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: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 115 insertions, 0 deletions

diff --git a/drivers/firmware/sigma.c b/drivers/firmware/sigma.c
new file mode 100644
index 000000000000..c19cd2c39fa6
--- /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);