firewire: core: add CSR SPLIT_TIMEOUT support
Implement the SPLIT_TIMEOUT registers. Besides being required by the
spec, this is desirable for some IIDC devices and necessary for many
audio devices to be able to increase the timeout from userspace.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 0034229..9a7d3ec 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -339,7 +339,8 @@
setup_timer(&t->split_timeout_timer,
split_transaction_timeout_callback, (unsigned long)t);
/* FIXME: start this timer later, relative to t->timestamp */
- mod_timer(&t->split_timeout_timer, jiffies + DIV_ROUND_UP(HZ, 10));
+ mod_timer(&t->split_timeout_timer,
+ jiffies + card->split_timeout_jiffies);
t->callback = callback;
t->callback_data = callback_data;
@@ -673,11 +674,28 @@
}
EXPORT_SYMBOL(fw_fill_response);
-static struct fw_request *allocate_request(struct fw_packet *p)
+static u32 compute_split_timeout_timestamp(struct fw_card *card,
+ u32 request_timestamp)
+{
+ unsigned int cycles;
+ u32 timestamp;
+
+ cycles = card->split_timeout_cycles;
+ cycles += request_timestamp & 0x1fff;
+
+ timestamp = request_timestamp & ~0x1fff;
+ timestamp += (cycles / 8000) << 13;
+ timestamp |= cycles % 8000;
+
+ return timestamp;
+}
+
+static struct fw_request *allocate_request(struct fw_card *card,
+ struct fw_packet *p)
{
struct fw_request *request;
u32 *data, length;
- int request_tcode, t;
+ int request_tcode;
request_tcode = HEADER_GET_TCODE(p->header[0]);
switch (request_tcode) {
@@ -712,14 +730,9 @@
if (request == NULL)
return NULL;
- t = (p->timestamp & 0x1fff) + 4000;
- if (t >= 8000)
- t = (p->timestamp & ~0x1fff) + 0x2000 + t - 8000;
- else
- t = (p->timestamp & ~0x1fff) + t;
-
request->response.speed = p->speed;
- request->response.timestamp = t;
+ request->response.timestamp =
+ compute_split_timeout_timestamp(card, p->timestamp);
request->response.generation = p->generation;
request->response.ack = 0;
request->response.callback = free_response_callback;
@@ -845,7 +858,7 @@
if (p->ack != ACK_PENDING && p->ack != ACK_COMPLETE)
return;
- request = allocate_request(p);
+ request = allocate_request(card, p);
if (request == NULL) {
/* FIXME: send statically allocated busy packet. */
return;
@@ -993,6 +1006,19 @@
return 0;
}
+static void update_split_timeout(struct fw_card *card)
+{
+ unsigned int cycles;
+
+ cycles = card->split_timeout_hi * 8000 + (card->split_timeout_lo >> 19);
+
+ cycles = max(cycles, 800u); /* minimum as per the spec */
+ cycles = min(cycles, 3u * 8000u); /* maximum OHCI timeout */
+
+ card->split_timeout_cycles = cycles;
+ card->split_timeout_jiffies = DIV_ROUND_UP(cycles * HZ, 8000);
+}
+
static void handle_registers(struct fw_card *card, struct fw_request *request,
int tcode, int destination, int source, int generation,
int speed, unsigned long long offset,
@@ -1001,6 +1027,7 @@
int reg = offset & ~CSR_REGISTER_BASE;
__be32 *data = payload;
int rcode = RCODE_COMPLETE;
+ unsigned long flags;
switch (reg) {
case CSR_STATE_CLEAR:
@@ -1039,6 +1066,33 @@
rcode = RCODE_TYPE_ERROR;
break;
+ case CSR_SPLIT_TIMEOUT_HI:
+ if (tcode == TCODE_READ_QUADLET_REQUEST) {
+ *data = cpu_to_be32(card->split_timeout_hi);
+ } else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
+ spin_lock_irqsave(&card->lock, flags);
+ card->split_timeout_hi = be32_to_cpu(*data) & 7;
+ update_split_timeout(card);
+ spin_unlock_irqrestore(&card->lock, flags);
+ } else {
+ rcode = RCODE_TYPE_ERROR;
+ }
+ break;
+
+ case CSR_SPLIT_TIMEOUT_LO:
+ if (tcode == TCODE_READ_QUADLET_REQUEST) {
+ *data = cpu_to_be32(card->split_timeout_lo);
+ } else if (tcode == TCODE_WRITE_QUADLET_REQUEST) {
+ spin_lock_irqsave(&card->lock, flags);
+ card->split_timeout_lo =
+ be32_to_cpu(*data) & 0xfff80000;
+ update_split_timeout(card);
+ spin_unlock_irqrestore(&card->lock, flags);
+ } else {
+ rcode = RCODE_TYPE_ERROR;
+ }
+ break;
+
case CSR_CYCLE_TIME:
if (TCODE_IS_READ_REQUEST(tcode) && length == 4)
*data = cpu_to_be32(card->driver->