drivers/thermal/spear_thermal.c: add Device Tree probing capability

SPEAr platforms now support DT and so must convert all drivers to support
DT.  This patch adds DT probing support for SPEAr thermal sensor driver
and updates its documentation too.

Also, as SPEAr is the only user of this driver and is only available with
DT, make this an only DT driver.  So, platform_data is completely removed
and passed via DT now.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@st.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

Documentation/devicetree/bindings/thermal/spear-thermal.txt

@@ -0,0 +1,14 @@
+* SPEAr Thermal
+
+Required properties:
+- compatible : "st,thermal-spear1340"
+- reg : Address range of the thermal registers
+- st,thermal-flags: flags used to enable thermal sensor
+
+Example:
+
+	thermal@fc000000 {
+		compatible = "st,thermal-spear1340";
+		reg = <0xfc000000 0x1000>;
+		st,thermal-flags = <0x7000>;
+	};

drivers/thermal/Kconfig

@@ -23,6 +23,7 @@ config SPEAR_THERMAL
 	bool "SPEAr thermal sensor driver"
 	depends on THERMAL
 	depends on PLAT_SPEAR
+	depends on OF
 	help
 	  Enable this to plug the SPEAr thermal sensor driver into the Linux
 	  thermal framework

drivers/thermal/spear_thermal.c

@@ -20,9 +20,9 @@
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/of.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
-#include <linux/platform_data/spear_thermal.h>
 #include <linux/thermal.h>
 
 #define MD_FACTOR	1000
@@ -103,21 +103,20 @@ static int spear_thermal_probe(struct platform_device *pdev)
 {
 	struct thermal_zone_device *spear_thermal = NULL;
 	struct spear_thermal_dev *stdev;
-	struct spear_thermal_pdata *pdata;
-	int ret = 0;
+	struct device_node *np = pdev->dev.of_node;
 	struct resource *stres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	int ret = 0, val;
+
+	if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) {
+		dev_err(&pdev->dev, "Failed: DT Pdata not passed\n");
+		return -EINVAL;
+	}
 
 	if (!stres) {
 		dev_err(&pdev->dev, "memory resource missing\n");
 		return -ENODEV;
 	}
 
-	pdata = dev_get_platdata(&pdev->dev);
-	if (!pdata) {
-		dev_err(&pdev->dev, "platform data is NULL\n");
-		return -EINVAL;
-	}
-
 	stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL);
 	if (!stdev) {
 		dev_err(&pdev->dev, "kzalloc fail\n");
@@ -144,7 +143,7 @@ static int spear_thermal_probe(struct platform_device *pdev)
 		goto put_clk;
 	}
 
-	stdev->flags = pdata->thermal_flags;
+	stdev->flags = val;
 	writel_relaxed(stdev->flags, stdev->thermal_base);
 
 	spear_thermal = thermal_zone_device_register("spear_thermal", 0,
@@ -189,13 +188,20 @@ static int spear_thermal_exit(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct of_device_id spear_thermal_id_table[] = {
+	{ .compatible = "st,thermal-spear1340" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, spear_thermal_id_table);
+
 static struct platform_driver spear_thermal_driver = {
 	.probe = spear_thermal_probe,
 	.remove = spear_thermal_exit,
 	.driver = {
 		.name = "spear_thermal",
 		.owner = THIS_MODULE,
 		.pm = &spear_thermal_pm_ops,
+		.of_match_table = of_match_ptr(spear_thermal_id_table),
 	},
 };