On Fri, Nov 20, 2020 at 8:31 AM Matt Ranostay
<matt.ranostay@xxxxxxxxxxxx> wrote:
>
> Add support for the three 10-bit ADC channels registered via
> the IIO subsystem.
>
> Cc: linux-input@xxxxxxxxxxxxxxx
> Cc: linux-iio@xxxxxxxxxxxxxxx
> CC: Rishi Gupta <gupt21@xxxxxxxxx>
> Signed-off-by: Matt Ranostay <matt.ranostay@xxxxxxxxxxxx>
> ---
> drivers/hid/Kconfig | 1 +
> drivers/hid/hid-mcp2221.c | 65 ++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 65 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
> index 05315b434276..4795744d9979 100644
> --- a/drivers/hid/Kconfig
> +++ b/drivers/hid/Kconfig
> @@ -1157,6 +1157,7 @@ config HID_MCP2221
> tristate "Microchip MCP2221 HID USB-to-I2C/SMbus host support"
> depends on USB_HID && I2C
> depends on GPIOLIB
> + depends on IIO
I am wondering what will happen on systems which do not enable IIO.
This driver can not be used there.
Is my understanding correct?
> help
> Provides I2C and SMBUS host adapter functionality over USB-HID
> through MCP2221 device.
> diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c
> index 0d27ccb55dd9..7e62f1dc54d3 100644
> --- a/drivers/hid/hid-mcp2221.c
> +++ b/drivers/hid/hid-mcp2221.c
> @@ -18,6 +18,9 @@
> #include <linux/gpio/driver.h>
> #include "hid-ids.h"
>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> /* Commands codes in a raw output report */
> enum {
> MCP2221_I2C_WR_DATA = 0x90,
> @@ -56,6 +59,7 @@ enum {
> */
> struct mcp2221 {
> struct hid_device *hdev;
> + struct iio_dev *indio_dev;
> struct i2c_adapter adapter;
> struct mutex lock;
> struct completion wait_in_report;
> @@ -67,6 +71,11 @@ struct mcp2221 {
> struct gpio_chip *gc;
> u8 gp_idx;
> u8 gpio_dir;
> + u16 adc_values[3];
> +};
> +
> +struct mcp2221_iio {
> + struct mcp2221 *mcp;
> };
>
> /*
> @@ -712,6 +721,7 @@ static int mcp2221_raw_event(struct hid_device *hdev,
> break;
> }
> mcp->status = mcp_get_i2c_eng_state(mcp, data, 8);
> + memcpy(&mcp->adc_values, &data[50], 6);
> break;
> default:
> mcp->status = -EIO;
> @@ -791,11 +801,54 @@ static int mcp2221_raw_event(struct hid_device *hdev,
> return 1;
> }
>
> +static int mcp2221_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *channel, int *val,
> + int *val2, long mask)
> +{
> +
> + struct mcp2221_iio *priv = iio_priv(indio_dev);
> + struct mcp2221 *mcp = priv->mcp;
> + int ret;
> +
> + mutex_lock(&mcp->lock);
> +
> + /* Read ADC values */
> + ret = mcp_chk_last_cmd_status(mcp);
> + if (ret < 0)
> + return ret;
> +
> + *val = le16_to_cpu(mcp->adc_values[channel->channel]);
> +
> + mutex_unlock(&mcp->lock);
> +
> + return IIO_VAL_INT;
> +}
> +
> +static const struct iio_info mcp2221_info = {
> + .read_raw = &mcp2221_read_raw,
> +};
> +
> +#define MCP2221_ADC_CHANNEL(idx) \
> + { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = idx, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .scan_index = -1, \
> + }
> +
> +static const struct iio_chan_spec mcp2221_channels[] = {
> + MCP2221_ADC_CHANNEL(0),
> + MCP2221_ADC_CHANNEL(1),
> + MCP2221_ADC_CHANNEL(2),
> +};
> +
> static int mcp2221_probe(struct hid_device *hdev,
> const struct hid_device_id *id)
> {
> int ret;
> struct mcp2221 *mcp;
> + struct mcp2221_iio *iio;
>
> mcp = devm_kzalloc(&hdev->dev, sizeof(*mcp), GFP_KERNEL);
> if (!mcp)
> @@ -869,8 +922,17 @@ static int mcp2221_probe(struct hid_device *hdev,
> if (ret)
> goto err_gc;
>
> - return 0;
> + mcp->indio_dev = devm_iio_device_alloc(&hdev->dev, sizeof(*iio));
> + iio = iio_priv(mcp->indio_dev);
> + iio->mcp = mcp;
> +
> + mcp->indio_dev->name = "mcp2221_adc";
> + mcp->indio_dev->modes = INDIO_DIRECT_MODE;
> + mcp->indio_dev->info = &mcp2221_info;
> + mcp->indio_dev->channels = mcp2221_channels;
> + mcp->indio_dev->num_channels = ARRAY_SIZE(mcp2221_channels);
>
> + return iio_device_register(mcp->indio_dev);
> err_gc:
> i2c_del_adapter(&mcp->adapter);
> err_i2c:
> @@ -884,6 +946,7 @@ static void mcp2221_remove(struct hid_device *hdev)
> {
> struct mcp2221 *mcp = hid_get_drvdata(hdev);
>
> + iio_device_unregister(mcp->indio_dev);
> i2c_del_adapter(&mcp->adapter);
> hid_hw_close(mcp->hdev);
> hid_hw_stop(mcp->hdev);
> --
> 2.20.1
>
