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

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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: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/YLXR2brkc4H54xtK@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Dmitry Torokhov 2021-06-01 15:18:11 -07:00
parent 08729298c4
commit 60b7db914d
1 changed files with 52 additions and 64 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

116
drivers/input/touchscreen/resistive-adc-touch.c
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@ -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;
unsigned int x, y, press;
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;
}
}
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_map_channel(struct grts_state *st, struct device *dev,
enum grts_ch_type type, const char *name,
bool optional)
{
int idx;
idx = device_property_match_string(dev, "io-channel-names", name);
if (idx < 0) {
if (!optional)
return idx;
idx = GRTS_MAX_CHANNELS;
} else if (idx >= GRTS_MAX_CHANNELS) {
return -EOVERFLOW;
}
st->ch_map[type] = idx;
return 0;
}
static int grts_get_properties(struct grts_state *st, struct device *dev)
{
int idx, error;
int error;
idx = device_property_match_string(dev, "io-channel-names", "x");
if (idx < 0)
return idx;
error = grts_map_channel(st, dev, GRTS_CH_X, "x", false);
if (error)
return error;
if (idx >= ARRAY_SIZE(st->ch))
return -EOVERFLOW;
st->ch[idx] = GRTS_CH_X;
idx = device_property_match_string(dev, "io-channel-names", "y");
if (idx < 0)
return idx;
if (idx >= ARRAY_SIZE(st->ch))
return -EOVERFLOW;
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)
error = grts_map_channel(st, dev, GRTS_CH_Z1, "z1", true);
if (error)
return error;
if (st->ch_map[GRTS_CH_Z1] >= GRTS_MAX_CHANNELS)
return 0;
if (idx >= ARRAY_SIZE(st->ch))
return -EOVERFLOW;
st->ch[idx] = GRTS_CH_Z1;
/* 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;
}