[PATCH 2/2] phy: exynos5-usbdrd: Calibrate LOS levels for exynos5420/5800
Felipe Balbi
balbi at kernel.org
Mon Sep 18 03:38:21 PDT 2017
Hi,
Andrzej Pietrasiewicz <andrzej.p at samsung.com> writes:
> From: Vivek Gautam <gautam.vivek at samsung.com>
>
> Adding phy calibration sequence for USB 3.0 DRD PHY present on
> Exynos5420/5800 systems.
> This calibration facilitates setting certain PHY parameters viz.
> the Loss-of-Signal (LOS) Detector Threshold Level, as well as
> Tx-Vboost-Level for Super-Speed operations.
> Additionally we also set proper time to wait for RxDetect measurement,
> for desired PHY reference clock, so as to solve issue with enumeration
> of few USB 3.0 devices, like Samsung SUM-TSB16S 3.0 USB drive
> on the controller.
>
> We are using CR_port for this purpose to send required data
> to override the LOS values.
>
> On testing with USB 3.0 devices on USB 3.0 port present on
> SMDK5420, and peach-pit boards should see following message:
> usb 2-1: new SuperSpeed USB device number 2 using xhci-hcd
>
> and without this patch, should see below shown message:
> usb 1-1: new high-speed USB device number 2 using xhci-hcd
>
> [Also removed unnecessary extra lines in the register macro definitions]
>
> Signed-off-by: Vivek Gautam <gautam.vivek at samsung.com>
> [adapted to use phy_reset as entry point]
> Signed-off-by: Andrzej Pietrasiewicz <andrzej.p at samsung.com>
> ---
> drivers/phy/samsung/phy-exynos5-usbdrd.c | 183 +++++++++++++++++++++++++++++++
> drivers/usb/dwc3/core.c | 8 +-
> 2 files changed, 189 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/phy/samsung/phy-exynos5-usbdrd.c b/drivers/phy/samsung/phy-exynos5-usbdrd.c
> index 7c41daa..f7de067 100644
> --- a/drivers/phy/samsung/phy-exynos5-usbdrd.c
> +++ b/drivers/phy/samsung/phy-exynos5-usbdrd.c
> @@ -89,7 +89,17 @@
> #define PHYCLKRST_COMMONONN BIT(0)
>
> #define EXYNOS5_DRD_PHYREG0 0x14
> +#define PHYREG0_SSC_REF_CLK_SEL BIT(21)
> +#define PHYREG0_SSC_RANGE BIT(20)
> +#define PHYREG0_CR_WRITE BIT(19)
> +#define PHYREG0_CR_READ BIT(18)
> +#define PHYREG0_CR_DATA_IN(_x) ((_x) << 2)
> +#define PHYREG0_CR_CAP_DATA BIT(1)
> +#define PHYREG0_CR_CAP_ADDR BIT(0)
> +
> #define EXYNOS5_DRD_PHYREG1 0x18
> +#define PHYREG1_CR_DATA_OUT(_x) ((_x) << 1)
> +#define PHYREG1_CR_ACK BIT(0)
>
> #define EXYNOS5_DRD_PHYPARAM0 0x1c
>
> @@ -118,6 +128,25 @@
> #define EXYNOS5_DRD_PHYRESUME 0x34
> #define EXYNOS5_DRD_LINKPORT 0x44
>
> +/* USB 3.0 DRD PHY SS Function Control Reg; accessed by CR_PORT */
> +#define EXYNOS5_DRD_PHYSS_LOSLEVEL_OVRD_IN (0x15)
> +#define LOSLEVEL_OVRD_IN_LOS_BIAS_5420 (0x5 << 13)
> +#define LOSLEVEL_OVRD_IN_LOS_BIAS_DEFAULT (0x0 << 13)
> +#define LOSLEVEL_OVRD_IN_EN (0x1 << 10)
> +#define LOSLEVEL_OVRD_IN_LOS_LEVEL_DEFAULT (0x9 << 0)
> +
> +#define EXYNOS5_DRD_PHYSS_TX_VBOOSTLEVEL_OVRD_IN (0x12)
> +#define TX_VBOOSTLEVEL_OVRD_IN_VBOOST_5420 (0x5 << 13)
> +#define TX_VBOOSTLEVEL_OVRD_IN_VBOOST_DEFAULT (0x4 << 13)
> +
> +#define EXYNOS5_DRD_PHYSS_LANE0_TX_DEBUG (0x1010)
> +#define LANE0_TX_DEBUG_RXDET_MEAS_TIME_19M2_20M (0x4 << 4)
> +#define LANE0_TX_DEBUG_RXDET_MEAS_TIME_24M (0x8 << 4)
> +#define LANE0_TX_DEBUG_RXDET_MEAS_TIME_25M_26M (0x8 << 4)
> +#define LANE0_TX_DEBUG_RXDET_MEAS_TIME_48M_50M_52M (0x20 << 4)
> +#define LANE0_TX_DEBUG_RXDET_MEAS_TIME_62M5 (0x20 << 4)
> +#define LANE0_TX_DEBUG_RXDET_MEAS_TIME_96M_100M (0x40 << 4)
> +
> #define KHZ 1000
> #define MHZ (KHZ * KHZ)
>
> @@ -526,6 +555,151 @@ static int exynos5_usbdrd_phy_power_off(struct phy *phy)
> return 0;
> }
>
> +static int crport_handshake(struct exynos5_usbdrd_phy *phy_drd,
> + u32 val, u32 cmd)
> +{
> + u32 usec = 100;
> + unsigned int result;
> +
> + writel(val | cmd, phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);
> +
> + do {
> + result = readl(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1);
> + if (result & PHYREG1_CR_ACK)
> + break;
> +
> + udelay(1);
> + } while (usec-- > 0);
> +
> + if (!usec) {
> + dev_err(phy_drd->dev,
> + "CRPORT handshake timeout1 (0x%08x)\n", val);
> + return -ETIME;
> + }
> +
> + usec = 100;
> +
> + writel(val, phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);
> +
> + do {
> + result = readl(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1);
> + if (!(result & PHYREG1_CR_ACK))
> + break;
> +
> + udelay(1);
> + } while (usec-- > 0);
> +
> + if (!usec) {
> + dev_err(phy_drd->dev,
> + "CRPORT handshake timeout2 (0x%08x)\n", val);
> + return -ETIME;
> + }
> +
> + return 0;
> +}
> +
> +static int crport_ctrl_write(struct exynos5_usbdrd_phy *phy_drd,
> + u32 addr, u32 data)
> +{
> + int ret;
> +
> + /* Write Address */
> + writel(PHYREG0_CR_DATA_IN(addr),
> + phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);
> + ret = crport_handshake(phy_drd, PHYREG0_CR_DATA_IN(addr),
> + PHYREG0_CR_CAP_ADDR);
> + if (ret)
> + return ret;
> +
> + /* Write Data */
> + writel(PHYREG0_CR_DATA_IN(data),
> + phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);
> + ret = crport_handshake(phy_drd, PHYREG0_CR_DATA_IN(data),
> + PHYREG0_CR_CAP_DATA);
> + if (ret)
> + return ret;
> +
> + ret = crport_handshake(phy_drd, PHYREG0_CR_DATA_IN(data),
> + PHYREG0_CR_WRITE);
> +
> + return ret;
> +}
> +
> +/*
> + * Calibrate few PHY parameters using CR_PORT register to meet
> + * SuperSpeed requirements on Exynos5420 and Exynos5800 systems,
> + * which have 28nm USB 3.0 DRD PHY.
> + */
> +static int exynos5420_usbdrd_phy_calibrate(struct exynos5_usbdrd_phy *phy_drd)
> +{
> + unsigned int temp;
> + int ret = 0;
> +
> + /*
> + * Change los_bias to (0x5) for 28nm PHY from a
> + * default value (0x0); los_level is set as default
> + * (0x9) as also reflected in los_level[30:26] bits
> + * of PHYPARAM0 register.
> + */
> + temp = LOSLEVEL_OVRD_IN_LOS_BIAS_5420 |
> + LOSLEVEL_OVRD_IN_EN |
> + LOSLEVEL_OVRD_IN_LOS_LEVEL_DEFAULT;
> + ret = crport_ctrl_write(phy_drd,
> + EXYNOS5_DRD_PHYSS_LOSLEVEL_OVRD_IN,
> + temp);
> + if (ret) {
> + dev_err(phy_drd->dev,
> + "Failed setting Loss-of-Signal level for SuperSpeed\n");
> + return ret;
> + }
> +
> + /*
> + * Set tx_vboost_lvl to (0x5) for 28nm PHY Tuning,
> + * to raise Tx signal level from its default value of (0x4)
> + */
> + temp = TX_VBOOSTLEVEL_OVRD_IN_VBOOST_5420;
> + ret = crport_ctrl_write(phy_drd,
> + EXYNOS5_DRD_PHYSS_TX_VBOOSTLEVEL_OVRD_IN,
> + temp);
> + if (ret) {
> + dev_err(phy_drd->dev,
> + "Failed setting Tx-Vboost-Level for SuperSpeed\n");
> + return ret;
> + }
> +
> + /*
> + * Set proper time to wait for RxDetect measurement, for
> + * desired reference clock of PHY, by tuning the CR_PORT
> + * register LANE0.TX_DEBUG which is internal to PHY.
> + * This fixes issue with few USB 3.0 devices, which are
> + * not detected (not even generate interrupts on the bus
> + * on insertion) without this change.
> + * e.g. Samsung SUM-TSB16S 3.0 USB drive.
> + */
> + switch (phy_drd->extrefclk) {
> + case EXYNOS5_FSEL_50MHZ:
> + temp = LANE0_TX_DEBUG_RXDET_MEAS_TIME_48M_50M_52M;
> + break;
> + case EXYNOS5_FSEL_20MHZ:
> + case EXYNOS5_FSEL_19MHZ2:
> + temp = LANE0_TX_DEBUG_RXDET_MEAS_TIME_19M2_20M;
> + break;
> + case EXYNOS5_FSEL_24MHZ:
> + default:
> + temp = LANE0_TX_DEBUG_RXDET_MEAS_TIME_24M;
> + break;
> + }
> +
> + ret = crport_ctrl_write(phy_drd,
> + EXYNOS5_DRD_PHYSS_LANE0_TX_DEBUG,
> + temp);
> + if (ret)
> + dev_err(phy_drd->dev,
> + "Failed setting RxDetect measurement time for SuperSpeed\n");
> +
> + return ret;
> +}
> +
> static struct phy *exynos5_usbdrd_phy_xlate(struct device *dev,
> struct of_phandle_args *args)
> {
> @@ -537,11 +711,20 @@ static struct phy *exynos5_usbdrd_phy_xlate(struct device *dev,
> return phy_drd->phys[args->args[0]].phy;
> }
>
> +static int exynos5_usbdrd_phy_reset(struct phy *phy)
> +{
> + struct phy_usb_instance *inst = phy_get_drvdata(phy);
> + struct exynos5_usbdrd_phy *phy_drd = to_usbdrd_phy(inst);
> +
> + return exynos5420_usbdrd_phy_calibrate(phy_drd);
> +}
> +
> static const struct phy_ops exynos5_usbdrd_phy_ops = {
> .init = exynos5_usbdrd_phy_init,
> .exit = exynos5_usbdrd_phy_exit,
> .power_on = exynos5_usbdrd_phy_power_on,
> .power_off = exynos5_usbdrd_phy_power_off,
> + .reset = exynos5_usbdrd_phy_reset,
> .owner = THIS_MODULE,
> };
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 03474d3..1d5836e 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -156,9 +156,10 @@ static void __dwc3_set_mode(struct work_struct *work)
> } else {
> if (dwc->usb2_phy)
> otg_set_vbus(dwc->usb2_phy->otg, true);
> - if (dwc->usb2_generic_phy)
> + if (dwc->usb2_generic_phy) {
> phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
> -
> + phy_reset(dwc->usb2_generic_phy);
it doesn't look like this is the best place to reset the phy. Also,
->reset() doesn't seem to match correctly with a calibration. That seems
to be more fitting to a ->power_on() or ->init() implementation.
Kishon, any comments?
--
balbi
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