Re: [PATCH 2/3] usb: cdns3: add StarFive JH7110 USB glue layer
From: Minda Chen
Date: Tue Mar 07 2023 - 02:49:49 EST
On 2023/3/7 2:24, Emil Renner Berthing wrote:
> On Mon, 6 Mar 2023 at 10:53, Minda Chen <minda.chen@xxxxxxxxxxxxxxxx> wrote:
>>
>> There is a Cadence USB3 core for JH7110 SoCs, the cdns
>> core is the child for this glue layer device.
>>
>> Signed-off-by: Minda Chen <minda.chen@xxxxxxxxxxxxxxxx>
>> ---
>> MAINTAINERS | 7 +
>> drivers/usb/cdns3/Kconfig | 11 +
>> drivers/usb/cdns3/Makefile | 1 +
>> drivers/usb/cdns3/cdns3-starfive.c | 399 +++++++++++++++++++++++++++++
>> 4 files changed, 418 insertions(+)
>> create mode 100644 drivers/usb/cdns3/cdns3-starfive.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index ee21213d4388..2a9e89922cad 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -19957,6 +19957,13 @@ M: William Qiu <william.qiu@xxxxxxxxxxxxxxxx>
>> S: Supported
>> F: Documentation/devicetree/bindings/soc/starfive/jh7110-syscon.yaml
>>
>> +STARFIVE JH71X0 USB PHY DRIVERS
>> +M: Emil Renner Berthing <kernel@xxxxxxxx>
>> +M: Minda Chen <minda.chen@xxxxxxxxxxxxxxxx>
>> +S: Maintained
>> +F: Documentation/devicetree/bindings/phy/starfive,jh7110-usb*.yaml
>> +F: drivers/usb/cdns3/cdns3-starfive.c
>> +
>> STATIC BRANCH/CALL
>> M: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
>> M: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
>> diff --git a/drivers/usb/cdns3/Kconfig b/drivers/usb/cdns3/Kconfig
>> index b98ca0a1352a..a0b0a2c5430b 100644
>> --- a/drivers/usb/cdns3/Kconfig
>> +++ b/drivers/usb/cdns3/Kconfig
>> @@ -78,6 +78,17 @@ config USB_CDNS3_IMX
>>
>> For example, imx8qm and imx8qxp.
>>
>> +config USB_CDNS3_STARFIVE
>> + tristate "Cadence USB3 support on StarFive SoC platforms"
>> + depends on SOC_STARFIVE || COMPILE_TEST || USB_CDNS3
>
> This entry is already under "if USB_CDNS3" and SOC_STARFIVE will
> become ARCH_STARFIVE in 6.3, so
> depends ARCH_STARFIVE || COMPILE_TEST
>
>> + help
>> + Say 'Y' or 'M' here if you are building for StarFive SoCs
>> + platforms that contain Cadence USB3 controller core.
>> +
>> + e.g. JH7110.
>> +
>> + If you choose to build this driver as module it will
>> + be dynamically linked and module will be called cdns3-starfive.ko
>> endif
>>
>> if USB_CDNS_SUPPORT
>> diff --git a/drivers/usb/cdns3/Makefile b/drivers/usb/cdns3/Makefile
>> index 61edb2f89276..48dfae75b5aa 100644
>> --- a/drivers/usb/cdns3/Makefile
>> +++ b/drivers/usb/cdns3/Makefile
>> @@ -24,6 +24,7 @@ endif
>> obj-$(CONFIG_USB_CDNS3_PCI_WRAP) += cdns3-pci-wrap.o
>> obj-$(CONFIG_USB_CDNS3_TI) += cdns3-ti.o
>> obj-$(CONFIG_USB_CDNS3_IMX) += cdns3-imx.o
>> +obj-$(CONFIG_USB_CDNS3_STARFIVE) += cdns3-starfive.o
>>
>> cdnsp-udc-pci-y := cdnsp-pci.o
>>
>> diff --git a/drivers/usb/cdns3/cdns3-starfive.c b/drivers/usb/cdns3/cdns3-starfive.c
>> new file mode 100644
>> index 000000000000..54d9978cfa59
>> --- /dev/null
>> +++ b/drivers/usb/cdns3/cdns3-starfive.c
>> @@ -0,0 +1,399 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/**
>> + * cdns-starfive.c - StarFive specific Glue layer for Cadence USB Controller
>> + *
>> + * Copyright (C) 2022 Starfive, Inc.
>> + * Author: yanhong <yanhong.wang@xxxxxxxxxxxxxxxx>
>
> Here their name is "yanhong", but below it's "YanHong Wang". I'm
> guessing the 2nd version is correct, but please make sure.
>
>> + * Author: Mason Huo <mason.huo@xxxxxxxxxxxxxxxx>
>> + * Author: Minda Chen <minda.chen@xxxxxxxxxxxxxxxx>
>> + */
>> +
>> +#include <linux/bits.h>
>> +#include <linux/clk.h>
>> +#include <linux/module.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/kernel.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/io.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/regmap.h>
>> +#include <linux/reset.h>
>> +#include <linux/usb/otg.h>
>> +#include "core.h"
>> +
>> +#define USB_STRAP_HOST BIT(17)
>> +#define USB_STRAP_DEVICE BIT(18)
>> +#define USB_STRAP_MASK GENMASK(18, 16)
>> +
>> +#define USB_SUSPENDM_HOST BIT(19)
>> +#define USB_SUSPENDM_DEVICE (0 << 19)
>> +#define USB_SUSPENDM_MASK BIT(19)
>> +
>> +#define USB_SUSPENDM_BYPS BIT(20)
>> +#define USB_REFCLK_MODE BIT(23)
>> +#define USB_PLL_EN BIT(22)
>> +#define USB_PDRSTN_SPLIT BIT(17)
>> +
>> +#define PCIE_CKREF_SRC_MASK GENMASK(19, 18)
>> +#define PCIE_CLK_SEL_MASK GENMASK(21, 20)
>> +#define PCIE_PHY_MODE BIT(20)
>> +#define PCIE_PHY_MODE_MASK GENMASK(21, 20)
>> +#define PCIE_USB3_BUS_WIDTH_MASK GENMASK(3, 2)
>> +#define PCIE_USB3_RATE_MASK GENMASK(6, 5)
>> +#define PCIE_USB3_RX_STANDBY_MASK BIT(7)
>> +#define PCIE_USB3_PHY_ENABLE BIT(4)
>> +#define PCIE_USB3_PHY_PLL_CTL_OFF (0x1f * 4)
>> +
>> +#define USB_125M_CLK_RATE 125000000
>> +
>> +#define USB_LS_KEEPALIVE_OFF 0x4
>> +#define USB_LS_KEEPALIVE_ENABLE BIT(4)
>> +
>> +#define USB3_DOWN_SS_MODE BIT(4)
>> +
>> +struct cdns_starfive {
>> + struct device *dev;
>> + struct regmap *stg_syscon;
>> + struct regmap *sys_syscon;
>> + struct reset_control *resets;
>> + struct clk_bulk_data *clks;
>> + int num_clks;
>> + struct clk *usb_125m_clk;
>> + u32 sys_offset;
>> + u32 stg_offset_4;
>> + u32 stg_offset_196;
>> + u32 stg_offset_328;
>> + u32 stg_offset_500;
>> + bool usb2_only;
>> + enum usb_dr_mode mode;
>> + void __iomem *phybase_20;
>> + void __iomem *phybase_30;
>> +};
>> +
>> +static int cdns_mode_init(struct platform_device *pdev,
>> + struct cdns_starfive *data)
>> +{
>> + enum usb_dr_mode mode;
>> +
>> + /* Init usb 2.0 utmi phy */
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_4,
>> + USB_SUSPENDM_BYPS, USB_SUSPENDM_BYPS);
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_4,
>> + USB_PLL_EN, USB_PLL_EN);
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_4,
>> + USB_REFCLK_MODE, USB_REFCLK_MODE);
>> +
>> + if (data->usb2_only) {
>> + /* Disconnect usb 3.0 phy mode */
>> + regmap_update_bits(data->sys_syscon, data->sys_offset,
>> + USB_PDRSTN_SPLIT, USB_PDRSTN_SPLIT);
>> + } else {
>> + /* Config usb 3.0 pipe phy */
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_196,
>> + PCIE_CKREF_SRC_MASK, 0);
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_196,
>> + PCIE_CLK_SEL_MASK, 0);
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_328,
>> + PCIE_PHY_MODE_MASK, PCIE_PHY_MODE);
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_500,
>> + PCIE_USB3_BUS_WIDTH_MASK, 0);
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_500,
>> + PCIE_USB3_RATE_MASK, 0);
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_500,
>> + PCIE_USB3_RX_STANDBY_MASK, 0);
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_500,
>> + PCIE_USB3_PHY_ENABLE, PCIE_USB3_PHY_ENABLE);
>> +
>> + /* Connect usb 3.0 phy mode */
>> + regmap_update_bits(data->sys_syscon, data->sys_offset,
>> + USB_PDRSTN_SPLIT, 0);
>> + }
>> + mode = usb_get_dr_mode(&pdev->dev);
>> + data->mode = mode;
>> +
>> + switch (mode) {
>> + case USB_DR_MODE_HOST:
>> + regmap_update_bits(data->stg_syscon,
>> + data->stg_offset_4,
>> + USB_STRAP_MASK,
>> + USB_STRAP_HOST);
>> + regmap_update_bits(data->stg_syscon,
>> + data->stg_offset_4,
>> + USB_SUSPENDM_MASK,
>> + USB_SUSPENDM_HOST);
>> + break;
>> +
>> + case USB_DR_MODE_PERIPHERAL:
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_4,
>> + USB_STRAP_MASK, USB_STRAP_DEVICE);
>> + regmap_update_bits(data->stg_syscon, data->stg_offset_4,
>> + USB_SUSPENDM_MASK, USB_SUSPENDM_DEVICE);
>> + break;
>> +
>> + case USB_DR_MODE_UNKNOWN:
>> + case USB_DR_MODE_OTG:
>> + default:
>> + break;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +
>> +static int cdns_clk_rst_init(struct cdns_starfive *data)
>> +{
>> + int ret;
>> +
>> + data->usb_125m_clk = devm_clk_get(data->dev, "usb_125m");
>> + if (IS_ERR(data->usb_125m_clk)) {
>> + dev_err(data->dev, "Failed to get usb 125m clock\n");
>> + ret = PTR_ERR(data->usb_125m_clk);
>> + goto exit;
>> + }
>
> This can be
> if (IS_ERR(data->usb_125m_clk))
> return dev_err_probe(data->dev, PTR_ERR(data->usb_125m_clk), "Failed
> to get usb 125m clock\n");
>
> This will also silence errors on -EPROBE_DEFER.
>
>> +
>> + data->num_clks = devm_clk_bulk_get_all(data->dev, &data->clks);
>> + if (data->num_clks < 0) {
>> + dev_err(data->dev, "Failed to get usb clocks\n");
>> + ret = -ENODEV;
>> + goto exit;
>> + }
>
> Again return dev_err_probe(data->dev, -ENODEV, ..
>
>> +
>> + /* Needs to set the USB_125M clock explicitly,
>> + * since it's divided from pll0 clock, and the pll0 clock
>> + * changes per the cpu frequency.
>> + */
>> + ret = clk_set_rate(data->usb_125m_clk, USB_125M_CLK_RATE);
>> + if (ret) {
>> + dev_err(data->dev, "Failed to set usb 125m clock\n");
>> + goto exit;
>> + }
>
> return dev_err_probe
>
>> + ret = clk_bulk_prepare_enable(data->num_clks, data->clks);
>> + if (ret) {
>> + dev_err(data->dev, "Failed to enable clocks\n");
>> + goto exit;
>> + }
>
> return dev_err_probe
>
>> +
>> + data->resets = devm_reset_control_array_get_exclusive(data->dev);
>> + if (IS_ERR(data->resets)) {
>> + ret = PTR_ERR(data->resets);
>> + dev_err(data->dev, "Failed to get usb resets");
>> + goto err_clk_init;
>> + }
>
> This can be
> ret = dev_err_probe(data->dev, PTR_ERR(data->resets), ..)
> goto err_clk_init;
>
>> + ret = reset_control_deassert(data->resets);
>
> This is where the driver fails for me, but the only place you don't
> write why. Add return dev_err_probe to be consistent.
>
>> + goto exit;
>> +
>> +err_clk_init:
>> + clk_bulk_disable_unprepare(data->num_clks, data->clks);
>> +exit:
>> + return ret;
>> +}
>> +
>> +static void cdns_starfive_set_phy(struct cdns_starfive *data)
>> +{
>> + unsigned int val;
>> +
>> + if (data->mode != USB_DR_MODE_PERIPHERAL) {
>> + /* Enable the LS speed keep-alive signal */
>> + val = readl(data->phybase_20 + USB_LS_KEEPALIVE_OFF);
>> + val |= USB_LS_KEEPALIVE_ENABLE;
>> + writel(val, data->phybase_20 + USB_LS_KEEPALIVE_OFF);
>> + }
>> +
>> + if (!data->usb2_only) {
>> + /* Configuare spread-spectrum mode: down-spread-spectrum */
>> + writel(USB3_DOWN_SS_MODE, data->phybase_30 + PCIE_USB3_PHY_PLL_CTL_OFF);
>> + }
>> +}
>> +
>> +static int cdns_starfive_phy_init(struct platform_device *pdev,
>> + struct cdns_starfive *data)
>> +{
>> + struct device *dev = &pdev->dev;
>> + int ret = 0;
>> +
>> + data->phybase_20 = devm_platform_ioremap_resource_byname(pdev, "usb2");
>> + if (IS_ERR(data->phybase_20)) {
>> + dev_err(dev, "Can't map phybase_20 IOMEM resource\n");
>> + ret = PTR_ERR(data->phybase_20);
>> + goto get_res_err;
>> + }
>
> return dev_err_probe(dev, PTR_ERROR(...
>
>> +
>> + data->phybase_30 = devm_platform_ioremap_resource_byname(pdev, "usb3");
>> + if (IS_ERR(data->phybase_30)) {
>> + dev_err(dev, "Can't map phybase_30 IOMEM resource\n");
>> + ret = PTR_ERR(data->phybase_30);
>> + goto get_res_err;
>> + }
>
> return dev_err_probe
>
>> +
>> + cdns_starfive_set_phy(data);
>> +
>> +get_res_err:
>> + return ret;
>
> now this can just be return 0;
>
>> +}
>> +
>> +static int cdns_starfive_probe(struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct device_node *node = pdev->dev.of_node;
>> + struct cdns_starfive *data;
>> + struct of_phandle_args args;
>> + int ret;
>> +
>> + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>> + if (!data)
>> + return -ENOMEM;
>> +
>> + platform_set_drvdata(pdev, data);
>> +
>> + data->dev = dev;
>> +
>> + data->usb2_only = device_property_read_bool(dev, "starfive,usb2-only");
>> + ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node,
>> + "starfive,stg-syscon", 4, 0, &args);
>
> This looks like syscon_regmap_lookup_by_phandle_args
>
>> + if (ret < 0) {
>> + dev_err(dev, "Failed to parse starfive,stg-syscon\n");
>> + return -EINVAL;
>> + }
>
> return dev_err_probe(dev, ret, ..
>
>> + data->stg_syscon = syscon_node_to_regmap(args.np);
>> + of_node_put(args.np);
>> + if (IS_ERR(data->stg_syscon))
>> + return PTR_ERR(data->stg_syscon);
>> + data->stg_offset_4 = args.args[0];
>> + data->stg_offset_196 = args.args[1];
>> + data->stg_offset_328 = args.args[2];
>> + data->stg_offset_500 = args.args[3];
>> +
>> + ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node,
>> + "starfive,sys-syscon", 1, 0, &args);
>
> syscon_regmap_lookup_by_phandle_args
>
>> + if (ret < 0) {
>> + dev_err(dev, "Failed to parse starfive,sys-syscon\n");
>> + return -EINVAL;
>> + }
>> +
>> + data->sys_syscon = syscon_node_to_regmap(args.np);
>> + of_node_put(args.np);
>> + if (IS_ERR(data->sys_syscon))
>> + return PTR_ERR(data->sys_syscon);
>> + data->sys_offset = args.args[0];
>> +
>> + cdns_mode_init(pdev, data);
>> +
>> + ret = cdns_clk_rst_init(data);
>> + if (ret < 0) {
>> + dev_err(&pdev->dev, "Failed to init usb clk reset: %d\n", ret);
>> + goto exit;
>> + }
>
> cdns_clk_rst_init already logs errors, so just
> if (ret)
> return ret;
>
>> + ret = cdns_starfive_phy_init(pdev, data);
>> + if (ret) {
>> + dev_err(dev, "Failed to init sratfive usb phy: %d\n", ret);
>> + goto exit;
>> + }
>
> if (ret)
> return ret;
>
>> + ret = of_platform_populate(node, NULL, NULL, dev);
>> + if (ret) {
>> + dev_err(dev, "Failed to create children: %d\n", ret);
>> + goto exit;
>> + }
>
> return dev_err_probe(dev, ret, "Failed to create children\n")
>
>> + device_set_wakeup_capable(dev, true);
>> + pm_runtime_set_active(dev);
>> + pm_runtime_enable(dev);
>> +
>> + dev_info(dev, "usb mode %d %s probe success\n",
>> + data->mode, data->usb2_only ? "2.0" : "3.0");
>> +
>> + return 0;
>> +exit:
>> + return ret;
>> +}
>> +
>> +static int cdns_starfive_remove_core(struct device *dev, void *c)
>> +{
>> + struct platform_device *pdev = to_platform_device(dev);
>> +
>> + platform_device_unregister(pdev);
>> +
>> + return 0;
>> +}
>> +
>> +static int cdns_starfive_remove(struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct cdns_starfive *data = dev_get_drvdata(dev);
>> +
>> + pm_runtime_get_sync(dev);
>> + device_for_each_child(dev, NULL, cdns_starfive_remove_core);
>> +
>> + reset_control_assert(data->resets);
>> + clk_bulk_disable_unprepare(data->num_clks, data->clks);
>> + pm_runtime_disable(dev);
>> + pm_runtime_put_noidle(dev);
>> + platform_set_drvdata(pdev, NULL);
>> +
>> + return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM
>> +static int cdns_starfive_resume(struct device *dev)
>> +{
>> + struct cdns_starfive *data = dev_get_drvdata(dev);
>> + int ret;
>> +
>> + ret = clk_set_rate(data->usb_125m_clk, USB_125M_CLK_RATE);
>> + if (ret)
>> + goto err;
>
> return ret;
>
>> +
>> + ret = clk_bulk_prepare_enable(data->num_clks, data->clks);
>> + if (ret)
>> + goto err;
>
> return ret;
>
>> + ret = reset_control_deassert(data->resets);
>> + if (ret)
>> + goto err;
>
> return ret;
>> + cdns_starfive_set_phy(data);
>> +err:
>> + return ret;
> now this can just be return 0;
>> +}
>> +
>> +static int cdns_starfive_suspend(struct device *dev)
>> +{
>> + struct cdns_starfive *data = dev_get_drvdata(dev);
>> +
>> + clk_bulk_disable_unprepare(data->num_clks, data->clks);
>> + reset_control_assert(data->resets);
>> +
>> + return 0;
>> +}
>> +#endif
>> +
>> +static const struct dev_pm_ops cdns_starfive_pm_ops = {
>> + SET_RUNTIME_PM_OPS(cdns_starfive_suspend, cdns_starfive_resume, NULL)
>> + SET_SYSTEM_SLEEP_PM_OPS(cdns_starfive_suspend, cdns_starfive_resume)
>> +};
>> +
>> +static const struct of_device_id cdns_starfive_of_match[] = {
>> + { .compatible = "starfive,jh7110-usb", },
>> + {},
>
> I like the idiom of using { /* sentinel */ } here
>
>> +};
>> +MODULE_DEVICE_TABLE(of, cdns_starfive_of_match);
>> +
>> +static struct platform_driver cdns_starfive_driver = {
>> + .probe = cdns_starfive_probe,
>> + .remove = cdns_starfive_remove,
>> + .driver = {
>> + .name = "cdns3-starfive",
>> + .of_match_table = cdns_starfive_of_match,
>> + .pm = &cdns_starfive_pm_ops,
>> + },
>> +};
>> +
>
> Empty line not needed like above.
>
ok, thanks. I will follow all the comments and change.
>> +module_platform_driver(cdns_starfive_driver);
>> +
>> +MODULE_ALIAS("platform:cdns3-starfive");
>> +MODULE_AUTHOR("YanHong Wang <yanhong.wang@xxxxxxxxxxxxxxxx>");
>> +MODULE_AUTHOR("Mason Huo <mason.huo@xxxxxxxxxxxxxxxx>");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("Cadence USB3 StarFive Glue Layer");
>> --
>> 2.17.1
>>