1 // SPDX-License-Identifier: GPL-2.0-or-later
32 	struct hwrng rng;  member
39 static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)  in stm32_rng_read()  argument
42 	    container_of(rng, struct stm32_rng_private, rng);  in stm32_rng_read()
46 	pm_runtime_get_sync((struct device *) priv->rng.priv);  in stm32_rng_read()
49 		sr = readl_relaxed(priv->base + RNG_SR);  in stm32_rng_read()
51 		/* care of initial delay time when enabling rng	*/  in stm32_rng_read()
55 			err = readl_relaxed_poll_timeout_atomic(priv->base  in stm32_rng_read()
60 				dev_err((struct device *)priv->rng.priv,  in stm32_rng_read()
67 					"bad RNG status - %x\n", sr))  in stm32_rng_read()
68 				writel_relaxed(0, priv->base + RNG_SR);  in stm32_rng_read()
72 		*(u32 *)data = readl_relaxed(priv->base + RNG_DR);  in stm32_rng_read()
76 		max -= sizeof(u32);  in stm32_rng_read()
79 	pm_runtime_mark_last_busy((struct device *) priv->rng.priv);  in stm32_rng_read()
80 	pm_runtime_put_sync_autosuspend((struct device *) priv->rng.priv);  in stm32_rng_read()
82 	return retval || !wait ? retval : -EIO;  in stm32_rng_read()
85 static int stm32_rng_init(struct hwrng *rng)  in stm32_rng_init()  argument
88 	    container_of(rng, struct stm32_rng_private, rng);  in stm32_rng_init()
91 	err = clk_prepare_enable(priv->clk);  in stm32_rng_init()
95 	if (priv->ced)  in stm32_rng_init()
96 		writel_relaxed(RNG_CR_RNGEN, priv->base + RNG_CR);  in stm32_rng_init()
99 			       priv->base + RNG_CR);  in stm32_rng_init()
102 	writel_relaxed(0, priv->base + RNG_SR);  in stm32_rng_init()
107 static void stm32_rng_cleanup(struct hwrng *rng)  in stm32_rng_cleanup()  argument
110 	    container_of(rng, struct stm32_rng_private, rng);  in stm32_rng_cleanup()
112 	writel_relaxed(0, priv->base + RNG_CR);  in stm32_rng_cleanup()
113 	clk_disable_unprepare(priv->clk);  in stm32_rng_cleanup()
118 	struct device *dev = &ofdev->dev;  in stm32_rng_probe()
119 	struct device_node *np = ofdev->dev.of_node;  in stm32_rng_probe()
126 		return -ENOMEM;  in stm32_rng_probe()
132 	priv->base = devm_ioremap_resource(dev, &res);  in stm32_rng_probe()
133 	if (IS_ERR(priv->base))  in stm32_rng_probe()
134 		return PTR_ERR(priv->base);  in stm32_rng_probe()
136 	priv->clk = devm_clk_get(&ofdev->dev, NULL);  in stm32_rng_probe()
137 	if (IS_ERR(priv->clk))  in stm32_rng_probe()
138 		return PTR_ERR(priv->clk);  in stm32_rng_probe()
140 	priv->rst = devm_reset_control_get(&ofdev->dev, NULL);  in stm32_rng_probe()
141 	if (!IS_ERR(priv->rst)) {  in stm32_rng_probe()
142 		reset_control_assert(priv->rst);  in stm32_rng_probe()
144 		reset_control_deassert(priv->rst);  in stm32_rng_probe()
147 	priv->ced = of_property_read_bool(np, "clock-error-detect");  in stm32_rng_probe()
151 	priv->rng.name = dev_driver_string(dev);  in stm32_rng_probe()
153 	priv->rng.init = stm32_rng_init;  in stm32_rng_probe()
154 	priv->rng.cleanup = stm32_rng_cleanup;  in stm32_rng_probe()
156 	priv->rng.read = stm32_rng_read;  in stm32_rng_probe()
157 	priv->rng.priv = (unsigned long) dev;  in stm32_rng_probe()
158 	priv->rng.quality = 900;  in stm32_rng_probe()
164 	return devm_hwrng_register(dev, &priv->rng);  in stm32_rng_probe()
169 	pm_runtime_disable(&ofdev->dev);  in stm32_rng_remove()
179 	stm32_rng_cleanup(&priv->rng);  in stm32_rng_runtime_suspend()
188 	return stm32_rng_init(&priv->rng);  in stm32_rng_runtime_resume()
202 		.compatible = "st,stm32-rng",
210 		.name = "stm32-rng",
222 MODULE_DESCRIPTION("STMicroelectronics STM32 RNG device driver");