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MIPS: jz4740: Acquire and enable DMA controller clock

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Previously, it was assumed that the DMA controller clock is not gated
when the kernel starts running. While that is the power-on state, it is
safer to not rely on that.

Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Maarten ter Huurne
2013-05-30 18:25:01 +02:00
committed by Vinod Koul
parent 8e3c518fba
commit c8c81f32ee
1 changed files with 22 additions and 2 deletions
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24
arch/mips/jz4740/dma.c
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@@ -16,6 +16,7 @@
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/spinlock.h> #include <linux/spinlock.h>
#include <linux/clk.h>
#include <linux/interrupt.h> #include <linux/interrupt.h>
#include <linux/dma-mapping.h> #include <linux/dma-mapping.h>
@@ -268,6 +269,7 @@ static irqreturn_t jz4740_dma_irq(int irq, void *dev_id)
static int jz4740_dma_init(void) static int jz4740_dma_init(void)
{ {
struct clk *clk;
unsigned int ret; unsigned int ret;
jz4740_dma_base = ioremap(JZ4740_DMAC_BASE_ADDR, 0x400); jz4740_dma_base = ioremap(JZ4740_DMAC_BASE_ADDR, 0x400);
@@ -277,11 +279,29 @@ static int jz4740_dma_init(void)
spin_lock_init(&jz4740_dma_lock); spin_lock_init(&jz4740_dma_lock);
clk = clk_get(NULL, "dma");
if (IS_ERR(clk)) {
ret = PTR_ERR(clk);
printk(KERN_ERR "JZ4740 DMA: Failed to request clock: %d\n",
ret);
goto err_iounmap;
}
ret = request_irq(JZ4740_IRQ_DMAC, jz4740_dma_irq, 0, "DMA", NULL); ret = request_irq(JZ4740_IRQ_DMAC, jz4740_dma_irq, 0, "DMA", NULL);
if (ret) {
if (ret)
printk(KERN_ERR "JZ4740 DMA: Failed to request irq: %d\n", ret); printk(KERN_ERR "JZ4740 DMA: Failed to request irq: %d\n", ret);
goto err_clkput;
}
clk_prepare_enable(clk);
return 0;
err_clkput:
clk_put(clk);
err_iounmap:
iounmap(jz4740_dma_base);
return ret; return ret;
} }
arch_initcall(jz4740_dma_init); arch_initcall(jz4740_dma_init);