First round of IIO fixes for the 4.14 cycle

Note this includes fixes from recent merge window.  As such the tree
 is based on top of a prior staging/staging-next tree.
 
 * iio core
   - return and error for a failed read_reg debugfs call rather than
     eating the error.
 * ad7192
   - Use the dedicated reset function in the ad_sigma_delta library
     instead of an spi transfer with the data on the stack which
     could cause problems with DMA.
 * ad7793
   - Implement a dedicate reset function in the ad_sigma_delta library
     and use it to correctly reset this part.
 * bme280
   - ctrl_reg write must occur after any register writes
   for updates to take effect.
 * mcp320x
   - negative voltage readout was broken.
   - Fix an oops on module unload due to spi_set_drvdata not being called
     in probe.
 * st_magn
   - Fix the data ready line configuration for the lis3mdl. It is not
     configurable so the st_magn core was assuming it didn't exist
     and so wasn't consuming interrupts resulting in an unhandled
     interrupt.
 * stm32-adc
   - off by one error on max channels checking.
 * stm32-timer
   - preset should not be buffered - reorganising register writes avoids
   this.
   - fix a corner case in which write preset goes wrong when a timer is
   used first as a trigger then as a counter with preset. Odd case but
   you never know.
 * ti-ads1015
   - Fix setting of comparator polarity by fixing bitfield definition.
 * twl4030
   - Error path handling fix to cleanup in event of regulator
     registration failure.
   - Disable the vusb3v1 regulator correctly in error handling
   - Don't paper over a regulator enable failure.
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Merge tag 'iio-fixes-for-4.14a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus

Jonathan writes:

First round of IIO fixes for the 4.14 cycle

Note this includes fixes from recent merge window.  As such the tree
is based on top of a prior staging/staging-next tree.

* iio core
  - return and error for a failed read_reg debugfs call rather than
    eating the error.
* ad7192
  - Use the dedicated reset function in the ad_sigma_delta library
    instead of an spi transfer with the data on the stack which
    could cause problems with DMA.
* ad7793
  - Implement a dedicate reset function in the ad_sigma_delta library
    and use it to correctly reset this part.
* bme280
  - ctrl_reg write must occur after any register writes
  for updates to take effect.
* mcp320x
  - negative voltage readout was broken.
  - Fix an oops on module unload due to spi_set_drvdata not being called
    in probe.
* st_magn
  - Fix the data ready line configuration for the lis3mdl. It is not
    configurable so the st_magn core was assuming it didn't exist
    and so wasn't consuming interrupts resulting in an unhandled
    interrupt.
* stm32-adc
  - off by one error on max channels checking.
* stm32-timer
  - preset should not be buffered - reorganising register writes avoids
  this.
  - fix a corner case in which write preset goes wrong when a timer is
  used first as a trigger then as a counter with preset. Odd case but
  you never know.
* ti-ads1015
  - Fix setting of comparator polarity by fixing bitfield definition.
* twl4030
  - Error path handling fix to cleanup in event of regulator
    registration failure.
  - Disable the vusb3v1 regulator correctly in error handling
  - Don't paper over a regulator enable failure.

drivers/iio/adc/ad7793.c

@@ -257,7 +257,7 @@ static int ad7793_setup(struct iio_dev *indio_dev,
 	unsigned int vref_mv)
 {
 	struct ad7793_state *st = iio_priv(indio_dev);
-	int i, ret = -1;
+	int i, ret;
 	unsigned long long scale_uv;
 	u32 id;
 
@@ -266,7 +266,7 @@ static int ad7793_setup(struct iio_dev *indio_dev,
 		return ret;
 
 	/* reset the serial interface */
-	ret = spi_write(st->sd.spi, (u8 *)&ret, sizeof(ret));
+	ret = ad_sd_reset(&st->sd, 32);
 	if (ret < 0)
 		goto out;
 	usleep_range(500, 2000); /* Wait for at least 500us */

drivers/iio/adc/ad_sigma_delta.c

@@ -177,6 +177,34 @@ out:
 }
 EXPORT_SYMBOL_GPL(ad_sd_read_reg);
 
+/**
+ * ad_sd_reset() - Reset the serial interface
+ *
+ * @sigma_delta: The sigma delta device
+ * @reset_length: Number of SCLKs with DIN = 1
+ *
+ * Returns 0 on success, an error code otherwise.
+ **/
+int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
+	unsigned int reset_length)
+{
+	uint8_t *buf;
+	unsigned int size;
+	int ret;
+
+	size = DIV_ROUND_UP(reset_length, 8);
+	buf = kcalloc(size, sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	memset(buf, 0xff, size);
+	ret = spi_write(sigma_delta->spi, buf, size);
+	kfree(buf);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ad_sd_reset);
+
 static int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
 	unsigned int mode, unsigned int channel)
 {

drivers/iio/adc/mcp320x.c

@@ -17,6 +17,8 @@
  * MCP3204
  * MCP3208
  * ------------
+ * 13 bit converter
+ * MCP3301
  *
  * Datasheet can be found here:
  * http://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf  mcp3001
@@ -96,7 +98,7 @@ static int mcp320x_channel_to_tx_data(int device_index,
 }
 
 static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel,
-				  bool differential, int device_index)
+				  bool differential, int device_index, int *val)
 {
 	int ret;
 
@@ -117,19 +119,25 @@ static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel,
 
 	switch (device_index) {
 	case mcp3001:
-		return (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);
+		*val = (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);
+		return 0;
 	case mcp3002:
 	case mcp3004:
 	case mcp3008:
-		return (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);
+		*val = (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);
+		return 0;
 	case mcp3201:
-		return (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);
+		*val = (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);
+		return 0;
 	case mcp3202:
 	case mcp3204:
 	case mcp3208:
-		return (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);
+		*val = (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);
+		return 0;
 	case mcp3301:
-		return sign_extend32((adc->rx_buf[0] & 0x1f) << 8 | adc->rx_buf[1], 12);
+		*val = sign_extend32((adc->rx_buf[0] & 0x1f) << 8
+				    | adc->rx_buf[1], 12);
+		return 0;
 	default:
 		return -EINVAL;
 	}
@@ -150,12 +158,10 @@ static int mcp320x_read_raw(struct iio_dev *indio_dev,
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		ret = mcp320x_adc_conversion(adc, channel->address,
-			channel->differential, device_index);
-
+			channel->differential, device_index, val);
 		if (ret < 0)
 			goto out;
 
-		*val = ret;
 		ret = IIO_VAL_INT;
 		break;
 
@@ -312,6 +318,7 @@ static int mcp320x_probe(struct spi_device *spi)
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &mcp320x_info;
+	spi_set_drvdata(spi, indio_dev);
 
 	chip_info = &mcp320x_chip_infos[spi_get_device_id(spi)->driver_data];
 	indio_dev->channels = chip_info->channels;

drivers/iio/adc/stm32-adc.c

@@ -1666,7 +1666,7 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
 
 	num_channels = of_property_count_u32_elems(node, "st,adc-channels");
 	if (num_channels < 0 ||
-	    num_channels >= adc_info->max_channels) {
+	    num_channels > adc_info->max_channels) {
 		dev_err(&indio_dev->dev, "Bad st,adc-channels?\n");
 		return num_channels < 0 ? num_channels : -EINVAL;
 	}

drivers/iio/adc/ti-ads1015.c

@@ -52,7 +52,7 @@
 
 #define ADS1015_CFG_COMP_QUE_MASK	GENMASK(1, 0)
 #define ADS1015_CFG_COMP_LAT_MASK	BIT(2)
-#define ADS1015_CFG_COMP_POL_MASK	BIT(2)
+#define ADS1015_CFG_COMP_POL_MASK	BIT(3)
 #define ADS1015_CFG_COMP_MODE_MASK	BIT(4)
 #define ADS1015_CFG_DR_MASK	GENMASK(7, 5)
 #define ADS1015_CFG_MOD_MASK	BIT(8)
@@ -1017,10 +1017,12 @@ static int ads1015_probe(struct i2c_client *client,
 
 		switch (irq_trig) {
 		case IRQF_TRIGGER_LOW:
-			cfg_comp |= ADS1015_CFG_COMP_POL_LOW;
+			cfg_comp |= ADS1015_CFG_COMP_POL_LOW <<
+					ADS1015_CFG_COMP_POL_SHIFT;
 			break;
 		case IRQF_TRIGGER_HIGH:
-			cfg_comp |= ADS1015_CFG_COMP_POL_HIGH;
+			cfg_comp |= ADS1015_CFG_COMP_POL_HIGH <<
+					ADS1015_CFG_COMP_POL_SHIFT;
 			break;
 		default:
 			return -EINVAL;

drivers/iio/adc/twl4030-madc.c

@@ -887,21 +887,27 @@ static int twl4030_madc_probe(struct platform_device *pdev)
 
 	/* Enable 3v1 bias regulator for MADC[3:6] */
 	madc->usb3v1 = devm_regulator_get(madc->dev, "vusb3v1");
-	if (IS_ERR(madc->usb3v1))
-		return -ENODEV;
+	if (IS_ERR(madc->usb3v1)) {
+		ret = -ENODEV;
+		goto err_i2c;
+	}
 
 	ret = regulator_enable(madc->usb3v1);
-	if (ret)
+	if (ret) {
 		dev_err(madc->dev, "could not enable 3v1 bias regulator\n");
+		goto err_i2c;
+	}
 
 	ret = iio_device_register(iio_dev);
 	if (ret) {
 		dev_err(&pdev->dev, "could not register iio device\n");
-		goto err_i2c;
+		goto err_usb3v1;
 	}
 
 	return 0;
 
+err_usb3v1:
+	regulator_disable(madc->usb3v1);
 err_i2c:
 	twl4030_madc_set_current_generator(madc, 0, 0);
 err_current_generator:

drivers/iio/common/st_sensors/st_sensors_core.c

@@ -463,8 +463,17 @@ int st_sensors_set_dataready_irq(struct iio_dev *indio_dev, bool enable)
 	u8 drdy_mask;
 	struct st_sensor_data *sdata = iio_priv(indio_dev);
 
-	if (!sdata->sensor_settings->drdy_irq.addr)
+	if (!sdata->sensor_settings->drdy_irq.addr) {
+		/*
+		 * there are some devices (e.g. LIS3MDL) where drdy line is
+		 * routed to a given pin and it is not possible to select a
+		 * different one. Take into account irq status register
+		 * to understand if irq trigger can be properly supported
+		 */
+		if (sdata->sensor_settings->drdy_irq.addr_stat_drdy)
+			sdata->hw_irq_trigger = enable;
 		return 0;
+	}
 
 	/* Enable/Disable the interrupt generator 1. */
 	if (sdata->sensor_settings->drdy_irq.ig1.en_addr > 0) {

drivers/iio/industrialio-core.c

@@ -310,8 +310,10 @@ static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
 						  indio_dev->cached_reg_addr,
 						  0, &val);
-	if (ret)
+	if (ret) {
 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
+		return ret;
+	}
 
 	len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 

drivers/iio/magnetometer/st_magn_core.c

@@ -315,6 +315,10 @@ static const struct st_sensor_settings st_magn_sensors_settings[] = {
 				},
 			},
 		},
+		.drdy_irq = {
+			/* drdy line is routed drdy pin */
+			.addr_stat_drdy = ST_SENSORS_DEFAULT_STAT_ADDR,
+		},
 		.multi_read_bit = true,
 		.bootime = 2,
 	},

drivers/iio/pressure/bmp280-core.c

@@ -573,7 +573,7 @@ static int bmp280_chip_config(struct bmp280_data *data)
 	u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) |
 		  BMP280_OSRS_PRESS_X(data->oversampling_press + 1);
 
-	ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS,
+	ret = regmap_write_bits(data->regmap, BMP280_REG_CTRL_MEAS,
 				 BMP280_OSRS_TEMP_MASK |
 				 BMP280_OSRS_PRESS_MASK |
 				 BMP280_MODE_MASK,

drivers/iio/trigger/stm32-timer-trigger.c

@@ -174,6 +174,7 @@ static void stm32_timer_stop(struct stm32_timer_trigger *priv)
 		clk_disable(priv->clk);
 
 	/* Stop timer */
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
 	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
 	regmap_write(priv->regmap, TIM_PSC, 0);
 	regmap_write(priv->regmap, TIM_ARR, 0);
@@ -715,8 +716,9 @@ static ssize_t stm32_count_set_preset(struct iio_dev *indio_dev,
 	if (ret)
 		return ret;
 
+	/* TIMx_ARR register shouldn't be buffered (ARPE=0) */
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
 	regmap_write(priv->regmap, TIM_ARR, preset);
-	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE);
 
 	return len;
 }

drivers/staging/iio/adc/ad7192.c

@@ -223,11 +223,9 @@ static int ad7192_setup(struct ad7192_state *st,
 	struct iio_dev *indio_dev = spi_get_drvdata(st->sd.spi);
 	unsigned long long scale_uv;
 	int i, ret, id;
-	u8 ones[6];
 
 	/* reset the serial interface */
-	memset(&ones, 0xFF, 6);
-	ret = spi_write(st->sd.spi, &ones, 6);
+	ret = ad_sd_reset(&st->sd, 48);
 	if (ret < 0)
 		goto out;
 	usleep_range(500, 1000); /* Wait for at least 500us */

include/linux/iio/adc/ad_sigma_delta.h

@@ -111,6 +111,9 @@ int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
 	unsigned int size, unsigned int *val);
 
+int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
+	unsigned int reset_length);
+
 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
 	const struct iio_chan_spec *chan, int *val);
 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,