[PATCH v2 2/3] ARM: imx: Add imx5 cpuidle driver

Sascha,

On Wed, May 2, 2012 at 2:33 AM, Sascha Hauer [off-list ref] wrote:

On Tue, May 01, 2012 at 09:12:39PM -0500, Robert Lee wrote:

quoted

Add imx5 cpuidle driver.

Signed-off-by: Robert Lee <redacted>
---
?arch/arm/mach-imx/mm-imx5.c | ? 42 +++++++++++++++++++++++++++++++++++++++---
?1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-imx/mm-imx5.c b/arch/arm/mach-imx/mm-imx5.c
index d6b7e9f..cbd9bad 100644
--- a/arch/arm/mach-imx/mm-imx5.c
+++ b/arch/arm/mach-imx/mm-imx5.c

@@ -22,24 +22,59 @@

?#include <mach/common.h>
?#include <mach/devices-common.h>
?#include <mach/iomux-v3.h>
+#include <mach/cpuidle.h>

?static struct clk *gpc_dvfs_clk;

-static void imx5_idle(void)
+static int imx5_idle(void)
?{
+ ? ? int ret = 0;
+
? ? ? /* gpc clock is needed for SRPG */
? ? ? if (gpc_dvfs_clk == NULL) {
? ? ? ? ? ? ? gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
? ? ? ? ? ? ? if (IS_ERR(gpc_dvfs_clk))
- ? ? ? ? ? ? ? ? ? ? return;
+ ? ? ? ? ? ? ? ? ? ? return -ENODEV;
? ? ? }
? ? ? clk_enable(gpc_dvfs_clk);
? ? ? mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
? ? ? if (!tzic_enable_wake())
? ? ? ? ? ? ? cpu_do_idle();
+ ? ? else
+ ? ? ? ? ? ? ret = -EBUSY;
? ? ? clk_disable(gpc_dvfs_clk);
+
+ ? ? return ret;
+}
+
+static int imx5_cpuidle_enter(struct cpuidle_device *dev,
+ ? ? ? ? ? ? ? ? ? ? ? ? ? ? struct cpuidle_driver *drv, int idx)
+{
+ ? ? int ret;
+
+ ? ? ret = imx5_idle();
+
+ ? ? if (ret < 0)
+ ? ? ? ? ? ? return ret;
+
+ ? ? return idx;
?}

+static struct cpuidle_driver imx5_cpuidle_driver = {
+ ? ? .name ? ? ? ? ? ? ? ? ? = "imx5_cpuidle",
+ ? ? .owner ? ? ? ? ? ? ? ? ?= THIS_MODULE,
+ ? ? .en_core_tk_irqen ? ? ? = 1,
+ ? ? .states[0] ? ? ?= {
+ ? ? ? ? ? ? .enter ? ? ? ? ? ? ? ? ?= imx5_cpuidle_enter,
+ ? ? ? ? ? ? .exit_latency ? ? ? ? ? = 20, /* max latency at 160MHz */
+ ? ? ? ? ? ? .target_residency ? ? ? = 1,
+ ? ? ? ? ? ? .flags ? ? ? ? ? ? ? ? ?= CPUIDLE_FLAG_TIME_VALID,
+ ? ? ? ? ? ? .name ? ? ? ? ? ? ? ? ? = "IMX5 SRPG",
+ ? ? ? ? ? ? .desc ? ? ? ? ? ? ? ? ? = "CPU state retained,powered off",
+ ? ? },
+ ? ? .state_count ? ? ? ? ? ?= 1,
+};
+
?/*
? * Define the MX50 memory map.
? */

@@ -103,7 +138,7 @@ void __init imx51_init_early(void)

? ? ? mxc_set_cpu_type(MXC_CPU_MX51);
? ? ? mxc_iomux_v3_init(MX51_IO_ADDRESS(MX51_IOMUXC_BASE_ADDR));
? ? ? mxc_arch_reset_init(MX51_IO_ADDRESS(MX51_WDOG1_BASE_ADDR));
- ? ? arm_pm_idle = imx5_idle;
+ ? ? arm_pm_idle = (void *)imx5_idle;

I don't like this. It will cover all warnings when the prototype of
arm_pm_idle changes in future. Better add a static void imx5_idle
which calls a static int imx5_do_idle, then you have an idle function
which returns an int.

What about using the following:

arm_pm_idle =  (void (*)(void))imx5_idle;

This will give warnings if arm_pm_idle prototype changes.

Thanks,
Rob

quoted

?}

?void __init imx53_init_early(void)

@@ -238,4 +273,5 @@ void __init imx53_soc_init(void)

?void __init imx51_init_late(void)
?{
? ? ? mx51_neon_fixup();
+ ? ? imx_cpuidle_init(&imx5_cpuidle_driver);
?}
--
1.7.10

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