This patch adds device tree bindings to the ads7846 driver, and
documents the required and optional binding properties.
Successfully tested on an OMAP3 board.
Signed-off-by: Daniel Mack <zonque@xxxxxxxxx>
---
.../devicetree/bindings/input/ads7846.txt | 86 ++++++++++
drivers/input/touchscreen/ads7846.c | 189 ++++++++++++++++-----
2 files changed, 231 insertions(+), 44 deletions(-)
create mode 100644 Documentation/devicetree/bindings/input/ads7846.txt
diff --git a/Documentation/devicetree/bindings/input/ads7846.txt b/Documentation/devicetree/bindings/input/ads7846.txt
new file mode 100644
index 0000000..ac564a1
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/ads7846.txt
@@ -0,0 +1,86 @@
+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
+ ti,vref-mv The VREF voltage, in millivolts.
+ 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.
+ 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.
+ ti,x-plate-ohms Resistance of the X-plate, in Ohms.
+ ti,y-plate-ohms Resistance of the Y-plate, in Ohms.
+ ti,x-min Minimum value on the X axis.
+ ti,y-min Minimum value on the Y axis.
+ ti,x-max Maximum value on the X axis.
+ ti,y-max Minimum value on the Y axis.
+ ti,pressure-min Minimum reported pressure value (threshold).
+ ti,pressure-max Maximum reported pressure value.
+ ti,debounce-max Max number of additional readings per sample.
+ ti,debounce-tol Tolerance used for filtering.
+ ti,debounce-rep Additional consecutive good readings
+ required after the first two.
+ ti,pendown-gpio-debounce Platform specific debounce time for the
+ pendown-gpio.
+ 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 = <®_vcc3>;
+
+ ti,x-min = <0>;
+ ti,x-max = <8000>;
+ ti,y-min = <0>;
+ ti,y-max = <4800>;
+ ti,x-plate-ohms = <40>;
+ ti,pressure-max = <255>;
+
+ linux,wakeup;
+ };
+ };
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 1c9c83a..31d1879 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -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>
@@ -1202,6 +1205,99 @@ 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 int ads7846_probe_dt(struct device *dev, struct ads7846 *ts)
+{
+ const struct of_device_id *match;
+ u32 val;
+
+ match = of_match_device(ads7846_dt_ids, dev);
+ if (!match)
+ return -ENODEV;
+
+ ts->model = (unsigned int) match->data;
+
+ if (of_property_read_u32(dev->of_node, "ti,vref-delay-usecs", &val) == 0)
+ ts->vref_delay_usecs = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,vref-mv", &val) == 0)
+ ts->vref_mv = val;
+
+ if (of_get_property(dev->of_node, "ti,keep-vref-on", NULL))
+ ts->keep_vref_on = true;
+
+ if (of_get_property(dev->of_node, "ti,swap-xy", NULL))
+ ts->swap_xy = true;
+
+ if (of_property_read_u32(dev->of_node, "ti,settle-delay-usec",
+ &val) == 0)
+ ts->settle_delay_usecs = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,penirq-recheck-delay-usecs",
+ &val) == 0)
+ ts->penirq_recheck_delay_usecs = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,x-plate-ohms", &val) == 0)
+ ts->x_plate_ohms = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,y-plate-ohms", &val) == 0)
+ ts->y_plate_ohms = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,x-min", &val) == 0)
+ ts->x_min = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,y-min", &val) == 0)
+ ts->y_min = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,x-max", &val) == 0)
+ ts->x_max = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,y-max", &val) == 0)
+ ts->y_max = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,pressure-min", &val) == 0)
+ ts->pressure_min = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,pressure-max", &val) == 0)
+ ts->pressure_max = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,debounce-max", &val) == 0)
+ ts->debounce_max = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,debounce-tol", &val) == 0)
+ ts->debounce_tol = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,debounce-rep", &val) == 0)
+ ts->debounce_rep = val;
+
+ if (of_property_read_u32(dev->of_node, "ti,pendown-gpio-debounce",
+ &val) == 0)
+ ts->gpio_pendown_debounce = val;
+
+ ts->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
+
+ if (of_get_property(dev->of_node, "linux,wakeup", NULL))
+ ts->wakeup = true;
+
+ return 0;
+}
+#else
+static inline struct ads7846_platform_data ads7846_probe_dt(struct device *dev)
+{
+ return -ENODEV;
+}
+#endif
+
static int ads7846_probe(struct spi_device *spi)
{
struct ads7846 *ts;
@@ -1216,11 +1312,6 @@ static int ads7846_probe(struct spi_device *spi)
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 * SAMPLE_BITS)) {
dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
@@ -1247,39 +1338,52 @@ static int ads7846_probe(struct spi_device *spi)
}
spi_set_drvdata(spi, ts);
-
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);
- ts->model = pdata->model;
- ts->keep_vref_on = pdata->keep_vref_on;
- ts->swap_xy = pdata->swap_xy;
- ts->vref_delay_usecs = pdata->vref_delay_usecs;
- ts->x_plate_ohms = pdata->x_plate_ohms;
- ts->y_plate_ohms = pdata->y_plate_ohms;
- ts->x_min = pdata->x_min;
- ts->x_max = pdata->x_max;
- ts->y_min = pdata->y_min;
- ts->y_max = pdata->y_max;
- ts->pressure_min = pdata->pressure_min;
- ts->pressure_max = pdata->pressure_max;
- ts->debounce_max = pdata->debounce_max;
- ts->debounce_tol = pdata->debounce_tol;
- ts->debounce_rep = pdata->debounce_rep;
- ts->gpio_pendown = pdata->gpio_pendown;
- ts->gpio_pendown_debounce = pdata->gpio_pendown_debounce;
- ts->penirq_recheck_delay_usecs = pdata->penirq_recheck_delay_usecs;
- ts->filter = pdata->filter;
- ts->filter_cleanup = pdata->filter_cleanup;
- ts->wait_for_sync = pdata->wait_for_sync;
- ts->wakeup = pdata->wakeup;
- ts->irq_flags = pdata->irq_flags;
+ if (pdata) {
+ ts->vref_mv = pdata->vref_mv;
+ ts->swap_xy = pdata->swap_xy;
+ ts->model = pdata->model;
+ ts->keep_vref_on = pdata->keep_vref_on;
+ ts->swap_xy = pdata->swap_xy;
+ ts->vref_delay_usecs = pdata->vref_delay_usecs;
+ ts->x_plate_ohms = pdata->x_plate_ohms;
+ ts->y_plate_ohms = pdata->y_plate_ohms;
+ ts->x_min = pdata->x_min;
+ ts->x_max = pdata->x_max;
+ ts->y_min = pdata->y_min;
+ ts->y_max = pdata->y_max;
+ ts->pressure_min = pdata->pressure_min;
+ ts->pressure_max = pdata->pressure_max;
+ ts->debounce_max = pdata->debounce_max;
+ ts->debounce_tol = pdata->debounce_tol;
+ ts->debounce_rep = pdata->debounce_rep;
+ ts->gpio_pendown = pdata->gpio_pendown;
+ ts->gpio_pendown_debounce = pdata->gpio_pendown_debounce;
+ ts->penirq_recheck_delay_usecs = pdata->penirq_recheck_delay_usecs;
+ ts->filter = pdata->filter;
+ ts->filter_cleanup = pdata->filter_cleanup;
+ ts->wait_for_sync = pdata->wait_for_sync;
+ ts->wakeup = pdata->wakeup;
+ ts->irq_flags = pdata->irq_flags;
+
+ if (pdata->filter && pdata->filter_init) {
+ err = pdata->filter_init(pdata, &ts->filter_data);
+ if (err < 0)
+ goto err_free_mem;
+ }
+ } else {
+ err = ads7846_probe_dt(&spi->dev, ts);
+ if (err < 0) {
+ dev_dbg(&spi->dev, "no platform data and no DT match?\n");
+ err = -ENODEV;
+ goto err_free_mem;
+ }
+ }
if (ts->model == 0)
ts->model = 7846;
@@ -1296,19 +1400,15 @@ static int ads7846_probe(struct spi_device *spi)
if (ts->wait_for_sync == NULL)
ts->wait_for_sync = null_wait_for_sync;
- if (pdata->filter != NULL) {
- if (pdata->filter_init != NULL) {
- err = pdata->filter_init(pdata, &ts->filter_data);
- if (err < 0)
- goto err_free_mem;
+ if (ts->filter == NULL) {
+ if (ts->debounce_max) {
+ if (ts->debounce_max < 2)
+ ts->debounce_max = 2;
+ ts->filter = ads7846_debounce_filter;
+ ts->filter_data = ts;
+ } else {
+ ts->filter = ads7846_no_filter;
}
- } else if (ts->debounce_max) {
- if (ts->debounce_max < 2)
- ts->debounce_max = 2;
- ts->filter = ads7846_debounce_filter;
- ts->filter_data = ts;
- } else {
- ts->filter = ads7846_no_filter;
}
err = ads7846_setup_pendown(spi, ts);
@@ -1461,6 +1561,7 @@ 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,
--
1.8.1.4
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