1 // SPDX-License-Identifier: GPL-2.0
3  * rockchip-rng.c True Random Number Generator driver for Rockchip RK3568 SoC
5  * Copyright (c) 2018, Fuzhou Rockchip Electronics Co., Ltd.
8  *  Lin Jinhan <troy.lin@rock-chips.com>
31  * of ~900 (~87.5% of FIPS 140-2 successes).
35 /* TRNG registers from RK3568 TRM-Part2, section 5.4.1 */
62 	writel((mask << 16) | val, rng->base + TRNG_RNG_CTL);  in rk_rng_write_ctl()
71 	ret = clk_bulk_prepare_enable(rk_rng->clk_num, rk_rng->clk_bulks);  in rk_rng_init()
73 		dev_err((struct device *) rk_rng->rng.priv,  in rk_rng_init()
79 	writel(RK_RNG_SAMPLE_CNT, rk_rng->base + TRNG_RNG_SAMPLE_CNT);  in rk_rng_init()
98 	clk_bulk_disable_unprepare(rk_rng->clk_num, rk_rng->clk_bulks);  in rk_rng_cleanup()
108 	ret = pm_runtime_resume_and_get((struct device *) rk_rng->rng.priv);  in rk_rng_read()
115 	ret = readl_poll_timeout(rk_rng->base + TRNG_RNG_CTL, reg,  in rk_rng_read()
123 	memcpy_fromio(buf, rk_rng->base + TRNG_RNG_DOUT, to_read);  in rk_rng_read()
125 	pm_runtime_mark_last_busy((struct device *) rk_rng->rng.priv);  in rk_rng_read()
126 	pm_runtime_put_sync_autosuspend((struct device *) rk_rng->rng.priv);  in rk_rng_read()
133 	struct device *dev = &pdev->dev;  in rk_rng_probe()
140 		return -ENOMEM;  in rk_rng_probe()
142 	rk_rng->base = devm_platform_ioremap_resource(pdev, 0);  in rk_rng_probe()
143 	if (IS_ERR(rk_rng->base))  in rk_rng_probe()
144 		return PTR_ERR(rk_rng->base);  in rk_rng_probe()
146 	rk_rng->clk_num = devm_clk_bulk_get_all(dev, &rk_rng->clk_bulks);  in rk_rng_probe()
147 	if (rk_rng->clk_num < 0)  in rk_rng_probe()
148 		return dev_err_probe(dev, rk_rng->clk_num,  in rk_rng_probe()
151 	rst = devm_reset_control_array_get_exclusive(&pdev->dev);  in rk_rng_probe()
161 	rk_rng->rng.name = dev_driver_string(dev);  in rk_rng_probe()
163 		rk_rng->rng.init = rk_rng_init;  in rk_rng_probe()
164 		rk_rng->rng.cleanup = rk_rng_cleanup;  in rk_rng_probe()
166 	rk_rng->rng.read = rk_rng_read;  in rk_rng_probe()
167 	rk_rng->rng.priv = (unsigned long) dev;  in rk_rng_probe()
168 	rk_rng->rng.quality = 900;  in rk_rng_probe()
174 		return dev_err_probe(&pdev->dev, ret, "Runtime pm activation failed.\n");  in rk_rng_probe()
176 	ret = devm_hwrng_register(dev, &rk_rng->rng);  in rk_rng_probe()
178 		return dev_err_probe(&pdev->dev, ret, "Failed to register Rockchip hwrng\n");  in rk_rng_probe()
183 static int __maybe_unused rk_rng_runtime_suspend(struct device *dev)  in rk_rng_runtime_suspend()
187 	rk_rng_cleanup(&rk_rng->rng);  in rk_rng_runtime_suspend()
192 static int __maybe_unused rk_rng_runtime_resume(struct device *dev)  in rk_rng_runtime_resume()
196 	return rk_rng_init(&rk_rng->rng);  in rk_rng_runtime_resume()
207 	{ .compatible = "rockchip,rk3568-rng", },
215 		.name	= "rockchip-rng",
224 MODULE_DESCRIPTION("Rockchip RK3568 True Random Number Generator driver");
225 MODULE_AUTHOR("Lin Jinhan <troy.lin@rock-chips.com>");