[PATCH v5 3/3] mailbox: mediatek: add support for adsp mailbox controller

[allen-kh.cheng <allen-kh.cheng@mediatek.com>]

From: Allen-KH Cheng <Allen-KH.Cheng@mediatek.com>

This patch is to for MediaTek ADSP IPC mailbox controller driver
It is used to send short messages between processors with adsp

Signed-off-by: Allen-KH Cheng <Allen-KH.Cheng@mediatek.com>
---
 drivers/mailbox/Kconfig            |   7 ++
 drivers/mailbox/Makefile           |   2 +
 drivers/mailbox/mtk-adsp-mailbox.c | 178 +++++++++++++++++++++++++++++
 3 files changed, 187 insertions(+)
 create mode 100644 drivers/mailbox/mtk-adsp-mailbox.c

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index c9fc06c7e685..c44a0102585d 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -226,6 +226,13 @@ 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_ADSP_IPC_MBOX
+	tristate "MediaTek ADSP Mailbox Controller"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	help
+	  Say yes here to add support for MediaTek ADSP IPC mailbox controller
+	  driver. It is used to send short messages between processors with dsp.
+
 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 c2089f04887e..13d5c81852ca 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-$(CONFIG_MTK_ADSP_IPC_MBOX)	+= mtk-adsp-mailbox.o
+
 obj-$(CONFIG_MTK_CMDQ_MBOX)	+= mtk-cmdq-mailbox.o
 
 obj-$(CONFIG_ZYNQMP_IPI_MBOX)	+= zynqmp-ipi-mailbox.o
diff --git a/drivers/mailbox/mtk-adsp-mailbox.c b/drivers/mailbox/mtk-adsp-mailbox.c
new file mode 100644
index 000000000000..64be6e30e5a2
--- /dev/null
+++ b/drivers/mailbox/mtk-adsp-mailbox.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 MediaTek Corporation. All rights reserved.
+ * Author: Allen-KH Cheng <allen-kh.cheng@mediatek.com>
+ */
+
+#include <linux/firmware/mediatek/mtk-adsp-ipc.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+
+/* adsp mbox register offset */
+#define MTK_ADSP_MBOX_IN_CMD 0x00
+#define MTK_ADSP_MBOX_IN_CMD_CLR 0x04
+#define MTK_ADSP_MBOX_OUT_CMD 0x1c
+#define MTK_ADSP_MBOX_OUT_CMD_CLR 0x20
+#define MTK_ADSP_MBOX_IN_MSG0 0x08
+#define MTK_ADSP_MBOX_IN_MSG1 0x0C
+#define MTK_ADSP_MBOX_OUT_MSG0 0x24
+#define MTK_ADSP_MBOX_OUT_MSG1 0x28
+
+struct mtk_adsp_mbox_priv {
+	struct device *dev;
+	struct mbox_controller mbox;
+	void __iomem *va_mboxreg;
+};
+
+static irqreturn_t mtk_adsp_ipc_irq_handler(int irq, void *data)
+{
+	struct mbox_chan *ch = data;
+	struct adsp_mbox_ch_info *ch_info = ch->con_priv;
+	void __iomem *reg = ch_info->va_reg;
+	u32 op = readl(reg + MTK_ADSP_MBOX_OUT_CMD);
+
+	writel(op, reg + MTK_ADSP_MBOX_OUT_CMD_CLR);
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t mtk_adsp_ipc_handler(int irq, void *data)
+{
+	struct mbox_chan *ch = data;
+	struct adsp_mbox_ch_info *ch_info = ch->con_priv;
+
+	mbox_chan_received_data(ch, ch_info);
+
+	return IRQ_HANDLED;
+}
+
+static struct mbox_chan *mtk_adsp_mbox_xlate(struct mbox_controller *mbox,
+					     const struct of_phandle_args *sp)
+{
+	return &mbox->chans[sp->args[0]];
+}
+
+static int mtk_adsp_mbox_startup(struct mbox_chan *chan)
+{
+	struct adsp_mbox_ch_info *ch_info = chan->con_priv;
+	void __iomem *reg = ch_info->va_reg;
+
+	/* Clear DSP mbox command */
+	writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_IN_CMD_CLR);
+	writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_OUT_CMD_CLR);
+
+	return 0;
+}
+
+static void mtk_adsp_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct adsp_mbox_ch_info *ch_info = chan->con_priv;
+	void __iomem *reg = ch_info->va_reg;
+
+	/* Clear DSP mbox command */
+	writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_IN_CMD_CLR);
+	writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_OUT_CMD_CLR);
+	chan->con_priv = NULL;
+}
+
+static int mtk_adsp_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct adsp_mbox_ch_info *ch_info = chan->con_priv;
+	void __iomem *reg = ch_info->va_reg;
+
+	writel(ch_info->ipc_op_val, reg + MTK_ADSP_MBOX_IN_CMD);
+
+	return 0;
+}
+
+static bool mtk_adsp_mbox_last_tx_done(struct mbox_chan *chan)
+{
+	struct adsp_mbox_ch_info *ch_info = chan->con_priv;
+	void __iomem *reg = ch_info->va_reg;
+
+	return readl(reg + MTK_ADSP_MBOX_IN_CMD) == 0 ? true : false;
+}
+
+static const struct mbox_chan_ops adsp_mbox_chan_ops = {
+	.send_data	= mtk_adsp_mbox_send_data,
+	.startup	= mtk_adsp_mbox_startup,
+	.shutdown	= mtk_adsp_mbox_shutdown,
+	.last_tx_done	= mtk_adsp_mbox_last_tx_done,
+};
+
+static int mtk_adsp_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mbox_controller *mbox;
+	struct mtk_adsp_mbox_priv *priv;
+	struct resource *res;
+	struct adsp_mbox_ch_info *ch_info;
+	int ret;
+	int irq;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mbox = &priv->mbox;
+	mbox->dev = dev;
+	mbox->ops = &adsp_mbox_chan_ops;
+	mbox->txdone_irq = false;
+	mbox->txdone_poll = true;
+	mbox->of_xlate = mtk_adsp_mbox_xlate;
+	mbox->num_chans = 1;
+	mbox->chans = devm_kzalloc(mbox->dev, sizeof(*mbox->chans), GFP_KERNEL);
+	if (!mbox->chans)
+		return -ENOMEM;
+
+	priv->va_mboxreg = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->va_mboxreg))
+		return PTR_ERR(priv->va_mboxreg);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = devm_request_threaded_irq(dev, irq,
+					mtk_adsp_ipc_irq_handler, mtk_adsp_ipc_handler,
+					IRQF_TRIGGER_NONE, dev_name(dev),
+					mbox->chans);
+	if (ret < 0)
+		return ret;
+
+	/* set adsp mbox channel info */
+	ch_info = devm_kzalloc(dev, sizeof(*ch_info), GFP_KERNEL);
+	if (!ch_info)
+		return -ENOMEM;
+
+	ch_info->va_reg = priv->va_mboxreg;
+	mbox->chans->con_priv = ch_info;
+	platform_set_drvdata(pdev, priv);
+
+	return devm_mbox_controller_register(dev, &priv->mbox);
+}
+
+static const struct of_device_id mtk_adsp_mbox_of_match[] = {
+	{ .compatible = "mediatek,mt8195-adsp-mbox", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mtk_adsp_mbox_of_match);
+
+static struct platform_driver mtk_adsp_ipc_mbox_driver = {
+	.probe		= mtk_adsp_mbox_probe,
+	.driver = {
+		.name	= "mtk_adsp_mbox",
+		.of_match_table = mtk_adsp_mbox_of_match,
+	},
+};
+module_platform_driver(mtk_adsp_ipc_mbox_driver);
+
+MODULE_AUTHOR("Allen-KH Cheng <Allen-KH.Cheng@mediatek.com>");
+MODULE_DESCRIPTION("MTK ADSP mailbox IPC driver");
+MODULE_LICENSE("GPL v2");
-- 
2.18.0