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From b1ab71156cd49b2389397d3be54b93fe394a1cb2 Mon Sep 17 00:00:00 2001
From: Maarten ter Huurne <maarten@treewalker.org>
Date: Tue, 9 Oct 2012 13:09:57 +0200
Subject: [PATCH 13/16] MIPS: JZ4740: Acquire and enable DMA controller clock
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: Lars-Peter Clausen <lars@metafoo.de>
---
arch/mips/jz4740/clock.c | 2 +-
arch/mips/jz4740/dma.c | 24 ++++++++++++++++++++++--
2 files changed, 23 insertions(+), 3 deletions(-)
diff --git a/arch/mips/jz4740/clock.c b/arch/mips/jz4740/clock.c
index 1b5f554..b3eba60 100644
--- a/arch/mips/jz4740/clock.c
+++ b/arch/mips/jz4740/clock.c
@@ -921,4 +921,4 @@ static int jz4740_clock_init(void)
return 0;
}
-arch_initcall(jz4740_clock_init);
+postcore_initcall(jz4740_clock_init);
diff --git a/arch/mips/jz4740/dma.c b/arch/mips/jz4740/dma.c
index 317ec6f..fb5266c 100644
--- a/arch/mips/jz4740/dma.c
+++ b/arch/mips/jz4740/dma.c
@@ -16,6 +16,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spinlock.h>
+#include <linux/clk.h>
#include <linux/interrupt.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)
{
+ struct clk *clk;
unsigned int ret;
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);
- ret = request_irq(JZ4740_IRQ_DMAC, jz4740_dma_irq, 0, "DMA", NULL);
+ 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;
+ }
- if (ret)
+ ret = request_irq(JZ4740_IRQ_DMAC, jz4740_dma_irq, 0, "DMA", NULL);
+ if (ret) {
printk(KERN_ERR "JZ4740 DMA: Failed to request irq: %d\n", ret);
+ goto err_clkput;
+ }
+
+ clk_enable(clk);
+
+ return 0;
+
+err_clkput:
+ clk_put(clk);
+err_iounmap:
+ iounmap(jz4740_dma_base);
return ret;
}
arch_initcall(jz4740_dma_init);
--
1.7.10.4
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