2 files changed, 195 insertions, 11 deletions

diff --git a/Documentation/devicetree/bindings/input/ads7846.txt b/Documentation/devicetree/bindings/input/ads7846.txt
new file mode 100644
index 000000000000..5f7619c22743
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/ads7846.txt
@@ -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;
+                };
+        };
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 5ff041995198..ea195360747e 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>
@@ -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,