// SPDX-License-Identifier: GPL-2.0-only
/*
* Amlogic Secure Monitor driver
*
* Copyright (C) 2016 Endless Mobile, Inc.
* Author: Carlo Caione <[email protected]>
*/
#define pr_fmt(fmt) "meson-sm: " fmt
#include <linux/arm-smccc.h>
#include <linux/bug.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/property.h>
#include <linux/types.h>
#include <linux/sizes.h>
#include <linux/slab.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[];
};
static const struct meson_sm_chip gxbb_chip = {
.shmem_size = SZ_4K,
.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),
CMD(SM_GET_CHIP_ID, 0x82000044),
CMD(SM_A1_PWRC_SET, 0x82000093),
CMD(SM_A1_PWRC_GET, 0x82000095),
{ /* sentinel */ },
},
};
struct meson_sm_firmware {
const struct meson_sm_chip *chip;
void __iomem *sm_shmem_in_base;
void __iomem *sm_shmem_out_base;
};
static u32 meson_sm_get_cmd(const struct meson_sm_chip *chip,
unsigned int cmd_index)
{
const struct meson_sm_cmd *cmd = chip->cmd;
while (cmd->smc_id && cmd->index != cmd_index)
cmd++;
return cmd->smc_id;
}
static s32 __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 NULL;
return ioremap_cache(sm_phy_base, size);
}
/**
* meson_sm_call - generic SMC32 call to the secure-monitor
*
* @fw: Pointer to secure-monitor firmware
* @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,
s32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)
{
u32 cmd;
s32 lret;
if (!fw->chip)
return -ENOENT;
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: Pointer to secure-monitor firmware
* @buffer: Buffer to store the retrieved data
* @bsize: Size of the buffer
* @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
* When 0 is returned there is no guarantee about the amount of
* data read and bsize bytes are copied in buffer.
*/
int meson_sm_call_read(struct meson_sm_firmware *fw, void *buffer,
unsigned int bsize, unsigned int cmd_index, u32 arg0,
u32 arg1, u32 arg2, u32 arg3, u32 arg4)
{
s32 size;
int ret;
if (!fw->chip)
return -ENOENT;
if (!fw->chip->cmd_shmem_out_base)
return -EINVAL;
if (bsize > fw->chip->shmem_size)
return -EINVAL;
if (meson_sm_call(fw, cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)
return -EINVAL;
if (size < 0 || size > bsize)
return -EINVAL;
ret = size;
/* In some cases (for example GET_CHIP_ID command),
* SMC doesn't return the number of bytes read, even
* though the bytes were actually read into sm_shmem_out.
* So this check is needed.
*/
if (!size)
size = bsize;
if (buffer)
memcpy(buffer, fw->sm_shmem_out_base, size);
return ret;
}
EXPORT_SYMBOL(meson_sm_call_read);
/**
* meson_sm_call_write - send data to secure-monitor
*
* @fw: Pointer to secure-monitor firmware
* @buffer: Buffer containing data to send
* @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 size, unsigned int cmd_index, u32 arg0,
u32 arg1, u32 arg2, u32 arg3, u32 arg4)
{
s32 written;
if (!fw->chip)
return -ENOENT;
if (size > fw->chip->shmem_size)
return -EINVAL;
if (!fw->chip->cmd_shmem_in_base)
return -EINVAL;
memcpy(fw->sm_shmem_in_base, buffer, size);
if (meson_sm_call(fw, cmd_index, &written, arg0, arg1, arg2, arg3, arg4) < 0)
return -EINVAL;
if (written <= 0 || written > size)
return -EINVAL;
return written;
}
EXPORT_SYMBOL(meson_sm_call_write);
/**
* meson_sm_get - get pointer to meson_sm_firmware structure.
*
* @sm_node: Pointer to the secure-monitor Device Tree node.
*
* Return: NULL is the secure-monitor device is not ready.
*/
struct meson_sm_firmware *meson_sm_get(struct device_node *sm_node)
{
struct platform_device *pdev = of_find_device_by_node(sm_node);
if (!pdev)
return NULL;
return platform_get_drvdata(pdev);
}
EXPORT_SYMBOL_GPL(meson_sm_get);
#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)
{
struct platform_device *pdev = to_platform_device(dev);
struct meson_sm_firmware *fw;
uint8_t *id_buf;
int ret;
fw = platform_get_drvdata(pdev);
id_buf = kmalloc(SM_CHIP_ID_LENGTH, GFP_KERNEL);
if (!id_buf)
return -ENOMEM;
ret = meson_sm_call_read(fw, 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, "%12phN\n", &id_buf[SM_CHIP_ID_OFFSET]);
kfree(id_buf);
return ret;
}
static DEVICE_ATTR_RO(serial);
static struct attribute *meson_sm_sysfs_attrs[] = {
&dev_attr_serial.attr,
NULL,
};
ATTRIBUTE_GROUPS(meson_sm_sysfs);
static const struct of_device_id meson_sm_ids[] = {
{ .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip },
{ /* sentinel */ },
};
static int __init meson_sm_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct meson_sm_chip *chip;
struct meson_sm_firmware *fw;
fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL);
if (!fw)
return -ENOMEM;
chip = device_get_match_data(dev);
if (!chip)
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 unmap_in_base;
}
fw->chip = chip;
platform_set_drvdata(pdev, fw);
if (devm_of_platform_populate(dev))
goto unmap_out_base;
pr_info("secure-monitor enabled\n");
return 0;
unmap_out_base:
iounmap(fw->sm_shmem_out_base);
unmap_in_base:
iounmap(fw->sm_shmem_in_base);
out:
return -EINVAL;
}
static struct platform_driver meson_sm_driver = {
.driver = {
.name = "meson-sm",
.of_match_table = of_match_ptr(meson_sm_ids),
.dev_groups = meson_sm_sysfs_groups,
},
};
module_platform_driver_probe(meson_sm_driver, meson_sm_probe);
MODULE_DESCRIPTION("Amlogic Secure Monitor driver");
MODULE_LICENSE("GPL v2");
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