ARM: imx7d: clk: make sure OCOTP clock is always on

Some device make use of the OCOTP via syscon. While the OCOTP node
specifies a clock, in newer kernels the access via syscon does not
enable the clock! During the main boot phase this is not usually a
problem since the clock is initially on. However, after unused
clocks get disabled, any access leads to a freeze. This has been
observed when the i.MX Thermal driver probe has been deferred: The
driver tried to read the calibration data from OCOTP via syscon
and caused a system freeze.

In upstream Linux this has recently been resolved using the NVMEM
framework, see:
Commit ae6215576d6b ("thermal: imx: Add support for reading OCOTP
through nvmem")
Commit a6c856e9a8cd ("ARM: dts: imx6sx: Use nvmem-cells for tempmon")

Use a simpler work around by just adding the clock to the list of
clocks which should kept on.

Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Acked-by: Max Krummenacher <max.krummenacher@toradex.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/clk/imx/clk-imx7d.c b/drivers/clk/imx/clk-imx7d.c
index 593229494763..a44f31e1c1f6 100644
--- a/drivers/clk/imx/clk-imx7d.c
+++ b/drivers/clk/imx/clk-imx7d.c
@@ -393,7 +393,7 @@ static int const clks_init_on[] __initconst = {
 	IMX7D_DRAM_PHYM_ROOT_CLK, IMX7D_DRAM_ROOT_CLK,
 	IMX7D_DRAM_PHYM_ALT_ROOT_CLK, IMX7D_DRAM_ALT_ROOT_CLK,
 	IMX7D_AHB_CHANNEL_ROOT_CLK, IMX7D_IPG_ROOT_CLK,
-	IMX7D_PLL_SYS_MAIN_240M_CLK,
+	IMX7D_PLL_SYS_MAIN_240M_CLK, IMX7D_OCOTP_CLK,
 };
 
 static struct clk_onecell_data clk_data;