From: Neil Armstrong <narmstrong@baylibre.com>
To: "Noralf Trønnes" <noralf@tronnes.org>,
broonie@kernel.org, balbi@kernel.org, lee.jones@linaro.org
Cc: linux-usb@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [RFC 0/9] Regmap over USB for Multifunction USB Device (gpio, display, ...)
Date: Mon, 17 Feb 2020 11:32:30 +0100 [thread overview]
Message-ID: <62e6e9b1-f44a-42ae-a971-8b947763284b@baylibre.com> (raw)
In-Reply-To: <20200216172117.49832-1-noralf@tronnes.org>
Hi,
On 16/02/2020 18:21, Noralf Trønnes wrote:
> Hi,
>
> A while back I had the idea to turn a Raspberry Pi Zero into a $5
> USB to HDMI/SDTV/DSI/DPI display adapter.
>
> Thinking about how to represent the display to the driver I realised
> that hardware use registers as API. And Linux does have a generic
> register abstraction: regmap. Furthermore this means that if I can do a
> regmap over USB implementation, it will be easy to do other functions
> like gpio, adc and others. After a few iterations trying to understand
> the USB subsystem and satisfying driver requirements, I now have
> something that looks promising.
>
> I'm sending out an early version hoping to get feedback especially on
> the core parts that handles regmap and interrupts.
>
> Overview:
>
> USB Host : USB Device
> :
> -------------- : ------------------
> ---------- | mfd: mud | : | f_mud | ----------
> | Driver | -------------- : | | | Driver |
> ---------- | regmap-usb | : | (mud_regmap) | ----------
> -------------- : ------------------
>
The idea is really like ARA's greybus, but much simpler !
Anyway nice idea, do you have good performance over USB2 and
RPi's awful DWC2 gagdet controller ?
Neil
>
> I've attached 2 drivers:
> - gpio/pinctrl: is more or less finished
> - display: needs a lot more work
>
>
> USB3 device
> I've only tested this with usb2 devices (Pi, BBB) so I should get myself
> a usb3 gadget capable board. My searching didn't turn up much, so this
> seems to be quite rare. ROCK960 has USB 3.0 type C OTG but the price is
> $139 which is a bit expensive for this hobby project. Does anyone know
> of a cheap board?
>
> Noralf.
>
>
> Noralf Trønnes (9):
> regmap: Add USB support
> mfd: Add driver for Multifunction USB Device
> usb: gadget: function: Add Multifunction USB Device support
> pinctrl: Add Multifunction USB Device pinctrl driver
> usb: gadget: function: mud: Add gpio support
> regmap: Speed up _regmap_raw_write_impl() for large buffers
> drm: Add Multifunction USB Device display driver
> drm/client: Add drm_client_init_from_id() and drm_client_modeset_set()
> usb: gadget: function: mud: Add display support
>
> drivers/base/regmap/Kconfig | 8 +-
> drivers/base/regmap/Makefile | 1 +
> drivers/base/regmap/regmap-usb.c | 1026 ++++++++++++++++++
> drivers/base/regmap/regmap.c | 10 +-
> drivers/gpu/drm/Kconfig | 2 +
> drivers/gpu/drm/Makefile | 1 +
> drivers/gpu/drm/drm_client.c | 37 +
> drivers/gpu/drm/drm_client_modeset.c | 52 +
> drivers/gpu/drm/mud/Kconfig | 18 +
> drivers/gpu/drm/mud/Makefile | 4 +
> drivers/gpu/drm/mud/mud_drm.c | 1198 ++++++++++++++++++++++
> drivers/gpu/drm/mud/mud_drm.h | 137 +++
> drivers/gpu/drm/mud/mud_drm_gadget.c | 889 ++++++++++++++++
> drivers/mfd/Kconfig | 8 +
> drivers/mfd/Makefile | 1 +
> drivers/mfd/mud.c | 580 +++++++++++
> drivers/pinctrl/Kconfig | 9 +
> drivers/pinctrl/Makefile | 1 +
> drivers/pinctrl/pinctrl-mud.c | 657 ++++++++++++
> drivers/pinctrl/pinctrl-mud.h | 89 ++
> drivers/usb/gadget/Kconfig | 36 +
> drivers/usb/gadget/function/Makefile | 6 +
> drivers/usb/gadget/function/f_mud.c | 913 +++++++++++++++++
> drivers/usb/gadget/function/f_mud.h | 210 ++++
> drivers/usb/gadget/function/f_mud_drm.c | 181 ++++
> drivers/usb/gadget/function/f_mud_pins.c | 962 +++++++++++++++++
> drivers/usb/gadget/function/mud_regmap.c | 936 +++++++++++++++++
> include/drm/drm_client.h | 4 +
> include/linux/mfd/mud.h | 16 +
> include/linux/regmap.h | 23 +
> include/linux/regmap_usb.h | 97 ++
> 31 files changed, 8107 insertions(+), 5 deletions(-)
> create mode 100644 drivers/base/regmap/regmap-usb.c
> create mode 100644 drivers/gpu/drm/mud/Kconfig
> create mode 100644 drivers/gpu/drm/mud/Makefile
> create mode 100644 drivers/gpu/drm/mud/mud_drm.c
> create mode 100644 drivers/gpu/drm/mud/mud_drm.h
> create mode 100644 drivers/gpu/drm/mud/mud_drm_gadget.c
> create mode 100644 drivers/mfd/mud.c
> create mode 100644 drivers/pinctrl/pinctrl-mud.c
> create mode 100644 drivers/pinctrl/pinctrl-mud.h
> create mode 100644 drivers/usb/gadget/function/f_mud.c
> create mode 100644 drivers/usb/gadget/function/f_mud.h
> create mode 100644 drivers/usb/gadget/function/f_mud_drm.c
> create mode 100644 drivers/usb/gadget/function/f_mud_pins.c
> create mode 100644 drivers/usb/gadget/function/mud_regmap.c
> create mode 100644 include/linux/mfd/mud.h
> create mode 100644 include/linux/regmap_usb.h
>
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next prev parent reply other threads:[~2020-02-17 10:32 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-16 17:21 [RFC 0/9] Regmap over USB for Multifunction USB Device (gpio, display, ...) Noralf Trønnes
2020-02-16 17:21 ` [RFC 1/9] regmap: Add USB support Noralf Trønnes
2020-02-17 12:11 ` Mark Brown
2020-02-17 21:33 ` Noralf Trønnes
2020-02-17 21:39 ` Mark Brown
2020-02-17 22:15 ` Noralf Trønnes
2020-02-17 22:44 ` Mark Brown
2020-02-16 17:21 ` [RFC 2/9] mfd: Add driver for Multifunction USB Device Noralf Trønnes
2020-02-27 9:09 ` Lee Jones
2020-02-29 13:26 ` Noralf Trønnes
2020-02-29 16:02 ` Alan Stern
2020-02-16 17:21 ` [RFC 3/9] usb: gadget: function: Add Multifunction USB Device support Noralf Trønnes
2020-02-16 17:21 ` [RFC 4/9] pinctrl: Add Multifunction USB Device pinctrl driver Noralf Trønnes
2020-02-16 17:21 ` [RFC 5/9] usb: gadget: function: mud: Add gpio support Noralf Trønnes
2020-02-16 17:21 ` [RFC 6/9] regmap: Speed up _regmap_raw_write_impl() for large buffers Noralf Trønnes
2020-02-17 12:15 ` Mark Brown
2020-02-16 17:21 ` [RFC 7/9] drm: Add Multifunction USB Device display driver Noralf Trønnes
2020-02-16 17:21 ` [RFC 8/9] drm/client: Add drm_client_init_from_id() and drm_client_modeset_set() Noralf Trønnes
2020-02-17 9:38 ` Daniel Vetter
2020-02-23 17:43 ` Noralf Trønnes
2020-02-23 20:59 ` Daniel Vetter
2020-02-16 17:21 ` [RFC 9/9] usb: gadget: function: mud: Add display support Noralf Trønnes
2020-02-17 9:40 ` [RFC 0/9] Regmap over USB for Multifunction USB Device (gpio, display, ...) Daniel Vetter
2020-02-17 10:32 ` Neil Armstrong [this message]
2020-02-17 14:05 ` Noralf Trønnes
2020-02-18 20:57 ` Andy Shevchenko
2020-02-18 21:31 ` Noralf Trønnes
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