We could see that state is defined as unsigned type, so it
should never be less than zero. Let' remove this check.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

If the allocation fails then we can't continue.

Fixes: a76caf55e5b3 ('thermal: Add devfreq cooling')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

The prototype of do_div() is:

uint32_t do_div(uint64_t *n, uint32_t base);

Make power u64 to avoid the following warning:

   drivers/thermal/devfreq_cooling.c: In function 'get_dynamic_power':
   drivers/thermal/devfreq_cooling.c:267:2: warning: comparison of distinct pointer types lacks a cast [enabled by default]
   drivers/thermal/devfreq_cooling.c:267:2: warning: right shift count >= width of type [enabled by default]
   drivers/thermal/devfreq_cooling.c:267:2: warning: passing argument 1 of '__div64_32' from incompatible pointer type [enabled by default]
   include/asm-generic/div64.h:35:17: note: expected 'uint64_t *' but argument is of type 'long unsigned int *'

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

Be consistent with what other cooling devices do and return a struct
thermal_cooling_device * on register.  Also, for the unregister, accept
a struct thermal_cooling_device * as parameter.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

Tracing is useful for debugging and performance tuning.  Add similar
traces to what's present in the cpu cooling device.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

Add a generic thermal cooling device for devfreq, that is similar to
cpu_cooling.

The device must use devfreq.  In order to use the power extension of the
cooling device, it must have registered its OPPs using the OPP library.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Ørjan Eide <orjan.eide@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>