| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| 552 | 97.70% | 3 | 50.00% | |
| 6 | 1.06% | 1 | 16.67% | |
| 5 | 0.88% | 1 | 16.67% | |
| 2 | 0.35% | 1 | 16.67% | |
| Total | 565 | 6 |
| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Lee Jones | 552 | 97.70% | 3 | 50.00% |
| Chuhong Yuan | 6 | 1.06% | 1 | 16.67% |
| Wei Yongjun | 5 | 0.88% | 1 | 16.67% |
| Thomas Gleixner | 2 | 0.35% | 1 | 16.67% |
| Total | 565 | 6 |
// SPDX-License-Identifier: GPL-2.0-only /* * ST Random Number Generator Driver ST's Platforms * * Author: Pankaj Dev: <pankaj.dev@st.com> * Lee Jones <lee.jones@linaro.org> * * Copyright (C) 2015 STMicroelectronics (R&D) Limited */ #include <linux/clk.h> #include <linux/delay.h> #include <linux/hw_random.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/slab.h> /* Registers */ #define ST_RNG_STATUS_REG 0x20 #define ST_RNG_DATA_REG 0x24 /* Registers fields */ #define ST_RNG_STATUS_BAD_SEQUENCE BIT(0) #define ST_RNG_STATUS_BAD_ALTERNANCE BIT(1) #define ST_RNG_STATUS_FIFO_FULL BIT(5) #define ST_RNG_SAMPLE_SIZE 2 /* 2 Byte (16bit) samples */ #define ST_RNG_FIFO_DEPTH 4 #define ST_RNG_FIFO_SIZE (ST_RNG_FIFO_DEPTH * ST_RNG_SAMPLE_SIZE) /* * Samples are documented to be available every 0.667us, so in theory * the 4 sample deep FIFO should take 2.668us to fill. However, during * thorough testing, it became apparent that filling the FIFO actually * takes closer to 12us. We then multiply by 2 in order to account for * the lack of udelay()'s reliability, suggested by Russell King. */ #define ST_RNG_FILL_FIFO_TIMEOUT (12 * 2) struct st_rng_data { void __iomem *base; struct clk *clk; struct hwrng ops; }; static int st_rng_read(struct hwrng *rng, void *data, size_t max, bool wait) { struct st_rng_data *ddata = (struct st_rng_data *)rng->priv; u32 status; int i; /* Wait until FIFO is full - max 4uS*/ for (i = 0; i < ST_RNG_FILL_FIFO_TIMEOUT; i++) { status = readl_relaxed(ddata->base + ST_RNG_STATUS_REG); if (status & ST_RNG_STATUS_FIFO_FULL) break; udelay(1); } if (i == ST_RNG_FILL_FIFO_TIMEOUT) return 0; for (i = 0; i < ST_RNG_FIFO_SIZE && i < max; i += 2) *(u16 *)(data + i) = readl_relaxed(ddata->base + ST_RNG_DATA_REG); return i; /* No of bytes read */ } static int st_rng_probe(struct platform_device *pdev) { struct st_rng_data *ddata; struct resource *res; struct clk *clk; void __iomem *base; int ret; ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL); if (!ddata) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(base)) return PTR_ERR(base); clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(clk)) return PTR_ERR(clk); ret = clk_prepare_enable(clk); if (ret) return ret; ddata->ops.priv = (unsigned long)ddata; ddata->ops.read = st_rng_read; ddata->ops.name = pdev->name; ddata->base = base; ddata->clk = clk; dev_set_drvdata(&pdev->dev, ddata); ret = devm_hwrng_register(&pdev->dev, &ddata->ops); if (ret) { dev_err(&pdev->dev, "Failed to register HW RNG\n"); clk_disable_unprepare(clk); return ret; } dev_info(&pdev->dev, "Successfully registered HW RNG\n"); return 0; } static int st_rng_remove(struct platform_device *pdev) { struct st_rng_data *ddata = dev_get_drvdata(&pdev->dev); clk_disable_unprepare(ddata->clk); return 0; } static const struct of_device_id st_rng_match[] = { { .compatible = "st,rng" }, {}, }; MODULE_DEVICE_TABLE(of, st_rng_match); static struct platform_driver st_rng_driver = { .driver = { .name = "st-hwrandom", .of_match_table = of_match_ptr(st_rng_match), }, .probe = st_rng_probe, .remove = st_rng_remove }; module_platform_driver(st_rng_driver); MODULE_AUTHOR("Pankaj Dev <pankaj.dev@st.com>"); MODULE_LICENSE("GPL v2");