This series grew out of a touchscreen validation activity on a custom
board. Oscilloscope measurements and driver source analysis led to these
patches.
Added Rob Herring 'Acked-by' tag to commit "dt-bindings: input:
ti-tsc-adc: fix tsc node example".
Dario Binacchi (6):
input: ti_am335x_tsc: set ADCREFM for X configuration
input: ti_am335x_tsc: fix STEPCONFIG setup for Z2
input: ti_am335x_tsc: lower the X and Y sampling time
dt-bindings: input: ti-tsc-adc: fix tsc node example
mfd: ti_am335x_tscadc: fix reading a tsc property from DT
mfd: ti_am335x_tscadc: drop the CNTRLREG_8WIRE macro
.../bindings/input/touchscreen/ti-tsc-adc.txt | 2 +-
drivers/input/touchscreen/ti_am335x_tsc.c | 18 +++++++++++++-----
drivers/mfd/ti_am335x_tscadc.c | 7 ++++++-
include/linux/mfd/ti_am335x_tscadc.h | 1 -
4 files changed, 20 insertions(+), 8 deletions(-)
--
2.17.1
As reported by the STEPCONFIG[1-16] registered field descriptions of the
TI reference manual, for the ADC "in single ended, SEL_INM_SWC_3_0 must
be 1xxx".
Unlike the Y and Z coordinates, this bit has not been set for the step
configuration registers used to sample the X coordinate.
Fixes: 1b8be32e691 ("Input: add support for TI Touchscreen controller")
Signed-off-by: Dario Binacchi <[email protected]>
---
drivers/input/touchscreen/ti_am335x_tsc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index 83e685557a19..fd3ffdd23470 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -131,7 +131,8 @@ static void titsc_step_config(struct titsc *ts_dev)
u32 stepenable;
config = STEPCONFIG_MODE_HWSYNC |
- STEPCONFIG_AVG_16 | ts_dev->bit_xp;
+ STEPCONFIG_AVG_16 | ts_dev->bit_xp |
+ STEPCONFIG_INM_ADCREFM;
switch (ts_dev->wires) {
case 4:
config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
--
2.17.1
The Z2 step configuration doesn't erase the SEL_INP_SWC_3_0 bit-field
before setting the ADC channel. This way its value could be corrupted by
the ADC channel selected for the Z1 coordinate.
Fixes: 8c896308fea ("input: ti_am335x_adc: use only FIFO0 and clean up a little")
Signed-off-by: Dario Binacchi <[email protected]>
---
drivers/input/touchscreen/ti_am335x_tsc.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index fd3ffdd23470..cfc943423241 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -196,7 +196,10 @@ static void titsc_step_config(struct titsc *ts_dev)
STEPCONFIG_OPENDLY);
end_step++;
- config |= STEPCONFIG_INP(ts_dev->inp_yn);
+ config = STEPCONFIG_MODE_HWSYNC |
+ STEPCONFIG_AVG_16 | ts_dev->bit_yp |
+ ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
+ STEPCONFIG_INP(ts_dev->inp_yn);
titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
titsc_writel(ts_dev, REG_STEPDELAY(end_step),
STEPCONFIG_OPENDLY);
--
2.17.1
There was a spelling mistake on TSC/ADC binding where "coordinate" was
spelled as "coordiante".
As done by commit c9aeb249bf72 ("Input: ti_am335x_tsc - fix spelling
mistake in TSC/ADC DT binding"), "the approach taken was to first use
correct spelling and if that fails, fall back to miss-spelled version".
Signed-off-by: Dario Binacchi <[email protected]>
---
drivers/mfd/ti_am335x_tscadc.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index 55adc379f94b..53b7a8b7f571 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -141,7 +141,12 @@ static int ti_tscadc_probe(struct platform_device *pdev)
node = of_get_child_by_name(pdev->dev.of_node, "tsc");
of_property_read_u32(node, "ti,wires", &tsc_wires);
- of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
+ /*
+ * Try with the new binding first. If it fails, try again with
+ * bogus, miss-spelled version.
+ */
+ if (of_property_read_u32(node, "ti,coordinate-readouts", &readouts))
+ of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
node = of_get_child_by_name(pdev->dev.of_node, "adc");
of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
--
2.17.1
In TI's reference manual description for the `AFE_Pen_Ctrl' bit-field
of the TSC's CTRL register, there is no mention of 8-wire touchscreens.
Even commit f0933a60d190 ("mfd: ti_am335x_tscadc: Update logic in CTRL
register for 5-wire TS") says that the value of this bit-field must be
the same for 4-wire and 8-wire touchscreens. So let's remove the
CNTRLREG_8WIRE macro to avoid misunderstandings.
Signed-off-by: Dario Binacchi <[email protected]>
---
include/linux/mfd/ti_am335x_tscadc.h | 1 -
1 file changed, 1 deletion(-)
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index ffc091b77633..155b2ab13bf8 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -126,7 +126,6 @@
#define CNTRLREG_AFE_CTRL(val) ((val) << 5)
#define CNTRLREG_4WIRE CNTRLREG_AFE_CTRL(1)
#define CNTRLREG_5WIRE CNTRLREG_AFE_CTRL(2)
-#define CNTRLREG_8WIRE CNTRLREG_AFE_CTRL(3)
#define CNTRLREG_TSCENB BIT(7)
/* FIFO READ Register */
--
2.17.1
The open delay time has to be applied only on the first sample of the
X/Y coordinates because on the following samples the ADC channel is not
changed. Removing this time from the samples after the first one,
"ti,coordinate-readouts" greater than 1, decreases the total acquisition
time, allowing to increase the number of acquired coordinates in the time
unit.
Signed-off-by: Dario Binacchi <[email protected]>
---
drivers/input/touchscreen/ti_am335x_tsc.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index cfc943423241..f4ef218bc1b8 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -126,7 +126,7 @@ static int titsc_config_wires(struct titsc *ts_dev)
static void titsc_step_config(struct titsc *ts_dev)
{
unsigned int config;
- int i;
+ int i, n;
int end_step, first_step, tsc_steps;
u32 stepenable;
@@ -151,9 +151,11 @@ static void titsc_step_config(struct titsc *ts_dev)
first_step = TOTAL_STEPS - tsc_steps;
/* Steps 16 to 16-coordinate_readouts is for X */
end_step = first_step + tsc_steps;
+ n = 0;
for (i = end_step - ts_dev->coordinate_readouts; i < end_step; i++) {
titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
- titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
+ titsc_writel(ts_dev, REG_STEPDELAY(i),
+ n++ == 0 ? STEPCONFIG_OPENDLY : 0);
}
config = 0;
@@ -175,9 +177,11 @@ static void titsc_step_config(struct titsc *ts_dev)
/* 1 ... coordinate_readouts is for Y */
end_step = first_step + ts_dev->coordinate_readouts;
+ n = 0;
for (i = first_step; i < end_step; i++) {
titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
- titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
+ titsc_writel(ts_dev, REG_STEPDELAY(i),
+ n++ == 0 ? STEPCONFIG_OPENDLY : 0);
}
/* Make CHARGECONFIG same as IDLECONFIG */
--
2.17.1
The commit c9aeb249bf72e ("Input: ti_am335x_tsc - fix spelling mistake
in TSC/ADC DT binding") didn't fix the typo mistake in the tsc node of
the example.
Signed-off-by: Dario Binacchi <[email protected]>
Acked-by: Rob Herring <[email protected]>
---
.../devicetree/bindings/input/touchscreen/ti-tsc-adc.txt | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
index aad5e34965eb..2013fd7c4a10 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
@@ -77,7 +77,7 @@ Example:
tsc {
ti,wires = <4>;
ti,x-plate-resistance = <200>;
- ti,coordiante-readouts = <5>;
+ ti,coordinate-readouts = <5>;
ti,wire-config = <0x00 0x11 0x22 0x33>;
ti,charge-delay = <0x400>;
};
--
2.17.1
On Sun, 07 Nov 2021, Dario Binacchi wrote:
>
> This series grew out of a touchscreen validation activity on a custom
> board. Oscilloscope measurements and driver source analysis led to these
> patches.
>
> Added Rob Herring 'Acked-by' tag to commit "dt-bindings: input:
> ti-tsc-adc: fix tsc node example".
>
>
>
> Dario Binacchi (6):
> input: ti_am335x_tsc: set ADCREFM for X configuration
> input: ti_am335x_tsc: fix STEPCONFIG setup for Z2
> input: ti_am335x_tsc: lower the X and Y sampling time
> dt-bindings: input: ti-tsc-adc: fix tsc node example
> mfd: ti_am335x_tscadc: fix reading a tsc property from DT
> mfd: ti_am335x_tscadc: drop the CNTRLREG_8WIRE macro
>
> .../bindings/input/touchscreen/ti-tsc-adc.txt | 2 +-
> drivers/input/touchscreen/ti_am335x_tsc.c | 18 +++++++++++++-----
> drivers/mfd/ti_am335x_tscadc.c | 7 ++++++-
> include/linux/mfd/ti_am335x_tscadc.h | 1 -
> 4 files changed, 20 insertions(+), 8 deletions(-)
You're going to need to rebase this set onto v5.16-rc1.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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