ALSA: add LaCie FireWire Speakers/Griffin FireWave Surround driver
Add a driver for two playback-only FireWire devices based on the OXFW970
chip.
v2: better AMDTP API abstraction; fix fw_unit leak; small fixes
v3: cache the iPCR value
v4: FireWave constraints; fix fw_device reference counting;
fix PCR caching; small changes and fixes
v5: volume/mute support; fix crashing due to pcm stop races
v6: fix build; one-channel volume for LaCie
v7: use signed values to make volume (range checks) work; fix function
block IDs for volume/mute; always use channel 0 for LaCie volume
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/firewire/packets-buffer.c b/sound/firewire/packets-buffer.c
new file mode 100644
index 0000000..1e20e60
--- /dev/null
+++ b/sound/firewire/packets-buffer.c
@@ -0,0 +1,74 @@
+/*
+ * helpers for managing a buffer for many packets
+ *
+ * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include <linux/firewire.h>
+#include <linux/slab.h>
+#include "packets-buffer.h"
+
+/**
+ * iso_packets_buffer_init - allocates the memory for packets
+ * @b: the buffer structure to initialize
+ * @unit: the device at the other end of the stream
+ * @count: the number of packets
+ * @packet_size: the (maximum) size of a packet, in bytes
+ * @direction: %DMA_TO_DEVICE or %DMA_FROM_DEVICE
+ */
+int iso_packets_buffer_init(struct iso_packets_buffer *b, struct fw_unit *unit,
+ unsigned int count, unsigned int packet_size,
+ enum dma_data_direction direction)
+{
+ unsigned int packets_per_page, pages;
+ unsigned int i, page_index, offset_in_page;
+ void *p;
+ int err;
+
+ b->packets = kmalloc(count * sizeof(*b->packets), GFP_KERNEL);
+ if (!b->packets) {
+ err = -ENOMEM;
+ goto error;
+ }
+
+ packet_size = L1_CACHE_ALIGN(packet_size);
+ packets_per_page = PAGE_SIZE / packet_size;
+ if (WARN_ON(!packets_per_page)) {
+ err = -EINVAL;
+ goto error;
+ }
+ pages = DIV_ROUND_UP(count, packets_per_page);
+
+ err = fw_iso_buffer_init(&b->iso_buffer, fw_parent_device(unit)->card,
+ pages, direction);
+ if (err < 0)
+ goto err_packets;
+
+ for (i = 0; i < count; ++i) {
+ page_index = i / packets_per_page;
+ p = page_address(b->iso_buffer.pages[page_index]);
+ offset_in_page = (i % packets_per_page) * packet_size;
+ b->packets[i].buffer = p + offset_in_page;
+ b->packets[i].offset = page_index * PAGE_SIZE + offset_in_page;
+ }
+
+ return 0;
+
+err_packets:
+ kfree(b->packets);
+error:
+ return err;
+}
+
+/**
+ * iso_packets_buffer_destroy - frees packet buffer resources
+ * @b: the buffer structure to free
+ * @unit: the device at the other end of the stream
+ */
+void iso_packets_buffer_destroy(struct iso_packets_buffer *b,
+ struct fw_unit *unit)
+{
+ fw_iso_buffer_destroy(&b->iso_buffer, fw_parent_device(unit)->card);
+ kfree(b->packets);
+}