[PATCH v3 2/8] mfd: Add atmel-st driver
Lee Jones
lee.jones at linaro.org
Mon Jan 19 01:42:24 PST 2015
On Mon, 12 Jan 2015, Alexandre Belloni wrote:
> The Atmel System Timer IP available on the at91rm9200 exposes both a timer and a
> watchdog.
>
> Signed-off-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>
> Acked-by: Boris Brezillon <boris.brezillon at free-electrons.com>
> ---
> drivers/mfd/Kconfig | 7 ++++
> drivers/mfd/Makefile | 1 +
> drivers/mfd/atmel-st.c | 77 ++++++++++++++++++++++++++++++++++++++++++++
> include/linux/mfd/atmel-st.h | 47 +++++++++++++++++++++++++++
> 4 files changed, 132 insertions(+)
> create mode 100644 drivers/mfd/atmel-st.c
> create mode 100644 include/linux/mfd/atmel-st.h
This driver looks pretty pointless. Why can't you request the sysconf
registers from within the drivers themselves?
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 2e6b7311fabc..3c5185c0cf06 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -78,6 +78,13 @@ config MFD_BCM590XX
> help
> Support for the BCM590xx PMUs from Broadcom
>
> +config MFD_ATMEL_ST
> + bool "Atmel System Timer"
> + select MFD_CORE
> + default SOC_AT91RM9200
> + help
> + If you say Y here you get support for the Atmel System Timer.
> +
> config MFD_AXP20X
> bool "X-Powers AXP20X"
> select MFD_CORE
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 53467e211381..1ecd416f25c5 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -104,6 +104,7 @@ obj-$(CONFIG_PMIC_DA9052) += da9052-core.o
> obj-$(CONFIG_MFD_DA9052_SPI) += da9052-spi.o
> obj-$(CONFIG_MFD_DA9052_I2C) += da9052-i2c.o
> obj-$(CONFIG_MFD_AXP20X) += axp20x.o
> +obj-$(CONFIG_MFD_ATMEL_ST) += atmel-st.o
>
> obj-$(CONFIG_MFD_LP3943) += lp3943.o
> obj-$(CONFIG_MFD_LP8788) += lp8788.o lp8788-irq.o
> diff --git a/drivers/mfd/atmel-st.c b/drivers/mfd/atmel-st.c
> new file mode 100644
> index 000000000000..54106fcfe898
> --- /dev/null
> +++ b/drivers/mfd/atmel-st.c
> @@ -0,0 +1,77 @@
> +/*
> + * Copyright (C) 2014 Free Electrons
> + * Copyright (C) 2014 Atmel
> + *
> + * Author: Alexandre Belloni <alexandre.belloni at free-electrons.com>
> + *
> + * 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/mfd/atmel-st.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +static const struct mfd_cell atmel_st_cells[] = {
> + {
> + .name = "atmel_st_timer",
> + },
> + {
> + .name = "atmel_st_watchdog",
> + },
> +};
> +
> +static int atmel_st_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct regmap *regmap_st;
> +
> + regmap_st = syscon_node_to_regmap(dev->of_node);
> + if (IS_ERR(regmap_st))
> + return PTR_ERR(regmap_st);
> + dev_set_drvdata(dev, regmap_st);
> +
> + return mfd_add_devices(dev, -1, atmel_st_cells,
> + ARRAY_SIZE(atmel_st_cells),
> + NULL, 0, NULL);
> +}
> +
> +static int atmel_st_remove(struct platform_device *pdev)
> +{
> + mfd_remove_devices(&pdev->dev);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id atmel_st_match[] = {
> + { .compatible = "atmel,at91rm9200-st" },
> + { /* sentinel */ },
> +};
> +
> +static struct platform_driver atmel_st_driver = {
> + .probe = atmel_st_probe,
> + .remove = atmel_st_remove,
> + .driver = {
> + .name = "atmel-system-timer",
> + .owner = THIS_MODULE,
> + .of_match_table = atmel_st_match,
> + },
> +};
> +module_platform_driver(atmel_st_driver);
> +
> +MODULE_ALIAS("platform:atmel-st");
> +MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni at free-electrons.com>");
> +MODULE_DESCRIPTION("Atmel ST (System Timer) driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/atmel-st.h b/include/linux/mfd/atmel-st.h
> new file mode 100644
> index 000000000000..88c6cf8eeb2b
> --- /dev/null
> +++ b/include/linux/mfd/atmel-st.h
> @@ -0,0 +1,47 @@
> +/*
> + * Copyright (C) 2005 Ivan Kokshaysky
> + * Copyright (C) SAN People
> + *
> + * System Timer (ST) - System peripherals registers.
> + * Based on AT91RM9200 datasheet revision E.
> + *
> + * 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.
> + */
> +
> +#ifndef __LINUX_MFD_ATMEL_ST_H
> +#define __LINUX_MFD_ATMEL_ST_H
> +
> +#define AT91_ST_CR 0x00 /* Control Register */
> +#define AT91_ST_WDRST (1 << 0) /* Watchdog Timer Restart */
> +
> +#define AT91_ST_PIMR 0x04 /* Period Interval Mode Register */
> +#define AT91_ST_PIV (0xffff << 0) /* Period Interval Value */
> +
> +#define AT91_ST_WDMR 0x08 /* Watchdog Mode Register */
> +#define AT91_ST_WDV (0xffff << 0) /* Watchdog Counter Value */
> +#define AT91_ST_RSTEN (1 << 16) /* Reset Enable */
> +#define AT91_ST_EXTEN (1 << 17) /* External Signal Assertion Enable */
> +
> +#define AT91_ST_RTMR 0x0c /* Real-time Mode Register */
> +#define AT91_ST_RTPRES (0xffff << 0) /* Real-time Prescalar Value */
> +
> +#define AT91_ST_SR 0x10 /* Status Register */
> +#define AT91_ST_PITS (1 << 0) /* Period Interval Timer Status */
> +#define AT91_ST_WDOVF (1 << 1) /* Watchdog Overflow */
> +#define AT91_ST_RTTINC (1 << 2) /* Real-time Timer Increment */
> +#define AT91_ST_ALMS (1 << 3) /* Alarm Status */
> +
> +#define AT91_ST_IER 0x14 /* Interrupt Enable Register */
> +#define AT91_ST_IDR 0x18 /* Interrupt Disable Register */
> +#define AT91_ST_IMR 0x1c /* Interrupt Mask Register */
> +
> +#define AT91_ST_RTAR 0x20 /* Real-time Alarm Register */
> +#define AT91_ST_ALMV (0xfffff << 0) /* Alarm Value */
> +
> +#define AT91_ST_CRTR 0x24 /* Current Real-time Register */
> +#define AT91_ST_CRTV (0xfffff << 0) /* Current Real-Time Value */
> +
> +#endif /* __LINUX_MFD_ATMEL_ST_H */
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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