[PATCH 06/28] phy: phy-mt65xx-usb3: improve HS eye diagram

Kishon Vijay Abraham I
2015-12-22T10:46:32Z

From: Chunfeng Yun <chunfeng.yun@mediatek.com>

calibrate HS slew rate and switch 100uA current to SSUSB
to improve HS eye diagram of HQA test.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/phy/phy-mt65xx-usb3.c | 99 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 96 insertions(+), 3 deletions(-)

diff --git a/drivers/phy/phy-mt65xx-usb3.c b/drivers/phy/phy-mt65xx-usb3.c
index 2afbf9f3..c0e7b4b 100644
--- a/drivers/phy/phy-mt65xx-usb3.c
+++ b/drivers/phy/phy-mt65xx-usb3.c
@@ -17,6 +17,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/phy/phy.h>
@@ -27,6 +28,7 @@
* relative to USB3_SIF2_BASE base address
*/
#define SSUSB_SIFSLV_SPLLC 0x0000
+#define SSUSB_SIFSLV_U2FREQ 0x0100

/* offsets of sub-segment in each port registers */
#define SSUSB_SIFSLV_U2PHY_COM_BASE 0x0000
@@ -41,6 +43,7 @@
#define PA2_RG_SIF_U2PLL_FORCE_EN BIT(18)

#define U3P_USBPHYACR5 (SSUSB_SIFSLV_U2PHY_COM_BASE + 0x0014)
+#define PA5_RG_U2_HSTX_SRCAL_EN BIT(15)
#define PA5_RG_U2_HSTX_SRCTRL GENMASK(14, 12)
#define PA5_RG_U2_HSTX_SRCTRL_VAL(x) ((0x7 & (x)) << 12)
#define PA5_RG_U2_HS_100U_U3_EN BIT(11)
@@ -113,6 +116,24 @@
#define XC3_RG_U3_XTAL_RX_PWD BIT(9)
#define XC3_RG_U3_FRC_XTAL_RX_PWD BIT(8)

+#define U3P_U2FREQ_FMCR0 (SSUSB_SIFSLV_U2FREQ + 0x00)
+#define P2F_RG_MONCLK_SEL GENMASK(27, 26)
+#define P2F_RG_MONCLK_SEL_VAL(x) ((0x3 & (x)) << 26)
+#define P2F_RG_FREQDET_EN BIT(24)
+#define P2F_RG_CYCLECNT GENMASK(23, 0)
+#define P2F_RG_CYCLECNT_VAL(x) ((P2F_RG_CYCLECNT) & (x))
+
+#define U3P_U2FREQ_VALUE (SSUSB_SIFSLV_U2FREQ + 0x0c)
+
+#define U3P_U2FREQ_FMMONR1 (SSUSB_SIFSLV_U2FREQ + 0x10)
+#define P2F_USB_FM_VALID BIT(0)
+#define P2F_RG_FRCK_EN BIT(8)
+
+#define U3P_REF_CLK 26 /* MHZ */
+#define U3P_SLEW_RATE_COEF 28
+#define U3P_SR_COEF_DIVISOR 1000
+#define U3P_FM_DET_CYCLE_CNT 1024
+
struct mt65xx_phy_instance {
struct phy *phy;
void __iomem *port_base;
@@ -128,6 +149,77 @@ struct mt65xx_u3phy {
int nphys;
};

+static void hs_slew_rate_calibrate(struct mt65xx_u3phy *u3phy,
+ struct mt65xx_phy_instance *instance)
+{
+ void __iomem *sif_base = u3phy->sif_base;
+ int calibration_val;
+ int fm_out;
+ u32 tmp;
+
+ /* enable USB ring oscillator */
+ tmp = readl(instance->port_base + U3P_USBPHYACR5);
+ tmp |= PA5_RG_U2_HSTX_SRCAL_EN;
+ writel(tmp, instance->port_base + U3P_USBPHYACR5);
+ udelay(1);
+
+ /*enable free run clock */
+ tmp = readl(sif_base + U3P_U2FREQ_FMMONR1);
+ tmp |= P2F_RG_FRCK_EN;
+ writel(tmp, sif_base + U3P_U2FREQ_FMMONR1);
+
+ /* set cycle count as 1024, and select u2 channel */
+ tmp = readl(sif_base + U3P_U2FREQ_FMCR0);
+ tmp &= ~(P2F_RG_CYCLECNT | P2F_RG_MONCLK_SEL);
+ tmp |= P2F_RG_CYCLECNT_VAL(U3P_FM_DET_CYCLE_CNT);
+ tmp |= P2F_RG_MONCLK_SEL_VAL(instance->index);
+ writel(tmp, sif_base + U3P_U2FREQ_FMCR0);
+
+ /* enable frequency meter */
+ tmp = readl(sif_base + U3P_U2FREQ_FMCR0);
+ tmp |= P2F_RG_FREQDET_EN;
+ writel(tmp, sif_base + U3P_U2FREQ_FMCR0);
+
+ /* ignore return value */
+ readl_poll_timeout(sif_base + U3P_U2FREQ_FMMONR1, tmp,
+ (tmp & P2F_USB_FM_VALID), 10, 200);
+
+ fm_out = readl(sif_base + U3P_U2FREQ_VALUE);
+
+ /* disable frequency meter */
+ tmp = readl(sif_base + U3P_U2FREQ_FMCR0);
+ tmp &= ~P2F_RG_FREQDET_EN;
+ writel(tmp, sif_base + U3P_U2FREQ_FMCR0);
+
+ /*disable free run clock */
+ tmp = readl(sif_base + U3P_U2FREQ_FMMONR1);
+ tmp &= ~P2F_RG_FRCK_EN;
+ writel(tmp, sif_base + U3P_U2FREQ_FMMONR1);
+
+ if (fm_out) {
+ /* ( 1024 / FM_OUT ) x reference clock frequency x 0.028 */
+ tmp = U3P_FM_DET_CYCLE_CNT * U3P_REF_CLK * U3P_SLEW_RATE_COEF;
+ tmp /= fm_out;
+ calibration_val = DIV_ROUND_CLOSEST(tmp, U3P_SR_COEF_DIVISOR);
+ } else {
+ /* if FM detection fail, set default value */
+ calibration_val = 4;
+ }
+ dev_dbg(u3phy->dev, "phy:%d, fm_out:%d, calib:%d\n",
+ instance->index, fm_out, calibration_val);
+
+ /* set HS slew rate */
+ tmp = readl(instance->port_base + U3P_USBPHYACR5);
+ tmp &= ~PA5_RG_U2_HSTX_SRCTRL;
+ tmp |= PA5_RG_U2_HSTX_SRCTRL_VAL(calibration_val);
+ writel(tmp, instance->port_base + U3P_USBPHYACR5);
+
+ /* disable USB ring oscillator */
+ tmp = readl(instance->port_base + U3P_USBPHYACR5);
+ tmp &= ~PA5_RG_U2_HSTX_SRCAL_EN;
+ writel(tmp, instance->port_base + U3P_USBPHYACR5);
+}
+
static void phy_instance_init(struct mt65xx_u3phy *u3phy,
struct mt65xx_phy_instance *instance)
{
@@ -226,9 +318,9 @@ static void phy_instance_power_on(struct mt65xx_u3phy *u3phy,
tmp |= XC3_RG_U3_XTAL_RX_PWD | XC3_RG_U3_FRC_XTAL_RX_PWD;
writel(tmp, u3phy->sif_base + U3P_XTALCTL3);

- /* [mt8173]disable Change 100uA current from SSUSB */
+ /* [mt8173]switch 100uA current to SSUSB */
tmp = readl(port_base + U3P_USBPHYACR5);
- tmp &= ~PA5_RG_U2_HS_100U_U3_EN;
+ tmp |= PA5_RG_U2_HS_100U_U3_EN;
writel(tmp, port_base + U3P_USBPHYACR5);
}

@@ -273,7 +365,7 @@ static void phy_instance_power_off(struct mt65xx_u3phy *u3phy,
writel(tmp, port_base + U3P_USBPHYACR6);

if (!index) {
- /* (also disable)Change 100uA current switch to USB2.0 */
+ /* switch 100uA current back to USB2.0 */
tmp = readl(port_base + U3P_USBPHYACR5);
tmp &= ~PA5_RG_U2_HS_100U_U3_EN;
writel(tmp, port_base + U3P_USBPHYACR5);
@@ -343,6 +435,7 @@ static int mt65xx_phy_power_on(struct phy *phy)
struct mt65xx_u3phy *u3phy = dev_get_drvdata(phy->dev.parent);

phy_instance_power_on(u3phy, instance);
+ hs_slew_rate_calibrate(u3phy, instance);
return 0;
}

--
1.7.9.5