From: Daniel Thompson <daniel.thompson@linaro.org>
To: Kiran Gunda <kgunda@codeaurora.org>,
bjorn.andersson@linaro.org, jingoohan1@gmail.com,
lee.jones@linaro.org, b.zolnierkie@samsung.com,
dri-devel@lists.freedesktop.org, jacek.anaszewski@gmail.com,
pavel@ucw.cz, robh+dt@kernel.org, mark.rutland@arm.com,
linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org
Cc: linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH V4 7/8] backlight: qcom-wled: add support for short circuit handling
Date: Fri, 20 Jul 2018 15:07:17 +0100 [thread overview]
Message-ID: <1a708fea-0759-fcd0-d169-a36e21c31c28@linaro.org> (raw)
In-Reply-To: <1531131741-19971-8-git-send-email-kgunda@codeaurora.org>
On 09/07/18 11:22, Kiran Gunda wrote:
> Handle the short circuit interrupt and check if the short circuit
> interrupt is valid. Re-enable the module to check if it goes
> away. Disable the module altogether if the short circuit event
> persists.
>
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> Changes from V3:
> - Added Reviewed by tag.
> - Addressed minor comments from Vinod
>
> drivers/video/backlight/qcom-wled.c | 132 ++++++++++++++++++++++++++++++++++--
> 1 file changed, 128 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index 362d254..a14f1a6 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -10,6 +10,9 @@
> * GNU General Public License for more details.
> */
>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/ktime.h>
> #include <linux/kernel.h>
> #include <linux/backlight.h>
> #include <linux/module.h>
> @@ -64,6 +67,16 @@
> #define WLED3_SINK_REG_STR_CABC(n) (0x66 + (n * 0x10))
> #define WLED3_SINK_REG_STR_CABC_MASK BIT(7)
>
> +/* WLED4 specific control registers */
> +#define WLED4_CTRL_REG_SHORT_PROTECT 0x5e
> +#define WLED4_CTRL_REG_SHORT_EN_MASK BIT(7)
> +
> +#define WLED4_CTRL_REG_SEC_ACCESS 0xd0
> +#define WLED4_CTRL_REG_SEC_UNLOCK 0xa5
> +
> +#define WLED4_CTRL_REG_TEST1 0xe2
> +#define WLED4_CTRL_REG_TEST1_EXT_FET_DTEST2 0x09
> +
> /* WLED4 specific sink registers */
> #define WLED4_SINK_REG_CURR_SINK 0x46
> #define WLED4_SINK_REG_CURR_SINK_MASK GENMASK(7, 4)
> @@ -113,17 +126,23 @@ struct wled_config {
> bool cs_out_en;
> bool ext_gen;
> bool cabc;
> + bool external_pfet;
> };
>
> struct wled {
> const char *name;
> struct device *dev;
> struct regmap *regmap;
> + struct mutex lock; /* Lock to avoid race from thread irq handler */
> + ktime_t last_short_event;
> u16 ctrl_addr;
> u16 sink_addr;
> u16 max_string_count;
> u32 brightness;
> u32 max_brightness;
> + u32 short_count;
> + bool disabled_by_short;
> + bool has_short_detect;
>
> struct wled_config cfg;
> int (*wled_set_brightness)(struct wled *wled, u16 brightness);
> @@ -174,6 +193,9 @@ static int wled_module_enable(struct wled *wled, int val)
> {
> int rc;
>
> + if (wled->disabled_by_short)
> + return -EFAULT;
EFAULT means bad address (memory fault). Perhaps EIO or maybe even
something more exotic like ENXIO might be more appropriate?
> +
> rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
> WLED_CTRL_REG_MOD_EN,
> WLED_CTRL_REG_MOD_EN_MASK,
> @@ -210,18 +232,19 @@ static int wled_update_status(struct backlight_device *bl)
> bl->props.state & BL_CORE_FBBLANK)
> brightness = 0;
>
> + mutex_lock(&wled->lock);
> if (brightness) {
> rc = wled->wled_set_brightness(wled, brightness);
> if (rc < 0) {
> dev_err(wled->dev, "wled failed to set brightness rc:%d\n",
> rc);
> - return rc;
> + goto unlock_mutex;
> }
>
> rc = wled_sync_toggle(wled);
> if (rc < 0) {
> dev_err(wled->dev, "wled sync failed rc:%d\n", rc);
> - return rc;
> + goto unlock_mutex;
> }
> }
>
> @@ -229,15 +252,61 @@ static int wled_update_status(struct backlight_device *bl)
> rc = wled_module_enable(wled, !!brightness);
> if (rc < 0) {
> dev_err(wled->dev, "wled enable failed rc:%d\n", rc);
> - return rc;
> + goto unlock_mutex;
> }
> }
>
> wled->brightness = brightness;
>
> +unlock_mutex:
> + mutex_unlock(&wled->lock);
> +
> return rc;
> }
>
> +#define WLED_SHORT_DLY_MS 20
> +#define WLED_SHORT_CNT_MAX 5
> +#define WLED_SHORT_RESET_CNT_DLY_US USEC_PER_SEC
> +
> +static irqreturn_t wled_short_irq_handler(int irq, void *_wled)
> +{
> + struct wled *wled = _wled;
> + int rc;
> + s64 elapsed_time;
> +
> + wled->short_count++;
> + mutex_lock(&wled->lock);
> + rc = wled_module_enable(wled, false);
> + if (rc < 0) {
> + dev_err(wled->dev, "wled disable failed rc:%d\n", rc);
> + goto unlock_mutex;
> + }
> +
> + elapsed_time = ktime_us_delta(ktime_get(),
> + wled->last_short_event);
> + if (elapsed_time > WLED_SHORT_RESET_CNT_DLY_US)
> + wled->short_count = 0;
Shouldn't this reset to 1 (e.g. we have just seen a short).
Daniel.
next prev parent reply other threads:[~2018-07-20 14:07 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-09 10:22 [PATCH V4 0/8] backlight: qcom-wled: Support for QCOM wled driver Kiran Gunda
2018-07-09 10:22 ` [PATCH V4 1/8] backlight: qcom-wled: Rename pm8941-wled.c to qcom-wled.c Kiran Gunda
2018-07-09 10:22 ` [PATCH V4 2/8] backlight: qcom-wled: restructure the qcom-wled bindings Kiran Gunda
2018-07-09 10:22 ` [PATCH V4 3/8] backlight: qcom-wled: Add new properties for PMI8998 Kiran Gunda
2018-07-11 15:12 ` Rob Herring
2018-07-20 13:15 ` Daniel Thompson
2018-08-07 5:23 ` Bjorn Andersson
2018-08-16 5:23 ` kgunda
2018-09-03 18:55 ` Bjorn Andersson
2018-09-26 5:31 ` kgunda
2018-07-09 10:22 ` [PATCH V4 4/8] backlight: qcom-wled: Rename PM8941* to WLED3 Kiran Gunda
2018-07-20 13:23 ` Daniel Thompson
2018-07-23 5:55 ` kgunda
2018-08-07 5:41 ` Bjorn Andersson
2018-08-16 5:30 ` kgunda
2018-07-09 10:22 ` [PATCH V4 5/8] backlight: qcom-wled: Restructure the driver for WLED3 Kiran Gunda
2018-07-20 13:40 ` Daniel Thompson
2018-08-07 5:37 ` Bjorn Andersson
2018-08-16 5:28 ` kgunda
2018-07-09 10:22 ` [PATCH V4 6/8] backlight: qcom-wled: Add support for WLED4 peripheral Kiran Gunda
2018-07-20 13:47 ` Daniel Thompson
2018-07-20 21:21 ` Pavel Machek
2018-07-23 6:16 ` kgunda
2018-08-07 5:45 ` Bjorn Andersson
2018-07-09 10:22 ` [PATCH V4 7/8] backlight: qcom-wled: add support for short circuit handling Kiran Gunda
2018-07-20 14:07 ` Daniel Thompson [this message]
2018-07-23 6:05 ` kgunda
2018-07-09 10:22 ` [PATCH V4 8/8] backlight: qcom-wled: Add auto string detection logic Kiran Gunda
2018-08-07 6:32 ` Bjorn Andersson
2018-08-16 5:33 ` kgunda
2018-08-03 7:19 ` [PATCH V4 0/8] backlight: qcom-wled: Support for QCOM wled driver kgunda
2018-08-03 7:45 ` Daniel Thompson
2018-08-06 10:58 ` 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=1a708fea-0759-fcd0-d169-a36e21c31c28@linaro.org \
--to=daniel.thompson@linaro.org \
--cc=b.zolnierkie@samsung.com \
--cc=bjorn.andersson@linaro.org \
--cc=devicetree@vger.kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=jacek.anaszewski@gmail.com \
--cc=jingoohan1@gmail.com \
--cc=kgunda@codeaurora.org \
--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 \
--cc=mark.rutland@arm.com \
--cc=pavel@ucw.cz \
--cc=robh+dt@kernel.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).