On Sun, Sep 17, 2023 at 5:45 PM Peng Fan (OSS) <peng.fan@xxxxxxxxxxx> wrote:
>
> From: Peng Fan <peng.fan@xxxxxxx>
>
> The Message Unit(MU) General Purpose Control registers are used for
> TX doorbell, but there is no hardware ACK support.
>
> The current TX doorbell channel is using tasklet to emulate hardware
> ACK support to kick the TX tick from controller driver side.
>
> The new added TX doorbell channel V2 not using tasklet to emulate the
> hardware ACK support. The behavior for the channel is just writing the
> GCR register, and no else. This will be used for SCMI mailbox.
>
> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> ---
> drivers/mailbox/imx-mailbox.c | 32 +++++++++++++++++++++++++++++---
> 1 file changed, 29 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
> index 3ef4dd8adf5d..0af739ab571c 100644
> --- a/drivers/mailbox/imx-mailbox.c
> +++ b/drivers/mailbox/imx-mailbox.c
> @@ -20,7 +20,9 @@
> #include <linux/suspend.h>
> #include <linux/slab.h>
>
> -#define IMX_MU_CHANS 17
> +#include "mailbox.h"
> +
> +#define IMX_MU_CHANS 24
> /* TX0/RX0/RXDB[0-3] */
> #define IMX_MU_SCU_CHANS 6
> /* TX0/RX0 */
> @@ -39,6 +41,7 @@ enum imx_mu_chan_type {
> IMX_MU_TYPE_TXDB = 2, /* Tx doorbell */
> IMX_MU_TYPE_RXDB = 3, /* Rx doorbell */
> IMX_MU_TYPE_RST = 4, /* Reset */
> + IMX_MU_TYPE_TXDB_V2 = 5, /* Tx doorbell with S/W ACK */
> };
>
> enum imx_mu_xcr {
> @@ -226,6 +229,9 @@ static int imx_mu_generic_tx(struct imx_mu_priv *priv,
> imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
> tasklet_schedule(&cp->txdb_tasklet);
> break;
> + case IMX_MU_TYPE_TXDB_V2:
> + imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
> + break;
> default:
> dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
> return -EINVAL;
> @@ -554,6 +560,9 @@ static int imx_mu_startup(struct mbox_chan *chan)
> int ret;
>
> pm_runtime_get_sync(priv->dev);
> + if (cp->type == IMX_MU_TYPE_TXDB_V2)
> + return 0;
> +
> if (cp->type == IMX_MU_TYPE_TXDB) {
> /* Tx doorbell don't have ACK support */
> tasklet_init(&cp->txdb_tasklet, imx_mu_txdb_tasklet,
> @@ -595,6 +604,11 @@ static void imx_mu_shutdown(struct mbox_chan *chan)
> int ret;
> u32 sr;
>
> + if (cp->type == IMX_MU_TYPE_TXDB_V2) {
> + pm_runtime_put_sync(priv->dev);
> + return;
> + }
> +
> if (cp->type == IMX_MU_TYPE_TXDB) {
> tasklet_kill(&cp->txdb_tasklet);
> pm_runtime_put_sync(priv->dev);
> @@ -671,6 +685,7 @@ static struct mbox_chan *imx_mu_specific_xlate(struct mbox_controller *mbox,
> static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox,
> const struct of_phandle_args *sp)
> {
> + struct mbox_chan *p_chan;
> u32 type, idx, chan;
>
> if (sp->args_count != 2) {
> @@ -680,14 +695,25 @@ static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox,
>
> type = sp->args[0]; /* channel type */
> idx = sp->args[1]; /* index */
> - chan = type * 4 + idx;
>
> + /* RST only supports 1 channel */
> + if ((type == IMX_MU_TYPE_RST) && idx) {
> + dev_err(mbox->dev, "Invalid RST channel %d\n", idx);
> + return ERR_PTR(-EINVAL);
> + }
I don't understand how is this related to introduction of a new
doorbell channel. Can you please
add it in a separate patch with proper explanation?
> +
> + chan = type * 4 + idx;
> if (chan >= mbox->num_chans) {
> dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
> return ERR_PTR(-EINVAL);
> }
>
> - return &mbox->chans[chan];
> + p_chan = &mbox->chans[chan];
> +
> + if (type == IMX_MU_TYPE_TXDB_V2)
> + p_chan->txdone_method = TXDONE_BY_ACK;
> +
> + return p_chan;
> }
>
> static struct mbox_chan *imx_mu_seco_xlate(struct mbox_controller *mbox,
>
> --
> 2.37.1
>
