[PATCH 06/22] mailbox: Add TI K3 Secure Proxy Driver

[Sascha Hauer <s.hauer@pengutronix.de>]

This adds a mailbox interface driver to communicate with other
processors in a TI K3 SoC. We need that to control clocks and power
domains on K3 Socs.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/mailbox/Kconfig       |  12 +
 drivers/mailbox/Makefile      |   1 +
 drivers/mailbox/ti-msgmgr.c   | 402 ++++++++++++++++++++++++++++++++++
 include/soc/ti/k3-sec-proxy.h |  25 +++
 4 files changed, 440 insertions(+)
 create mode 100644 drivers/mailbox/ti-msgmgr.c
 create mode 100644 include/soc/ti/k3-sec-proxy.h

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 7839a44729..80a501d235 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -7,4 +7,16 @@ menuconfig MAILBOX
 
 if MAILBOX
 
+config TI_MESSAGE_MANAGER
+	tristate "Texas Instruments Message Manager Driver"
+	depends on ARCH_K3
+	default y
+	help
+	  An implementation of Message Manager slave driver for Keystone
+	  and K3 architecture SoCs from Texas Instruments. Message Manager
+	  is a communication entity found on few of Texas Instrument's keystone
+	  and K3 architecture SoCs. These may be used for communication between
+	  multiple processors within the SoC. Select this driver if your
+	  platform has support for the hardware block.
+
 endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 9dec4e3b3b..8ec2af96f4 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_MAILBOX) += mailbox.o
+obj-$(CONFIG_TI_MESSAGE_MANAGER) += ti-msgmgr.o
diff --git a/drivers/mailbox/ti-msgmgr.c b/drivers/mailbox/ti-msgmgr.c
new file mode 100644
index 0000000000..58ec8697fc
--- /dev/null
+++ b/drivers/mailbox/ti-msgmgr.c
@@ -0,0 +1,402 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Texas Instruments' K3 Secure proxy Driver
+ *
+ * Copyright (C) 2017-2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Lokesh Vutla <lokeshvutla@ti.com>
+ */
+
+#include <common.h>
+#include <mailbox.h>
+#include <soc/ti/k3-sec-proxy.h>
+
+/* SEC PROXY RT THREAD STATUS */
+#define RT_THREAD_STATUS			0x0
+#define RT_THREAD_THRESHOLD			0x4
+#define RT_THREAD_STATUS_ERROR_SHIFT		31
+#define RT_THREAD_STATUS_ERROR_MASK		BIT(31)
+#define RT_THREAD_STATUS_CUR_CNT_SHIFT		0
+#define RT_THREAD_STATUS_CUR_CNT_MASK		GENMASK(7, 0)
+
+/* SEC PROXY SCFG THREAD CTRL */
+#define SCFG_THREAD_CTRL			0x1000
+#define SCFG_THREAD_CTRL_DIR_SHIFT		31
+#define SCFG_THREAD_CTRL_DIR_MASK		BIT(31)
+
+#define SEC_PROXY_THREAD(base, x)		((base) + (0x1000 * (x)))
+#define THREAD_IS_RX				1
+#define THREAD_IS_TX				0
+
+/**
+ * struct k3_sec_proxy_desc - Description of secure proxy integration.
+ * @thread_count:	Number of Threads.
+ * @max_msg_size:	Message size in bytes.
+ * @data_start_offset:	Offset of the First data register of the thread
+ * @data_end_offset:	Offset of the Last data register of the thread
+ * @valid_threads:	List of Valid threads that the processor can access
+ * @num_valid_threads:	Number of valid threads.
+ */
+struct k3_sec_proxy_desc {
+	u16 thread_count;
+	u16 max_msg_size;
+	u16 data_start_offset;
+	u16 data_end_offset;
+	const u32 *valid_threads;
+	u32 num_valid_threads;
+};
+
+/**
+ * struct k3_sec_proxy_thread - Description of a secure proxy Thread
+ * @id:		Thread ID
+ * @data:	Thread Data path region for target
+ * @scfg:	Secure Config Region for Thread
+ * @rt:		RealTime Region for Thread
+ * @rx_buf:	Receive buffer data, max message size.
+ */
+struct k3_sec_proxy_thread {
+	u32 id;
+	void __iomem *data;
+	void __iomem *scfg;
+	void __iomem *rt;
+	u32 *rx_buf;
+};
+
+/**
+ * struct k3_sec_proxy_mbox - Description of a Secure Proxy Instance
+ * @chan:		Mailbox Channel
+ * @desc:		Description of the SoC integration
+ * @chans:		Array for valid thread instances
+ * @target_data:	Secure Proxy region for Target Data
+ * @scfg:		Secure Proxy Region for Secure configuration.
+ * @rt:			Secure proxy Region for Real Time Region.
+ */
+struct k3_sec_proxy_mbox {
+	struct device *dev;
+	struct mbox_controller mbox;
+	const struct k3_sec_proxy_desc *desc;
+	struct k3_sec_proxy_thread *k3_chans;
+	void __iomem *target_data;
+	void __iomem *scfg;
+	void __iomem *rt;
+};
+
+static inline u32 sp_readl(void __iomem *addr, unsigned int offset)
+{
+	return readl(addr + offset);
+}
+
+static inline void sp_writel(void __iomem *addr, unsigned int offset, u32 data)
+{
+	writel(data, addr + offset);
+}
+
+/**
+ * k3_sec_proxy_request() - Request for mailbox channel
+ * @chan:	Channel Pointer
+ */
+static int k3_sec_proxy_request(struct mbox_chan *chan)
+{
+	dev_dbg(chan->dev, "%s(chan=%p)\n", __func__, chan);
+
+	return 0;
+}
+
+/**
+ * k3_sec_proxy_free() - Free the mailbox channel
+ * @chan:	Channel Pointer
+ */
+static int k3_sec_proxy_free(struct mbox_chan *chan)
+{
+	dev_dbg(chan->dev, "%s(chan=%p)\n", __func__, chan);
+
+	return 0;
+}
+
+/**
+ * k3_sec_proxy_verify_thread() - Verify thread status before
+ *				  sending/receiving data.
+ * @spt:	pointer to secure proxy thread description
+ * @dir:	Direction of the thread
+ *
+ * Return: 0 if all goes good, else appropriate error message.
+ */
+static inline int k3_sec_proxy_verify_thread(struct mbox_chan *chan, u8 dir)
+{
+	struct k3_sec_proxy_thread *spt = chan->con_priv;
+
+	/* Check for any errors already available */
+	if (sp_readl(spt->rt, RT_THREAD_STATUS) &
+	    RT_THREAD_STATUS_ERROR_MASK) {
+		dev_err(chan->dev, "%s: Thread %d is corrupted, cannot send data.\n",
+		       __func__, spt->id);
+		return -EINVAL;
+	}
+
+	/* Make sure thread is configured for right direction */
+	if ((sp_readl(spt->scfg, SCFG_THREAD_CTRL)
+	    & SCFG_THREAD_CTRL_DIR_MASK) >> SCFG_THREAD_CTRL_DIR_SHIFT != dir) {
+		if (dir)
+			dev_err(chan->dev, "%s: Trying to receive data on tx Thread %d\n",
+			       __func__, spt->id);
+		else
+			dev_err(chan->dev, "%s: Trying to send data on rx Thread %d\n",
+			       __func__, spt->id);
+		return -EINVAL;
+	}
+
+	/* Check the message queue before sending/receiving data */
+	if (!(sp_readl(spt->rt, RT_THREAD_STATUS) &
+	      RT_THREAD_STATUS_CUR_CNT_MASK))
+		return -ENODATA;
+
+	return 0;
+}
+
+/**
+ * k3_sec_proxy_send() - Send data via mailbox channel
+ * @chan:	Channel Pointer
+ * @data:	Pointer to k3_sec_proxy_msg
+ *
+ * Return: 0 if all goes good, else appropriate error message.
+ */
+static int k3_sec_proxy_send(struct mbox_chan *chan, const void *data)
+{
+	const struct k3_sec_proxy_msg *msg = (struct k3_sec_proxy_msg *)data;
+	struct mbox_controller *mbox = chan->mbox;
+	struct k3_sec_proxy_mbox *spm = container_of(mbox, struct k3_sec_proxy_mbox, mbox);
+	struct k3_sec_proxy_thread *spt = chan->con_priv;
+	int num_words, trail_bytes, ret;
+	void __iomem *data_reg;
+	u32 *word_data;
+
+	dev_dbg(chan->dev, "%s(chan=%p, data=%p)\n", __func__, chan, data);
+
+	ret = k3_sec_proxy_verify_thread(chan, THREAD_IS_TX);
+	if (ret) {
+		dev_err(chan->dev,
+			"%s: Thread%d verification failed. ret = %d\n",
+			__func__, spt->id, ret);
+		return ret;
+	}
+
+	/* Check the message size. */
+	if (msg->len > spm->desc->max_msg_size)
+		return -EINVAL;
+
+	/* Send the message */
+	data_reg = spt->data + spm->desc->data_start_offset;
+	for (num_words = msg->len / sizeof(u32), word_data = (u32 *)msg->buf;
+	     num_words;
+	     num_words--, data_reg += sizeof(u32), word_data++)
+		writel(*word_data, data_reg);
+
+	trail_bytes = msg->len % sizeof(u32);
+	if (trail_bytes) {
+		u32 data_trail = *word_data;
+
+		/* Ensure all unused data is 0 */
+		data_trail &= 0xFFFFFFFF >> (8 * (sizeof(u32) - trail_bytes));
+		writel(data_trail, data_reg);
+		data_reg++;
+	}
+
+	/*
+	 * 'data_reg' indicates next register to write. If we did not already
+	 * write on tx complete reg(last reg), we must do so for transmit
+	 */
+	if (data_reg <= (spt->data + spm->desc->data_end_offset))
+		sp_writel(spt->data, spm->desc->data_end_offset, 0);
+
+	return 0;
+}
+
+/**
+ * k3_sec_proxy_recv() - Receive data via mailbox channel
+ * @chan:	Channel Pointer
+ * @data:	Pointer to k3_sec_proxy_msg
+ *
+ * Return: 0 if all goes good, else appropriate error message.
+ */
+static int k3_sec_proxy_recv(struct mbox_chan *chan, void *data)
+{
+	struct mbox_controller *mbox = chan->mbox;
+	struct k3_sec_proxy_mbox *spm = container_of(mbox, struct k3_sec_proxy_mbox, mbox);
+	struct k3_sec_proxy_thread *spt = chan->con_priv;
+	struct k3_sec_proxy_msg *msg = data;
+	void __iomem *data_reg;
+	int num_words, ret;
+	u32 *word_data;
+
+	dev_dbg(chan->dev, "%s(chan=%p, data=%p)\n", __func__, chan, data);
+
+	ret = k3_sec_proxy_verify_thread(chan, THREAD_IS_RX);
+	if (ret)
+		return ret;
+
+	msg->len = spm->desc->max_msg_size;
+	msg->buf = spt->rx_buf;
+	data_reg = spt->data + spm->desc->data_start_offset;
+	word_data = spt->rx_buf;
+	for (num_words = spm->desc->max_msg_size / sizeof(u32);
+	     num_words;
+	     num_words--, data_reg += sizeof(u32), word_data++)
+		*word_data = readl(data_reg);
+
+	return 0;
+}
+
+static struct mbox_chan *k3_sec_proxy_of_xlate(struct mbox_controller *mbox,
+					       const struct of_phandle_args *p)
+{
+	struct k3_sec_proxy_mbox *spm = container_of(mbox, struct k3_sec_proxy_mbox, mbox);
+	int ncells = 1;
+	int req_pid;
+	int i;
+
+	if (p->args_count != ncells) {
+		dev_err(mbox->dev, "Invalid arguments in dt[%d]. Must be %d\n",
+			p->args_count, ncells);
+		return ERR_PTR(-EINVAL);
+	}
+
+	req_pid = p->args[0];
+
+	for (i = 0; i < spm->desc->num_valid_threads; i++) {
+		struct mbox_chan *chan;
+
+		if (spm->k3_chans[i].id == req_pid) {
+			chan = &spm->mbox.chans[i];
+			return chan;
+		}
+	}
+
+	return NULL;
+}
+
+static struct mbox_chan_ops k3_sec_proxy_mbox_ops = {
+	.request = k3_sec_proxy_request,
+	.rfree = k3_sec_proxy_free,
+	.send = k3_sec_proxy_send,
+	.recv = k3_sec_proxy_recv,
+};
+
+/**
+ * k3_sec_proxy_thread_setup - Initialize the parameters for all valid threads
+ * @spm:	Mailbox instance for which threads needs to be initialized
+ *
+ * Return: 0 if all went ok, else corresponding error message
+ */
+static int k3_sec_proxy_thread_setup(struct k3_sec_proxy_mbox *spm)
+{
+	struct k3_sec_proxy_thread *spt;
+	int i, ind;
+
+	for (i = 0; i < spm->desc->num_valid_threads; i++) {
+		spt = &spm->k3_chans[i];
+		ind = spm->desc->valid_threads[i];
+		spt->id = ind;
+		spt->data = (void *)SEC_PROXY_THREAD(spm->target_data, ind);
+		spt->scfg = (void *)SEC_PROXY_THREAD(spm->scfg, ind);
+		spt->rt = (void *)SEC_PROXY_THREAD(spm->rt, ind);
+		spt->rx_buf = xzalloc(spm->desc->max_msg_size);
+	}
+
+	return 0;
+}
+
+/**
+ * k3_sec_proxy_probe() - Basic probe
+ * @dev:	corresponding mailbox device
+ *
+ * Return: 0 if all went ok, else corresponding error message
+ */
+static int k3_sec_proxy_probe(struct device *dev)
+{
+	struct k3_sec_proxy_mbox *spm;
+	struct mbox_controller *mbox;
+	struct resource *res;
+	const void *data;
+	int i, ret;
+
+	spm = xzalloc(sizeof(*spm));
+
+	spm->dev = dev;
+
+	res = dev_request_mem_resource_by_name(spm->dev, "target_data");
+	if (IS_ERR(res))
+		return PTR_ERR(res);
+
+	spm->target_data = IOMEM(res->start);
+
+	res = dev_request_mem_resource_by_name(spm->dev, "scfg");
+	if (IS_ERR(res))
+		return PTR_ERR(res);
+
+	spm->scfg = IOMEM(res->start);
+
+	res = dev_request_mem_resource_by_name(spm->dev, "rt");
+	if (IS_ERR(res))
+		return PTR_ERR(res);
+
+	spm->rt = IOMEM(res->start);
+
+	ret = dev_get_drvdata(dev, &data);
+        if (ret)
+                return ret;
+
+	spm->desc = data;
+	spm->k3_chans = xzalloc(spm->desc->num_valid_threads * sizeof(*spm->k3_chans));
+
+	ret = k3_sec_proxy_thread_setup(spm);
+	if (ret) {
+		dev_err(dev, "secure proxy thread setup failed\n");
+		return ret;
+	}
+
+	mbox = &spm->mbox;
+	mbox->dev = dev;
+	mbox->ops = &k3_sec_proxy_mbox_ops;
+	mbox->of_xlate = k3_sec_proxy_of_xlate;
+	mbox->chans = xzalloc(spm->desc->num_valid_threads * sizeof(*mbox->chans));
+	mbox->num_chans = spm->desc->num_valid_threads;
+
+	for (i = 0; i < spm->desc->num_valid_threads; i++) {
+		mbox->chans[i].dev = dev;
+		mbox->chans[i].mbox = mbox;
+		mbox->chans[i].con_priv = &spm->k3_chans[i];
+	}
+
+	ret = mbox_controller_register(mbox);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const u32 am6x_valid_threads[] = { 0, 1, 4, 5, 6, 7, 8, 9, 11, 12, 13, 20, 21, 22, 23 };
+
+static const struct k3_sec_proxy_desc am654_desc = {
+	.thread_count = 90,
+	.max_msg_size = 60,
+	.data_start_offset = 0x4,
+	.data_end_offset = 0x3C,
+	.valid_threads = am6x_valid_threads,
+	.num_valid_threads = ARRAY_SIZE(am6x_valid_threads),
+};
+
+static const struct of_device_id k3_sec_proxy_ids[] = {
+	{
+		.compatible = "ti,am654-secure-proxy",
+		.data = &am654_desc
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, k3_sec_proxy_ids);
+
+static struct driver k3_sec_proxy_driver = {
+        .name   = "k3-secure-proxy",
+        .probe  = k3_sec_proxy_probe,
+        .of_compatible = DRV_OF_COMPAT(k3_sec_proxy_ids),
+};
+core_platform_driver(k3_sec_proxy_driver);
diff --git a/include/soc/ti/k3-sec-proxy.h b/include/soc/ti/k3-sec-proxy.h
new file mode 100644
index 0000000000..f34854ceeb
--- /dev/null
+++ b/include/soc/ti/k3-sec-proxy.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Texas Instruments' K3 Secure proxy
+ *
+ * Copyright (C) 2017-2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Lokesh Vutla <lokeshvutla@ti.com>
+ *
+ */
+
+#ifndef K3_SEC_PROXY_H
+#define K3_SEC_PROXY_H
+
+/**
+ * struct k3_sec_proxy_msg - Secure proxy message structure
+ * @len: Length of data in the Buffer
+ * @buf: Buffer pointer
+ *
+ * This is the structure for data used in mbox_send() and mbox_recv().
+ */
+struct k3_sec_proxy_msg {
+	size_t len;
+	u32 *buf;
+};
+
+#endif /* K3_SEC_PROXY_H */
-- 
2.39.2