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phy: phy-rockchip-naneng-usb2: add Rref calibrate in tuning

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This patch can change phy internal 45 Ohm resistance accord to
reference resistance. The larger the reference resistance, the
greater the internal resistance, and accordingly, high speed
eye diagram amplitude will become lower.

The maximum adjustable range of the reference is +-20% of the
default value (200 Ohm).

Signed-off-by: Ren Jianing <jianing.ren@rock-chips.com>
Change-Id: Ibd746283c06609b944fa2a148066ba0a661e761a
This commit is contained in:
Ren Jianing
2020-06-08 19:01:10 +08:00
committed by Tao Huang
parent 8b73d9a650
commit 68c654fa7a
1 changed files with 26 additions and 0 deletions
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26
drivers/phy/rockchip/phy-rockchip-naneng-usb2.c
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@@ -11,6 +11,7 @@
#include <linux/extcon-provider.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/gpio/consumer.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
@@ -1464,6 +1465,7 @@ static int rockchip_usb2phy_remove(struct platform_device *pdev)
static int rv1126_usb2phy_tuning(struct rockchip_usb2phy *rphy)
{
int ret = 0;
u32 rcal, reg;
if (rphy->phy_cfg->reg == 0xff4c0000) {
/* set iddig interrupt filter time to 10ms */
@@ -1475,6 +1477,30 @@ static int rv1126_usb2phy_tuning(struct rockchip_usb2phy *rphy)
ret = regmap_write(rphy->grf, 0x1027c, 0x0f0f0100);
if (ret)
goto out;
reg = readl(rphy->base + 0x10);
/* Enable Rterm self calibration and wait for rcal trim done */
writel(reg & ~BIT(2), rphy->base + 0x10);
/*
* If Rterm is disconnected, self calibration will fail and
* rcal trim done will be set in about 3.5 us
*/
udelay(10);
if (readl(rphy->base + 0x34) & BIT(4)) {
dev_dbg(rphy->dev, "Rterm disconnected");
} else {
ret = readl_poll_timeout(rphy->base + 0x34, rcal,
rcal & BIT(4),
100, 600);
if (ret == -ETIMEDOUT)
dev_err(rphy->dev, "Rterm calibration timeout");
else
/* Use rcal out calibration code */
reg = (reg & ~(0x0f << 3)) |
((rcal & 0x0f) << 3);
}
/* Disable Rterm self calibration */
writel(reg | BIT(2), rphy->base + 0x10);
}
if (rphy->phy_cfg->reg == 0xff4c8000) {