From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH 1/2] mfd: sm-usb-dig: Add support for the TI SM-USB-DIG Date: Thu, 9 Jun 2016 15:23:25 +0100 Message-ID: <20160609142325.GD2385@dell> References: <20160531173045.5742-1-afd@ti.com> <20160608130647.GD14888@dell> <575857B0.3090504@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-wm0-f51.google.com ([74.125.82.51]:36241 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751497AbcFIOWx (ORCPT ); Thu, 9 Jun 2016 10:22:53 -0400 Received: by mail-wm0-f51.google.com with SMTP id n184so227826526wmn.1 for ; Thu, 09 Jun 2016 07:22:52 -0700 (PDT) Content-Disposition: inline In-Reply-To: <575857B0.3090504@ti.com> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: "Andrew F. Davis" Cc: Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org 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: > >=20 > >> 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. > >> =20 > >> +config MFD_SM_USB_DIG > >> + tristate "Texas Instruments SM-USB-DIG interface adapter" > >=20 > > 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. > >=20 >=20 > Okay, will CC for next version. >=20 > >> + select MFD_CORE > >> + help > >> + Support for the TI SM-USB-DIG USB to SPI/I2C/1Wire/GPIO adapte= r. > >> + Additional drivers such as SPI_SM_USB_DIG, I2C_SM_USB_DIG, etc= =2E 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-$(CONFIG_MFD_WM8350_I2C) +=3D wm8350-i2c.o > >> wm8994-objs :=3D wm8994-core.o wm8994-irq.o wm8994-regmap.o > >> obj-$(CONFIG_MFD_WM8994) +=3D wm8994.o > >> =20 > >> +obj-$(CONFIG_MFD_SM_USB_DIG) +=3D sm-usb-dig.o > >> + > >> obj-$(CONFIG_TPS6105X) +=3D tps6105x.o > >> obj-$(CONFIG_TPS65010) +=3D tps65010.o > >> obj-$(CONFIG_TPS6507X) +=3D 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 > >=20 > > This should probably be ti-sm-usb-dig.c > >=20 >=20 > 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? > >> @@ -0,0 +1,138 @@ > >> +/* > >> + * MFD Core driver for TI SM-USB-DIG > >> + * > >> + * Copyright (C) 2016 Texas Instruments Incorporated - http://www= =2Eti.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 ve= rsion 2 as > >> + * published by the Free Software Foundation. > >> + * > >> + * This program is distributed "as is" WITHOUT ANY WARRANTY of an= y > >> + * kind, whether expressed or implied; without even the implied w= arranty > >> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See t= he > >> + * GNU General Public License version 2 for more details. > >> + */ > >> + > >> +#include > >> +#include > >> +#include > >> + > >> +#include > >=20 > > All alphabetical. > >=20 >=20 > ACK >=20 > >> +#define USB_VENDOR_ID_TI 0x0451 > >> +#define USB_DEVICE_ID_TI_SM_USB_DIG 0x2f90 > >=20 > > TI at the beginning. > >=20 >=20 > ACK >=20 > >> +#define SMUSBDIG_USB_TIMEOUT 1000 /* in ms */ > >=20 > > Rename to SMUSBDIG_USB_TIMEOUT_MS > >=20 >=20 > ACK >=20 > >> +struct smusbdig_device { > >> + struct usb_device *usb_dev; > >> + struct usb_interface *interface; > >> +}; > >=20 > > s/smusbdig/ti_smusbdig/ > >=20 > > ... throughout. > >=20 >=20 > 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 > >> +int smusbdig_xfer(struct smusbdig_device *smusbdig, u8 *buffer, i= nt size) > >> +{ > >> + struct device *dev =3D &smusbdig->interface->dev; > >> + int actual_length, ret; > >> + > >> + if (!smusbdig || !buffer || size <=3D 0) > >> + return -EINVAL; > >> + > >> + ret =3D 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 =3D 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[] =3D { > >> + { .name =3D "sm-usb-dig-gpio", }, > >> + { .name =3D "sm-usb-dig-i2c", }, > >> + { .name =3D "sm-usb-dig-spi", }, > >> + { .name =3D "sm-usb-dig-w1", }, > >> +}; > >> + > >> +static int smusbdig_probe(struct usb_interface *interface, > >> + const struct usb_device_id *usb_id) > >> +{ > >> + struct usb_host_interface *hostif =3D interface->cur_altsetting; > >> + struct device *dev =3D &interface->dev; > >> + struct smusbdig_device *smusbdig; > >> + u8 buffer[SMUSBDIG_PACKET_SIZE]; > >> + int ret; > >> + > >> + if (hostif->desc.bInterfaceNumber !=3D 0 || > >> + hostif->desc.bNumEndpoints < 2) > >> + return -ENODEV; > >> + > >> + smusbdig =3D devm_kzalloc(dev, sizeof(*smusbdig), GFP_KERNEL); > >> + if (!smusbdig) > >> + return -ENOMEM; > >> + > >> + smusbdig->usb_dev =3D usb_get_dev(interface_to_usbdev(interface)= ); > >> + smusbdig->interface =3D interface; > >> + usb_set_intfdata(interface, smusbdig); > >> + > >> + buffer[0] =3D SMUSBDIG_VERSION; > >> + ret =3D 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] =3D SMUSBDIG_COMMAND; > >> + buffer[1] =3D SMUSBDIG_COMMAND_DUTPOWERON; > >> + ret =3D smusbdig_xfer(smusbdig, buffer, 2); > >> + if (ret) > >> + return ret; > >> + > >> + dev_set_drvdata(dev, smusbdig); > >> + ret =3D 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[] =3D { > >> + { 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 =3D { > >> + .name =3D "sm-usb-dig", > >> + .probe =3D smusbdig_probe, > >> + .disconnect =3D smusbdig_disconnect, > >> + .id_table =3D smusbdig_id_table, > >> +}; > >> +module_usb_driver(smusbdig_driver); > >=20 > > This doesn't look like an MFD driver. > >=20 > > Why aren't you putting this in the USB subsystem? > >=20 >=20 > 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, driv= ers > tend to go into folders based on the functionality they expose, and t= his > exposes multiple functions, not USB functionality, so MFD makes the m= ost > sense to me. >=20 > This device/driver is just like the dln2 and viperboard drivers > currently in the MFD subsystem. Okay. --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog