Early samples without fuses written report "0 0" which means consumer
segment and minimum speed grading. According to datasheet the minimum speed
grade is not supported for consumer parts so all OPPs are disabled
which results in stack dumps later on.
Fix by clamping minimum consumer speed grade to 1 on imx8mm and imx8mq.
Fixes: 4d28ba1d62 ("cpufreq: Add imx-cpufreq-dt driver")
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
[ Viresh: s/minumum/minimum/ in patch and log ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Right now in upstream imx8m cpufreq support just lists a common subset
of OPPs because the higher ones should only be attempted after checking
speed grading in fuses.
Add a small driver which checks speed grading from nvmem cells before
registering cpufreq-dt.
This driver allows unlocking all frequencies for imx8mm and imx8mq and
could be applied to other chips like imx7d
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
