On 08/24/2012 01:13 PM, Manjunathappa, Prakash wrote:
> 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 <[email protected]>
Applied.
Thanks,
Florian Tobias Schandinat
> ---
> 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();
>
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