Commit 0789724f authored by Neil Armstrong's avatar Neil Armstrong Committed by Kevin Hilman
Browse files

firmware: meson_sm: Add serial number sysfs entry 



The Amlogic Meson SoC Secure Monitor implements a call to retrieve an unique
SoC ID starting from the GX Family and all new families.

The serial number is simply exposed as a sysfs entry under the firmware
sysfs directory.

Signed-off-by: default avatarNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: default avatarKevin Hilman <khilman@baylibre.com>
parent 5b394b2d

drivers/firmware/meson/meson_sm.c

+56 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/printk.h>

#include <linux/types.h>

#include <linux/sizes.h>

 #include <linux/slab.h>



#include <linux/firmware/meson/meson_sm.h>
@@ -48,6 +49,7 @@ struct meson_sm_chip gxbb_chip = { 
		CMD(SM_EFUSE_READ,	0x82000030),

		CMD(SM_EFUSE_WRITE,	0x82000031),

		CMD(SM_EFUSE_USER_MAX,	0x82000033),

		CMD(SM_GET_CHIP_ID,	0x82000044),

		{ /* sentinel */ },

	},

};
@@ -214,6 +216,57 @@ int meson_sm_call_write(void *buffer, unsigned int size, unsigned int cmd_index, 
}

EXPORT_SYMBOL(meson_sm_call_write);



#define SM_CHIP_ID_LENGTH	119

#define SM_CHIP_ID_OFFSET	4

#define SM_CHIP_ID_SIZE		12



static ssize_t serial_show(struct device *dev, struct device_attribute *attr,

			 char *buf)

{

	uint8_t *id_buf;

	int ret;



	id_buf = kmalloc(SM_CHIP_ID_LENGTH, GFP_KERNEL);

	if (!id_buf)

		return -ENOMEM;



	ret = meson_sm_call_read(id_buf, SM_CHIP_ID_LENGTH, SM_GET_CHIP_ID,

				 0, 0, 0, 0, 0);

	if (ret < 0) {

		kfree(id_buf);

		return ret;

	}



	ret = sprintf(buf, "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n",

			id_buf[SM_CHIP_ID_OFFSET + 0],

			id_buf[SM_CHIP_ID_OFFSET + 1],

			id_buf[SM_CHIP_ID_OFFSET + 2],

			id_buf[SM_CHIP_ID_OFFSET + 3],

			id_buf[SM_CHIP_ID_OFFSET + 4],

			id_buf[SM_CHIP_ID_OFFSET + 5],

			id_buf[SM_CHIP_ID_OFFSET + 6],

			id_buf[SM_CHIP_ID_OFFSET + 7],

			id_buf[SM_CHIP_ID_OFFSET + 8],

			id_buf[SM_CHIP_ID_OFFSET + 9],

			id_buf[SM_CHIP_ID_OFFSET + 10],

			id_buf[SM_CHIP_ID_OFFSET + 11]);



	kfree(id_buf);



	return ret;

}



static DEVICE_ATTR_RO(serial);



static struct attribute *meson_sm_sysfs_attributes[] = {

	&dev_attr_serial.attr,

	NULL,

};



static const struct attribute_group meson_sm_sysfs_attr_group = {

	.attrs = meson_sm_sysfs_attributes,

};



static const struct of_device_id meson_sm_ids[] = {

	{ .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip },

	{ /* sentinel */ },
@@ -242,6 +295,9 @@ static int __init meson_sm_probe(struct platform_device *pdev) 
	fw.chip = chip;

	pr_info("secure-monitor enabled\n");



	if (sysfs_create_group(&pdev->dev.kobj, &meson_sm_sysfs_attr_group))

		goto out_in_base;



	return 0;



out_in_base:

include/linux/firmware/meson/meson_sm.h

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ enum { 
	SM_EFUSE_READ,

	SM_EFUSE_WRITE,

	SM_EFUSE_USER_MAX,

	SM_GET_CHIP_ID,

};



struct meson_sm_firmware;

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