mailbox: Introduce K3 Secure Proxy Driver

Secure Proxy module manages hardware threads that are meant
for communication between the processor entities. Adding
support for this driver.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>

3 files changed, 449 insertions, 0 deletions

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 9649b70589..2836ee4a7b 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -24,4 +24,14 @@ config TEGRA_HSP
 	  This enables support for the NVIDIA Tegra HSP Hw module, which
 	  implements doorbells, mailboxes, semaphores, and shared interrupts.
 
+config K3_SEC_PROXY
+	bool "Texas Instruments K3 Secure Proxy Driver"
+	depends on DM_MAILBOX && ARCH_K3
+	help
+	  An implementation of Secure proxy slave driver for K3 SoCs from
+	  Texas Instruments. Secure proxy is a communication entity mainly
+	  used for communication between multiple processors with the SoC.
+	  Select this driver if your platform has support for this hardware
+	  block.
+
 endmenu
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 155dbeb099..4ac85d412f 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_DM_MAILBOX) += mailbox-uclass.o
 obj-$(CONFIG_SANDBOX_MBOX) += sandbox-mbox.o
 obj-$(CONFIG_SANDBOX_MBOX) += sandbox-mbox-test.o
 obj-$(CONFIG_TEGRA_HSP) += tegra-hsp.o
+obj-$(CONFIG_K3_SEC_PROXY) += k3-sec-proxy.o
diff --git a/drivers/mailbox/k3-sec-proxy.c b/drivers/mailbox/k3-sec-proxy.c
new file mode 100644
index 0000000000..b07b56cf97
--- /dev/null
+++ b/drivers/mailbox/k3-sec-proxy.c
@@ -0,0 +1,438 @@
+// 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 <asm/io.h>
+#include <linux/types.h>
+#include <linux/bitops.h>
+#include <linux/soc/ti/k3-sec-proxy.h>
+#include <dm.h>
+#include <mailbox-uclass.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* 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 mbox_chan chan;
+	struct k3_sec_proxy_desc *desc;
+	struct k3_sec_proxy_thread *chans;
+	phys_addr_t target_data;
+	phys_addr_t scfg;
+	phys_addr_t 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_of_xlate() - Translation of phandle to channel
+ * @chan:	Mailbox channel
+ * @args:	Phandle Pointer
+ *
+ * Translates the phandle args and fills up the Mailbox channel from client.
+ * Return: 0 if all goes good, else return corresponding error message.
+ */
+static int k3_sec_proxy_of_xlate(struct mbox_chan *chan,
+				 struct ofnode_phandle_args *args)
+{
+	struct k3_sec_proxy_mbox *spm = dev_get_priv(chan->dev);
+	int ind, i;
+
+	debug("%s(chan=%p)\n", __func__, chan);
+
+	if (args->args_count != 1) {
+		debug("Invaild args_count: %d\n", args->args_count);
+		return -EINVAL;
+	}
+	ind = args->args[0];
+
+	for (i = 0; i < spm->desc->num_valid_threads; i++)
+		if (spm->chans[i].id == ind) {
+			chan->id = ind;
+			chan->con_priv = &spm->chans[i];
+			return 0;
+		}
+
+	dev_err(chan->dev, "%s: Invalid Thread ID %d\n", __func__, ind);
+	return -ENOENT;
+}
+
+/**
+ * k3_sec_proxy_request() - Request for mailbox channel
+ * @chan:	Channel Pointer
+ */
+static int k3_sec_proxy_request(struct mbox_chan *chan)
+{
+	debug("%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)
+{
+	debug("%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 k3_sec_proxy_thread *spt,
+					     u8 dir)
+{
+	/* Check for any errors already available */
+	if (sp_readl(spt->rt, RT_THREAD_STATUS) &
+	    RT_THREAD_STATUS_ERROR_MASK) {
+		printf("%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)
+			printf("%s: Trying to receive data on tx Thread %d\n",
+			       __func__, spt->id);
+		else
+			printf("%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 k3_sec_proxy_mbox *spm = dev_get_priv(chan->dev);
+	struct k3_sec_proxy_thread *spt = chan->con_priv;
+	int num_words, trail_bytes, ret;
+	void __iomem *data_reg;
+	u32 *word_data;
+
+	debug("%s(chan=%p, data=%p)\n", __func__, chan, data);
+
+	ret = k3_sec_proxy_verify_thread(spt, THREAD_IS_TX);
+	if (ret) {
+		dev_err(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) {
+		printf("%s: Thread %ld message length %zu > max msg size %d\n",
+		       __func__, chan->id, 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);
+
+	debug("%s: Message successfully sent on thread %ld\n",
+	      __func__, chan->id);
+
+	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 k3_sec_proxy_mbox *spm = dev_get_priv(chan->dev);
+	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;
+
+	debug("%s(chan=%p, data=%p)\n", __func__, chan, data);
+
+	ret = k3_sec_proxy_verify_thread(spt, 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);
+
+	debug("%s: Message successfully received from thread %ld\n",
+	      __func__, chan->id);
+
+	return 0;
+}
+
+struct mbox_ops k3_sec_proxy_mbox_ops = {
+	.of_xlate = k3_sec_proxy_of_xlate,
+	.request = k3_sec_proxy_request,
+	.free = k3_sec_proxy_free,
+	.send = k3_sec_proxy_send,
+	.recv = k3_sec_proxy_recv,
+};
+
+/**
+ * k3_sec_proxy_of_to_priv() - generate private data from device tree
+ * @dev:	corresponding k3 secure proxy device
+ * @spm:	pointer to driver specific private data
+ *
+ * Return: 0 if all went ok, else corresponding error message.
+ */
+static int k3_sec_proxy_of_to_priv(struct udevice *dev,
+				   struct k3_sec_proxy_mbox *spm)
+{
+	const void *blob = gd->fdt_blob;
+
+	if (!blob) {
+		debug("'%s' no dt?\n", dev->name);
+		return -ENODEV;
+	}
+
+	spm->target_data = devfdt_get_addr_name(dev, "target_data");
+	if (spm->target_data == FDT_ADDR_T_NONE) {
+		dev_err(dev, "No reg property for target data base\n");
+		return -EINVAL;
+	}
+
+	spm->scfg = devfdt_get_addr_name(dev, "scfg");
+	if (spm->rt == FDT_ADDR_T_NONE) {
+		dev_err(dev, "No reg property for Secure Cfg base\n");
+		return -EINVAL;
+	}
+
+	spm->rt = devfdt_get_addr_name(dev, "rt");
+	if (spm->rt == FDT_ADDR_T_NONE) {
+		dev_err(dev, "No reg property for Real Time Cfg base\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * 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->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 = calloc(1, spm->desc->max_msg_size);
+		if (!spt->rx_buf)
+			return -ENOMEM;
+	}
+
+	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 udevice *dev)
+{
+	struct k3_sec_proxy_mbox *spm = dev_get_priv(dev);
+	int ret;
+
+	debug("%s(dev=%p)\n", __func__, dev);
+
+	ret = k3_sec_proxy_of_to_priv(dev, spm);
+	if (ret)
+		return ret;
+
+	spm->desc = (void *)dev_get_driver_data(dev);
+	spm->chans = calloc(spm->desc->num_valid_threads,
+			    sizeof(struct k3_sec_proxy_thread));
+	if (!spm->chans)
+		return -ENOMEM;
+
+	ret = k3_sec_proxy_thread_setup(spm);
+	if (ret) {
+		debug("%s: secure proxy thread setup failed\n", __func__);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int k3_sec_proxy_remove(struct udevice *dev)
+{
+	struct k3_sec_proxy_mbox *spm = dev_get_priv(dev);
+
+	debug("%s(dev=%p)\n", __func__, dev);
+
+	free(spm->chans);
+
+	return 0;
+}
+
+/*
+ * Thread ID #4: ROM request
+ * Thread ID #5: ROM response, SYSFW notify
+ * Thread ID #6: SYSFW request response
+ * Thread ID #7: SYSFW request high priority
+ * Thread ID #8: SYSFW request low priority
+ * Thread ID #9: SYSFW notify response
+ */
+static const u32 am6x_valid_threads[] = { 4, 5, 6, 7, 8, 9, 11, 13 };
+
+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 udevice_id k3_sec_proxy_ids[] = {
+	{ .compatible = "ti,am654-secure-proxy", .data = (ulong)&am654_desc},
+	{ }
+};
+
+U_BOOT_DRIVER(k3_sec_proxy) = {
+	.name = "k3-secure-proxy",
+	.id = UCLASS_MAILBOX,
+	.of_match = k3_sec_proxy_ids,
+	.probe = k3_sec_proxy_probe,
+	.remove = k3_sec_proxy_remove,
+	.priv_auto_alloc_size = sizeof(struct k3_sec_proxy_mbox),
+	.ops = &k3_sec_proxy_mbox_ops,
+};