On Fri, Nov 20, 2020 at 5:15 AM rishi gupta <gupt21@xxxxxxxxx> wrote:
>
> 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?
Actually yeah this should be "select IIO" to avoid that issue.
- Matt
> > 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
> >
