From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gilad Avidov Subject: =?UTF-8?q?=5BPATCH=200/1=5D=20Compact=20interface=20for=20Device-Tree?= Date: Thu, 30 Oct 2014 16:59:23 -0600 Message-ID: <1414709964-27284-1-git-send-email-gavidov@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Sender: linux-arm-msm-owner@vger.kernel.org To: robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, grant.likely@linaro.org Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, sdharia@codeaurora.org, linux-arm-msm@vger.kernel.org, Gilad Avidov List-Id: devicetree@vger.kernel.org Device-Tree compact API ------------------------ Common code seen in driver=E2=80=99s probe reads device tree values and= handling erroneous return codes from all those of_property_read_xxx() APIs. Thi= s common code is factored out by the of_property_map module which allows driver=E2=80=99s probe to replace that (often lengthy) code with a conc= ise table: struct of_prop_map map[] =3D { {"i2c", &dev->id, OF_REQ, OF_ID, -1}, {"qcom,clk-freq-out", &dev->clk_freq_out, OF_REQ, OF_U32, 0= }, {"qcom,clk-freq-in", &dev->clk_freq_in, OF_REQ, OF_U32, 0}, {"qcom,disable-dma", &dev->disable_dma, OF_OPT, OF_BOOL, 0}, {"qcom,master-id", &dev->mstr_id, OF_SGST, OF_U32, 0}, {NULL, NULL, 0, 0, 0}, }; Then call populate to read the values into the device=E2=80=99s variabl= es: ret =3D of_prop_populate(dev, dev->of_node, map); An equivalent code snippet using the traditional of_property_read_XXXX(= ) API. Note that the equivalent is longer and more difficult to follow an= d debug: /* optional property */ dev->disable_dma =3D of_property_read_bool(node, "qcom,disable-dma"); ret =3D of_property_read_u32(dev->node, "qcom,clk-freq-out", &dev->clk_= freq_out); if (ret) { dev_err(dev, "error: missing 'qcom,clk-freq-out' DT property\n"); if (!err) err =3D ret; } ret =3D of_property_read_u32(dev->node, "qcom,clk-freq-in", &dev->clk_f= req_in); if (ret) { dev_err(dev, "error: missing 'qcom,clk-freq-in' DT property\n"); if (!err) err =3D ret; } /* suggested property */ ret =3D of_property_read_u32(dev->node, "qcom,master-id", &dev->mstr_id= ); if (ret && !err) err =3D ret; ret =3D of_alias_get_id(dev->node, "i2c"); if (ret < 0) { dev_err(dev, "error: missing '"i2c"' DT property\n"); if (!err) err =3D ret; } else { dev->id =3D ret; } The Device-Tree node and alias which are read by the above code snippet= s: aliases { i2c0 =3D &i2c_0; /* I2C0 controller device */ }; i2c_0: i2c@78b6000 { /* BLSP1 QUP2 */ compatible =3D "qcom,i2c-msm-v2"; reg-names =3D "qup_phys_addr", "bam_phys_addr"; reg =3D <0x78b6000 0x600>, <0x7884000 0x23000>; qcom,clk-freq-out =3D <100000>; qcom,clk-freq-in =3D <19200000>; qcom,disable-dma; qcom,master-id =3D <86>; };=20 Gilad Avidov (1): of_propery_map: compact interface for Device-Tree Documentation/devicetree/of_property_map.txt | 76 ++++++++++++++++++= ++++ drivers/of/Makefile | 2 +- drivers/of/of_property_map.c | 88 ++++++++++++++++++= ++++++++ include/linux/of_property_map.h | 74 ++++++++++++++++++= ++++ 4 files changed, 239 insertions(+), 1 deletion(-) create mode 100644 Documentation/devicetree/of_property_map.txt create mode 100644 drivers/of/of_property_map.c create mode 100644 include/linux/of_property_map.h --=20 The Qualcomm Innovation Center, Inc. is a member of the Code Aurora For= um, hosted by The Linux Foundation