[PATCH v2 0/6] Atmel sama5d2 security module support

[PATCH v2 0/6] Atmel sama5d2 security module support

[Alexandre Belloni]

Hi,

There has already been multiple tentatives trying to add support for the
Sama5d2 security module and in particular, access to its SRAM.
After multiple discussions, I believe adding support in the sram
driver/framework is probably the best because it allows exporting the
SRAM to the kernel, to userspace and also to run code from it.

As the support for the sama5d2 securam is fairly small, I've included it
directly in the mmio-sram driver.

Changes in v2:
 - Fixed an issued in the sama5d2 dtsi
 - Use regmap_read_poll_timeout and of_device_get_match_data as suggested by
   Philipp
 - Shrink the timeout to 500ms
 - Added Rob's acks

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Alexandre Belloni (6):
  Documentation: dt: atmel-at91: Document secumod bindings
  ARM: at91: add secumod register definitions
  ARM: dts: at91: sama5d2: Add secumod node
  misc: sram: document new compatible
  misc: sram: add Atmel securam support
  ARM: dts: at91: sama5d2: Add securam node

 .../devicetree/bindings/arm/atmel-at91.txt         | 17 +++++++++
 Documentation/devicetree/bindings/sram/sram.txt    |  2 +-
 arch/arm/boot/dts/sama5d2.dtsi                     | 19 ++++++++++
 drivers/misc/sram.c                                | 42 ++++++++++++++++++----
 include/soc/at91/atmel-secumod.h                   | 20 +++++++++++
 5 files changed, 92 insertions(+), 8 deletions(-)
 create mode 100644 include/soc/at91/atmel-secumod.h

-- 
2.9.3

[PATCH v2 0/6] Atmel sama5d2 security module support

[Alexandre Belloni]

Hi,

There has already been multiple tentatives trying to add support for the
Sama5d2 security module and in particular, access to its SRAM.
After multiple discussions, I believe adding support in the sram
driver/framework is probably the best because it allows exporting the
SRAM to the kernel, to userspace and also to run code from it.

As the support for the sama5d2 securam is fairly small, I've included it
directly in the mmio-sram driver.

Changes in v2:
 - Fixed an issued in the sama5d2 dtsi
 - Use regmap_read_poll_timeout and of_device_get_match_data as suggested by
   Philipp
 - Shrink the timeout to 500ms
 - Added Rob's acks

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Alexandre Belloni (6):
  Documentation: dt: atmel-at91: Document secumod bindings
  ARM: at91: add secumod register definitions
  ARM: dts: at91: sama5d2: Add secumod node
  misc: sram: document new compatible
  misc: sram: add Atmel securam support
  ARM: dts: at91: sama5d2: Add securam node

 .../devicetree/bindings/arm/atmel-at91.txt         | 17 +++++++++
 Documentation/devicetree/bindings/sram/sram.txt    |  2 +-
 arch/arm/boot/dts/sama5d2.dtsi                     | 19 ++++++++++
 drivers/misc/sram.c                                | 42 ++++++++++++++++++----
 include/soc/at91/atmel-secumod.h                   | 20 +++++++++++
 5 files changed, 92 insertions(+), 8 deletions(-)
 create mode 100644 include/soc/at91/atmel-secumod.h

-- 
2.9.3

[PATCH v2 1/6] Documentation: dt: atmel-at91: Document secumod bindings

[Alexandre Belloni]

A security module is available starting with sama5d2, add its bindings.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/arm/atmel-at91.txt | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/atmel-at91.txt b/Documentation/devicetree/bindings/arm/atmel-at91.txt
index e1f5ad855f14..eea1f44d5666 100644
--- a/Documentation/devicetree/bindings/arm/atmel-at91.txt
+++ b/Documentation/devicetree/bindings/arm/atmel-at91.txt
@@ -225,3 +225,20 @@ required properties:
 		compatible = "atmel,sama5d3-sfr", "syscon";
 		reg = <0xf0038000 0x60>;
 	};
+
+Security Module (SECUMOD)
+
+The Security Module macrocell provides all necessary secure functions to avoid
+voltage, temperature, frequency and mechanical attacks on the chip. It also
+embeds secure memories that can be scrambled
+
+required properties:
+- compatible: Should be "atmel,<chip>-secumod", "syscon".
+  <chip> can be "sama5d2".
+- reg: Should contain registers location and length
+
+	secumod at fc040000 {
+		compatible = "atmel,sama5d2-secumod", "syscon";
+		reg = <0xfc040000 0x100>;
+	};
+
-- 
2.9.3

[PATCH v2 1/6] Documentation: dt: atmel-at91: Document secumod bindings

[Alexandre Belloni]

A security module is available starting with sama5d2, add its bindings.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/arm/atmel-at91.txt | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/atmel-at91.txt b/Documentation/devicetree/bindings/arm/atmel-at91.txt
index e1f5ad855f14..eea1f44d5666 100644
--- a/Documentation/devicetree/bindings/arm/atmel-at91.txt
+++ b/Documentation/devicetree/bindings/arm/atmel-at91.txt
@@ -225,3 +225,20 @@ required properties:
 		compatible = "atmel,sama5d3-sfr", "syscon";
 		reg = <0xf0038000 0x60>;
 	};
+
+Security Module (SECUMOD)
+
+The Security Module macrocell provides all necessary secure functions to avoid
+voltage, temperature, frequency and mechanical attacks on the chip. It also
+embeds secure memories that can be scrambled
+
+required properties:
+- compatible: Should be "atmel,<chip>-secumod", "syscon".
+  <chip> can be "sama5d2".
+- reg: Should contain registers location and length
+
+	secumod@fc040000 {
+		compatible = "atmel,sama5d2-secumod", "syscon";
+		reg = <0xfc040000 0x100>;
+	};
+
-- 
2.9.3

[PATCH v2 2/6] ARM: at91: add secumod register definitions

[Alexandre Belloni]

Add registers and bits definitions for the security module found on
sama5d2.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 include/soc/at91/atmel-secumod.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 include/soc/at91/atmel-secumod.h

diff --git a/include/soc/at91/atmel-secumod.h b/include/soc/at91/atmel-secumod.h
new file mode 100644
index 000000000000..7139e8eb1aca
--- /dev/null
+++ b/include/soc/at91/atmel-secumod.h
@@ -0,0 +1,20 @@
+/*
+ * Atmel Security Module register offsets and bit definitions.
+ *
+ * Copyright (C) 2016 Atmel
+ *
+ * Author: Alexandre Belloni <alexandre.belloni@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _LINUX_SOC_AT91_ATMEL_SECUMOD_H
+#define _LINUX_SOC_AT91_ATMEL_SECUMOD_H
+
+#define AT91_SECUMOD_RAMRDY	0x14
+#define AT91_SECUMOD_RAMRDY_READY	BIT(0)
+
+#endif /* _LINUX_SOC_AT91_ATMEL_SECUMOD_H */
+
-- 
2.9.3

[PATCH v2 2/6] ARM: at91: add secumod register definitions

[Alexandre Belloni]

Add registers and bits definitions for the security module found on
sama5d2.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 include/soc/at91/atmel-secumod.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 include/soc/at91/atmel-secumod.h

diff --git a/include/soc/at91/atmel-secumod.h b/include/soc/at91/atmel-secumod.h
new file mode 100644
index 000000000000..7139e8eb1aca
--- /dev/null
+++ b/include/soc/at91/atmel-secumod.h
@@ -0,0 +1,20 @@
+/*
+ * Atmel Security Module register offsets and bit definitions.
+ *
+ * Copyright (C) 2016 Atmel
+ *
+ * Author: Alexandre Belloni <alexandre.belloni@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _LINUX_SOC_AT91_ATMEL_SECUMOD_H
+#define _LINUX_SOC_AT91_ATMEL_SECUMOD_H
+
+#define AT91_SECUMOD_RAMRDY	0x14
+#define AT91_SECUMOD_RAMRDY_READY	BIT(0)
+
+#endif /* _LINUX_SOC_AT91_ATMEL_SECUMOD_H */
+
-- 
2.9.3

[PATCH v2 3/6] ARM: dts: at91: sama5d2: Add secumod node

[Alexandre Belloni]

The sama5d2 has a security module, add its node.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 arch/arm/boot/dts/sama5d2.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/sama5d2.dtsi b/arch/arm/boot/dts/sama5d2.dtsi
index 353d0e5ec83b..0b62bff86f49 100644
--- a/arch/arm/boot/dts/sama5d2.dtsi
+++ b/arch/arm/boot/dts/sama5d2.dtsi
@@ -1231,6 +1231,11 @@
 				clocks = <&pioA_clk>;
 			};
 
+			secumod at fc040000 {
+				compatible = "atmel,sama5d2-secumod", "syscon";
+				reg = <0xfc040000 0x100>;
+			};
+
 			tdes at fc044000 {
 				compatible = "atmel,at91sam9g46-tdes";
 				reg = <0xfc044000 0x100>;
-- 
2.9.3

[PATCH v2 3/6] ARM: dts: at91: sama5d2: Add secumod node

[Alexandre Belloni]

The sama5d2 has a security module, add its node.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 arch/arm/boot/dts/sama5d2.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/sama5d2.dtsi b/arch/arm/boot/dts/sama5d2.dtsi
index 353d0e5ec83b..0b62bff86f49 100644
--- a/arch/arm/boot/dts/sama5d2.dtsi
+++ b/arch/arm/boot/dts/sama5d2.dtsi
@@ -1231,6 +1231,11 @@
 				clocks = <&pioA_clk>;
 			};
 
+			secumod@fc040000 {
+				compatible = "atmel,sama5d2-secumod", "syscon";
+				reg = <0xfc040000 0x100>;
+			};
+
 			tdes@fc044000 {
 				compatible = "atmel,at91sam9g46-tdes";
 				reg = <0xfc044000 0x100>;
-- 
2.9.3

[PATCH v2 4/6] misc: sram: document new compatible

[Alexandre Belloni]

Add atmel,sama5d2-securam to the compatible list.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/sram/sram.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/sram/sram.txt b/Documentation/devicetree/bindings/sram/sram.txt
index add48f09015e..068c2c03c38f 100644
--- a/Documentation/devicetree/bindings/sram/sram.txt
+++ b/Documentation/devicetree/bindings/sram/sram.txt
@@ -4,7 +4,7 @@ Simple IO memory regions to be managed by the genalloc API.
 
 Required properties:
 
-- compatible : mmio-sram
+- compatible : mmio-sram or atmel,sama5d2-securam
 
 - reg : SRAM iomem address range
 
-- 
2.9.3

[PATCH v2 4/6] misc: sram: document new compatible

[Alexandre Belloni]

Add atmel,sama5d2-securam to the compatible list.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/sram/sram.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/sram/sram.txt b/Documentation/devicetree/bindings/sram/sram.txt
index add48f09015e..068c2c03c38f 100644
--- a/Documentation/devicetree/bindings/sram/sram.txt
+++ b/Documentation/devicetree/bindings/sram/sram.txt
@@ -4,7 +4,7 @@ Simple IO memory regions to be managed by the genalloc API.
 
 Required properties:
 
-- compatible : mmio-sram
+- compatible : mmio-sram or atmel,sama5d2-securam
 
 - reg : SRAM iomem address range
 
-- 
2.9.3

[PATCH v2 5/6] misc: sram: add Atmel securam support

[Alexandre Belloni]

The Atmel secure SRAM is connected to a security module and may be erased
automatically under certain conditions. For that reason, it is necessary to
wait for the security module to flag that SRAM accesses are allowed before
accessing it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

 drivers/misc/sram.c | 42 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 35 insertions(+), 7 deletions(-)

diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
index f84b53d6ce50..b0d4dd9b0586 100644
--- a/drivers/misc/sram.c
+++ b/drivers/misc/sram.c
@@ -19,12 +19,17 @@
  */
 
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/genalloc.h>
 #include <linux/io.h>
 #include <linux/list_sort.h>
 #include <linux/of_address.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <soc/at91/atmel-secumod.h>
 
 #define SRAM_GRANULARITY	32
 
@@ -334,12 +339,35 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
 	return ret;
 }
 
+static int atmel_securam_wait(void)
+{
+	struct regmap *regmap;
+	u32 val;
+
+	regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod");
+	if (IS_ERR(regmap))
+		return -ENODEV;
+
+	return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val,
+					val & AT91_SECUMOD_RAMRDY_READY,
+					10000, 500000);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id sram_dt_ids[] = {
+	{ .compatible = "mmio-sram" },
+	{ .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait },
+	{}
+};
+#endif
+
 static int sram_probe(struct platform_device *pdev)
 {
 	struct sram_dev *sram;
 	struct resource *res;
 	size_t size;
 	int ret;
+	int (*init_func)(void);
 
 	sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
 	if (!sram)
@@ -384,6 +412,13 @@ static int sram_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, sram);
 
+	init_func = of_device_get_match_data(&pdev->dev);
+	if (init_func) {
+		ret = init_func();
+		if (ret)
+			return ret;
+	}
+
 	dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
 		gen_pool_size(sram->pool) / 1024, sram->virt_base);
 
@@ -405,13 +440,6 @@ static int sram_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_OF
-static const struct of_device_id sram_dt_ids[] = {
-	{ .compatible = "mmio-sram" },
-	{}
-};
-#endif
-
 static struct platform_driver sram_driver = {
 	.driver = {
 		.name = "sram",
-- 
2.9.3

[PATCH v2 5/6] misc: sram: add Atmel securam support

[Alexandre Belloni]

The Atmel secure SRAM is connected to a security module and may be erased
automatically under certain conditions. For that reason, it is necessary to
wait for the security module to flag that SRAM accesses are allowed before
accessing it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

 drivers/misc/sram.c | 42 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 35 insertions(+), 7 deletions(-)

diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
index f84b53d6ce50..b0d4dd9b0586 100644
--- a/drivers/misc/sram.c
+++ b/drivers/misc/sram.c
@@ -19,12 +19,17 @@
  */
 
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/genalloc.h>
 #include <linux/io.h>
 #include <linux/list_sort.h>
 #include <linux/of_address.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <soc/at91/atmel-secumod.h>
 
 #define SRAM_GRANULARITY	32
 
@@ -334,12 +339,35 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
 	return ret;
 }
 
+static int atmel_securam_wait(void)
+{
+	struct regmap *regmap;
+	u32 val;
+
+	regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod");
+	if (IS_ERR(regmap))
+		return -ENODEV;
+
+	return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val,
+					val & AT91_SECUMOD_RAMRDY_READY,
+					10000, 500000);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id sram_dt_ids[] = {
+	{ .compatible = "mmio-sram" },
+	{ .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait },
+	{}
+};
+#endif
+
 static int sram_probe(struct platform_device *pdev)
 {
 	struct sram_dev *sram;
 	struct resource *res;
 	size_t size;
 	int ret;
+	int (*init_func)(void);
 
 	sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
 	if (!sram)
@@ -384,6 +412,13 @@ static int sram_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, sram);
 
+	init_func = of_device_get_match_data(&pdev->dev);
+	if (init_func) {
+		ret = init_func();
+		if (ret)
+			return ret;
+	}
+
 	dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
 		gen_pool_size(sram->pool) / 1024, sram->virt_base);
 
@@ -405,13 +440,6 @@ static int sram_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_OF
-static const struct of_device_id sram_dt_ids[] = {
-	{ .compatible = "mmio-sram" },
-	{}
-};
-#endif
-
 static struct platform_driver sram_driver = {
 	.driver = {
 		.name = "sram",
-- 
2.9.3

[PATCH v2 5/6] misc: sram: add Atmel securam support

[Alexandre Belloni]

Greg,

As a reminder, I think we agreed that this one could go through the at91
tree because of the dependency on patch 2/6.

I'd like to get your ack though.

On 22/09/2016 at 00:09:38 +0200, Alexandre Belloni wrote :
> The Atmel secure SRAM is connected to a security module and may be erased
> automatically under certain conditions. For that reason, it is necessary to
> wait for the security module to flag that SRAM accesses are allowed before
> accessing it.
> 
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
>  drivers/misc/sram.c | 42 +++++++++++++++++++++++++++++++++++-------
>  1 file changed, 35 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
> index f84b53d6ce50..b0d4dd9b0586 100644
> --- a/drivers/misc/sram.c
> +++ b/drivers/misc/sram.c
> @@ -19,12 +19,17 @@
>   */
>  
>  #include <linux/clk.h>
> +#include <linux/delay.h>
>  #include <linux/genalloc.h>
>  #include <linux/io.h>
>  #include <linux/list_sort.h>
>  #include <linux/of_address.h>
> +#include <linux/of_device.h>
>  #include <linux/platform_device.h>
> +#include <linux/regmap.h>
>  #include <linux/slab.h>
> +#include <linux/mfd/syscon.h>
> +#include <soc/at91/atmel-secumod.h>
>  
>  #define SRAM_GRANULARITY	32
>  
> @@ -334,12 +339,35 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
>  	return ret;
>  }
>  
> +static int atmel_securam_wait(void)
> +{
> +	struct regmap *regmap;
> +	u32 val;
> +
> +	regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod");
> +	if (IS_ERR(regmap))
> +		return -ENODEV;
> +
> +	return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val,
> +					val & AT91_SECUMOD_RAMRDY_READY,
> +					10000, 500000);
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id sram_dt_ids[] = {
> +	{ .compatible = "mmio-sram" },
> +	{ .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait },
> +	{}
> +};
> +#endif
> +
>  static int sram_probe(struct platform_device *pdev)
>  {
>  	struct sram_dev *sram;
>  	struct resource *res;
>  	size_t size;
>  	int ret;
> +	int (*init_func)(void);
>  
>  	sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
>  	if (!sram)
> @@ -384,6 +412,13 @@ static int sram_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, sram);
>  
> +	init_func = of_device_get_match_data(&pdev->dev);
> +	if (init_func) {
> +		ret = init_func();
> +		if (ret)
> +			return ret;
> +	}
> +
>  	dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
>  		gen_pool_size(sram->pool) / 1024, sram->virt_base);
>  
> @@ -405,13 +440,6 @@ static int sram_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -#ifdef CONFIG_OF
> -static const struct of_device_id sram_dt_ids[] = {
> -	{ .compatible = "mmio-sram" },
> -	{}
> -};
> -#endif
> -
>  static struct platform_driver sram_driver = {
>  	.driver = {
>  		.name = "sram",
> -- 
> 2.9.3
> 

-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH v2 5/6] misc: sram: add Atmel securam support

[Alexandre Belloni]

Greg,

As a reminder, I think we agreed that this one could go through the at91
tree because of the dependency on patch 2/6.

I'd like to get your ack though.

On 22/09/2016 at 00:09:38 +0200, Alexandre Belloni wrote :
> The Atmel secure SRAM is connected to a security module and may be erased
> automatically under certain conditions. For that reason, it is necessary to
> wait for the security module to flag that SRAM accesses are allowed before
> accessing it.
> 
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
>  drivers/misc/sram.c | 42 +++++++++++++++++++++++++++++++++++-------
>  1 file changed, 35 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
> index f84b53d6ce50..b0d4dd9b0586 100644
> --- a/drivers/misc/sram.c
> +++ b/drivers/misc/sram.c
> @@ -19,12 +19,17 @@
>   */
>  
>  #include <linux/clk.h>
> +#include <linux/delay.h>
>  #include <linux/genalloc.h>
>  #include <linux/io.h>
>  #include <linux/list_sort.h>
>  #include <linux/of_address.h>
> +#include <linux/of_device.h>
>  #include <linux/platform_device.h>
> +#include <linux/regmap.h>
>  #include <linux/slab.h>
> +#include <linux/mfd/syscon.h>
> +#include <soc/at91/atmel-secumod.h>
>  
>  #define SRAM_GRANULARITY	32
>  
> @@ -334,12 +339,35 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
>  	return ret;
>  }
>  
> +static int atmel_securam_wait(void)
> +{
> +	struct regmap *regmap;
> +	u32 val;
> +
> +	regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod");
> +	if (IS_ERR(regmap))
> +		return -ENODEV;
> +
> +	return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val,
> +					val & AT91_SECUMOD_RAMRDY_READY,
> +					10000, 500000);
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id sram_dt_ids[] = {
> +	{ .compatible = "mmio-sram" },
> +	{ .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait },
> +	{}
> +};
> +#endif
> +
>  static int sram_probe(struct platform_device *pdev)
>  {
>  	struct sram_dev *sram;
>  	struct resource *res;
>  	size_t size;
>  	int ret;
> +	int (*init_func)(void);
>  
>  	sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
>  	if (!sram)
> @@ -384,6 +412,13 @@ static int sram_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, sram);
>  
> +	init_func = of_device_get_match_data(&pdev->dev);
> +	if (init_func) {
> +		ret = init_func();
> +		if (ret)
> +			return ret;
> +	}
> +
>  	dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
>  		gen_pool_size(sram->pool) / 1024, sram->virt_base);
>  
> @@ -405,13 +440,6 @@ static int sram_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -#ifdef CONFIG_OF
> -static const struct of_device_id sram_dt_ids[] = {
> -	{ .compatible = "mmio-sram" },
> -	{}
> -};
> -#endif
> -
>  static struct platform_driver sram_driver = {
>  	.driver = {
>  		.name = "sram",
> -- 
> 2.9.3
> 

-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[PATCH v2 5/6] misc: sram: add Atmel securam support

[Greg Kroah-Hartman]

On Thu, Sep 22, 2016 at 12:09:38AM +0200, Alexandre Belloni wrote:
> The Atmel secure SRAM is connected to a security module and may be erased
> automatically under certain conditions. For that reason, it is necessary to
> wait for the security module to flag that SRAM accesses are allowed before
> accessing it.
> 
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
>  drivers/misc/sram.c | 42 +++++++++++++++++++++++++++++++++++-------
>  1 file changed, 35 insertions(+), 7 deletions(-)

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH v2 5/6] misc: sram: add Atmel securam support

[Greg Kroah-Hartman]

On Thu, Sep 22, 2016 at 12:09:38AM +0200, Alexandre Belloni wrote:
> The Atmel secure SRAM is connected to a security module and may be erased
> automatically under certain conditions. For that reason, it is necessary to
> wait for the security module to flag that SRAM accesses are allowed before
> accessing it.
> 
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
>  drivers/misc/sram.c | 42 +++++++++++++++++++++++++++++++++++-------
>  1 file changed, 35 insertions(+), 7 deletions(-)

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[PATCH v2 6/6] ARM: dts: at91: sama5d2: Add securam node

[Alexandre Belloni]

The sama5d2 has some static RAM that can be erased by the security module,
add its node

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 arch/arm/boot/dts/sama5d2.dtsi | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/arm/boot/dts/sama5d2.dtsi b/arch/arm/boot/dts/sama5d2.dtsi
index 0b62bff86f49..a3653751a7d6 100644
--- a/arch/arm/boot/dts/sama5d2.dtsi
+++ b/arch/arm/boot/dts/sama5d2.dtsi
@@ -706,6 +706,11 @@
 						atmel,clk-output-range = <0 83000000>;
 					};
 
+					securam_clk: securam_clk {
+						#clock-cells = <0>;
+						reg = <51>;
+					};
+
 					i2s0_clk: i2s0_clk {
 						#clock-cells = <0>;
 						reg = <54>;
@@ -1029,6 +1034,15 @@
 				status = "disabled";
 			};
 
+			securam: sram at f8044000 {
+				compatible = "atmel,sama5d2-securam", "mmio-sram";
+				reg = <0xf8044000 0x1420>;
+				clocks = <&securam_clk>;
+				#address-cells = <1>;
+				#size-cells = <1>;
+				ranges = <0 0xf8044000 0x1420>;
+			};
+
 			rstc at f8048000 {
 				compatible = "atmel,sama5d3-rstc";
 				reg = <0xf8048000 0x10>;
-- 
2.9.3

[PATCH v2 6/6] ARM: dts: at91: sama5d2: Add securam node

[Alexandre Belloni]

The sama5d2 has some static RAM that can be erased by the security module,
add its node

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 arch/arm/boot/dts/sama5d2.dtsi | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/arm/boot/dts/sama5d2.dtsi b/arch/arm/boot/dts/sama5d2.dtsi
index 0b62bff86f49..a3653751a7d6 100644
--- a/arch/arm/boot/dts/sama5d2.dtsi
+++ b/arch/arm/boot/dts/sama5d2.dtsi
@@ -706,6 +706,11 @@
 						atmel,clk-output-range = <0 83000000>;
 					};
 
+					securam_clk: securam_clk {
+						#clock-cells = <0>;
+						reg = <51>;
+					};
+
 					i2s0_clk: i2s0_clk {
 						#clock-cells = <0>;
 						reg = <54>;
@@ -1029,6 +1034,15 @@
 				status = "disabled";
 			};
 
+			securam: sram@f8044000 {
+				compatible = "atmel,sama5d2-securam", "mmio-sram";
+				reg = <0xf8044000 0x1420>;
+				clocks = <&securam_clk>;
+				#address-cells = <1>;
+				#size-cells = <1>;
+				ranges = <0 0xf8044000 0x1420>;
+			};
+
 			rstc@f8048000 {
 				compatible = "atmel,sama5d3-rstc";
 				reg = <0xf8048000 0x10>;
-- 
2.9.3