diff options
| -rw-r--r-- | drivers/video/atmel_lcdfb.c | 57 | ||||
| -rw-r--r-- | include/video/atmel_lcdc.h | 1 |
2 files changed, 57 insertions, 1 deletions
diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c index b004036d408..d335bb96b03 100644 --- a/drivers/video/atmel_lcdfb.c +++ b/drivers/video/atmel_lcdfb.c @@ -379,6 +379,35 @@ static int atmel_lcdfb_check_var(struct fb_var_screeninfo *var, return 0; } +/* + * LCD reset sequence + */ +static void atmel_lcdfb_reset(struct atmel_lcdfb_info *sinfo) +{ + might_sleep(); + + /* LCD power off */ + lcdc_writel(sinfo, ATMEL_LCDC_PWRCON, sinfo->guard_time << ATMEL_LCDC_GUARDT_OFFSET); + + /* wait for the LCDC core to become idle */ + while (lcdc_readl(sinfo, ATMEL_LCDC_PWRCON) & ATMEL_LCDC_BUSY) + msleep(10); + + /* DMA disable */ + lcdc_writel(sinfo, ATMEL_LCDC_DMACON, 0); + + /* wait for DMA engine to become idle */ + while (lcdc_readl(sinfo, ATMEL_LCDC_DMACON) & ATMEL_LCDC_DMABUSY) + msleep(10); + + /* LCD power on */ + lcdc_writel(sinfo, ATMEL_LCDC_PWRCON, + (sinfo->guard_time << ATMEL_LCDC_GUARDT_OFFSET) | ATMEL_LCDC_PWR); + + /* DMA enable */ + lcdc_writel(sinfo, ATMEL_LCDC_DMACON, sinfo->default_dmacon); +} + /** * atmel_lcdfb_set_par - Alters the hardware state. * @info: frame buffer structure that represents a single frame buffer @@ -401,6 +430,8 @@ static int atmel_lcdfb_set_par(struct fb_info *info) unsigned long clk_value_khz; unsigned long bits_per_line; + might_sleep(); + dev_dbg(info->device, "%s:\n", __func__); dev_dbg(info->device, " * resolution: %ux%u (%ux%u virtual)\n", info->var.xres, info->var.yres, @@ -511,6 +542,8 @@ static int atmel_lcdfb_set_par(struct fb_info *info) /* Disable all interrupts */ lcdc_writel(sinfo, ATMEL_LCDC_IDR, ~0UL); + /* Enable FIFO & DMA errors */ + lcdc_writel(sinfo, ATMEL_LCDC_IER, ATMEL_LCDC_UFLWI | ATMEL_LCDC_OWRI | ATMEL_LCDC_MERI); /* ...wait for DMA engine to become idle... */ while (lcdc_readl(sinfo, ATMEL_LCDC_DMACON) & ATMEL_LCDC_DMABUSY) @@ -645,10 +678,26 @@ static irqreturn_t atmel_lcdfb_interrupt(int irq, void *dev_id) u32 status; status = lcdc_readl(sinfo, ATMEL_LCDC_ISR); - lcdc_writel(sinfo, ATMEL_LCDC_IDR, status); + if (status & ATMEL_LCDC_UFLWI) { + dev_warn(info->device, "FIFO underflow %#x\n", status); + /* reset DMA and FIFO to avoid screen shifting */ + schedule_work(&sinfo->task); + } + lcdc_writel(sinfo, ATMEL_LCDC_ICR, status); return IRQ_HANDLED; } +/* + * LCD controller task (to reset the LCD) + */ +static void atmel_lcdfb_task(struct work_struct *work) +{ + struct atmel_lcdfb_info *sinfo = + container_of(work, struct atmel_lcdfb_info, task); + + atmel_lcdfb_reset(sinfo); +} + static int __init atmel_lcdfb_init_fbinfo(struct atmel_lcdfb_info *sinfo) { struct fb_info *info = sinfo->info; @@ -824,6 +873,10 @@ static int __init atmel_lcdfb_probe(struct platform_device *pdev) goto unmap_mmio; } + /* Some operations on the LCDC might sleep and + * require a preemptible task context */ + INIT_WORK(&sinfo->task, atmel_lcdfb_task); + ret = atmel_lcdfb_init_fbinfo(sinfo); if (ret < 0) { dev_err(dev, "init fbinfo failed: %d\n", ret); @@ -866,6 +919,7 @@ static int __init atmel_lcdfb_probe(struct platform_device *pdev) free_cmap: fb_dealloc_cmap(&info->cmap); unregister_irqs: + cancel_work_sync(&sinfo->task); free_irq(sinfo->irq_base, info); unmap_mmio: exit_backlight(sinfo); @@ -903,6 +957,7 @@ static int __exit atmel_lcdfb_remove(struct platform_device *pdev) if (!sinfo) return 0; + cancel_work_sync(&sinfo->task); exit_backlight(sinfo); if (sinfo->atmel_lcdfb_power_control) sinfo->atmel_lcdfb_power_control(0); diff --git a/include/video/atmel_lcdc.h b/include/video/atmel_lcdc.h index ed64862c4e1..1ccf462b433 100644 --- a/include/video/atmel_lcdc.h +++ b/include/video/atmel_lcdc.h @@ -37,6 +37,7 @@ struct atmel_lcdfb_info { struct fb_info *info; void __iomem *mmio; unsigned long irq_base; + struct work_struct task; unsigned int guard_time; struct platform_device *pdev; |