summaryrefslogtreecommitdiff
path: root/arch/sh/drivers/dma/dma-sh.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/sh/drivers/dma/dma-sh.c')
-rw-r--r--arch/sh/drivers/dma/dma-sh.c46
1 files changed, 27 insertions, 19 deletions
diff --git a/arch/sh/drivers/dma/dma-sh.c b/arch/sh/drivers/dma/dma-sh.c
index b22565623142..306fba1564e5 100644
--- a/arch/sh/drivers/dma/dma-sh.c
+++ b/arch/sh/drivers/dma/dma-sh.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* arch/sh/drivers/dma/dma-sh.c
*
@@ -6,10 +7,6 @@
* Copyright (C) 2000 Takashi YOSHII
* Copyright (C) 2003, 2004 Paul Mundt
* Copyright (C) 2005 Andriy Skulysh
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
*/
#include <linux/init.h>
#include <linux/interrupt.h>
@@ -22,17 +19,29 @@
#include <cpu/dma.h>
/*
+ * Some of the SoCs feature two DMAC modules. In such a case, the channels are
+ * distributed equally among them.
+ */
+#ifdef SH_DMAC_BASE1
+#define SH_DMAC_NR_MD_CH (CONFIG_NR_ONCHIP_DMA_CHANNELS / 2)
+#else
+#define SH_DMAC_NR_MD_CH CONFIG_NR_ONCHIP_DMA_CHANNELS
+#endif
+
+#define SH_DMAC_CH_SZ 0x10
+
+/*
* Define the default configuration for dual address memory-memory transfer.
* The 0x400 value represents auto-request, external->external.
*/
-#define RS_DUAL (DM_INC | SM_INC | 0x400 | TS_INDEX2VAL(XMIT_SZ_32BIT))
+#define RS_DUAL (DM_INC | SM_INC | RS_AUTO | TS_INDEX2VAL(XMIT_SZ_32BIT))
static unsigned long dma_find_base(unsigned int chan)
{
unsigned long base = SH_DMAC_BASE0;
#ifdef SH_DMAC_BASE1
- if (chan >= 6)
+ if (chan >= SH_DMAC_NR_MD_CH)
base = SH_DMAC_BASE1;
#endif
@@ -43,13 +52,13 @@ static unsigned long dma_base_addr(unsigned int chan)
{
unsigned long base = dma_find_base(chan);
- /* Normalize offset calculation */
- if (chan >= 9)
- chan -= 6;
- if (chan >= 4)
- base += 0x10;
+ chan = (chan % SH_DMAC_NR_MD_CH) * SH_DMAC_CH_SZ;
+
+ /* DMAOR is placed inside the channel register space. Step over it. */
+ if (chan >= DMAOR)
+ base += SH_DMAC_CH_SZ;
- return base + (chan * 0x10);
+ return base + chan;
}
#ifdef CONFIG_SH_DMA_IRQ_MULTI
@@ -253,12 +262,11 @@ static int sh_dmac_get_dma_residue(struct dma_channel *chan)
#define NR_DMAOR 1
#endif
-/*
- * DMAOR bases are broken out amongst channel groups. DMAOR0 manages
- * channels 0 - 5, DMAOR1 6 - 11 (optional).
- */
-#define dmaor_read_reg(n) __raw_readw(dma_find_base((n)*6))
-#define dmaor_write_reg(n, data) __raw_writew(data, dma_find_base(n)*6)
+#define dmaor_read_reg(n) __raw_readw(dma_find_base((n) * \
+ SH_DMAC_NR_MD_CH) + DMAOR)
+#define dmaor_write_reg(n, data) __raw_writew(data, \
+ dma_find_base((n) * \
+ SH_DMAC_NR_MD_CH) + DMAOR)
static inline int dmaor_reset(int no)
{
@@ -414,4 +422,4 @@ module_exit(sh_dmac_exit);
MODULE_AUTHOR("Takashi YOSHII, Paul Mundt, Andriy Skulysh");
MODULE_DESCRIPTION("SuperH On-Chip DMAC Support");
-MODULE_LICENSE("GPL");
+MODULE_LICENSE("GPL v2");