[PATCH v3 7/8] qcom: cpuidle: Add cpuidle driver for QCOM cpus

From: Lina Iyer <lina.iyer@linaro.org>
To: daniel.lezcano@linaro.org, khilman@linaro.org,
	sboyd@codeaurora.org, davidb@codeaurora.org,
	galak@codeaurora.org, linux-arm-msm@vger.kernel.org,
	lorenzo.pieralisi@arm.com
Cc: msivasub@codeauorora.org, Lina Iyer <lina.iyer@linaro.org>
Subject: [PATCH v3 7/8] qcom: cpuidle: Add cpuidle driver for QCOM cpus
Date: Mon, 18 Aug 2014 16:23:33 -0600	[thread overview]
Message-ID: <1408400614-45419-8-git-send-email-lina.iyer@linaro.org> (raw)
In-Reply-To: <1408400614-45419-1-git-send-email-lina.iyer@linaro.org>

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@linaro.org>
---
 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>
+#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);
+}
+
+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" },
+		{ 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;
+			}
+		}
+	}
+}
+
+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);
+
+	/**
+	 * Default to standard for WFI (index = 0)
+	 * Probe only for other states
+	 */
+	ret = dt_init_idle_driver(drv, 1);
+	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;
+
+	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);
-- 
1.9.1
