Blackfin: bfin_spi: add optional DMA support
This moves the last piece from the old spi_flash driver to the new SPI
framework -- optional DMA RX support. This typically cuts speeds by ~40%
at the cost of additional ~300 bytes.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/include/asm/dma.h b/arch/blackfin/include/asm/dma.h
new file mode 100644
index 0000000..21ff1cf
--- /dev/null
+++ b/arch/blackfin/include/asm/dma.h
@@ -0,0 +1,75 @@
+/*
+ * dma.h - Blackfin DMA defines/structures/etc...
+ *
+ * Copyright 2004-2008 Analog Devices Inc.
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef _BLACKFIN_DMA_H_
+#define _BLACKFIN_DMA_H_
+
+#include <asm/mach-common/bits/dma.h>
+
+struct dmasg_large {
+ void *next_desc_addr;
+ unsigned long start_addr;
+ unsigned short cfg;
+ unsigned short x_count;
+ short x_modify;
+ unsigned short y_count;
+ short y_modify;
+} __attribute__((packed));
+
+struct dmasg {
+ unsigned long start_addr;
+ unsigned short cfg;
+ unsigned short x_count;
+ short x_modify;
+ unsigned short y_count;
+ short y_modify;
+} __attribute__((packed));
+
+struct dma_register {
+ void *next_desc_ptr; /* DMA Next Descriptor Pointer register */
+ unsigned long start_addr; /* DMA Start address register */
+
+ unsigned short cfg; /* DMA Configuration register */
+ unsigned short dummy1; /* DMA Configuration register */
+
+ unsigned long reserved;
+
+ unsigned short x_count; /* DMA x_count register */
+ unsigned short dummy2;
+
+ short x_modify; /* DMA x_modify register */
+ unsigned short dummy3;
+
+ unsigned short y_count; /* DMA y_count register */
+ unsigned short dummy4;
+
+ short y_modify; /* DMA y_modify register */
+ unsigned short dummy5;
+
+ void *curr_desc_ptr; /* DMA Current Descriptor Pointer
+ register */
+ unsigned long curr_addr_ptr; /* DMA Current Address Pointer
+ register */
+ unsigned short irq_status; /* DMA irq status register */
+ unsigned short dummy6;
+
+ unsigned short peripheral_map; /* DMA peripheral map register */
+ unsigned short dummy7;
+
+ unsigned short curr_x_count; /* DMA Current x-count register */
+ unsigned short dummy8;
+
+ unsigned long reserved2;
+
+ unsigned short curr_y_count; /* DMA Current y-count register */
+ unsigned short dummy9;
+
+ unsigned long reserved3;
+
+};
+
+#endif
diff --git a/drivers/spi/bfin_spi.c b/drivers/spi/bfin_spi.c
index 556b97a..d7e1474 100644
--- a/drivers/spi/bfin_spi.c
+++ b/drivers/spi/bfin_spi.c
@@ -1,7 +1,7 @@
/*
* Driver for Blackfin On-Chip SPI device
*
- * Copyright (c) 2005-2008 Analog Devices Inc.
+ * Copyright (c) 2005-2010 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
@@ -13,6 +13,7 @@
#include <spi.h>
#include <asm/blackfin.h>
+#include <asm/dma.h>
#include <asm/gpio.h>
#include <asm/portmux.h>
#include <asm/mach-common/bits/spi.h>
@@ -237,10 +238,131 @@
SSYNC();
}
+#ifdef __ADSPBF54x__
+# define SPI_DMA_BASE DMA4_NEXT_DESC_PTR
+#elif defined(__ADSPBF533__) || defined(__ADSPBF532__) || defined(__ADSPBF531__) || \
+ defined(__ADSPBF538__) || defined(__ADSPBF539__)
+# define SPI_DMA_BASE DMA5_NEXT_DESC_PTR
+#elif defined(__ADSPBF561__)
+# define SPI_DMA_BASE DMA2_4_NEXT_DESC_PTR
+#elif defined(__ADSPBF537__) || defined(__ADSPBF536__) || defined(__ADSPBF534__) || \
+ defined(__ADSPBF52x__) || defined(__ADSPBF51x__)
+# define SPI_DMA_BASE DMA7_NEXT_DESC_PTR
+#else
+# error "Please provide SPI DMA channel defines"
+#endif
+static volatile struct dma_register *dma = (void *)SPI_DMA_BASE;
+
#ifndef CONFIG_BFIN_SPI_IDLE_VAL
# define CONFIG_BFIN_SPI_IDLE_VAL 0xff
#endif
+#ifdef CONFIG_BFIN_SPI_NO_DMA
+# define SPI_DMA 0
+#else
+# define SPI_DMA 1
+#endif
+
+static int spi_dma_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx,
+ uint bytes)
+{
+ int ret = -1;
+ u16 ndsize, spi_config, dma_config;
+ struct dmasg dmasg[2];
+ const u8 *buf;
+
+ if (tx) {
+ debug("%s: doing half duplex TX\n", __func__);
+ buf = tx;
+ spi_config = TDBR_DMA;
+ dma_config = 0;
+ } else {
+ debug("%s: doing half duplex RX\n", __func__);
+ buf = rx;
+ spi_config = RDBR_DMA;
+ dma_config = WNR;
+ }
+
+ dmasg[0].start_addr = (unsigned long)buf;
+ dmasg[0].x_modify = 1;
+ dma_config |= WDSIZE_8 | DMAEN;
+ if (bytes <= 65536) {
+ blackfin_dcache_flush_invalidate_range(buf, buf + bytes);
+ ndsize = NDSIZE_5;
+ dmasg[0].cfg = NDSIZE_0 | dma_config | FLOW_STOP | DI_EN;
+ dmasg[0].x_count = bytes;
+ } else {
+ blackfin_dcache_flush_invalidate_range(buf, buf + 65536 - 1);
+ ndsize = NDSIZE_7;
+ dmasg[0].cfg = NDSIZE_5 | dma_config | FLOW_ARRAY | DMA2D;
+ dmasg[0].x_count = 0; /* 2^16 */
+ dmasg[0].y_count = bytes >> 16; /* count / 2^16 */
+ dmasg[0].y_modify = 1;
+ dmasg[1].start_addr = (unsigned long)(buf + (bytes & ~0xFFFF));
+ dmasg[1].cfg = NDSIZE_0 | dma_config | FLOW_STOP | DI_EN;
+ dmasg[1].x_count = bytes & 0xFFFF; /* count % 2^16 */
+ dmasg[1].x_modify = 1;
+ }
+
+ dma->cfg = 0;
+ dma->irq_status = DMA_DONE | DMA_ERR;
+ dma->curr_desc_ptr = dmasg;
+ write_SPI_CTL(bss, (bss->ctl & ~TDBR_CORE));
+ write_SPI_STAT(bss, -1);
+ SSYNC();
+
+ write_SPI_TDBR(bss, CONFIG_BFIN_SPI_IDLE_VAL);
+ dma->cfg = ndsize | FLOW_ARRAY | DMAEN;
+ write_SPI_CTL(bss, (bss->ctl & ~TDBR_CORE) | spi_config);
+ SSYNC();
+
+ /*
+ * We already invalidated the first 64k,
+ * now while we just wait invalidate the remaining part.
+ * Its not likely that the DMA is going to overtake
+ */
+ if (bytes > 65536)
+ blackfin_dcache_flush_invalidate_range(buf + 65536, buf + bytes);
+
+ while (!(dma->irq_status & DMA_DONE))
+ if (ctrlc())
+ goto done;
+
+ dma->cfg = 0;
+
+ ret = 0;
+ done:
+ write_SPI_CTL(bss, bss->ctl);
+ return ret;
+}
+
+static int spi_pio_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx,
+ uint bytes)
+{
+ /* todo: take advantage of hardware fifos */
+ while (bytes--) {
+ u8 value = (tx ? *tx++ : CONFIG_BFIN_SPI_IDLE_VAL);
+ debug("%s: tx:%x ", __func__, value);
+ write_SPI_TDBR(bss, value);
+ SSYNC();
+ while ((read_SPI_STAT(bss) & TXS))
+ if (ctrlc())
+ return -1;
+ while (!(read_SPI_STAT(bss) & SPIF))
+ if (ctrlc())
+ return -1;
+ while (!(read_SPI_STAT(bss) & RXS))
+ if (ctrlc())
+ return -1;
+ value = read_SPI_RDBR(bss);
+ if (rx)
+ *rx++ = value;
+ debug("rx:%x\n", value);
+ }
+
+ return 0;
+}
+
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
@@ -265,32 +387,11 @@
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave);
- /* todo: take advantage of hardware fifos and setup RX dma */
- while (bytes--) {
- u8 value = (tx ? *tx++ : CONFIG_BFIN_SPI_IDLE_VAL);
- debug("%s: tx:%x ", __func__, value);
- write_SPI_TDBR(bss, value);
- SSYNC();
- while ((read_SPI_STAT(bss) & TXS))
- if (ctrlc()) {
- ret = -1;
- goto done;
- }
- while (!(read_SPI_STAT(bss) & SPIF))
- if (ctrlc()) {
- ret = -1;
- goto done;
- }
- while (!(read_SPI_STAT(bss) & RXS))
- if (ctrlc()) {
- ret = -1;
- goto done;
- }
- value = read_SPI_RDBR(bss);
- if (rx)
- *rx++ = value;
- debug("rx:%x\n", value);
- }
+ /* TX DMA doesn't work quite right */
+ if (SPI_DMA && bytes > 6 && (!tx /*|| !rx*/))
+ ret = spi_dma_xfer(bss, tx, rx, bytes);
+ else
+ ret = spi_pio_xfer(bss, tx, rx, bytes);
done:
if (flags & SPI_XFER_END)