1 // SPDX-License-Identifier: GPL-2.0
3  * RNG driver for Exynos TRNGs
9  * Based on the Exynos PRNG driver drivers/crypto/exynos-rng by
13 #include <linux/arm-smccc.h>
77 	struct clk	*pclk;	/* bus clock */
85 	struct exynos_trng_dev *trng = (struct exynos_trng_dev *)rng->priv;  in exynos_trng_do_read_reg()
89 	writel_relaxed(max * 8, trng->mem + EXYNOS_TRNG_FIFO_CTRL);  in exynos_trng_do_read_reg()
90 	val = readl_poll_timeout(trng->mem + EXYNOS_TRNG_FIFO_CTRL, val,  in exynos_trng_do_read_reg()
95 	memcpy_fromio(data, trng->mem + EXYNOS_TRNG_FIFO_0, max);  in exynos_trng_do_read_reg()
126 			return -EIO;  in exynos_trng_do_read_smc()
135 	struct exynos_trng_dev *trng = (struct exynos_trng_dev *)rng->priv;  in exynos_trng_init_reg()
139 	sss_rate = clk_get_rate(trng->clk);  in exynos_trng_init_reg()
147 		dev_err(trng->dev, "clock divider too large: %d\n", val);  in exynos_trng_init_reg()
148 		return -ERANGE;  in exynos_trng_init_reg()
151 	writel_relaxed(val, trng->mem + EXYNOS_TRNG_CLKDIV);  in exynos_trng_init_reg()
155 	writel_relaxed(val, trng->mem + EXYNOS_TRNG_CTRL);  in exynos_trng_init_reg()
158 	 * Disable post-processing. /dev/hwrng is supposed to deliver  in exynos_trng_init_reg()
161 	writel_relaxed(0, trng->mem + EXYNOS_TRNG_POST_CTRL);  in exynos_trng_init_reg()
168 	struct exynos_trng_dev *trng = (struct exynos_trng_dev *)rng->priv;  in exynos_trng_init_smc()
174 		dev_err(trng->dev, "SMC command for TRNG init failed (%d)\n",  in exynos_trng_init_smc()
176 		ret = -EIO;  in exynos_trng_init_smc()
178 	if ((int)res.a0 == -1)  in exynos_trng_init_smc()
179 		dev_info(trng->dev, "Make sure LDFW is loaded by your BL\n");  in exynos_trng_init_smc()
187 	int ret = -ENOMEM;  in exynos_trng_probe()
189 	trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);  in exynos_trng_probe()
194 	trng->dev = &pdev->dev;  in exynos_trng_probe()
196 	trng->flags = (unsigned long)device_get_match_data(&pdev->dev);  in exynos_trng_probe()
198 	trng->rng.name = devm_kstrdup(&pdev->dev, dev_name(&pdev->dev),  in exynos_trng_probe()
200 	if (!trng->rng.name)  in exynos_trng_probe()
203 	trng->rng.priv = (unsigned long)trng;  in exynos_trng_probe()
205 	if (trng->flags & EXYNOS_SMC) {  in exynos_trng_probe()
206 		trng->rng.init = exynos_trng_init_smc;  in exynos_trng_probe()
207 		trng->rng.read = exynos_trng_do_read_smc;  in exynos_trng_probe()
209 		trng->rng.init = exynos_trng_init_reg;  in exynos_trng_probe()
210 		trng->rng.read = exynos_trng_do_read_reg;  in exynos_trng_probe()
212 		trng->mem = devm_platform_ioremap_resource(pdev, 0);  in exynos_trng_probe()
213 		if (IS_ERR(trng->mem))  in exynos_trng_probe()
214 			return PTR_ERR(trng->mem);  in exynos_trng_probe()
217 	pm_runtime_enable(&pdev->dev);  in exynos_trng_probe()
218 	ret = pm_runtime_resume_and_get(&pdev->dev);  in exynos_trng_probe()
220 		dev_err(&pdev->dev, "Could not get runtime PM.\n");  in exynos_trng_probe()
224 	trng->clk = devm_clk_get_enabled(&pdev->dev, "secss");  in exynos_trng_probe()
225 	if (IS_ERR(trng->clk)) {  in exynos_trng_probe()
226 		ret = dev_err_probe(&pdev->dev, PTR_ERR(trng->clk),  in exynos_trng_probe()
231 	trng->pclk = devm_clk_get_optional_enabled(&pdev->dev, "pclk");  in exynos_trng_probe()
232 	if (IS_ERR(trng->pclk)) {  in exynos_trng_probe()
233 		ret = dev_err_probe(&pdev->dev, PTR_ERR(trng->pclk),  in exynos_trng_probe()
238 	ret = devm_hwrng_register(&pdev->dev, &trng->rng);  in exynos_trng_probe()
240 		dev_err(&pdev->dev, "Could not register hwrng device.\n");  in exynos_trng_probe()
244 	dev_info(&pdev->dev, "Exynos True Random Number Generator.\n");  in exynos_trng_probe()
249 	pm_runtime_put_noidle(&pdev->dev);  in exynos_trng_probe()
252 	pm_runtime_disable(&pdev->dev);  in exynos_trng_probe()
261 	if (trng->flags & EXYNOS_SMC) {  in exynos_trng_remove()
268 	pm_runtime_put_sync(&pdev->dev);  in exynos_trng_remove()
269 	pm_runtime_disable(&pdev->dev);  in exynos_trng_remove()
277 	if (trng->flags & EXYNOS_SMC) {  in exynos_trng_suspend()
281 			return -EIO;  in exynos_trng_suspend()
300 	if (trng->flags & EXYNOS_SMC) {  in exynos_trng_resume()
306 			return -EIO;  in exynos_trng_resume()
311 			return -EIO;  in exynos_trng_resume()
322 		.compatible = "samsung,exynos5250-trng",
324 		.compatible = "samsung,exynos850-trng",
333 		.name = "exynos-trng",
344 MODULE_DESCRIPTION("H/W TRNG driver for Exynos chips");