1 // SPDX-License-Identifier: GPL-2.0-only
3  * Random Number Generator driver for the Keystone SOC
5  * Copyright (C) 2016 Texas Instruments Incorporated - https://www.ti.com
68 /* Maximum retries to get rng data */
84 	struct hwrng	rng;  member
112 static int ks_sa_rng_init(struct hwrng *rng)  in ks_sa_rng_init()  argument
115 	struct ks_sa_rng *ks_sa_rng = container_of(rng, struct ks_sa_rng, rng);  in ks_sa_rng_init()
116 	unsigned long clk_rate = clk_get_rate(ks_sa_rng->clk);  in ks_sa_rng_init()
118 	/* Enable RNG module */  in ks_sa_rng_init()
119 	regmap_write_bits(ks_sa_rng->regmap_cfg, SA_CMD_STATUS_OFS,  in ks_sa_rng_init()
123 	/* Configure RNG module */  in ks_sa_rng_init()
124 	writel(0, &ks_sa_rng->reg_rng->control);  in ks_sa_rng_init()
126 	writel(value, &ks_sa_rng->reg_rng->control);  in ks_sa_rng_init()
135 	writel(value, &ks_sa_rng->reg_rng->config);  in ks_sa_rng_init()
138 	writel(0, &ks_sa_rng->reg_rng->intmask);  in ks_sa_rng_init()
140 	/* Enable RNG */  in ks_sa_rng_init()
141 	value = readl(&ks_sa_rng->reg_rng->control);  in ks_sa_rng_init()
143 	writel(value, &ks_sa_rng->reg_rng->control);  in ks_sa_rng_init()
145 	ks_sa_rng->refill_delay_ns = refill_delay_ns(clk_rate);  in ks_sa_rng_init()
146 	ks_sa_rng->ready_ts = ktime_get_ns() +  in ks_sa_rng_init()
152 static void ks_sa_rng_cleanup(struct hwrng *rng)  in ks_sa_rng_cleanup()  argument
154 	struct ks_sa_rng *ks_sa_rng = container_of(rng, struct ks_sa_rng, rng);  in ks_sa_rng_cleanup()
156 	/* Disable RNG */  in ks_sa_rng_cleanup()
157 	writel(0, &ks_sa_rng->reg_rng->control);  in ks_sa_rng_cleanup()
158 	regmap_write_bits(ks_sa_rng->regmap_cfg, SA_CMD_STATUS_OFS,  in ks_sa_rng_cleanup()
162 static int ks_sa_rng_data_read(struct hwrng *rng, u32 *data)  in ks_sa_rng_data_read()  argument
164 	struct ks_sa_rng *ks_sa_rng = container_of(rng, struct ks_sa_rng, rng);  in ks_sa_rng_data_read()
167 	data[0] = readl(&ks_sa_rng->reg_rng->output_l);  in ks_sa_rng_data_read()
168 	data[1] = readl(&ks_sa_rng->reg_rng->output_h);  in ks_sa_rng_data_read()
170 	writel(TRNG_INTACK_REG_READY, &ks_sa_rng->reg_rng->intack);  in ks_sa_rng_data_read()
171 	ks_sa_rng->ready_ts = ktime_get_ns() + ks_sa_rng->refill_delay_ns;  in ks_sa_rng_data_read()
176 static int ks_sa_rng_data_present(struct hwrng *rng, int wait)  in ks_sa_rng_data_present()  argument
178 	struct ks_sa_rng *ks_sa_rng = container_of(rng, struct ks_sa_rng, rng);  in ks_sa_rng_data_present()
184 	if (wait && now < ks_sa_rng->ready_ts) {  in ks_sa_rng_data_present()
187 			DIV_ROUND_UP((u32)(ks_sa_rng->ready_ts - now), 1000);  in ks_sa_rng_data_present()
193 		ready = readl(&ks_sa_rng->reg_rng->status);  in ks_sa_rng_data_present()
208 	struct device		*dev = &pdev->dev;  in ks_sa_rng_probe()
213 		return -ENOMEM;  in ks_sa_rng_probe()
215 	ks_sa_rng->rng = (struct hwrng) {  in ks_sa_rng_probe()
223 	ks_sa_rng->reg_rng = devm_platform_ioremap_resource(pdev, 0);  in ks_sa_rng_probe()
224 	if (IS_ERR(ks_sa_rng->reg_rng))  in ks_sa_rng_probe()
225 		return PTR_ERR(ks_sa_rng->reg_rng);  in ks_sa_rng_probe()
227 	ks_sa_rng->regmap_cfg =  in ks_sa_rng_probe()
228 		syscon_regmap_lookup_by_phandle(dev->of_node,  in ks_sa_rng_probe()
229 						"ti,syscon-sa-cfg");  in ks_sa_rng_probe()
231 	if (IS_ERR(ks_sa_rng->regmap_cfg))  in ks_sa_rng_probe()
232 		return dev_err_probe(dev, -EINVAL, "syscon_node_to_regmap failed\n");  in ks_sa_rng_probe()
238 		return dev_err_probe(dev, ret, "Failed to enable SA power-domain\n");  in ks_sa_rng_probe()
241 	return devm_hwrng_register(&pdev->dev, &ks_sa_rng->rng);  in ks_sa_rng_probe()
246 	pm_runtime_put_sync(&pdev->dev);  in ks_sa_rng_remove()
247 	pm_runtime_disable(&pdev->dev);  in ks_sa_rng_remove()
252 		.compatible = "ti,keystone-rng",
260 		.name	= "ks-sa-rng",
269 MODULE_DESCRIPTION("Keystone NETCP SA H/W Random Number Generator driver");