Input: wm97xx - add possibility to control the GPIO_STATUS shift

This patch allows tweaking the behaviour of GPIO_STATUS register
shift quirk that's in wm97xx-core. The problem with GPIO_STATUS
register being shifted by one doesn't appear on all hardware it
seems and causes problems with accelerated touchscreen drivers on
Palm hardware. Therefore an accelerated touchscreen driver can select
if the shift is/isn't happening on the hardware.

Signed-off-by: Marek Vasut <[e-mail]>
Acked-by: Mark Brown <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/touchscreen/mainstone-wm97xx.c

···
 	if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
 		pen_int = 1;
 		irq = 27;
+		/* There is some obscure mutant of WM9712 interbred with WM9713
+		 * used on Palm HW */
+		wm->variant = WM97xx_WM1613;
 	} else if (machine_is_mainstone() && pen_int)
 		irq = 4;
 

drivers/input/touchscreen/wm97xx-core.c

···
 	else
 		reg &= ~gpio;
 
-	if (wm->id == WM9712_ID2)
+	if (wm->id == WM9712_ID2 && wm->variant != WM97xx_WM1613)
 		wm97xx_reg_write(wm, AC97_GPIO_STATUS, reg << 1);
 	else
 		wm97xx_reg_write(wm, AC97_GPIO_STATUS, reg);
···
 					 WM97XX_GPIO_13);
 		}
 
-		if (wm->id == WM9712_ID2)
+		if (wm->id == WM9712_ID2 && wm->variant != WM97xx_WM1613)
 			wm97xx_reg_write(wm, AC97_GPIO_STATUS, (status &
 						~WM97XX_GPIO_13) << 1);
 		else
···
 	}
 
 	wm->id = wm97xx_reg_read(wm, AC97_VENDOR_ID2);
+
+	wm->variant = WM97xx_GENERIC;
 
 	dev_info(wm->dev, "detected a wm97%02x codec\n", wm->id & 0xff);
 

include/linux/wm97xx.h

···
 #include <linux/platform_device.h>
 
 /*
+ * WM97xx variants
+ */
+#define	WM97xx_GENERIC			0x0000
+#define	WM97xx_WM1613			0x1613
+
+/*
  * WM97xx AC97 Touchscreen registers
  */
 #define AC97_WM97XX_DIGITISER1		0x76
···
 	unsigned pen_is_down:1;		/* Pen is down */
 	unsigned aux_waiting:1;		/* aux measurement waiting */
 	unsigned pen_probably_down:1;	/* used in polling mode */
+	u16 variant;			/* WM97xx chip variant */
 	u16 suspend_mode;               /* PRP in suspend mode */
 };