IIO: AT91: Add DT support to at91_adc driver

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Maxime Ripard 2012-05-11 15:35:37 +02:00 committed by Greg Kroah-Hartman
parent 5d449e4b2f
commit e364185f3e
2 changed files with 196 additions and 1 deletions

View File

@ -0,0 +1,65 @@
* AT91's Analog to Digital Converter (ADC)
Required properties:
- compatible: Should be "atmel,at91sam9260-adc"
- reg: Should contain ADC registers location and length
- interrupts: Should contain the IRQ line for the ADC
- atmel,adc-channel-base: Offset 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: Offset of the Interrupt Status Register
- atmel,adc-trigger-register: Offset 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@fffb0000 {
compatible = "atmel,at91sam9260-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@0 {
trigger-name = "external-rising";
trigger-value = <0x1>;
trigger-external;
};
trigger@1 {
trigger-name = "external-falling";
trigger-value = <0x2>;
trigger-external;
};
trigger@2 {
trigger-name = "external-any";
trigger-value = <0x3>;
trigger-external;
};
trigger@3 {
trigger-name = "continuous";
trigger-value = <0x6>;
};
};

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@ -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>
@ -415,6 +417,123 @@ 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");
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(trig_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(trig_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(trig_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)
{
@ -456,7 +575,11 @@ 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;
@ -657,11 +780,18 @@ static int __devexit at91_adc_remove(struct platform_device *pdev)
return 0;
}
static const struct of_device_id at91_adc_dt_ids[] = {
{ .compatible = "atmel,at91sam9260-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),
},
};