On Fri, 2018-03-02 at 11:57 +0100, Thierry Reding wrote:

On Thu, Mar 01, 2018 at 04:19:12PM +0800, sean.wang@mediatek.com wrote:

...

From: Sean Wang sean.wang@mediatek.com

Since the offset for both registers, PWMDWIDTH and PWMTHRES, used to control PWM4 or PWM5 are distinct from the other PWMs, whose wrong programming on PWM hardware causes waveform cannot be output as expected. Thus, the patch adds the extra condition for fixing up the weird case to let PWM4 or PWM5 able to work on MT7623.

v1 -> v2: use pwm45_fixup naming instead of pwm45_quirk v2 -> v3: add more tags for Reviewed-by, Fixes, and Cc stable

Cc: stable@vger.kernel.org Fixes: caf065f8fd58 ("pwm: Add MediaTek PWM support") Signed-off-by: Sean Wang sean.wang@mediatek.com Reviewed-by: Matthias Brugger matthias.bgg@gmail.com Cc: Zhi Mao zhi.mao@mediatek.com Cc: John Crispin john@phrozen.org Cc: Matthias Brugger matthias.bgg@gmail.com

---

drivers/pwm/pwm-mediatek.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c

[...]

...

@@ -151,9 +156,18 @@ static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, return -EINVAL; }

• if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) {

• /*
  

•  * PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES
  

•  * from the other PWMs on MT7623.
  

•  */
  

• reg_width = PWM45DWIDTH_FIXUP;
  

• reg_thres = PWM45THRES_FIXUP;
  

• }

I don't understand this. According to the condition above the above would also use the PWM[4,5] "fixup" register offsets with PWM[3]. Should the condition be pwm->hwpwm > 3?

Thierry

PWM[4,5] are the naming specified in datasheet and kept it as is here and driver or userspace would use index 3 and 4 to have a reference to them respectively.