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
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
