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Commit 4e3d6065 authored by Eric Anholt's avatar Eric Anholt
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ARM: bcm2835: Add the Raspberry Pi firmware driver 



This gives us a function for making mailbox property channel requests
of the firmware, which is most notable in that it will let us get and
set clock rates.

Signed-off-by: default avatarEric Anholt <eric@anholt.net>
Acked-by: default avatarStephen Warren <swarren@wwwdotorg.org>
parent 6ff33f39

drivers/firmware/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -139,6 +139,13 @@ config QCOM_SCM 
	bool

	depends on ARM || ARM64



config RASPBERRYPI_FIRMWARE

	tristate "Raspberry Pi Firmware Driver"

	depends on BCM2835_MBOX

	help

	  This option enables support for communicating with the firmware on the

	  Raspberry Pi.



source "drivers/firmware/broadcom/Kconfig"

source "drivers/firmware/google/Kconfig"

source "drivers/firmware/efi/Kconfig"

drivers/firmware/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ obj-$(CONFIG_FIRMWARE_MEMMAP) += memmap.o 
obj-$(CONFIG_QCOM_SCM)		+= qcom_scm.o

obj-$(CONFIG_QCOM_SCM)		+= qcom_scm-32.o

CFLAGS_qcom_scm-32.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1)

obj-$(CONFIG_RASPBERRYPI_FIRMWARE) += raspberrypi.o



obj-y				+= broadcom/

obj-$(CONFIG_GOOGLE_FIRMWARE)	+= google/

drivers/firmware/raspberrypi.c

0 → 100644
+260 −0
Original line number Diff line number Diff line 
/*

 * 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 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) {

		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;

}



/**

 * 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);



	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);



	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,

	.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");

include/soc/bcm2835/raspberrypi-firmware.h

0 → 100644
+115 −0
Original line number Diff line number Diff line 
/*

 *  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/types.h>

#include <linux/of_device.h>



struct rpi_firmware;



enum rpi_firmware_property_status {

	RPI_FIRMWARE_STATUS_REQUEST = 0,

	RPI_FIRMWARE_STATUS_SUCCESS = 0x80000000,

	RPI_FIRMWARE_STATUS_ERROR =   0x80000001,

};



/**

 * struct rpi_firmware_property_tag_header - Firmware property tag header

 * @tag:		One of enum_mbox_property_tag.

 * @buf_size:		The number of bytes in the value buffer following this

 *			struct.

 * @req_resp_size:	On submit, the length of the request (though it doesn't

 *			appear to be currently used by the firmware).  On return,

 *			the length of the response (always 4 byte aligned), with

 *			the low bit set.

 */

struct rpi_firmware_property_tag_header {

	u32 tag;

	u32 buf_size;

	u32 req_resp_size;

};



enum rpi_firmware_property_tag {

	RPI_FIRMWARE_PROPERTY_END =                           0,

	RPI_FIRMWARE_GET_FIRMWARE_REVISION =                  0x00000001,



	RPI_FIRMWARE_SET_CURSOR_INFO =                        0x00008010,

	RPI_FIRMWARE_SET_CURSOR_STATE =                       0x00008011,



	RPI_FIRMWARE_GET_BOARD_MODEL =                        0x00010001,

	RPI_FIRMWARE_GET_BOARD_REVISION =                     0x00010002,

	RPI_FIRMWARE_GET_BOARD_MAC_ADDRESS =                  0x00010003,

	RPI_FIRMWARE_GET_BOARD_SERIAL =                       0x00010004,

	RPI_FIRMWARE_GET_ARM_MEMORY =                         0x00010005,

	RPI_FIRMWARE_GET_VC_MEMORY =                          0x00010006,

	RPI_FIRMWARE_GET_CLOCKS =                             0x00010007,

	RPI_FIRMWARE_GET_POWER_STATE =                        0x00020001,

	RPI_FIRMWARE_GET_TIMING =                             0x00020002,

	RPI_FIRMWARE_SET_POWER_STATE =                        0x00028001,

	RPI_FIRMWARE_GET_CLOCK_STATE =                        0x00030001,

	RPI_FIRMWARE_GET_CLOCK_RATE =                         0x00030002,

	RPI_FIRMWARE_GET_VOLTAGE =                            0x00030003,

	RPI_FIRMWARE_GET_MAX_CLOCK_RATE =                     0x00030004,

	RPI_FIRMWARE_GET_MAX_VOLTAGE =                        0x00030005,

	RPI_FIRMWARE_GET_TEMPERATURE =                        0x00030006,

	RPI_FIRMWARE_GET_MIN_CLOCK_RATE =                     0x00030007,

	RPI_FIRMWARE_GET_MIN_VOLTAGE =                        0x00030008,

	RPI_FIRMWARE_GET_TURBO =                              0x00030009,

	RPI_FIRMWARE_GET_MAX_TEMPERATURE =                    0x0003000a,

	RPI_FIRMWARE_ALLOCATE_MEMORY =                        0x0003000c,

	RPI_FIRMWARE_LOCK_MEMORY =                            0x0003000d,

	RPI_FIRMWARE_UNLOCK_MEMORY =                          0x0003000e,

	RPI_FIRMWARE_RELEASE_MEMORY =                         0x0003000f,

	RPI_FIRMWARE_EXECUTE_CODE =                           0x00030010,

	RPI_FIRMWARE_EXECUTE_QPU =                            0x00030011,

	RPI_FIRMWARE_SET_ENABLE_QPU =                         0x00030012,

	RPI_FIRMWARE_GET_DISPMANX_RESOURCE_MEM_HANDLE =       0x00030014,

	RPI_FIRMWARE_GET_EDID_BLOCK =                         0x00030020,

	RPI_FIRMWARE_SET_CLOCK_STATE =                        0x00038001,

	RPI_FIRMWARE_SET_CLOCK_RATE =                         0x00038002,

	RPI_FIRMWARE_SET_VOLTAGE =                            0x00038003,

	RPI_FIRMWARE_SET_TURBO =                              0x00038009,



	/* Dispmanx TAGS */

	RPI_FIRMWARE_FRAMEBUFFER_ALLOCATE =                   0x00040001,

	RPI_FIRMWARE_FRAMEBUFFER_BLANK =                      0x00040002,

	RPI_FIRMWARE_FRAMEBUFFER_GET_PHYSICAL_WIDTH_HEIGHT =  0x00040003,

	RPI_FIRMWARE_FRAMEBUFFER_GET_VIRTUAL_WIDTH_HEIGHT =   0x00040004,

	RPI_FIRMWARE_FRAMEBUFFER_GET_DEPTH =                  0x00040005,

	RPI_FIRMWARE_FRAMEBUFFER_GET_PIXEL_ORDER =            0x00040006,

	RPI_FIRMWARE_FRAMEBUFFER_GET_ALPHA_MODE =             0x00040007,

	RPI_FIRMWARE_FRAMEBUFFER_GET_PITCH =                  0x00040008,

	RPI_FIRMWARE_FRAMEBUFFER_GET_VIRTUAL_OFFSET =         0x00040009,

	RPI_FIRMWARE_FRAMEBUFFER_GET_OVERSCAN =               0x0004000a,

	RPI_FIRMWARE_FRAMEBUFFER_GET_PALETTE =                0x0004000b,

	RPI_FIRMWARE_FRAMEBUFFER_RELEASE =                    0x00048001,

	RPI_FIRMWARE_FRAMEBUFFER_TEST_PHYSICAL_WIDTH_HEIGHT = 0x00044003,

	RPI_FIRMWARE_FRAMEBUFFER_TEST_VIRTUAL_WIDTH_HEIGHT =  0x00044004,

	RPI_FIRMWARE_FRAMEBUFFER_TEST_DEPTH =                 0x00044005,

	RPI_FIRMWARE_FRAMEBUFFER_TEST_PIXEL_ORDER =           0x00044006,

	RPI_FIRMWARE_FRAMEBUFFER_TEST_ALPHA_MODE =            0x00044007,

	RPI_FIRMWARE_FRAMEBUFFER_TEST_VIRTUAL_OFFSET =        0x00044009,

	RPI_FIRMWARE_FRAMEBUFFER_TEST_OVERSCAN =              0x0004400a,

	RPI_FIRMWARE_FRAMEBUFFER_TEST_PALETTE =               0x0004400b,

	RPI_FIRMWARE_FRAMEBUFFER_SET_PHYSICAL_WIDTH_HEIGHT =  0x00048003,

	RPI_FIRMWARE_FRAMEBUFFER_SET_VIRTUAL_WIDTH_HEIGHT =   0x00048004,

	RPI_FIRMWARE_FRAMEBUFFER_SET_DEPTH =                  0x00048005,

	RPI_FIRMWARE_FRAMEBUFFER_SET_PIXEL_ORDER =            0x00048006,

	RPI_FIRMWARE_FRAMEBUFFER_SET_ALPHA_MODE =             0x00048007,

	RPI_FIRMWARE_FRAMEBUFFER_SET_VIRTUAL_OFFSET =         0x00048009,

	RPI_FIRMWARE_FRAMEBUFFER_SET_OVERSCAN =               0x0004800a,

	RPI_FIRMWARE_FRAMEBUFFER_SET_PALETTE =                0x0004800b,



	RPI_FIRMWARE_GET_COMMAND_LINE =                       0x00050001,

	RPI_FIRMWARE_GET_DMA_CHANNELS =                       0x00060001,

};



int rpi_firmware_property(struct rpi_firmware *fw,

			  u32 tag, void *data, size_t len);

int rpi_firmware_property_list(struct rpi_firmware *fw,

			       void *data, size_t tag_size);

struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node);