diff options
Diffstat (limited to 'ANDROID_3.4.5/sound/firewire/iso-resources.c')
| -rw-r--r-- | ANDROID_3.4.5/sound/firewire/iso-resources.c | 232 |
1 files changed, 0 insertions, 232 deletions
diff --git a/ANDROID_3.4.5/sound/firewire/iso-resources.c b/ANDROID_3.4.5/sound/firewire/iso-resources.c deleted file mode 100644 index 5f17b77e..00000000 --- a/ANDROID_3.4.5/sound/firewire/iso-resources.c +++ /dev/null @@ -1,232 +0,0 @@ -/* - * isochronous resources helper functions - * - * Copyright (c) Clemens Ladisch <clemens@ladisch.de> - * Licensed under the terms of the GNU General Public License, version 2. - */ - -#include <linux/device.h> -#include <linux/firewire.h> -#include <linux/firewire-constants.h> -#include <linux/export.h> -#include <linux/jiffies.h> -#include <linux/mutex.h> -#include <linux/sched.h> -#include <linux/spinlock.h> -#include "iso-resources.h" - -/** - * fw_iso_resources_init - initializes a &struct fw_iso_resources - * @r: the resource manager to initialize - * @unit: the device unit for which the resources will be needed - * - * If the device does not support all channel numbers, change @r->channels_mask - * after calling this function. - */ -int fw_iso_resources_init(struct fw_iso_resources *r, struct fw_unit *unit) -{ - r->channels_mask = ~0uLL; - r->unit = fw_unit_get(unit); - mutex_init(&r->mutex); - r->allocated = false; - - return 0; -} -EXPORT_SYMBOL(fw_iso_resources_init); - -/** - * fw_iso_resources_destroy - destroy a resource manager - * @r: the resource manager that is no longer needed - */ -void fw_iso_resources_destroy(struct fw_iso_resources *r) -{ - WARN_ON(r->allocated); - mutex_destroy(&r->mutex); - fw_unit_put(r->unit); -} -EXPORT_SYMBOL(fw_iso_resources_destroy); - -static unsigned int packet_bandwidth(unsigned int max_payload_bytes, int speed) -{ - unsigned int bytes, s400_bytes; - - /* iso packets have three header quadlets and quadlet-aligned payload */ - bytes = 3 * 4 + ALIGN(max_payload_bytes, 4); - - /* convert to bandwidth units (quadlets at S1600 = bytes at S400) */ - if (speed <= SCODE_400) - s400_bytes = bytes * (1 << (SCODE_400 - speed)); - else - s400_bytes = DIV_ROUND_UP(bytes, 1 << (speed - SCODE_400)); - - return s400_bytes; -} - -static int current_bandwidth_overhead(struct fw_card *card) -{ - /* - * Under the usual pessimistic assumption (cable length 4.5 m), the - * isochronous overhead for N cables is 1.797 µs + N * 0.494 µs, or - * 88.3 + N * 24.3 in bandwidth units. - * - * The calculation below tries to deduce N from the current gap count. - * If the gap count has been optimized by measuring the actual packet - * transmission time, this derived overhead should be near the actual - * overhead as well. - */ - return card->gap_count < 63 ? card->gap_count * 97 / 10 + 89 : 512; -} - -static int wait_isoch_resource_delay_after_bus_reset(struct fw_card *card) -{ - for (;;) { - s64 delay = (card->reset_jiffies + HZ) - get_jiffies_64(); - if (delay <= 0) - return 0; - if (schedule_timeout_interruptible(delay) > 0) - return -ERESTARTSYS; - } -} - -/** - * fw_iso_resources_allocate - allocate isochronous channel and bandwidth - * @r: the resource manager - * @max_payload_bytes: the amount of data (including CIP headers) per packet - * @speed: the speed (e.g., SCODE_400) at which the packets will be sent - * - * This function allocates one isochronous channel and enough bandwidth for the - * specified packet size. - * - * Returns the channel number that the caller must use for streaming, or - * a negative error code. Due to potentionally long delays, this function is - * interruptible and can return -ERESTARTSYS. On success, the caller is - * responsible for calling fw_iso_resources_update() on bus resets, and - * fw_iso_resources_free() when the resources are not longer needed. - */ -int fw_iso_resources_allocate(struct fw_iso_resources *r, - unsigned int max_payload_bytes, int speed) -{ - struct fw_card *card = fw_parent_device(r->unit)->card; - int bandwidth, channel, err; - - if (WARN_ON(r->allocated)) - return -EBADFD; - - r->bandwidth = packet_bandwidth(max_payload_bytes, speed); - -retry_after_bus_reset: - spin_lock_irq(&card->lock); - r->generation = card->generation; - r->bandwidth_overhead = current_bandwidth_overhead(card); - spin_unlock_irq(&card->lock); - - err = wait_isoch_resource_delay_after_bus_reset(card); - if (err < 0) - return err; - - mutex_lock(&r->mutex); - - bandwidth = r->bandwidth + r->bandwidth_overhead; - fw_iso_resource_manage(card, r->generation, r->channels_mask, - &channel, &bandwidth, true); - if (channel == -EAGAIN) { - mutex_unlock(&r->mutex); - goto retry_after_bus_reset; - } - if (channel >= 0) { - r->channel = channel; - r->allocated = true; - } else { - if (channel == -EBUSY) - dev_err(&r->unit->device, - "isochronous resources exhausted\n"); - else - dev_err(&r->unit->device, - "isochronous resource allocation failed\n"); - } - - mutex_unlock(&r->mutex); - - return channel; -} -EXPORT_SYMBOL(fw_iso_resources_allocate); - -/** - * fw_iso_resources_update - update resource allocations after a bus reset - * @r: the resource manager - * - * This function must be called from the driver's .update handler to reallocate - * any resources that were allocated before the bus reset. It is safe to call - * this function if no resources are currently allocated. - * - * Returns a negative error code on failure. If this happens, the caller must - * stop streaming. - */ -int fw_iso_resources_update(struct fw_iso_resources *r) -{ - struct fw_card *card = fw_parent_device(r->unit)->card; - int bandwidth, channel; - - mutex_lock(&r->mutex); - - if (!r->allocated) { - mutex_unlock(&r->mutex); - return 0; - } - - spin_lock_irq(&card->lock); - r->generation = card->generation; - r->bandwidth_overhead = current_bandwidth_overhead(card); - spin_unlock_irq(&card->lock); - - bandwidth = r->bandwidth + r->bandwidth_overhead; - - fw_iso_resource_manage(card, r->generation, 1uLL << r->channel, - &channel, &bandwidth, true); - /* - * When another bus reset happens, pretend that the allocation - * succeeded; we will try again for the new generation later. - */ - if (channel < 0 && channel != -EAGAIN) { - r->allocated = false; - if (channel == -EBUSY) - dev_err(&r->unit->device, - "isochronous resources exhausted\n"); - else - dev_err(&r->unit->device, - "isochronous resource allocation failed\n"); - } - - mutex_unlock(&r->mutex); - - return channel; -} -EXPORT_SYMBOL(fw_iso_resources_update); - -/** - * fw_iso_resources_free - frees allocated resources - * @r: the resource manager - * - * This function deallocates the channel and bandwidth, if allocated. - */ -void fw_iso_resources_free(struct fw_iso_resources *r) -{ - struct fw_card *card = fw_parent_device(r->unit)->card; - int bandwidth, channel; - - mutex_lock(&r->mutex); - - if (r->allocated) { - bandwidth = r->bandwidth + r->bandwidth_overhead; - fw_iso_resource_manage(card, r->generation, 1uLL << r->channel, - &channel, &bandwidth, false); - if (channel < 0) - dev_err(&r->unit->device, - "isochronous resource deallocation failed\n"); - - r->allocated = false; - } - - mutex_unlock(&r->mutex); -} -EXPORT_SYMBOL(fw_iso_resources_free); |