Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752659AbcDXLgc (ORCPT ); Sun, 24 Apr 2016 07:36:32 -0400 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:35830 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751770AbcDXLga (ORCPT ); Sun, 24 Apr 2016 07:36:30 -0400 Subject: Re: [RFC PATCH 2/3] iio: dummy: Convert IIO dummy to configfs To: Daniel Baluta References: <1461167126-23399-1-git-send-email-daniel.baluta@intel.com> <1461167126-23399-3-git-send-email-daniel.baluta@intel.com> Cc: knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org From: Jonathan Cameron Message-ID: <2ddba9c6-1f62-468d-da71-7819934f0869@kernel.org> Date: Sun, 24 Apr 2016 12:36:28 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: <1461167126-23399-3-git-send-email-daniel.baluta@intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6213 Lines: 209 On 20/04/16 16:45, Daniel Baluta wrote: > We register a new device type named "dummy", this will create a > configfs entry under: > * /config/iio/devices/dummy. > > Creating dummy devices is now as simple as: > > $ mkdir /config/iio/devices/dummy/my_dummy_device > > Signed-off-by: Daniel Baluta Looks very nice. I don't think it is unreasonable to demand people have configfs for the dummy driver so very happy to have this cleaned up. Now to try it with a few thousand devices and see what breaks ;) 1 trivial point inline. Jonathan > --- > drivers/iio/dummy/iio_simple_dummy.c | 98 ++++++++++++------------------------ > 1 file changed, 33 insertions(+), 65 deletions(-) > > diff --git a/drivers/iio/dummy/iio_simple_dummy.c b/drivers/iio/dummy/iio_simple_dummy.c > index 43fe4ba..65f92f8 100644 > --- a/drivers/iio/dummy/iio_simple_dummy.c > +++ b/drivers/iio/dummy/iio_simple_dummy.c > @@ -22,21 +22,12 @@ > #include > #include > #include > +#include > #include "iio_simple_dummy.h" > > -/* > - * A few elements needed to fake a bus for this driver > - * Note instances parameter controls how many of these > - * dummy devices are registered. > - */ > -static unsigned instances = 1; > -module_param(instances, uint, 0); > - > -/* Pointer array used to fake bus elements */ > -static struct iio_dev **iio_dummy_devs; > - > -/* Fake a name for the part number, usually obtained from the id table */ > -static const char *iio_dummy_part_number = "iio_dummy_part_no"; > +static struct config_item_type iio_dummy_type = { > + .ct_owner = THIS_MODULE, > +}; > > /** > * struct iio_dummy_accel_calibscale - realworld to register mapping > @@ -572,12 +563,18 @@ static int iio_dummy_init_device(struct iio_dev *indio_dev) > * const struct i2c_device_id *id) > * SPI: iio_dummy_probe(struct spi_device *spi) > */ > -static int iio_dummy_probe(int index) > +static struct iio_sw_device *iio_dummy_probe(const char *name) > { > int ret; > struct iio_dev *indio_dev; > struct iio_dummy_state *st; > + struct iio_sw_device *swd; > > + swd = kzalloc(sizeof(*swd), GFP_KERNEL); > + if (!swd) { > + ret = -ENOMEM; > + goto error_kzalloc; > + } > /* > * Allocate an IIO device. > * > @@ -608,7 +605,7 @@ static int iio_dummy_probe(int index) > * i2c_set_clientdata(client, indio_dev); > * spi_set_drvdata(spi, indio_dev); > */ > - iio_dummy_devs[index] = indio_dev; > + swd->device = indio_dev; > > /* > * Set the device name. > @@ -619,7 +616,7 @@ static int iio_dummy_probe(int index) > * indio_dev->name = id->name; > * indio_dev->name = spi_get_device_id(spi)->name; > */ > - indio_dev->name = iio_dummy_part_number; > + indio_dev->name = name; > > /* Provide description of available channels */ > indio_dev->channels = iio_dummy_channels; > @@ -646,7 +643,8 @@ static int iio_dummy_probe(int index) > if (ret < 0) > goto error_unconfigure_buffer; > > - return 0; > + iio_swd_group_init_type_name(swd, name, &iio_dummy_type); > + return swd; > error_unconfigure_buffer: > iio_simple_dummy_unconfigure_buffer(indio_dev); > error_unregister_events: > @@ -654,16 +652,18 @@ error_unregister_events: > error_free_device: > iio_device_free(indio_dev); > error_ret: > - return ret; > + kfree(swd); > +error_kzalloc: > + return ERR_PTR(ret); > } > > /** > * iio_dummy_remove() - device instance removal function > - * @index: device index. > + * @swd: pointer to software IIO device abstraction > * > * Parameters follow those of iio_dummy_probe for buses. > */ > -static void iio_dummy_remove(int index) > +static int iio_dummy_remove(struct iio_sw_device *swd) > { > /* > * Get a pointer to the device instance iio_dev structure > @@ -671,7 +671,7 @@ static void iio_dummy_remove(int index) > * struct iio_dev *indio_dev = i2c_get_clientdata(client); > * struct iio_dev *indio_dev = spi_get_drvdata(spi); > */ > - struct iio_dev *indio_dev = iio_dummy_devs[index]; > + struct iio_dev *indio_dev = swd->device; > > /* Unregister the device */ > iio_device_unregister(indio_dev); > @@ -685,10 +685,10 @@ static void iio_dummy_remove(int index) > > /* Free all structures */ > iio_device_free(indio_dev); blank line here (nitpick of the day ;) > + return 0; > } > - > /** > - * iio_dummy_init() - device driver registration > + * module_iio_sw_device_driver() - device driver registration > * > * Varies depending on bus type of the device. As there is no device > * here, call probe directly. For information on device registration > @@ -697,50 +697,18 @@ static void iio_dummy_remove(int index) > * spi: > * Documentation/spi/spi-summary > */ > -static __init int iio_dummy_init(void) > -{ > - int i, ret; > - > - if (instances > 10) { > - instances = 1; > - return -EINVAL; > - } > - > - /* Fake a bus */ > - iio_dummy_devs = kcalloc(instances, sizeof(*iio_dummy_devs), > - GFP_KERNEL); > - /* Here we have no actual device so call probe */ > - for (i = 0; i < instances; i++) { > - ret = iio_dummy_probe(i); > - if (ret < 0) > - goto error_remove_devs; > - } > - return 0; > - > -error_remove_devs: > - while (i--) > - iio_dummy_remove(i); > - > - kfree(iio_dummy_devs); > - return ret; > -} > -module_init(iio_dummy_init); > +static const struct iio_sw_device_ops iio_dummy_device_ops = { > + .probe = iio_dummy_probe, > + .remove = iio_dummy_remove, > +}; > > -/** > - * iio_dummy_exit() - device driver removal > - * > - * Varies depending on bus type of the device. > - * As there is no device here, call remove directly. > - */ > -static __exit void iio_dummy_exit(void) > -{ > - int i; > +static struct iio_sw_device_type iio_dummy_device = { > + .name = "dummy", > + .owner = THIS_MODULE, > + .ops = &iio_dummy_device_ops, > +}; > > - for (i = 0; i < instances; i++) > - iio_dummy_remove(i); > - kfree(iio_dummy_devs); > -} > -module_exit(iio_dummy_exit); > +module_iio_sw_device_driver(iio_dummy_device); > > MODULE_AUTHOR("Jonathan Cameron "); > MODULE_DESCRIPTION("IIO dummy driver"); >