From: Soren Brinkmann <soren.brinkmann@xilinx.com>
To: Michal Simek <michal.simek@xilinx.com>,
Russell King <linux@arm.linux.org.uk>
Cc: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Soren Brinkmann <soren.brinkmann@xilinx.com>
Subject: [PATCH 3/3] arm: zynq: slcr: Use read-modify-write for register writes
Date: Wed, 17 Jul 2013 10:10:15 -0700 [thread overview]
Message-ID: <1374081015-31431-4-git-send-email-soren.brinkmann@xilinx.com> (raw)
In-Reply-To: <1374081015-31431-1-git-send-email-soren.brinkmann@xilinx.com>
zynq_slcr_cpu_start/stop() ignored the current register state when
writing to a register. Fixing this by implementing proper
read-modify-write.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
---
arch/arm/mach-zynq/slcr.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/arm/mach-zynq/slcr.c b/arch/arm/mach-zynq/slcr.c
index 44a4ab6..1836d5a 100644
--- a/arch/arm/mach-zynq/slcr.c
+++ b/arch/arm/mach-zynq/slcr.c
@@ -61,11 +61,11 @@ void zynq_slcr_system_reset(void)
*/
void zynq_slcr_cpu_start(int cpu)
{
- /* enable CPUn */
- writel(SLCR_A9_CPU_CLKSTOP << cpu,
- zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
- /* enable CLK for CPUn */
- writel(0x0 << cpu, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+ u32 reg = readl(zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+ reg &= ~(SLCR_A9_CPU_RST << cpu);
+ writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+ reg &= ~(SLCR_A9_CPU_CLKSTOP << cpu);
+ writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
}
/**
@@ -74,9 +74,9 @@ void zynq_slcr_cpu_start(int cpu)
*/
void zynq_slcr_cpu_stop(int cpu)
{
- /* stop CLK and reset CPUn */
- writel((SLCR_A9_CPU_CLKSTOP | SLCR_A9_CPU_RST) << cpu,
- zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+ u32 reg = readl(zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
+ reg |= (SLCR_A9_CPU_CLKSTOP | SLCR_A9_CPU_RST) << cpu;
+ writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
}
/**
--
1.8.3.3
next prev parent reply other threads:[~2013-07-17 17:10 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-17 17:10 [PATCH 0/3] arm: zynq: SLCR clean up Soren Brinkmann
2013-07-17 17:10 ` [PATCH 1/3] arm: zynq: slcr: Remove redundant header #includes Soren Brinkmann
2013-07-17 17:10 ` [PATCH 2/3] arm: zynq: slcr: Clean up #defines Soren Brinkmann
2013-07-17 17:10 ` Soren Brinkmann [this message]
2013-07-18 7:21 ` [PATCH 3/3] arm: zynq: slcr: Use read-modify-write for register writes Steffen Trumtrar
2013-07-18 15:45 ` Sören Brinkmann
2013-07-26 12:15 ` [PATCH 0/3] arm: zynq: SLCR clean up Michal Simek
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