Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/spi-2.6

3 files changed, 639 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 21d55ed..2c67402 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -11,6 +11,19 @@ menuconfig INPUT_TOUCHSCREEN
 
 if INPUT_TOUCHSCREEN
 
+config TOUCHSCREEN_ADS7846
+	tristate "ADS 7846 based touchscreens"
+	depends on SPI_MASTER
+	help
+	  Say Y here if you have a touchscreen interface using the
+	  ADS7846 controller, and your board-specific initialization
+	  code includes that in its table of SPI devices.
+
+	  If unsure, say N (but it's safe to say "Y").
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ads7846.
+
 config TOUCHSCREEN_BITSY
 	tristate "Compaq iPAQ H3600 (Bitsy) touchscreen"
 	depends on SA1100_BITSY
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 6842869..5e5557c 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -4,6 +4,7 @@
 
 # Each configuration option enables a list of files.
 
+obj-$(CONFIG_TOUCHSCREEN_ADS7846)	+= ads7846.o
 obj-$(CONFIG_TOUCHSCREEN_BITSY)	+= h3600_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_CORGI)	+= corgi_ts.o
 obj-$(CONFIG_TOUCHSCREEN_GUNZE)	+= gunze.o
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
new file mode 100644
index 0000000..dd8c6a9
--- /dev/null
+++ b/drivers/input/touchscreen/ads7846.c
@@ -0,0 +1,625 @@
+/*
+ * ADS7846 based touchscreen and sensor driver
+ *
+ * Copyright (c) 2005 David Brownell
+ *
+ * Using code from:
+ *  - corgi_ts.c
+ *	Copyright (C) 2004-2005 Richard Purdie
+ *  - omap_ts.[hc], ads7846.h, ts_osk.c
+ *	Copyright (C) 2002 MontaVista Software
+ *	Copyright (C) 2004 Texas Instruments
+ *	Copyright (C) 2005 Dirk Behme
+ *
+ *  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.
+ */
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/ads7846.h>
+
+#ifdef	CONFIG_ARM
+#include <asm/mach-types.h>
+#ifdef	CONFIG_ARCH_OMAP
+#include <asm/arch/gpio.h>
+#endif
+
+#else
+#define	set_irq_type(irq,type)	do{}while(0)
+#endif
+
+
+/*
+ * This code has been lightly tested on an ads7846.
+ * Support for ads7843 and ads7845 has only been stubbed in.
+ *
+ * Not yet done:  investigate the values reported.  Are x/y/pressure
+ * event values sane enough for X11?  How accurate are the temperature
+ * and voltage readings?  (System-specific calibration should support
+ * accuracy of 0.3 degrees C; otherwise it's 2.0 degrees.)
+ *
+ * app note sbaa036 talks in more detail about accurate sampling...
+ * that ought to help in situations like LCDs inducing noise (which
+ * can also be helped by using synch signals) and more generally.
+ */
+
+#define	TS_POLL_PERIOD	msecs_to_jiffies(10)
+
+struct ts_event {
+	/* For portability, we can't read 12 bit values using SPI (which
+	 * would make the controller deliver them as native byteorder u16
+	 * with msbs zeroed).  Instead, we read them as two 8-byte values,
+	 * which need byteswapping then range adjustment.
+	 */
+	__be16 x;
+	__be16 y;
+	__be16 z1, z2;
+};
+
+struct ads7846 {
+	struct input_dev	input;
+	char			phys[32];
+
+	struct spi_device	*spi;
+	u16			model;
+	u16			vref_delay_usecs;
+	u16			x_plate_ohms;
+
+	struct ts_event		tc;
+
+	struct spi_transfer	xfer[8];
+	struct spi_message	msg;
+
+	spinlock_t		lock;
+	struct timer_list	timer;		/* P: lock */
+	unsigned		pendown:1;	/* P: lock */
+	unsigned		pending:1;	/* P: lock */
+// FIXME remove "irq_disabled"
+	unsigned		irq_disabled:1;	/* P: lock */
+};
+
+/* leave chip selected when we're done, for quicker re-select? */
+#if	0
+#define	CS_CHANGE(xfer)	((xfer).cs_change = 1)
+#else
+#define	CS_CHANGE(xfer)	((xfer).cs_change = 0)
+#endif
+
+/*--------------------------------------------------------------------------*/
+
+/* The ADS7846 has touchscreen and other sensors.
+ * Earlier ads784x chips are somewhat compatible.
+ */
+#define	ADS_START		(1 << 7)
+#define	ADS_A2A1A0_d_y		(1 << 4)	/* differential */
+#define	ADS_A2A1A0_d_z1		(3 << 4)	/* differential */
+#define	ADS_A2A1A0_d_z2		(4 << 4)	/* differential */
+#define	ADS_A2A1A0_d_x		(5 << 4)	/* differential */
+#define	ADS_A2A1A0_temp0	(0 << 4)	/* non-differential */
+#define	ADS_A2A1A0_vbatt	(2 << 4)	/* non-differential */
+#define	ADS_A2A1A0_vaux		(6 << 4)	/* non-differential */
+#define	ADS_A2A1A0_temp1	(7 << 4)	/* non-differential */
+#define	ADS_8_BIT		(1 << 3)
+#define	ADS_12_BIT		(0 << 3)
+#define	ADS_SER			(1 << 2)	/* non-differential */
+#define	ADS_DFR			(0 << 2)	/* differential */
+#define	ADS_PD10_PDOWN		(0 << 0)	/* lowpower mode + penirq */
+#define	ADS_PD10_ADC_ON		(1 << 0)	/* ADC on */
+#define	ADS_PD10_REF_ON		(2 << 0)	/* vREF on + penirq */
+#define	ADS_PD10_ALL_ON		(3 << 0)	/* ADC + vREF on */
+
+#define	MAX_12BIT	((1<<12)-1)
+
+/* leave ADC powered up (disables penirq) between differential samples */
+#define	READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \
+	| ADS_12_BIT | ADS_DFR)
+
+static const u8	read_y  = READ_12BIT_DFR(y)  | ADS_PD10_ADC_ON;
+static const u8	read_z1 = READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON;
+static const u8	read_z2 = READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON;
+static const u8	read_x  = READ_12BIT_DFR(x)  | ADS_PD10_PDOWN;	/* LAST */
+
+/* single-ended samples need to first power up reference voltage;
+ * we leave both ADC and VREF powered
+ */
+#define	READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
+	| ADS_12_BIT | ADS_SER)
+
+static const u8	ref_on = READ_12BIT_DFR(x) | ADS_PD10_ALL_ON;
+static const u8	ref_off = READ_12BIT_DFR(y) | ADS_PD10_PDOWN;
+
+/*--------------------------------------------------------------------------*/
+
+/*
+ * Non-touchscreen sensors only use single-ended conversions.
+ */
+
+struct ser_req {
+	u8			command;
+	u16			scratch;
+	__be16			sample;
+	struct spi_message	msg;
+	struct spi_transfer	xfer[6];
+};
+
+static int ads7846_read12_ser(struct device *dev, unsigned command)
+{
+	struct spi_device	*spi = to_spi_device(dev);
+	struct ads7846		*ts = dev_get_drvdata(dev);
+	struct ser_req		*req = kzalloc(sizeof *req, SLAB_KERNEL);
+	int			status;
+	int			sample;
+	int 			i;
+
+	if (!req)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&req->msg.transfers);
+
+	/* activate reference, so it has time to settle; */
+	req->xfer[0].tx_buf = &ref_on;
+	req->xfer[0].len = 1;
+	req->xfer[1].rx_buf = &req->scratch;
+	req->xfer[1].len = 2;
+
+	/*
+	 * for external VREF, 0 usec (and assume it's always on);
+	 * for 1uF, use 800 usec;
+	 * no cap, 100 usec.
+	 */
+	req->xfer[1].delay_usecs = ts->vref_delay_usecs;
+
+	/* take sample */
+	req->command = (u8) command;
+	req->xfer[2].tx_buf = &req->command;
+	req->xfer[2].len = 1;
+	req->xfer[3].rx_buf = &req->sample;
+	req->xfer[3].len = 2;
+
+	/* REVISIT:  take a few more samples, and compare ... */
+
+	/* turn off reference */
+	req->xfer[4].tx_buf = &ref_off;
+	req->xfer[4].len = 1;
+	req->xfer[5].rx_buf = &req->scratch;
+	req->xfer[5].len = 2;
+
+	CS_CHANGE(req->xfer[5]);
+
+	/* group all the transfers together, so we can't interfere with
+	 * reading touchscreen state; disable penirq while sampling
+	 */
+	for (i = 0; i < 6; i++)
+		spi_message_add_tail(&req->xfer[i], &req->msg);
+
+	disable_irq(spi->irq);
+	status = spi_sync(spi, &req->msg);
+	enable_irq(spi->irq);
+
+	if (req->msg.status)
+		status = req->msg.status;
+	sample = be16_to_cpu(req->sample);
+	sample = sample >> 4;
+	kfree(req);
+
+	return status ? status : sample;
+}
+
+#define SHOW(name) static ssize_t \
+name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
+{ \
+	ssize_t v = ads7846_read12_ser(dev, \
+			READ_12BIT_SER(name) | ADS_PD10_ALL_ON); \
+	if (v < 0) \
+		return v; \
+	return sprintf(buf, "%u\n", (unsigned) v); \
+} \
+static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
+
+SHOW(temp0)
+SHOW(temp1)
+SHOW(vaux)
+SHOW(vbatt)
+
+/*--------------------------------------------------------------------------*/
+
+/*
+ * PENIRQ only kicks the timer.  The timer only reissues the SPI transfer,
+ * to retrieve touchscreen status.
+ *
+ * The SPI transfer completion callback does the real work.  It reports
+ * touchscreen events and reactivates the timer (or IRQ) as appropriate.
+ */
+
+static void ads7846_rx(void *ads)
+{
+	struct ads7846	*ts = ads;
+	unsigned	Rt;
+	unsigned	sync = 0;
+	u16		x, y, z1, z2;
+	unsigned long	flags;
+
+	/* adjust:  12 bit samples (left aligned), built from
+	 * two 8 bit values writen msb-first.
+	 */
+	x = be16_to_cpu(ts->tc.x) >> 4;
+	y = be16_to_cpu(ts->tc.y) >> 4;
+	z1 = be16_to_cpu(ts->tc.z1) >> 4;
+	z2 = be16_to_cpu(ts->tc.z2) >> 4;
+
+	/* range filtering */
+	if (x == MAX_12BIT)
+		x = 0;
+
+	if (x && z1 && ts->spi->dev.power.power_state.event == PM_EVENT_ON) {
+		/* compute touch pressure resistance using equation #2 */
+		Rt = z2;
+		Rt -= z1;
+		Rt *= x;
+		Rt *= ts->x_plate_ohms;
+		Rt /= z1;
+		Rt = (Rt + 2047) >> 12;
+	} else
+		Rt = 0;
+
+	/* NOTE:  "pendown" is inferred from pressure; we don't rely on
+	 * being able to check nPENIRQ status, or "friendly" trigger modes
+	 * (both-edges is much better than just-falling or low-level).
+	 *
+	 * REVISIT:  some boards may require reading nPENIRQ; it's
+	 * needed on 7843.  and 7845 reads pressure differently...
+	 *
+	 * REVISIT:  the touchscreen might not be connected; this code
+	 * won't notice that, even if nPENIRQ never fires ...
+	 */
+	if (!ts->pendown && Rt != 0) {
+		input_report_key(&ts->input, BTN_TOUCH, 1);
+		sync = 1;
+	} else if (ts->pendown && Rt == 0) {
+		input_report_key(&ts->input, BTN_TOUCH, 0);
+		sync = 1;
+	}
+
+	if (Rt) {
+		input_report_abs(&ts->input, ABS_X, x);
+		input_report_abs(&ts->input, ABS_Y, y);
+		input_report_abs(&ts->input, ABS_PRESSURE, Rt);
+		sync = 1;
+	}
+	if (sync)
+		input_sync(&ts->input);
+
+#ifdef	VERBOSE
+	if (Rt || ts->pendown)
+		pr_debug("%s: %d/%d/%d%s\n", ts->spi->dev.bus_id,
+			x, y, Rt, Rt ? "" : " UP");
+#endif
+
+	/* don't retrigger while we're suspended */
+	spin_lock_irqsave(&ts->lock, flags);
+
+	ts->pendown = (Rt != 0);
+	ts->pending = 0;
+
+	if (ts->spi->dev.power.power_state.event == PM_EVENT_ON) {
+		if (ts->pendown)
+			mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD);
+		else if (ts->irq_disabled) {
+			ts->irq_disabled = 0;
+			enable_irq(ts->spi->irq);
+		}
+	}
+
+	spin_unlock_irqrestore(&ts->lock, flags);
+}
+
+static void ads7846_timer(unsigned long handle)
+{
+	struct ads7846	*ts = (void *)handle;
+	int		status = 0;
+	unsigned long	flags;
+
+	spin_lock_irqsave(&ts->lock, flags);
+	if (!ts->pending) {
+		ts->pending = 1;
+		if (!ts->irq_disabled) {
+			ts->irq_disabled = 1;
+			disable_irq(ts->spi->irq);
+		}
+		status = spi_async(ts->spi, &ts->msg);
+		if (status)
+			dev_err(&ts->spi->dev, "spi_async --> %d\n",
+					status);
+	}
+	spin_unlock_irqrestore(&ts->lock, flags);
+}
+
+static irqreturn_t ads7846_irq(int irq, void *handle, struct pt_regs *regs)
+{
+	ads7846_timer((unsigned long) handle);
+	return IRQ_HANDLED;
+}
+
+/*--------------------------------------------------------------------------*/
+
+static int
+ads7846_suspend(struct spi_device *spi, pm_message_t message)
+{
+	struct ads7846 *ts = dev_get_drvdata(&spi->dev);
+	unsigned long	flags;
+
+	spin_lock_irqsave(&ts->lock, flags);
+
+	spi->dev.power.power_state = message;
+
+	/* are we waiting for IRQ, or polling? */
+	if (!ts->pendown) {
+		if (!ts->irq_disabled) {
+			ts->irq_disabled = 1;
+			disable_irq(ts->spi->irq);
+		}
+	} else {
+		/* polling; force a final SPI completion;
+		 * that will clean things up neatly
+		 */
+		if (!ts->pending)
+			mod_timer(&ts->timer, jiffies);
+
+		while (ts->pendown || ts->pending) {
+			spin_unlock_irqrestore(&ts->lock, flags);
+			udelay(10);
+			spin_lock_irqsave(&ts->lock, flags);
+		}
+	}
+
+	/* we know the chip's in lowpower mode since we always
+	 * leave it that way after every request
+	 */
+
+	spin_unlock_irqrestore(&ts->lock, flags);
+	return 0;
+}
+
+static int ads7846_resume(struct spi_device *spi)
+{
+	struct ads7846 *ts = dev_get_drvdata(&spi->dev);
+
+	ts->irq_disabled = 0;
+	enable_irq(ts->spi->irq);
+	spi->dev.power.power_state = PMSG_ON;
+	return 0;
+}
+
+static int __devinit ads7846_probe(struct spi_device *spi)
+{
+	struct ads7846			*ts;
+	struct ads7846_platform_data	*pdata = spi->dev.platform_data;
+	struct spi_transfer		*x;
+	int				i;
+
+	if (!spi->irq) {
+		dev_dbg(&spi->dev, "no IRQ?\n");
+		return -ENODEV;
+	}
+
+	if (!pdata) {
+		dev_dbg(&spi->dev, "no platform data?\n");
+		return -ENODEV;
+	}
+
+	/* don't exceed max specified sample rate */
+	if (spi->max_speed_hz > (125000 * 16)) {
+		dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
+				(spi->max_speed_hz/16)/1000);
+		return -EINVAL;
+	}
+
+	/* We'd set the wordsize to 12 bits ... except that some controllers
+	 * will then treat the 8 bit command words as 12 bits (and drop the
+	 * four MSBs of the 12 bit result).  Result: inputs must be shifted
+	 * to discard the four garbage LSBs.
+	 */
+
+	if (!(ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL)))
+		return -ENOMEM;
+
+	dev_set_drvdata(&spi->dev, ts);
+
+	ts->spi = spi;
+	spi->dev.power.power_state = PMSG_ON;
+
+	init_timer(&ts->timer);
+	ts->timer.data = (unsigned long) ts;
+	ts->timer.function = ads7846_timer;
+
+	ts->model = pdata->model ? : 7846;
+	ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
+	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
+
+	init_input_dev(&ts->input);
+
+	ts->input.dev = &spi->dev;
+	ts->input.name = "ADS784x Touchscreen";
+	snprintf(ts->phys, sizeof ts->phys, "%s/input0", spi->dev.bus_id);
+	ts->input.phys = ts->phys;
+
+	ts->input.evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
+	ts->input.keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
+	input_set_abs_params(&ts->input, ABS_X,
+			pdata->x_min ? : 0,
+			pdata->x_max ? : MAX_12BIT,
+			0, 0);
+	input_set_abs_params(&ts->input, ABS_Y,
+			pdata->y_min ? : 0,
+			pdata->y_max ? : MAX_12BIT,
+			0, 0);
+	input_set_abs_params(&ts->input, ABS_PRESSURE,
+			pdata->pressure_min, pdata->pressure_max, 0, 0);
+
+	input_register_device(&ts->input);
+
+	/* set up the transfers to read touchscreen state; this assumes we
+	 * use formula #2 for pressure, not #3.
+	 */
+	x = ts->xfer;
+
+	/* y- still on; turn on only y+ (and ADC) */
+	x->tx_buf = &read_y;
+	x->len = 1;
+	x++;
+	x->rx_buf = &ts->tc.y;
+	x->len = 2;
+	x++;
+
+	/* turn y+ off, x- on; we'll use formula #2 */
+	if (ts->model == 7846) {
+		x->tx_buf = &read_z1;
+		x->len = 1;
+		x++;
+		x->rx_buf = &ts->tc.z1;
+		x->len = 2;
+		x++;
+
+		x->tx_buf = &read_z2;
+		x->len = 1;
+		x++;
+		x->rx_buf = &ts->tc.z2;
+		x->len = 2;
+		x++;
+	}
+
+	/* turn y- off, x+ on, then leave in lowpower */
+	x->tx_buf = &read_x;
+	x->len = 1;
+	x++;
+	x->rx_buf = &ts->tc.x;
+	x->len = 2;
+	x++;
+
+	CS_CHANGE(x[-1]);
+
+	for (i = 0; i < x - ts->xfer; i++)
+		spi_message_add_tail(&ts->xfer[i], &ts->msg);
+	ts->msg.complete = ads7846_rx;
+	ts->msg.context = ts;
+
+	if (request_irq(spi->irq, ads7846_irq, SA_SAMPLE_RANDOM,
+				spi->dev.bus_id, ts)) {
+		dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
+		input_unregister_device(&ts->input);
+		kfree(ts);
+		return -EBUSY;
+	}
+	set_irq_type(spi->irq, IRQT_FALLING);
+
+	dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
+
+	/* take a first sample, leaving nPENIRQ active; avoid
+	 * the touchscreen, in case it's not connected.
+	 */
+	(void) ads7846_read12_ser(&spi->dev,
+			  READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON);
+
+	/* ads7843/7845 don't have temperature sensors, and
+	 * use the other sensors a bit differently too
+	 */
+	if (ts->model == 7846) {
+		device_create_file(&spi->dev, &dev_attr_temp0);
+		device_create_file(&spi->dev, &dev_attr_temp1);
+	}
+	if (ts->model != 7845)
+		device_create_file(&spi->dev, &dev_attr_vbatt);
+	device_create_file(&spi->dev, &dev_attr_vaux);
+
+	return 0;
+}
+
+static int __devexit ads7846_remove(struct spi_device *spi)
+{
+	struct ads7846		*ts = dev_get_drvdata(&spi->dev);
+
+	ads7846_suspend(spi, PMSG_SUSPEND);
+	free_irq(ts->spi->irq, ts);
+	if (ts->irq_disabled)
+		enable_irq(ts->spi->irq);
+
+	if (ts->model == 7846) {
+		device_remove_file(&spi->dev, &dev_attr_temp0);
+		device_remove_file(&spi->dev, &dev_attr_temp1);
+	}
+	if (ts->model != 7845)
+		device_remove_file(&spi->dev, &dev_attr_vbatt);
+	device_remove_file(&spi->dev, &dev_attr_vaux);
+
+	input_unregister_device(&ts->input);
+	kfree(ts);
+
+	dev_dbg(&spi->dev, "unregistered touchscreen\n");
+	return 0;
+}
+
+static struct spi_driver ads7846_driver = {
+	.driver = {
+		.name	= "ads7846",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ads7846_probe,
+	.remove		= __devexit_p(ads7846_remove),
+	.suspend	= ads7846_suspend,
+	.resume		= ads7846_resume,
+};
+
+static int __init ads7846_init(void)
+{
+	/* grr, board-specific init should stay out of drivers!! */
+
+#ifdef	CONFIG_ARCH_OMAP
+	if (machine_is_omap_osk()) {
+		/* GPIO4 = PENIRQ; GPIO6 = BUSY */
+		omap_request_gpio(4);
+		omap_set_gpio_direction(4, 1);
+		omap_request_gpio(6);
+		omap_set_gpio_direction(6, 1);
+	}
+	// also TI 1510 Innovator, bitbanging through FPGA
+	// also Nokia 770
+	// also Palm Tungsten T2
+#endif
+
+	// PXA:
+	// also Dell Axim X50
+	// also HP iPaq H191x/H192x/H415x/H435x
+	// also Intel Lubbock (additional to UCB1400; as temperature sensor)
+	// also Sharp Zaurus C7xx, C8xx (corgi/sheperd/husky)
+
+	// Atmel at91sam9261-EK uses ads7843
+
+	// also various AMD Au1x00 devel boards
+
+	return spi_register_driver(&ads7846_driver);
+}
+module_init(ads7846_init);
+
+static void __exit ads7846_exit(void)
+{
+	spi_unregister_driver(&ads7846_driver);
+
+#ifdef	CONFIG_ARCH_OMAP
+	if (machine_is_omap_osk()) {
+		omap_free_gpio(4);
+		omap_free_gpio(6);
+	}
+#endif
+
+}
+module_exit(ads7846_exit);
+
+MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
+MODULE_LICENSE("GPL");