diff options
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/cpu/arm1176/bcm2835/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/cpu/arm1176/bcm2835/mbox.c | 164 | ||||
| -rw-r--r-- | arch/arm/include/asm/arch-bcm2835/mbox.h | 407 |
3 files changed, 572 insertions, 1 deletions
diff --git a/arch/arm/cpu/arm1176/bcm2835/Makefile b/arch/arm/cpu/arm1176/bcm2835/Makefile index 95da6a8..135de42 100644 --- a/arch/arm/cpu/arm1176/bcm2835/Makefile +++ b/arch/arm/cpu/arm1176/bcm2835/Makefile @@ -17,7 +17,7 @@ include $(TOPDIR)/config.mk LIB = $(obj)lib$(SOC).o SOBJS := lowlevel_init.o -COBJS := init.o reset.o timer.o +COBJS := init.o reset.o timer.o mbox.o SRCS := $(SOBJS:.o=.c) $(COBJS:.o=.c) OBJS := $(addprefix $(obj),$(SOBJS) $(COBJS)) diff --git a/arch/arm/cpu/arm1176/bcm2835/mbox.c b/arch/arm/cpu/arm1176/bcm2835/mbox.c new file mode 100644 index 0000000..fd65e33 --- /dev/null +++ b/arch/arm/cpu/arm1176/bcm2835/mbox.c @@ -0,0 +1,164 @@ +/* + * (C) Copyright 2012 Stephen Warren + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/mbox.h> + +#define TIMEOUT (100 * 1000) /* 100mS in uS */ + +int bcm2835_mbox_call_raw(u32 chan, u32 send, u32 *recv) +{ + struct bcm2835_mbox_regs *regs = + (struct bcm2835_mbox_regs *)BCM2835_MBOX_PHYSADDR; + ulong endtime = get_timer(0) + TIMEOUT; + u32 val; + + debug("time: %lu timeout: %lu\n", get_timer(0), endtime); + + if (send & BCM2835_CHAN_MASK) { + printf("mbox: Illegal mbox data 0x%08x\n", send); + return -1; + } + + /* Drain any stale responses */ + + for (;;) { + val = readl(®s->status); + if (val & BCM2835_MBOX_STATUS_RD_EMPTY) + break; + if (get_timer(0) >= endtime) { + printf("mbox: Timeout draining stale responses\n"); + return -1; + } + val = readl(®s->read); + } + + /* Wait for space to send */ + + for (;;) { + val = readl(®s->status); + if (!(val & BCM2835_MBOX_STATUS_WR_FULL)) + break; + if (get_timer(0) >= endtime) { + printf("mbox: Timeout waiting for send space\n"); + return -1; + } + } + + /* Send the request */ + + val = BCM2835_MBOX_PACK(chan, send); + debug("mbox: TX raw: 0x%08x\n", val); + writel(val, ®s->write); + + /* Wait for the response */ + + for (;;) { + val = readl(®s->status); + if (!(val & BCM2835_MBOX_STATUS_RD_EMPTY)) + break; + if (get_timer(0) >= endtime) { + printf("mbox: Timeout waiting for response\n"); + return -1; + } + } + + /* Read the response */ + + val = readl(®s->read); + debug("mbox: RX raw: 0x%08x\n", val); + + /* Validate the response */ + + if (BCM2835_MBOX_UNPACK_CHAN(val) != chan) { + printf("mbox: Response channel mismatch\n"); + return -1; + } + + *recv = BCM2835_MBOX_UNPACK_DATA(val); + + return 0; +} + +#ifdef DEBUG +void dump_buf(struct bcm2835_mbox_hdr *buffer) +{ + u32 *p; + u32 words; + int i; + + p = (u32 *)buffer; + words = buffer->buf_size / 4; + for (i = 0; i < words; i++) + printf(" 0x%04x: 0x%08x\n", i * 4, p[i]); +} +#endif + +int bcm2835_mbox_call_prop(u32 chan, struct bcm2835_mbox_hdr *buffer) +{ + int ret; + u32 rbuffer; + struct bcm2835_mbox_tag_hdr *tag; + int tag_index; + +#ifdef DEBUG + printf("mbox: TX buffer\n"); + dump_buf(buffer); +#endif + + ret = bcm2835_mbox_call_raw(chan, (u32)buffer, &rbuffer); + if (ret) + return ret; + if (rbuffer != (u32)buffer) { + printf("mbox: Response buffer mismatch\n"); + return -1; + } + +#ifdef DEBUG + printf("mbox: RX buffer\n"); + dump_buf(buffer); +#endif + + /* Validate overall response status */ + + if (buffer->code != BCM2835_MBOX_RESP_CODE_SUCCESS) { + printf("mbox: Header response code invalid\n"); + return -1; + } + + /* Validate each tag's response status */ + + tag = (void *)(buffer + 1); + tag_index = 0; + while (tag->tag) { + if (!(tag->val_len & BCM2835_MBOX_TAG_VAL_LEN_RESPONSE)) { + printf("mbox: Tag %d missing val_len response bit\n", + tag_index); + return -1; + } + /* + * Clear the reponse bit so clients can just look right at the + * length field without extra processing + */ + tag->val_len &= ~BCM2835_MBOX_TAG_VAL_LEN_RESPONSE; + tag = (void *)(((u8 *)tag) + sizeof(*tag) + tag->val_buf_size); + tag_index++; + } + + return 0; +} diff --git a/arch/arm/include/asm/arch-bcm2835/mbox.h b/arch/arm/include/asm/arch-bcm2835/mbox.h new file mode 100644 index 0000000..4752091 --- /dev/null +++ b/arch/arm/include/asm/arch-bcm2835/mbox.h @@ -0,0 +1,407 @@ +/* + * (C) Copyright 2012 Stephen Warren + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _BCM2835_MBOX_H +#define _BCM2835_MBOX_H + +#include <linux/compiler.h> + +/* + * The BCM2835 SoC contains (at least) two CPUs; the VideoCore (a/k/a "GPU") + * and the ARM CPU. The ARM CPU is often thought of as the main CPU. + * However, the VideoCore actually controls the initial SoC boot, and hides + * much of the hardware behind a protocol. This protocol is transported + * using the SoC's mailbox hardware module. + * + * The mailbox hardware supports passing 32-bit values back and forth. + * Presumably by software convention of the firmware, the bottom 4 bits of the + * value are used to indicate a logical channel, and the upper 28 bits are the + * actual payload. Various channels exist using these simple raw messages. See + * https://github.com/raspberrypi/firmware/wiki/Mailboxes for a list. As an + * example, the messages on the power management channel are a bitmask of + * devices whose power should be enabled. + * + * The property mailbox channel passes messages that contain the (16-byte + * aligned) ARM physical address of a memory buffer. This buffer is passed to + * the VC for processing, is modified in-place by the VC, and the address then + * passed back to the ARM CPU as the response mailbox message to indicate + * request completion. The buffers have a generic and extensible format; each + * buffer contains a standard header, a list of "tags", and a terminating zero + * entry. Each tag contains an ID indicating its type, and length fields for + * generic parsing. With some limitations, an arbitrary set of tags may be + * combined together into a single message buffer. This file defines structs + * representing the header and many individual tag layouts and IDs. + */ + +/* Raw mailbox HW */ + +#define BCM2835_MBOX_PHYSADDR 0x2000b880 + +struct bcm2835_mbox_regs { + u32 read; + u32 rsvd0[5]; + u32 status; + u32 config; + u32 write; +}; + +#define BCM2835_MBOX_STATUS_WR_FULL 0x80000000 +#define BCM2835_MBOX_STATUS_RD_EMPTY 0x40000000 + +/* Lower 4-bits are channel ID */ +#define BCM2835_CHAN_MASK 0xf +#define BCM2835_MBOX_PACK(chan, data) (((data) & (~BCM2835_CHAN_MASK)) | \ + (chan & BCM2835_CHAN_MASK)) +#define BCM2835_MBOX_UNPACK_CHAN(val) ((val) & BCM2835_CHAN_MASK) +#define BCM2835_MBOX_UNPACK_DATA(val) ((val) & (~BCM2835_CHAN_MASK)) + +/* Property mailbox buffer structures */ + +#define BCM2835_MBOX_PROP_CHAN 8 + +/* All message buffers must start with this header */ +struct bcm2835_mbox_hdr { + u32 buf_size; + u32 code; +}; + +#define BCM2835_MBOX_REQ_CODE 0 +#define BCM2835_MBOX_RESP_CODE_SUCCESS 0x80000000 + +#define BCM2835_MBOX_INIT_HDR(_m_) { \ + memset((_m_), 0, sizeof(*(_m_))); \ + (_m_)->hdr.buf_size = sizeof(*(_m_)); \ + (_m_)->hdr.code = 0; \ + (_m_)->end_tag = 0; \ + } + +/* + * A message buffer contains a list of tags. Each tag must also start with + * a standardized header. + */ +struct bcm2835_mbox_tag_hdr { + u32 tag; + u32 val_buf_size; + u32 val_len; +}; + +#define BCM2835_MBOX_INIT_TAG(_t_, _id_) { \ + (_t_)->tag_hdr.tag = BCM2835_MBOX_TAG_##_id_; \ + (_t_)->tag_hdr.val_buf_size = sizeof((_t_)->body); \ + (_t_)->tag_hdr.val_len = sizeof((_t_)->body.req); \ + } + +#define BCM2835_MBOX_INIT_TAG_NO_REQ(_t_, _id_) { \ + (_t_)->tag_hdr.tag = BCM2835_MBOX_TAG_##_id_; \ + (_t_)->tag_hdr.val_buf_size = sizeof((_t_)->body); \ + (_t_)->tag_hdr.val_len = 0; \ + } + +/* When responding, the VC sets this bit in val_len to indicate a response */ +#define BCM2835_MBOX_TAG_VAL_LEN_RESPONSE 0x80000000 + +/* + * Below we define the ID and struct for many possible tags. This header only + * defines individual tag structs, not entire message structs, since in + * general an arbitrary set of tags may be combined into a single message. + * Clients of the mbox API are expected to define their own overall message + * structures by combining the header, a set of tags, and a terminating + * entry. For example, + * + * struct msg { + * struct bcm2835_mbox_hdr hdr; + * struct bcm2835_mbox_tag_get_arm_mem get_arm_mem; + * ... perhaps other tags here ... + * u32 end_tag; + * }; + */ + +#define BCM2835_MBOX_TAG_GET_ARM_MEMORY 0x00010005 + +struct bcm2835_mbox_tag_get_arm_mem { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + struct { + } req; + struct { + u32 mem_base; + u32 mem_size; + } resp; + } body; +}; + +#define BCM2835_MBOX_TAG_ALLOCATE_BUFFER 0x00040001 + +struct bcm2835_mbox_tag_allocate_buffer { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + struct { + u32 alignment; + } req; + struct { + u32 fb_address; + u32 fb_size; + } resp; + } body; +}; + +#define BCM2835_MBOX_TAG_RELEASE_BUFFER 0x00048001 + +struct bcm2835_mbox_tag_release_buffer { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + struct { + } req; + struct { + } resp; + } body; +}; + +#define BCM2835_MBOX_TAG_BLANK_SCREEN 0x00040002 + +struct bcm2835_mbox_tag_blank_screen { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + struct { + /* bit 0 means on, other bots reserved */ + u32 state; + } req; + struct { + u32 state; + } resp; + } body; +}; + +/* Physical means output signal */ +#define BCM2835_MBOX_TAG_GET_PHYSICAL_W_H 0x00040003 +#define BCM2835_MBOX_TAG_TEST_PHYSICAL_W_H 0x00044003 +#define BCM2835_MBOX_TAG_SET_PHYSICAL_W_H 0x00048003 + +struct bcm2835_mbox_tag_physical_w_h { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + /* req not used for get */ + struct { + u32 width; + u32 height; + } req; + struct { + u32 width; + u32 height; + } resp; + } body; +}; + +/* Virtual means display buffer */ +#define BCM2835_MBOX_TAG_GET_VIRTUAL_W_H 0x00040004 +#define BCM2835_MBOX_TAG_TEST_VIRTUAL_W_H 0x00044004 +#define BCM2835_MBOX_TAG_SET_VIRTUAL_W_H 0x00048004 + +struct bcm2835_mbox_tag_virtual_w_h { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + /* req not used for get */ + struct { + u32 width; + u32 height; + } req; + struct { + u32 width; + u32 height; + } resp; + } body; +}; + +#define BCM2835_MBOX_TAG_GET_DEPTH 0x00040005 +#define BCM2835_MBOX_TAG_TEST_DEPTH 0x00044005 +#define BCM2835_MBOX_TAG_SET_DEPTH 0x00048005 + +struct bcm2835_mbox_tag_depth { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + /* req not used for get */ + struct { + u32 bpp; + } req; + struct { + u32 bpp; + } resp; + } body; +}; + +#define BCM2835_MBOX_TAG_GET_PIXEL_ORDER 0x00040006 +#define BCM2835_MBOX_TAG_TEST_PIXEL_ORDER 0x00044005 +#define BCM2835_MBOX_TAG_SET_PIXEL_ORDER 0x00048006 + +#define BCM2835_MBOX_PIXEL_ORDER_BGR 0 +#define BCM2835_MBOX_PIXEL_ORDER_RGB 1 + +struct bcm2835_mbox_tag_pixel_order { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + /* req not used for get */ + struct { + u32 order; + } req; + struct { + u32 order; + } resp; + } body; +}; + +#define BCM2835_MBOX_TAG_GET_ALPHA_MODE 0x00040007 +#define BCM2835_MBOX_TAG_TEST_ALPHA_MODE 0x00044007 +#define BCM2835_MBOX_TAG_SET_ALPHA_MODE 0x00048007 + +#define BCM2835_MBOX_ALPHA_MODE_0_OPAQUE 0 +#define BCM2835_MBOX_ALPHA_MODE_0_TRANSPARENT 1 +#define BCM2835_MBOX_ALPHA_MODE_IGNORED 2 + +struct bcm2835_mbox_tag_alpha_mode { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + /* req not used for get */ + struct { + u32 alpha; + } req; + struct { + u32 alpha; + } resp; + } body; +}; + +#define BCM2835_MBOX_TAG_GET_PITCH 0x00040008 + +struct bcm2835_mbox_tag_pitch { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + struct { + } req; + struct { + u32 pitch; + } resp; + } body; +}; + +/* Offset of display window within buffer */ +#define BCM2835_MBOX_TAG_GET_VIRTUAL_OFFSET 0x00040009 +#define BCM2835_MBOX_TAG_TEST_VIRTUAL_OFFSET 0x00044009 +#define BCM2835_MBOX_TAG_SET_VIRTUAL_OFFSET 0x00048009 + +struct bcm2835_mbox_tag_virtual_offset { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + /* req not used for get */ + struct { + u32 x; + u32 y; + } req; + struct { + u32 x; + u32 y; + } resp; + } body; +}; + +#define BCM2835_MBOX_TAG_GET_OVERSCAN 0x0004000a +#define BCM2835_MBOX_TAG_TEST_OVERSCAN 0x0004400a +#define BCM2835_MBOX_TAG_SET_OVERSCAN 0x0004800a + +struct bcm2835_mbox_tag_overscan { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + /* req not used for get */ + struct { + u32 top; + u32 bottom; + u32 left; + u32 right; + } req; + struct { + u32 top; + u32 bottom; + u32 left; + } resp; + } body; +}; + +#define BCM2835_MBOX_TAG_GET_PALETTE 0x0004000b + +struct bcm2835_mbox_tag_get_palette { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + struct { + } req; + struct { + u32 data[1024]; + } resp; + } body; +}; + +#define BCM2835_MBOX_TAG_TEST_PALETTE 0x0004400b + +struct bcm2835_mbox_tag_test_palette { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + struct { + u32 offset; + u32 num_entries; + u32 data[256]; + } req; + struct { + u32 is_invalid; + } resp; + } body; +}; + +#define BCM2835_MBOX_TAG_SET_PALETTE 0x0004800b + +struct bcm2835_mbox_tag_set_palette { + struct bcm2835_mbox_tag_hdr tag_hdr; + union { + struct { + u32 offset; + u32 num_entries; + u32 data[256]; + } req; + struct { + u32 is_invalid; + } resp; + } body; +}; + +/* + * Pass a raw u32 message to the VC, and receive a raw u32 back. + * + * Returns 0 for success, any other value for error. + */ +int bcm2835_mbox_call_raw(u32 chan, u32 send, u32 *recv); + +/* + * Pass a complete property-style buffer to the VC, and wait until it has + * been processed. + * + * This function expects a pointer to the mbox_hdr structure in an attempt + * to ensure some degree of type safety. However, some number of tags and + * a termination value are expected to immediately follow the header in + * memory, as required by the property protocol. + * + * Returns 0 for success, any other value for error. + */ +int bcm2835_mbox_call_prop(u32 chan, struct bcm2835_mbox_hdr *buffer); + +#endif |