spi_driver);
+
+MODULE_AUTHOR("Andi Shyti <andi@etezian.org>");
+MODULE_DESCRIPTION("SPI IR LED");
+MODULE_LICENSE("GPL v2");