[PATCH V6 1/2] coresight: trbe: Add a representative coresight_platform_data for TRBE

[Anshuman Khandual]

TRBE coresight devices do not need regular connections information, as the
paths get built between all percpu source and their respective percpu sink
devices. Please refer 'commit 2cd87a7b293d ("coresight: core: Add support
for dedicated percpu sinks")' which added support for percpu sink devices.

coresight_register() expect device connections via the platform_data. TRBE
devices do not have any graph connections and thus is empty. With upcoming
ACPI support for TRBE, we do not get a real acpi_device and thus
coresight_get_platform_dat() will end up in failures. Hence this allocates
a zeroed coresight_platform_data structure and assigns that back into the
device.

Cc: Suzuki K Poulose <suzuki.poulose at arm.com>
Cc: Mike Leach <mike.leach at linaro.org>
Cc: Leo Yan <leo.yan at linaro.org>
Cc: Alexander Shishkin <alexander.shishkin at linux.intel.com>
Cc: coresight at lists.linaro.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual at arm.com>
---
 drivers/hwtracing/coresight/coresight-trbe.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index e20c1c6acc73..97b9e72965e6 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -1253,8 +1253,18 @@ static void arm_trbe_register_coresight_cpu(struct trbe_drvdata *drvdata, int cp
 	desc.name = devm_kasprintf(dev, GFP_KERNEL, "trbe%d", cpu);
 	if (!desc.name)
 		goto cpu_clear;
-
-	desc.pdata = coresight_get_platform_data(dev);
+	/*
+	 * TRBE coresight devices do not need regular connections
+	 * information, as the paths get built between all percpu
+	 * source and their respective percpu sink devices. Though
+	 * coresight_register() expect device connections via the
+	 * platform_data, which TRBE devices do not have. As they
+	 * are not real ACPI devices, coresight_get_platform_data()
+	 * ends up failing. Instead let's allocate a dummy zeroed
+	 * coresight_platform_data structure and assign that back
+	 * into the device for that purpose.
+	 */
+	desc.pdata = devm_kzalloc(dev, sizeof(*desc.pdata), GFP_KERNEL);
 	if (IS_ERR(desc.pdata))
 		goto cpu_clear;
 
-- 
2.25.1