projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blame
| Commit | Line | Data |
|---|---|---|
| b8cb3448 OJ |
1 | /* |
| 2 | * Copyright (C) 2006-2007 PA Semi, Inc | |
| 3 | * | |
| 4 | * Maintained by: Olof Johansson <olof@lixom.net> | |
| 5 | * | |
| 6 | * Driver for the PWRficient onchip rng | |
| 7 | * | |
| 8 | * This program is free software; you can redistribute it and/or modify | |
| 9 | * it under the terms of the GNU General Public License version 2 as | |
| 10 | * published by the Free Software Foundation. | |
| 11 | * | |
| 12 | * This program is distributed in the hope that it will be useful, | |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 15 | * GNU General Public License for more details. | |
| 16 | * | |
| 17 | * You should have received a copy of the GNU General Public License | |
| 18 | * along with this program; if not, write to the Free Software | |
| 19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 20 | */ | |
| 21 | ||
| 22 | #include <linux/module.h> | |
| 23 | #include <linux/kernel.h> | |
| 24 | #include <linux/platform_device.h> | |
| 25 | #include <linux/hw_random.h> | |
| 26 | #include <asm/of_platform.h> | |
| 27 | #include <asm/io.h> | |
| 28 | ||
| 29 | #define SDCRNG_CTL_REG 0x00 | |
| 30 | #define SDCRNG_CTL_FVLD_M 0x0000f000 | |
| 31 | #define SDCRNG_CTL_FVLD_S 12 | |
| 32 | #define SDCRNG_CTL_KSZ 0x00000800 | |
| 33 | #define SDCRNG_CTL_RSRC_CRG 0x00000010 | |
| 34 | #define SDCRNG_CTL_RSRC_RRG 0x00000000 | |
| 35 | #define SDCRNG_CTL_CE 0x00000004 | |
| 36 | #define SDCRNG_CTL_RE 0x00000002 | |
| 37 | #define SDCRNG_CTL_DR 0x00000001 | |
| 38 | #define SDCRNG_CTL_SELECT_RRG_RNG (SDCRNG_CTL_RE | SDCRNG_CTL_RSRC_RRG) | |
| 39 | #define SDCRNG_CTL_SELECT_CRG_RNG (SDCRNG_CTL_CE | SDCRNG_CTL_RSRC_CRG) | |
| 40 | #define SDCRNG_VAL_REG 0x20 | |
| 41 | ||
| 42 | #define MODULE_NAME "pasemi_rng" | |
| 43 | ||
| 44 | static int pasemi_rng_data_present(struct hwrng *rng) | |
| 45 | { | |
| 46 | void __iomem *rng_regs = (void __iomem *)rng->priv; | |
| 47 | ||
| 48 | return (in_le32(rng_regs + SDCRNG_CTL_REG) | |
| 49 | & SDCRNG_CTL_FVLD_M) ? 1 : 0; | |
| 50 | } | |
| 51 | ||
| 52 | static int pasemi_rng_data_read(struct hwrng *rng, u32 *data) | |
| 53 | { | |
| 54 | void __iomem *rng_regs = (void __iomem *)rng->priv; | |
| 55 | *data = in_le32(rng_regs + SDCRNG_VAL_REG); | |
| 56 | return 4; | |
| 57 | } | |
| 58 | ||
| 59 | static int pasemi_rng_init(struct hwrng *rng) | |
| 60 | { | |
| 61 | void __iomem *rng_regs = (void __iomem *)rng->priv; | |
| 62 | u32 ctl; | |
| 63 | ||
| 64 | ctl = SDCRNG_CTL_DR | SDCRNG_CTL_SELECT_RRG_RNG | SDCRNG_CTL_KSZ; | |
| 65 | out_le32(rng_regs + SDCRNG_CTL_REG, ctl); | |
| 66 | out_le32(rng_regs + SDCRNG_CTL_REG, ctl & ~SDCRNG_CTL_DR); | |
| 67 | ||
| 68 | return 0; | |
| 69 | } | |
| 70 | ||
| 71 | static void pasemi_rng_cleanup(struct hwrng *rng) | |
| 72 | { | |
| 73 | void __iomem *rng_regs = (void __iomem *)rng->priv; | |
| 74 | u32 ctl; | |
| 75 | ||
| 76 | ctl = SDCRNG_CTL_RE | SDCRNG_CTL_CE; | |
| 77 | out_le32(rng_regs + SDCRNG_CTL_REG, | |
| 78 | in_le32(rng_regs + SDCRNG_CTL_REG) & ~ctl); | |
| 79 | } | |
| 80 | ||
| 81 | static struct hwrng pasemi_rng = { | |
| 82 | .name = MODULE_NAME, | |
| 83 | .init = pasemi_rng_init, | |
| 84 | .cleanup = pasemi_rng_cleanup, | |
| 85 | .data_present = pasemi_rng_data_present, | |
| 86 | .data_read = pasemi_rng_data_read, | |
| 87 | }; | |
| 88 | ||
| 89 | static int __devinit rng_probe(struct of_device *ofdev, | |
| 90 | const struct of_device_id *match) | |
| 91 | { | |
| 92 | void __iomem *rng_regs; | |
| 93 | struct device_node *rng_np = ofdev->node; | |
| 94 | struct resource res; | |
| 95 | int err = 0; | |
| 96 | ||
| 97 | err = of_address_to_resource(rng_np, 0, &res); | |
| 98 | if (err) | |
| 99 | return -ENODEV; | |
| 100 | ||
| 101 | rng_regs = ioremap(res.start, 0x100); | |
| 102 | ||
| 103 | if (!rng_regs) | |
| 104 | return -ENOMEM; | |
| 105 | ||
| 106 | pasemi_rng.priv = (unsigned long)rng_regs; | |
| 107 | ||
| 108 | printk(KERN_INFO "Registering PA Semi RNG\n"); | |
| 109 | ||
| 110 | err = hwrng_register(&pasemi_rng); | |
| 111 | ||
| 112 | if (err) | |
| 113 | iounmap(rng_regs); | |
| 114 | ||
| 115 | return err; | |
| 116 | } | |
| 117 | ||
| 118 | static int __devexit rng_remove(struct of_device *dev) | |
| 119 | { | |
| 120 | void __iomem *rng_regs = (void __iomem *)pasemi_rng.priv; | |
| 121 | ||
| 122 | hwrng_unregister(&pasemi_rng); | |
| 123 | iounmap(rng_regs); | |
| 124 | ||
| 125 | return 0; | |
| 126 | } | |
| 127 | ||
| 128 | static struct of_device_id rng_match[] = { | |
| 129 | { | |
| 130 | .compatible = "1682m-rng", | |
| 131 | }, | |
| 132 | {}, | |
| 133 | }; | |
| 134 | ||
| 135 | static struct of_platform_driver rng_driver = { | |
| 136 | .name = "pasemi-rng", | |
| 137 | .match_table = rng_match, | |
| 138 | .probe = rng_probe, | |
| 139 | .remove = rng_remove, | |
| 140 | }; | |
| 141 | ||
| 142 | static int __init rng_init(void) | |
| 143 | { | |
| 144 | return of_register_platform_driver(&rng_driver); | |
| 145 | } | |
| 146 | module_init(rng_init); | |
| 147 | ||
| 148 | static void __exit rng_exit(void) | |
| 149 | { | |
| 150 | of_unregister_platform_driver(&rng_driver); | |
| 151 | } | |
| 152 | module_exit(rng_exit); | |
| 153 | ||
| 154 | MODULE_LICENSE("GPL"); | |
| 155 | MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>"); | |
| 156 | MODULE_DESCRIPTION("H/W RNG driver for PA Semi processor"); |