[PATCH 2/2] phy: meson: add USB2 PHY support for Meson GXL and GXM
Hendrik v. Raven
hendrik at consetetur.de
Mon Mar 6 00:50:56 PST 2017
Currently just trying to learn by reading, but a minor comment inline.
On Sat, Mar 04, 2017 at 11:22:31PM +0100, Martin Blumenstingl 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 any of these PHYs.
> Both drivers were written by reading the reference drivers provided by
> Amlogic and analyzing the registers on the kernel that was shipped on
> the boards I have.
>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
> ---
> drivers/phy/Kconfig | 13 ++
> drivers/phy/Makefile | 1 +
> drivers/phy/phy-meson-gxl-usb2.c | 263 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 277 insertions(+)
> create mode 100644 drivers/phy/phy-meson-gxl-usb2.c
>
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index e8eb7f225a88..7d64711a837f 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -486,4 +486,17 @@ 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 USB_COMMON
> + 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 65eb2f436a41..a3a2c7dd5c06 100644
> --- a/drivers/phy/Makefile
> +++ b/drivers/phy/Makefile
> @@ -59,3 +59,4 @@ 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..841a6d9722d4
> --- /dev/null
> +++ b/drivers/phy/phy-meson-gxl-usb2.c
> @@ -0,0 +1,263 @@
> +/*
> + * 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>
> +#include <linux/usb/of.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_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;
> + }
> +
> + if (priv->is_enabled) {
> + /* 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);
> + }
> +
> + 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);
Shouldn't priv->is_enabled be reseted to 0 in this case?
> + return ret;
> + }
> +
> + return 0;
This can be merged with return ret from the error case.
> +}
> +
> +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,
> + .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);
> +
> + switch (of_usb_get_dr_mode_by_phy(dev->of_node, -1)) {
> + case USB_DR_MODE_PERIPHERAL:
> + priv->mode = PHY_MODE_USB_DEVICE;
> + break;
> + case USB_DR_MODE_OTG:
> + priv->mode = PHY_MODE_USB_OTG;
> + break;
> + case USB_DR_MODE_HOST:
> + default:
> + priv->mode = PHY_MODE_USB_HOST;
> + break;
> + }
> +
> + 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");
> --
> 2.12.0
>
>
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