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tegra124: Move transfer size handling to spi_xfer()

Browse source 
This moves the math involved in splitting apart a large request from
tegra_spi_cbfs_read() to spi_xfer() with the intention of making the
logic more generic for other possible uses.

BUG=none
BRANCH=none
TEST=built and booted on Nyan

Change-Id: Ice05f1cd9ab1699b656f44b9dd8a2e18c03c583b
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/173680
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
This commit is contained in:
David Hendricks 2013-10-17 19:35:14 -07:00 • committed by chrome-internal-fetch
commit 4a9b7b47b3
1 changed files with 57 additions and 35 deletions
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90
src/soc/nvidia/tegra124/spi.c
View file

@ -46,7 +46,8 @@
*/
#define SPI_PACKET_SIZE_BYTES 1
#define SPI_MAX_TRANSFER_BYTES_FIFO (64 * SPI_PACKET_SIZE_BYTES)
#define SPI_MAX_TRANSFER_BYTES_DMA (65536 * SPI_PACKET_SIZE_BYTES)
#define SPI_MAX_TRANSFER_BYTES_DMA ((65536 * SPI_PACKET_SIZE_BYTES) - \
TEGRA_DMA_ALIGN_BYTES)
/* COMMAND1 */
#define SPI_CMD1_GO (1 << 31)
@ -523,9 +524,9 @@ static int tegra_spi_dma_send(struct tegra_spi_channel *spi,
int spi_xfer(struct spi_slave *slave, const void *dout, unsigned int bitsout,
void *din, unsigned int bitsin)
{
unsigned int dma_out, dma_in, fifo_out, fifo_in;
int ret = 0;
unsigned int out_bytes = bitsout / 8, in_bytes = bitsin / 8;
struct tegra_spi_channel *spi = to_tegra_spi(slave->bus);
int ret = 0;
u8 *out_buf = (u8 *)dout;
u8 *in_buf = (u8 *)din;
@ -541,32 +542,61 @@ int spi_xfer(struct spi_slave *slave, const void *dout, unsigned int bitsout,
* outside the specified buffers we'll only use DMA for 4-byte aligned
* transactions accesses and transfer remaining bytes using FIFO access.
*/
fifo_out = (bitsout / 8) % TEGRA_DMA_ALIGN_BYTES;
dma_out = (bitsout / 8) - fifo_out;
fifo_in = (bitsin / 8) % TEGRA_DMA_ALIGN_BYTES;
dma_in = (bitsin / 8) - fifo_in;
if (dma_out) {
tegra_spi_dma_send(spi, out_buf, dma_out);
out_buf += dma_out;
while (out_bytes > 0) {
unsigned int dma_out, fifo_out;
dma_out = MIN(out_bytes, SPI_MAX_TRANSFER_BYTES_DMA);
fifo_out = dma_out % TEGRA_DMA_ALIGN_BYTES;
dma_out -= fifo_out;
if (dma_out) {
tegra_spi_dma_send(spi, out_buf, dma_out);
out_buf += dma_out;
out_bytes -= dma_out;
}
if (fifo_out) {
tegra_spi_fifo_send(spi, out_buf, fifo_out);
out_buf += fifo_out;
out_bytes -= fifo_out;
}
if (read32(&spi->regs->fifo_status) & SPI_FIFO_STATUS_ERR) {
ret = -1;
goto spi_xfer_exit;
}
}
if (fifo_out)
tegra_spi_fifo_send(spi, out_buf, fifo_out);
if (dma_in) {
tegra_spi_dma_receive(spi, in_buf, dma_in);
in_buf += dma_in;
while (in_bytes > 0) {
unsigned int dma_in, fifo_in;
dma_in = MIN(in_bytes, SPI_MAX_TRANSFER_BYTES_DMA);
fifo_in = dma_in % TEGRA_DMA_ALIGN_BYTES;
dma_in -= fifo_in;
if (dma_in) {
tegra_spi_dma_receive(spi, in_buf, dma_in);
in_buf += dma_in;
in_bytes -= dma_in;
}
if (fifo_in) {
tegra_spi_fifo_receive(spi, in_buf, fifo_in);
in_buf += fifo_in;
in_bytes -= fifo_in;
}
if (read32(&spi->regs->fifo_status) & SPI_FIFO_STATUS_ERR) {
ret = -1;
break;
}
}
if (fifo_in)
tegra_spi_fifo_receive(spi, in_buf, fifo_in);
if (read32(&spi->regs->fifo_status) & SPI_FIFO_STATUS_ERR) {
ret = -1;
spi_xfer_exit:
if (ret < 0) {
dump_spi_regs(spi);
print_fifo_status(spi);
clear_fifo_status(spi);
}
return ret;
}
@ -611,23 +641,15 @@ static size_t tegra_spi_cbfs_read(struct cbfs_media *media, void *dest,
if (spi_xfer(spi->slave, spi_read_cmd,
sizeof(spi_read_cmd) * 8, NULL, 0) < 0) {
ret = -1;
printk(BIOS_ERR, "SPI failed to transfer %u bytes\n",
sizeof(spi_read_cmd));
printk(BIOS_ERR, "%s: Failed to transfer %u bytes\n",
__func__, sizeof(spi_read_cmd));
goto tegra_spi_cbfs_read_exit;
}
while (count > 0) {
unsigned int remaining;
/* FIXME: shouldn't need to subtract 4 here... */
remaining = MIN(count, SPI_MAX_TRANSFER_BYTES_DMA - 4);
count -= remaining;
if (spi_xfer(spi->slave, NULL, 0, dest, remaining * 8)) {
ret = -1;
printk(BIOS_ERR, "SPI failed to transfer %u bytes\n",
remaining);
break;
}
if (spi_xfer(spi->slave, NULL, 0, dest, count * 8)) {
ret = -1;
printk(BIOS_ERR, "%s: Failed to transfer %u bytes\n",
__func__, count);
}
tegra_spi_cbfs_read_exit: