thermal: ti-soc-thermal: use standard GPIO DT bindings

This change updates the ti-soc-thermal driver to use
standard GPIO DT bindings to read the GPIO number associated
to thermal shutdown IRQ, in case the device features it.

Previously, the code was using a specific DT bindings.
As now OMAP supports the standard way to model GPIOs,
there is no point in having a ti specific binding.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: NEduardo Valentin <eduardo.valentin@ti.com>

Documentation/devicetree/bindings/thermal/ti_soc_thermal.txt

@@ -17,8 +17,9 @@ Required properties:
 - interrupts : this entry should indicate which interrupt line
 the talert signal is routed to;
 Specific:
-- ti,tshut-gpio : this entry should be used to inform which GPIO
-line the tshut signal is routed to;
+- gpios : this entry should be used to inform which GPIO
+line the tshut signal is routed to. The informed GPIO will
+be treated as an IRQ;
 - regs : this entry must also be specified and it is specific
 to each bandgap version, because the mapping may change from
 soc to soc, apart of depending on available features.
@@ -37,7 +38,7 @@ bandgap {
 		0x4a002378 0x18>;
 	compatible = "ti,omap4460-bandgap";
 	interrupts = <0 126 4>; /* talert */
-	ti,tshut-gpio = <86>;
+	gpios = <&gpio3 22 0>; /* tshut */
 };
 
 OMAP4470:
@@ -47,7 +48,7 @@ bandgap {
 		0x4a002378 0x18>;
 	compatible = "ti,omap4470-bandgap";
 	interrupts = <0 126 4>; /* talert */
-	ti,tshut-gpio = <86>;
+	gpios = <&gpio3 22 0>; /* tshut */
 };
 
 OMAP5430:

drivers/thermal/ti-soc-thermal/ti-bandgap.c

@@ -38,6 +38,7 @@
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
 #include <linux/of_irq.h>
+#include <linux/of_gpio.h>
 #include <linux/io.h>
 
 #include "ti-bandgap.h"
@@ -1129,7 +1130,6 @@ static struct ti_bandgap *ti_bandgap_build(struct platform_device *pdev)
 	const struct of_device_id *of_id;
 	struct ti_bandgap *bgp;
 	struct resource *res;
-	u32 prop;
 	int i;
 
 	/* just for the sake */
@@ -1173,11 +1173,7 @@ static struct ti_bandgap *ti_bandgap_build(struct platform_device *pdev)
 	} while (res);
 
 	if (TI_BANDGAP_HAS(bgp, TSHUT)) {
-		if (of_property_read_u32(node, "ti,tshut-gpio", &prop) < 0) {
-			dev_err(&pdev->dev, "missing tshut gpio in device tree\n");
-			return ERR_PTR(-EINVAL);
-		}
-		bgp->tshut_gpio = prop;
+		bgp->tshut_gpio = of_get_gpio(node, 0);
 		if (!gpio_is_valid(bgp->tshut_gpio)) {
 			dev_err(&pdev->dev, "invalid gpio for tshut (%d)\n",
 				bgp->tshut_gpio);