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 <lovewilliam@xxxxxxxxx>
Cc: Olliver Schinagl <o.schinagl@xxxxxxxxxxxxx>
Reported-by: Tong Zhang <lovewilliam@xxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
.../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
--
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