2 * Broadcom BCM63xx Random Number Generator support
4 * Copyright (C) 2011, Florian Fainelli <florian@openwrt.org>
5 * Copyright (C) 2009, Broadcom Corporation
8 #include <linux/module.h>
9 #include <linux/slab.h>
11 #include <linux/err.h>
12 #include <linux/clk.h>
13 #include <linux/platform_device.h>
14 #include <linux/hw_random.h>
17 #define RNG_EN (1 << 0)
20 #define RNG_AVAIL_MASK (0xff000000)
23 #define RNG_THRES 0x0c
26 struct bcm63xx_rng_priv
{
32 #define to_rng_priv(rng) container_of(rng, struct bcm63xx_rng_priv, rng)
34 static int bcm63xx_rng_init(struct hwrng
*rng
)
36 struct bcm63xx_rng_priv
*priv
= to_rng_priv(rng
);
40 error
= clk_prepare_enable(priv
->clk
);
44 val
= __raw_readl(priv
->regs
+ RNG_CTRL
);
46 __raw_writel(val
, priv
->regs
+ RNG_CTRL
);
51 static void bcm63xx_rng_cleanup(struct hwrng
*rng
)
53 struct bcm63xx_rng_priv
*priv
= to_rng_priv(rng
);
56 val
= __raw_readl(priv
->regs
+ RNG_CTRL
);
58 __raw_writel(val
, priv
->regs
+ RNG_CTRL
);
60 clk_disable_unprepare(priv
->clk
);
63 static int bcm63xx_rng_data_present(struct hwrng
*rng
, int wait
)
65 struct bcm63xx_rng_priv
*priv
= to_rng_priv(rng
);
67 return __raw_readl(priv
->regs
+ RNG_STAT
) & RNG_AVAIL_MASK
;
70 static int bcm63xx_rng_data_read(struct hwrng
*rng
, u32
*data
)
72 struct bcm63xx_rng_priv
*priv
= to_rng_priv(rng
);
74 *data
= __raw_readl(priv
->regs
+ RNG_DATA
);
79 static int bcm63xx_rng_probe(struct platform_device
*pdev
)
84 struct bcm63xx_rng_priv
*priv
;
87 r
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
89 dev_err(&pdev
->dev
, "no iomem resource\n");
93 priv
= devm_kzalloc(&pdev
->dev
, sizeof(*priv
), GFP_KERNEL
);
97 priv
->rng
.name
= pdev
->name
;
98 priv
->rng
.init
= bcm63xx_rng_init
;
99 priv
->rng
.cleanup
= bcm63xx_rng_cleanup
;
100 priv
->rng
.data_present
= bcm63xx_rng_data_present
;
101 priv
->rng
.data_read
= bcm63xx_rng_data_read
;
103 priv
->clk
= devm_clk_get(&pdev
->dev
, "ipsec");
104 if (IS_ERR(priv
->clk
)) {
105 ret
= PTR_ERR(priv
->clk
);
106 dev_err(&pdev
->dev
, "no clock for device: %d\n", ret
);
110 if (!devm_request_mem_region(&pdev
->dev
, r
->start
,
111 resource_size(r
), pdev
->name
)) {
112 dev_err(&pdev
->dev
, "request mem failed");
116 priv
->regs
= devm_ioremap_nocache(&pdev
->dev
, r
->start
,
119 dev_err(&pdev
->dev
, "ioremap failed");
123 ret
= devm_hwrng_register(&pdev
->dev
, &priv
->rng
);
125 dev_err(&pdev
->dev
, "failed to register rng device: %d\n",
130 dev_info(&pdev
->dev
, "registered RNG driver\n");
135 static struct platform_driver bcm63xx_rng_driver
= {
136 .probe
= bcm63xx_rng_probe
,
138 .name
= "bcm63xx-rng",
142 module_platform_driver(bcm63xx_rng_driver
);
144 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
145 MODULE_DESCRIPTION("Broadcom BCM63xx RNG driver");
146 MODULE_LICENSE("GPL");