[PATCH 1/7] mfd: add imx syscon driver based on regmap
Richard Zhao
richard.zhao at freescale.com
Wed Aug 22 04:29:41 EDT 2012
On Wed, Aug 22, 2012 at 03:18:42PM +0800, Dong Aisheng wrote:
> From: Dong Aisheng <dong.aisheng at linaro.org>
>
> Add regmap based imx syscon driver.
> This is usually used for access misc bits in registers which does not belong
> to a specific module, for example, IOMUXC GPR and ANATOP.
> With this driver, we provide a standard API for client driver to call to
> access registers which are registered into syscon.
>
> Signed-off-by: Dong Aisheng <dong.aisheng at linaro.org>
> ---
> Currently it's just simply for IMX, however the driver really is not too
> much imx specific.
> If people want, we probably could extend it to support other platforms too.
> ---
> .../devicetree/bindings/mfd/imx-syscon.txt | 11 +
> drivers/mfd/Kconfig | 8 +
> drivers/mfd/Makefile | 1 +
> drivers/mfd/imx-syscon.c | 193 ++++++++++++++++++++
> include/linux/mfd/imx-syscon.h | 22 +++
> 5 files changed, 235 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mfd/imx-syscon.txt b/Documentation/devicetree/bindings/mfd/imx-syscon.txt
> new file mode 100644
> index 0000000..4a72994
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/imx-syscon.txt
> @@ -0,0 +1,11 @@
> +* Freescale IMX System Controller Registers R/W driver
> +
> +Required properties:
> +- compatible: Should contain "fsl,imx-syscon".
> +- reg: the register range can be access from imx-syscon
> +
> +Examples:
> +gpr: iomuxc-gpr at 020e0000 {
> + compatible = "fsl,imx6q-iomuxc", "fsl,imx-syscon";
why is it compatible with iomuxc?
> + reg = <0x020e0000 0x38>;
> +};
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index b1a1462..20a050e 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -993,6 +993,14 @@ config MFD_ANATOP
> MFD controller. This controller embeds regulator and
> thermal devices for Freescale i.MX platforms.
>
> +config MFD_IMX_SYSCON
> + bool "Freescale i.MX System Controller Register R/W Based on Regmap"
> + depends on ARCH_MXC
> + select REGMAP_MMIO
> + help
> + Select this option to enable access Freescale i.MX system control
> + registers like iomuxc gpr and anatop via regmap.
> +
> config MFD_PALMAS
> bool "Support for the TI Palmas series chips"
> select MFD_CORE
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 79dd22d..82c7ee1 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -131,4 +131,5 @@ obj-$(CONFIG_MFD_PALMAS) += palmas.o
> obj-$(CONFIG_MFD_RC5T583) += rc5t583.o rc5t583-irq.o
> obj-$(CONFIG_MFD_SEC_CORE) += sec-core.o sec-irq.o
> obj-$(CONFIG_MFD_ANATOP) += anatop-mfd.o
> +obj-$(CONFIG_MFD_IMX_SYSCON) += imx-syscon.o
> obj-$(CONFIG_MFD_LM3533) += lm3533-core.o lm3533-ctrlbank.o
> diff --git a/drivers/mfd/imx-syscon.c b/drivers/mfd/imx-syscon.c
> new file mode 100644
> index 0000000..141b456
> --- /dev/null
> +++ b/drivers/mfd/imx-syscon.c
> @@ -0,0 +1,193 @@
> +/*
> + * Freescale IMX System Control Driver
> + *
> + * Copyright (C) 2012 Freescale Semiconductor, Inc.
> + * Copyright (C) 2012 Linaro Ltd.
> + *
> + * Author: Dong Aisheng <dong.aisheng at linaro.org>
> + *
> + * 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/err.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +static struct platform_driver imx_syscon_driver;
> +
> +struct imx_syscon {
> + struct device *dev;
> + void __iomem *base;
> + struct regmap *regmap;
> +};
> +
> +static int imx_syscon_match(struct device *dev, void *data)
> +{
> + struct imx_syscon *syscon = dev_get_drvdata(dev);
> + struct device_node *dn = data;
> +
> + return (syscon->dev->of_node == dn) ? 1 : 0;
> +}
> +
> +int imx_syscon_write(struct device_node *np, u32 reg, u32 val)
For API function, is it better to use struct device rather not np?
- it won't need to search dev in below code every time it access
registers.
> +{
> + struct device *dev;
> + struct imx_syscon *syscon;
> + int ret = 0;
> +
> + dev = driver_find_device(&imx_syscon_driver.driver, NULL, np,
> + imx_syscon_match);
> + if (!dev)
> + return -EPROBE_DEFER;
> +
> + syscon = dev_get_drvdata(dev);
> + ret = regmap_write(syscon->regmap, reg, val);
> + if (ret)
> + dev_err(dev, "failed to write regmap(%s) reg 0x%x (%d)\n",
> + np->name, reg, ret);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(imx_syscon_write);
> +
> +int imx_syscon_read(struct device_node *np, u32 reg, u32 *val)
> +{
> + struct device *dev;
> + struct imx_syscon *syscon;
> + int ret = 0;
> +
> + dev = driver_find_device(&imx_syscon_driver.driver, NULL, np,
> + imx_syscon_match);
> + if (!dev)
> + return -EPROBE_DEFER;
> +
> + syscon = dev_get_drvdata(dev);
> + ret = regmap_read(syscon->regmap, reg, val);
> + if (ret)
> + dev_err(dev, "failed to read regmap(%s) reg 0x%x (%d)\n",
> + np->name, reg, ret);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(imx_syscon_read);
> +
> +int imx_syscon_update_bits(struct device_node *np, u32 reg,
> + u32 mask, u32 val)
> +{
> + struct device *dev;
> + struct imx_syscon *syscon;
> + int ret = 0;
> +
> + dev = driver_find_device(&imx_syscon_driver.driver, NULL, np,
> + imx_syscon_match);
> + if (!dev)
> + return -EPROBE_DEFER;
> +
> + syscon = dev_get_drvdata(dev);
> + ret = regmap_update_bits(syscon->regmap, reg, mask, val);
> + if (ret)
> + dev_err(dev, "failed to update regmap(%s) reg 0x%x (%d)\n",
> + np->name, reg, ret);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(imx_syscon_update_bits);
> +
> +static const struct of_device_id of_imx_syscon_match[] = {
> + { .compatible = "fsl,imx-syscon", },
> + { },
> +};
> +
> +static struct regmap_config imx_syscon_regmap_config = {
> + .reg_bits = 32,
> + .val_bits = 32,
> + .reg_stride = 4,
> +};
> +
> +static int __devinit imx_syscon_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *np = dev->of_node;
> + struct imx_syscon *syscon;
> + struct resource res;
> + int ret;
> +
> + if (!np)
> + return -ENOENT;
> +
> + syscon = devm_kzalloc(&pdev->dev, sizeof(struct imx_syscon),
> + GFP_KERNEL);
> + if (!syscon)
> + return -ENOMEM;
> +
> + syscon->base = of_iomap(np, 0);
no request? use devm_request_and_ioremap?
Thanks
Richard
> + if (!syscon->base)
> + return -EADDRNOTAVAIL;
> +
> + ret = of_address_to_resource(np, 0, &res);
> + if (ret)
> + return ret;
> +
> + imx_syscon_regmap_config.max_register = res.end - res.start - 3;
> + syscon->regmap = devm_regmap_init_mmio(&pdev->dev, syscon->base,
> + &imx_syscon_regmap_config);
> + if (IS_ERR(syscon->regmap)) {
> + dev_err(&pdev->dev, "regmap init failed\n");
> + return PTR_ERR(syscon->regmap);
> + }
> +
> + regcache_cache_only(syscon->regmap, false);
> +
> + dev_info(dev, "syscon regmap start 0x%x end 0x%x registered\n",
> + res.start, res.end);
> +
> + syscon->dev = &pdev->dev;
> + platform_set_drvdata(pdev, syscon);
> +
> + return 0;
> +}
> +
> +static int __devexit imx_syscon_remove(struct platform_device *pdev)
> +{
> + struct imx_syscon *syscon;
> +
> + syscon = platform_get_drvdata(pdev);
> + iounmap(syscon->base);
> + platform_set_drvdata(pdev, NULL);
> +
> + return 0;
> +}
> +
> +static struct platform_driver imx_syscon_driver = {
> + .driver = {
> + .name = "imx-syscon",
> + .owner = THIS_MODULE,
> + .of_match_table = of_imx_syscon_match,
> + },
> + .probe = imx_syscon_probe,
> + .remove = imx_syscon_remove,
> +};
> +
> +static int __init imx_syscon_init(void)
> +{
> + return platform_driver_register(&imx_syscon_driver);
> +}
> +postcore_initcall(imx_syscon_init);
> +
> +static void __exit anatop_exit(void)
> +{
> + platform_driver_unregister(&imx_syscon_driver);
> +}
> +module_exit(anatop_exit);
> +
> +MODULE_AUTHOR("Dong Aisheng <dong.aisheng at linaro.org>");
> +MODULE_DESCRIPTION("Freescale IMX System Control driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/mfd/imx-syscon.h b/include/linux/mfd/imx-syscon.h
> new file mode 100644
> index 0000000..be8b6db
> --- /dev/null
> +++ b/include/linux/mfd/imx-syscon.h
> @@ -0,0 +1,22 @@
> +/*
> + * Freescale IMX System Control Driver
> + *
> + * Copyright (C) 2012 Freescale Semiconductor, Inc.
> + * Copyright (C) 2012 Linaro Ltd.
> + *
> + * Author: Dong Aisheng <dong.aisheng at linaro.org>
> + *
> + * 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_IMX_SYSCON_H__
> +#define __LINUX_MFD_IMX_SYSCON_H__
> +
> +extern int imx_syscon_write(struct device_node *np, u32 reg, u32 val);
> +extern int imx_syscon_read(struct device_node *np, u32 reg, u32 *val);
> +extern int imx_syscon_update_bits(struct device_node *np, u32 reg,
> + u32 mask, u32 val);
> +#endif /* __LINUX_MFD_IMX_SYSCON_H__ */
> --
> 1.7.0.4
>
More information about the linux-arm-kernel
mailing list