From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH V5 2/6] of/slimbus: OF helper for SLIMbus Date: Thu, 28 Apr 2016 12:11:11 +0100 Message-ID: <20160428111110.GD21145@leverpostej> References: <1461801489-16254-1-git-send-email-sdharia@codeaurora.org> <1461801489-16254-3-git-send-email-sdharia@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1461801489-16254-3-git-send-email-sdharia@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org To: Sagar Dharia Cc: gregkh@linuxfoundation.org, bp@suse.de, poeschel@lemonage.de, treding@nvidia.com, broonie@kernel.org, gong.chen@linux.intel.com, andreas.noever@gmail.com, alan@linux.intel.com, mathieu.poirier@linaro.org, daniel@ffwll.ch, jkosina@suse.cz, sharon.dvir1@mail.huji.ac.il, joe@perches.com, davem@davemloft.net, james.hogan@imgtec.com, michael.opdenacker@free-electrons.com, daniel.thompson@linaro.org, robh+dt@kernel.org, pawel.moll@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kheitke@audience.com, mlocke@codeaurora.org, agross@codeaurora.org, sheetal.tigadoli@gmail.com, linux-arm-msm@vger.kernel.org List-Id: devicetree@vger.kernel.org On Wed, Apr 27, 2016 at 05:58:05PM -0600, Sagar Dharia wrote: > OF helper routine scans the SLIMbus DeviceTree, allocates resources, > and creates slim_devices according to the hierarchy. > > Signed-off-by: Sagar Dharia > --- > Documentation/devicetree/bindings/slimbus/bus.txt | 55 ++++++++++++++++++++++ > drivers/slimbus/slim-core.c | 57 +++++++++++++++++++++++ > 2 files changed, 112 insertions(+) > create mode 100644 Documentation/devicetree/bindings/slimbus/bus.txt > > diff --git a/Documentation/devicetree/bindings/slimbus/bus.txt b/Documentation/devicetree/bindings/slimbus/bus.txt > new file mode 100644 > index 0000000..c5bb54a > --- /dev/null > +++ b/Documentation/devicetree/bindings/slimbus/bus.txt > @@ -0,0 +1,55 @@ > +SLIM(Serial Low Power Interchip Media Bus) bus > + > +SLIMbus is a 2-wire bus, and is used to communicate with peripheral > +components like audio-codec. > + > +Controller is a normal device using binding for whatever bus it is > +on (e.g. platform bus). > +Required property for SLIMbus controller node: > +- compatible - name of SLIMbus controller following generic names > + recommended practice. > +- #address-cells - should be 4 (number of cells required to define > + 4 fields of the enumeration address for the SLIMbus > + slave device) > +- #size-cells - should be 0 > + > +No other properties are required in the SLIMbus controller bus node. > + > +Child nodes: > +Every SLIMbus controller node can contain zero or more child nodes > +representing slave devices on the bus. Every SLIMbus slave device is > +uniquely determined by the enumeration address containing 4 fields: > +Manufacturer ID, Product code, Device index, and Instance value for > +the device. > +If child node is not present and it is instantiated after device > +discovery (slave device reporting itself present), > +its name will be in this format: "217:60:1:0" Per the below code, this naming detail is Linux-specific, and should go from the binding. > +However, the device may need additional non-standard way to power it > +up so that it can start functioning. In that case, child node will > +need to be present as slave of the slimbus-controller device. > +The compatible property will be necessary so that corresponding > +driver can probe and execute the required procedure to make it > +functional. > + I imagine there may be other properties in some cases for more than just power management, so it may be better to say: In some cases it may be necessary to describe non-probeable details such as non-standard ways of powering up a device. In such cases, child nodes for those devices will be present as slaves of the slimbus-controller, as detailed below. > +Required property for SLIMbus child node if it is present: > +- reg - enumeration address fields of the device > + > +- compatible - name of SLIMbus child node using practice typically > + followed by discoverable buses: > + ",", "slim" What's the point in the "slim" fallback? That seems to imply nothing useful, and other busses don't do that. > + > +SLIMbus example for Qualcomm's slimbus manager component: > + > + slim@28080000 { > + compatible = "qcom,slim-msm"; > + reg = <0x28080000 0x2000>, > + interrupts = <0 33 0>; > + clocks = <&lcc SLIMBUS_SRC>, <&lcc AUDIO_SLIMBUS_CLK>; > + clock-names = "iface_clk", "core_clk"; > + > + codec@0217.0060.01.00 { > + compatible = "qcom,wcdv1", "slim"; > + reg = <0x217 0x60 0x1 0x0>; > + }; > + }; I'm not familiar with SLIMbus, but other than the above comments this binding looks ok to me. > diff --git a/drivers/slimbus/slim-core.c b/drivers/slimbus/slim-core.c > index 6024f74..6aaa08f 100644 > --- a/drivers/slimbus/slim-core.c > +++ b/drivers/slimbus/slim-core.c > @@ -18,6 +18,7 @@ > #include > #include > #include > +#include > > static DEFINE_MUTEX(slim_lock); > static DEFINE_IDR(ctrl_idr); > @@ -265,6 +266,61 @@ static LIST_HEAD(board_list); > static LIST_HEAD(slim_ctrl_list); > static DEFINE_MUTEX(board_lock); > > +#if IS_ENABLED(CONFIG_OF) > +/* OF helpers for SLIMbus */ > +static void of_register_slim_devices(struct slim_controller *ctrl) > +{ > + struct device_node *node; > + > + if (!ctrl->dev.of_node) > + return; > + > + for_each_child_of_node(ctrl->dev.of_node, node) { > + int ret; > + u32 ea[4]; > + struct slim_device *slim; > + char *name; > + > + ret = of_property_read_u32_array(node, "reg", ea, 4); > + if (ret) { > + dev_err(&ctrl->dev, "of_slim: E-addr err:%d\n", ret); > + continue; > + } > + name = kcalloc(SLIMBUS_NAME_SIZE, sizeof(char), GFP_KERNEL); > + if (!name) > + return; > + > + slim = kzalloc(sizeof(struct slim_device), GFP_KERNEL); sizeof(*slim) would be nicer here. Thanks, Mark.