[PATCH v2 3/3] mailbox: sophgo: add mailbox driver for cv18x SoCs

[Yuntao Dai]

Add mailbox controller driver for cv18x SoCs, tested on mailbox-test
client.

Signed-off-by: Yuntao Dai <d1581209858@xxxxxxxx>
---
 drivers/mailbox/Kconfig          |  11 ++
 drivers/mailbox/Makefile         |   2 +
 drivers/mailbox/cv1800-mailbox.c | 203 +++++++++++++++++++++++++++++++
 3 files changed, 216 insertions(+)
 create mode 100644 drivers/mailbox/cv1800-mailbox.c

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 3b8842c4a..db856ec7e 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -286,4 +286,15 @@ config QCOM_IPCC
 	  acts as an interrupt controller for receiving interrupts from clients.
 	  Say Y here if you want to build this driver.
 
+config CV1800_MBOX
+	tristate "cv1800 mailbox"
+	depends on OF
+	depends on ARCH_SOPHGO || COMPILE_TEST
+	help
+	  Mailbox driver implementation for Sophgo cv180x SoCs. This driver
+	  can be used to send message between different processors in SoC. Any
+	  processer can write data in a channel, and set co-responding register
+	  to raise interrupt to notice another processor, and it is allowed to
+	  send data to itself.
+
 endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 5cf2f54de..2c6db8c5c 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -62,3 +62,5 @@ obj-$(CONFIG_SUN6I_MSGBOX)	+= sun6i-msgbox.o
 obj-$(CONFIG_SPRD_MBOX)		+= sprd-mailbox.o
 
 obj-$(CONFIG_QCOM_IPCC)		+= qcom-ipcc.o
+
+obj-$(CONFIG_CV1800_MBOX)	+= cv1800-mailbox.o
\ No newline at end of file
diff --git a/drivers/mailbox/cv1800-mailbox.c b/drivers/mailbox/cv1800-mailbox.c
new file mode 100644
index 000000000..a3b214b4d
--- /dev/null
+++ b/drivers/mailbox/cv1800-mailbox.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kfifo.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define RECV_CPU 2
+
+#define MAILBOX_MAX_CHAN 0x0008
+#define MAILBOX_DONE_OFFSET 0x0002
+#define MAILBOX_CONTEXT_SIZE 0x0040
+#define MAILBOX_CONTEXT_OFFSET 0x0400
+
+#define MBOX_EN_REG(cpu) (cpu << 2)
+#define MBOX_DONE_REG(cpu) ((cpu << 2) + MAILBOX_DONE_OFFSET)
+
+#define MBOX_SET_CLR_REG(cpu) (0x10 + (cpu << 4))
+#define MBOX_SET_INT_REG(cpu) (0x18 + (cpu << 4))
+
+#define MBOX_SET_REG 0x60
+
+/**
+ * cv1800 mailbox channel private data
+ * @idx: index of channel
+ * @cpu: send to which processor
+ */
+struct cv1800_mbox_chan_priv {
+	int idx;
+	int cpu;
+};
+
+struct cv1800_mbox {
+	struct mbox_controller mbox;
+	struct cv1800_mbox_chan_priv priv[MAILBOX_MAX_CHAN];
+	struct mbox_chan chans[MAILBOX_MAX_CHAN];
+	u64 __iomem *content[MAILBOX_MAX_CHAN];
+	void __iomem *mbox_base;
+	int recvid;
+};
+
+static irqreturn_t cv1800_mbox_isr(int irq, void *dev_id)
+{
+	struct cv1800_mbox *mbox = (struct cv1800_mbox *)dev_id;
+	size_t i;
+
+	for (i = 0; i < MAILBOX_MAX_CHAN; i++) {
+		if (mbox->content[i] && mbox->chans[i].cl) {
+			mbox_chan_received_data(&mbox->chans[i],
+						mbox->content[i]);
+			mbox->content[i] = NULL;
+			return IRQ_HANDLED;
+		}
+	}
+	return IRQ_NONE;
+}
+
+static irqreturn_t cv1800_mbox_irq(int irq, void *dev_id)
+{
+	struct cv1800_mbox *mbox = (struct cv1800_mbox *)dev_id;
+	u64 __iomem *addr;
+	u8 set, valid;
+	size_t i;
+
+	set = readb(mbox->mbox_base + MBOX_SET_INT_REG(RECV_CPU));
+
+	if (!set)
+		return IRQ_NONE;
+
+	for (i = 0; i < MAILBOX_MAX_CHAN; i++) {
+		valid = set & (1 << i);
+		addr = (u64 *)(mbox->mbox_base + MAILBOX_CONTEXT_OFFSET) + i;
+		if (valid) {
+			mbox->content[i] = addr;
+			writeb(valid,
+			       mbox->mbox_base + MBOX_SET_CLR_REG(RECV_CPU));
+			writeb(~valid, mbox->mbox_base + MBOX_EN_REG(RECV_CPU));
+			return IRQ_WAKE_THREAD;
+		}
+	}
+
+	return IRQ_NONE;
+}
+
+static int cv1800_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct cv1800_mbox_chan_priv *priv =
+		(struct cv1800_mbox_chan_priv *)chan->con_priv;
+	struct cv1800_mbox *mbox = dev_get_drvdata(chan->mbox->dev);
+	u64 __iomem *addr;
+	u8 en, valid;
+
+	int idx = priv->idx;
+	int cpu = priv->cpu;
+
+	addr = (u64 *)(mbox->mbox_base + MAILBOX_CONTEXT_OFFSET) + idx;
+	memcpy_toio(addr, data, 8);
+
+	valid = 1 << idx;
+	writeb(valid, mbox->mbox_base + MBOX_SET_CLR_REG(cpu));
+	en = readb(mbox->mbox_base + MBOX_EN_REG(cpu));
+	writeb(en | valid, mbox->mbox_base + MBOX_EN_REG(cpu));
+	writeb(valid, mbox->mbox_base + MBOX_SET_REG);
+
+	return 0;
+}
+
+static bool cv1800_last_tx_done(struct mbox_chan *chan)
+{
+	return true;
+}
+
+static const struct mbox_chan_ops cv1800_mbox_chan_ops = {
+	.send_data = cv1800_mbox_send_data,
+	.last_tx_done = cv1800_last_tx_done,
+};
+
+static struct mbox_chan *cv1800_mbox_xlate(struct mbox_controller *mbox,
+					   const struct of_phandle_args *spec)
+{
+	struct cv1800_mbox_chan_priv *priv;
+
+	int idx = spec->args[0];
+	int cpu = spec->args[1];
+
+	if (idx >= mbox->num_chans)
+		return ERR_PTR(-EINVAL);
+
+	priv = mbox->chans[idx].con_priv;
+	priv->cpu = cpu;
+
+	return &mbox->chans[idx];
+}
+
+static const struct of_device_id cv1800_mbox_of_match[] = {
+	{ .compatible = "sophgo,cv1800-mailbox", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, cv1800_mbox_of_match);
+
+static int cv1800_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cv1800_mbox *mb;
+	int irq, idx, err;
+
+	if (!dev->of_node)
+		return -ENODEV;
+
+	mb = devm_kzalloc(dev, sizeof(*mb), GFP_KERNEL);
+	if (!mb)
+		return -ENOMEM;
+
+	mb->mbox_base = devm_of_iomap(dev, dev->of_node, 0, NULL);
+	if (IS_ERR(mb->mbox_base))
+		return dev_err_probe(dev, PTR_ERR(mb->mbox_base),
+				     "Failed to map resource\n");
+
+	mb->mbox.dev = dev;
+	mb->mbox.chans = mb->chans;
+	mb->mbox.txdone_poll = true;
+	mb->mbox.ops = &cv1800_mbox_chan_ops;
+	mb->mbox.num_chans = MAILBOX_MAX_CHAN;
+	mb->mbox.of_xlate = cv1800_mbox_xlate;
+
+	irq = platform_get_irq_byname(pdev, "mailbox");
+	err = devm_request_threaded_irq(dev, irq, cv1800_mbox_irq,
+					cv1800_mbox_isr, IRQF_ONESHOT,
+					dev_name(&pdev->dev), mb);
+	if (err < 0)
+		return dev_err_probe(dev, err, "Failed to register irq\n");
+
+	for (idx = 0; idx < MAILBOX_MAX_CHAN; idx++) {
+		mb->priv[idx].idx = idx;
+		mb->mbox.chans[idx].con_priv = &mb->priv[idx];
+	}
+
+	err = devm_mbox_controller_register(dev, &mb->mbox);
+	if (err)
+		return dev_err_probe(dev, err, "Failed to register mailbox\n");
+
+	platform_set_drvdata(pdev, mb);
+	return 0;
+}
+
+static struct platform_driver cv1800_mbox_driver = {
+	.driver = {
+		.name = "cv1800-mbox",
+		.of_match_table = cv1800_mbox_of_match,
+	},
+	.probe	= cv1800_mbox_probe,
+};
+
+module_platform_driver(cv1800_mbox_driver);
+
+MODULE_DESCRIPTION("cv1800 mailbox driver");
+MODULE_LICENSE("GPL");
-- 
2.17.1