160 lines
3.5 KiB
C
Executable File
160 lines
3.5 KiB
C
Executable File
/**
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Novatek TRNG driver
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License version 2 as
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published by the Free Software Foundation.
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*/
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/hw_random.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/random.h>
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#include <linux/clk.h>
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#define TRNG_VERION "1.00.000"
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#define RNG_CTRL 0x0
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#define RNG_CASR 0x100
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#define RNG_POST 0x200
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#define RNG_SEED_UPDATE 0x400
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#define RNG_TDES_DONE 0x10000
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#define RNG_RAND_NUM 0x0C
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#define to_nvt_rng(p) container_of(p, struct nvt_rng, rng)
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struct nvt_rng {
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void __iomem *base;
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struct hwrng rng;
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struct clk *clk;
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struct clk *ro_clk;
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};
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static inline void nvt_rng_write_reg(struct nvt_rng *nvt_rng, int reg, u32 val)
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{
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__raw_writel(val, nvt_rng->base + reg);
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}
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static inline u32 nvt_rng_read_reg(struct nvt_rng *nvt_rng, int reg)
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{
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return __raw_readl(nvt_rng->base + reg);
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}
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static int nvt_rng_init(struct hwrng *rng)
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{
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struct nvt_rng *hrng = to_nvt_rng(rng);
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u32 data;
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//printk("nvt_rng_init\r\n");
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/* Seed init */
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//get_random_bytes(&seed, sizeof(seed));
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// Set config
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data = nvt_rng_read_reg(hrng, RNG_CTRL);
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nvt_rng_write_reg(hrng, RNG_CTRL, data|RNG_CASR|RNG_POST);
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return 0;
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}
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static void nvt_rng_cleanup(struct hwrng *rng)
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{
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struct nvt_rng *hrng = to_nvt_rng(rng);
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clk_disable(hrng->clk);
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//printk("nvt_rng_cleanup\r\n");
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//writel_relaxed(0, hrng->base + RNG_CTRL);
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}
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static int nvt_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
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{
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struct nvt_rng *hrng = to_nvt_rng(rng);
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u32 *data = buf;
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u32 count = max;
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u32 ret = 0;
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while(count >= 4) {
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*(data++) = nvt_rng_read_reg(hrng, RNG_RAND_NUM);
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count -= 4;
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ret +=4;
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}
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return ret;
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}
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static int nvt_rng_probe(struct platform_device *pdev)
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{
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struct nvt_rng *rng;
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struct resource *res;
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int ret;
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//printk("[nvt_rng_probe]\r\n");
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rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
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if (!rng)
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return -ENOMEM;
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platform_set_drvdata(pdev, rng);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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rng->base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(rng->base))
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return PTR_ERR(rng->base);
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rng->clk = devm_clk_get(&pdev->dev, dev_name(&pdev->dev));
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if (IS_ERR(rng->clk))
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return -ENODEV;
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else {
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rng->ro_clk = clk_get(NULL, "f0680000.rngro");
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if (IS_ERR(rng->ro_clk))
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return -ENODEV;
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else
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clk_prepare_enable(rng->ro_clk);
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clk_prepare_enable(rng->clk);
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//clk_set_rate(rng->clk, 40000000);
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//printk("Clock Rate: %d\r\n",clk_get_rate(rng->clk));
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}
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rng->rng.name = pdev->name;
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rng->rng.init = nvt_rng_init;
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rng->rng.cleanup = nvt_rng_cleanup;
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rng->rng.read = nvt_rng_read;
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ret = devm_hwrng_register(&pdev->dev, &rng->rng);
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if (ret) {
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dev_err(&pdev->dev, "failed to register hwrng\n");
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return ret;
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}
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dev_info(&pdev->dev, "Register %s successfully\n", __func__);
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return 0;
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}
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static const struct of_device_id nvt_rng_dt_ids[] = {
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{ .compatible = "nvt,nvt_rng" },
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{},
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};
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MODULE_DEVICE_TABLE(of, nvt_rng_dt_ids);
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static struct platform_driver nvt_rng_driver = {
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.probe = nvt_rng_probe,
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.driver = {
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.name = "nvt_rng",
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.of_match_table = of_match_ptr(nvt_rng_dt_ids),
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},
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};
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module_platform_driver(nvt_rng_driver);
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MODULE_AUTHOR("Novatek");
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MODULE_DESCRIPTION("NA51055 random number generator driver");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(TRNG_VERION);
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