Wait for active frame transfer to complete after disabling LCDC.
At the same this wait is not be required when there are sync and
underflow errors.
Patch applies for revision 2 of LCDC present am335x.
More information on disable and reset sequence can be found in
section 13.4.6 of AM335x TRM @www.ti.com/am335x.
Signed-off-by: Manjunathappa, Prakash <prakash.pm@xxxxxx>
---
Applies on top of fbdev-next of Florian Tobias Schandinat's tree.
Since v4:
Minor nit, removed extra line.
Since v3:
Rely on frame done interrupt instead of polling for it.
Since v2:
Optimized the lcd_disable_raster function.
Since v1:
Changed the commit message, also added link to hardware specification.
drivers/video/da8xx-fb.c | 52 +++++++++++++++++++++++++++++++++++----------
1 files changed, 40 insertions(+), 12 deletions(-)
diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c
index 7ae9d53..32f0d06 100644
--- a/drivers/video/da8xx-fb.c
+++ b/drivers/video/da8xx-fb.c
@@ -27,6 +27,7 @@
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/interrupt.h>
+#include <linux/wait.h>
#include <linux/clk.h>
#include <linux/cpufreq.h>
#include <linux/console.h>
@@ -48,6 +49,7 @@
#define LCD_PL_LOAD_DONE BIT(6)
#define LCD_FIFO_UNDERFLOW BIT(5)
#define LCD_SYNC_LOST BIT(2)
+#define LCD_FRAME_DONE BIT(0)
/* LCD DMA Control Register */
#define LCD_DMA_BURST_SIZE(x) ((x) << 4)
@@ -135,6 +137,8 @@ static resource_size_t da8xx_fb_reg_base;
static struct resource *lcdc_regs;
static unsigned int lcd_revision;
static irq_handler_t lcdc_irq_handler;
+static wait_queue_head_t frame_done_wq;
+static int frame_done_flag;
static inline unsigned int lcdc_read(unsigned int addr)
{
@@ -288,13 +292,26 @@ static inline void lcd_enable_raster(void)
}
/* Disable the Raster Engine of the LCD Controller */
-static inline void lcd_disable_raster(void)
+static inline void lcd_disable_raster(bool wait_for_frame_done)
{
u32 reg;
+ int ret;
reg = lcdc_read(LCD_RASTER_CTRL_REG);
if (reg & LCD_RASTER_ENABLE)
lcdc_write(reg & ~LCD_RASTER_ENABLE, LCD_RASTER_CTRL_REG);
+ else
+ /* return if already disabled */
+ return;
+
+ if ((wait_for_frame_done == true) && (lcd_revision == LCD_VERSION_2)) {
+ frame_done_flag = 0;
+ ret = wait_event_interruptible_timeout(frame_done_wq,
+ frame_done_flag != 0,
+ msecs_to_jiffies(50));
+ if (ret == 0)
+ pr_err("LCD Controller timed out\n");
+ }
}
static void lcd_blit(int load_mode, struct da8xx_fb_par *par)
@@ -321,7 +338,8 @@ static void lcd_blit(int load_mode, struct da8xx_fb_par *par)
} else {
reg_int = lcdc_read(LCD_INT_ENABLE_SET_REG) |
LCD_V2_END_OF_FRAME0_INT_ENA |
- LCD_V2_END_OF_FRAME1_INT_ENA;
+ LCD_V2_END_OF_FRAME1_INT_ENA |
+ LCD_FRAME_DONE;
lcdc_write(reg_int, LCD_INT_ENABLE_SET_REG);
}
reg_dma |= LCD_DUAL_FRAME_BUFFER_ENABLE;
@@ -638,7 +656,7 @@ static int fb_setcolreg(unsigned regno, unsigned red, unsigned green,
static void lcd_reset(struct da8xx_fb_par *par)
{
/* Disable the Raster if previously Enabled */
- lcd_disable_raster();
+ lcd_disable_raster(false);
/* DMA has to be disabled */
lcdc_write(0, LCD_DMA_CTRL_REG);
@@ -734,7 +752,7 @@ static irqreturn_t lcdc_irq_handler_rev02(int irq, void *arg)
u32 stat = lcdc_read(LCD_MASKED_STAT_REG);
if ((stat & LCD_SYNC_LOST) && (stat & LCD_FIFO_UNDERFLOW)) {
- lcd_disable_raster();
+ lcd_disable_raster(false);
lcdc_write(stat, LCD_MASKED_STAT_REG);
lcd_enable_raster();
} else if (stat & LCD_PL_LOAD_DONE) {
@@ -744,7 +762,7 @@ static irqreturn_t lcdc_irq_handler_rev02(int irq, void *arg)
* interrupt via the following write to the status register. If
* this is done after then one gets multiple PL done interrupts.
*/
- lcd_disable_raster();
+ lcd_disable_raster(false);
lcdc_write(stat, LCD_MASKED_STAT_REG);
@@ -775,6 +793,14 @@ static irqreturn_t lcdc_irq_handler_rev02(int irq, void *arg)
par->vsync_flag = 1;
wake_up_interruptible(&par->vsync_wait);
}
+
+ /* Set only when controller is disabled and at the end of
+ * active frame
+ */
+ if (stat & BIT(0)) {
+ frame_done_flag = 1;
+ wake_up_interruptible(&frame_done_wq);
+ }
}
lcdc_write(0, LCD_END_OF_INT_IND_REG);
@@ -789,7 +815,7 @@ static irqreturn_t lcdc_irq_handler_rev01(int irq, void *arg)
u32 reg_ras;
if ((stat & LCD_SYNC_LOST) && (stat & LCD_FIFO_UNDERFLOW)) {
- lcd_disable_raster();
+ lcd_disable_raster(false);
lcdc_write(stat, LCD_STAT_REG);
lcd_enable_raster();
} else if (stat & LCD_PL_LOAD_DONE) {
@@ -799,7 +825,7 @@ static irqreturn_t lcdc_irq_handler_rev01(int irq, void *arg)
* interrupt via the following write to the status register. If
* this is done after then one gets multiple PL done interrupts.
*/
- lcd_disable_raster();
+ lcd_disable_raster(false);
lcdc_write(stat, LCD_STAT_REG);
@@ -898,7 +924,7 @@ static int lcd_da8xx_cpufreq_transition(struct notifier_block *nb,
if (val == CPUFREQ_POSTCHANGE) {
if (par->lcd_fck_rate != clk_get_rate(par->lcdc_clk)) {
par->lcd_fck_rate = clk_get_rate(par->lcdc_clk);
- lcd_disable_raster();
+ lcd_disable_raster(true);
lcd_calc_clk_divider(par);
lcd_enable_raster();
}
@@ -935,7 +961,7 @@ static int __devexit fb_remove(struct platform_device *dev)
if (par->panel_power_ctrl)
par->panel_power_ctrl(0);
- lcd_disable_raster();
+ lcd_disable_raster(true);
lcdc_write(0, LCD_RASTER_CTRL_REG);
/* disable DMA */
@@ -1051,7 +1077,7 @@ static int cfb_blank(int blank, struct fb_info *info)
if (par->panel_power_ctrl)
par->panel_power_ctrl(0);
- lcd_disable_raster();
+ lcd_disable_raster(true);
break;
default:
ret = -EINVAL;
@@ -1356,8 +1382,10 @@ static int __devinit fb_probe(struct platform_device *device)
if (lcd_revision == LCD_VERSION_1)
lcdc_irq_handler = lcdc_irq_handler_rev01;
- else
+ else {
+ init_waitqueue_head(&frame_done_wq);
lcdc_irq_handler = lcdc_irq_handler_rev02;
+ }
ret = request_irq(par->irq, lcdc_irq_handler, 0,
DRIVER_NAME, par);
@@ -1411,7 +1439,7 @@ static int fb_suspend(struct platform_device *dev, pm_message_t state)
par->panel_power_ctrl(0);
fb_set_suspend(info, 1);
- lcd_disable_raster();
+ lcd_disable_raster(true);
clk_disable(par->lcdc_clk);
console_unlock();
--
1.7.1
--
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