From 36dd7f530ae7d9ce9e853ffb8aa337de65c6600b Mon Sep 17 00:00:00 2001 From: AngeloGioacchino Del Regno Date: Mon, 3 Apr 2023 15:30:53 +0200 Subject: pwm: mtk-disp: Disable shadow registers before setting backlight values MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If shadow registers usage is not desired, disable that before performing any write to CON0/1 registers in the .apply() callback, otherwise we may lose clkdiv or period/width updates. Fixes: cd4b45ac449a ("pwm: Add MediaTek MT2701 display PWM driver support") Signed-off-by: AngeloGioacchino Del Regno Reviewed-by: Nícolas F. R. A. Prado Tested-by: Nícolas F. R. A. Prado Reviewed-by: Alexandre Mergnat Tested-by: Alexandre Mergnat Signed-off-by: Thierry Reding --- drivers/pwm/pwm-mtk-disp.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) (limited to 'drivers/pwm') diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c index 4cfe88d54652..ea361976eb34 100644 --- a/drivers/pwm/pwm-mtk-disp.c +++ b/drivers/pwm/pwm-mtk-disp.c @@ -138,6 +138,19 @@ static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, high_width = mul_u64_u64_div_u64(state->duty_cycle, rate, div); value = period | (high_width << PWM_HIGH_WIDTH_SHIFT); + if (mdp->data->bls_debug && !mdp->data->has_commit) { + /* + * For MT2701, disable double buffer before writing register + * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH. + */ + mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug, + mdp->data->bls_debug_mask, + mdp->data->bls_debug_mask); + mtk_disp_pwm_update_bits(mdp, mdp->data->con0, + mdp->data->con0_sel, + mdp->data->con0_sel); + } + mtk_disp_pwm_update_bits(mdp, mdp->data->con0, PWM_CLKDIV_MASK, clk_div << PWM_CLKDIV_SHIFT); @@ -152,17 +165,6 @@ static int mtk_disp_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, mtk_disp_pwm_update_bits(mdp, mdp->data->commit, mdp->data->commit_mask, 0x0); - } else { - /* - * For MT2701, disable double buffer before writing register - * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH. - */ - mtk_disp_pwm_update_bits(mdp, mdp->data->bls_debug, - mdp->data->bls_debug_mask, - mdp->data->bls_debug_mask); - mtk_disp_pwm_update_bits(mdp, mdp->data->con0, - mdp->data->con0_sel, - mdp->data->con0_sel); } mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, mdp->data->enable_mask, -- cgit v1.2.3