Lines Matching +full:can +full:- +full:transceiver
15 Instead, these embedded UDC rely on the USB On-the-Go (OTG)
18 Dual-Role Controller (MUSB HDRC) found in the Mentor Graphics Inventra™
21 As a self-taught exercise I have written an MUSB glue layer for the
23 kernel source tree. This layer can be found at
28 .. _musb-basics:
33 To get started on the topic, please read USB On-the-Go Basics (see
46 ------------------------
47 | | <------- drivers/usb/gadget
48 | Linux USB Core Stack | <------- drivers/usb/host
49 | | <------- drivers/usb/core
50 ------------------------
52 --------------------------
53 | | <------ drivers/usb/musb/musb_gadget.c
54 | MUSB Controller driver | <------ drivers/usb/musb/musb_host.c
55 | | <------ drivers/usb/musb/musb_core.c
56 --------------------------
58 ---------------------------------
60 | | <-- drivers/usb/musb/jz4740.c
62 ---------------------------------
64 ---------------------------------
66 ---------------------------------
77 run-time.
86 .name = "musb-jz4740",
123 .. code-block:: c
124 :emphasize-lines: 8,12,18
133 glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
135 return -ENOMEM;
137 musb = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
139 dev_err(&pdev->dev, "failed to allocate musb device\n");
140 return -ENOMEM;
143 clk = devm_clk_get(&pdev->dev, "udc");
145 dev_err(&pdev->dev, "failed to get clock\n");
152 dev_err(&pdev->dev, "failed to enable clock\n");
156 musb->dev.parent = &pdev->dev;
158 glue->dev = &pdev->dev;
159 glue->musb = musb;
160 glue->clk = clk;
175 (line 18) the glue layer allocates the clock -- the ``devm_`` prefix
177 allocated clock resource data when the device is released -- and enable
184 .. code-block:: c
185 :emphasize-lines: 3,5,7,9,16
191 pdata->platform_ops = &jz4740_musb_ops;
195 ret = platform_device_add_resources(musb, pdev->resource,
196 pdev->num_resources);
198 dev_err(&pdev->dev, "failed to add resources\n");
204 dev_err(&pdev->dev, "failed to add platform_data\n");
224 :ref:`musb-dev-platform-data`, but here we are looking at the
239 between OTG and non-OTG modes, for instance.
244 .. code-block:: c
245 :emphasize-lines: 12,14
249 musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
250 if (!musb->xceiv) {
251 pr_err("HS UDC: no transceiver configured\n");
252 return -ENODEV;
258 musb->dyn_fifo = true;
260 musb->isr = jz4740_musb_interrupt;
265 The goal of ``jz4740_musb_init()`` is to get hold of the transceiver
267 controller driver, as usual. The transceiver is the circuitry inside the
270 the transceiver is also referred to as PHY.
276 will be discussed later in :ref:`musb-dev-quirks` and
277 :ref:`musb-handling-irqs`\ ::
281 usb_put_phy(musb->xceiv);
301 dev_err(&pdev->dev, "failed to register musb device\n");
319 .. code-block:: c
320 :emphasize-lines: 5,6
326 platform_device_unregister(glue->musb);
327 clk_disable_unprepare(glue->clk);
336 .. _musb-handling-irqs:
344 .. code-block:: c
345 :emphasize-lines: 7,9-11,14,24
353 spin_lock_irqsave(&musb->lock, flags);
355 musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
356 musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);
357 musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX);
364 musb->int_usb &= MUSB_INTR_SUSPEND | MUSB_INTR_RESUME |
367 if (musb->int_usb || musb->int_tx || musb->int_rx)
370 spin_unlock_irqrestore(&musb->lock, flags);
386 - ``MUSB_INTRUSB``: indicates which USB interrupts are currently active,
388 - ``MUSB_INTRTX``: indicates which of the interrupts for TX endpoints are
391 - ``MUSB_INTRRX``: indicates which of the interrupts for TX endpoints are
394 Note that :c:func:`musb_readb` is used to read 8-bit registers at most, while
395 :c:func:`musb_readw` allows us to read at most 16-bit registers. There are
396 other functions that can be used depending on the size of your device
400 device controller, which will be discussed later in :ref:`musb-dev-quirks`.
407 musb->isr = jz4740_musb_interrupt;
417 .. _musb-dev-platform-data:
437 .. code-block:: c
438 :emphasize-lines: 2,7,14-17,21,22,25,26,28,29
449 .end = JZ4740_UDC_BASE_ADDR + 0x10000 - 1,
461 .name = "musb-jz4740",
462 .id = -1,
472 describes the UDC transceiver with a name and id number.
475 specific name to be used for all transceivers that are either built-in
478 kernel configuration to make use of the corresponding transceiver
479 driver. The id field could be set to -1 (equivalent to
480 ``PLATFORM_DEVID_NONE``), -2 (equivalent to ``PLATFORM_DEVID_AUTO``) or
495 resources, and the name ``mc`` is in fact hard-coded in the MUSB core in
502 The ``musb-jz4740`` name (line 22) defines the MUSB driver that is used
504 ``jz4740_driver`` platform driver structure in :ref:`musb-basics`.
505 The id field (line 23) is set to -1 (equivalent to ``PLATFORM_DEVID_NONE``)
507 already set to allocate an automatic id in :ref:`musb-basics`. In the dev field
521 .. code-block:: c
522 :emphasize-lines: 3,5,7-9,11
527 /* Max EPs scanned, driver will decide which EP can be used. */
553 :ref:`musb-dev-quirks`. Last two fields (line 8 and 9) are also
557 :ref:`musb-dev-quirks`.
567 :ref:`musb-basics`.
569 .. _musb-dev-quirks:
577 the result of an incomplete implementation of the USB On-the-Go
586 .. code-block:: c
587 :emphasize-lines: 12
591 musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
592 if (!musb->xceiv) {
593 pr_err("HS UDC: no transceiver configured\n");
594 return -ENODEV;
600 musb->dyn_fifo = true;
602 musb->isr = jz4740_musb_interrupt;
614 hard-coded table that describes the endpoints configuration instead::
627 that can be transmitted over that endpoint. Reading from the table, the
628 controller driver knows that endpoint 1 can be used to send and receive
630 endpoint), and endpoint 2 can be used to send data packets of 64 bytes
640 .. code-block:: c
641 :emphasize-lines: 18-19
649 spin_lock_irqsave(&musb->lock, flags);
651 musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
652 musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);
653 musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX);
660 musb->int_usb &= MUSB_INTR_SUSPEND | MUSB_INTR_RESUME |
663 if (musb->int_usb || musb->int_tx || musb->int_rx)
666 spin_unlock_irqrestore(&musb->lock, flags);
694 guidance to get started; should anything gets out of hand, the linux-usb
700 Many thanks to Lars-Peter Clausen and Maarten ter Huurne for answering
704 I would also like to thank the Qi-Hardware community at large for its
712 linux-usb Mailing List Archives: https://marc.info/?l=linux-usb
714 USB On-the-Go Basics:
715 https://www.maximintegrated.com/app-notes/index.mvp/id/1822
717 :ref:`Writing USB Device Drivers <writing-usb-driver>`