cpufreq: ti-cpufreq: Introduce quirks to handle syscon fails appropriately

[ Upstream commit abc00ffda43bd4ba85896713464c7510c39f8165 ]

Commit b4bc9f9e27ed ("cpufreq: ti-cpufreq: add support for omap34xx
and omap36xx") introduced special handling for OMAP3 class devices
where syscon node may not be present. However, this also creates a bug
where the syscon node is present, however the offset used to read
is beyond the syscon defined range.

Fix this by providing a quirk option that is populated when such
special handling is required. This allows proper failure for all other
platforms when the syscon node and efuse offsets are mismatched.

Fixes: b4bc9f9e27ed ("cpufreq: ti-cpufreq: add support for omap34xx and omap36xx")
Signed-off-by: Nishanth Menon <nm@ti.com>
Tested-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/cpufreq/ti-cpufreq.c b/drivers/cpufreq/ti-cpufreq.c
index d88ee87b1cd6f38f977ded0d1df77678e779b196..cb5d1c8fefeb4420f0231ab090a2c44ead01a832 100644 (file)
--- a/drivers/cpufreq/ti-cpufreq.c
+++ b/drivers/cpufreq/ti-cpufreq.c
@@ -61,6 +61,9 @@ struct ti_cpufreq_soc_data {
        unsigned long efuse_shift;
        unsigned long rev_offset;
        bool multi_regulator;
+/* Backward compatibility hack: Might have missing syscon */
+#define TI_QUIRK_SYSCON_MAY_BE_MISSING 0x1
+       u8 quirks;
 };
 
 struct ti_cpufreq_data {
@@ -182,6 +185,7 @@ static struct ti_cpufreq_soc_data omap34xx_soc_data = {
        .efuse_mask = BIT(3),
        .rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
        .multi_regulator = false,
+       .quirks = TI_QUIRK_SYSCON_MAY_BE_MISSING,
 };
 
 /*
@@ -209,6 +213,7 @@ static struct ti_cpufreq_soc_data omap36xx_soc_data = {
        .efuse_mask = BIT(9),
        .rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
        .multi_regulator = true,
+       .quirks = TI_QUIRK_SYSCON_MAY_BE_MISSING,
 };
 
 /*
@@ -223,6 +228,7 @@ static struct ti_cpufreq_soc_data am3517_soc_data = {
        .efuse_mask = 0,
        .rev_offset = OMAP3_CONTROL_IDCODE - OMAP3_SYSCON_BASE,
        .multi_regulator = false,
+       .quirks = TI_QUIRK_SYSCON_MAY_BE_MISSING,
 };
 
 static struct ti_cpufreq_soc_data am625_soc_data = {
@@ -250,7 +256,7 @@ static int ti_cpufreq_get_efuse(struct ti_cpufreq_data *opp_data,
 
        ret = regmap_read(opp_data->syscon, opp_data->soc_data->efuse_offset,
                          &efuse);
-       if (ret == -EIO) {
+       if (opp_data->soc_data->quirks & TI_QUIRK_SYSCON_MAY_BE_MISSING && ret == -EIO) {
                /* not a syscon register! */
                void __iomem *regs = ioremap(OMAP3_SYSCON_BASE +
                                opp_data->soc_data->efuse_offset, 4);
@@ -291,7 +297,7 @@ static int ti_cpufreq_get_rev(struct ti_cpufreq_data *opp_data,
 
        ret = regmap_read(opp_data->syscon, opp_data->soc_data->rev_offset,
                          &revision);
-       if (ret == -EIO) {
+       if (opp_data->soc_data->quirks & TI_QUIRK_SYSCON_MAY_BE_MISSING && ret == -EIO) {
                /* not a syscon register! */
                void __iomem *regs = ioremap(OMAP3_SYSCON_BASE +
                                opp_data->soc_data->rev_offset, 4);