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

Kishon Vijay Abraham I kishon at ti.com
Mon May 8 22:15:07 PDT 2017



On Tuesday 09 May 2017 10:17 AM, Vivek Gautam wrote:
> Hi,
> 
> 
> On 05/08/2017 05:51 PM, Kishon Vijay Abraham I wrote:
>> Hi,
>>
>> On Thursday 04 May 2017 11:38 PM, Martin Blumenstingl wrote:
>>> 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
>> I don't have any further comments. I'll queue this once -rc1 is tagged. Btw
>> Vivek Gautam has plans to change the directory structure of phy, so you might
>> have to resend this patch once his patch is merged.
>>
>> Vivek, since phy tree is already merged to Linus, can you send your
>> restructuring patch asap based on linus latest?
> 
> Sure, I will send the patch soon this week.

Thanks Vivek.

-Kishon



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