From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH v2 1/8] i2c: i2c-qcom-geni: Provide support for ACPI Date: Mon, 10 Jun 2019 07:44:28 +0100 Message-ID: <20190610064428.GF4797@dell> References: <20190607082901.6491-1-lee.jones@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Ard Biesheuvel Cc: alokc@codeaurora.org, Andy Gross , David Brown , wsa+renesas@sang-engineering.com, Bjorn Andersson , Linus Walleij , balbi@kernel.org, Greg Kroah-Hartman , linux-arm-msm , linux-usb , Linux Kernel Mailing List , "open list:GPIO SUBSYSTEM" , linux-i2c , Jeffrey Hugo , linux-arm-kernel List-Id: linux-i2c@vger.kernel.org On Fri, 07 Jun 2019, Ard Biesheuvel wrote: > On Fri, 7 Jun 2019 at 10:29, Lee Jones wrote: > > > > Add a match table to allow automatic probing of ACPI device > > QCOM0220. Ignore clock attainment errors. Set default clock > > frequency value. > > > > Signed-off-by: Lee Jones > > --- > > drivers/i2c/busses/i2c-qcom-geni.c | 19 +++++++++++++++++-- > > 1 file changed, 17 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c > > index db075bc0d952..0fa93b448e8d 100644 > > --- a/drivers/i2c/busses/i2c-qcom-geni.c > > +++ b/drivers/i2c/busses/i2c-qcom-geni.c > > @@ -1,6 +1,7 @@ > > // SPDX-License-Identifier: GPL-2.0 > > // Copyright (c) 2017-2018, The Linux Foundation. All rights reserved. > > > > +#include > > #include > > #include > > #include > > @@ -483,6 +484,12 @@ static const struct i2c_algorithm geni_i2c_algo = { > > .functionality = geni_i2c_func, > > }; > > > > +static const struct acpi_device_id geni_i2c_acpi_match[] = { > > + { "QCOM0220"}, > > + { }, > > +}; > > +MODULE_DEVICE_TABLE(acpi, geni_i2c_acpi_match); > > + > > We usually put #ifdef CONFIG_ACPI/#endif around these, otherwise you > end up with acpi:XXXX modaliases even though ACPI is not compiled in. No problem. > > static int geni_i2c_probe(struct platform_device *pdev) > > { > > struct geni_i2c_dev *gi2c; > > @@ -502,7 +509,7 @@ static int geni_i2c_probe(struct platform_device *pdev) > > return PTR_ERR(gi2c->se.base); > > > > gi2c->se.clk = devm_clk_get(&pdev->dev, "se"); > > Can we avoid this call altogether in ACPI mode? Also, please use I'm trying not to place all non-ACPI specific callers into if () statements. The tabbing becomes ridiculous in some places. A great deal of these calls are requesting optional resources too, so it's better to simply ignore the returning error in the cases where non-optional resources (such as this one) are requested, since it has the least impact on the existing code. > 'has_acpi_companion()' to test whether we are probing via ACPI. Sure. > > - if (IS_ERR(gi2c->se.clk)) { > > + if (IS_ERR(gi2c->se.clk) && !ACPI_HANDLE(&pdev->dev)) { > > > > ret = PTR_ERR(gi2c->se.clk); > > dev_err(&pdev->dev, "Err getting SE Core clk %d\n", ret); > > return ret; > > @@ -510,12 +517,19 @@ static int geni_i2c_probe(struct platform_device *pdev) > > > > ret = device_property_read_u32(&pdev->dev, "clock-frequency", > > &gi2c->clk_freq_out); > > - if (ret) { > > + if (ret && !ACPI_HANDLE(&pdev->dev)) { > > dev_info(&pdev->dev, > > "Bus frequency not specified, default to 100kHz.\n"); > > gi2c->clk_freq_out = KHZ(100); > > } > > > > + if (ACPI_HANDLE(&pdev->dev)) { > > + ACPI_COMPANION_SET(&gi2c->adap.dev, ACPI_COMPANION(&pdev->dev)); > > + > > + /* Using default, same as the !ACPI case above */ > > + gi2c->clk_freq_out = KHZ(100); > > + } > > + > > You are overriding the speed to 100 kHz even if the ACPI device has a > "clock-frequency" property. Will look at this. Thanks Ard. -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog