diff options
Diffstat (limited to 'drivers/firmware/meson/meson_sm.c')
| -rw-r--r-- | drivers/firmware/meson/meson_sm.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c new file mode 100644 index 000000000000..b0d254930ed3 --- /dev/null +++ b/drivers/firmware/meson/meson_sm.c @@ -0,0 +1,248 @@ +/* + * 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/>. + */ + +#define pr_fmt(fmt) "meson-sm: " fmt + +#include <linux/arm-smccc.h> +#include <linux/bug.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/printk.h> +#include <linux/types.h> +#include <linux/sizes.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 = 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), + { /* 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) +{ + 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 + * + * @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(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 + * + * @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(void *buffer, unsigned int cmd_index, u32 arg0, + u32 arg1, u32 arg2, u32 arg3, u32 arg4) +{ + u32 size; + + if (!fw.chip) + return -ENOENT; + + if (!fw.chip->cmd_shmem_out_base) + return -EINVAL; + + if (meson_sm_call(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 + * + * @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(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(cmd_index, &written, arg0, arg1, arg2, arg3, arg4) < 0) + return -EINVAL; + + if (!written) + return -EINVAL; + + return written; +} +EXPORT_SYMBOL(meson_sm_call_write); + +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) + return -ENODEV; + + chip = matched_np->data; + if (!chip) { + pr_err("unable to setup secure-monitor data\n"); + goto out; + } + + 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; + pr_info("secure-monitor enabled\n"); + + return 0; + +out_in_base: + iounmap(fw.sm_shmem_in_base); +out: + return -EINVAL; +} +device_initcall(meson_sm_init); |