diff options
Diffstat (limited to 'drivers/eeprom/eeprom-sunxi-sid.c')
| -rw-r--r-- | drivers/eeprom/eeprom-sunxi-sid.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/drivers/eeprom/eeprom-sunxi-sid.c b/drivers/eeprom/eeprom-sunxi-sid.c new file mode 100644 index 000000000000..58f7d24c8386 --- /dev/null +++ b/drivers/eeprom/eeprom-sunxi-sid.c @@ -0,0 +1,136 @@ +/* + * Allwinner sunXi SoCs Security ID support. + * + * Copyright (c) 2013 Oliver Schinagl <oliver@schinagl.nl> + * Copyright (C) 2014 Maxime Ripard <maxime.ripard@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 as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + * + */ + +#include <linux/device.h> +#include <linux/eeprom-provider.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> + +struct eeprom_sid { + void __iomem *membase; + struct eeprom_device *eeprom; +}; + +static struct eeprom_config econfig = { + .stride = 1, + .name = "sunix-sid", +}; + +/* We read the entire key, due to a 32 bit read alignment requirement. Since we + * want to return the requested byte, this results in somewhat slower code and + * uses 4 times more reads as needed but keeps code simpler. Since the SID is + * only very rarely probed, this is not really an issue. + */ +static int sunxi_sid_reg_read(void *context, + unsigned int offset, unsigned int *val) +{ + struct eeprom_sid *sid = context; + u32 sid_key; + + sid_key = ioread32be(sid->membase + round_down(offset, 4)); + sid_key >>= (offset % 4) * 8; + + *val = sid_key; + + return 0; +} + +static bool sunxi_sid_writeable_reg(struct device *dev, unsigned int reg) +{ + return false; +} + +static const struct of_device_id sunxi_sid_of_match[] = { + { .compatible = "allwinner,sun4i-a10-sid", .data = (void *)16}, + { .compatible = "allwinner,sun7i-a20-sid", .data = (void *)512}, + {/* sentinel */}, +}; +MODULE_DEVICE_TABLE(of, sunxi_sid_of_match); + +static struct regmap_config sunxi_sid_regmap_config = { + .reg_bits = 32, + .val_bits = 8, + .reg_stride = 1, + .reg_read = sunxi_sid_reg_read, + .writeable_reg = sunxi_sid_writeable_reg, +}; + +static int sunxi_sid_probe(struct platform_device *pdev) +{ + const struct of_device_id *device; + struct eeprom_sid *sid; + struct resource *res; + struct eeprom_device *eeprom; + struct device *dev = &pdev->dev; + + sid = devm_kzalloc(dev, sizeof(*sid), GFP_KERNEL); + if (!sid) + return -ENOMEM; + + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + sid->membase = devm_ioremap_resource(dev, res); + if (IS_ERR(sid->membase)) + return PTR_ERR(sid->membase); + + device = of_match_device(sunxi_sid_of_match, dev); + if (!device) + return -ENODEV; + + sunxi_sid_regmap_config.max_register = (unsigned int)device->data - 1; + + econfig.regmap = devm_regmap_init(dev, NULL, + sid, &sunxi_sid_regmap_config); + if (IS_ERR(econfig.regmap)) + return PTR_ERR(econfig.regmap); + + econfig.dev = dev; + econfig.owner = THIS_MODULE; + econfig.size = sunxi_sid_regmap_config.max_register; + + eeprom = eeprom_register(&econfig); + if (IS_ERR(eeprom)) + return PTR_ERR(eeprom); + + platform_set_drvdata(pdev, eeprom); + + return 0; +} + +static int sunxi_sid_remove(struct platform_device *pdev) +{ + struct eeprom_device *eeprom = platform_get_drvdata(pdev); + + return eeprom_unregister(eeprom); +} + +static struct platform_driver sunxi_sid_driver = { + .probe = sunxi_sid_probe, + .remove = sunxi_sid_remove, + .driver = { + .name = "eeprom-sunxi-sid", + .of_match_table = sunxi_sid_of_match, + }, +}; +module_platform_driver(sunxi_sid_driver); + +MODULE_AUTHOR("Oliver Schinagl <oliver@schinagl.nl>"); +MODULE_DESCRIPTION("Allwinner sunxi security id driver"); +MODULE_LICENSE("GPL"); |