Input: ads7846 - add device tree bindings

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Daniel Mack 2013-06-27 23:42:17 -07:00 committed by Dmitry Torokhov
parent 57691a1e27
commit a608026eac
2 changed files with 195 additions and 11 deletions

View file

@ -0,0 +1,91 @@
Device tree bindings for TI's ADS7843, ADS7845, ADS7846, ADS7873, TSC2046
SPI driven touch screen controllers.
The node for this driver must be a child node of a SPI controller, hence
all mandatory properties described in
Documentation/devicetree/bindings/spi/spi-bus.txt
must be specified.
Additional required properties:
compatible Must be one of the following, depending on the
model:
"ti,tsc2046"
"ti,ads7843"
"ti,ads7845"
"ti,ads7846"
"ti,ads7873"
interrupt-parent
interrupts An interrupt node describing the IRQ line the chip's
!PENIRQ pin is connected to.
vcc-supply A regulator node for the supply voltage.
Optional properties:
ti,vref-delay-usecs vref supply delay in usecs, 0 for
external vref (u16).
ti,vref-mv The VREF voltage, in millivolts (u16).
ti,keep-vref-on set to keep vref on for differential
measurements as well
ti,swap-xy swap x and y axis
ti,settle-delay-usec Settling time of the analog signals;
a function of Vcc and the capacitance
on the X/Y drivers. If set to non-zero,
two samples are taken with settle_delay
us apart, and the second one is used.
~150 uSec with 0.01uF caps (u16).
ti,penirq-recheck-delay-usecs If set to non-zero, after samples are
taken this delay is applied and penirq
is rechecked, to help avoid false
events. This value is affected by the
material used to build the touch layer
(u16).
ti,x-plate-ohms Resistance of the X-plate,
in Ohms (u16).
ti,y-plate-ohms Resistance of the Y-plate,
in Ohms (u16).
ti,x-min Minimum value on the X axis (u16).
ti,y-min Minimum value on the Y axis (u16).
ti,x-max Maximum value on the X axis (u16).
ti,y-max Minimum value on the Y axis (u16).
ti,pressure-min Minimum reported pressure value
(threshold) - u16.
ti,pressure-max Maximum reported pressure value (u16).
ti,debounce-max Max number of additional readings per
sample (u16).
ti,debounce-tol Tolerance used for filtering (u16).
ti,debounce-rep Additional consecutive good readings
required after the first two (u16).
ti,pendown-gpio-debounce Platform specific debounce time for the
pendown-gpio (u32).
pendown-gpio GPIO handle describing the pin the !PENIRQ
line is connected to.
linux,wakeup use any event on touchscreen as wakeup event.
Example for a TSC2046 chip connected to an McSPI controller of an OMAP SoC::
spi_controller {
tsc2046@0 {
reg = <0>; /* CS0 */
compatible = "ti,tsc2046";
interrupt-parent = <&gpio1>;
interrupts = <8 0>; /* BOOT6 / GPIO 8 */
spi-max-frequency = <1000000>;
pendown-gpio = <&gpio1 8 0>;
vcc-supply = <&reg_vcc3>;
ti,x-min = /bits/ 16 <0>;
ti,x-max = /bits/ 16 <8000>;
ti,y-min = /bits/ 16 <0>;
ti,y-max = /bits/ 16 <4800>;
ti,x-plate-ohms = /bits/ 16 <40>;
ti,pressure-max = /bits/ 16 <255>;
linux,wakeup;
};
};

View file

@ -27,6 +27,9 @@
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/pm.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/of_device.h>
#include <linux/gpio.h>
#include <linux/spi/spi.h>
#include <linux/spi/ads7846.h>
@ -1201,9 +1204,87 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts,
spi_message_add_tail(x, m);
}
#ifdef CONFIG_OF
static const struct of_device_id ads7846_dt_ids[] = {
{ .compatible = "ti,tsc2046", .data = (void *) 7846 },
{ .compatible = "ti,ads7843", .data = (void *) 7843 },
{ .compatible = "ti,ads7845", .data = (void *) 7845 },
{ .compatible = "ti,ads7846", .data = (void *) 7846 },
{ .compatible = "ti,ads7873", .data = (void *) 7873 },
{ }
};
MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
{
struct ads7846_platform_data *pdata;
struct device_node *node = dev->of_node;
const struct of_device_id *match;
if (!node) {
dev_err(dev, "Device does not have associated DT data\n");
return ERR_PTR(-EINVAL);
}
match = of_match_device(ads7846_dt_ids, dev);
if (!match) {
dev_err(dev, "Unknown device model\n");
return ERR_PTR(-EINVAL);
}
pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return ERR_PTR(-ENOMEM);
pdata->model = (unsigned long)match->data;
of_property_read_u16(node, "ti,vref-delay-usecs",
&pdata->vref_delay_usecs);
of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
of_property_read_u16(node, "ti,settle-delay-usec",
&pdata->settle_delay_usecs);
of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
&pdata->penirq_recheck_delay_usecs);
of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
of_property_read_u16(node, "ti,x-min", &pdata->x_min);
of_property_read_u16(node, "ti,y-min", &pdata->y_min);
of_property_read_u16(node, "ti,x-max", &pdata->x_max);
of_property_read_u16(node, "ti,y-max", &pdata->y_max);
of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
of_property_read_u32(node, "ti,pendown-gpio-debounce",
&pdata->gpio_pendown_debounce);
pdata->wakeup = of_property_read_bool(node, "linux,wakeup");
pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
return pdata;
}
#else
static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
{
dev_err(dev, "no platform data defined\n");
return ERR_PTR(-EINVAL);
}
#endif
static int ads7846_probe(struct spi_device *spi)
{
const struct ads7846_platform_data *pdata = dev_get_platdata(&spi->dev);
const struct ads7846_platform_data *pdata;
struct ads7846 *ts;
struct ads7846_packet *packet;
struct input_dev *input_dev;
@ -1212,22 +1293,18 @@ static int ads7846_probe(struct spi_device *spi)
if (!spi->irq) {
dev_dbg(&spi->dev, "no IRQ?\n");
return -ENODEV;
}
if (!pdata) {
dev_dbg(&spi->dev, "no platform data?\n");
return -ENODEV;
return -EINVAL;
}
/* don't exceed max specified sample rate */
if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
dev_err(&spi->dev, "f(sample) %d KHz?\n",
(spi->max_speed_hz/SAMPLE_BITS)/1000);
return -EINVAL;
}
/* We'd set TX word size 8 bits and RX word size to 13 bits ... except
/*
* We'd set TX word size 8 bits and RX word size 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.
*/
@ -1250,17 +1327,25 @@ static int ads7846_probe(struct spi_device *spi)
ts->packet = packet;
ts->spi = spi;
ts->input = input_dev;
ts->vref_mv = pdata->vref_mv;
ts->swap_xy = pdata->swap_xy;
mutex_init(&ts->lock);
init_waitqueue_head(&ts->wait);
pdata = dev_get_platdata(&spi->dev);
if (!pdata) {
pdata = ads7846_probe_dt(&spi->dev);
if (IS_ERR(pdata))
return PTR_ERR(pdata);
}
ts->model = pdata->model ? : 7846;
ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
ts->pressure_max = pdata->pressure_max ? : ~0;
ts->vref_mv = pdata->vref_mv;
ts->swap_xy = pdata->swap_xy;
if (pdata->filter != NULL) {
if (pdata->filter_init != NULL) {
err = pdata->filter_init(pdata, &ts->filter_data);
@ -1370,6 +1455,13 @@ static int ads7846_probe(struct spi_device *spi)
device_init_wakeup(&spi->dev, pdata->wakeup);
/*
* If device does not carry platform data we must have allocated it
* when parsing DT data.
*/
if (!dev_get_platdata(&spi->dev))
devm_kfree(&spi->dev, (void *)pdata);
return 0;
err_remove_attr_group:
@ -1437,6 +1529,7 @@ static struct spi_driver ads7846_driver = {
.name = "ads7846",
.owner = THIS_MODULE,
.pm = &ads7846_pm,
.of_match_table = of_match_ptr(ads7846_dt_ids),
},
.probe = ads7846_probe,
.remove = ads7846_remove,