Input: WM97xx - add chip driver for WM9705 touchscreen

Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Graeme Gregory <gg@opensource.wolfsonmicro.com>
Signed-off-by: Mike Arthur <mike.arthur@wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

3 files changed, 363 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index a95a87cd1d59..4939a96d12b9 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -199,6 +199,15 @@ config TOUCHSCREEN_WM97XX
           To compile this driver as a module, choose M here: the
           module will be called wm97xx-ts.
 
+config TOUCHSCREEN_WM9705
+        bool "WM9705 Touchscreen interface support"
+        depends on TOUCHSCREEN_WM97XX
+        help
+          Say Y here if you have a Wolfson Microelectronics WM9705
+          touchscreen controller connected to your system.
+
+          If unsure, say N.
+
 config TOUCHSCREEN_USB_COMPOSITE
         tristate "USB Touchscreen Driver"
         depends on USB_ARCH_HAS_HCD
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index b4e7b5dbf649..5829a435efd1 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)	+= touchright.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN)      += touchwin.o
 obj-$(CONFIG_TOUCHSCREEN_UCB1400)       += ucb1400_ts.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX)        += wm97xx-ts.o
+wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9705)  += wm9705.o
diff --git a/drivers/input/touchscreen/wm9705.c b/drivers/input/touchscreen/wm9705.c
new file mode 100644
index 000000000000..978e1a13ffc7
--- /dev/null
+++ b/drivers/input/touchscreen/wm9705.c
@@ -0,0 +1,353 @@
+/*
+ * wm9705.c  --  Codec driver for Wolfson WM9705 AC97 Codec.
+ *
+ * Copyright 2003, 2004, 2005, 2006, 2007 Wolfson Microelectronics PLC.
+ * Author: Liam Girdwood
+ *         liam.girdwood@wolfsonmicro.com or linux@wolfsonmicro.com
+ * Parts Copyright : Ian Molton <spyro@f2s.com>
+ *                   Andrew Zabolotny <zap@homelink.ru>
+ *                   Russell King <rmk@arm.linux.org.uk>
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/input.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
+#include <linux/wm97xx.h>
+
+#define TS_NAME                 "wm97xx"
+#define WM9705_VERSION          "1.00"
+#define DEFAULT_PRESSURE        0xb0c0
+
+/*
+ * Module parameters
+ */
+
+/*
+ * Set current used for pressure measurement.
+ *
+ * Set pil = 2 to use 400uA
+ *     pil = 1 to use 200uA and
+ *     pil = 0 to disable pressure measurement.
+ *
+ * This is used to increase the range of values returned by the adc
+ * when measureing touchpanel pressure.
+ */
+static int pil;
+module_param(pil, int, 0);
+MODULE_PARM_DESC(pil, "Set current used for pressure measurement.");
+
+/*
+ * Set threshold for pressure measurement.
+ *
+ * Pen down pressure below threshold is ignored.
+ */
+static int pressure = DEFAULT_PRESSURE & 0xfff;
+module_param(pressure, int, 0);
+MODULE_PARM_DESC(pressure, "Set threshold for pressure measurement.");
+
+/*
+ * Set adc sample delay.
+ *
+ * For accurate touchpanel measurements, some settling time may be
+ * required between the switch matrix applying a voltage across the
+ * touchpanel plate and the ADC sampling the signal.
+ *
+ * This delay can be set by setting delay = n, where n is the array
+ * position of the delay in the array delay_table below.
+ * Long delays > 1ms are supported for completeness, but are not
+ * recommended.
+ */
+static int delay = 4;
+module_param(delay, int, 0);
+MODULE_PARM_DESC(delay, "Set adc sample delay.");
+
+/*
+ * Pen detect comparator threshold.
+ *
+ * 0 to Vmid in 15 steps, 0 = use zero power comparator with Vmid threshold
+ * i.e. 1 =  Vmid/15 threshold
+ *      15 =  Vmid/1 threshold
+ *
+ * Adjust this value if you are having problems with pen detect not
+ * detecting any down events.
+ */
+static int pdd = 8;
+module_param(pdd, int, 0);
+MODULE_PARM_DESC(pdd, "Set pen detect comparator threshold");
+
+/*
+ * Set adc mask function.
+ *
+ * Sources of glitch noise, such as signals driving an LCD display, may feed
+ * through to the touch screen plates and affect measurement accuracy. In
+ * order to minimise this, a signal may be applied to the MASK pin to delay or
+ * synchronise the sampling.
+ *
+ * 0 = No delay or sync
+ * 1 = High on pin stops conversions
+ * 2 = Edge triggered, edge on pin delays conversion by delay param (above)
+ * 3 = Edge triggered, edge on pin starts conversion after delay param
+ */
+static int mask;
+module_param(mask, int, 0);
+MODULE_PARM_DESC(mask, "Set adc mask function.");
+
+/*
+ * ADC sample delay times in uS
+ */
+static const int delay_table[] = {
+        21,    /* 1 AC97 Link frames */
+        42,    /* 2                  */
+        84,    /* 4                  */
+        167,   /* 8                  */
+        333,   /* 16                 */
+        667,   /* 32                 */
+        1000,  /* 48                 */
+        1333,  /* 64                 */
+        2000,  /* 96                 */
+        2667,  /* 128                */
+        3333,  /* 160                */
+        4000,  /* 192                */
+        4667,  /* 224                */
+        5333,  /* 256                */
+        6000,  /* 288                */
+        0      /* No delay, switch matrix always on */
+};
+
+/*
+ * Delay after issuing a POLL command.
+ *
+ * The delay is 3 AC97 link frames + the touchpanel settling delay
+ */
+static inline void poll_delay(int d)
+{
+        udelay(3 * AC97_LINK_FRAME + delay_table[d]);
+}
+
+/*
+ * set up the physical settings of the WM9705
+ */
+static void wm9705_phy_init(struct wm97xx *wm)
+{
+        u16 dig1 = 0, dig2 = WM97XX_RPR;
+
+        /*
+        * mute VIDEO and AUX as they share X and Y touchscreen
+        * inputs on the WM9705
+        */
+        wm97xx_reg_write(wm, AC97_AUX, 0x8000);
+        wm97xx_reg_write(wm, AC97_VIDEO, 0x8000);
+
+        /* touchpanel pressure current*/
+        if (pil == 2) {
+                dig2 |= WM9705_PIL;
+                dev_dbg(wm->dev,
+                        "setting pressure measurement current to 400uA.");
+        } else if (pil)
+                dev_dbg(wm->dev,
+                        "setting pressure measurement current to 200uA.");
+        if (!pil)
+                pressure = 0;