Input: ads7846 - add device tree bindings

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 104 insertions, 11 deletions

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 5ff0419..ea19536 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,