diff options
Diffstat (limited to 'drivers/firmware/imx/imx-scu.c')
| -rw-r--r-- | drivers/firmware/imx/imx-scu.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/firmware/imx/imx-scu.c b/drivers/firmware/imx/imx-scu.c index 03b43b7a6d1d..f71eaa5bf52d 100644 --- a/drivers/firmware/imx/imx-scu.c +++ b/drivers/firmware/imx/imx-scu.c @@ -29,6 +29,7 @@ struct imx_sc_chan { struct mbox_client cl; struct mbox_chan *ch; int idx; + struct completion tx_done; }; struct imx_sc_ipc { @@ -100,6 +101,14 @@ int imx_scu_get_handle(struct imx_sc_ipc **ipc) } EXPORT_SYMBOL(imx_scu_get_handle); +/* Callback called when the word of a message is ack-ed, eg read by SCU */ +static void imx_scu_tx_done(struct mbox_client *cl, void *mssg, int r) +{ + struct imx_sc_chan *sc_chan = container_of(cl, struct imx_sc_chan, cl); + + complete(&sc_chan->tx_done); +} + static void imx_scu_rx_callback(struct mbox_client *c, void *msg) { struct imx_sc_chan *sc_chan = container_of(c, struct imx_sc_chan, cl); @@ -149,6 +158,19 @@ static int imx_scu_ipc_write(struct imx_sc_ipc *sc_ipc, void *msg) for (i = 0; i < hdr->size; i++) { sc_chan = &sc_ipc->chans[i % 4]; + + /* + * SCU requires that all messages words are written + * sequentially but linux MU driver implements multiple + * independent channels for each register so ordering between + * different channels must be ensured by SCU API interface. + * + * Wait for tx_done before every send to ensure that no + * queueing happens at the mailbox channel level. + */ + wait_for_completion(&sc_chan->tx_done); + reinit_completion(&sc_chan->tx_done); + ret = mbox_send_message(sc_chan->ch, &data[i]); if (ret < 0) return ret; @@ -247,6 +269,11 @@ static int imx_scu_probe(struct platform_device *pdev) cl->knows_txdone = true; cl->rx_callback = imx_scu_rx_callback; + /* Initial tx_done completion as "done" */ + cl->tx_done = imx_scu_tx_done; + init_completion(&sc_chan->tx_done); + complete(&sc_chan->tx_done); + sc_chan->sc_ipc = sc_ipc; sc_chan->idx = i % 4; sc_chan->ch = mbox_request_channel_byname(cl, chan_name); |