soc: imx8m: Enable OCOTP clock for imx8mm before reading registers

[ Upstream commit 9d1e8275a28f51599d754ce661c91e0a689c0234 ]

Commit 836fb30949d9 ("soc: imx8m: Enable OCOTP clock before reading the
register") added configuration to enable the OCOTP clock before
attempting to read from the associated registers.

This same kexec issue is present with the imx8m SoCs that use the
imx8mm_soc_uid function (e.g. imx8mp). This requires the imx8mm_soc_uid
function to configure the OCOTP clock before accessing the associated
registers. This change implements the same clock enable functionality
that is present in the imx8mq_soc_revision function for the
imx8mm_soc_uid function.

Signed-off-by: Nathan Rossi <nathan.rossi@digi.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Fixes: 836fb30949d9 ("soc: imx8m: Enable OCOTP clock before reading the register")
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
index 32ed9dc88e45563e346bbfdfda8b22d34b9c2139..08197b03955dda504256c0242254a3c5833c4058 100644 (file)
--- a/drivers/soc/imx/soc-imx8m.c
+++ b/drivers/soc/imx/soc-imx8m.c
@@ -100,6 +100,7 @@ static void __init imx8mm_soc_uid(void)
 {
        void __iomem *ocotp_base;
        struct device_node *np;
+       struct clk *clk;
        u32 offset = of_machine_is_compatible("fsl,imx8mp") ?
                     IMX8MP_OCOTP_UID_OFFSET : 0;
 
@@ -109,11 +110,20 @@ static void __init imx8mm_soc_uid(void)
 
        ocotp_base = of_iomap(np, 0);
        WARN_ON(!ocotp_base);
+       clk = of_clk_get_by_name(np, NULL);
+       if (IS_ERR(clk)) {
+               WARN_ON(IS_ERR(clk));
+               return;
+       }
+
+       clk_prepare_enable(clk);
 
        soc_uid = readl_relaxed(ocotp_base + OCOTP_UID_HIGH + offset);
        soc_uid <<= 32;
        soc_uid |= readl_relaxed(ocotp_base + OCOTP_UID_LOW + offset);
 
+       clk_disable_unprepare(clk);
+       clk_put(clk);
        iounmap(ocotp_base);
        of_node_put(np);
 }