[PATCH v2 1/2] Input: touchscreen: ads7846: keep copy of pdata in private struct

[PATCH v2 1/2] Input: touchscreen: ads7846: keep copy of pdata in private struct

[Daniel Mack]

Allocate a copy of the pdata, and keep a pointer to it in the private
struct ads7846. Also, kill some members that used to be in both structs.

This is needed for the upcoming DT support.

Signed-off-by: Daniel Mack <zonque@gmail.com>
---

Hi Dmitry,

this is the alternative approach, as described eariler in our email
thread. It works equally well.

Thanks for having another look.


Daniel


 drivers/input/touchscreen/ads7846.c | 78 ++++++++++++++++++++-----------------
 1 file changed, 43 insertions(+), 35 deletions(-)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 84ccf14..198677d 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -104,12 +104,8 @@ struct ads7846 {
 #endif
 
 	u16			model;
-	u16			vref_mv;
 	u16			vref_delay_usecs;
-	u16			x_plate_ohms;
-	u16			pressure_max;
 
-	bool			swap_xy;
 	bool			use_internal;
 
 	struct ads7846_packet	*packet;
@@ -143,6 +139,9 @@ struct ads7846 {
 	int			gpio_pendown;
 
 	void			(*wait_for_sync)(void);
+
+	/* platform data from board file or DT */
+	struct ads7846_platform_data *pdata;
 };
 
 /* leave chip selected when we're done, for quicker re-select? */
@@ -456,7 +455,7 @@ static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
 	unsigned retval = v;
 
 	/* external resistors may scale vAUX into 0..vREF */
-	retval *= ts->vref_mv;
+	retval *= ts->pdata->vref_mv;
 	retval = retval >> 12;
 
 	return retval;
@@ -515,25 +514,25 @@ static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
 	/* hwmon sensors need a reference voltage */
 	switch (ts->model) {
 	case 7846:
-		if (!ts->vref_mv) {
+		if (!ts->pdata->vref_mv) {
 			dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
-			ts->vref_mv = 2500;
+			ts->pdata->vref_mv = 2500;
 			ts->use_internal = true;
 		}
 		break;
 	case 7845:
 	case 7843:
-		if (!ts->vref_mv) {
+		if (!ts->pdata->vref_mv) {
 			dev_warn(&spi->dev,
 				"external vREF for ADS%d not specified\n",
-				ts->model);
+				ts->pdata->model);
 			return 0;
 		}
 		break;
 	}
 
 	/* different chips have different sensor groups */
-	switch (ts->model) {
+	switch (ts->pdata->model) {
 	case 7846:
 		ts->attr_group = &ads7846_attr_group;
 		break;
@@ -544,7 +543,7 @@ static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
 		ts->attr_group = &ads7843_attr_group;
 		break;
 	default:
-		dev_dbg(&spi->dev, "ADS%d not recognized\n", ts->model);
+		dev_dbg(&spi->dev, "ADS%d not recognized\n", ts->pdata->model);
 		return 0;
 	}
 
@@ -700,7 +699,7 @@ static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
 	struct spi_transfer *t =
 		list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 
-	if (ts->model == 7845) {
+	if (ts->pdata->model == 7845) {
 		return be16_to_cpup((__be16 *)&(((char*)t->rx_buf)[1])) >> 3;
 	} else {
 		/*
@@ -776,6 +775,7 @@ static void ads7846_read_state(struct ads7846 *ts)
 static void ads7846_report_state(struct ads7846 *ts)
 {
 	struct ads7846_packet *packet = ts->packet;
+	struct ads7846_platform_data *pdata = ts->pdata;
 	unsigned int Rt;
 	u16 x, y, z1, z2;
 
@@ -784,7 +784,7 @@ static void ads7846_report_state(struct ads7846 *ts)
 	 * from on-the-wire format as part of debouncing to get stable
 	 * readings.
 	 */
-	if (ts->model == 7845) {
+	if (pdata->model == 7845) {
 		x = *(u16 *)packet->tc.x_buf;
 		y = *(u16 *)packet->tc.y_buf;
 		z1 = 0;
@@ -800,11 +800,11 @@ static void ads7846_report_state(struct ads7846 *ts)
 	if (x == MAX_12BIT)
 		x = 0;
 
-	if (ts->model == 7843) {
-		Rt = ts->pressure_max / 2;
-	} else if (ts->model == 7845) {
+	if (pdata->model == 7843) {
+		Rt = pdata->pressure_max / 2;
+	} else if (pdata->model == 7845) {
 		if (get_pendown_state(ts))
-			Rt = ts->pressure_max / 2;
+			Rt = pdata->pressure_max / 2;
 		else
 			Rt = 0;
 		dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
@@ -813,7 +813,7 @@ static void ads7846_report_state(struct ads7846 *ts)
 		Rt = z2;
 		Rt -= z1;
 		Rt *= x;
-		Rt *= ts->x_plate_ohms;
+		Rt *= pdata->x_plate_ohms;
 		Rt /= z1;
 		Rt = (Rt + 2047) >> 12;
 	} else {
@@ -825,7 +825,7 @@ static void ads7846_report_state(struct ads7846 *ts)
 	 * the maximum. Don't report it to user space, repeat at least
 	 * once more the measurement
 	 */
-	if (packet->tc.ignore || Rt > ts->pressure_max) {
+	if (packet->tc.ignore || Rt > pdata->pressure_max) {
 		dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
 			 packet->tc.ignore, Rt);
 		return;
@@ -853,7 +853,7 @@ static void ads7846_report_state(struct ads7846 *ts)
 	if (Rt) {
 		struct input_dev *input = ts->input;
 
-		if (ts->swap_xy)
+		if (pdata->swap_xy)
 			swap(x, y);
 
 		if (!ts->pendown) {
@@ -864,7 +864,7 @@ static void ads7846_report_state(struct ads7846 *ts)
 
 		input_report_abs(input, ABS_X, x);
 		input_report_abs(input, ABS_Y, y);
-		input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
+		input_report_abs(input, ABS_PRESSURE, pdata->pressure_max - Rt);
 
 		input_sync(input);
 		dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
@@ -963,7 +963,7 @@ static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume);
 static int ads7846_setup_pendown(struct spi_device *spi,
 					   struct ads7846 *ts)
 {
-	struct ads7846_platform_data *pdata = spi->dev.platform_data;
+	struct ads7846_platform_data *pdata = ts->pdata;
 	int err;
 
 	/*
@@ -1003,20 +1003,20 @@ static int ads7846_setup_pendown(struct spi_device *spi,
  * use formula #2 for pressure, not #3.
  */
 static void ads7846_setup_spi_msg(struct ads7846 *ts,
-				const struct ads7846_platform_data *pdata)
+				  struct ads7846_platform_data *pdata)
 {
 	struct spi_message *m = &ts->msg[0];
 	struct spi_transfer *x = ts->xfer;
 	struct ads7846_packet *packet = ts->packet;
 	int vref = pdata->keep_vref_on;
 
-	if (ts->model == 7873) {
+	if (pdata->model == 7873) {
 		/*
 		 * The AD7873 is almost identical to the ADS7846
 		 * keep VREF off during differential/ratiometric
 		 * conversion modes.
 		 */
-		ts->model = 7846;
+		pdata->model = 7846;
 		vref = 0;
 	}
 
@@ -1024,7 +1024,7 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts,
 	spi_message_init(m);
 	m->context = ts;
 
-	if (ts->model == 7845) {
+	if (pdata->model == 7845) {
 		packet->read_y_cmd[0] = READ_Y(vref);
 		packet->read_y_cmd[1] = 0;
 		packet->read_y_cmd[2] = 0;
@@ -1069,7 +1069,7 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts,
 	spi_message_init(m);
 	m->context = ts;
 
-	if (ts->model == 7845) {
+	if (pdata->model == 7845) {
 		x++;
 		packet->read_x_cmd[0] = READ_X(vref);
 		packet->read_x_cmd[1] = 0;
@@ -1108,7 +1108,7 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts,
 	}
 
 	/* turn y+ off, x- on; we'll use formula #2 */
-	if (ts->model == 7846) {
+	if (pdata->model == 7846) {
 		ts->msg_count++;
 		m++;
 		spi_message_init(m);
@@ -1178,7 +1178,7 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts,
 	spi_message_init(m);
 	m->context = ts;
 
-	if (ts->model == 7845) {
+	if (pdata->model == 7845) {
 		x++;
 		packet->pwrdown_cmd[0] = PWRDOWN;
 		packet->pwrdown_cmd[1] = 0;
@@ -1247,19 +1247,27 @@ static int ads7846_probe(struct spi_device *spi)
 
 	spi_set_drvdata(spi, ts);
 
+	ts->pdata = pdata;
 	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 ? : 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;
+	/* pdata fallback defaults */
+
+	if (!pdata->model)
+		pdata->model = 7846;
+
+	if (!pdata->vref_delay_usecs)
+		pdata->vref_delay_usecs = 100;
+
+	if (!pdata->x_plate_ohms)
+		pdata->x_plate_ohms = 400;
+
+	if (!pdata->pressure_max)
+		pdata->pressure_max = ~0;
 
 	if (pdata->filter != NULL) {
 		if (pdata->filter_init != NULL) {
-- 
1.8.1.4

[PATCH v2 2/2] Input: touchscreen: ads7846: add device tree bindings

[Daniel Mack]

Signed-off-by: Daniel Mack <zonque@gmail.com>
---
 .../devicetree/bindings/input/ads7846.txt          |  86 ++++++++++++++++
 drivers/input/touchscreen/ads7846.c                | 109 ++++++++++++++++++++-
 2 files changed, 194 insertions(+), 1 deletion(-)
 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 = <&reg_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 198677d..b78354b 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>
@@ -1201,12 +1204,110 @@ 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 struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
+{
+	struct ads7846_platform_data *pdata = NULL;
+	const struct of_device_id *match;
+	u32 val;
+
+	match = of_match_device(ads7846_dt_ids, dev);
+	if (!match)
+		return NULL;
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return NULL;
+
+	pdata->model = (unsigned int) match->data;
+
+	if (of_property_read_u32(dev->of_node, "ti,vref-delay-usecs", &val) == 0)
+		pdata->vref_delay_usecs = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,vref-mv", &val) == 0)
+		pdata->vref_mv = val;
+
+	if (of_get_property(dev->of_node, "ti,keep-vref-on", NULL))
+		pdata->keep_vref_on = true;
+
+	if (of_get_property(dev->of_node, "ti,swap-xy", NULL))
+		pdata->swap_xy = true;
+
+	if (of_property_read_u32(dev->of_node, "ti,settle-delay-usec",
+				 &val) == 0)
+		pdata->settle_delay_usecs = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,penirq-recheck-delay-usecs",
+				 &val) == 0)
+		pdata->penirq_recheck_delay_usecs = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,x-plate-ohms", &val) == 0)
+		pdata->x_plate_ohms = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,y-plate-ohms", &val) == 0)
+		pdata->y_plate_ohms = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,x-min", &val) == 0)
+		pdata->x_min = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,y-min", &val) == 0)
+		pdata->y_min = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,x-max", &val) == 0)
+		pdata->x_max = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,y-max", &val) == 0)
+		pdata->y_max = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,pressure-min", &val) == 0)
+		pdata->pressure_min = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,pressure-max", &val) == 0)
+		pdata->pressure_max = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,debounce-max", &val) == 0)
+		pdata->debounce_max = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,debounce-tol", &val) == 0)
+		pdata->debounce_tol = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,debounce-rep", &val) == 0)
+		pdata->debounce_rep = val;
+
+	if (of_property_read_u32(dev->of_node, "ti,pendown-gpio-debounce",
+				 &val) == 0)
+		pdata->gpio_pendown_debounce = val;
+
+	pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
+
+	if (of_get_property(dev->of_node, "linux,wakeup", NULL))
+		pdata->wakeup = true;
+
+	return pdata;
+}
+#else
+static inline struct ads7846_platform_data ads7846_probe_dt(struct device *dev)
+{
+	return NULL;
+}
+#endif
+
 static int 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 ads7846_platform_data *pdata = NULL;
 	unsigned long irq_flags;
 	int err;
 
@@ -1215,6 +1316,11 @@ static int ads7846_probe(struct spi_device *spi)
 		return -ENODEV;
 	}
 
+	if (spi->dev.platform_data)
+		pdata = spi->dev.platform_data;
+	else
+		pdata = ads7846_probe_dt(&spi->dev);
+
 	if (!pdata) {
 		dev_dbg(&spi->dev, "no platform data?\n");
 		return -ENODEV;
@@ -1445,6 +1551,7 @@ 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