[PATCH 2/3] ARM: bcm2835: Add the Raspberry Pi firmware driver
Eric Anholt
eric at anholt.net
Mon Apr 27 16:14:08 PDT 2015
This gives us a function for making mailbox property channel requests
of the firmware, and uses it to control the 3 power domains provided
by the firmware.
Signed-off-by: Eric Anholt <eric at anholt.net>
---
arch/arm/mach-bcm/Kconfig | 2 +
arch/arm/mach-bcm/Makefile | 1 +
arch/arm/mach-bcm/raspberrypi-firmware.c | 285 +++++++++++++++++++++
.../dt-bindings/arm/raspberrypi-firmware-power.h | 16 ++
include/soc/bcm2835/raspberrypi-mailbox-property.h | 110 ++++++++
5 files changed, 414 insertions(+)
create mode 100644 arch/arm/mach-bcm/raspberrypi-firmware.c
create mode 100644 include/dt-bindings/arm/raspberrypi-firmware-power.h
create mode 100644 include/soc/bcm2835/raspberrypi-mailbox-property.h
diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig
index 8b11f44..a907bf4 100644
--- a/arch/arm/mach-bcm/Kconfig
+++ b/arch/arm/mach-bcm/Kconfig
@@ -116,6 +116,8 @@ config ARCH_BCM2835
select CLKSRC_OF
select PINCTRL
select PINCTRL_BCM2835
+ select PM_GENERIC_DOMAINS if PM
+ select PM_GENERIC_DOMAINS_OF if PM
help
This enables support for the Broadcom BCM2835 SoC. This SoC is
used in the Raspberry Pi and Roku 2 devices.
diff --git a/arch/arm/mach-bcm/Makefile b/arch/arm/mach-bcm/Makefile
index 4c38674..bbdde34 100644
--- a/arch/arm/mach-bcm/Makefile
+++ b/arch/arm/mach-bcm/Makefile
@@ -33,6 +33,7 @@ endif
# BCM2835
obj-$(CONFIG_ARCH_BCM2835) += board_bcm2835.o
+obj-$(CONFIG_BCM2835_MBOX) += raspberrypi-firmware.o
# BCM5301X
obj-$(CONFIG_ARCH_BCM_5301X) += bcm_5301x.o
diff --git a/arch/arm/mach-bcm/raspberrypi-firmware.c b/arch/arm/mach-bcm/raspberrypi-firmware.c
new file mode 100644
index 0000000..194f05f
--- /dev/null
+++ b/arch/arm/mach-bcm/raspberrypi-firmware.c
@@ -0,0 +1,285 @@
+/*
+ * 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,
+ * and registers some of those services with the kernel.
+ */
+
+#include <dt-bindings/arm/raspberrypi-firmware-power.h>
+#include <linux/dma-mapping.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <soc/bcm2835/raspberrypi-mailbox-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 raspberrypi_firmware {
+ struct device *dev;
+ struct genpd_onecell_data genpd_xlate;
+ struct mbox_client cl;
+ struct mbox_chan *chan; /* The property channel. */
+ struct completion c;
+ u32 enabled;
+};
+
+static struct raspberrypi_firmware *firmware;
+static DEFINE_MUTEX(transaction_lock);
+
+static void response_callback(struct mbox_client *cl, void *msg)
+{
+ complete(&firmware->c);
+}
+
+/*
+ * Sends a request to the firmware through the BCM2835 mailbox driver,
+ * and synchronously waits for the reply.
+ */
+static int
+raspberrypi_firmware_transaction(u32 chan, u32 data)
+{
+ u32 message = MBOX_MSG(chan, data);
+ int ret;
+
+ WARN_ON(data & 0xf);
+
+ mutex_lock(&transaction_lock);
+ reinit_completion(&firmware->c);
+ ret = mbox_send_message(firmware->chan, &message);
+ if (ret >= 0) {
+ wait_for_completion(&firmware->c);
+ ret = 0;
+ } else {
+ dev_err(firmware->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 raspberrypi_firmware_property_tag_header for the per-tag structure.
+ */
+int raspberrypi_firmware_property(void *data, size_t tag_size)
+{
+ size_t size = tag_size + 12;
+ u32 *buf;
+ dma_addr_t bus_addr;
+ int ret = 0;
+
+ if (!firmware)
+ return -EPROBE_DEFER;
+
+ /* Packets are processed a dword at a time. */
+ if (size & 3)
+ return -EINVAL;
+
+ buf = dma_alloc_coherent(NULL, 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] = raspberrypi_firmware_status_request;
+ memcpy(&buf[2], data, tag_size);
+ buf[size / 4 - 1] = raspberrypi_firmware_property_end;
+ wmb();
+
+ ret = raspberrypi_firmware_transaction(MBOX_CHAN_PROPERTY, bus_addr);
+
+ rmb();
+ memcpy(data, &buf[2], tag_size);
+ if (ret == 0 && buf[1] != raspberrypi_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(firmware->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(raspberrypi_firmware_property);
+
+struct raspberrypi_power_domain {
+ u32 domain;
+ struct generic_pm_domain base;
+};
+
+/*
+ * Asks the firmware to enable or disable power on a specific power
+ * domain.
+ */
+static int raspberrypi_firmware_set_power(uint32_t domain, bool on)
+{
+ struct {
+ struct raspberrypi_firmware_property_tag_header header;
+ u32 domain;
+ u32 on;
+ } packet;
+ int ret;
+
+ memset(&packet, 0, sizeof(packet));
+ packet.header.tag = raspberrypi_firmware_set_power_state;
+ packet.header.buf_size = 8;
+ packet.domain = domain;
+ packet.on = on;
+ ret = raspberrypi_firmware_property(&packet, sizeof(packet));
+ if (!ret && !packet.on)
+ ret = -EINVAL;
+ return ret;
+}
+
+static int raspberrypi_domain_off(struct generic_pm_domain *domain)
+{
+ struct raspberrypi_power_domain *raspberrpi_domain =
+ container_of(domain, struct raspberrypi_power_domain, base);
+
+ return raspberrypi_firmware_set_power(raspberrpi_domain->domain, false);
+}
+
+static int raspberrypi_domain_on(struct generic_pm_domain *domain)
+{
+ struct raspberrypi_power_domain *raspberrpi_domain =
+ container_of(domain, struct raspberrypi_power_domain, base);
+
+ return raspberrypi_firmware_set_power(raspberrpi_domain->domain, true);
+}
+
+struct raspberrypi_power_domain raspberrypi_power_domain_sdcard = {
+ .domain = 0,
+ .base = {
+ .name = "SDCARD",
+ .power_off = raspberrypi_domain_off,
+ .power_on = raspberrypi_domain_on,
+ }
+};
+
+struct raspberrypi_power_domain raspberrypi_power_domain_usb = {
+ .domain = 3,
+ .base = {
+ .name = "USB",
+ .power_off = raspberrypi_domain_off,
+ .power_on = raspberrypi_domain_on,
+ }
+};
+
+struct raspberrypi_power_domain raspberrypi_power_domain_dsi = {
+ .domain = 9,
+ .base = {
+ .name = "DSI",
+ .power_off = raspberrypi_domain_off,
+ .power_on = raspberrypi_domain_on,
+ }
+};
+
+static struct generic_pm_domain *raspberrypi_power_domains[] = {
+ [POWER_DOMAIN_SDCARD] = &raspberrypi_power_domain_sdcard.base,
+ [POWER_DOMAIN_USB] = &raspberrypi_power_domain_usb.base,
+ [POWER_DOMAIN_DSI] = &raspberrypi_power_domain_dsi.base,
+};
+
+static int raspberrypi_firmware_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ int ret = 0;
+ int i;
+
+ firmware = devm_kzalloc(dev, sizeof(*firmware), GFP_KERNEL);
+ if (!firmware)
+ return -ENOMEM;
+
+ firmware->cl.dev = dev;
+ firmware->cl.rx_callback = response_callback;
+ firmware->cl.tx_block = true;
+
+ firmware->chan = mbox_request_channel(&firmware->cl, 0);
+ if (IS_ERR(firmware->chan)) {
+ ret = PTR_ERR(firmware->chan);
+ /* An -EBUSY from the core means it couldn't find our
+ * channel, because the mailbox driver hadn't
+ * registered yet.
+ */
+ if (ret == -EBUSY)
+ ret = -EPROBE_DEFER;
+ else
+ dev_err(dev, "Failed to get mbox channel: %d\n", ret);
+ goto fail;
+ }
+
+ init_completion(&firmware->c);
+
+ platform_set_drvdata(pdev, firmware);
+
+ firmware->genpd_xlate.domains =
+ raspberrypi_power_domains;
+ firmware->genpd_xlate.num_domains =
+ ARRAY_SIZE(raspberrypi_power_domains);
+
+ for (i = 0; i < ARRAY_SIZE(raspberrypi_power_domains); i++)
+ pm_genpd_init(raspberrypi_power_domains[i], NULL, true);
+
+ of_genpd_add_provider_onecell(dev->of_node, &firmware->genpd_xlate);
+
+ return 0;
+
+fail:
+ firmware = NULL;
+ return ret;
+}
+
+static int raspberrypi_firmware_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+
+ of_genpd_del_provider(dev->of_node);
+ mbox_free_channel(firmware->chan);
+
+ return 0;
+}
+
+static const struct of_device_id raspberrypi_firmware_of_match[] = {
+ { .compatible = "raspberrypi,firmware", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, raspberrypi_firmware_of_match);
+
+static struct platform_driver raspberrypi_firmware_driver = {
+ .driver = {
+ .name = "raspberrypi-firmware",
+ .owner = THIS_MODULE,
+ .of_match_table = raspberrypi_firmware_of_match,
+ },
+ .probe = raspberrypi_firmware_probe,
+ .remove = raspberrypi_firmware_remove,
+};
+module_platform_driver(raspberrypi_firmware_driver);
+
+MODULE_AUTHOR("Eric Anholt <eric at anholt.net>");
+MODULE_DESCRIPTION("Raspberry Pi firmware driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/dt-bindings/arm/raspberrypi-firmware-power.h b/include/dt-bindings/arm/raspberrypi-firmware-power.h
new file mode 100644
index 0000000..1e1ef3b
--- /dev/null
+++ b/include/dt-bindings/arm/raspberrypi-firmware-power.h
@@ -0,0 +1,16 @@
+/*
+ * 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.
+ */
+
+#ifndef _DT_BINDINGS_ARM_BCM2835_MBOX_POWER_H
+#define _DT_BINDINGS_ARM_BCM2835_MBOX_POWER_H
+
+#define POWER_DOMAIN_SDCARD 0
+#define POWER_DOMAIN_USB 1
+#define POWER_DOMAIN_DSI 2
+
+#endif
diff --git a/include/soc/bcm2835/raspberrypi-mailbox-property.h b/include/soc/bcm2835/raspberrypi-mailbox-property.h
new file mode 100644
index 0000000..787bd75
--- /dev/null
+++ b/include/soc/bcm2835/raspberrypi-mailbox-property.h
@@ -0,0 +1,110 @@
+/*
+ * 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>
+
+enum raspberrypi_firmware_property_status {
+ raspberrypi_firmware_status_request = 0,
+ raspberrypi_firmware_status_success = 0x80000000,
+ raspberrypi_firmware_status_error = 0x80000001,
+};
+
+struct raspberrypi_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 raspberrypi_firmware_property_tag {
+ raspberrypi_firmware_property_end = 0,
+ raspberrypi_firmware_get_firmware_revision = 0x00000001,
+
+ raspberrypi_firmware_set_cursor_info = 0x00008010,
+ raspberrypi_firmware_set_cursor_state = 0x00008011,
+
+ raspberrypi_firmware_get_board_model = 0x00010001,
+ raspberrypi_firmware_get_board_revision = 0x00010002,
+ raspberrypi_firmware_get_board_mac_address = 0x00010003,
+ raspberrypi_firmware_get_board_serial = 0x00010004,
+ raspberrypi_firmware_get_arm_memory = 0x00010005,
+ raspberrypi_firmware_get_vc_memory = 0x00010006,
+ raspberrypi_firmware_get_clocks = 0x00010007,
+ raspberrypi_firmware_get_power_state = 0x00020001,
+ raspberrypi_firmware_get_timing = 0x00020002,
+ raspberrypi_firmware_set_power_state = 0x00028001,
+ raspberrypi_firmware_get_clock_state = 0x00030001,
+ raspberrypi_firmware_get_clock_rate = 0x00030002,
+ raspberrypi_firmware_get_voltage = 0x00030003,
+ raspberrypi_firmware_get_max_clock_rate = 0x00030004,
+ raspberrypi_firmware_get_max_voltage = 0x00030005,
+ raspberrypi_firmware_get_temperature = 0x00030006,
+ raspberrypi_firmware_get_min_clock_rate = 0x00030007,
+ raspberrypi_firmware_get_min_voltage = 0x00030008,
+ raspberrypi_firmware_get_turbo = 0x00030009,
+ raspberrypi_firmware_get_max_temperature = 0x0003000a,
+ raspberrypi_firmware_allocate_memory = 0x0003000c,
+ raspberrypi_firmware_lock_memory = 0x0003000d,
+ raspberrypi_firmware_unlock_memory = 0x0003000e,
+ raspberrypi_firmware_release_memory = 0x0003000f,
+ raspberrypi_firmware_execute_code = 0x00030010,
+ raspberrypi_firmware_execute_qpu = 0x00030011,
+ raspberrypi_firmware_set_enable_qpu = 0x00030012,
+ raspberrypi_firmware_get_dispmanx_resource_mem_handle = 0x00030014,
+ raspberrypi_firmware_get_edid_block = 0x00030020,
+ raspberrypi_firmware_set_clock_state = 0x00038001,
+ raspberrypi_firmware_set_clock_rate = 0x00038002,
+ raspberrypi_firmware_set_voltage = 0x00038003,
+ raspberrypi_firmware_set_turbo = 0x00038009,
+
+ /* Dispmanx tags */
+ raspberrypi_firmware_framebuffer_allocate = 0x00040001,
+ raspberrypi_firmware_framebuffer_blank = 0x00040002,
+ raspberrypi_firmware_framebuffer_get_physical_width_height = 0x00040003,
+ raspberrypi_firmware_framebuffer_get_virtual_width_height = 0x00040004,
+ raspberrypi_firmware_framebuffer_get_depth = 0x00040005,
+ raspberrypi_firmware_framebuffer_get_pixel_order = 0x00040006,
+ raspberrypi_firmware_framebuffer_get_alpha_mode = 0x00040007,
+ raspberrypi_firmware_framebuffer_get_pitch = 0x00040008,
+ raspberrypi_firmware_framebuffer_get_virtual_offset = 0x00040009,
+ raspberrypi_firmware_framebuffer_get_overscan = 0x0004000a,
+ raspberrypi_firmware_framebuffer_get_palette = 0x0004000b,
+ raspberrypi_firmware_framebuffer_release = 0x00048001,
+ raspberrypi_firmware_framebuffer_test_physical_width_height = 0x00044003,
+ raspberrypi_firmware_framebuffer_test_virtual_width_height = 0x00044004,
+ raspberrypi_firmware_framebuffer_test_depth = 0x00044005,
+ raspberrypi_firmware_framebuffer_test_pixel_order = 0x00044006,
+ raspberrypi_firmware_framebuffer_test_alpha_mode = 0x00044007,
+ raspberrypi_firmware_framebuffer_test_virtual_offset = 0x00044009,
+ raspberrypi_firmware_framebuffer_test_overscan = 0x0004400a,
+ raspberrypi_firmware_framebuffer_test_palette = 0x0004400b,
+ raspberrypi_firmware_framebuffer_set_physical_width_height = 0x00048003,
+ raspberrypi_firmware_framebuffer_set_virtual_width_height = 0x00048004,
+ raspberrypi_firmware_framebuffer_set_depth = 0x00048005,
+ raspberrypi_firmware_framebuffer_set_pixel_order = 0x00048006,
+ raspberrypi_firmware_framebuffer_set_alpha_mode = 0x00048007,
+ raspberrypi_firmware_framebuffer_set_virtual_offset = 0x00048009,
+ raspberrypi_firmware_framebuffer_set_overscan = 0x0004800a,
+ raspberrypi_firmware_framebuffer_set_palette = 0x0004800b,
+
+ raspberrypi_firmware_get_command_line = 0x00050001,
+ raspberrypi_firmware_get_dma_channels = 0x00060001,
+};
+
+int raspberrypi_firmware_property(void *data, size_t tag_size);
--
2.1.4
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