#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
+#include <linux/gpio.h>
#include <linux/spi/spi.h>
#include <linux/spi/ads7846.h>
#include <asm/irq.h>
-#ifdef CONFIG_ARM
-#include <asm/mach-types.h>
-#ifdef CONFIG_ARCH_OMAP
-#include <asm/arch/gpio.h>
-#endif
-#endif
-
/*
* This code has been heavily tested on a Nokia 770, and lightly
* tested on other ads7846 devices (OSK/Mistral, Lubbock).
- * Support for ads7843 and ads7845 has only been stubbed in.
+ * TSC2046 is just newer ads7846 silicon.
+ * Support for ads7843 tested on Atmel at91sam926x-EK.
+ * Support for ads7845 has only been stubbed in.
*
* IRQ handling needs a workaround because of a shortcoming in handling
* edge triggered IRQs on some platforms like the OMAP1/2. These
int ignore;
};
+/*
+ * We allocate this separately to avoid cache line sharing issues when
+ * driver is used with DMA-based SPI controllers (like atmel_spi) on
+ * systems where main memory is not DMA-coherent (most non-x86 boards).
+ */
+struct ads7846_packet {
+ u8 read_x, read_y, read_z1, read_z2, pwrdown;
+ u16 dummy; /* for the pwrdown read */
+ struct ts_event tc;
+};
+
struct ads7846 {
struct input_dev *input;
char phys[32];
#if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
struct attribute_group *attr_group;
- struct class_device *hwmon;
+ struct device *hwmon;
#endif
u16 model;
+ u16 vref_mv;
u16 vref_delay_usecs;
u16 x_plate_ohms;
u16 pressure_max;
- u8 read_x, read_y, read_z1, read_z2, pwrdown;
- u16 dummy; /* for the pwrdown read */
- struct ts_event tc;
+ struct ads7846_packet *packet;
- struct spi_transfer xfer[10];
+ struct spi_transfer xfer[18];
struct spi_message msg[5];
struct spi_message *last_msg;
int msg_idx;
u16 debounce_tol;
u16 debounce_rep;
+ u16 penirq_recheck_delay_usecs;
+
spinlock_t lock;
struct hrtimer timer;
unsigned pendown:1; /* P: lock */
// FIXME remove "irq_disabled"
unsigned irq_disabled:1; /* P: lock */
unsigned disabled:1;
+ unsigned is_suspended:1;
int (*filter)(void *data, int data_idx, int *val);
void *filter_data;
void (*filter_cleanup)(void *data);
int (*get_pendown_state)(void);
+ int gpio_pendown;
};
/* leave chip selected when we're done, for quicker re-select? */
* The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
* ads7846 lets that pin be unconnected, to use internal vREF.
*/
-static unsigned vREF_mV;
-module_param(vREF_mV, uint, 0);
-MODULE_PARM_DESC(vREF_mV, "external vREF voltage, in milliVolts");
struct ser_req {
u8 ref_on;
static int device_suspended(struct device *dev)
{
struct ads7846 *ts = dev_get_drvdata(dev);
- return dev->power.power_state.event != PM_EVENT_ON || ts->disabled;
+ return ts->is_suspended || ts->disabled;
}
static int ads7846_read12_ser(struct device *dev, unsigned command)
struct ads7846 *ts = dev_get_drvdata(dev);
struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL);
int status;
- int sample;
int use_internal;
if (!req)
/* REVISIT: take a few more samples, and compare ... */
- /* maybe off internal vREF */
- if (use_internal) {
- req->ref_off = REF_OFF;
- req->xfer[4].tx_buf = &req->ref_off;
- req->xfer[4].len = 1;
- spi_message_add_tail(&req->xfer[4], &req->msg);
-
- req->xfer[5].rx_buf = &req->scratch;
- req->xfer[5].len = 2;
- CS_CHANGE(req->xfer[5]);
- spi_message_add_tail(&req->xfer[5], &req->msg);
- }
+ /* converter in low power mode & enable PENIRQ */
+ req->ref_off = PWRDOWN;
+ req->xfer[4].tx_buf = &req->ref_off;
+ req->xfer[4].len = 1;
+ spi_message_add_tail(&req->xfer[4], &req->msg);
+
+ req->xfer[5].rx_buf = &req->scratch;
+ req->xfer[5].len = 2;
+ CS_CHANGE(req->xfer[5]);
+ spi_message_add_tail(&req->xfer[5], &req->msg);
ts->irq_disabled = 1;
disable_irq(spi->irq);
ts->irq_disabled = 0;
enable_irq(spi->irq);
- if (req->msg.status)
- status = req->msg.status;
-
- /* on-wire is a must-ignore bit, a BE12 value, then padding */
- sample = be16_to_cpu(req->sample);
- sample = sample >> 3;
- sample &= 0x0fff;
+ if (status == 0) {
+ /* on-wire is a must-ignore bit, a BE12 value, then padding */
+ status = be16_to_cpu(req->sample);
+ status = status >> 3;
+ status &= 0x0fff;
+ }
kfree(req);
- return status ? status : sample;
+ return status;
}
#if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
-/* Sysfs conventions report temperatures in millidegrees Celcius.
+/* Sysfs conventions report temperatures in millidegrees Celsius.
* ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
* accuracy scheme without calibration data. For now we won't try either;
* userspace sees raw sensor values, and must scale/calibrate appropriately.
unsigned retval = v;
/* external resistors may scale vAUX into 0..vREF */
- retval *= vREF_mV;
+ retval *= ts->vref_mv;
retval = retval >> 12;
return retval;
}
static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
{
- struct class_device *hwmon;
+ struct device *hwmon;
int err;
/* hwmon sensors need a reference voltage */
switch (ts->model) {
case 7846:
- if (!vREF_mV) {
+ if (!ts->vref_mv) {
dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
- vREF_mV = 2500;
+ ts->vref_mv = 2500;
}
break;
case 7845:
case 7843:
- if (!vREF_mV) {
+ if (!ts->vref_mv) {
dev_warn(&spi->dev,
"external vREF for ADS%d not specified\n",
ts->model);
const char *buf, size_t count)
{
struct ads7846 *ts = dev_get_drvdata(dev);
- char *endp;
- int i;
+ unsigned long i;
+
+ if (strict_strtoul(buf, 10, &i))
+ return -EINVAL;
- i = simple_strtoul(buf, &endp, 10);
spin_lock_irq(&ts->lock);
if (i)
/*--------------------------------------------------------------------------*/
+static int get_pendown_state(struct ads7846 *ts)
+{
+ if (ts->get_pendown_state)
+ return ts->get_pendown_state();
+
+ return !gpio_get_value(ts->gpio_pendown);
+}
+
/*
* PENIRQ only kicks the timer. The timer only reissues the SPI transfer,
* to retrieve touchscreen status.
static void ads7846_rx(void *ads)
{
struct ads7846 *ts = ads;
+ struct ads7846_packet *packet = ts->packet;
unsigned Rt;
u16 x, y, z1, z2;
/* ads7846_rx_val() did in-place conversion (including byteswap) from
* on-the-wire format as part of debouncing to get stable readings.
*/
- x = ts->tc.x;
- y = ts->tc.y;
- z1 = ts->tc.z1;
- z2 = ts->tc.z2;
+ x = packet->tc.x;
+ y = packet->tc.y;
+ z1 = packet->tc.z1;
+ z2 = packet->tc.z2;
/* range filtering */
if (x == MAX_12BIT)
x = 0;
- if (likely(x && z1)) {
+ if (ts->model == 7843) {
+ Rt = ts->pressure_max / 2;
+ } else if (likely(x && z1)) {
/* compute touch pressure resistance using equation #2 */
Rt = z2;
Rt -= z1;
Rt *= ts->x_plate_ohms;
Rt /= z1;
Rt = (Rt + 2047) >> 12;
- } else
+ } else {
Rt = 0;
+ }
/* Sample found inconsistent by debouncing or pressure is beyond
* the maximum. Don't report it to user space, repeat at least
* once more the measurement
*/
- if (ts->tc.ignore || Rt > ts->pressure_max) {
+ if (packet->tc.ignore || Rt > ts->pressure_max) {
#ifdef VERBOSE
pr_debug("%s: ignored %d pressure %d\n",
- ts->spi->dev.bus_id, ts->tc.ignore, Rt);
+ dev_name(&ts->spi->dev), packet->tc.ignore, Rt);
#endif
hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
HRTIMER_MODE_REL);
return;
}
+ /* Maybe check the pendown state before reporting. This discards
+ * false readings when the pen is lifted.
+ */
+ if (ts->penirq_recheck_delay_usecs) {
+ udelay(ts->penirq_recheck_delay_usecs);
+ if (!get_pendown_state(ts))
+ Rt = 0;
+ }
+
/* NOTE: We can't rely on the pressure to determine the pen down
* state, even this controller has a pressure sensor. The pressure
* value can fluctuate for quite a while after lifting the pen and
static void ads7846_rx_val(void *ads)
{
struct ads7846 *ts = ads;
+ struct ads7846_packet *packet = ts->packet;
struct spi_message *m;
struct spi_transfer *t;
- u16 *rx_val;
int val;
int action;
int status;
m = &ts->msg[ts->msg_idx];
t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
- rx_val = t->rx_buf;
/* adjust: on-wire is a must-ignore bit, a BE12 value, then padding;
* built from two 8 bit values written msb-first.
*/
- val = be16_to_cpu(*rx_val) >> 3;
+ val = be16_to_cpup((__be16 *)t->rx_buf) >> 3;
action = ts->filter(ts->filter_data, ts->msg_idx, &val);
switch (action) {
case ADS7846_FILTER_REPEAT:
break;
case ADS7846_FILTER_IGNORE:
- ts->tc.ignore = 1;
+ packet->tc.ignore = 1;
/* Last message will contain ads7846_rx() as the
* completion function.
*/
m = ts->last_msg;
break;
case ADS7846_FILTER_OK:
- *rx_val = val;
- ts->tc.ignore = 0;
+ *(u16 *)t->rx_buf = val;
+ packet->tc.ignore = 0;
m = &ts->msg[++ts->msg_idx];
break;
default:
struct ads7846 *ts = container_of(handle, struct ads7846, timer);
int status = 0;
- spin_lock_irq(&ts->lock);
+ spin_lock(&ts->lock);
- if (unlikely(!ts->get_pendown_state() ||
+ if (unlikely(!get_pendown_state(ts) ||
device_suspended(&ts->spi->dev))) {
if (ts->pendown) {
struct input_dev *input = ts->input;
dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
}
- spin_unlock_irq(&ts->lock);
+ spin_unlock(&ts->lock);
return HRTIMER_NORESTART;
}
unsigned long flags;
spin_lock_irqsave(&ts->lock, flags);
- if (likely(ts->get_pendown_state())) {
+ if (likely(get_pendown_state(ts))) {
if (!ts->irq_disabled) {
/* The ARM do_simple_IRQ() dispatcher doesn't act
* like the other dispatchers: it will report IRQs
/* we know the chip's in lowpower mode since we always
* leave it that way after every request
*/
-
}
/* Must be called with ts->lock held */
spin_lock_irq(&ts->lock);
- spi->dev.power.power_state = message;
+ ts->is_suspended = 1;
ads7846_disable(ts);
spin_unlock_irq(&ts->lock);
spin_lock_irq(&ts->lock);
- spi->dev.power.power_state = PMSG_ON;
+ ts->is_suspended = 0;
ads7846_enable(ts);
spin_unlock_irq(&ts->lock);
return 0;
}
+static int __devinit setup_pendown(struct spi_device *spi, struct ads7846 *ts)
+{
+ struct ads7846_platform_data *pdata = spi->dev.platform_data;
+ int err;
+
+ /* REVISIT when the irq can be triggered active-low, or if for some
+ * reason the touchscreen isn't hooked up, we don't need to access
+ * the pendown state.
+ */
+ if (!pdata->get_pendown_state && !gpio_is_valid(pdata->gpio_pendown)) {
+ dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
+ return -EINVAL;
+ }
+
+ if (pdata->get_pendown_state) {
+ ts->get_pendown_state = pdata->get_pendown_state;
+ return 0;
+ }
+
+ err = gpio_request(pdata->gpio_pendown, "ads7846_pendown");
+ if (err) {
+ dev_err(&spi->dev, "failed to request pendown GPIO%d\n",
+ pdata->gpio_pendown);
+ return err;
+ }
+
+ ts->gpio_pendown = pdata->gpio_pendown;
+ return 0;
+}
+
static int __devinit ads7846_probe(struct spi_device *spi)
{
struct ads7846 *ts;
+ struct ads7846_packet *packet;
struct input_dev *input_dev;
struct ads7846_platform_data *pdata = spi->dev.platform_data;
struct spi_message *m;
return -EINVAL;
}
- /* REVISIT when the irq can be triggered active-low, or if for some
- * reason the touchscreen isn't hooked up, we don't need to access
- * the pendown state.
- */
- if (pdata->get_pendown_state == NULL) {
- dev_dbg(&spi->dev, "no get_pendown_state function?\n");
- return -EINVAL;
- }
-
/* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except
* that even if the hardware can do that, the SPI controller driver
* may not. So we stick to very-portable 8 bit words, both RX and TX.
*/
spi->bits_per_word = 8;
- spi->mode = SPI_MODE_1;
+ spi->mode = SPI_MODE_0;
err = spi_setup(spi);
if (err < 0)
return err;
ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
+ packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
input_dev = input_allocate_device();
- if (!ts || !input_dev) {
+ if (!ts || !packet || !input_dev) {
err = -ENOMEM;
goto err_free_mem;
}
dev_set_drvdata(&spi->dev, ts);
- spi->dev.power.power_state = PMSG_ON;
+ ts->packet = packet;
ts->spi = spi;
ts->input = input_dev;
+ ts->vref_mv = pdata->vref_mv;
hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
ts->timer.function = ads7846_timer;
ts->filter_data = ts;
} else
ts->filter = ads7846_no_filter;
- ts->get_pendown_state = pdata->get_pendown_state;
- snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id);
+ err = setup_pendown(spi, ts);
+ if (err)
+ goto err_cleanup_filter;
+
+ if (pdata->penirq_recheck_delay_usecs)
+ ts->penirq_recheck_delay_usecs =
+ pdata->penirq_recheck_delay_usecs;
+
+ snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
input_dev->name = "ADS784x Touchscreen";
input_dev->phys = ts->phys;
- input_dev->cdev.dev = &spi->dev;
+ input_dev->dev.parent = &spi->dev;
- input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
- input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
+ input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+ input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
input_set_abs_params(input_dev, ABS_X,
pdata->x_min ? : 0,
pdata->x_max ? : MAX_12BIT,
spi_message_init(m);
/* y- still on; turn on only y+ (and ADC) */
- ts->read_y = READ_Y(vref);
- x->tx_buf = &ts->read_y;
+ packet->read_y = READ_Y(vref);
+ x->tx_buf = &packet->read_y;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.y;
+ x->rx_buf = &packet->tc.y;
x->len = 2;
spi_message_add_tail(x, m);
+ /* the first sample after switching drivers can be low quality;
+ * optionally discard it, using a second one after the signals
+ * have had enough time to stabilize.
+ */
+ if (pdata->settle_delay_usecs) {
+ x->delay_usecs = pdata->settle_delay_usecs;
+
+ x++;
+ x->tx_buf = &packet->read_y;
+ x->len = 1;
+ spi_message_add_tail(x, m);
+
+ x++;
+ x->rx_buf = &packet->tc.y;
+ x->len = 2;
+ spi_message_add_tail(x, m);
+ }
+
m->complete = ads7846_rx_val;
m->context = ts;
/* turn y- off, x+ on, then leave in lowpower */
x++;
- ts->read_x = READ_X(vref);
- x->tx_buf = &ts->read_x;
+ packet->read_x = READ_X(vref);
+ x->tx_buf = &packet->read_x;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.x;
+ x->rx_buf = &packet->tc.x;
x->len = 2;
spi_message_add_tail(x, m);
+ /* ... maybe discard first sample ... */
+ if (pdata->settle_delay_usecs) {
+ x->delay_usecs = pdata->settle_delay_usecs;
+
+ x++;
+ x->tx_buf = &packet->read_x;
+ x->len = 1;
+ spi_message_add_tail(x, m);
+
+ x++;
+ x->rx_buf = &packet->tc.x;
+ x->len = 2;
+ spi_message_add_tail(x, m);
+ }
+
m->complete = ads7846_rx_val;
m->context = ts;
spi_message_init(m);
x++;
- ts->read_z1 = READ_Z1(vref);
- x->tx_buf = &ts->read_z1;
+ packet->read_z1 = READ_Z1(vref);
+ x->tx_buf = &packet->read_z1;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.z1;
+ x->rx_buf = &packet->tc.z1;
x->len = 2;
spi_message_add_tail(x, m);
+ /* ... maybe discard first sample ... */
+ if (pdata->settle_delay_usecs) {
+ x->delay_usecs = pdata->settle_delay_usecs;
+
+ x++;
+ x->tx_buf = &packet->read_z1;
+ x->len = 1;
+ spi_message_add_tail(x, m);
+
+ x++;
+ x->rx_buf = &packet->tc.z1;
+ x->len = 2;
+ spi_message_add_tail(x, m);
+ }
+
m->complete = ads7846_rx_val;
m->context = ts;
spi_message_init(m);
x++;
- ts->read_z2 = READ_Z2(vref);
- x->tx_buf = &ts->read_z2;
+ packet->read_z2 = READ_Z2(vref);
+ x->tx_buf = &packet->read_z2;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->tc.z2;
+ x->rx_buf = &packet->tc.z2;
x->len = 2;
spi_message_add_tail(x, m);
+ /* ... maybe discard first sample ... */
+ if (pdata->settle_delay_usecs) {
+ x->delay_usecs = pdata->settle_delay_usecs;
+
+ x++;
+ x->tx_buf = &packet->read_z2;
+ x->len = 1;
+ spi_message_add_tail(x, m);
+
+ x++;
+ x->rx_buf = &packet->tc.z2;
+ x->len = 2;
+ spi_message_add_tail(x, m);
+ }
+
m->complete = ads7846_rx_val;
m->context = ts;
}
spi_message_init(m);
x++;
- ts->pwrdown = PWRDOWN;
- x->tx_buf = &ts->pwrdown;
+ packet->pwrdown = PWRDOWN;
+ x->tx_buf = &packet->pwrdown;
x->len = 1;
spi_message_add_tail(x, m);
x++;
- x->rx_buf = &ts->dummy;
+ x->rx_buf = &packet->dummy;
x->len = 2;
CS_CHANGE(*x);
spi_message_add_tail(x, m);
spi->dev.driver->name, ts)) {
dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
err = -EBUSY;
- goto err_cleanup_filter;
+ goto err_free_gpio;
}
err = ads784x_hwmon_register(spi, ts);
ads784x_hwmon_unregister(spi, ts);
err_free_irq:
free_irq(spi->irq, ts);
+ err_free_gpio:
+ if (ts->gpio_pendown != -1)
+ gpio_free(ts->gpio_pendown);
err_cleanup_filter:
if (ts->filter_cleanup)
ts->filter_cleanup(ts->filter_data);
err_free_mem:
input_free_device(input_dev);
+ kfree(packet);
kfree(ts);
return err;
}
/* suspend left the IRQ disabled */
enable_irq(ts->spi->irq);
+ if (ts->gpio_pendown != -1)
+ gpio_free(ts->gpio_pendown);
+
if (ts->filter_cleanup)
ts->filter_cleanup(ts->filter_data);
+ kfree(ts->packet);
kfree(ts);
dev_dbg(&spi->dev, "unregistered touchscreen\n");
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);