[PATCH 0/6] Add Amlogic secure monitor and NVMEM drivers

[PATCH 0/6] Add Amlogic secure monitor and NVMEM drivers

[Carlo Caione]

From: Carlo Caione <carlo@endlessm.com>

I decided to respin again the secure monitor driver this time with the NVMEM
driver in the same patchset to have a clear view on how a generic driver can
use the monitor.

The latest patchset for the secure monitor with the Changelog is here [1].

[1] http://www.spinics.net/lists/arm-kernel/msg510441.html

Carlo Caione (6):
  firmware: Amlogic: Add secure monitor driver
  documentation: Add secure monitor bindings documentation
  ARM64: dts: amlogic: gxbb: Enable secure monitor
  nvmem: amlogic: Add Amlogic Meson EFUSE driver
  documentation: Add nvmem bindings documentation
  ARM64: dts: amlogic: gxbb: Enable NVMEM

 .../bindings/firmware/meson/meson_sm.txt           |  15 ++
 .../devicetree/bindings/nvmem/amlogic-efuse.txt    |  39 +++
 arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi        |  24 ++
 drivers/firmware/Kconfig                           |   1 +
 drivers/firmware/Makefile                          |   1 +
 drivers/firmware/meson/Kconfig                     |   8 +
 drivers/firmware/meson/Makefile                    |   1 +
 drivers/firmware/meson/meson_sm.c                  | 266 +++++++++++++++++++++
 drivers/nvmem/Kconfig                              |  11 +
 drivers/nvmem/Makefile                             |   2 +
 drivers/nvmem/meson-efuse.c                        | 130 ++++++++++
 include/linux/firmware/meson/meson_sm.h            |  32 +++
 12 files changed, 530 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/firmware/meson/meson_sm.txt
 create mode 100644 Documentation/devicetree/bindings/nvmem/amlogic-efuse.txt
 create mode 100644 drivers/firmware/meson/Kconfig
 create mode 100644 drivers/firmware/meson/Makefile
 create mode 100644 drivers/firmware/meson/meson_sm.c
 create mode 100644 drivers/nvmem/meson-efuse.c
 create mode 100644 include/linux/firmware/meson/meson_sm.h

-- 
2.7.4

[PATCH 1/6] firmware: Amlogic: Add secure monitor driver

[Carlo Caione]

From: Carlo Caione <carlo@endlessm.com>

Introduce a driver to provide calls into secure monitor mode.

In the Amlogic SoCs these calls are used for multiple reasons: access to
NVMEM, set USB boot, enable JTAG, etc...

Signed-off-by: Carlo Caione <carlo@endlessm.com>
---
 drivers/firmware/Kconfig                |   1 +
 drivers/firmware/Makefile               |   1 +
 drivers/firmware/meson/Kconfig          |   8 +
 drivers/firmware/meson/Makefile         |   1 +
 drivers/firmware/meson/meson_sm.c       | 266 ++++++++++++++++++++++++++++++++
 include/linux/firmware/meson/meson_sm.h |  32 ++++
 6 files changed, 309 insertions(+)
 create mode 100644 drivers/firmware/meson/Kconfig
 create mode 100644 drivers/firmware/meson/Makefile
 create mode 100644 drivers/firmware/meson/meson_sm.c
 create mode 100644 include/linux/firmware/meson/meson_sm.h

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 6664f11..686e395 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -199,5 +199,6 @@ config HAVE_ARM_SMCCC
 source "drivers/firmware/broadcom/Kconfig"
 source "drivers/firmware/google/Kconfig"
 source "drivers/firmware/efi/Kconfig"
+source "drivers/firmware/meson/Kconfig"
 
 endmenu
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 474bada..fc4bb09 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_QCOM_SCM_32)	+= qcom_scm-32.o
 CFLAGS_qcom_scm-32.o :=$(call as-instr,.arch armv7-a\n.arch_extension sec,-DREQUIRES_SEC=1) -march=armv7-a
 
 obj-y				+= broadcom/
+obj-y				+= meson/
 obj-$(CONFIG_GOOGLE_FIRMWARE)	+= google/
 obj-$(CONFIG_EFI)		+= efi/
 obj-$(CONFIG_UEFI_CPER)		+= efi/
diff --git a/drivers/firmware/meson/Kconfig b/drivers/firmware/meson/Kconfig
new file mode 100644
index 0000000..fff11a3
--- /dev/null
+++ b/drivers/firmware/meson/Kconfig
@@ -0,0 +1,8 @@
+#
+# Amlogic Secure Monitor driver
+#
+config MESON_SM
+	bool
+	default ARCH_MESON
+	help
+	  Say y here to enable the Amlogic secure monitor driver
diff --git a/drivers/firmware/meson/Makefile b/drivers/firmware/meson/Makefile
new file mode 100644
index 0000000..9ab3884
--- /dev/null
+++ b/drivers/firmware/meson/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_MESON_SM) +=	meson_sm.o
diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c
new file mode 100644
index 0000000..8e6b9dc
--- /dev/null
+++ b/drivers/firmware/meson/meson_sm.c
@@ -0,0 +1,266 @@
+/*
+ * Amlogic Secure Monitor driver
+ *
+ * Copyright (C) 2016 Endless Mobile, Inc.
+ * Author: Carlo Caione <carlo@endlessm.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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdarg.h>
+#include <asm/cacheflush.h>
+#include <asm/compiler.h>
+#include <linux/arm-smccc.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/smp.h>
+#include <linux/firmware/meson/meson_sm.h>
+
+struct meson_sm_cmd {
+	unsigned int index;
+	u32 smc_id;
+};
+#define CMD(d, s) { .index = (d), .smc_id = (s), }
+
+struct meson_sm_chip {
+	unsigned int shmem_size;
+	u32 cmd_shmem_in_base;
+	u32 cmd_shmem_out_base;
+	struct meson_sm_cmd cmd[];
+};
+
+struct meson_sm_chip gxbb_chip = {
+	.shmem_size		= 0x1000,
+	.cmd_shmem_in_base	= 0x82000020,
+	.cmd_shmem_out_base	= 0x82000021,
+	.cmd = {
+		CMD(SM_EFUSE_READ,	0x82000030),
+		CMD(SM_EFUSE_WRITE,	0x82000031),
+		CMD(SM_EFUSE_USER_MAX,	0x82000033),
+		{ /* sentinel */ },
+	},
+};
+
+struct meson_sm_firmware {
+	const struct meson_sm_chip *chip;
+	void __iomem *sm_shmem_in_base;
+	void __iomem *sm_shmem_out_base;
+};
+
+static struct meson_sm_firmware fw;
+
+static u32 meson_sm_get_cmd(const struct meson_sm_chip *chip, unsigned int cmd_index)
+{
+	unsigned int i;
+
+	for (i = 0; chip->cmd[i].smc_id; i++)
+		if (chip->cmd[i].index == cmd_index)
+			return chip->cmd[i].smc_id;
+
+	return 0;
+}
+
+static u32 __meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(cmd, arg0, arg1, arg2, arg3, arg4, 0, 0, &res);
+	return res.a0;
+}
+
+static void __iomem *meson_sm_map_shmem(u32 cmd_shmem, unsigned int size)
+{
+	u32 sm_phy_base;
+
+	sm_phy_base = __meson_sm_call(cmd_shmem, 0, 0, 0, 0, 0);
+	if (!sm_phy_base)
+		return 0;
+
+	return ioremap_cache(sm_phy_base, size);
+}
+
+/**
+ * meson_sm_call - generic SMC32 call to the secure-monitor
+ *
+ * @fw:		Meson secure-monitor firmware pointer
+ * @cmd_index:	Index of the SMC32 function ID
+ * @ret:	Returned value
+ * @arg0:	SMC32 Argument 0
+ * @arg1:	SMC32 Argument 1
+ * @arg2:	SMC32 Argument 2
+ * @arg3:	SMC32 Argument 3
+ * @arg4:	SMC32 Argument 4
+ *
+ * Return:	0 on success, a negative value on error
+ */
+int meson_sm_call(struct meson_sm_firmware *fw, unsigned int cmd_index,
+		  u32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
+{
+	u32 cmd, lret;
+
+	if (!fw)
+		return -EINVAL;
+
+	cmd = meson_sm_get_cmd(fw->chip, cmd_index);
+	if (!cmd)
+		return -EINVAL;
+
+	lret = __meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4);
+
+	if (ret)
+		*ret = lret;
+
+	return 0;
+}
+EXPORT_SYMBOL(meson_sm_call);
+
+/**
+ * meson_sm_call_read - retrieve data from secure-monitor
+ *
+ * @fw:		Meson secure-monitor firmware pointer
+ * @buffer:	Buffer to store the retrieved data
+ * @cmd_index:	Index of the SMC32 function ID
+ * @arg0:	SMC32 Argument 0
+ * @arg1:	SMC32 Argument 1
+ * @arg2:	SMC32 Argument 2
+ * @arg3:	SMC32 Argument 3
+ * @arg4:	SMC32 Argument 4
+ *
+ * Return:	size of read data on success, a negative value on error
+ */
+int meson_sm_call_read(struct meson_sm_firmware *fw, void *buffer,
+		       unsigned int cmd_index, u32 arg0, u32 arg1,
+		       u32 arg2, u32 arg3, u32 arg4)
+{
+	u32 size;
+
+	if (!fw->chip->cmd_shmem_out_base)
+		return -EINVAL;
+
+	if (meson_sm_call(fw, cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)
+		return -EINVAL;
+
+	if (!size || size > fw->chip->shmem_size)
+		return -EINVAL;
+
+	if (buffer)
+		memcpy(buffer, fw->sm_shmem_out_base, size);
+
+	return size;
+}
+EXPORT_SYMBOL(meson_sm_call_read);
+
+/**
+ * meson_sm_call_write - send data to secure-monitor
+ *
+ * @fw:		Meson secure-monitor firmware pointer
+ * @buffer:	Buffer containing data to send
+ * @b_size:	Size of the data to send
+ * @cmd_index:	Index of the SMC32 function ID
+ * @arg0:	SMC32 Argument 0
+ * @arg1:	SMC32 Argument 1
+ * @arg2:	SMC32 Argument 2
+ * @arg3:	SMC32 Argument 3
+ * @arg4:	SMC32 Argument 4
+ *
+ * Return:	size of sent data on success, a negative value on error
+ */
+int meson_sm_call_write(struct meson_sm_firmware *fw, void *buffer,
+			unsigned int b_size, unsigned int cmd_index,
+			u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
+{
+	u32 size;
+
+	if (b_size > fw->chip->shmem_size)
+		return -EINVAL;
+
+	if (!fw->chip->cmd_shmem_in_base)
+		return -EINVAL;
+
+	memcpy(fw->sm_shmem_in_base, buffer, b_size);
+
+	if (meson_sm_call(fw, cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)
+		return -EINVAL;
+
+	if (!size)
+		return -EINVAL;
+
+	return size;
+}
+EXPORT_SYMBOL(meson_sm_call_write);
+
+/**
+ * meson_sm_get_fw - get Meson firmware struct
+ *
+ * Return:		Meson secure-monitor firmware struct on success, NULL on error
+ */
+struct meson_sm_firmware *meson_sm_get_fw(void)
+{
+	/*
+	 * Returns NULL is the firmware device is not ready.
+	 */
+	if (!fw.chip)
+		return NULL;
+
+	return &fw;
+}
+EXPORT_SYMBOL(meson_sm_get_fw);
+
+static const struct of_device_id meson_sm_ids[] = {
+	{ .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip },
+	{ /* sentinel */ },
+};
+
+int __init meson_sm_init(void)
+{
+	const struct meson_sm_chip *chip;
+	const struct of_device_id *matched_np;
+	struct device_node *np;
+
+	np = of_find_matching_node_and_match(NULL, meson_sm_ids, &matched_np);
+	if (!np) {
+		pr_err("no matching node\n");
+		return -EINVAL;
+	}
+
+	chip = matched_np->data;
+	if (!chip) {
+		pr_err("unable to setup secure-monitor data\n");
+		return -EINVAL;
+	}
+
+	if (chip->cmd_shmem_in_base) {
+		fw.sm_shmem_in_base = meson_sm_map_shmem(chip->cmd_shmem_in_base,
+							 chip->shmem_size);
+		if (WARN_ON(!fw.sm_shmem_in_base))
+			goto out;
+	}
+
+	if (chip->cmd_shmem_out_base) {
+		fw.sm_shmem_out_base = meson_sm_map_shmem(chip->cmd_shmem_out_base,
+							  chip->shmem_size);
+		if (WARN_ON(!fw.sm_shmem_out_base))
+			goto out;
+	}
+
+	fw.chip = chip;
+	pr_info("secure-monitor enabled\n");
+
+	return 0;
+
+out:
+	if (fw.sm_shmem_in_base)
+		iounmap(fw.sm_shmem_in_base);
+
+	return -EINVAL;
+}
+device_initcall(meson_sm_init);
diff --git a/include/linux/firmware/meson/meson_sm.h b/include/linux/firmware/meson/meson_sm.h
new file mode 100644
index 0000000..81136b0
--- /dev/null
+++ b/include/linux/firmware/meson/meson_sm.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2016 Endless Mobile, Inc.
+ * Author: Carlo Caione <carlo@endlessm.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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _MESON_SM_FW_H_
+#define _MESON_SM_FW_H_
+
+#define SM_EFUSE_READ		0
+#define SM_EFUSE_WRITE		1
+#define SM_EFUSE_USER_MAX	2
+
+struct meson_sm_firmware;
+
+int meson_sm_call(struct meson_sm_firmware *fw, unsigned int cmd_index,
+		  u32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4);
+int meson_sm_call_write(struct meson_sm_firmware *fw, void *buffer,
+			unsigned int b_size, unsigned int cmd_index,
+			u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4);
+int meson_sm_call_read(struct meson_sm_firmware *fw, void *buffer,
+		       unsigned int cmd_index, u32 arg0, u32 arg1,
+		       u32 arg2, u32 arg3, u32 arg4);
+struct meson_sm_firmware *meson_sm_get_fw(void);
+
+#endif /* _MESON_SM_FW_H_ */
-- 
2.7.4

[PATCH 1/6] firmware: Amlogic: Add secure monitor driver

[Carlo Caione]

On 19/06/16 14:38, Carlo Caione wrote:
> From: Carlo Caione <carlo@endlessm.com>
> 
> Introduce a driver to provide calls into secure monitor mode.
> 
> In the Amlogic SoCs these calls are used for multiple reasons: access to
> NVMEM, set USB boot, enable JTAG, etc...
> 
> Signed-off-by: Carlo Caione <carlo@endlessm.com>

Hey Mark,
can you take a look to this patch? Not sure who is supposed to ACK /
review it.

Thanks,

-- 
Carlo Caione

[PATCH 1/6] firmware: Amlogic: Add secure monitor driver

[Mark Rutland]

Hi,

On Sun, Jun 19, 2016 at 02:38:59PM +0200, Carlo Caione wrote:
> From: Carlo Caione <carlo@endlessm.com>
> 
> Introduce a driver to provide calls into secure monitor mode.
> 
> In the Amlogic SoCs these calls are used for multiple reasons: access to
> NVMEM, set USB boot, enable JTAG, etc...
> 
> Signed-off-by: Carlo Caione <carlo@endlessm.com>
> ---
>  drivers/firmware/Kconfig                |   1 +
>  drivers/firmware/Makefile               |   1 +
>  drivers/firmware/meson/Kconfig          |   8 +
>  drivers/firmware/meson/Makefile         |   1 +
>  drivers/firmware/meson/meson_sm.c       | 266 ++++++++++++++++++++++++++++++++
>  include/linux/firmware/meson/meson_sm.h |  32 ++++
>  6 files changed, 309 insertions(+)
>  create mode 100644 drivers/firmware/meson/Kconfig
>  create mode 100644 drivers/firmware/meson/Makefile
>  create mode 100644 drivers/firmware/meson/meson_sm.c
>  create mode 100644 include/linux/firmware/meson/meson_sm.h
> 
> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
> index 6664f11..686e395 100644
> --- a/drivers/firmware/Kconfig
> +++ b/drivers/firmware/Kconfig
> @@ -199,5 +199,6 @@ config HAVE_ARM_SMCCC
>  source "drivers/firmware/broadcom/Kconfig"
>  source "drivers/firmware/google/Kconfig"
>  source "drivers/firmware/efi/Kconfig"
> +source "drivers/firmware/meson/Kconfig"
>  
>  endmenu
> diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
> index 474bada..fc4bb09 100644
> --- a/drivers/firmware/Makefile
> +++ b/drivers/firmware/Makefile
> @@ -21,6 +21,7 @@ obj-$(CONFIG_QCOM_SCM_32)	+= qcom_scm-32.o
>  CFLAGS_qcom_scm-32.o :=$(call as-instr,.arch armv7-a\n.arch_extension sec,-DREQUIRES_SEC=1) -march=armv7-a
>  
>  obj-y				+= broadcom/
> +obj-y				+= meson/
>  obj-$(CONFIG_GOOGLE_FIRMWARE)	+= google/
>  obj-$(CONFIG_EFI)		+= efi/
>  obj-$(CONFIG_UEFI_CPER)		+= efi/
> diff --git a/drivers/firmware/meson/Kconfig b/drivers/firmware/meson/Kconfig
> new file mode 100644
> index 0000000..fff11a3
> --- /dev/null
> +++ b/drivers/firmware/meson/Kconfig
> @@ -0,0 +1,8 @@
> +#
> +# Amlogic Secure Monitor driver
> +#
> +config MESON_SM
> +	bool
> +	default ARCH_MESON
> +	help
> +	  Say y here to enable the Amlogic secure monitor driver
> diff --git a/drivers/firmware/meson/Makefile b/drivers/firmware/meson/Makefile
> new file mode 100644
> index 0000000..9ab3884
> --- /dev/null
> +++ b/drivers/firmware/meson/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_MESON_SM) +=	meson_sm.o
> diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c
> new file mode 100644
> index 0000000..8e6b9dc
> --- /dev/null
> +++ b/drivers/firmware/meson/meson_sm.c
> @@ -0,0 +1,266 @@
> +/*
> + * Amlogic Secure Monitor driver
> + *
> + * Copyright (C) 2016 Endless Mobile, Inc.
> + * Author: Carlo Caione <carlo@endlessm.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.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <stdarg.h>
> +#include <asm/cacheflush.h>
> +#include <asm/compiler.h>

As far as I can see, these aren't necessary. There aren't any variadic
functions, there's no cache maintenance. I'm guessing compiler.h is left
over from pre-SMCCCC code that used __asmeq().

> +#include <linux/arm-smccc.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/module.h>

Likewise for ioport.h and module.h. All the io accessors we use are in
io.h, and we only need export.h for EXPORT_SYMBOL().

> +#include <linux/platform_device.h>

This isn't a platform_driver. Was it meant to be? It would be nicer if
so, using builtin_platform_driver and having the usual infrastrucutre
drive the matching.

> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/smp.h>

We don't appear to use anything from smp.h any more, so I beleive that
can go too.

> +#include <linux/firmware/meson/meson_sm.h>

You also need <linux/printk.h>, and <linux/bug.h> for pr_* and WARN_ON
respectively. I believe that <linux/types.h> is mean to be included for
u32 and friends, though they're defined through some magic in transitive
includes.

> +
> +struct meson_sm_cmd {
> +	unsigned int index;
> +	u32 smc_id;
> +};
> +#define CMD(d, s) { .index = (d), .smc_id = (s), }
> +
> +struct meson_sm_chip {
> +	unsigned int shmem_size;
> +	u32 cmd_shmem_in_base;
> +	u32 cmd_shmem_out_base;
> +	struct meson_sm_cmd cmd[];
> +};
> +
> +struct meson_sm_chip gxbb_chip = {
> +	.shmem_size		= 0x1000,
> +	.cmd_shmem_in_base	= 0x82000020,
> +	.cmd_shmem_out_base	= 0x82000021,
> +	.cmd = {
> +		CMD(SM_EFUSE_READ,	0x82000030),
> +		CMD(SM_EFUSE_WRITE,	0x82000031),
> +		CMD(SM_EFUSE_USER_MAX,	0x82000033),
> +		{ /* sentinel */ },
> +	},
> +};
> +
> +struct meson_sm_firmware {
> +	const struct meson_sm_chip *chip;
> +	void __iomem *sm_shmem_in_base;
> +	void __iomem *sm_shmem_out_base;
> +};
> +
> +static struct meson_sm_firmware fw;
> +
> +static u32 meson_sm_get_cmd(const struct meson_sm_chip *chip, unsigned int cmd_index)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; chip->cmd[i].smc_id; i++)
> +		if (chip->cmd[i].index == cmd_index)
> +			return chip->cmd[i].smc_id;
> +
> +	return 0;
> +}

Given that the sentinel has index == 0 and smc_id == 0, you could
simplify this to something like:

	struct meson_sm_cmd *cmd = chip->cmd;

	while (cmd->smc_id && cmd->index != cmd_index)
		cmd++;

	return cmd->smc_id;

> +
> +static u32 __meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
> +{
> +	struct arm_smccc_res res;
> +
> +	arm_smccc_smc(cmd, arg0, arg1, arg2, arg3, arg4, 0, 0, &res);
> +	return res.a0;
> +}
> +
> +static void __iomem *meson_sm_map_shmem(u32 cmd_shmem, unsigned int size)
> +{
> +	u32 sm_phy_base;
> +
> +	sm_phy_base = __meson_sm_call(cmd_shmem, 0, 0, 0, 0, 0);
> +	if (!sm_phy_base)
> +		return 0;
> +
> +	return ioremap_cache(sm_phy_base, size);
> +}

Does this work on !4K page kernels?

Above I saw that for GXBB the shmem_size was 0x1000. I can imagine that
mapping an extra 60K with cacheable attributes isn't going to be safe,
even if the kernel happens to do that.

Either we need to handle that, or rule out working for !4K kernels
(either with a Kconfig dependency, or some runtime detection).

> +/**
> + * meson_sm_call - generic SMC32 call to the secure-monitor
> + *
> + * @fw:		Meson secure-monitor firmware pointer
> + * @cmd_index:	Index of the SMC32 function ID
> + * @ret:	Returned value
> + * @arg0:	SMC32 Argument 0
> + * @arg1:	SMC32 Argument 1
> + * @arg2:	SMC32 Argument 2
> + * @arg3:	SMC32 Argument 3
> + * @arg4:	SMC32 Argument 4
> + *
> + * Return:	0 on success, a negative value on error
> + */
> +int meson_sm_call(struct meson_sm_firmware *fw, unsigned int cmd_index,
> +		  u32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
> +{
> +	u32 cmd, lret;
> +
> +	if (!fw)
> +		return -EINVAL;
> +
> +	cmd = meson_sm_get_cmd(fw->chip, cmd_index);
> +	if (!cmd)
> +		return -EINVAL;
> +
> +	lret = __meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4);
> +
> +	if (ret)
> +		*ret = lret;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(meson_sm_call);
> +
> +/**
> + * meson_sm_call_read - retrieve data from secure-monitor
> + *
> + * @fw:		Meson secure-monitor firmware pointer
> + * @buffer:	Buffer to store the retrieved data
> + * @cmd_index:	Index of the SMC32 function ID
> + * @arg0:	SMC32 Argument 0
> + * @arg1:	SMC32 Argument 1
> + * @arg2:	SMC32 Argument 2
> + * @arg3:	SMC32 Argument 3
> + * @arg4:	SMC32 Argument 4
> + *
> + * Return:	size of read data on success, a negative value on error
> + */
> +int meson_sm_call_read(struct meson_sm_firmware *fw, void *buffer,
> +		       unsigned int cmd_index, u32 arg0, u32 arg1,
> +		       u32 arg2, u32 arg3, u32 arg4)
> +{
> +	u32 size;
> +
> +	if (!fw->chip->cmd_shmem_out_base)
> +		return -EINVAL;
> +
> +	if (meson_sm_call(fw, cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)
> +		return -EINVAL;
> +
> +	if (!size || size > fw->chip->shmem_size)
> +		return -EINVAL;
> +
> +	if (buffer)
> +		memcpy(buffer, fw->sm_shmem_out_base, size);
> +
> +	return size;
> +}
> +EXPORT_SYMBOL(meson_sm_call_read);
> +
> +/**
> + * meson_sm_call_write - send data to secure-monitor
> + *
> + * @fw:		Meson secure-monitor firmware pointer
> + * @buffer:	Buffer containing data to send
> + * @b_size:	Size of the data to send
> + * @cmd_index:	Index of the SMC32 function ID
> + * @arg0:	SMC32 Argument 0
> + * @arg1:	SMC32 Argument 1
> + * @arg2:	SMC32 Argument 2
> + * @arg3:	SMC32 Argument 3
> + * @arg4:	SMC32 Argument 4
> + *
> + * Return:	size of sent data on success, a negative value on error
> + */
> +int meson_sm_call_write(struct meson_sm_firmware *fw, void *buffer,
> +			unsigned int b_size, unsigned int cmd_index,
> +			u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
> +{
> +	u32 size;

The b_size vs size thing is somewhat confusing.

could we s/size/written/ and s/b_size/size/ ?

> +
> +	if (b_size > fw->chip->shmem_size)
> +		return -EINVAL;
> +
> +	if (!fw->chip->cmd_shmem_in_base)
> +		return -EINVAL;
> +
> +	memcpy(fw->sm_shmem_in_base, buffer, b_size);
> +
> +	if (meson_sm_call(fw, cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)
> +		return -EINVAL;
> +
> +	if (!size)
> +		return -EINVAL;
> +
> +	return size;
> +}
> +EXPORT_SYMBOL(meson_sm_call_write);
> +
> +/**
> + * meson_sm_get_fw - get Meson firmware struct
> + *
> + * Return:		Meson secure-monitor firmware struct on success, NULL on error
> + */
> +struct meson_sm_firmware *meson_sm_get_fw(void)
> +{
> +	/*
> +	 * Returns NULL is the firmware device is not ready.
> +	 */
> +	if (!fw.chip)
> +		return NULL;
> +
> +	return &fw;
> +}
> +EXPORT_SYMBOL(meson_sm_get_fw);

Do any external callers actually need direct access to the fw struct
fields? Or is this just so they can pass this to meson_sm_call and
friends?

Given we have a singleton anyway, can't we just have the meson_sm_call*
functions check whether fw is initialised, and return -ENOENT/-ENXIO if
not?

> +
> +static const struct of_device_id meson_sm_ids[] = {
> +	{ .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip },
> +	{ /* sentinel */ },
> +};
> +
> +int __init meson_sm_init(void)
> +{
> +	const struct meson_sm_chip *chip;
> +	const struct of_device_id *matched_np;
> +	struct device_node *np;
> +
> +	np = of_find_matching_node_and_match(NULL, meson_sm_ids, &matched_np);
> +	if (!np) {
> +		pr_err("no matching node\n");
> +		return -EINVAL;
> +	}
> +

This is going to be pointlessly noisy on every non-amlogic board out
there.

Please make this a platform driver, such that this is only called when a
node is present, avoiding some mess there.

> +	chip = matched_np->data;
> +	if (!chip) {
> +		pr_err("unable to setup secure-monitor data\n");
> +		return -EINVAL;
> +	}

Using a platform driver would also avoid the necessity of this check, so
long as you know each of_device_id entry has a valid data field.

> +
> +	if (chip->cmd_shmem_in_base) {
> +		fw.sm_shmem_in_base = meson_sm_map_shmem(chip->cmd_shmem_in_base,
> +							 chip->shmem_size);
> +		if (WARN_ON(!fw.sm_shmem_in_base))
> +			goto out;
> +	}

As above, I'm worried this may explode on !4K kernels (and also somewhat
worried that it might not blow up here, but rather elsewhere at
runtime).

> +
> +	if (chip->cmd_shmem_out_base) {
> +		fw.sm_shmem_out_base = meson_sm_map_shmem(chip->cmd_shmem_out_base,
> +							  chip->shmem_size);
> +		if (WARN_ON(!fw.sm_shmem_out_base))
> +			goto out;
> +	}
> +
> +	fw.chip = chip;
> +	pr_info("secure-monitor enabled\n");

This may be ambiguous to those not familiar with this driver. It would
be worth having:

#define pr_fmt(fmt) "meson-sm: " fmt

before the include of <linux/printk.h>, which would make it clear that
the log messages came from this particular secure monitor driver.

> +
> +	return 0;
> +
> +out:
> +	if (fw.sm_shmem_in_base)
> +		iounmap(fw.sm_shmem_in_base);
> +
> +	return -EINVAL;

It would be nicer to have:

out_in_base:
	iounmap(fw.sm_shmem_in_base);
out:
	return -EINVAL

With the earlier gotos fixed up appropriately.

> +}
> +device_initcall(meson_sm_init);
> diff --git a/include/linux/firmware/meson/meson_sm.h b/include/linux/firmware/meson/meson_sm.h
> new file mode 100644
> index 0000000..81136b0
> --- /dev/null
> +++ b/include/linux/firmware/meson/meson_sm.h
> @@ -0,0 +1,32 @@
> +/*
> + * Copyright (C) 2016 Endless Mobile, Inc.
> + * Author: Carlo Caione <carlo@endlessm.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.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#ifndef _MESON_SM_FW_H_
> +#define _MESON_SM_FW_H_
> +
> +#define SM_EFUSE_READ		0
> +#define SM_EFUSE_WRITE		1
> +#define SM_EFUSE_USER_MAX	2

This looks like enum material, even if only for the definitions here.

> +
> +struct meson_sm_firmware;
> +
> +int meson_sm_call(struct meson_sm_firmware *fw, unsigned int cmd_index,
> +		  u32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4);
> +int meson_sm_call_write(struct meson_sm_firmware *fw, void *buffer,
> +			unsigned int b_size, unsigned int cmd_index,
> +			u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4);
> +int meson_sm_call_read(struct meson_sm_firmware *fw, void *buffer,
> +		       unsigned int cmd_index, u32 arg0, u32 arg1,
> +		       u32 arg2, u32 arg3, u32 arg4);
> +struct meson_sm_firmware *meson_sm_get_fw(void);

As above, I'm not sure if it makes sense for meson_sm_firmware to leak
into drivers, though you may have a use-case for that describe in a
previous bit of reply.

Thanks,
Mark.

[PATCH 1/6] firmware: Amlogic: Add secure monitor driver

[Carlo Caione]

On 27/06/16 18:28, Mark Rutland wrote:
> Hi,
> 
> On Sun, Jun 19, 2016 at 02:38:59PM +0200, Carlo Caione wrote:

[...]
> > +#include <stdarg.h>
> > +#include <asm/cacheflush.h>
> > +#include <asm/compiler.h>
> 
> As far as I can see, these aren't necessary. There aren't any variadic
> functions, there's no cache maintenance. I'm guessing compiler.h is left
> over from pre-SMCCCC code that used __asmeq().

Also I forgot to clean-up the headers list from the previous iterations.

> > +#include <linux/arm-smccc.h>
> > +#include <linux/io.h>
> > +#include <linux/ioport.h>
> > +#include <linux/module.h>
> 
> Likewise for ioport.h and module.h. All the io accessors we use are in
> io.h, and we only need export.h for EXPORT_SYMBOL().

ok

> > +#include <linux/platform_device.h>
> 
> This isn't a platform_driver. Was it meant to be? It would be nicer if
> so, using builtin_platform_driver and having the usual infrastrucutre
> drive the matching.

It was a platform driver in the first versions but I changed to this
form after Rob suggested to have it in the /firmware node and without
compatibility to the "simple-bus".

> > +#include <linux/of.h>
> > +#include <linux/of_device.h>
> > +#include <linux/smp.h>
> 
> We don't appear to use anything from smp.h any more, so I beleive that
> can go too.

ok

> > +#include <linux/firmware/meson/meson_sm.h>
> 
> You also need <linux/printk.h>, and <linux/bug.h> for pr_* and WARN_ON
> respectively. I believe that <linux/types.h> is mean to be included for
> u32 and friends, though they're defined through some magic in transitive
> includes.

ok

[...]
> > +static u32 meson_sm_get_cmd(const struct meson_sm_chip *chip, unsigned int cmd_index)
> > +{
> > +	unsigned int i;
> > +
> > +	for (i = 0; chip->cmd[i].smc_id; i++)
> > +		if (chip->cmd[i].index == cmd_index)
> > +			return chip->cmd[i].smc_id;
> > +
> > +	return 0;
> > +}
> 
> Given that the sentinel has index == 0 and smc_id == 0, you could
> simplify this to something like:
> 
> 	struct meson_sm_cmd *cmd = chip->cmd;
> 
> 	while (cmd->smc_id && cmd->index != cmd_index)
> 		cmd++;
> 
> 	return cmd->smc_id;

yeah, better I think

> > +
> > +static u32 __meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
> > +{
> > +	struct arm_smccc_res res;
> > +
> > +	arm_smccc_smc(cmd, arg0, arg1, arg2, arg3, arg4, 0, 0, &res);
> > +	return res.a0;
> > +}
> > +
> > +static void __iomem *meson_sm_map_shmem(u32 cmd_shmem, unsigned int size)
> > +{
> > +	u32 sm_phy_base;
> > +
> > +	sm_phy_base = __meson_sm_call(cmd_shmem, 0, 0, 0, 0, 0);
> > +	if (!sm_phy_base)
> > +		return 0;
> > +
> > +	return ioremap_cache(sm_phy_base, size);
> > +}
> 
> Does this work on !4K page kernels?
> 
> Above I saw that for GXBB the shmem_size was 0x1000. I can imagine that
> mapping an extra 60K with cacheable attributes isn't going to be safe,
> even if the kernel happens to do that.

Agree

> Either we need to handle that, or rule out working for !4K kernels
> (either with a Kconfig dependency, or some runtime detection).

Probably it's better to stay on the safe side and just to rule !4K
kernels out with Kconfig

[...]
> > + * Return:	size of sent data on success, a negative value on error
> > + */
> > +int meson_sm_call_write(struct meson_sm_firmware *fw, void *buffer,
> > +			unsigned int b_size, unsigned int cmd_index,
> > +			u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
> > +{
> > +	u32 size;
> 
> The b_size vs size thing is somewhat confusing.
> 
> could we s/size/written/ and s/b_size/size/ ?

ok

> > +
> > +	if (b_size > fw->chip->shmem_size)
> > +		return -EINVAL;
> > +
> > +	if (!fw->chip->cmd_shmem_in_base)
> > +		return -EINVAL;
> > +
> > +	memcpy(fw->sm_shmem_in_base, buffer, b_size);
> > +
> > +	if (meson_sm_call(fw, cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)
> > +		return -EINVAL;
> > +
> > +	if (!size)
> > +		return -EINVAL;
> > +
> > +	return size;
> > +}
> > +EXPORT_SYMBOL(meson_sm_call_write);
> > +
> > +/**
> > + * meson_sm_get_fw - get Meson firmware struct
> > + *
> > + * Return:		Meson secure-monitor firmware struct on success, NULL on error
> > + */
> > +struct meson_sm_firmware *meson_sm_get_fw(void)
> > +{
> > +	/*
> > +	 * Returns NULL is the firmware device is not ready.
> > +	 */
> > +	if (!fw.chip)
> > +		return NULL;
> > +
> > +	return &fw;
> > +}
> > +EXPORT_SYMBOL(meson_sm_get_fw);
> 
> Do any external callers actually need direct access to the fw struct
> fields? Or is this just so they can pass this to meson_sm_call and
> friends?
> 
> Given we have a singleton anyway, can't we just have the meson_sm_call*
> functions check whether fw is initialised, and return -ENOENT/-ENXIO if
> not?

Yes, the meson_sm_get_fw() was used to enforce probe ordering when the
driver was a platform driver. Since this is now probed on
device_initcall() I think we can safely remove this.

> > +
> > +static const struct of_device_id meson_sm_ids[] = {
> > +	{ .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip },
> > +	{ /* sentinel */ },
> > +};
> > +
> > +int __init meson_sm_init(void)
> > +{
> > +	const struct meson_sm_chip *chip;
> > +	const struct of_device_id *matched_np;
> > +	struct device_node *np;
> > +
> > +	np = of_find_matching_node_and_match(NULL, meson_sm_ids, &matched_np);
> > +	if (!np) {
> > +		pr_err("no matching node\n");
> > +		return -EINVAL;
> > +	}
> > +
> 
> This is going to be pointlessly noisy on every non-amlogic board out
> there.

ouch, right

> Please make this a platform driver, such that this is only called when a
> node is present, avoiding some mess there.

Since Rob required this to be under /firmware (and using no "simple-bus"
compatible to trigger the automatic creation) making it a platform
driver just adds a lot of boilerplate code. If this doesn't mean a NACK
on your side, I still would leave the code as is with the
device_initcall() calling the init.

> > +	chip = matched_np->data;
> > +	if (!chip) {
> > +		pr_err("unable to setup secure-monitor data\n");
> > +		return -EINVAL;
> > +	}
> 
> Using a platform driver would also avoid the necessity of this check, so
> long as you know each of_device_id entry has a valid data field.
> 
> > +
> > +	if (chip->cmd_shmem_in_base) {
> > +		fw.sm_shmem_in_base = meson_sm_map_shmem(chip->cmd_shmem_in_base,
> > +							 chip->shmem_size);
> > +		if (WARN_ON(!fw.sm_shmem_in_base))
> > +			goto out;
> > +	}
> 
> As above, I'm worried this may explode on !4K kernels (and also somewhat
> worried that it might not blow up here, but rather elsewhere at
> runtime).

ok

> > +
> > +	if (chip->cmd_shmem_out_base) {
> > +		fw.sm_shmem_out_base = meson_sm_map_shmem(chip->cmd_shmem_out_base,
> > +							  chip->shmem_size);
> > +		if (WARN_ON(!fw.sm_shmem_out_base))
> > +			goto out;
> > +	}
> > +
> > +	fw.chip = chip;
> > +	pr_info("secure-monitor enabled\n");
> 
> This may be ambiguous to those not familiar with this driver. It would
> be worth having:
> 
> #define pr_fmt(fmt) "meson-sm: " fmt
> 
> before the include of <linux/printk.h>, which would make it clear that
> the log messages came from this particular secure monitor driver.

good idea

> > +
> > +	return 0;
> > +
> > +out:
> > +	if (fw.sm_shmem_in_base)
> > +		iounmap(fw.sm_shmem_in_base);
> > +
> > +	return -EINVAL;
> 
> It would be nicer to have:
> 
> out_in_base:
> 	iounmap(fw.sm_shmem_in_base);
> out:
> 	return -EINVAL
> 
> With the earlier gotos fixed up appropriately.

agreed

> > +}
> > +device_initcall(meson_sm_init);
> > diff --git a/include/linux/firmware/meson/meson_sm.h b/include/linux/firmware/meson/meson_sm.h
> > new file mode 100644
> > index 0000000..81136b0
> > --- /dev/null
> > +++ b/include/linux/firmware/meson/meson_sm.h
> > @@ -0,0 +1,32 @@
> > +/*
> > + * Copyright (C) 2016 Endless Mobile, Inc.
> > + * Author: Carlo Caione <carlo@endlessm.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.
> > + *
> > + * You should have received a copy of the GNU General Public License
> > + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> > + */
> > +
> > +#ifndef _MESON_SM_FW_H_
> > +#define _MESON_SM_FW_H_
> > +
> > +#define SM_EFUSE_READ		0
> > +#define SM_EFUSE_WRITE		1
> > +#define SM_EFUSE_USER_MAX	2
> 
> This looks like enum material, even if only for the definitions here.

ok

> > +
> > +struct meson_sm_firmware;
> > +
> > +int meson_sm_call(struct meson_sm_firmware *fw, unsigned int cmd_index,
> > +		  u32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4);
> > +int meson_sm_call_write(struct meson_sm_firmware *fw, void *buffer,
> > +			unsigned int b_size, unsigned int cmd_index,
> > +			u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4);
> > +int meson_sm_call_read(struct meson_sm_firmware *fw, void *buffer,
> > +		       unsigned int cmd_index, u32 arg0, u32 arg1,
> > +		       u32 arg2, u32 arg3, u32 arg4);
> > +struct meson_sm_firmware *meson_sm_get_fw(void);
> 
> As above, I'm not sure if it makes sense for meson_sm_firmware to leak
> into drivers, though you may have a use-case for that describe in a
> previous bit of reply.

Not really, as written before that was used to enforce probe ordering.
I'll take that out in the next revision.

Thank you for your review,

-- 
Carlo Caione

[PATCH 1/6] firmware: Amlogic: Add secure monitor driver

[Mark Rutland]

Hi,

On Tue, Jun 28, 2016 at 10:10:57AM +0200, Carlo Caione wrote:
> On 27/06/16 18:28, Mark Rutland wrote:
> > On Sun, Jun 19, 2016 at 02:38:59PM +0200, Carlo Caione wrote:
> > > +	np = of_find_matching_node_and_match(NULL, meson_sm_ids, &matched_np);
> > > +	if (!np) {
> > > +		pr_err("no matching node\n");
> > > +		return -EINVAL;
> > > +	}
> > > +
> > 
> > This is going to be pointlessly noisy on every non-amlogic board out
> > there.
> 
> ouch, right
> 
> > Please make this a platform driver, such that this is only called when a
> > node is present, avoiding some mess there.
> 
> Since Rob required this to be under /firmware (and using no "simple-bus"
> compatible to trigger the automatic creation) making it a platform
> driver just adds a lot of boilerplate code. If this doesn't mean a NACK
> on your side, I still would leave the code as is with the
> device_initcall() calling the init.

Ok. So long as this isn't noisy where the node is not present, that's
fine by me.

Thanks,
Mark.

[PATCH 2/6] documentation: Add secure monitor bindings documentation

[Carlo Caione]

From: Carlo Caione <carlo@endlessm.com>

Add the binding documentation for the Amlogic secure monitor driver.

Signed-off-by: Carlo Caione <carlo@endlessm.com>
---
 .../devicetree/bindings/firmware/meson/meson_sm.txt       | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/firmware/meson/meson_sm.txt

diff --git a/Documentation/devicetree/bindings/firmware/meson/meson_sm.txt b/Documentation/devicetree/bindings/firmware/meson/meson_sm.txt
new file mode 100644
index 0000000..c248cd4
--- /dev/null
+++ b/Documentation/devicetree/bindings/firmware/meson/meson_sm.txt
@@ -0,0 +1,15 @@
+* Amlogic Secure Monitor
+
+In the Amlogic SoCs the Secure Monitor code is used to provide access to the
+NVMEM, enable JTAG, set USB boot, etc...
+
+Required properties for the secure monitor node:
+- compatible: Should be "amlogic,meson-gxbb-sm"
+
+Example:
+
+	firmware {
+		sm: secure-monitor {
+			compatible = "amlogic,meson-gxbb-sm";
+		};
+	};
-- 
2.7.4

[PATCH 2/6] documentation: Add secure monitor bindings documentation

[Rob Herring]

On Sun, Jun 19, 2016 at 02:39:00PM +0200, Carlo Caione wrote:
> From: Carlo Caione <carlo@endlessm.com>
> 
> Add the binding documentation for the Amlogic secure monitor driver.
> 
> Signed-off-by: Carlo Caione <carlo@endlessm.com>
> ---
>  .../devicetree/bindings/firmware/meson/meson_sm.txt       | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/firmware/meson/meson_sm.txt

Please add acks when reposting.

Rob

[PATCH 2/6] documentation: Add secure monitor bindings documentation

[Carlo Caione]

On Mon, Jun 20, 2016 at 8:06 PM, Rob Herring <robh@kernel.org> wrote:
> On Sun, Jun 19, 2016 at 02:39:00PM +0200, Carlo Caione wrote:
>> From: Carlo Caione <carlo@endlessm.com>
>>
>> Add the binding documentation for the Amlogic secure monitor driver.
>>
>> Signed-off-by: Carlo Caione <carlo@endlessm.com>
>> ---
>>  .../devicetree/bindings/firmware/meson/meson_sm.txt       | 15 +++++++++++++++
>>  1 file changed, 15 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/firmware/meson/meson_sm.txt
>
> Please add acks when reposting.

I didn't add your ACK since the patch is slightly different.
I'll add it back in the next revision.

Thanks,

-- 
Carlo Caione  |  +39.340.80.30.096  |  Endless

[PATCH 3/6] ARM64: dts: amlogic: gxbb: Enable secure monitor

[Carlo Caione]

From: Carlo Caione <carlo@endlessm.com>

Add the secure monitor node in the Amlogic Meson GXBB DTSI file to
enable it.

Signed-off-by: Carlo Caione <carlo@endlessm.com>
---
 arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
index 76b3b6d..407f24c 100644
--- a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
@@ -98,6 +98,12 @@
 		method = "smc";
 	};
 
+	firmware {
+		sm: secure-monitor {
+			compatible = "amlogic,meson-gxbb-sm";
+		};
+	};
+
 	timer {
 		compatible = "arm,armv8-timer";
 		interrupts = <GIC_PPI 13
-- 
2.7.4

[PATCH 4/6] nvmem: amlogic: Add Amlogic Meson EFUSE driver

[Carlo Caione]

From: Carlo Caione <carlo@endlessm.com>

Add Amlogic EFUSE driver to access hardware data like ethernet address,
serial number or IDs.

Signed-off-by: Carlo Caione <carlo@endlessm.com>
---
 drivers/nvmem/Kconfig       |  11 ++++
 drivers/nvmem/Makefile      |   2 +
 drivers/nvmem/meson-efuse.c | 130 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 143 insertions(+)
 create mode 100644 drivers/nvmem/meson-efuse.c

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index ca52952..ef17bc9 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -102,4 +102,15 @@ config NVMEM_VF610_OCOTP
 	  This driver can also be build as a module. If so, the module will
 	  be called nvmem-vf610-ocotp.
 
+config MESON_EFUSE
+	tristate "Amlogic eFuse Support"
+	depends on ARCH_MESON || COMPILE_TEST
+	select REGMAP_MMIO
+	help
+	  This is a driver to retrieve specific values from the eFuse found on
+	  the Amlogic Meson SoCs.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called nvmem_meson_efuse.
+
 endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 45ab1ae..8f942a0 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -22,3 +22,5 @@ obj-$(CONFIG_NVMEM_SUNXI_SID)	+= nvmem_sunxi_sid.o
 nvmem_sunxi_sid-y		:= sunxi_sid.o
 obj-$(CONFIG_NVMEM_VF610_OCOTP)	+= nvmem-vf610-ocotp.o
 nvmem-vf610-ocotp-y		:= vf610-ocotp.o
+obj-$(CONFIG_MESON_EFUSE)	+= nvmem_meson_efuse.o
+nvmem_meson_efuse-y		:= meson-efuse.o
diff --git a/drivers/nvmem/meson-efuse.c b/drivers/nvmem/meson-efuse.c
new file mode 100644
index 0000000..7c80e1c
--- /dev/null
+++ b/drivers/nvmem/meson-efuse.c
@@ -0,0 +1,130 @@
+/*
+ * Amlogic eFuse Driver
+ *
+ * Copyright (c) 2016 Endless Computers, Inc.
+ * Author: Carlo Caione <carlo@endlessm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/firmware/meson/meson_sm.h>
+
+static struct meson_sm_firmware *fw;
+
+static int meson_efuse_write(void *context, const void *data, size_t count)
+{
+	/* Nothing TBD, Read-Only */
+	return 0;
+}
+
+static int meson_efuse_read(void *context,
+			    const void *reg, size_t reg_size,
+			    void *val, size_t val_size)
+{
+	unsigned int offset = *(u32 *)reg;
+	u8 *buf = val;
+	int ret;
+
+	ret = meson_sm_call_read(fw, buf, SM_EFUSE_READ, offset,
+				 val_size, 0, 0, 0);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static struct nvmem_config econfig = {
+	.name = "meson-efuse",
+	.owner = THIS_MODULE,
+	.read_only = true,
+};
+
+static struct regmap_bus meson_efuse_bus = {
+	.read = meson_efuse_read,
+	.write = meson_efuse_write,
+	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+};
+
+static struct regmap_config meson_efuse_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 1,
+	.val_bits = 8,
+};
+
+static const struct of_device_id meson_efuse_match[] = {
+	{ .compatible = "amlogic,meson-gxbb-efuse", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, meson_efuse_match);
+
+static int meson_efuse_probe(struct platform_device *pdev)
+{
+	struct nvmem_device *nvmem;
+	struct regmap *regmap;
+	unsigned int size;
+
+	fw = meson_sm_get_fw();
+	if (!fw)
+		return -EPROBE_DEFER;
+
+	if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0)
+		return -EINVAL;
+	meson_efuse_regmap_config.max_register = size - 1;
+
+	regmap = devm_regmap_init(&pdev->dev, &meson_efuse_bus,
+				  NULL, &meson_efuse_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&pdev->dev, "regmap init failed\n");
+		return PTR_ERR(regmap);
+	}
+
+	econfig.dev = &pdev->dev;
+	nvmem = nvmem_register(&econfig);
+	if (IS_ERR(nvmem))
+		return PTR_ERR(nvmem);
+
+	platform_set_drvdata(pdev, nvmem);
+
+	return 0;
+}
+
+static int meson_efuse_remove(struct platform_device *pdev)
+{
+	struct nvmem_device *nvmem = platform_get_drvdata(pdev);
+
+	return nvmem_unregister(nvmem);
+}
+
+static struct platform_driver meson_efuse_driver = {
+	.probe = meson_efuse_probe,
+	.remove = meson_efuse_remove,
+	.driver = {
+		.name = "meson-efuse",
+		.of_match_table = meson_efuse_match,
+	},
+};
+
+module_platform_driver(meson_efuse_driver);
+
+MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
+MODULE_DESCRIPTION("Amlogic Meson NVMEM driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

[PATCH 4/6] nvmem: amlogic: Add Amlogic Meson EFUSE driver

[Srinivas Kandagatla]

Hi Carlo,

On 19/06/16 13:39, Carlo Caione wrote:
> From: Carlo Caione <carlo@endlessm.com>
>
> Add Amlogic EFUSE driver to access hardware data like ethernet address,
> serial number or IDs.
>
> Signed-off-by: Carlo Caione <carlo@endlessm.com>
> ---
>   drivers/nvmem/Kconfig       |  11 ++++
>   drivers/nvmem/Makefile      |   2 +
>   drivers/nvmem/meson-efuse.c | 130 ++++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 143 insertions(+)
>   create mode 100644 drivers/nvmem/meson-efuse.c
>
> diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
> index ca52952..ef17bc9 100644
> --- a/drivers/nvmem/Kconfig
> +++ b/drivers/nvmem/Kconfig
> @@ -102,4 +102,15 @@ config NVMEM_VF610_OCOTP
>   	  This driver can also be build as a module. If so, the module will
>   	  be called nvmem-vf610-ocotp.
>
> +config MESON_EFUSE
> +	tristate "Amlogic eFuse Support"
> +	depends on ARCH_MESON || COMPILE_TEST
> +	select REGMAP_MMIO

NVMEM recently moved out of using regmap, as regmap did not provide 
better abstraction, could you rebase your patch on top of mainline.

Thanks,
srini

> +	help
> +	  This is a driver to retrieve specific values from the eFuse found on
> +	  the Amlogic Meson SoCs.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called nvmem_meson_efuse.
> +
>   endif
> diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
> index 45ab1ae..8f942a0 100644
> --- a/drivers/nvmem/Makefile
> +++ b/drivers/nvmem/Makefile
> @@ -22,3 +22,5 @@ obj-$(CONFIG_NVMEM_SUNXI_SID)	+= nvmem_sunxi_sid.o
>   nvmem_sunxi_sid-y		:= sunxi_sid.o
>   obj-$(CONFIG_NVMEM_VF610_OCOTP)	+= nvmem-vf610-ocotp.o
>   nvmem-vf610-ocotp-y		:= vf610-ocotp.o
> +obj-$(CONFIG_MESON_EFUSE)	+= nvmem_meson_efuse.o
> +nvmem_meson_efuse-y		:= meson-efuse.o
> diff --git a/drivers/nvmem/meson-efuse.c b/drivers/nvmem/meson-efuse.c
> new file mode 100644
> index 0000000..7c80e1c
> --- /dev/null
> +++ b/drivers/nvmem/meson-efuse.c
> @@ -0,0 +1,130 @@
> +/*
> + * Amlogic eFuse Driver
> + *
> + * Copyright (c) 2016 Endless Computers, Inc.
> + * Author: Carlo Caione <carlo@endlessm.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of version 2 of the GNU General Public License as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/nvmem-provider.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#include <linux/firmware/meson/meson_sm.h>
> +
> +static struct meson_sm_firmware *fw;
> +
> +static int meson_efuse_write(void *context, const void *data, size_t count)
> +{
> +	/* Nothing TBD, Read-Only */
> +	return 0;
> +}
> +
> +static int meson_efuse_read(void *context,
> +			    const void *reg, size_t reg_size,
> +			    void *val, size_t val_size)
> +{
> +	unsigned int offset = *(u32 *)reg;
> +	u8 *buf = val;
> +	int ret;
> +
> +	ret = meson_sm_call_read(fw, buf, SM_EFUSE_READ, offset,
> +				 val_size, 0, 0, 0);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static struct nvmem_config econfig = {
> +	.name = "meson-efuse",
> +	.owner = THIS_MODULE,
> +	.read_only = true,
> +};
> +
> +static struct regmap_bus meson_efuse_bus = {
> +	.read = meson_efuse_read,
> +	.write = meson_efuse_write,
> +	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
> +	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
> +};
> +
> +static struct regmap_config meson_efuse_regmap_config = {
> +	.reg_bits = 32,
> +	.reg_stride = 1,
> +	.val_bits = 8,
> +};
> +
> +static const struct of_device_id meson_efuse_match[] = {
> +	{ .compatible = "amlogic,meson-gxbb-efuse", },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, meson_efuse_match);
> +
> +static int meson_efuse_probe(struct platform_device *pdev)
> +{
> +	struct nvmem_device *nvmem;
> +	struct regmap *regmap;
> +	unsigned int size;
> +
> +	fw = meson_sm_get_fw();
> +	if (!fw)
> +		return -EPROBE_DEFER;
> +
> +	if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0)
> +		return -EINVAL;
> +	meson_efuse_regmap_config.max_register = size - 1;
> +
> +	regmap = devm_regmap_init(&pdev->dev, &meson_efuse_bus,
> +				  NULL, &meson_efuse_regmap_config);
> +	if (IS_ERR(regmap)) {
> +		dev_err(&pdev->dev, "regmap init failed\n");
> +		return PTR_ERR(regmap);
> +	}
> +
> +	econfig.dev = &pdev->dev;
> +	nvmem = nvmem_register(&econfig);
> +	if (IS_ERR(nvmem))
> +		return PTR_ERR(nvmem);
> +
> +	platform_set_drvdata(pdev, nvmem);
> +
> +	return 0;
> +}
> +
> +static int meson_efuse_remove(struct platform_device *pdev)
> +{
> +	struct nvmem_device *nvmem = platform_get_drvdata(pdev);
> +
> +	return nvmem_unregister(nvmem);
> +}
> +
> +static struct platform_driver meson_efuse_driver = {
> +	.probe = meson_efuse_probe,
> +	.remove = meson_efuse_remove,
> +	.driver = {
> +		.name = "meson-efuse",
> +		.of_match_table = meson_efuse_match,
> +	},
> +};
> +
> +module_platform_driver(meson_efuse_driver);
> +
> +MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
> +MODULE_DESCRIPTION("Amlogic Meson NVMEM driver");
> +MODULE_LICENSE("GPL v2");
>

[PATCH 5/6] documentation: Add nvmem bindings documentation

[Carlo Caione]

From: Carlo Caione <carlo@endlessm.com>

This patch add the bindings document of Amlogic eFuse driver.

Signed-off-by: Carlo Caione <carlo@endlessm.com>
---
 .../devicetree/bindings/nvmem/amlogic-efuse.txt    | 39 ++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nvmem/amlogic-efuse.txt

diff --git a/Documentation/devicetree/bindings/nvmem/amlogic-efuse.txt b/Documentation/devicetree/bindings/nvmem/amlogic-efuse.txt
new file mode 100644
index 0000000..fafd85b
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/amlogic-efuse.txt
@@ -0,0 +1,39 @@
+= Amlogic eFuse device tree bindings =
+
+Required properties:
+- compatible: should be "amlogic,meson-gxbb-efuse"
+
+= Data cells =
+Are child nodes of eFuse, bindings of which as described in
+bindings/nvmem/nvmem.txt
+
+Example:
+
+	efuse: efuse {
+		compatible = "amlogic,meson-gxbb-efuse";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		sn: sn at 14 {
+			reg = <0x14 0x10>;
+		};
+
+		eth_mac: eth_mac at 34 {
+			reg = <0x34 0x10>;
+		};
+
+		bid: bid at 46 {
+			reg = <0x46 0x30>;
+		};
+	};
+
+= Data consumers =
+Are device nodes which consume nvmem data cells.
+
+For example:
+
+	eth_mac {
+		...
+		nvmem-cells = <&eth_mac>;
+		nvmem-cell-names = "eth_mac";
+	};
-- 
2.7.4

[PATCH 5/6] documentation: Add nvmem bindings documentation

[Rob Herring]

On Sun, Jun 19, 2016 at 02:39:03PM +0200, Carlo Caione wrote:
> From: Carlo Caione <carlo@endlessm.com>
> 
> This patch add the bindings document of Amlogic eFuse driver.
> 
> Signed-off-by: Carlo Caione <carlo@endlessm.com>
> ---
>  .../devicetree/bindings/nvmem/amlogic-efuse.txt    | 39 ++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/nvmem/amlogic-efuse.txt

Acked-by: Rob Herring <robh@kernel.org>

[PATCH 6/6] ARM64: dts: amlogic: gxbb: Enable NVMEM

[Carlo Caione]

From: Carlo Caione <carlo@endlessm.com>

Add the NVMEM device node in the DTSI.

Signed-off-by: Carlo Caione <carlo@endlessm.com>
---
 arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
index 407f24c..0e0f7c0 100644
--- a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
@@ -104,6 +104,24 @@
 		};
 	};
 
+	efuse: efuse {
+		compatible = "amlogic,meson-gxbb-efuse";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		sn: sn at 14 {
+			reg = <0x14 0x10>;
+		};
+
+		eth_mac: eth_mac at 34 {
+			reg = <0x34 0x10>;
+		};
+
+		bid: bid at 46 {
+			reg = <0x46 0x30>;
+		};
+	};
+
 	timer {
 		compatible = "arm,armv8-timer";
 		interrupts = <GIC_PPI 13
-- 
2.7.4