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 72F18C43334 for ; Sat, 25 Jun 2022 12:45:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232898AbiFYMpG (ORCPT ); Sat, 25 Jun 2022 08:45:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39066 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232897AbiFYMpG (ORCPT ); Sat, 25 Jun 2022 08:45:06 -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 ACAE3EE3B; Sat, 25 Jun 2022 05:45:04 -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 452B061203; Sat, 25 Jun 2022 12:45:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D29FC3411C; Sat, 25 Jun 2022 12:45:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1656161103; bh=jtBOB+fEQAt8XVOj1YNbq/Dy66rjLUV3m39esLC9KpM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Lh1W4tH+kxjI+Tw/faCkYC40dOFtswR21Dr9YpHd9I5Z7AY0n+239LZ0xM7XNGciG /YPSQuMCuJFVqWMnnfzik6SFywa0c/HbU8mLQOmywALNDFOeyR6UPM07b/MwQCVDJT nKCnCCQCVD1TbQ2FdlteYVQME/v2LHwFZ8qJcyb/BKyfDcf/ug5P595rf+2yEvNKK6 gpN/bKzJAnD/c5f+7Xu0S8y3x9ejS7XqwOKUTG4RAEJV/+2EeYU3KuE6fKMl4BK8mv QMldjqu7RGlpBOqgedNXXUdpABrgy0+PSz4F1bjW1gPBz6FpkFErF/WuPyBgEbC7rF ADpiQzXq2XMMg== Date: Sat, 25 Jun 2022 13:54:31 +0100 From: Jonathan Cameron To: Marcus Folkesson Cc: Kent Gustavsson , Lars-Peter Clausen , Rob Herring , Krzysztof Kozlowski , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 10/10] iio: adc: mcp3911: add support to set PGA Message-ID: <20220625135431.3f82148a@jic23-huawei> In-Reply-To: <20220625103853.2470346-10-marcus.folkesson@gmail.com> References: <20220625103853.2470346-1-marcus.folkesson@gmail.com> <20220625103853.2470346-10-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 Sat, 25 Jun 2022 12:38:53 +0200 Marcus Folkesson wrote: > Add support for setting the Programmable Gain Amplifiers by adjust the > scale value. > > Signed-off-by: Marcus Folkesson A few minor things inline. Thanks, Jonathan > --- > > Notes: > v2: > - add missing comma > - Address comments from Andy Shevchenko > > drivers/iio/adc/mcp3911.c | 134 +++++++++++++++++++++++++++++++------- > 1 file changed, 110 insertions(+), 24 deletions(-) > > diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c > index a019264e73e3..f0179385485f 100644 > --- a/drivers/iio/adc/mcp3911.c > +++ b/drivers/iio/adc/mcp3911.c > @@ -26,6 +26,8 @@ > #define MCP3911_REG_MOD 0x06 > #define MCP3911_REG_PHASE 0x07 > #define MCP3911_REG_GAIN 0x09 > +#define MCP3911_GAIN_MASK(ch) (0x7 << 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) > @@ -55,8 +57,10 @@ > #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; > @@ -65,6 +69,7 @@ struct mcp3911 { > struct clk *clki; > u32 dev_addr; > struct iio_trigger *trig; > + u32 gain[MCP3911_NUM_CHANNELS]; > struct { > u32 channels[2]; > s64 ts __aligned(8); > @@ -113,6 +118,37 @@ static int mcp3911_update(struct mcp3911 *adc, u8 reg, u32 mask, > return mcp3911_write(adc, reg, val, len); > } > > +static int mcp3911_get_gain(struct mcp3911 *adc, u8 channel, u32 *val) > +{ > + int ret; > + > + ret = mcp3911_read(adc, MCP3911_REG_GAIN, val, 1); > + if (ret) > + return ret; > + > + *val >>= channel * 3; > + *val &= GENMASK(2, 0); > + *val = BIT(*val); > + > + return 0; > +} > + > +static int mcp3911_write_raw_get_fmt(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + long mask) > +{ > + switch (mask) { > + case IIO_CHAN_INFO_SCALE: > + return IIO_VAL_INT_PLUS_NANO; > + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_PHASE: > + return IIO_VAL_INT; Ah. here is what I asked for earlier. Please move it back to the patches that introduced the other features. > + default: > + return IIO_VAL_INT_PLUS_NANO; > + } > +} > + > static int mcp3911_read_avail(struct iio_dev *indio_dev, > struct iio_chan_spec const *chan, > const int **vals, int *type, int *length, > @@ -124,6 +160,11 @@ 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; > } > @@ -180,29 +221,9 @@ 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; > } > > @@ -220,6 +241,18 @@ 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 +297,48 @@ 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; > + int tmp0, tmp1; > + s64 tmp2; > + > + 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 24bit Conversion > + * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5 > + * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5) > + */ > + > + /* ref = Reference voltage comment syntax is wrong. Also a bit odd to have two comment blocks next to each other. Please combine them. > + * div = (2^23 * 1.5 * gain) = 12582912 * gain > + */ > + for (int i = 0; i < MCP3911_NUM_SCALES; i++) { > + div = 12582912 * BIT(i); > + tmp2 = div_s64((s64)ref * 1000000000LL, div); > + tmp1 = div; > + tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1); > + > + mcp3911_scale_table[i][0] = 0; > + mcp3911_scale_table[i][1] = tmp1; > + } > + > + return 0; > +} > + > #define MCP3911_CHAN(idx) { \ > .type = IIO_VOLTAGE, \ > .indexed = 1, \ > @@ -276,8 +351,10 @@ 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, \ > @@ -330,6 +407,7 @@ static const struct iio_info mcp3911_info = { > .read_raw = mcp3911_read_raw, > .write_raw = mcp3911_write_raw, > .read_avail = mcp3911_read_avail, > + .write_raw_get_fmt = mcp3911_write_raw_get_fmt, > }; > > static irqreturn_t mcp3911_interrupt(int irq, void *dev_id) > @@ -460,6 +538,14 @@ static int mcp3911_probe(struct spi_device *spi) > if (ret) > goto clk_disable; > > + ret = mcp3911_calc_scale_table(adc); > + if (ret) > + goto clk_disable; > + > + /* Store gain values to better calculate scale values */ Run checkpatch.pl You have spaces here which should be a tab. > + mcp3911_get_gain(adc, 0, &adc->gain[0]); > + mcp3911_get_gain(adc, 1, &adc->gain[1]); We'd normally set something like this to default value rather than rely on sane state from a previous startup. Either that or rely on reset (which device has, but I don't think driver supports yet). > + > if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz")) > ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ, > 0, 2);