[linux-block.git] / drivers / firmware / raspberrypi.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Defines interfaces for interacting with the Raspberry Pi firmware's
 * property channel.
 *
 * Copyright © 2015 Broadcom
 */

#include <linux/dma-mapping.h>
#include <linux/kref.h>
#include <linux/mailbox_client.h>
#include <linux/mailbox_controller.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <soc/bcm2835/raspberrypi-firmware.h>

#define MBOX_MSG(chan, data28)		(((data28) & ~0xf) | ((chan) & 0xf))
#define MBOX_CHAN(msg)			((msg) & 0xf)
#define MBOX_DATA28(msg)		((msg) & ~0xf)
#define MBOX_CHAN_PROPERTY		8

static struct platform_device *rpi_hwmon;
static struct platform_device *rpi_clk;

struct rpi_firmware {
	struct mbox_client cl;
	struct mbox_chan *chan; /* The property channel. */
	struct completion c;
	u32 enabled;

	struct kref consumers;
};

static DEFINE_MUTEX(transaction_lock);

static void response_callback(struct mbox_client *cl, void *msg)
{
	struct rpi_firmware *fw = container_of(cl, struct rpi_firmware, cl);
	complete(&fw->c);
}

/*
 * Sends a request to the firmware through the BCM2835 mailbox driver,
 * and synchronously waits for the reply.
 */
static int
rpi_firmware_transaction(struct rpi_firmware *fw, u32 chan, u32 data)
{
	u32 message = MBOX_MSG(chan, data);
	int ret;

	WARN_ON(data & 0xf);

	mutex_lock(&transaction_lock);
	reinit_completion(&fw->c);
	ret = mbox_send_message(fw->chan, &message);
	if (ret >= 0) {
		if (wait_for_completion_timeout(&fw->c, HZ)) {
			ret = 0;
		} else {
			ret = -ETIMEDOUT;
		}
	} else {
		dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret);
	}
	mutex_unlock(&transaction_lock);

	return ret;
}

/**
 * rpi_firmware_property_list - Submit firmware property list
 * @fw:		Pointer to firmware structure from rpi_firmware_get().
 * @data:	Buffer holding tags.
 * @tag_size:	Size of tags buffer.
 *
 * Submits a set of concatenated tags to the VPU firmware through the
 * mailbox property interface.
 *
 * The buffer header and the ending tag are added by this function and
 * don't need to be supplied, just the actual tags for your operation.
 * See struct rpi_firmware_property_tag_header for the per-tag
 * structure.
 */
int rpi_firmware_property_list(struct rpi_firmware *fw,
			       void *data, size_t tag_size)
{
	size_t size = tag_size + 12;
	u32 *buf;
	dma_addr_t bus_addr;
	int ret;

	/* Packets are processed a dword at a time. */
	if (size & 3)
		return -EINVAL;

	buf = dma_alloc_coherent(fw->chan->mbox->dev, PAGE_ALIGN(size),
				 &bus_addr, GFP_ATOMIC);
	if (!buf)
		return -ENOMEM;

	/* The firmware will error out without parsing in this case. */
	WARN_ON(size >= 1024 * 1024);

	buf[0] = size;
	buf[1] = RPI_FIRMWARE_STATUS_REQUEST;
	memcpy(&buf[2], data, tag_size);
	buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END;
	wmb();

	ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr);

	rmb();
	memcpy(data, &buf[2], tag_size);
	if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) {
		/*
		 * The tag name here might not be the one causing the
		 * error, if there were multiple tags in the request.
		 * But single-tag is the most common, so go with it.
		 */
		dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n",
			buf[2], buf[1]);
		ret = -EINVAL;
	} else if (ret == -ETIMEDOUT) {
		WARN_ONCE(1, "Firmware transaction 0x%08x timeout", buf[2]);
	}

	dma_free_coherent(fw->chan->mbox->dev, PAGE_ALIGN(size), buf, bus_addr);

	return ret;
}
EXPORT_SYMBOL_GPL(rpi_firmware_property_list);

/**
 * rpi_firmware_property - Submit single firmware property
 * @fw:		Pointer to firmware structure from rpi_firmware_get().
 * @tag:	One of enum_mbox_property_tag.
 * @tag_data:	Tag data buffer.
 * @buf_size:	Buffer size.
 *
 * Submits a single tag to the VPU firmware through the mailbox
 * property interface.
 *
 * This is a convenience wrapper around
 * rpi_firmware_property_list() to avoid some of the
 * boilerplate in property calls.
 */
int rpi_firmware_property(struct rpi_firmware *fw,
			  u32 tag, void *tag_data, size_t buf_size)
{
	struct rpi_firmware_property_tag_header *header;
	int ret;

	/* Some mailboxes can use over 1k bytes. Rather than checking
	 * size and using stack or kmalloc depending on requirements,
	 * just use kmalloc. Mailboxes don't get called enough to worry
	 * too much about the time taken in the allocation.
	 */
	void *data = kmalloc(sizeof(*header) + buf_size, GFP_KERNEL);

	if (!data)
		return -ENOMEM;

	header = data;
	header->tag = tag;
	header->buf_size = buf_size;
	header->req_resp_size = 0;
	memcpy(data + sizeof(*header), tag_data, buf_size);

	ret = rpi_firmware_property_list(fw, data, buf_size + sizeof(*header));

	memcpy(tag_data, data + sizeof(*header), buf_size);

	kfree(data);

	return ret;
}
EXPORT_SYMBOL_GPL(rpi_firmware_property);

static void
rpi_firmware_print_firmware_revision(struct rpi_firmware *fw)
{
	time64_t date_and_time;
	u32 packet;
	int ret = rpi_firmware_property(fw,
					RPI_FIRMWARE_GET_FIRMWARE_REVISION,
					&packet, sizeof(packet));

	if (ret)
		return;

	/* This is not compatible with y2038 */
	date_and_time = packet;
	dev_info(fw->cl.dev, "Attached to firmware from %ptT\n", &date_and_time);
}

static void
rpi_register_hwmon_driver(struct device *dev, struct rpi_firmware *fw)
{
	u32 packet;
	int ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_THROTTLED,
					&packet, sizeof(packet));

	if (ret)
		return;

	rpi_hwmon = platform_device_register_data(dev, "raspberrypi-hwmon",
						  -1, NULL, 0);
}

static void rpi_register_clk_driver(struct device *dev)
{
	struct device_node *firmware;

	/*
	 * Earlier DTs don't have a node for the firmware clocks but
	 * rely on us creating a platform device by hand. If we do
	 * have a node for the firmware clocks, just bail out here.
	 */
	firmware = of_get_compatible_child(dev->of_node,
					   "raspberrypi,firmware-clocks");
	if (firmware) {
		of_node_put(firmware);
		return;
	}

	rpi_clk = platform_device_register_data(dev, "raspberrypi-clk",
						-1, NULL, 0);
}

unsigned int rpi_firmware_clk_get_max_rate(struct rpi_firmware *fw, unsigned int id)
{
	struct rpi_firmware_clk_rate_request msg =
		RPI_FIRMWARE_CLK_RATE_REQUEST(id);
	int ret;

	ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_MAX_CLOCK_RATE,
				    &msg, sizeof(msg));
	if (ret)
		/*
		 * If our firmware doesn't support that operation, or fails, we
		 * assume the maximum clock rate is absolute maximum we can
		 * store over our type.
		 */
		 return UINT_MAX;

	return le32_to_cpu(msg.rate);
}
EXPORT_SYMBOL_GPL(rpi_firmware_clk_get_max_rate);

static void rpi_firmware_delete(struct kref *kref)
{
	struct rpi_firmware *fw = container_of(kref, struct rpi_firmware,
					       consumers);

	mbox_free_channel(fw->chan);
	kfree(fw);
}

void rpi_firmware_put(struct rpi_firmware *fw)
{
	kref_put(&fw->consumers, rpi_firmware_delete);
}
EXPORT_SYMBOL_GPL(rpi_firmware_put);

static void devm_rpi_firmware_put(void *data)
{
	struct rpi_firmware *fw = data;

	rpi_firmware_put(fw);
}

static int rpi_firmware_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct rpi_firmware *fw;

	/*
	 * Memory will be freed by rpi_firmware_delete() once all users have
	 * released their firmware handles. Don't use devm_kzalloc() here.
	 */
	fw = kzalloc(sizeof(*fw), GFP_KERNEL);
	if (!fw)
		return -ENOMEM;

	fw->cl.dev = dev;
	fw->cl.rx_callback = response_callback;
	fw->cl.tx_block = true;

	fw->chan = mbox_request_channel(&fw->cl, 0);
	if (IS_ERR(fw->chan)) {
		int ret = PTR_ERR(fw->chan);
		kfree(fw);
		return dev_err_probe(dev, ret, "Failed to get mbox channel\n");
	}

	init_completion(&fw->c);
	kref_init(&fw->consumers);

	platform_set_drvdata(pdev, fw);

	rpi_firmware_print_firmware_revision(fw);
	rpi_register_hwmon_driver(dev, fw);
	rpi_register_clk_driver(dev);

	return 0;
}

static void rpi_firmware_shutdown(struct platform_device *pdev)
{
	struct rpi_firmware *fw = platform_get_drvdata(pdev);

	if (!fw)
		return;

	rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_REBOOT, NULL, 0);
}

static void rpi_firmware_remove(struct platform_device *pdev)
{
	struct rpi_firmware *fw = platform_get_drvdata(pdev);

	platform_device_unregister(rpi_hwmon);
	rpi_hwmon = NULL;
	platform_device_unregister(rpi_clk);
	rpi_clk = NULL;

	rpi_firmware_put(fw);
}

static const struct of_device_id rpi_firmware_of_match[] = {
	{ .compatible = "raspberrypi,bcm2835-firmware", },
	{},
};
MODULE_DEVICE_TABLE(of, rpi_firmware_of_match);

struct device_node *rpi_firmware_find_node(void)
{
	return of_find_matching_node(NULL, rpi_firmware_of_match);
}
EXPORT_SYMBOL_GPL(rpi_firmware_find_node);

/**
 * rpi_firmware_get - Get pointer to rpi_firmware structure.
 * @firmware_node:    Pointer to the firmware Device Tree node.
 *
 * The reference to rpi_firmware has to be released with rpi_firmware_put().
 *
 * Returns NULL is the firmware device is not ready.
 */
struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node)
{
	struct platform_device *pdev = of_find_device_by_node(firmware_node);
	struct rpi_firmware *fw;

	if (!pdev)
		return NULL;

	fw = platform_get_drvdata(pdev);
	if (!fw)
		goto err_put_device;

	if (!kref_get_unless_zero(&fw->consumers))
		goto err_put_device;

	put_device(&pdev->dev);

	return fw;

err_put_device:
	put_device(&pdev->dev);
	return NULL;
}
EXPORT_SYMBOL_GPL(rpi_firmware_get);

/**
 * devm_rpi_firmware_get - Get pointer to rpi_firmware structure.
 * @dev:              The firmware device structure
 * @firmware_node:    Pointer to the firmware Device Tree node.
 *
 * Returns NULL is the firmware device is not ready.
 */
struct rpi_firmware *devm_rpi_firmware_get(struct device *dev,
					   struct device_node *firmware_node)
{
	struct rpi_firmware *fw;

	fw = rpi_firmware_get(firmware_node);
	if (!fw)
		return NULL;

	if (devm_add_action_or_reset(dev, devm_rpi_firmware_put, fw))
		return NULL;

	return fw;
}
EXPORT_SYMBOL_GPL(devm_rpi_firmware_get);

static struct platform_driver rpi_firmware_driver = {
	.driver = {
		.name = "raspberrypi-firmware",
		.of_match_table = rpi_firmware_of_match,
	},
	.probe		= rpi_firmware_probe,
	.shutdown	= rpi_firmware_shutdown,
	.remove		= rpi_firmware_remove,
};
module_platform_driver(rpi_firmware_driver);

MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
MODULE_DESCRIPTION("Raspberry Pi firmware driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
502b431c	1	// SPDX-License-Identifier: GPL-2.0
4e3d6065	2	/*
60aa8782	3	* Defines interfaces for interacting with the Raspberry Pi firmware's
4e3d6065 EA	4	* property channel.
	5	*
	6	* Copyright © 2015 Broadcom
4e3d6065 EA	7	*/
	8
	9	#include <linux/dma-mapping.h>
1e7c5735	10	#include <linux/kref.h>
4e3d6065	11	#include <linux/mailbox_client.h>
df518a0a	12	#include <linux/mailbox_controller.h>
4e3d6065	13	#include <linux/module.h>
5b45759c	14	#include <linux/of.h>
4e3d6065 EA	15	#include <linux/of_platform.h>
4e3d6065 EA	16	#include <linux/platform_device.h>
91c6ada6	17	#include <linux/slab.h>
4e3d6065 EA	18	#include <soc/bcm2835/raspberrypi-firmware.h>
	19
	20	#define MBOX_MSG(chan, data28) (((data28) & ~0xf) \| ((chan) & 0xf))
	21	#define MBOX_CHAN(msg) ((msg) & 0xf)
	22	#define MBOX_DATA28(msg) ((msg) & ~0xf)
	23	#define MBOX_CHAN_PROPERTY 8
	24
70eea1bb	25	static struct platform_device *rpi_hwmon;
91f2cf4a	26	static struct platform_device *rpi_clk;
70eea1bb	27
4e3d6065 EA	28	struct rpi_firmware {
	29	struct mbox_client cl;
	30	struct mbox_chan chan; / The property channel. */
	31	struct completion c;
	32	u32 enabled;
1e7c5735 NSJ	33
1e7c5735 NSJ	34	struct kref consumers;
4e3d6065 EA	35	};
	36
	37	static DEFINE_MUTEX(transaction_lock);
	38
	39	static void response_callback(struct mbox_client cl, void msg)
	40	{
	41	struct rpi_firmware *fw = container_of(cl, struct rpi_firmware, cl);
	42	complete(&fw->c);
	43	}
	44
	45	/*
	46	* Sends a request to the firmware through the BCM2835 mailbox driver,
	47	* and synchronously waits for the reply.
	48	*/
	49	static int
	50	rpi_firmware_transaction(struct rpi_firmware *fw, u32 chan, u32 data)
	51	{
	52	u32 message = MBOX_MSG(chan, data);
	53	int ret;
	54
	55	WARN_ON(data & 0xf);
	56
	57	mutex_lock(&transaction_lock);
	58	reinit_completion(&fw->c);
	59	ret = mbox_send_message(fw->chan, &message);
	60	if (ret >= 0) {
0829187b SW	61	if (wait_for_completion_timeout(&fw->c, HZ)) {
	62	ret = 0;
	63	} else {
	64	ret = -ETIMEDOUT;
0829187b	65	}
4e3d6065 EA	66	} else {
	67	dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret);
	68	}
	69	mutex_unlock(&transaction_lock);
	70
	71	return ret;
	72	}
	73
	74	/**
	75	* rpi_firmware_property_list - Submit firmware property list
	76	* @fw: Pointer to firmware structure from rpi_firmware_get().
	77	* @data: Buffer holding tags.
	78	* @tag_size: Size of tags buffer.
	79	*
	80	* Submits a set of concatenated tags to the VPU firmware through the
	81	* mailbox property interface.
	82	*
	83	* The buffer header and the ending tag are added by this function and
	84	* don't need to be supplied, just the actual tags for your operation.
	85	* See struct rpi_firmware_property_tag_header for the per-tag
	86	* structure.
	87	*/
	88	int rpi_firmware_property_list(struct rpi_firmware *fw,
	89	void *data, size_t tag_size)
	90	{
	91	size_t size = tag_size + 12;
	92	u32 *buf;
	93	dma_addr_t bus_addr;
	94	int ret;
	95
	96	/* Packets are processed a dword at a time. */
	97	if (size & 3)
	98	return -EINVAL;
	99
df518a0a LP	100	buf = dma_alloc_coherent(fw->chan->mbox->dev, PAGE_ALIGN(size),
df518a0a LP	101	&bus_addr, GFP_ATOMIC);
4e3d6065 EA	102	if (!buf)
	103	return -ENOMEM;
	104
	105	/* The firmware will error out without parsing in this case. */
	106	WARN_ON(size >= 1024 * 1024);
	107
	108	buf[0] = size;
	109	buf[1] = RPI_FIRMWARE_STATUS_REQUEST;
	110	memcpy(&buf[2], data, tag_size);
	111	buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END;
	112	wmb();
	113
	114	ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr);
	115
	116	rmb();
	117	memcpy(data, &buf[2], tag_size);
	118	if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) {
	119	/*
	120	* The tag name here might not be the one causing the
	121	* error, if there were multiple tags in the request.
	122	* But single-tag is the most common, so go with it.
	123	*/
	124	dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n",
	125	buf[2], buf[1]);
	126	ret = -EINVAL;
70c2cf28 SW	127	} else if (ret == -ETIMEDOUT) {
70c2cf28 SW	128	WARN_ONCE(1, "Firmware transaction 0x%08x timeout", buf[2]);
4e3d6065 EA	129	}
4e3d6065 EA	130
df518a0a	131	dma_free_coherent(fw->chan->mbox->dev, PAGE_ALIGN(size), buf, bus_addr);
4e3d6065 EA	132
	133	return ret;
	134	}
	135	EXPORT_SYMBOL_GPL(rpi_firmware_property_list);
	136
	137	/**
	138	* rpi_firmware_property - Submit single firmware property
	139	* @fw: Pointer to firmware structure from rpi_firmware_get().
	140	* @tag: One of enum_mbox_property_tag.
	141	* @tag_data: Tag data buffer.
	142	* @buf_size: Buffer size.
	143	*
	144	* Submits a single tag to the VPU firmware through the mailbox
	145	* property interface.
	146	*
	147	* This is a convenience wrapper around
	148	* rpi_firmware_property_list() to avoid some of the
	149	* boilerplate in property calls.
	150	*/
	151	int rpi_firmware_property(struct rpi_firmware *fw,
	152	u32 tag, void *tag_data, size_t buf_size)
	153	{
91c6ada6	154	struct rpi_firmware_property_tag_header *header;
4e3d6065 EA	155	int ret;
4e3d6065 EA	156
91c6ada6 JH	157	/* Some mailboxes can use over 1k bytes. Rather than checking
	158	* size and using stack or kmalloc depending on requirements,
	159	* just use kmalloc. Mailboxes don't get called enough to worry
	160	* too much about the time taken in the allocation.
	161	*/
	162	void data = kmalloc(sizeof(header) + buf_size, GFP_KERNEL);
a1547e0b	163
91c6ada6 JH	164	if (!data)
	165	return -ENOMEM;
	166
	167	header = data;
4e3d6065 EA	168	header->tag = tag;
	169	header->buf_size = buf_size;
	170	header->req_resp_size = 0;
91c6ada6 JH	171	memcpy(data + sizeof(*header), tag_data, buf_size);
	172
	173	ret = rpi_firmware_property_list(fw, data, buf_size + sizeof(*header));
	174
	175	memcpy(tag_data, data + sizeof(*header), buf_size);
4e3d6065	176
91c6ada6	177	kfree(data);
4e3d6065 EA	178
	179	return ret;
	180	}
	181	EXPORT_SYMBOL_GPL(rpi_firmware_property);
	182
	183	static void
	184	rpi_firmware_print_firmware_revision(struct rpi_firmware *fw)
	185	{
da785a87	186	time64_t date_and_time;
4e3d6065 EA	187	u32 packet;
	188	int ret = rpi_firmware_property(fw,
	189	RPI_FIRMWARE_GET_FIRMWARE_REVISION,
	190	&packet, sizeof(packet));
	191
4a60f58e AS	192	if (ret)
4a60f58e AS	193	return;
4e3d6065	194
da785a87 AS	195	/* This is not compatible with y2038 */
	196	date_and_time = packet;
	197	dev_info(fw->cl.dev, "Attached to firmware from %ptT\n", &date_and_time);
4e3d6065 EA	198	}
4e3d6065 EA	199
70eea1bb SW	200	static void
	201	rpi_register_hwmon_driver(struct device dev, struct rpi_firmware fw)
	202	{
	203	u32 packet;
	204	int ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_THROTTLED,
	205	&packet, sizeof(packet));
	206
	207	if (ret)
	208	return;
	209
	210	rpi_hwmon = platform_device_register_data(dev, "raspberrypi-hwmon",
	211	-1, NULL, 0);
	212	}
	213
91f2cf4a NSJ	214	static void rpi_register_clk_driver(struct device *dev)
91f2cf4a NSJ	215	{
511aba09 MR	216	struct device_node *firmware;
	217
	218	/*
	219	* Earlier DTs don't have a node for the firmware clocks but
	220	* rely on us creating a platform device by hand. If we do
	221	* have a node for the firmware clocks, just bail out here.
	222	*/
	223	firmware = of_get_compatible_child(dev->of_node,
	224	"raspberrypi,firmware-clocks");
	225	if (firmware) {
	226	of_node_put(firmware);
	227	return;
	228	}
	229
91f2cf4a NSJ	230	rpi_clk = platform_device_register_data(dev, "raspberrypi-clk",
	231	-1, NULL, 0);
	232	}
	233
40c31955 MR	234	unsigned int rpi_firmware_clk_get_max_rate(struct rpi_firmware *fw, unsigned int id)
	235	{
	236	struct rpi_firmware_clk_rate_request msg =
	237	RPI_FIRMWARE_CLK_RATE_REQUEST(id);
	238	int ret;
	239
	240	ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_MAX_CLOCK_RATE,
	241	&msg, sizeof(msg));
	242	if (ret)
	243	/*
	244	* If our firmware doesn't support that operation, or fails, we
	245	* assume the maximum clock rate is absolute maximum we can
	246	* store over our type.
	247	*/
	248	return UINT_MAX;
	249
	250	return le32_to_cpu(msg.rate);
	251	}
	252	EXPORT_SYMBOL_GPL(rpi_firmware_clk_get_max_rate);
	253
1e7c5735 NSJ	254	static void rpi_firmware_delete(struct kref *kref)
	255	{
	256	struct rpi_firmware *fw = container_of(kref, struct rpi_firmware,
	257	consumers);
	258
	259	mbox_free_channel(fw->chan);
	260	kfree(fw);
	261	}
	262
	263	void rpi_firmware_put(struct rpi_firmware *fw)
	264	{
	265	kref_put(&fw->consumers, rpi_firmware_delete);
	266	}
	267	EXPORT_SYMBOL_GPL(rpi_firmware_put);
	268
f663204c NSJ	269	static void devm_rpi_firmware_put(void *data)
	270	{
	271	struct rpi_firmware *fw = data;
	272
	273	rpi_firmware_put(fw);
	274	}
	275
4e3d6065 EA	276	static int rpi_firmware_probe(struct platform_device *pdev)
	277	{
	278	struct device *dev = &pdev->dev;
	279	struct rpi_firmware *fw;
	280
1e7c5735 NSJ	281	/*
	282	* Memory will be freed by rpi_firmware_delete() once all users have
	283	* released their firmware handles. Don't use devm_kzalloc() here.
	284	*/
	285	fw = kzalloc(sizeof(*fw), GFP_KERNEL);
4e3d6065 EA	286	if (!fw)
	287	return -ENOMEM;
	288
	289	fw->cl.dev = dev;
	290	fw->cl.rx_callback = response_callback;
	291	fw->cl.tx_block = true;
	292
	293	fw->chan = mbox_request_channel(&fw->cl, 0);
	294	if (IS_ERR(fw->chan)) {
	295	int ret = PTR_ERR(fw->chan);
7b511616	296	kfree(fw);
ba54ff1f	297	return dev_err_probe(dev, ret, "Failed to get mbox channel\n");
4e3d6065 EA	298	}
	299
	300	init_completion(&fw->c);
1e7c5735	301	kref_init(&fw->consumers);
4e3d6065 EA	302
	303	platform_set_drvdata(pdev, fw);
	304
	305	rpi_firmware_print_firmware_revision(fw);
70eea1bb	306	rpi_register_hwmon_driver(dev, fw);
91f2cf4a	307	rpi_register_clk_driver(dev);
4e3d6065 EA	308
	309	return 0;
	310	}
	311
b80ec7c0 SW	312	static void rpi_firmware_shutdown(struct platform_device *pdev)
	313	{
	314	struct rpi_firmware *fw = platform_get_drvdata(pdev);
	315
	316	if (!fw)
	317	return;
	318
	319	rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_REBOOT, NULL, 0);
	320	}
	321
ffc3c929	322	static void rpi_firmware_remove(struct platform_device *pdev)
4e3d6065 EA	323	{
	324	struct rpi_firmware *fw = platform_get_drvdata(pdev);
	325
70eea1bb SW	326	platform_device_unregister(rpi_hwmon);
70eea1bb SW	327	rpi_hwmon = NULL;
91f2cf4a NSJ	328	platform_device_unregister(rpi_clk);
91f2cf4a NSJ	329	rpi_clk = NULL;
1e7c5735 NSJ	330
1e7c5735 NSJ	331	rpi_firmware_put(fw);
4e3d6065 EA	332	}
4e3d6065 EA	333
bc63897b MR	334	static const struct of_device_id rpi_firmware_of_match[] = {
	335	{ .compatible = "raspberrypi,bcm2835-firmware", },
	336	{},
	337	};
	338	MODULE_DEVICE_TABLE(of, rpi_firmware_of_match);
	339
	340	struct device_node *rpi_firmware_find_node(void)
	341	{
	342	return of_find_matching_node(NULL, rpi_firmware_of_match);
	343	}
	344	EXPORT_SYMBOL_GPL(rpi_firmware_find_node);
	345
4e3d6065 EA	346	/**
	347	* rpi_firmware_get - Get pointer to rpi_firmware structure.
	348	* @firmware_node: Pointer to the firmware Device Tree node.
	349	*
1e7c5735 NSJ	350	* The reference to rpi_firmware has to be released with rpi_firmware_put().
1e7c5735 NSJ	351	*
4e3d6065 EA	352	* Returns NULL is the firmware device is not ready.
	353	*/
	354	struct rpi_firmware rpi_firmware_get(struct device_node firmware_node)
	355	{
	356	struct platform_device *pdev = of_find_device_by_node(firmware_node);
1e7c5735	357	struct rpi_firmware *fw;
4e3d6065 EA	358
	359	if (!pdev)
	360	return NULL;
	361
1e7c5735 NSJ	362	fw = platform_get_drvdata(pdev);
1e7c5735 NSJ	363	if (!fw)
09cbd1df	364	goto err_put_device;
1e7c5735 NSJ	365
1e7c5735 NSJ	366	if (!kref_get_unless_zero(&fw->consumers))
09cbd1df CJ	367	goto err_put_device;
	368
	369	put_device(&pdev->dev);
1e7c5735 NSJ	370
1e7c5735 NSJ	371	return fw;
09cbd1df CJ	372
	373	err_put_device:
	374	put_device(&pdev->dev);
	375	return NULL;
4e3d6065 EA	376	}
	377	EXPORT_SYMBOL_GPL(rpi_firmware_get);
	378
f663204c NSJ	379	/**
f663204c NSJ	380	* devm_rpi_firmware_get - Get pointer to rpi_firmware structure.
a21ecc52	381	* @dev: The firmware device structure
f663204c NSJ	382	* @firmware_node: Pointer to the firmware Device Tree node.
	383	*
	384	* Returns NULL is the firmware device is not ready.
	385	*/
	386	struct rpi_firmware devm_rpi_firmware_get(struct device dev,
	387	struct device_node *firmware_node)
	388	{
	389	struct rpi_firmware *fw;
	390
	391	fw = rpi_firmware_get(firmware_node);
	392	if (!fw)
	393	return NULL;
	394
	395	if (devm_add_action_or_reset(dev, devm_rpi_firmware_put, fw))
	396	return NULL;
	397
	398	return fw;
	399	}
	400	EXPORT_SYMBOL_GPL(devm_rpi_firmware_get);
	401
4e3d6065 EA	402	static struct platform_driver rpi_firmware_driver = {
	403	.driver = {
	404	.name = "raspberrypi-firmware",
	405	.of_match_table = rpi_firmware_of_match,
	406	},
	407	.probe = rpi_firmware_probe,
b80ec7c0	408	.shutdown = rpi_firmware_shutdown,
5770e9f2	409	.remove = rpi_firmware_remove,
4e3d6065 EA	410	};
	411	module_platform_driver(rpi_firmware_driver);
	412
	413	MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
	414	MODULE_DESCRIPTION("Raspberry Pi firmware driver");
	415	MODULE_LICENSE("GPL v2");