1 // SPDX-License-Identifier: GPL-2.0
21 #define NPCM_RNG_CLK_SET_25MHZ	GENMASK(4, 3) /* 20-25 MHz */
29 #define to_npcm_rng(p)	container_of(p, struct npcm_rng, rng)
33 	struct hwrng rng;  member
36 static int npcm_rng_init(struct hwrng *rng)  in npcm_rng_init()  argument
38 	struct npcm_rng *priv = to_npcm_rng(rng);  in npcm_rng_init()
41 	       priv->base + NPCM_RNGCS_REG);  in npcm_rng_init()
46 static void npcm_rng_cleanup(struct hwrng *rng)  in npcm_rng_cleanup()  argument
48 	struct npcm_rng *priv = to_npcm_rng(rng);  in npcm_rng_cleanup()
50 	writel(NPCM_RNG_CLK_SET_25MHZ, priv->base + NPCM_RNGCS_REG);  in npcm_rng_cleanup()
53 static int npcm_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)  in npcm_rng_read()  argument
55 	struct npcm_rng *priv = to_npcm_rng(rng);  in npcm_rng_read()
59 	pm_runtime_get_sync((struct device *)priv->rng.priv);  in npcm_rng_read()
63 			if (readb_poll_timeout(priv->base + NPCM_RNGCS_REG,  in npcm_rng_read()
70 			if ((readb(priv->base + NPCM_RNGCS_REG) &  in npcm_rng_read()
75 		*(u8 *)buf = readb(priv->base + NPCM_RNGD_REG);  in npcm_rng_read()
78 		max--;  in npcm_rng_read()
81 	pm_runtime_mark_last_busy((struct device *)priv->rng.priv);  in npcm_rng_read()
82 	pm_runtime_put_sync_autosuspend((struct device *)priv->rng.priv);  in npcm_rng_read()
84 	return retval || !wait ? retval : -EIO;  in npcm_rng_read()
92 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);  in npcm_rng_probe()
94 		return -ENOMEM;  in npcm_rng_probe()
96 	priv->base = devm_platform_ioremap_resource(pdev, 0);  in npcm_rng_probe()
97 	if (IS_ERR(priv->base))  in npcm_rng_probe()
98 		return PTR_ERR(priv->base);  in npcm_rng_probe()
100 	dev_set_drvdata(&pdev->dev, priv);  in npcm_rng_probe()
101 	pm_runtime_set_autosuspend_delay(&pdev->dev, 100);  in npcm_rng_probe()
102 	pm_runtime_use_autosuspend(&pdev->dev);  in npcm_rng_probe()
103 	pm_runtime_enable(&pdev->dev);  in npcm_rng_probe()
106 	priv->rng.init = npcm_rng_init;  in npcm_rng_probe()
107 	priv->rng.cleanup = npcm_rng_cleanup;  in npcm_rng_probe()
109 	priv->rng.name = pdev->name;  in npcm_rng_probe()
110 	priv->rng.read = npcm_rng_read;  in npcm_rng_probe()
111 	priv->rng.priv = (unsigned long)&pdev->dev;  in npcm_rng_probe()
112 	priv->rng.quality = 1000;  in npcm_rng_probe()
114 	writel(NPCM_RNG_M1ROSEL, priv->base + NPCM_RNGMODE_REG);  in npcm_rng_probe()
116 	ret = devm_hwrng_register(&pdev->dev, &priv->rng);  in npcm_rng_probe()
118 		dev_err(&pdev->dev, "Failed to register rng device: %d\n",  in npcm_rng_probe()
120 		pm_runtime_disable(&pdev->dev);  in npcm_rng_probe()
121 		pm_runtime_set_suspended(&pdev->dev);  in npcm_rng_probe()
132 	devm_hwrng_unregister(&pdev->dev, &priv->rng);  in npcm_rng_remove()
133 	pm_runtime_disable(&pdev->dev);  in npcm_rng_remove()
134 	pm_runtime_set_suspended(&pdev->dev);  in npcm_rng_remove()
144 	npcm_rng_cleanup(&priv->rng);  in npcm_rng_runtime_suspend()
153 	return npcm_rng_init(&priv->rng);  in npcm_rng_runtime_resume()
165 	{ .compatible = "nuvoton,npcm750-rng",  },
172 		.name		= "npcm-rng",