On 08/20/2014 12:15 AM, Lina Iyer wrote:
Add cpuidle driver interface to allow cpus to go into C-States. Use the cpuidle DT interfacecommon across ARM architectures to provide
^^^^^^^^
the C-State information to the cpuidle framework. Signed-off-by: Lina Iyer <lina.iyer@xxxxxxxxxx> --- drivers/cpuidle/Kconfig.arm | 7 +++ drivers/cpuidle/Makefile | 1 + drivers/cpuidle/cpuidle-qcom.c | 119 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 127 insertions(+) create mode 100644 drivers/cpuidle/cpuidle-qcom.c diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm index e339c7f..26e31bd 100644 --- a/drivers/cpuidle/Kconfig.arm +++ b/drivers/cpuidle/Kconfig.arm @@ -63,3 +63,10 @@ config ARM_MVEBU_V7_CPUIDLE depends on ARCH_MVEBU help Select this to enable cpuidle on Armada 370, 38x and XP processors. + +config ARM_QCOM_CPUIDLE + bool "CPU Idle drivers for Qualcomm processors" + depends on QCOM_PM + select DT_IDLE_STATES + help + Select this to enable cpuidle for QCOM processors diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile index 4d177b9..6c222d5 100644 --- a/drivers/cpuidle/Makefile +++ b/drivers/cpuidle/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_ARM_ZYNQ_CPUIDLE) += cpuidle-zynq.o obj-$(CONFIG_ARM_U8500_CPUIDLE) += cpuidle-ux500.o obj-$(CONFIG_ARM_AT91_CPUIDLE) += cpuidle-at91.o obj-$(CONFIG_ARM_EXYNOS_CPUIDLE) += cpuidle-exynos.o +obj-$(CONFIG_ARM_QCOM_CPUIDLE) += cpuidle-qcom.o ############################################################################### # MIPS drivers diff --git a/drivers/cpuidle/cpuidle-qcom.c b/drivers/cpuidle/cpuidle-qcom.c new file mode 100644 index 0000000..4aae672 --- /dev/null +++ b/drivers/cpuidle/cpuidle-qcom.c @@ -0,0 +1,119 @@ +/* Copyright (c) 2014, The Linux Foundation. All rights reserved. + * Copyright (c) 2014, Linaro Limited. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/cpuidle.h> +#include <linux/cpumask.h> +#include <linux/slab.h>
See below, cpumask is not needed, you can remove slab.h and cpumask.h.
+#include <linux/of_device.h> + +#include <soc/qcom/pm.h> +#include "dt_idle_states.h" + +static enum msm_pm_sleep_mode modes[CPUIDLE_STATE_MAX]; + +static int qcom_lpm_enter(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + return msm_cpu_pm_enter_sleep(modes[index], true);
You should return the index here.
+} + +static struct cpuidle_driver qcom_cpuidle_driver = { + .name = "qcom_cpuidle", + .owner = THIS_MODULE, +}; + +static void parse_state_translations(struct cpuidle_driver *drv) +{ + struct device_node *state_node, *cpu_node; + const char *mode_name; + int i, j; + + struct name_map { + enum msm_pm_sleep_mode mode; + char *name; + }; + static struct name_map c_states[] = { + { MSM_PM_SLEEP_MODE_POWER_COLLAPSE_STANDALONE, + "standalone-pc" },
What is standalone-pc and collapse ? Core power down ?
+ { MSM_PM_SLEEP_MODE_WAIT_FOR_INTERRUPT, "wfi" }, + }; + + cpu_node = of_cpu_device_node_get(cpumask_first(drv->cpumask)); + if (!cpu_node) + return; + + /** + * Get the state description from idle-state node entry-method + * First state is always WFI, per spec. + */ + modes[0] = MSM_PM_SLEEP_MODE_WAIT_FOR_INTERRUPT; + for (i = 1; i < drv->state_count; i++) { + mode_name = NULL; + state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i); + of_property_read_string(state_node, "entry-method", + &mode_name); + for (j = 0; mode_name && (j < ARRAY_SIZE(c_states)); j++) { + if (!strcmp(mode_name, c_states[j].name)) { + modes[i] = c_states[j].mode; + break; + } + } + } +}
For the function above, I believe we can do better with the idle_dt_init function to prevent to have to reparse the infos.
I had the opportunity to discuss with Lorenzo privately and we found a solution he will submit to solve that.
+static int qcom_cpuidle_init(void) +{ + struct cpuidle_driver *drv = &qcom_cpuidle_driver; + int ret; + int i; + + drv->cpumask = kzalloc(cpumask_size(), GFP_KERNEL); + if (!drv->cpumask) + return -ENOMEM; + cpumask_copy(drv->cpumask, cpu_possible_mask);
You can get rid of this because the driver does not rely on the multiple driver support. If the drv->cpumask is NULL it will be automatically set to cpu_possible_mask by the cpuidle framework.
+ + /** + * Default to standard for WFI (index = 0) + * Probe only for other states + */ + ret = dt_init_idle_driver(drv, 1);
So IIUC, if you specify the index 1, that means the state[0] will be the default WFI. But you override the callback below in the loop.
I recommend you use the default arm wfi callback but you implement the cpu_do_idle for your platform.
+ if (ret < 0) { + pr_err("%s: failed to initialize idle states\n", __func__); + goto failed; + } + + /* Parse the idle states for C-States on this cpu */ + parse_state_translations(drv); + + /* Register entry point for all low states */ + for (i = 0; i < drv->state_count; i++) + drv->states[i].enter = qcom_lpm_enter; + drv->safe_state_index = 0;
The safe_state index is only used for the couple c-states and as the driver is statically defined, it is pointless to initialize this variable.
+ + ret = cpuidle_register(drv, NULL); + if (ret) { + pr_err("%s: failed to register cpuidle driver\n", __func__); + goto failed; + } + + return 0; + +failed: + kfree(drv->cpumask); + return ret; +} +module_init(qcom_cpuidle_init);
Can you stick to the platform_driver paradigm like the other drivers ? Thanks -- Daniel -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html