[PATCH v3 2/2] phy: meson: add USB2 PHY support for Meson GXL and GXM

Martin Blumenstingl martin.blumenstingl at googlemail.com
Thu May 4 11:08:54 PDT 2017


Hi Kishon,

On Mon, Apr 17, 2017 at 9:11 PM, Martin Blumenstingl
<martin.blumenstingl at googlemail.com> wrote:
> This adds a new driver for the USB2 PHYs found on Meson GXL and GXM SoCs
> (both SoCs are using the same USB PHY register layout).
>
> The USB2 PHY is a simple PHY which only has a few registers to configure
> the mode (host/device) and a reset register (to enable/disable the PHY).
>
> Unfortunately there are no datasheets available for this PHY. The driver
> was written by reading the code from Amlogic's GPL kernel sources and
> by analyzing the registers on an actual GXL and GXM device running the
> kernel that was shipped on the boards I have.
>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
> ---
>  drivers/phy/Kconfig              |  12 ++
>  drivers/phy/Makefile             |   1 +
>  drivers/phy/phy-meson-gxl-usb2.c | 261 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 274 insertions(+)
>  create mode 100644 drivers/phy/phy-meson-gxl-usb2.c
>
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index 005cadb7a3f8..fada8354c0fe 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -511,4 +511,16 @@ config PHY_MESON8B_USB2
>           and GXBB SoCs.
>           If unsure, say N.
>
> +config PHY_MESON_GXL_USB
> +       tristate "Meson GXL and GXM USB2 PHY drivers"
> +       default ARCH_MESON
> +       depends on OF && (ARCH_MESON || COMPILE_TEST)
> +       depends on USB_SUPPORT
> +       select GENERIC_PHY
> +       select REGMAP_MMIO
> +       help
> +         Enable this to support the Meson USB2 PHYs found in Meson
> +         GXL and GXM SoCs.
> +         If unsure, say N.
> +
>  endmenu
> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> index dd8f3b5d2918..4f5ede46b0b9 100644
> --- a/drivers/phy/Makefile
> +++ b/drivers/phy/Makefile
> @@ -62,3 +62,4 @@ obj-$(CONFIG_PHY_CYGNUS_PCIE)         += phy-bcm-cygnus-pcie.o
>  obj-$(CONFIG_ARCH_TEGRA) += tegra/
>  obj-$(CONFIG_PHY_NS2_PCIE)             += phy-bcm-ns2-pcie.o
>  obj-$(CONFIG_PHY_MESON8B_USB2)         += phy-meson8b-usb2.o
> +obj-$(CONFIG_PHY_MESON_GXL_USB)                += phy-meson-gxl-usb2.o
> diff --git a/drivers/phy/phy-meson-gxl-usb2.c b/drivers/phy/phy-meson-gxl-usb2.c
> new file mode 100644
> index 000000000000..f5fbd3c09542
> --- /dev/null
> +++ b/drivers/phy/phy-meson-gxl-usb2.c
> @@ -0,0 +1,261 @@
> +/*
> + * Meson GXL and GXM USB2 PHY driver
> + *
> + * Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl at googlemail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/regmap.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +
> +/* bits [31:27] are read-only */
> +#define U2P_R0                                                 0x0
> +       #define U2P_R0_BYPASS_SEL                               BIT(0)
> +       #define U2P_R0_BYPASS_DM_EN                             BIT(1)
> +       #define U2P_R0_BYPASS_DP_EN                             BIT(2)
> +       #define U2P_R0_TXBITSTUFF_ENH                           BIT(3)
> +       #define U2P_R0_TXBITSTUFF_EN                            BIT(4)
> +       #define U2P_R0_DM_PULLDOWN                              BIT(5)
> +       #define U2P_R0_DP_PULLDOWN                              BIT(6)
> +       #define U2P_R0_DP_VBUS_VLD_EXT_SEL                      BIT(7)
> +       #define U2P_R0_DP_VBUS_VLD_EXT                          BIT(8)
> +       #define U2P_R0_ADP_PRB_EN                               BIT(9)
> +       #define U2P_R0_ADP_DISCHARGE                            BIT(10)
> +       #define U2P_R0_ADP_CHARGE                               BIT(11)
> +       #define U2P_R0_DRV_VBUS                                 BIT(12)
> +       #define U2P_R0_ID_PULLUP                                BIT(13)
> +       #define U2P_R0_LOOPBACK_EN_B                            BIT(14)
> +       #define U2P_R0_OTG_DISABLE                              BIT(15)
> +       #define U2P_R0_COMMON_ONN                               BIT(16)
> +       #define U2P_R0_FSEL_MASK                                GENMASK(19, 17)
> +       #define U2P_R0_REF_CLK_SEL_MASK                         GENMASK(21, 20)
> +       #define U2P_R0_POWER_ON_RESET                           BIT(22)
> +       #define U2P_R0_V_ATE_TEST_EN_B_MASK                     GENMASK(24, 23)
> +       #define U2P_R0_ID_SET_ID_DQ                             BIT(25)
> +       #define U2P_R0_ATE_RESET                                BIT(26)
> +       #define U2P_R0_FSV_MINUS                                BIT(27)
> +       #define U2P_R0_FSV_PLUS                                 BIT(28)
> +       #define U2P_R0_BYPASS_DM_DATA                           BIT(29)
> +       #define U2P_R0_BYPASS_DP_DATA                           BIT(30)
> +
> +#define U2P_R1                                                 0x4
> +       #define U2P_R1_BURN_IN_TEST                             BIT(0)
> +       #define U2P_R1_ACA_ENABLE                               BIT(1)
> +       #define U2P_R1_DCD_ENABLE                               BIT(2)
> +       #define U2P_R1_VDAT_SRC_EN_B                            BIT(3)
> +       #define U2P_R1_VDAT_DET_EN_B                            BIT(4)
> +       #define U2P_R1_CHARGES_SEL                              BIT(5)
> +       #define U2P_R1_TX_PREEMP_PULSE_TUNE                     BIT(6)
> +       #define U2P_R1_TX_PREEMP_AMP_TUNE_MASK                  GENMASK(8, 7)
> +       #define U2P_R1_TX_RES_TUNE_MASK                         GENMASK(10, 9)
> +       #define U2P_R1_TX_RISE_TUNE_MASK                        GENMASK(12, 11)
> +       #define U2P_R1_TX_VREF_TUNE_MASK                        GENMASK(16, 13)
> +       #define U2P_R1_TX_FSLS_TUNE_MASK                        GENMASK(20, 17)
> +       #define U2P_R1_TX_HSXV_TUNE_MASK                        GENMASK(22, 21)
> +       #define U2P_R1_OTG_TUNE_MASK                            GENMASK(25, 23)
> +       #define U2P_R1_SQRX_TUNE_MASK                           GENMASK(28, 26)
> +       #define U2P_R1_COMP_DIS_TUNE_MASK                       GENMASK(31, 29)
> +
> +/* bits [31:14] are read-only */
> +#define U2P_R2                                                 0x8
> +       #define U2P_R2_DATA_IN_MASK                             GENMASK(3, 0)
> +       #define U2P_R2_DATA_IN_EN_MASK                          GENMASK(7, 4)
> +       #define U2P_R2_ADDR_MASK                                GENMASK(11, 8)
> +       #define U2P_R2_DATA_OUT_SEL                             BIT(12)
> +       #define U2P_R2_CLK                                      BIT(13)
> +       #define U2P_R2_DATA_OUT_MASK                            GENMASK(17, 14)
> +       #define U2P_R2_ACA_PIN_RANGE_C                          BIT(18)
> +       #define U2P_R2_ACA_PIN_RANGE_B                          BIT(19)
> +       #define U2P_R2_ACA_PIN_RANGE_A                          BIT(20)
> +       #define U2P_R2_ACA_PIN_GND                              BIT(21)
> +       #define U2P_R2_ACA_PIN_FLOAT                            BIT(22)
> +       #define U2P_R2_CHARGE_DETECT                            BIT(23)
> +       #define U2P_R2_DEVICE_SESSION_VALID                     BIT(24)
> +       #define U2P_R2_ADP_PROBE                                BIT(25)
> +       #define U2P_R2_ADP_SENSE                                BIT(26)
> +       #define U2P_R2_SESSION_END                              BIT(27)
> +       #define U2P_R2_VBUS_VALID                               BIT(28)
> +       #define U2P_R2_B_VALID                                  BIT(29)
> +       #define U2P_R2_A_VALID                                  BIT(30)
> +       #define U2P_R2_ID_DIG                                   BIT(31)
> +
> +#define U2P_R3                                                 0xc
> +
> +#define RESET_COMPLETE_TIME                            500
> +
> +struct phy_meson_gxl_usb2_priv {
> +       struct regmap           *regmap;
> +       enum phy_mode           mode;
> +       int                     is_enabled;
> +};
> +
> +static const struct regmap_config phy_meson_gxl_usb2_regmap_conf = {
> +       .reg_bits = 8,
> +       .val_bits = 32,
> +       .reg_stride = 4,
> +       .max_register = U2P_R3,
> +};
> +
> +static int phy_meson_gxl_usb2_reset(struct phy *phy)
> +{
> +       struct phy_meson_gxl_usb2_priv *priv = phy_get_drvdata(phy);
> +
> +       if (!priv->is_enabled)
> +               return 0;
> +
> +       /* reset the PHY and wait until settings are stabilized */
> +       regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_POWER_ON_RESET,
> +                          U2P_R0_POWER_ON_RESET);
> +       udelay(RESET_COMPLETE_TIME);
> +       regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_POWER_ON_RESET, 0);
> +       udelay(RESET_COMPLETE_TIME);
> +
> +       return 0;
> +}
> +
> +static int phy_meson_gxl_usb2_set_mode(struct phy *phy, enum phy_mode mode)
> +{
> +       struct phy_meson_gxl_usb2_priv *priv = phy_get_drvdata(phy);
> +
> +       switch (mode) {
> +       case PHY_MODE_USB_HOST:
> +       case PHY_MODE_USB_OTG:
> +               regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_DM_PULLDOWN,
> +                                  U2P_R0_DM_PULLDOWN);
> +               regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_DP_PULLDOWN,
> +                                  U2P_R0_DP_PULLDOWN);
> +               regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_ID_PULLUP, 0);
> +               break;
> +
> +       case PHY_MODE_USB_DEVICE:
> +               regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_DM_PULLDOWN,
> +                                  0);
> +               regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_DP_PULLDOWN,
> +                                  0);
> +               regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_ID_PULLUP,
> +                                  U2P_R0_ID_PULLUP);
> +               break;
> +
> +       default:
> +               return -EINVAL;
> +       }
> +
> +       phy_meson_gxl_usb2_reset(phy);
> +
> +       priv->mode = mode;
> +
> +       return 0;
> +}
> +
> +static int phy_meson_gxl_usb2_power_off(struct phy *phy)
> +{
> +       struct phy_meson_gxl_usb2_priv *priv = phy_get_drvdata(phy);
> +
> +       priv->is_enabled = 0;
> +
> +       /* power off the PHY by putting it into reset mode */
> +       regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_POWER_ON_RESET,
> +                          U2P_R0_POWER_ON_RESET);
> +
> +       return 0;
> +}
> +
> +static int phy_meson_gxl_usb2_power_on(struct phy *phy)
> +{
> +       struct phy_meson_gxl_usb2_priv *priv = phy_get_drvdata(phy);
> +       int ret;
> +
> +       priv->is_enabled = 1;
> +
> +       /* power on the PHY by taking it out of reset mode */
> +       regmap_update_bits(priv->regmap, U2P_R0, U2P_R0_POWER_ON_RESET, 0);
> +
> +       ret = phy_meson_gxl_usb2_set_mode(phy, priv->mode);
> +       if (ret) {
> +               phy_meson_gxl_usb2_power_off(phy);
> +
> +               dev_err(&phy->dev, "Failed to initialize PHY with mode %d\n",
> +                       priv->mode);
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static const struct phy_ops phy_meson_gxl_usb2_ops = {
> +       .power_on       = phy_meson_gxl_usb2_power_on,
> +       .power_off      = phy_meson_gxl_usb2_power_off,
> +       .set_mode       = phy_meson_gxl_usb2_set_mode,
> +       .reset          = phy_meson_gxl_usb2_reset,
> +       .owner          = THIS_MODULE,
> +};
> +
> +static int phy_meson_gxl_usb2_probe(struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct phy_provider *phy_provider;
> +       struct resource *res;
> +       struct phy_meson_gxl_usb2_priv *priv;
> +       struct phy *phy;
> +       void __iomem *base;
> +
> +       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +       if (!priv)
> +               return -ENOMEM;
> +
> +       platform_set_drvdata(pdev, priv);
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       base = devm_ioremap_resource(dev, res);
> +       if (IS_ERR(base))
> +               return PTR_ERR(base);
> +
> +       priv->mode = PHY_MODE_USB_HOST;
> +
> +       priv->regmap = devm_regmap_init_mmio(dev, base,
> +                                            &phy_meson_gxl_usb2_regmap_conf);
> +       if (IS_ERR(priv->regmap))
> +               return PTR_ERR(priv->regmap);
> +
> +       phy = devm_phy_create(dev, NULL, &phy_meson_gxl_usb2_ops);
> +       if (IS_ERR(phy)) {
> +               dev_err(dev, "failed to create PHY\n");
> +               return PTR_ERR(phy);
> +       }
> +
> +       phy_set_drvdata(phy, priv);
> +
> +       phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> +
> +       return PTR_ERR_OR_ZERO(phy_provider);
> +}
> +
> +static const struct of_device_id phy_meson_gxl_usb2_of_match[] = {
> +       { .compatible = "amlogic,meson-gxl-usb2-phy", },
> +       { },
> +};
> +MODULE_DEVICE_TABLE(of, phy_meson_gxl_usb2_of_match);
> +
> +static struct platform_driver phy_meson_gxl_usb2_driver = {
> +       .probe  = phy_meson_gxl_usb2_probe,
> +       .driver = {
> +               .name           = "phy-meson-gxl-usb2",
> +               .of_match_table = phy_meson_gxl_usb2_of_match,
> +       },
> +};
> +module_platform_driver(phy_meson_gxl_usb2_driver);
> +
> +MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl at googlemail.com>");
> +MODULE_DESCRIPTION("Meson GXL and GXM USB2 PHY driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.12.2
>
the devicetree documentation already got Rob's ACK. is there anything
that I still need to fix? I would really like to see this getting into
4.13



More information about the linux-amlogic mailing list