| Message ID | 20240317193714.403132-4-ayushdevel1325@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | misc: Add mikroBUS driver | expand |
On 18/03/24 01:07, Ayush Singh wrote: > DONOTMERGE > Why? > mikroBUS addon boards allow using same mikroBUS connector for a wide > range of peripherals. It is also possible for the addon board not to use > all the pins in mikroBUS socket (marked by NC or Not Connected). This > would require the need to create an almost new overlays for each > permutation of the hardware. > > To overcome this, a manifest format based on Greybus manifest > specification was created which allows describing mikroBUS addon boards. > The reason for choosing greybus manifest for the identifier is that so far > we discussed only about physical mikroBUS ports on the board, but we can you will need to reword the commit message properly in imperative mood, here and in multiple other places. > also have mikroBUS ports on a remote microcontroller appearing on host > over greybus and there a device tree overlay solution does not work as the > standard identifier mechanism. > > The patch introduces 3 new greybus descriptor types: > 1. mikrobus-descriptor: > Is a fixed-length descriptor (12 bytes), and the manifest shall have > precisely one mikroBUS descriptor. Each byte describes a configuration > of the corresponding pin on the mikroBUS addon board in a clockwise > direction starting from the PWM pin omitting power (VCC and ground) > pins as same as the default state of the pin. > There are mikroBUS addon boards that use some dedicated SPI, UART, PWM, > and I2C pins as GPIO pins, so it is necessary to redefine the default > pin configuration of that pins on the host system. Also, sometimes it is > required the pull-up on the host pin for correct functionality > 2. property-descriptor: > Are used to pass named properties or named GPIOs to the host. The host > system uses this information to properly configure specific board > drivers by passing the properties and GPIO name. There can be multiple > instances of property descriptors per add-on board manifest. > 3. device-descriptor: > Describes a device on the mikroBUS port. The device descriptor is a > fixed-length descriptor, and there can be multiple instances of device > descriptors in an add-on board manifest in cases where the add-on board > presents more than one device to the host. > > New mikroBUS addon boards also sometimes contain a 1-wire EEPROM with > the mikroBUS manifest, thus enabling plug and play support. > new mikroBUS sometimes contain an EEPROM? aren't these called Click ID compliant add-on boards? there should be clarity in the commit message. > I have also created PR to add mikrobus descriptors in Greybus spec and I > think the old PR on manifesto by Vaishnav should also work. However, > both of these repositories seem to be inactive. I am guessing the > greybus mailing list can provide more information on how I should go > about these. Why is information like these inside the commit message, these go below the tear line. > > Here is a sample mikroBUS manifest: > ``` > ;; > ; PRESSURE CLICK > ; https://www.mikroe.com/pressure-click > ; CONFIG_IIO_ST_PRESS > ; > ; Copyright 2020 BeagleBoard.org Foundation > ; Copyright 2020 Texas Instruments > ; > > [manifest-header] > version-major = 0 > version-minor = 1 > > [interface-descriptor] > vendor-string-id = 1 > product-string-id = 2 > > [string-descriptor 1] > string = MIKROE > > [string-descriptor 2] > string = Pressure > > [mikrobus-descriptor] > pwm-state = 4 > int-state = 1 > rx-state = 7 > tx-state = 7 > scl-state = 6 > sda-state = 6 > mosi-state = 5 > miso-state = 5 > sck-state = 5 > cs-state = 5 > rst-state = 2 > an-state = 1 > > [device-descriptor 1] > driver-string-id = 3 > protocol = 0x3 > reg = 0x5d > > [string-descriptor 3] > string = lps331ap > ``` > > Link: https://www.mikroe.com/clickid ClickID > Link: > https://docs.beagleboard.org/latest/projects/beagleconnect/index.html > beagleconnect > Link: https://github.com/projectara/greybus-spec Greybus Spec > Link: https://github.com/projectara/greybus-spec/pull/4 Greybus Spec PR > Link: https://github.com/projectara/manifesto/pull/2 manifesto PR > The manifesto PR might not be updated. Thanks and Regards, Vaishnav > Co-developed-by: Vaishnav M A <vaishnav@beagleboard.org> > Signed-off-by: Vaishnav M A <vaishnav@beagleboard.org> > Signed-off-by: Ayush Singh <ayushdevel1325@gmail.com> > --- > include/linux/greybus/greybus_manifest.h | 49 ++++++++++++++++++++++++ > 1 file changed, 49 insertions(+) > > diff --git a/include/linux/greybus/greybus_manifest.h b/include/linux/greybus/greybus_manifest.h > index bef9eb2093e9..83241e19d9b3 100644 > --- a/include/linux/greybus/greybus_manifest.h > +++ b/include/linux/greybus/greybus_manifest.h > @@ -23,6 +23,9 @@ enum greybus_descriptor_type { > GREYBUS_TYPE_STRING = 0x02, > GREYBUS_TYPE_BUNDLE = 0x03, > GREYBUS_TYPE_CPORT = 0x04, > + GREYBUS_TYPE_MIKROBUS = 0x05, > + GREYBUS_TYPE_PROPERTY = 0x06, > + GREYBUS_TYPE_DEVICE = 0x07, > }; > > enum greybus_protocol { > @@ -151,6 +154,49 @@ struct greybus_descriptor_cport { > __u8 protocol_id; /* enum greybus_protocol */ > } __packed; > > +/* > + * A mikrobus descriptor is used to describe the details > + * about the bus ocnfiguration for the add-on board > + * connected to the mikrobus port. > + */ > +struct greybus_descriptor_mikrobus { > + __u8 pin_state[12]; > +} __packed; > + > +/* > + * A property descriptor is used to pass named properties > + * to device drivers through the unified device properties > + * interface under linux/property.h > + */ > +struct greybus_descriptor_property { > + __u8 length; > + __u8 id; > + __u8 propname_stringid; > + __u8 type; > + __u8 value[]; > +} __packed; > + > +/* > + * A device descriptor is used to describe the > + * details required by a add-on board device > + * driver. > + */ > +struct greybus_descriptor_device { > + __u8 id; > + __u8 driver_stringid; > + __u8 protocol; > + __u8 reg; > + __le32 max_speed_hz; > + __u8 irq; > + __u8 irq_type; > + __u8 mode; > + __u8 prop_link; > + __u8 gpio_link; > + __u8 reg_link; > + __u8 clock_link; > + __u8 pad[1]; > +} __packed; > + > struct greybus_descriptor_header { > __le16 size; > __u8 type; /* enum greybus_descriptor_type */ > @@ -164,6 +210,9 @@ struct greybus_descriptor { > struct greybus_descriptor_interface interface; > struct greybus_descriptor_bundle bundle; > struct greybus_descriptor_cport cport; > + struct greybus_descriptor_mikrobus mikrobus; > + struct greybus_descriptor_property property; > + struct greybus_descriptor_device device; > }; > } __packed; >
diff --git a/include/linux/greybus/greybus_manifest.h b/include/linux/greybus/greybus_manifest.h index bef9eb2093e9..83241e19d9b3 100644 --- a/include/linux/greybus/greybus_manifest.h +++ b/include/linux/greybus/greybus_manifest.h @@ -23,6 +23,9 @@ enum greybus_descriptor_type { GREYBUS_TYPE_STRING = 0x02, GREYBUS_TYPE_BUNDLE = 0x03, GREYBUS_TYPE_CPORT = 0x04, + GREYBUS_TYPE_MIKROBUS = 0x05, + GREYBUS_TYPE_PROPERTY = 0x06, + GREYBUS_TYPE_DEVICE = 0x07, }; enum greybus_protocol { @@ -151,6 +154,49 @@ struct greybus_descriptor_cport { __u8 protocol_id; /* enum greybus_protocol */ } __packed; +/* + * A mikrobus descriptor is used to describe the details + * about the bus ocnfiguration for the add-on board + * connected to the mikrobus port. + */ +struct greybus_descriptor_mikrobus { + __u8 pin_state[12]; +} __packed; + +/* + * A property descriptor is used to pass named properties + * to device drivers through the unified device properties + * interface under linux/property.h + */ +struct greybus_descriptor_property { + __u8 length; + __u8 id; + __u8 propname_stringid; + __u8 type; + __u8 value[]; +} __packed; + +/* + * A device descriptor is used to describe the + * details required by a add-on board device + * driver. + */ +struct greybus_descriptor_device { + __u8 id; + __u8 driver_stringid; + __u8 protocol; + __u8 reg; + __le32 max_speed_hz; + __u8 irq; + __u8 irq_type; + __u8 mode; + __u8 prop_link; + __u8 gpio_link; + __u8 reg_link; + __u8 clock_link; + __u8 pad[1]; +} __packed; + struct greybus_descriptor_header { __le16 size; __u8 type; /* enum greybus_descriptor_type */ @@ -164,6 +210,9 @@ struct greybus_descriptor { struct greybus_descriptor_interface interface; struct greybus_descriptor_bundle bundle; struct greybus_descriptor_cport cport; + struct greybus_descriptor_mikrobus mikrobus; + struct greybus_descriptor_property property; + struct greybus_descriptor_device device; }; } __packed;