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 once > for all, when the Flexcom is probed, using the "reg" property of the first > (should be unique) available DT child node. > > 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 USART > drivers. > > Also the Flexcom embeds FIFOs: the latest patches of the SPI, I2C and > USART drivers take advantage of this new feature. > > Signed-off-by: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx> > --- > 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 > > 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. > > +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 time > + by the probe function of this MFD driver according to a device tree > + 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-$(CONFIG_MFD_SPMI_PMIC) += qcom-spmi-pmic.o > obj-$(CONFIG_TPS65911_COMPARATOR) += tps65911-comparator.o > obj-$(CONFIG_MFD_TPS65090) += tps65090.o > obj-$(CONFIG_MFD_AAT2870_CORE) += aat2870-core.o > +obj-$(CONFIG_MFD_ATMEL_FLEXCOM) += atmel-flexcom.o > obj-$(CONFIG_MFD_ATMEL_HLCDC) += atmel-hlcdc.o > obj-$(CONFIG_MFD_INTEL_MSIC) += intel_msic.o > obj-$(CONFIG_MFD_PALMAS) += 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 <cyrille.pitchen@xxxxxxxxx> > + * > + * 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 in the hope that it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License along with > + * this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <linux/module.h> > +#include <linux/types.h> > +#include <linux/kernel.h> > +#include <linux/platform_device.h> > +#include <linux/of.h> > +#include <linux/of_platform.h> > +#include <linux/err.h> > +#include <linux/io.h> > +#include <linux/clk.h> > + > +/* 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 = pdev->dev.of_node; > + struct clk *clk; > + struct resource *res; > + void __iomem *base; > + u32 opmode; > + int err; > + > + child = of_get_next_available_child(np, NULL); > + if (!child) > + return -ENODEV; > + > + /* > + * The Operating Mode is stored into the first u32 of the reg property > + * of the child. > + */ > + err = 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 == FLEX_MR_OPMODE_NO_COM) || > + (opmode & ~FLEX_MR_OPMODE_MASK)) > + return -EINVAL; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(base)) > + return PTR_ERR(base); > + > + clk = devm_clk_get(&pdev->dev, NULL); > + if (IS_ERR(clk)) > + return PTR_ERR(clk); > + > + err = clk_prepare_enable(clk); > + if (err) > + return err; > + > + /* > + * Set the Operating Mode in the Mode Register: only the selected device > + * is clocked. Hence, registers of the other serial devices remain > + * inaccessible and are read as zero. Also the external I/O lines of 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[] = { > + { .compatible = "atmel,sama5d2-flexcom" }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, atmel_flexcom_of_match); > + > +static struct platform_driver atmel_flexcom_driver = { > + .probe = atmel_flexcom_probe, > + .driver = { > + .name = "atmel_flexcom", > + .of_match_table = atmel_flexcom_of_match, > + }, > +}; > + > +module_platform_driver(atmel_flexcom_driver); > + > +MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>"); > +MODULE_DESCRIPTION("Atmel Flexcom MFD driver"); > +MODULE_LICENSE("GPL v2"); -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
