mfd: ti_am335x_tscadc: Add DT support

Add DT support in the MFD core driver. The node name is "am3359" because
it was tested on this platform.
Signed-off-by: NPantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: NPatil, Rachna <rachna@ti.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>

drivers/mfd/ti_am335x_tscadc.c

@@ -22,6 +22,8 @@
 #include <linux/regmap.h>
 #include <linux/mfd/core.h>
 #include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include <linux/mfd/ti_am335x_tscadc.h>
 #include <linux/input/ti_am335x_tsc.h>
@@ -90,20 +92,31 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
 	struct resource		*res;
 	struct clk		*clk;
 	struct mfd_tscadc_board	*pdata = pdev->dev.platform_data;
+	struct device_node	*node = pdev->dev.of_node;
 	struct mfd_cell		*cell;
 	int			err, ctrl;
 	int			clk_value, clock_rate;
-	int			tsc_wires, adc_channels = 0, total_channels;
+	int			tsc_wires = 0, adc_channels = 0, total_channels;
 
-	if (!pdata) {
+	if (!pdata && !pdev->dev.of_node) {
 		dev_err(&pdev->dev, "Could not find platform data\n");
 		return -EINVAL;
 	}
 
-	if (pdata->adc_init)
-		adc_channels = pdata->adc_init->adc_channels;
+	if (pdev->dev.platform_data) {
+		if (pdata->tsc_init)
+			tsc_wires = pdata->tsc_init->wires;
+
+		if (pdata->adc_init)
+			adc_channels = pdata->adc_init->adc_channels;
+	} else {
+		node = of_get_child_by_name(pdev->dev.of_node, "tsc");
+		of_property_read_u32(node, "ti,wires", &tsc_wires);
+
+		node = of_get_child_by_name(pdev->dev.of_node, "adc");
+		of_property_read_u32(node, "ti,adc-channels", &adc_channels);
+	}
 
-	tsc_wires = pdata->tsc_init->wires;
 	total_channels = tsc_wires + adc_channels;
 
 	if (total_channels > 8) {
@@ -285,11 +298,18 @@ static const struct dev_pm_ops tscadc_pm_ops = {
 #define TSCADC_PM_OPS NULL
 #endif
 
+static const struct of_device_id ti_tscadc_dt_ids[] = {
+	{ .compatible = "ti,am3359-tscadc", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);
+
 static struct platform_driver ti_tscadc_driver = {
 	.driver = {
-		.name   = "ti_tscadc",
+		.name   = "ti_am3359-tscadc",
 		.owner	= THIS_MODULE,
 		.pm	= TSCADC_PM_OPS,
+		.of_match_table = of_match_ptr(ti_tscadc_dt_ids),
 	},
 	.probe	= ti_tscadc_probe,
 	.remove	= ti_tscadc_remove,