Tony,
Here is the first patch as promised.
From: Santosh Shilimkar <[email protected]>
This patch set up a cmdline option for omap dma for masking the
available channels. It is needed since the OMAP DMA is a system wide
resource and can be used by another software apart from the kernel.
To reserve the omap SDMA channels for kernel dma usage, use cmdline
bootarg "omap_dma_reserve_ch=". The valid range is 1 to 32.
Signed-off-by: Santosh Shilimkar <[email protected]>
Acked By: Nishant Kamat <[email protected]>
cc: Tony Lindgren <[email protected]>
---
arch/arm/plat-omap/dma.c | 20 +++++++++++++++++++-
1 files changed, 19 insertions(+), 1 deletion(-)
Index: omapkernel/arch/arm/plat-omap/dma.c
===================================================================
--- omapkernel.orig/arch/arm/plat-omap/dma.c 2009-02-04 12:11:55.779687209
+0530
+++ omapkernel/arch/arm/plat-omap/dma.c 2009-02-04 14:05:32.971853579 +0530
@@ -131,6 +131,7 @@ static struct dma_link_info *dma_linked_
static int dma_lch_count;
static int dma_chan_count;
+static int omap_dma_reserve_channels;
static spinlock_t dma_chan_lock;
static struct omap_dma_lch *dma_chan;
@@ -2409,6 +2410,10 @@ static int __init omap_init_dma(void)
return -ENODEV;
}
+ if (cpu_class_is_omap2() && omap_dma_reserve_channels
+ && (omap_dma_reserve_channels <= dma_lch_count))
+ dma_lch_count = omap_dma_reserve_channels;
+
dma_chan = kzalloc(sizeof(struct omap_dma_lch) * dma_lch_count,
GFP_KERNEL);
if (!dma_chan)
@@ -2459,7 +2464,7 @@ static int __init omap_init_dma(void)
u8 revision = dma_read(REVISION) & 0xff;
printk(KERN_INFO "OMAP DMA hardware revision %d.%d\n",
revision >> 4, revision & 0xf);
- dma_chan_count = OMAP_DMA4_LOGICAL_DMA_CH_COUNT;
+ dma_chan_count = dma_lch_count;
} else {
dma_chan_count = 0;
return 0;
@@ -2525,4 +2530,17 @@ static int __init omap_init_dma(void)
arch_initcall(omap_init_dma);
+/*
+ * Reserve the omap SDMA channels using cmdline bootarg
+ * "omap_dma_reserve_ch=". The valid range is 1 to 32
+ */
+static int __init omap_dma_cmdline_reserve_ch(char *str)
+{
+ if (get_option(&str, &omap_dma_reserve_channels) != 1)
+ omap_dma_reserve_channels = 0;
+ return 1;
+}
+
+__setup("omap_dma_reserve_ch=", omap_dma_cmdline_reserve_ch);
+
Regards,
Santosh
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