iio: adc: axp288_adc: do not use internal iio_dev lock

The iio_device lock is only meant for internal use. Hence define a
device local lock to protect against concurrent accesses.

While at it, properly include "mutex.h" for mutex related APIs.

Signed-off-by: Nuno Sá <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/adc/axp288_adc.c

···
 
 #include <linux/dmi.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/kernel.h>
 #include <linux/device.h>
 #include <linux/regmap.h>
···
 struct axp288_adc_info {
 	int irq;
 	struct regmap *regmap;
+	/* lock to protect against multiple access to the device */
+	struct mutex lock;
 	bool ts_enabled;
 };
 
···
 	int ret;
 	struct axp288_adc_info *info = iio_priv(indio_dev);
 
-	mutex_lock(&indio_dev->mlock);
+	mutex_lock(&info->lock);
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
···
 	default:
 		ret = -EINVAL;
 	}
-	mutex_unlock(&indio_dev->mlock);
+	mutex_unlock(&info->lock);
 
 	return ret;
 }
···
 	ret = devm_iio_map_array_register(&pdev->dev, indio_dev, axp288_adc_default_maps);
 	if (ret < 0)
 		return ret;
+
+	mutex_init(&info->lock);
 
 	return devm_iio_device_register(&pdev->dev, indio_dev);
 }