Add mtk-apu-mailbox driver to support communication with
APU remote microprocessor.
Signed-off-by: Pi-Cheng Chen <pi-cheng.chen@xxxxxxxxxxxx>
Signed-off-by: Flora Fu <flora.fu@xxxxxxxxxxxx>
---
drivers/mailbox/Kconfig | 9 ++
drivers/mailbox/Makefile | 2 +
drivers/mailbox/mtk-apu-mailbox.c | 162 ++++++++++++++++++++++++++++++
3 files changed, 173 insertions(+)
create mode 100644 drivers/mailbox/mtk-apu-mailbox.c
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index d9cd3606040e..aeaaadd4cb8d 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -238,6 +238,15 @@ config STM32_IPCC
with hardware for Inter-Processor Communication Controller (IPCC)
between processors. Say Y here if you want to have this support.
+config MTK_APU_MBOX
+ tristate "MediaTek APU Mailbox Support"
+ depends on ARCH_MEDIATEK || COMPILE_TEST
+ help
+ Say yes here to add support for the MediaTek APU Mailbox
+ driver. The mailbox implementation provides access from the
+ application processor to the MediaTek AI Processing Unit.
+ If unsure say N.
+
config MTK_CMDQ_MBOX
tristate "MediaTek CMDQ Mailbox Support"
depends on ARCH_MEDIATEK || COMPILE_TEST
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 338cc05e5431..e24ad25c3378 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -49,6 +49,8 @@ obj-$(CONFIG_TEGRA_HSP_MBOX) += tegra-hsp.o
obj-$(CONFIG_STM32_IPCC) += stm32-ipcc.o
+obj-$(CONFIG_MTK_APU_MBOX) += mtk-apu-mailbox.o
+
obj-$(CONFIG_MTK_CMDQ_MBOX) += mtk-cmdq-mailbox.o
obj-$(CONFIG_ZYNQMP_IPI_MBOX) += zynqmp-ipi-mailbox.o
diff --git a/drivers/mailbox/mtk-apu-mailbox.c b/drivers/mailbox/mtk-apu-mailbox.c
new file mode 100644
index 000000000000..860db0504907
--- /dev/null
+++ b/drivers/mailbox/mtk-apu-mailbox.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 MediaTek Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/mailbox_controller.h>
+
+#define INBOX (0x0)
+#define OUTBOX (0x20)
+#define INBOX_IRQ (0xc0)
+#define OUTBOX_IRQ (0xc4)
+#define INBOX_IRQ_MASK (0xd0)
+
+#define MSG_MBOX_SLOTS (4)
+
+struct mtk_apu_mailbox {
+ struct device *dev;
+ void __iomem *regs;
+ spinlock_t lock; /* register access lock */
+ struct mbox_controller controller;
+ u32 msgs[MSG_MBOX_SLOTS];
+};
+
+static irqreturn_t mtk_apu_mailbox_threaded_irq(int irq, void *dev_id)
+{
+ struct mtk_apu_mailbox *mbox = dev_id;
+ struct mbox_chan *link = &mbox->controller.chans[0];
+ int i;
+
+ for (i = 0; i < MSG_MBOX_SLOTS; i++)
+ mbox->msgs[i] = readl(mbox->regs + OUTBOX + i * sizeof(u32));
+
+ mbox_chan_received_data(link, &mbox->msgs);
+ writel(readl(mbox->regs + OUTBOX_IRQ), mbox->regs + OUTBOX_IRQ);
+
+ return IRQ_HANDLED;
+}
+
+static int mtk_apu_mailbox_send_data(struct mbox_chan *chan, void *data)
+{
+ struct mtk_apu_mailbox *mbox = container_of(chan->mbox,
+ struct mtk_apu_mailbox,
+ controller);
+ int i;
+
+ spin_lock(&mbox->lock);
+ writel(~BIT(MSG_MBOX_SLOTS - 1), mbox->regs + INBOX_IRQ_MASK);
+ for (i = 0; i < MSG_MBOX_SLOTS; i++)
+ writel(((u32 *)data)[i], mbox->regs + INBOX + i * sizeof(u32));
+ spin_unlock(&mbox->lock);
+
+ return 0;
+}
+
+static bool mtk_apu_mailbox_last_tx_done(struct mbox_chan *chan)
+{
+ struct mtk_apu_mailbox *mbox = container_of(chan->mbox,
+ struct mtk_apu_mailbox,
+ controller);
+
+ return readl(mbox->regs + INBOX_IRQ) == 0;
+}
+
+static const struct mbox_chan_ops mtk_apu_mailbox_ops = {
+ .send_data = mtk_apu_mailbox_send_data,
+ .last_tx_done = mtk_apu_mailbox_last_tx_done,
+};
+
+static int mtk_apu_mailbox_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ struct mtk_apu_mailbox *mbox;
+ int ret = 0;
+
+ mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+ if (!mbox)
+ return -ENOMEM;
+
+ mbox->dev = dev;
+ platform_set_drvdata(pdev, mbox);
+ spin_lock_init(&mbox->lock);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+
+ mbox->regs = devm_ioremap_resource(dev, res);
+ if (IS_ERR(mbox->regs))
+ return PTR_ERR(mbox->regs);
+
+ ret = devm_request_threaded_irq(dev,
+ irq_of_parse_and_map(dev->of_node, 0),
+ NULL, mtk_apu_mailbox_threaded_irq,
+ IRQF_ONESHOT, dev_name(dev), mbox);
+ if (ret) {
+ dev_err(dev, "Failed to register apu mailbox IRQ: %d\n", ret);
+ return -ENODEV;
+ }
+
+ mbox->controller.txdone_irq = false;
+ mbox->controller.txdone_poll = true;
+ mbox->controller.txpoll_period = 1;
+ mbox->controller.ops = &mtk_apu_mailbox_ops;
+ mbox->controller.dev = dev;
+ mbox->controller.num_chans = 1;
+ mbox->controller.chans = devm_kcalloc(dev, mbox->controller.num_chans,
+ sizeof(*mbox->controller.chans),
+ GFP_KERNEL);
+ if (!mbox->controller.chans)
+ return -ENOMEM;
+
+ ret = devm_mbox_controller_register(dev, &mbox->controller);
+ if (ret)
+ return ret;
+
+ dev_info(dev, "registered apu mailbox\n");
+
+ return 0;
+}
+
+static int mtk_apu_mailbox_remove(struct platform_device *pdev)
+{
+ return 0;
+}
+
+static const struct of_device_id mtk_apu_mailbox_of_match[] = {
+ {.compatible = "mediatek,mtk-apu-mailbox"},
+ {}
+};
+MODULE_DEVICE_TABLE(of, mtk_apu_mailbox_of_match);
+
+static struct platform_driver mtk_apu_mailbox_driver = {
+ .probe = mtk_apu_mailbox_probe,
+ .remove = mtk_apu_mailbox_remove,
+ .driver = {
+ .name = "mtk-apu-mailbox",
+ .of_match_table = mtk_apu_mailbox_of_match,
+ },
+};
+
+static int __init apu_mailbox_init(void)
+{
+ return platform_driver_register(&mtk_apu_mailbox_driver);
+}
+
+static void __exit apu_mailbox_exit(void)
+{
+ platform_driver_unregister(&mtk_apu_mailbox_driver);
+}
+
+module_init(apu_mailbox_init);
+module_exit(apu_mailbox_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("APU Mailbox Driver");
--
2.18.0
