diff options
Diffstat (limited to 'drivers/firmware/meson/meson_sm.c')
| -rw-r--r-- | drivers/firmware/meson/meson_sm.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c new file mode 100644 index 000000000..bf19dd66c --- /dev/null +++ b/drivers/firmware/meson/meson_sm.c @@ -0,0 +1,339 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Amlogic Secure Monitor driver + * + * Copyright (C) 2016 Endless Mobile, Inc. + * Author: Carlo Caione <carlo@endlessm.com> + */ + +#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_device.h> +#include <linux/platform_device.h> +#include <linux/printk.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 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: 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, + u32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4) +{ + u32 cmd, 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) +{ + u32 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 > bsize) + return -EINVAL; + + ret = size; + + 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) +{ + u32 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) + 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_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 */ }, +}; + +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 = of_match_device(meson_sm_ids, dev)->data; + 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 out_in_base; + } + + fw->chip = chip; + + platform_set_drvdata(pdev, fw); + + if (devm_of_platform_populate(dev)) + goto out_in_base; + + if (sysfs_create_group(&pdev->dev.kobj, &meson_sm_sysfs_attr_group)) + goto out_in_base; + + pr_info("secure-monitor enabled\n"); + + return 0; + +out_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), + }, +}; +module_platform_driver_probe(meson_sm_driver, meson_sm_probe); +MODULE_LICENSE("GPL v2"); |