On Sat, Feb 13, 2021 at 8:23 PM Orson Zhai <orsonzhai@xxxxxxxxx> wrote:
>
> From: Orson Zhai <orson.zhai@xxxxxxxxxx>
>
> Some sensors connected to Unisoc mailbox will send data very frequently.
> This makes channel 0 very busy and the messages from other remote cores
> not able to be handled as soon as possible.
>
> It's a trick (un-documented) from Unisoc ASIC designers to resolve this
> special requirement that an inbox assigned to one of the remote cores
> before was modified to be exposed to host cpu core.
>
> Then from host side, a supplementary inbox is added for transferring mass
> but not emergency messages from the remote cores, such as step counting
> sensor, with an independent FIFO and interrupt which is as same as channel
> 0. Meanwihle, inbox part of this channel is still kept for original remote
> core to use.
>
> Signed-off-by: Orson Zhai <orson.zhai@xxxxxxxxxx>
Reviewed-by: Baolin Wang <baolin.wang7@xxxxxxxxx>
> ---
> drivers/mailbox/sprd-mailbox.c | 88 +++++++++++++++++++++++++++-------
> 1 file changed, 71 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/mailbox/sprd-mailbox.c b/drivers/mailbox/sprd-mailbox.c
> index 920de7b9dce1..7abd6c6d655d 100644
> --- a/drivers/mailbox/sprd-mailbox.c
> +++ b/drivers/mailbox/sprd-mailbox.c
> @@ -11,6 +11,7 @@
> #include <linux/io.h>
> #include <linux/mailbox_controller.h>
> #include <linux/module.h>
> +#include <linux/of_device.h>
> #include <linux/platform_device.h>
> #include <linux/clk.h>
>
> @@ -50,13 +51,17 @@
> #define SPRD_OUTBOX_FIFO_NOT_EMPTY_IRQ BIT(0)
> #define SPRD_OUTBOX_FIFO_IRQ_MASK GENMASK(4, 0)
>
> +#define SPRD_OUTBOX_BASE_SPAN 0x1000
> #define SPRD_MBOX_CHAN_MAX 8
> +#define SPRD_SUPP_INBOX_ID_SC9863A 7
>
> struct sprd_mbox_priv {
> struct mbox_controller mbox;
> struct device *dev;
> void __iomem *inbox_base;
> void __iomem *outbox_base;
> + /* Base register address for supplementary outbox */
> + void __iomem *supp_base;
> struct clk *clk;
> u32 outbox_fifo_depth;
>
> @@ -96,14 +101,13 @@ static u32 sprd_mbox_get_fifo_len(struct sprd_mbox_priv *priv, u32 fifo_sts)
> return fifo_len;
> }
>
> -static irqreturn_t sprd_mbox_outbox_isr(int irq, void *data)
> +static irqreturn_t do_outbox_isr(void __iomem *base, struct sprd_mbox_priv *priv)
> {
> - struct sprd_mbox_priv *priv = data;
> struct mbox_chan *chan;
> u32 fifo_sts, fifo_len, msg[2];
> int i, id;
>
> - fifo_sts = readl(priv->outbox_base + SPRD_MBOX_FIFO_STS);
> + fifo_sts = readl(base + SPRD_MBOX_FIFO_STS);
>
> fifo_len = sprd_mbox_get_fifo_len(priv, fifo_sts);
> if (!fifo_len) {
> @@ -112,9 +116,9 @@ static irqreturn_t sprd_mbox_outbox_isr(int irq, void *data)
> }
>
> for (i = 0; i < fifo_len; i++) {
> - msg[0] = readl(priv->outbox_base + SPRD_MBOX_MSG_LOW);
> - msg[1] = readl(priv->outbox_base + SPRD_MBOX_MSG_HIGH);
> - id = readl(priv->outbox_base + SPRD_MBOX_ID);
> + msg[0] = readl(base + SPRD_MBOX_MSG_LOW);
> + msg[1] = readl(base + SPRD_MBOX_MSG_HIGH);
> + id = readl(base + SPRD_MBOX_ID);
>
> chan = &priv->chan[id];
> if (chan->cl)
> @@ -124,15 +128,29 @@ static irqreturn_t sprd_mbox_outbox_isr(int irq, void *data)
> "message's been dropped at ch[%d]\n", id);
>
> /* Trigger to update outbox FIFO pointer */
> - writel(0x1, priv->outbox_base + SPRD_MBOX_TRIGGER);
> + writel(0x1, base + SPRD_MBOX_TRIGGER);
> }
>
> /* Clear irq status after reading all message. */
> - writel(SPRD_MBOX_IRQ_CLR, priv->outbox_base + SPRD_MBOX_IRQ_STS);
> + writel(SPRD_MBOX_IRQ_CLR, base + SPRD_MBOX_IRQ_STS);
>
> return IRQ_HANDLED;
> }
>
> +static irqreturn_t sprd_mbox_outbox_isr(int irq, void *data)
> +{
> + struct sprd_mbox_priv *priv = data;
> +
> + return do_outbox_isr(priv->outbox_base, priv);
> +}
> +
> +static irqreturn_t sprd_mbox_supp_isr(int irq, void *data)
> +{
> + struct sprd_mbox_priv *priv = data;
> +
> + return do_outbox_isr(priv->supp_base, priv);
> +}
> +
> static irqreturn_t sprd_mbox_inbox_isr(int irq, void *data)
> {
> struct sprd_mbox_priv *priv = data;
> @@ -235,6 +253,14 @@ static int sprd_mbox_startup(struct mbox_chan *chan)
> val = readl(priv->outbox_base + SPRD_MBOX_IRQ_MSK);
> val &= ~SPRD_OUTBOX_FIFO_NOT_EMPTY_IRQ;
> writel(val, priv->outbox_base + SPRD_MBOX_IRQ_MSK);
> +
> + /* Enable supplementary outbox as the fundamental one */
> + if (priv->supp_base) {
> + writel(0x0, priv->supp_base + SPRD_MBOX_FIFO_RST);
> + val = readl(priv->supp_base + SPRD_MBOX_IRQ_MSK);
> + val &= ~SPRD_OUTBOX_FIFO_NOT_EMPTY_IRQ;
> + writel(val, priv->supp_base + SPRD_MBOX_IRQ_MSK);
> + }
> }
> mutex_unlock(&priv->lock);
>
> @@ -250,6 +276,10 @@ static void sprd_mbox_shutdown(struct mbox_chan *chan)
> /* Disable inbox & outbox interrupt */
> writel(SPRD_INBOX_FIFO_IRQ_MASK, priv->inbox_base + SPRD_MBOX_IRQ_MSK);
> writel(SPRD_OUTBOX_FIFO_IRQ_MASK, priv->outbox_base + SPRD_MBOX_IRQ_MSK);
> +
> + if (priv->supp_base)
> + writel(SPRD_OUTBOX_FIFO_IRQ_MASK,
> + priv->supp_base + SPRD_MBOX_IRQ_MSK);
> }
> mutex_unlock(&priv->lock);
> }
> @@ -272,8 +302,8 @@ static int sprd_mbox_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> struct sprd_mbox_priv *priv;
> - int ret, inbox_irq, outbox_irq;
> - unsigned long id;
> + int ret, inbox_irq, outbox_irq, supp_irq;
> + unsigned long id, supp;
>
> priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> if (!priv)
> @@ -283,11 +313,15 @@ static int sprd_mbox_probe(struct platform_device *pdev)
> mutex_init(&priv->lock);
>
> /*
> - * The Spreadtrum mailbox uses an inbox to send messages to the target
> - * core, and uses an outbox to receive messages from other cores.
> + * Unisoc mailbox uses an inbox to send messages to the target
> + * core, and uses (an) outbox(es) to receive messages from other
> + * cores.
> + *
> + * Thus in general the mailbox controller supplies 2 different
> + * register addresses and IRQ numbers for inbox and outbox.
> *
> - * Thus the mailbox controller supplies 2 different register addresses
> - * and IRQ numbers for inbox and outbox.
> + * If necessary, a supplementary inbox could be enabled optionally
> + * with an independent FIFO and an extra interrupt.
> */
> priv->inbox_base = devm_platform_ioremap_resource(pdev, 0);
> if (IS_ERR(priv->inbox_base))
> @@ -313,7 +347,7 @@ static int sprd_mbox_probe(struct platform_device *pdev)
> return ret;
> }
>
> - inbox_irq = platform_get_irq(pdev, 0);
> + inbox_irq = platform_get_irq_byname(pdev, "inbox");
> if (inbox_irq < 0)
> return inbox_irq;
>
> @@ -324,7 +358,7 @@ static int sprd_mbox_probe(struct platform_device *pdev)
> return ret;
> }
>
> - outbox_irq = platform_get_irq(pdev, 1);
> + outbox_irq = platform_get_irq_byname(pdev, "outbox");
> if (outbox_irq < 0)
> return outbox_irq;
>
> @@ -335,6 +369,24 @@ static int sprd_mbox_probe(struct platform_device *pdev)
> return ret;
> }
>
> + /* Supplementary outbox IRQ is optional */
> + supp_irq = platform_get_irq_byname(pdev, "supp-outbox");
> + if (supp_irq > 0) {
> + ret = devm_request_irq(dev, supp_irq, sprd_mbox_supp_isr,
> + IRQF_NO_SUSPEND, dev_name(dev), priv);
> + if (ret) {
> + dev_err(dev, "failed to request outbox IRQ: %d\n", ret);
> + return ret;
> + }
> +
> + supp = (unsigned long) of_device_get_match_data(dev);
> + if (!supp) {
> + dev_err(dev, "no supplementary outbox specified\n");
> + return -ENODEV;
> + }
> + priv->supp_base = priv->outbox_base + (SPRD_OUTBOX_BASE_SPAN * supp);
> + }
> +
> /* Get the default outbox FIFO depth */
> priv->outbox_fifo_depth =
> readl(priv->outbox_base + SPRD_MBOX_FIFO_DEPTH) + 1;
> @@ -357,7 +409,9 @@ static int sprd_mbox_probe(struct platform_device *pdev)
> }
>
> static const struct of_device_id sprd_mbox_of_match[] = {
> - { .compatible = "sprd,sc9860-mailbox", },
> + { .compatible = "sprd,sc9860-mailbox" },
> + { .compatible = "sprd,sc9863a-mailbox",
> + .data = (void *)SPRD_SUPP_INBOX_ID_SC9863A },
> { },
> };
> MODULE_DEVICE_TABLE(of, sprd_mbox_of_match);
> --
> 2.17.1
>
--
Baolin Wang
