Release 4.7 drivers/char/hw_random/omap-rng.c

/*
 * omap-rng.c - RNG driver for TI OMAP CPU family
 *
 * Author: Deepak Saxena <dsaxena@plexity.net>
 *
 * Copyright 2005 (c) MontaVista Software, Inc.
 *
 * Mostly based on original driver:
 *
 * Copyright (C) 2005 Nokia Corporation
 * Author: Juha Yrjölä <juha.yrjola@nokia.com>
 *
 * 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/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 <asm/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

enum {
	
RNG_OUTPUT_L_REG = 0,
	
RNG_OUTPUT_H_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_L_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_L_REG]	= 0x0,
	[RNG_OUTPUT_H_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,
};

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;
};



static inline u32 omap_rng_read(struct omap_rng_dev *priv, u16 reg)
{
	return __raw_readl(priv->base + priv->pdata->regs[reg]);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
michael buesch
michael buesch
14
43.75%
1
25.00%
lokesh vutla
lokesh vutla
10
31.25%
1
25.00%
paul walmsley
paul walmsley
7
21.88%
1
25.00%
david brownell
david brownell
1
3.12%
1
25.00%
Total
32
100.00%
4
100.00%



static inline void omap_rng_write(struct omap_rng_dev *priv, u16 reg,
				      u32 val)
{
	__raw_writel(val, priv->base + priv->pdata->regs[reg]);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
michael buesch
michael buesch
18
50.00%
1
25.00%
lokesh vutla
lokesh vutla
10
27.78%
1
25.00%
paul walmsley
paul walmsley
7
19.44%
1
25.00%
david brownell
david brownell
1
2.78%
1
25.00%
Total
36
100.00%
4
100.00%



static int omap_rng_data_present(struct hwrng *rng, int wait)
{
	struct omap_rng_dev *priv;
	int data, i;

	priv = (struct omap_rng_dev *)rng->priv;

	for (i = 0; i < 20; i++) {
		data = priv->pdata->data_present(priv);
		if (data || !wait)
			break;
		/* RNG produces data fast enough (2+ MBit/sec, even
                 * during "rngtest" loads, that these delays don't
                 * seem to trigger.  We *could* use the RNG IRQ, but
                 * that'd be higher overhead ... so why bother?
                 */
		udelay(10);
	}
	return data;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
lokesh vutla
lokesh vutla
54
69.23%
1
33.33%
patrick mchardy
patrick mchardy
14
17.95%
1
33.33%
paul walmsley
paul walmsley
10
12.82%
1
33.33%
Total
78
100.00%
3
100.00%



static int omap_rng_data_read(struct hwrng *rng, u32 *data)
{
	struct omap_rng_dev *priv;
	u32 data_size, i;

	priv = (struct omap_rng_dev *)rng->priv;
	data_size = priv->pdata->data_size;

	for (i = 0; i < data_size / sizeof(u32); i++)
		data[i] = omap_rng_read(priv, RNG_OUTPUT_L_REG + i);

	if (priv->pdata->regs[RNG_INTACK_REG])
		omap_rng_write(priv, RNG_INTACK_REG, RNG_REG_INTACK_RDY_MASK);
	return data_size;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
lokesh vutla
lokesh vutla
68
68.69%
1
50.00%
olof johansson
olof johansson
31
31.31%
1
50.00%
Total
99
100.00%
2
100.00%



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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
olof johansson
olof johansson
37
100.00%
1
100.00%
Total
37
100.00%
1
100.00%



static void omap_rng_cleanup(struct hwrng *rng)
{
	struct omap_rng_dev *priv;

	priv = (struct omap_rng_dev *)rng->priv;
	priv->pdata->cleanup(priv);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
olof johansson
olof johansson
36
100.00%
1
100.00%
Total
36
100.00%
1
100.00%


static struct hwrng omap_rng_ops = {
	.name		= "omap",
	.data_present	= omap_rng_data_present,
	.data_read	= omap_rng_data_read,
	.init		= omap_rng_init,
	.cleanup	= omap_rng_cleanup,
};



static inline u32 omap2_rng_data_present(struct omap_rng_dev *priv)
{
	return omap_rng_read(priv, RNG_STATUS_REG) ? 0 : 1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
olof johansson
olof johansson
24
100.00%
1
100.00%
Total
24
100.00%
1
100.00%



static int omap2_rng_init(struct omap_rng_dev *priv)
{
	omap_rng_write(priv, RNG_SYSCONFIG_REG, 0x1);
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
olof johansson
olof johansson
23
100.00%
1
100.00%
Total
23
100.00%
1
100.00%



static void omap2_rng_cleanup(struct omap_rng_dev *priv)
{
	omap_rng_write(priv, RNG_SYSCONFIG_REG, 0x0);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
olof johansson
olof johansson
20
100.00%
1
100.00%
Total
20
100.00%
1
100.00%


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,
};

#if defined(CONFIG_OF)


static inline u32 omap4_rng_data_present(struct omap_rng_dev *priv)
{
	return omap_rng_read(priv, RNG_STATUS_REG) & RNG_REG_STATUS_RDY;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
olof johansson
olof johansson
15
68.18%
1
50.00%
lokesh vutla
lokesh vutla
7
31.82%
1
50.00%
Total
22
100.00%
2
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
lokesh vutla
lokesh vutla
110
99.10%
1
50.00%
andre wolokita
andre wolokita
1
0.90%
1
50.00%
Total
111
100.00%
2
100.00%



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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
lokesh vutla
lokesh vutla
36
97.30%
1
50.00%
andre wolokita
andre wolokita
1
2.70%
1
50.00%
Total
37
100.00%
2
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
lokesh vutla
lokesh vutla
105
100.00%
1
100.00%
Total
105
100.00%
1
100.00%


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 const struct of_device_id omap_rng_of_match[] = {
		{
			.compatible	= "ti,omap2-rng",
			.data		= &omap2_rng_pdata,
                },
		{
			.compatible	= "ti,omap4-rng",
			.data		= &omap4_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)
{
	const struct of_device_id *match;
	struct device *dev = &pdev->dev;
	int irq, err;

	match = of_match_device(of_match_ptr(omap_rng_of_match), dev);
	if (!match) {
		dev_err(dev, "no compatible OF match\n");
		return -EINVAL;
	}
	priv->pdata = match->data;

	if (of_device_is_compatible(dev->of_node, "ti,omap4-rng")) {
		irq = platform_get_irq(pdev, 0);
		if (irq < 0) {
			dev_err(dev, "%s: error getting IRQ resource - %d\n",
				__func__, irq);
			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;
		}
		omap_rng_write(priv, RNG_INTMASK_REG, RNG_SHUTDOWN_OFLO_MASK);
	}
	return 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
lokesh vutla
lokesh vutla
156
91.23%
1
25.00%
patrick mchardy
patrick mchardy
10
5.85%
1
25.00%
michael buesch
michael buesch
4
2.34%
1
25.00%
paul walmsley
paul walmsley
1
0.58%
1
25.00%
Total
171
100.00%
4
100.00%

#else


static int of_get_omap_rng_device_details(struct omap_rng_dev *omap_rng,
					  struct platform_device *pdev)
{
	return -EINVAL;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
michael buesch
michael buesch
12
60.00%
1
50.00%
lokesh vutla
lokesh vutla
8
40.00%
1
50.00%
Total
20
100.00%
2
100.00%

#endif



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
lokesh vutla
lokesh vutla
22
100.00%
2
100.00%
Total
22
100.00%
2
100.00%



static int omap_rng_probe(struct platform_device *pdev)
{
	struct omap_rng_dev *priv;
	struct resource *res;
	struct device *dev = &pdev->dev;
	int ret;

	priv = devm_kzalloc(dev, sizeof(struct omap_rng_dev), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	omap_rng_ops.priv = (unsigned long)priv;
	platform_set_drvdata(pdev, priv);
	priv->dev = dev;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	priv->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(priv->base)) {
		ret = PTR_ERR(priv->base);
		goto err_ioremap;
	}

	pm_runtime_enable(&pdev->dev);
	pm_runtime_get_sync(&pdev->dev);

	ret = (dev->of_node) ? of_get_omap_rng_device_details(priv, pdev) :
				get_omap_rng_device_details(priv);
	if (ret)
		goto err_ioremap;

	ret = hwrng_register(&omap_rng_ops);
	if (ret)
		goto err_register;

	dev_info(&pdev->dev, "OMAP Random Number Generator ver. %02x\n",
		 omap_rng_read(priv, RNG_REV_REG));

	return 0;

err_register:
	priv->base = NULL;
	pm_runtime_disable(&pdev->dev);
err_ioremap:
	dev_err(dev, "initialization failed.\n");
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
paul walmsley
paul walmsley
67
28.88%
2
20.00%
lokesh vutla
lokesh vutla
61
26.29%
2
20.00%
michael buesch
michael buesch
56
24.14%
1
10.00%
russell king
russell king
26
11.21%
1
10.00%
david brownell
david brownell
11
4.74%
2
20.00%
thierry reding
thierry reding
10
4.31%
1
10.00%
jingoo han
jingoo han
1
0.43%
1
10.00%
Total
232
100.00%
10
100.00%



static int omap_rng_remove(struct platform_device *pdev)
{
	struct omap_rng_dev *priv = platform_get_drvdata(pdev);

	hwrng_unregister(&omap_rng_ops);

	priv->pdata->cleanup(priv);

	pm_runtime_put_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
michael buesch
michael buesch
26
47.27%
1
16.67%
paul walmsley
paul walmsley
20
36.36%
2
33.33%
lokesh vutla
lokesh vutla
6
10.91%
1
16.67%
david brownell
david brownell
2
3.64%
1
16.67%
jingoo han
jingoo han
1
1.82%
1
16.67%
Total
55
100.00%
6
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
michael buesch
michael buesch
15
38.46%
1
16.67%
paul walmsley
paul walmsley
15
38.46%
2
33.33%
lokesh vutla
lokesh vutla
6
15.38%
1
16.67%
rafael j. wysocki
rafael j. wysocki
2
5.13%
1
16.67%
dmitry torokhov
dmitry torokhov
1
2.56%
1
16.67%
Total
39
100.00%
6
100.00%



static int __maybe_unused omap_rng_resume(struct device *dev)
{
	struct omap_rng_dev *priv = dev_get_drvdata(dev);

	pm_runtime_get_sync(dev);
	priv->pdata->init(priv);

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
paul walmsley
paul walmsley
15
38.46%
2
28.57%
michael buesch
michael buesch
14
35.90%
1
14.29%
lokesh vutla
lokesh vutla
6
15.38%
1
14.29%
rafael j. wysocki
rafael j. wysocki
2
5.13%
1
14.29%
dmitry torokhov
dmitry torokhov
1
2.56%
1
14.29%
david brownell
david brownell
1
2.56%
1
14.29%
Total
39
100.00%
7
100.00%

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");
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
lokesh vutla
lokesh vutla
1084
58.72%
4
22.22%
olof johansson
olof johansson
259
14.03%
1
5.56%
michael buesch
michael buesch
235
12.73%
1
5.56%
paul walmsley
paul walmsley
153
8.29%
2
11.11%
david brownell
david brownell
27
1.46%
2
11.11%
patrick mchardy
patrick mchardy
27
1.46%
1
5.56%
russell king
russell king
26
1.41%
1
5.56%
rafael j. wysocki
rafael j. wysocki
17
0.92%
1
5.56%
thierry reding
thierry reding
10
0.54%
1
5.56%
dmitry torokhov
dmitry torokhov
4
0.22%
1
5.56%
jingoo han
jingoo han
2
0.11%
1
5.56%
andre wolokita
andre wolokita
2
0.11%
2
11.11%
Total
1846
100.00%
18
100.00%
  
Directory: drivers/char/hw_random

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.