diff options
Diffstat (limited to 'drivers/mfd/syscon.c')
| -rw-r--r-- | drivers/mfd/syscon.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c new file mode 100644 index 0000000..65fe609 --- /dev/null +++ b/drivers/mfd/syscon.c @@ -0,0 +1,176 @@ +/* + * 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 syscon_driver; + +struct syscon { + struct device *dev; + void __iomem *base; + struct regmap *regmap; +}; + +static int syscon_match(struct device *dev, void *data) +{ + struct syscon *syscon = dev_get_drvdata(dev); + struct device_node *dn = data; + + return (syscon->dev->of_node == dn) ? 1 : 0; +} + +struct regmap *syscon_node_to_regmap(struct device_node *np) +{ + struct syscon *syscon; + struct device *dev; + + dev = driver_find_device(&syscon_driver.driver, NULL, np, + syscon_match); + if (!dev) + return ERR_PTR(-EPROBE_DEFER); + + syscon = dev_get_drvdata(dev); + + return syscon->regmap; +} +EXPORT_SYMBOL_GPL(syscon_node_to_regmap); + +struct regmap *syscon_regmap_lookup_by_compatible(const char *s) +{ + struct device_node *syscon_np; + struct regmap *regmap; + + syscon_np = of_find_compatible_node(NULL, NULL, s); + if (!syscon_np) + return ERR_PTR(-ENODEV); + + regmap = syscon_node_to_regmap(syscon_np); + of_node_put(syscon_np); + + return regmap; +} +EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible); + +struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np, + const char *property) +{ + struct device_node *syscon_np; + struct regmap *regmap; + + syscon_np = of_parse_phandle(np, property, 0); + if (!syscon_np) + return ERR_PTR(-ENODEV); + + regmap = syscon_node_to_regmap(syscon_np); + of_node_put(syscon_np); + + return regmap; +} +EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle); + +static const struct of_device_id of_syscon_match[] = { + { .compatible = "syscon", }, + { }, +}; + +static struct regmap_config syscon_regmap_config = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = 4, +}; + +static int __devinit syscon_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct syscon *syscon; + struct resource res; + int ret; + + if (!np) + return -ENOENT; + + syscon = devm_kzalloc(dev, sizeof(struct syscon), + GFP_KERNEL); + if (!syscon) + return -ENOMEM; + + syscon->base = of_iomap(np, 0); + if (!syscon->base) + return -EADDRNOTAVAIL; + + ret = of_address_to_resource(np, 0, &res); + if (ret) + return ret; + + syscon_regmap_config.max_register = res.end - res.start - 3; + syscon->regmap = devm_regmap_init_mmio(dev, syscon->base, + &syscon_regmap_config); + if (IS_ERR(syscon->regmap)) { + dev_err(dev, "regmap init failed\n"); + return PTR_ERR(syscon->regmap); + } + + syscon->dev = dev; + platform_set_drvdata(pdev, syscon); + + dev_info(dev, "syscon regmap start 0x%x end 0x%x registered\n", + res.start, res.end); + + return 0; +} + +static int __devexit syscon_remove(struct platform_device *pdev) +{ + struct syscon *syscon; + + syscon = platform_get_drvdata(pdev); + iounmap(syscon->base); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_driver syscon_driver = { + .driver = { + .name = "syscon", + .owner = THIS_MODULE, + .of_match_table = of_syscon_match, + }, + .probe = syscon_probe, + .remove = __devexit_p(syscon_remove), +}; + +static int __init syscon_init(void) +{ + return platform_driver_register(&syscon_driver); +} +postcore_initcall(syscon_init); + +static void __exit syscon_exit(void) +{ + platform_driver_unregister(&syscon_driver); +} +module_exit(syscon_exit); + +MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>"); +MODULE_DESCRIPTION("System Control driver"); +MODULE_LICENSE("GPL v2"); |
