[PATCH 1/3] touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve
From: Hans de Goede <hidden>
Date: 2015-03-08 20:53:40
Also in:
linux-devicetree
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, open firmware and flattened device tree bindings, the rest · Maintainers:
Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2015-03-09 · Re: [PATCH 1/3] touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve · Hans de Goede <hidden>
- 2015-03-08 · Re: [PATCH 1/3] touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve · Dmitry Torokhov <hidden>
Testing has revealed that the temperature in the rtp controller of the A10
(sun4i) SoC has a different curve then on the A13 (sun5i) and later models.
Add a new sun5i-a13-ts compatible to differentiate the newer models and
set the curve based on the compatible string.
The new curve is still not ideal on all A10-s, that seems to have to
do with there being a large spread between different A10-s out there,
the new curve us based on callibration results on 4 completely different
models:
raw min raw max temp min temp max stepsize offset
Tong Zhang's hackberry 2402 2680 45.0 80.0 0.125 -255.3
Hansg's Cubieboard 2207 2300 36.0 45.0 0.096 -175.8
Olliver's lime 1 (*): 2258 2537 48.3 87.1 0.139 -265.7
Olliver's lime 2 (*): 2222 2486 46.7 91.7 0.170 -331.0
*) from: http://linux-sunxi.org/Temperature_Calibration
Average all 4: 0.133 -257.0
Average without outliers (middle 2): 0.132 -261.0
Since it is better to slightly overreport the temperature this patch uses
the average of all 4 as curve.
This fixes the temperature reported on the A10 being much higher then
expected.
Cc: Tong Zhang <redacted>
Cc: Olliver Schinagl <redacted>
Reported-by: Tong Zhang <redacted>
Signed-off-by: Hans de Goede <redacted>
---
.../devicetree/bindings/input/touchscreen/sun4i.txt | 3 ++-
drivers/input/touchscreen/sun4i-ts.c | 16 +++++++++++++---
2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt b/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
index 433332d..d59d252 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt@@ -2,7 +2,8 @@ sun4i resistive touchscreen controller -------------------------------------- Required properties: - - compatible: "allwinner,sun4i-a10-ts" or "allwinner,sun6i-a31-ts" + - compatible: "allwinner,sun4i-a10-ts", "allwinner,sun5i-a13-ts" or + "allwinner,sun6i-a31-ts" - reg: mmio address range of the chip - interrupts: interrupt to which the chip is connected - #thermal-sensor-cells: shall be 0
diff --git a/drivers/input/touchscreen/sun4i-ts.c b/drivers/input/touchscreen/sun4i-ts.c
index b93a28b..66ccd5a 100644
--- a/drivers/input/touchscreen/sun4i-ts.c
+++ b/drivers/input/touchscreen/sun4i-ts.c@@ -258,6 +258,15 @@ static int sun4i_ts_probe(struct platform_device *pdev) /* Allwinner SDK has temperature = -271 + (value / 6) (C) */ ts->temp_offset = 1626; ts->temp_step = 167; + } else if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts")) { + /* + * The A10 temperature sensor has quite a wide spread, these + * parameters are based on the averaging of the calibration + * results of 4 completely different boards, with a spread of + * temp_step from 96 - 170 and temp_offset from 1758 - 3310. + */ + ts->temp_offset = 2570; + ts->temp_step = 133; } else { /* * The user manuals do not contain the formula for calculating
@@ -330,10 +339,10 @@ static int sun4i_ts_probe(struct platform_device *pdev) * finally enable tp mode. */ reg = STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1); - if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts")) - reg |= TP_MODE_EN(1); - else + if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts")) reg |= SUN6I_TP_MODE_EN(1); + else + reg |= TP_MODE_EN(1); writel(reg, ts->base + TP_CTRL1); /*
@@ -383,6 +392,7 @@ static int sun4i_ts_remove(struct platform_device *pdev) static const struct of_device_id sun4i_ts_of_match[] = { { .compatible = "allwinner,sun4i-a10-ts", }, + { .compatible = "allwinner,sun5i-a13-ts", }, { .compatible = "allwinner,sun6i-a31-ts", }, { /* sentinel */ } };
--
2.3.1