| Message ID | 20240222174343.3482354-2-robh@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | dt-bindings: i2c: Remove obsolete i2c.txt | expand |
On Thu, Feb 22, 2024 at 10:43:42AM -0700, Rob Herring wrote: > Everything in i2c.txt is covered by schemas/i2c/i2c-controller.yaml in > dtschema project, so remove i2c.txt and update links to it in the tree. Acked-by: Mark Brown <broonie@kernel.org>
On Thu, Feb 22, 2024 at 10:43:42AM -0700, Rob Herring wrote: > Everything in i2c.txt is covered by schemas/i2c/i2c-controller.yaml in > dtschema project, so remove i2c.txt and update links to it in the tree. > > Signed-off-by: Rob Herring <robh@kernel.org> Differences to i2c.txt: * In the schema, "clock-frequency" has a minimum of 1kHz and a maximum of 3MHz. Why? The specs do not say anything about a minimum freq and fastest speed mentioned in the docs is 5Mhz (Ultra fast mode). * new binding "i2c-scl-clk-low-timeout-us" has a description which I do not understand. What is a waiting state? * new binding "no-detect" is broken. At the least, it should be named something like "bus-fully-described" and then the OS can decide to leave out auto-detection mechanisms. If you are interested in the latter, you can simply disable class based instantiation on the host controller. No need to describe this in DT. > Wolfram, you can take it or I can. Once we are done, I guess it is better if you take it. Thanks for the work, Wolfram
On Thu, Feb 22, 2024 at 12:55 PM Wolfram Sang <wsa+renesas@sang-engineering.com> wrote: > > On Thu, Feb 22, 2024 at 10:43:42AM -0700, Rob Herring wrote: > > Everything in i2c.txt is covered by schemas/i2c/i2c-controller.yaml in > > dtschema project, so remove i2c.txt and update links to it in the tree. > > > > Signed-off-by: Rob Herring <robh@kernel.org> > > Differences to i2c.txt: Thanks > * In the schema, "clock-frequency" has a minimum of 1kHz and a maximum > of 3MHz. Why? The specs do not say anything about a minimum freq and > fastest speed mentioned in the docs is 5Mhz (Ultra fast mode). IIRC, the high speed mode originally topped out at 3MHz. I guess that's been revised. We can drop the minimum. > * new binding "i2c-scl-clk-low-timeout-us" has a description which I do > not understand. What is a waiting state? Shrug. May have to look at the MPC h/w that uses the property. > > * new binding "no-detect" is broken. At the least, it should be named > something like "bus-fully-described" and then the OS can decide to > leave out auto-detection mechanisms. If you are interested in the > latter, you can simply disable class based instantiation on the host > controller. No need to describe this in DT. I've reverted the property now. Rob
Hi Rob, > > * In the schema, "clock-frequency" has a minimum of 1kHz and a maximum > > of 3MHz. Why? The specs do not say anything about a minimum freq and > > fastest speed mentioned in the docs is 5Mhz (Ultra fast mode). > > IIRC, the high speed mode originally topped out at 3MHz. I guess > that's been revised. Hs-mode has a max of 3.4MHz... > > We can drop the minimum. ... but I see you changed min/max now to 1/5000000. That's what I would have suggested as well. > > * new binding "i2c-scl-clk-low-timeout-us" has a description which I do > > not understand. What is a waiting state? > > Shrug. May have to look at the MPC h/w that uses the property. I will also have another look. My gut feeling is that the binding is okay, only the description might need an update. > > > > * new binding "no-detect" is broken. At the least, it should be named > > something like "bus-fully-described" and then the OS can decide to > > leave out auto-detection mechanisms. If you are interested in the > > latter, you can simply disable class based instantiation on the host > > controller. No need to describe this in DT. > > I've reverted the property now. Cool, thanks! Kind regards, Wolfram
On Fri, Feb 23, 2024 at 4:34 PM Wolfram Sang <wsa+renesas@sang-engineering.com> wrote: > > Hi Rob, > > > > * In the schema, "clock-frequency" has a minimum of 1kHz and a maximum > > > of 3MHz. Why? The specs do not say anything about a minimum freq and > > > fastest speed mentioned in the docs is 5Mhz (Ultra fast mode). > > > > IIRC, the high speed mode originally topped out at 3MHz. I guess > > that's been revised. > > Hs-mode has a max of 3.4MHz... > > > > > We can drop the minimum. > > ... but I see you changed min/max now to 1/5000000. That's what I would > have suggested as well. > > > > > * new binding "i2c-scl-clk-low-timeout-us" has a description which I do > > > not understand. What is a waiting state? > > > > Shrug. May have to look at the MPC h/w that uses the property. > > I will also have another look. My gut feeling is that the binding is > okay, only the description might need an update. > > > > > > > * new binding "no-detect" is broken. At the least, it should be named > > > something like "bus-fully-described" and then the OS can decide to > > > leave out auto-detection mechanisms. If you are interested in the > > > latter, you can simply disable class based instantiation on the host > > > controller. No need to describe this in DT. > > > > I've reverted the property now. > > Cool, thanks! I don't think there's anything else to discuss on this patch, can I get your ack? Rob
On Thu, Feb 22, 2024 at 10:43:42AM -0700, Rob Herring wrote: > Everything in i2c.txt is covered by schemas/i2c/i2c-controller.yaml in > dtschema project, so remove i2c.txt and update links to it in the tree. > > Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
diff --git a/Documentation/devicetree/bindings/gpio/gateworks,pld-gpio.txt b/Documentation/devicetree/bindings/gpio/gateworks,pld-gpio.txt index 6e81f8b755c5..d543fd1b8b23 100644 --- a/Documentation/devicetree/bindings/gpio/gateworks,pld-gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gateworks,pld-gpio.txt @@ -1,7 +1,6 @@ Gateworks PLD GPIO controller bindings -The GPIO controller should be a child node on an I2C bus, -see: i2c/i2c.txt for details. +The GPIO controller should be a child node on an I2C bus. Required properties: - compatible: Should be "gateworks,pld-gpio" diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt deleted file mode 100644 index fc3dd7ec0445..000000000000 --- a/Documentation/devicetree/bindings/i2c/i2c.txt +++ /dev/null @@ -1,151 +0,0 @@ -Generic device tree bindings for I2C busses -=========================================== - -This document describes generic bindings which can be used to describe I2C -busses and their child devices in a device tree. - -Required properties (per bus) ------------------------------ - -- #address-cells - should be <1>. Read more about addresses below. -- #size-cells - should be <0>. -- compatible - name of I2C bus controller - -For other required properties e.g. to describe register sets, -clocks, etc. check the binding documentation of the specific driver. - -The cells properties above define that an address of children of an I2C bus -are described by a single value. - -Optional properties (per bus) ------------------------------ - -These properties may not be supported by all drivers. However, if a driver -wants to support one of the below features, it should adapt these bindings. - -- clock-frequency - frequency of bus clock in Hz. - -- i2c-bus - For I2C adapters that have child nodes that are a mixture of both I2C - devices and non-I2C devices, the 'i2c-bus' subnode can be used for - populating I2C devices. If the 'i2c-bus' subnode is present, only - subnodes of this will be considered as I2C slaves. The properties, - '#address-cells' and '#size-cells' must be defined under this subnode - if present. - -- i2c-scl-falling-time-ns - Number of nanoseconds the SCL signal takes to fall; t(f) in the I2C - specification. - -- i2c-scl-internal-delay-ns - Number of nanoseconds the IP core additionally needs to setup SCL. - -- i2c-scl-rising-time-ns - Number of nanoseconds the SCL signal takes to rise; t(r) in the I2C - specification. - -- i2c-sda-falling-time-ns - Number of nanoseconds the SDA signal takes to fall; t(f) in the I2C - specification. - -- i2c-analog-filter - Enable analog filter for i2c lines. - -- i2c-digital-filter - Enable digital filter for i2c lines. - -- i2c-digital-filter-width-ns - Width of spikes which can be filtered by digital filter - (i2c-digital-filter). This width is specified in nanoseconds. - -- i2c-analog-filter-cutoff-frequency - Frequency that the analog filter (i2c-analog-filter) uses to distinguish - which signal to filter. Signal with higher frequency than specified will - be filtered out. Only lower frequency will pass (this is applicable to - a low-pass analog filter). Typical value should be above the normal - i2c bus clock frequency (clock-frequency). - Specified in Hz. - -- multi-master - states that there is another master active on this bus. The OS can use - this information to adapt power management to keep the arbitration awake - all the time, for example. Can not be combined with 'single-master'. - -- pinctrl - add extra pinctrl to configure SCL/SDA pins to GPIO function for bus - recovery, call it "gpio" or "recovery" (deprecated) state - -- scl-gpios - specify the gpio related to SCL pin. Used for GPIO bus recovery. - -- sda-gpios - specify the gpio related to SDA pin. Optional for GPIO bus recovery. - -- single-master - states that there is no other master active on this bus. The OS can use - this information to detect a stalled bus more reliably, for example. - Can not be combined with 'multi-master'. - -- smbus - states that additional SMBus restrictions and features apply to this bus. - An example of feature is SMBusHostNotify. Examples of restrictions are - more reserved addresses and timeout definitions. - -- smbus-alert - states that the optional SMBus-Alert feature apply to this bus. - -- mctp-controller - indicates that the system is accessible via this bus as an endpoint for - MCTP over I2C transport. - -Required properties (per child device) --------------------------------------- - -- compatible - name of I2C slave device - -- reg - One or many I2C slave addresses. These are usually a 7 bit addresses. - However, flags can be attached to an address. I2C_TEN_BIT_ADDRESS is - used to mark a 10 bit address. It is needed to avoid the ambiguity - between e.g. a 7 bit address of 0x50 and a 10 bit address of 0x050 - which, in theory, can be on the same bus. - Another flag is I2C_OWN_SLAVE_ADDRESS to mark addresses on which we - listen to be devices ourselves. - -Optional properties (per child device) --------------------------------------- - -These properties may not be supported by all drivers. However, if a driver -wants to support one of the below features, it should adapt these bindings. - -- host-notify - device uses SMBus host notify protocol instead of interrupt line. - -- interrupts - interrupts used by the device. - -- interrupt-names - "irq", "wakeup" and "smbus_alert" names are recognized by I2C core, - other names are left to individual drivers. - -- reg-names - Names of map programmable addresses. - It can contain any map needing another address than default one. - -- wakeup-source - device can be used as a wakeup source. - -Binding may contain optional "interrupts" property, describing interrupts -used by the device. I2C core will assign "irq" interrupt (or the very first -interrupt if not using interrupt names) as primary interrupt for the slave. - -Alternatively, devices supporting SMBus Host Notify, and connected to -adapters that support this feature, may use "host-notify" property. I2C -core will create a virtual interrupt for Host Notify and assign it as -primary interrupt for the slave. - -Also, if device is marked as a wakeup source, I2C core will set up "wakeup" -interrupt for the device. If "wakeup" interrupt name is not present in the -binding, then primary interrupt will be used as wakeup interrupt. diff --git a/Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.yaml b/Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.yaml index b8319dcf3d8a..8676335e9e94 100644 --- a/Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.yaml +++ b/Documentation/devicetree/bindings/i2c/nvidia,tegra186-bpmp-i2c.yaml @@ -21,8 +21,7 @@ description: | See ../firmware/nvidia,tegra186-bpmp.yaml for details of the BPMP binding. - This node represents an I2C controller. See ../i2c/i2c.txt for details - of the core I2C binding. + This node represents an I2C controller. properties: compatible: diff --git a/Documentation/devicetree/bindings/i3c/i3c.yaml b/Documentation/devicetree/bindings/i3c/i3c.yaml index c816e295d565..87cadbcdc61c 100644 --- a/Documentation/devicetree/bindings/i3c/i3c.yaml +++ b/Documentation/devicetree/bindings/i3c/i3c.yaml @@ -71,7 +71,7 @@ patternProperties: description: | I2C child, should be named: <device-type>@<i2c-address> - All properties described in Documentation/devicetree/bindings/i2c/i2c.txt + All properties described in dtschema schemas/i2c/i2c-controller.yaml are valid here, except the reg property whose content is changed. properties: diff --git a/Documentation/devicetree/bindings/sound/cs4341.txt b/Documentation/devicetree/bindings/sound/cs4341.txt index 12b4aa8ef0db..c1d5c8ad1a36 100644 --- a/Documentation/devicetree/bindings/sound/cs4341.txt +++ b/Documentation/devicetree/bindings/sound/cs4341.txt @@ -9,7 +9,7 @@ Required properties: number for SPI. For required properties on I2C-bus, please consult -Documentation/devicetree/bindings/i2c/i2c.txt +dtschema schemas/i2c/i2c-controller.yaml For required properties on SPI-bus, please consult Documentation/devicetree/bindings/spi/spi-bus.txt diff --git a/MAINTAINERS b/MAINTAINERS index 45c6c13b4edf..50a906eb8dfd 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10074,7 +10074,6 @@ S: Maintained W: https://i2c.wiki.kernel.org/ Q: https://patchwork.ozlabs.org/project/linux-i2c/list/ T: git git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git -F: Documentation/devicetree/bindings/i2c/i2c.txt F: Documentation/i2c/ F: drivers/i2c/* F: include/dt-bindings/i2c/i2c.h
Everything in i2c.txt is covered by schemas/i2c/i2c-controller.yaml in dtschema project, so remove i2c.txt and update links to it in the tree. Signed-off-by: Rob Herring <robh@kernel.org> --- Wolfram, you can take it or I can. .../bindings/gpio/gateworks,pld-gpio.txt | 3 +- Documentation/devicetree/bindings/i2c/i2c.txt | 151 ------------------ .../i2c/nvidia,tegra186-bpmp-i2c.yaml | 3 +- .../devicetree/bindings/i3c/i3c.yaml | 2 +- .../devicetree/bindings/sound/cs4341.txt | 2 +- MAINTAINERS | 1 - 6 files changed, 4 insertions(+), 158 deletions(-) delete mode 100644 Documentation/devicetree/bindings/i2c/i2c.txt