[linux.git] / drivers / mailbox / mailbox-sti.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * STi Mailbox
 *
 * Copyright (C) 2015 ST Microelectronics
 *
 * Author: Lee Jones <[email protected]> for ST Microelectronics
 *
 * Based on the original driver written by;
 *   Alexandre Torgue, Olivier Lebreton and Loic Pallardy
 */

#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;
};

/**
 * STi Mailbox platform specific 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 const 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
	},
	{ }
};
MODULE_DEVICE_TABLE(of, sti_mailbox_match);

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 (IS_ERR(mdev->base))
		return PTR_ERR(mdev->base);

	ret = of_property_read_string(np, "mbox-name", &mdev->name);
	if (ret)
		mdev->name = np->full_name;

	mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
	if (!mbox)
		return -ENOMEM;

	chans = devm_kcalloc(&pdev->dev,
			     STI_MBOX_CHAN_MAX, sizeof(*chans), 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 = devm_mbox_controller_register(&pdev->dev, 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);
		return -EINVAL;
	}

	dev_info(&pdev->dev, "%s: Registered Tx/Rx Mailbox\n", mdev->name);

	return 0;
}

static struct platform_driver sti_mbox_driver = {
	.probe = sti_mbox_probe,
	.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 <[email protected]");
MODULE_ALIAS("platform:mailbox-sti");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
9ef4546c LJ	2	/*
	3	* STi Mailbox
	4	*
	5	* Copyright (C) 2015 ST Microelectronics
	6	*
	7	* Author: Lee Jones <[email protected]> for ST Microelectronics
	8	*
	9	* Based on the original driver written by;
	10	* Alexandre Torgue, Olivier Lebreton and Loic Pallardy
9ef4546c LJ	11	*/
	12
	13	#include <linux/err.h>
	14	#include <linux/interrupt.h>
	15	#include <linux/io.h>
	16	#include <linux/kernel.h>
	17	#include <linux/mailbox_controller.h>
	18	#include <linux/module.h>
	19	#include <linux/of.h>
	20	#include <linux/of_device.h>
	21	#include <linux/platform_device.h>
	22	#include <linux/slab.h>
	23
	24	#include "mailbox.h"
	25
	26	#define STI_MBOX_INST_MAX 4 /* RAM saving: Max supported instances */
	27	#define STI_MBOX_CHAN_MAX 20 /* RAM saving: Max supported channels */
	28
	29	#define STI_IRQ_VAL_OFFSET 0x04 /* Read interrupt status */
	30	#define STI_IRQ_SET_OFFSET 0x24 /* Generate a Tx channel interrupt */
	31	#define STI_IRQ_CLR_OFFSET 0x44 /* Clear pending Rx interrupts */
	32	#define STI_ENA_VAL_OFFSET 0x64 /* Read enable status */
	33	#define STI_ENA_SET_OFFSET 0x84 /* Enable a channel */
	34	#define STI_ENA_CLR_OFFSET 0xa4 /* Disable a channel */
	35
	36	#define MBOX_BASE(mdev, inst) ((mdev)->base + ((inst) * 4))
	37
	38	/**
	39	* STi Mailbox device data
	40	*
	41	* An IP Mailbox is currently composed of 4 instances
	42	* Each instance is currently composed of 32 channels
	43	* This means that we have 128 channels per Mailbox
	44	* A channel an be used for TX or RX
	45	*
	46	* @dev: Device to which it is attached
	47	* @mbox: Representation of a communication channel controller
	48	* @base: Base address of the register mapping region
	49	* @name: Name of the mailbox
	50	* @enabled: Local copy of enabled channels
	51	* @lock: Mutex protecting enabled status
	52	*/
	53	struct sti_mbox_device {
	54	struct device *dev;
	55	struct mbox_controller *mbox;
	56	void __iomem *base;
	57	const char *name;
	58	u32 enabled[STI_MBOX_INST_MAX];
	59	spinlock_t lock;
	60	};
	61
	62	/**
6c03663f	63	* STi Mailbox platform specific configuration
9ef4546c LJ	64	*
	65	* @num_inst: Maximum number of instances in one HW Mailbox
	66	* @num_chan: Maximum number of channel per instance
	67	*/
	68	struct sti_mbox_pdata {
	69	unsigned int num_inst;
	70	unsigned int num_chan;
	71	};
	72
	73	/**
	74	* STi Mailbox allocated channel information
	75	*
	76	* @mdev: Pointer to parent Mailbox device
	77	* @instance: Instance number channel resides in
	78	* @channel: Channel number pertaining to this container
	79	*/
	80	struct sti_channel {
	81	struct sti_mbox_device *mdev;
	82	unsigned int instance;
	83	unsigned int channel;
	84	};
	85
	86	static inline bool sti_mbox_channel_is_enabled(struct mbox_chan *chan)
	87	{
	88	struct sti_channel *chan_info = chan->con_priv;
	89	struct sti_mbox_device *mdev = chan_info->mdev;
	90	unsigned int instance = chan_info->instance;
	91	unsigned int channel = chan_info->channel;
	92
	93	return mdev->enabled[instance] & BIT(channel);
	94	}
	95
	96	static inline
	97	struct mbox_chan sti_mbox_to_channel(struct mbox_controller mbox,
	98	unsigned int instance,
	99	unsigned int channel)
	100	{
	101	struct sti_channel *chan_info;
	102	int i;
	103
	104	for (i = 0; i < mbox->num_chans; i++) {
	105	chan_info = mbox->chans[i].con_priv;
	106	if (chan_info &&
	107	chan_info->instance == instance &&
	108	chan_info->channel == channel)
	109	return &mbox->chans[i];
	110	}
	111
	112	dev_err(mbox->dev,
	113	"Channel not registered: instance: %d channel: %d\n",
	114	instance, channel);
	115
	116	return NULL;
	117	}
	118
	119	static void sti_mbox_enable_channel(struct mbox_chan *chan)
	120	{
	121	struct sti_channel *chan_info = chan->con_priv;
	122	struct sti_mbox_device *mdev = chan_info->mdev;
	123	unsigned int instance = chan_info->instance;
	124	unsigned int channel = chan_info->channel;
	125	unsigned long flags;
	126	void __iomem *base = MBOX_BASE(mdev, instance);
	127
128	spin_lock_irqsave(&mdev->lock, flags);
129	mdev->enabled[instance] \|= BIT(channel);
130	writel_relaxed(BIT(channel), base + STI_ENA_SET_OFFSET);
131	spin_unlock_irqrestore(&mdev->lock, flags);
132	}
133
134	static void sti_mbox_disable_channel(struct mbox_chan *chan)
135	{
136	struct sti_channel *chan_info = chan->con_priv;
137	struct sti_mbox_device *mdev = chan_info->mdev;
138	unsigned int instance = chan_info->instance;
139	unsigned int channel = chan_info->channel;
140	unsigned long flags;
141	void __iomem *base = MBOX_BASE(mdev, instance);
142
143	spin_lock_irqsave(&mdev->lock, flags);
144	mdev->enabled[instance] &= ~BIT(channel);
145	writel_relaxed(BIT(channel), base + STI_ENA_CLR_OFFSET);
146	spin_unlock_irqrestore(&mdev->lock, flags);
147	}
148
149	static void sti_mbox_clear_irq(struct mbox_chan *chan)
150	{
151	struct sti_channel *chan_info = chan->con_priv;
152	struct sti_mbox_device *mdev = chan_info->mdev;
153	unsigned int instance = chan_info->instance;
154	unsigned int channel = chan_info->channel;
155	void __iomem *base = MBOX_BASE(mdev, instance);
156
157	writel_relaxed(BIT(channel), base + STI_IRQ_CLR_OFFSET);
158	}
159
160	static struct mbox_chan sti_mbox_irq_to_channel(struct sti_mbox_device mdev,
161	unsigned int instance)
162	{
163	struct mbox_controller *mbox = mdev->mbox;
164	struct mbox_chan *chan = NULL;
165	unsigned int channel;
166	unsigned long bits;
167	void __iomem *base = MBOX_BASE(mdev, instance);
168
169	bits = readl_relaxed(base + STI_IRQ_VAL_OFFSET);
170	if (!bits)
171	/* No IRQs fired in specified instance */
172	return NULL;
173
174	/* An IRQ has fired, find the associated channel */
175	for (channel = 0; bits; channel++) {
176	if (!test_and_clear_bit(channel, &bits))
177	continue;
178
179	chan = sti_mbox_to_channel(mbox, instance, channel);
180	if (chan) {
181	dev_dbg(mbox->dev,
182	"IRQ fired on instance: %d channel: %d\n",
183	instance, channel);
184	break;
185	}
186	}
187
188	return chan;
189	}
190
191	static irqreturn_t sti_mbox_thread_handler(int irq, void *data)
192	{
193	struct sti_mbox_device *mdev = data;
194	struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
195	struct mbox_chan *chan;
196	unsigned int instance;
197
198	for (instance = 0; instance < pdata->num_inst; instance++) {
199	keep_looking:
200	chan = sti_mbox_irq_to_channel(mdev, instance);
201	if (!chan)
202	continue;
203
204	mbox_chan_received_data(chan, NULL);
205	sti_mbox_clear_irq(chan);
206	sti_mbox_enable_channel(chan);
207	goto keep_looking;
208	}
209
210	return IRQ_HANDLED;
211	}
212
213	static irqreturn_t sti_mbox_irq_handler(int irq, void *data)
214	{
215	struct sti_mbox_device *mdev = data;
216	struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
217	struct sti_channel *chan_info;
218	struct mbox_chan *chan;
219	unsigned int instance;
220	int ret = IRQ_NONE;
221
222	for (instance = 0; instance < pdata->num_inst; instance++) {
223	chan = sti_mbox_irq_to_channel(mdev, instance);
224	if (!chan)
225	continue;
226	chan_info = chan->con_priv;
227
228	if (!sti_mbox_channel_is_enabled(chan)) {
229	dev_warn(mdev->dev,
230	"Unexpected IRQ: %s\n"
231	" instance: %d: channel: %d [enabled: %x]\n",
232	mdev->name, chan_info->instance,
233	chan_info->channel, mdev->enabled[instance]);
234
235	/* Only handle IRQ if no other valid IRQs were found */
236	if (ret == IRQ_NONE)
237	ret = IRQ_HANDLED;
238	continue;
239	}
240
241	sti_mbox_disable_channel(chan);
242	ret = IRQ_WAKE_THREAD;
243	}
244
245	if (ret == IRQ_NONE)
246	dev_err(mdev->dev, "Spurious IRQ - was a channel requested?\n");
247
248	return ret;
249	}
250
251	static bool sti_mbox_tx_is_ready(struct mbox_chan *chan)
252	{
253	struct sti_channel *chan_info = chan->con_priv;
254	struct sti_mbox_device *mdev = chan_info->mdev;
255	unsigned int instance = chan_info->instance;
256	unsigned int channel = chan_info->channel;
257	void __iomem *base = MBOX_BASE(mdev, instance);
258
259	if (!(readl_relaxed(base + STI_ENA_VAL_OFFSET) & BIT(channel))) {
260	dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d disabled\n",
261	mdev->name, instance, channel);
262	return false;
263	}
264
265	if (readl_relaxed(base + STI_IRQ_VAL_OFFSET) & BIT(channel)) {
266	dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d not ready\n",
267	mdev->name, instance, channel);
268	return false;
269	}
270
271	return true;
272	}
273
274	static int sti_mbox_send_data(struct mbox_chan chan, void data)
275	{
276	struct sti_channel *chan_info = chan->con_priv;
277	struct sti_mbox_device *mdev = chan_info->mdev;
278	unsigned int instance = chan_info->instance;
279	unsigned int channel = chan_info->channel;
280	void __iomem *base = MBOX_BASE(mdev, instance);
281
282	/* Send event to co-processor */
283	writel_relaxed(BIT(channel), base + STI_IRQ_SET_OFFSET);
284
285	dev_dbg(mdev->dev,
286	"Sent via Mailbox %s: instance: %d channel: %d\n",
287	mdev->name, instance, channel);
288
289	return 0;
290	}
291
292	static int sti_mbox_startup_chan(struct mbox_chan *chan)
293	{
294	sti_mbox_clear_irq(chan);
295	sti_mbox_enable_channel(chan);
296
297	return 0;
298	}
299
300	static void sti_mbox_shutdown_chan(struct mbox_chan *chan)
301	{
302	struct sti_channel *chan_info = chan->con_priv;
303	struct mbox_controller *mbox = chan_info->mdev->mbox;
304	int i;
305
306	for (i = 0; i < mbox->num_chans; i++)
307	if (chan == &mbox->chans[i])
308	break;
309
310	if (mbox->num_chans == i) {
311	dev_warn(mbox->dev, "Request to free non-existent channel\n");
312	return;
313	}
314
315	/* Reset channel */
316	sti_mbox_disable_channel(chan);
317	sti_mbox_clear_irq(chan);
318	chan->con_priv = NULL;
319	}
320
321	static struct mbox_chan sti_mbox_xlate(struct mbox_controller mbox,
322	const struct of_phandle_args *spec)
323	{
324	struct sti_mbox_device *mdev = dev_get_drvdata(mbox->dev);
325	struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
326	struct sti_channel *chan_info;
327	struct mbox_chan *chan = NULL;
328	unsigned int instance = spec->args[0];
329	unsigned int channel = spec->args[1];
330	int i;
331
332	/* Bounds checking */
333	if (instance >= pdata->num_inst \|\| channel >= pdata->num_chan) {
334	dev_err(mbox->dev,
335	"Invalid channel requested instance: %d channel: %d\n",
336	instance, channel);
337	return ERR_PTR(-EINVAL);
338	}
339
340	for (i = 0; i < mbox->num_chans; i++) {
341	chan_info = mbox->chans[i].con_priv;
342
343	/* Is requested channel free? */
344	if (chan_info &&
345	mbox->dev == chan_info->mdev->dev &&
346	instance == chan_info->instance &&
347	channel == chan_info->channel) {
348
349	dev_err(mbox->dev, "Channel in use\n");
350	return ERR_PTR(-EBUSY);
351	}
352
353	/*
354	* Find the first free slot, then continue checking
355	* to see if requested channel is in use
356	*/
357	if (!chan && !chan_info)
358	chan = &mbox->chans[i];
359	}
360
361	if (!chan) {
362	dev_err(mbox->dev, "No free channels left\n");
363	return ERR_PTR(-EBUSY);
364	}
365
366	chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL);
367	if (!chan_info)
368	return ERR_PTR(-ENOMEM);
369
370	chan_info->mdev = mdev;
371	chan_info->instance = instance;
372	chan_info->channel = channel;
373
374	chan->con_priv = chan_info;
375
376	dev_info(mbox->dev,
377	"Mbox: %s: Created channel: instance: %d channel: %d\n",
378	mdev->name, instance, channel);
379
380	return chan;
381	}
382
bfbcfa77	383	static const struct mbox_chan_ops sti_mbox_ops = {
9ef4546c LJ	384	.startup = sti_mbox_startup_chan,
	385	.shutdown = sti_mbox_shutdown_chan,
	386	.send_data = sti_mbox_send_data,
	387	.last_tx_done = sti_mbox_tx_is_ready,
	388	};
	389
	390	static const struct sti_mbox_pdata mbox_stih407_pdata = {
	391	.num_inst = 4,
	392	.num_chan = 32,
	393	};
	394
	395	static const struct of_device_id sti_mailbox_match[] = {
	396	{
	397	.compatible = "st,stih407-mailbox",
	398	.data = (void *)&mbox_stih407_pdata
	399	},
	400	{ }
	401	};
2f50497d	402	MODULE_DEVICE_TABLE(of, sti_mailbox_match);
9ef4546c LJ	403
	404	static int sti_mbox_probe(struct platform_device *pdev)
	405	{
	406	const struct of_device_id *match;
	407	struct mbox_controller *mbox;
	408	struct sti_mbox_device *mdev;
	409	struct device_node *np = pdev->dev.of_node;
	410	struct mbox_chan *chans;
	411	struct resource *res;
	412	int irq;
	413	int ret;
	414
	415	match = of_match_device(sti_mailbox_match, &pdev->dev);
	416	if (!match) {
	417	dev_err(&pdev->dev, "No configuration found\n");
	418	return -ENODEV;
	419	}
	420	pdev->dev.platform_data = (struct sti_mbox_pdata *) match->data;
	421
	422	mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
	423	if (!mdev)
	424	return -ENOMEM;
	425
	426	platform_set_drvdata(pdev, mdev);
	427
	428	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	429	mdev->base = devm_ioremap_resource(&pdev->dev, res);
c430cf37 AKC	430	if (IS_ERR(mdev->base))
c430cf37 AKC	431	return PTR_ERR(mdev->base);
9ef4546c LJ	432
	433	ret = of_property_read_string(np, "mbox-name", &mdev->name);
	434	if (ret)
	435	mdev->name = np->full_name;
	436
	437	mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
	438	if (!mbox)
	439	return -ENOMEM;
	440
a86854d0 KC	441	chans = devm_kcalloc(&pdev->dev,
a86854d0 KC	442	STI_MBOX_CHAN_MAX, sizeof(*chans), GFP_KERNEL);
9ef4546c LJ	443	if (!chans)
	444	return -ENOMEM;
	445
	446	mdev->dev = &pdev->dev;
	447	mdev->mbox = mbox;
	448
	449	spin_lock_init(&mdev->lock);
	450
	451	/* STi Mailbox does not have a Tx-Done or Tx-Ready IRQ */
	452	mbox->txdone_irq = false;
	453	mbox->txdone_poll = true;
	454	mbox->txpoll_period = 100;
	455	mbox->ops = &sti_mbox_ops;
	456	mbox->dev = mdev->dev;
	457	mbox->of_xlate = sti_mbox_xlate;
	458	mbox->chans = chans;
	459	mbox->num_chans = STI_MBOX_CHAN_MAX;
	460
d0c196db	461	ret = devm_mbox_controller_register(&pdev->dev, mbox);
9ef4546c LJ	462	if (ret)
	463	return ret;
	464
	465	/* It's okay for Tx Mailboxes to not supply IRQs */
	466	irq = platform_get_irq(pdev, 0);
	467	if (irq < 0) {
	468	dev_info(&pdev->dev,
	469	"%s: Registered Tx only Mailbox\n", mdev->name);
	470	return 0;
	471	}
	472
	473	ret = devm_request_threaded_irq(&pdev->dev, irq,
	474	sti_mbox_irq_handler,
	475	sti_mbox_thread_handler,
	476	IRQF_ONESHOT, mdev->name, mdev);
	477	if (ret) {
	478	dev_err(&pdev->dev, "Can't claim IRQ %d\n", irq);
9ef4546c LJ	479	return -EINVAL;
	480	}
	481
	482	dev_info(&pdev->dev, "%s: Registered Tx/Rx Mailbox\n", mdev->name);
	483
	484	return 0;
	485	}
	486
9ef4546c LJ	487	static struct platform_driver sti_mbox_driver = {
9ef4546c LJ	488	.probe = sti_mbox_probe,
9ef4546c LJ	489	.driver = {
	490	.name = "sti-mailbox",
	491	.of_match_table = sti_mailbox_match,
	492	},
	493	};
	494	module_platform_driver(sti_mbox_driver);
	495
	496	MODULE_LICENSE("GPL");
	497	MODULE_DESCRIPTION("STMicroelectronics Mailbox Controller");
	498	MODULE_AUTHOR("Lee Jones <[email protected]");
	499	MODULE_ALIAS("platform:mailbox-sti");