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- /*
- * omap-rng.c - RNG driver for TI OMAP CPU family
- *
- * Author: Deepak Saxena <[email protected]>
- *
- * Copyright 2005 (c) MontaVista Software, Inc.
- *
- * Mostly based on original driver:
- *
- * Copyright (C) 2005 Nokia Corporation
- * Author: Juha Yrjölä <[email protected]>
- *
- * 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/err.h>
- #include <linux/platform_device.h>
- #include <linux/hw_random.h>
- #include <linux/delay.h>
- #include <linux/kernel.h>
- #include <linux/slab.h>
- #include <linux/pm_runtime.h>
- #include <linux/of.h>
- #include <linux/of_device.h>
- #include <linux/of_address.h>
- #include <linux/interrupt.h>
- #include <linux/clk.h>
- #include <linux/io.h>
- #define RNG_REG_STATUS_RDY (1 << 0)
- #define RNG_REG_INTACK_RDY_MASK (1 << 0)
- #define RNG_REG_INTACK_SHUTDOWN_OFLO_MASK (1 << 1)
- #define RNG_SHUTDOWN_OFLO_MASK (1 << 1)
- #define RNG_CONTROL_STARTUP_CYCLES_SHIFT 16
- #define RNG_CONTROL_STARTUP_CYCLES_MASK (0xffff << 16)
- #define RNG_CONTROL_ENABLE_TRNG_SHIFT 10
- #define RNG_CONTROL_ENABLE_TRNG_MASK (1 << 10)
- #define RNG_CONFIG_MAX_REFIL_CYCLES_SHIFT 16
- #define RNG_CONFIG_MAX_REFIL_CYCLES_MASK (0xffff << 16)
- #define RNG_CONFIG_MIN_REFIL_CYCLES_SHIFT 0
- #define RNG_CONFIG_MIN_REFIL_CYCLES_MASK (0xff << 0)
- #define RNG_CONTROL_STARTUP_CYCLES 0xff
- #define RNG_CONFIG_MIN_REFIL_CYCLES 0x21
- #define RNG_CONFIG_MAX_REFIL_CYCLES 0x22
- #define RNG_ALARMCNT_ALARM_TH_SHIFT 0x0
- #define RNG_ALARMCNT_ALARM_TH_MASK (0xff << 0)
- #define RNG_ALARMCNT_SHUTDOWN_TH_SHIFT 16
- #define RNG_ALARMCNT_SHUTDOWN_TH_MASK (0x1f << 16)
- #define RNG_ALARM_THRESHOLD 0xff
- #define RNG_SHUTDOWN_THRESHOLD 0x4
- #define RNG_REG_FROENABLE_MASK 0xffffff
- #define RNG_REG_FRODETUNE_MASK 0xffffff
- #define OMAP2_RNG_OUTPUT_SIZE 0x4
- #define OMAP4_RNG_OUTPUT_SIZE 0x8
- #define EIP76_RNG_OUTPUT_SIZE 0x10
- /*
- * EIP76 RNG takes approx. 700us to produce 16 bytes of output data
- * as per testing results. And to account for the lack of udelay()'s
- * reliability, we keep the timeout as 1000us.
- */
- #define RNG_DATA_FILL_TIMEOUT 100
- enum {
- RNG_OUTPUT_0_REG = 0,
- RNG_OUTPUT_1_REG,
- RNG_OUTPUT_2_REG,
- RNG_OUTPUT_3_REG,
- RNG_STATUS_REG,
- RNG_INTMASK_REG,
- RNG_INTACK_REG,
- RNG_CONTROL_REG,
- RNG_CONFIG_REG,
- RNG_ALARMCNT_REG,
- RNG_FROENABLE_REG,
- RNG_FRODETUNE_REG,
- RNG_ALARMMASK_REG,
- RNG_ALARMSTOP_REG,
- RNG_REV_REG,
- RNG_SYSCONFIG_REG,
- };
- static const u16 reg_map_omap2[] = {
- [RNG_OUTPUT_0_REG] = 0x0,
- [RNG_STATUS_REG] = 0x4,
- [RNG_CONFIG_REG] = 0x28,
- [RNG_REV_REG] = 0x3c,
- [RNG_SYSCONFIG_REG] = 0x40,
- };
- static const u16 reg_map_omap4[] = {
- [RNG_OUTPUT_0_REG] = 0x0,
- [RNG_OUTPUT_1_REG] = 0x4,
- [RNG_STATUS_REG] = 0x8,
- [RNG_INTMASK_REG] = 0xc,
- [RNG_INTACK_REG] = 0x10,
- [RNG_CONTROL_REG] = 0x14,
- [RNG_CONFIG_REG] = 0x18,
- [RNG_ALARMCNT_REG] = 0x1c,
- [RNG_FROENABLE_REG] = 0x20,
- [RNG_FRODETUNE_REG] = 0x24,
- [RNG_ALARMMASK_REG] = 0x28,
- [RNG_ALARMSTOP_REG] = 0x2c,
- [RNG_REV_REG] = 0x1FE0,
- [RNG_SYSCONFIG_REG] = 0x1FE4,
- };
- static const u16 reg_map_eip76[] = {
- [RNG_OUTPUT_0_REG] = 0x0,
- [RNG_OUTPUT_1_REG] = 0x4,
- [RNG_OUTPUT_2_REG] = 0x8,
- [RNG_OUTPUT_3_REG] = 0xc,
- [RNG_STATUS_REG] = 0x10,
- [RNG_INTACK_REG] = 0x10,
- [RNG_CONTROL_REG] = 0x14,
- [RNG_CONFIG_REG] = 0x18,
- [RNG_ALARMCNT_REG] = 0x1c,
- [RNG_FROENABLE_REG] = 0x20,
- [RNG_FRODETUNE_REG] = 0x24,
- [RNG_ALARMMASK_REG] = 0x28,
- [RNG_ALARMSTOP_REG] = 0x2c,
- [RNG_REV_REG] = 0x7c,
- };
- struct omap_rng_dev;
- /**
- * struct omap_rng_pdata - RNG IP block-specific data
- * @regs: Pointer to the register offsets structure.
- * @data_size: No. of bytes in RNG output.
- * @data_present: Callback to determine if data is available.
- * @init: Callback for IP specific initialization sequence.
- * @cleanup: Callback for IP specific cleanup sequence.
- */
- struct omap_rng_pdata {
- u16 *regs;
- u32 data_size;
- u32 (*data_present)(struct omap_rng_dev *priv);
- int (*init)(struct omap_rng_dev *priv);
- void (*cleanup)(struct omap_rng_dev *priv);
- };
- struct omap_rng_dev {
- void __iomem *base;
- struct device *dev;
- const struct omap_rng_pdata *pdata;
- struct hwrng rng;
- struct clk *clk;
- struct clk *clk_reg;
- };
- static inline u32 omap_rng_read(struct omap_rng_dev *priv, u16 reg)
- {
- return __raw_readl(priv->base + priv->pdata->regs[reg]);
- }
- static inline void omap_rng_write(struct omap_rng_dev *priv, u16 reg,
- u32 val)
- {
- __raw_writel(val, priv->base + priv->pdata->regs[reg]);
- }
- static int omap_rng_do_read(struct hwrng *rng, void *data, size_t max,
- bool wait)
- {
- struct omap_rng_dev *priv;
- int i, present;
- priv = (struct omap_rng_dev *)rng->priv;
- if (max < priv->pdata->data_size)
- return 0;
- for (i = 0; i < RNG_DATA_FILL_TIMEOUT; i++) {
- present = priv->pdata->data_present(priv);
- if (present || !wait)
- break;
- udelay(10);
- }
- if (!present)
- return 0;
- memcpy_fromio(data, priv->base + priv->pdata->regs[RNG_OUTPUT_0_REG],
- priv->pdata->data_size);
- if (priv->pdata->regs[RNG_INTACK_REG])
- omap_rng_write(priv, RNG_INTACK_REG, RNG_REG_INTACK_RDY_MASK);
- return priv->pdata->data_size;
- }
- static int omap_rng_init(struct hwrng *rng)
- {
- struct omap_rng_dev *priv;
- priv = (struct omap_rng_dev *)rng->priv;
- return priv->pdata->init(priv);
- }
- static void omap_rng_cleanup(struct hwrng *rng)
- {
- struct omap_rng_dev *priv;
- priv = (struct omap_rng_dev *)rng->priv;
- priv->pdata->cleanup(priv);
- }
- static inline u32 omap2_rng_data_present(struct omap_rng_dev *priv)
- {
- return omap_rng_read(priv, RNG_STATUS_REG) ? 0 : 1;
- }
- static int omap2_rng_init(struct omap_rng_dev *priv)
- {
- omap_rng_write(priv, RNG_SYSCONFIG_REG, 0x1);
- return 0;
- }
- static void omap2_rng_cleanup(struct omap_rng_dev *priv)
- {
- omap_rng_write(priv, RNG_SYSCONFIG_REG, 0x0);
- }
- static struct omap_rng_pdata omap2_rng_pdata = {
- .regs = (u16 *)reg_map_omap2,
- .data_size = OMAP2_RNG_OUTPUT_SIZE,
- .data_present = omap2_rng_data_present,
- .init = omap2_rng_init,
- .cleanup = omap2_rng_cleanup,
- };
- static inline u32 omap4_rng_data_present(struct omap_rng_dev *priv)
- {
- return omap_rng_read(priv, RNG_STATUS_REG) & RNG_REG_STATUS_RDY;
- }
- static int eip76_rng_init(struct omap_rng_dev *priv)
- {
- u32 val;
- /* Return if RNG is already running. */
- if (omap_rng_read(priv, RNG_CONTROL_REG) & RNG_CONTROL_ENABLE_TRNG_MASK)
- return 0;
- /* Number of 512 bit blocks of raw Noise Source output data that must
- * be processed by either the Conditioning Function or the
- * SP 800-90 DRBG ‘BC_DF’ functionality to yield a ‘full entropy’
- * output value.
- */
- val = 0x5 << RNG_CONFIG_MIN_REFIL_CYCLES_SHIFT;
- /* Number of FRO samples that are XOR-ed together into one bit to be
- * shifted into the main shift register
- */
- val |= RNG_CONFIG_MAX_REFIL_CYCLES << RNG_CONFIG_MAX_REFIL_CYCLES_SHIFT;
- omap_rng_write(priv, RNG_CONFIG_REG, val);
- /* Enable all available FROs */
- omap_rng_write(priv, RNG_FRODETUNE_REG, 0x0);
- omap_rng_write(priv, RNG_FROENABLE_REG, RNG_REG_FROENABLE_MASK);
- /* Enable TRNG */
- val = RNG_CONTROL_ENABLE_TRNG_MASK;
- omap_rng_write(priv, RNG_CONTROL_REG, val);
- return 0;
- }
- static int omap4_rng_init(struct omap_rng_dev *priv)
- {
- u32 val;
- /* Return if RNG is already running. */
- if (omap_rng_read(priv, RNG_CONTROL_REG) & RNG_CONTROL_ENABLE_TRNG_MASK)
- return 0;
- val = RNG_CONFIG_MIN_REFIL_CYCLES << RNG_CONFIG_MIN_REFIL_CYCLES_SHIFT;
- val |= RNG_CONFIG_MAX_REFIL_CYCLES << RNG_CONFIG_MAX_REFIL_CYCLES_SHIFT;
- omap_rng_write(priv, RNG_CONFIG_REG, val);
- omap_rng_write(priv, RNG_FRODETUNE_REG, 0x0);
- omap_rng_write(priv, RNG_FROENABLE_REG, RNG_REG_FROENABLE_MASK);
- val = RNG_ALARM_THRESHOLD << RNG_ALARMCNT_ALARM_TH_SHIFT;
- val |= RNG_SHUTDOWN_THRESHOLD << RNG_ALARMCNT_SHUTDOWN_TH_SHIFT;
- omap_rng_write(priv, RNG_ALARMCNT_REG, val);
- val = RNG_CONTROL_STARTUP_CYCLES << RNG_CONTROL_STARTUP_CYCLES_SHIFT;
- val |= RNG_CONTROL_ENABLE_TRNG_MASK;
- omap_rng_write(priv, RNG_CONTROL_REG, val);
- return 0;
- }
- static void omap4_rng_cleanup(struct omap_rng_dev *priv)
- {
- int val;
- val = omap_rng_read(priv, RNG_CONTROL_REG);
- val &= ~RNG_CONTROL_ENABLE_TRNG_MASK;
- omap_rng_write(priv, RNG_CONTROL_REG, val);
- }
- static irqreturn_t omap4_rng_irq(int irq, void *dev_id)
- {
- struct omap_rng_dev *priv = dev_id;
- u32 fro_detune, fro_enable;
- /*
- * Interrupt raised by a fro shutdown threshold, do the following:
- * 1. Clear the alarm events.
- * 2. De tune the FROs which are shutdown.
- * 3. Re enable the shutdown FROs.
- */
- omap_rng_write(priv, RNG_ALARMMASK_REG, 0x0);
- omap_rng_write(priv, RNG_ALARMSTOP_REG, 0x0);
- fro_enable = omap_rng_read(priv, RNG_FROENABLE_REG);
- fro_detune = ~fro_enable & RNG_REG_FRODETUNE_MASK;
- fro_detune = fro_detune | omap_rng_read(priv, RNG_FRODETUNE_REG);
- fro_enable = RNG_REG_FROENABLE_MASK;
- omap_rng_write(priv, RNG_FRODETUNE_REG, fro_detune);
- omap_rng_write(priv, RNG_FROENABLE_REG, fro_enable);
- omap_rng_write(priv, RNG_INTACK_REG, RNG_REG_INTACK_SHUTDOWN_OFLO_MASK);
- return IRQ_HANDLED;
- }
- static struct omap_rng_pdata omap4_rng_pdata = {
- .regs = (u16 *)reg_map_omap4,
- .data_size = OMAP4_RNG_OUTPUT_SIZE,
- .data_present = omap4_rng_data_present,
- .init = omap4_rng_init,
- .cleanup = omap4_rng_cleanup,
- };
- static struct omap_rng_pdata eip76_rng_pdata = {
- .regs = (u16 *)reg_map_eip76,
- .data_size = EIP76_RNG_OUTPUT_SIZE,
- .data_present = omap4_rng_data_present,
- .init = eip76_rng_init,
- .cleanup = omap4_rng_cleanup,
- };
- static const struct of_device_id omap_rng_of_match[] __maybe_unused = {
- {
- .compatible = "ti,omap2-rng",
- .data = &omap2_rng_pdata,
- },
- {
- .compatible = "ti,omap4-rng",
- .data = &omap4_rng_pdata,
- },
- {
- .compatible = "inside-secure,safexcel-eip76",
- .data = &eip76_rng_pdata,
- },
- {},
- };
- MODULE_DEVICE_TABLE(of, omap_rng_of_match);
- static int of_get_omap_rng_device_details(struct omap_rng_dev *priv,
- struct platform_device *pdev)
- {
- struct device *dev = &pdev->dev;
- int irq, err;
- priv->pdata = of_device_get_match_data(dev);
- if (!priv->pdata)
- return -ENODEV;
- if (of_device_is_compatible(dev->of_node, "ti,omap4-rng") ||
- of_device_is_compatible(dev->of_node, "inside-secure,safexcel-eip76")) {
- irq = platform_get_irq(pdev, 0);
- if (irq < 0)
- return irq;
- err = devm_request_irq(dev, irq, omap4_rng_irq,
- IRQF_TRIGGER_NONE, dev_name(dev), priv);
- if (err) {
- dev_err(dev, "unable to request irq %d, err = %d\n",
- irq, err);
- return err;
- }
- /*
- * On OMAP4, enabling the shutdown_oflo interrupt is
- * done in the interrupt mask register. There is no
- * such register on EIP76, and it's enabled by the
- * same bit in the control register
- */
- if (priv->pdata->regs[RNG_INTMASK_REG])
- omap_rng_write(priv, RNG_INTMASK_REG,
- RNG_SHUTDOWN_OFLO_MASK);
- else
- omap_rng_write(priv, RNG_CONTROL_REG,
- RNG_SHUTDOWN_OFLO_MASK);
- }
- return 0;
- }
- static int get_omap_rng_device_details(struct omap_rng_dev *omap_rng)
- {
- /* Only OMAP2/3 can be non-DT */
- omap_rng->pdata = &omap2_rng_pdata;
- return 0;
- }
- static int omap_rng_probe(struct platform_device *pdev)
- {
- struct omap_rng_dev *priv;
- struct device *dev = &pdev->dev;
- int ret;
- priv = devm_kzalloc(dev, sizeof(struct omap_rng_dev), GFP_KERNEL);
- if (!priv)
- return -ENOMEM;
- priv->rng.read = omap_rng_do_read;
- priv->rng.init = omap_rng_init;
- priv->rng.cleanup = omap_rng_cleanup;
- priv->rng.quality = 900;
- priv->rng.priv = (unsigned long)priv;
- platform_set_drvdata(pdev, priv);
- priv->dev = dev;
- priv->base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(priv->base)) {
- ret = PTR_ERR(priv->base);
- goto err_ioremap;
- }
- priv->rng.name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL);
- if (!priv->rng.name) {
- ret = -ENOMEM;
- goto err_ioremap;
- }
- pm_runtime_enable(&pdev->dev);
- ret = pm_runtime_resume_and_get(&pdev->dev);
- if (ret < 0) {
- dev_err(&pdev->dev, "Failed to runtime_get device: %d\n", ret);
- goto err_ioremap;
- }
- priv->clk = devm_clk_get(&pdev->dev, NULL);
- if (PTR_ERR(priv->clk) == -EPROBE_DEFER)
- return -EPROBE_DEFER;
- if (!IS_ERR(priv->clk)) {
- ret = clk_prepare_enable(priv->clk);
- if (ret) {
- dev_err(&pdev->dev,
- "Unable to enable the clk: %d\n", ret);
- goto err_register;
- }
- }
- priv->clk_reg = devm_clk_get(&pdev->dev, "reg");
- if (PTR_ERR(priv->clk_reg) == -EPROBE_DEFER)
- return -EPROBE_DEFER;
- if (!IS_ERR(priv->clk_reg)) {
- ret = clk_prepare_enable(priv->clk_reg);
- if (ret) {
- dev_err(&pdev->dev,
- "Unable to enable the register clk: %d\n",
- ret);
- goto err_register;
- }
- }
- ret = (dev->of_node) ? of_get_omap_rng_device_details(priv, pdev) :
- get_omap_rng_device_details(priv);
- if (ret)
- goto err_register;
- ret = devm_hwrng_register(&pdev->dev, &priv->rng);
- if (ret)
- goto err_register;
- dev_info(&pdev->dev, "Random Number Generator ver. %02x\n",
- omap_rng_read(priv, RNG_REV_REG));
- return 0;
- err_register:
- priv->base = NULL;
- pm_runtime_put_sync(&pdev->dev);
- pm_runtime_disable(&pdev->dev);
- clk_disable_unprepare(priv->clk_reg);
- clk_disable_unprepare(priv->clk);
- err_ioremap:
- dev_err(dev, "initialization failed.\n");
- return ret;
- }
- static int omap_rng_remove(struct platform_device *pdev)
- {
- struct omap_rng_dev *priv = platform_get_drvdata(pdev);
- priv->pdata->cleanup(priv);
- pm_runtime_put_sync(&pdev->dev);
- pm_runtime_disable(&pdev->dev);
- clk_disable_unprepare(priv->clk);
- clk_disable_unprepare(priv->clk_reg);
- return 0;
- }
- static int __maybe_unused omap_rng_suspend(struct device *dev)
- {
- struct omap_rng_dev *priv = dev_get_drvdata(dev);
- priv->pdata->cleanup(priv);
- pm_runtime_put_sync(dev);
- return 0;
- }
- static int __maybe_unused omap_rng_resume(struct device *dev)
- {
- struct omap_rng_dev *priv = dev_get_drvdata(dev);
- int ret;
- ret = pm_runtime_resume_and_get(dev);
- if (ret < 0) {
- dev_err(dev, "Failed to runtime_get device: %d\n", ret);
- return ret;
- }
- priv->pdata->init(priv);
- return 0;
- }
- static SIMPLE_DEV_PM_OPS(omap_rng_pm, omap_rng_suspend, omap_rng_resume);
- static struct platform_driver omap_rng_driver = {
- .driver = {
- .name = "omap_rng",
- .pm = &omap_rng_pm,
- .of_match_table = of_match_ptr(omap_rng_of_match),
- },
- .probe = omap_rng_probe,
- .remove = omap_rng_remove,
- };
- module_platform_driver(omap_rng_driver);
- MODULE_ALIAS("platform:omap_rng");
- MODULE_AUTHOR("Deepak Saxena (and others)");
- MODULE_LICENSE("GPL");
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