Re: [PATCH 06/31] usb: usbssp: added template functions used by upper layer.

From: Roger Quadros
Date: Mon Aug 06 2018 - 04:57:11 EST




On 04/08/18 09:37, Pawel Laszczak wrote:
>>> Patch adds some functionality for initialization process.
>>> It adds to driver usbssp_reset and usbssp_start function.
>>>
>>> Next elements added are objects usbssp_gadget_ep0_ops,
>>> usbssp_gadget_ep_ops and usbssp_gadget_ops. These objects
>>> constitute the interface used by gadget subsystem.
>>> At this moment functions related to these objects are empty
>>> and do nothing.
>>>
>>> This patch also implements usbssp_gadget_init_endpoint and
>>> usbssp_gadget_free_endpoint used during initialization.
>>>
>>> Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
>>> ---
>>> drivers/usb/usbssp/gadget-ext-caps.h | 3 +
>>> drivers/usb/usbssp/gadget-if.c | 269 ++++++++++++++++++++++++++-
>>> drivers/usb/usbssp/gadget.c | 84 ++++++++-
>>> 3 files changed, 350 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/usb/usbssp/gadget-ext-caps.h b/drivers/usb/usbssp/gadget-ext-caps.h
>>> index 2bf327046376..86c0ce331037 100644
>>> --- a/drivers/usb/usbssp/gadget-ext-caps.h
>>> +++ b/drivers/usb/usbssp/gadget-ext-caps.h
>>> @@ -51,3 +51,6 @@
>>> #define USBSSP_CMD_EWE BIT(10)
>>>
>>> #define USBSSP_IRQS (USBSSP_CMD_EIE | USBSSP_CMD_HSEIE | USBSSP_CMD_EWE)
>>> +
>>> +/* true: Controller Not Ready to accept doorbell or op reg writes after reset */
>>> +#define USBSSP_STS_CNR BIT(11)
>>> diff --git a/drivers/usb/usbssp/gadget-if.c b/drivers/usb/usbssp/gadget-if.c
>>> index d53e0fb65299..70def978b085 100644
>>> --- a/drivers/usb/usbssp/gadget-if.c
>>> +++ b/drivers/usb/usbssp/gadget-if.c
>>> @@ -12,13 +12,278 @@
>>> #include <linux/usb/composite.h>
>>> #include "gadget.h"
>>>
>>> +static int usbssp_gadget_ep_enable(struct usb_ep *ep,
>>> + const struct usb_endpoint_descriptor *desc)
>>> +{
>>> + struct usbssp_ep *ep_priv = to_usbssp_ep(ep);
>>> + int ret = 0;
>>> +
>>> + if (!ep_priv)
>>> + return -EINVAL;
>>> +
>>> + /*TODO: implements this function*/
>>> + return ret;
>>> +}
>>> +
>>> +int usbssp_gadget_ep_disable(struct usb_ep *ep)
>>> +{
>>> + struct usbssp_ep *ep_priv = to_usbssp_ep(ep);
>>> + int ret = 0;
>>> +
>>> + if (!ep_priv)
>>> + return -EINVAL;
>>> +
>>> + /*TODO: implements this function*/
>>> + return ret;
>>> +}
>>> +
>>> +static struct usb_request *usbssp_gadget_ep_alloc_request(struct usb_ep *ep,
>>> + gfp_t gfp_flags)
>>> +{
>>> + struct usbssp_ep *ep_priv = to_usbssp_ep(ep);
>>> +
>>> + if (!ep_priv)
>>> + return NULL;
>>> +
>>> + /*TODO: implements this function*/
>>> + return NULL;
>>> +}
>>> +
>>> +static void usbssp_gadget_ep_free_request(struct usb_ep *ep,
>>> + struct usb_request *request)
>>> +{
>>> + struct usbssp_ep *ep_priv = to_usbssp_ep(ep);
>>> +
>>> + if (!ep_priv)
>>> + return;
>>> +
>>> + /*TODO: implements this function*/
>>> +}
>>> +
>>> +static int usbssp_gadget_ep_queue(struct usb_ep *ep,
>>> + struct usb_request *request,
>>> + gfp_t gfp_flags)
>>> +{
>>> + struct usbssp_ep *ep_priv = to_usbssp_ep(ep);
>>> + int ret = 0;
>>> +
>>> + if (!ep_priv)
>>> + return -EINVAL;
>>> +
>>> + /*TODO: implements this function*/
>>> + return ret;
>>> +}
>>> +
>>> +static int usbssp_gadget_ep_dequeue(struct usb_ep *ep,
>>> + struct usb_request *request)
>>> +{
>>> + struct usbssp_ep *ep_priv = to_usbssp_ep(ep);
>>> + int ret = 0;
>>> +
>>> + if (!ep_priv)
>>> + return -EINVAL;
>>> +
>>> + /*TODO: implements this function*/
>>> + return ret;
>>> +}
>>> +
>>> +static int usbssp_gadget_ep_set_halt(struct usb_ep *ep, int value)
>>> +{
>>> + struct usbssp_ep *ep_priv = to_usbssp_ep(ep);
>>> + int ret = 0;
>>> +
>>> + if (!ep_priv)
>>> + return -EINVAL;
>>> +
>>> + /*TODO: implements this function*/
>>> + return ret;
>>> +}
>>> +
>>> +static int usbssp_gadget_ep_set_wedge(struct usb_ep *ep)
>>> +{
>>> + struct usbssp_ep *ep_priv = to_usbssp_ep(ep);
>>> + int ret = 0;
>>> +
>>> + if (!ep_priv)
>>> + return -EINVAL;
>>> +
>>> + /*TODO: implements this function*/
>>> + return ret;
>>> +}
>>> +
>>> +static const struct usb_ep_ops usbssp_gadget_ep0_ops = {
>>> + .enable = usbssp_gadget_ep_enable,
>>> + .disable = usbssp_gadget_ep_disable,
>>> + .alloc_request = usbssp_gadget_ep_alloc_request,
>>> + .free_request = usbssp_gadget_ep_free_request,
>>> + .queue = usbssp_gadget_ep_queue,
>>> + .dequeue = usbssp_gadget_ep_dequeue,
>>> + .set_halt = usbssp_gadget_ep_set_halt,
>>> + .set_wedge = usbssp_gadget_ep_set_wedge,
>>> +};
>>> +
>>> +static const struct usb_ep_ops usbssp_gadget_ep_ops = {
>>> + .enable = usbssp_gadget_ep_enable,
>>> + .disable = usbssp_gadget_ep_disable,
>>> + .alloc_request = usbssp_gadget_ep_alloc_request,
>>> + .free_request = usbssp_gadget_ep_free_request,
>>> + .queue = usbssp_gadget_ep_queue,
>>> + .dequeue = usbssp_gadget_ep_dequeue,
>>> + .set_halt = usbssp_gadget_ep_set_halt,
>>> + .set_wedge = usbssp_gadget_ep_set_wedge,
>>> +};
>>> +
>>> +static struct usb_endpoint_descriptor usbssp_gadget_ep0_desc = {
>>> + .bLength = USB_DT_ENDPOINT_SIZE,
>>> + .bDescriptorType = USB_DT_ENDPOINT,
>>> + .bmAttributes = USB_ENDPOINT_XFER_CONTROL,
>>> +};
>>> +
>>> +static int usbssp_gadget_start(struct usb_gadget *g,
>>> + struct usb_gadget_driver *driver)
>>> +{
>>> + struct usbssp_udc *usbssp_data = gadget_to_usbssp(g);
>>> + int ret = 0;
>>> +
>>> + if (usbssp_data->gadget_driver) {
>>> + dev_err(usbssp_data->dev, "%s is already bound to %s\n",
>>> + usbssp_data->gadget.name,
>>> + usbssp_data->gadget_driver->driver.name);
>>> + ret = -EBUSY;
>>> + }
>>> +
>>> + /*TODO: add implementation*/
>>> + return ret;
>>> +}
>>> +
>>> +static int usbssp_gadget_stop(struct usb_gadget *g)
>>> +{
>>> + struct usbssp_udc *usbssp_data = gadget_to_usbssp(g);
>>> +
>>> + if (!usbssp_data)
>>> + return -EINVAL;
>>> + /*TODO: add implementation*/
>>> + return 0;
>>> +}
>>> +
>>> +static int usbssp_gadget_get_frame(struct usb_gadget *g)
>>> +{
>>> + struct usbssp_udc *usbssp_data = gadget_to_usbssp(g);
>>> +
>>> + if (!usbssp_data)
>>> + return -EINVAL;
>>> +
>>> + /*TODO: add implementation*/
>>> + return 0;
>>> +}
>>> +
>>> +static int usbssp_gadget_wakeup(struct usb_gadget *g)
>>> +{
>>> + struct usbssp_udc *usbssp_data = gadget_to_usbssp(g);
>>> +
>>> + if (!usbssp_data)
>>> + return -EINVAL;
>>> +
>>> + /*TODO: add implementation*/
>>> + return 0;
>>> +}
>>> +
>>> +static int usbssp_gadget_set_selfpowered(struct usb_gadget *g,
>>> + int is_selfpowered)
>>> +{
>>> + struct usbssp_udc *usbssp_data = gadget_to_usbssp(g);
>>> +
>>> + if (!usbssp_data)
>>> + return -EINVAL;
>>> +
>>> + /*TODO: add implementation*/
>>> + return 0;
>>> +}
>>> +
>>> +static const struct usb_gadget_ops usbssp_gadget_ops = {
>>> + .get_frame = usbssp_gadget_get_frame,
>>> + .wakeup = usbssp_gadget_wakeup,
>>> + .set_selfpowered = usbssp_gadget_set_selfpowered,
>>> + .udc_start = usbssp_gadget_start,
>>> + .udc_stop = usbssp_gadget_stop,
>>> +};
>>> +
>>> int usbssp_gadget_init_endpoint(struct usbssp_udc *usbssp_data)
>>
>> Since we're initializing all endpoints this function should be named usbssp_gadget_init_endpoints().
>>
>>> {
>>> - /*TODO: it has to be implemented*/
>>> + int i = 0;
>>> + struct usbssp_ep *ep_priv;
>>> +
>>> + usbssp_data->num_endpoints = USBSSP_ENDPOINTS_NUM;
>>> + INIT_LIST_HEAD(&usbssp_data->gadget.ep_list);
>>> +
>>> + for (i = 1; i < usbssp_data->num_endpoints; i++) {
>>> + bool direction = i & 1; /*start from OUT endpoint*/
>>> + u8 epnum = (i >> 1);
>>> +
>>> + ep_priv = &usbssp_data->devs.eps[i-1];
>>> + ep_priv->usbssp_data = usbssp_data;
>>> + ep_priv->number = epnum;
>>> + ep_priv->direction = direction; /*0 for OUT, 1 for IN*/
>>> +
>>> + snprintf(ep_priv->name, sizeof(ep_priv->name), "ep%d%s", epnum,
>>> + (ep_priv->direction) ? "in" : "out");
>>> +
>>> + ep_priv->endpoint.name = ep_priv->name;
>>> +
>>> + if (ep_priv->number < 2) {
>>> + ep_priv->endpoint.desc = &usbssp_gadget_ep0_desc;
>>> + ep_priv->endpoint.comp_desc = NULL;
>>> + }
>>> +
>>> + if (epnum == 0) {
>>> + /*EP0 is bidirectional endpoint*/
>>> + usb_ep_set_maxpacket_limit(&ep_priv->endpoint, 512);
>>> + dev_dbg(usbssp_data->dev,
>>> + "Initializing %s, MaxPack: %04x Type: Ctrl\n",
>>> + ep_priv->name, 512);
>>> + ep_priv->endpoint.maxburst = 1;
>>> + ep_priv->endpoint.ops = &usbssp_gadget_ep0_ops;
>>> + ep_priv->endpoint.caps.type_control = true;
>>> +
>>> + usbssp_data->usb_req_ep0_in.epnum = ep_priv->number;
>>> + usbssp_data->usb_req_ep0_in.dep = ep_priv;
>>> +
>>> + if (!epnum)
>>> + usbssp_data->gadget.ep0 = &ep_priv->endpoint;
>>> + } else {
>>> + usb_ep_set_maxpacket_limit(&ep_priv->endpoint, 1024);
>>> + ep_priv->endpoint.maxburst = 15;
>>> + ep_priv->endpoint.ops = &usbssp_gadget_ep_ops;
>>> + list_add_tail(&ep_priv->endpoint.ep_list,
>>> + &usbssp_data->gadget.ep_list);
>>> + ep_priv->endpoint.caps.type_iso = true;
>>> + ep_priv->endpoint.caps.type_bulk = true;
>>> + ep_priv->endpoint.caps.type_int = true;
>>> +
>>> + }
>>> +
>>> + ep_priv->endpoint.caps.dir_in = direction;
>>> + ep_priv->endpoint.caps.dir_out = !direction;
>>
>> Since you start from 1, ep0 will only be initialized as dir_in.
>> Is it better to represent EP0in and EP0out separately?
>> If so you can start i from 0 and use
>> ep_priv = &usbssp_data->devs.eps[i];
>>
>> This should fix the direction. eps[0] will be ep0out and eps[1] will be ep0in.
>
> I wanted to be consistent with Device Context Data Structure from
> XHCI specification (EP Context 0 BiDir, EP Context 1 OUT, EP Context 1 IN ...).
>
> I little change this function, and now it look like this:
> int usbssp_gadget_init_endpoints(struct usbssp_udc *usbssp_data)
> {
> int i = 0;
> struct usbssp_ep *ep_priv;
>
> usbssp_data->num_endpoints = USBSSP_ENDPOINTS_NUM;
> INIT_LIST_HEAD(&usbssp_data->gadget.ep_list);
>
> for (i = 0; i < usbssp_data->num_endpoints; i++) {
> bool direction = i & 1; /*start from OUT endpoint*/
> u8 epnum = ((i + 1) >> 1);
>
> ep_priv = &usbssp_data->devs.eps[i];
> ep_priv->usbssp_data = usbssp_data;
> ep_priv->number = epnum;
> ep_priv->direction = direction; /*0 for OUT, 1 for IN*/
>
> /*
> *Ep0 is bidirectional so Ep0In and Ep0Out is represented by
> * usbssp_data->devs.eps[0]
> */
> if (epnum == 0) {
> snprintf(ep_priv->name, sizeof(ep_priv->name), "ep%d%s",
> epnum, "BiDir");
>
> usb_ep_set_maxpacket_limit(&ep_priv->endpoint, 512);
> ep_priv->endpoint.maxburst = 1;
> ep_priv->endpoint.ops = &usbssp_gadget_ep0_ops;
> ep_priv->endpoint.desc = &usbssp_gadget_ep0_desc;
>
> ep_priv->endpoint.comp_desc = NULL;
> ep_priv->endpoint.caps.type_control = true;
> ep_priv->endpoint.caps.dir_in = true;
> ep_priv->endpoint.caps.dir_out = true;
>
> usbssp_data->usb_req_ep0_in.epnum = ep_priv->number;
> usbssp_data->usb_req_ep0_in.dep = ep_priv;
> usbssp_data->gadget.ep0 = &ep_priv->endpoint;
>
> } else {
> snprintf(ep_priv->name, sizeof(ep_priv->name), "ep%d%s",
> epnum, (ep_priv->direction) ? "in" : "out");
>
> usb_ep_set_maxpacket_limit(&ep_priv->endpoint, 1024);
> ep_priv->endpoint.maxburst = 15;
> ep_priv->endpoint.ops = &usbssp_gadget_ep_ops;
> list_add_tail(&ep_priv->endpoint.ep_list,
> &usbssp_data->gadget.ep_list);
>
> ep_priv->endpoint.caps.type_iso = true;
> ep_priv->endpoint.caps.type_bulk = true;
> ep_priv->endpoint.caps.type_int = true;
>
> ep_priv->endpoint.caps.dir_in = direction;
> ep_priv->endpoint.caps.dir_out = !direction;
> }
>
> ep_priv->endpoint.name = ep_priv->name;

I think this is much better now.

>
> dev_dbg(usbssp_data->dev, "Init %s, MaxPack: %04x SupType: "
> "CTRL: %s, INT: %s, BULK: %s, ISOC %s, "
> "SupDir IN: %s, OUT: %s\n",
> ep_priv->name, 1024,
> (ep_priv->endpoint.caps.type_control) ? "yes" : "no",
> (ep_priv->endpoint.caps.type_int) ? "yes" : "no",
> (ep_priv->endpoint.caps.type_bulk) ? "yes" : "no",
> (ep_priv->endpoint.caps.type_iso) ? "yes" : "no",
> (ep_priv->endpoint.caps.dir_in) ? "yes" : "no",
> (ep_priv->endpoint.caps.dir_out) ? "yes" : "no");
>

In some places you use usbssp_dbg_trace() and at others you use dev_dbg().
Is it better to stick with one throughout?

> INIT_LIST_HEAD(&ep_priv->pending_list);
> }
>
> return 0;
> }
>
>>> +
>>> + dev_dbg(usbssp_data->dev, "Init %s, MaxPack: %04x SupType:"
>>> + " INT/BULK/ISOC , SupDir %s\n",
>>> + ep_priv->name, 1024,
>>> + (ep_priv->endpoint.caps.dir_in) ? "IN" : "OUT");
>>> +
>>> + INIT_LIST_HEAD(&ep_priv->pending_list);
>>> + }
>>> return 0;
>>> }
>>>
>>> void usbssp_gadget_free_endpoint(struct usbssp_udc *usbssp_data)
>>> {
>>> - /*TODO: it has to be implemented*/
>>> + int i;
>>> + struct usbssp_ep *ep_priv;
>>> +
>>> + for (i = 0; i < usbssp_data->num_endpoints; i++) {
>>> + ep_priv = &usbssp_data->devs.eps[i];
>>> +
>>
>> if you start i from 1 then you can skip the if().
>>
>>> + if (ep_priv->number != 0)
>>> + list_del(&ep_priv->endpoint.ep_list);
>>> + }
>>> }
>>> diff --git a/drivers/usb/usbssp/gadget.c b/drivers/usb/usbssp/gadget.c
>>> index 338ec2ec18b1..195f5777cf8a 100644
>>> --- a/drivers/usb/usbssp/gadget.c
>>> +++ b/drivers/usb/usbssp/gadget.c
>>> @@ -103,6 +103,83 @@ int usbssp_halt(struct usbssp_udc *usbssp_data)
>>> return ret;
>>> }
>>>
>>> +/*
>>> + * Set the run bit and wait for the device to be running.
>>> + */
>>> +int usbssp_start(struct usbssp_udc *usbssp_data)
>>> +{
>>> + u32 temp;
>>> + int ret;
>>> +
>>> + temp = readl(&usbssp_data->op_regs->command);
>>> + temp |= (CMD_RUN | CMD_DEVEN);
>>> + usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_init,
>>> + "// Turn on USBSSP, cmd = 0x%x.", temp);
>>> + writel(temp, &usbssp_data->op_regs->command);
>>> +
>>> + /*
>>> + * Wait for the HCHalted Staus bit to be 0 to indicate the device is
>>> + * running.
>>> + */
>>> + ret = usbssp_handshake(&usbssp_data->op_regs->status,
>>> + STS_HALT, 0, USBSSP_MAX_HALT_USEC);
>>> +
>>> + if (ret == -ETIMEDOUT)
>>> + dev_err(usbssp_data->dev, "Device took too long to start, waited %u microseconds.\n",
>>> + USBSSP_MAX_HALT_USEC);
>>> + if (!ret)
>>> + /* clear state flags. Including dying, halted or removing */
>>> + usbssp_data->usbssp_state = 0;
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +/*
>>> + * Reset a halted DC.
>>> + *
>>> + * This resets pipelines, timers, counters, state machines, etc.
>>> + * Transactions will be terminated immediately, and operational registers
>>> + * will be set to their defaults.
>>> + */
>>> +int usbssp_reset(struct usbssp_udc *usbssp_data)
>>> +{
>>> + u32 command;
>>> + u32 state;
>>> + int ret;
>>> +
>>> + state = readl(&usbssp_data->op_regs->status);
>>> +
>>> + if (state == ~(u32)0) {
>>> + dev_warn(usbssp_data->dev, "Device not accessible, reset failed.\n");
>>> + return -ENODEV;
>>> + }
>>> +
>>> + if ((state & STS_HALT) == 0) {
>>> + dev_warn(usbssp_data->dev, "DC not halted, aborting reset.\n");
>>
>> DC is not a familiar abbreviation. Mabe just use Controller? or Device controller.
>
> In xhci driver is often used HC for host controller. In device driver I change this abbreviation
> to DC. I will review the patches and change this to Controller.
>
>>
>>> + return 0;
>>> + }
>>> +
>>> + usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_init, "// Reset the DC");
>>> + command = readl(&usbssp_data->op_regs->command);
>>> + command |= CMD_RESET;
>>> + writel(command, &usbssp_data->op_regs->command);
>>> +
>>> + ret = usbssp_handshake(&usbssp_data->op_regs->command,
>>> + CMD_RESET, 0, 10 * 1000 * 1000);
>>> +
>>> + if (ret)
>>> + return ret;
>>> + usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_init,
>>> + "Wait for controller to be ready for doorbell rings");
>>> + /*
>>> + * USBSSP cannot write to any doorbells or operational registers other
>>> + * than status until the "Controller Not Ready" flag is cleared.
>>> + */
>>> + ret = usbssp_handshake(&usbssp_data->op_regs->status,
>>> + STS_CNR, 0, 10 * 1000 * 1000);
>>> +
>>> + return ret;
>>> +}
>>>
>>> /*
>>> * Initialize memory for gadget driver and USBSSP (one-time init).
>>> @@ -179,8 +256,7 @@ int usbssp_gen_setup(struct usbssp_udc *usbssp_data)
>>>
>>> dev_dbg(usbssp_data->dev, "Resetting Device Controller\n");
>>> /* Reset the internal DC memory state and registers. */
>>> - /*TODO: add implementation of usbssp_reset function*/
>>> - //retval = usbssp_reset(usbssp_data);
>>> + retval = usbssp_reset(usbssp_data);
>>> if (retval)
>>> return retval;
>>> dev_dbg(usbssp_data->dev, "Reset complete\n");
>>> @@ -244,8 +320,7 @@ int usbssp_gadget_init(struct usbssp_udc *usbssp_data)
>>> BUILD_BUG_ON(sizeof(struct usbssp_run_regs) != (8+8*128)*32/8);
>>>
>>> /* fill gadget fields */
>>> - /*TODO: implements usbssp_gadget_ops object*/
>>> - //usbssp_data->gadget.ops = &usbssp_gadget_ops;
>>> + usbssp_data->gadget.ops = &usbssp_gadget_ops;
>>> usbssp_data->gadget.name = "usbssp-gadget";
>>> usbssp_data->gadget.max_speed = USB_SPEED_SUPER_PLUS;
>>> usbssp_data->gadget.speed = USB_SPEED_UNKNOWN;
>>> @@ -288,6 +363,7 @@ int usbssp_gadget_init(struct usbssp_udc *usbssp_data)
>>> usbssp_halt(usbssp_data);
>>> /*TODO add implementation of usbssp_reset function*/
>>> //usbssp_reset(usbssp_data);
>>> + usbssp_reset(usbssp_data);
>>> /*TODO add implementation of freeing memory*/
>>> //usbssp_mem_cleanup(usbssp_data);
>>> err3:
>>>
>>
>> --
>> cheers,
>> -roger
>>
>> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
>> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>
> Cheers
> Pawel
>

--
cheers,
-roger

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki