diff options
Diffstat (limited to 'arch/arm/mach-bcm283x/mbox.c')
| -rw-r--r-- | arch/arm/mach-bcm283x/mbox.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/arch/arm/mach-bcm283x/mbox.c b/arch/arm/mach-bcm283x/mbox.c new file mode 100644 index 0000000000..9d69bc8ea7 --- /dev/null +++ b/arch/arm/mach-bcm283x/mbox.c @@ -0,0 +1,154 @@ +/* + * based on U-Boot code + * + * (C) Copyright 2012 Stephen Warren + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <asm/io.h> +#include <common.h> +#include <clock.h> +#include <dma.h> + +#include <mach/mbox.h> + +#define TIMEOUT (MSECOND * 1000) + +static int bcm2835_mbox_call_raw(u32 chan, struct bcm2835_mbox_hdr *buffer, + u32 *recv) +{ + struct bcm2835_mbox_regs __iomem *regs = + (struct bcm2835_mbox_regs *)BCM2835_MBOX_PHYSADDR; + uint64_t starttime = get_time_ns(); + u32 send = virt_to_phys(buffer); + u32 val; + + if (send & BCM2835_CHAN_MASK) { + printf("mbox: Illegal mbox data 0x%08x\n", send); + return -EINVAL; + } + + /* Drain any stale responses */ + for (;;) { + val = readl(®s->status); + if (val & BCM2835_MBOX_STATUS_RD_EMPTY) + break; + if (is_timeout(starttime, TIMEOUT)) { + printf("mbox: Timeout draining stale responses\n"); + return -ETIMEDOUT; + } + val = readl(®s->read); + } + + /* Wait for space to send */ + for (;;) { + val = readl(®s->status); + if (!(val & BCM2835_MBOX_STATUS_WR_FULL)) + break; + if (is_timeout(starttime, TIMEOUT)) { + printf("mbox: Timeout waiting for send space\n"); + return -ETIMEDOUT; + } + } + + /* Send the request */ + val = BCM2835_MBOX_PACK(chan, send); + debug("mbox: TX raw: 0x%08x\n", val); + dma_sync_single_for_device((unsigned long)send, buffer->buf_size, + DMA_BIDIRECTIONAL); + writel(val, ®s->write); + + /* Wait for the response */ + for (;;) { + val = readl(®s->status); + if (!(val & BCM2835_MBOX_STATUS_RD_EMPTY)) + break; + if (is_timeout(starttime, TIMEOUT)) { + printf("mbox: Timeout waiting for response\n"); + return -ETIMEDOUT; + } + } + + /* Read the response */ + val = readl(®s->read); + debug("mbox: RX raw: 0x%08x\n", val); + dma_sync_single_for_cpu((unsigned long)send, buffer->buf_size, + DMA_BIDIRECTIONAL); + + /* Validate the response */ + if (BCM2835_MBOX_UNPACK_CHAN(val) != chan) { + printf("mbox: Response channel mismatch\n"); + return -EIO; + } + + *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, buffer, &rbuffer); + if (ret) + return ret; + if (rbuffer != (u32)buffer) { + printf("mbox: Response buffer mismatch\n"); + return -EIO; + } + +#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 -EIO; + } + + /* 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 -EIO; + } + /* + * 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; +} |