From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH v7 2/2] mfd: atmel-flexcom: add a driver for Atmel Flexible Serial Communication Unit Date: Fri, 24 Jul 2015 09:43:55 +0100 Message-ID: <20150724084355.GY3436@x1> References: <55921f08b2d5d14256141edbe12287fba55860c4.1437669004.git.cyrille.pitchen@atmel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <55921f08b2d5d14256141edbe12287fba55860c4.1437669004.git.cyrille.pitchen-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Cyrille Pitchen Cc: nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org, boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, sameo-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On Thu, 23 Jul 2015, Cyrille Pitchen wrote: > This driver supports the new Atmel Flexcom. The Flexcom is a wrapper = which > integrates one SPI controller, one I2C controller and one USART. Only= one > function can be enabled at a time. This driver selects the function o= nce > for all, when the Flexcom is probed, using the "reg" property of the = first > (should be unique) available DT child node. >=20 > This driver has chosen to present the Flexcom to the system as a MFD = so > the implementation is seamless for the existing Atmel SPI, I2C and US= ART > drivers. >=20 > Also the Flexcom embeds FIFOs: the latest patches of the SPI, I2C and > USART drivers take advantage of this new feature. >=20 > Signed-off-by: Cyrille Pitchen > --- > drivers/mfd/Kconfig | 11 +++++ > drivers/mfd/Makefile | 1 + > drivers/mfd/atmel-flexcom.c | 113 ++++++++++++++++++++++++++++++++++= ++++++++++ > 3 files changed, 125 insertions(+) > create mode 100644 drivers/mfd/atmel-flexcom.c >=20 > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > index 653815950aa2..2c75472c679c 100644 > --- a/drivers/mfd/Kconfig > +++ b/drivers/mfd/Kconfig > @@ -60,6 +60,17 @@ config MFD_AAT2870_CORE > additional drivers must be enabled in order to use the > functionality of the device. > =20 > +config MFD_ATMEL_FLEXCOM > + tristate "Atmel Flexcom (Flexible Serial Communication Unit)" > + select MFD_CORE > + depends on OF > + help > + Select this to get support for Atmel Flexcom. This is a wrapper > + which embeds a SPI controller, a I2C controller and a USART. Only > + one function can be used at a time. The choice is done at boot ti= me > + by the probe function of this MFD driver according to a device tr= ee > + property. Please grep for QCOM_GSBI in drivers/soc/qcom/* Similar right? Perhaps this should live in drivers/soc/atmel/* instead? > config MFD_ATMEL_HLCDC > tristate "Atmel HLCDC (High-end LCD Controller)" > select MFD_CORE > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile > index ea40e076cb61..0705eb2d873d 100644 > --- a/drivers/mfd/Makefile > +++ b/drivers/mfd/Makefile > @@ -160,6 +160,7 @@ obj-$(CONFIG_MFD_SPMI_PMIC) +=3D qcom-spmi-pmic.o > obj-$(CONFIG_TPS65911_COMPARATOR) +=3D tps65911-comparator.o > obj-$(CONFIG_MFD_TPS65090) +=3D tps65090.o > obj-$(CONFIG_MFD_AAT2870_CORE) +=3D aat2870-core.o > +obj-$(CONFIG_MFD_ATMEL_FLEXCOM) +=3D atmel-flexcom.o > obj-$(CONFIG_MFD_ATMEL_HLCDC) +=3D atmel-hlcdc.o > obj-$(CONFIG_MFD_INTEL_MSIC) +=3D intel_msic.o > obj-$(CONFIG_MFD_PALMAS) +=3D palmas.o > diff --git a/drivers/mfd/atmel-flexcom.c b/drivers/mfd/atmel-flexcom.= c > new file mode 100644 > index 000000000000..0d06b70696b0 > --- /dev/null > +++ b/drivers/mfd/atmel-flexcom.c > @@ -0,0 +1,113 @@ > +/* > + * Driver for Atmel Flexcom > + * > + * Copyright (C) 2015 Atmel Corporation > + * > + * Author: Cyrille Pitchen > + * > + * This program is free software; you can redistribute it and/or mod= ify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, b= ut WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILIT= Y or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public Lic= ense for > + * more details. > + * > + * You should have received a copy of the GNU General Public License= along with > + * this program. If not, see . > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* I/O register offsets */ > +#define FLEX_MR 0x0 /* Mode Register */ > +#define FLEX_VERSION 0xfc /* Version Register */ > + > +/* Mode Register bit fields */ > +#define FLEX_MR_OPMODE_MASK 0x3 > +#define FLEX_MR_OPMODE_NO_COM 0x0 > +#define FLEX_MR_OPMODE_USART 0x1 > +#define FLEX_MR_OPMODE_SPI 0x2 > +#define FLEX_MR_OPMODE_TWI 0x3 > + > + > +static int atmel_flexcom_probe(struct platform_device *pdev) > +{ > + struct device_node *child, *np =3D pdev->dev.of_node; > + struct clk *clk; > + struct resource *res; > + void __iomem *base; > + u32 opmode; > + int err; > + > + child =3D of_get_next_available_child(np, NULL); > + if (!child) > + return -ENODEV; > + > + /* > + * The Operating Mode is stored into the first u32 of the reg prope= rty > + * of the child. > + */ > + err =3D of_property_read_u32_index(child, "reg", 0, &opmode); > + of_node_put(child); Don't think you need to of_node_put() after a u32 read. > + if (err) > + return -EINVAL; Why are you making up your own return value. Just return err. > + if ((opmode =3D=3D FLEX_MR_OPMODE_NO_COM) || > + (opmode & ~FLEX_MR_OPMODE_MASK)) > + return -EINVAL; > + > + res =3D platform_get_resource(pdev, IORESOURCE_MEM, 0); > + base =3D devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(base)) > + return PTR_ERR(base); > + > + clk =3D devm_clk_get(&pdev->dev, NULL); > + if (IS_ERR(clk)) > + return PTR_ERR(clk); > + > + err =3D clk_prepare_enable(clk); > + if (err) > + return err; > + > + /* > + * Set the Operating Mode in the Mode Register: only the selected d= evice > + * is clocked. Hence, registers of the other serial devices remain > + * inaccessible and are read as zero. Also the external I/O lines o= f the > + * Flexcom are muxed to reach the selected device. > + */ > + writel(opmode, base + FLEX_MR); > + > + clk_disable_unprepare(clk); > + > + return of_platform_populate(np, NULL, NULL, &pdev->dev); > +} > + > +static const struct of_device_id atmel_flexcom_of_match[] =3D { > + { .compatible =3D "atmel,sama5d2-flexcom" }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, atmel_flexcom_of_match); > + > +static struct platform_driver atmel_flexcom_driver =3D { > + .probe =3D atmel_flexcom_probe, > + .driver =3D { > + .name =3D "atmel_flexcom", > + .of_match_table =3D atmel_flexcom_of_match, > + }, > +}; > + > +module_platform_driver(atmel_flexcom_driver); > + > +MODULE_AUTHOR("Cyrille Pitchen "); > +MODULE_DESCRIPTION("Atmel Flexcom MFD driver"); > +MODULE_LICENSE("GPL v2"); --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html