MIPS: Lantiq: Add DMA support

This patch adds support for the DMA engine found inside the XWAY family of
SoCs. The engine has 5 ports and 20 channels.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Ralph Hempel <ralph.hempel@lantiq.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2355/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 62 insertions, 1 deletions

diff --git a/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h b/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
index 343e82cbf60..4827afbe373 100644
--- a/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
+++ b/arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h
@@ -86,7 +86,8 @@
 #define LTQ_PPE32_SIZE          0x40000
 
 /* DMA */
-#define LTQ_DMA_BASE_ADDR       0xBE104100
+#define LTQ_DMA_BASE_ADDR       0x1E104100
+#define LTQ_DMA_SIZE            0x800
 
 /* PCI */
 #define PCI_CR_BASE_ADDR        0x1E105400
diff --git a/arch/mips/include/asm/mach-lantiq/xway/xway_dma.h b/arch/mips/include/asm/mach-lantiq/xway/xway_dma.h
new file mode 100644
index 00000000000..872943a4b90
--- /dev/null
+++ b/arch/mips/include/asm/mach-lantiq/xway/xway_dma.h
@@ -0,0 +1,60 @@
+/*
+ *   This program is free software; you can redistribute it and/or modify it
+ *   under the terms of the GNU General Public License version 2 as published
+ *   by the Free Software Foundation.
+ *
+ *   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.
+ *
+ *   Copyright (C) 2011 John Crispin <blogic@openwrt.org>
+ */
+
+#ifndef LTQ_DMA_H__
+#define LTQ_DMA_H__
+
+#define LTQ_DESC_SIZE           0x08    /* each descriptor is 64bit */
+#define LTQ_DESC_NUM            0x40    /* 64 descriptors / channel */
+
+#define LTQ_DMA_OWN             BIT(31) /* owner bit */
+#define LTQ_DMA_C               BIT(30) /* complete bit */
+#define LTQ_DMA_SOP             BIT(29) /* start of packet */
+#define LTQ_DMA_EOP             BIT(28) /* end of packet */
+#define LTQ_DMA_TX_OFFSET(x)    ((x & 0x1f) << 23) /* data bytes offset */
+#define LTQ_DMA_RX_OFFSET(x)    ((x & 0x7) << 23) /* data bytes offset */
+#define LTQ_DMA_SIZE_MASK       (0xffff) /* the size field is 16 bit */
+
+struct ltq_dma_desc {
+        u32 ctl;
+        u32 addr;
+};
+
+struct ltq_dma_channel {
+        int nr;                         /* the channel number */
+        int irq;                        /* the mapped irq */
+        int desc;                       /* the current descriptor */
+        struct ltq_dma_desc *desc_base; /* the descriptor base */
+        int phys;                       /* physical addr */
+};
+
+enum {
+        DMA_PORT_ETOP = 0,
+        DMA_PORT_DEU,
+};
+
+extern void ltq_dma_enable_irq(struct ltq_dma_channel *ch);
+extern void ltq_dma_disable_irq(struct ltq_dma_channel *ch);
+extern void ltq_dma_ack_irq(struct ltq_dma_channel *ch);
+extern void ltq_dma_open(struct ltq_dma_channel *ch);
+extern void ltq_dma_close(struct ltq_dma_channel *ch);
+extern void ltq_dma_alloc_tx(struct ltq_dma_channel *ch);
+extern void ltq_dma_alloc_rx(struct ltq_dma_channel *ch);
+extern void ltq_dma_free(struct ltq_dma_channel *ch);
+extern void ltq_dma_init_port(int p);
+
+#endif