diff options
Diffstat (limited to 'drivers/pwm/pwm-meson.c')
| -rw-r--r-- | drivers/pwm/pwm-meson.c | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c index c1ed641b3e26..f6e738ad7bd9 100644 --- a/drivers/pwm/pwm-meson.c +++ b/drivers/pwm/pwm-meson.c @@ -111,6 +111,10 @@ struct meson_pwm { const struct meson_pwm_data *data; void __iomem *base; u8 inverter_mask; + /* + * Protects register (write) access to the REG_MISC_AB register + * that is shared between the two PWMs. + */ spinlock_t lock; }; @@ -235,6 +239,7 @@ static void meson_pwm_enable(struct meson_pwm *meson, { u32 value, clk_shift, clk_enable, enable; unsigned int offset; + unsigned long flags; switch (id) { case 0: @@ -255,6 +260,8 @@ static void meson_pwm_enable(struct meson_pwm *meson, return; } + spin_lock_irqsave(&meson->lock, flags); + value = readl(meson->base + REG_MISC_AB); value &= ~(MISC_CLK_DIV_MASK << clk_shift); value |= channel->pre_div << clk_shift; @@ -267,11 +274,14 @@ static void meson_pwm_enable(struct meson_pwm *meson, value = readl(meson->base + REG_MISC_AB); value |= enable; writel(value, meson->base + REG_MISC_AB); + + spin_unlock_irqrestore(&meson->lock, flags); } static void meson_pwm_disable(struct meson_pwm *meson, unsigned int id) { u32 value, enable; + unsigned long flags; switch (id) { case 0: @@ -286,9 +296,13 @@ static void meson_pwm_disable(struct meson_pwm *meson, unsigned int id) return; } + spin_lock_irqsave(&meson->lock, flags); + value = readl(meson->base + REG_MISC_AB); value &= ~enable; writel(value, meson->base + REG_MISC_AB); + + spin_unlock_irqrestore(&meson->lock, flags); } static int meson_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, @@ -296,19 +310,16 @@ static int meson_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, { struct meson_pwm_channel *channel = pwm_get_chip_data(pwm); struct meson_pwm *meson = to_meson_pwm(chip); - unsigned long flags; int err = 0; if (!state) return -EINVAL; - spin_lock_irqsave(&meson->lock, flags); - if (!state->enabled) { meson_pwm_disable(meson, pwm->hwpwm); channel->state.enabled = false; - goto unlock; + return 0; } if (state->period != channel->state.period || @@ -329,7 +340,7 @@ static int meson_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, err = meson_pwm_calc(meson, channel, pwm->hwpwm, state->duty_cycle, state->period); if (err < 0) - goto unlock; + return err; channel->state.polarity = state->polarity; channel->state.period = state->period; @@ -341,9 +352,7 @@ static int meson_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, channel->state.enabled = true; } -unlock: - spin_unlock_irqrestore(&meson->lock, flags); - return err; + return 0; } static void meson_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, |