[PATCH 2/3 v2] ARM: bcm2835: Add the Raspberry Pi firmware driver
From: Eric Anholt
Date: Wed May 13 2015 - 15:00:51 EST
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: Eric Anholt <eric@xxxxxxxxxx>
---
v2: Drop power-domains stuff for now since we don't have the driver
core support to make it useful. Move to drivers/firmware/.
Capitalize the enums. De-global the firmware variable. Use the
firmware device to allocate our DMA buffer, so that the dma-ranges
DT property gets respected. Simplify the property tag transaction
interface even more, leaving a multi-tag interface still
available. For conciseness, rename "raspberrypi" to "rpi" on all
functions/enums/structs, and the "firmware" variable to "fw".
Print when the driver is probed successfully, since debugging
-EPROBE_DEFER handling is such a big part of bcm2835 development.
Drop -EBUSY mailbox handling since the mailbox core has been fixed
to return -EPROBE_DEFER in -next.
Note that I don't think I've done what srwarren wanted for
-EPROBE_DEFER, because I'm not clear what he wants. I think he might
just be asking for a function that does:
/*
* Returns 0 if the firmware device is probed and available, otherwise
* -EPROBE_DEFER.
*/
int rpi_firmware_get(struct device_node *firmware_node)
{
struct platform_device *pdev = of_find_device_by_node(of_node);
if (!platform_get_drvdata(pdev))
return -EPROBE_DEFER;
return 0;
}
EXPORT_SYMBOL(rpi_firmware_get)
If that's all, I'm happy to add it.
Note that a client could currently do this:
ret = rpi_firmware_property_list(firmware_node, NULL, 0);
in exchange for a bit of overhead in the case that it's actually probed already.
drivers/firmware/Makefile | 1 +
drivers/firmware/raspberrypi.c | 224 +++++++++++++++++++++
.../soc/bcm2835/raspberrypi-firmware-property.h | 114 +++++++++++
3 files changed, 339 insertions(+)
create mode 100644 drivers/firmware/raspberrypi.c
create mode 100644 include/soc/bcm2835/raspberrypi-firmware-property.h
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 3fdd391..41ced28 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_ISCSI_IBFT) += iscsi_ibft.o
obj-$(CONFIG_FIRMWARE_MEMMAP) += memmap.o
obj-$(CONFIG_QCOM_SCM) += qcom_scm.o
CFLAGS_qcom_scm.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1)
+obj-$(CONFIG_BCM2835_MBOX) += raspberrypi.o
obj-$(CONFIG_GOOGLE_FIRMWARE) += google/
obj-$(CONFIG_EFI) += efi/
diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c
new file mode 100644
index 0000000..61bde1b
--- /dev/null
+++ b/drivers/firmware/raspberrypi.c
@@ -0,0 +1,224 @@
+/*
+ * 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.
+ */
+
+/*
+ * Defines interfaces for interacting wtih the Raspberry Pi firmware's
+ * property channel.
+ */
+
+#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-property.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;
+}
+
+/*
+ * 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 device_node *of_node,
+ void *data, size_t tag_size)
+{
+ struct platform_device *pdev = of_find_device_by_node(of_node);
+ struct rpi_firmware *fw = platform_get_drvdata(pdev);
+ size_t size = tag_size + 12;
+ u32 *buf;
+ dma_addr_t bus_addr;
+ int ret = 0;
+
+ if (!fw)
+ return -EPROBE_DEFER;
+
+ /* 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(NULL, PAGE_ALIGN(size), buf, bus_addr);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(rpi_firmware_property_list);
+
+/*
+ * 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 device_node *of_node,
+ 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(of_node, &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 int rpi_firmware_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ int ret = 0;
+ 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)) {
+ ret = PTR_ERR(fw->chan);
+ /* An -EBUSY from the core means it couldn't find our
+ * channel, because the mailbox driver hadn't
+ * registered yet.
+ */
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "Failed to get mbox channel: %d\n", ret);
+ return ret;
+ }
+
+ init_completion(&fw->c);
+
+ dev_info(dev, "Firmware driver\n");
+ platform_set_drvdata(pdev, 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;
+}
+
+static const struct of_device_id rpi_firmware_of_match[] = {
+ { .compatible = "raspberrypi,firmware", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, rpi_firmware_of_match);
+
+static struct platform_driver rpi_firmware_driver = {
+ .driver = {
+ .name = "raspberrypi-firmware",
+ .owner = THIS_MODULE,
+ .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@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Raspberry Pi firmware driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/soc/bcm2835/raspberrypi-firmware-property.h b/include/soc/bcm2835/raspberrypi-firmware-property.h
new file mode 100644
index 0000000..2557cab
--- /dev/null
+++ b/include/soc/bcm2835/raspberrypi-firmware-property.h
@@ -0,0 +1,114 @@
+/*
+ * 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>
+
+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 {
+ /* One of enum_mbox_property_tag. */
+ u32 tag;
+
+ /* The number of bytes in the value buffer following this
+ * struct.
+ */
+ u32 buf_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.
+ */
+ 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 device_node *of_node,
+ u32 tag, void *data, size_t len);
+int rpi_firmware_property_list(struct device_node *of_node,
+ void *data, size_t tag_size);
--
2.1.4
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