1 files changed, 312 insertions, 0 deletions

diff --git a/drivers/mailbox/hi3660-mailbox.c b/drivers/mailbox/hi3660-mailbox.c
new file mode 100644
index 000000000000..3eea6b642484
--- /dev/null
+++ b/drivers/mailbox/hi3660-mailbox.c
@@ -0,0 +1,312 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017-2018 Hisilicon Limited.
+// Copyright (c) 2017-2018 Linaro Limited.
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "mailbox.h"
+
+#define MBOX_CHAN_MAX			32
+
+#define MBOX_RX				0x0
+#define MBOX_TX				0x1
+
+#define MBOX_BASE(mbox, ch)		((mbox)->base + ((ch) * 0x40))
+#define MBOX_SRC_REG			0x00
+#define MBOX_DST_REG			0x04
+#define MBOX_DCLR_REG			0x08
+#define MBOX_DSTAT_REG			0x0c
+#define MBOX_MODE_REG			0x10
+#define MBOX_IMASK_REG			0x14
+#define MBOX_ICLR_REG			0x18
+#define MBOX_SEND_REG			0x1c
+#define MBOX_DATA_REG			0x20
+
+#define MBOX_IPC_LOCK_REG		0xa00
+#define MBOX_IPC_UNLOCK			0x1acce551
+
+#define MBOX_AUTOMATIC_ACK		1
+
+#define MBOX_STATE_IDLE			BIT(4)
+#define MBOX_STATE_ACK			BIT(7)
+
+#define MBOX_MSG_LEN			8
+
+/**
+ * Hi3660 mailbox channel information
+ *
+ * A channel can be used for TX or RX, it can trigger remote
+ * processor interrupt to notify remote processor and can receive
+ * interrupt if has incoming message.
+ *
+ * @dst_irq:	Interrupt vector for remote processor
+ * @ack_irq:	Interrupt vector for local processor
+ */
+struct hi3660_chan_info {
+	unsigned int dst_irq;
+	unsigned int ack_irq;
+};
+
+/**
+ * Hi3660 mailbox controller data
+ *
+ * Mailbox controller includes 32 channels and can allocate
+ * channel for message transferring.
+ *
+ * @dev:	Device to which it is attached
+ * @base:	Base address of the register mapping region
+ * @chan:	Representation of channels in mailbox controller
+ * @mchan:	Representation of channel info
+ * @controller:	Representation of a communication channel controller
+ */
+struct hi3660_mbox {
+	struct device *dev;
+	void __iomem *base;
+	struct mbox_chan chan[MBOX_CHAN_MAX];
+	struct hi3660_chan_info mchan[MBOX_CHAN_MAX];
+	struct mbox_controller controller;
+};
+
+static struct hi3660_mbox *to_hi3660_mbox(struct mbox_controller *mbox)
+{
+	return container_of(mbox, struct hi3660_mbox, controller);
+}
+
+static int hi3660_mbox_check_state(struct mbox_chan *chan)
+{
+	unsigned long ch = (unsigned long)chan->con_priv;
+	struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
+	struct hi3660_chan_info *mchan = &mbox->mchan[ch];
+	void __iomem *base = MBOX_BASE(mbox, ch);
+	unsigned long val;
+	unsigned int ret;
+
+	/* Mailbox is idle so directly bail out */
+	if (readl(base + MBOX_MODE_REG) & MBOX_STATE_IDLE)
+		return 0;
+
+	/* Wait for acknowledge from remote */
+	ret = readx_poll_timeout_atomic(readl, base + MBOX_MODE_REG,
+			val, (val & MBOX_STATE_ACK), 1000, 300000);
+	if (ret) {
+		dev_err(mbox->dev, "%s: timeout for receiving ack\n", __func__);
+		return ret;
+	}
+
+	/* Ensure channel is released */
+	writel(0xffffffff, base + MBOX_IMASK_REG);
+	writel(BIT(mchan->ack_irq), base + MBOX_SRC_REG);
+	return 0;
+}
+
+static int hi3660_mbox_unlock(struct mbox_chan *chan)
+{
+	struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
+	unsigned int val, retry = 3;
+
+	do {
+		writel(MBOX_IPC_UNLOCK, mbox->base + MBOX_IPC_LOCK_REG);
+
+		val = readl(mbox->base + MBOX_IPC_LOCK_REG);
+		if (!val)
+			break;
+
+		udelay(10);
+	} while (retry--);
+
+	if (val)
+		dev_err(mbox->dev, "%s: failed to unlock mailbox\n", __func__);
+
+	return (!val) ? 0 : -ETIMEDOUT;
+}
+
+static int hi3660_mbox_acquire_channel(struct mbox_chan *chan)
+{
+	unsigned long ch = (unsigned long)chan->con_priv;
+	struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
+	struct hi3660_chan_info *mchan = &mbox->mchan[ch];
+	void __iomem *base = MBOX_BASE(mbox, ch);
+	unsigned int val, retry;
+
+	for (retry = 10; retry; retry--) {
+		/* Check if channel is in idle state */
+		if (readl(base + MBOX_MODE_REG) & MBOX_STATE_IDLE) {
+			writel(BIT(mchan->ack_irq), base + MBOX_SRC_REG);
+
+			/* Check ack bit has been set successfully */
+			val = readl(base + MBOX_SRC_REG);
+			if (val & BIT(mchan->ack_irq))
+				break;
+		}
+	}
+
+	if (!retry)
+		dev_err(mbox->dev, "%s: failed to acquire channel\n", __func__);
+
+	return retry ? 0 : -ETIMEDOUT;
+}
+
+static int hi3660_mbox_startup(struct mbox_chan *chan)
+{
+	int ret;
+
+	ret = hi3660_mbox_check_state(chan);
+	if (ret)
+		return ret;
+
+	ret = hi3660_mbox_unlock(chan);
+	if (ret)
+		return ret;
+
+	ret = hi3660_mbox_acquire_channel(chan);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int hi3660_mbox_send_data(struct mbox_chan *chan, void *msg)
+{
+	unsigned long ch = (unsigned long)chan->con_priv;
+	struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
+	struct hi3660_chan_info *mchan = &mbox->mchan[ch];
+	void __iomem *base = MBOX_BASE(mbox, ch);
+	u32 *buf = msg;
+	unsigned int i;
+
+	/* Ensure channel is released */
+	writel_relaxed(0xffffffff, base + MBOX_IMASK_REG);
+	writel_relaxed(BIT(mchan->ack_irq), base + MBOX_SRC_REG);
+
+	/* Clear mask for destination interrupt */
+	writel_relaxed(~BIT(mchan->dst_irq), base + MBOX_IMASK_REG);
+
+	/* Config destination for interrupt vector */
+	writel_relaxed(BIT(mchan->dst_irq), base + MBOX_DST_REG);
+
+	/* Automatic acknowledge mode */
+	writel_relaxed(MBOX_AUTOMATIC_ACK, base + MBOX_MODE_REG);
+
+	/* Fill message data */
+	for (i = 0; i < MBOX_MSG_LEN; i++)
+		writel_relaxed(buf[i], base + MBOX_DATA_REG + i * 4);
+
+	/* Trigger data transferring */
+	writel(BIT(mchan->ack_irq), base + MBOX_SEND_REG);
+	return 0;
+}
+
+static struct mbox_chan_ops hi3660_mbox_ops = {
+	.startup	= hi3660_mbox_startup,
+	.send_data	= hi3660_mbox_send_data,
+};
+
+static struct mbox_chan *hi3660_mbox_xlate(struct mbox_controller *controller,
+					   const struct of_phandle_args *spec)
+{
+	struct hi3660_mbox *mbox = to_hi3660_mbox(controller);
+	struct hi3660_chan_info *mchan;
+	unsigned int ch = spec->args[0];
+
+	if (ch >= MBOX_CHAN_MAX) {
+		dev_err(mbox->dev, "Invalid channel idx %d\n", ch);
+		return ERR_PTR(-EINVAL);
+	}
+
+	mchan = &mbox->mchan[ch];
+	mchan->dst_irq = spec->args[1];
+	mchan->ack_irq = spec->args[2];
+
+	return &mbox->chan[ch];
+}
+
+static const struct of_device_id hi3660_mbox_of_match[] = {
+	{ .compatible = "hisilicon,hi3660-mbox", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, hi3660_mbox_of_match);
+
+static int hi3660_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct hi3660_mbox *mbox;
+	struct mbox_chan *chan;
+	struct resource *res;
+	unsigned long ch;
+	int err;
+
+	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mbox->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(mbox->base))
+		return PTR_ERR(mbox->base);
+
+	mbox->dev = dev;
+	mbox->controller.dev = dev;
+	mbox->controller.chans = mbox->chan;
+	mbox->controller.num_chans = MBOX_CHAN_MAX;
+	mbox->controller.ops = &hi3660_mbox_ops;
+	mbox->controller.of_xlate = hi3660_mbox_xlate;
+
+	/* Initialize mailbox channel data */
+	chan = mbox->chan;
+	for (ch = 0; ch < MBOX_CHAN_MAX; ch++)
+		chan[ch].con_priv = (void *)ch;
+
+	err = mbox_controller_register(&mbox->controller);
+	if (err) {
+		dev_err(dev, "Failed to register mailbox %d\n", err);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, mbox);
+	dev_info(dev, "Mailbox enabled\n");
+	return 0;
+}
+
+static int hi3660_mbox_remove(struct platform_device *pdev)
+{
+	struct hi3660_mbox *mbox = platform_get_drvdata(pdev);
+
+	mbox_controller_unregister(&mbox->controller);
+	return 0;
+}
+
+static struct platform_driver hi3660_mbox_driver = {
+	.probe  = hi3660_mbox_probe,
+	.remove = hi3660_mbox_remove,
+	.driver = {
+		.name = "hi3660-mbox",
+		.of_match_table = hi3660_mbox_of_match,
+	},
+};
+
+static int __init hi3660_mbox_init(void)
+{
+	return platform_driver_register(&hi3660_mbox_driver);
+}
+core_initcall(hi3660_mbox_init);
+
+static void __exit hi3660_mbox_exit(void)
+{
+	platform_driver_unregister(&hi3660_mbox_driver);
+}
+module_exit(hi3660_mbox_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Hisilicon Hi3660 Mailbox Controller");
+MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");