From patchwork Thu Jul 26 09:15:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Enric Balletbo i Serra X-Patchwork-Id: 10546703 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 39F72174A for ; Fri, 27 Jul 2018 07:03:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2C2C92B508 for ; Fri, 27 Jul 2018 07:03:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2074F2B50D; Fri, 27 Jul 2018 07:03:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 29D192B508 for ; Fri, 27 Jul 2018 07:03:37 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 257FE6E937; Fri, 27 Jul 2018 07:02:48 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by gabe.freedesktop.org (Postfix) with ESMTPS id 299E789956 for ; Thu, 26 Jul 2018 09:15:47 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id 4171726048B From: Enric Balletbo i Serra To: linux-kernel@vger.kernel.org Subject: [PATCH] backlight: pwm_bl: switch to using "atomic" PWM API Date: Thu, 26 Jul 2018 11:15:34 +0200 Message-Id: <20180726091534.27521-1-enric.balletbo@collabora.com> X-Mailer: git-send-email 2.18.0 X-Mailman-Approved-At: Fri, 27 Jul 2018 07:01:20 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, Bartlomiej Zolnierkiewicz , Jingoo Han , Daniel Thompson , dri-devel@lists.freedesktop.org, Thierry Reding , kernel@collabora.com, Lee Jones , cl@rock-chips.com MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP The "atomic" API allows us to configure PWM period and duty_cycle and enable it in one call. The patch also moves the pwm_init_state just before any use of the pwm_state struct, this fixes a potential bug where pwm_get_state can be called before pwm_init_state. Signed-off-by: Enric Balletbo i Serra --- drivers/video/backlight/pwm_bl.c | 48 ++++++++++++++++++++------------ 1 file changed, 30 insertions(+), 18 deletions(-) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index bdfcc0a71db1..2c734d55d607 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -46,7 +46,8 @@ struct pwm_bl_data { void (*exit)(struct device *); }; -static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness) +static void pwm_backlight_power_on(struct pwm_bl_data *pb, + struct pwm_state *state) { int err; @@ -57,7 +58,8 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness) if (err < 0) dev_err(pb->dev, "failed to enable power supply\n"); - pwm_enable(pb->pwm); + state->enabled = true; + pwm_apply_state(pb->pwm, state); if (pb->post_pwm_on_delay) msleep(pb->post_pwm_on_delay); @@ -70,6 +72,8 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness) static void pwm_backlight_power_off(struct pwm_bl_data *pb) { + struct pwm_state state; + if (!pb->enabled) return; @@ -79,8 +83,11 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb) if (pb->pwm_off_delay) msleep(pb->pwm_off_delay); - pwm_config(pb->pwm, 0, pb->period); - pwm_disable(pb->pwm); + pwm_get_state(pb->pwm, &state); + state.enabled = false; + state.period = pb->period; + state.duty_cycle = 0; + pwm_apply_state(pb->pwm, &state); regulator_disable(pb->power_supply); pb->enabled = false; @@ -106,6 +113,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) { struct pwm_bl_data *pb = bl_get_data(bl); int brightness = bl->props.brightness; + struct pwm_state state; int duty_cycle; if (bl->props.power != FB_BLANK_UNBLANK || @@ -118,8 +126,13 @@ static int pwm_backlight_update_status(struct backlight_device *bl) if (brightness > 0) { duty_cycle = compute_duty_cycle(pb, brightness); - pwm_config(pb->pwm, duty_cycle, pb->period); - pwm_backlight_power_on(pb, brightness); + pwm_get_state(pb->pwm, &state); + state.duty_cycle = duty_cycle; + state.period = pb->period; + if (!state.enabled) + pwm_backlight_power_on(pb, &state); + else + pwm_apply_state(pb->pwm, &state); } else pwm_backlight_power_off(pb); @@ -447,7 +460,6 @@ static int pwm_backlight_probe(struct platform_device *pdev) struct device_node *node = pdev->dev.of_node; struct pwm_bl_data *pb; struct pwm_state state; - struct pwm_args pargs; unsigned int i; int ret; @@ -539,10 +551,17 @@ static int pwm_backlight_probe(struct platform_device *pdev) dev_dbg(&pdev->dev, "got pwm for backlight\n"); - if (!data->levels) { - /* Get the PWM period (in nanoseconds) */ - pwm_get_state(pb->pwm, &state); + /* Sync up PWM state and ensure it is off. */ + pwm_init_state(pb->pwm, &state); + state.enabled = false; + ret = pwm_apply_state(pb->pwm, &state); + if (ret) { + dev_err(&pdev->dev, "failed to apply initial PWM state: %d\n", + ret); + goto err_alloc; + } + if (!data->levels) { ret = pwm_backlight_brightness_default(&pdev->dev, data, state.period); if (ret < 0) { @@ -559,20 +578,13 @@ static int pwm_backlight_probe(struct platform_device *pdev) pb->levels = data->levels; } - /* - * FIXME: pwm_apply_args() should be removed when switching to - * the atomic PWM API. - */ - pwm_apply_args(pb->pwm); - /* * The DT case will set the pwm_period_ns field to 0 and store the * period, parsed from the DT, in the PWM device. For the non-DT case, * set the period from platform data if it has not already been set * via the PWM lookup table. */ - pwm_get_args(pb->pwm, &pargs); - pb->period = pargs.period; + pb->period = state.period; if (!pb->period && (data->pwm_period_ns > 0)) pb->period = data->pwm_period_ns;