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 <[email protected]> Acked-by: Boris Brezillon <[email protected]> Acked-by: Alexandre Belloni <[email protected]> --- drivers/mfd/Kconfig | 11 +++++ drivers/mfd/Makefile | 1 + drivers/mfd/atmel-flexcom.c | 98 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 110 insertions(+) create mode 100644 drivers/mfd/atmel-flexcom.c diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index d5ad04d..9b33ad0 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -59,6 +59,17 @@ 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 0e5cfeb..c666bf5 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 0000000..7e7d4b8 --- /dev/null +++ b/drivers/mfd/atmel-flexcom.c @@ -0,0 +1,98 @@ +/* + * Driver for Atmel Flexcom + * + * Copyright (C) 2015 Atmel Corporation + * + * Author: Cyrille Pitchen <[email protected]> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#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> + +#define FX_MR 0x0 +#define FX_RHR 0x10 +#define FX_THR 0x20 +#define FX_VERSION 0xfc + +#define FX_MR_NO_COM 0 +#define FX_MR_USART 1 +#define FX_MR_SPI 2 +#define FX_MR_TWI 3 + + +static int atmel_flexcom_probe(struct platform_device *pdev) +{ + struct clk *clk; + struct resource *res; + unsigned char __iomem *map; + unsigned int version, mr; + const char *mode; + int err; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + map = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(map)) + return PTR_ERR(map); + + clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + err = of_property_read_string(pdev->dev.of_node, + "atmel,flexcom-mode", &mode); + if (err) + return err; + + if (!strcmp(mode, "usart")) + mr = FX_MR_USART; + else if (!strcmp(mode, "spi")) + mr = FX_MR_SPI; + else if (!strcmp(mode, "twi") || !strcmp(mode, "i2c")) + mr = FX_MR_TWI; + else + return -EINVAL; + + err = clk_prepare_enable(clk); + if (err) + return err; + version = readl(map + FX_VERSION); + writel(mr, map + FX_MR); + clk_disable_unprepare(clk); + + dev_info(&pdev->dev, "version: %#x, mode: %s\n", version, mode); + + return of_platform_populate(pdev->dev.of_node, 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 = { + .driver = { + .name = "atmel_flexcom", + .of_match_table = atmel_flexcom_of_match, + }, + .probe = atmel_flexcom_probe, +}; + +module_platform_driver(atmel_flexcom_driver); + +MODULE_AUTHOR("Cyrille Pitchen <[email protected]>"); +MODULE_DESCRIPTION("Atmel Flexcom MFD driver"); +MODULE_LICENSE("GPL"); -- 1.8.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/
