u-boot/arch/arm/mach-bcm283x/mbox.c
Masahiro Yamada ddf6bd4876 ARM: bcm283x: merge BCM2835/BCM2836 directories into mach-bcm283x
BCM2835 (used on Raspberry Pi) and BCM2836 (used on Raspberry Pi 2)
are similar enough.  One of the biggest differences is the ARM
processor.  It is reasonable to collect the source files into a
single place, arch/arm/mach-bcm283x/.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
2015-03-28 09:03:09 -04:00

153 lines
3 KiB
C

/*
* (C) Copyright 2012 Stephen Warren
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/mbox.h>
#define TIMEOUT 1000 /* ms */
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(&regs->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(&regs->read);
}
/* Wait for space to send */
for (;;) {
val = readl(&regs->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, &regs->write);
/* Wait for the response */
for (;;) {
val = readl(&regs->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(&regs->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;
}