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-rw-r--r--drivers/char/hw_random/Kconfig14
-rw-r--r--drivers/char/hw_random/Makefile1
-rw-r--r--drivers/char/hw_random/omap-rng.c208
3 files changed, 223 insertions, 0 deletions
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 1100fd7428e4..9f7635f75178 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -74,3 +74,17 @@ config HW_RANDOM_IXP4XX
74 module will be called ixp4xx-rng. 74 module will be called ixp4xx-rng.
75 75
76 If unsure, say Y. 76 If unsure, say Y.
77
78config HW_RANDOM_OMAP
79 tristate "OMAP Random Number Generator support"
80 depends on HW_RANDOM && (ARCH_OMAP16XX || ARCH_OMAP24XX)
81 default y
82 ---help---
83 This driver provides kernel-side support for the Random Number
84 Generator hardware found on OMAP16xx and OMAP24xx multimedia
85 processors.
86
87 To compile this driver as a module, choose M here: the
88 module will be called omap-rng.
89
90 If unsure, say Y.
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 46076dfbd3f0..e263ae96f940 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o
8obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o 8obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
9obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o 9obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o
10obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o 10obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o
11obj-$(CONFIG_HW_RANDOM_OMAP) += omap-rng.o
diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c
new file mode 100644
index 000000000000..819516b35a79
--- /dev/null
+++ b/drivers/char/hw_random/omap-rng.c
@@ -0,0 +1,208 @@
1/*
2 * driver/char/hw_random/omap-rng.c
3 *
4 * RNG driver for TI OMAP CPU family
5 *
6 * Author: Deepak Saxena <dsaxena@plexity.net>
7 *
8 * Copyright 2005 (c) MontaVista Software, Inc.
9 *
10 * Mostly based on original driver:
11 *
12 * Copyright (C) 2005 Nokia Corporation
13 * Author: Juha Yrj��<juha.yrjola@nokia.com>
14 *
15 * This file is licensed under the terms of the GNU General Public
16 * License version 2. This program is licensed "as is" without any
17 * warranty of any kind, whether express or implied.
18 *
19 * TODO:
20 *
21 * - Make status updated be interrupt driven so we don't poll
22 *
23 */
24
25#include <linux/module.h>
26#include <linux/init.h>
27#include <linux/random.h>
28#include <linux/err.h>
29#include <linux/device.h>
30#include <linux/hw_random.h>
31
32#include <asm/io.h>
33#include <asm/hardware/clock.h>
34
35#define RNG_OUT_REG 0x00 /* Output register */
36#define RNG_STAT_REG 0x04 /* Status register
37 [0] = STAT_BUSY */
38#define RNG_ALARM_REG 0x24 /* Alarm register
39 [7:0] = ALARM_COUNTER */
40#define RNG_CONFIG_REG 0x28 /* Configuration register
41 [11:6] = RESET_COUNT
42 [5:3] = RING2_DELAY
43 [2:0] = RING1_DELAY */
44#define RNG_REV_REG 0x3c /* Revision register
45 [7:0] = REV_NB */
46#define RNG_MASK_REG 0x40 /* Mask and reset register
47 [2] = IT_EN
48 [1] = SOFTRESET
49 [0] = AUTOIDLE */
50#define RNG_SYSSTATUS 0x44 /* System status
51 [0] = RESETDONE */
52
53static void __iomem *rng_base;
54static struct clk *rng_ick;
55static struct device *rng_dev;
56
57static u32 omap_rng_read_reg(int reg)
58{
59 return __raw_readl(rng_base + reg);
60}
61
62static void omap_rng_write_reg(int reg, u32 val)
63{
64 __raw_writel(val, rng_base + reg);
65}
66
67/* REVISIT: Does the status bit really work on 16xx? */
68static int omap_rng_data_present(struct hwrng *rng)
69{
70 return omap_rng_read_reg(RNG_STAT_REG) ? 0 : 1;
71}
72
73static int omap_rng_data_read(struct hwrng *rng, u32 *data)
74{
75 *data = omap_rng_read_reg(RNG_OUT_REG);
76
77 return 4;
78}
79
80static struct hwrng omap_rng_ops = {
81 .name = "omap",
82 .data_present = omap_rng_data_present,
83 .data_read = omap_rng_data_read,
84};
85
86static int __init omap_rng_probe(struct device *dev)
87{
88 struct platform_device *pdev = to_platform_device(dev);
89 struct resource *res, *mem;
90 int ret;
91
92 /*
93 * A bit ugly, and it will never actually happen but there can
94 * be only one RNG and this catches any bork
95 */
96 BUG_ON(rng_dev);
97
98 if (cpu_is_omap24xx()) {
99 rng_ick = clk_get(NULL, "rng_ick");
100 if (IS_ERR(rng_ick)) {
101 dev_err(dev, "Could not get rng_ick\n");
102 ret = PTR_ERR(rng_ick);
103 return ret;
104 }
105 else {
106 clk_use(rng_ick);
107 }
108 }
109
110 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
111
112 if (!res)
113 return -ENOENT;
114
115 mem = request_mem_region(res->start, res->end - res->start + 1,
116 pdev->name);
117 if (mem == NULL)
118 return -EBUSY;
119
120 dev_set_drvdata(dev, mem);
121 rng_base = (u32 __iomem *)io_p2v(res->start);
122
123 ret = hwrng_register(&omap_rng_ops);
124 if (ret) {
125 release_resource(mem);
126 rng_base = NULL;
127 return ret;
128 }
129
130 dev_info(dev, "OMAP Random Number Generator ver. %02x\n",
131 omap_rng_read_reg(RNG_REV_REG));
132 omap_rng_write_reg(RNG_MASK_REG, 0x1);
133
134 rng_dev = dev;
135
136 return 0;
137}
138
139static int __exit omap_rng_remove(struct device *dev)
140{
141 struct resource *mem = dev_get_drvdata(dev);
142
143 hwrng_unregister(&omap_rng_ops);
144
145 omap_rng_write_reg(RNG_MASK_REG, 0x0);
146
147 if (cpu_is_omap24xx()) {
148 clk_unuse(rng_ick);
149 clk_put(rng_ick);
150 }
151
152 release_resource(mem);
153 rng_base = NULL;
154
155 return 0;
156}
157
158#ifdef CONFIG_PM
159
160static int omap_rng_suspend(struct device *dev, pm_message_t message, u32 level)
161{
162 omap_rng_write_reg(RNG_MASK_REG, 0x0);
163
164 return 0;
165}
166
167static int omap_rng_resume(struct device *dev, pm_message_t message, u32 level)
168{
169 omap_rng_write_reg(RNG_MASK_REG, 0x1);
170
171 return 1;
172}
173
174#else
175
176#define omap_rng_suspend NULL
177#define omap_rng_resume NULL
178
179#endif
180
181
182static struct device_driver omap_rng_driver = {
183 .name = "omap_rng",
184 .bus = &platform_bus_type,
185 .probe = omap_rng_probe,
186 .remove = __exit_p(omap_rng_remove),
187 .suspend = omap_rng_suspend,
188 .resume = omap_rng_resume
189};
190
191static int __init omap_rng_init(void)
192{
193 if (!cpu_is_omap16xx() && !cpu_is_omap24xx())
194 return -ENODEV;
195
196 return driver_register(&omap_rng_driver);
197}
198
199static void __exit omap_rng_exit(void)
200{
201 driver_unregister(&omap_rng_driver);
202}
203
204module_init(omap_rng_init);
205module_exit(omap_rng_exit);
206
207MODULE_AUTHOR("Deepak Saxena (and others)");
208MODULE_LICENSE("GPL");