Re: [PATCH 2/2] Input: edt-ft5x06: Add DT support
From: Mark Rutland <mark.rutland@arm.com>
Date: 2014-01-13 13:44:46
Also in:
linux-devicetree, lkml
On Mon, Jan 13, 2014 at 10:17:04AM +0000, Lothar Waßmann wrote:
quoted hunk ↗ jump to hunk
This patch allows the edt-ft5x06 multitouch panel driver to be configured via DT. Signed-off-by: Lothar Waßmann <redacted> --- .../bindings/input/touchscreen/edt-ft5x06.txt | 31 ++++ drivers/input/touchscreen/edt-ft5x06.c | 145 +++++++++++++++---- 2 files changed, 145 insertions(+), 31 deletions(-) create mode 100644 Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txtdiff --git a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt new file mode 100644 index 0000000..629dbdd --- /dev/null +++ b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt@@ -0,0 +1,31 @@ +* EDT FT5x06 Multiple Touch Controller + +Required properties: +- compatible: must be "edt,ft5x06" +- reg: i2c slave address +- interrupt-parent: the phandle for the interrupt controller +- interrupts: touch controller interrupt + +Optional properties: +- reset-gpios: the gpio pin to be used for resetting the controller +- wakeup-gpios: the gpio pin to be used for waking up the controller + + The following properties provide default values for the + corresponding parameters configurable via sysfs + (see Documentation/input/edt-ft5x06.txt)
The sysfs interface shouldn't matter for the binding, it's a Linux detail. There's no reason for it to be mentioned in the binding.
+- threshold: allows setting the "click"-threshold in the range from 20 to 80. +- gain: sensitivity (0..31) (lower value -> higher sensitivity) +- offset: edge compensation (0..31) +- report_rate: report rate (3..14)
s/_/-/ on property names please. Also, it may make sense to prefix these as they're rather generic sounding names. Could you elaborate on these a litle please? What units are each of these in? Why does it make sense to have them in the dt?
+
+Example:
+
+ edt_ft5x06@38 {
+ compatible = "edt,ft5x06";
+ reg = <0x38>;
+ interrupt-parent = <&gpio2>;
+ interrupts = <5 0>;
+ wakeup-gpios = <&gpio1 9 0>;
+ reset-gpios = <&gpio2 6 1>;
+ wakeup-gpios = <&gpio4 9 0>;
+ };One of those wakeup-gpios properties should go. [...]
+#define EDT_GET_PROP(name, reg) { \
+ const u32 *prop = of_get_property(np, #name, NULL); \
+ if (prop) \
+ edt_ft5x06_register_write(tsdata, reg, be32_to_cpu(*prop)); \
+}Use of_property_read_u32, which does endianness conversion and property length checking (which you're not doing). Sparse _will_ complain here because you've not maintained the __be32 annotation.
+static void edt_ft5x06_ts_get_dt_defaults(struct device_node *np,
+ struct edt_ft5x06_ts_data *tsdata)
+{
+ EDT_GET_PROP(threshold, WORK_REGISTER_THRESHOLD);
+ EDT_GET_PROP(gain, WORK_REGISTER_GAIN);
+ EDT_GET_PROP(offset, WORK_REGISTER_OFFSET);
+ EDT_GET_PROP(report_rate, WORK_REGISTER_REPORT_RATE);These should probably have sanity checks given you've described valid ranges in the documentation. [...]
+static int edt_ft5x06_i2c_ts_probe_dt(struct device *dev,
+ struct edt_ft5x06_ts_data *tsdata)
+{
+ int ret;
+ struct device_node *np = dev->of_node;
+ enum of_gpio_flags gpio_flags;
+
+ if (!np)
+ return -ENODEV;
+
+ /*
+ * irq_pin is not needed for DT setup.
+ * irq is associated via 'interrupts' property in DT
+ */
+ tsdata->irq_pin = -EINVAL;
+
+ ret = of_get_named_gpio_flags(np, "reset-gpios", 0, &gpio_flags);
+ tsdata->reset_pin = ret;
+
+ ret = of_get_named_gpio_flags(np, "wake-gpios", 0, &gpio_flags);
+ tsdata->wake_pin = ret;Shouldn't that be "wakeup-gpios"? Do you not need the value of flags? I'm not that familiar with the GPIO subsystem, and it feels odd to rtequest the flags and throw them away. Thanks, Mark.