[PATCH v3 0/5] Mailbox: Provide support STi based platforms

[PATCH v3 0/5] Mailbox: Provide support STi based platforms

[Lee Jones]

ST's platforms currently support a maximum of 5 Mailboxes, one for
each of the supported co-processors situated on the platform.  Each
Mailbox is divided up into 4 instances which consist of 32 channels.
Messages are passed between the application and co-processors using
shared memory areas.

Also included in the set is an example Client which should be generic
enough to use as a testing environment for all Mailbox IPs which use
shared memory or the API to pass messages.  With small changes, it
should also be able to test more extravagant implementations.

v2 => v3:
 - Controller
   - Shared (DT <=> Device Driver) defines removed
   - Return actual error codes instead of NULL in xlate()
   - Not passing 'direction' configuration via DT anymore
     - Removed all accompanying configuration checking code
 - Test F/W
   - Allow Rx-only and Tx-only controllers to be tested
   - Cater for controllers requiring pre-Tx 'signal' to be sent
   - Supply 'wr-' message debugfs file
     - When written to, will Tx message through Mailbox Framework
     - When read from, will print out a hexdump of Rx'ed message
 
v1 => v2:
 - New MACRO() to obtain base address for a given instance
 - Move locking into the structure it protects
 - Stop checking for 'ready' state when sending data
 - Don't clear channel data (that belongs to the API)
 - #define register offsets instead of providing via pdata
 - Register driver with module_platform_driver()

Lee Jones (5):
  mailbox: dt: Supply bindings for ST's Mailbox IP
  mailbox: Add support for ST's Mailbox IP
  ARM: STi: stih407-family: Add nodes for Mailbox
  mailbox: Add generic mechanism for testing Mailbox Controllers
  ARM: STi: DT: STiH407: Enable Mailbox testing facility

 .../devicetree/bindings/mailbox/sti-mailbox.txt    |  52 +++
 arch/arm/boot/dts/stih407-family.dtsi              |  42 ++
 drivers/mailbox/Kconfig                            |  14 +
 drivers/mailbox/Makefile                           |   4 +
 drivers/mailbox/mailbox-sti.c                      | 516 +++++++++++++++++++++
 drivers/mailbox/mailbox-test.c                     | 361 ++++++++++++++
 6 files changed, 989 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/sti-mailbox.txt
 create mode 100644 drivers/mailbox/mailbox-sti.c
 create mode 100644 drivers/mailbox/mailbox-test.c

-- 
1.9.1

[PATCH v3 1/5] mailbox: dt: Supply bindings for ST's Mailbox IP

[Lee Jones]

Signed-off-by: Lee Jones <lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 .../devicetree/bindings/mailbox/sti-mailbox.txt    | 52 ++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/sti-mailbox.txt

diff --git a/Documentation/devicetree/bindings/mailbox/sti-mailbox.txt b/Documentation/devicetree/bindings/mailbox/sti-mailbox.txt
new file mode 100644
index 0000000..9fb4400
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/sti-mailbox.txt
@@ -0,0 +1,52 @@
+ST Microelectronics Mailbox Driver
+
+Each ST Mailbox IP currently consists of 4 instances of 32 channels.  Messages
+are passed between Application and Remote processors using shared memory.
+
+Controller
+----------
+
+Required properties:
+- compatible		: Should be "st,stih407-mailbox"
+- reg			: Offset and length of the device's register set
+- mbox-name		: Name of the mailbox
+- #mbox-cells:		: Must be 2
+			  <&phandle instance channel direction>
+			    phandle   : Label name of controller
+			    instance  : Instance number
+			    channel   : Channel number
+
+Optional properties
+- interrupts		: Contains the IRQ line for a Rx mailbox
+- tx-only		: Denotes Mailbox cannot receive messages
+
+Example:
+
+mailbox0: mailbox@0  {
+	compatible	= "st,stih407-mailbox";
+	reg		= <0x08f00000 0x1000>;
+	interrupts	= <GIC_SPI 1 IRQ_TYPE_NONE>;
+	#mbox-cells	= <2>;
+	mbox-name	= "a9";
+};
+
+Client
+------
+
+Required properties:
+- compatible		: Many (See the client docs)
+- reg			: Shared (between Application and Remote) memory address
+- mboxes		: Standard property to specify a Mailbox (See ./mailbox.txt)
+			  Cells must match 'mbox-cells' (See Controller docs above)
+
+Optional properties
+- mbox-names		: Name given to channels seen in the 'mboxes' property.
+
+Example:
+
+mailbox_test {
+	compatible	= "mailbox_test";
+	reg		= <0x[shared_memory_address], [shared_memory_size]>;
+	mboxes		= <&mailbox2 0 1>, <&mailbox0 2 1>;
+	mbox-names	= "tx",	"rx";
+};
-- 
1.9.1

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[PATCH v3 2/5] mailbox: Add support for ST's Mailbox IP

[Lee Jones]

ST's platforms currently support a maximum of 5 Mailboxes, one for
each of the supported co-processors situated on the platform.  Each
Mailbox is divided up into 4 instances which consist of 32 channels.
Messages are passed between the application and co-processors using
shared memory areas.  It is the Client's responsibility to manage
these areas.

Signed-off-by: Lee Jones <lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 drivers/mailbox/Kconfig       |   7 +
 drivers/mailbox/Makefile      |   2 +
 drivers/mailbox/mailbox-sti.c | 516 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 525 insertions(+)
 create mode 100644 drivers/mailbox/mailbox-sti.c

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index e269f08..2cc4c39 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -70,4 +70,11 @@ config BCM2835_MBOX
 	  the services of the Videocore. Say Y here if you want to use the
 	  BCM2835 Mailbox.
 
+config STI_MBOX
+	tristate "STI Mailbox framework support"
+	depends on ARCH_STI && OF
+	help
+	  Mailbox implementation for STMicroelectonics family chips with
+	  hardware for interprocessor communication.
+
 endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 8e6d822..7cb4766 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -13,3 +13,5 @@ obj-$(CONFIG_PCC)		+= pcc.o
 obj-$(CONFIG_ALTERA_MBOX)	+= mailbox-altera.o
 
 obj-$(CONFIG_BCM2835_MBOX)	+= bcm2835-mailbox.o
+
+obj-$(CONFIG_STI_MBOX)		+= mailbox-sti.o
diff --git a/drivers/mailbox/mailbox-sti.c b/drivers/mailbox/mailbox-sti.c
new file mode 100644
index 0000000..b1618d2
--- /dev/null
+++ b/drivers/mailbox/mailbox-sti.c
@@ -0,0 +1,516 @@
+/*
+ * STi Mailbox
+ *
+ * Copyright (C) 2015 ST Microelectronics
+ *
+ * Author: Lee Jones <lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> for ST Microelectronics
+ *
+ * Based on the original driver written by;
+ *   Alexandre Torgue, Olivier Lebreton and Loic Pallardy
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "mailbox.h"
+
+#define STI_MBOX_INST_MAX	4      /* RAM saving: Max supported instances */
+#define STI_MBOX_CHAN_MAX	20     /* RAM saving: Max supported channels  */
+
+#define STI_IRQ_VAL_OFFSET	0x04   /* Read interrupt status	              */
+#define STI_IRQ_SET_OFFSET	0x24   /* Generate a Tx channel interrupt     */
+#define STI_IRQ_CLR_OFFSET	0x44   /* Clear pending Rx interrupts	      */
+#define STI_ENA_VAL_OFFSET	0x64   /* Read enable status		      */
+#define STI_ENA_SET_OFFSET	0x84   /* Enable a channel		      */
+#define STI_ENA_CLR_OFFSET	0xa4   /* Disable a channel		      */
+
+#define MBOX_BASE(mdev, inst)   ((mdev)->base + (inst * 4))
+
+/**
+ * STi Mailbox device data
+ *
+ * An IP Mailbox is currently composed of 4 instances
+ * Each instance is currently composed of 32 channels
+ * This means that we have 128 channels per Mailbox
+ * A channel an be used for TX or RX
+ *
+ * @dev:	Device to which it is attached
+ * @mbox:	Representation of a communication channel controller
+ * @base:	Base address of the register mapping region
+ * @name:	Name of the mailbox
+ * @enabled:	Local copy of enabled channels
+ * @lock:	Mutex protecting enabled status
+ */
+struct sti_mbox_device {
+	struct device		*dev;
+	struct mbox_controller	*mbox;
+	void __iomem		*base;
+	const char		*name;
+	u32			enabled[STI_MBOX_INST_MAX];
+	spinlock_t		lock;
+	bool			txonly;
+};
+
+/**
+ * STi Mailbox platform specfic configuration
+ *
+ * @num_inst:	Maximum number of instances in one HW Mailbox
+ * @num_chan:	Maximum number of channel per instance
+ */
+struct sti_mbox_pdata {
+	unsigned int		num_inst;
+	unsigned int		num_chan;
+};
+
+/**
+ * STi Mailbox allocated channel information
+ *
+ * @mdev:	Pointer to parent Mailbox device
+ * @instance:	Instance number channel resides in
+ * @channel:	Channel number pertaining to this container
+ */
+struct sti_channel {
+	struct sti_mbox_device	*mdev;
+	unsigned int		instance;
+	unsigned int		channel;
+};
+
+static inline bool sti_mbox_channel_is_enabled(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+
+	return mdev->enabled[instance] & BIT(channel);
+}
+
+static inline
+struct mbox_chan *sti_mbox_to_channel(struct mbox_controller *mbox,
+				      unsigned int instance,
+				      unsigned int channel)
+{
+	struct sti_channel *chan_info;
+	int i;
+
+	for (i = 0; i < mbox->num_chans; i++) {
+		chan_info = mbox->chans[i].con_priv;
+		if (chan_info &&
+		    chan_info->instance == instance &&
+		    chan_info->channel == channel)
+			return &mbox->chans[i];
+	}
+
+	dev_err(mbox->dev,
+		"Channel not registered: instance: %d channel: %d\n",
+		instance, channel);
+
+	return NULL;
+}
+
+static void sti_mbox_enable_channel(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+	unsigned long flags;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	spin_lock_irqsave(&mdev->lock, flags);
+	mdev->enabled[instance] |= BIT(channel);
+	writel_relaxed(BIT(channel), base + STI_ENA_SET_OFFSET);
+	spin_unlock_irqrestore(&mdev->lock, flags);
+}
+
+static void sti_mbox_disable_channel(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+	unsigned long flags;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	spin_lock_irqsave(&mdev->lock, flags);
+	mdev->enabled[instance] &= ~BIT(channel);
+	writel_relaxed(BIT(channel), base + STI_ENA_CLR_OFFSET);
+	spin_unlock_irqrestore(&mdev->lock, flags);
+}
+
+static void sti_mbox_clear_irq(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	writel_relaxed(BIT(channel), base + STI_IRQ_CLR_OFFSET);
+}
+
+static struct mbox_chan *sti_mbox_irq_to_channel(struct sti_mbox_device *mdev,
+						 unsigned int instance)
+{
+	struct mbox_controller *mbox = mdev->mbox;
+	struct mbox_chan *chan = NULL;
+	unsigned int channel;
+	unsigned long bits;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	bits = readl_relaxed(base + STI_IRQ_VAL_OFFSET);
+	if (!bits)
+		/* No IRQs fired in specified instance */
+		return NULL;
+
+	/* An IRQ has fired, find the associated channel */
+	for (channel = 0; bits; channel++) {
+		if (!test_and_clear_bit(channel, &bits))
+			continue;
+
+		chan = sti_mbox_to_channel(mbox, instance, channel);
+		if (chan) {
+			dev_dbg(mbox->dev,
+				"IRQ fired on instance: %d channel: %d\n",
+				instance, channel);
+			break;
+		}
+	}
+
+	return chan;
+}
+
+static irqreturn_t sti_mbox_thread_handler(int irq, void *data)
+{
+	struct sti_mbox_device *mdev = data;
+	struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
+	struct mbox_chan *chan;
+	unsigned int instance;
+
+	for (instance = 0; instance < pdata->num_inst; instance++) {
+keep_looking:
+		chan = sti_mbox_irq_to_channel(mdev, instance);
+		if (!chan)
+			continue;
+
+		mbox_chan_received_data(chan, NULL);
+		sti_mbox_clear_irq(chan);
+		sti_mbox_enable_channel(chan);
+		goto keep_looking;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sti_mbox_irq_handler(int irq, void *data)
+{
+	struct sti_mbox_device *mdev = data;
+	struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
+	struct sti_channel *chan_info;
+	struct mbox_chan *chan;
+	unsigned int instance;
+	int ret = IRQ_NONE;
+
+	for (instance = 0; instance < pdata->num_inst; instance++) {
+		chan = sti_mbox_irq_to_channel(mdev, instance);
+		if (!chan)
+			continue;
+		chan_info = chan->con_priv;
+
+		if (!sti_mbox_channel_is_enabled(chan)) {
+			dev_warn(mdev->dev,
+				 "Unexpected IRQ: %s\n"
+				 "  instance: %d: channel: %d [enabled: %x]\n",
+				 mdev->name, chan_info->instance,
+				 chan_info->channel, mdev->enabled[instance]);
+
+			/* Only handle IRQ if no other valid IRQs were found */
+			if (ret == IRQ_NONE)
+				ret = IRQ_HANDLED;
+			continue;
+		}
+
+		sti_mbox_disable_channel(chan);
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	if (ret == IRQ_NONE)
+		dev_err(mdev->dev, "Spurious IRQ - was a channel requested?\n");
+
+	return ret;
+}
+
+static bool sti_mbox_tx_is_ready(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	if (!(readl_relaxed(base + STI_ENA_VAL_OFFSET) & BIT(channel))) {
+		dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d disabled\n",
+			mdev->name, instance, channel);
+		return false;
+	}
+
+	if (readl_relaxed(base + STI_IRQ_VAL_OFFSET) & BIT(channel)) {
+		dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d not ready\n",
+			mdev->name, instance, channel);
+		return false;
+	}
+
+	return true;
+}
+
+static int sti_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	/* Send event to co-processor */
+	writel_relaxed(BIT(channel), base + STI_IRQ_SET_OFFSET);
+
+	dev_dbg(mdev->dev,
+		"Sent via Mailbox %s: instance: %d channel: %d\n",
+		mdev->name, instance, channel);
+
+	return 0;
+}
+
+static int sti_mbox_startup_chan(struct mbox_chan *chan)
+{
+	sti_mbox_clear_irq(chan);
+	sti_mbox_enable_channel(chan);
+
+	return 0;
+}
+
+static void sti_mbox_shutdown_chan(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct mbox_controller *mbox = chan_info->mdev->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 */
+	sti_mbox_disable_channel(chan);
+	sti_mbox_clear_irq(chan);
+	chan->con_priv = NULL;
+}
+
+static struct mbox_chan *sti_mbox_xlate(struct mbox_controller *mbox,
+					const struct of_phandle_args *spec)
+{
+	struct sti_mbox_device *mdev = dev_get_drvdata(mbox->dev);
+	struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
+	struct sti_channel *chan_info;
+	struct mbox_chan *chan = NULL;
+	unsigned int instance  = spec->args[0];
+	unsigned int channel   = spec->args[1];
+	int i;
+
+	/* Bounds checking */
+	if (instance >= pdata->num_inst || channel  >= pdata->num_chan) {
+		dev_err(mbox->dev,
+			"Invalid channel requested instance: %d channel: %d\n",
+			instance, channel);
+		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->mdev->dev &&
+		    instance == chan_info->instance &&
+		    channel == chan_info->channel) {
+
+			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->mdev		= mdev;
+	chan_info->instance	= instance;
+	chan_info->channel	= channel;
+
+	chan->con_priv = chan_info;
+
+	dev_info(mbox->dev,
+		 "Mbox: %s: Created channel: instance: %d channel: %d\n",
+		 mdev->name, instance, channel);
+
+	return chan;
+}
+
+static struct mbox_chan_ops sti_mbox_ops = {
+	.startup	= sti_mbox_startup_chan,
+	.shutdown	= sti_mbox_shutdown_chan,
+	.send_data	= sti_mbox_send_data,
+	.last_tx_done	= sti_mbox_tx_is_ready,
+};
+
+static const struct sti_mbox_pdata mbox_stih407_pdata = {
+	.num_inst	= 4,
+	.num_chan	= 32,
+};
+
+static const struct of_device_id sti_mailbox_match[] = {
+	{
+		.compatible = "st,stih407-mailbox",
+		.data = (void *)&mbox_stih407_pdata
+	},
+	{ }
+};
+
+static int sti_mbox_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct mbox_controller *mbox;
+	struct sti_mbox_device *mdev;
+	struct device_node *np = pdev->dev.of_node;
+	struct mbox_chan *chans;
+	struct resource *res;
+	int irq;
+	int ret;
+
+	match = of_match_device(sti_mailbox_match, &pdev->dev);
+	if (!match) {
+		dev_err(&pdev->dev, "No configuration found\n");
+		return -ENODEV;
+	}
+	pdev->dev.platform_data = (struct sti_mbox_pdata *) match->data;
+
+	mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
+	if (!mdev)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, mdev);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mdev->base = devm_ioremap_resource(&pdev->dev, res);
+	if (!mdev->base)
+		return -ENOMEM;
+
+	ret = of_property_read_string(np, "mbox-name", &mdev->name);
+	if (ret)
+		mdev->name = np->full_name;
+
+	mdev->txonly = of_property_read_bool(np, "tx-only");
+
+	mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	chans = devm_kzalloc(&pdev->dev,
+			     sizeof(*chans) * STI_MBOX_CHAN_MAX, GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+
+	mdev->dev		= &pdev->dev;
+	mdev->mbox		= mbox;
+
+	spin_lock_init(&mdev->lock);
+
+	/* STi Mailbox does not have a Tx-Done or Tx-Ready IRQ */
+	mbox->txdone_irq	= false;
+	mbox->txdone_poll	= true;
+	mbox->txpoll_period	= 100;
+	mbox->ops		= &sti_mbox_ops;
+	mbox->dev		= mdev->dev;
+	mbox->of_xlate		= sti_mbox_xlate;
+	mbox->chans		= chans;
+	mbox->num_chans		= STI_MBOX_CHAN_MAX;
+
+	ret = mbox_controller_register(mbox);
+	if (ret)
+		return ret;
+
+	/* It's okay for Tx Mailboxes to not supply IRQs */
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_info(&pdev->dev,
+			 "%s: Registered Tx only Mailbox\n", mdev->name);
+		return 0;
+	}
+
+	ret = devm_request_threaded_irq(&pdev->dev, irq,
+					sti_mbox_irq_handler,
+					sti_mbox_thread_handler,
+					IRQF_ONESHOT, mdev->name, mdev);
+	if (ret) {
+		dev_err(&pdev->dev, "Can't claim IRQ %d\n", irq);
+		mbox_controller_unregister(mbox);
+		return -EINVAL;
+	}
+
+	dev_info(&pdev->dev, "%s: Registered Tx/Rx Mailbox\n", mdev->name);
+
+	return 0;
+}
+
+static int sti_mbox_remove(struct platform_device *pdev)
+{
+	struct sti_mbox_device *mdev = platform_get_drvdata(pdev);
+
+	mbox_controller_unregister(mdev->mbox);
+
+	return 0;
+}
+
+static struct platform_driver sti_mbox_driver = {
+	.probe = sti_mbox_probe,
+	.remove = sti_mbox_remove,
+	.driver = {
+		.name = "sti-mailbox",
+		.of_match_table = sti_mailbox_match,
+	},
+};
+module_platform_driver(sti_mbox_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("STMicroelectronics Mailbox Controller");
+MODULE_AUTHOR("Lee Jones <lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org");
+MODULE_ALIAS("platform:mailbox-sti");
-- 
1.9.1

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Re: [PATCH v3 2/5] mailbox: Add support for ST's Mailbox IP

[Jassi Brar]

On Wed, Aug 19, 2015 at 7:52 PM, Lee Jones <lee.jones@linaro.org> wrote:

....

> +
> +#define MBOX_BASE(mdev, inst)   ((mdev)->base + (inst * 4))
>
It should be    (inst) * 4

> +/**
> + * STi Mailbox device data
> + *
> + * An IP Mailbox is currently composed of 4 instances
> + * Each instance is currently composed of 32 channels
> + * This means that we have 128 channels per Mailbox
> + * A channel an be used for TX or RX
> + *
> + * @dev:       Device to which it is attached
> + * @mbox:      Representation of a communication channel controller
> + * @base:      Base address of the register mapping region
> + * @name:      Name of the mailbox
> + * @enabled:   Local copy of enabled channels
> + * @lock:      Mutex protecting enabled status
> + */
> +struct sti_mbox_device {
> +       struct device           *dev;
> +       struct mbox_controller  *mbox;
> +       void __iomem            *base;
> +       const char              *name;
> +       u32                     enabled[STI_MBOX_INST_MAX];
> +       spinlock_t              lock;
> +       bool                    txonly;
>
txonly is never used after being initialized from DT :)   which is a
good sign. So maybe just drop it and the optional property 'tx-only'.

Cheers!

Re: [PATCH v3 2/5] mailbox: Add support for ST's Mailbox IP

[Lee Jones]

On Fri, 02 Oct 2015, Jassi Brar wrote:

> On Wed, Aug 19, 2015 at 7:52 PM, Lee Jones <lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> 
> ....
> 
> > +
> > +#define MBOX_BASE(mdev, inst)   ((mdev)->base + (inst * 4))
> >
> It should be    (inst) * 4

I'm guessing you mean:

  ((mdev)->base + ((inst) * 4))

?

> > +/**
> > + * STi Mailbox device data
> > + *
> > + * An IP Mailbox is currently composed of 4 instances
> > + * Each instance is currently composed of 32 channels
> > + * This means that we have 128 channels per Mailbox
> > + * A channel an be used for TX or RX
> > + *
> > + * @dev:       Device to which it is attached
> > + * @mbox:      Representation of a communication channel controller
> > + * @base:      Base address of the register mapping region
> > + * @name:      Name of the mailbox
> > + * @enabled:   Local copy of enabled channels
> > + * @lock:      Mutex protecting enabled status
> > + */
> > +struct sti_mbox_device {
> > +       struct device           *dev;
> > +       struct mbox_controller  *mbox;
> > +       void __iomem            *base;
> > +       const char              *name;
> > +       u32                     enabled[STI_MBOX_INST_MAX];
> > +       spinlock_t              lock;
> > +       bool                    txonly;
> >
> txonly is never used after being initialized from DT :)   which is a
> good sign. So maybe just drop it and the optional property 'tx-only'.

Okay.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
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Re: [PATCH v3 2/5] mailbox: Add support for ST's Mailbox IP

[Jassi Brar]

On 2 October 2015 at 15:02, Lee Jones <lee.jones@linaro.org> wrote:
> On Fri, 02 Oct 2015, Jassi Brar wrote:
>
>> On Wed, Aug 19, 2015 at 7:52 PM, Lee Jones <lee.jones@linaro.org> wrote:
>>
>> ....
>>
>> > +
>> > +#define MBOX_BASE(mdev, inst)   ((mdev)->base + (inst * 4))
>> >
>> It should be    (inst) * 4
>
> I'm guessing you mean:
>
>   ((mdev)->base + ((inst) * 4))
>
> ?
yes.

[PATCH v3 3/5] ARM: STi: stih407-family: Add nodes for Mailbox

[Lee Jones]

This patch supplies the Mailbox Controller nodes.  In order to
request channels, these nodes will be referenced by Mailbox
Client nodes.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/arm/boot/dts/stih407-family.dtsi | 36 +++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/arch/arm/boot/dts/stih407-family.dtsi b/arch/arm/boot/dts/stih407-family.dtsi
index 838b812..32da3f8 100644
--- a/arch/arm/boot/dts/stih407-family.dtsi
+++ b/arch/arm/boot/dts/stih407-family.dtsi
@@ -565,5 +565,41 @@
 						  <&phy_port2 PHY_TYPE_USB3>;
 			};
 		};
+
+		mailbox0: mailbox@0  {
+			compatible	= "st,stih407-mailbox";
+			reg		= <0x8f00000 0x1000>;
+			interrupts	= <GIC_SPI 1 IRQ_TYPE_NONE>;
+			#mbox-cells	= <2>;
+			mbox-name	= "a9";
+			status		= "okay";
+		};
+
+		mailbox1: mailbox@1 {
+			compatible	= "st,stih407-mailbox";
+			reg		= <0x8f01000 0x1000>;
+			#mbox-cells	= <2>;
+			mbox-name	= "st231_gp_1";
+			status		= "okay";
+			tx-only;
+		};
+
+		mailbox2: mailbox@2 {
+			compatible	= "st,stih407-mailbox";
+			reg		= <0x8f02000 0x1000>;
+			#mbox-cells	= <2>;
+			mbox-name	= "st231_gp_0";
+			status		= "okay";
+			tx-only;
+		};
+
+		mailbox3: mailbox@3 {
+			compatible	= "st,stih407-mailbox";
+			reg		= <0x8f03000 0x1000>;
+			#mbox-cells	= <2>;
+			mbox-name	= "st231_audio_video";
+			status		= "okay";
+			tx-only;
+		};
 	};
 };
-- 
1.9.1

[PATCH v3 4/5] mailbox: Add generic mechanism for testing Mailbox Controllers

[Lee Jones]

This particular Client implementation uses shared memory in order
to pass messages between Mailbox users; however, it can be easily
hacked to support any type of Controller.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/mailbox/Kconfig        |   7 +
 drivers/mailbox/Makefile       |   2 +
 drivers/mailbox/mailbox-test.c | 361 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 370 insertions(+)
 create mode 100644 drivers/mailbox/mailbox-test.c

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 2cc4c39..7720bde 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -77,4 +77,11 @@ config STI_MBOX
 	  Mailbox implementation for STMicroelectonics family chips with
 	  hardware for interprocessor communication.
 
+config MAILBOX_TEST
+	tristate "Mailbox Test Client"
+	depends on OF
+	help
+	  Test client to help with testing new Controller driver
+	  implementations.
+
 endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 7cb4766..92435ef 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -2,6 +2,8 @@
 
 obj-$(CONFIG_MAILBOX)		+= mailbox.o
 
+obj-$(CONFIG_MAILBOX_TEST)	+= mailbox-test.o
+
 obj-$(CONFIG_ARM_MHU)	+= arm_mhu.o
 
 obj-$(CONFIG_PL320_MBOX)	+= pl320-ipc.o
diff --git a/drivers/mailbox/mailbox-test.c b/drivers/mailbox/mailbox-test.c
new file mode 100644
index 0000000..cac1ba2
--- /dev/null
+++ b/drivers/mailbox/mailbox-test.c
@@ -0,0 +1,361 @@
+/*
+ * Copyright (C) 2015 ST Microelectronics
+ *
+ * Author: Lee Jones <lee.jones@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#define MBOX_MAX_SIG_LEN	8
+#define MBOX_MAX_MSG_LEN	128
+#define MBOX_BYTES_PER_LINE	16
+#define MBOX_HEXDUMP_LINE_LEN 	((MBOX_BYTES_PER_LINE * 4) + 2)
+#define MBOX_HEXDUMP_MAX_LEN	(MBOX_HEXDUMP_LINE_LEN *		\
+				 (MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))
+
+static struct dentry *root_debugfs_dir;
+
+struct mbox_test_device {
+	struct device		*dev;
+	void __iomem		*mmio;
+	struct mbox_chan	*tx_channel;
+	struct mbox_chan	*rx_channel;
+	char			*rx_buffer;
+	char			*signal;
+	char			*message;
+	spinlock_t		lock;
+};
+
+static ssize_t mbox_test_signal_write(struct file *filp,
+				       const char __user *userbuf,
+				       size_t count, loff_t *ppos)
+{
+	struct mbox_test_device *tdev = filp->private_data;
+	int ret;
+
+	if (!tdev->tx_channel) {
+		dev_err(tdev->dev, "Channel cannot do Tx\n");
+		return -EINVAL;
+	}
+
+	if (count > MBOX_MAX_SIG_LEN) {
+		dev_err(tdev->dev,
+			"Signal length %d greater than max allowed %d\n",
+			count, MBOX_MAX_SIG_LEN);
+		return -EINVAL;
+	}
+
+	tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
+	if (!tdev->signal)
+		return -ENOMEM;
+
+	ret = copy_from_user(tdev->signal, userbuf, count);
+	if (ret) {
+		kfree(tdev->signal);
+		return -EFAULT;
+	}
+
+	return ret < 0 ? ret : count;
+}
+
+static const struct file_operations mbox_test_signal_ops = {
+	.write	= mbox_test_signal_write,
+	.open	= simple_open,
+	.llseek	= generic_file_llseek,
+};
+
+static ssize_t mbox_test_message_write(struct file *filp,
+				       const char __user *userbuf,
+				       size_t count, loff_t *ppos)
+{
+	struct mbox_test_device *tdev = filp->private_data;
+	void *data;
+	int ret;
+
+	if (!tdev->tx_channel) {
+		dev_err(tdev->dev, "Channel cannot do Tx\n");
+		return -EINVAL;
+	}
+
+	if (count > MBOX_MAX_MSG_LEN) {
+		dev_err(tdev->dev,
+			"Message length %d greater than max allowed %d\n",
+			count, MBOX_MAX_MSG_LEN);
+		return -EINVAL;
+	}
+
+	tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
+	if (!tdev->message)
+		return -ENOMEM;
+
+	ret = copy_from_user(tdev->message, userbuf, count);
+	if (ret) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	/*
+	 * A separate signal is only of use if there is
+	 * MMIO to subsequently pass the message through
+	 */
+	if (tdev->mmio && tdev->signal) {
+		print_hex_dump(KERN_INFO, "Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
+			       MBOX_BYTES_PER_LINE, 1, tdev->signal, MBOX_MAX_SIG_LEN, true);
+
+		data = tdev->signal;
+	} else
+		data = tdev->message;
+
+	print_hex_dump(KERN_INFO, "Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
+		       MBOX_BYTES_PER_LINE, 1, tdev->message, MBOX_MAX_MSG_LEN, true);
+
+	ret = mbox_send_message(tdev->tx_channel, data);
+	if (ret < 0)
+		dev_err(tdev->dev, "Failed to send message via mailbox\n");
+
+out:
+	kfree(tdev->signal);
+	kfree(tdev->message);
+
+	return ret < 0 ? ret : count;
+}
+
+static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
+				      size_t count, loff_t *ppos)
+{
+	struct mbox_test_device *tdev = filp->private_data;
+	unsigned long flags;
+	char *touser, *ptr;
+	int l = 0;
+	int ret;
+
+	touser = kzalloc(MBOX_HEXDUMP_MAX_LEN, GFP_KERNEL);
+	if (!touser)
+		return -ENOMEM;
+
+	if (!tdev->rx_channel) {
+		ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
+		ret = simple_read_from_buffer(userbuf, count, ppos,
+					      touser, ret);
+		goto out;
+	}
+
+	if (tdev->rx_buffer[0] == '\0') {
+		ret = snprintf(touser, 9, "<EMPTY>\n");
+		ret = simple_read_from_buffer(userbuf, count, ppos,
+					      touser, ret);
+		goto out;
+	}
+
+	spin_lock_irqsave(&tdev->lock, flags);
+
+	ptr = tdev->rx_buffer;
+	while (l < MBOX_HEXDUMP_MAX_LEN) {
+		hex_dump_to_buffer(ptr,
+				   MBOX_BYTES_PER_LINE,
+				   MBOX_BYTES_PER_LINE, 1, touser + l,
+				   MBOX_HEXDUMP_LINE_LEN, true);
+
+		ptr += MBOX_BYTES_PER_LINE;
+		l += MBOX_HEXDUMP_LINE_LEN;
+		*(touser + (l - 1)) = '\n';
+	}
+	*(touser + l) = '\0';
+
+	memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
+
+	spin_unlock_irqrestore(&tdev->lock, flags);
+
+	ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
+out:
+	kfree(touser);
+	return ret;
+}
+
+static const struct file_operations mbox_test_message_ops = {
+	.write	= mbox_test_message_write,
+	.read	= mbox_test_message_read,
+	.open	= simple_open,
+	.llseek	= generic_file_llseek,
+};
+
+static int mbox_test_add_debugfs(struct platform_device *pdev,
+				 struct mbox_test_device *tdev)
+{
+	if (!debugfs_initialized())
+		return 0;
+
+	root_debugfs_dir = debugfs_create_dir("mailbox", NULL);
+	if (!root_debugfs_dir) {
+		dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
+		return -EINVAL;
+	}
+
+	debugfs_create_file("message", 0600, root_debugfs_dir,
+			    tdev, &mbox_test_message_ops);
+
+	debugfs_create_file("signal", 0200, root_debugfs_dir,
+			    tdev, &mbox_test_signal_ops);
+
+	return 0;
+}
+
+static void mbox_test_receive_message(struct mbox_client *client, void *message)
+{
+	struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&tdev->lock, flags);
+	if (tdev->mmio) {
+		print_hex_dump(KERN_INFO, "Client: Received [MMIO]: ",
+			       DUMP_PREFIX_ADDRESS, MBOX_BYTES_PER_LINE, 1,
+			       tdev->mmio, MBOX_MAX_MSG_LEN, true);
+		memcpy(tdev->rx_buffer, tdev->mmio, MBOX_MAX_MSG_LEN);
+
+	} else if (message) {
+		print_hex_dump(KERN_INFO, "Client: Received [API]: ",
+			       DUMP_PREFIX_ADDRESS, MBOX_BYTES_PER_LINE, 1,
+			       message, MBOX_MAX_MSG_LEN, true);
+		memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
+	}
+	spin_unlock_irqrestore(&tdev->lock, flags);
+}
+
+static void mbox_test_prepare_message(struct mbox_client *client, void *message)
+{
+	struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
+
+	if (tdev->mmio) {
+		if (tdev->signal)
+			memcpy(tdev->mmio, tdev->message, MBOX_MAX_MSG_LEN);
+		else
+			memcpy(tdev->mmio, message, MBOX_MAX_MSG_LEN);
+	}
+}
+
+static void mbox_test_message_sent(struct mbox_client *client,
+				   void *message, int r)
+{
+	if (r)
+		dev_warn(client->dev,
+			 "Client: Message could not be sent: %d\n", r);
+	else
+		dev_info(client->dev,
+			 "Client: Message sent\n");
+}
+
+static struct mbox_chan *
+mbox_test_request_channel(struct platform_device *pdev, const char *name)
+{
+	struct mbox_client *client;
+	struct mbox_chan *channel;
+
+	client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
+	if (!client)
+		return ERR_PTR(-ENOMEM);
+
+	client->dev		= &pdev->dev;
+	client->rx_callback	= mbox_test_receive_message;
+	client->tx_prepare	= mbox_test_prepare_message;
+	client->tx_done		= mbox_test_message_sent;
+	client->tx_block	= true;
+	client->knows_txdone	= false;
+	client->tx_tout		= 500;
+
+	channel = mbox_request_channel_byname(client, name);
+	if (IS_ERR(channel)) {
+		dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
+		return NULL;
+	}
+
+	return channel;
+}
+
+static int mbox_test_probe(struct platform_device *pdev)
+{
+	struct mbox_test_device *tdev;
+	struct resource *res;
+	int ret;
+
+	tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
+	if (!tdev)
+		return -ENOMEM;
+
+	/* It's okay for MMIO to be NULL */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	tdev->mmio = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(tdev->mmio))
+		tdev->mmio = NULL;
+
+	tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
+	tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
+
+	if (!tdev->tx_channel && !tdev->tx_channel)
+		return -EPROBE_DEFER;
+
+	tdev->dev = &pdev->dev;
+	platform_set_drvdata(pdev, tdev);
+
+	spin_lock_init(&tdev->lock);
+
+	if (tdev->rx_channel) {
+		tdev->rx_buffer = devm_kzalloc(&pdev->dev,
+					       MBOX_MAX_MSG_LEN, GFP_KERNEL);
+		if (!tdev->rx_buffer)
+			return -ENOMEM;
+	}
+
+	ret = mbox_test_add_debugfs(pdev, tdev);
+	if (ret)
+		return ret;
+
+	dev_info(&pdev->dev, "Successfully registered\n");
+
+	return 0;
+}
+
+static int mbox_test_remove(struct platform_device *pdev)
+{
+	struct mbox_test_device *tdev = platform_get_drvdata(pdev);
+
+	debugfs_remove_recursive(root_debugfs_dir);
+
+	if (tdev->tx_channel)
+		mbox_free_channel(tdev->tx_channel);
+	if (tdev->rx_channel)
+		mbox_free_channel(tdev->rx_channel);
+
+	return 0;
+}
+
+static const struct of_device_id mbox_test_match[] = {
+	{ .compatible = "mailbox_test" },
+	{},
+};
+
+static struct platform_driver mbox_test_driver = {
+	.driver = {
+		.name = "mailbox_sti_test",
+		.of_match_table = mbox_test_match,
+	},
+	.probe  = mbox_test_probe,
+	.remove = mbox_test_remove,
+};
+module_platform_driver(mbox_test_driver);
+
+MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
+MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

[PATCH v3 5/5] ARM: STi: DT: STiH407: Enable Mailbox testing facility

[Lee Jones]

This patch supplies a Client node to enable the Mailbox testing
facility.  It will be used to send and receive messages from any
given co-processor in order to test the STi Mailbox Controller
driver.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/arm/boot/dts/stih407-family.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/stih407-family.dtsi b/arch/arm/boot/dts/stih407-family.dtsi
index 32da3f8..ac1d1ee 100644
--- a/arch/arm/boot/dts/stih407-family.dtsi
+++ b/arch/arm/boot/dts/stih407-family.dtsi
@@ -566,6 +566,12 @@
 			};
 		};
 
+		mailbox_test {
+			compatible = "mailbox_test";
+			mboxes = <&mailbox2 1 31>, <&mailbox0 1 31>;
+			mbox-names = "tx", "rx";
+		};
+
 		mailbox0: mailbox@0  {
 			compatible	= "st,stih407-mailbox";
 			reg		= <0x8f00000 0x1000>;
-- 
1.9.1