msm: thermal: Use the new device framework API

Modify the thermal driver to use the new device framework API
instead of the cpu_up/cpu_down call. The new framework API, will
keep the online/offline value reported in sysfs in sync with the
actual core status. Bypassing this framework by using cpu_up/cpu_down
will not update the value reported in the sysfs.

Also protect the device framework APIs with device hotplug lock to
provide mutual exclusion between multiple drivers using the same API.

Change-Id: I55e578ec6afdcdd7537ff7afc411bd03f277d59e
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>

1 files changed, 33 insertions, 9 deletions

diff --git a/drivers/thermal/msm_thermal.c b/drivers/thermal/msm_thermal.c
index 0fa7188b2581..06965fe63843 100644
--- a/drivers/thermal/msm_thermal.c
+++ b/drivers/thermal/msm_thermal.c
@@ -2799,6 +2799,7 @@ static void __ref do_core_control(long temp)
 {
 	int i = 0;
 	int ret = 0;
+	struct device *cpu_dev = NULL;
 
 	if (!core_control_enabled)
 		return;
@@ -2813,15 +2814,18 @@ static void __ref do_core_control(long temp)
 				continue;
 			pr_info("Set Offline: CPU%d Temp: %ld\n",
 					i, temp);
+			lock_device_hotplug();
 			if (cpu_online(i)) {
+				cpu_dev = get_cpu_device(i);
 				trace_thermal_pre_core_offline(i);
-				ret = cpu_down(i);
+				ret = device_offline(cpu_dev);
 				if (ret)
 					pr_err("Error %d offline core %d\n",
 					       ret, i);
 				trace_thermal_post_core_offline(i,
 					cpumask_test_cpu(i, cpu_online_mask));
 			}
+			unlock_device_hotplug();
 			cpus_offlined |= BIT(i);
 			break;
 		}
@@ -2838,19 +2842,26 @@ static void __ref do_core_control(long temp)
 			 * If this core is already online, then bring up the
 			 * next offlined core.
 			 */
-			if (cpu_online(i))
+			lock_device_hotplug();
+			if (cpu_online(i)) {
+				unlock_device_hotplug();
 				continue;
+			}
 			/* If this core wasn't previously online don't put it
 			   online */
-			if (!(cpumask_test_cpu(i, cpus_previously_online)))
+			if (!(cpumask_test_cpu(i, cpus_previously_online))) {
+				unlock_device_hotplug();
 				continue;
+			}
+			cpu_dev = get_cpu_device(i);
 			trace_thermal_pre_core_online(i);
-			ret = cpu_up(i);
+			ret = device_online(cpu_dev);
 			if (ret)
 				pr_err("Error %d online core %d\n",
 						ret, i);
 			trace_thermal_post_core_online(i,
 				cpumask_test_cpu(i, cpu_online_mask));
+			unlock_device_hotplug();
 			break;
 		}
 	}
@@ -2863,6 +2874,7 @@ static int __ref update_offline_cores(int val)
 	int ret = 0;
 	uint32_t previous_cpus_offlined = 0;
 	bool pend_hotplug_req = false;
+	struct device *cpu_dev = NULL;
 
 	if (!core_control_enabled)
 		return 0;
@@ -2872,10 +2884,14 @@ static int __ref update_offline_cores(int val)
 
 	for_each_possible_cpu(cpu) {
 		if (cpus_offlined & BIT(cpu)) {
-			if (!cpu_online(cpu))
+			lock_device_hotplug();
+			if (!cpu_online(cpu)) {
+				unlock_device_hotplug();
 				continue;
+			}
+			cpu_dev = get_cpu_device(cpu);
 			trace_thermal_pre_core_offline(cpu);
-			ret = cpu_down(cpu);
+			ret = device_offline(cpu_dev);
 			if (ret) {
 				pr_err_ratelimited(
 					"Unable to offline CPU%d. err:%d\n",
@@ -2886,15 +2902,22 @@ static int __ref update_offline_cores(int val)
 			}
 			trace_thermal_post_core_offline(cpu,
 				cpumask_test_cpu(cpu, cpu_online_mask));
+			unlock_device_hotplug();
 		} else if (online_core && (previous_cpus_offlined & BIT(cpu))) {
-			if (cpu_online(cpu))
+			lock_device_hotplug();
+			if (cpu_online(cpu)) {
+				unlock_device_hotplug();
 				continue;
+			}
 			/* If this core wasn't previously online don't put it
 			   online */
-			if (!(cpumask_test_cpu(cpu, cpus_previously_online)))
+			if (!(cpumask_test_cpu(cpu, cpus_previously_online))) {
+				unlock_device_hotplug();
 				continue;
+			}
+			cpu_dev = get_cpu_device(cpu);
 			trace_thermal_pre_core_online(cpu);
-			ret = cpu_up(cpu);
+			ret = device_online(cpu_dev);
 			if (ret && ret == notifier_to_errno(NOTIFY_BAD)) {
 				pr_debug("Onlining CPU%d is vetoed\n", cpu);
 			} else if (ret) {
@@ -2908,6 +2931,7 @@ static int __ref update_offline_cores(int val)
 				trace_thermal_post_core_online(cpu,
 					cpumask_test_cpu(cpu, cpu_online_mask));
 			}
+			unlock_device_hotplug();
 		}
 	}