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SubjectRe: [RESEND PATCH v3 2/2] usb: dwc3: Add driver for Xilinx platforms
Hi Manish!

On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:
>Add a new driver for supporting Xilinx platforms. This driver is used
>for some sequence of operations required for Xilinx USB controllers.
>This driver is also used to choose between PIPE clock coming from SerDes
>and the Suspend Clock. Before the controller is out of reset, the clock
>selection should be changed to PIPE clock in order to make the USB
>controller work. There is a register added in Xilinx USB controller
>register space for the same.
>
>Signed-off-by: Manish Narani <manish.narani@xilinx.com>
>---
> drivers/usb/dwc3/Kconfig | 9 +
> drivers/usb/dwc3/Makefile | 1 +
> drivers/usb/dwc3/dwc3-of-simple.c | 1 -
> drivers/usb/dwc3/dwc3-xilinx.c | 334 ++++++++++++++++++++++++++++++
> 4 files changed, 344 insertions(+), 1 deletion(-)
> create mode 100644 drivers/usb/dwc3/dwc3-xilinx.c
>
>diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
>index 7a2304565a73..0e00e6dfccd8 100644
>--- a/drivers/usb/dwc3/Kconfig
>+++ b/drivers/usb/dwc3/Kconfig
>@@ -139,4 +139,13 @@ config USB_DWC3_QCOM
> for peripheral mode support.
> Say 'Y' or 'M' if you have one such device.
>
>+config USB_DWC3_XILINX
>+ tristate "Xilinx Platforms"
>+ depends on (ARCH_ZYNQMP || ARCH_VERSAL) && OF
>+ default USB_DWC3
>+ help
>+ Support Xilinx SoCs with DesignWare Core USB3 IP.
>+ This driver handles both ZynqMP and Versal SoC operations.
>+ Say 'Y' or 'M' if you have one such device.
>+
> endif
>diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
>index ae86da0dc5bd..add567578b1f 100644
>--- a/drivers/usb/dwc3/Makefile
>+++ b/drivers/usb/dwc3/Makefile
>@@ -51,3 +51,4 @@ obj-$(CONFIG_USB_DWC3_MESON_G12A) += dwc3-meson-g12a.o
> obj-$(CONFIG_USB_DWC3_OF_SIMPLE) += dwc3-of-simple.o
> obj-$(CONFIG_USB_DWC3_ST) += dwc3-st.o
> obj-$(CONFIG_USB_DWC3_QCOM) += dwc3-qcom.o
>+obj-$(CONFIG_USB_DWC3_XILINX) += dwc3-xilinx.o
>diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
>index e62ecd22b3ed..71fd620c5161 100644
>--- a/drivers/usb/dwc3/dwc3-of-simple.c
>+++ b/drivers/usb/dwc3/dwc3-of-simple.c
>@@ -172,7 +172,6 @@ static const struct dev_pm_ops dwc3_of_simple_dev_pm_ops = {
>
> static const struct of_device_id of_dwc3_simple_match[] = {
> { .compatible = "rockchip,rk3399-dwc3" },
>- { .compatible = "xlnx,zynqmp-dwc3" },
> { .compatible = "cavium,octeon-7130-usb-uctl" },
> { .compatible = "sprd,sc9860-dwc3" },
> { .compatible = "allwinner,sun50i-h6-dwc3" },
>diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-xilinx.c
>new file mode 100644
>index 000000000000..7e485951d2f7
>--- /dev/null
>+++ b/drivers/usb/dwc3/dwc3-xilinx.c
>@@ -0,0 +1,334 @@
>+// SPDX-License-Identifier: GPL-2.0
>+/**
>+ * dwc3-xilinx.c - Xilinx DWC3 controller specific glue driver
>+ *
>+ * Authors: Manish Narani <manish.narani@xilinx.com>
>+ * Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
>+ */
>+
>+#include <linux/module.h>
>+#include <linux/kernel.h>
>+#include <linux/slab.h>
>+#include <linux/clk.h>
>+#include <linux/of.h>
>+#include <linux/platform_device.h>
>+#include <linux/dma-mapping.h>
>+#include <linux/of_platform.h>
>+#include <linux/pm_runtime.h>
>+#include <linux/reset.h>
>+#include <linux/of_address.h>
>+#include <linux/delay.h>
>+#include <linux/firmware/xlnx-zynqmp.h>
>+#include <linux/io.h>
>+
>+#include <linux/phy/phy.h>
>+
>+/* USB phy reset mask register */
>+#define XLNX_USB_PHY_RST_EN 0x001C
>+#define XLNX_PHY_RST_MASK 0x1
>+
>+/* Xilinx USB 3.0 IP Register */
>+#define XLNX_USB_TRAFFIC_ROUTE_CONFIG 0x005C
>+#define XLNX_USB_TRAFFIC_ROUTE_FPD 0x1
>+
>+/* Versal USB Reset ID */
>+#define VERSAL_USB_RESET_ID 0xC104036
>+
>+#define XLNX_USB_FPD_PIPE_CLK 0x7c
>+#define PIPE_CLK_DESELECT 1
>+#define PIPE_CLK_SELECT 0
>+#define XLNX_USB_FPD_POWER_PRSNT 0x80
>+#define PIPE_POWER_ON 1
>+#define PIPE_POWER_OFF 0
>+
>+struct dwc3_xlnx {
>+ int num_clocks;
>+ struct clk_bulk_data *clks;
>+ struct device *dev;
>+ void __iomem *regs;
>+ int (*pltfm_init)(struct dwc3_xlnx *data);
>+};
>+
>+static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool mask)
>+{
>+ u32 reg;
>+
>+ /*
>+ * Enable or disable ULPI PHY reset from USB Controller.
>+ * This does not actually reset the phy, but just controls
>+ * whether USB controller can or cannot reset ULPI PHY.
>+ */
>+ reg = readl(priv_data->regs + XLNX_USB_PHY_RST_EN);
>+
>+ if (mask)
>+ reg &= ~XLNX_PHY_RST_MASK;
>+ else
>+ reg |= XLNX_PHY_RST_MASK;
>+
>+ writel(reg, priv_data->regs + XLNX_USB_PHY_RST_EN);
>+}
>+
>+static int dwc3_xlnx_init_versal(struct dwc3_xlnx *priv_data)
>+{
>+ struct device *dev = priv_data->dev;
>+ int ret;
>+
>+ dwc3_xlnx_mask_phy_rst(priv_data, false);
>+
>+ /* Assert and De-assert reset */
>+ ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
>+ PM_RESET_ACTION_ASSERT);
>+ if (ret < 0) {
>+ dev_err_probe(dev, ret, "failed to assert Reset\n");
>+ return ret;
>+ }
>+
>+ ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
>+ PM_RESET_ACTION_RELEASE);
>+ if (ret < 0) {
>+ dev_err_probe(dev, ret, "failed to De-assert Reset\n");
>+ return ret;
>+ }
>+
>+ dwc3_xlnx_mask_phy_rst(priv_data, true);
>+
>+ return 0;
>+}
>+
>+static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data)
>+{
>+ struct device *dev = priv_data->dev;
>+ struct reset_control *crst, *hibrst, *apbrst;
>+ struct phy *usb3_phy;
>+ int ret;
>+ u32 reg;
>+
>+ crst = devm_reset_control_get_exclusive(dev, "usb_crst");
>+ if (IS_ERR(crst)) {
>+ ret = PTR_ERR(crst);
>+ dev_err_probe(dev, ret,
>+ "failed to get core reset signal\n");
>+ goto err;
>+ }
>+
>+ hibrst = devm_reset_control_get_exclusive(dev, "usb_hibrst");
>+ if (IS_ERR(hibrst)) {
>+ ret = PTR_ERR(hibrst);
>+ dev_err_probe(dev, ret,
>+ "failed to get hibernation reset signal\n");
>+ goto err;
>+ }
>+
>+ apbrst = devm_reset_control_get_exclusive(dev, "usb_apbrst");
>+ if (IS_ERR(apbrst)) {
>+ ret = PTR_ERR(apbrst);
>+ dev_err_probe(dev, ret,
>+ "failed to get APB reset signal\n");
>+ goto err;
>+ }
>+
>+ ret = reset_control_assert(crst);
>+ if (ret < 0) {
>+ dev_err(dev, "Failed to assert core reset\n");
>+ goto err;
>+ }
>+
>+ ret = reset_control_assert(hibrst);
>+ if (ret < 0) {
>+ dev_err(dev, "Failed to assert hibernation reset\n");
>+ goto err;
>+ }
>+
>+ ret = reset_control_assert(apbrst);
>+ if (ret < 0) {
>+ dev_err(dev, "Failed to assert APB reset\n");
>+ goto err;
>+ }
>+
>+ usb3_phy = devm_phy_get(dev, "usb3-phy");

You should move this phy get to probe code and skip the call of
pltfm_init if no phy was found.

As I understand this glue now, you will set an defined fixed-clock
frequency from dts in the ps-gtr phy. If no phy and therefor also no
clock is defined, the call of dwc3_xlnx_init_zynqmp can be skipped, as
you will not need to switch the clocks to an external lane source.

For example for the host case with node option dr_mode = "host" set and
no external physical external clksrc connected, this glue still needs to
be used. The current version would break this case.

Thanks,
Michael

>+ ret = phy_init(usb3_phy);
>+ if (ret < 0) {
>+ phy_exit(usb3_phy);
>+ goto err;
>+ }
>+
>+ ret = reset_control_deassert(apbrst);
>+ if (ret < 0) {
>+ dev_err(dev, "Failed to release APB reset\n");
>+ goto err;
>+ }
>+
>+ /* Set PIPE Power Present signal in FPD Power Present Register*/
>+ writel(PIPE_POWER_ON, priv_data->regs + XLNX_USB_FPD_POWER_PRSNT);
>+
>+ /* Set the PIPE Clock Select bit in FPD PIPE Clock register */
>+ writel(PIPE_CLK_SELECT, priv_data->regs + XLNX_USB_FPD_PIPE_CLK);
>+
>+ ret = reset_control_deassert(crst);
>+ if (ret < 0) {
>+ dev_err(dev, "Failed to release core reset\n");
>+ goto err;
>+ }
>+
>+ ret = reset_control_deassert(hibrst);
>+ if (ret < 0) {
>+ dev_err(dev, "Failed to release hibernation reset\n");
>+ goto err;
>+ }
>+
>+ ret = phy_power_on(usb3_phy);
>+ if (ret < 0) {
>+ phy_exit(usb3_phy);
>+ goto err;
>+ }
>+
>+ /*
>+ * This routes the USB DMA traffic to go through FPD path instead
>+ * of reaching DDR directly. This traffic routing is needed to
>+ * make SMMU and CCI work with USB DMA.
>+ */
>+ if (of_dma_is_coherent(dev->of_node) || device_iommu_mapped(dev)) {
>+ reg = readl(priv_data->regs + XLNX_USB_TRAFFIC_ROUTE_CONFIG);
>+ reg |= XLNX_USB_TRAFFIC_ROUTE_FPD;
>+ writel(reg, priv_data->regs + XLNX_USB_TRAFFIC_ROUTE_CONFIG);
>+ }
>+
>+err:
>+ return ret;
>+}
>+
>+static const struct of_device_id dwc3_xlnx_of_match[] = {
>+ {
>+ .compatible = "xlnx,zynqmp-dwc3",
>+ .data = &dwc3_xlnx_init_zynqmp,
>+ },
>+ {
>+ .compatible = "xlnx,versal-dwc3",
>+ .data = &dwc3_xlnx_init_versal,
>+ },
>+ { /* Sentinel */ }
>+};
>+MODULE_DEVICE_TABLE(of, dwc3_xlnx_of_match);
>+
>+static int dwc3_xlnx_probe(struct platform_device *pdev)
>+{
>+ struct dwc3_xlnx *priv_data;
>+ struct device *dev = &pdev->dev;
>+ struct device_node *np = dev->of_node;
>+ const struct of_device_id *match;
>+ void __iomem *regs;
>+ int ret;
>+
>+ priv_data = devm_kzalloc(dev, sizeof(*priv_data), GFP_KERNEL);
>+ if (!priv_data)
>+ return -ENOMEM;
>+
>+ regs = devm_platform_ioremap_resource(pdev, 0);
>+ if (IS_ERR(regs)) {
>+ ret = PTR_ERR(regs);
>+ dev_err_probe(dev, ret, "failed to map registers\n");
>+ return ret;
>+ }
>+
>+ match = of_match_node(dwc3_xlnx_of_match, pdev->dev.of_node);
>+
>+ priv_data->pltfm_init = match->data;
>+ priv_data->regs = regs;
>+ priv_data->dev = dev;
>+
>+ platform_set_drvdata(pdev, priv_data);
>+
>+ ret = devm_clk_bulk_get_all(priv_data->dev, &priv_data->clks);
>+ if (ret < 0)
>+ return ret;
>+
>+ priv_data->num_clocks = ret;
>+
>+ ret = clk_bulk_prepare_enable(priv_data->num_clocks, priv_data->clks);
>+ if (ret)
>+ return ret;
>+
>+ ret = priv_data->pltfm_init(priv_data);
>+ if (ret)
>+ goto err_clk_put;
>+
>+ ret = of_platform_populate(np, NULL, NULL, dev);
>+ if (ret)
>+ goto err_clk_put;
>+
>+ pm_runtime_set_active(dev);
>+ pm_runtime_enable(dev);
>+ pm_suspend_ignore_children(dev, false);
>+ pm_runtime_get_sync(dev);
>+
>+ return 0;
>+
>+err_clk_put:
>+ clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data->clks);
>+ clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
>+
>+ return ret;
>+}
>+
>+static int dwc3_xlnx_remove(struct platform_device *pdev)
>+{
>+ struct dwc3_xlnx *priv_data = platform_get_drvdata(pdev);
>+ struct device *dev = &pdev->dev;
>+
>+ of_platform_depopulate(dev);
>+
>+ clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data->clks);
>+ clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
>+ priv_data->num_clocks = 0;
>+
>+ pm_runtime_disable(dev);
>+ pm_runtime_put_noidle(dev);
>+ pm_runtime_set_suspended(dev);
>+
>+ return 0;
>+}
>+
>+static int __maybe_unused dwc3_xlnx_suspend_common(struct device *dev)
>+{
>+ struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
>+
>+ clk_bulk_disable(priv_data->num_clocks, priv_data->clks);
>+
>+ return 0;
>+}
>+
>+static int __maybe_unused dwc3_xlnx_resume_common(struct device *dev)
>+{
>+ struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
>+
>+ return clk_bulk_enable(priv_data->num_clocks, priv_data->clks);
>+}
>+
>+static int __maybe_unused dwc3_xlnx_runtime_idle(struct device *dev)
>+{
>+ pm_runtime_mark_last_busy(dev);
>+ pm_runtime_autosuspend(dev);
>+
>+ return 0;
>+}
>+
>+static UNIVERSAL_DEV_PM_OPS(dwc3_xlnx_dev_pm_ops, dwc3_xlnx_suspend_common,
>+ dwc3_xlnx_resume_common, dwc3_xlnx_runtime_idle);
>+
>+static struct platform_driver dwc3_xlnx_driver = {
>+ .probe = dwc3_xlnx_probe,
>+ .remove = dwc3_xlnx_remove,
>+ .driver = {
>+ .name = "dwc3-xilinx",
>+ .of_match_table = dwc3_xlnx_of_match,
>+ .pm = &dwc3_xlnx_dev_pm_ops,
>+ },
>+};
>+
>+module_platform_driver(dwc3_xlnx_driver);
>+
>+MODULE_LICENSE("GPL v2");
>+MODULE_DESCRIPTION("Xilinx DWC3 controller specific glue driver");
>+MODULE_AUTHOR("Manish Narani <manish.narani@xilinx.com>");
>+MODULE_AUTHOR("Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>");
>--
>2.17.1
>
>
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>linux-arm-kernel@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

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