diff options
Diffstat (limited to 'drivers/char/hw_random/omap-rng.c')
| -rw-r--r-- | drivers/char/hw_random/omap-rng.c | 455 | 
1 files changed, 347 insertions, 108 deletions
diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c index 06aad0831c7..f66ea258382 100644 --- a/drivers/char/hw_random/omap-rng.c +++ b/drivers/char/hw_random/omap-rng.c @@ -18,52 +18,137 @@  #include <linux/module.h>  #include <linux/init.h>  #include <linux/random.h> -#include <linux/clk.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_OUT_REG		0x00		/* Output register */ -#define RNG_STAT_REG		0x04		/* Status register -							[0] = STAT_BUSY */ -#define RNG_ALARM_REG		0x24		/* Alarm register -							[7:0] = ALARM_COUNTER */ -#define RNG_CONFIG_REG		0x28		/* Configuration register -							[11:6] = RESET_COUNT -							[5:3]  = RING2_DELAY -							[2:0]  = RING1_DELAY */ -#define RNG_REV_REG		0x3c		/* Revision register -							[7:0] = REV_NB */ -#define RNG_MASK_REG		0x40		/* Mask and reset register -							[2] = IT_EN -							[1] = SOFTRESET -							[0] = AUTOIDLE */ -#define RNG_SYSSTATUS		0x44		/* System status -							[0] = RESETDONE */ +#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 void __iomem *rng_base; -static struct clk *rng_ick; -static struct platform_device *rng_dev; +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); +}; -static inline u32 omap_rng_read_reg(int reg) +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(rng_base + reg); +	return __raw_readl(priv->base + priv->pdata->regs[reg]);  } -static inline void omap_rng_write_reg(int reg, u32 val) +static inline void omap_rng_write(struct omap_rng_dev *priv, u16 reg, +				      u32 val)  { -	__raw_writel(val, rng_base + reg); +	__raw_writel(val, priv->base + priv->pdata->regs[reg]);  }  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 = omap_rng_read_reg(RNG_STAT_REG) ? 0 : 1; +		data = priv->pdata->data_present(priv);  		if (data || !wait)  			break;  		/* RNG produces data fast enough (2+ MBit/sec, even @@ -78,154 +163,308 @@ static int omap_rng_data_present(struct hwrng *rng, int wait)  static int omap_rng_data_read(struct hwrng *rng, u32 *data)  { -	*data = omap_rng_read_reg(RNG_OUT_REG); +	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; +} + +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; -	return 4; +	priv = (struct omap_rng_dev *)rng->priv; +	priv->pdata->cleanup(priv);  }  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 int __devinit omap_rng_probe(struct platform_device *pdev) +static inline u32 omap2_rng_data_present(struct omap_rng_dev *priv)  { -	struct resource *res, *mem; -	int ret; +	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, +}; + +#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; +} + +static int omap4_rng_init(struct omap_rng_dev *priv) +{ +	u32 val; + +	/* Return if RNG is already running. */ +	if (omap_rng_read(priv, RNG_CONFIG_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_CONFIG_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;  	/* -	 * A bit ugly, and it will never actually happen but there can -	 * be only one RNG and this catches any bork +	 * 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.  	 */ -	if (rng_dev) -		return -EBUSY; - -	if (cpu_is_omap24xx()) { -		rng_ick = clk_get(&pdev->dev, "ick"); -		if (IS_ERR(rng_ick)) { -			dev_err(&pdev->dev, "Could not get rng_ick\n"); -			ret = PTR_ERR(rng_ick); -			return ret; -		} else -			clk_enable(rng_ick); -	} +	omap_rng_write(priv, RNG_ALARMMASK_REG, 0x0); +	omap_rng_write(priv, RNG_ALARMSTOP_REG, 0x0); -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0); +	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; -	if (!res) -		return -ENOENT; +	omap_rng_write(priv, RNG_FRODETUNE_REG, fro_detune); +	omap_rng_write(priv, RNG_FROENABLE_REG, fro_enable); -	mem = request_mem_region(res->start, resource_size(res), -				 pdev->name); -	if (mem == NULL) { -		ret = -EBUSY; -		goto err_region; +	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 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; +} +#else +static int of_get_omap_rng_device_details(struct omap_rng_dev *omap_rng, +					  struct platform_device *pdev) +{ +	return -EINVAL; +} +#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; +} -	dev_set_drvdata(&pdev->dev, mem); -	rng_base = ioremap(res->start, resource_size(res)); -	if (!rng_base) { -		ret = -ENOMEM; +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_reg(RNG_REV_REG)); -	omap_rng_write_reg(RNG_MASK_REG, 0x1); - -	rng_dev = pdev; +		 omap_rng_read(priv, RNG_REV_REG));  	return 0;  err_register: -	iounmap(rng_base); -	rng_base = NULL; +	priv->base = NULL; +	pm_runtime_disable(&pdev->dev);  err_ioremap: -	release_resource(mem); -err_region: -	if (cpu_is_omap24xx()) { -		clk_disable(rng_ick); -		clk_put(rng_ick); -	} +	dev_err(dev, "initialization failed.\n");  	return ret;  }  static int __exit omap_rng_remove(struct platform_device *pdev)  { -	struct resource *mem = dev_get_drvdata(&pdev->dev); +	struct omap_rng_dev *priv = platform_get_drvdata(pdev);  	hwrng_unregister(&omap_rng_ops); -	omap_rng_write_reg(RNG_MASK_REG, 0x0); +	priv->pdata->cleanup(priv); -	iounmap(rng_base); - -	if (cpu_is_omap24xx()) { -		clk_disable(rng_ick); -		clk_put(rng_ick); -	} - -	release_resource(mem); -	rng_base = NULL; +	pm_runtime_put_sync(&pdev->dev); +	pm_runtime_disable(&pdev->dev);  	return 0;  } -#ifdef CONFIG_PM +#ifdef CONFIG_PM_SLEEP -static int omap_rng_suspend(struct platform_device *pdev, pm_message_t message) +static int omap_rng_suspend(struct device *dev)  { -	omap_rng_write_reg(RNG_MASK_REG, 0x0); +	struct omap_rng_dev *priv = dev_get_drvdata(dev); + +	priv->pdata->cleanup(priv); +	pm_runtime_put_sync(dev); +  	return 0;  } -static int omap_rng_resume(struct platform_device *pdev) +static int omap_rng_resume(struct device *dev)  { -	omap_rng_write_reg(RNG_MASK_REG, 0x1); +	struct omap_rng_dev *priv = dev_get_drvdata(dev); + +	pm_runtime_get_sync(dev); +	priv->pdata->init(priv); +  	return 0;  } +static SIMPLE_DEV_PM_OPS(omap_rng_pm, omap_rng_suspend, omap_rng_resume); +#define	OMAP_RNG_PM	(&omap_rng_pm) +  #else -#define	omap_rng_suspend	NULL -#define	omap_rng_resume		NULL +#define	OMAP_RNG_PM	NULL  #endif -/* work with hotplug and coldplug */ -MODULE_ALIAS("platform:omap_rng"); -  static struct platform_driver omap_rng_driver = {  	.driver = {  		.name		= "omap_rng",  		.owner		= THIS_MODULE, +		.pm		= OMAP_RNG_PM, +		.of_match_table = of_match_ptr(omap_rng_of_match),  	},  	.probe		= omap_rng_probe,  	.remove		= __exit_p(omap_rng_remove), -	.suspend	= omap_rng_suspend, -	.resume		= omap_rng_resume  }; -static int __init omap_rng_init(void) -{ -	if (!cpu_is_omap16xx() && !cpu_is_omap24xx()) -		return -ENODEV; - -	return platform_driver_register(&omap_rng_driver); -} - -static void __exit omap_rng_exit(void) -{ -	platform_driver_unregister(&omap_rng_driver); -} - -module_init(omap_rng_init); -module_exit(omap_rng_exit); - +module_platform_driver(omap_rng_driver); +MODULE_ALIAS("platform:omap_rng");  MODULE_AUTHOR("Deepak Saxena (and others)");  MODULE_LICENSE("GPL");  | 
