[RFC,6/8] mailbox: ti-msgmgr: Add support for Secure Proxy

diff --git a/drivers/mailbox/ti-msgmgr.c b/drivers/mailbox/ti-msgmgr.c
index a37d6a4b392f..3e30b80c6401 100644
--- a/drivers/mailbox/ti-msgmgr.c
+++ b/drivers/mailbox/ti-msgmgr.c
@@ -25,6 +25,17 @@ 
 #define Q_STATE_OFFSET(queue)			((queue) * 0x4)
 #define Q_STATE_ENTRY_COUNT_MASK		(0xFFF000)
 
+#define SPROXY_THREAD_OFFSET(tid) (0x1000 * (tid))
+#define SPROXY_THREAD_DATA_OFFSET(tid, reg) \
+	(SPROXY_THREAD_OFFSET(tid) + ((reg) * 0x4) + 0x4)
+
+#define SPROXY_THREAD_STATUS_OFFSET(tid) (SPROXY_THREAD_OFFSET(tid))
+
+#define SPROXY_THREAD_STATUS_COUNT_MASK (0xFF)
+
+#define SPROXY_THREAD_CTRL_OFFSET(tid) (0x1000 + SPROXY_THREAD_OFFSET(tid))
+#define SPROXY_THREAD_CTRL_DIR_MASK (0x1 << 31)
+
 /**
  * struct ti_msgmgr_valid_queue_desc - SoC valid queues meant for this processor
  * @queue_id:	Queue Number for this path
@@ -45,12 +56,15 @@  struct ti_msgmgr_valid_queue_desc {
  * @data_first_reg:	First data register for proxy data region
  * @data_last_reg:	Last data register for proxy data region
  * @status_cnt_mask:	Mask for getting the status value
+ * @status_err_mask:	Mask for getting the error value, if applicable
  * @tx_polled:		Do I need to use polled mechanism for tx
  * @tx_poll_timeout_ms: Timeout in ms if polled
  * @valid_queues:	List of Valid queues that the processor can access
  * @data_region_name:	Name of the proxy data region
  * @status_region_name:	Name of the proxy status region
+ * @ctrl_region_name:	Name of the proxy control region
  * @num_valid_queues:	Number of valid queues
+ * @is_sproxy:		Is this an Secure Proxy instance?
  *
  * This structure is used in of match data to describe how integration
  * for a specific compatible SoC is done.
@@ -62,12 +76,15 @@  struct ti_msgmgr_desc {
 	u8 data_first_reg;
 	u8 data_last_reg;
 	u32 status_cnt_mask;
+	u32 status_err_mask;
 	bool tx_polled;
 	int tx_poll_timeout_ms;
 	const struct ti_msgmgr_valid_queue_desc *valid_queues;
 	const char *data_region_name;
 	const char *status_region_name;
+	const char *ctrl_region_name;
 	int num_valid_queues;
+	bool is_sproxy;
 };
 
 /**
@@ -80,6 +97,7 @@  struct ti_msgmgr_desc {
  * @queue_buff_start: First register of Data Buffer
  * @queue_buff_end: Last (or confirmation) register of Data buffer
  * @queue_state: Queue status register
+ * @queue_ctrl: Queue Control register
  * @chan:	Mailbox channel
  * @rx_buff:	Receive buffer pointer allocated at probe, max_message_size
  */
@@ -92,6 +110,7 @@  struct ti_queue_inst {
 	void __iomem *queue_buff_start;
 	void __iomem *queue_buff_end;
 	void __iomem *queue_state;
+	void __iomem *queue_ctrl;
 	struct mbox_chan *chan;
 	u32 *rx_buff;
 };
@@ -102,6 +121,7 @@  struct ti_queue_inst {
  * @desc:	Description of the SoC integration
  * @queue_proxy_region:	Queue proxy region where queue buffers are located
  * @queue_state_debug_region:	Queue status register regions
+ * @queue_ctrl_region:	Queue Control register regions
  * @num_valid_queues:	Number of valid queues defined for the processor
  *		Note: other queues are probably reserved for other processors
  *		in the SoC.
@@ -114,6 +134,7 @@  struct ti_msgmgr_inst {
 	const struct ti_msgmgr_desc *desc;
 	void __iomem *queue_proxy_region;
 	void __iomem *queue_state_debug_region;
+	void __iomem *queue_ctrl_region;
 	u8 num_valid_queues;
 	struct ti_queue_inst *qinsts;
 	struct mbox_controller mbox;
@@ -144,6 +165,31 @@  ti_msgmgr_queue_get_num_messages(const struct ti_msgmgr_desc *d,
 	return val;
 }
 
+/**
+ * ti_msgmgr_queue_is_error() - Check to see if there is queue error
+ * @d:		Description of message manager
+ * @qinst:	Queue instance for which we check the number of pending messages
+ *
+ * Return: true if error, else false
+ */
+static inline bool ti_msgmgr_queue_is_error(const struct ti_msgmgr_desc *d,
+					    struct ti_queue_inst *qinst)
+{
+	u32 val;
+
+	/* Msgmgr has no error detection */
+	if (!d->is_sproxy)
+		return false;
+
+	/*
+	 * We cannot use relaxed operation here - update may happen
+	 * real-time.
+	 */
+	val = readl(qinst->queue_state) & d->status_err_mask;
+
+	return val ? true : false;
+}
+
 /**
  * ti_msgmgr_queue_rx_interrupt() - Interrupt handler for receive Queue
  * @irq:	Interrupt number
@@ -178,6 +224,11 @@  static irqreturn_t ti_msgmgr_queue_rx_interrupt(int irq, void *p)
 	}
 
 	desc = inst->desc;
+	if (ti_msgmgr_queue_is_error(desc, qinst)) {
+		dev_err(dev, "Error on Rx channel %s\n", qinst->name);
+		return IRQ_NONE;
+	}
+
 	/* Do I actually have messages to read? */
 	msg_count = ti_msgmgr_queue_get_num_messages(desc, qinst);
 	if (!msg_count) {
@@ -236,12 +287,18 @@  static bool ti_msgmgr_queue_peek_data(struct mbox_chan *chan)
 	struct ti_queue_inst *qinst = chan->con_priv;
 	struct device *dev = chan->mbox->dev;
 	struct ti_msgmgr_inst *inst = dev_get_drvdata(dev);
+	const struct ti_msgmgr_desc *desc = inst->desc;
 	int msg_count;
 
 	if (qinst->is_tx)
 		return false;
 
-	msg_count = ti_msgmgr_queue_get_num_messages(inst->desc, qinst);
+	if (ti_msgmgr_queue_is_error(desc, qinst)) {
+		dev_err(dev, "Error on channel %s\n", qinst->name);
+		return false;
+	}
+
+	msg_count = ti_msgmgr_queue_get_num_messages(desc, qinst);
 
 	return msg_count ? true : false;
 }
@@ -257,12 +314,23 @@  static bool ti_msgmgr_last_tx_done(struct mbox_chan *chan)
 	struct ti_queue_inst *qinst = chan->con_priv;
 	struct device *dev = chan->mbox->dev;
 	struct ti_msgmgr_inst *inst = dev_get_drvdata(dev);
+	const struct ti_msgmgr_desc *desc = inst->desc;
 	int msg_count;
 
 	if (!qinst->is_tx)
 		return false;
 
-	msg_count = ti_msgmgr_queue_get_num_messages(inst->desc, qinst);
+	if (ti_msgmgr_queue_is_error(desc, qinst)) {
+		dev_err(dev, "Error on channel %s\n", qinst->name);
+		return false;
+	}
+
+	msg_count = ti_msgmgr_queue_get_num_messages(desc, qinst);
+
+	if (desc->is_sproxy) {
+		/* In secure proxy, msg_count indicates how many we can send */
+		return msg_count ? true : false;
+	}
 
 	/* if we have any messages pending.. */
 	return msg_count ? false : true;
@@ -292,6 +360,11 @@  static int ti_msgmgr_send_data(struct mbox_chan *chan, void *data)
 	}
 	desc = inst->desc;
 
+	if (ti_msgmgr_queue_is_error(desc, qinst)) {
+		dev_err(dev, "Error on channel %s\n", qinst->name);
+		return false;
+	}
+
 	if (desc->max_message_size < message->len) {
 		dev_err(dev, "Queue %s message length %zu > max %d\n",
 			qinst->name, message->len, desc->max_message_size);
@@ -327,10 +400,12 @@  static int ti_msgmgr_send_data(struct mbox_chan *chan, void *data)
 /**
  *  ti_msgmgr_queue_rx_irq_req() - RX IRQ request
  *  @dev:	device pointer
+ *  @d:		descriptor for ti_msgmgr
  *  @qinst:	Queue instance
  *  @chan:	Channel pointer
  */
 static int ti_msgmgr_queue_rx_irq_req(struct device *dev,
+				      const struct ti_msgmgr_desc *d,
 				      struct ti_queue_inst *qinst,
 				      struct mbox_chan *chan)
 {
@@ -339,7 +414,7 @@  static int ti_msgmgr_queue_rx_irq_req(struct device *dev,
 	struct device_node *np;
 
 	snprintf(of_rx_irq_name, sizeof(of_rx_irq_name),
-		 "rx_%03d", qinst->queue_id);
+		 "rx_%03d", d->is_sproxy ? qinst->proxy_id : qinst->queue_id);
 
 	/* Get the IRQ if not found */
 	if (qinst->irq < 0) {
@@ -382,6 +457,24 @@  static int ti_msgmgr_queue_startup(struct mbox_chan *chan)
 	struct ti_queue_inst *qinst = chan->con_priv;
 	const struct ti_msgmgr_desc *d = inst->desc;
 	int ret;
+	int msg_count;
+
+	/*
+	 * If sproxy is starting and can send messages, we are a Tx thread,
+	 * else Rx
+	 */
+	if (d->is_sproxy) {
+		qinst->is_tx = (readl(qinst->queue_ctrl) &
+				SPROXY_THREAD_CTRL_DIR_MASK) ? false : true;
+
+		msg_count = ti_msgmgr_queue_get_num_messages(d, qinst);
+
+		if (!msg_count && qinst->is_tx) {
+			dev_err(dev, "%s: Cannot transmit with 0 credits!\n",
+				qinst->name);
+			return -EINVAL;
+		}
+	}
 
 	if (!qinst->is_tx) {
 		/* Allocate usage buffer for rx */
@@ -389,7 +482,7 @@  static int ti_msgmgr_queue_startup(struct mbox_chan *chan)
 		if (!qinst->rx_buff)
 			return -ENOMEM;
 		/* Request IRQ */
-		ret = ti_msgmgr_queue_rx_irq_req(dev, qinst, chan);
+		ret = ti_msgmgr_queue_rx_irq_req(dev, d, qinst, chan);
 		if (ret) {
 			kfree(qinst->rx_buff);
 			return ret;
@@ -427,20 +520,38 @@  static struct mbox_chan *ti_msgmgr_of_xlate(struct mbox_controller *mbox,
 	struct ti_msgmgr_inst *inst;
 	int req_qid, req_pid;
 	struct ti_queue_inst *qinst;
-	int i;
+	const struct ti_msgmgr_desc *d;
+	int i, ncells;
 
 	inst = container_of(mbox, struct ti_msgmgr_inst, mbox);
 	if (WARN_ON(!inst))
 		return ERR_PTR(-EINVAL);
 
-	/* #mbox-cells is 2 */
-	if (p->args_count != 2) {
-		dev_err(inst->dev, "Invalid arguments in dt[%d] instead of 2\n",
-			p->args_count);
+	d = inst->desc;
+
+	if (d->is_sproxy)
+		ncells = 1;
+	else
+		ncells = 2;
+	if (p->args_count != ncells) {
+		dev_err(inst->dev, "Invalid arguments in dt[%d]. Must be %d\n",
+			p->args_count, ncells);
 		return ERR_PTR(-EINVAL);
 	}
-	req_qid = p->args[0];
-	req_pid = p->args[1];
+	if (ncells == 1) {
+		req_qid = 0;
+		req_pid = p->args[0];
+	} else {
+		req_qid = p->args[0];
+		req_pid = p->args[1];
+	}
+
+	if (d->is_sproxy) {
+		if (req_pid > d->num_valid_queues)
+			goto err;
+		qinst = &inst->qinsts[req_pid];
+		return qinst->chan;
+	}
 
 	for (qinst = inst->qinsts, i = 0; i < inst->num_valid_queues;
 	     i++, qinst++) {
@@ -448,6 +559,7 @@  static struct mbox_chan *ti_msgmgr_of_xlate(struct mbox_controller *mbox,
 			return qinst->chan;
 	}
 
+err:
 	dev_err(inst->dev, "Queue ID %d, Proxy ID %d is wrong on %s\n",
 		req_qid, req_pid, p->np->name);
 	return ERR_PTR(-ENOENT);
@@ -474,6 +586,8 @@  static int ti_msgmgr_queue_setup(int idx, struct device *dev,
 				 struct ti_queue_inst *qinst,
 				 struct mbox_chan *chan)
 {
+	char *dir;
+
 	qinst->proxy_id = qd->proxy_id;
 	qinst->queue_id = qd->queue_id;
 
@@ -483,17 +597,38 @@  static int ti_msgmgr_queue_setup(int idx, struct device *dev,
 		return -ERANGE;
 	}
 
-	qinst->is_tx = qd->is_tx;
-	snprintf(qinst->name, sizeof(qinst->name), "%s %s_%03d_%03d",
-		 dev_name(dev), qinst->is_tx ? "tx" : "rx", qinst->queue_id,
-		 qinst->proxy_id);
-
-	qinst->queue_buff_start = inst->queue_proxy_region +
-	    Q_DATA_OFFSET(qinst->proxy_id, qinst->queue_id, d->data_first_reg);
-	qinst->queue_buff_end = inst->queue_proxy_region +
-	    Q_DATA_OFFSET(qinst->proxy_id, qinst->queue_id, d->data_last_reg);
-	qinst->queue_state = inst->queue_state_debug_region +
-	    Q_STATE_OFFSET(qinst->queue_id);
+	if (d->is_sproxy) {
+		qinst->queue_buff_start = inst->queue_proxy_region +
+		    SPROXY_THREAD_DATA_OFFSET(qinst->proxy_id,
+					      d->data_first_reg);
+		qinst->queue_buff_end = inst->queue_proxy_region +
+		    SPROXY_THREAD_DATA_OFFSET(qinst->proxy_id,
+					      d->data_last_reg);
+		qinst->queue_state = inst->queue_state_debug_region +
+		    SPROXY_THREAD_STATUS_OFFSET(qinst->proxy_id);
+		qinst->queue_ctrl = inst->queue_ctrl_region +
+		    SPROXY_THREAD_CTRL_OFFSET(qinst->proxy_id);
+
+		/* XXX: DONOT read registers here!.. Some may be unusable */
+		dir = "thr";
+		snprintf(qinst->name, sizeof(qinst->name), "%s %s_%03d",
+			 dev_name(dev), dir, qinst->proxy_id);
+	} else {
+		qinst->queue_buff_start = inst->queue_proxy_region +
+		    Q_DATA_OFFSET(qinst->proxy_id, qinst->queue_id,
+				  d->data_first_reg);
+		qinst->queue_buff_end = inst->queue_proxy_region +
+		    Q_DATA_OFFSET(qinst->proxy_id, qinst->queue_id,
+				  d->data_last_reg);
+		qinst->queue_state =
+		    inst->queue_state_debug_region +
+		    Q_STATE_OFFSET(qinst->queue_id);
+		qinst->is_tx = qd->is_tx;
+		dir = qinst->is_tx ? "tx" : "rx";
+		snprintf(qinst->name, sizeof(qinst->name), "%s %s_%03d_%03d",
+			 dev_name(dev), dir, qinst->queue_id, qinst->proxy_id);
+	}
+
 	qinst->chan = chan;
 
 	/* Setup an error value for IRQ - Lazy allocation */
@@ -543,12 +678,29 @@  static const struct ti_msgmgr_desc k2g_desc = {
 	.tx_polled = false,
 	.valid_queues = k2g_valid_queues,
 	.num_valid_queues = ARRAY_SIZE(k2g_valid_queues),
+	.is_sproxy = false,
+};
+
+static const struct ti_msgmgr_desc am654_desc = {
+	.queue_count = 190,
+	.num_valid_queues = 190,
+	.max_message_size = 60,
+	.data_region_name = "target_data",
+	.status_region_name = "rt",
+	.ctrl_region_name = "scfg",
+	.data_first_reg = 0,
+	.data_last_reg = 14,
+	.status_cnt_mask = SPROXY_THREAD_STATUS_COUNT_MASK,
+	.tx_polled = false,
+	.is_sproxy = true,
 };
 
 static const struct of_device_id ti_msgmgr_of_match[] = {
 	{.compatible = "ti,k2g-message-manager", .data = &k2g_desc},
+	{.compatible = "ti,am654-secure-proxy", .data = &am654_desc},
 	{ /* Sentinel */ }
 };
+
 MODULE_DEVICE_TABLE(of, ti_msgmgr_of_match);
 
 static int ti_msgmgr_probe(struct platform_device *pdev)
@@ -599,6 +751,14 @@  static int ti_msgmgr_probe(struct platform_device *pdev)
 	if (IS_ERR(inst->queue_state_debug_region))
 		return PTR_ERR(inst->queue_state_debug_region);
 
+	if (desc->is_sproxy) {
+		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						   desc->ctrl_region_name);
+		inst->queue_ctrl_region = devm_ioremap_resource(dev, res);
+		if (IS_ERR(inst->queue_ctrl_region))
+			return PTR_ERR(inst->queue_ctrl_region);
+	}
+
 	dev_dbg(dev, "proxy region=%p, queue_state=%p\n",
 		inst->queue_proxy_region, inst->queue_state_debug_region);
 
@@ -620,12 +780,29 @@  static int ti_msgmgr_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	inst->chans = chans;
 
-	for (i = 0, queue_desc = desc->valid_queues;
-	     i < queue_count; i++, qinst++, chans++, queue_desc++) {
-		ret = ti_msgmgr_queue_setup(i, dev, np, inst,
-					    desc, queue_desc, qinst, chans);
-		if (ret)
-			return ret;
+	if (desc->is_sproxy) {
+		struct ti_msgmgr_valid_queue_desc sproxy_desc;
+
+		/* All proxies may be valid in Secure Proxy instance */
+		for (i = 0; i < queue_count; i++, qinst++, chans++) {
+			sproxy_desc.queue_id = 0;
+			sproxy_desc.proxy_id = i;
+			ret = ti_msgmgr_queue_setup(i, dev, np, inst,
+						    desc, &sproxy_desc, qinst,
+						    chans);
+			if (ret)
+				return ret;
+		}
+	} else {
+		/* Only Some proxies are valid in Message Manager */
+		for (i = 0, queue_desc = desc->valid_queues;
+		     i < queue_count; i++, qinst++, chans++, queue_desc++) {
+			ret = ti_msgmgr_queue_setup(i, dev, np, inst,
+						    desc, queue_desc, qinst,
+						    chans);
+			if (ret)
+				return ret;
+		}
 	}
 
 	mbox = &inst->mbox;