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 bac1634502167bbac687fe49eec161e903fead35..16da8af7425c42c607dafafc172531596a791c83 100644 (file)
--- a/drivers/video/atmel_lcdfb.c
+++ b/drivers/video/atmel_lcdfb.c
@@ -68,7 +68,7 @@ static void atmel_lcdfb_update_dma2d(struct atmel_lcdfb_info *sinfo,
 }
 #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 exit_backlight(struct atmel_lcdfb_info *sinfo)
 
 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 @@ static int __init atmel_lcdfb_probe(struct platform_device *pdev)
                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");

diff --git a/include/video/atmel_lcdc.h b/include/video/atmel_lcdc.h
index 0c864db1a4662a5e1c89f902830e5cf4a7f91efc..28447f1594fa3fcf5a3a337cf34b4671528a424f 100644 (file)
--- a/include/video/atmel_lcdc.h
+++ b/include/video/atmel_lcdc.h
@@ -52,6 +52,7 @@ struct atmel_lcdfb_info {
        u8                      bl_power;
 #endif
        bool                    lcdcon_is_backlight;
+       bool                    lcdcon_pol_negative;
        u8                      saved_lcdcon;
 
        u8                      default_bpp;