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

From: Roger Quadros
Date: Fri Aug 03 2018 - 06:42:34 EST


On 19/07/18 20:57, 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.

> +
> + 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.

> + 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

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