[mirror_ubuntu-artful-kernel.git] / drivers / firmware / raspberrypi.c

/*
 * Defines interfaces for interacting wtih the Raspberry Pi firmware's
 * property channel.
 *
 * Copyright © 2015 Broadcom
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#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 <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

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

static struct platform_device *g_pdev;

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.
 */
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) {
		wait_for_completion(&fw->c);
		ret = 0;
	} else {
		dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret);
	}
	mutex_unlock(&transaction_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(rpi_firmware_transaction);

/**
 * 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)
{
	/* Single tags are very small (generally 8 bytes), so the
	 * stack should be safe.
	 */
	u8 data[buf_size + sizeof(struct rpi_firmware_property_tag_header)];
	struct rpi_firmware_property_tag_header *header =
		(struct rpi_firmware_property_tag_header *)data;
	int ret;

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

	ret = rpi_firmware_property_list(fw, &data, sizeof(data));
	memcpy(tag_data,
	       data + sizeof(struct rpi_firmware_property_tag_header),
	       buf_size);

	return ret;
}
EXPORT_SYMBOL_GPL(rpi_firmware_property);

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

	if (ret == 0) {
		struct tm tm;

		time_to_tm(packet, 0, &tm);

		dev_info(fw->cl.dev,
			 "Attached to firmware from %04ld-%02d-%02d %02d:%02d\n",
			 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
			 tm.tm_hour, tm.tm_min);
	}
}

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);
	g_pdev = pdev;

	rpi_firmware_print_firmware_revision(fw);

	return 0;
}

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

	mbox_free_channel(fw->chan);
	g_pdev = NULL;

	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 = g_pdev;

	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,
	.remove		= rpi_firmware_remove,
};

static int __init rpi_firmware_init(void)
{
	return platform_driver_register(&rpi_firmware_driver);
}
subsys_initcall(rpi_firmware_init);

static void __init rpi_firmware_exit(void)
{
	platform_driver_unregister(&rpi_firmware_driver);
}
module_exit(rpi_firmware_exit);

MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
MODULE_DESCRIPTION("Raspberry Pi firmware driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
4e3d6065 EA	1	/*
	2	* Defines interfaces for interacting wtih the Raspberry Pi firmware's
	3	* property channel.
	4	*
	5	* Copyright © 2015 Broadcom
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	#include <linux/dma-mapping.h>
	13	#include <linux/mailbox_client.h>
	14	#include <linux/module.h>
	15	#include <linux/of_platform.h>
	16	#include <linux/platform_device.h>
	17	#include <soc/bcm2835/raspberrypi-firmware.h>
	18
	19	#define MBOX_MSG(chan, data28) (((data28) & ~0xf) \| ((chan) & 0xf))
	20	#define MBOX_CHAN(msg) ((msg) & 0xf)
	21	#define MBOX_DATA28(msg) ((msg) & ~0xf)
	22	#define MBOX_CHAN_PROPERTY 8
	23
	24	struct rpi_firmware {
	25	struct mbox_client cl;
	26	struct mbox_chan chan; / The property channel. */
	27	struct completion c;
	28	u32 enabled;
	29	};
	30
874b518a NT	31	static struct platform_device *g_pdev;
874b518a NT	32
4e3d6065 EA	33	static DEFINE_MUTEX(transaction_lock);
	34
	35	static void response_callback(struct mbox_client cl, void msg)
	36	{
	37	struct rpi_firmware *fw = container_of(cl, struct rpi_firmware, cl);
	38	complete(&fw->c);
	39	}
	40
	41	/*
	42	* Sends a request to the firmware through the BCM2835 mailbox driver,
	43	* and synchronously waits for the reply.
	44	*/
95cda0b9	45	int
4e3d6065 EA	46	rpi_firmware_transaction(struct rpi_firmware *fw, u32 chan, u32 data)
	47	{
	48	u32 message = MBOX_MSG(chan, data);
	49	int ret;
	50
	51	WARN_ON(data & 0xf);
	52
	53	mutex_lock(&transaction_lock);
	54	reinit_completion(&fw->c);
	55	ret = mbox_send_message(fw->chan, &message);
	56	if (ret >= 0) {
	57	wait_for_completion(&fw->c);
	58	ret = 0;
	59	} else {
	60	dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret);
	61	}
	62	mutex_unlock(&transaction_lock);
	63
	64	return ret;
	65	}
95cda0b9	66	EXPORT_SYMBOL_GPL(rpi_firmware_transaction);
4e3d6065 EA	67
	68	/**
	69	* rpi_firmware_property_list - Submit firmware property list
	70	* @fw: Pointer to firmware structure from rpi_firmware_get().
	71	* @data: Buffer holding tags.
	72	* @tag_size: Size of tags buffer.
	73	*
	74	* Submits a set of concatenated tags to the VPU firmware through the
	75	* mailbox property interface.
	76	*
	77	* The buffer header and the ending tag are added by this function and
	78	* don't need to be supplied, just the actual tags for your operation.
	79	* See struct rpi_firmware_property_tag_header for the per-tag
	80	* structure.
	81	*/
	82	int rpi_firmware_property_list(struct rpi_firmware *fw,
	83	void *data, size_t tag_size)
	84	{
	85	size_t size = tag_size + 12;
	86	u32 *buf;
	87	dma_addr_t bus_addr;
	88	int ret;
	89
	90	/* Packets are processed a dword at a time. */
	91	if (size & 3)
	92	return -EINVAL;
	93
	94	buf = dma_alloc_coherent(fw->cl.dev, PAGE_ALIGN(size), &bus_addr,
	95	GFP_ATOMIC);
	96	if (!buf)
	97	return -ENOMEM;
	98
	99	/* The firmware will error out without parsing in this case. */
	100	WARN_ON(size >= 1024 * 1024);
	101
	102	buf[0] = size;
	103	buf[1] = RPI_FIRMWARE_STATUS_REQUEST;
	104	memcpy(&buf[2], data, tag_size);
	105	buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END;
	106	wmb();
	107
	108	ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr);
	109
	110	rmb();
	111	memcpy(data, &buf[2], tag_size);
	112	if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) {
	113	/*
	114	* The tag name here might not be the one causing the
	115	* error, if there were multiple tags in the request.
	116	* But single-tag is the most common, so go with it.
	117	*/
	118	dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n",
	119	buf[2], buf[1]);
	120	ret = -EINVAL;
	121	}
	122
	123	dma_free_coherent(fw->cl.dev, PAGE_ALIGN(size), buf, bus_addr);
	124
	125	return ret;
	126	}
	127	EXPORT_SYMBOL_GPL(rpi_firmware_property_list);
	128
	129	/**
	130	* rpi_firmware_property - Submit single firmware property
131	* @fw: Pointer to firmware structure from rpi_firmware_get().
132	* @tag: One of enum_mbox_property_tag.
133	* @tag_data: Tag data buffer.
134	* @buf_size: Buffer size.
135	*
136	* Submits a single tag to the VPU firmware through the mailbox
137	* property interface.
138	*
139	* This is a convenience wrapper around
140	* rpi_firmware_property_list() to avoid some of the
141	* boilerplate in property calls.
142	*/
143	int rpi_firmware_property(struct rpi_firmware *fw,
144	u32 tag, void *tag_data, size_t buf_size)
145	{
146	/* Single tags are very small (generally 8 bytes), so the
147	* stack should be safe.
148	*/
149	u8 data[buf_size + sizeof(struct rpi_firmware_property_tag_header)];
150	struct rpi_firmware_property_tag_header *header =
151	(struct rpi_firmware_property_tag_header *)data;
152	int ret;
153
154	header->tag = tag;
155	header->buf_size = buf_size;
156	header->req_resp_size = 0;
157	memcpy(data + sizeof(struct rpi_firmware_property_tag_header),
158	tag_data, buf_size);
159
160	ret = rpi_firmware_property_list(fw, &data, sizeof(data));
161	memcpy(tag_data,
162	data + sizeof(struct rpi_firmware_property_tag_header),
163	buf_size);
164
165	return ret;
166	}
167	EXPORT_SYMBOL_GPL(rpi_firmware_property);
168
169	static void
170	rpi_firmware_print_firmware_revision(struct rpi_firmware *fw)
171	{
172	u32 packet;
173	int ret = rpi_firmware_property(fw,
174	RPI_FIRMWARE_GET_FIRMWARE_REVISION,
175	&packet, sizeof(packet));
176
177	if (ret == 0) {
178	struct tm tm;
179
180	time_to_tm(packet, 0, &tm);
181
182	dev_info(fw->cl.dev,
183	"Attached to firmware from %04ld-%02d-%02d %02d:%02d\n",
184	tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
185	tm.tm_hour, tm.tm_min);
186	}
187	}
188
189	static int rpi_firmware_probe(struct platform_device *pdev)
190	{
191	struct device *dev = &pdev->dev;
192	struct rpi_firmware *fw;
193
194	fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL);
195	if (!fw)
196	return -ENOMEM;
197
198	fw->cl.dev = dev;
199	fw->cl.rx_callback = response_callback;
200	fw->cl.tx_block = true;
201
202	fw->chan = mbox_request_channel(&fw->cl, 0);
203	if (IS_ERR(fw->chan)) {
204	int ret = PTR_ERR(fw->chan);
205	if (ret != -EPROBE_DEFER)
206	dev_err(dev, "Failed to get mbox channel: %d\n", ret);
207	return ret;
208	}
209
210	init_completion(&fw->c);
211
212	platform_set_drvdata(pdev, fw);
874b518a	213	g_pdev = pdev;
4e3d6065 EA	214
	215	rpi_firmware_print_firmware_revision(fw);
	216
	217	return 0;
	218	}
	219
	220	static int rpi_firmware_remove(struct platform_device *pdev)
	221	{
	222	struct rpi_firmware *fw = platform_get_drvdata(pdev);
	223
	224	mbox_free_channel(fw->chan);
874b518a	225	g_pdev = NULL;
4e3d6065 EA	226
	227	return 0;
	228	}
	229
	230	/**
	231	* rpi_firmware_get - Get pointer to rpi_firmware structure.
	232	* @firmware_node: Pointer to the firmware Device Tree node.
	233	*
	234	* Returns NULL is the firmware device is not ready.
	235	*/
	236	struct rpi_firmware rpi_firmware_get(struct device_node firmware_node)
	237	{
874b518a	238	struct platform_device *pdev = g_pdev;
4e3d6065 EA	239
	240	if (!pdev)
	241	return NULL;
	242
	243	return platform_get_drvdata(pdev);
	244	}
	245	EXPORT_SYMBOL_GPL(rpi_firmware_get);
	246
	247	static const struct of_device_id rpi_firmware_of_match[] = {
	248	{ .compatible = "raspberrypi,bcm2835-firmware", },
	249	{},
	250	};
	251	MODULE_DEVICE_TABLE(of, rpi_firmware_of_match);
	252
	253	static struct platform_driver rpi_firmware_driver = {
	254	.driver = {
	255	.name = "raspberrypi-firmware",
	256	.of_match_table = rpi_firmware_of_match,
	257	},
	258	.probe = rpi_firmware_probe,
	259	.remove = rpi_firmware_remove,
	260	};
874b518a NT	261
	262	static int __init rpi_firmware_init(void)
	263	{
	264	return platform_driver_register(&rpi_firmware_driver);
	265	}
	266	subsys_initcall(rpi_firmware_init);
	267
	268	static void __init rpi_firmware_exit(void)
	269	{
	270	platform_driver_unregister(&rpi_firmware_driver);
	271	}
	272	module_exit(rpi_firmware_exit);
4e3d6065 EA	273
	274	MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
	275	MODULE_DESCRIPTION("Raspberry Pi firmware driver");
	276	MODULE_LICENSE("GPL v2");