u-boot/board/gdsys/common/dp501.c
Dirk Eibach d054c2f8c6 board: gdsys: Consider DP501 limits on link training
DP501 only supports DP 1.1a.
Limit settings for link bandwidth and lane count to
values allowed by DP 1.1a.

Signed-off-by: Dirk Eibach <dirk.eibach@gdsys.cc>
2015-11-12 15:59:03 -05:00

127 lines
3.7 KiB
C

/*
* (C) Copyright 2012
* Dirk Eibach, Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
*
* SPDX-License-Identifier: GPL-2.0+
*/
/* Parade Technologies Inc. DP501 DisplayPort DVI/HDMI Transmitter */
#include <common.h>
#include <asm/io.h>
#include <errno.h>
#include <i2c.h>
static void dp501_setbits(u8 addr, u8 reg, u8 mask)
{
u8 val;
val = i2c_reg_read(addr, reg);
setbits_8(&val, mask);
i2c_reg_write(addr, reg, val);
}
static void dp501_clrbits(u8 addr, u8 reg, u8 mask)
{
u8 val;
val = i2c_reg_read(addr, reg);
clrbits_8(&val, mask);
i2c_reg_write(addr, reg, val);
}
static int dp501_detect_cable_adapter(u8 addr)
{
u8 val = i2c_reg_read(addr, 0x00);
return !(val & 0x04);
}
static void dp501_link_training(u8 addr)
{
u8 val;
u8 link_bw;
u8 max_lane_cnt;
u8 lane_cnt;
val = i2c_reg_read(addr, 0x51);
if (val >= 0x0a)
link_bw = 0x0a;
else
link_bw = 0x06;
if (link_bw != val)
printf("DP sink supports %d Mbps link rate, set to %d Mbps\n",
val * 270, link_bw * 270);
i2c_reg_write(addr, 0x5d, link_bw); /* set link_bw */
val = i2c_reg_read(addr, 0x52);
max_lane_cnt = val & 0x1f;
if (max_lane_cnt >= 4)
lane_cnt = 4;
else
lane_cnt = max_lane_cnt;
if (lane_cnt != max_lane_cnt)
printf("DP sink supports %d lanes, set to %d lanes\n",
max_lane_cnt, lane_cnt);
i2c_reg_write(addr, 0x5e, lane_cnt | (val & 0x80)); /* set lane_cnt */
val = i2c_reg_read(addr, 0x53);
i2c_reg_write(addr, 0x5c, val); /* set downspread_ctl */
i2c_reg_write(addr, 0x5f, 0x0d); /* start training */
}
void dp501_powerup(u8 addr)
{
dp501_clrbits(addr, 0x0a, 0x30); /* power on encoder */
dp501_setbits(addr, 0x0a, 0x0e); /* block HDCP and MCCS on I2C bride*/
i2c_reg_write(addr, 0x27, 0x30); /* Hardware auto detect DVO timing */
dp501_setbits(addr, 0x72, 0x80); /* DPCD read enable */
dp501_setbits(addr, 0x30, 0x20); /* RS polynomial select */
i2c_reg_write(addr, 0x71, 0x20); /* Enable Aux burst write */
dp501_setbits(addr, 0x78, 0x30); /* Disable HPD2 IRQ */
dp501_clrbits(addr, 0x2f, 0x40); /* Link FIFO reset selection */
dp501_clrbits(addr, 0x60, 0x20); /* Enable scrambling */
#ifdef CONFIG_SYS_DP501_VCAPCTRL0
i2c_reg_write(addr, 0x24, CONFIG_SYS_DP501_VCAPCTRL0);
#else
i2c_reg_write(addr, 0x24, 0xc0); /* SDR mode 0, ext. H/VSYNC */
#endif
#ifdef CONFIG_SYS_DP501_DIFFERENTIAL
i2c_reg_write(addr + 2, 0x24, 0x10); /* clock input differential */
i2c_reg_write(addr + 2, 0x25, 0x04);
i2c_reg_write(addr + 2, 0x26, 0x10);
#else
i2c_reg_write(addr + 2, 0x24, 0x02); /* clock input single ended */
#endif
i2c_reg_write(addr + 2, 0x1a, 0x04); /* SPDIF input method TTL */
i2c_reg_write(addr + 2, 0x00, 0x18); /* driving strength */
i2c_reg_write(addr + 2, 0x03, 0x06); /* driving strength */
i2c_reg_write(addr, 0x2c, 0x00); /* configure N value */
i2c_reg_write(addr, 0x2d, 0x00); /* configure N value */
i2c_reg_write(addr, 0x2e, 0x0c); /* configure N value */
i2c_reg_write(addr, 0x76, 0xff); /* clear all interrupt */
dp501_setbits(addr, 0x78, 0x03); /* clear all interrupt */
i2c_reg_write(addr, 0x75, 0xf8); /* aux channel reset */
i2c_reg_write(addr, 0x75, 0x00); /* clear aux channel reset */
i2c_reg_write(addr, 0x87, 0x7f); /* set retry counter as 7
retry interval 400us */
if (dp501_detect_cable_adapter(addr)) {
printf("DVI/HDMI cable adapter detected\n");
i2c_reg_write(addr, 0x5e, 0x04); /* enable 4 channel */
dp501_clrbits(addr, 0x00, 0x08); /* DVI/HDMI HDCP operation */
} else {
printf("no DVI/HDMI cable adapter detected\n");
dp501_setbits(addr, 0x00, 0x08); /* for DP HDCP operation */
dp501_link_training(addr);
}
}
void dp501_powerdown(u8 addr)
{
dp501_setbits(addr, 0x0a, 0x30); /* power down encoder, standby mode */
}