[PATCH 6/9] IIO: AT91: Add DT support to at91_adc driver
Jonathan Cameron
jic23 at cam.ac.uk
Thu May 10 04:04:06 EDT 2012
All this is fine with me. I'm far from expert at device tree though so
over to those that are :)
On 5/9/2012 2:02 PM, Maxime Ripard wrote:
> Signed-off-by: Maxime Ripard<maxime.ripard at free-electrons.com>
> Acked-by: Nicolas Ferre<nicolas.ferre at atmel.com>
> ---
> .../devicetree/bindings/arm/atmel-adc.txt | 65 ++++++++++
> drivers/iio/adc/at91_adc.c | 132 +++++++++++++++++++-
> 2 files changed, 196 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..c63097d
> --- /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,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 at 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 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 e5d73b1..d2eca64 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>
> @@ -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;
> @@ -658,11 +781,18 @@ 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),
> },
> };
>
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