[media] Input: atmel_mxt_ts - read touchscreen size

The touchscreen may have a margin where not all the matrix is used. Read
the parameters from T9 and T100 and take account of the difference.

Note: this does not read the XORIGIN/YORIGIN fields so it assumes that
the touchscreen starts at (0,0)

Signed-off-by: Nick Dyer <nick@shmanahar.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/atmel_mxt_ts.c

@@ -103,6 +103,8 @@ struct t7_config {
 
 /* MXT_TOUCH_MULTI_T9 field */
 #define MXT_T9_CTRL		0
+#define MXT_T9_XSIZE		3
+#define MXT_T9_YSIZE		4
 #define MXT_T9_ORIENT		9
 #define MXT_T9_RANGE		18
 
@@ -150,7 +152,9 @@ struct t37_debug {
 #define MXT_T100_CTRL		0
 #define MXT_T100_CFG1		1
 #define MXT_T100_TCHAUX		3
+#define MXT_T100_XSIZE		9
 #define MXT_T100_XRANGE		13
+#define MXT_T100_YSIZE		20
 #define MXT_T100_YRANGE		24
 
 #define MXT_T100_CFG_SWITCHXY	BIT(5)
@@ -259,6 +263,8 @@ struct mxt_data {
 	unsigned int max_x;
 	unsigned int max_y;
 	bool xy_switch;
+	u8 xsize;
+	u8 ysize;
 	bool in_bootloader;
 	u16 mem_size;
 	u8 t100_aux_ampl;
@@ -1713,6 +1719,18 @@ static int mxt_read_t9_resolution(struct mxt_data *data)
 	if (!object)
 		return -EINVAL;
 
+	error = __mxt_read_reg(client,
+			       object->start_address + MXT_T9_XSIZE,
+			       sizeof(data->xsize), &data->xsize);
+	if (error)
+		return error;
+
+	error = __mxt_read_reg(client,
+			       object->start_address + MXT_T9_YSIZE,
+			       sizeof(data->ysize), &data->ysize);
+	if (error)
+		return error;
+
 	error = __mxt_read_reg(client,
 			       object->start_address + MXT_T9_RANGE,
 			       sizeof(range), &range);
@@ -1763,6 +1781,18 @@ static int mxt_read_t100_config(struct mxt_data *data)
 
 	data->max_y = get_unaligned_le16(&range_y);
 
+	error = __mxt_read_reg(client,
+			       object->start_address + MXT_T100_XSIZE,
+			       sizeof(data->xsize), &data->xsize);
+	if (error)
+		return error;
+
+	error = __mxt_read_reg(client,
+			       object->start_address + MXT_T100_YSIZE,
+			       sizeof(data->ysize), &data->ysize);
+	if (error)
+		return error;
+
 	/* read orientation config */
 	error =  __mxt_read_reg(client,
 				object->start_address + MXT_T100_CFG1,
@@ -2121,7 +2151,7 @@ static int mxt_convert_debug_pages(struct mxt_data *data, u16 *outbuf)
 		outbuf[i] = mxt_get_debug_value(data, x, y);
 
 		/* Next value */
-		if (++x >= data->info.matrix_xsize) {
+		if (++x >= data->xsize) {
 			x = 0;
 			y++;
 		}
@@ -2276,8 +2306,8 @@ static int mxt_set_input(struct mxt_data *data, unsigned int i)
 	if (i > 0)
 		return -EINVAL;
 
-	f->width = data->info.matrix_xsize;
-	f->height = data->info.matrix_ysize;
+	f->width = data->xsize;
+	f->height = data->ysize;
 	f->pixelformat = V4L2_TCH_FMT_DELTA_TD16;
 	f->field = V4L2_FIELD_NONE;
 	f->colorspace = V4L2_COLORSPACE_RAW;
@@ -2392,9 +2422,9 @@ static void mxt_debug_init(struct mxt_data *data)
 	dbg->t37_address = object->start_address;
 
 	/* Calculate size of data and allocate buffer */
-	dbg->t37_nodes = data->info.matrix_xsize * data->info.matrix_ysize;
-	dbg->t37_pages = DIV_ROUND_UP(dbg->t37_nodes * sizeof(u16),
-				      sizeof(dbg->t37_buf->data));
+	dbg->t37_nodes = data->xsize * data->ysize;
+	dbg->t37_pages = DIV_ROUND_UP(data->xsize * data->info.matrix_ysize *
+				      sizeof(u16), sizeof(dbg->t37_buf->data));
 
 	dbg->t37_buf = devm_kmalloc_array(&data->client->dev, dbg->t37_pages,
 					  sizeof(struct t37_debug), GFP_KERNEL);