[PATCH 6/9] IIO: AT91: Add DT support to at91_adc driver
Maxime Ripard
maxime.ripard at free-electrons.com
Wed May 9 05:06:03 EDT 2012
Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
---
.../devicetree/bindings/arm/atmel-adc.txt | 65 ++++++++++
drivers/iio/adc/at91_adc.c | 133 +++++++++++++++++++-
2 files changed, 197 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/arm/atmel-adc.txt
diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt
new file mode 100644
index 0000000..da2b67d
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt
@@ -0,0 +1,65 @@
+* AT91's Analog to Digital Converter (ADC)
+
+Required properties:
+ - compatible: Should be "atmel,at91-adc"
+ - reg: Should contain ADC registers location and length
+ - interrupts: Should contain the IRQ line for the ADC
+ - atmel,adc-channel-base: Address of the first channel data register
+ - atmel,adc-channels-used: Bitmask of the channels muxed and enable for this
+ device
+ - atmel,adc-drdy-mask: Mask of the DRDY interruption in the ADC
+ - atmel,adc-num-channels: Number of channels available in the ADC
+ - atmel,adc-startup-time: Startup Time of the ADC in microseconds as
+ defined in the datasheet
+ - atmel,adc-status-register: Address of the Interrupt Status Register
+ - atmel,adc-trigger-register: Address of the Trigger Register
+ - atmel,adc-vref: Reference voltage in millivolts for the conversions
+
+Optional properties:
+ - atmel,adc-use-external: Boolean to enable of external triggers
+
+Optional trigger Nodes:
+ - Required properties:
+ * trigger-name: Name of the trigger exposed to the user
+ * trigger-value: Value to put in the Trigger register
+ to activate this trigger
+ - Optional properties:
+ * trigger-external: Is the trigger an external trigger?
+
+Examples:
+adc0: adc at fffb0000 {
+ compatible = "atmel,at91-adc";
+ reg = <0xfffb0000 0x100>;
+ interrupts = <20 4>;
+ atmel,adc-channel-base = <0x30>;
+ atmel,adc-channels-used = <0xff>;
+ atmel,adc-drdy-mask = <0x10000>;
+ atmel,adc-num-channels = <8>;
+ atmel,adc-startup-time = <40>;
+ atmel,adc-status-register = <0x1c>;
+ atmel,adc-trigger-register = <0x08>;
+ atmel,adc-use-external;
+ atmel,adc-vref = <3300>;
+
+ trigger at 0 {
+ trigger-name = "external-rising";
+ trigger-value = <0x1>;
+ trigger-external;
+ };
+ trigger at 1 {
+ trigger-name = "external-falling";
+ trigger-value = <0x2>;
+ trigger-external;
+ };
+
+ trigger at 2 {
+ trigger-name = "external-any";
+ trigger-value = <0x3>;
+ trigger-external;
+ };
+
+ trigger at 3 {
+ trigger-name = "continuous";
+ trigger-value = <0x6>;
+ };
+};
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index febad23..35892fa 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -15,6 +15,8 @@
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
@@ -416,6 +418,124 @@ static int at91_adc_read_raw(struct iio_dev *idev,
return -EINVAL;
}
+static int at91_adc_probe_dt(struct at91_adc_state *st,
+ struct platform_device *pdev)
+{
+ struct iio_dev *idev = iio_priv_to_dev(st);
+ struct device_node *node = pdev->dev.of_node;
+ struct device_node *trig_node;
+ int i = 0, ret;
+ u32 prop;
+
+ if (!node)
+ return -EINVAL;
+
+ st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
+ st->use_external = true;
+
+ if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
+ dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->channels_mask = prop;
+
+ if (of_property_read_u32(node, "atmel,adc-num-channels", &prop)) {
+ dev_err(&idev->dev, "Missing adc-num-channels property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->num_channels = prop;
+
+ if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
+ dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->startup_time = prop;
+
+
+ if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
+ dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->vref_mv = prop;
+
+ st->registers = devm_kzalloc(&idev->dev,
+ sizeof(struct at91_adc_reg_desc),
+ GFP_KERNEL);
+ if (!st->registers) {
+ dev_err(&idev->dev, "Could not allocate register memory.\n");
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ if (of_property_read_u32(node, "atmel,adc-channel-base", &prop)) {
+ dev_err(&idev->dev, "Missing adc-channel-base property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->registers->channel_base = prop;
+
+ if (of_property_read_u32(node, "atmel,adc-drdy-mask", &prop)) {
+ dev_err(&idev->dev, "Missing adc-drdy-mask property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->registers->drdy_mask = prop;
+
+ if (of_property_read_u32(node, "atmel,adc-status-register", &prop)) {
+ dev_err(&idev->dev, "Missing adc-status-register property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->registers->status_register = prop;
+
+ if (of_property_read_u32(node, "atmel,adc-trigger-register", &prop)) {
+ dev_err(&idev->dev, "Missing adc-trigger-register property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ st->registers->trigger_register = prop;
+
+ st->trigger_number = of_get_child_count(node);
+ st->trigger_list = devm_kzalloc(&idev->dev, st->trigger_number *
+ sizeof(struct at91_adc_trigger),
+ GFP_KERNEL);
+ if (!st->trigger_list) {
+ dev_err(&idev->dev, "Could not allocate trigger list memory.\n");
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ for_each_child_of_node(node, trig_node) {
+ struct at91_adc_trigger *trig = st->trigger_list + i;
+ const char* name;
+
+ if (of_property_read_string(node, "trigger-name", &name)) {
+ dev_err(&idev->dev, "Missing trigger-name property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ trig->name = name;
+
+ if (of_property_read_u32(node, "trigger-value", &prop)) {
+ dev_err(&idev->dev, "Missing trigger-value property in the DT.\n");
+ ret = -EINVAL;
+ goto error_ret;
+ }
+ trig->value = prop;
+ trig->is_external = of_property_read_bool(node, "trigger-external");
+ i++;
+ }
+
+ return 0;
+
+error_ret:
+ return ret;
+}
+
static int at91_adc_probe_pdata(struct at91_adc_state *st,
struct platform_device *pdev)
{
@@ -457,7 +577,11 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
st = iio_priv(idev);
- ret = at91_adc_probe_pdata(st, pdev);
+ if (pdev->dev.of_node)
+ ret = at91_adc_probe_dt(st, pdev);
+ else
+ ret = at91_adc_probe_pdata(st, pdev);
+
if (ret) {
dev_err(&pdev->dev, "No platform data available.\n");
ret = -EINVAL;
@@ -659,11 +783,18 @@ static int __devexit at91_adc_remove(struct platform_device *pdev)
return 0;
}
+static const struct of_device_id at91_adc_dt_ids[] = {
+ { .compatible = "atmel,at91sam9g20-adc" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
+
static struct platform_driver at91_adc_driver = {
.probe = at91_adc_probe,
.remove = __devexit_p(at91_adc_remove),
.driver = {
.name = "at91_adc",
+ .of_match_table = of_match_ptr(at91_adc_dt_ids),
},
};
--
1.7.9.5
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