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authorHarald Welte <laforge@openmoko.org>2008-11-19 17:11:00 +0000
committerAndy Green <agreen@pads.home.warmcat.com>2008-11-19 17:11:00 +0000
commitd6456697fa63719b245bf1cfe35b77e6ac7fe63c (patch)
tree35a38f50fe27499d0a24495e3b2e535df8a04715
parent1736f7caf067fac336181f7e59ba3b7aae1d7a9f (diff)
glamo_fb: Implement screen blanking
This patch implements fb_blank() for the glamo-fb driver, which switches off the pixel clock (DCLK) for power saving. We currently delay the actual pixel clock switch until we enter FB_BLANK_POWERDOWN, since the backlight fade is slow and we don't want the user to see artefacts on the screen while the backlight is fading out. So since the X server first sends FB_BLANK_{V,H}SYNC_SUSPEND, we start the backlight fade here, and only once we get FB_BLANK_POWERDOWN the pixel clock is disabled. There are no measurements yet, but the power savings should be double, since there is no longer any generation of the high-frequency LCM signals, and there are no video-related SDRAM accesses anymore. Signed-off-by: Harald Welte <laforge@openmoko.org>
-rw-r--r--drivers/mfd/glamo/glamo-core.c32
-rw-r--r--drivers/mfd/glamo/glamo-core.h6
-rw-r--r--drivers/mfd/glamo/glamo-fb.c29
3 files changed, 66 insertions, 1 deletions
diff --git a/drivers/mfd/glamo/glamo-core.c b/drivers/mfd/glamo/glamo-core.c
index 0fea4f4ea0e..77e25a65a9b 100644
--- a/drivers/mfd/glamo/glamo-core.c
+++ b/drivers/mfd/glamo/glamo-core.c
@@ -526,6 +526,38 @@ int glamo_engine_disable(struct glamo_core *glamo, enum glamo_engine engine)
}
EXPORT_SYMBOL_GPL(glamo_engine_disable);
+static const u_int16_t engine_clock_regs[__NUM_GLAMO_ENGINES] = {
+ [GLAMO_ENGINE_LCD] = GLAMO_REG_CLOCK_LCD,
+ [GLAMO_ENGINE_MMC] = GLAMO_REG_CLOCK_MMC,
+ [GLAMO_ENGINE_ISP] = GLAMO_REG_CLOCK_ISP,
+ [GLAMO_ENGINE_JPEG] = GLAMO_REG_CLOCK_JPEG,
+ [GLAMO_ENGINE_3D] = GLAMO_REG_CLOCK_3D,
+ [GLAMO_ENGINE_2D] = GLAMO_REG_CLOCK_2D,
+ [GLAMO_ENGINE_MPEG_ENC] = GLAMO_REG_CLOCK_MPEG,
+ [GLAMO_ENGINE_MPEG_DEC] = GLAMO_REG_CLOCK_MPEG,
+};
+
+void glamo_engine_clkreg_set(struct glamo_core *glamo,
+ enum glamo_engine engine,
+ u_int16_t mask, u_int16_t val)
+{
+ reg_set_bit_mask(glamo, engine_clock_regs[engine], mask, val);
+}
+EXPORT_SYMBOL_GPL(glamo_engine_clkreg_set);
+
+u_int16_t glamo_engine_clkreg_get(struct glamo_core *glamo,
+ enum glamo_engine engine)
+{
+ u_int16_t val;
+
+ spin_lock(&glamo->lock);
+ val = __reg_read(glamo, engine_clock_regs[engine]);
+ spin_unlock(&glamo->lock);
+
+ return val;
+}
+EXPORT_SYMBOL_GPL(glamo_engine_clkreg_get);
+
struct glamo_script reset_regs[] = {
[GLAMO_ENGINE_LCD] = {
GLAMO_REG_CLOCK_LCD, GLAMO_CLOCK_LCD_RESET
diff --git a/drivers/mfd/glamo/glamo-core.h b/drivers/mfd/glamo/glamo-core.h
index ce8d4c7e79e..4c52bc44eaf 100644
--- a/drivers/mfd/glamo/glamo-core.h
+++ b/drivers/mfd/glamo/glamo-core.h
@@ -96,4 +96,10 @@ void glamo_engine_reset(struct glamo_core *glamo, enum glamo_engine engine);
int glamo_engine_reclock(struct glamo_core *glamo,
enum glamo_engine engine, int ps);
+void glamo_engine_clkreg_set(struct glamo_core *glamo,
+ enum glamo_engine engine,
+ u_int16_t mask, u_int16_t val);
+
+u_int16_t glamo_engine_clkreg_get(struct glamo_core *glamo,
+ enum glamo_engine engine);
#endif /* __GLAMO_CORE_H */
diff --git a/drivers/mfd/glamo/glamo-fb.c b/drivers/mfd/glamo/glamo-fb.c
index 0bc6a1be63f..1ae933e9a3e 100644
--- a/drivers/mfd/glamo/glamo-fb.c
+++ b/drivers/mfd/glamo/glamo-fb.c
@@ -422,7 +422,34 @@ static int glamofb_set_par(struct fb_info *info)
static int glamofb_blank(int blank_mode, struct fb_info *info)
{
- /* FIXME */
+ struct glamofb_handle *gfb = info->par;
+ struct glamo_core *gcore = gfb->mach_info->glamo;
+
+ dev_dbg(gfb->dev, "glamofb_blank(%u)\n", blank_mode);
+
+ switch (blank_mode) {
+ case FB_BLANK_VSYNC_SUSPEND:
+ case FB_BLANK_HSYNC_SUSPEND:
+ /* FIXME: add pdata hook/flag to indicate whether
+ * we should already switch off pixel clock here */
+ break;
+ case FB_BLANK_POWERDOWN:
+ /* disable the pixel clock */
+ glamo_engine_clkreg_set(gcore, GLAMO_ENGINE_LCD,
+ GLAMO_CLOCK_LCD_EN_DCLK, 0);
+ break;
+ case FB_BLANK_UNBLANK:
+ case FB_BLANK_NORMAL:
+ /* enable the pixel clock */
+ glamo_engine_clkreg_set(gcore, GLAMO_ENGINE_LCD,
+ GLAMO_CLOCK_LCD_EN_DCLK,
+ GLAMO_CLOCK_LCD_EN_DCLK);
+ break;
+ }
+
+ /* FIXME: once we have proper clock management in glamo-core,
+ * we can determine if other units need MCLK1 or the PLL, and
+ * disable it if not used. */
return 0;
}