From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752727AbeEGRUe (ORCPT ); Mon, 7 May 2018 13:20:34 -0400 Received: from mail-pl0-f68.google.com ([209.85.160.68]:37357 "EHLO mail-pl0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752706AbeEGRUa (ORCPT ); Mon, 7 May 2018 13:20:30 -0400 X-Google-Smtp-Source: AB8JxZr1BiDiEsQVhYqSiDdVcZ2ci0isX054ARy1p/UUqR22FybCqyFl9KYdUGlmcRtJLA2IHYYjkw== Date: Mon, 7 May 2018 10:21:52 -0700 From: Bjorn Andersson To: Kiran Gunda Cc: Lee Jones , Daniel Thompson , Jingoo Han , Bartlomiej Zolnierkiewicz , dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-leds@vger.kernel.org Subject: Re: [PATCH V1 4/5] backlight: qcom-wled: Add support for OVP interrupt handling Message-ID: <20180507172152.GD2259@tuxbook-pro> References: <1525341432-15818-1-git-send-email-kgunda@codeaurora.org> <1525341432-15818-5-git-send-email-kgunda@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1525341432-15818-5-git-send-email-kgunda@codeaurora.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 03 May 02:57 PDT 2018, Kiran Gunda wrote: > WLED peripheral has over voltage protection(OVP) circuitry and the OVP > fault is notified through an interrupt. Though this fault condition rising > is due to an incorrect hardware configuration is mitigated in the hardware, > it still needs to be detected and handled. Add support for it. > > When WLED module is enabled, keep OVP fault interrupt disabled for 10 ms to > account for soft start delay. > > Signed-off-by: Kiran Gunda > --- > drivers/video/backlight/qcom-wled.c | 118 +++++++++++++++++++++++++++++++++++- > 1 file changed, 116 insertions(+), 2 deletions(-) > > diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c > index 2cfba77..80ae084 100644 > --- a/drivers/video/backlight/qcom-wled.c > +++ b/drivers/video/backlight/qcom-wled.c > @@ -23,14 +23,20 @@ > > /* From DT binding */ > #define WLED_DEFAULT_BRIGHTNESS 2048 > - > +#define WLED_SOFT_START_DLY_US 10000 > #define WLED3_SINK_REG_BRIGHT_MAX 0xFFF > > /* WLED3 Control registers */ > #define WLED3_CTRL_REG_FAULT_STATUS 0x08 > +#define WLED3_CTRL_REG_ILIM_FAULT_BIT BIT(0) > +#define WLED3_CTRL_REG_OVP_FAULT_BIT BIT(1) > +#define WLED4_CTRL_REG_SC_FAULT_BIT BIT(2) > + > +#define WLED3_CTRL_REG_INT_RT_STS 0x10 > > #define WLED3_CTRL_REG_MOD_EN 0x46 > #define WLED3_CTRL_REG_MOD_EN_MASK BIT(7) > +#define WLED3_CTRL_REG_MOD_EN_BIT BIT(7) "BIT(7)" is not a "bit" it's a "mask", so perhaps you could use the define with that name...which has the same value? > > #define WLED3_CTRL_REG_FREQ 0x4c > #define WLED3_CTRL_REG_FREQ_MASK GENMASK(3, 0) > @@ -161,9 +167,12 @@ struct wled { > u32 short_count; > const int *version; > int short_irq; > + int ovp_irq; > bool force_mod_disable; > + bool ovp_irq_disabled; > > struct wled_config cfg; > + struct delayed_work ovp_work; > int (*wled_set_brightness)(struct wled *wled, u16 brightness); > int (*wled_sync_toggle)(struct wled *wled); > }; > @@ -209,6 +218,32 @@ static int wled4_set_brightness(struct wled *wled, u16 brightness) > return 0; > } > > +static void wled_ovp_work(struct work_struct *work) > +{ > + u32 val; > + int rc; > + > + struct wled *wled = container_of(work, > + struct wled, ovp_work.work); > + > + rc = regmap_read(wled->regmap, wled->ctrl_addr + WLED3_CTRL_REG_MOD_EN, > + &val); > + if (rc < 0) > + return; > + > + if (val & WLED3_CTRL_REG_MOD_EN_BIT) { > + if (wled->ovp_irq > 0 && wled->ovp_irq_disabled) { > + enable_irq(wled->ovp_irq); > + wled->ovp_irq_disabled = false; > + } > + } else { > + if (wled->ovp_irq > 0 && !wled->ovp_irq_disabled) { > + disable_irq(wled->ovp_irq); > + wled->ovp_irq_disabled = true; > + } > + } > +} > + > static int wled_module_enable(struct wled *wled, int val) > { > int rc; > @@ -220,7 +255,12 @@ static int wled_module_enable(struct wled *wled, int val) > WLED3_CTRL_REG_MOD_EN, > WLED3_CTRL_REG_MOD_EN_MASK, > WLED3_CTRL_REG_MOD_EN_MASK); > - return rc; > + if (rc < 0) > + return rc; > + > + schedule_delayed_work(&wled->ovp_work, WLED_SOFT_START_DLY_US); Do you really want to delay the work on disable? Wouldn't it be better to use a delay worker for the enablement and in the disable case you cancel the work and just disable_irq() directly here. But more importantly, if this is only related to auto detection, do you really want to enable/disable the ovp_irq after you have detected the string configuration? > + > + return 0; > } > > static int wled3_sync_toggle(struct wled *wled) > @@ -346,6 +386,36 @@ static irqreturn_t wled_short_irq_handler(int irq, void *_wled) > return IRQ_HANDLED; > } > > +static irqreturn_t wled_ovp_irq_handler(int irq, void *_wled) > +{ > + struct wled *wled = _wled; > + int rc; > + u32 int_sts, fault_sts; > + > + rc = regmap_read(wled->regmap, > + wled->ctrl_addr + WLED3_CTRL_REG_INT_RT_STS, &int_sts); > + if (rc < 0) { > + dev_err(wled->dev, "Error in reading WLED3_INT_RT_STS rc=%d\n", > + rc); > + return IRQ_HANDLED; > + } > + > + rc = regmap_read(wled->regmap, wled->ctrl_addr + > + WLED3_CTRL_REG_FAULT_STATUS, &fault_sts); > + if (rc < 0) { > + dev_err(wled->dev, "Error in reading WLED_FAULT_STATUS rc=%d\n", > + rc); > + return IRQ_HANDLED; > + } > + > + if (fault_sts & > + (WLED3_CTRL_REG_OVP_FAULT_BIT | WLED3_CTRL_REG_ILIM_FAULT_BIT)) > + dev_dbg(wled->dev, "WLED OVP fault detected, int_sts=%x fault_sts= %x\n", > + int_sts, fault_sts); > + It's hard to give a good review on this, as the actual logic comes in the next patch. And as these two patches both implement auto detection (without a clear separation) I think you should squash them. > + return IRQ_HANDLED; > +} > + > static int wled3_setup(struct wled *wled) > { > u16 addr; > @@ -821,6 +891,44 @@ static int wled_configure_short_irq(struct wled *wled, > return rc; > } > > +static int wled_configure_ovp_irq(struct wled *wled, > + struct platform_device *pdev) > +{ > + int rc = 0; > + u32 val; > + > + if (*wled->version == WLED_PM8941) > + return 0; > + > + wled->ovp_irq = platform_get_irq_byname(pdev, "ovp"); > + if (wled->ovp_irq < 0) { > + dev_dbg(&pdev->dev, "ovp irq is not used\n"); > + return 0; > + } > + > + rc = devm_request_threaded_irq(wled->dev, wled->ovp_irq, NULL, > + wled_ovp_irq_handler, IRQF_ONESHOT, > + "wled_ovp_irq", wled); > + if (rc < 0) { > + dev_err(wled->dev, "Unable to request ovp_irq (err:%d)\n", > + rc); wled->ovp_irq might be > 0 here which means wled_ovp_work() will find it valid and call enabled_irq()/disable_irq() on it. > + return 0; > + } > + Regards, Bjorn