[PATCH] input: ti_am335x_tsc: Add open delay parameter
From: Michael Welling <hidden>
Date: 2015-08-11 18:45:17
Also in:
linux-devicetree, lkml
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
Adds a device tree parameter to set the open delay on the touchscreen conversion steps. Increasing this parameter helps the touch accuracy on some screens. Signed-off-by: Michael Welling <redacted> --- .../bindings/input/touchscreen/ti-tsc-adc.txt | 5 +++++ drivers/input/touchscreen/ti_am335x_tsc.c | 18 ++++++++++++++---- 2 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
index b1163bf..cb11fda 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt@@ -41,6 +41,11 @@ Optional properties: charge step, so this does in fact function as a hardware knob for adjusting the amount of "settling time". + ti,open-delay: Open delay applied to all touchscreen conversion steps. + The value corresponds to the number of ADC clock + cycles to wait after applying the step configuration + registers and before sending the start of ADC + conversion. Maximum value is 0x3FFFF. - child "adc" ti,chan-step-opendelay: List of open delays for each channel of
diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index 191a1b8..37a9729 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c@@ -54,6 +54,7 @@ struct titsc { u32 inp_xp, inp_xn, inp_yp, inp_yn; u32 step_mask; u32 charge_delay; + u32 open_delay; }; static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
@@ -148,7 +149,7 @@ static void titsc_step_config(struct titsc *ts_dev) end_step = first_step + tsc_steps; 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), ts_dev->open_delay); } config = 0;
@@ -172,7 +173,7 @@ static void titsc_step_config(struct titsc *ts_dev) end_step = first_step + ts_dev->coordinate_readouts; 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), ts_dev->open_delay); } /* Make CHARGECONFIG same as IDLECONFIG */
@@ -188,13 +189,13 @@ static void titsc_step_config(struct titsc *ts_dev) STEPCONFIG_INP(ts_dev->inp_xp); titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config); titsc_writel(ts_dev, REG_STEPDELAY(end_step), - STEPCONFIG_OPENDLY); + ts_dev->open_delay); end_step++; config |= 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); + ts_dev->open_delay); /* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */ stepenable = 1;
@@ -392,6 +393,15 @@ static int titsc_parse_dt(struct platform_device *pdev, dev_warn(&pdev->dev, "ti,charge-delay not specified\n"); } + err = of_property_read_u32(node, "ti,open-delay", + &ts_dev->open_delay); + /* + * If ti,open-delay value is not specified, then use + * STEPCONFIG_OPENDLY as the default value. + */ + if (err < 0) + ts_dev->open_delay = STEPCONFIG_OPENDLY; + return of_property_read_u32_array(node, "ti,wire-config", ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp)); }
--
2.1.4