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    SubjectRe: [PATCH v2 7/7] [media] rc: add support for IR LEDs driven through SPI
    Thanks Andi, this is looking great!

    On Fri, Sep 02, 2016 at 02:16:29AM +0900, Andi Shyti wrote:
    > The ir-spi is a simple device driver which supports the
    > connection between an IR LED and the MOSI line of an SPI device.
    >
    > The driver, indeed, uses the SPI framework to stream the raw data
    > provided by userspace through an rc character device. The chardev
    > is handled by the LIRC framework and its functionality basically
    > provides:
    >
    > - write: the driver gets a pulse/space signal and translates it
    > to a binary signal that will be streamed to the IR led through
    > the SPI framework.
    > - set frequency: sets the frequency whith which the data should
    > be sent. This is handle with ioctl with the
    > LIRC_SET_SEND_CARRIER flag (as per lirc documentation)
    > - set duty cycle: this is also handled with ioctl with the
    > LIRC_SET_SEND_DUTY_CYCLE flag. The driver handles duty cycles
    > of 50%, 60%, 70%, 75%, 80% and 90%, calculated on 16bit data.
    >
    > The character device is created under /dev/lircX name, where X is
    > and ID assigned by the LIRC framework.
    >
    > Example of usage:
    >
    > fd = open("/dev/lirc0", O_RDWR);
    > if (fd < 0)
    > return -1;
    >
    > val = 608000;
    > ret = ioctl(fd, LIRC_SET_SEND_CARRIER, &val);
    > if (ret < 0)
    > return -1;
    >
    > val = 60;
    > ret = ioctl(fd, LIRC_SET_SEND_DUTY_CYCLE, &val);
    > if (ret < 0)
    > return -1;
    >
    > n = write(fd, buffer, BUF_LEN);
    > if (n < 0 || n != BUF_LEN)
    > ret = -1;
    >
    > close(fd);
    >
    > Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
    > ---
    > drivers/media/rc/Kconfig | 9 ++
    > drivers/media/rc/Makefile | 1 +
    > drivers/media/rc/ir-spi.c | 221 ++++++++++++++++++++++++++++++++++++++++++++++
    > 3 files changed, 231 insertions(+)
    > create mode 100644 drivers/media/rc/ir-spi.c
    >
    > diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
    > index 370e16e..207dfcc 100644
    > --- a/drivers/media/rc/Kconfig
    > +++ b/drivers/media/rc/Kconfig
    > @@ -261,6 +261,15 @@ config IR_REDRAT3
    > To compile this driver as a module, choose M here: the
    > module will be called redrat3.
    >
    > +config IR_SPI
    > + tristate "SPI connected IR LED"
    > + depends on SPI && LIRC
    > + ---help---
    > + Say Y if you want to use an IR LED connected through SPI bus.
    > +
    > + To compile this driver as a module, choose M here: the module will be
    > + called ir-spi.
    > +
    > config IR_STREAMZAP
    > tristate "Streamzap PC Remote IR Receiver"
    > depends on USB_ARCH_HAS_HCD
    > diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
    > index 379a5c0..1417c8d 100644
    > --- a/drivers/media/rc/Makefile
    > +++ b/drivers/media/rc/Makefile
    > @@ -27,6 +27,7 @@ obj-$(CONFIG_IR_NUVOTON) += nuvoton-cir.o
    > obj-$(CONFIG_IR_ENE) += ene_ir.o
    > obj-$(CONFIG_IR_REDRAT3) += redrat3.o
    > obj-$(CONFIG_IR_RX51) += ir-rx51.o
    > +obj-$(CONFIG_IR_SPI) += ir-spi.o
    > obj-$(CONFIG_IR_STREAMZAP) += streamzap.o
    > obj-$(CONFIG_IR_WINBOND_CIR) += winbond-cir.o
    > obj-$(CONFIG_RC_LOOPBACK) += rc-loopback.o
    > diff --git a/drivers/media/rc/ir-spi.c b/drivers/media/rc/ir-spi.c
    > new file mode 100644
    > index 0000000..34d5a0c
    > --- /dev/null
    > +++ b/drivers/media/rc/ir-spi.c
    > @@ -0,0 +1,221 @@
    > +/*
    > + * Copyright (c) 2016 Samsung Electronics Co., Ltd.
    > + * Author: Andi Shyti <andi.shyti@samsung.com>
    > + *
    > + * This program is free software; you can redistribute it and/or modify
    > + * it under the terms of the GNU General Public License version 2 as
    > + * published by the Free Software Foundation.
    > + *
    > + * SPI driven IR LED device driver
    > + */
    > +
    > +#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"
    > +
    > +/* pulse value for different duty cycles */
    > +#define IR_SPI_PULSE_DC_50 0xff00
    > +#define IR_SPI_PULSE_DC_60 0xfc00
    > +#define IR_SPI_PULSE_DC_70 0xf800
    > +#define IR_SPI_PULSE_DC_75 0xf000
    > +#define IR_SPI_PULSE_DC_80 0xc000
    > +#define IR_SPI_PULSE_DC_90 0x8000
    > +
    > +/* duty cycles values */
    > +#define IR_SPI_DUTY_CYCLE_50 50
    > +#define IR_SPI_DUTY_CYCLE_60 60
    > +#define IR_SPI_DUTY_CYCLE_70 70
    > +#define IR_SPI_DUTY_CYCLE_75 75
    > +#define IR_SPI_DUTY_CYCLE_80 80
    > +#define IR_SPI_DUTY_CYCLE_90 90

    Not sure what these defines are for. 50 = 50?

    > +
    > +#define IR_SPI_DEFAULT_FREQUENCY 38000
    > +#define IR_SPI_BIT_PER_WORD 8
    > +#define IR_SPI_MAX_BUFSIZE 4096
    > +
    > +struct ir_spi_data {
    > + u32 freq;
    > + u8 duty_cycle;
    > + 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++) {
    > + int j;
    > + u16 val = ((i+1) % 2) ? idata->pulse : idata->space;
    > +
    > + if (len + buffer[i] >= 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 < buffer[i]; j++)
    > + idata->tx_buf[len++] = val;
    > + }
    > +
    > + pr_info("from %u data, we originated %u raw data\n", count, len);
    > +
    > + memset(&xfer, 0, sizeof(xfer));
    > +
    > + xfer.speed_hz = idata->freq;
    > + 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 : len;

    On success you should be returning count, not the length of the spi
    bitstream.

    > +}
    > +
    > +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;
    > +
    > + switch (duty_cycle) {
    > + case IR_SPI_DUTY_CYCLE_90:
    > + idata->pulse = IR_SPI_PULSE_DC_90;
    > + break;
    > + case IR_SPI_DUTY_CYCLE_80:
    > + idata->pulse = IR_SPI_PULSE_DC_80;
    > + break;
    > + case IR_SPI_DUTY_CYCLE_75:
    > + idata->pulse = IR_SPI_PULSE_DC_75;
    > + break;
    > + case IR_SPI_DUTY_CYCLE_70:
    > + idata->pulse = IR_SPI_PULSE_DC_70;
    > + break;
    > + case IR_SPI_DUTY_CYCLE_60:
    > + idata->pulse = IR_SPI_PULSE_DC_60;
    > + break;
    > + case IR_SPI_DUTY_CYCLE_50:
    > + default:
    > + idata->pulse = IR_SPI_PULSE_DC_50;
    > + }

    It seems a bit odd that if you set a duty cycle of (say) 61 get a duty
    cycle of 50. Maybe something like:

    if (duty_cycle >= 90)
    idata->pulse = IR_SPI_PULSE_DC_90;
    else if (duty_cycle >= 80)
    idata->pulse = IR_SPI_PULSE_DC_80;
    else if (duty_cycle >= 75)
    idata->pulse = IR_SPI_PULSE_DC_75;
    else if (duty_cycle >= 70)
    idata->pulse = IR_SPI_PULSE_DC_70;
    else if (duty_cycle >= 60)
    idata->pulse = IR_SPI_PULSE_DC_60;
    else
    idata->pulse = IR_SPI_PULSE_DC_50;

    > +
    > + 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 = rc_allocate_device(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->driver_name = IR_SPI_DRIVER_NAME;
    > + idata->rc->priv = idata;
    > + idata->spi = spi;
    > +
    > + idata->negated = of_property_read_bool(spi->dev.of_node, "negated");
    > + ret = of_property_read_u8(spi->dev.of_node, "duty-cycle", &dc);
    > + if (ret)
    > + dc = IR_SPI_DUTY_CYCLE_50;
    > +
    > + ret = ir_spi_set_duty_cycle(idata->rc, dc);
    > + if (ret)
    > + return ret;
    > +
    > + idata->freq = IR_SPI_DEFAULT_FREQUENCY;
    > +
    > + ret = rc_register_device(idata->rc);
    > + if (ret)
    > + rc_unregister_device(idata->rc);

    Surely you mean rc_free_device(idata->rc) here.

    > +
    > + return ret;
    > +}
    > +
    > +static int ir_spi_remove(struct spi_device *spi)
    > +{
    > + struct ir_spi_data *idata = spi_get_drvdata(spi);
    > +
    > + rc_unregister_device(idata->rc);
    > +
    > + return 0;
    > +}
    > +
    > +static const struct of_device_id ir_spi_of_match[] = {
    > + { .compatible = "ir-spi" },
    > + {},
    > +};
    > +
    > +static struct spi_driver ir_spi_driver = {
    > + .probe = ir_spi_probe,
    > + .remove = ir_spi_remove,
    > + .driver = {
    > + .name = IR_SPI_DRIVER_NAME,
    > + .of_match_table = ir_spi_of_match,
    > + },
    > +};
    > +
    > +module_spi_driver(ir_spi_driver);
    > +
    > +MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
    > +MODULE_DESCRIPTION("SPI IR LED");
    > +MODULE_LICENSE("GPL v2");
    > --
    > 2.9.3

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      Last update: 2016-09-17 09:58    [W:4.312 / U:0.208 seconds]
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