[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/module.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;
			WARN_ONCE(1, "Firmware transaction timeout");
		}
	} 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->cl.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;
	}

	dma_free_coherent(fw->cl.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 int 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);

	return 0;
}

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