/* Try to find a free mailbox. Note mailbox 0 is reserved for DMA and so is not
attempted here. */
static int get_mailbox(struct ivtv *itv, struct ivtv_mailbox_data *mbdata, int flags)
{
unsigned long then = jiffies;
int i, mb;
int max_mbox = mbdata->max_mbox;
int retries = 100;
/* All slow commands use the same mailbox, serializing them and also
leaving the other mailbox free for simple fast commands. */
if ((flags & API_FAST_RESULT) == API_RESULT)
max_mbox = 1;
/* find free non-DMA mailbox */
for (i = 0; i < retries; i++) {
for (mb = 1; mb <= max_mbox; mb++)
if (try_mailbox(itv, mbdata, mb))
return mb;
/* Sleep before a retry, if not atomic */
if (!(flags & API_NO_WAIT_MB)) {
if (time_after(jiffies,
then + msecs_to_jiffies(10*retries)))
break;
ivtv_msleep_timeout(10, 0);
}
}
return -ENODEV
static int ivtv_api_call(struct ivtv *itv, int cmd, int args, u32 data[])
{
struct ivtv_mailbox_data *mbdata = (cmd >= 128) ? &itv->enc_mbox : &itv->dec_mbox;
volatile struct ivtv_mailbox __iomem *mbox;
int api_timeout = msecs_to_jiffies(1000);
int flags, mb, i;
unsigned long then;
/* sanity checks */
if (NULL == mbdata) {
IVTV_ERR("No mailbox allocated\n");
return -ENODEV;
}
if (args < 0 || args > CX2341X_MBOX_MAX_DATA ||
cmd < 0 || cmd > 255 || api_info[cmd].name == NULL) {
IVTV_ERR("Invalid MB call: cmd = 0x%02x, args = %d\n", cmd, args);
return -EINVAL;
}
if (api_info[cmd].flags & API_HIGH_VOL) {
IVTV_DEBUG_HI_MB("MB Call: %s\n", api_info[cmd].name);
}
else {
IVTV_DEBUG_MB("MB Call: %s\n", api_info[cmd].name);
}
/* clear possibly uninitialized part of data array */
for (i = args; i < CX2341X_MBOX_MAX_DATA; i++)
data[i] = 0;
/* If this command was issued within the last 30 minutes and with identical
data, then just return 0 as there is no need to issue this command again.
Just an optimization to prevent unnecessary use of mailboxes. */
if (itv->api_cache[cmd].last_jiffies &&
time_before(jiffies,
itv->api_cache[cmd].last_jiffies +
msecs_to_jiffies(1800000)) &&
!memcmp(data, itv->api_cache[cmd].data, sizeof(itv->api_cache[cmd].data))) {
itv->api_cache[cmd].last_jiffies = jiffies;
return 0;
}
flags = api_info[cmd].flags;
if (flags & API_DMA) {
for (i = 0; i < 100; i++) {
mb = i % (mbdata->max_mbox + 1);
if (try_mailbox(itv, mbdata, mb)) {
write_mailbox(&mbdata->mbox[mb], cmd, args, data);
clear_bit(mb, &mbdata->busy);
return 0;
}
IVTV_DEBUG_WARN("%s: mailbox %d not free %08x\n",
api_info[cmd].name, mb, readl(&mbdata->mbox[mb].flags));
}
IVTV_WARN("Could not find free DMA mailbox for %s\n", api_info[cmd].name);
clear_all_mailboxes(itv, mbdata);
return -EBUSY;
}
if ((flags & API_FAST_RESULT) == API_FAST_RESULT)
api_timeout = msecs_to_jiffies(100);
mb = get_mailbox(itv, mbdata, flags);
if (mb < 0) {
IVTV_DEBUG_WARN("No free mailbox found (%s)\n", api_info[cmd].name);
clear_all_mailboxes(itv, mbdata);
return -EBUSY;
}
mbox = &mbdata->mbox[mb];
write_mailbox(mbox, cmd, args, data);
if (flags & API_CACHE) {
memcpy(itv->api_cache[cmd].data, data, sizeof(itv->api_cache[cmd].data));
itv->api_cache[cmd].last_jiffies = jiffies;
}
if ((flags & API_RESULT) == 0) {
clear_bit(mb, &mbdata->busy);
return 0;
}
/* Get results */
then = jiffies;
if (!(flags & API_NO_POLL)) {
/* First try to poll, then switch to delays */
for (i = 0; i < 100; i++) {
if (readl(&mbox->flags) & IVTV_MBOX_FIRMWARE_DONE)
break;
}
}
while (!(readl(&mbox->flags) & IVTV_MBOX_FIRMWARE_DONE)) {
if (time_after(jiffies, then + api_timeout)) {
IVTV_DEBUG_WARN("Could not get result (%s)\n", api_info[cmd].name);
/* reset the mailbox, but it is likely too late already */
write_sync(0, &mbox->flags);
clear_bit(mb, &mbdata->busy);
return -EIO;
}
if (flags & API_NO_WAIT_RES)
mdelay(1);
else
ivtv_msleep_timeout(1, 0);
}
if (time_after(jiffies, then + msecs_to_jiffies(100)))
IVTV_DEBUG_WARN("%s took %u jiffies\n",
api_info[cmd].name,
jiffies_to_msecs(jiffies - then));
for (i = 0; i < CX2341X_MBOX_MAX_DATA; i++)
data[i] = readl(&mbox->data[i]);
write_sync(0, &mbox->flags);
clear_bit(mb, &mbdata->busy);
return 0;
}
