diff options
| -rw-r--r-- | mailbox/arm_mhu_v2.c | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/mailbox/arm_mhu_v2.c b/mailbox/arm_mhu_v2.c index 5bb943a..365715b 100644 --- a/mailbox/arm_mhu_v2.c +++ b/mailbox/arm_mhu_v2.c @@ -2,7 +2,7 @@ /* * Message Handling Unit version 2 controller driver - * Copyright (C) 2019 ARM Ltd. + * Copyright (C) 2019-2020 ARM Ltd. * * Based on drivers/mailbox/arm_mhu.c * @@ -78,11 +78,46 @@ static int mhuv2_send_data(struct mbox_chan *chan, void *data) { struct mhuv2_link *mlink = chan->con_priv; + struct arm_mhuv2 *mhuv2 = mbox_to_arm_mhuv2(chan->mbox); u32 *arg = data; + u32 tmo = 100000; + + /* If ACCESS_REQUEST is low, we have to wait for the other side + * to relase ACCESS_READY before continuing. */ + if (!readl_relaxed(mhuv2->base + MHU_V2_REG_ACC_REQ_OFS)) { + while (readl_relaxed(mhuv2->base + MHU_V2_REG_ACC_RDY_OFS) && + --tmo != 0) + continue; + + if (!tmo) + goto err; + + /* Request access and wait for other side to ack */ + writel_relaxed(0x1, mhuv2->base + MHU_V2_REG_ACC_REQ_OFS); + tmo = 100000; + while (!readl_relaxed(mhuv2->base + MHU_V2_REG_ACC_RDY_OFS) && + --tmo != 0) + continue; + + if (!tmo) + goto err; + } else { + while (!readl_relaxed(mhuv2->base + MHU_V2_REG_ACC_RDY_OFS) && + --tmo != 0) + continue; + + if (!tmo) + goto err; + } writel_relaxed(*arg, mlink->tx_reg + MHU_V2_REG_SET_OFS); return 0; + +err: + dev_err(chan->mbox->dev, "Failed to acquire access to mhu.\n"); + + return 1; } static int mhuv2_startup(struct mbox_chan *chan) |