Hi Daniel,
On Wed, Jul 25, 2012 at 08:25:14PM +0200, Daniel Mack wrote:
> +#ifdef CONFIG_OF
> +static struct of_device_id rotary_encoder_of_match[] = {
> + { .compatible = "rotary-encoder", },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, rotary_encoder_of_match);
> +
> +static int rotary_encoder_probe_dt(struct platform_device *pdev,
> + struct rotary_encoder *encoder)
> +{
> + int tmp;
> + enum of_gpio_flags flags;
> + struct rotary_encoder_platform_data *pdata = &encoder->pdata;
> + struct device_node *np = pdev->dev.of_node;
> + const struct of_device_id *of_id =
> + of_match_device(rotary_encoder_of_match, &pdev->dev);
> +
> + if (!of_id)
> + return 0;
> +
> + if (of_property_read_u32(np, "rotary-encoder,steps", &tmp) == 0)
> + pdata->steps = tmp;
> + if (of_property_read_u32(np, "linux,axis", &tmp) == 0)
> + pdata->axis = tmp;
You should be able to simply say
of_property_read_u32(np, "linux,axis", &pdata->axis);
> +
> + pdata->gpio_a = of_get_gpio_flags(np, 0, &flags);
> + pdata->inverted_a = flags & OF_GPIO_ACTIVE_LOW;
> +
> + pdata->gpio_b = of_get_gpio_flags(np, 1, &flags);
> + pdata->inverted_b = flags & OF_GPIO_ACTIVE_LOW;
> +
> + if (of_get_property(np, "rotary-encoder,relative-axis", NULL))
> + pdata->relative_axis = 1;
> + if (of_get_property(np, "rotary-encoder,rollover", NULL))
> + pdata->rollover = 1;
> + if (of_get_property(np, "rotary-encoder,half-period", NULL))
> + pdata->half_period = 1;
> +
> + return 1;
> +}
> +#else
> +static inline int rotary_encoder_probe_dt(struct platform_device *)
This does not match the other instance (you are missing the 2nd
argument).
> +{
> + return 0;
> +}
> +#endif
> +
> static int __devinit rotary_encoder_probe(struct platform_device *pdev)
> {
> - struct rotary_encoder_platform_data *pdata = pdev->dev.platform_data;
> + struct rotary_encoder_platform_data *pdata;
> struct rotary_encoder *encoder;
> struct input_dev *input;
> struct device *dev = &pdev->dev;
> irq_handler_t handler;
> + bool use_of = 0;
> int err;
>
> - if (!pdata) {
> + encoder = kzalloc(sizeof(struct rotary_encoder), GFP_KERNEL);
> + if (!encoder)
> + return -ENOMEM;
> +
> + err = rotary_encoder_probe_dt(pdev, encoder);
> + if (err < 0)
> + return err;
Not that your implementation can fail, but why do you fail device
initialization even if we have kernel-supplied platform data?
> + if (err > 0)
> + use_of = 1;
> +
> + if (!&pdev->dev.platform_data && !use_of) {
!&pdev->dev.platform_data is never false, you meant
!pdev->dev.platform_data
BTW, we have an accessor function dev_get_platdata().
Still, I do not line the copying of pdata over, maybe we coudl have
something like the patch below?
Thanks!
--
Dmitry
Input: rotary-encoder - add DT bindings
From: Daniel Mack <zonque@xxxxxxxxx>
This adds devicetree bindings to the rotary encoder driver and some
documentation about how to use them. Tested on a PXA3xx platform.
Signed-off-by: Daniel Mack <zonque@xxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
.../devicetree/bindings/input/rotary-encoder.txt | 36 ++++++++
drivers/input/misc/rotary_encoder.c | 96 +++++++++++++++++---
2 files changed, 116 insertions(+), 16 deletions(-)
create mode 100644 Documentation/devicetree/bindings/input/rotary-encoder.txt
diff --git a/Documentation/devicetree/bindings/input/rotary-encoder.txt b/Documentation/devicetree/bindings/input/rotary-encoder.txt
new file mode 100644
index 0000000..3315495
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/rotary-encoder.txt
@@ -0,0 +1,36 @@
+Rotary encoder DT bindings
+
+Required properties:
+- gpios: a spec for two GPIOs to be used
+
+Optional properties:
+- linux,axis: the input subsystem axis to map to this rotary encoder.
+ Defaults to 0 (ABS_X / REL_X)
+- rotary-encoder,steps: Number of steps in a full turnaround of the
+ encoder. Only relevant for absolute axis. Defaults to 24 which is a
+ typical value for such devices.
+- rotary-encoder,relative-axis: register a relative axis rather than an
+ absolute one. Relative axis will only generate +1/-1 events on the input
+ device, hence no steps need to be passed.
+- rotary-encoder,rollover: Automatic rollove when the rotary value becomes
+ greater than the specified steps or smaller than 0. For absolute axis only.
+- rotary-encoder,half-period: Makes the driver work on half-period mode.
+
+See Documentation/input/rotary-encoder.txt for more information.
+
+Example:
+
+ rotary@0 {
+ compatible = "rotary-encoder";
+ gpios = <&gpio 19 1>, <&gpio 20 0>; /* GPIO19 is inverted */
+ linux,axis = <0>; /* REL_X */
+ rotary-encoder,relative-axis;
+ };
+
+ rotary@1 {
+ compatible = "rotary-encoder";
+ gpios = <&gpio 21 0>, <&gpio 22 0>;
+ linux,axis = <1>; /* ABS_Y */
+ rotary-encoder,steps = <24>;
+ rotary-encoder,rollover;
+ };
diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
index ea51265..0f9d746 100644
--- a/drivers/input/misc/rotary_encoder.c
+++ b/drivers/input/misc/rotary_encoder.c
@@ -24,6 +24,8 @@
#include <linux/gpio.h>
#include <linux/rotary_encoder.h>
#include <linux/slab.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
#define DRV_NAME "rotary-encoder"
@@ -140,6 +142,56 @@ static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id)
return IRQ_HANDLED;
}
+#ifdef CONFIG_OF
+static struct of_device_id rotary_encoder_of_match[] = {
+ { .compatible = "rotary-encoder", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, rotary_encoder_of_match);
+
+static struct rotary_encoder_platform_data * __devinit
+rotary_encoder_parse_dt(struct device *dev)
+{
+ const struct of_device_id *of_id =
+ of_match_device(rotary_encoder_of_match, dev);
+ struct device_node *np = dev->of_node;
+ struct rotary_encoder_platform_data *pdata;
+ enum of_gpio_flags flags;
+
+ if (!of_id || !np)
+ return NULL;
+
+ pdata = kzalloc(sizeof(struct rotary_encoder_platform_data),
+ GFP_KERNEL);
+ if (!pdata)
+ return ERR_PTR(-ENOMEM);
+
+ of_property_read_u32(np, "rotary-encoder,steps", &pdata->steps);
+ of_property_read_u32(np, "linux,axis", &pdata->axis);
+
+ pdata->gpio_a = of_get_gpio_flags(np, 0, &flags);
+ pdata->inverted_a = flags & OF_GPIO_ACTIVE_LOW;
+
+ pdata->gpio_b = of_get_gpio_flags(np, 1, &flags);
+ pdata->inverted_b = flags & OF_GPIO_ACTIVE_LOW;
+
+ pdata->relative_axis = !!of_get_property(np,
+ "rotary-encoder,relative-axis", NULL);
+ pdata->rollover = !!of_get_property(np,
+ "rotary-encoder,rollover", NULL);
+ pdata->half_period = !!of_get_property(np,
+ "rotary-encoder,half-period", NULL))
+
+ return pdata;
+}
+#else
+static inline struct rotary_encoder_platform_data *
+rotary_encoder_parse_dt(struct device *dev)
+{
+ return NULL;
+}
+#endif
+
static int __devinit rotary_encoder_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -150,14 +202,19 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev)
int err;
if (!pdata) {
- dev_err(&pdev->dev, "missing platform data\n");
- return -ENOENT;
+ pdata = rotary_encoder_parse_dt(dev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+
+ if (!pdata) {
+ dev_err(dev, "missing platform data\n");
+ return -EINVAL;
+ }
}
encoder = kzalloc(sizeof(struct rotary_encoder), GFP_KERNEL);
input = input_allocate_device();
if (!encoder || !input) {
- dev_err(&pdev->dev, "failed to allocate memory for device\n");
err = -ENOMEM;
goto exit_free_mem;
}
@@ -165,10 +222,9 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev)
encoder->input = input;
encoder->pdata = pdata;
- /* create and register the input driver */
input->name = pdev->name;
input->id.bustype = BUS_HOST;
- input->dev.parent = &pdev->dev;
+ input->dev.parent = dev;
if (pdata->relative_axis) {
input->evbit[0] = BIT_MASK(EV_REL);
@@ -179,17 +235,11 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev)
pdata->axis, 0, pdata->steps, 0, 1);
}
- err = input_register_device(input);
- if (err) {
- dev_err(dev, "failed to register input device\n");
- goto exit_free_mem;
- }
-
/* request the GPIOs */
err = gpio_request_one(pdata->gpio_a, GPIOF_IN, dev_name(dev));
if (err) {
dev_err(dev, "unable to request GPIO %d\n", pdata->gpio_a);
- goto exit_unregister_input;
+ goto exit_free_mem;
}
err = gpio_request_one(pdata->gpio_b, GPIOF_IN, dev_name(dev));
@@ -225,22 +275,30 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev)
goto exit_free_irq_a;
}
+ err = input_register_device(input);
+ if (err) {
+ dev_err(dev, "failed to register input device\n");
+ goto exit_free_irq_b;
+ }
+
platform_set_drvdata(pdev, encoder);
return 0;
+exit_free_irq_b:
+ free_irq(encoder->irq_b, encoder);
exit_free_irq_a:
free_irq(encoder->irq_a, encoder);
exit_free_gpio_b:
gpio_free(pdata->gpio_b);
exit_free_gpio_a:
gpio_free(pdata->gpio_a);
-exit_unregister_input:
- input_unregister_device(input);
- input = NULL; /* so we don't try to free it */
exit_free_mem:
input_free_device(input);
kfree(encoder);
+ if (!dev_get_platdata(&pdev->dev))
+ kfree(pdata);
+
return err;
}
@@ -253,10 +311,15 @@ static int __devexit rotary_encoder_remove(struct platform_device *pdev)
free_irq(encoder->irq_b, encoder);
gpio_free(pdata->gpio_a);
gpio_free(pdata->gpio_b);
+
input_unregister_device(encoder->input);
- platform_set_drvdata(pdev, NULL);
kfree(encoder);
+ if (!dev_get_platdata(&pdev->dev))
+ kfree(pdata);
+
+ platform_set_drvdata(pdev, NULL);
+
return 0;
}
@@ -266,6 +329,7 @@ static struct platform_driver rotary_encoder_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(rotary_encoder_of_match),
}
};
module_platform_driver(rotary_encoder_driver);
--
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