Re: [PATCH 1/7] mfd: add imx syscon driver based on regmap
From: Richard Zhao <hidden>
Date: 2012-08-22 08:29:49
Also in:
linux-arm-kernel, lkml
On Wed, Aug 22, 2012 at 03:18:42PM +0800, Dong Aisheng wrote:
quoted hunk ↗ jump to hunk
From: Dong Aisheng <redacted> 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 <redacted> --- 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@020e0000 { + compatible = "fsl,imx6q-iomuxc", "fsl,imx-syscon";
why is it compatible with iomuxc?
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+ 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_COREdiff --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.odiff --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@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
quoted hunk ↗ jump to hunk
+ 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 [off-list ref]"); +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@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