[PATCH 1/5] soc: qcom: Add suspend to idle support

[Andy Gross]

This patch adds suspend to idle support for Qualcomm processors.  While
suspend to memory will be a valid state, there won't be any special
handling or power savings over the suspend to idle.

Signed-off-by: Andy Gross <andy.gross at linaro.org>
---
 drivers/soc/qcom/Makefile  |  1 +
 drivers/soc/qcom/suspend.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+)
 create mode 100644 drivers/soc/qcom/suspend.c

diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index fdd664e..7c479d3 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
 obj-$(CONFIG_QCOM_SMP2P)	+= smp2p.o
 obj-$(CONFIG_QCOM_SMSM)	+= smsm.o
 obj-$(CONFIG_QCOM_WCNSS_CTRL) += wcnss_ctrl.o
+obj-$(CONFIG_SUSPEND)	+=	suspend.o
diff --git a/drivers/soc/qcom/suspend.c b/drivers/soc/qcom/suspend.c
new file mode 100644
index 0000000..7d3f2dd
--- /dev/null
+++ b/drivers/soc/qcom/suspend.c
@@ -0,0 +1,77 @@
+/*
+ * (C) Copyright 2016 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/cpuidle.h>
+#include <linux/suspend.h>
+
+
+static void qcom_pm_enter_freeze(struct cpuidle_device *dev,
+	struct cpuidle_driver *drv,
+	int index)
+{
+	drv->states[index].enter(dev, drv, index);
+}
+
+static const struct of_device_id qcom_idle_state_match[] = {
+	{ .compatible = "qcom,idle-state-spc", },
+	{ },
+};
+
+static const struct platform_suspend_ops qcom_suspend_ops = {
+	.valid          = suspend_valid_only_mem,
+};
+
+static int __init qcom_pm_init(void)
+{
+	struct cpuidle_device *cpu_dev;
+	struct cpuidle_driver *cpu_drv;
+	int state_count;
+	struct device_node *state_np, *cpu_np;
+	const struct of_device_id *match;
+	int i;
+
+	/* configure CPU enter_freeze if applicable */
+	for_each_present_cpu(i) {
+		cpu_np = of_get_cpu_node(i, NULL);
+		cpu_dev = per_cpu_ptr(cpuidle_devices, i);
+		cpu_drv = cpuidle_get_cpu_driver(cpu_dev);
+
+		if (!cpu_dev || !cpu_drv) {
+			of_node_put(cpu_np);
+			return -EPROBE_DEFER;
+		}
+
+		state_count = 0;
+		state_np = of_parse_phandle(cpu_np, "cpu-idle-states",
+						  state_count);
+
+		while (state_np) {
+			match = of_match_node(qcom_idle_state_match,
+					      state_np);
+
+			state_count++;
+			if (match)
+				cpu_drv->states[state_count].enter_freeze =
+						&qcom_pm_enter_freeze;
+			of_node_put(state_np);
+
+			state_np = of_parse_phandle(cpu_np, "cpu-idle-states",
+						    state_count);
+		}
+
+		of_node_put(cpu_np);
+	}
+
+	suspend_set_ops(&qcom_suspend_ops);
+
+	return 0;
+}
+
+late_initcall(qcom_pm_init);
-- 
1.9.1