Re: [PATCH v4 1/2] usb: dwc3: add Realtek DHC RTD SoC dwc3 glue layer driver
From: Thinh Nguyen
Date: Thu Aug 17 2023 - 20:39:36 EST
On Tue, Aug 15, 2023, Stanley Chang wrote:
> Realtek DHC RTD SoCs integrate dwc3 IP and has some customizations to
> support different generations of SoCs.
Please provide a summary of what "customizations" are done here.
>
> Signed-off-by: Stanley Chang <stanley_chang@xxxxxxxxxxx>
> ---
> v3 to v4 change:
> Get max-speed from dwc3 node.
> Add the register set for pm control.
> v2 to v3 change:
> Remove the support_drd_mode of struct dwc3_rtk.
> Remove unlink_usb3_port and disable_usb3_phy.
> Disabled usb3 phy if the max speed is not super-speed.
> v1 to v2 change:
> Remove the code about the property realtek,enable-l4icg.
> Select USB_ROLE_SWITCH in Kconfig.
> Add dependency OF and ARCH_REALTEK in Kconfig.
> ---
> drivers/usb/dwc3/Kconfig | 11 +
> drivers/usb/dwc3/Makefile | 1 +
> drivers/usb/dwc3/dwc3-rtk.c | 512 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 524 insertions(+)
> create mode 100644 drivers/usb/dwc3/dwc3-rtk.c
>
> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> index 98efcbb76c88..5fc27b20df63 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -178,4 +178,15 @@ config USB_DWC3_OCTEON
> Only the host mode is currently supported.
> Say 'Y' or 'M' here if you have one such device.
>
> +config USB_DWC3_RTK
> + tristate "Realtek DWC3 Platform Driver"
> + depends on OF && ARCH_REALTEK
> + default USB_DWC3
> + select USB_ROLE_SWITCH
> + help
> + RTK DHC RTD SoCs with DesignWare Core USB3 IP inside,
> + and IP Core configured for USB 2.0 and USB 3.0 in host
> + or dual-role mode.
> + Say 'Y' or 'M' if you have such device.
> +
> endif
> diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> index fe1493d4bbe5..124eda2522d9 100644
> --- a/drivers/usb/dwc3/Makefile
> +++ b/drivers/usb/dwc3/Makefile
> @@ -55,3 +55,4 @@ obj-$(CONFIG_USB_DWC3_QCOM) += dwc3-qcom.o
> obj-$(CONFIG_USB_DWC3_IMX8MP) += dwc3-imx8mp.o
> obj-$(CONFIG_USB_DWC3_XILINX) += dwc3-xilinx.o
> obj-$(CONFIG_USB_DWC3_OCTEON) += dwc3-octeon.o
> +obj-$(CONFIG_USB_DWC3_RTK) += dwc3-rtk.o
> diff --git a/drivers/usb/dwc3/dwc3-rtk.c b/drivers/usb/dwc3/dwc3-rtk.c
> new file mode 100644
> index 000000000000..70d298471d26
> --- /dev/null
> +++ b/drivers/usb/dwc3/dwc3-rtk.c
> @@ -0,0 +1,512 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * dwc3-rtk.c - Realtek DWC3 Specific Glue layer
> + *
> + * Copyright (C) 2023 Realtek Semiconductor Corporation
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/platform_device.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/suspend.h>
> +#include <linux/sys_soc.h>
> +#include <linux/usb/otg.h>
> +#include <linux/usb/of.h>
> +#include <linux/usb/role.h>
> +
> +#include "core.h"
> +
> +#define WRAP_CTR_REG 0x0
> +#define DISABLE_MULTI_REQ BIT(1)
> +#define DESC_R2W_MULTI_DISABLE BIT(9)
> +#define FORCE_PIPE3_PHY_STATUS_TO_0 BIT(13)
> +
> +#define WRAP_USB2_PHY_UTMI_REG 0x8
> +#define TXHSVM_EN BIT(3)
> +
> +#define WRAP_PHY_PIPE_REG 0xC
> +#define RESET_DISABLE_PIPE3_P0 BIT(0)
> +#define CLOCK_ENABLE_FOR_PIPE3_PCLK BIT(1)
> +
> +#define WRAP_USB_HMAC_CTR0_REG 0x60
> +#define U3PORT_DIS BIT(8)
> +
> +#define WRAP_USB2_PHY_REG 0x70
> +#define USB2_PHY_EN_PHY_PLL_PORT0 BIT(12)
> +#define USB2_PHY_EN_PHY_PLL_PORT1 BIT(13)
> +#define USB2_PHY_SWITCH_MASK 0x707
> +#define USB2_PHY_SWITCH_DEVICE 0x0
> +#define USB2_PHY_SWITCH_HOST 0x606
> +
> +#define WRAP_APHY_REG 0x128
> +#define USB3_MBIAS_ENABLE BIT(1)
> +
> +/* pm control */
> +#define WRAP_USB_DBUS_PWR_CTRL_REG 0x160
> +#define USB_DBUS_PWR_CTRL_REG 0x0
> +#define DBUS_PWR_CTRL_EN BIT(0)
> +
> +struct dwc3_rtk {
> + struct device *dev;
> + void __iomem *regs;
> + size_t regs_size;
> + void __iomem *pm_base;
> +
> + struct dwc3 *dwc;
> +
> + int cur_dr_mode; /* current dr mode */
Why not use enum for dr_mode? And I don't think you need the comment.
> + struct usb_role_switch *role_switch;
> +};
> +
> +static void switch_usb2_dr_mode(struct dwc3_rtk *rtk, int dr_mode)
> +{
> + switch (dr_mode) {
> + case USB_DR_MODE_PERIPHERAL:
> + writel(USB2_PHY_SWITCH_DEVICE |
> + (~USB2_PHY_SWITCH_MASK &
> + readl(rtk->regs + WRAP_USB2_PHY_REG)),
> + rtk->regs + WRAP_USB2_PHY_REG);
Please split the register read and write to separate operations here and
everywhere else. ie:
val = readl(offset);
writel(val | mod, offset);
> + break;
> + case USB_DR_MODE_HOST:
> + writel(USB2_PHY_SWITCH_HOST |
> + (~USB2_PHY_SWITCH_MASK &
> + readl(rtk->regs + WRAP_USB2_PHY_REG)),
> + rtk->regs + WRAP_USB2_PHY_REG);
> + break;
> + default:
> + dev_dbg(rtk->dev, "%s: dr_mode=%d\n", __func__, dr_mode);
> + break;
> + }
> +}
> +
> +static void switch_dwc3_dr_mode(struct dwc3_rtk *rtk, int dr_mode)
> +{
> + if (!rtk->dwc->role_sw)
> + goto out;
> +
> + switch (dr_mode) {
> + case USB_DR_MODE_PERIPHERAL:
> + usb_role_switch_set_role(rtk->dwc->role_sw, USB_ROLE_DEVICE);
> + break;
> + case USB_DR_MODE_HOST:
> + usb_role_switch_set_role(rtk->dwc->role_sw, USB_ROLE_HOST);
> + break;
> + default:
> + dev_dbg(rtk->dev, "%s dr_mode=%d\n", __func__, dr_mode);
> + break;
> + }
> +
> +out:
> + return;
> +}
> +
> +static int dwc3_rtk_get_dr_mode(struct dwc3_rtk *rtk)
> +{
> + enum usb_role role;
> +
> + role = rtk->cur_dr_mode;
> +
> + if (rtk->dwc && rtk->dwc->role_sw)
> + role = usb_role_switch_get_role(rtk->dwc->role_sw);
> + else
> + dev_dbg(rtk->dev, "%s not usb_role_switch role=%d\n", __func__, role);
> +
> + return role;
> +}
> +
> +static void dwc3_rtk_set_dr_mode(struct dwc3_rtk *rtk, int dr_mode)
> +{
> + rtk->cur_dr_mode = dr_mode;
> +
> + switch_dwc3_dr_mode(rtk, dr_mode);
> + mdelay(10);
> + switch_usb2_dr_mode(rtk, dr_mode);
> +}
> +
> +#if IS_ENABLED(CONFIG_USB_ROLE_SWITCH)
> +static int dwc3_usb_role_switch_set(struct usb_role_switch *sw, enum usb_role role)
> +{
> + struct dwc3_rtk *rtk = usb_role_switch_get_drvdata(sw);
> +
> + switch (role) {
> + case USB_ROLE_HOST:
> + dwc3_rtk_set_dr_mode(rtk, USB_DR_MODE_HOST);
> + break;
> + case USB_ROLE_DEVICE:
> + dwc3_rtk_set_dr_mode(rtk, USB_DR_MODE_PERIPHERAL);
> + break;
> + default:
> + dwc3_rtk_set_dr_mode(rtk, 0);
Any other value should be invalid and should not invoke
dwc3_rtk_set_dr_mode().
> + }
> +
> + return 0;
> +}
> +
> +static enum usb_role dwc3_usb_role_switch_get(struct usb_role_switch *sw)
> +{
> + struct dwc3_rtk *rtk = usb_role_switch_get_drvdata(sw);
> + enum usb_role role = USB_ROLE_NONE;
> + int dr_mode;
> +
> + dr_mode = dwc3_rtk_get_dr_mode(rtk);
dwc3_rtk_get_dr_mode() returns int converted from enum usb_role. Now
you're mixing dr_mode with usb_role. Please use enum and avoid casting.
> + switch (dr_mode) {
> + case USB_DR_MODE_HOST:
> + role = USB_ROLE_HOST;
> + break;
> + case USB_DR_MODE_PERIPHERAL:
> + role = USB_ROLE_DEVICE;
> + break;
> + default:
> + dev_dbg(rtk->dev, "%s dr_mode=%d", __func__, dr_mode);
> + break;
> + }
> + return role;
> +}
> +
> +static int dwc3_rtk_setup_role_switch(struct dwc3_rtk *rtk)
> +{
> + struct usb_role_switch_desc dwc3_role_switch = {NULL};
> +
> + dwc3_role_switch.name = strchrnul(dev_name(rtk->dev), '.') + 1;
Why not just use dev_name(rtk->dev)?
> + dwc3_role_switch.driver_data = rtk;
> + dwc3_role_switch.allow_userspace_control = true;
> + dwc3_role_switch.fwnode = dev_fwnode(rtk->dev);
> + dwc3_role_switch.set = dwc3_usb_role_switch_set;
> + dwc3_role_switch.get = dwc3_usb_role_switch_get;
> + rtk->role_switch = usb_role_switch_register(rtk->dev, &dwc3_role_switch);
> + if (IS_ERR(rtk->role_switch))
> + return PTR_ERR(rtk->role_switch);
> +
> + return 0;
> +}
> +
> +static int dwc3_rtk_remove_role_switch(struct dwc3_rtk *rtk)
> +{
> + if (rtk->role_switch)
> + usb_role_switch_unregister(rtk->role_switch);
> +
> + rtk->role_switch = NULL;
> +
> + return 0;
> +}
> +#else
> +#define dwc3_rtk_setup_role_switch(x) 0
> +#define dwc3_rtk_remove_role_switch(x) 0
> +#endif
> +
> +static const char *const speed_names[] = {
> + [USB_SPEED_UNKNOWN] = "UNKNOWN",
> + [USB_SPEED_LOW] = "low-speed",
> + [USB_SPEED_FULL] = "full-speed",
> + [USB_SPEED_HIGH] = "high-speed",
> + [USB_SPEED_WIRELESS] = "wireless",
> + [USB_SPEED_SUPER] = "super-speed",
> + [USB_SPEED_SUPER_PLUS] = "super-speed-plus",
> +};
> +
> +static enum usb_device_speed __get_dwc3_maximum_speed(struct device_node *np)
> +{
> + struct device_node *dwc3_np;
> + const char *maximum_speed;
> + int ret;
> +
> + dwc3_np = of_get_compatible_child(np, "snps,dwc3");
> + if (!dwc3_np)
> + return USB_SPEED_UNKNOWN;
> +
> + ret = of_property_read_string(dwc3_np, "maximum-speed", &maximum_speed);
> + if (ret < 0)
> + return USB_SPEED_UNKNOWN;
> +
> + ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
> +
> + return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
> +}
> +
> +static int dwc3_rtk_init(struct dwc3_rtk *rtk)
> +{
> + struct device *dev = rtk->dev;
> + void __iomem *regs = rtk->regs;
> + enum usb_device_speed maximum_speed;
> + const struct soc_device_attribute rtk_soc_kylin_a00[] = {
> + { .family = "Realtek Kylin", .revision = "A00", },
> + { /* empty */ } };
> + const struct soc_device_attribute rtk_soc_hercules[] = {
> + { .family = "Realtek Hercules", }, { /* empty */ } };
> + const struct soc_device_attribute rtk_soc_thor[] = {
> + { .family = "Realtek Thor", }, { /* empty */ } };
> +
> + if (soc_device_match(rtk_soc_kylin_a00)) {
> + writel(DISABLE_MULTI_REQ | readl(regs + WRAP_CTR_REG),
> + regs + WRAP_CTR_REG);
> + dev_info(dev, "[bug fixed] 1295/1296 A00: add workaround to disable multiple request for D-Bus");
> + }
> +
> + if (soc_device_match(rtk_soc_hercules)) {
> + writel(USB2_PHY_EN_PHY_PLL_PORT1 |
> + readl(regs + WRAP_USB2_PHY_REG),
> + regs + WRAP_USB2_PHY_REG);
> + dev_info(dev, "[bug fixed] 1395 add workaround to disable usb2 port 2 suspend!");
> + }
> +
> + writel(TXHSVM_EN | readl(regs + WRAP_USB2_PHY_UTMI_REG),
> + regs + WRAP_USB2_PHY_UTMI_REG);
> +
> + maximum_speed = __get_dwc3_maximum_speed(dev->of_node);
> + if (maximum_speed != USB_SPEED_UNKNOWN && maximum_speed <= USB_SPEED_HIGH) {
> + void __iomem *reg;
> + int val;
> +
> + if (soc_device_match(rtk_soc_thor)) {
> + reg = regs + WRAP_USB_HMAC_CTR0_REG;
> + val = U3PORT_DIS | readl(reg);
> + writel(val, reg);
> + } else {
> + reg = regs + WRAP_CTR_REG;
> + val = FORCE_PIPE3_PHY_STATUS_TO_0 | readl(reg);
> + writel(val, reg);
> +
> + reg = regs + WRAP_PHY_PIPE_REG;
> + val = ~CLOCK_ENABLE_FOR_PIPE3_PCLK & readl(reg);
> + val |= RESET_DISABLE_PIPE3_P0;
> + writel(val, reg);
> +
> + reg = regs + WRAP_USB_HMAC_CTR0_REG;
> + val = U3PORT_DIS | readl(reg);
> + writel(val, reg);
> +
> + reg = regs + WRAP_APHY_REG;
> + val = ~USB3_MBIAS_ENABLE & readl(reg);
> + writel(val, reg);
> +
> + dev_info(rtk->dev, "%s: disable usb 3.0 phy\n", __func__);
> + }
> + }
> +
> + writel(DESC_R2W_MULTI_DISABLE | readl(regs + WRAP_CTR_REG),
> + regs + WRAP_CTR_REG);
> +
> + /* Set phy Dp/Dm initial state to host mode to avoid the Dp glitch */
> + writel(USB2_PHY_SWITCH_HOST |
> + (~USB2_PHY_SWITCH_MASK & readl(regs + WRAP_USB2_PHY_REG)),
> + regs + WRAP_USB2_PHY_REG);
> +
> + if (rtk->pm_base) {
> + void __iomem *reg;
> + int val;
> +
> + reg = rtk->pm_base + USB_DBUS_PWR_CTRL_REG;
> + val = DBUS_PWR_CTRL_EN | readl(reg);
> + writel(val, reg);
> + }
> +
> + return 0;
> +}
> +
> +static int dwc3_rtk_probe_dwc3_core(struct dwc3_rtk *rtk)
> +{
> + struct device *dev = rtk->dev;
> + struct device_node *node = dev->of_node;
> + struct platform_device *dwc3_pdev;
> + struct device *dwc3_dev;
> + struct device_node *dwc3_node;
> + int dr_mode;
> + int ret = 0;
> +
> + ret = dwc3_rtk_init(rtk);
> + if (ret)
> + return -EINVAL;
> +
> + ret = of_platform_populate(node, NULL, NULL, dev);
> + if (ret) {
> + dev_err(dev, "failed to add dwc3 core\n");
> + return ret;
> + }
> +
> + dwc3_node = of_get_compatible_child(node, "snps,dwc3");
> + if (!dwc3_node) {
> + dev_err(dev, "failed to find dwc3 core node\n");
> + ret = -ENODEV;
> + goto depopulate;
> + }
> +
> + dwc3_pdev = of_find_device_by_node(dwc3_node);
> + if (!dwc3_pdev) {
> + dev_err(dev, "failed to find dwc3 core platform_device\n");
> + ret = -ENODEV;
> + goto err_node_put;
> + }
> +
> + dwc3_dev = &dwc3_pdev->dev;
> + rtk->dwc = platform_get_drvdata(dwc3_pdev);
> + if (!rtk->dwc) {
> + dev_err(dev, "failed to find dwc3 core\n");
> + ret = -ENODEV;
> + goto err_pdev_put;
> + }
> +
> + dr_mode = usb_get_dr_mode(dwc3_dev);
> + if (dr_mode != rtk->dwc->dr_mode) {
> + dev_info(dev, "dts set dr_mode=%d, but dwc3 set dr_mode=%d\n",
> + dr_mode, rtk->dwc->dr_mode);
> + dr_mode = rtk->dwc->dr_mode;
> + }
> +
> + rtk->cur_dr_mode = dr_mode;
> +
> + if (device_property_read_bool(dwc3_dev, "usb-role-switch")) {
> + ret = dwc3_rtk_setup_role_switch(rtk);
> + if (ret) {
> + dev_err(dev, "dwc3_rtk_setup_role_switch fail=%d\n", ret);
> + goto err_pdev_put;
> + }
> + rtk->cur_dr_mode = dwc3_rtk_get_dr_mode(rtk);
> + }
> +
> + switch_usb2_dr_mode(rtk, rtk->cur_dr_mode);
> +
> + return 0;
> +
> +err_pdev_put:
> + platform_device_put(dwc3_pdev);
> +err_node_put:
> + of_node_put(dwc3_node);
> +depopulate:
> + of_platform_depopulate(dev);
> +
> + return ret;
> +}
> +
> +static int dwc3_rtk_probe(struct platform_device *pdev)
> +{
> + struct dwc3_rtk *rtk;
> + struct device *dev = &pdev->dev;
> + struct resource *res;
> + void __iomem *regs;
> + int ret = 0;
> + unsigned long probe_time = jiffies;
> +
> + rtk = devm_kzalloc(dev, sizeof(*rtk), GFP_KERNEL);
> + if (!rtk) {
> + ret = -ENOMEM;
> + goto err1;
> + }
> +
> + platform_set_drvdata(pdev, rtk);
> +
> + rtk->dev = dev;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(dev, "missing memory resource\n");
> + ret = -ENODEV;
> + goto err1;
> + }
> +
> + regs = devm_ioremap_resource(dev, res);
> + if (IS_ERR(regs)) {
> + ret = PTR_ERR(regs);
> + goto err1;
> + }
> +
> + rtk->regs = regs;
> + rtk->regs_size = resource_size(res);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> + if (res) {
> + rtk->pm_base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(rtk->pm_base)) {
> + ret = PTR_ERR(rtk->pm_base);
> + goto err1;
> + }
> + }
> +
> + ret = dwc3_rtk_probe_dwc3_core(rtk);
> + if (ret)
> + goto err1;
> +
> + dev_dbg(dev, "%s ok! (take %d ms)\n", __func__,
> + jiffies_to_msecs(jiffies - probe_time));
This debug message doesn't look like it should be here unless it's early
in the development cycle. Do we need this debug message?
> +
> + return 0;
> +
> +err1:
Where's err2? If there are multiple gotos, provide more descriptive
names instead of just numbers.
> + return ret;
> +}
> +
> +static void dwc3_rtk_remove(struct platform_device *pdev)
> +{
> + struct dwc3_rtk *rtk = platform_get_drvdata(pdev);
> +
> + rtk->dwc = NULL;
> +
> + dwc3_rtk_remove_role_switch(rtk);
> +
> + of_platform_depopulate(rtk->dev);
> +}
> +
> +static void dwc3_rtk_shutdown(struct platform_device *pdev)
> +{
> + struct dwc3_rtk *rtk = platform_get_drvdata(pdev);
> +
> + of_platform_depopulate(rtk->dev);
> +}
> +
> +static const struct of_device_id rtk_dwc3_match[] = {
> + { .compatible = "realtek,rtd-dwc3" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, rtk_dwc3_match);
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int dwc3_rtk_suspend(struct device *dev)
> +{
> + return 0;
> +}
> +
> +static int dwc3_rtk_resume(struct device *dev)
> +{
> + struct dwc3_rtk *rtk = dev_get_drvdata(dev);
> +
> + dwc3_rtk_init(rtk);
> +
> + switch_usb2_dr_mode(rtk, rtk->cur_dr_mode);
> +
> + /* runtime set active to reflect active state. */
> + pm_runtime_disable(dev);
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> +
> + return 0;
> +}
> +
> +static const struct dev_pm_ops dwc3_rtk_dev_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(dwc3_rtk_suspend, dwc3_rtk_resume)
> +};
> +
> +#define DEV_PM_OPS (&dwc3_rtk_dev_pm_ops)
> +#else
> +#define DEV_PM_OPS NULL
> +#endif /* CONFIG_PM_SLEEP */
> +
> +static struct platform_driver dwc3_rtk_driver = {
> + .probe = dwc3_rtk_probe,
> + .remove_new = dwc3_rtk_remove,
> + .driver = {
> + .name = "rtk-dwc3",
> + .of_match_table = rtk_dwc3_match,
> + .pm = DEV_PM_OPS,
> + },
> + .shutdown = dwc3_rtk_shutdown,
> +};
> +
> +module_platform_driver(dwc3_rtk_driver);
> +
> +MODULE_AUTHOR("Stanley Chang <stanley_chang@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("DesignWare USB3 Realtek Glue Layer");
> +MODULE_ALIAS("platform:rtk-dwc3");
> +MODULE_LICENSE("GPL");
> +MODULE_SOFTDEP("pre: phy_rtk_usb2 phy_rtk_usb3");
> --
> 2.34.1
>
Thanks,
Thinh