Merge tag 'iio-for-v4.2c' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

Third round of new IIO drivers, cleanups and functionality for the 4.2 cycle.

Given Linus announced a 4.8rc coming up, hopefully time for one more
lot of IIO patches this cycle.  Some of these are actually
improvements / fixes for patches earlier in the cycle.

New device support
* st_accel driver - support devices with 8 bit channels.

Cleanup
* A general cleanup of the iio tools under /tools/ from Hartmut.
  I'm more than a little embarassed by how bad some of these were! Are well,
  much more refined and less bug prone now.
  These cover lots of stuff like unhandled error returns, memory leaks as
  well as general refactoring to tidy the code up.
* iio_simple_dummy - fix memory leaks in the init functions, drop some
  pointless error returns from functions that never generate errors and
  make the module parameter explicitly unsigned.
* More buffer handling reworks from Lars-Peter, this time targetting hardware
  buffers (a little used corner that looks likely to get more use in the near
  future). Specifically:
  - Always compute the masklength as inkernel buffer users may need it.
  - Add a means of labeling which buffer modes a given buffer implementation
    supports.
  - In the case of hardware buffers, require strict scan matching rather than
    matching to a superset.  Currently the demux is bypassed by these drivers
    (this may well not change for efficiency reasons) so allowing a superset
    of channels to be selected would otherwise lead to more data than requested
    confusing userspace.

Driver funcationality improvments
* mmc35240 - adds a compensation to the raw values as borrowed form Memsic's
  own input driver.
* mma8452
  - event support
  - event debouncing
  - high  pass filter configuration
  - triggers
* vf610 - allow conversion mode to be adjusted

Fixlets
* mmc35240
  - Off by one error that by coincidence had no real effect.
  - i2c_device_name should be lowercase.
  - Lack of null terminator at end of attributes array.
  - Avoid computing the fractional part of the magnetic field by moving
    the scaling into userspace where floating point is available to simplify
    the maths.
  - Use a smaller sleep before assuming the measurement is done.  This is
    safe and improves the possible polling rate.
  - Fix sensitivity on z-axis - datasheet disagrees with Memsic's releasedd
    code and the value used in the code seems to be correct.
* stk3310 - make a local variable signed to ensure error handling works.
* twl4030
  - fix calculation of the temperature sense current - bug unlikely
    to have ever been noticed as the difference is small.
  - Fix errors in descriptions.

1 files changed, 91 insertions, 24 deletions

diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c
index aa6e25d3bfc3..7a2ea71c659a 100644
--- a/drivers/iio/magnetometer/mmc35240.c
+++ b/drivers/iio/magnetometer/mmc35240.c
@@ -58,6 +58,31 @@
 #define MMC35240_WAIT_CHARGE_PUMP	50000	/* us */
 #define MMC53240_WAIT_SET_RESET		1000	/* us */
 
+/*
+ * Memsic OTP process code piece is put here for reference:
+ *
+ * #define OTP_CONVERT(REG)  ((float)((REG) >=32 ? (32 - (REG)) : (REG)) * 0.006
+ * 1) For X axis, the COEFFICIENT is always 1.
+ * 2) For Y axis, the COEFFICIENT is as below:
+ *    f_OTP_matrix[4] = OTP_CONVERT(((reg_data[1] & 0x03) << 4) |
+ *                                   (reg_data[2] >> 4)) + 1.0;
+ * 3) For Z axis, the COEFFICIENT is as below:
+ *    f_OTP_matrix[8] = (OTP_CONVERT(reg_data[3] & 0x3f) + 1) * 1.35;
+ * We implemented the OTP logic into driver.
+ */
+
+/* scale = 1000 here for Y otp */
+#define MMC35240_OTP_CONVERT_Y(REG) (((REG) >= 32 ? (32 - (REG)) : (REG)) * 6)
+
+/* 0.6 * 1.35 = 0.81, scale 10000 for Z otp */
+#define MMC35240_OTP_CONVERT_Z(REG) (((REG) >= 32 ? (32 - (REG)) : (REG)) * 81)
+
+#define MMC35240_X_COEFF(x)	(x)
+#define MMC35240_Y_COEFF(y)	(y + 1000)
+#define MMC35240_Z_COEFF(z)	(z + 13500)
+
+#define MMC35240_OTP_START_ADDR		0x1B
+
 enum mmc35240_resolution {
 	MMC35240_16_BITS_SLOW = 0, /* 100 Hz */
 	MMC35240_16_BITS_FAST,     /* 200 Hz */
@@ -77,7 +102,7 @@ static const struct {
 } mmc35240_props_table[] = {
 	/* 16 bits, 100Hz ODR */
 	{
-		{1024, 1024, 770},
+		{1024, 1024, 1024},
 		32768,
 	},
 	/* 16 bits, 200Hz ODR */
@@ -102,6 +127,10 @@ struct mmc35240_data {
 	struct mutex mutex;
 	struct regmap *regmap;
 	enum mmc35240_resolution res;
+
+	/* OTP compensation */
+	int axis_coef[3];
+	int axis_scale[3];
 };
 
 static const int mmc35240_samp_freq[] = {100, 200, 333, 666};
@@ -113,8 +142,9 @@ static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("100 200 333 666");
 	.modified = 1, \
 	.channel2 = IIO_MOD_ ## _axis, \
 	.address = AXIS_ ## _axis, \
-	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
-	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
+			BIT(IIO_CHAN_INFO_SCALE), \
 }
 
 static const struct iio_chan_spec mmc35240_channels[] = {
@@ -125,6 +155,7 @@ static const struct iio_chan_spec mmc35240_channels[] = {
 
 static struct attribute *mmc35240_attributes[] = {
 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	NULL
 };
 
 static const struct attribute_group mmc35240_attribute_group = {
@@ -170,8 +201,9 @@ static int mmc35240_hw_set(struct mmc35240_data *data, bool set)
 
 static int mmc35240_init(struct mmc35240_data *data)
 {
-	int ret;
+	int ret, y_convert, z_convert;
 	unsigned int reg_id;
+	u8 otp_data[6];
 
 	ret = regmap_read(data->regmap, MMC35240_REG_ID, &reg_id);
 	if (ret < 0) {
@@ -195,9 +227,30 @@ static int mmc35240_init(struct mmc35240_data *data)
 		return ret;
 
 	/* set default sampling frequency */
-	return regmap_update_bits(data->regmap, MMC35240_REG_CTRL1,
-				  MMC35240_CTRL1_BW_MASK,
-				  data->res << MMC35240_CTRL1_BW_SHIFT);
+	ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL1,
+				 MMC35240_CTRL1_BW_MASK,
+				 data->res << MMC35240_CTRL1_BW_SHIFT);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_bulk_read(data->regmap, MMC35240_OTP_START_ADDR,
+			       (u8 *)otp_data, sizeof(otp_data));
+	if (ret < 0)
+		return ret;
+
+	y_convert = MMC35240_OTP_CONVERT_Y(((otp_data[1] & 0x03) << 4) |
+					   (otp_data[2] >> 4));
+	z_convert = MMC35240_OTP_CONVERT_Z(otp_data[3] & 0x3f);
+
+	data->axis_coef[0] = MMC35240_X_COEFF(1);
+	data->axis_coef[1] = MMC35240_Y_COEFF(y_convert);
+	data->axis_coef[2] = MMC35240_Z_COEFF(z_convert);
+
+	data->axis_scale[0] = 1;
+	data->axis_scale[1] = 1000;
+	data->axis_scale[2] = 10000;
+
+	return 0;
 }
 
 static int mmc35240_take_measurement(struct mmc35240_data *data)
@@ -217,7 +270,8 @@ static int mmc35240_take_measurement(struct mmc35240_data *data)
 			return ret;
 		if (reg_status & MMC35240_STATUS_MEAS_DONE_BIT)
 			break;
-		msleep(20);
+		/* minimum wait time to complete measurement is 10 ms */
+		usleep_range(10000, 11000);
 	}
 
 	if (tries < 0) {
@@ -240,9 +294,19 @@ static int mmc35240_read_measurement(struct mmc35240_data *data, __le16 buf[3])
 				3 * sizeof(__le16));
 }
 
-static int mmc35240_raw_to_gauss(struct mmc35240_data *data, int index,
-				 __le16 buf[],
-				 int *val, int *val2)
+/**
+ * mmc35240_raw_to_mgauss - convert raw readings to milli gauss. Also apply
+			    compensation for output value.
+ *
+ * @data: device private data
+ * @index: axis index for which we want the conversion
+ * @buf: raw data to be converted, 2 bytes in little endian format
+ * @val: compensated output reading (unit is milli gauss)
+ *
+ * Returns: 0 in case of success, -EINVAL when @index is not valid
+ */
+static int mmc35240_raw_to_mgauss(struct mmc35240_data *data, int index,
+				  __le16 buf[], int *val)
 {
 	int raw_x, raw_y, raw_z;
 	int sens_x, sens_y, sens_z;
@@ -260,22 +324,22 @@ static int mmc35240_raw_to_gauss(struct mmc35240_data *data, int index,
 
 	switch (index) {
 	case AXIS_X:
-		*val = (raw_x - nfo) / sens_x;
-		*val2 = ((raw_x - nfo) % sens_x) * 1000000;
+		*val = (raw_x - nfo) * 1000 / sens_x;
 		break;
 	case AXIS_Y:
-		*val = (raw_y - nfo) / sens_y - (raw_z - nfo) / sens_z;
-		*val2 = (((raw_y - nfo) % sens_y - (raw_z - nfo) % sens_z))
-			* 1000000;
+		*val = (raw_y - nfo) * 1000 / sens_y -
+			(raw_z - nfo)  * 1000 / sens_z;
 		break;
 	case AXIS_Z:
-		*val = (raw_y - nfo) / sens_y + (raw_z - nfo) / sens_z;
-		*val2 = (((raw_y - nfo) % sens_y + (raw_z - nfo) % sens_z))
-			* 1000000;
+		*val = (raw_y - nfo) * 1000 / sens_y +
+			(raw_z - nfo) * 1000 / sens_z;
 		break;
 	default:
 		return -EINVAL;
 	}
+	/* apply OTP compensation */
+	*val = (*val) * data->axis_coef[index] / data->axis_scale[index];
+
 	return 0;
 }
 
@@ -289,16 +353,19 @@ static int mmc35240_read_raw(struct iio_dev *indio_dev,
 	__le16 buf[3];
 
 	switch (mask) {
-	case IIO_CHAN_INFO_PROCESSED:
+	case IIO_CHAN_INFO_RAW:
 		mutex_lock(&data->mutex);
 		ret = mmc35240_read_measurement(data, buf);
 		mutex_unlock(&data->mutex);
 		if (ret < 0)
 			return ret;
-		ret = mmc35240_raw_to_gauss(data, chan->address,
-					    buf, val, val2);
+		ret = mmc35240_raw_to_mgauss(data, chan->address, buf, val);
 		if (ret < 0)
 			return ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = 1000;
 		return IIO_VAL_INT_PLUS_MICRO;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		mutex_lock(&data->mutex);
@@ -308,7 +375,7 @@ static int mmc35240_read_raw(struct iio_dev *indio_dev,
 			return ret;
 
 		i = (reg & MMC35240_CTRL1_BW_MASK) >> MMC35240_CTRL1_BW_SHIFT;
-		if (i < 0 || i > ARRAY_SIZE(mmc35240_samp_freq))
+		if (i < 0 || i >= ARRAY_SIZE(mmc35240_samp_freq))
 			return -EINVAL;
 
 		*val = mmc35240_samp_freq[i];
@@ -490,7 +557,7 @@ static const struct acpi_device_id mmc35240_acpi_match[] = {
 MODULE_DEVICE_TABLE(acpi, mmc35240_acpi_match);
 
 static const struct i2c_device_id mmc35240_id[] = {
-	{"MMC35240", 0},
+	{"mmc35240", 0},
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, mmc35240_id);