android_kernel_xiaomi_sm8350/drivers/input/touchscreen/ads7846.c
Russell King f43aaba191 [ARM] Convert request_irq+set_irq_type to request_irq with SA_TRIGGER
There's no need to have request_irq followed by set_irq_type.
Just use request_irq with the appropriate SA_TRIGGER flags.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-19 12:26:57 +00:00

623 lines
16 KiB
C

/*
* 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
#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 | SA_TRIGGER_FALLING,
spi->dev.bus_id, ts)) {
dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
input_unregister_device(&ts->input);
kfree(ts);
return -EBUSY;
}
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");