[RFC v2 4/7] phy: qcom: Add QCOM SNPS eUSB2 repeater driver

From: Abel Vesa
Date: Thu Jan 26 2023 - 09:00:21 EST


PM8550B contains a eUSB2 repeater used for making the eUSB2 from
SM8550 USB 2.0 compliant. This can be modelled SW-wise as a Phy.
So add a new phy driver for it.

Signed-off-by: Abel Vesa <abel.vesa@xxxxxxxxxx>
---
drivers/phy/qualcomm/Kconfig | 9 +
drivers/phy/qualcomm/Makefile | 1 +
.../phy/qualcomm/phy-qcom-eusb2-repeater.c | 278 ++++++++++++++++++
3 files changed, 288 insertions(+)
create mode 100644 drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c

diff --git a/drivers/phy/qualcomm/Kconfig b/drivers/phy/qualcomm/Kconfig
index 27b5a2a3637d..a70631b04522 100644
--- a/drivers/phy/qualcomm/Kconfig
+++ b/drivers/phy/qualcomm/Kconfig
@@ -79,6 +79,15 @@ config PHY_QCOM_SNPS_EUSB2
chipsets. The PHY is paired with a Synopsys DWC3 USB controller
on Qualcomm SOCs.

+config PHY_QCOM_EUSB2_REPEATER
+ tristate "Qualcomm SNPS eUSB2 Repeater Driver"
+ depends on OF && (ARCH_QCOM || COMPILE_TEST)
+ select GENERIC_PHY
+ help
+ Enable support for the USB high-speed SNPS eUSB2 repeater on Qualcomm
+ PMICs. The repeater is paired with a Synopsys eUSB2 Phy
+ on Qualcomm SOCs.
+
config PHY_QCOM_USB_HS
tristate "Qualcomm USB HS PHY module"
depends on USB_ULPI_BUS
diff --git a/drivers/phy/qualcomm/Makefile b/drivers/phy/qualcomm/Makefile
index 3ee118f4dfc7..7dcba9537b69 100644
--- a/drivers/phy/qualcomm/Makefile
+++ b/drivers/phy/qualcomm/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_PHY_QCOM_QMP) += \

obj-$(CONFIG_PHY_QCOM_QUSB2) += phy-qcom-qusb2.o
obj-$(CONFIG_PHY_QCOM_SNPS_EUSB2) += phy-qcom-snps-eusb2.o
+obj-$(CONFIG_PHY_QCOM_EUSB2_REPEATER) += phy-qcom-eusb2-repeater.o
obj-$(CONFIG_PHY_QCOM_USB_HS) += phy-qcom-usb-hs.o
obj-$(CONFIG_PHY_QCOM_USB_HSIC) += phy-qcom-usb-hsic.o
obj-$(CONFIG_PHY_QCOM_USB_HS_28NM) += phy-qcom-usb-hs-28nm.o
diff --git a/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c b/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
new file mode 100644
index 000000000000..f7f822f2973f
--- /dev/null
+++ b/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023, Linaro Limited
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/phy/phy.h>
+
+/* eUSB2 status registers */
+#define EUSB2_RPTR_STATUS 0x08
+#define RPTR_OK BIT(7)
+
+/* eUSB2 control registers */
+#define EUSB2_EN_CTL1 0x46
+#define EUSB2_RPTR_EN BIT(7)
+
+#define PHY_HOST_MODE BIT(0)
+#define EUSB2_FORCE_EN_5 0xE8
+#define F_CLK_19P2M_EN BIT(6)
+#define F_CLK_19P2M_EN_SHIFT 6
+
+#define EUSB2_FORCE_VAL_5 0xED
+#define V_CLK_19P2M_EN BIT(6)
+#define V_CLK_19P2M_EN_SHIFT 6
+
+#define EUSB2_TUNE_IUSB2 0x51
+#define EUSB2_TUNE_SQUELCH_U 0x54
+#define EUSB2_TUNE_USB2_PREEM 0x57
+
+#define QCOM_EUSB2_REPEATER_INIT_CFG(o, v) \
+ { \
+ .offset = o, \
+ .val = v, \
+ }
+
+enum repeater_mode {
+ REPEATER_HOST_MODE,
+ REPEATER_PERIPH_MODE,
+};
+
+struct eusb2_repeater_init_tbl {
+ unsigned int offset;
+ unsigned int val;
+};
+
+struct eusb2_repeater_cfg {
+ const struct eusb2_repeater_init_tbl *init_tbl;
+ int init_tbl_num;
+ /* regulators to be requested */
+ const char * const *vreg_list;
+ int num_vregs;
+};
+
+struct eusb2_repeater {
+ struct device *dev;
+ struct regmap *regmap;
+ struct phy *phy;
+ struct regulator_bulk_data *vregs;
+ const struct eusb2_repeater_cfg *cfg;
+ u16 base;
+ enum phy_mode mode;
+};
+
+static const char * const pm8550b_vreg_l[] = {
+ "vdd18", "vdd3",
+};
+
+static const struct eusb2_repeater_init_tbl pm8550b_init_tbl[] = {
+ QCOM_EUSB2_REPEATER_INIT_CFG(EUSB2_TUNE_IUSB2, 0x8),
+ QCOM_EUSB2_REPEATER_INIT_CFG(EUSB2_TUNE_SQUELCH_U, 0x3),
+ QCOM_EUSB2_REPEATER_INIT_CFG(EUSB2_TUNE_USB2_PREEM, 0x5),
+};
+
+static const struct eusb2_repeater_cfg pm8550b_eusb2_cfg = {
+ .init_tbl = pm8550b_init_tbl,
+ .init_tbl_num = ARRAY_SIZE(pm8550b_init_tbl),
+ .vreg_list = pm8550b_vreg_l,
+ .num_vregs = ARRAY_SIZE(pm8550b_vreg_l),
+};
+
+static int eusb2_repeater_init_vregs(struct eusb2_repeater *rptr)
+{
+ int num = rptr->cfg->num_vregs;
+ struct device *dev = rptr->dev;
+ int i;
+
+ rptr->vregs = devm_kcalloc(dev, num, sizeof(*rptr->vregs), GFP_KERNEL);
+ if (!rptr->vregs)
+ return -ENOMEM;
+
+ for (i = 0; i < num; i++)
+ rptr->vregs[i].supply = rptr->cfg->vreg_list[i];
+
+ return devm_regulator_bulk_get(dev, num, rptr->vregs);
+}
+
+static int eusb2_repeater_init(struct phy *phy)
+{
+ struct eusb2_repeater *rptr = phy_get_drvdata(phy);
+ const struct eusb2_repeater_init_tbl *init_tbl = rptr->cfg->init_tbl;
+ int num = rptr->cfg->init_tbl_num;
+ int ret = 0;
+ u32 val;
+ int i;
+
+ ret = regulator_bulk_enable(rptr->cfg->num_vregs, rptr->vregs);
+ if (ret)
+ return ret;
+
+ regmap_update_bits(rptr->regmap, rptr->base + EUSB2_EN_CTL1,
+ EUSB2_RPTR_EN, EUSB2_RPTR_EN);
+
+ for (i = 0; i < num; i++)
+ regmap_update_bits(rptr->regmap,
+ rptr->base + init_tbl[i].offset,
+ init_tbl[i].val, init_tbl[i].val);
+
+ ret = regmap_read_poll_timeout(rptr->regmap,
+ rptr->base + EUSB2_RPTR_STATUS, val,
+ val & RPTR_OK, 10, 5);
+ if (ret)
+ dev_err(rptr->dev, "initialization timed-out\n");
+
+ return ret;
+}
+
+static int eusb2_repeater_set_mode(struct phy *phy,
+ enum phy_mode mode, int submode)
+{
+ struct eusb2_repeater *rptr = phy_get_drvdata(phy);
+
+ switch (mode) {
+ case PHY_MODE_USB_HOST:
+ /*
+ * CM.Lx is prohibited when repeater is already into Lx state as
+ * per eUSB 1.2 Spec. Below implement software workaround until
+ * PHY and controller is fixing seen observation.
+ */
+ regmap_update_bits(rptr->regmap, rptr->base + EUSB2_FORCE_EN_5,
+ F_CLK_19P2M_EN, F_CLK_19P2M_EN);
+ regmap_update_bits(rptr->regmap, rptr->base + EUSB2_FORCE_VAL_5,
+ V_CLK_19P2M_EN, V_CLK_19P2M_EN);
+ break;
+ case PHY_MODE_USB_DEVICE:
+ /*
+ * In device mode clear host mode related workaround as there
+ * is no repeater reset available, and enable/disable of
+ * repeater doesn't clear previous value due to shared
+ * regulators (say host <-> device mode switch).
+ */
+ regmap_update_bits(rptr->regmap, rptr->base + EUSB2_FORCE_EN_5,
+ F_CLK_19P2M_EN, 0);
+ regmap_update_bits(rptr->regmap, rptr->base + EUSB2_FORCE_VAL_5,
+ V_CLK_19P2M_EN, 0);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int eusb2_repeater_exit(struct phy *phy)
+{
+ struct eusb2_repeater *rptr = phy_get_drvdata(phy);
+
+ return regulator_bulk_disable(rptr->cfg->num_vregs, rptr->vregs);
+}
+
+
+static const struct phy_ops eusb2_repeater_ops = {
+ .init = eusb2_repeater_init,
+ .exit = eusb2_repeater_exit,
+ .set_mode = eusb2_repeater_set_mode,
+ .owner = THIS_MODULE,
+};
+
+static int eusb2_repeater_probe(struct platform_device *pdev)
+{
+ struct eusb2_repeater *rptr;
+ struct device *dev = &pdev->dev;
+ struct phy_provider *phy_provider;
+ struct device_node *np;
+ u32 res;
+ int ret;
+
+ np = of_node_get(dev->of_node);
+
+ rptr = devm_kzalloc(dev, sizeof(*rptr), GFP_KERNEL);
+ if (!rptr)
+ goto err_node_put;
+
+ rptr->dev = dev;
+ dev_set_drvdata(dev, rptr);
+
+ rptr->cfg = of_device_get_match_data(dev);
+ if (!rptr->cfg)
+ goto err_node_put;
+
+ rptr->regmap = dev_get_regmap(dev->parent, NULL);
+ if (!rptr->regmap)
+ goto err_node_put;
+
+ ret = of_property_read_u32(np, "reg", &res);
+ if (ret < 0)
+ goto err_node_put;
+
+ rptr->base = res;
+
+ ret = eusb2_repeater_init_vregs(rptr);
+ if (ret < 0) {
+ dev_err(dev, "unable to get supplies\n");
+ goto err_node_put;
+ }
+
+ rptr->phy = devm_phy_create(dev, np, &eusb2_repeater_ops);
+ if (IS_ERR(rptr->phy)) {
+ ret = PTR_ERR(rptr->phy);
+ dev_err(dev, "failed to create PHY: %d\n", ret);
+ goto err_node_put;
+ }
+
+ phy_set_drvdata(rptr->phy, rptr);
+
+ of_node_put(np);
+
+ phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+ if (IS_ERR(phy_provider))
+ return PTR_ERR(phy_provider);
+
+ dev_info(dev, "Registered Qcom-eUSB2 repeater\n");
+
+ return 0;
+
+err_node_put:
+ of_node_put(np);
+ return ret;
+}
+
+static int eusb2_repeater_remove(struct platform_device *pdev)
+{
+ struct eusb2_repeater *rptr = platform_get_drvdata(pdev);
+
+ if (!rptr)
+ return 0;
+
+ eusb2_repeater_exit(rptr->phy);
+ return 0;
+}
+
+
+static const struct of_device_id eusb2_repeater_of_match_table[] = {
+ {
+ .compatible = "qcom,pm8550b-eusb2-repeater",
+ .data = &pm8550b_eusb2_cfg,
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, eusb2_repeater_of_match_table);
+
+static struct platform_driver eusb2_repeater_driver = {
+ .probe = eusb2_repeater_probe,
+ .remove = eusb2_repeater_remove,
+ .driver = {
+ .name = "qcom-eusb2-repeater",
+ .of_match_table = eusb2_repeater_of_match_table,
+ },
+};
+
+module_platform_driver(eusb2_repeater_driver);
+
+MODULE_DESCRIPTION("Qualcomm PMIC eUSB2 Repeater driver");
+MODULE_LICENSE("GPL v2");
--
2.34.1