[PATCH] sigma-firmware: loader for Analog Devices' SigmaStudio

[PATCH] sigma-firmware: loader for Analog Devices' SigmaStudio

[Mike Frysinger]

Analog Devices' SigmaStudio can produce firmware blobs for devices with
these DSPs embedded (like some audio codecs).  Allow these device drivers
to easily parse and load them.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---
 drivers/firmware/Kconfig  |   12 +++++
 drivers/firmware/Makefile |    1 +
 drivers/firmware/sigma.c  |  110 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/sigma.h     |   60 ++++++++++++++++++++++++
 4 files changed, 183 insertions(+), 0 deletions(-)
 create mode 100644 drivers/firmware/sigma.c
 create mode 100644 include/linux/sigma.h

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index e8b6a13..8f4f7b2 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -134,4 +134,16 @@ config ISCSI_IBFT
 	  detect iSCSI boot parameters dynamically during system boot, say Y.
 	  Otherwise, say N.
 
+config SIGMA
+	tristate "SigmaStudio firmware loader"
+	depends on I2C
+	select CRC32
+	default n
+	help
+	  Enable helper functions for working with Analog Devices SigmaDSP
+	  parts and binary firmwares produced by Analog Devices SigmaStudio.
+
+	  If unsure, say N here.  Drivers that need these helpers will select
+	  this option automatically.
+
 endmenu
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 1c3c173..ede9722 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_DMIID)		+= dmi-id.o
 obj-$(CONFIG_ISCSI_IBFT_FIND)	+= iscsi_ibft_find.o
 obj-$(CONFIG_ISCSI_IBFT)	+= iscsi_ibft.o
 obj-$(CONFIG_FIRMWARE_MEMMAP)	+= memmap.o
+obj-$(CONFIG_SIGMA)		+= sigma.o
diff --git a/drivers/firmware/sigma.c b/drivers/firmware/sigma.c
new file mode 100644
index 0000000..e2945be
--- /dev/null
+++ b/drivers/firmware/sigma.c
@@ -0,0 +1,110 @@
+/*
+ * Load Analog Devices SigmaStudio firmware files
+ *
+ * Copyright 2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/crc32.h>
+#include <linux/delay.h>
+#include <linux/firmware.h>
+#include <linux/kernel.h>
+#include <linux/i2c.h>
+#include <linux/sigma.h>
+
+/* Return: 0==OK, <0==error, =1 ==no more actions */
+int process_sigma_action(struct i2c_client *client, struct sigma_firmware *ssfw)
+{
+	struct sigma_action *sa = (void *)(ssfw->fw->data + ssfw->pos);
+	size_t len = sigma_action_len(sa);
+	int ret = 0;
+
+	pr_debug("%s: instr:%i addr:%#x len:%zu\n", __func__,
+		sa->instr, sa->addr, len);
+
+	switch (sa->instr) {
+		case SIGMA_ACTION_WRITEXBYTES:
+		case SIGMA_ACTION_WRITESINGLE:
+		case SIGMA_ACTION_WRITESAFELOAD:
+			if (ssfw->fw->size < ssfw->pos + len)
+				return -EINVAL;
+			ret = i2c_master_send(client, (void *)&sa->addr, len);
+			if (ret < 0)
+				return -EINVAL;
+			break;
+
+		case SIGMA_ACTION_DELAY:
+			ret = 0;
+			udelay(len);
+			len = 0;
+			break;
+
+		case SIGMA_ACTION_END:
+			return 1;
+
+		default:
+			return -EINVAL;
+	}
+
+	/* when arrive here ret=0 or sent data */
+	ssfw->pos += sigma_action_size(sa, len);
+	return ssfw->pos == ssfw->fw->size;
+}
+
+int process_sigma_actions(struct i2c_client *client, struct sigma_firmware *ssfw)
+{
+	pr_debug("%s: processing %p\n", __func__, ssfw);
+
+	while (1) {
+		int ret = process_sigma_action(client, ssfw);
+		pr_debug("%s: action returned %i\n", __func__, ret);
+		if (ret == 1)
+			return 0;
+		else if (ret)
+			return ret;
+	}
+}
+
+int process_sigma_firmware(struct i2c_client *client, const char *name)
+{
+	int ret;
+	struct sigma_firmware_header *ssfw_head;
+	struct sigma_firmware ssfw;
+	const struct firmware *fw;
+
+	pr_debug("%s: loading firmware %s\n", __func__, name);
+
+	/* first load the blob */
+	ret = request_firmware(&fw, name, &client->dev);
+	if (ret) {
+		pr_debug("%s: request_firmware() failed with %i\n", __func__, ret);
+		return ret;
+	}
+	ssfw.fw = fw;
+
+	/* then verify the header */
+	if (fw->size < sizeof(*ssfw_head)) {
+		ret = -ENODATA;
+		goto done;
+	}
+	ssfw_head = (void *)fw->data;
+	if (memcmp(ssfw_head->magic, SIGMA_MAGIC, ARRAY_SIZE(ssfw_head->magic))) {
+		ret = -EINVAL;
+		goto done;
+	}
+	pr_debug("%s: crc=%x\n", __func__, crc32(0, fw->data, fw->size));
+
+	ssfw.pos = sizeof(*ssfw_head);
+
+	/* finally process all of the actions */
+	ret = process_sigma_actions(client, &ssfw);
+
+ done:
+	release_firmware(fw);
+
+	pr_debug("%s: loaded %s\n", __func__, name);
+
+	return ret;
+}
+EXPORT_SYMBOL(process_sigma_firmware);
diff --git a/include/linux/sigma.h b/include/linux/sigma.h
new file mode 100644
index 0000000..510765f
--- /dev/null
+++ b/include/linux/sigma.h
@@ -0,0 +1,60 @@
+/*
+ * Load firmware files from Analog Devices SigmaStudio
+ *
+ * Copyright 2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __SIGMA_FIRMWARE_H__
+#define __SIGMA_FIRMWARE_H__
+
+#include <linux/firmware.h>
+#include <linux/types.h>
+
+#define SIGMA_MAGIC "ADISIGM"
+
+struct sigma_firmware {
+	const struct firmware *fw;
+	size_t pos;
+};
+
+struct sigma_firmware_header {
+	unsigned char magic[7];
+	u8 version;
+	u32 crc;
+};
+
+enum {
+	SIGMA_ACTION_WRITEXBYTES = 0,
+	SIGMA_ACTION_WRITESINGLE,
+	SIGMA_ACTION_WRITESAFELOAD,
+	SIGMA_ACTION_DELAY,
+	SIGMA_ACTION_PLLWAIT,
+	SIGMA_ACTION_NOOP,
+	SIGMA_ACTION_END,
+};
+
+struct sigma_action {
+	u8 instr;
+	u8 len_hi;
+	u16 len;
+	u16 addr;
+	unsigned char payload[];
+};
+
+static inline u32 sigma_action_len(struct sigma_action *sa)
+{
+	return (sa->len_hi << 16) | sa->len;
+}
+
+static inline size_t sigma_action_size(struct sigma_action *sa, u32 payload_len)
+{
+	return sizeof(*sa) + payload_len + (payload_len % 2);
+}
+
+struct i2c_client;
+
+extern int process_sigma_firmware(struct i2c_client *client, const char *name);
+
+#endif
-- 
1.7.4.rc1

Re: [PATCH] sigma-firmware: loader for Analog Devices' SigmaStudio

[Andrew Morton]

On Wed, 12 Jan 2011 00:41:31 -0500
Mike Frysinger <vapier@gentoo.org> wrote:

> Analog Devices' SigmaStudio can produce firmware blobs for devices with
> these DSPs embedded (like some audio codecs).  Allow these device drivers
> to easily parse and load them.
> 
> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
> ---
>  drivers/firmware/Kconfig  |   12 +++++
>  drivers/firmware/Makefile |    1 +
>  drivers/firmware/sigma.c  |  110 +++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/sigma.h     |   60 ++++++++++++++++++++++++

The newly-added code has no callsites.  What are we to make of this?

> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
> index e8b6a13..8f4f7b2 100644
> --- a/drivers/firmware/Kconfig
> +++ b/drivers/firmware/Kconfig
> @@ -134,4 +134,16 @@ config ISCSI_IBFT
>  	  detect iSCSI boot parameters dynamically during system boot, say Y.
>  	  Otherwise, say N.
>  
> +config SIGMA
> +	tristate "SigmaStudio firmware loader"
> +	depends on I2C

The dependence on just I2C looks odd.  What's the rationale here?

> +	select CRC32
> +	default n
> +	help
> +	  Enable helper functions for working with Analog Devices SigmaDSP
> +	  parts and binary firmwares produced by Analog Devices SigmaStudio.
> +
> +	  If unsure, say N here.  Drivers that need these helpers will select
> +	  this option automatically.
> +
>  endmenu
> diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
> index 1c3c173..ede9722 100644
> --- a/drivers/firmware/Makefile
> +++ b/drivers/firmware/Makefile
> @@ -11,3 +11,4 @@ obj-$(CONFIG_DMIID)		+= dmi-id.o
>  obj-$(CONFIG_ISCSI_IBFT_FIND)	+= iscsi_ibft_find.o
>  obj-$(CONFIG_ISCSI_IBFT)	+= iscsi_ibft.o
>  obj-$(CONFIG_FIRMWARE_MEMMAP)	+= memmap.o
> +obj-$(CONFIG_SIGMA)		+= sigma.o
> diff --git a/drivers/firmware/sigma.c b/drivers/firmware/sigma.c
> new file mode 100644
> index 0000000..e2945be
> --- /dev/null
> +++ b/drivers/firmware/sigma.c
> @@ -0,0 +1,110 @@
> +/*
> + * Load Analog Devices SigmaStudio firmware files
> + *
> +__* Copyright 2009 Analog Devices Inc.
> +__*
> +__* Licensed under the GPL-2 or later.
> + */

Code had weird non-ascii chars.

> +
> +#include <linux/crc32.h>
> +#include <linux/delay.h>
> +#include <linux/firmware.h>
> +#include <linux/kernel.h>
> +#include <linux/i2c.h>
> +#include <linux/sigma.h>
> +
> +/* Return: 0==OK, <0==error, =1 ==no more actions */
> +int process_sigma_action(struct i2c_client *client, struct sigma_firmware *ssfw)
> +{
> +	struct sigma_action *sa = (void *)(ssfw->fw->data + ssfw->pos);
> +	size_t len = sigma_action_len(sa);
> +	int ret = 0;
> +
> +	pr_debug("%s: instr:%i addr:%#x len:%zu\n", __func__,
> +		sa->instr, sa->addr, len);
> +
> +	switch (sa->instr) {
> +		case SIGMA_ACTION_WRITEXBYTES:
> +		case SIGMA_ACTION_WRITESINGLE:
> +		case SIGMA_ACTION_WRITESAFELOAD:
> +			if (ssfw->fw->size < ssfw->pos + len)
> +				return -EINVAL;
> +			ret = i2c_master_send(client, (void *)&sa->addr, len);
> +			if (ret < 0)
> +				return -EINVAL;
> +			break;
> +
> +		case SIGMA_ACTION_DELAY:
> +			ret = 0;
> +			udelay(len);
> +			len = 0;
> +			break;
> +
> +		case SIGMA_ACTION_END:
> +			return 1;
> +
> +		default:
> +			return -EINVAL;
> +	}

Indent in the switch was wrong.  Please use checkpatch.

> +	/* when arrive here ret=0 or sent data */
> +	ssfw->pos += sigma_action_size(sa, len);
> +	return ssfw->pos == ssfw->fw->size;
> +}
> +
> +int process_sigma_actions(struct i2c_client *client, struct sigma_firmware *ssfw)

Global scope appears to be unnecessary.

> +{
> +	pr_debug("%s: processing %p\n", __func__, ssfw);
> +
> +	while (1) {
> +		int ret = process_sigma_action(client, ssfw);
> +		pr_debug("%s: action returned %i\n", __func__, ret);
> +		if (ret == 1)
> +			return 0;
> +		else if (ret)
> +			return ret;
> +	}
> +}
> +
> +int process_sigma_firmware(struct i2c_client *client, const char *name)

Global scope appears to be unnecessary.

> +{
> +	int ret;
> +	struct sigma_firmware_header *ssfw_head;
> +	struct sigma_firmware ssfw;
> +	const struct firmware *fw;
> +
> +	pr_debug("%s: loading firmware %s\n", __func__, name);
> +
> +	/* first load the blob */
> +	ret = request_firmware(&fw, name, &client->dev);
> +	if (ret) {
> +		pr_debug("%s: request_firmware() failed with %i\n", __func__, ret);
> +		return ret;
> +	}
> +	ssfw.fw = fw;
> +
> +	/* then verify the header */
> +	if (fw->size < sizeof(*ssfw_head)) {
> +		ret = -ENODATA;
> +		goto done;
> +	}
> +	ssfw_head = (void *)fw->data;
> +	if (memcmp(ssfw_head->magic, SIGMA_MAGIC, ARRAY_SIZE(ssfw_head->magic))) {
> +		ret = -EINVAL;
> +		goto done;
> +	}
> +	pr_debug("%s: crc=%x\n", __func__, crc32(0, fw->data, fw->size));

The code calculates and prints the crc but doesn't actually check it
against anything.  What's up with that?

> +	ssfw.pos = sizeof(*ssfw_head);
> +
> +	/* finally process all of the actions */
> +	ret = process_sigma_actions(client, &ssfw);
> +
> + done:
> +	release_firmware(fw);
> +
> +	pr_debug("%s: loaded %s\n", __func__, name);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(process_sigma_firmware);
> diff --git a/include/linux/sigma.h b/include/linux/sigma.h
> new file mode 100644
> index 0000000..510765f
> --- /dev/null
> +++ b/include/linux/sigma.h
> @@ -0,0 +1,60 @@
> +/*
> + * Load firmware files from Analog Devices SigmaStudio
> + *
> +__* Copyright 2009 Analog Devices Inc.
> +__*
> +__* Licensed under the GPL-2 or later.
> + */

More weird non-ascii chars.

> +#ifndef __SIGMA_FIRMWARE_H__
> +#define __SIGMA_FIRMWARE_H__
> +
> +#include <linux/firmware.h>
> +#include <linux/types.h>
> +
> +#define SIGMA_MAGIC "ADISIGM"
> +
> +struct sigma_firmware {
> +	const struct firmware *fw;
> +	size_t pos;
> +};
> +
> +struct sigma_firmware_header {
> +	unsigned char magic[7];
> +	u8 version;
> +	u32 crc;
> +};
> +
> +enum {
> +	SIGMA_ACTION_WRITEXBYTES = 0,
> +	SIGMA_ACTION_WRITESINGLE,
> +	SIGMA_ACTION_WRITESAFELOAD,
> +	SIGMA_ACTION_DELAY,
> +	SIGMA_ACTION_PLLWAIT,
> +	SIGMA_ACTION_NOOP,
> +	SIGMA_ACTION_END,
> +};
> +
> +struct sigma_action {
> +	u8 instr;
> +	u8 len_hi;
> +	u16 len;
> +	u16 addr;
> +	unsigned char payload[];
> +};
> +
> +static inline u32 sigma_action_len(struct sigma_action *sa)
> +{
> +	return (sa->len_hi << 16) | sa->len;
> +}
> +
> +static inline size_t sigma_action_size(struct sigma_action *sa, u32 payload_len)
> +{
> +	return sizeof(*sa) + payload_len + (payload_len % 2);
> +}

Did these two functions need to be in a header?  If they're only ever
used in sigma.c then they should be located in that file.

> +struct i2c_client;

It's best to put forward declarations of this form right at the top of
the header file.  Otherwise, we end up with duplicated
forward-declarations as people add references to `struct i2c_client' at
earlier sites in this file.  This has happened before.

> +extern int process_sigma_firmware(struct i2c_client *client, const char *name);
> +
> +#endif


A patch to address some of the above:

--- a/drivers/firmware/sigma.c~sigma-firmware-loader-for-analog-devices-sigmastudio-fix
+++ a/drivers/firmware/sigma.c
@@ -1,9 +1,9 @@
 /*
  * Load Analog Devices SigmaStudio firmware files
  *
- * Copyright 2009 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
+_* Copyright 2009 Analog Devices Inc.
+_*
+_* Licensed under the GPL-2 or later.
  */
 
 #include <linux/crc32.h>
@@ -14,7 +14,8 @@
 #include <linux/sigma.h>
 
 /* Return: 0==OK, <0==error, =1 ==no more actions */
-int process_sigma_action(struct i2c_client *client, struct sigma_firmware *ssfw)
+static int process_sigma_action(struct i2c_client *client,
+				struct sigma_firmware *ssfw)
 {
 	struct sigma_action *sa = (void *)(ssfw->fw->data + ssfw->pos);
 	size_t len = sigma_action_len(sa);
@@ -24,27 +25,27 @@ int process_sigma_action(struct i2c_clie
 		sa->instr, sa->addr, len);
 
 	switch (sa->instr) {
-		case SIGMA_ACTION_WRITEXBYTES:
-		case SIGMA_ACTION_WRITESINGLE:
-		case SIGMA_ACTION_WRITESAFELOAD:
-			if (ssfw->fw->size < ssfw->pos + len)
-				return -EINVAL;
-			ret = i2c_master_send(client, (void *)&sa->addr, len);
-			if (ret < 0)
-				return -EINVAL;
-			break;
-
-		case SIGMA_ACTION_DELAY:
-			ret = 0;
-			udelay(len);
-			len = 0;
-			break;
+	case SIGMA_ACTION_WRITEXBYTES:
+	case SIGMA_ACTION_WRITESINGLE:
+	case SIGMA_ACTION_WRITESAFELOAD:
+		if (ssfw->fw->size < ssfw->pos + len)
+			return -EINVAL;
+		ret = i2c_master_send(client, (void *)&sa->addr, len);
+		if (ret < 0)
+			return -EINVAL;
+		break;
 
-		case SIGMA_ACTION_END:
-			return 1;
+	case SIGMA_ACTION_DELAY:
+		ret = 0;
+		udelay(len);
+		len = 0;
+		break;
 
-		default:
-			return -EINVAL;
+	case SIGMA_ACTION_END:
+		return 1;
+
+	default:
+		return -EINVAL;
 	}
 
 	/* when arrive here ret=0 or sent data */
@@ -52,7 +53,8 @@ int process_sigma_action(struct i2c_clie
 	return ssfw->pos == ssfw->fw->size;
 }
 
-int process_sigma_actions(struct i2c_client *client, struct sigma_firmware *ssfw)
+static int process_sigma_actions(struct i2c_client *client,
+				 struct sigma_firmware *ssfw)
 {
 	pr_debug("%s: processing %p\n", __func__, ssfw);
 
@@ -78,7 +80,8 @@ int process_sigma_firmware(struct i2c_cl
 	/* first load the blob */
 	ret = request_firmware(&fw, name, &client->dev);
 	if (ret) {
-		pr_debug("%s: request_firmware() failed with %i\n", __func__, ret);
+		pr_debug("%s: request_firmware() failed with %i\n",
+			 __func__, ret);
 		return ret;
 	}
 	ssfw.fw = fw;
diff -puN include/linux/sigma.h~sigma-firmware-loader-for-analog-devices-sigmastudio-fix include/linux/sigma.h
--- a/include/linux/sigma.h~sigma-firmware-loader-for-analog-devices-sigmastudio-fix
+++ a/include/linux/sigma.h
@@ -1,9 +1,9 @@
 /*
  * Load firmware files from Analog Devices SigmaStudio
  *
- * Copyright 2009 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
+_* Copyright 2009 Analog Devices Inc.
+_*
+_* Licensed under the GPL-2 or later.
  */
 
 #ifndef __SIGMA_FIRMWARE_H__
@@ -12,6 +12,8 @@
 #include <linux/firmware.h>
 #include <linux/types.h>
 
+struct i2c_client;
+
 #define SIGMA_MAGIC "ADISIGM"
 
 struct sigma_firmware {
@@ -53,8 +55,6 @@ static inline size_t sigma_action_size(s
 	return sizeof(*sa) + payload_len + (payload_len % 2);
 }
 
-struct i2c_client;
-
 extern int process_sigma_firmware(struct i2c_client *client, const char *name);
 
 #endif
_

Re: [Device-drivers-devel] [PATCH] sigma-firmware: loader for Analog Devices' SigmaStudio

[Mike Frysinger]

On Wed, Jan 19, 2011 at 19:37, Andrew Morton wrote:
> On Wed, 12 Jan 2011 00:41:31 -0500 Mike Frysinger wrote:
> The newly-added code has no callsites.  What are we to make of this?

the ASoC drivers have already been submitted and are going through the process

>> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
>> index e8b6a13..8f4f7b2 100644
>> --- a/drivers/firmware/Kconfig
>> +++ b/drivers/firmware/Kconfig
>> @@ -134,4 +134,16 @@ config ISCSI_IBFT
>>         detect iSCSI boot parameters dynamically during system boot, say Y.
>>         Otherwise, say N.
>>
>> +config SIGMA
>> +     tristate "SigmaStudio firmware loader"
>> +     depends on I2C
>
> The dependence on just I2C looks odd.  What's the rationale here?

the code clearly calls i2c_master_send

>> +int process_sigma_actions(struct i2c_client *client, struct sigma_firmware *ssfw)
>
> Global scope appears to be unnecessary.

idea originally was to let people process things more directly, but
there hasnt been a need so far.  so localizing them until someone
needs them is probably fine.

>> +     pr_debug("%s: crc=%x\n", __func__, crc32(0, fw->data, fw->size));
>
> The code calculates and prints the crc but doesn't actually check it
> against anything.  What's up with that?

it's supposed to abort.  guess we forgot to.

>> +static inline u32 sigma_action_len(struct sigma_action *sa)
>> +{
>> +     return (sa->len_hi << 16) | sa->len;
>> +}
>> +
>> +static inline size_t sigma_action_size(struct sigma_action *sa, u32 payload_len)
>> +{
>> +     return sizeof(*sa) + payload_len + (payload_len % 2);
>> +}
>
> Did these two functions need to be in a header?  If they're only ever
> used in sigma.c then they should be located in that file.

part of the original idea of allowing the callers to process things
more directly if necessary.  should be harmless to leave it here.
-mike

[PATCH v2] sigma-firmware: loader for Analog Devices' SigmaStudio

[Mike Frysinger]

Analog Devices' SigmaStudio can produce firmware blobs for devices with
these DSPs embedded (like some audio codecs).  Allow these device drivers
to easily parse and load them.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---
v2
	- address feedback from Andrew

 drivers/firmware/Kconfig  |   12 +++++
 drivers/firmware/Makefile |    1 +
 drivers/firmware/sigma.c  |  115 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/sigma.h     |   60 +++++++++++++++++++++++
 4 files changed, 188 insertions(+), 0 deletions(-)
 create mode 100644 drivers/firmware/sigma.c
 create mode 100644 include/linux/sigma.h

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index e8b6a13..8f4f7b2 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -134,4 +134,16 @@ config ISCSI_IBFT
 	  detect iSCSI boot parameters dynamically during system boot, say Y.
 	  Otherwise, say N.
 
+config SIGMA
+	tristate "SigmaStudio firmware loader"
+	depends on I2C
+	select CRC32
+	default n
+	help
+	  Enable helper functions for working with Analog Devices SigmaDSP
+	  parts and binary firmwares produced by Analog Devices SigmaStudio.
+
+	  If unsure, say N here.  Drivers that need these helpers will select
+	  this option automatically.
+
 endmenu
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 1c3c173..ede9722 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_DMIID)		+= dmi-id.o
 obj-$(CONFIG_ISCSI_IBFT_FIND)	+= iscsi_ibft_find.o
 obj-$(CONFIG_ISCSI_IBFT)	+= iscsi_ibft.o
 obj-$(CONFIG_FIRMWARE_MEMMAP)	+= memmap.o
+obj-$(CONFIG_SIGMA)		+= sigma.o
diff --git a/drivers/firmware/sigma.c b/drivers/firmware/sigma.c
new file mode 100644
index 0000000..c19cd2c
--- /dev/null
+++ b/drivers/firmware/sigma.c
@@ -0,0 +1,115 @@
+/*
+ * Load Analog Devices SigmaStudio firmware files
+ *
+ * Copyright 2009-2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/crc32.h>
+#include <linux/delay.h>
+#include <linux/firmware.h>
+#include <linux/kernel.h>
+#include <linux/i2c.h>
+#include <linux/sigma.h>
+
+/* Return: 0==OK, <0==error, =1 ==no more actions */
+static int
+process_sigma_action(struct i2c_client *client, struct sigma_firmware *ssfw)
+{
+	struct sigma_action *sa = (void *)(ssfw->fw->data + ssfw->pos);
+	size_t len = sigma_action_len(sa);
+	int ret = 0;
+
+	pr_debug("%s: instr:%i addr:%#x len:%zu\n", __func__,
+		sa->instr, sa->addr, len);
+
+	switch (sa->instr) {
+	case SIGMA_ACTION_WRITEXBYTES:
+	case SIGMA_ACTION_WRITESINGLE:
+	case SIGMA_ACTION_WRITESAFELOAD:
+		if (ssfw->fw->size < ssfw->pos + len)
+			return -EINVAL;
+		ret = i2c_master_send(client, (void *)&sa->addr, len);
+		if (ret < 0)
+			return -EINVAL;
+		break;
+
+	case SIGMA_ACTION_DELAY:
+		ret = 0;
+		udelay(len);
+		len = 0;
+		break;
+
+	case SIGMA_ACTION_END:
+		return 1;
+
+	default:
+		return -EINVAL;
+	}
+
+	/* when arrive here ret=0 or sent data */
+	ssfw->pos += sigma_action_size(sa, len);
+	return ssfw->pos == ssfw->fw->size;
+}
+
+static int
+process_sigma_actions(struct i2c_client *client, struct sigma_firmware *ssfw)
+{
+	pr_debug("%s: processing %p\n", __func__, ssfw);
+
+	while (1) {
+		int ret = process_sigma_action(client, ssfw);
+		pr_debug("%s: action returned %i\n", __func__, ret);
+		if (ret == 1)
+			return 0;
+		else if (ret)
+			return ret;
+	}
+}
+
+int process_sigma_firmware(struct i2c_client *client, const char *name)
+{
+	int ret;
+	struct sigma_firmware_header *ssfw_head;
+	struct sigma_firmware ssfw;
+	const struct firmware *fw;
+	u32 crc;
+
+	pr_debug("%s: loading firmware %s\n", __func__, name);
+
+	/* first load the blob */
+	ret = request_firmware(&fw, name, &client->dev);
+	if (ret) {
+		pr_debug("%s: request_firmware() failed with %i\n", __func__, ret);
+		return ret;
+	}
+	ssfw.fw = fw;
+
+	/* then verify the header */
+	ret = -EINVAL;
+	if (fw->size < sizeof(*ssfw_head))
+		goto done;
+
+	ssfw_head = (void *)fw->data;
+	if (memcmp(ssfw_head->magic, SIGMA_MAGIC, ARRAY_SIZE(ssfw_head->magic)))
+		goto done;
+
+	crc = crc32(0, fw->data, fw->size);
+	pr_debug("%s: crc=%x\n", __func__, crc);
+	if (crc != ssfw_head->crc)
+		goto done;
+
+	ssfw.pos = sizeof(*ssfw_head);
+
+	/* finally process all of the actions */
+	ret = process_sigma_actions(client, &ssfw);
+
+ done:
+	release_firmware(fw);
+
+	pr_debug("%s: loaded %s\n", __func__, name);
+
+	return ret;
+}
+EXPORT_SYMBOL(process_sigma_firmware);
diff --git a/include/linux/sigma.h b/include/linux/sigma.h
new file mode 100644
index 0000000..e2accb3
--- /dev/null
+++ b/include/linux/sigma.h
@@ -0,0 +1,60 @@
+/*
+ * Load firmware files from Analog Devices SigmaStudio
+ *
+ * Copyright 2009-2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __SIGMA_FIRMWARE_H__
+#define __SIGMA_FIRMWARE_H__
+
+#include <linux/firmware.h>
+#include <linux/types.h>
+
+struct i2c_client;
+
+#define SIGMA_MAGIC "ADISIGM"
+
+struct sigma_firmware {
+	const struct firmware *fw;
+	size_t pos;
+};
+
+struct sigma_firmware_header {
+	unsigned char magic[7];
+	u8 version;
+	u32 crc;
+};
+
+enum {
+	SIGMA_ACTION_WRITEXBYTES = 0,
+	SIGMA_ACTION_WRITESINGLE,
+	SIGMA_ACTION_WRITESAFELOAD,
+	SIGMA_ACTION_DELAY,
+	SIGMA_ACTION_PLLWAIT,
+	SIGMA_ACTION_NOOP,
+	SIGMA_ACTION_END,
+};
+
+struct sigma_action {
+	u8 instr;
+	u8 len_hi;
+	u16 len;
+	u16 addr;
+	unsigned char payload[];
+};
+
+static inline u32 sigma_action_len(struct sigma_action *sa)
+{
+	return (sa->len_hi << 16) | sa->len;
+}
+
+static inline size_t sigma_action_size(struct sigma_action *sa, u32 payload_len)
+{
+	return sizeof(*sa) + payload_len + (payload_len % 2);
+}
+
+extern int process_sigma_firmware(struct i2c_client *client, const char *name);
+
+#endif
-- 
1.7.4.rc2