[MFD] Add code UCB1200/UCB1300 touchscreen support
Russell King [Sun, 11 Sep 2005 09:26:57 +0000 (10:26 +0100)]
Add support for Philips UCB1200 and UCB1300 touchscreen
interfaces found on ARM devices.

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

drivers/mfd/Kconfig
drivers/mfd/Makefile
drivers/mfd/ucb1x00-ts.c [new file with mode: 0644]

index 1f8563b..550f297 100644 (file)
@@ -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
index 90815b2..a05cd15 100644 (file)
@@ -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 (file)
index 0000000..52e0699
--- /dev/null
@@ -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);
+       for (;;) {
+               unsigned int x, y, p, val;
+               signed long timeout;
+
+               ts->restart = 0;
+
+               ucb1x00_adc_enable(ts->ucb);
+
+               x = ucb1x00_ts_read_xpos(ts);
+               y = ucb1x00_ts_read_ypos(ts);
+               p = ucb1x00_ts_read_pressure(ts);
+
+               /*
+                * Switch back to interrupt mode.
+                */
+               ucb1x00_ts_mode_int(ts);
+               ucb1x00_adc_disable(ts->ucb);
+
+               set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+               schedule_timeout(HZ / 100);
+               if (signal_pending(tsk))
+                       break;
+
+               ucb1x00_enable(ts->ucb);
+               val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
+
+               if (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW)) {
+                       set_task_state(tsk, TASK_INTERRUPTIBLE);
+
+                       ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
+                       ucb1x00_disable(ts->ucb);
+
+                       /*
+                        * If we spat out a valid sample set last time,
+                        * spit out a "pen off" sample here.
+                        */
+                       if (valid) {
+                               ucb1x00_ts_event_release(ts);
+                               valid = 0;
+                       }
+
+                       timeout = MAX_SCHEDULE_TIMEOUT;
+               } else {
+                       ucb1x00_disable(ts->ucb);
+
+                       /*
+                        * Filtering is policy.  Policy belongs in user
+                        * space.  We therefore leave it to user space
+                        * to do any filtering they please.
+                        */
+                       if (!ts->restart) {
+                               ucb1x00_ts_evt_add(ts, p, x, y);
+                               valid = 1;
+                       }
+
+                       set_task_state(tsk, TASK_INTERRUPTIBLE);
+                       timeout = HZ / 100;
+               }
+
+               try_to_freeze();
+
+               schedule_timeout(timeout);
+               if (signal_pending(tsk))
+                       break;
+       }
+
+       remove_wait_queue(&ts->irq_wait, &wait);
+
+       ts->rtask = NULL;
+       complete_and_exit(&ts->init_exit, 0);
+}
+
+/*
+ * We only detect touch screen _touches_ with this interrupt
+ * handler, and even then we just schedule our task.
+ */
+static void ucb1x00_ts_irq(int idx, void *id)
+{
+       struct ucb1x00_ts *ts = id;
+       ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
+       wake_up(&ts->irq_wait);
+}
+
+static int ucb1x00_ts_open(struct input_dev *idev)
+{
+       struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
+       int ret = 0;
+
+       if (down_interruptible(&ts->sem))
+               return -EINTR;
+
+       if (ts->use_count++ != 0)
+               goto out;
+
+       if (ts->rtask)
+               panic("ucb1x00: rtask running?");
+
+       init_waitqueue_head(&ts->irq_wait);
+       ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
+       if (ret < 0)
+               goto out;
+
+       /*
+        * If we do this at all, we should allow the user to
+        * measure and read the X and Y resistance at any time.
+        */
+       ucb1x00_adc_enable(ts->ucb);
+       ts->x_res = ucb1x00_ts_read_xres(ts);
+       ts->y_res = ucb1x00_ts_read_yres(ts);
+       ucb1x00_adc_disable(ts->ucb);
+
+       init_completion(&ts->init_exit);
+       ret = kernel_thread(ucb1x00_thread, ts, CLONE_KERNEL);
+       if (ret >= 0) {
+               wait_for_completion(&ts->init_exit);
+               ret = 0;
+       } else {
+               ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+       }
+
+ out:
+       if (ret)
+               ts->use_count--;
+       up(&ts->sem);
+       return ret;
+}
+
+/*
+ * Release touchscreen resources.  Disable IRQs.
+ */
+static void ucb1x00_ts_close(struct input_dev *idev)
+{
+       struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
+
+       down(&ts->sem);
+       if (--ts->use_count == 0) {
+               if (ts->rtask) {
+                       send_sig(SIGKILL, ts->rtask, 1);
+                       wait_for_completion(&ts->init_exit);
+               }
+
+               ucb1x00_enable(ts->ucb);
+               ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+               ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
+               ucb1x00_disable(ts->ucb);
+       }
+       up(&ts->sem);
+}
+
+#ifdef CONFIG_PM
+static int ucb1x00_ts_resume(struct ucb1x00_dev *dev)
+{
+       struct ucb1x00_ts *ts = dev->priv;
+
+       if (ts->rtask != NULL) {
+               /*
+                * Restart the TS thread to ensure the
+                * TS interrupt mode is set up again
+                * after sleep.
+                */
+               ts->restart = 1;
+               wake_up(&ts->irq_wait);
+       }
+       return 0;
+}
+#else
+#define ucb1x00_ts_resume NULL
+#endif
+
+
+/*
+ * Initialisation.
+ */
+static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
+{
+       struct ucb1x00_ts *ts;
+
+       ts = kmalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
+       if (!ts)
+               return -ENOMEM;
+
+       memset(ts, 0, sizeof(struct ucb1x00_ts));
+
+       ts->ucb = dev->ucb;
+       ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
+       init_MUTEX(&ts->sem);
+
+       ts->idev.name       = "Touchscreen panel";
+       ts->idev.id.product = ts->ucb->id;
+       ts->idev.open       = ucb1x00_ts_open;
+       ts->idev.close      = ucb1x00_ts_close;
+
+       __set_bit(EV_ABS, ts->idev.evbit);
+       __set_bit(ABS_X, ts->idev.absbit);
+       __set_bit(ABS_Y, ts->idev.absbit);
+       __set_bit(ABS_PRESSURE, ts->idev.absbit);
+
+       input_register_device(&ts->idev);
+
+       dev->priv = ts;
+
+       return 0;
+}
+
+static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
+{
+       struct ucb1x00_ts *ts = dev->priv;
+       input_unregister_device(&ts->idev);
+       kfree(ts);
+}
+
+static struct ucb1x00_driver ucb1x00_ts_driver = {
+       .add            = ucb1x00_ts_add,
+       .remove         = ucb1x00_ts_remove,
+       .resume         = ucb1x00_ts_resume,
+};
+
+static int __init ucb1x00_ts_init(void)
+{
+       return ucb1x00_register_driver(&ucb1x00_ts_driver);
+}
+
+static void __exit ucb1x00_ts_exit(void)
+{
+       ucb1x00_unregister_driver(&ucb1x00_ts_driver);
+}
+
+module_param(adcsync, int, 0444);
+module_init(ucb1x00_ts_init);
+module_exit(ucb1x00_ts_exit);
+
+MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
+MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
+MODULE_LICENSE("GPL");