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author | Clemens Ladisch <clemens@ladisch.de> | 2011-03-15 07:53:21 +0100 |
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committer | Takashi Iwai <tiwai@suse.de> | 2011-03-15 08:42:22 +0100 |
commit | 31ef9134eb52636d383a7d0626cbbd345cb94f2f (patch) | |
tree | 5d994932a8773e844190cbea43ef31d67f605cf8 /sound/firewire/fcp.c | |
parent | a5abba989deceb731047425812d268daf7536575 (diff) | |
download | op-kernel-dev-31ef9134eb52636d383a7d0626cbbd345cb94f2f.zip op-kernel-dev-31ef9134eb52636d383a7d0626cbbd345cb94f2f.tar.gz |
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>
Diffstat (limited to 'sound/firewire/fcp.c')
-rw-r--r-- | sound/firewire/fcp.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/sound/firewire/fcp.c b/sound/firewire/fcp.c new file mode 100644 index 0000000..c20bd9c --- /dev/null +++ b/sound/firewire/fcp.c @@ -0,0 +1,223 @@ +/* + * Function Control Protocol (IEC 61883-1) 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/list.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/wait.h> +#include "fcp.h" +#include "lib.h" + +#define CTS_AVC 0x00 + +#define ERROR_RETRIES 3 +#define ERROR_DELAY_MS 5 +#define FCP_TIMEOUT_MS 125 + +static DEFINE_SPINLOCK(transactions_lock); +static LIST_HEAD(transactions); + +enum fcp_state { + STATE_PENDING, + STATE_BUS_RESET, + STATE_COMPLETE, +}; + +struct fcp_transaction { + struct list_head list; + struct fw_unit *unit; + void *response_buffer; + unsigned int response_size; + unsigned int response_match_bytes; + enum fcp_state state; + wait_queue_head_t wait; +}; + +/** + * fcp_avc_transaction - send an AV/C command and wait for its response + * @unit: a unit on the target device + * @command: a buffer containing the command frame; must be DMA-able + * @command_size: the size of @command + * @response: a buffer for the response frame + * @response_size: the maximum size of @response + * @response_match_bytes: a bitmap specifying the bytes used to detect the + * correct response frame + * + * This function sends a FCP command frame to the target and waits for the + * corresponding response frame to be returned. + * + * Because it is possible for multiple FCP transactions to be active at the + * same time, the correct response frame is detected by the value of certain + * bytes. These bytes must be set in @response before calling this function, + * and the corresponding bits must be set in @response_match_bytes. + * + * @command and @response can point to the same buffer. + * + * Asynchronous operation (INTERIM, NOTIFY) is not supported at the moment. + * + * Returns the actual size of the response frame, or a negative error code. + */ +int fcp_avc_transaction(struct fw_unit *unit, + const void *command, unsigned int command_size, + void *response, unsigned int response_size, + unsigned int response_match_bytes) +{ + struct fcp_transaction t; + int tcode, ret, tries = 0; + + t.unit = unit; + t.response_buffer = response; + t.response_size = response_size; + t.response_match_bytes = response_match_bytes; + t.state = STATE_PENDING; + init_waitqueue_head(&t.wait); + + spin_lock_irq(&transactions_lock); + list_add_tail(&t.list, &transactions); + spin_unlock_irq(&transactions_lock); + + for (;;) { + tcode = command_size == 4 ? TCODE_WRITE_QUADLET_REQUEST + : TCODE_WRITE_BLOCK_REQUEST; + ret = snd_fw_transaction(t.unit, tcode, + CSR_REGISTER_BASE + CSR_FCP_COMMAND, + (void *)command, command_size); + if (ret < 0) + break; + + wait_event_timeout(t.wait, t.state != STATE_PENDING, + msecs_to_jiffies(FCP_TIMEOUT_MS)); + + if (t.state == STATE_COMPLETE) { + ret = t.response_size; + break; + } else if (t.state == STATE_BUS_RESET) { + msleep(ERROR_DELAY_MS); + } else if (++tries >= ERROR_RETRIES) { + dev_err(&t.unit->device, "FCP command timed out\n"); + ret = -EIO; + break; + } + } + + spin_lock_irq(&transactions_lock); + list_del(&t.list); + spin_unlock_irq(&transactions_lock); + + return ret; +} +EXPORT_SYMBOL(fcp_avc_transaction); + +/** + * fcp_bus_reset - inform the target handler about a bus reset + * @unit: the unit that might be used by fcp_avc_transaction() + * + * This function must be called from the driver's .update handler to inform + * the FCP transaction handler that a bus reset has happened. Any pending FCP + * transactions are retried. + */ +void fcp_bus_reset(struct fw_unit *unit) +{ + struct fcp_transaction *t; + + spin_lock_irq(&transactions_lock); + list_for_each_entry(t, &transactions, list) { + if (t->unit == unit && + t->state == STATE_PENDING) { + t->state = STATE_BUS_RESET; + wake_up(&t->wait); + } + } + spin_unlock_irq(&transactions_lock); +} +EXPORT_SYMBOL(fcp_bus_reset); + +/* checks whether the response matches the masked bytes in response_buffer */ +static bool is_matching_response(struct fcp_transaction *transaction, + const void *response, size_t length) +{ + const u8 *p1, *p2; + unsigned int mask, i; + + p1 = response; + p2 = transaction->response_buffer; + mask = transaction->response_match_bytes; + + for (i = 0; ; ++i) { + if ((mask & 1) && p1[i] != p2[i]) + return false; + mask >>= 1; + if (!mask) + return true; + if (--length == 0) + return false; + } +} + +static void fcp_response(struct fw_card *card, struct fw_request *request, + int tcode, int destination, int source, + int generation, unsigned long long offset, + void *data, size_t length, void *callback_data) +{ + struct fcp_transaction *t; + unsigned long flags; + + if (length < 1 || (*(const u8 *)data & 0xf0) != CTS_AVC) + return; + + spin_lock_irqsave(&transactions_lock, flags); + list_for_each_entry(t, &transactions, list) { + struct fw_device *device = fw_parent_device(t->unit); + if (device->card != card || + device->generation != generation) + continue; + smp_rmb(); /* node_id vs. generation */ + if (device->node_id != source) + continue; + + if (t->state == STATE_PENDING && + is_matching_response(t, data, length)) { + t->state = STATE_COMPLETE; + t->response_size = min((unsigned int)length, + t->response_size); + memcpy(t->response_buffer, data, t->response_size); + wake_up(&t->wait); + } + } + spin_unlock_irqrestore(&transactions_lock, flags); +} + +static struct fw_address_handler response_register_handler = { + .length = 0x200, + .address_callback = fcp_response, +}; + +static int __init fcp_module_init(void) +{ + static const struct fw_address_region response_register_region = { + .start = CSR_REGISTER_BASE + CSR_FCP_RESPONSE, + .end = CSR_REGISTER_BASE + CSR_FCP_END, + }; + + fw_core_add_address_handler(&response_register_handler, + &response_register_region); + + return 0; +} + +static void __exit fcp_module_exit(void) +{ + WARN_ON(!list_empty(&transactions)); + fw_core_remove_address_handler(&response_register_handler); +} + +module_init(fcp_module_init); +module_exit(fcp_module_exit); |