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| author | Santosh Shilimkar <santosh.shilimkar@ti.com> | 2009-03-23 18:07:48 -0700 |
|---|---|---|
| committer | Tony Lindgren <tony@atomide.com> | 2009-03-23 18:51:20 -0700 |
| commit | 2263f0222e836c7b2c144e0546a2701661e2f517 (patch) | |
| tree | f2438344e9caa2a8418fbb7e73e8377a53fe656d /arch/arm/plat-omap/dma.c | |
| parent | 7954763bb95fd484a76d1151b40956fe331d23b9 (diff) | |
| download | blackbird-op-linux-2263f0222e836c7b2c144e0546a2701661e2f517.tar.gz blackbird-op-linux-2263f0222e836c7b2c144e0546a2701661e2f517.zip | |
ARM: OMAP: Get available DMA channels from cmdline
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 <santosh.shilimkar@ti.com>
Acked-by: Nishant Kamat <nskamat@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'arch/arm/plat-omap/dma.c')
| -rw-r--r-- | arch/arm/plat-omap/dma.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index dcc9e83a61ee..b1d3c7991ffd 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -123,6 +123,7 @@ static struct dma_link_info *dma_linked_lch; 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; @@ -2321,6 +2322,10 @@ 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) @@ -2371,7 +2376,7 @@ 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; @@ -2437,4 +2442,17 @@ 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); + |
