[U-Boot] [PATCH 3/4] omap3: Add interface for omap3 DMA
Simon Schwarz
simonschwarzcor at googlemail.com
Wed Sep 28 17:00:26 CEST 2011
Adds an interface to use the OMAP3 DMA.
Signed-off-by: Simon Schwarz <simonschwarzcor at gmail.com>
---
arch/arm/include/asm/arch-omap3/dma.h | 77 ++++++++++++++
doc/README.omap3 | 18 ++++
drivers/dma/Makefile | 1 +
drivers/dma/omap3_dma.c | 180 +++++++++++++++++++++++++++++++++
4 files changed, 276 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/include/asm/arch-omap3/dma.h
create mode 100644 drivers/dma/omap3_dma.c
diff --git a/arch/arm/include/asm/arch-omap3/dma.h b/arch/arm/include/asm/arch-omap3/dma.h
new file mode 100644
index 0000000..ba5e057
--- /dev/null
+++ b/arch/arm/include/asm/arch-omap3/dma.h
@@ -0,0 +1,77 @@
+#ifndef __SDMA_H
+#define __SDMA_H
+
+/* Copyright (C) 2011
+ * Corscience GmbH & Co. KG - Simon Schwarz <schwarz at corscience.de>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/* Functions */
+void omap3_dma_init(void);
+int omap3_dma_conf_transfer(uint32_t chan, uint32_t *src, uint32_t *dst,
+ uint32_t sze);
+int omap3_dma_start_transfer(uint32_t chan);
+int omap3_dma_wait_for_transfer(uint32_t chan);
+int omap3_dma_conf_chan(uint32_t chan, struct dma4_chan *config);
+int omap3_dma_get_conf_chan(uint32_t chan, struct dma4_chan *config);
+
+/* Register settings */
+#define CSDP_DATA_TYPE_8BIT 0x0
+#define CSDP_DATA_TYPE_16BIT 0x1
+#define CSDP_DATA_TYPE_32BIT 0x2
+#define CSDP_SRC_BURST_SINGLE (0x0 << 7)
+#define CSDP_SRC_BURST_EN_16BYTES (0x1 << 7)
+#define CSDP_SRC_BURST_EN_32BYTES (0x2 << 7)
+#define CSDP_SRC_BURST_EN_64BYTES (0x3 << 7)
+#define CSDP_DST_BURST_SINGLE (0x0 << 14)
+#define CSDP_DST_BURST_EN_16BYTES (0x1 << 14)
+#define CSDP_DST_BURST_EN_32BYTES (0x2 << 14)
+#define CSDP_DST_BURST_EN_64BYTES (0x3 << 14)
+#define CSDP_DST_ENDIAN_LOCK_ADAPT (0x0 << 18)
+#define CSDP_DST_ENDIAN_LOCK_LOCK (0x1 << 18)
+#define CSDP_DST_ENDIAN_LITTLE (0x0 << 19)
+#define CSDP_DST_ENDIAN_BIG (0x1 << 19)
+#define CSDP_SRC_ENDIAN_LOCK_ADAPT (0x0 << 20)
+#define CSDP_SRC_ENDIAN_LOCK_LOCK (0x1 << 20)
+#define CSDP_SRC_ENDIAN_LITTLE (0x0 << 21)
+#define CSDP_SRC_ENDIAN_BIG (0x1 << 21)
+
+#define CCR_READ_PRIORITY_LOW (0x0 << 6)
+#define CCR_READ_PRIORITY_HIGH (0x1 << 6)
+#define CCR_ENABLE_DISABLED (0x0 << 7)
+#define CCR_ENABLE_ENABLE (0x1 << 7)
+#define CCR_SRC_AMODE_CONSTANT (0x0 << 12)
+#define CCR_SRC_AMODE_POST_INC (0x1 << 12)
+#define CCR_SRC_AMODE_SINGLE_IDX (0x2 << 12)
+#define CCR_SRC_AMODE_DOUBLE_IDX (0x3 << 12)
+#define CCR_DST_AMODE_CONSTANT (0x0 << 14)
+#define CCR_DST_AMODE_POST_INC (0x1 << 14)
+#define CCR_DST_AMODE_SINGLE_IDX (0x2 << 14)
+#define CCR_DST_AMODE_SOUBLE_IDX (0x3 << 14)
+
+#define CCR_RD_ACTIVE_MASK (1 << 9)
+#define CCR_WR_ACTIVE_MASK (1 << 10)
+
+#define CSR_TRANS_ERR (1 << 8)
+#define CSR_SUPERVISOR_ERR (1 << 10)
+#define CSR_MISALIGNED_ADRS_ERR (1 << 11)
+
+/* others */
+#define CHAN_NR_MIN 0
+#define CHAN_NR_MAX 31
+
+#endif /* __SDMA_H */
diff --git a/doc/README.omap3 b/doc/README.omap3
index 1768cdd..2a3f46b 100644
--- a/doc/README.omap3
+++ b/doc/README.omap3
@@ -95,6 +95,7 @@ Interfaces
==========
gpio
+----
To set a bit :
@@ -122,6 +123,23 @@ To read a bit :
else
printf("GPIO N is clear\n");
+dma
+---
+void omap3_dma_init(void)
+ Init the DMA module
+int omap3_dma_get_conf_chan(uint32_t chan, struct dma4_chan *config);
+ Read config of the channel
+int omap3_dma_conf_chan(uint32_t chan, struct dma4_chan *config);
+ Write config to the channel
+int omap3_dma_conf_transfer(uint32_t chan, uint32_t *src, uint32_t *dst,
+ uint32_t sze)
+ Config source, destination and size of a transfer
+int omap3_dma_wait_for_transfer(uint32_t chan)
+ Wait for a transfer to end - this hast to be called before a channel
+ or the data the channel transferd are used.
+int omap3_dma_get_revision(uint32_t *minor, uint32_t *major)
+ Read silicon Revision of the DMA module
+
Acknowledgements
================
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 9d945a0..3d9c9f1 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -27,6 +27,7 @@ LIB := $(obj)libdma.o
COBJS-$(CONFIG_FSLDMAFEC) += MCD_tasksInit.o MCD_dmaApi.o MCD_tasks.o
COBJS-$(CONFIG_FSL_DMA) += fsl_dma.o
+COBJS-$(CONFIG_OMAP3_DMA) += omap3_dma.o
COBJS := $(COBJS-y)
SRCS := $(COBJS:.o=.c)
diff --git a/drivers/dma/omap3_dma.c b/drivers/dma/omap3_dma.c
new file mode 100644
index 0000000..b98eca1
--- /dev/null
+++ b/drivers/dma/omap3_dma.c
@@ -0,0 +1,180 @@
+/* Copyright (C) 2011
+ * Corscience GmbH & Co. KG - Simon Schwarz <schwarz at corscience.de>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/* This is a basic implementation of the SDMA/DMA4 controller of OMAP3
+ * Tested on Silicon Revision major:0x4 minor:0x0
+ */
+
+#include <common.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/omap3.h>
+#include <asm/arch/dma.h>
+#include <asm/io.h>
+#include <asm/errno.h>
+
+static struct dma4 *dma4_cfg = (struct dma4 *)OMAP34XX_DMA4_BASE;
+uint32_t dma_active; /* if a transfer is started the respective
+ bit is set for the logical channel */
+
+/* Check if we have the given channel
+ * PARAMETERS:
+ * chan: Channel number
+ *
+ * RETURN of non-zero means error */
+static inline int check_channel(uint32_t chan)
+{
+ if (chan < CHAN_NR_MIN || chan > CHAN_NR_MAX)
+ return -EINVAL;
+ return 0;
+}
+
+static inline void reset_irq(uint32_t chan)
+{
+ /* reset IRQ reason */
+ writel(0x1DFE, &dma4_cfg->chan[chan].csr);
+ /* reset IRQ */
+ writel((1 << chan), &dma4_cfg->irqstatus_l[0]);
+ dma_active &= ~(1 << chan);
+}
+
+/* Set Source, Destination and Size of DMA transfer for the
+ * specified channel.
+ * PARAMETERS:
+ * chan: channel to use
+ * src: source of the transfer
+ * dst: destination of the transfer
+ * sze: Size of the transfer
+ *
+ * RETURN of non-zero means error */
+int omap3_dma_conf_transfer(uint32_t chan, uint32_t *src, uint32_t *dst,
+ uint32_t sze)
+{
+ if (check_channel(chan))
+ return -EINVAL;
+ /* CDSA0 */
+ writel((uint32_t)src, &dma4_cfg->chan[chan].cssa);
+ writel((uint32_t)dst, &dma4_cfg->chan[chan].cdsa);
+ writel(sze, &dma4_cfg->chan[chan].cen);
+return 0;
+}
+
+/* Start the DMA transfer */
+int omap3_dma_start_transfer(uint32_t chan)
+{
+ uint32_t val;
+
+ if (check_channel(chan))
+ return -EINVAL;
+
+ val = readl(&dma4_cfg->chan[chan].ccr);
+ /* Test for channel already in use */
+ if (val & CCR_ENABLE_ENABLE)
+ return -EBUSY;
+
+ writel((val | CCR_ENABLE_ENABLE), &dma4_cfg->chan[chan].ccr);
+ dma_active |= (1 << chan);
+ debug("started transfer...\n");
+ return 0;
+}
+
+/* Busy-waiting for a DMA transfer
+ * This has to be called before another transfer is started
+ * PARAMETER
+ * chan: Channel to wait for
+ *
+ * RETURN of non-zero means error*/
+int omap3_dma_wait_for_transfer(uint32_t chan)
+{
+ uint32_t val;
+
+ if (!(dma_active & (1 << chan))) {
+ val = readl(&dma4_cfg->irqstatus_l[0]);
+ if (!(val & chan)) {
+ debug("dma: The channel you are trying to wait for "
+ "was never activated - ERROR\n");
+ return -1; /* channel was never active */
+ }
+ }
+
+ /* all irqs on line 0 */
+ while (!(readl(&dma4_cfg->irqstatus_l[0]) & (1 << chan)))
+ asm("nop");
+
+ val = readl(&dma4_cfg->chan[chan].csr);
+ if ((val & CSR_TRANS_ERR) | (val & CSR_SUPERVISOR_ERR) |
+ (val & CSR_MISALIGNED_ADRS_ERR)) {
+ debug("err code: %X\n", val);
+ debug("dma: transfer error detected\n");
+ reset_irq(chan);
+ return -1;
+ }
+ reset_irq(chan);
+ return 0;
+}
+
+/* Get the revision of the DMA module
+ * PARAMETER
+ * minor: Address of minor revision to write
+ * major: Address of major revision to write
+ *
+ * RETURN of non-zero means error
+ */
+int omap3_dma_get_revision(uint32_t *minor, uint32_t *major)
+{
+ uint32_t val;
+
+ /* debug information */
+ val = readl(&dma4_cfg->revision);
+ *major = (val & 0x000000F0) >> 4;
+ *minor = (val & 0x0000000F);
+ debug("DMA Silicon revision (maj/min): 0x%X/0x%X\n", *major, *minor);
+ return 0;
+}
+
+/* Initial config of omap dma
+ */
+void omap3_dma_init(void)
+{
+ dma_active = 0;
+ /* All interrupts on channel 0 */
+ writel(0xFFFFFFFF, &dma4_cfg->irqenable_l[0]);
+}
+
+/* set channel config to config
+ *
+ * RETURN of non-zero means error */
+int omap3_dma_conf_chan(uint32_t chan, struct dma4_chan *config)
+{
+ if (check_channel(chan))
+ return -EINVAL;
+
+ dma4_cfg->chan[chan] = *config;
+ return 0;
+}
+
+/* get channel config to config
+ *
+ * RETURN of non-zero means error */
+int omap3_dma_get_conf_chan(uint32_t chan, struct dma4_chan *config)
+{
+ if (check_channel(chan))
+ return -EINVAL;
+ *config = dma4_cfg->chan[chan];
+ return 0;
+}
--
1.7.4.1
More information about the U-Boot
mailing list