All of lore.kernel.org
 help / color / mirror / Atom feed
From: "H. Nikolaus Schaller" <hns@goldelico.com>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	"H. Nikolaus Schaller" <hns@goldelico.com>,
	Jonathan Cameron <jic23@kernel.org>,
	sre@kernel.org
Cc: linux-input@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, letux-kernel@openphoenux.org
Subject: [PATCH 2/3] Input: tsc2007 - correctly report pressure and not resistance to user space
Date: Mon, 20 Feb 2017 17:56:35 +0100	[thread overview]
Message-ID: <9e249276be9e20aab1a74617373bf6587f1acd4b.1487609795.git.hns@goldelico.com> (raw)
In-Reply-To: <cover.1487609795.git.hns@goldelico.com>
In-Reply-To: <cover.1487609795.git.hns@goldelico.com>

previously, tsc2007 will report as ABS_PRESSURE:
0              for no pressure (resistance infinite)
high value     for soft pressure (high resistance)
low value      for firm pressure (lower resistance)

This does not matter for most applications (e.g. GUI, Menu, Scrolling
etc.) where the ABS_PRESSURE is ignored and only BTN_TOUCH is processed
to detect screen taps.

Only some special graphics applications read the pressure channel and
they will be mixed up by this non-monotonic relation.

So we fix it to become:
0              for no pressure (resistance infinite)
low value      for soft pressure (high resistance)
high value     for firm pressure (lower resistance)

While this patch changes the values reported to userspace,
ABS_PRESSURE is used rarely by userspace. Most software only
relies on BTN_TOUCH (boolean), which is not affected by this
patch. Some graphics software makes use of the interface and
does not work correctly with the currently used inverted
behaviour.

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 drivers/input/touchscreen/tsc2007_core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/input/touchscreen/tsc2007_core.c b/drivers/input/touchscreen/tsc2007_core.c
index 30b53ca..fc73849 100644
--- a/drivers/input/touchscreen/tsc2007_core.c
+++ b/drivers/input/touchscreen/tsc2007_core.c
@@ -141,6 +141,8 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 				"DOWN point(%4d,%4d), resistance (%4u)\n",
 				tc.x, tc.y, rt);
 
+			rt = ts->max_rt - rt;
+
 			input_report_key(input, BTN_TOUCH, 1);
 			input_report_abs(input, ABS_X, tc.x);
 			input_report_abs(input, ABS_Y, tc.y);
-- 
2.7.3

WARNING: multiple messages have this Message-ID (diff)
From: "H. Nikolaus Schaller" <hns-xXXSsgcRVICgSpxsJD1C4w@public.gmane.org>
To: Dmitry Torokhov
	<dmitry.torokhov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>,
	"H. Nikolaus Schaller"
	<hns-xXXSsgcRVICgSpxsJD1C4w@public.gmane.org>,
	Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	sre-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org
Cc: linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	letux-kernel-S0jZdbWzriLCfDggNXIi3w@public.gmane.org
Subject: [PATCH 2/3] Input: tsc2007 - correctly report pressure and not resistance to user space
Date: Mon, 20 Feb 2017 17:56:35 +0100	[thread overview]
Message-ID: <9e249276be9e20aab1a74617373bf6587f1acd4b.1487609795.git.hns@goldelico.com> (raw)
In-Reply-To: <cover.1487609795.git.hns-xXXSsgcRVICgSpxsJD1C4w@public.gmane.org>
In-Reply-To: <cover.1487609795.git.hns-xXXSsgcRVICgSpxsJD1C4w@public.gmane.org>

previously, tsc2007 will report as ABS_PRESSURE:
0              for no pressure (resistance infinite)
high value     for soft pressure (high resistance)
low value      for firm pressure (lower resistance)

This does not matter for most applications (e.g. GUI, Menu, Scrolling
etc.) where the ABS_PRESSURE is ignored and only BTN_TOUCH is processed
to detect screen taps.

Only some special graphics applications read the pressure channel and
they will be mixed up by this non-monotonic relation.

So we fix it to become:
0              for no pressure (resistance infinite)
low value      for soft pressure (high resistance)
high value     for firm pressure (lower resistance)

While this patch changes the values reported to userspace,
ABS_PRESSURE is used rarely by userspace. Most software only
relies on BTN_TOUCH (boolean), which is not affected by this
patch. Some graphics software makes use of the interface and
does not work correctly with the currently used inverted
behaviour.

Signed-off-by: H. Nikolaus Schaller <hns-xXXSsgcRVICgSpxsJD1C4w@public.gmane.org>
---
 drivers/input/touchscreen/tsc2007_core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/input/touchscreen/tsc2007_core.c b/drivers/input/touchscreen/tsc2007_core.c
index 30b53ca..fc73849 100644
--- a/drivers/input/touchscreen/tsc2007_core.c
+++ b/drivers/input/touchscreen/tsc2007_core.c
@@ -141,6 +141,8 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 				"DOWN point(%4d,%4d), resistance (%4u)\n",
 				tc.x, tc.y, rt);
 
+			rt = ts->max_rt - rt;
+
 			input_report_key(input, BTN_TOUCH, 1);
 			input_report_abs(input, ABS_X, tc.x);
 			input_report_abs(input, ABS_Y, tc.y);
-- 
2.7.3

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

  parent reply	other threads:[~2017-02-20 16:57 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-20 16:56 [PATCH 0/3] Fix tsc2007 to report ABS_PRESSURE correctly H. Nikolaus Schaller
2017-02-20 16:56 ` [PATCH 1/3] Input: tsc2007 - rename function tsc2007_calculate_pressure to tsc2007_calculate_resistance because that is what it does H. Nikolaus Schaller
2017-02-23  8:45   ` Dmitry Torokhov
2017-02-20 16:56 ` H. Nikolaus Schaller [this message]
2017-02-20 16:56   ` [PATCH 2/3] Input: tsc2007 - correctly report pressure and not resistance to user space H. Nikolaus Schaller
2017-02-21 17:13   ` Sebastian Reichel
2017-02-21 17:13     ` Sebastian Reichel
2017-02-23  8:45     ` Dmitry Torokhov
2017-02-23  8:45       ` Dmitry Torokhov
2017-02-20 16:56 ` [PATCH 3/3] Input: tsc2007 - add a property "ti,report-resistance" to restore the old pressure reporting state if needed H. Nikolaus Schaller
2017-02-21 11:07   ` Pavel Machek
2017-02-21 11:43     ` H. Nikolaus Schaller
2017-02-21 11:43       ` H. Nikolaus Schaller
2017-02-21 17:19       ` Sebastian Reichel

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=9e249276be9e20aab1a74617373bf6587f1acd4b.1487609795.git.hns@goldelico.com \
    --to=hns@goldelico.com \
    --cc=devicetree@vger.kernel.org \
    --cc=dmitry.torokhov@gmail.com \
    --cc=jic23@kernel.org \
    --cc=letux-kernel@openphoenux.org \
    --cc=linux-input@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=robh+dt@kernel.org \
    --cc=sre@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.