Commit 60b7db91 authored by Dmitry Torokhov's avatar Dmitry Torokhov
Browse files

Input: resistive-adc-touch - rework mapping of channels 



Instead of iterating over channels establish and use channel map to
retrieve data. As a side effect this will silence "uninitialized variable"
warnings.

Tested-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/YLXR2brkc4H54xtK@google.com


Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 08729298

drivers/input/touchscreen/resistive-adc-touch.c

+51 −63
Original line number Diff line number Diff line
@@ -25,12 +25,12 @@ 
#define GRTS_MAX_CHANNELS				4



enum grts_ch_type {

	GRTS_CH_NONE = 0,

	GRTS_CH_X,

	GRTS_CH_Y,

	GRTS_CH_PRESSURE,

	GRTS_CH_Z1,

	GRTS_CH_Z2,

	GRTS_CH_MAX = GRTS_CH_Z2 + 1

};



/**
@@ -42,7 +42,7 @@ enum grts_ch_type { 
 * @iio_cb:		iio_callback buffer for the data

 * @input:		the input device structure that we register

 * @prop:		touchscreen properties struct

 * @ch:			channels that are defined for the touchscreen

 * @ch_map:		map of channels that are defined for the touchscreen

 */

struct grts_state {

	u32				x_plate_ohms;
@@ -52,37 +52,25 @@ struct grts_state { 
	struct iio_cb_buffer		*iio_cb;

	struct input_dev		*input;

	struct touchscreen_properties	prop;

	u8				ch[GRTS_MAX_CHANNELS];

	u8				ch_map[GRTS_CH_MAX];

};



static int grts_cb(const void *data, void *private)

{

	const u16 *touch_info = data;

	struct grts_state *st = private;

	unsigned int x, y, press = 0, z1 = 0, z2;

	unsigned int Rt, i;



	for (i = 0; i < ARRAY_SIZE(st->ch) && st->ch[i] != GRTS_CH_NONE; i++) {

		switch (st->ch[i]) {

		case GRTS_CH_X:

			x = touch_info[i];

			break;

		case GRTS_CH_Y:

			y = touch_info[i];

			break;

		case GRTS_CH_PRESSURE:

			press = touch_info[i];

			break;

		case GRTS_CH_Z1:

			z1 = touch_info[i];

			break;

		case GRTS_CH_Z2:

			z2 = touch_info[i];

			break;

		}

	}

	unsigned int x, y, press;



	x = touch_info[st->ch_map[GRTS_CH_X]];

	y = touch_info[st->ch_map[GRTS_CH_Y]];



	if (st->ch_map[GRTS_CH_PRESSURE] < GRTS_MAX_CHANNELS) {

		press = touch_info[st->ch_map[GRTS_CH_PRESSURE]];

	} else if (st->ch_map[GRTS_CH_Z1] < GRTS_MAX_CHANNELS) {

		unsigned int z1 = touch_info[st->ch_map[GRTS_CH_Z1]];

		unsigned int z2 = touch_info[st->ch_map[GRTS_CH_Z2]];

		unsigned int Rt;



	if (z1) {

		Rt = z2;

		Rt -= z1;

		Rt *= st->x_plate_ohms;
@@ -142,60 +130,59 @@ static void grts_disable(void *data) 
	iio_channel_release_all_cb(data);

}



static int grts_get_properties(struct grts_state *st, struct device *dev)

static int grts_map_channel(struct grts_state *st, struct device *dev,

			    enum grts_ch_type type, const char *name,

			    bool optional)

{

	int idx, error;

	int idx;



	idx = device_property_match_string(dev, "io-channel-names", "x");

	if (idx < 0)

	idx = device_property_match_string(dev, "io-channel-names", name);

	if (idx < 0) {

		if (!optional)

			return idx;



	if (idx >= ARRAY_SIZE(st->ch))

		idx = GRTS_MAX_CHANNELS;

	} else if (idx >= GRTS_MAX_CHANNELS) {

		return -EOVERFLOW;

	}



	st->ch[idx] = GRTS_CH_X;

	st->ch_map[type] = idx;

	return 0;

}



	idx = device_property_match_string(dev, "io-channel-names", "y");

	if (idx < 0)

		return idx;

static int grts_get_properties(struct grts_state *st, struct device *dev)

{

	int error;



	if (idx >= ARRAY_SIZE(st->ch))

		return -EOVERFLOW;

	error = grts_map_channel(st, dev, GRTS_CH_X, "x", false);

	if (error)

		return error;



	st->ch[idx] = GRTS_CH_Y;

	error = grts_map_channel(st, dev, GRTS_CH_Y, "y", false);

	if (error)

		return error;



	/* pressure is optional */

	idx = device_property_match_string(dev, "io-channel-names", "pressure");

	if (idx >= 0) {

		if (idx >= ARRAY_SIZE(st->ch))

			return -EOVERFLOW;

	error = grts_map_channel(st, dev, GRTS_CH_PRESSURE, "pressure", true);

	if (error)

		return error;



		st->ch[idx] = GRTS_CH_PRESSURE;

	if (st->ch_map[GRTS_CH_PRESSURE] < GRTS_MAX_CHANNELS) {

		st->pressure = true;



		return 0;

	}



	/* if no pressure is defined, try optional z1 + z2 */

	idx = device_property_match_string(dev, "io-channel-names", "z1");

	if (idx < 0)

		return 0;



	if (idx >= ARRAY_SIZE(st->ch))

		return -EOVERFLOW;

	error = grts_map_channel(st, dev, GRTS_CH_Z1, "z1", true);

	if (error)

		return error;



	st->ch[idx] = GRTS_CH_Z1;

	if (st->ch_map[GRTS_CH_Z1] >= GRTS_MAX_CHANNELS)

		return 0;



	/* if z1 is provided z2 is not optional */

	idx = device_property_match_string(dev, "io-channel-names", "z2");

	if (idx < 0)

		return idx;



	if (idx >= ARRAY_SIZE(st->ch))

		return -EOVERFLOW;



	st->ch[idx] = GRTS_CH_Z2;

	st->pressure = true;

	error = grts_map_channel(st, dev, GRTS_CH_Z2, "z2", true);

	if (error)

		return error;



	error = device_property_read_u32(dev,

					 "touchscreen-x-plate-ohms",
@@ -205,6 +192,7 @@ static int grts_get_properties(struct grts_state *st, struct device *dev) 
		return error;

	}



	st->pressure = true;

	return 0;

}