From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH linux-next v11 3/3] mfd: atmel-flexcom: add a driver for Atmel Flexible Serial Communication Unit Date: Thu, 1 Oct 2015 12:56:21 +0100 Message-ID: <20151001115621.GU3214@x1> References: <9cb5e3b697b701868b78d8bd7130345a6b87be49.1443431309.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: <9cb5e3b697b701868b78d8bd7130345a6b87be49.1443431309.git.cyrille.pitchen@atmel.com> Sender: linux-kernel-owner@vger.kernel.org To: Cyrille Pitchen Cc: nicolas.ferre@atmel.com, boris.brezillon@free-electrons.com, alexandre.belloni@free-electrons.com, sameo@linux.intel.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, devicetree@vger.kernel.org, akpm@linux-foundation.org List-Id: devicetree@vger.kernel.org On Mon, 28 Sep 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, according to the value of the ne= w > "atmel,flexcom-mode" device tree property. >=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 > Acked-by: Boris Brezillon > Acked-by: Alexandre Belloni > Acked-by: Nicolas Ferre > --- > drivers/mfd/Kconfig | 11 +++++ > drivers/mfd/Makefile | 1 + > drivers/mfd/atmel-flexcom.c | 104 ++++++++++++++++++++++++++++++++++= ++++++++++ > 3 files changed, 116 insertions(+) > create mode 100644 drivers/mfd/atmel-flexcom.c Applied, thanks. > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > index 99d63675f073..87e84e7c71da 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. > + > 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 d6c21e3c409f..a8b76b81b467 100644 > --- a/drivers/mfd/Makefile > +++ b/drivers/mfd/Makefile > @@ -164,6 +164,7 @@ 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-$(CONFIG_MFD_INTEL_LPSS) +=3D intel-lpss.o > obj-$(CONFIG_MFD_INTEL_LPSS_PCI) +=3D intel-lpss-pci.o > diff --git a/drivers/mfd/atmel-flexcom.c b/drivers/mfd/atmel-flexcom.= c > new file mode 100644 > index 000000000000..e8e67be6b493 > --- /dev/null > +++ b/drivers/mfd/atmel-flexcom.c > @@ -0,0 +1,104 @@ > +/* > + * 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 > +#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_OFFSET (0) /* Operating Mode */ > +#define FLEX_MR_OPMODE_MASK (0x3 << FLEX_MR_OPMODE_OFFSET) > +#define FLEX_MR_OPMODE(opmode) (((opmode) << FLEX_MR_OPMODE_OFFSET) = & \ > + FLEX_MR_OPMODE_MASK) > + > + > +static int atmel_flexcom_probe(struct platform_device *pdev) > +{ > + struct device_node *np =3D pdev->dev.of_node; > + struct clk *clk; > + struct resource *res; > + void __iomem *base; > + u32 opmode; > + int err; > + > + err =3D of_property_read_u32(np, "atmel,flexcom-mode", &opmode); > + if (err) > + return err; > + > + if (opmode < ATMEL_FLEXCOM_MODE_USART || > + opmode > ATMEL_FLEXCOM_MODE_TWI) > + 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(FLEX_MR_OPMODE(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