[PATCH v3 2/2] phy: meson: add USB2 PHY support for Meson GXL and GXM
Martin Blumenstingl
martin.blumenstingl at googlemail.com
Mon Apr 17 12:11:42 PDT 2017
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
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