Re: [PATCH v5 2/2] mailbox: mediatek: Add mtk-vcp-mailbox driver
From: Chen-Yu Tsai <wenst@chromium.org>
Date: 2025-08-22 05:48:44
Also in:
linux-devicetree, linux-mediatek, lkml
On Fri, Aug 22, 2025 at 10:12 AM Jjian Zhou [off-list ref] wrote:
Add mtk-vcp-mailbox driver to support the communication with VCP remote microprocessor. Signed-off-by: Jjian Zhou <redacted>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org> A couple minor comments below.
quoted hunk ↗ jump to hunk
--- drivers/mailbox/Kconfig | 9 ++ drivers/mailbox/Makefile | 2 + drivers/mailbox/mtk-vcp-mailbox.c | 174 ++++++++++++++++++++++++ include/linux/mailbox/mtk-vcp-mailbox.h | 32 +++++ 4 files changed, 217 insertions(+) create mode 100644 drivers/mailbox/mtk-vcp-mailbox.c create mode 100644 include/linux/mailbox/mtk-vcp-mailbox.hdiff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig index 02432d4a5ccd..c28bdb855663 100644 --- a/drivers/mailbox/Kconfig +++ b/drivers/mailbox/Kconfig@@ -294,6 +294,15 @@ config MTK_CMDQ_MBOX critical time limitation, such as updating display configuration during the vblank. +config MTK_VCP_MBOX + tristate "MediaTek VCP Mailbox Support" + depends on ARCH_MEDIATEK || COMPILE_TEST + help + Say yes here to add support for the MediaTek VCP mailbox driver. + The mailbox implementation provides access from the application + processor to Video Companion Processor Unit. + If unsure say N. + config ZYNQMP_IPI_MBOX tristate "Xilinx ZynqMP IPI Mailbox" depends on ARCH_ZYNQMP && OFdiff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile index 98a68f838486..07278871d254 100644 --- a/drivers/mailbox/Makefile +++ b/drivers/mailbox/Makefile@@ -63,6 +63,8 @@ obj-$(CONFIG_MTK_ADSP_MBOX) += mtk-adsp-mailbox.o obj-$(CONFIG_MTK_CMDQ_MBOX) += mtk-cmdq-mailbox.o +obj-$(CONFIG_MTK_VCP_MBOX) += mtk-vcp-mailbox.o + obj-$(CONFIG_ZYNQMP_IPI_MBOX) += zynqmp-ipi-mailbox.o obj-$(CONFIG_SUN6I_MSGBOX) += sun6i-msgbox.odiff --git a/drivers/mailbox/mtk-vcp-mailbox.c b/drivers/mailbox/mtk-vcp-mailbox.c new file mode 100644 index 000000000000..6f48215896d2 --- /dev/null +++ b/drivers/mailbox/mtk-vcp-mailbox.c@@ -0,0 +1,174 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2025 MediaTek Corporation. All rights reserved. + * Author: Jjian Zhou <jjian.zhou.@mediatek.com> + */ + +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/mailbox_controller.h> +#include <linux/mailbox/mtk-vcp-mailbox.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +struct mtk_vcp_mbox_priv { + void __iomem *base; + struct device *dev; + struct mbox_controller mbox; + const struct mtk_vcp_mbox_cfg *cfg; + struct mtk_ipi_info ipi_recv; +}; + +struct mtk_vcp_mbox_cfg { + u32 set_in; + u32 clr_out; +}; + +static inline struct mtk_vcp_mbox_priv *get_mtk_vcp_mbox_priv(struct mbox_controller *mbox) +{ + return container_of(mbox, struct mtk_vcp_mbox_priv, mbox); +} + +static irqreturn_t mtk_vcp_mbox_irq_thread(int irq, void *data) +{ + struct mbox_chan *chan = data; + struct mtk_vcp_mbox_priv *priv = get_mtk_vcp_mbox_priv(chan->mbox);
Since there's only one mailbox, you can just pass the private data, instead of passing the mbox_chan.
+
+ /* get irq status */
+ priv->ipi_recv.irq_status = readl(priv->base + priv->cfg->clr_out);
+
+ __ioread32_copy(priv->ipi_recv.msg, priv->base, MBOX_SLOT_MAX_SIZE / 4);
+
+ mbox_chan_received_data(chan, &priv->ipi_recv);
+
+ /* clear irq status */
+ writel(priv->ipi_recv.irq_status, priv->base + priv->cfg->clr_out);
+
+ return IRQ_HANDLED;
+}
+
+static struct mbox_chan *mtk_vcp_mbox_xlate(struct mbox_controller *mbox,
+ const struct of_phandle_args *sp)
+{
+ if (sp->args_count)
+ return NULL;
+
+ return mbox->chans;
+}
+
+static int mtk_vcp_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+ struct mtk_vcp_mbox_priv *priv = get_mtk_vcp_mbox_priv(chan->mbox);
+ struct mtk_ipi_info *ipi_info = data;
+ u32 status;
+
+ if (!ipi_info->msg) {
+ dev_err(priv->dev, "msg buffer is NULL.\n");
+ return -EINVAL;
+ }
+
+ status = readl(priv->base + priv->cfg->set_in) & BIT(ipi_info->index);
+ if (status) {
+ dev_warn(priv->dev, "mailbox IPI %d is busy.\n", ipi_info->id);
+ return -EBUSY;
+ }
+
+ if (ipi_info->slot_ofs + ipi_info->len > MBOX_SLOT_MAX_SIZE)
+ return -EINVAL;
+ __iowrite32_copy(priv->base + ipi_info->slot_ofs, ipi_info->msg,
+ ipi_info->len);
+
+ writel(BIT(ipi_info->index), priv->base + priv->cfg->set_in);
+
+ return 0;
+}
+
+static bool mtk_vcp_mbox_last_tx_done(struct mbox_chan *chan)
+{
+ struct mtk_ipi_info *ipi_info = chan->active_req;
+ struct mtk_vcp_mbox_priv *priv = get_mtk_vcp_mbox_priv(chan->mbox);
+
+ return !(readl(priv->base + priv->cfg->set_in) & BIT(ipi_info->index));
+}
+
+static const struct mbox_chan_ops mtk_vcp_mbox_chan_ops = {
+ .send_data = mtk_vcp_mbox_send_data,
+ .last_tx_done = mtk_vcp_mbox_last_tx_done,
+};
+
+static int mtk_vcp_mbox_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mtk_vcp_mbox_priv *priv;
+ struct mbox_controller *mbox;
+ int ret, irq;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = dev;
+ mbox = &priv->mbox;
+ mbox->dev = dev;
+ mbox->ops = &mtk_vcp_mbox_chan_ops;
+ mbox->txdone_irq = false;
+ mbox->txdone_poll = true;
+ mbox->of_xlate = mtk_vcp_mbox_xlate;
+ mbox->num_chans = 1;
+ mbox->chans = devm_kzalloc(dev, sizeof(*mbox->chans), GFP_KERNEL);
+ if (!mbox->chans)
+ return -ENOMEM;
+
+ priv->ipi_recv.msg = devm_kzalloc(dev, MBOX_SLOT_MAX_SIZE, GFP_KERNEL);
+ if (!priv->ipi_recv.msg)
+ return -ENOMEM;
+
+ priv->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ priv->cfg = of_device_get_match_data(dev);
+ if (!priv->cfg)
+ return -EINVAL;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ ret = devm_request_threaded_irq(dev, irq, NULL,
+ mtk_vcp_mbox_irq_thread, IRQF_ONESHOT,
+ dev_name(dev), mbox->chans);
+ if (ret < 0)
+ return ret;
+
+ platform_set_drvdata(pdev, priv);
+
+ return devm_mbox_controller_register(dev, &priv->mbox);
+}
+
+static const struct mtk_vcp_mbox_cfg mt8196_cfg = {
+ .set_in = 0x100,
+ .clr_out = 0x10C,
^ use lowercase for hex numbers.
quoted hunk ↗ jump to hunk
+}; + +static const struct of_device_id mtk_vcp_mbox_of_match[] = { + { .compatible = "mediatek,mt8196-vcp-mbox", .data = &mt8196_cfg }, + {}, +}; +MODULE_DEVICE_TABLE(of, mtk_vcp_mbox_of_match); + +static struct platform_driver mtk_vcp_mbox_driver = { + .probe = mtk_vcp_mbox_probe, + .driver = { + .name = "mtk_vcp_mbox", + .of_match_table = mtk_vcp_mbox_of_match, + }, +}; +module_platform_driver(mtk_vcp_mbox_driver); + +MODULE_AUTHOR("Jjian Zhou [off-list ref]"); +MODULE_DESCRIPTION("MTK VCP Mailbox Controller"); +MODULE_LICENSE("GPL");diff --git a/include/linux/mailbox/mtk-vcp-mailbox.h b/include/linux/mailbox/mtk-vcp-mailbox.h new file mode 100644 index 000000000000..143fb0d06e30 --- /dev/null +++ b/include/linux/mailbox/mtk-vcp-mailbox.h@@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */ +/* + * Copyright (c) 2025 MediaTek Inc. + */ + +#ifndef __MTK_VCP_MAILBOX_H__ +#define __MTK_VCP_MAILBOX_H__ + +#define MBOX_SLOT_MAX_SIZE 0x100 /* mbox max slot size */ + +/** + * struct mtk_ipi_info - mailbox message info for mtk-vcp-mailbox + * @msg: The share buffer between IPC and mailbox driver + * @len: Message length + * @id: This is for identification purposes and not actually used + * by the mailbox hardware. + * @index: The signal number of the mailbox message. + * @slot_ofs: Data slot offset. + * @irq_status: Captures incoming signals for the RX path. + * + * It is used between IPC with mailbox driver. + */ +struct mtk_ipi_info { + void *msg; + u32 len; + u32 id; + u32 index; + u32 slot_ofs; + u32 irq_status; +}; + +#endif --2.46.0