From: Carlo Caione <carlo@xxxxxxxxxxxx> Add Amlogic EFUSE driver to access hardware data like ethernet address, serial number or IDs. Signed-off-by: Carlo Caione <carlo@xxxxxxxxxxxx> --- drivers/nvmem/Kconfig | 11 ++++ drivers/nvmem/Makefile | 2 + drivers/nvmem/meson-efuse.c | 130 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 143 insertions(+) create mode 100644 drivers/nvmem/meson-efuse.c diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig index ca52952..ef17bc9 100644 --- a/drivers/nvmem/Kconfig +++ b/drivers/nvmem/Kconfig @@ -102,4 +102,15 @@ config NVMEM_VF610_OCOTP This driver can also be build as a module. If so, the module will be called nvmem-vf610-ocotp. +config MESON_EFUSE + tristate "Amlogic eFuse Support" + depends on ARCH_MESON || COMPILE_TEST + select REGMAP_MMIO + help + This is a driver to retrieve specific values from the eFuse found on + the Amlogic Meson SoCs. + + This driver can also be built as a module. If so, the module + will be called nvmem_meson_efuse. + endif diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile index 45ab1ae..8f942a0 100644 --- a/drivers/nvmem/Makefile +++ b/drivers/nvmem/Makefile @@ -22,3 +22,5 @@ obj-$(CONFIG_NVMEM_SUNXI_SID) += nvmem_sunxi_sid.o nvmem_sunxi_sid-y := sunxi_sid.o obj-$(CONFIG_NVMEM_VF610_OCOTP) += nvmem-vf610-ocotp.o nvmem-vf610-ocotp-y := vf610-ocotp.o +obj-$(CONFIG_MESON_EFUSE) += nvmem_meson_efuse.o +nvmem_meson_efuse-y := meson-efuse.o diff --git a/drivers/nvmem/meson-efuse.c b/drivers/nvmem/meson-efuse.c new file mode 100644 index 0000000..7c80e1c --- /dev/null +++ b/drivers/nvmem/meson-efuse.c @@ -0,0 +1,130 @@ +/* + * Amlogic eFuse Driver + * + * Copyright (c) 2016 Endless Computers, Inc. + * Author: Carlo Caione <carlo@xxxxxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2 of the GNU General Public License 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. + */ + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/nvmem-provider.h> +#include <linux/slab.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#include <linux/firmware/meson/meson_sm.h> + +static struct meson_sm_firmware *fw; + +static int meson_efuse_write(void *context, const void *data, size_t count) +{ + /* Nothing TBD, Read-Only */ + return 0; +} + +static int meson_efuse_read(void *context, + const void *reg, size_t reg_size, + void *val, size_t val_size) +{ + unsigned int offset = *(u32 *)reg; + u8 *buf = val; + int ret; + + ret = meson_sm_call_read(fw, buf, SM_EFUSE_READ, offset, + val_size, 0, 0, 0); + if (ret < 0) + return ret; + + return 0; +} + +static struct nvmem_config econfig = { + .name = "meson-efuse", + .owner = THIS_MODULE, + .read_only = true, +}; + +static struct regmap_bus meson_efuse_bus = { + .read = meson_efuse_read, + .write = meson_efuse_write, + .reg_format_endian_default = REGMAP_ENDIAN_NATIVE, + .val_format_endian_default = REGMAP_ENDIAN_NATIVE, +}; + +static struct regmap_config meson_efuse_regmap_config = { + .reg_bits = 32, + .reg_stride = 1, + .val_bits = 8, +}; + +static const struct of_device_id meson_efuse_match[] = { + { .compatible = "amlogic,meson-gxbb-efuse", }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, meson_efuse_match); + +static int meson_efuse_probe(struct platform_device *pdev) +{ + struct nvmem_device *nvmem; + struct regmap *regmap; + unsigned int size; + + fw = meson_sm_get_fw(); + if (!fw) + return -EPROBE_DEFER; + + if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) + return -EINVAL; + meson_efuse_regmap_config.max_register = size - 1; + + regmap = devm_regmap_init(&pdev->dev, &meson_efuse_bus, + NULL, &meson_efuse_regmap_config); + if (IS_ERR(regmap)) { + dev_err(&pdev->dev, "regmap init failed\n"); + return PTR_ERR(regmap); + } + + econfig.dev = &pdev->dev; + nvmem = nvmem_register(&econfig); + if (IS_ERR(nvmem)) + return PTR_ERR(nvmem); + + platform_set_drvdata(pdev, nvmem); + + return 0; +} + +static int meson_efuse_remove(struct platform_device *pdev) +{ + struct nvmem_device *nvmem = platform_get_drvdata(pdev); + + return nvmem_unregister(nvmem); +} + +static struct platform_driver meson_efuse_driver = { + .probe = meson_efuse_probe, + .remove = meson_efuse_remove, + .driver = { + .name = "meson-efuse", + .of_match_table = meson_efuse_match, + }, +}; + +module_platform_driver(meson_efuse_driver); + +MODULE_AUTHOR("Carlo Caione <carlo@xxxxxxxxxxxx>"); +MODULE_DESCRIPTION("Amlogic Meson NVMEM driver"); +MODULE_LICENSE("GPL v2"); -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html