Skip to content

Commit

Permalink
jz4740-slcd-fb: Use DMA to transfer frame from main RAM to the panel'…
Browse files Browse the repository at this point in the history 
…s GRAM.
  • Loading branch information
@mthuurne
mthuurne committed May 17, 2010
1 parent 7149db9 commit c569e4a
Show file tree
Hide file tree
Showing 2 changed files with 59 additions and 73 deletions.
2 changes: 1 addition & 1 deletion drivers/video/Kconfig
View file
Expand Up @@ -2225,7 +2225,7 @@ config FB_JZ4740

config FB_JZ4740_SLCD
tristate "JZ4740 Smart LCD framebuffer support"
depends on FB && SOC_JZ4740
depends on FB && SOC_JZ4740 && HAS_DMA
select FB_SYS_FILLRECT
select FB_SYS_COPYAREA
select FB_SYS_IMAGEBLIT
Expand Down
130 changes: 58 additions & 72 deletions drivers/video/jz4740_slcd_fb.c
View file
Expand Up @@ -216,17 +216,57 @@ static int jzfb_check_var(struct fb_var_screeninfo *var, struct fb_info *fb)
return 0;
}

static void sync_framebuffer(struct jzfb *jzfb)
static struct jz4740_dma_config jzfb_slcd_dma_config = {
.src_width = JZ4740_DMA_WIDTH_32BIT,
.dst_width = JZ4740_DMA_WIDTH_16BIT,
.transfer_size = JZ4740_DMA_TRANSFER_SIZE_16BYTE,
.request_type = JZ4740_DMA_TYPE_SLCD,
.flags = JZ4740_DMA_SRC_AUTOINC,
.mode = JZ4740_DMA_MODE_BLOCK,
};

static void jzfb_refresh_work_complete(
struct jz4740_dma_chan *dma, int res, void *dev)
{
struct jzfb *jzfb = dev_get_drvdata(dev);
// TODO: Stick to refresh rate in mode description.
int interval = HZ / 60;

while (readb(jzfb->base + JZ_REG_SLCD_STATE) & SLCD_STATE_BUSY);
writeb(readb(jzfb->base + JZ_REG_SLCD_CTRL) & ~SLCD_CTRL_DMA_EN,
jzfb->base + JZ_REG_SLCD_CTRL);

schedule_delayed_work(&jzfb->refresh_work, interval);
}

static void jzfb_refresh_work(struct work_struct *work)
{
struct jzfb *jzfb = container_of(work, struct jzfb, refresh_work.work);
int num_pixels = 320 * 240;
int i;
uint16_t *p = jzfb->vidmem;

// TODO: How to signal the start of a transfer?
for (i = 0; i < num_pixels; i++) {
uint16_t rgb = *p++;
if (1) {
/* Transfer frame by DMA. */
jz4740_dma_set_src_addr(jzfb->dma, jzfb->vidmem_phys);
jz4740_dma_set_dst_addr(jzfb->dma,
CPHYSADDR(jzfb->base + JZ_REG_SLCD_FIFO));
jz4740_dma_set_transfer_count(jzfb->dma, num_pixels * 2);

while (readb(jzfb->base + JZ_REG_SLCD_STATE) & SLCD_STATE_BUSY);
writel(SLCD_DATA_RS_DATA | rgb, jzfb->base + JZ_REG_SLCD_DATA);
writeb(readb(jzfb->base + JZ_REG_SLCD_CTRL) | SLCD_CTRL_DMA_EN,
jzfb->base + JZ_REG_SLCD_CTRL);
jz4740_dma_enable(jzfb->dma);
} else {
/* Transfer frame by CPU. */
int i;
uint16_t *p = jzfb->vidmem;

for (i = 0; i < num_pixels; i++) {
uint16_t rgb = *p++;
while (readb(jzfb->base + JZ_REG_SLCD_STATE)
& SLCD_STATE_BUSY);
writel(SLCD_DATA_RS_DATA | rgb,
jzfb->base + JZ_REG_SLCD_DATA);
}
}
}

Expand Down Expand Up @@ -355,18 +395,11 @@ static int jzfb_set_par(struct fb_info *info)
clk_disable(jzfb->ldclk);
mutex_unlock(&jzfb->lock);

// TODO(MtH): Compute values instead of hardcoding them.
//clk_set_rate(jzfb->lpclk, rate);
//clk_set_rate(jzfb->ldclk, rate * 3);
// TODO(MtH): Use maximum transfer speed that panel can handle.
// ILI9325 can do 10 MHz.
clk_set_rate(jzfb->lpclk, 16800000);
clk_set_rate(jzfb->ldclk, 42000000);

//sync_framebuffer(jzfb);

// TODO: Configure DMA.
if (jzfb->is_enabled)
; // TODO: Enable DMA.

return 0;
}

Expand Down Expand Up @@ -404,19 +437,13 @@ static void jzfb_enable(struct jzfb *jzfb)

static void jzfb_disable(struct jzfb *jzfb)
{
//uint32_t ctrl;

cancel_delayed_work_sync(&jzfb->refresh_work);

// TODO: SLCD equivalents:
#if 0
ctrl = readl(jzfb->base + JZ_REG_LCD_CTRL);
ctrl |= JZ_LCD_CTRL_DISABLE;
writel(ctrl, jzfb->base + JZ_REG_LCD_CTRL);
do {
ctrl = readl(jzfb->base + JZ_REG_LCD_STATE);
} while (!(ctrl & JZ_LCD_STATE_DISABLED));
#endif
/* Abort any DMA transfer that might be in progress. */
jz4740_dma_disable(jzfb->dma);
while (readb(jzfb->base + JZ_REG_SLCD_STATE) & SLCD_STATE_BUSY);
writeb(readb(jzfb->base + JZ_REG_SLCD_CTRL) & ~SLCD_CTRL_DMA_EN,
jzfb->base + JZ_REG_SLCD_CTRL);

jzfb->panel->disable(jzfb);
jz_gpio_bulk_suspend(jz_slcd_ctrl_pins, jzfb_num_ctrl_pins(jzfb));
Expand Down Expand Up @@ -451,41 +478,6 @@ static int jzfb_blank(int blank_mode, struct fb_info *info)
return 0;
}

static struct jz4740_dma_config jzfb_slcd_dma_config = {
.src_width = JZ4740_DMA_WIDTH_32BIT,
.dst_width = JZ4740_DMA_WIDTH_16BIT,
.transfer_size = JZ4740_DMA_TRANSFER_SIZE_32BYTE,
.request_type = JZ4740_DMA_TYPE_SLCD,
.flags = JZ4740_DMA_SRC_AUTOINC,
.mode = JZ4740_DMA_MODE_BLOCK,
};

#if 0
static int jzfb_slcd_dma_init(void)
{
/* Request DMA channel and setup irq handler */
dma_chan = jz_request_dma(DMA_ID_AUTO, "auto", slcd_dma_irq, 0, NULL);
if (dma_chan < 0) {
printk("Request DMA Failed\n");
return -1;
}
printk("DMA channel %d is requested by SLCD!\n", dma_chan);

/*Init the SLCD DMA and Enable*/
REG_DMAC_DRSR(dma_chan) = DMAC_DRSR_RS_SLCD;
REG_DMAC_DCCSR(dma_chan) = DMAC_DCCSR_EN; /*Descriptor Transfer*/

if (jzfb.bpp <= 8)
REG_DMAC_DDA(dma_chan) = slcd_palette_desc_phys_addr;
else
REG_DMAC_DDA(dma_chan) = slcd_frame_desc_phys_addr;

/* DMA doorbell set -- start DMA now ... */
__dmac_channel_set_doorbell(dma_chan);
return 0;
}
#endif

static int jzfb_alloc_devmem(struct jzfb *jzfb)
{
int max_videosize = 0;
Expand Down Expand Up @@ -554,16 +546,6 @@ static struct fb_ops jzfb_ops = {
.fb_imageblit = sys_imageblit,
};

static void jzfb_refresh_work(struct work_struct *work)
{
// TODO: Stick to refresh rate in mode description.
const int interval = HZ / 60;
struct jzfb *jzfb = container_of(work, struct jzfb, refresh_work.work);

sync_framebuffer(jzfb);
schedule_delayed_work(&jzfb->refresh_work, interval);
}

static int __devinit jzfb_probe(struct platform_device *pdev)
{
int ret;
Expand Down Expand Up @@ -613,6 +595,10 @@ static int __devinit jzfb_probe(struct platform_device *pdev)
ret = -EBUSY;
goto err_framebuffer_release;
}
/* MtH: Configuring the DMA only once is essential:
if configured twice all following transfers will lose data. */
jz4740_dma_configure(jzfb->dma, &jzfb_slcd_dma_config);
jz4740_dma_set_complete_cb(jzfb->dma, &jzfb_refresh_work_complete);

jzfb->ldclk = clk_get(&pdev->dev, "lcd");
if (IS_ERR(jzfb->ldclk)) {
Expand Down

0 comments on commit c569e4a

Please sign in to comment.