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authorLinus Torvalds <torvalds@linux-foundation.org>2011-03-18 10:46:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-18 10:46:37 -0700
commitd3e458d78167102cc961237cfceef6fffc80c0b3 (patch)
treee9195c1294daf053614e63ac52b0b44a28479017 /sound/firewire/packets-buffer.c
parentf2e1fbb5f2177227f71c4fc0491e531dd7acd385 (diff)
parentd351cf4603edb2a5bfa9a48d06c425511c63f2a3 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: (308 commits) ALSA: sound/pci/asihpi: check adapter index in hpi_ioctl ALSA: aloop - Fix possible IRQ lock inversion ALSA: sound/core: merge list_del()/list_add_tail() to list_move_tail() ALSA: ctxfi - use list_move() instead of list_del()/list_add() combination ALSA: firewire - msleep needs delay.h ALSA: firewire-lib, firewire-speakers: handle packet queueing errors ALSA: firewire-lib: allocate DMA buffer separately ALSA: firewire-lib: use no-info SYT for packets without SYT sample ALSA: add LaCie FireWire Speakers/Griffin FireWave Surround driver ALSA: hda - Remove an unused variable in patch_realtek.c ALSA: hda - pin-adc-mux-dmic auto-configuration of 92HD8X codecs ALSA: hda - fix digital mic selection in mixer on 92HD8X codecs ALSA: hda - Move default input-src selection to init part ALSA: hda - Initialize special cases for input src in init phase ALSA: ctxfi - Clear input settings before initialization ALSA: ctxfi - Fix SPDIF status retrieval ALSA: ctxfi - Fix incorrect SPDIF status bit mask ALSA: ctxfi - Fix microphone boost codes/comments ALSA: atiixp - Fix wrong time-out checks during ac-link reset ALSA: intel8x0m: append 'm' to "r_intel8x0" ...
Diffstat (limited to 'sound/firewire/packets-buffer.c')
-rw-r--r--sound/firewire/packets-buffer.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/sound/firewire/packets-buffer.c b/sound/firewire/packets-buffer.c
new file mode 100644
index 00000000000..1e20e60ba6a
--- /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);
+}