LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Kiran Gunda <kgunda@codeaurora.org>
To: bjorn.andersson@linaro.org, Lee Jones <lee.jones@linaro.org>,
	Daniel Thompson <daniel.thompson@linaro.org>,
	Jingoo Han <jingoohan1@gmail.com>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: linux-arm-msm@vger.kernel.org, linux-leds@vger.kernel.org,
	Kiran Gunda <kgunda@codeaurora.org>
Subject: [PATCH V1 4/5] backlight: qcom-wled: Add support for OVP interrupt handling
Date: Thu,  3 May 2018 15:27:11 +0530	[thread overview]
Message-ID: <1525341432-15818-5-git-send-email-kgunda@codeaurora.org> (raw)
In-Reply-To: <1525341432-15818-1-git-send-email-kgunda@codeaurora.org>

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 <kgunda@codeaurora.org>
---
 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)
 
 #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);
+
+	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);
+
+	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);
+		return 0;
+	}
+
+	rc = regmap_read(wled->regmap, wled->ctrl_addr +
+			 WLED3_CTRL_REG_MOD_EN, &val);
+	if (rc < 0)
+		return rc;
+
+	/* Keep OVP irq disabled until module is enabled */
+	if (!rc && !(val & WLED3_CTRL_REG_MOD_EN_MASK)) {
+		disable_irq(wled->ovp_irq);
+		wled->ovp_irq_disabled = true;
+	}
+
+	return rc;
+}
+
 static const struct backlight_ops wled_ops = {
 	.update_status = wled_update_status,
 };
@@ -874,10 +982,16 @@ static int wled_probe(struct platform_device *pdev)
 		}
 	}
 
+	INIT_DELAYED_WORK(&wled->ovp_work, wled_ovp_work);
+
 	rc = wled_configure_short_irq(wled, pdev);
 	if (rc < 0)
 		return rc;
 
+	rc = wled_configure_ovp_irq(wled, pdev);
+	if (rc < 0)
+		return rc;
+
 	val = WLED_DEFAULT_BRIGHTNESS;
 	of_property_read_u32(pdev->dev.of_node, "default-brightness", &val);
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

  parent reply	other threads:[~2018-05-03  9:59 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-03  9:57 [PATCH V1 0/5] backlight: qcom-wled: Support for QCOM wled driver Kiran Gunda
2018-05-03  9:57 ` [PATCH V1 1/5] qcom: wled: Rename pm8941-wled.c to qcom-wled.c Kiran Gunda
2018-05-07 15:41   ` Bjorn Andersson
2018-05-10 11:10   ` Pavel Machek
2018-05-03  9:57 ` [PATCH V1 2/5] backlight: qcom-wled: Add support for WLED4 peripheral Kiran Gunda
2018-05-07 16:20   ` Bjorn Andersson
2018-05-08 10:25     ` kgunda
2018-05-08 17:17       ` Bjorn Andersson
2018-05-09  5:15         ` kgunda
2018-05-17  9:47       ` kgunda
2018-05-17 12:31         ` Rob Herring
2018-05-17 15:10           ` kgunda
2018-05-18 12:20             ` Rob Herring
2018-05-14 16:57   ` Pavel Machek
2018-05-15  4:55     ` kgunda
2018-05-03  9:57 ` [PATCH V1 3/5] backlight: qcom-wled: Add support for short circuit handling Kiran Gunda
2018-05-07  8:06   ` Dan Carpenter
2018-05-07  9:08     ` kgunda
2018-05-07 17:06   ` Bjorn Andersson
2018-05-08 10:35     ` kgunda
2018-05-03  9:57 ` Kiran Gunda [this message]
2018-05-07 17:21   ` [PATCH V1 4/5] backlight: qcom-wled: Add support for OVP interrupt handling Bjorn Andersson
2018-05-08 12:26     ` kgunda
2018-05-08 17:19       ` Bjorn Andersson
2018-05-09  5:06         ` kgunda
2018-05-09  6:16           ` kgunda
2018-05-03  9:57 ` [PATCH V1 5/5] backlight: qcom-wled: Add auto string detection logic Kiran Gunda
2018-05-07 18:10   ` Bjorn Andersson
2018-05-09  7:14     ` kgunda
2018-05-14 17:02       ` Bjorn Andersson
2018-05-15  4:50         ` kgunda

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1525341432-15818-5-git-send-email-kgunda@codeaurora.org \
    --to=kgunda@codeaurora.org \
    --cc=b.zolnierkie@samsung.com \
    --cc=bjorn.andersson@linaro.org \
    --cc=daniel.thompson@linaro.org \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=jingoohan1@gmail.com \
    --cc=lee.jones@linaro.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-fbdev@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-leds@vger.kernel.org \
    --subject='Re: [PATCH V1 4/5] backlight: qcom-wled: Add support for OVP interrupt handling' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).