-static int ath6kl_get_bmi_cmd_credits(struct ath6kl *ar)
-{
- u32 addr;
- unsigned long timeout;
- int ret;
-
- ar->bmi.cmd_credits = 0;
-
- /* Read the counter register to get the command credits */
- addr = COUNT_DEC_ADDRESS + (HTC_MAILBOX_NUM_MAX + ENDPOINT1) * 4;
-
- timeout = jiffies + msecs_to_jiffies(BMI_COMMUNICATION_TIMEOUT);
- while (time_before(jiffies, timeout) && !ar->bmi.cmd_credits) {
-
- /*
- * Hit the credit counter with a 4-byte access, the first byte
- * read will hit the counter and cause a decrement, while the
- * remaining 3 bytes has no effect. The rationale behind this
- * is to make all HIF accesses 4-byte aligned.
- */
- ret = hif_read_write_sync(ar, addr,
- (u8 *)&ar->bmi.cmd_credits, 4,
- HIF_RD_SYNC_BYTE_INC);
- if (ret) {
- ath6kl_err("Unable to decrement the command credit count register: %d\n",
- ret);
- return ret;
- }
-
- /* The counter is only 8 bits.
- * Ignore anything in the upper 3 bytes
- */
- ar->bmi.cmd_credits &= 0xFF;
- }
-
- if (!ar->bmi.cmd_credits) {
- ath6kl_err("bmi communication timeout\n");
- return -ETIMEDOUT;
- }
-
- return 0;
-}
-
-static int ath6kl_bmi_get_rx_lkahd(struct ath6kl *ar)
-{
- unsigned long timeout;
- u32 rx_word = 0;
- int ret = 0;
-
- timeout = jiffies + msecs_to_jiffies(BMI_COMMUNICATION_TIMEOUT);
- while (time_before(jiffies, timeout) && !rx_word) {
- ret = hif_read_write_sync(ar, RX_LOOKAHEAD_VALID_ADDRESS,
- (u8 *)&rx_word, sizeof(rx_word),
- HIF_RD_SYNC_BYTE_INC);
- if (ret) {
- ath6kl_err("unable to read RX_LOOKAHEAD_VALID\n");
- return ret;
- }
-
- /* all we really want is one bit */
- rx_word &= (1 << ENDPOINT1);
- }
-
- if (!rx_word) {
- ath6kl_err("bmi_recv_buf FIFO empty\n");
- return -EINVAL;
- }
-
- return ret;
-}
-
-static int ath6kl_bmi_send_buf(struct ath6kl *ar, u8 *buf, u32 len)
-{
- int ret;
- u32 addr;
-
- ret = ath6kl_get_bmi_cmd_credits(ar);
- if (ret)
- return ret;
-
- addr = ar->mbox_info.htc_addr;
-
- ret = hif_read_write_sync(ar, addr, buf, len,
- HIF_WR_SYNC_BYTE_INC);
- if (ret)
- ath6kl_err("unable to send the bmi data to the device\n");
-
- return ret;
-}
-
-static int ath6kl_bmi_recv_buf(struct ath6kl *ar, u8 *buf, u32 len)
-{
- int ret;
- u32 addr;
-
- /*
- * During normal bootup, small reads may be required.
- * Rather than issue an HIF Read and then wait as the Target
- * adds successive bytes to the FIFO, we wait here until
- * we know that response data is available.
- *
- * This allows us to cleanly timeout on an unexpected
- * Target failure rather than risk problems at the HIF level.
- * In particular, this avoids SDIO timeouts and possibly garbage
- * data on some host controllers. And on an interconnect
- * such as Compact Flash (as well as some SDIO masters) which
- * does not provide any indication on data timeout, it avoids
- * a potential hang or garbage response.
- *
- * Synchronization is more difficult for reads larger than the
- * size of the MBOX FIFO (128B), because the Target is unable
- * to push the 129th byte of data until AFTER the Host posts an
- * HIF Read and removes some FIFO data. So for large reads the
- * Host proceeds to post an HIF Read BEFORE all the data is
- * actually available to read. Fortunately, large BMI reads do
- * not occur in practice -- they're supported for debug/development.
- *
- * So Host/Target BMI synchronization is divided into these cases:
- * CASE 1: length < 4
- * Should not happen
- *
- * CASE 2: 4 <= length <= 128
- * Wait for first 4 bytes to be in FIFO
- * If CONSERVATIVE_BMI_READ is enabled, also wait for
- * a BMI command credit, which indicates that the ENTIRE
- * response is available in the the FIFO
- *
- * CASE 3: length > 128
- * Wait for the first 4 bytes to be in FIFO
- *
- * For most uses, a small timeout should be sufficient and we will
- * usually see a response quickly; but there may be some unusual
- * (debug) cases of BMI_EXECUTE where we want an larger timeout.
- * For now, we use an unbounded busy loop while waiting for
- * BMI_EXECUTE.
- *
- * If BMI_EXECUTE ever needs to support longer-latency execution,
- * especially in production, this code needs to be enhanced to sleep
- * and yield. Also note that BMI_COMMUNICATION_TIMEOUT is currently
- * a function of Host processor speed.
- */
- if (len >= 4) { /* NB: Currently, always true */
- ret = ath6kl_bmi_get_rx_lkahd(ar);
- if (ret)
- return ret;
- }
-
- addr = ar->mbox_info.htc_addr;
- ret = hif_read_write_sync(ar, addr, buf, len,
- HIF_RD_SYNC_BYTE_INC);
- if (ret) {
- ath6kl_err("Unable to read the bmi data from the device: %d\n",
- ret);
- return ret;
- }
-
- return 0;
-}
-