Commit | Line | Data |
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ebc915ad | 1 | /* |
c49a7f18 | 2 | * omap-rng.c - RNG driver for TI OMAP CPU family |
ebc915ad MB |
3 | * |
4 | * Author: Deepak Saxena <dsaxena@plexity.net> | |
5 | * | |
6 | * Copyright 2005 (c) MontaVista Software, Inc. | |
7 | * | |
8 | * Mostly based on original driver: | |
9 | * | |
10 | * Copyright (C) 2005 Nokia Corporation | |
96de0e25 | 11 | * Author: Juha Yrjölä <juha.yrjola@nokia.com> |
ebc915ad MB |
12 | * |
13 | * This file is licensed under the terms of the GNU General Public | |
14 | * License version 2. This program is licensed "as is" without any | |
15 | * warranty of any kind, whether express or implied. | |
ebc915ad MB |
16 | */ |
17 | ||
18 | #include <linux/module.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/random.h> | |
21 | #include <linux/err.h> | |
af2bc7d2 | 22 | #include <linux/platform_device.h> |
ebc915ad | 23 | #include <linux/hw_random.h> |
984e976f | 24 | #include <linux/delay.h> |
02666360 | 25 | #include <linux/slab.h> |
665d92fa | 26 | #include <linux/pm_runtime.h> |
c903970c LV |
27 | #include <linux/of.h> |
28 | #include <linux/of_device.h> | |
29 | #include <linux/of_address.h> | |
ebc915ad MB |
30 | |
31 | #include <asm/io.h> | |
ebc915ad MB |
32 | |
33 | #define RNG_OUT_REG 0x00 /* Output register */ | |
34 | #define RNG_STAT_REG 0x04 /* Status register | |
35 | [0] = STAT_BUSY */ | |
36 | #define RNG_ALARM_REG 0x24 /* Alarm register | |
37 | [7:0] = ALARM_COUNTER */ | |
38 | #define RNG_CONFIG_REG 0x28 /* Configuration register | |
39 | [11:6] = RESET_COUNT | |
40 | [5:3] = RING2_DELAY | |
41 | [2:0] = RING1_DELAY */ | |
42 | #define RNG_REV_REG 0x3c /* Revision register | |
43 | [7:0] = REV_NB */ | |
44 | #define RNG_MASK_REG 0x40 /* Mask and reset register | |
45 | [2] = IT_EN | |
46 | [1] = SOFTRESET | |
47 | [0] = AUTOIDLE */ | |
48 | #define RNG_SYSSTATUS 0x44 /* System status | |
49 | [0] = RESETDONE */ | |
50 | ||
02666360 PW |
51 | /** |
52 | * struct omap_rng_private_data - RNG IP block-specific data | |
53 | * @base: virtual address of the beginning of the RNG IP block registers | |
02666360 PW |
54 | * @mem_res: struct resource * for the IP block registers physical memory |
55 | */ | |
56 | struct omap_rng_private_data { | |
57 | void __iomem *base; | |
02666360 PW |
58 | struct resource *mem_res; |
59 | }; | |
ebc915ad | 60 | |
02666360 | 61 | static inline u32 omap_rng_read_reg(struct omap_rng_private_data *priv, int reg) |
ebc915ad | 62 | { |
02666360 | 63 | return __raw_readl(priv->base + reg); |
ebc915ad MB |
64 | } |
65 | ||
02666360 PW |
66 | static inline void omap_rng_write_reg(struct omap_rng_private_data *priv, |
67 | int reg, u32 val) | |
ebc915ad | 68 | { |
02666360 | 69 | __raw_writel(val, priv->base + reg); |
ebc915ad MB |
70 | } |
71 | ||
984e976f | 72 | static int omap_rng_data_present(struct hwrng *rng, int wait) |
ebc915ad | 73 | { |
02666360 | 74 | struct omap_rng_private_data *priv; |
984e976f PM |
75 | int data, i; |
76 | ||
02666360 PW |
77 | priv = (struct omap_rng_private_data *)rng->priv; |
78 | ||
984e976f | 79 | for (i = 0; i < 20; i++) { |
02666360 | 80 | data = omap_rng_read_reg(priv, RNG_STAT_REG) ? 0 : 1; |
984e976f PM |
81 | if (data || !wait) |
82 | break; | |
c49a7f18 DB |
83 | /* RNG produces data fast enough (2+ MBit/sec, even |
84 | * during "rngtest" loads, that these delays don't | |
85 | * seem to trigger. We *could* use the RNG IRQ, but | |
86 | * that'd be higher overhead ... so why bother? | |
87 | */ | |
984e976f PM |
88 | udelay(10); |
89 | } | |
90 | return data; | |
ebc915ad MB |
91 | } |
92 | ||
93 | static int omap_rng_data_read(struct hwrng *rng, u32 *data) | |
94 | { | |
02666360 PW |
95 | struct omap_rng_private_data *priv; |
96 | ||
97 | priv = (struct omap_rng_private_data *)rng->priv; | |
98 | ||
99 | *data = omap_rng_read_reg(priv, RNG_OUT_REG); | |
ebc915ad | 100 | |
02666360 | 101 | return sizeof(u32); |
ebc915ad MB |
102 | } |
103 | ||
104 | static struct hwrng omap_rng_ops = { | |
105 | .name = "omap", | |
106 | .data_present = omap_rng_data_present, | |
107 | .data_read = omap_rng_data_read, | |
108 | }; | |
109 | ||
c903970c LV |
110 | #if defined(CONFIG_OF) |
111 | static const struct of_device_id omap_rng_of_match[] = { | |
112 | { .compatible = "ti,omap2-rng" }, | |
113 | {}, | |
114 | }; | |
115 | MODULE_DEVICE_TABLE(of, omap_rng_of_match); | |
116 | #endif | |
117 | ||
bcd2982a | 118 | static int omap_rng_probe(struct platform_device *pdev) |
ebc915ad | 119 | { |
02666360 | 120 | struct omap_rng_private_data *priv; |
ebc915ad MB |
121 | int ret; |
122 | ||
d52dc81e LV |
123 | priv = devm_kzalloc(&pdev->dev, sizeof(struct omap_rng_private_data), |
124 | GFP_KERNEL); | |
02666360 PW |
125 | if (!priv) { |
126 | dev_err(&pdev->dev, "could not allocate memory\n"); | |
127 | return -ENOMEM; | |
128 | }; | |
129 | ||
130 | omap_rng_ops.priv = (unsigned long)priv; | |
1f539bcb | 131 | platform_set_drvdata(pdev, priv); |
ebc915ad | 132 | |
02666360 | 133 | priv->mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
c7c9e1c3 TR |
134 | priv->base = devm_ioremap_resource(&pdev->dev, priv->mem_res); |
135 | if (IS_ERR(priv->base)) { | |
136 | ret = PTR_ERR(priv->base); | |
55c381e4 RK |
137 | goto err_ioremap; |
138 | } | |
ebc915ad | 139 | |
665d92fa PW |
140 | pm_runtime_enable(&pdev->dev); |
141 | pm_runtime_get_sync(&pdev->dev); | |
142 | ||
ebc915ad | 143 | ret = hwrng_register(&omap_rng_ops); |
55c381e4 RK |
144 | if (ret) |
145 | goto err_register; | |
ebc915ad | 146 | |
af2bc7d2 | 147 | dev_info(&pdev->dev, "OMAP Random Number Generator ver. %02x\n", |
02666360 PW |
148 | omap_rng_read_reg(priv, RNG_REV_REG)); |
149 | ||
02666360 | 150 | omap_rng_write_reg(priv, RNG_MASK_REG, 0x1); |
ebc915ad MB |
151 | |
152 | return 0; | |
55c381e4 RK |
153 | |
154 | err_register: | |
02666360 | 155 | priv->base = NULL; |
665d92fa | 156 | pm_runtime_disable(&pdev->dev); |
55c381e4 | 157 | err_ioremap: |
55c381e4 | 158 | return ret; |
ebc915ad MB |
159 | } |
160 | ||
af2bc7d2 | 161 | static int __exit omap_rng_remove(struct platform_device *pdev) |
ebc915ad | 162 | { |
1f539bcb | 163 | struct omap_rng_private_data *priv = platform_get_drvdata(pdev); |
02666360 | 164 | |
ebc915ad MB |
165 | hwrng_unregister(&omap_rng_ops); |
166 | ||
02666360 PW |
167 | omap_rng_write_reg(priv, RNG_MASK_REG, 0x0); |
168 | ||
665d92fa PW |
169 | pm_runtime_put_sync(&pdev->dev); |
170 | pm_runtime_disable(&pdev->dev); | |
ebc915ad | 171 | |
ebc915ad MB |
172 | return 0; |
173 | } | |
174 | ||
59596df6 | 175 | #ifdef CONFIG_PM_SLEEP |
ebc915ad | 176 | |
7650572a | 177 | static int omap_rng_suspend(struct device *dev) |
ebc915ad | 178 | { |
02666360 PW |
179 | struct omap_rng_private_data *priv = dev_get_drvdata(dev); |
180 | ||
181 | omap_rng_write_reg(priv, RNG_MASK_REG, 0x0); | |
665d92fa | 182 | pm_runtime_put_sync(dev); |
02666360 | 183 | |
ebc915ad MB |
184 | return 0; |
185 | } | |
186 | ||
7650572a | 187 | static int omap_rng_resume(struct device *dev) |
ebc915ad | 188 | { |
02666360 PW |
189 | struct omap_rng_private_data *priv = dev_get_drvdata(dev); |
190 | ||
665d92fa | 191 | pm_runtime_get_sync(dev); |
02666360 PW |
192 | omap_rng_write_reg(priv, RNG_MASK_REG, 0x1); |
193 | ||
af2bc7d2 | 194 | return 0; |
ebc915ad MB |
195 | } |
196 | ||
7650572a RW |
197 | static SIMPLE_DEV_PM_OPS(omap_rng_pm, omap_rng_suspend, omap_rng_resume); |
198 | #define OMAP_RNG_PM (&omap_rng_pm) | |
199 | ||
ebc915ad MB |
200 | #else |
201 | ||
7650572a | 202 | #define OMAP_RNG_PM NULL |
ebc915ad MB |
203 | |
204 | #endif | |
205 | ||
af2bc7d2 DB |
206 | static struct platform_driver omap_rng_driver = { |
207 | .driver = { | |
208 | .name = "omap_rng", | |
209 | .owner = THIS_MODULE, | |
7650572a | 210 | .pm = OMAP_RNG_PM, |
c903970c | 211 | .of_match_table = of_match_ptr(omap_rng_of_match), |
af2bc7d2 | 212 | }, |
ebc915ad MB |
213 | .probe = omap_rng_probe, |
214 | .remove = __exit_p(omap_rng_remove), | |
ebc915ad MB |
215 | }; |
216 | ||
4390f77b LV |
217 | module_platform_driver(omap_rng_driver); |
218 | MODULE_ALIAS("platform:omap_rng"); | |
ebc915ad MB |
219 | MODULE_AUTHOR("Deepak Saxena (and others)"); |
220 | MODULE_LICENSE("GPL"); |