backlight: jornada720: Minimise code duplication and handle errors better

Rickard Strandqvi's ran a code analysis application which found that
jornada_lcd_get_contrast(() and jornada_lcd_set_contrast() contained
some code duplication (calling the same functions during various
code execution paths) and failed to return errors in a consistent
manner.  This patch aims to simplify the code, coercing it into
behaving at a level expected of a driver in the Linux kernel.

Suggested-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Reviewed-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/video/backlight/jornada720_lcd.c b/drivers/video/backlight/jornada720_lcd.c
index da3876c9b3ae70465b887838958687c7fd2a9675..228bc319de1922251d3c4cffb5adf190c375393b 100644 (file)
--- a/drivers/video/backlight/jornada720_lcd.c
+++ b/drivers/video/backlight/jornada720_lcd.c
@@ -43,37 +43,38 @@ static int jornada_lcd_get_contrast(struct lcd_device *ld)
 
        jornada_ssp_start();
 
-       if (jornada_ssp_byte(GETCONTRAST) != TXDUMMY) {
-               dev_err(&ld->dev, "get contrast failed\n");
-               jornada_ssp_end();
-               return -ETIMEDOUT;
-       } else {
+       if (jornada_ssp_byte(GETCONTRAST) == TXDUMMY) {
                ret = jornada_ssp_byte(TXDUMMY);
-               jornada_ssp_end();
-               return ret;
+               goto success;
        }
+
+       dev_err(&ld->dev, "failed to set contrast\n");
+       ret = -ETIMEDOUT;
+
+success:
+       jornada_ssp_end();
+       return ret;
 }
 
 static int jornada_lcd_set_contrast(struct lcd_device *ld, int value)
 {
-       int ret;
+       int ret = 0;
 
        jornada_ssp_start();
 
        /* start by sending our set contrast cmd to mcu */
-       ret = jornada_ssp_byte(SETCONTRAST);
-
-       /* push the new value */
-       if (jornada_ssp_byte(value) != TXDUMMY) {
-               dev_err(&ld->dev, "set contrast failed\n");
-               jornada_ssp_end();
-               return -ETIMEDOUT;
+       if (jornada_ssp_byte(SETCONTRAST) == TXDUMMY) {
+               /* if successful push the new value */
+               if (jornada_ssp_byte(value) == TXDUMMY)
+                       goto success;
        }
 
-       /* if we get here we can assume everything went well */
-       jornada_ssp_end();
+       dev_err(&ld->dev, "failed to set contrast\n");
+       ret = -ETIMEDOUT;
 
-       return 0;
+success:
+       jornada_ssp_end();
+       return ret;
 }
 
 static int jornada_lcd_set_power(struct lcd_device *ld, int power)