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Commit a2a28229 authored by Patrick Havelange's avatar Patrick Havelange Committed by Thierry Reding
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pwm: fsl-ftm: Use write protection for prescaler & polarity 



Modifying the prescaler or polarity value must be done with the
write protection disabled. Currently this is working by chance as
the write protection is in a disabled state by default.
This patch makes sure that we enable/disable the write protection
when needed.

Signed-off-by: default avatarPatrick Havelange <patrick.havelange@essensium.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent 3479bbd1

drivers/pwm/pwm-fsl-ftm.c

+21 −0
Original line number Diff line number Diff line
@@ -63,6 +63,21 @@ static inline struct fsl_pwm_chip *to_fsl_chip(struct pwm_chip *chip) 
	return container_of(chip, struct fsl_pwm_chip, chip);

}



static void ftm_clear_write_protection(struct fsl_pwm_chip *fpc)

{

	u32 val;



	regmap_read(fpc->regmap, FTM_FMS, &val);

	if (val & FTM_FMS_WPEN)

		regmap_update_bits(fpc->regmap, FTM_MODE, FTM_MODE_WPDIS,

				   FTM_MODE_WPDIS);

}



static void ftm_set_write_protection(struct fsl_pwm_chip *fpc)

{

	regmap_update_bits(fpc->regmap, FTM_FMS, FTM_FMS_WPEN, FTM_FMS_WPEN);

}



static bool fsl_pwm_periodcfg_are_equal(const struct fsl_pwm_periodcfg *a,

					const struct fsl_pwm_periodcfg *b)

{
@@ -257,6 +272,8 @@ static int fsl_pwm_apply_config(struct fsl_pwm_chip *fpc, 
		do_write_period = true;

	}



	ftm_clear_write_protection(fpc);



	if (do_write_period) {

		regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK,

				   FTM_SC_CLK(periodcfg.clk_select));
@@ -283,6 +300,8 @@ static int fsl_pwm_apply_config(struct fsl_pwm_chip *fpc, 
					       fpc->period.mod_period + 1);

	newstate->duty_cycle = fsl_pwm_ticks_to_ns(fpc, duty);



	ftm_set_write_protection(fpc);



	return 0;

}
@@ -367,6 +386,8 @@ static int fsl_pwm_init(struct fsl_pwm_chip *fpc) 
static bool fsl_pwm_volatile_reg(struct device *dev, unsigned int reg)

{

	switch (reg) {

	case FTM_FMS:

	case FTM_MODE:

	case FTM_CNT:

		return true;

	}