Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752529AbdCALL0 (ORCPT ); Wed, 1 Mar 2017 06:11:26 -0500 Received: from lucky1.263xmail.com ([211.157.147.133]:55055 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752305AbdCALLT (ORCPT ); Wed, 1 Mar 2017 06:11:19 -0500 X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-RL-SENDER: david.wu@rock-chips.com X-FST-TO: boris.brezillon@free-electrons.com X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: david.wu@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 From: David Wu To: boris.brezillon@free-electrons.com, briannorris@chromium.org, heiko@sntech.de, thierry.reding@gmail.com Cc: dianders@chromium.org, b.galvani@gmail.com, caesar.wang@rock-chips.com, huangtao@rock-chips.com, linux-rockchip@lists.infradead.org, linux-pwm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, "david.wu" Subject: [PATCH v3] pwm: rockchip: State of pwm clock should synchronize with pwm enabled state Date: Wed, 1 Mar 2017 19:10:55 +0800 Message-Id: <1488366655-31387-1-git-send-email-david.wu@rock-chips.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2890 Lines: 94 From: "david.wu" If the pwm was not enabled at uboot loader, pwm could not work for clock always disabled at pwm driver. The pwm clock is enabled at beginning of pwm_apply(), but disabled at end of pwm_apply(). If the pwm was enabled at uboot loader, pwm clock is always enabled unless closed by ATF. The pwm-backlight might turn off the power at early suspend, should disable pwm clock for saving power consume. It is important to provide opportunity to enable/disable clock at pwm driver, the pwm consumer should ensure correct order to call pwm enable/disable, and pwm driver ensure state of pwm clock synchronized with pwm enabled state. Fixes: 2bf1c98aa5a4 ("pwm: rockchip: Add support for atomic update") Cc: stable@vger.kernel.org Signed-off-by: David Wu Reviewed-by: Boris Brezillon --- change in v2: - change the function name from rk_pwm_enable to rockchip_pwm_enable drivers/pwm/pwm-rockchip.c | 40 +++++++++++++++++++++++++++++++++------- 1 file changed, 33 insertions(+), 7 deletions(-) diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c index ef89df1..744d561 100644 --- a/drivers/pwm/pwm-rockchip.c +++ b/drivers/pwm/pwm-rockchip.c @@ -191,6 +191,28 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, return 0; } +static int rockchip_pwm_enable(struct pwm_chip *chip, + struct pwm_device *pwm, + bool enable, + enum pwm_polarity polarity) +{ + struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); + int ret; + + if (enable) { + ret = clk_enable(pc->clk); + if (ret) + return ret; + } + + pc->data->set_enable(chip, pwm, enable, polarity); + + if (!enable) + clk_disable(pc->clk); + + return 0; +} + static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state) { @@ -207,22 +229,26 @@ static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, return ret; if (state->polarity != curstate.polarity && enabled) { - pc->data->set_enable(chip, pwm, false, state->polarity); + ret = rockchip_pwm_enable(chip, pwm, false, state->polarity); + if (ret) + goto out; enabled = false; } ret = rockchip_pwm_config(chip, pwm, state->duty_cycle, state->period); if (ret) { if (enabled != curstate.enabled) - pc->data->set_enable(chip, pwm, !enabled, - state->polarity); - + rockchip_pwm_enable(chip, pwm, !enabled, + state->polarity); goto out; } - if (state->enabled != enabled) - pc->data->set_enable(chip, pwm, state->enabled, - state->polarity); + if (state->enabled != enabled) { + ret = rockchip_pwm_enable(chip, pwm, state->enabled, + state->polarity); + if (ret) + goto out; + } /* * Update the state with the real hardware, which can differ a bit -- 1.9.1