From patchwork Fri Aug 24 09:53:16 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: 10575027 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 3725A1390 for ; Fri, 24 Aug 2018 09:54:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2807B2C134 for ; Fri, 24 Aug 2018 09:54:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1BBB62C2D7; Fri, 24 Aug 2018 09:54:24 +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 95C812C134 for ; Fri, 24 Aug 2018 09:54:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727142AbeHXN2K (ORCPT ); Fri, 24 Aug 2018 09:28:10 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:47012 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727099AbeHXN2K (ORCPT ); Fri, 24 Aug 2018 09:28:10 -0400 Received: by mail-pg1-f193.google.com with SMTP id b129-v6so4061483pga.13 for ; Fri, 24 Aug 2018 02:54:16 -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=DF9G9tqxmnzsm6POWCrdpkzd6m/XTvoEdqvrpLp5sus=; b=fJdTLnxBGdlUv37iCJsWi/nBMDF6sRzONsCfaYp8EdPN9MtkTQQL1RFYku5f7ngvJp AjD0SgO3N1ZH9n7DfQ2hnjG83+n9jhExZpFVoAth+OZ10fihfFnxwaiL/GBML9MAXOQ+ JNC7peIYOyVT1c1V/Xe3o4G0EmOii2sLl/su0= 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=DF9G9tqxmnzsm6POWCrdpkzd6m/XTvoEdqvrpLp5sus=; b=acX7RQwQ1NyofiXMlXmCi8xPRs7sstm+4aXwXfHrc+O8j7J5oNOX9erPr8UZUP9qDZ thxwFkrwC2ymb6qHjHdHyRkrba8eWwy3+OtwR7H5abGhE0CX02wPWDX/MjBM9vpa3dnp 0zAzJCmTxiKhR3d562mGgIFjLgKzcUr8qvM+J90GTiwxu5Ld5bB7FmXETlRLcDI+MbLP jfkcc3icWGR1EZCozFQFnqvQi0adhdmYViPaAVyRMeVO6JH+CmGimtRKVEszUOvTVWI+ Qwkm9vVdDxX0AV1eYx9lhk2h95rdxBZc+tBHxABuQWsQ6iNpBmeevnHvP4bIB8R4ro2s iqPQ== X-Gm-Message-State: APzg51BFE3pVaAV8H/nm/vU/fje4rjUutKCbR+LWN14O+ioT9bFXIz/R sVed0GYRvE9Hv565yjGEjTCrxg== X-Google-Smtp-Source: ANB0Vdb0Qg+Z3gkhEHFw0v27jeYYU8ClG7TLwsxNnXa37N1tqhHZaHupEBN5UUTsifEKxafUhp6XFw== X-Received: by 2002:a63:a919:: with SMTP id u25-v6mr994691pge.211.1535104456351; Fri, 24 Aug 2018 02:54:16 -0700 (PDT) Received: from baolinwangubtpc.spreadtrum.com ([117.18.48.102]) by smtp.gmail.com with ESMTPSA id j16-v6sm22046560pfk.125.2018.08.24.02.54.12 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 24 Aug 2018 02:54:15 -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 2/2] iio: adc: sc27xx: Add ADC scale calibration Date: Fri, 24 Aug 2018 17:53:16 +0800 Message-Id: X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <4a7e33457617e6f0f7c9627fe20ddd3039e4fe82.1535103920.git.baolin.wang@linaro.org> References: <4a7e33457617e6f0f7c9627fe20ddd3039e4fe82.1535103920.git.baolin.wang@linaro.org> In-Reply-To: <4a7e33457617e6f0f7c9627fe20ddd3039e4fe82.1535103920.git.baolin.wang@linaro.org> References: <4a7e33457617e6f0f7c9627fe20ddd3039e4fe82.1535103920.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 --- .../bindings/iio/adc/sprd,sc27xx-adc.txt | 4 ++ drivers/iio/adc/sc27xx_adc.c | 52 ++++++++++++++++++-- 2 files changed, 53 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..7ac78eda 100644 --- a/drivers/iio/adc/sc27xx_adc.c +++ b/drivers/iio/adc/sc27xx_adc.c @@ -5,6 +5,7 @@ #include #include #include +#include #include #include #include @@ -87,16 +88,48 @@ 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 void +sc27xx_adc_scale_calibration(const struct sc27xx_adc_linear_graph *calib_graph, + u32 calib_data, bool big_scale) +{ + struct sc27xx_adc_linear_graph *graph; + + if (big_scale) + graph = &big_scale_graph; + else + graph = &small_scale_graph; + + /* 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); +} + static int sc27xx_adc_get_ratio(int channel, int scale) { switch (channel) { @@ -209,7 +242,7 @@ 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; @@ -371,6 +404,7 @@ static int sc27xx_adc_write_raw(struct iio_dev *indio_dev, static int sc27xx_adc_enable(struct sc27xx_adc_data *data) { + u32 val; int ret; ret = regmap_update_bits(data->regmap, SC27XX_MODULE_EN, @@ -390,6 +424,18 @@ static int sc27xx_adc_enable(struct sc27xx_adc_data *data) if (ret) goto disable_clk; + /* ADC channel scales' calibration from nvmem device */ + ret = nvmem_cell_read_u32(data->dev, "big_scale_calib", &val); + if (ret) + goto disable_clk; + + sc27xx_adc_scale_calibration(&big_scale_graph_calib, val, true); + + ret = nvmem_cell_read_u32(data->dev, "small_scale_calib", &val); + if (ret) + goto disable_clk; + + sc27xx_adc_scale_calibration(&small_scale_graph_calib, val, false); return 0; disable_clk: