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>
---
Changes from v1:
* Removed 'select IIO' from Kconfig
* Removed useless iio/sysfs.h include
* Add IS_REACHABLE checks for IIO subsystem
drivers/hid/hid-mcp2221.c | 89 +++++++++++++++++++++++++++++++++++++++
1 file changed, 89 insertions(+)
diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c
index 0d27ccb55dd9..36fa9336c4c5 100644
--- a/drivers/hid/hid-mcp2221.c
+++ b/drivers/hid/hid-mcp2221.c
@@ -16,6 +16,7 @@
#include <linux/hidraw.h>
#include <linux/i2c.h>
#include <linux/gpio/driver.h>
+#include <linux/iio/iio.h>
#include "hid-ids.h"
/* Commands codes in a raw output report */
@@ -56,6 +57,7 @@ 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 +69,11 @@ struct mcp2221 {
struct gpio_chip *gc;
u8 gp_idx;
u8 gpio_dir;
+ u16 adc_values[3];
+};
+
+struct mcp2221_iio {
+ struct mcp2221 *mcp;
};
/*
@@ -712,6 +719,7 @@ 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;
@@ -791,6 +799,79 @@ static int mcp2221_raw_event(struct hid_device *hdev,
return 1;
}
+#if IS_REACHABLE(CONFIG_IIO)
+
+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_register_adcs(struct device *dev, struct mcp2221 *mcp)
+{
+ struct mcp2221_iio *iio;
+
+ mcp->indio_dev = devm_iio_device_alloc(dev, sizeof(*iio));
+ if (!mcp->indio_dev)
+ return -ENOMEM;
+
+ 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);
+}
+
+#else
+
+static int mcp2221_register_adcs(struct device *dev, struct mcp2221 *mcp)
+{
+ return 0;
+}
+
+#endif
+
static int mcp2221_probe(struct hid_device *hdev,
const struct hid_device_id *id)
{
@@ -869,6 +950,10 @@ static int mcp2221_probe(struct hid_device *hdev,
if (ret)
goto err_gc;
+ ret = mcp2221_register_adcs(&hdev->dev, mcp);
+ if (ret)
+ goto err_gc;
+
return 0;
err_gc:
@@ -884,6 +969,10 @@ static void mcp2221_remove(struct hid_device *hdev)
{
struct mcp2221 *mcp = hid_get_drvdata(hdev);
+#if IS_REACHABLE(CONFIG_IIO)
+ iio_device_unregister(mcp->indio_dev);
+#endif
+
i2c_del_adapter(&mcp->adapter);
hid_hw_close(mcp->hdev);
hid_hw_stop(mcp->hdev);
--
2.20.1
