1 files changed, 337 insertions, 51 deletions

diff --git a/drivers/mailbox/arm_mhu.c b/drivers/mailbox/arm_mhu.c
index 99befa76e37c..4ed389d8f3dd 100644
--- a/drivers/mailbox/arm_mhu.c
+++ b/drivers/mailbox/arm_mhu.c
@@ -13,16 +13,16 @@
  * GNU General Public License for more details.
  */
 
-#include <linux/interrupt.h>
-#include <linux/spinlock.h>
-#include <linux/mutex.h>
-#include <linux/delay.h>
-#include <linux/slab.h>
+#include <linux/amba/bus.h>
+#include <linux/device.h>
 #include <linux/err.h>
+#include <linux/interrupt.h>
 #include <linux/io.h>
-#include <linux/module.h>
-#include <linux/amba/bus.h>
+#include <linux/kernel.h>
 #include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #define INTR_STAT_OFS	0x0
 #define INTR_SET_OFS	0x8
@@ -33,7 +33,8 @@
 #define MHU_SEC_OFFSET	0x200
 #define TX_REG_OFFSET	0x100
 
-#define MHU_CHANS	3
+#define MHU_NUM_PCHANS	3	/* Secure, Non-Secure High and Low Priority */
+#define MHU_CHAN_MAX	20	/* Max channels to save on unused RAM */
 
 struct mhu_link {
 	unsigned irq;
@@ -43,88 +44,341 @@ struct mhu_link {
 
 struct arm_mhu {
 	void __iomem *base;
-	struct mhu_link mlink[MHU_CHANS];
-	struct mbox_chan chan[MHU_CHANS];
+	struct mhu_link mlink[MHU_NUM_PCHANS];
 	struct mbox_controller mbox;
+	struct device *dev;
+	const char *name;
+};
+
+/**
+ * ARM MHU Mailbox platform specific configuration
+ *
+ * @num_pchans: Maximum number of physical channels
+ * @num_doorbells: Maximum number of doorbells per physical channel
+ */
+struct mhu_mbox_pdata {
+	unsigned int num_pchans;
+	unsigned int num_doorbells;
+	bool support_doorbells;
+};
+
+/**
+ * ARM MHU Mailbox allocated channel information
+ *
+ * @mhu: Pointer to parent mailbox device
+ * @pchan: Physical channel within which this doorbell resides in
+ * @doorbell: doorbell number pertaining to this channel
+ */
+struct mhu_channel {
+	struct arm_mhu *mhu;
+	unsigned int pchan;
+	unsigned int doorbell;
 };
 
+static inline struct mbox_chan *
+mhu_mbox_to_channel(struct mbox_controller *mbox,
+		    unsigned int pchan, unsigned int doorbell)
+{
+	int i;
+	struct mhu_channel *chan_info;
+
+	for (i = 0; i < mbox->num_chans; i++) {
+		chan_info = mbox->chans[i].con_priv;
+		if (chan_info && chan_info->pchan == pchan &&
+		    chan_info->doorbell == doorbell)
+			return &mbox->chans[i];
+	}
+
+	dev_err(mbox->dev,
+		"Channel not registered: physical channel: %d doorbell: %d\n",
+		pchan, doorbell);
+
+	return NULL;
+}
+
+static void mhu_mbox_clear_irq(struct mbox_chan *chan)
+{
+	struct mhu_channel *chan_info = chan->con_priv;
+	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].rx_reg;
+
+	writel_relaxed(BIT(chan_info->doorbell), base + INTR_CLR_OFS);
+}
+
+static unsigned int mhu_mbox_irq_to_pchan_num(struct arm_mhu *mhu, int irq)
+{
+	unsigned int pchan;
+	struct mhu_mbox_pdata *pdata = dev_get_platdata(mhu->dev);
+
+	for (pchan = 0; pchan < pdata->num_pchans; pchan++)
+		if (mhu->mlink[pchan].irq == irq)
+			break;
+	return pchan;
+}
+
+static struct mbox_chan *mhu_mbox_irq_to_channel(struct arm_mhu *mhu,
+						 unsigned int pchan)
+{
+	unsigned long bits;
+	unsigned int doorbell;
+	struct mbox_chan *chan = NULL;
+	struct mbox_controller *mbox = &mhu->mbox;
+	void __iomem *base = mhu->mlink[pchan].rx_reg;
+
+	bits = readl_relaxed(base + INTR_STAT_OFS);
+	if (!bits)
+		/* No IRQs fired in specified physical channel */
+		return NULL;
+
+	/* An IRQ has fired, find the associated channel */
+	for (doorbell = 0; bits; doorbell++) {
+		if (!test_and_clear_bit(doorbell, &bits))
+			continue;
+
+		chan = mhu_mbox_to_channel(mbox, pchan, doorbell);
+		if (chan)
+			break;
+	}
+
+	return chan;
+}
+
+static irqreturn_t mhu_mbox_thread_handler(int irq, void *data)
+{
+	struct mbox_chan *chan;
+	struct arm_mhu *mhu = data;
+	unsigned int pchan = mhu_mbox_irq_to_pchan_num(mhu, irq);
+
+	while (NULL != (chan = mhu_mbox_irq_to_channel(mhu, pchan))) {
+		mbox_chan_received_data(chan, NULL);
+		mhu_mbox_clear_irq(chan);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static bool mhu_doorbell_last_tx_done(struct mbox_chan *chan)
+{
+	struct mhu_channel *chan_info = chan->con_priv;
+	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;
+
+	if (readl_relaxed(base + INTR_STAT_OFS) & BIT(chan_info->doorbell))
+		return false;
+
+	return true;
+}
+
+static int mhu_doorbell_send_data(struct mbox_chan *chan, void *data)
+{
+	struct mhu_channel *chan_info = chan->con_priv;
+	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;
+
+	/* Send event to co-processor */
+	writel_relaxed(BIT(chan_info->doorbell), base + INTR_SET_OFS);
+
+	return 0;
+}
+
+static int mhu_doorbell_startup(struct mbox_chan *chan)
+{
+	mhu_mbox_clear_irq(chan);
+	return 0;
+}
+
+static void mhu_doorbell_shutdown(struct mbox_chan *chan)
+{
+	struct mhu_channel *chan_info = chan->con_priv;
+	struct mbox_controller *mbox = &chan_info->mhu->mbox;
+	int i;
+
+	for (i = 0; i < mbox->num_chans; i++)
+		if (chan == &mbox->chans[i])
+			break;
+
+	if (mbox->num_chans == i) {
+		dev_warn(mbox->dev, "Request to free non-existent channel\n");
+		return;
+	}
+
+	/* Reset channel */
+	mhu_mbox_clear_irq(chan);
+	chan->con_priv = NULL;
+}
+
+static struct mbox_chan *mhu_mbox_xlate(struct mbox_controller *mbox,
+					const struct of_phandle_args *spec)
+{
+	struct arm_mhu *mhu = dev_get_drvdata(mbox->dev);
+	struct mhu_mbox_pdata *pdata = dev_get_platdata(mhu->dev);
+	struct mhu_channel *chan_info;
+	struct mbox_chan *chan = NULL;
+	unsigned int pchan = spec->args[0];
+	unsigned int doorbell = pdata->support_doorbells ? spec->args[1] : 0;
+	int i;
+
+	/* Bounds checking */
+	if (pchan >= pdata->num_pchans || doorbell >= pdata->num_doorbells) {
+		dev_err(mbox->dev,
+			"Invalid channel requested pchan: %d doorbell: %d\n",
+			pchan, doorbell);
+		return ERR_PTR(-EINVAL);
+	}
+
+	for (i = 0; i < mbox->num_chans; i++) {
+		chan_info = mbox->chans[i].con_priv;
+
+		/* Is requested channel free? */
+		if (chan_info &&
+		    mbox->dev == chan_info->mhu->dev &&
+		    pchan == chan_info->pchan &&
+		    doorbell == chan_info->doorbell) {
+			dev_err(mbox->dev, "Channel in use\n");
+			return ERR_PTR(-EBUSY);
+		}
+
+		/*
+		 * Find the first free slot, then continue checking
+		 * to see if requested channel is in use
+		 */
+		if (!chan && !chan_info)
+			chan = &mbox->chans[i];
+	}
+
+	if (!chan) {
+		dev_err(mbox->dev, "No free channels left\n");
+		return ERR_PTR(-EBUSY);
+	}
+
+	chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL);
+	if (!chan_info)
+		return ERR_PTR(-ENOMEM);
+
+	chan_info->mhu = mhu;
+	chan_info->pchan = pchan;
+	chan_info->doorbell = doorbell;
+
+	chan->con_priv = chan_info;
+
+	dev_dbg(mbox->dev, "mbox: %s, created channel phys: %d doorbell: %d\n",
+		mhu->name, pchan, doorbell);
+
+	return chan;
+}
+
 static irqreturn_t mhu_rx_interrupt(int irq, void *p)
 {
-	struct mbox_chan *chan = p;
-	struct mhu_link *mlink = chan->con_priv;
+	struct arm_mhu *mhu = p;
+	unsigned int pchan = mhu_mbox_irq_to_pchan_num(mhu, irq);
+	struct mbox_chan *chan = mhu_mbox_to_channel(&mhu->mbox, pchan, 0);
+	void __iomem *base = mhu->mlink[pchan].rx_reg;
 	u32 val;
 
-	val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS);
+	val = readl_relaxed(base + INTR_STAT_OFS);
 	if (!val)
 		return IRQ_NONE;
 
 	mbox_chan_received_data(chan, (void *)&val);
 
-	writel_relaxed(val, mlink->rx_reg + INTR_CLR_OFS);
+	writel_relaxed(val, base + INTR_CLR_OFS);
 
 	return IRQ_HANDLED;
 }
 
 static bool mhu_last_tx_done(struct mbox_chan *chan)
 {
-	struct mhu_link *mlink = chan->con_priv;
-	u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+	struct mhu_channel *chan_info = chan->con_priv;
+	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;
+	u32 val = readl_relaxed(base + INTR_STAT_OFS);
 
 	return (val == 0);
 }
 
 static int mhu_send_data(struct mbox_chan *chan, void *data)
 {
-	struct mhu_link *mlink = chan->con_priv;
+	struct mhu_channel *chan_info = chan->con_priv;
+	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;
 	u32 *arg = data;
 
-	writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS);
+	writel_relaxed(*arg, base + INTR_SET_OFS);
 
 	return 0;
 }
 
 static int mhu_startup(struct mbox_chan *chan)
 {
-	struct mhu_link *mlink = chan->con_priv;
+	struct mhu_channel *chan_info = chan->con_priv;
+	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;
 	u32 val;
-	int ret;
-
-	val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
-	writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS);
 
-	ret = request_irq(mlink->irq, mhu_rx_interrupt,
-			  IRQF_SHARED, "mhu_link", chan);
-	if (ret) {
-		dev_err(chan->mbox->dev,
-			"Unable to acquire IRQ %d\n", mlink->irq);
-		return ret;
-	}
+	val = readl_relaxed(base + INTR_STAT_OFS);
+	writel_relaxed(val, base + INTR_CLR_OFS);
 
 	return 0;
 }
 
-static void mhu_shutdown(struct mbox_chan *chan)
-{
-	struct mhu_link *mlink = chan->con_priv;
-
-	free_irq(mlink->irq, chan);
-}
-
 static const struct mbox_chan_ops mhu_ops = {
 	.send_data = mhu_send_data,
 	.startup = mhu_startup,
-	.shutdown = mhu_shutdown,
 	.last_tx_done = mhu_last_tx_done,
 };
 
+static const struct mbox_chan_ops mhu_doorbell_ops = {
+	.send_data = mhu_doorbell_send_data,
+	.startup = mhu_doorbell_startup,
+	.shutdown = mhu_doorbell_shutdown,
+	.last_tx_done = mhu_doorbell_last_tx_done,
+};
+
+static const struct mhu_mbox_pdata arm_mhu_pdata = {
+	.num_pchans = 3,
+	.num_doorbells = 1,
+	.support_doorbells = false,
+};
+
+static const struct mhu_mbox_pdata arm_mhu_doorbell_pdata = {
+	.num_pchans = 2,	/* Secure can't be used */
+	.num_doorbells = 32,
+	.support_doorbells = true,
+};
+
 static int mhu_probe(struct amba_device *adev, const struct amba_id *id)
 {
-	int i, err;
+	u32 cell_count;
+	int i, err, max_chans;
+	irq_handler_t handler;
 	struct arm_mhu *mhu;
+	struct mbox_chan *chans;
+	struct mhu_mbox_pdata *pdata;
 	struct device *dev = &adev->dev;
-	int mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET};
+	struct device_node *np = dev->of_node;
+	int mhu_reg[MHU_NUM_PCHANS] = {
+		MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET,
+	};
+
+	err = of_property_read_u32(np, "#mbox-cells", &cell_count);
+	if (err) {
+		dev_err(dev, "failed to read #mbox-cells in %s\n",
+			np->full_name);
+		return err;
+	}
+
+	if (cell_count == 1) {
+		max_chans = MHU_NUM_PCHANS;
+		pdata = (struct mhu_mbox_pdata *)&arm_mhu_pdata;
+	} else if (cell_count == 2) {
+		max_chans = MHU_CHAN_MAX;
+		pdata = (struct mhu_mbox_pdata *)&arm_mhu_doorbell_pdata;
+	} else {
+		dev_err(dev, "incorrect value of #mbox-cells in %s\n",
+			np->full_name);
+		return -EINVAL;
+	}
+
+	if (pdata->num_pchans > MHU_NUM_PCHANS) {
+		dev_err(dev, "Number of physical channel can't exceed %d\n",
+			MHU_NUM_PCHANS);
+		return -EINVAL;
+	}
 
-	/* Allocate memory for device */
 	mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
 	if (!mhu)
 		return -ENOMEM;
@@ -135,30 +389,62 @@ static int mhu_probe(struct amba_device *adev, const struct amba_id *id)
 		return PTR_ERR(mhu->base);
 	}
 
-	for (i = 0; i < MHU_CHANS; i++) {
-		mhu->chan[i].con_priv = &mhu->mlink[i];
-		mhu->mlink[i].irq = adev->irq[i];
-		mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i];
-		mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;
-	}
+	err = of_property_read_string(np, "mbox-name", &mhu->name);
+	if (err)
+		mhu->name = np->full_name;
+
+	chans = devm_kcalloc(dev, max_chans, sizeof(*chans), GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+
+	dev->platform_data = pdata;
 
+	mhu->dev = dev;
 	mhu->mbox.dev = dev;
-	mhu->mbox.chans = &mhu->chan[0];
-	mhu->mbox.num_chans = MHU_CHANS;
-	mhu->mbox.ops = &mhu_ops;
+	mhu->mbox.chans = chans;
+	mhu->mbox.num_chans = max_chans;
 	mhu->mbox.txdone_irq = false;
 	mhu->mbox.txdone_poll = true;
 	mhu->mbox.txpoll_period = 1;
 
+	mhu->mbox.of_xlate = mhu_mbox_xlate;
 	amba_set_drvdata(adev, mhu);
 
+	if (pdata->support_doorbells) {
+		mhu->mbox.ops = &mhu_doorbell_ops;
+		handler = mhu_mbox_thread_handler;
+	} else {
+		mhu->mbox.ops = &mhu_ops;
+		handler = mhu_rx_interrupt;
+	}
+
 	err = mbox_controller_register(&mhu->mbox);
 	if (err) {
 		dev_err(dev, "Failed to register mailboxes %d\n", err);
 		return err;
 	}
 
-	dev_info(dev, "ARM MHU Mailbox registered\n");
+	for (i = 0; i < pdata->num_pchans; i++) {
+		int irq = mhu->mlink[i].irq = adev->irq[i];
+
+		if (irq <= 0) {
+			dev_dbg(dev, "No IRQ found for Channel %d\n", i);
+			continue;
+		}
+
+		mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i];
+		mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;
+
+		err = devm_request_threaded_irq(dev, irq, NULL, handler,
+						IRQF_ONESHOT, "mhu_link", mhu);
+		if (err) {
+			dev_err(dev, "Can't claim IRQ %d\n", irq);
+			mbox_controller_unregister(&mhu->mbox);
+			return err;
+		}
+	}
+
+	dev_info(dev, "%s mailbox registered\n", mhu->name);
 	return 0;
 }