Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 | /* * omap3-rom-rng.c - RNG driver for TI OMAP3 CPU family * * Copyright (C) 2009 Nokia Corporation * Author: Juha Yrjola <juha.yrjola@solidboot.com> * * Copyright (C) 2013 Pali Rohár <pali@kernel.org> * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #include <linux/module.h> #include <linux/init.h> #include <linux/random.h> #include <linux/hw_random.h> #include <linux/workqueue.h> #include <linux/clk.h> #include <linux/err.h> #include <linux/io.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #define RNG_RESET 0x01 #define RNG_GEN_PRNG_HW_INIT 0x02 #define RNG_GEN_HW 0x08 struct omap_rom_rng { struct clk *clk; struct device *dev; struct hwrng ops; u32 (*rom_rng_call)(u32 ptr, u32 count, u32 flag); }; static int omap3_rom_rng_read(struct hwrng *rng, void *data, size_t max, bool w) { struct omap_rom_rng *ddata; u32 ptr; int r; ddata = (struct omap_rom_rng *)rng->priv; r = pm_runtime_get_sync(ddata->dev); if (r < 0) { pm_runtime_put_noidle(ddata->dev); return r; } ptr = virt_to_phys(data); r = ddata->rom_rng_call(ptr, 4, RNG_GEN_HW); if (r != 0) r = -EINVAL; else r = 4; pm_runtime_mark_last_busy(ddata->dev); pm_runtime_put_autosuspend(ddata->dev); return r; } static int __maybe_unused omap_rom_rng_runtime_suspend(struct device *dev) { struct omap_rom_rng *ddata; int r; ddata = dev_get_drvdata(dev); r = ddata->rom_rng_call(0, 0, RNG_RESET); if (r != 0) dev_err(dev, "reset failed: %d\n", r); clk_disable_unprepare(ddata->clk); return 0; } static int __maybe_unused omap_rom_rng_runtime_resume(struct device *dev) { struct omap_rom_rng *ddata; int r; ddata = dev_get_drvdata(dev); r = clk_prepare_enable(ddata->clk); if (r < 0) return r; r = ddata->rom_rng_call(0, 0, RNG_GEN_PRNG_HW_INIT); if (r != 0) { clk_disable_unprepare(ddata->clk); dev_err(dev, "HW init failed: %d\n", r); return -EIO; } return 0; } static void omap_rom_rng_finish(void *data) { struct omap_rom_rng *ddata = data; pm_runtime_dont_use_autosuspend(ddata->dev); pm_runtime_disable(ddata->dev); } static int omap3_rom_rng_probe(struct platform_device *pdev) { struct omap_rom_rng *ddata; int ret = 0; ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL); if (!ddata) return -ENOMEM; ddata->dev = &pdev->dev; ddata->ops.priv = (unsigned long)ddata; ddata->ops.name = "omap3-rom"; ddata->ops.read = of_device_get_match_data(&pdev->dev); ddata->ops.quality = 900; if (!ddata->ops.read) { dev_err(&pdev->dev, "missing rom code handler\n"); return -ENODEV; } dev_set_drvdata(ddata->dev, ddata); ddata->rom_rng_call = pdev->dev.platform_data; if (!ddata->rom_rng_call) { dev_err(ddata->dev, "rom_rng_call is NULL\n"); return -EINVAL; } ddata->clk = devm_clk_get(ddata->dev, "ick"); if (IS_ERR(ddata->clk)) { dev_err(ddata->dev, "unable to get RNG clock\n"); return PTR_ERR(ddata->clk); } pm_runtime_enable(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, 500); pm_runtime_use_autosuspend(&pdev->dev); ret = devm_add_action_or_reset(ddata->dev, omap_rom_rng_finish, ddata); if (ret) return ret; return devm_hwrng_register(ddata->dev, &ddata->ops); } static const struct of_device_id omap_rom_rng_match[] = { { .compatible = "nokia,n900-rom-rng", .data = omap3_rom_rng_read, }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, omap_rom_rng_match); static const struct dev_pm_ops omap_rom_rng_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(omap_rom_rng_runtime_suspend, omap_rom_rng_runtime_resume) }; static struct platform_driver omap3_rom_rng_driver = { .driver = { .name = "omap3-rom-rng", .of_match_table = omap_rom_rng_match, .pm = &omap_rom_rng_pm_ops, }, .probe = omap3_rom_rng_probe, }; module_platform_driver(omap3_rom_rng_driver); MODULE_ALIAS("platform:omap3-rom-rng"); MODULE_AUTHOR("Juha Yrjola"); MODULE_AUTHOR("Pali Rohár <pali@kernel.org>"); MODULE_LICENSE("GPL"); |