Merge tag 'iio-for-4.3b-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

Second set of new device support, features and cleanup for the 4.3 cycle.
Take 2 also includes a fix set that was too late for the 4.2 cycle.

As we had a lot of tools and docs work in this set, I have broken those
out into their own categories in this description.

Fixes from the pull request '4th set of IIO fixes for the 4.2 cycle'.
* Poll functions for both event chardev and the buffer one were returning
  negative error codes (via a positive value).
* A recent change to lsiio adding some error handling that was wrong and
  stopped the tool working.
* bmg160 was missing some dependencies in Kconfig
* berlin2-adc had a misshandled register (wrote a value rather than a bitmap)

New device support
* TI opt3001 light sensor
* TXC PA12 ALS and proximity sensor.
* mcp3301 ADC support (in mcp320x driver)
* ST lsm303agr accelerometer and magnetometer drivers (plus some st-sensors
  common support to allow different WHOAMI register addresses, devices with
  fixed scale and allow interrupt equiped magnetometers).
* ADIS16305, ADIS16367, ADIS16445IMUs (in the adis16400 driver)
* ADIS16266 gyro (in the adis16260 driver)
* ADIS16137 gyro (in the adis16136 driver)

New functionality
* mmc35240 DT bindings.
* Inverse unit conversion macros to aid handing of values written to sysfs
  attributes.

Core cleanup
* Forward declaration of struct iio_trigger to avoid a compile warning.

Driver cleanup / fixes
* mxs-lradc
  - Clarify which parts are supported.
  - Fix spelling erorrs.
  - Missing/extra includes
  - reorder includes
  - add datasheet name listings for all usable channels (to allow them
    to be bound by name from consumer drivers)
* acpi-als - add some function prefixes as per general iio style.
* bmc150_magn - replace a magic value with the existing define.
* vf610 - determine possible sample frequencies taking into account the
  electrical characteristics (defining a minimum sample time)
* dht11
  - whitespace
  - additional docs
  - avoid mulitple assignments in one line
  - Use the new funciton ktime_get_resolution_ns to cleanup a nasty trick
    previously used for timing.
* Fix all drivers that consider 0 a valid IRQ for historical reasons.
* Export I2C module alias info where previously missing (to allow autoprobing)
* Export OF module alias info where previously missing.
* mmc35240 - switch some variables into arrays to improve readability.
* mlx90614 - define some magic numbers for readability.
* bmc150_magn
  - expand area locked by a mutex to cover all the use of the
    data->buffer.
  - use descriptive naming for a mask instead of a magic value.
* berin2-adc
  - pass up an error code rather that a generic error
  - constify the iio_chan_spec
  - some other little tidy ups.
* stk8312
  - fix a dependency on triggered buffers in kconfig
  - add a check for invalid attribute values
  - improve error handling by returning error codes where possible and
    return immediately where relevant
  - rework macro defs to use GENMASK etc
  - change some variable types to reduce unnecessary casting
  - clean up code style
  - drop a local buffer copy for bulk reads and use the one in data->buffer
     instead.
* adis16400 - the adis16448 gyroscope scale was wrong.
* adis16480 - some more wrong scales for various parts.
* adis16300 - has an undocumented product id and serial number registers so
  use them.
* iio_simple_dummy - fix some wrong code indentation.
* bmc150-accel - use the chip ID to detect the chip present rather than
  verifying the expected part was there.  This was in response to a wrong
  ACPI entry on the WinBook TW100.
* mma8452
  - fix _get_hp_filter_index
  - drop a double include
  - pass up an error code rather than rewriting it
  - range check input values to attribute writes
  - register defs tidy up using GENMASK and reordering them to be easier to
    follow.
  - various coding style cleanups
  - put the Kconfig entry in the write place (alphabetically).

Tools related
* Tools cleanup - drop an explicity NULL comparison, some unnecessary braces,
  use the ARRAY_SIZE macro, send error messages to stderr instead of dropping
  them in the middle of normal output.
* Fix tools to allow that scale and offset attributes are optional.
* More tools fixes including allowing true 32bit data (previously an overflow
  prevented more than 31bits)
* Drop a stray header guard that ended up in a c file.
* Make calc_digits static as it isn't exported or in the header.
* Set ci_array pointer to NULL after free as a protection against non safe
  usage of the tools core code.  Also convert a double pointer to a single
  one as the extra level of indirection was unnecessary.

Docs
* DocBook introduction by Daniel Baluta.  Glad we are beginning to
  draw together some more introductory docs to suplement the various
  tools / examples.
* Drop bytes_per_datum sysfs attribute docs as it no longer exists.
* A whole load of missing / fixing of kernel-doc for the core of IIO.
* Document the trigger name sysfs attribute in the ABI docs.
* Minor typos in the ABI docs related to power down modes.

drivers/iio/adc/vf610_adc.c

@@ -68,6 +68,9 @@
 #define VF610_ADC_CLK_DIV8		0x60
 #define VF610_ADC_CLK_MASK		0x60
 #define VF610_ADC_ADLSMP_LONG		0x10
+#define VF610_ADC_ADSTS_SHORT   0x100
+#define VF610_ADC_ADSTS_NORMAL  0x200
+#define VF610_ADC_ADSTS_LONG    0x300
 #define VF610_ADC_ADSTS_MASK		0x300
 #define VF610_ADC_ADLPC_EN		0x80
 #define VF610_ADC_ADHSC_EN		0x400
@@ -98,6 +101,8 @@
 #define VF610_ADC_CALF			0x2
 #define VF610_ADC_TIMEOUT		msecs_to_jiffies(100)
 
+#define DEFAULT_SAMPLE_TIME		1000
+
 enum clk_sel {
 	VF610_ADCIOC_BUSCLK_SET,
 	VF610_ADCIOC_ALTCLK_SET,
@@ -124,6 +129,17 @@ enum conversion_mode_sel {
 	VF610_ADC_CONV_LOW_POWER,
 };
 
+enum lst_adder_sel {
+	VF610_ADCK_CYCLES_3,
+	VF610_ADCK_CYCLES_5,
+	VF610_ADCK_CYCLES_7,
+	VF610_ADCK_CYCLES_9,
+	VF610_ADCK_CYCLES_13,
+	VF610_ADCK_CYCLES_17,
+	VF610_ADCK_CYCLES_21,
+	VF610_ADCK_CYCLES_25,
+};
+
 struct vf610_adc_feature {
 	enum clk_sel	clk_sel;
 	enum vol_ref	vol_ref;
@@ -132,6 +148,8 @@ struct vf610_adc_feature {
 	int	clk_div;
 	int     sample_rate;
 	int	res_mode;
+	u32 lst_adder_index;
+	u32 default_sample_time;
 
 	bool	calibration;
 	bool	ovwren;
@@ -155,11 +173,13 @@ struct vf610_adc {
 };
 
 static const u32 vf610_hw_avgs[] = { 1, 4, 8, 16, 32 };
+static const u32 vf610_lst_adder[] = { 3, 5, 7, 9, 13, 17, 21, 25 };
 
 static inline void vf610_adc_calculate_rates(struct vf610_adc *info)
 {
 	struct vf610_adc_feature *adc_feature = &info->adc_feature;
 	unsigned long adck_rate, ipg_rate = clk_get_rate(info->clk);
+	u32 adck_period, lst_addr_min;
 	int divisor, i;
 
 	adck_rate = info->max_adck_rate[adc_feature->conv_mode];
@@ -173,6 +193,19 @@ static inline void vf610_adc_calculate_rates(struct vf610_adc *info)
 		adc_feature->clk_div = 8;
 	}
 
+	/*
+	 * Determine the long sample time adder value to be used based
+	 * on the default minimum sample time provided.
+	 */
+	adck_period = NSEC_PER_SEC / adck_rate;
+	lst_addr_min = adc_feature->default_sample_time / adck_period;
+	for (i = 0; i < ARRAY_SIZE(vf610_lst_adder); i++) {
+		if (vf610_lst_adder[i] > lst_addr_min) {
+			adc_feature->lst_adder_index = i;
+			break;
+		}
+	}
+
 	/*
 	 * Calculate ADC sample frequencies
 	 * Sample time unit is ADCK cycles. ADCK clk source is ipg clock,
@@ -182,12 +215,13 @@ static inline void vf610_adc_calculate_rates(struct vf610_adc *info)
 	 * SFCAdder: fixed to 6 ADCK cycles
 	 * AverageNum: 1, 4, 8, 16, 32 samples for hardware average.
 	 * BCT (Base Conversion Time): fixed to 25 ADCK cycles for 12 bit mode
-	 * LSTAdder(Long Sample Time): fixed to 3 ADCK cycles
+	 * LSTAdder(Long Sample Time): 3, 5, 7, 9, 13, 17, 21, 25 ADCK cycles
 	 */
 	adck_rate = ipg_rate / info->adc_feature.clk_div;
 	for (i = 0; i < ARRAY_SIZE(vf610_hw_avgs); i++)
 		info->sample_freq_avail[i] =
-			adck_rate / (6 + vf610_hw_avgs[i] * (25 + 3));
+			adck_rate / (6 + vf610_hw_avgs[i] *
+			 (25 + vf610_lst_adder[adc_feature->lst_adder_index]));
 }
 
 static inline void vf610_adc_cfg_init(struct vf610_adc *info)
@@ -347,8 +381,40 @@ static void vf610_adc_sample_set(struct vf610_adc *info)
 		break;
 	}
 
-	/* Use the short sample mode */
-	cfg_data &= ~(VF610_ADC_ADLSMP_LONG | VF610_ADC_ADSTS_MASK);
+	/*
+	 * Set ADLSMP and ADSTS based on the Long Sample Time Adder value
+	 * determined.
+	 */
+	switch (adc_feature->lst_adder_index) {
+	case VF610_ADCK_CYCLES_3:
+		break;
+	case VF610_ADCK_CYCLES_5:
+		cfg_data |= VF610_ADC_ADSTS_SHORT;
+		break;
+	case VF610_ADCK_CYCLES_7:
+		cfg_data |= VF610_ADC_ADSTS_NORMAL;
+		break;
+	case VF610_ADCK_CYCLES_9:
+		cfg_data |= VF610_ADC_ADSTS_LONG;
+		break;
+	case VF610_ADCK_CYCLES_13:
+		cfg_data |= VF610_ADC_ADLSMP_LONG;
+		break;
+	case VF610_ADCK_CYCLES_17:
+		cfg_data |= VF610_ADC_ADLSMP_LONG;
+		cfg_data |= VF610_ADC_ADSTS_SHORT;
+		break;
+	case VF610_ADCK_CYCLES_21:
+		cfg_data |= VF610_ADC_ADLSMP_LONG;
+		cfg_data |= VF610_ADC_ADSTS_NORMAL;
+		break;
+	case VF610_ADCK_CYCLES_25:
+		cfg_data |= VF610_ADC_ADLSMP_LONG;
+		cfg_data |= VF610_ADC_ADSTS_NORMAL;
+		break;
+	default:
+		dev_err(info->dev, "error in sample time select\n");
+	}
 
 	/* update hardware average selection */
 	cfg_data &= ~VF610_ADC_AVGS_MASK;
@@ -713,6 +779,11 @@ static int vf610_adc_probe(struct platform_device *pdev)
 	of_property_read_u32_array(pdev->dev.of_node, "fsl,adck-max-frequency",
 			info->max_adck_rate, 3);
 
+	ret = of_property_read_u32(pdev->dev.of_node, "min-sample-time",
+			&info->adc_feature.default_sample_time);
+	if (ret)
+		info->adc_feature.default_sample_time = DEFAULT_SAMPLE_TIME;
+
 	platform_set_drvdata(pdev, indio_dev);
 
 	init_completion(&info->completion);