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
{
31 #define to_rng_priv(rng) ((struct bcm63xx_rng_priv *)rng->priv)
33 static int bcm63xx_rng_init(struct hwrng
*rng
)
35 struct bcm63xx_rng_priv
*priv
= to_rng_priv(rng
);
38 val
= __raw_readl(priv
->regs
+ RNG_CTRL
);
40 __raw_writel(val
, priv
->regs
+ RNG_CTRL
);
45 static void bcm63xx_rng_cleanup(struct hwrng
*rng
)
47 struct bcm63xx_rng_priv
*priv
= to_rng_priv(rng
);
50 val
= __raw_readl(priv
->regs
+ RNG_CTRL
);
52 __raw_writel(val
, priv
->regs
+ RNG_CTRL
);
55 static int bcm63xx_rng_data_present(struct hwrng
*rng
, int wait
)
57 struct bcm63xx_rng_priv
*priv
= to_rng_priv(rng
);
59 return __raw_readl(priv
->regs
+ RNG_STAT
) & RNG_AVAIL_MASK
;
62 static int bcm63xx_rng_data_read(struct hwrng
*rng
, u32
*data
)
64 struct bcm63xx_rng_priv
*priv
= to_rng_priv(rng
);
66 *data
= __raw_readl(priv
->regs
+ RNG_DATA
);
71 static int bcm63xx_rng_probe(struct platform_device
*pdev
)
76 struct bcm63xx_rng_priv
*priv
;
79 r
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
81 dev_err(&pdev
->dev
, "no iomem resource\n");
86 priv
= kzalloc(sizeof(*priv
), GFP_KERNEL
);
88 dev_err(&pdev
->dev
, "no memory for private structure\n");
93 rng
= kzalloc(sizeof(*rng
), GFP_KERNEL
);
95 dev_err(&pdev
->dev
, "no memory for rng structure\n");
100 platform_set_drvdata(pdev
, rng
);
101 rng
->priv
= (unsigned long)priv
;
102 rng
->name
= pdev
->name
;
103 rng
->init
= bcm63xx_rng_init
;
104 rng
->cleanup
= bcm63xx_rng_cleanup
;
105 rng
->data_present
= bcm63xx_rng_data_present
;
106 rng
->data_read
= bcm63xx_rng_data_read
;
108 clk
= clk_get(&pdev
->dev
, "ipsec");
110 dev_err(&pdev
->dev
, "no clock for device\n");
117 if (!devm_request_mem_region(&pdev
->dev
, r
->start
,
118 resource_size(r
), pdev
->name
)) {
119 dev_err(&pdev
->dev
, "request mem failed");
124 priv
->regs
= devm_ioremap_nocache(&pdev
->dev
, r
->start
,
127 dev_err(&pdev
->dev
, "ioremap failed");
134 ret
= hwrng_register(rng
);
136 dev_err(&pdev
->dev
, "failed to register rng device\n");
137 goto out_clk_disable
;
140 dev_info(&pdev
->dev
, "registered RNG driver\n");
154 static int bcm63xx_rng_remove(struct platform_device
*pdev
)
156 struct hwrng
*rng
= platform_get_drvdata(pdev
);
157 struct bcm63xx_rng_priv
*priv
= to_rng_priv(rng
);
159 hwrng_unregister(rng
);
160 clk_disable(priv
->clk
);
167 static struct platform_driver bcm63xx_rng_driver
= {
168 .probe
= bcm63xx_rng_probe
,
169 .remove
= bcm63xx_rng_remove
,
171 .name
= "bcm63xx-rng",
175 module_platform_driver(bcm63xx_rng_driver
);
177 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
178 MODULE_DESCRIPTION("Broadcom BCM63xx RNG driver");
179 MODULE_LICENSE("GPL");