iio:adc:palmas: add DT support

Code was found at:
https://android.googlesource.com/kernel/tegra/+/a90856a6626d502d42c6e7abccbdf9d730b36270%5E%21/#F1

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Marek Belisko <marek@goldelico.com> [Fixed minor typos + add channels list to documentation]
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/Documentation/devicetree/bindings/iio/adc/palmas-gpadc.txt b/Documentation/devicetree/bindings/iio/adc/palmas-gpadc.txt
new file mode 100644 (file)
index 0000000..4bb9a86
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/palmas-gpadc.txt
@@ -0,0 +1,48 @@
+* Palmas general purpose ADC IP block devicetree bindings
+
+Channels list:
+       0 battery type
+       1 battery temp NTC (optional current source)
+       2 GP
+       3 temp (with ext. diode, optional current source)
+       4 GP
+       5 GP
+       6 VBAT_SENSE
+       7 VCC_SENSE
+       8 Backup Battery voltage
+       9 external charger (VCHG)
+       10 VBUS
+       11 DC-DC current probe (how does this work?)
+       12 internal die temp
+       13 internal die temp
+       14 USB ID pin voltage
+       15 test network
+
+Required properties:
+- compatible : Must be "ti,palmas-gpadc".
+- #io-channel-cells: Should be set to <1>.
+
+Optional sub-nodes:
+ti,channel0-current-microamp: Channel 0 current in uA.
+       Values are rounded to derive 0uA, 5uA, 15uA, 20uA.
+ti,channel3-current-microamp: Channel 3 current in uA.
+       Values are rounded to derive 0uA, 10uA, 400uA, 800uA.
+ti,enable-extended-delay: Enable extended delay.
+
+Example:
+
+pmic {
+       compatible = "ti,twl6035-pmic", "ti,palmas-pmic";
+       ...
+       gpadc {
+               compatible = "ti,palmas-gpadc";
+               interrupts = <18 0
+                             16 0
+                             17 0>;
+               #io-channel-cells = <1>;
+               ti,channel0-current-microamp = <5>;
+               ti,channel3-current-microamp = <10>;
+               };
+       };
+       ...
+};

diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
index 71763c5da2ab1d7ede9c1046d3a4c7d7590e368f..f42eb8a7d21f01b99379f69d0704c0efe1361dbc 100644 (file)
--- a/drivers/iio/adc/palmas_gpadc.c
+++ b/drivers/iio/adc/palmas_gpadc.c
@@ -21,6 +21,8 @@
 #include <linux/pm.h>
 #include <linux/mfd/palmas.h>
 #include <linux/completion.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/machine.h>
 #include <linux/iio/driver.h>
@@ -460,6 +462,34 @@ static const struct iio_chan_spec palmas_gpadc_iio_channel[] = {
        PALMAS_ADC_CHAN_IIO(IN15, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
 };
 
+static int palmas_gpadc_get_adc_dt_data(struct platform_device *pdev,
+       struct palmas_gpadc_platform_data **gpadc_pdata)
+{
+       struct device_node *np = pdev->dev.of_node;
+       struct palmas_gpadc_platform_data *gp_data;
+       int ret;
+       u32 pval;
+
+       gp_data = devm_kzalloc(&pdev->dev, sizeof(*gp_data), GFP_KERNEL);
+       if (!gp_data)
+               return -ENOMEM;
+
+       ret = of_property_read_u32(np, "ti,channel0-current-microamp", &pval);
+       if (!ret)
+               gp_data->ch0_current = pval;
+
+       ret = of_property_read_u32(np, "ti,channel3-current-microamp", &pval);
+       if (!ret)
+               gp_data->ch3_current = pval;
+
+       gp_data->extended_delay = of_property_read_bool(np,
+                                       "ti,enable-extended-delay");
+
+       *gpadc_pdata = gp_data;
+
+       return 0;
+}
+
 static int palmas_gpadc_probe(struct platform_device *pdev)
 {
        struct palmas_gpadc *adc;
@@ -469,12 +499,17 @@ static int palmas_gpadc_probe(struct platform_device *pdev)
        int ret, i;
 
        pdata = dev_get_platdata(pdev->dev.parent);
-       if (!pdata || !pdata->gpadc_pdata) {
-               dev_err(&pdev->dev, "No platform data\n");
-               return -ENODEV;
-       }
 
-       gpadc_pdata = pdata->gpadc_pdata;
+       if (pdata && pdata->gpadc_pdata)
+               gpadc_pdata = pdata->gpadc_pdata;
+
+       if (!gpadc_pdata && pdev->dev.of_node) {
+               ret = palmas_gpadc_get_adc_dt_data(pdev, &gpadc_pdata);
+               if (ret < 0)
+                       return ret;
+       }
+       if (!gpadc_pdata)
+               return -EINVAL;
 
        indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
        if (!indio_dev) {
@@ -790,12 +825,19 @@ static const struct dev_pm_ops palmas_pm_ops = {
                                palmas_gpadc_resume)
 };
 
+static const struct of_device_id of_palmas_gpadc_match_tbl[] = {
+       { .compatible = "ti,palmas-gpadc", },
+       { /* end */ }
+};
+MODULE_DEVICE_TABLE(of, of_palmas_gpadc_match_tbl);
+
 static struct platform_driver palmas_gpadc_driver = {
        .probe = palmas_gpadc_probe,
        .remove = palmas_gpadc_remove,
        .driver = {
                .name = MOD_NAME,
                .pm = &palmas_pm_ops,
+               .of_match_table = of_palmas_gpadc_match_tbl,
        },
 };