u-boot/drivers/video/mxsfb.c
Marek Vasut 84f957f80b video: Implement continuous screen refresh for SmartLCD into mxsfb
The LCDIF interface doesn't give us any means to do continuous refresh
when driving a SmartLCD. To work this around, we produce a special
circular DMA descriptor, which only writes the HW_LCDIF_CTRL0 register
and sets the RUN bit.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Stefano Babic <sbabic@denx.de>
2013-08-09 21:48:57 +02:00

224 lines
5.8 KiB
C

/*
* Freescale i.MX23/i.MX28 LCDIF driver
*
* Copyright (C) 2011-2013 Marek Vasut <marex@denx.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <malloc.h>
#include <video_fb.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/clock.h>
#include <asm/arch/sys_proto.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/imx-common/dma.h>
#include "videomodes.h"
#define PS2KHZ(ps) (1000000000UL / (ps))
static GraphicDevice panel;
struct mxs_dma_desc desc;
/**
* mxsfb_system_setup() - Fine-tune LCDIF configuration
*
* This function is used to adjust the LCDIF configuration. This is usually
* needed when driving the controller in System-Mode to operate an 8080 or
* 6800 connected SmartLCD.
*/
__weak void mxsfb_system_setup(void)
{
}
/*
* DENX M28EVK:
* setenv videomode
* video=ctfb:x:800,y:480,depth:18,mode:0,pclk:30066,
* le:0,ri:256,up:0,lo:45,hs:1,vs:1,sync:100663296,vmode:0
*
* Freescale mx23evk/mx28evk with a Seiko 4.3'' WVGA panel:
* setenv videomode
* video=ctfb:x:800,y:480,depth:24,mode:0,pclk:29851,
* le:89,ri:164,up:23,lo:10,hs:10,vs:10,sync:0,vmode:0
*/
static void mxs_lcd_init(GraphicDevice *panel,
struct ctfb_res_modes *mode, int bpp)
{
struct mxs_lcdif_regs *regs = (struct mxs_lcdif_regs *)MXS_LCDIF_BASE;
uint32_t word_len = 0, bus_width = 0;
uint8_t valid_data = 0;
/* Kick in the LCDIF clock */
mxs_set_lcdclk(PS2KHZ(mode->pixclock));
/* Restart the LCDIF block */
mxs_reset_block(&regs->hw_lcdif_ctrl_reg);
switch (bpp) {
case 24:
word_len = LCDIF_CTRL_WORD_LENGTH_24BIT;
bus_width = LCDIF_CTRL_LCD_DATABUS_WIDTH_24BIT;
valid_data = 0x7;
break;
case 18:
word_len = LCDIF_CTRL_WORD_LENGTH_24BIT;
bus_width = LCDIF_CTRL_LCD_DATABUS_WIDTH_18BIT;
valid_data = 0x7;
break;
case 16:
word_len = LCDIF_CTRL_WORD_LENGTH_16BIT;
bus_width = LCDIF_CTRL_LCD_DATABUS_WIDTH_16BIT;
valid_data = 0xf;
break;
case 8:
word_len = LCDIF_CTRL_WORD_LENGTH_8BIT;
bus_width = LCDIF_CTRL_LCD_DATABUS_WIDTH_8BIT;
valid_data = 0xf;
break;
}
writel(bus_width | word_len | LCDIF_CTRL_DOTCLK_MODE |
LCDIF_CTRL_BYPASS_COUNT | LCDIF_CTRL_LCDIF_MASTER,
&regs->hw_lcdif_ctrl);
writel(valid_data << LCDIF_CTRL1_BYTE_PACKING_FORMAT_OFFSET,
&regs->hw_lcdif_ctrl1);
mxsfb_system_setup();
writel((mode->yres << LCDIF_TRANSFER_COUNT_V_COUNT_OFFSET) | mode->xres,
&regs->hw_lcdif_transfer_count);
writel(LCDIF_VDCTRL0_ENABLE_PRESENT | LCDIF_VDCTRL0_ENABLE_POL |
LCDIF_VDCTRL0_VSYNC_PERIOD_UNIT |
LCDIF_VDCTRL0_VSYNC_PULSE_WIDTH_UNIT |
mode->vsync_len, &regs->hw_lcdif_vdctrl0);
writel(mode->upper_margin + mode->lower_margin +
mode->vsync_len + mode->yres,
&regs->hw_lcdif_vdctrl1);
writel((mode->hsync_len << LCDIF_VDCTRL2_HSYNC_PULSE_WIDTH_OFFSET) |
(mode->left_margin + mode->right_margin +
mode->hsync_len + mode->xres),
&regs->hw_lcdif_vdctrl2);
writel(((mode->left_margin + mode->hsync_len) <<
LCDIF_VDCTRL3_HORIZONTAL_WAIT_CNT_OFFSET) |
(mode->upper_margin + mode->vsync_len),
&regs->hw_lcdif_vdctrl3);
writel((0 << LCDIF_VDCTRL4_DOTCLK_DLY_SEL_OFFSET) | mode->xres,
&regs->hw_lcdif_vdctrl4);
writel(panel->frameAdrs, &regs->hw_lcdif_cur_buf);
writel(panel->frameAdrs, &regs->hw_lcdif_next_buf);
/* Flush FIFO first */
writel(LCDIF_CTRL1_FIFO_CLEAR, &regs->hw_lcdif_ctrl1_set);
#ifndef CONFIG_VIDEO_MXS_MODE_SYSTEM
/* Sync signals ON */
setbits_le32(&regs->hw_lcdif_vdctrl4, LCDIF_VDCTRL4_SYNC_SIGNALS_ON);
#endif
/* FIFO cleared */
writel(LCDIF_CTRL1_FIFO_CLEAR, &regs->hw_lcdif_ctrl1_clr);
/* RUN! */
writel(LCDIF_CTRL_RUN, &regs->hw_lcdif_ctrl_set);
}
void *video_hw_init(void)
{
int bpp = -1;
char *penv;
void *fb;
struct ctfb_res_modes mode;
puts("Video: ");
/* Suck display configuration from "videomode" variable */
penv = getenv("videomode");
if (!penv) {
puts("MXSFB: 'videomode' variable not set!\n");
return NULL;
}
bpp = video_get_params(&mode, penv);
/* fill in Graphic device struct */
sprintf(panel.modeIdent, "%dx%dx%d",
mode.xres, mode.yres, bpp);
panel.winSizeX = mode.xres;
panel.winSizeY = mode.yres;
panel.plnSizeX = mode.xres;
panel.plnSizeY = mode.yres;
switch (bpp) {
case 24:
case 18:
panel.gdfBytesPP = 4;
panel.gdfIndex = GDF_32BIT_X888RGB;
break;
case 16:
panel.gdfBytesPP = 2;
panel.gdfIndex = GDF_16BIT_565RGB;
break;
case 8:
panel.gdfBytesPP = 1;
panel.gdfIndex = GDF__8BIT_INDEX;
break;
default:
printf("MXSFB: Invalid BPP specified! (bpp = %i)\n", bpp);
return NULL;
}
panel.memSize = mode.xres * mode.yres * panel.gdfBytesPP;
/* Allocate framebuffer */
fb = memalign(ARCH_DMA_MINALIGN,
roundup(panel.memSize, ARCH_DMA_MINALIGN));
if (!fb) {
printf("MXSFB: Error allocating framebuffer!\n");
return NULL;
}
/* Wipe framebuffer */
memset(fb, 0, panel.memSize);
panel.frameAdrs = (u32)fb;
printf("%s\n", panel.modeIdent);
/* Start framebuffer */
mxs_lcd_init(&panel, &mode, bpp);
#ifdef CONFIG_VIDEO_MXS_MODE_SYSTEM
/*
* If the LCD runs in system mode, the LCD refresh has to be triggered
* manually by setting the RUN bit in HW_LCDIF_CTRL register. To avoid
* having to set this bit manually after every single change in the
* framebuffer memory, we set up specially crafted circular DMA, which
* sets the RUN bit, then waits until it gets cleared and repeats this
* infinitelly. This way, we get smooth continuous updates of the LCD.
*/
struct mxs_lcdif_regs *regs = (struct mxs_lcdif_regs *)MXS_LCDIF_BASE;
memset(&desc, 0, sizeof(struct mxs_dma_desc));
desc.address = (dma_addr_t)&desc;
desc.cmd.data = MXS_DMA_DESC_COMMAND_NO_DMAXFER | MXS_DMA_DESC_CHAIN |
MXS_DMA_DESC_WAIT4END |
(1 << MXS_DMA_DESC_PIO_WORDS_OFFSET);
desc.cmd.pio_words[0] = readl(&regs->hw_lcdif_ctrl) | LCDIF_CTRL_RUN;
desc.cmd.next = (uint32_t)&desc.cmd;
/* Execute the DMA chain. */
mxs_dma_circ_start(MXS_DMA_CHANNEL_AHB_APBH_LCDIF, &desc);
#endif
return (void *)&panel;
}