[PATCH] staging: fbtft: fb_st7789v: support setting offset

[purofle]

Some screen sizes using st7789v chips are different from 240x320,
and offsets need to be set to display all images properly.

Signed-off-by: purofle <purofle at gmail.com>
---
 drivers/staging/fbtft/fb_st7789v.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/staging/fbtft/fb_st7789v.c b/drivers/staging/fbtft/fb_st7789v.c
index 861a15414..d47ab4262 100644
--- a/drivers/staging/fbtft/fb_st7789v.c
+++ b/drivers/staging/fbtft/fb_st7789v.c
@@ -30,6 +30,12 @@
 
 #define HSD20_IPS 1
 
+#define WIDTH 240
+#define HEIGHT 320
+
+#define LEFT_OFFSET 0
+#define TOP_OFFSET 0
+
 /**
  * enum st7789v_command - ST7789V display controller commands
  *
@@ -349,6 +355,21 @@ static int set_gamma(struct fbtft_par *par, u32 *curves)
 	return 0;
 }
 
+static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
+{
+	unsigned int x = xs + TOP_OFFSET, y = xe + TOP_OFFSET;
+
+	write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS, (x >> 8) & 0xFF, xs & 0xFF,
+		  (y >> 8) & 0xFF, xe & 0xFF);
+
+	x = ys + LEFT_OFFSET, y = ye + LEFT_OFFSET;
+
+	write_reg(par, MIPI_DCS_SET_PAGE_ADDRESS, (x >> 8) & 0xFF, ys & 0xFF,
+		  (y >> 8) & 0xFF, ye & 0xFF);
+
+	write_reg(par, MIPI_DCS_WRITE_MEMORY_START);
+}
+
 /**
  * blank() - blank the display
  *
@@ -379,6 +400,7 @@ static struct fbtft_display display = {
 		.set_var = set_var,
 		.set_gamma = set_gamma,
 		.blank = blank,
+		.set_addr_win = set_addr_win,
 	},
 };
 
-- 
2.44.0