[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/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;
};

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);
}

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

	fw = devm_kzalloc(dev, 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);
		if (ret != -EPROBE_DEFER)
			dev_err(dev, "Failed to get mbox channel: %d\n", ret);
		return ret;
	}

	init_completion(&fw->c);

	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;
	mbox_free_channel(fw->chan);

	return 0;
}

/**
 * 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 *rpi_firmware_get(struct device_node *firmware_node)
{
	struct platform_device *pdev = of_find_device_by_node(firmware_node);

	if (!pdev)
		return NULL;

	return platform_get_drvdata(pdev);
}
EXPORT_SYMBOL_GPL(rpi_firmware_get);

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

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