On Fri, Feb 11, 2011 at 10:36:12AM +0100, yong.shen@linaro.org wrote:
From: Yong Shen yong.shen@freescale.com
implement cpuidle driver for iMX5 SOCs, leave cpuidle params to board related code.
Signed-off-by: Yong Shen yong.shen@freescale.com
arch/arm/mach-mx5/Makefile | 1 + arch/arm/mach-mx5/cpuidle.c | 113 +++++++++++++++++++++++++++++++++++++++++++ arch/arm/mach-mx5/cpuidle.h | 26 ++++++++++ 3 files changed, 140 insertions(+), 0 deletions(-) create mode 100644 arch/arm/mach-mx5/cpuidle.c create mode 100644 arch/arm/mach-mx5/cpuidle.h
diff --git a/arch/arm/mach-mx5/Makefile b/arch/arm/mach-mx5/Makefile index 0d43be9..12239e0 100644 --- a/arch/arm/mach-mx5/Makefile +++ b/arch/arm/mach-mx5/Makefile @@ -7,6 +7,7 @@ obj-y := cpu.o mm.o clock-mx51-mx53.o devices.o obj-$(CONFIG_SOC_IMX50) += mm-mx50.o obj-$(CONFIG_CPU_FREQ_IMX) += cpu_op-mx51.o +obj-$(CONFIG_CPU_IDLE) += cpuidle.o obj-$(CONFIG_MACH_MX51_BABBAGE) += board-mx51_babbage.o obj-$(CONFIG_MACH_MX51_3DS) += board-mx51_3ds.o obj-$(CONFIG_MACH_MX53_EVK) += board-mx53_evk.o diff --git a/arch/arm/mach-mx5/cpuidle.c b/arch/arm/mach-mx5/cpuidle.c new file mode 100644 index 0000000..9d77c47 --- /dev/null +++ b/arch/arm/mach-mx5/cpuidle.c @@ -0,0 +1,113 @@ +/*
- arch/arm/mach-mx5/cpuidle.c
- This file is licensed under the terms of the GNU General Public
- License version 2. This program is licensed "as is" without any
- warranty of any kind, whether express or implied.
- */
+#include <linux/io.h> +#include <linux/cpuidle.h> +#include <asm/proc-fns.h> +#include <mach/hardware.h> +#include "cpuidle.h" +#include "crm_regs.h"
+static struct imx_cpuidle_params *imx_cpuidle_params; +void imx_cpuidle_board_params(struct imx_cpuidle_params *cpuidle_params) +{
- imx_cpuidle_params = cpuidle_params;
+}
+extern int tzic_enable_wake(int is_idle);
Please put this into a header file.
+static int imx_enter_idle(struct cpuidle_device *dev,
struct cpuidle_state *state)+{
- struct timeval before, after;
- int idle_time;
- u32 plat_lpc, arm_srpgcr, ccm_clpcr;
- u32 empgc0, empgc1;
- local_irq_disable();
- do_gettimeofday(&before);
- plat_lpc = __raw_readl(MXC_CORTEXA8_PLAT_LPC) &
~(MXC_CORTEXA8_PLAT_LPC_DSM);- ccm_clpcr = __raw_readl(MXC_CCM_CLPCR) & ~(MXC_CCM_CLPCR_LPM_MASK);
- arm_srpgcr = __raw_readl(MXC_SRPG_ARM_SRPGCR) & ~(MXC_SRPGCR_PCR);
- empgc0 = __raw_readl(MXC_SRPG_EMPGC0_SRPGCR) & ~(MXC_SRPGCR_PCR);
- empgc1 = __raw_readl(MXC_SRPG_EMPGC1_SRPGCR) & ~(MXC_SRPGCR_PCR);
- if (state == &dev->states[WAIT_CLK_ON])
;
An if without code? This looks strange.
- else if (state == &dev->states[WAIT_CLK_OFF])
ccm_clpcr |= (0x1 << MXC_CCM_CLPCR_LPM_OFFSET);- else if (state == &dev->states[WAIT_CLK_OFF_POWER_OFF]) {
/* Wait unclocked, power off */plat_lpc |= MXC_CORTEXA8_PLAT_LPC_DSM| MXC_CORTEXA8_PLAT_LPC_DBG_DSM;arm_srpgcr |= MXC_SRPGCR_PCR;ccm_clpcr |= (0x1 << MXC_CCM_CLPCR_LPM_OFFSET);ccm_clpcr &= ~MXC_CCM_CLPCR_VSTBY;ccm_clpcr &= ~MXC_CCM_CLPCR_SBYOS;if (tzic_enable_wake(1) != 0) {local_irq_enable();return 0;}- }
- __raw_writel(plat_lpc, MXC_CORTEXA8_PLAT_LPC);
- __raw_writel(ccm_clpcr, MXC_CCM_CLPCR);
- __raw_writel(arm_srpgcr, MXC_SRPG_ARM_SRPGCR);
- cpu_do_idle();
- do_gettimeofday(&after);
- local_irq_enable();
- idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
(after.tv_usec - before.tv_usec);- return idle_time;
+}
+static struct cpuidle_driver imx_cpuidle_driver = {
- .name = "imx_idle",
- .owner = THIS_MODULE,
+};
+static DEFINE_PER_CPU(struct cpuidle_device, imx_cpuidle_device);
+static int __init imx_cpuidle_init(void) +{
- struct cpuidle_device *device;
- int i;
- if (imx_cpuidle_params == NULL)
return -ENODEV;- cpuidle_register_driver(&imx_cpuidle_driver);
- device = &per_cpu(imx_cpuidle_device, smp_processor_id());
- device->state_count = IMX_MAX_CPUIDLE_STATE;
- for (i = 0; i < IMX_MAX_CPUIDLE_STATE && i < CPUIDLE_STATE_MAX; i++) {
device->states[i].enter = imx_enter_idle;device->states[i].exit_latency = imx_cpuidle_params[i].latency;device->states[i].flags = CPUIDLE_FLAG_TIME_VALID;- }
- strcpy(device->states[WAIT_CLK_ON].name, "WFI 0");
- strcpy(device->states[WAIT_CLK_ON].desc, "Wait with clock on");
- strcpy(device->states[WAIT_CLK_OFF].name, "WFI 1");
- strcpy(device->states[WAIT_CLK_OFF].desc, "Wait with clock off");
- strcpy(device->states[WAIT_CLK_OFF_POWER_OFF].name, "WFI 2");
- strcpy(device->states[WAIT_CLK_OFF_POWER_OFF].desc,
"Wait with clock off and power gating");- if (cpuidle_register_device(device)) {
printk(KERN_ERR "imx_cpuidle_init: Failed registering\n");return -ENODEV;- }
- return 0;
+}
+late_initcall(imx_cpuidle_init);
We have a late_initcall here which needs to be protected from other cpus. On the other hand we depend on board code calling imx_cpuidle_board_params() before this initcall. I think the board code should call a imx_cpuidle_init(struct imx_cpuidle_params *cpuidle_params) instead which makes the flow of execution more clear. Also, the function should be named mx51_cpuidle_init().
diff --git a/arch/arm/mach-mx5/cpuidle.h b/arch/arm/mach-mx5/cpuidle.h new file mode 100644 index 0000000..e5ba495 --- /dev/null +++ b/arch/arm/mach-mx5/cpuidle.h @@ -0,0 +1,26 @@ +/*
- arch/arm/mach-mx5/cpuidle.h
- This file is licensed under the terms of the GNU General Public
- License version 2. This program is licensed "as is" without any
- warranty of any kind, whether express or implied.
- */
+enum {
- WAIT_CLK_ON, /* c1 */
- WAIT_CLK_OFF, /* c2 */
- WAIT_CLK_OFF_POWER_OFF, /* c3 */
- IMX_MAX_CPUIDLE_STATE,
+};
+struct imx_cpuidle_params {
- unsigned int latency;
+};
+#ifdef CONFIG_CPU_IDLE +extern void imx_cpuidle_board_params(struct imx_cpuidle_params *cpuidle_params); +#else +inline void imx_cpuidle_board_params(struct imx_cpuidle_params *cpuidle_params) +{} +#endif
-- 1.7.1
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