sigma-firmware: loader for Analog Devices' SigmaStudio

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: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/firmware/Kconfig

@@ -145,4 +145,16 @@ 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

drivers/firmware/Makefile

@@ -12,3 +12,4 @@ 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

drivers/firmware/sigma.c

+/*
+ * 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);

include/linux/sigma.h

+/*
+ * 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