fbdev: ssd1307fb: return proper error code if write command fails

this patch fixes ssd1307fb_ssd1306_init() function to return
proper error codes in case of failures.

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 53 insertions, 14 deletions

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index 3d6611f1958f..f7ed6d9016f7 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -303,7 +303,10 @@ static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par)
 
         /* Set initial contrast */
         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
-        ret = ret & ssd1307fb_write_cmd(par->client, 0x7f);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client, 0x7f);
         if (ret < 0)
                 return ret;
 
@@ -319,63 +322,99 @@ static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par)
 
         /* Set multiplex ratio value */
         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO);
-        ret = ret & ssd1307fb_write_cmd(par->client, par->height - 1);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client, par->height - 1);
         if (ret < 0)
                 return ret;
 
         /* set display offset value */
         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET);
+        if (ret < 0)
+                return ret;
+
         ret = ssd1307fb_write_cmd(par->client, 0x20);
         if (ret < 0)
                 return ret;
 
         /* Set clock frequency */
         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ);
-        ret = ret & ssd1307fb_write_cmd(par->client, 0xf0);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client, 0xf0);
         if (ret < 0)
                 return ret;
 
         /* Set precharge period in number of ticks from the internal clock */
         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD);
-        ret = ret & ssd1307fb_write_cmd(par->client, 0x22);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client, 0x22);
         if (ret < 0)
                 return ret;
 
         /* Set COM pins configuration */
         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG);
-        ret = ret & ssd1307fb_write_cmd(par->client, 0x22);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client, 0x22);
         if (ret < 0)
                 return ret;
 
         /* Set VCOMH */
         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH);
-        ret = ret & ssd1307fb_write_cmd(par->client, 0x49);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client, 0x49);
         if (ret < 0)
                 return ret;
 
         /* Turn on the DC-DC Charge Pump */
         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP);
-        ret = ret & ssd1307fb_write_cmd(par->client, 0x14);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client, 0x14);
         if (ret < 0)
                 return ret;
 
         /* Switch to horizontal addressing mode */
         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE);
-        ret = ret & ssd1307fb_write_cmd(par->client,
-                                        SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client,
+                                  SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
         if (ret < 0)
                 return ret;
 
         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
-        ret = ret & ssd1307fb_write_cmd(par->client, 0x0);
-        ret = ret & ssd1307fb_write_cmd(par->client, par->width - 1);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client, 0x0);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client, par->width - 1);
         if (ret < 0)
                 return ret;
 
         ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
-        ret = ret & ssd1307fb_write_cmd(par->client, 0x0);
-        ret = ret & ssd1307fb_write_cmd(par->client,
-                                        par->page_offset + (par->height / 8) - 1);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client, 0x0);
+        if (ret < 0)
+                return ret;
+
+        ret = ssd1307fb_write_cmd(par->client,
+                                  par->page_offset + (par->height / 8) - 1);
         if (ret < 0)
                 return ret;