[media] atmel-isi: add code to setup correct resolution for preview path

Not like codec path, preview path can do downsampling, so we should setup
a extra preview width, height for it.

This patch add preview resolution setup without down sampling. So currently
preview path will output same size as sensor output size.
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/soc_camera/atmel-isi.c

@@ -131,7 +131,7 @@ static u32 setup_cfg2_yuv_swap(struct atmel_isi *isi,
 static void configure_geometry(struct atmel_isi *isi, u32 width,
 		u32 height, const struct soc_camera_format_xlate *xlate)
 {
-	u32 cfg2;
+	u32 cfg2, psize;
 
 	/* According to sensor's output format to set cfg2 */
 	switch (xlate->code) {
@@ -159,6 +159,16 @@ static void configure_geometry(struct atmel_isi *isi, u32 width,
 	cfg2 |= ((height - 1) << ISI_CFG2_IM_VSIZE_OFFSET)
 			& ISI_CFG2_IM_VSIZE_MASK;
 	isi_writel(isi, ISI_CFG2, cfg2);
+
+	/* No down sampling, preview size equal to sensor output size */
+	psize = ((width - 1) << ISI_PSIZE_PREV_HSIZE_OFFSET) &
+		ISI_PSIZE_PREV_HSIZE_MASK;
+	psize |= ((height - 1) << ISI_PSIZE_PREV_VSIZE_OFFSET) &
+		ISI_PSIZE_PREV_VSIZE_MASK;
+	isi_writel(isi, ISI_PSIZE, psize);
+	isi_writel(isi, ISI_PDECF, ISI_PDECF_NO_SAMPLING);
+
+	return;
 }
 
 static bool is_supported(struct soc_camera_device *icd,

drivers/media/platform/soc_camera/atmel-isi.h

@@ -79,6 +79,16 @@
 #define ISI_CFG2_IM_VSIZE_MASK		(0x7FF << ISI_CFG2_IM_VSIZE_OFFSET)
 #define ISI_CFG2_IM_HSIZE_MASK		(0x7FF << ISI_CFG2_IM_HSIZE_OFFSET)
 
+/* Bitfields in PSIZE */
+#define ISI_PSIZE_PREV_VSIZE_OFFSET	0
+#define ISI_PSIZE_PREV_HSIZE_OFFSET	16
+#define ISI_PSIZE_PREV_VSIZE_MASK	(0x3FF << ISI_PSIZE_PREV_VSIZE_OFFSET)
+#define ISI_PSIZE_PREV_HSIZE_MASK	(0x3FF << ISI_PSIZE_PREV_HSIZE_OFFSET)
+
+/* Bitfields in PDECF */
+#define ISI_PDECF_DEC_FACTOR_MASK	(0xFF << 0)
+#define	ISI_PDECF_NO_SAMPLING		(16)
+
 /* Bitfields in CTRL */
 /* Also using in SR(ISI_V2) */
 #define ISI_CTRL_EN				(1 << 0)