fsl_pwm_clk
enum fsl_pwm_clk index,
enum fsl_pwm_clk m0, m1;
enum fsl_pwm_clk oldclk = fpc->period.clk_select;
enum fsl_pwm_clk newclk = periodcfg.clk_select;
enum fsl_pwm_clk clk_select;