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1530b923a5
R-Car Gen4 SoCs contain fuses indicating hardware support or hardware
(e.g. tuning) parameters. Add a driver to access the state of the
fuses. This supports two types of hardware fuse providers:
1. E-FUSE non-volatile memory accessible through the Pin Function
Controller on R-Car V3U and S4-8,
2. E-FUSE non-volatile memory accessible through OTP_MEM on R-Car V4H
and V4M.
The state of the cells can be read using the NVMEM framework, either
from kernel space (e.g. by the Renesas UFSHCD driver), or from
userspace.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241030140315.40562-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
143 lines
3.2 KiB
C
143 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Renesas R-Car E-FUSE/OTP Driver
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*
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* Copyright (C) 2024 Glider bv
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*/
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#include <linux/device.h>
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#include <linux/export.h>
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#include <linux/io.h>
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#include <linux/mod_devicetable.h>
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#include <linux/nvmem-provider.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#include <linux/property.h>
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struct rcar_fuse {
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struct nvmem_keepout keepouts[2];
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struct nvmem_device *nvmem;
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struct device *dev;
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void __iomem *base;
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};
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struct rcar_fuse_data {
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unsigned int bank; /* 0: PFC + E-FUSE, 1: OPT_MEM + E-FUSE */
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unsigned int start; /* inclusive */
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unsigned int end; /* exclusive */
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};
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static int rcar_fuse_reg_read(void *priv, unsigned int offset, void *val,
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size_t bytes)
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{
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struct rcar_fuse *fuse = priv;
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int ret;
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ret = pm_runtime_resume_and_get(fuse->dev);
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if (ret < 0)
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return ret;
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__ioread32_copy(val, fuse->base + offset, bytes / 4);
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pm_runtime_put(fuse->dev);
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return 0;
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}
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static int rcar_fuse_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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const struct rcar_fuse_data *data = device_get_match_data(dev);
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struct nvmem_config config = {
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.dev = dev,
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.name = "rcar-fuse",
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.id = NVMEM_DEVID_NONE,
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.owner = THIS_MODULE,
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.type = NVMEM_TYPE_OTP,
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.read_only = true,
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.root_only = true,
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.reg_read = rcar_fuse_reg_read,
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.word_size = 4,
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.stride = 4,
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};
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struct rcar_fuse *fuse;
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struct resource *res;
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int ret;
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ret = devm_pm_runtime_enable(dev);
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if (ret < 0)
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return ret;
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fuse = devm_kzalloc(dev, sizeof(*fuse), GFP_KERNEL);
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if (!fuse)
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return -ENOMEM;
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fuse->base = devm_platform_get_and_ioremap_resource(pdev, data->bank,
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&res);
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if (IS_ERR(fuse->base))
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return PTR_ERR(fuse->base);
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fuse->dev = dev;
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fuse->keepouts[0].start = 0;
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fuse->keepouts[0].end = data->start;
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fuse->keepouts[1].start = data->end;
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fuse->keepouts[1].end = resource_size(res);
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config.keepout = fuse->keepouts;
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config.nkeepout = ARRAY_SIZE(fuse->keepouts);
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config.size = resource_size(res);
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config.priv = fuse;
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fuse->nvmem = devm_nvmem_register(dev, &config);
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if (IS_ERR(fuse->nvmem))
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return dev_err_probe(dev, PTR_ERR(fuse->nvmem),
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"Failed to register NVMEM device\n");
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return 0;
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}
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static const struct rcar_fuse_data rcar_fuse_v3u = {
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.bank = 0,
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.start = 0x0c0,
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.end = 0x0e8,
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};
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static const struct rcar_fuse_data rcar_fuse_s4 = {
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.bank = 0,
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.start = 0x0c0,
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.end = 0x14c,
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};
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static const struct rcar_fuse_data rcar_fuse_v4h = {
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.bank = 1,
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.start = 0x100,
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.end = 0x1a0,
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};
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static const struct rcar_fuse_data rcar_fuse_v4m = {
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.bank = 1,
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.start = 0x100,
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.end = 0x110,
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};
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static const struct of_device_id rcar_fuse_match[] = {
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{ .compatible = "renesas,r8a779a0-efuse", .data = &rcar_fuse_v3u },
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{ .compatible = "renesas,r8a779f0-efuse", .data = &rcar_fuse_s4 },
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{ .compatible = "renesas,r8a779g0-otp", .data = &rcar_fuse_v4h },
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{ .compatible = "renesas,r8a779h0-otp", .data = &rcar_fuse_v4m },
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{ /* sentinel */ }
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};
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static struct platform_driver rcar_fuse_driver = {
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.probe = rcar_fuse_probe,
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.driver = {
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.name = "rcar_fuse",
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.of_match_table = rcar_fuse_match,
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},
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};
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module_platform_driver(rcar_fuse_driver);
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MODULE_DESCRIPTION("Renesas R-Car E-FUSE/OTP driver");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Geert Uytterhoeven");
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