Hi Roger >On 18/11/18 12:09, Pawel Laszczak wrote: >> Patch adds core.c and core.h file that implements initialization >> of platform driver and adds function responsible for selecting, >> switching and running appropriate Device/Host mode. >> >> Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx> >> --- >> drivers/usb/cdns3/Makefile | 2 + >> drivers/usb/cdns3/core.c | 413 +++++++++++++++++++++++++++++++++++++ >> drivers/usb/cdns3/core.h | 100 +++++++++ >> 3 files changed, 515 insertions(+) >> create mode 100644 drivers/usb/cdns3/core.c >> create mode 100644 drivers/usb/cdns3/core.h >> >> diff --git a/drivers/usb/cdns3/Makefile b/drivers/usb/cdns3/Makefile >> index dcdd62003c6a..02d25b23c5d3 100644 >> --- a/drivers/usb/cdns3/Makefile >> +++ b/drivers/usb/cdns3/Makefile >> @@ -1,3 +1,5 @@ >> +obj-$(CONFIG_USB_CDNS3) += cdns3.o >> obj-$(CONFIG_USB_CDNS3_PCI_WRAP) += cdns3-pci.o >> >> +cdns3-y := core.o >> cdns3-pci-y := cdns3-pci-wrap.o >> diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c >> new file mode 100644 >> index 000000000000..f9055d4da67f >> --- /dev/null >> +++ b/drivers/usb/cdns3/core.c >> @@ -0,0 +1,413 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Cadence USBSS DRD Driver. >> + * >> + * Copyright (C) 2018 Cadence. >> + * >> + * Author: Peter Chen <peter.chen@xxxxxxx> >> + * Pawel Laszczak <pawell@xxxxxxxxxxx> >> + */ >> + >> +#include <linux/module.h> >> +#include <linux/kernel.h> >> +#include <linux/platform_device.h> >> +#include <linux/interrupt.h> >> +#include <linux/io.h> >> +#include <linux/pm_runtime.h> >> + >> +#include "gadget.h" >> +#include "core.h" >> + >> +static inline struct cdns3_role_driver *cdns3_get_current_role_driver(struct cdns3 *cdns) >> +{ >> + WARN_ON(cdns->role >= CDNS3_ROLE_END || !cdns->roles[cdns->role]); >> + return cdns->roles[cdns->role]; >> +} >> + >> +static inline int cdns3_role_start(struct cdns3 *cdns, enum cdns3_roles role) >> +{ >> + int ret; >> + >> + if (role >= CDNS3_ROLE_END) > >WARN_ON()? I agree. > >> + return 0; >> + >> + if (!cdns->roles[role]) >> + return -ENXIO; >> + >> + mutex_lock(&cdns->mutex); >> + cdns->role = role; >> + ret = cdns->roles[role]->start(cdns); >> + mutex_unlock(&cdns->mutex); >> + return ret; >> +} >> + >> +static inline void cdns3_role_stop(struct cdns3 *cdns) >> +{ >> + enum cdns3_roles role = cdns->role; >> + >> + if (role == CDNS3_ROLE_END) > >WARN_ON(role >= CNDS3_ROLE_END) ? I agree > >> + return; >> + >> + mutex_lock(&cdns->mutex); >> + cdns->roles[role]->stop(cdns); >> + cdns->role = CDNS3_ROLE_END; > >Why change the role here? You are just stopping the role not changing it. >I think cdns->role should remain unchanged, so we can call cdns3_role_start() >if required without error. This line is unnecessary. > >> + mutex_unlock(&cdns->mutex); >> +} >> + >> +static enum cdns3_roles cdns3_get_role(struct cdns3 *cdns) >> +{ >> + if (cdns->roles[CDNS3_ROLE_HOST] && cdns->roles[CDNS3_ROLE_GADGET]) { >> + //TODO: implements selecting device/host mode >> + return CDNS3_ROLE_HOST; >> + } >> + return cdns->roles[CDNS3_ROLE_HOST] >> + ? CDNS3_ROLE_HOST >> + : CDNS3_ROLE_GADGET; > >Why not just > return cdns->role; > >I'm wondering if we really need this function TODO will look likie: if (cdns3_is_host(cdns)) return CDNS3_ROLE_HOST; if (cdns3_is_device(cdns)) return CDNS3_ROLE_GADGET; Function selects initial role. Before invoking it the role is unknown. I think that function name should be changed because current name can be misleading. I will change it to cdns3_get_initial_role. . >> +} > >> + >> +/** >> + * cdns3_core_init_role - initialize role of operation >> + * @cdns: Pointer to cdns3 structure >> + * >> + * Returns 0 on success otherwise negative errno >> + */ >> +static int cdns3_core_init_role(struct cdns3 *cdns) >> +{ >> + struct device *dev = cdns->dev; >> + enum usb_dr_mode dr_mode; >> + >> + dr_mode = usb_get_dr_mode(dev); >> + cdns->role = CDNS3_ROLE_END; >> + >> + /* >> + * If driver can't read mode by means of usb_get_dr_mdoe function then >> + * chooses mode according with Kernel configuration. This setting >> + * can be restricted later depending on strap pin configuration. >> + */ >> + if (dr_mode == USB_DR_MODE_UNKNOWN) { >> + if (IS_ENABLED(CONFIG_USB_CDNS3_HOST) && >> + IS_ENABLED(CONFIG_USB_CDNS3_GADGET)) >> + dr_mode = USB_DR_MODE_OTG; >> + else if (IS_ENABLED(CONFIG_USB_CDNS3_HOST)) >> + dr_mode = USB_DR_MODE_HOST; >> + else if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET)) >> + dr_mode = USB_DR_MODE_PERIPHERAL; >> + } >> + >> + if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_HOST) { >> + //TODO: implements host initialization > > /* TODO: Add host role */ ? > >> + } >> + >> + if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_PERIPHERAL) { >> + //TODO: implements device initialization > > /* TODO: Add device role */ ? > >> + } >> + >> + if (!cdns->roles[CDNS3_ROLE_HOST] && !cdns->roles[CDNS3_ROLE_GADGET]) { >> + dev_err(dev, "no supported roles\n"); >> + return -ENODEV; >> + } >> + >> + cdns->dr_mode = dr_mode; >> + return 0; >> +} >> + >> +/** >> + * cdns3_irq - interrupt handler for cdns3 core device >> + * >> + * @irq: irq number for cdns3 core device >> + * @data: structure of cdns3 >> + * >> + * Returns IRQ_HANDLED or IRQ_NONE >> + */ >> +static irqreturn_t cdns3_irq(int irq, void *data) >> +{ >> + struct cdns3 *cdns = data; >> + irqreturn_t ret = IRQ_NONE; >> + >> + /* Handle device/host interrupt */ >> + if (cdns->role != CDNS3_ROLE_END) > >Is it because of this that you need to set role to END at role_stop? >I think it is better to add a state variable to struct cdns3_role_driver, so we can >check if it is active or stopped. > >e.g. > if (cdns3_get_current_role_driver(cdns)->state == CDNS3_ROLE_STATE_ACTIVE) Ok, I will do it in this way. >> + ret = cdns3_get_current_role_driver(cdns)->irq(cdns); >> + >> + return ret; >> +} >> + >> +static void cdns3_remove_roles(struct cdns3 *cdns) > >Should this be called cdns3_exit_roles() to be opposite of cdns3_init_roles()? Sounds better. I also change cdns3_host_remove to cdns3_host_exit and cdns3_gadget_remove to cdns3_gadget_exit. > >> +{ >> + //TODO: implements this function >> +} > >> + >> +static int cdns3_do_role_switch(struct cdns3 *cdns, enum cdns3_roles role) >> +{ >> + enum cdns3_roles current_role; >> + int ret = 0; >> + >> + current_role = cdns->role; >> + >> + if (role == CDNS3_ROLE_END) >> + return 0; > >role == END looks like error state. and it should never happen. >WARN here? Ok, will be changed. > >> + >> + dev_dbg(cdns->dev, "Switching role"); >> + > >Don't you have to stop the previous role before starting the new role? > >> + ret = cdns3_role_start(cdns, role); >> + if (ret) { >> + /* Back to current role */ >> + dev_err(cdns->dev, "set %d has failed, back to %d\n", >> + role, current_role); >> + ret = cdns3_role_start(cdns, current_role); >> + } >> + >> + return ret; >> +} >> + >> +/** >> + * cdns3_role_switch - work queue handler for role switch >> + * >> + * @work: work queue item structure >> + * >> + * Handles below events: >> + * - Role switch for dual-role devices >> + * - CDNS3_ROLE_GADGET <--> CDNS3_ROLE_END for peripheral-only devices >> + */ >> +static void cdns3_role_switch(struct work_struct *work) >> +{ >> + enum cdns3_roles role = CDNS3_ROLE_END; >> + struct cdns3 *cdns; >> + bool device, host; >> + >> + cdns = container_of(work, struct cdns3, role_switch_wq); >> + >> + //TODO: implements this functions. >> + //host = cdns3_is_host(cdns); >> + //device = cdns3_is_device(cdns); >> + host = 1; >> + device = 0; >> + >> + if (host) >> + role = CDNS3_ROLE_HOST; >> + else if (device) >> + role = CDNS3_ROLE_GADGET; >> + >> + if (cdns->desired_dr_mode == cdns->current_dr_mode && >> + cdns->role == role) >> + return; >> + > >I think all the below code can be moved to cdns3_do_role_switch(). Yes, I agree with you. cdns3_role_stop should be in cdns3_do_role_switch. >> + pm_runtime_get_sync(cdns->dev); >> + cdns3_role_stop(cdns); >> + >> + if (host) { >> + if (cdns->roles[CDNS3_ROLE_HOST]) >> + cdns3_do_role_switch(cdns, CDNS3_ROLE_HOST); >> + pm_runtime_put_sync(cdns->dev); >> + return; >> + } >> + >> + if (device) >> + cdns3_do_role_switch(cdns, CDNS3_ROLE_GADGET); >> + else >> + cdns3_do_role_switch(cdns, CDNS3_ROLE_END); >> + >> + pm_runtime_put_sync(cdns->dev); >> +} >> + >> +/** >> + * cdns3_probe - probe for cdns3 core device >> + * @pdev: Pointer to cdns3 core platform device >> + * >> + * Returns 0 on success otherwise negative errno >> + */ >> +static int cdns3_probe(struct platform_device *pdev) >> +{ >> + struct device *dev = &pdev->dev; >> + struct resource *res; >> + struct cdns3 *cdns; >> + void __iomem *regs; >> + int ret; >> + >> + cdns = devm_kzalloc(dev, sizeof(*cdns), GFP_KERNEL); >> + if (!cdns) >> + return -ENOMEM; >> + >> + cdns->dev = dev; >> + >> + platform_set_drvdata(pdev, cdns); >> + >> + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); >> + if (!res) { >> + dev_err(dev, "missing IRQ\n"); >> + return -ENODEV; >> + } >> + cdns->irq = res->start; >> + >> + /* >> + * Request memory region >> + * region-0: xHCI >> + * region-1: Peripheral >> + * region-2: OTG registers >> + */ > >The memory region order is different from the dt-binding. >There it is OTG, host(xhci), device (peripheral). I corrected dt-binding. > >> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> + regs = devm_ioremap_resource(dev, res); >> + >> + if (IS_ERR(regs)) >> + return PTR_ERR(regs); >> + cdns->xhci_regs = regs; >> + cdns->xhci_res = res; >> + >> + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); >> + regs = devm_ioremap_resource(dev, res); >> + if (IS_ERR(regs)) >> + return PTR_ERR(regs); >> + cdns->dev_regs = regs; >> + >> + res = platform_get_resource(pdev, IORESOURCE_MEM, 2); >> + regs = devm_ioremap_resource(dev, res); >> + if (IS_ERR(regs)) >> + return PTR_ERR(regs); >> + cdns->otg_regs = regs; >> + >> + mutex_init(&cdns->mutex); >> + >> + cdns->phy = devm_phy_get(dev, "cdns3,usbphy"); > >"cdns3,usbphy" is not documented in dt-binding. I assume that I should add to dt-binding (cdns3-usb.txt) something like: - phys: reference to the USB PHY - phy-names: name of the USB PHY, should be " cdns3,usbphy " > >> + if (IS_ERR(cdns->phy)) { >> + dev_info(dev, "no generic phy found\n"); >> + cdns->phy = NULL; >> + /* >> + * fall through here! >> + * if no generic phy found, phy init >> + * should be done under boot! >> + */ > >No you shouldn't fall through always if it is an error condition. >Something like this should work better. > > if (IS_ERR(cnds->phy)) { > ret = PTR_ERR(cdns->phy); > if (ret == -ENOSYS || ret == -ENODEV) { > cdns->phy = NULL; > } else if (ret == -EPROBE_DEFER) { > return ret; > } else { > dev_err(dev, "no phy found\n"); > goto err0; > } > } > >So if PHY was provided in DT, and PHY support/drivers is present >and error condition means something is wrong and we have to error out. > >> + } else { >> + phy_init(cdns->phy); >> + } > >You can do phy_init() outside the else. > Thank you for explanation. I will correct this. >> + >> + ret = cdns3_core_init_role(cdns); >> + if (ret) >> + goto err1; >> + >> + INIT_WORK(&cdns->role_switch_wq, cdns3_role_switch); >> + if (ret) >> + goto err2; >> + >> + if (ret) >> + goto err2; >> + >> + cdns->role = cdns3_get_role(cdns); > >I think this should move to cd I'll have a some though on ns3_core_init_role(). Ok, I will do it. > >> + >> + ret = devm_request_irq(dev, cdns->irq, cdns3_irq, IRQF_SHARED, >> + dev_name(dev), cdns); >> + >> + if (ret) >> + goto err2; > >How about moving request_irq to before cdsn3_core_init_role()? > >Then you can move cdns3_role_start() as well to core_init_role(). I'll give it some though on it, but probably I will probably have to change little other function.. So the new order should look like this: cdns3_drd_init devm_request_irq cdns3_core_init_role, cdns3_get_role, cdns3_role_start > >> + >> + ret = cdns3_role_start(cdns, cdns->role); >> + if (ret) { >> + dev_err(dev, "can't start %s role\n", >> + cdns3_get_current_role_driver(cdns)->name); >> + goto err2; >> + } >> + >> + device_set_wakeup_capable(dev, true); >> + pm_runtime_set_active(dev); >> + pm_runtime_enable(dev); >> + >> + /* >> + * The controller needs less time between bus and controller suspend, >> + * and we also needs a small delay to avoid frequently entering low >> + * power mode. >> + */ >> + pm_runtime_set_autosuspend_delay(dev, 20); >> + pm_runtime_mark_last_busy(dev); >> + pm_runtime_use_autosuspend(dev); >> + dev_dbg(dev, "Cadence USB3 core: probe succeed\n"); >> + >> + return 0; >> + >> +err2: >> + cdns3_remove_roles(cdns); >> +err1: > >phy_exit() ? I will add. > >> + return ret; >> +} >> + >> +/** >> + * cdns3_remove - unbind drd driver and clean up >> + * @pdev: Pointer to Linux platform device >> + * >> + * Returns 0 on success otherwise negative errno >> + */ >> +static int cdns3_remove(struct platform_device *pdev) >> +{ >> + struct cdns3 *cdns = platform_get_drvdata(pdev); >> + >> + pm_runtime_get_sync(&pdev->dev); >> + pm_runtime_disable(&pdev->dev); >> + pm_runtime_put_noidle(&pdev->dev); >> + cdns3_remove_roles(cdns); > >phy_exit() ? I will add. > >> + >> + return 0; >> +} >> + >> +#ifdef CONFIG_OF >> +static const struct of_device_id of_cdns3_match[] = { >> + { .compatible = "cdns,usb3" }, >> + { }, >> +}; >> +MODULE_DEVICE_TABLE(of, of_cdns3_match); >> +#endif >> + >> +#ifdef CONFIG_PM >> + >> +#ifdef CONFIG_PM_SLEEP >> +static int cdns3_suspend(struct device *dev) >> +{ >> + //TODO: implements this function >> + return 0; >> +} >> + >> +static int cdns3_resume(struct device *dev) >> +{ >> + //TODO: implements this function >> + return 0; >> +} >> +#endif /* CONFIG_PM_SLEEP */ >> +static int cdns3_runtime_suspend(struct device *dev) >> +{ //TODO: implements this function >> + return 0; >> +} >> + >> +static int cdns3_runtime_resume(struct device *dev) >> +{ >> + //TODO: implements this function >> + return 0; >> +} >> +#endif /* CONFIG_PM */ >> + >> +static const struct dev_pm_ops cdns3_pm_ops = { >> + SET_SYSTEM_SLEEP_PM_OPS(cdns3_suspend, cdns3_resume) >> + SET_RUNTIME_PM_OPS(cdns3_runtime_suspend, cdns3_runtime_resume, NULL) >> +}; >> + >> +static struct platform_driver cdns3_driver = { >> + .probe = cdns3_probe, >> + .remove = cdns3_remove, >> + .driver = { >> + .name = "cdns-usb3", >> + .of_match_table = of_match_ptr(of_cdns3_match), >> + .pm = &cdns3_pm_ops, >> + }, >> +}; >> + >> +static int __init cdns3_driver_platform_register(void) >> +{ >> + return platform_driver_register(&cdns3_driver); >> +} >> +module_init(cdns3_driver_platform_register); >> + >> +static void __exit cdns3_driver_platform_unregister(void) >> +{ >> + platform_driver_unregister(&cdns3_driver); >> +} >> +module_exit(cdns3_driver_platform_unregister); >> + >> +MODULE_ALIAS("platform:cdns3"); >> +MODULE_AUTHOR("Pawel Laszczak <pawell@xxxxxxxxxxx>"); >> +MODULE_LICENSE("GPL v2"); >> +MODULE_DESCRIPTION("Cadence USB3 DRD Controller Driver"); >> diff --git a/drivers/usb/cdns3/core.h b/drivers/usb/cdns3/core.h >> new file mode 100644 >> index 000000000000..7c8204fe4d3d >> --- /dev/null >> +++ b/drivers/usb/cdns3/core.h >> @@ -0,0 +1,100 @@ >> +/* SPDX-License-Identifier: GPL-2.0 */ >> +/* >> + * Cadence USBSS DRD Driver. >> + * >> + * Copyright (C) 2017 NXP >> + * Copyright (C) 2018 Cadence. >> + * >> + * Authors: Peter Chen <peter.chen@xxxxxxx> >> + * Pawel Laszczak <pawell@xxxxxxxxxxx> >> + */ >> +#include <linux/usb/otg.h> >> + >> +#ifndef __LINUX_CDNS3_CORE_H >> +#define __LINUX_CDNS3_CORE_H >> + >> +struct cdns3; >> +enum cdns3_roles { >> + CDNS3_ROLE_HOST = 0, >> + CDNS3_ROLE_GADGET, >> + CDNS3_ROLE_END, >> +}; >> + >> +/** >> + * struct cdns3_role_driver - host/gadget role driver >> + * @start: start this role >> + * @stop: stop this role >> + * @suspend: suspend callback for this role >> + * @resume: resume callback for this role >> + * @irq: irq handler for this role >> + * @name: role name string (host/gadget) >> + */ >> +struct cdns3_role_driver { >> + int (*start)(struct cdns3 *cdns); >> + void (*stop)(struct cdns3 *cdns); >> + int (*suspend)(struct cdns3 *cdns, bool do_wakeup); >> + int (*resume)(struct cdns3 *cdns, bool hibernated); >> + irqreturn_t (*irq)(struct cdns3 *cdns); >> + const char *name; >> +}; >> + >> +#define CDNS3_NUM_OF_CLKS 5 >> +/** >> + * struct cdns3 - Representation of Cadence USB3 DRD controller. >> + * @dev: pointer to Cadence device struct >> + * @xhci_regs: pointer to base of xhci registers >> + * @xhci_res: the resource for xhci >> + * @dev_regs: pointer to base of dev registers >> + * @otg_regs: pointer to base of otg registers >> + * @irq: irq number for controller >> + * @roles: array of supported roles for this controller >> + * @role: current role >> + * @host_dev: the child host device pointer for cdns3 core >> + * @gadget_dev: the child gadget device pointer for cdns3 core >> + * @usb: phy for this controller >> + * @role_switch_wq: work queue item for role switch >> + * @in_lpm: the controller in low power mode >> + * @wakeup_int: the wakeup interrupt >> + * @mutex: the mutex for concurrent code at driver >> + * @dr_mode: supported mode of operation it can be only Host, only Device >> + * or OTG mode that allow to switch between Device and Host mode. >> + * This field based on hardware configuration and cant't be changed. > >But dr_mode can be forced in device-tree. So it isn't really only hardware configuration. Right, I added dr_mode to dt-binding , so we have STRAP bits in registers and additionally optional dr_mode in device-tree. Driver should take into account this two options. I will remove this line. > >> + * @current_dr_role: current mode of operation when in dual-role mode >> + * @desired_dr_role: desired mode of operation when in dual-role mode. >> + * This value can be changed during runtime. >> + * Available options depends on dr_mode: >> + * dr_mode | desired_dr_role and current_dr_role >> + * ---------------------------------------------------------------- >> + * USB_DR_MODE_HOST | only USB_DR_MODE_HOST >> + * USB_DR_MODE_PERIPHERAL | only USB_DR_MODE_PERIPHERAL >> + * USB_DR_MODE_OTG | only USB_DR_MODE_HOST >> + * USB_DR_MODE_OTG | only USB_DR_MODE_PERIPHERAL >> + * USB_DR_MODE_OTG | USB_DR_MODE_OTG > >Do you need to update the right hand side to reflect ROLEs instead of MODE? I see that there are incorrect name. There should be mode instead role. In structure below the names are correct. > >> + * >> + * Desired_dr_role can be changed by means of debugfs. >> + * @root: debugfs root folder pointer >> + */ >> +struct cdns3 { >> + struct device *dev; >> + void __iomem *xhci_regs; >> + struct resource *xhci_res; >> + struct cdns3_usb_regs __iomem *dev_regs; >> + struct cdns3_otg_regs *otg_regs; >> + int irq; >> + struct cdns3_role_driver *roles[CDNS3_ROLE_END]; >> + enum cdns3_roles role; >> + struct device *host_dev; >> + struct device *gadget_dev; >> + struct phy *phy; >> + struct work_struct role_switch_wq; >> + int in_lpm:1; >> + int wakeup_int:1; >> + /* mutext used in workqueue*/ >> + struct mutex mutex; >> + enum usb_dr_mode dr_mode; >> + enum usb_dr_mode current_dr_mode; >> + enum usb_dr_mode desired_dr_mode; >> + struct dentry *root; >> +}; >> + >> +#endif /* __LINUX_CDNS3_CORE_H */ >> > >cheers, >-roger >-- >Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. >Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki Thank for all your comments, Cheers, Pawel