This is an RFC for the new touchscreen properties.
Signed-off-by: Juergen Beisert <jbe@xxxxxxxxxxxxxx>
CC: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
CC: devel@xxxxxxxxxxxxxxxxxxxx
CC: Marek Vasut <marex@xxxxxxx>
CC: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
CC: Jonathan Cameron <jic23@xxxxxxxxx>
CC: devicetree-discuss@xxxxxxxxxxxxxxxx
---
.../bindings/staging/iio/adc/mxs-lradc.txt | 36 ++++++++++++--
drivers/staging/iio/adc/mxs-lradc.c | 57 ++++++++++++++--------
2 files changed, 67 insertions(+), 26 deletions(-)
diff --git a/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt b/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt
index 4688205..ee05dc3 100644
--- a/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt
+++ b/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt
@@ -1,7 +1,8 @@
* Freescale i.MX28 LRADC device driver
Required properties:
-- compatible: Should be "fsl,imx28-lradc"
+- compatible: Should be "fsl,imx23-lradc" for i.MX23 SoC and "fsl,imx28-lradc"
+ for i.MX28 SoC
- reg: Address and length of the register set for the device
- interrupts: Should contain the LRADC interrupts
@@ -9,13 +10,38 @@ Optional properties:
- fsl,lradc-touchscreen-wires: Number of wires used to connect the touchscreen
to LRADC. Valid value is either 4 or 5. If this
property is not present, then the touchscreen is
- disabled.
+ disabled. 5 wires is valid for i.MX28 SoC only.
+- fsl,ave-ctrl: number of samples per direction to calculate an average value.
+ Allowed value is 1 ... 31, default is 4
+- fsl,ave-delay: delay between consecutive samples. Allowed value is
+ 1 ... 2047. It is used if 'fsl,ave-ctrl' > 1, counts at
+ 2 kHz and its default is 2 (= 1 ms)
+- fsl,settling: delay between plate switch to next sample. Allowed value is
+ 1 ... 2047. It counts at 2 kHz and its default is
+ 10 (= 5 ms)
-Examples:
+Example for i.MX23 SoC:
+
+ lradc@80050000 {
+ compatible = "fsl,imx23-lradc";
+ reg = <0x80050000 0x2000>;
+ interrupts = <36 37 38 39 40 41 42 43 44>;
+ status = "okay";
+ fsl,lradc-touchscreen-wires = <4>;
+ fsl,ave-ctrl = <4>;
+ fsl,ave-delay = <2>;
+ fsl,settling = <10>;
+ };
+
+Example for i.MX28 SoC:
lradc@80050000 {
compatible = "fsl,imx28-lradc";
reg = <0x80050000 0x2000>;
- interrupts = <10 14 15 16 17 18 19
- 20 21 22 23 24 25>;
+ interrupts = <10 14 15 16 17 18 19 20 21 22 23 24 25>;
+ status = "okay";
+ fsl,lradc-touchscreen-wires = <5>;
+ fsl,ave-ctrl = <4>;
+ fsl,ave-delay = <2>;
+ fsl,settling = <10>;
};
diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
index 122475f..ffcb0dd 100644
--- a/drivers/staging/iio/adc/mxs-lradc.c
+++ b/drivers/staging/iio/adc/mxs-lradc.c
@@ -1225,10 +1225,45 @@ MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids);
static int mxs_lradc_probe_touchscreen(struct mxs_lradc *lradc,
struct device_node *lradc_node)
{
- /* TODO retrieve from device tree */
+ int ret;
+ u32 ts_wires = 0, adapt;
+
+ ret = of_property_read_u32(lradc_node, "fsl,lradc-touchscreen-wires",
+ &ts_wires);
+ if (ret)
+ return -ENODEV; /* touchscreen feature disabled */
+
+ switch (ts_wires) {
+ case 4:
+ lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_4WIRE;
+ break;
+ case 5:
+ if (lradc->soc == IMX28_LRADC) {
+ lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_5WIRE;
+ break;
+ }
+ /* fall through an error message for i.MX23 */
+ default:
+ dev_err(lradc->dev,
+ "Unsupported number of touchscreen wires (%d)\n",
+ ts_wires);
+ return -EINVAL;
+ }
+
lradc->over_sample_cnt = 4;
+ ret = of_property_read_u32(lradc_node, "fsl,ave-ctrl", &adapt);
+ if (ret == 0)
+ lradc->over_sample_cnt = adapt;
+
lradc->over_sample_delay = 2;
+ ret = of_property_read_u32(lradc_node, "fsl,ave-delay", &adapt);
+ if (ret == 0)
+ lradc->over_sample_delay = adapt;
+
lradc->settling_delay = 10;
+ ret = of_property_read_u32(lradc_node, "fsl,settling", &adapt);
+ if (ret == 0)
+ lradc->settling_delay = adapt;
return 0;
}
@@ -1244,7 +1279,6 @@ static int mxs_lradc_probe(struct platform_device *pdev)
struct mxs_lradc *lradc;
struct iio_dev *iio;
struct resource *iores;
- uint32_t ts_wires = 0;
int ret = 0, touch_ret;
int i;
@@ -1267,25 +1301,6 @@ static int mxs_lradc_probe(struct platform_device *pdev)
touch_ret = mxs_lradc_probe_touchscreen(lradc, node);
- /* Check if touchscreen is enabled in DT. */
- ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
- &ts_wires);
- if (ret)
- dev_info(dev, "Touchscreen not enabled.\n");
- else if (ts_wires == 4)
- lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_4WIRE;
- else if (ts_wires == 5)
- lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_5WIRE;
- else
- dev_warn(dev, "Unsupported number of touchscreen wires (%d)\n",
- ts_wires);
-
- if ((lradc->soc == IMX23_LRADC) && (ts_wires == 5)) {
- dev_warn(dev, "No support for 5 wire touches on i.MX23\n");
- dev_warn(dev, "Falling back to 4 wire\n");
- ts_wires = 4;
- }
-
/* Grab all IRQ sources */
for (i = 0; i < of_cfg->irq_count; i++) {
lradc->irq[i] = platform_get_irq(pdev, i);
--
1.8.4.rc3
--
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