[PATCH AUTOSEL 4.19 01/32] cpufreq: imx6q: Fixes unwanted cpu overclocking on i.MX6ULL

[Sasha Levin <sashal@kernel.org>]

From: Christoph Niedermaier <cniedermaier@dh-electronics.com>

[ Upstream commit 36eb7dc1bd42fe5f850329c893768ff89b696fba ]

imx6ul_opp_check_speed_grading is called for both i.MX6UL and i.MX6ULL.
Since the i.MX6ULL was introduced to a separate ocotp compatible node
later, it is possible that the i.MX6ULL has also dtbs with
"fsl,imx6ull-ocotp". On a system without nvmem-cell speed grade a
missing check on this node causes a driver fail without considering
the cpu speed grade.

This patch prevents unwanted cpu overclocking on i.MX6ULL with compatible
node "fsl,imx6ull-ocotp" in old dtbs without nvmem-cell speed grade.

Fixes: 2733fb0d0699 ("cpufreq: imx6q: read OCOTP through nvmem for imx6ul/imx6ull")
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/cpufreq/imx6q-cpufreq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index d8c3595e90236..a0cbbdfc77359 100644
--- a/drivers/cpufreq/imx6q-cpufreq.c
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -310,6 +310,9 @@ static int imx6ul_opp_check_speed_grading(struct device *dev)
 		void __iomem *base;
 
 		np = of_find_compatible_node(NULL, NULL, "fsl,imx6ul-ocotp");
+		if (!np)
+			np = of_find_compatible_node(NULL, NULL,
+						     "fsl,imx6ull-ocotp");
 		if (!np)
 			return -ENOENT;
 
-- 
2.20.1