atmel_lcdfb: implement inverted contrast pwm
This patch introduces lcdc->lcdcon_pol_negative which set CONTRAST_CTR
register to inverted polarity.
Signed-off-by: Andreas Bießmann <biessmann@corscience.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c
index bac16345..16da8af 100644
--- a/drivers/video/atmel_lcdfb.c
+++ b/drivers/video/atmel_lcdfb.c
@@ -68,7 +68,7 @@
}
#endif
-static const u32 contrast_ctr = ATMEL_LCDC_PS_DIV8
+static u32 contrast_ctr = ATMEL_LCDC_PS_DIV8
| ATMEL_LCDC_POL_POSITIVE
| ATMEL_LCDC_ENA_PWMENABLE;
@@ -163,6 +163,10 @@
static void init_contrast(struct atmel_lcdfb_info *sinfo)
{
+ /* contrast pwm can be 'inverted' */
+ if (sinfo->lcdcon_pol_negative)
+ contrast_ctr &= ~(ATMEL_LCDC_POL_POSITIVE);
+
/* have some default contrast/backlight settings */
lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, contrast_ctr);
lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_VAL, ATMEL_LCDC_CVAL_DEFAULT);
@@ -816,6 +820,7 @@
sinfo->guard_time = pdata_sinfo->guard_time;
sinfo->smem_len = pdata_sinfo->smem_len;
sinfo->lcdcon_is_backlight = pdata_sinfo->lcdcon_is_backlight;
+ sinfo->lcdcon_pol_negative = pdata_sinfo->lcdcon_pol_negative;
sinfo->lcd_wiring_mode = pdata_sinfo->lcd_wiring_mode;
} else {
dev_err(dev, "cannot get default configuration\n");