Re: [PATCH 1/1] usb: cdns3: add NXP imx8qm glue layer

[Roger Quadros <rogerq@ti.com>]

Hi Peter,

On 27/12/2019 07:59, Peter Chen wrote:
> There is a Cadence USB3 core for imx8qm and imx8qxp SoCs, the cdns
> core is the child for this glue layer device.
> 
> Signed-off-by: Peter Chen <peter.chen@nxp.com>
> ---
>   drivers/usb/cdns3/Kconfig     |  10 ++
>   drivers/usb/cdns3/Makefile    |   1 +
>   drivers/usb/cdns3/cdns3-imx.c | 220 ++++++++++++++++++++++++++++++++++
>   3 files changed, 231 insertions(+)
>   create mode 100644 drivers/usb/cdns3/cdns3-imx.c
> 
> diff --git a/drivers/usb/cdns3/Kconfig b/drivers/usb/cdns3/Kconfig
> index 2a1e89d12ed9..b1f526d20f03 100644
> --- a/drivers/usb/cdns3/Kconfig
> +++ b/drivers/usb/cdns3/Kconfig
> @@ -53,4 +53,14 @@ config USB_CDNS3_TI
>   
>   	  e.g. J721e.
>   
> +config USB_CDNS3_IMX
> +	tristate "Cadence USB3 support on NXP i.MX platforms"
> +	depends on ARCH_MXC
> +	default USB_CDNS3
> +	help
> +	  Say 'Y' or 'M' here if you are building for NXP i.MX
> +	  platforms that contain Cadence USB3 controller core.
> +
> +	  For example, imx8qm and imx8qxp.
> +
>   endif
> diff --git a/drivers/usb/cdns3/Makefile b/drivers/usb/cdns3/Makefile
> index 948e6b88d1a9..d47e341a6f39 100644
> --- a/drivers/usb/cdns3/Makefile
> +++ b/drivers/usb/cdns3/Makefile
> @@ -15,3 +15,4 @@ cdns3-$(CONFIG_USB_CDNS3_HOST)		+= host.o
>   
>   obj-$(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
> diff --git a/drivers/usb/cdns3/cdns3-imx.c b/drivers/usb/cdns3/cdns3-imx.c
> new file mode 100644
> index 000000000000..53b47306bcc2
> --- /dev/null
> +++ b/drivers/usb/cdns3/cdns3-imx.c
> @@ -0,0 +1,220 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/**
> + * cdns3-imx.c - NXP i.MX specific Glue layer for Cadence USB Controller
> + *
> + * Copyright (C) 2019 NXP
> + */
> +
> +#include <linux/bits.h>
> +#include <linux/clk.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/io.h>
> +#include <linux/of_platform.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/iopoll.h>
> +
> +#define USB3_CORE_CTRL1    0x00
> +#define USB3_CORE_CTRL2    0x04
> +#define USB3_INT_REG       0x08
> +#define USB3_CORE_STATUS   0x0c
> +#define XHCI_DEBUG_LINK_ST 0x10
> +#define XHCI_DEBUG_BUS     0x14
> +#define USB3_SSPHY_CTRL1   0x40
> +#define USB3_SSPHY_CTRL2   0x44
> +#define USB3_SSPHY_STATUS  0x4c
> +#define USB2_PHY_CTRL1     0x50
> +#define USB2_PHY_CTRL2     0x54
> +#define USB2_PHY_STATUS    0x5c
> +
> +/* Register bits definition */
> +
> +/* USB3_CORE_CTRL1 */
> +#define SW_RESET_MASK	(0x3f << 26)
> +#define PWR_SW_RESET	(1 << 31)

You could use BIT() macro here.

> +#define APB_SW_RESET	(1 << 30)
> +#define AXI_SW_RESET	(1 << 29)
> +#define RW_SW_RESET	(1 << 28)
> +#define PHY_SW_RESET	(1 << 27)
> +#define PHYAHB_SW_RESET	(1 << 26)
> +#define ALL_SW_RESET	(PWR_SW_RESET | APB_SW_RESET | AXI_SW_RESET | \
> +		RW_SW_RESET | PHY_SW_RESET | PHYAHB_SW_RESET)
> +#define OC_DISABLE	(1 << 9)
> +#define MDCTRL_CLK_SEL	(1 << 7)
> +#define MODE_STRAP_MASK	(0x7)
> +#define DEV_MODE	(1 << 2)
> +#define HOST_MODE	(1 << 1)
> +#define OTG_MODE	(1 << 0)
> +
> +/* USB3_INT_REG */
> +#define CLK_125_REQ	(1 << 29)
> +#define LPM_CLK_REQ	(1 << 28)
> +#define DEVU3_WAEKUP_EN	(1 << 14)
> +#define OTG_WAKEUP_EN	(1 << 12)
> +#define DEV_INT_EN (3 << 8) /* DEV INT b9:8 */
> +#define HOST_INT1_EN (1 << 0) /* HOST INT b7:0 */
> +
> +/* USB3_CORE_STATUS */
> +#define MDCTRL_CLK_STATUS	(1 << 15)
> +#define DEV_POWER_ON_READY	(1 << 13)
> +#define HOST_POWER_ON_READY	(1 << 12)
> +
> +/* USB3_SSPHY_STATUS */
> +#define CLK_VALID_MASK		(0x3f << 26)
> +#define CLK_VALID_COMPARE_BITS	(0xf << 28)
> +#define PHY_REFCLK_REQ		(1 << 0)
> +
> +struct cdns_imx {
> +	struct device *dev;
> +	void __iomem *noncore;
> +	struct clk_bulk_data *clks;
> +	int num_clks;
> +};
> +
> +static inline u32 cdns_imx_readl(struct cdns_imx *data, u32 offset)
> +{
> +	return readl(data->noncore + offset);
> +}
> +
> +static inline void cdns_imx_writel(struct cdns_imx *data, u32 offset, u32 value)
> +{
> +	writel(value, data->noncore + offset);
> +}
> +
> +static const struct clk_bulk_data imx_cdns3_core_clks[] = {
> +	{ .id = "usb3_lpm_clk" },
> +	{ .id = "usb3_bus_clk" },
> +	{ .id = "usb3_aclk" },
> +	{ .id = "usb3_ipg_clk" },
> +	{ .id = "usb3_core_pclk" },
> +};
> +
> +static int cdns_imx_noncore_init(struct cdns_imx *data)
> +{
> +	u32 value;
> +	int ret;
> +	struct device *dev = data->dev;
> +
> +	cdns_imx_writel(data, USB3_SSPHY_STATUS, CLK_VALID_MASK);
> +	udelay(1);
> +	ret = readl_poll_timeout(data->noncore + USB3_SSPHY_STATUS, value,
> +		(value & CLK_VALID_COMPARE_BITS) == CLK_VALID_COMPARE_BITS,
> +		10, 100000);
> +	if (ret) {
> +		dev_err(dev, "wait clkvld timeout\n");
> +		return ret;
> +	}
> +
> +	value = cdns_imx_readl(data, USB3_CORE_CTRL1);
> +	value |= ALL_SW_RESET;
> +	cdns_imx_writel(data, USB3_CORE_CTRL1, value);
> +	udelay(1);
> +
> +	value = cdns_imx_readl(data, USB3_CORE_CTRL1);
> +	value = (value & ~MODE_STRAP_MASK) | OTG_MODE | OC_DISABLE;
> +	cdns_imx_writel(data, USB3_CORE_CTRL1, value);
> +
> +	value = cdns_imx_readl(data, USB3_INT_REG);
> +	value |= HOST_INT1_EN | DEV_INT_EN;
> +	cdns_imx_writel(data, USB3_INT_REG, value);
> +
> +	value = cdns_imx_readl(data, USB3_CORE_CTRL1);
> +	value &= ~ALL_SW_RESET;
> +	cdns_imx_writel(data, USB3_CORE_CTRL1, value);
> +	return ret;
> +}
> +
> +static int cdns_imx_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *node = dev->of_node;
> +	struct cdns_imx *data;
> +	int ret;
> +
> +	if (!node)
> +		return -ENODEV;
> +
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, data);
> +	data->dev = dev;
> +	data->noncore = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(data->noncore)) {
> +		dev_err(dev, "can't map IOMEM resource\n");
> +		return PTR_ERR(data->noncore);
> +	}
> +
> +	data->num_clks = ARRAY_SIZE(imx_cdns3_core_clks);
> +	data->clks = (struct clk_bulk_data *)imx_cdns3_core_clks;
> +	ret = devm_clk_bulk_get(dev, data->num_clks, data->clks);
> +	if (ret)
> +		return ret;
> +
> +	ret = clk_bulk_prepare_enable(data->num_clks, data->clks);
> +	if (ret)
> +		return ret;
> +
> +	ret = cdns_imx_noncore_init(data);
> +	if (ret)
> +		goto err;
> +
> +	ret = of_platform_populate(node, NULL, NULL, dev);
> +	if (ret) {
> +		dev_err(dev, "failed to create children: %d\n", ret);
> +		goto err;
> +	}
> +
> +	return ret;
> +
> +err:
> +	clk_bulk_disable_unprepare(data->num_clks, data->clks);
> +	return ret;
> +}
> +
> +static int cdns_imx_remove_core(struct device *dev, void *data)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +
> +	platform_device_unregister(pdev);
> +
> +	return 0;
> +}
> +
> +static int cdns_imx_remove(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +
> +	device_for_each_child(dev, NULL, cdns_imx_remove_core);
> +	pm_runtime_put_sync(dev);

You didn't do a pm_runtime_get_sync() in probe().
doesn't this complain on module remove?

> +	pm_runtime_disable(dev);
> +

What about disabling the bulk clocks that were enabled in probe?

> +	platform_set_drvdata(pdev, NULL);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id cdns_imx_of_match[] = {
> +	{ .compatible = "fsl,imx8qm-usb3", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, cdns_imx_of_match);
> +
> +static struct platform_driver cdns_imx_driver = {
> +	.probe		= cdns_imx_probe,
> +	.remove		= cdns_imx_remove,
> +	.driver		= {
> +		.name	= "cdns3-imx",
> +		.of_match_table	= cdns_imx_of_match,
> +	},
> +};
> +module_platform_driver(cdns_imx_driver);
> +
> +MODULE_ALIAS("platform:cdns3-imx");
> +MODULE_AUTHOR("Peter Chen <peter.chen@nxp.com>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Cadence USB3 i.MX Glue Layer");
> 

-- 
cheers,
-roger

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