omap3: Add interface for omap3 DMA

Adds an interface to use the OMAP3 DMA.

Signed-off-by: Simon Schwarz <simonschwarzcor@gmail.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

1 files changed, 180 insertions, 0 deletions

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@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;
+}