phy: qcom: Add QCOM SNPS eUSB2 repeater driver

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@linaro.org>
Link: https://lore.kernel.org/r/20230208190200.2966723-5-abel.vesa@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/qualcomm/Kconfig b/drivers/phy/qualcomm/Kconfig
index 513322c..4850d48 100644 (file)
--- a/drivers/phy/qualcomm/Kconfig
+++ b/drivers/phy/qualcomm/Kconfig
@@ -121,6 +121,15 @@ 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 b2c0166..de3dc9c 100644 (file)
--- a/drivers/phy/qualcomm/Makefile
+++ b/drivers/phy/qualcomm/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_PHY_QCOM_QMP_USB)                += phy-qcom-qmp-usb.o
 
 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 (file)
index 0000000..3f265ac
--- /dev/null
+++ b/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
@@ -0,0 +1,259 @@
+// 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 EUSB2_FORCE_EN_5               0xe8
+#define F_CLK_19P2M_EN                 BIT(6)
+
+#define EUSB2_FORCE_VAL_5              0xeD
+#define V_CLK_19P2M_EN                 BIT(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,                       \
+       }
+
+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;
+       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;
+       u32 val;
+       int ret;
+       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 = dev->of_node;
+       u32 res;
+       int ret;
+
+       rptr = devm_kzalloc(dev, sizeof(*rptr), GFP_KERNEL);
+       if (!rptr)
+               return -ENOMEM;
+
+       rptr->dev = dev;
+       dev_set_drvdata(dev, rptr);
+
+       rptr->cfg = of_device_get_match_data(dev);
+       if (!rptr->cfg)
+               return -EINVAL;
+
+       rptr->regmap = dev_get_regmap(dev->parent, NULL);
+       if (!rptr->regmap)
+               return -ENODEV;
+
+       ret = of_property_read_u32(np, "reg", &res);
+       if (ret < 0)
+               return ret;
+
+       rptr->base = res;
+
+       ret = eusb2_repeater_init_vregs(rptr);
+       if (ret < 0) {
+               dev_err(dev, "unable to get supplies\n");
+               return ret;
+       }
+
+       rptr->phy = devm_phy_create(dev, np, &eusb2_repeater_ops);
+       if (IS_ERR(rptr->phy)) {
+               dev_err(dev, "failed to create PHY: %d\n", ret);
+               return PTR_ERR(rptr->phy);
+       }
+
+       phy_set_drvdata(rptr->phy, rptr);
+
+       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;
+}
+
+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");