[PATCH 1/2] sam9g45: add trng clock and platform device

[PATCH 1/2] sam9g45: add trng clock and platform device

[Peter Korsgaard]

For the new hw_random driver.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
---
 arch/arm/mach-at91/at91sam9g45.c         |    7 +++++++
 arch/arm/mach-at91/at91sam9g45_devices.c |   29 +++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9g45.c b/arch/arm/mach-at91/at91sam9g45.c
index 6da8ace..6850f1d 100644
--- a/arch/arm/mach-at91/at91sam9g45.c
+++ b/arch/arm/mach-at91/at91sam9g45.c
@@ -54,6 +54,11 @@ static struct clk pioDE_clk = {
 	.pmc_mask	= 1 << AT91SAM9G45_ID_PIODE,
 	.type		= CLK_TYPE_PERIPHERAL,
 };
+static struct clk trng_clk = {
+	.name		= "trng_clk",
+	.pmc_mask	= 1 << AT91SAM9G45_ID_TRNG,
+	.type		= CLK_TYPE_PERIPHERAL,
+};
 static struct clk usart0_clk = {
 	.name		= "usart0_clk",
 	.pmc_mask	= 1 << AT91SAM9G45_ID_US0,
@@ -177,6 +182,7 @@ static struct clk *periph_clocks[] __initdata = {
 	&pioB_clk,
 	&pioC_clk,
 	&pioDE_clk,
+	&trng_clk,
 	&usart0_clk,
 	&usart1_clk,
 	&usart2_clk,
@@ -216,6 +222,7 @@ static struct clk_lookup periph_clocks_lookups[] = {
 	CLKDEV_CON_DEV_ID("t0_clk", "atmel_tcb.1", &tcb0_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc0_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
+	CLKDEV_CON_DEV_ID(NULL, "atmel-trng", &trng_clk),
 	/* fake hclk clock */
 	CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &uhphs_clk),
 };
diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index 2ee20bd..1ca6c62 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -1101,6 +1101,34 @@ static void __init at91_add_device_rtt(void)
 
 
 /* --------------------------------------------------------------------
+ *  TRNG
+ * -------------------------------------------------------------------- */
+
+#if defined(CONFIG_HW_RANDOM_ATMEL) || defined(CONFIG_HW_RANDOM_ATMEL_MODULE)
+static struct resource trng_resources[] = {
+	{
+		.start	= AT91SAM9G45_BASE_TRNG,
+		.end	= AT91SAM9G45_BASE_TRNG + SZ_16K - 1,
+		.flags	= IORESOURCE_MEM,
+	},
+};
+
+static struct platform_device at91sam9g45_trng_device = {
+	.name		= "atmel-trng",
+	.id		= -1,
+	.resource	= trng_resources,
+	.num_resources	= ARRAY_SIZE(trng_resources),
+};
+
+static void __init at91_add_device_trng(void)
+{
+	platform_device_register(&at91sam9g45_trng_device);
+}
+#else
+static void __init at91_add_device_trng(void) {}
+#endif
+
+/* --------------------------------------------------------------------
  *  Watchdog
  * -------------------------------------------------------------------- */
 
@@ -1589,6 +1617,7 @@ static int __init at91_add_standard_devices(void)
 	at91_add_device_hdmac();
 	at91_add_device_rtc();
 	at91_add_device_rtt();
+	at91_add_device_trng();
 	at91_add_device_watchdog();
 	at91_add_device_tc();
 	return 0;
-- 
1.7.6.3

[PATCH 2/2] hw_random: add driver for atmel true hardware random number generator

[Peter Korsgaard]

For the IP block on 9g45/9g46/9m10/9m11.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
---
 drivers/char/hw_random/Kconfig     |   13 +++
 drivers/char/hw_random/Makefile    |    1 +
 drivers/char/hw_random/atmel-rng.c |  168 ++++++++++++++++++++++++++++++++++++
 3 files changed, 182 insertions(+), 0 deletions(-)
 create mode 100644 drivers/char/hw_random/atmel-rng.c

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 1d2ebc7..e013587 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -60,6 +60,19 @@ config HW_RANDOM_AMD
 
 	  If unsure, say Y.
 
+config HW_RANDOM_ATMEL
+	tristate "Atmel Random Number Generator support"
+	depends on HW_RANDOM && ARCH_AT91SAM9G45
+	default HW_RANDOM
+	---help---
+	  This driver provides kernel-side support for the Random Number
+	  Generator hardware found on Atmel AT91 devices.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called atmel-rng.
+
+	  If unsure, say Y.
+
 config HW_RANDOM_GEODE
 	tristate "AMD Geode HW Random Number Generator support"
 	depends on HW_RANDOM && X86_32 && PCI
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index c88f244..b2ff526 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -7,6 +7,7 @@ rng-core-y := core.o
 obj-$(CONFIG_HW_RANDOM_TIMERIOMEM) += timeriomem-rng.o
 obj-$(CONFIG_HW_RANDOM_INTEL) += intel-rng.o
 obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o
+obj-$(CONFIG_HW_RANDOM_ATMEL) += atmel-rng.o
 obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
 obj-$(CONFIG_HW_RANDOM_N2RNG) += n2-rng.o
 n2-rng-y := n2-drv.o n2-asm.o
diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c
new file mode 100644
index 0000000..c69eccb
--- /dev/null
+++ b/drivers/char/hw_random/atmel-rng.c
@@ -0,0 +1,168 @@
+/*
+ * Copyright (c) 2011 Peter Korsgaard <jacmet@sunsite.dk>
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/hw_random.h>
+#include <linux/platform_device.h>
+
+#define TRNG_CR		0x00
+#define TRNG_ISR	0x1c
+#define TRNG_ODATA	0x50
+
+#define TRNG_KEY	0x524e4700 /* RNG */
+
+struct atmel_trng {
+	struct clk *clk;
+	void __iomem *base;
+};
+
+static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max,
+			   bool wait)
+{
+	struct atmel_trng *trng = (struct atmel_trng *)rng->priv;
+	u32 *data = buf;
+
+	/* data ready? */
+	if (readl(trng->base + TRNG_ODATA) & 1) {
+		*data = readl(trng->base + TRNG_ODATA);
+		return 4;
+	} else
+		return 0;
+}
+
+static struct hwrng atmel_trng = {
+	.name	= "atmel-trng",
+	.read	= atmel_trng_read,
+};
+
+static int atmel_trng_probe(struct platform_device *pdev)
+{
+	struct atmel_trng *trng;
+	struct resource *res;
+	int ret;
+
+	if (atmel_trng.priv) {
+		dev_err(&pdev->dev, "multiple instances not supported\n");
+		return -EBUSY;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
+	if (!trng)
+		return -ENOMEM;
+
+	if (!devm_request_mem_region(&pdev->dev, res->start,
+				     resource_size(res), pdev->name))
+		return -EBUSY;
+
+	trng->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (!trng->base)
+		return -EBUSY;
+
+	trng->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(trng->clk))
+		return PTR_ERR(trng->clk);
+
+	ret = clk_enable(trng->clk);
+	if (ret)
+		goto err_enable;
+
+	writel(TRNG_KEY | 1, trng->base + TRNG_CR);
+
+	atmel_trng.priv = (unsigned long)trng;
+
+	ret = hwrng_register(&atmel_trng);
+	if (ret)
+		goto err_register;
+
+	platform_set_drvdata(pdev, trng);
+
+	return 0;
+
+err_register:
+	atmel_trng.priv = 0;
+	clk_disable(trng->clk);
+err_enable:
+	clk_put(trng->clk);
+
+	return ret;
+}
+
+static int __devexit atmel_trng_remove(struct platform_device *pdev)
+{
+	struct atmel_trng *trng = platform_get_drvdata(pdev);
+
+	hwrng_unregister(&atmel_trng);
+
+	writel(TRNG_KEY, trng->base + TRNG_CR);
+	clk_disable(trng->clk);
+	clk_put(trng->clk);
+
+	atmel_trng.priv = 0;
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int atmel_trng_suspend(struct device *dev)
+{
+	struct atmel_trng *trng = dev_get_drvdata(dev);
+
+	clk_disable(trng->clk);
+
+	return 0;
+}
+
+static int atmel_trng_resume(struct device *dev)
+{
+	struct atmel_trng *trng = dev_get_drvdata(dev);
+
+	return clk_enable(trng->clk);
+}
+
+static const struct dev_pm_ops atmel_trng_pm_ops = {
+	.suspend	= atmel_trng_suspend,
+	.resume		= atmel_trng_resume,
+};
+#endif /* CONFIG_PM */
+
+static struct platform_driver atmel_trng_driver = {
+	.probe		= atmel_trng_probe,
+	.remove		= __devexit_p(atmel_trng_remove),
+	.driver		= {
+		.name	= "atmel-trng",
+		.owner	= THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm	= &atmel_trng_pm_ops,
+#endif /* CONFIG_PM */
+	},
+};
+
+static int __init atmel_trng_init(void)
+{
+	return platform_driver_register(&atmel_trng_driver);
+}
+module_init(atmel_trng_init);
+
+static void __exit atmel_trng_exit(void)
+{
+	platform_driver_unregister(&atmel_trng_driver);
+}
+module_exit(atmel_trng_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
+MODULE_DESCRIPTION("Atmel true random number generator driver");
-- 
1.7.6.3

[PATCH 2/2] hw_random: add driver for atmel true hardware random number generator

[Mark Brown]

On Thu, Oct 06, 2011 at 05:41:34PM +0200, Peter Korsgaard wrote:

> +	trng->clk = clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(trng->clk))
> +		return PTR_ERR(trng->clk);
> +
> +	ret = clk_enable(trng->clk);
> +	if (ret)
> +		goto err_enable;

Is it worth enabling the hardware enabled only when the device is open?

[PATCH 2/2] hw_random: add driver for atmel true hardware random number generator

[Peter Korsgaard]

>>>>> "Mark" == Mark Brown <broonie@opensource.wolfsonmicro.com> writes:

 Mark> On Thu, Oct 06, 2011 at 05:41:34PM +0200, Peter Korsgaard wrote:
 >> +	trng->clk = clk_get(&pdev->dev, NULL);
 >> +	if (IS_ERR(trng->clk))
 >> +		return PTR_ERR(trng->clk);
 >> +
 >> +	ret = clk_enable(trng->clk);
 >> +	if (ret)
 >> +		goto err_enable;

 Mark> Is it worth enabling the hardware enabled only when the device is open?

Potentially, though I doubt it uses significant power. I kept it like
this for simplicity, to match the other drivers and because hw_random
doesn't have an open/close callback (init is called right away in
hwrng_register or on current change).

-- 
Bye, Peter Korsgaard

[PATCH 2/2] hw_random: add driver for atmel true hardware random number generator

[Jamie Iles]

Hi Peter,

A couple of minor nits inline, but otherwise looks nice to me!

Jamie

On Thu, Oct 06, 2011 at 05:41:34PM +0200, Peter Korsgaard wrote:
> diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c
> new file mode 100644
> index 0000000..c69eccb
> --- /dev/null
> +++ b/drivers/char/hw_random/atmel-rng.c
> @@ -0,0 +1,168 @@
> +/*
> + * Copyright (c) 2011 Peter Korsgaard <jacmet@sunsite.dk>
> + *
> + * 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/kernel.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/err.h>
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/hw_random.h>
> +#include <linux/platform_device.h>
> +
> +#define TRNG_CR		0x00
> +#define TRNG_ISR	0x1c
> +#define TRNG_ODATA	0x50
> +
> +#define TRNG_KEY	0x524e4700 /* RNG */
> +
> +struct atmel_trng {
> +	struct clk *clk;
> +	void __iomem *base;
> +};
> +
> +static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max,
> +			   bool wait)
> +{
> +	struct atmel_trng *trng = (struct atmel_trng *)rng->priv;
> +	u32 *data = buf;
> +
> +	/* data ready? */
> +	if (readl(trng->base + TRNG_ODATA) & 1) {
> +		*data = readl(trng->base + TRNG_ODATA);
> +		return 4;
> +	} else
> +		return 0;
> +}
> +
> +static struct hwrng atmel_trng = {
> +	.name	= "atmel-trng",
> +	.read	= atmel_trng_read,
> +};

Could you do:

struct atmel_trng {
	struct clk *clk;
	void __iomem *base;
	struct hwrng rng;
};

#define to_atmel_trng(rng) \
	container_of(rng, struct amtel_trng, rng)

which would allow you to support more than one TRNG (although unlikely) 
but also means you don't need the cast for priv.

> +static int atmel_trng_probe(struct platform_device *pdev)
> +{
> +	struct atmel_trng *trng;
> +	struct resource *res;
> +	int ret;
> +
> +	if (atmel_trng.priv) {
> +		dev_err(&pdev->dev, "multiple instances not supported\n");
> +		return -EBUSY;
> +	}
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res)
> +		return -EINVAL;
> +
> +	trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
> +	if (!trng)
> +		return -ENOMEM;
> +
> +	if (!devm_request_mem_region(&pdev->dev, res->start,
> +				     resource_size(res), pdev->name))
> +		return -EBUSY;
> +
> +	trng->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> +	if (!trng->base)
> +		return -EBUSY;
> +
> +	trng->clk = clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(trng->clk))
> +		return PTR_ERR(trng->clk);
> +
> +	ret = clk_enable(trng->clk);
> +	if (ret)
> +		goto err_enable;
> +
> +	writel(TRNG_KEY | 1, trng->base + TRNG_CR);
> +
> +	atmel_trng.priv = (unsigned long)trng;
> +
> +	ret = hwrng_register(&atmel_trng);
> +	if (ret)
> +		goto err_register;
> +
> +	platform_set_drvdata(pdev, trng);
> +
> +	return 0;
> +
> +err_register:
> +	atmel_trng.priv = 0;
> +	clk_disable(trng->clk);
> +err_enable:
> +	clk_put(trng->clk);
> +
> +	return ret;
> +}
> +
> +static int __devexit atmel_trng_remove(struct platform_device *pdev)
> +{
> +	struct atmel_trng *trng = platform_get_drvdata(pdev);
> +
> +	hwrng_unregister(&atmel_trng);
> +
> +	writel(TRNG_KEY, trng->base + TRNG_CR);
> +	clk_disable(trng->clk);
> +	clk_put(trng->clk);
> +
> +	atmel_trng.priv = 0;

I think this should have a platform_set_drvdata(pdev, NULL) too.

[PATCH 2/2] hw_random: add driver for atmel true hardware random number generator

[Peter Korsgaard]

>>>>> "Jamie" == Jamie Iles <jamie@jamieiles.com> writes:

 Jamie> Hi Peter,
 Jamie> A couple of minor nits inline, but otherwise looks nice to me!

Thanks for the review.

 Jamie> Could you do:

 Jamie> struct atmel_trng {
 Jamie> 	struct clk *clk;
 Jamie> 	void __iomem *base;
 Jamie> 	struct hwrng rng;
 Jamie> };

Sure. Multiple trngs doesn't make much sense, but that approach leads to
slightly less lines, so ok.

I'll send an updated patch shortly.

-- 
Bye, Peter Korsgaard

[PATCH 1/2] sam9g45: add trng clock and platform device

[Nicolas Ferre]

On 10/06/2011 05:41 PM, Peter Korsgaard :
> For the new hw_random driver.
> 
> Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

I add it to at91-l2 and at91-next branches of:
git://github.com/at91linux/linux-at91.git

Thanks,

> ---
>  arch/arm/mach-at91/at91sam9g45.c         |    7 +++++++
>  arch/arm/mach-at91/at91sam9g45_devices.c |   29 +++++++++++++++++++++++++++++
>  2 files changed, 36 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/mach-at91/at91sam9g45.c b/arch/arm/mach-at91/at91sam9g45.c
> index 6da8ace..6850f1d 100644
> --- a/arch/arm/mach-at91/at91sam9g45.c
> +++ b/arch/arm/mach-at91/at91sam9g45.c
> @@ -54,6 +54,11 @@ static struct clk pioDE_clk = {
>  	.pmc_mask	= 1 << AT91SAM9G45_ID_PIODE,
>  	.type		= CLK_TYPE_PERIPHERAL,
>  };
> +static struct clk trng_clk = {
> +	.name		= "trng_clk",
> +	.pmc_mask	= 1 << AT91SAM9G45_ID_TRNG,
> +	.type		= CLK_TYPE_PERIPHERAL,
> +};
>  static struct clk usart0_clk = {
>  	.name		= "usart0_clk",
>  	.pmc_mask	= 1 << AT91SAM9G45_ID_US0,
> @@ -177,6 +182,7 @@ static struct clk *periph_clocks[] __initdata = {
>  	&pioB_clk,
>  	&pioC_clk,
>  	&pioDE_clk,
> +	&trng_clk,
>  	&usart0_clk,
>  	&usart1_clk,
>  	&usart2_clk,
> @@ -216,6 +222,7 @@ static struct clk_lookup periph_clocks_lookups[] = {
>  	CLKDEV_CON_DEV_ID("t0_clk", "atmel_tcb.1", &tcb0_clk),
>  	CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc0_clk),
>  	CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
> +	CLKDEV_CON_DEV_ID(NULL, "atmel-trng", &trng_clk),
>  	/* fake hclk clock */
>  	CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &uhphs_clk),
>  };
> diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
> index 2ee20bd..1ca6c62 100644
> --- a/arch/arm/mach-at91/at91sam9g45_devices.c
> +++ b/arch/arm/mach-at91/at91sam9g45_devices.c
> @@ -1101,6 +1101,34 @@ static void __init at91_add_device_rtt(void)
>  
>  
>  /* --------------------------------------------------------------------
> + *  TRNG
> + * -------------------------------------------------------------------- */
> +
> +#if defined(CONFIG_HW_RANDOM_ATMEL) || defined(CONFIG_HW_RANDOM_ATMEL_MODULE)
> +static struct resource trng_resources[] = {
> +	{
> +		.start	= AT91SAM9G45_BASE_TRNG,
> +		.end	= AT91SAM9G45_BASE_TRNG + SZ_16K - 1,
> +		.flags	= IORESOURCE_MEM,
> +	},
> +};
> +
> +static struct platform_device at91sam9g45_trng_device = {
> +	.name		= "atmel-trng",
> +	.id		= -1,
> +	.resource	= trng_resources,
> +	.num_resources	= ARRAY_SIZE(trng_resources),
> +};
> +
> +static void __init at91_add_device_trng(void)
> +{
> +	platform_device_register(&at91sam9g45_trng_device);
> +}
> +#else
> +static void __init at91_add_device_trng(void) {}
> +#endif
> +
> +/* --------------------------------------------------------------------
>   *  Watchdog
>   * -------------------------------------------------------------------- */
>  
> @@ -1589,6 +1617,7 @@ static int __init at91_add_standard_devices(void)
>  	at91_add_device_hdmac();
>  	at91_add_device_rtc();
>  	at91_add_device_rtt();
> +	at91_add_device_trng();
>  	at91_add_device_watchdog();
>  	at91_add_device_tc();
>  	return 0;


-- 
Nicolas Ferre