From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E6F1C07E9D for ; Sat, 24 Sep 2022 16:46:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233688AbiIXQqC (ORCPT ); Sat, 24 Sep 2022 12:46:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233703AbiIXQqB (ORCPT ); Sat, 24 Sep 2022 12:46:01 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB49D3BC43; Sat, 24 Sep 2022 09:46:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 898FA6148D; Sat, 24 Sep 2022 16:46:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE102C433D6; Sat, 24 Sep 2022 16:45:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664037959; bh=CDCusbtzZCdsfrWo/f/JHWe00c2E9k9abFe0a7tVAps=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=bKf6paN/mrZxYsYKl5ouPkyqLF1b3X6Rompx1/eSx+9US7OvSLlxKzMQlpB27F0+u ZP9HWslRqqoZWbfPuYLoSQW4oDsbzux2b4HbtbOPA9eE0iPZHIMj+3UTXcZi5JqoX7 5MaieVjfi8ODOxzVVsF+kFR3yPhLlouiL/qU8D1CCnfvdv7KpM/TPPpuMv7PKDVRBf s55m+jvA8CF8hl5Oy2/K1NWDQz+OwCN+T/xNqP7P8gDRyecwgCQyq0WZbKi6H7ydd/ Y9J6HRPwHhsWPfVO39BGyhH/QH5arQmW2VNeqMeBRqU+8RC2VWWhPqYKkHn/F+KNaY uJkxv/fTrZBxQ== Date: Sat, 24 Sep 2022 17:46:07 +0100 From: Jonathan Cameron To: Marcus Folkesson Cc: Kent Gustavsson , Lars-Peter Clausen , Rob Herring , Krzysztof Kozlowski , Andy Shevchenko , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7] iio: adc: mcp3911: add support to set PGA Message-ID: <20220924174607.5cf8019f@jic23-huawei> In-Reply-To: <20220922194639.1118971-1-marcus.folkesson@gmail.com> References: <20220922194639.1118971-1-marcus.folkesson@gmail.com> X-Mailer: Claws Mail 4.1.0 (GTK 3.24.34; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Thu, 22 Sep 2022 21:46:39 +0200 Marcus Folkesson wrote: > Add support for setting the Programmable Gain Amplifiers by adjust the > scale value. > > Signed-off-by: Marcus Folkesson > Reviewed-by: Andy Shevchenko Applied to the togreg branch of iio.git and pushed out as testing. I considered slipping this into my 2nd IIO pull request for this cycle at the last minute, but wasn't happy skipping normal time being beaten on by 0-day and time in next, so I didn't. Hence this probably won't make 6.1, but Linus did hint he might do an rc8 in which case I may see if GregKH will take a 3rd pull late next week. If not, it'll be 6.2 material. Thanks, Jonathan > --- > > Notes: > Based on > Link: https://lore.kernel.org/all/20220815061625.35568-1-marcus.folkesson@gmail.com/ > > But with tmp0, tmp1 and tmp2 removed as those are not needed. > Link: https://lore.kernel.org/all/202209220648.Wb6EtPat-lkp@intel.com/ > > drivers/iio/adc/mcp3911.c | 104 +++++++++++++++++++++++++++++--------- > 1 file changed, 80 insertions(+), 24 deletions(-) > > diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c > index 0151258b456c..0d768006eabb 100644 > --- a/drivers/iio/adc/mcp3911.c > +++ b/drivers/iio/adc/mcp3911.c > @@ -29,6 +29,8 @@ > #define MCP3911_REG_MOD 0x06 > #define MCP3911_REG_PHASE 0x07 > #define MCP3911_REG_GAIN 0x09 > +#define MCP3911_GAIN_MASK(ch) (GENMASK(2, 0) << 3 * ch) > +#define MCP3911_GAIN_VAL(ch, val) ((val << 3 * ch) & MCP3911_GAIN_MASK(ch)) > > #define MCP3911_REG_STATUSCOM 0x0a > #define MCP3911_STATUSCOM_DRHIZ BIT(12) > @@ -59,8 +61,10 @@ > #define MCP3911_REG_WRITE(reg, id) ((((reg) << 1) | ((id) << 5) | (0 << 0)) & 0xff) > > #define MCP3911_NUM_CHANNELS 2 > +#define MCP3911_NUM_SCALES 6 > > static const int mcp3911_osr_table[] = { 32, 64, 128, 256, 512, 1024, 2048, 4096 }; > +static u32 mcp3911_scale_table[MCP3911_NUM_SCALES][2]; > > struct mcp3911 { > struct spi_device *spi; > @@ -69,6 +73,7 @@ struct mcp3911 { > struct clk *clki; > u32 dev_addr; > struct iio_trigger *trig; > + u32 gain[MCP3911_NUM_CHANNELS]; > struct { > u32 channels[MCP3911_NUM_CHANNELS]; > s64 ts __aligned(8); > @@ -145,6 +150,11 @@ static int mcp3911_read_avail(struct iio_dev *indio_dev, > *vals = mcp3911_osr_table; > *length = ARRAY_SIZE(mcp3911_osr_table); > return IIO_AVAIL_LIST; > + case IIO_CHAN_INFO_SCALE: > + *type = IIO_VAL_INT_PLUS_NANO; > + *vals = (int *)mcp3911_scale_table; > + *length = ARRAY_SIZE(mcp3911_scale_table) * 2; > + return IIO_AVAIL_LIST; > default: > return -EINVAL; > } > @@ -189,29 +199,9 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev, > break; > > case IIO_CHAN_INFO_SCALE: > - if (adc->vref) { > - ret = regulator_get_voltage(adc->vref); > - if (ret < 0) { > - dev_err(indio_dev->dev.parent, > - "failed to get vref voltage: %d\n", > - ret); > - goto out; > - } > - > - *val = ret / 1000; > - } else { > - *val = MCP3911_INT_VREF_MV; > - } > - > - /* > - * For 24bit Conversion > - * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5 > - * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5) > - */ > - > - /* val2 = (2^23 * 1.5) */ > - *val2 = 12582912; > - ret = IIO_VAL_FRACTIONAL; > + *val = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][0]; > + *val2 = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][1]; > + ret = IIO_VAL_INT_PLUS_NANO; > break; > } > > @@ -229,6 +219,18 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev, > > mutex_lock(&adc->lock); > switch (mask) { > + case IIO_CHAN_INFO_SCALE: > + for (int i = 0; i < MCP3911_NUM_SCALES; i++) { > + if (val == mcp3911_scale_table[i][0] && > + val2 == mcp3911_scale_table[i][1]) { > + > + adc->gain[channel->channel] = BIT(i); > + ret = mcp3911_update(adc, MCP3911_REG_GAIN, > + MCP3911_GAIN_MASK(channel->channel), > + MCP3911_GAIN_VAL(channel->channel, i), 1); > + } > + } > + break; > case IIO_CHAN_INFO_OFFSET: > if (val2 != 0) { > ret = -EINVAL; > @@ -264,6 +266,44 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev, > return ret; > } > > +static int mcp3911_calc_scale_table(struct mcp3911 *adc) > +{ > + u32 ref = MCP3911_INT_VREF_MV; > + u32 div; > + int ret; > + u64 tmp; > + > + if (adc->vref) { > + ret = regulator_get_voltage(adc->vref); > + if (ret < 0) { > + dev_err(&adc->spi->dev, > + "failed to get vref voltage: %d\n", > + ret); > + return ret; > + } > + > + ref = ret / 1000; > + } > + > + /* > + * For 24-bit Conversion > + * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5 > + * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5) > + * > + * ref = Reference voltage > + * div = (2^23 * 1.5 * gain) = 12582912 * gain > + */ > + for (int i = 0; i < MCP3911_NUM_SCALES; i++) { > + div = 12582912 * BIT(i); > + tmp = div_s64((s64)ref * 1000000000LL, div); > + > + mcp3911_scale_table[i][0] = 0; > + mcp3911_scale_table[i][1] = tmp; > + } > + > + return 0; > +} > + > #define MCP3911_CHAN(idx) { \ > .type = IIO_VOLTAGE, \ > .indexed = 1, \ > @@ -273,8 +313,10 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev, > .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ > BIT(IIO_CHAN_INFO_OFFSET) | \ > BIT(IIO_CHAN_INFO_SCALE), \ > - .info_mask_shared_by_type_available = \ > + .info_mask_shared_by_type_available = \ > BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ > + .info_mask_separate_available = \ > + BIT(IIO_CHAN_INFO_SCALE), \ > .scan_type = { \ > .sign = 's', \ > .realbits = 24, \ > @@ -483,6 +525,20 @@ static int mcp3911_probe(struct spi_device *spi) > if (ret) > return ret; > > + ret = mcp3911_calc_scale_table(adc); > + if (ret) > + return ret; > + > + /* Set gain to 1 for all channels */ > + for (int i = 0; i < MCP3911_NUM_CHANNELS; i++) { > + adc->gain[i] = 1; > + ret = mcp3911_update(adc, MCP3911_REG_GAIN, > + MCP3911_GAIN_MASK(i), > + MCP3911_GAIN_VAL(i, 0), 1); > + if (ret) > + return ret; > + } > + > indio_dev->name = spi_get_device_id(spi)->name; > indio_dev->modes = INDIO_DIRECT_MODE; > indio_dev->info = &mcp3911_info;