[v11,1/2] dt: bindings: lm3692x: Add bindings for lm3692x LED driver

Message ID 20171212181550.22677-1-dmurphy@ti.com
State New
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Series
  • [v11,1/2] dt: bindings: lm3692x: Add bindings for lm3692x LED driver
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Commit Message

Dan Murphy Dec. 12, 2017, 6:15 p.m.
This adds the devicetree bindings for the LM3692x
I2C LED string driver.

Acked-by: Pavel Machek <pavel@ucw.cz>

Signed-off-by: Dan Murphy <dmurphy@ti.com>

---

v11 - No changes - https://patchwork.kernel.org/patch/10107893/

v10 - Changed label to add color - https://patchwork.kernel.org/patch/10105649/
v9 - Moved 2 nodes to Optional Child and renamed node names to device type
https://patchwork.kernel.org/patch/10093757/
v8 - Added address-cells and size-cells as well as child node reg - https://patchwork.kernel.org/patch/10091259/
v7 - No changes - https://patchwork.kernel.org/patch/10087475/
v6 - No changes -https://patchwork.kernel.org/patch/10085567/
v5 - No Changes - https://patchwork.kernel.org/patch/10081071/
v4 - Fix example node, added trigger entry, removed ambiguous x for compatible and
added common.txt pointer for label - https://patchwork.kernel.org/patch/10060107
v3 - No changes
v2 - No changes - https://patchwork.kernel.org/patch/10056677/

 .../devicetree/bindings/leds/leds-lm3692x.txt      | 49 ++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-lm3692x.txt

-- 
2.15.0.124.g7668cbc60

Comments

Jacek Anaszewski Dec. 12, 2017, 8:58 p.m. | #1
Hi Dan,

Thanks for the updated patch set.

I found two minor issues but fixed them by myself
and applied both patches to the for-next branch of
linux-leds.git.

Please refer below and let me know if you have any
objections to my amendments.

On 12/12/2017 07:15 PM, Dan Murphy wrote:
> Introducing the LM3692x Dual-String white LED driver.

> 

> Data sheet is located

> http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf

> 

> Signed-off-by: Dan Murphy <dmurphy@ti.com>

> ---

> 

> v11 - change DT label case to id->name from np->name - https://patchwork.kernel.org/patch/10107895/

> 

> v10 - No changes - https://patchwork.kernel.org/patch/10105651/

> v9 - Change the no DT label case to pull the device name from the i2c_id struct

> so that the device name can be part of the sysfs node - https://patchwork.kernel.org/patch/10093759/

> v8 - No changes

> v7 - Reverted back to creating the LED label within the driver -

> https://patchwork.kernel.org/patch/10087473/

> v6 - Use new LED API to compose LED label as opposed to creating it. -

> https://patchwork.kernel.org/patch/10085565/

> v5 - Added OF dependency in Kconfig, added extra fault flag read to ensure that

> if a fault exists and it is not a artifact, fixed LED class label to be derived

> from either the DT child "label" node or create a label based on 

> parent_node_name:led color:trigger, removed ifdef for CONFIG_OF and removed

> of_match_ptr - https://patchwork.kernel.org/patch/10081073/

> v4 - Converted to devm led class register, changed MODULE_LICENSE to GPL v2, 

> set the led name based on child node name or label entry, removed fault and

> returned read_buf for fault checking, added mutex_destroy to remove function,

> and removed LED_FULL - https://patchwork.kernel.org/patch/10060109/

> v3 - Add missing Makefile and Kconfig from v1 and v2 - https://patchwork.kernel.org/patch/10060075/

> v2 - Added data sheet link, fixed linuxdoc format, returned on failure in init

> routine, return on fault_check failure, updated brightness calculation and

> fixed capitalization issue - https://patchwork.kernel.org/patch/10056675/

> 

>  drivers/leds/Kconfig        |   7 +

>  drivers/leds/Makefile       |   1 +

>  drivers/leds/leds-lm3692x.c | 393 ++++++++++++++++++++++++++++++++++++++++++++

>  3 files changed, 401 insertions(+)

>  create mode 100644 drivers/leds/leds-lm3692x.c

> 

> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig

> index 318a28fd58fe..1d215b39cefd 100644

> --- a/drivers/leds/Kconfig

> +++ b/drivers/leds/Kconfig

> @@ -137,6 +137,13 @@ config LEDS_LM3642

>  	  converter plus 1.5A constant current driver for a high-current

>  	  white LED.

>  

> +config LEDS_LM3692X

> +	tristate "LED support for LM3692x Chips"

> +	depends on LEDS_CLASS && I2C && OF

> +	select REGMAP_I2C

> +	help

> +	  This option enables support for the TI LM3692x family

> +	  of white LED string drivers used for backlighting.

>  

>  config LEDS_LOCOMO

>  	tristate "LED Support for Locomo device"

> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile

> index a2a6b5a4f86d..987884a5b9a5 100644

> --- a/drivers/leds/Makefile

> +++ b/drivers/leds/Makefile

> @@ -74,6 +74,7 @@ obj-$(CONFIG_LEDS_PM8058)		+= leds-pm8058.o

>  obj-$(CONFIG_LEDS_MLXCPLD)		+= leds-mlxcpld.o

>  obj-$(CONFIG_LEDS_NIC78BX)		+= leds-nic78bx.o

>  obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o

> +obj-$(CONFIG_LEDS_LM3692X)		+= leds-lm3692x.o

>  

>  # LED SPI Drivers

>  obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o

> diff --git a/drivers/leds/leds-lm3692x.c b/drivers/leds/leds-lm3692x.c

> new file mode 100644

> index 000000000000..bfcffb8b9bd5

> --- /dev/null

> +++ b/drivers/leds/leds-lm3692x.c

> @@ -0,0 +1,393 @@

> +/*

> + * TI lm3692x LED Driver

> + *

> + * Copyright (C) 2017 Texas Instruments

> + *

> + * Author: Dan Murphy <dmurphy@ti.com>

> + *

> + * This program is free software; you can redistribute it and/or

> + * modify it under the terms of the GNU General Public License

> + * version 2 as published by the Free Software Foundation.

> + *

> + * Data sheet is located

> + * http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf

> + */

> +

> +#include <linux/i2c.h>

> +#include <linux/init.h>

> +#include <linux/leds.h>

> +#include <linux/regmap.h>

> +#include <linux/regulator/consumer.h>

> +#include <linux/module.h>

> +#include <linux/mutex.h>

> +#include <linux/of.h>

> +#include <linux/of_gpio.h>

> +#include <linux/gpio/consumer.h>

> +#include <linux/slab.h>

> +#include <uapi/linux/uleds.h>


Sorted includes lexicographically.

> +#define LM3692X_REV		0x0

> +#define LM3692X_RESET		0x1

> +#define LM3692X_EN		0x10

> +#define LM3692X_BRT_CTRL	0x11

> +#define LM3692X_PWM_CTRL	0x12

> +#define LM3692X_BOOST_CTRL	0x13

> +#define LM3692X_AUTO_FREQ_HI	0x15

> +#define LM3692X_AUTO_FREQ_LO	0x16

> +#define LM3692X_BL_ADJ_THRESH	0x17

> +#define LM3692X_BRT_LSB		0x18

> +#define LM3692X_BRT_MSB		0x19

> +#define LM3692X_FAULT_CTRL	0x1e

> +#define LM3692X_FAULT_FLAGS	0x1f

> +

> +#define LM3692X_SW_RESET	BIT(0)

> +#define LM3692X_DEVICE_EN	BIT(0)

> +#define LM3692X_LED1_EN		BIT(1)

> +#define LM3692X_LED2_EN		BIT(2)

> +

> +/* Brightness Control Bits */

> +#define LM3692X_BL_ADJ_POL	BIT(0)

> +#define LM3692X_RAMP_RATE_125us	0x00

> +#define LM3692X_RAMP_RATE_250us	BIT(1)

> +#define LM3692X_RAMP_RATE_500us BIT(2)

> +#define LM3692X_RAMP_RATE_1ms	(BIT(1) | BIT(2))

> +#define LM3692X_RAMP_RATE_2ms	BIT(3)

> +#define LM3692X_RAMP_RATE_4ms	(BIT(3) | BIT(1))

> +#define LM3692X_RAMP_RATE_8ms	(BIT(2) | BIT(3))

> +#define LM3692X_RAMP_RATE_16ms	(BIT(1) | BIT(2) | BIT(3))

> +#define LM3692X_RAMP_EN		BIT(4)

> +#define LM3692X_BRHT_MODE_REG	0x00

> +#define LM3692X_BRHT_MODE_PWM	BIT(5)

> +#define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)

> +#define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))

> +#define LM3692X_MAP_MODE_EXP	BIT(7)

> +

> +/* PWM Register Bits */

> +#define LM3692X_PWM_FILTER_100	BIT(0)

> +#define LM3692X_PWM_FILTER_150	BIT(1)

> +#define LM3692X_PWM_FILTER_200	(BIT(0) | BIT(1))

> +#define LM3692X_PWM_HYSTER_1LSB BIT(2)

> +#define LM3692X_PWM_HYSTER_2LSB	BIT(3)

> +#define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))

> +#define LM3692X_PWM_HYSTER_4LSB BIT(4)

> +#define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))

> +#define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))

> +#define LM3692X_PWM_POLARITY	BIT(5)

> +#define LM3692X_PWM_SAMP_4MHZ	BIT(6)

> +#define LM3692X_PWM_SAMP_24MHZ	BIT(7)

> +

> +/* Boost Control Bits */

> +#define LM3692X_OCP_PROT_1A	BIT(0)

> +#define LM3692X_OCP_PROT_1_25A	BIT(1)

> +#define LM3692X_OCP_PROT_1_5A	(BIT(0) | BIT(1))

> +#define LM3692X_OVP_21V		BIT(2)

> +#define LM3692X_OVP_25V		BIT(3)

> +#define LM3692X_OVP_29V		(BIT(2) | BIT(3))

> +#define LM3692X_MIN_IND_22UH	BIT(4)

> +#define LM3692X_BOOST_SW_1MHZ	BIT(5)

> +#define LM3692X_BOOST_SW_NO_SHIFT	BIT(6)

> +

> +/* Fault Control Bits */

> +#define LM3692X_FAULT_CTRL_OVP BIT(0)

> +#define LM3692X_FAULT_CTRL_OCP BIT(1)

> +#define LM3692X_FAULT_CTRL_TSD BIT(2)

> +#define LM3692X_FAULT_CTRL_OPEN BIT(3)

> +

> +/* Fault Flag Bits */

> +#define LM3692X_FAULT_FLAG_OVP BIT(0)

> +#define LM3692X_FAULT_FLAG_OCP BIT(1)

> +#define LM3692X_FAULT_FLAG_TSD BIT(2)

> +#define LM3692X_FAULT_FLAG_SHRT BIT(3)

> +#define LM3692X_FAULT_FLAG_OPEN BIT(4)

> +

> +/**

> + * struct lm3692x_led -

> + * @lock - Lock for reading/writing the device

> + * @client - Pointer to the I2C client

> + * @led_dev - LED class device pointer

> + * @regmap - Devices register map

> + * @enable_gpio - VDDIO/EN gpio to enable communication interface

> + * @regulator - LED supply regulator pointer

> + * @label - LED label

> + */

> +struct lm3692x_led {

> +	struct mutex lock;

> +	struct i2c_client *client;

> +	struct led_classdev led_dev;

> +	struct regmap *regmap;

> +	struct gpio_desc *enable_gpio;

> +	struct regulator *regulator;

> +	char label[LED_MAX_NAME_SIZE];

> +};

> +

> +static const struct reg_default lm3692x_reg_defs[] = {

> +	{LM3692X_EN, 0xf},

> +	{LM3692X_BRT_CTRL, 0x61},

> +	{LM3692X_PWM_CTRL, 0x73},

> +	{LM3692X_BOOST_CTRL, 0x6f},

> +	{LM3692X_AUTO_FREQ_HI, 0x0},

> +	{LM3692X_AUTO_FREQ_LO, 0x0},

> +	{LM3692X_BL_ADJ_THRESH, 0x0},

> +	{LM3692X_BRT_LSB, 0x7},

> +	{LM3692X_BRT_MSB, 0xff},

> +	{LM3692X_FAULT_CTRL, 0x7},

> +};

> +

> +static const struct regmap_config lm3692x_regmap_config = {

> +	.reg_bits = 8,

> +	.val_bits = 8,

> +

> +	.max_register = LM3692X_FAULT_FLAGS,

> +	.reg_defaults = lm3692x_reg_defs,

> +	.num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),

> +	.cache_type = REGCACHE_RBTREE,

> +};

> +

> +static int lm3692x_fault_check(struct lm3692x_led *led)

> +{

> +	int ret;

> +	unsigned int read_buf;

> +

> +	ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);

> +	if (ret)

> +		return ret;

> +

> +	if (read_buf)

> +		dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf);

> +

> +	/* The first read may clear the fault.  Check again to see if the fault

> +	 * still exits and return that value.

> +	 */

> +	regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);

> +	if (read_buf)

> +		dev_err(&led->client->dev, "Second read of fault flags 0x%X\n",

> +			read_buf);

> +

> +	return read_buf;

> +}

> +

> +static int lm3692x_brightness_set(struct led_classdev *led_cdev,

> +				enum led_brightness brt_val)

> +{

> +	struct lm3692x_led *led =

> +			container_of(led_cdev, struct lm3692x_led, led_dev);

> +	int ret;

> +	int led_brightness_lsb = (brt_val >> 5);

> +

> +	mutex_lock(&led->lock);

> +

> +	ret = lm3692x_fault_check(led);

> +	if (ret) {

> +		dev_err(&led->client->dev, "Cannot read/clear faults\n");

> +		goto out;

> +	}

> +

> +	ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);

> +	if (ret) {

> +		dev_err(&led->client->dev, "Cannot write MSB\n");

> +		goto out;

> +	}

> +

> +	ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);

> +	if (ret) {

> +		dev_err(&led->client->dev, "Cannot write LSB\n");

> +		goto out;

> +	}

> +out:

> +	mutex_unlock(&led->lock);

> +	return ret;

> +}

> +

> +static int lm3692x_init(struct lm3692x_led *led)

> +{

> +	int ret;

> +

> +	if (led->regulator) {

> +		ret = regulator_enable(led->regulator);

> +		if (ret) {

> +			dev_err(&led->client->dev,

> +				"Failed to enable regulator\n");

> +			return ret;

> +		}

> +	}

> +

> +	if (led->enable_gpio)

> +		gpiod_direction_output(led->enable_gpio, 1);

> +

> +	ret = lm3692x_fault_check(led);

> +	if (ret) {

> +		dev_err(&led->client->dev, "Cannot read/clear faults\n");

> +		goto out;

> +	}

> +

> +	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);

> +	if (ret)

> +		goto out;

> +

> +	/*

> +	 * For glitch free operation, the following data should

> +	 * only be written while device enable bit is 0

> +	 * per Section 7.5.14 of the data sheet

> +	 */

> +	ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,

> +		LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);

> +	if (ret)

> +		goto out;

> +

> +	ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,

> +			LM3692X_BRHT_MODE_RAMP_MULTI |

> +			LM3692X_BL_ADJ_POL |

> +			LM3692X_RAMP_RATE_250us);

> +	if (ret)

> +		goto out;

> +

> +	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);

> +	if (ret)

> +		goto out;

> +

> +	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);

> +	if (ret)

> +		goto out;

> +

> +	ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);

> +	if (ret)

> +		goto out;

> +

> +	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,

> +			LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB);

> +	if (ret)

> +		goto out;

> +

> +	return ret;

> +out:

> +	dev_err(&led->client->dev, "Fail writing initialization values\n");

> +

> +	if (led->enable_gpio)

> +		gpiod_direction_output(led->enable_gpio, 0);

> +

> +	if (led->regulator) {

> +		ret = regulator_disable(led->regulator);

> +		if (ret)

> +			dev_err(&led->client->dev,

> +				"Failed to disable regulator\n");

> +	}

> +

> +	return ret;

> +}

> +

> +static int lm3692x_probe(struct i2c_client *client,

> +			const struct i2c_device_id *id)

> +{

> +	int ret;

> +	struct lm3692x_led *led;

> +	struct device_node *np = client->dev.of_node;

> +	struct device_node *child_node;

> +	const char *name;

> +

> +	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);

> +	if (!led)

> +		return -ENOMEM;

> +

> +	for_each_available_child_of_node(np, child_node) {

> +		led->led_dev.default_trigger = of_get_property(child_node,

> +						    "linux,default-trigger",

> +						    NULL);

> +

> +		ret = of_property_read_string(child_node, "label", &name);

> +		if (!ret)

> +		    snprintf(led->label, sizeof(led->label), "%s:%s",

> +					id->name, name);

> +		else

> +		    snprintf(led->label, sizeof(led->label),

> +			     "%s::backlight_cluster", id->name);


checpatch.pl complains here about indentation:

WARNING: suspect code indent for conditional statements (16, 20)
#351: FILE: drivers/leds/leds-lm3692x.c:297:
+		if (!ret)
+		    snprintf(led->label, sizeof(led->label), "%s:%s",

WARNING: suspect code indent for conditional statements (16, 20)
#354: FILE: drivers/leds/leds-lm3692x.c:300:
+		else
+		    snprintf(led->label, sizeof(led->label),


Reformatted it as follows:

		if (!ret)
			snprintf(led->label, sizeof(led->label),
				 "%s:%s", id->name, name);
		else
			snprintf(led->label, sizeof(led->label),
				 "%s::backlight_cluster", id->name);


> +	};

> +

> +	led->enable_gpio = devm_gpiod_get_optional(&client->dev,

> +						   "enable", GPIOD_OUT_LOW);

> +	if (IS_ERR(led->enable_gpio)) {

> +		ret = PTR_ERR(led->enable_gpio);

> +		dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);

> +		return ret;

> +	}

> +

> +	led->regulator = devm_regulator_get(&client->dev, "vled");

> +	if (IS_ERR(led->regulator))

> +		led->regulator = NULL;

> +

> +	led->client = client;

> +	led->led_dev.name = led->label;

> +	led->led_dev.brightness_set_blocking = lm3692x_brightness_set;

> +

> +	mutex_init(&led->lock);

> +

> +	i2c_set_clientdata(client, led);

> +

> +	led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);

> +	if (IS_ERR(led->regmap)) {

> +		ret = PTR_ERR(led->regmap);

> +		dev_err(&client->dev, "Failed to allocate register map: %d\n",

> +			ret);

> +		return ret;

> +	}

> +

> +	ret = lm3692x_init(led);

> +	if (ret)

> +		return ret;

> +

> +	ret = devm_led_classdev_register(&client->dev, &led->led_dev);

> +	if (ret) {

> +		dev_err(&client->dev, "led register err: %d\n", ret);

> +		return ret;

> +	}

> +

> +	return 0;

> +}

> +

> +static int lm3692x_remove(struct i2c_client *client)

> +{

> +	struct lm3692x_led *led = i2c_get_clientdata(client);

> +	int ret;

> +

> +	if (led->enable_gpio)

> +		gpiod_direction_output(led->enable_gpio, 0);

> +

> +	if (led->regulator) {

> +		ret = regulator_disable(led->regulator);

> +		if (ret)

> +			dev_err(&led->client->dev,

> +				"Failed to disable regulator\n");

> +	}

> +

> +	mutex_destroy(&led->lock);

> +

> +	return 0;

> +}

> +

> +static const struct i2c_device_id lm3692x_id[] = {

> +	{ "lm36922", 0 },

> +	{ "lm36923", 1 },

> +	{ }

> +};

> +MODULE_DEVICE_TABLE(i2c, lm3692x_id);

> +

> +static const struct of_device_id of_lm3692x_leds_match[] = {

> +	{ .compatible = "ti,lm36922", },

> +	{ .compatible = "ti,lm36923", },

> +	{},

> +};

> +MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);

> +

> +static struct i2c_driver lm3692x_driver = {

> +	.driver = {

> +		.name	= "lm3692x",

> +		.of_match_table = of_lm3692x_leds_match,

> +	},

> +	.probe		= lm3692x_probe,

> +	.remove		= lm3692x_remove,

> +	.id_table	= lm3692x_id,

> +};

> +module_i2c_driver(lm3692x_driver);

> +

> +MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");

> +MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");

> +MODULE_LICENSE("GPL v2");

> 


-- 
Best regards,
Jacek Anaszewski

Patch

diff --git a/Documentation/devicetree/bindings/leds/leds-lm3692x.txt b/Documentation/devicetree/bindings/leds/leds-lm3692x.txt
new file mode 100644
index 000000000000..6c9074f84a51
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-lm3692x.txt
@@ -0,0 +1,49 @@ 
+* Texas Instruments - LM3692x Highly Efficient White LED Driver
+
+The LM3692x is an ultra-compact, highly efficient,
+white-LED driver designed for LCD display backlighting.
+
+The main difference between the LM36922 and LM36923 is the number of
+LED strings it supports.  The LM36922 supports two strings while the LM36923
+supports three strings.
+
+Required properties:
+	- compatible:
+		"ti,lm36922"
+		"ti,lm36923"
+	- reg :  I2C slave address
+	- #address-cells : 1
+	- #size-cells : 0
+
+Optional properties:
+	- enable-gpios : gpio pin to enable/disable the device.
+	- vled-supply : LED supply
+
+Required child properties:
+	- reg : 0
+
+Optional child properties:
+	- label : see Documentation/devicetree/bindings/leds/common.txt
+	- linux,default-trigger :
+	   see Documentation/devicetree/bindings/leds/common.txt
+
+Example:
+
+led-controller@36 {
+	compatible = "ti,lm3692x";
+	reg = <0x36>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	enable-gpios = <&gpio1 28 GPIO_ACTIVE_HIGH>;
+	vled-supply = <&vbatt>;
+
+	led@0 {
+		reg = <0>;
+		label = "white:backlight_cluster";
+		linux,default-trigger = "backlight";
+	};
+}
+
+For more product information please see the link below:
+http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf