Tidy up of the ft5406 driver to use DT

Driver was using a fixed resolution, this commit
adds coordinate size, flip and swap features
via device tree.

Adds overrides so the VC4 can adjust the DT parameters
appropriatley, there is a newer version of the VC4 side
driver that can now set up the appropriate DT values
if requried.

Author: James Hughes

arch/arm/boot/dts/overlays/rpi-ft5406-overlay.dts

@@ -11,7 +11,20 @@
 				compatible = "rpi,rpi-ft5406";
 				firmware = <&firmware>;
 				status = "okay";
+				touchscreen-size-x = <800>;
+				touchscreen-size-y = <600>;
+				touchscreen-inverted-x = <0>;
+				touchscreen-inverted-y = <0>;	
+				touchscreen-swapped-x-y = <0>;
 			};
 		};
 	};
+
+	__overrides__ {
+		touchscreen-size-x = <&rpi_ft5406>,"touchscreen-size-x:0";
+		touchscreen-size-y = <&rpi_ft5406>,"touchscreen-size-y:0";
+		touchscreen-inverted-x = <&rpi_ft5406>,"touchscreen-inverted-x:0";
+		touchscreen-inverted-y = <&rpi_ft5406>,"touchscreen-inverted-y:0";
+		touchscreen-swapped-x-y = <&rpi_ft5406>,"touchscreen-swapped-x-y:0";
+        };
 };

drivers/input/touchscreen/rpi-ft5406.c

@@ -1,7 +1,7 @@
 /*
  * Driver for memory based ft5406 touchscreen
  *
- * Copyright (C) 2015 Raspberry Pi
+ * Copyright (C) 2015, 2017 Raspberry Pi
  *
  *
  * This program is free software; you can redistribute it and/or modify
@@ -26,6 +26,7 @@
 #include <soc/bcm2835/raspberrypi-firmware.h>
 
 #define MAXIMUM_SUPPORTED_POINTS 10
+
 struct ft5406_regs {
 	uint8_t device_mode;
 	uint8_t gesture_id;
@@ -40,15 +41,22 @@ struct ft5406_regs {
 	} point[MAXIMUM_SUPPORTED_POINTS];
 };
 
-#define SCREEN_WIDTH  800
-#define SCREEN_HEIGHT 480
+// These are defaults if the DT entries are missing.
+#define DEFAULT_SCREEN_WIDTH  800
+#define DEFAULT_SCREEN_HEIGHT 480
 
 struct ft5406 {
-	struct platform_device * pdev;
-	struct input_dev       * input_dev;
-	void __iomem           * ts_base;
-	dma_addr_t		 bus_addr;
-	struct task_struct     * thread;
+	struct platform_device	* pdev;
+	struct input_dev	* input_dev;
+	void __iomem		* ts_base;
+	dma_addr_t		bus_addr;
+	struct task_struct	* thread;
+
+	uint16_t	max_x;
+	uint16_t	max_y;
+	uint8_t		hflip;
+	uint8_t		vflip;
+	uint8_t		xyswap;
 };
 
 /* Thread to poll for touchscreen events
@@ -81,12 +89,21 @@ static int ft5406_thread(void *arg)
 				int x = (((int) regs.point[i].xh & 0xf) << 8) + regs.point[i].xl;
 				int y = (((int) regs.point[i].yh & 0xf) << 8) + regs.point[i].yl;
 				int touchid = (regs.point[i].yh >> 4) & 0xf;
-				
+
 				modified_ids |= 1 << touchid;
 
+				if (ts->hflip)
+					x = ts->max_x - 1 - x;
+
+				if (ts->vflip)
+					y = ts->max_y - 1 - y;
+
+				if (ts->xyswap)
+					swap(x,y);
+
 				if(!((1 << touchid) & known_ids))
 					dev_dbg(&ts->pdev->dev, "x = %d, y = %d, touchid = %d\n", x, y, touchid);
-				
+
 				input_mt_slot(ts->input_dev, touchid);
 				input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, 1);
 
@@ -126,6 +143,7 @@ static int ft5406_probe(struct platform_device *pdev)
 	struct device_node *fw_node;
 	struct rpi_firmware *fw;
 	u32 touchbuf;
+	u32 val;
 
 	dev_info(dev, "Probing device\n");
 
@@ -136,8 +154,10 @@ static int ft5406_probe(struct platform_device *pdev)
 	}
 
 	fw = rpi_firmware_get(fw_node);
-	if (!fw)
+	if (!fw) {
+		dev_err(dev, "No firmware node - deferring\n");
 		return -EPROBE_DEFER;
+	}
 
 	ts = devm_kzalloc(dev, sizeof(struct ft5406), GFP_KERNEL);
 	if (!ts) {
@@ -202,15 +222,36 @@ static int ft5406_probe(struct platform_device *pdev)
 	ts->pdev = pdev;
 
 	ts->input_dev->name = "FT5406 memory based driver";
-	
+
+	if (of_property_read_u32(np, "touchscreen-size-x", &val) >= 0)
+		ts->max_x = val;
+	else
+		ts->max_x = DEFAULT_SCREEN_WIDTH;
+
+	if (of_property_read_u32(np, "touchscreen-size-y", &val) >= 0)
+		ts->max_y = val;
+	else
+		ts->max_y = DEFAULT_SCREEN_HEIGHT;
+
+	if (of_property_read_u32(np, "touchscreen-inverted-x", &val) >= 0)
+		ts->hflip = val;
+
+	if (of_property_read_u32(np, "touchscreen-inverted-y", &val) >= 0)
+		ts->vflip = val;
+
+	if (of_property_read_u32(np, "touchscreen-swapped-x-y", &val) >= 0)
+		ts->xyswap = val;
+
+	dev_dbg(dev, "Touchscreen parameters (%d,%d), hflip=%d, vflip=%d, xyswap=%d", ts->max_x, ts->max_y, ts->hflip, ts->vflip, ts->xyswap);
+
 	__set_bit(EV_KEY, ts->input_dev->evbit);
 	__set_bit(EV_SYN, ts->input_dev->evbit);
 	__set_bit(EV_ABS, ts->input_dev->evbit);
 
 	input_set_abs_params(ts->input_dev, ABS_MT_POSITION_X, 0,
-			     SCREEN_WIDTH, 0, 0);
+				ts->xyswap ? ts->max_y : ts->max_x, 0, 0);
 	input_set_abs_params(ts->input_dev, ABS_MT_POSITION_Y, 0,
-			     SCREEN_HEIGHT, 0, 0);
+				ts->xyswap ? ts->max_x : ts->max_y, 0, 0);
 
 	input_mt_init_slots(ts->input_dev, MAXIMUM_SUPPORTED_POINTS, INPUT_MT_DIRECT);