[PATCH 3/6] OMAP: PM: register to the per-device PM QoS framework

[jean.pihet at newoldbits.com]

From: Jean Pihet <j-pihet at ti.com>

Implement the devices wake-up latency constraints using the global
device PM QoS notification handler which applies the constraints to the
underlying layer by calling the corresponding function at hwmod level.

Tested on OMAP3 Beagleboard and OMAP4 Pandaboard in RET/OFF using wake-up
latency constraints on MPU, CORE and PER.

Signed-off-by: Jean Pihet <j-pihet at ti.com>
Reviewed-by: Kevin Hilman <khilman at ti.com>
---
 arch/arm/mach-omap2/pm.c |   71 +++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 70 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c
index 1881fe9..a40d4f3 100644
--- a/arch/arm/mach-omap2/pm.c
+++ b/arch/arm/mach-omap2/pm.c
@@ -11,15 +11,18 @@
 
 #include <linux/kernel.h>
 #include <linux/init.h>
+#include <linux/notifier.h>
 #include <linux/io.h>
 #include <linux/err.h>
 #include <linux/opp.h>
+#include <linux/pm_qos.h>
 #include <linux/export.h>
 
 #include <plat/omap-pm.h>
 #include <plat/omap_device.h>
-#include "common.h"
+#include <plat/omap_hwmod.h>
 
+#include "common.h"
 #include "voltage.h"
 #include "powerdomain.h"
 #include "clockdomain.h"
@@ -215,12 +218,78 @@ static void __init omap4_init_voltages(void)
 	omap2_set_init_voltage("iva", "dpll_iva_m5x2_ck", "iva");
 }
 
+/* Interface to the per-device PM QoS framework */
+static int omap2_dev_pm_qos_handler(struct notifier_block *nb,
+				    unsigned long new_value,
+				    void *req)
+{
+	struct omap_device *od;
+	struct omap_hwmod *oh;
+	struct platform_device *pdev;
+	struct dev_pm_qos_request *dev_pm_qos_req = req;
+
+	pr_debug("OMAP PM constraints: req at 0x%p, new_value=%lu\n",
+		 req, new_value);
+
+	/* Look for the platform device for the constraint target device */
+	pdev = to_platform_device(dev_pm_qos_req->dev);
+
+	/* Try to catch non platform devices */
+	if (pdev->name == NULL) {
+		pr_err("%s: Error: platform device for device %s not valid\n",
+		       __func__, dev_name(dev_pm_qos_req->dev));
+		return -EINVAL;
+	}
+
+	/* Find the associated omap_device for dev */
+	od = to_omap_device(pdev);
+	if (od == NULL) {
+		pr_err("%s: Error: no omap_device for device %s\n",
+		       __func__, dev_name(dev_pm_qos_req->dev));
+		return -EINVAL;
+	}
+
+	/* Check that the omap_device has an unique hwmod entry */
+	if (od->hwmods_cnt != 1) {
+		pr_err("%s: Error: No unique hwmod for device %s\n",
+		       __func__, dev_name(dev_pm_qos_req->dev));
+		return -EINVAL;
+	}
+
+	/* Find the primary omap_hwmod for dev */
+	oh = od->hwmods[0];
+
+	pr_debug("OMAP PM constraints: req at 0x%p, dev=0x%p, new_value=%lu\n",
+		 req, dev_pm_qos_req->dev, new_value);
+
+	/* Apply the constraint */
+	return omap_hwmod_set_wkup_lat_constraint(oh, dev_pm_qos_req,
+						  new_value);
+}
+
+static struct notifier_block omap2_dev_pm_qos_notifier = {
+	.notifier_call	= omap2_dev_pm_qos_handler,
+};
+
+static int __init omap2_dev_pm_qos_init(void)
+{
+	int ret;
+
+	ret = dev_pm_qos_add_global_notifier(&omap2_dev_pm_qos_notifier);
+	WARN(ret, KERN_ERR "Cannot add global notifier for dev PM QoS\n");
+
+	return ret;
+}
+
 static int __init omap2_common_pm_init(void)
 {
 	if (!of_have_populated_dt())
 		omap2_init_processor_devices();
 	omap_pm_if_init();
 
+	/* Register to the per-device PM QoS framework */
+	omap2_dev_pm_qos_init();
+
 	return 0;
 }
 postcore_initcall(omap2_common_pm_init);
-- 
1.7.5.4