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, according to the value of the new "atmel,flexcom-mode" device tree property. 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> Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> Acked-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx> Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx> --- 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 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. +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. + 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-$(CONFIG_MFD_SPMI_PMIC) += qcom-spmi-pmic.o obj-$(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-$(CONFIG_MFD_INTEL_LPSS) += intel-lpss.o obj-$(CONFIG_MFD_INTEL_LPSS_PCI) += 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 <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> +#include <dt-bindings/mfd/atmel-flexcom.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_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 = pdev->dev.of_node; + struct clk *clk; + struct resource *res; + void __iomem *base; + u32 opmode; + int err; + + err = 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 = 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(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[] = { + { .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"); -- 1.8.2.2 -- 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
