From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752869AbcFIQNh (ORCPT ); Thu, 9 Jun 2016 12:13:37 -0400 Received: from mail-wm0-f53.google.com ([74.125.82.53]:36634 "EHLO mail-wm0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752006AbcFIQNf (ORCPT ); Thu, 9 Jun 2016 12:13:35 -0400 Date: Thu, 9 Jun 2016 17:14:09 +0100 From: Lee Jones To: "Andrew F. Davis" Cc: Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] mfd: sm-usb-dig: Add support for the TI SM-USB-DIG Message-ID: <20160609161409.GD5438@dell> References: <20160531173045.5742-1-afd@ti.com> <20160608130647.GD14888@dell> <575857B0.3090504@ti.com> <20160609142325.GD2385@dell> <57598A99.9010109@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <57598A99.9010109@ti.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 09 Jun 2016, Andrew F. Davis wrote: > On 06/09/2016 09:23 AM, Lee Jones wrote: > > On Wed, 08 Jun 2016, Andrew F. Davis wrote: > > > >> On 06/08/2016 08:06 AM, Lee Jones wrote: > >>> On Tue, 31 May 2016, Andrew F. Davis wrote: > >>> > >>>> The TI SM-USB-DIG is a USB to SPI/I2C/1Wire/GPIO adapter. > >>>> Add MFD core support. > >>>> > >>>> Signed-off-by: Andrew F. Davis > >>>> --- > >>>> The SPI, GPIO, and 1Wire drivers are WIP. > >>>> > >>>> drivers/mfd/Kconfig | 8 +++ > >>>> drivers/mfd/Makefile | 2 + > >>>> drivers/mfd/sm-usb-dig.c | 138 +++++++++++++++++++++++++++++++++++++++++ > >>>> include/linux/mfd/sm-usb-dig.h | 73 ++++++++++++++++++++++ > >>>> 4 files changed, 221 insertions(+) > >>>> create mode 100644 drivers/mfd/sm-usb-dig.c > >>>> create mode 100644 include/linux/mfd/sm-usb-dig.h > >>>> > >>>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > >>>> index 1bcf601..455219a 100644 > >>>> --- a/drivers/mfd/Kconfig > >>>> +++ b/drivers/mfd/Kconfig > >>>> @@ -1373,6 +1373,14 @@ config MFD_LM3533 > >>>> additional drivers must be enabled in order to use the LED, > >>>> backlight or ambient-light-sensor functionality of the device. > >>>> > >>>> +config MFD_SM_USB_DIG > >>>> + tristate "Texas Instruments SM-USB-DIG interface adapter" > >>> > >>> If it is decided that MFD is truly the best place for this driver, you > >>> are still going to need a USB Ack for it. > >>> > >> > >> Okay, will CC for next version. > >> > >>>> + select MFD_CORE > >>>> + help > >>>> + Support for the TI SM-USB-DIG USB to SPI/I2C/1Wire/GPIO adapter. > >>>> + Additional drivers such as SPI_SM_USB_DIG, I2C_SM_USB_DIG, etc. must > >>>> + be enabled in order to use the functionality of the device. > >>>> + > >>>> config MFD_TIMBERDALE > >>>> tristate "Timberdale FPGA" > >>>> select MFD_CORE > >>>> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile > >>>> index 42a66e1..376013e 100644 > >>>> --- a/drivers/mfd/Makefile > >>>> +++ b/drivers/mfd/Makefile > >>>> @@ -68,6 +68,8 @@ obj-$(CONFIG_MFD_WM8350_I2C) += wm8350-i2c.o > >>>> wm8994-objs := wm8994-core.o wm8994-irq.o wm8994-regmap.o > >>>> obj-$(CONFIG_MFD_WM8994) += wm8994.o > >>>> > >>>> +obj-$(CONFIG_MFD_SM_USB_DIG) += sm-usb-dig.o > >>>> + > >>>> obj-$(CONFIG_TPS6105X) += tps6105x.o > >>>> obj-$(CONFIG_TPS65010) += tps65010.o > >>>> obj-$(CONFIG_TPS6507X) += tps6507x.o > >>>> diff --git a/drivers/mfd/sm-usb-dig.c b/drivers/mfd/sm-usb-dig.c > >>>> new file mode 100644 > >>>> index 0000000..cf7ccab > >>>> --- /dev/null > >>>> +++ b/drivers/mfd/sm-usb-dig.c > >>> > >>> This should probably be ti-sm-usb-dig.c > >>> > >> > >> There doesn't seem to be a standard of prefixing devices with their > >> manufacturers name, why would here be any different? > > > > Because most drivers have a standard naming convention; maxim, da, lp, > > tps, wm, etc. So they are easy to group and categorise. Others use > > their company or family name; qcom, st, omap, etc, which has the > > same effect. Where as "sm" doesn't really tell me much. > > > > What does the SM stand for anyway? > > > > I have no idea :), I think the original version may have only supported > SMbus. > > >>>> @@ -0,0 +1,138 @@ > >>>> +/* > >>>> + * MFD Core driver for TI SM-USB-DIG > >>>> + * > >>>> + * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/ > >>>> + * Andrew F. Davis > >>>> + * > >>>> + * This program is free software; you can redistribute it and/or > >>>> + * modify it under the terms of the GNU General Public License version 2 as > >>>> + * published by the Free Software Foundation. > >>>> + * > >>>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any > >>>> + * kind, whether expressed or implied; without even the implied warranty > >>>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > >>>> + * GNU General Public License version 2 for more details. > >>>> + */ > >>>> + > >>>> +#include > >>>> +#include > >>>> +#include > >>>> + > >>>> +#include > >>> > >>> All alphabetical. > >>> > >> > >> ACK > >> > >>>> +#define USB_VENDOR_ID_TI 0x0451 > >>>> +#define USB_DEVICE_ID_TI_SM_USB_DIG 0x2f90 > >>> > >>> TI at the beginning. > >>> > >> > >> ACK > >> > >>>> +#define SMUSBDIG_USB_TIMEOUT 1000 /* in ms */ > >>> > >>> Rename to SMUSBDIG_USB_TIMEOUT_MS > >>> > >> > >> ACK > >> > >>>> +struct smusbdig_device { > >>>> + struct usb_device *usb_dev; > >>>> + struct usb_interface *interface; > >>>> +}; > >>> > >>> s/smusbdig/ti_smusbdig/ > >>> > >>> ... throughout. > >>> > >> > >> I'm not sure about this, I don't think anyone else will be making one of > >> these and this only adds a lot of extra characters to a lot of lines. > > > > We usually prefix functions by vendor or platform name by convention. > > > > Examples: > > > > git grep "static struct.*(" -- drivers/mfd/ drivers/spi > > > > What was this supposed to return? It didn't give me any examples of > vendor prefixed functions. They are all prefixed by the driver name, > like I'm doing here (smusbdig). Which is why I am also suggesting you change the driver name. ;) It would be good to group TI's drivers together, and 3 chars really isn't an issue. ti_smusbdig.c > Not really a big deal, if you think it's better this way, I'll make the > change for v2. > > Thanks, > Andrew > > >>>> +int smusbdig_xfer(struct smusbdig_device *smusbdig, u8 *buffer, int size) > >>>> +{ > >>>> + struct device *dev = &smusbdig->interface->dev; > >>>> + int actual_length, ret; > >>>> + > >>>> + if (!smusbdig || !buffer || size <= 0) > >>>> + return -EINVAL; > >>>> + > >>>> + ret = usb_interrupt_msg(smusbdig->usb_dev, > >>>> + usb_sndctrlpipe(smusbdig->usb_dev, 1), > >>>> + buffer, size, &actual_length, > >>>> + SMUSBDIG_USB_TIMEOUT); > >>>> + if (ret) { > >>>> + dev_err(dev, "USB transaction failed\n"); > >>>> + return ret; > >>>> + } > >>>> + > >>>> + ret = usb_interrupt_msg(smusbdig->usb_dev, > >>>> + usb_rcvctrlpipe(smusbdig->usb_dev, 1), > >>>> + buffer, SMUSBDIG_PACKET_SIZE, &actual_length, > >>>> + SMUSBDIG_USB_TIMEOUT); > >>>> + if (ret) { > >>>> + dev_err(dev, "USB transaction failed\n"); > >>>> + return ret; > >>>> + } > >>>> + > >>>> + return 0; > >>>> +} > >>>> +EXPORT_SYMBOL_GPL(smusbdig_xfer); > >>>> + > >>>> +static const struct mfd_cell smusbdig_mfd_cells[] = { > >>>> + { .name = "sm-usb-dig-gpio", }, > >>>> + { .name = "sm-usb-dig-i2c", }, > >>>> + { .name = "sm-usb-dig-spi", }, > >>>> + { .name = "sm-usb-dig-w1", }, > >>>> +}; > >>>> + > >>>> +static int smusbdig_probe(struct usb_interface *interface, > >>>> + const struct usb_device_id *usb_id) > >>>> +{ > >>>> + struct usb_host_interface *hostif = interface->cur_altsetting; > >>>> + struct device *dev = &interface->dev; > >>>> + struct smusbdig_device *smusbdig; > >>>> + u8 buffer[SMUSBDIG_PACKET_SIZE]; > >>>> + int ret; > >>>> + > >>>> + if (hostif->desc.bInterfaceNumber != 0 || > >>>> + hostif->desc.bNumEndpoints < 2) > >>>> + return -ENODEV; > >>>> + > >>>> + smusbdig = devm_kzalloc(dev, sizeof(*smusbdig), GFP_KERNEL); > >>>> + if (!smusbdig) > >>>> + return -ENOMEM; > >>>> + > >>>> + smusbdig->usb_dev = usb_get_dev(interface_to_usbdev(interface)); > >>>> + smusbdig->interface = interface; > >>>> + usb_set_intfdata(interface, smusbdig); > >>>> + > >>>> + buffer[0] = SMUSBDIG_VERSION; > >>>> + ret = smusbdig_xfer(smusbdig, buffer, 1); > >>>> + if (ret) > >>>> + return ret; > >>>> + > >>>> + dev_info(dev, "TI SM-USB-DIG Version: %d.%02d Found\n", > >>>> + buffer[0], buffer[1]); > >>>> + > >>>> + /* Turn on power supply output */ > >>>> + buffer[0] = SMUSBDIG_COMMAND; > >>>> + buffer[1] = SMUSBDIG_COMMAND_DUTPOWERON; > >>>> + ret = smusbdig_xfer(smusbdig, buffer, 2); > >>>> + if (ret) > >>>> + return ret; > >>>> + > >>>> + dev_set_drvdata(dev, smusbdig); > >>>> + ret = mfd_add_hotplug_devices(dev, smusbdig_mfd_cells, > >>>> + ARRAY_SIZE(smusbdig_mfd_cells)); > >>>> + if (ret) { > >>>> + dev_err(dev, "unable to add MFD devices\n"); > >>>> + return ret; > >>>> + } > >>>> + > >>>> + return 0; > >>>> +} > >>>> + > >>>> +void smusbdig_disconnect(struct usb_interface *interface) > >>>> +{ > >>>> + mfd_remove_devices(&interface->dev); > >>>> +} > >>>> + > >>>> +static const struct usb_device_id smusbdig_id_table[] = { > >>>> + { USB_DEVICE(USB_VENDOR_ID_TI, USB_DEVICE_ID_TI_SM_USB_DIG) }, > >>>> + { /* sentinel */ } > >>>> +}; > >>>> +MODULE_DEVICE_TABLE(usb, smusbdig_id_table); > >>>> + > >>>> +static struct usb_driver smusbdig_driver = { > >>>> + .name = "sm-usb-dig", > >>>> + .probe = smusbdig_probe, > >>>> + .disconnect = smusbdig_disconnect, > >>>> + .id_table = smusbdig_id_table, > >>>> +}; > >>>> +module_usb_driver(smusbdig_driver); > >>> > >>> This doesn't look like an MFD driver. > >>> > >>> Why aren't you putting this in the USB subsystem? > >>> > >> > >> This is not a USB driver, it just attaches to the USB bus like other > >> drivers in this subsystem that attach to SPI/I2C/Platform buses, drivers > >> tend to go into folders based on the functionality they expose, and this > >> exposes multiple functions, not USB functionality, so MFD makes the most > >> sense to me. > >> > >> This device/driver is just like the dln2 and viperboard drivers > >> currently in the MFD subsystem. > > > > Okay. > > -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog