From patchwork Wed Aug 29 06:04:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "(Exiting) Baolin Wang" X-Patchwork-Id: 10579551 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C2EC5139B for ; Wed, 29 Aug 2018 06:04:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B53052A3D3 for ; Wed, 29 Aug 2018 06:04:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A892E2A593; Wed, 29 Aug 2018 06:04:41 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3488B2A45E for ; Wed, 29 Aug 2018 06:04:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727399AbeH2J7h (ORCPT ); Wed, 29 Aug 2018 05:59:37 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:36638 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726857AbeH2J7h (ORCPT ); Wed, 29 Aug 2018 05:59:37 -0400 Received: by mail-pf1-f196.google.com with SMTP id b11-v6so1800362pfo.3 for ; Tue, 28 Aug 2018 23:04:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :in-reply-to:references; bh=QYs/+wtywkNmEn4RKbGv+95uUTJD4f+z+ToiDyC70jw=; b=KJ9gNWIrTIbnMM84F7GPQrOdUeQ5Vd7OUPBeDIOV1lnn5zgJO5OQkXcaED86nWEQYh uMhDaq8MLcLSyDZ2Vjfok8mT579dEtFIwIjJFrVY55vxtKmgc9/nzU+yuLL4Ct1WCbgY agnZQE2Sx91wEhIw4iyvkdIzInWgKDYuW77ms= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=QYs/+wtywkNmEn4RKbGv+95uUTJD4f+z+ToiDyC70jw=; b=WyYhAv4+/SJHro12M0RdK4DJf7Btya1Fxu2z75I2JMRGh/qDbvSh8BK1RaMYRvprm2 /lgTP3Gp/FdTI3leRtQhavRx3tKJw4z56VwZydw5XNgbK/l4JJFdadZiOD+8jLSATyxs bKeiGBp35vADIAuyvCeGzZOQjnSCSzwMVaBhck8APTSzU5Kj5ZEAByCUSGKO7v6POhp8 Dm0YucXspkgRw5iYLMdVpt/m1utRObRW05mtiZksRSGrwJ8MDqqmV0TG0TfQ2bbRUULi oJRYS5WN+dT8nXrZaL3zMP93Doon06nJvTR1fjjNQfJKXi4oYB/l5MF2QmlUWStQO2Ub Lt9A== X-Gm-Message-State: APzg51D1JUudyP99sEhpuAZ9R5gp2FzbCyqYXAEJJDEeuPiFql4sDHTR gouqgzgDBn5bHk7Y5lUI182C/2u0KSdwvQ== X-Google-Smtp-Source: ANB0Vdbr+AVE7wAQ92tG1qes9It7RAP29McPzD05xKhxyS33BRYppudeai0ryygB6sMf3VsBhBJK1A== X-Received: by 2002:a63:1618:: with SMTP id w24-v6mr4489155pgl.43.1535522663479; Tue, 28 Aug 2018 23:04:23 -0700 (PDT) Received: from baolinwangubtpc.spreadtrum.com ([117.18.48.102]) by smtp.gmail.com with ESMTPSA id c85-v6sm5188729pfd.110.2018.08.28.23.04.19 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 28 Aug 2018 23:04:23 -0700 (PDT) From: Baolin Wang To: jic23@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com Cc: knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, freeman.liu@spreadtrum.com, broonie@kernel.org, baolin.wang@linaro.org, devicetree@vger.kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/2] iio: adc: sc27xx: Add ADC scale calibration Date: Wed, 29 Aug 2018 14:04:05 +0800 Message-Id: <61cad47d5d10c771d3cc371744533e87d192ee96.1535434262.git.baolin.wang@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <0adef2f9eafa913eb9f4bc1ed3dc643d09bf02a2.1535434262.git.baolin.wang@linaro.org> References: <0adef2f9eafa913eb9f4bc1ed3dc643d09bf02a2.1535434262.git.baolin.wang@linaro.org> In-Reply-To: <0adef2f9eafa913eb9f4bc1ed3dc643d09bf02a2.1535434262.git.baolin.wang@linaro.org> References: <0adef2f9eafa913eb9f4bc1ed3dc643d09bf02a2.1535434262.git.baolin.wang@linaro.org> Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds support to read calibration values from the eFuse controller to calibrate the ADC channel scales, which can make ADC sample data more accurate. Signed-off-by: Baolin Wang --- Changes from v1: - Use nvmem_cell_read() instead of nvmem_cell_read_u32(). --- .../bindings/iio/adc/sprd,sc27xx-adc.txt | 4 ++ drivers/iio/adc/sc27xx_adc.c | 74 +++++++++++++++++++- 2 files changed, 75 insertions(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/iio/adc/sprd,sc27xx-adc.txt b/Documentation/devicetree/bindings/iio/adc/sprd,sc27xx-adc.txt index 8aad960..b4daa15 100644 --- a/Documentation/devicetree/bindings/iio/adc/sprd,sc27xx-adc.txt +++ b/Documentation/devicetree/bindings/iio/adc/sprd,sc27xx-adc.txt @@ -12,6 +12,8 @@ Required properties: - interrupts: The interrupt number for the ADC device. - #io-channel-cells: Number of cells in an IIO specifier. - hwlocks: Reference to a phandle of a hwlock provider node. +- nvmem-cells: A phandle to the calibration cells provided by eFuse device. +- nvmem-cell-names: Should be "big_scale_calib", "small_scale_calib". Example: @@ -32,5 +34,7 @@ Example: interrupts = <0 IRQ_TYPE_LEVEL_HIGH>; #io-channel-cells = <1>; hwlocks = <&hwlock 4>; + nvmem-cells = <&adc_big_scale>, <&adc_small_scale>; + nvmem-cell-names = "big_scale_calib", "small_scale_calib"; }; }; diff --git a/drivers/iio/adc/sc27xx_adc.c b/drivers/iio/adc/sc27xx_adc.c index 153c311..7940b23 100644 --- a/drivers/iio/adc/sc27xx_adc.c +++ b/drivers/iio/adc/sc27xx_adc.c @@ -5,10 +5,12 @@ #include #include #include +#include #include #include #include #include +#include /* PMIC global registers definition */ #define SC27XX_MODULE_EN 0xc08 @@ -87,16 +89,73 @@ struct sc27xx_adc_linear_graph { * should use the small-scale graph, and if more than 1.2v, we should use the * big-scale graph. */ -static const struct sc27xx_adc_linear_graph big_scale_graph = { +static struct sc27xx_adc_linear_graph big_scale_graph = { 4200, 3310, 3600, 2832, }; -static const struct sc27xx_adc_linear_graph small_scale_graph = { +static struct sc27xx_adc_linear_graph small_scale_graph = { 1000, 3413, 100, 341, }; +static const struct sc27xx_adc_linear_graph big_scale_graph_calib = { + 4200, 856, + 3600, 733, +}; + +static const struct sc27xx_adc_linear_graph small_scale_graph_calib = { + 1000, 833, + 100, 80, +}; + +static int sc27xx_adc_get_calib_data(u32 calib_data, int calib_adc) +{ + return ((calib_data & 0xff) + calib_adc - 128) * 4; +} + +static int sc27xx_adc_scale_calibration(struct sc27xx_adc_data *data, + bool big_scale) +{ + const struct sc27xx_adc_linear_graph *calib_graph; + struct sc27xx_adc_linear_graph *graph; + struct nvmem_cell *cell; + const char *cell_name; + u32 calib_data = 0; + void *buf; + size_t len; + + if (big_scale) { + calib_graph = &big_scale_graph_calib; + graph = &big_scale_graph; + cell_name = "big_scale_calib"; + } else { + calib_graph = &small_scale_graph_calib; + graph = &small_scale_graph; + cell_name = "small_scale_calib"; + } + + cell = nvmem_cell_get(data->dev, cell_name); + if (IS_ERR(cell)) + return PTR_ERR(cell); + + buf = nvmem_cell_read(cell, &len); + nvmem_cell_put(cell); + + if (IS_ERR(buf)) + return PTR_ERR(buf); + + memcpy(&calib_data, buf, min(len, sizeof(u32))); + + /* Only need to calibrate the adc values in the linear graph. */ + graph->adc0 = sc27xx_adc_get_calib_data(calib_data, calib_graph->adc0); + graph->adc1 = sc27xx_adc_get_calib_data(calib_data >> 8, + calib_graph->adc1); + + kfree(buf); + return 0; +} + static int sc27xx_adc_get_ratio(int channel, int scale) { switch (channel) { @@ -209,7 +268,7 @@ static void sc27xx_adc_volt_ratio(struct sc27xx_adc_data *data, *div_denominator = ratio & SC27XX_RATIO_DENOMINATOR_MASK; } -static int sc27xx_adc_to_volt(const struct sc27xx_adc_linear_graph *graph, +static int sc27xx_adc_to_volt(struct sc27xx_adc_linear_graph *graph, int raw_adc) { int tmp; @@ -390,6 +449,15 @@ static int sc27xx_adc_enable(struct sc27xx_adc_data *data) if (ret) goto disable_clk; + /* ADC channel scales' calibration from nvmem device */ + ret = sc27xx_adc_scale_calibration(data, true); + if (ret) + goto disable_clk; + + ret = sc27xx_adc_scale_calibration(data, false); + if (ret) + goto disable_clk; + return 0; disable_clk: