[MFD] Add code UCB1200/UCB1300 touchscreen support

Add support for Philips UCB1200 and UCB1300 touchscreen
interfaces found on ARM devices.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 435 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 1f8563bde4..550f297448 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -18,4 +18,8 @@ config MCP_UCB1200
         tristate "Support for UCB1200 / UCB1300"
         depends on MCP
 
+config MCP_UCB1200_TS
+        tristate "Touchscreen interface support"
+        depends on MCP_UCB1200 && INPUT
+
 endmenu
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 90815b2840..a05cd1599a 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -5,3 +5,4 @@
 obj-$(CONFIG_MCP)               += mcp-core.o
 obj-$(CONFIG_MCP_SA11X0)        += mcp-sa11x0.o
 obj-$(CONFIG_MCP_UCB1200)       += ucb1x00-core.o
+obj-$(CONFIG_MCP_UCB1200_TS)    += ucb1x00-ts.o
diff --git a/drivers/mfd/ucb1x00-ts.c b/drivers/mfd/ucb1x00-ts.c
new file mode 100644
index 0000000000..52e0699eeb
--- /dev/null
+++ b/drivers/mfd/ucb1x00-ts.c
@@ -0,0 +1,430 @@
+/*
+ *  linux/drivers/mfd/ucb1x00-ts.c
+ *
+ *  Copyright (C) 2001 Russell King, All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 21-Jan-2002 <jco@ict.es> :
+ *
+ * Added support for synchronous A/D mode. This mode is useful to
+ * avoid noise induced in the touchpanel by the LCD, provided that
+ * the UCB1x00 has a valid LCD sync signal routed to its ADCSYNC pin.
+ * It is important to note that the signal connected to the ADCSYNC
+ * pin should provide pulses even when the LCD is blanked, otherwise
+ * a pen touch needed to unblank the LCD will never be read.
+ */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/input.h>
+#include <linux/device.h>
+#include <linux/suspend.h>
+#include <linux/slab.h>
+
+#include <asm/dma.h>
+#include <asm/semaphore.h>
+
+#include "ucb1x00.h"
+
+
+struct ucb1x00_ts {
+        struct input_dev        idev;
+        struct ucb1x00          *ucb;
+
+        wait_queue_head_t       irq_wait;
+        struct semaphore        sem;
+        struct completion       init_exit;
+        struct task_struct      *rtask;
+        int                     use_count;
+        u16                     x_res;
+        u16                     y_res;
+
+        int                     restart:1;
+        int                     adcsync:1;
+};
+
+static int adcsync;
+
+static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
+{
+        input_report_abs(&ts->idev, ABS_X, x);
+        input_report_abs(&ts->idev, ABS_Y, y);
+        input_report_abs(&ts->idev, ABS_PRESSURE, pressure);
+        input_sync(&ts->idev);
+}
+
+static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
+{
+        input_report_abs(&ts->idev, ABS_PRESSURE, 0);
+        input_sync(&ts->idev);
+}
+
+/*
+ * Switch to interrupt mode.
+ */
+static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts)
+{
+        ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
+                        UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
+                        UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
+                        UCB_TS_CR_MODE_INT);
+}
+
+/*
+ * Switch to pressure mode, and read pressure.  We don't need to wait
+ * here, since both plates are being driven.
+ */
+static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts)
+{
+        ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
+                        UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
+                        UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
+                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+
+        return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
+}
+
+/*
+ * Switch to X position mode and measure Y plate.  We switch the plate
+ * configuration in pressure mode, then switch to position mode.  This
+ * gives a faster response time.  Even so, we need to wait about 55us
+ * for things to stabilise.
+ */
+static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts)
+{
+        ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
+                        UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
+                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+        ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
+                        UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
+                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+        ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
+                        UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
+                        UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
+
+        udelay(55);
+
+        return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
+}
+
+/*
+ * Switch to Y position mode and measure X plate.  We switch the plate
+ * configuration in pressure mode, then switch to position mode.  This
+ * gives a faster response time.  Even so, we need to wait about 55us
+ * for things to stabilise.
+ */
+static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts)
+{
+        ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
+                        UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
+                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+        ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
+                        UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
+                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+        ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
+                        UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
+                        UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
+
+        udelay(55);
+
+        return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync);
+}
+
+/*
+ * Switch to X plate resistance mode.  Set MX to ground, PX to
+ * supply.  Measure current.
+ */
+static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts)
+{
+        ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
+                        UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
+                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+        return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
+}
+
+/*
+ * Switch to Y plate resistance mode.  Set MY to ground, PY to
+ * supply.  Measure current.
+ */
+static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts)
+{
+        ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
+                        UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
+                        UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+        return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
+}
+
+/*
+ * This is a RT kernel thread that handles the ADC accesses
+ * (mainly so we can use semaphores in the UCB1200 core code
+ * to serialise accesses to the ADC).
+ */
+static int ucb1x00_thread(void *_ts)
+{
+        struct ucb1x00_ts *ts = _ts;
+        struct task_struct *tsk = current;
+        DECLARE_WAITQUEUE(wait, tsk);
+        int valid;
+
+        ts->rtask = tsk;
+
+        daemonize("ktsd");
+        /* only want to receive SIGKILL */
+        allow_signal(SIGKILL);
+
+        /*
+         * We could run as a real-time thread.  However, thus far
+         * this doesn't seem to be necessary.
+         */
+//      tsk->policy = SCHED_FIFO;
+//      tsk->rt_priority = 1;
+
+        complete(&ts->init_exit);
+
+        valid = 0;
+
+        add_wait_queue(&ts->irq_wait, &wait);