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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Amlogic Secure Monitor driver4 *5 * Copyright (C) 2016 Endless Mobile, Inc.6 * Author: Carlo Caione <carlo@endlessm.com>7 */8 9#define pr_fmt(fmt) "meson-sm: " fmt10 11#include <linux/arm-smccc.h>12#include <linux/bug.h>13#include <linux/io.h>14#include <linux/module.h>15#include <linux/of.h>16#include <linux/of_platform.h>17#include <linux/platform_device.h>18#include <linux/printk.h>19#include <linux/property.h>20#include <linux/types.h>21#include <linux/sizes.h>22 #include <linux/slab.h>23 24#include <linux/firmware/meson/meson_sm.h>25 26struct meson_sm_cmd {27 unsigned int index;28 u32 smc_id;29};30#define CMD(d, s) { .index = (d), .smc_id = (s), }31 32struct meson_sm_chip {33 unsigned int shmem_size;34 u32 cmd_shmem_in_base;35 u32 cmd_shmem_out_base;36 struct meson_sm_cmd cmd[];37};38 39static const struct meson_sm_chip gxbb_chip = {40 .shmem_size = SZ_4K,41 .cmd_shmem_in_base = 0x82000020,42 .cmd_shmem_out_base = 0x82000021,43 .cmd = {44 CMD(SM_EFUSE_READ, 0x82000030),45 CMD(SM_EFUSE_WRITE, 0x82000031),46 CMD(SM_EFUSE_USER_MAX, 0x82000033),47 CMD(SM_GET_CHIP_ID, 0x82000044),48 CMD(SM_A1_PWRC_SET, 0x82000093),49 CMD(SM_A1_PWRC_GET, 0x82000095),50 { /* sentinel */ },51 },52};53 54struct meson_sm_firmware {55 const struct meson_sm_chip *chip;56 void __iomem *sm_shmem_in_base;57 void __iomem *sm_shmem_out_base;58};59 60static u32 meson_sm_get_cmd(const struct meson_sm_chip *chip,61 unsigned int cmd_index)62{63 const struct meson_sm_cmd *cmd = chip->cmd;64 65 while (cmd->smc_id && cmd->index != cmd_index)66 cmd++;67 68 return cmd->smc_id;69}70 71static s32 __meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2,72 u32 arg3, u32 arg4)73{74 struct arm_smccc_res res;75 76 arm_smccc_smc(cmd, arg0, arg1, arg2, arg3, arg4, 0, 0, &res);77 return res.a0;78}79 80static void __iomem *meson_sm_map_shmem(u32 cmd_shmem, unsigned int size)81{82 u32 sm_phy_base;83 84 sm_phy_base = __meson_sm_call(cmd_shmem, 0, 0, 0, 0, 0);85 if (!sm_phy_base)86 return NULL;87 88 return ioremap_cache(sm_phy_base, size);89}90 91/**92 * meson_sm_call - generic SMC32 call to the secure-monitor93 *94 * @fw: Pointer to secure-monitor firmware95 * @cmd_index: Index of the SMC32 function ID96 * @ret: Returned value97 * @arg0: SMC32 Argument 098 * @arg1: SMC32 Argument 199 * @arg2: SMC32 Argument 2100 * @arg3: SMC32 Argument 3101 * @arg4: SMC32 Argument 4102 *103 * Return: 0 on success, a negative value on error104 */105int meson_sm_call(struct meson_sm_firmware *fw, unsigned int cmd_index,106 s32 *ret, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)107{108 u32 cmd;109 s32 lret;110 111 if (!fw->chip)112 return -ENOENT;113 114 cmd = meson_sm_get_cmd(fw->chip, cmd_index);115 if (!cmd)116 return -EINVAL;117 118 lret = __meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4);119 120 if (ret)121 *ret = lret;122 123 return 0;124}125EXPORT_SYMBOL(meson_sm_call);126 127/**128 * meson_sm_call_read - retrieve data from secure-monitor129 *130 * @fw: Pointer to secure-monitor firmware131 * @buffer: Buffer to store the retrieved data132 * @bsize: Size of the buffer133 * @cmd_index: Index of the SMC32 function ID134 * @arg0: SMC32 Argument 0135 * @arg1: SMC32 Argument 1136 * @arg2: SMC32 Argument 2137 * @arg3: SMC32 Argument 3138 * @arg4: SMC32 Argument 4139 *140 * Return: size of read data on success, a negative value on error141 * When 0 is returned there is no guarantee about the amount of142 * data read and bsize bytes are copied in buffer.143 */144int meson_sm_call_read(struct meson_sm_firmware *fw, void *buffer,145 unsigned int bsize, unsigned int cmd_index, u32 arg0,146 u32 arg1, u32 arg2, u32 arg3, u32 arg4)147{148 s32 size;149 int ret;150 151 if (!fw->chip)152 return -ENOENT;153 154 if (!fw->chip->cmd_shmem_out_base)155 return -EINVAL;156 157 if (bsize > fw->chip->shmem_size)158 return -EINVAL;159 160 if (meson_sm_call(fw, cmd_index, &size, arg0, arg1, arg2, arg3, arg4) < 0)161 return -EINVAL;162 163 if (size < 0 || size > bsize)164 return -EINVAL;165 166 ret = size;167 168 /* In some cases (for example GET_CHIP_ID command),169 * SMC doesn't return the number of bytes read, even170 * though the bytes were actually read into sm_shmem_out.171 * So this check is needed.172 */173 if (!size)174 size = bsize;175 176 if (buffer)177 memcpy(buffer, fw->sm_shmem_out_base, size);178 179 return ret;180}181EXPORT_SYMBOL(meson_sm_call_read);182 183/**184 * meson_sm_call_write - send data to secure-monitor185 *186 * @fw: Pointer to secure-monitor firmware187 * @buffer: Buffer containing data to send188 * @size: Size of the data to send189 * @cmd_index: Index of the SMC32 function ID190 * @arg0: SMC32 Argument 0191 * @arg1: SMC32 Argument 1192 * @arg2: SMC32 Argument 2193 * @arg3: SMC32 Argument 3194 * @arg4: SMC32 Argument 4195 *196 * Return: size of sent data on success, a negative value on error197 */198int meson_sm_call_write(struct meson_sm_firmware *fw, void *buffer,199 unsigned int size, unsigned int cmd_index, u32 arg0,200 u32 arg1, u32 arg2, u32 arg3, u32 arg4)201{202 s32 written;203 204 if (!fw->chip)205 return -ENOENT;206 207 if (size > fw->chip->shmem_size)208 return -EINVAL;209 210 if (!fw->chip->cmd_shmem_in_base)211 return -EINVAL;212 213 memcpy(fw->sm_shmem_in_base, buffer, size);214 215 if (meson_sm_call(fw, cmd_index, &written, arg0, arg1, arg2, arg3, arg4) < 0)216 return -EINVAL;217 218 if (written <= 0 || written > size)219 return -EINVAL;220 221 return written;222}223EXPORT_SYMBOL(meson_sm_call_write);224 225/**226 * meson_sm_get - get pointer to meson_sm_firmware structure.227 *228 * @sm_node: Pointer to the secure-monitor Device Tree node.229 *230 * Return: NULL is the secure-monitor device is not ready.231 */232struct meson_sm_firmware *meson_sm_get(struct device_node *sm_node)233{234 struct platform_device *pdev = of_find_device_by_node(sm_node);235 236 if (!pdev)237 return NULL;238 239 return platform_get_drvdata(pdev);240}241EXPORT_SYMBOL_GPL(meson_sm_get);242 243#define SM_CHIP_ID_LENGTH 119244#define SM_CHIP_ID_OFFSET 4245#define SM_CHIP_ID_SIZE 12246 247static ssize_t serial_show(struct device *dev, struct device_attribute *attr,248 char *buf)249{250 struct platform_device *pdev = to_platform_device(dev);251 struct meson_sm_firmware *fw;252 uint8_t *id_buf;253 int ret;254 255 fw = platform_get_drvdata(pdev);256 257 id_buf = kmalloc(SM_CHIP_ID_LENGTH, GFP_KERNEL);258 if (!id_buf)259 return -ENOMEM;260 261 ret = meson_sm_call_read(fw, id_buf, SM_CHIP_ID_LENGTH, SM_GET_CHIP_ID,262 0, 0, 0, 0, 0);263 if (ret < 0) {264 kfree(id_buf);265 return ret;266 }267 268 ret = sprintf(buf, "%12phN\n", &id_buf[SM_CHIP_ID_OFFSET]);269 270 kfree(id_buf);271 272 return ret;273}274 275static DEVICE_ATTR_RO(serial);276 277static struct attribute *meson_sm_sysfs_attrs[] = {278 &dev_attr_serial.attr,279 NULL,280};281ATTRIBUTE_GROUPS(meson_sm_sysfs);282 283static const struct of_device_id meson_sm_ids[] = {284 { .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip },285 { /* sentinel */ },286};287 288static int __init meson_sm_probe(struct platform_device *pdev)289{290 struct device *dev = &pdev->dev;291 const struct meson_sm_chip *chip;292 struct meson_sm_firmware *fw;293 294 fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL);295 if (!fw)296 return -ENOMEM;297 298 chip = device_get_match_data(dev);299 if (!chip)300 return -EINVAL;301 302 if (chip->cmd_shmem_in_base) {303 fw->sm_shmem_in_base = meson_sm_map_shmem(chip->cmd_shmem_in_base,304 chip->shmem_size);305 if (WARN_ON(!fw->sm_shmem_in_base))306 goto out;307 }308 309 if (chip->cmd_shmem_out_base) {310 fw->sm_shmem_out_base = meson_sm_map_shmem(chip->cmd_shmem_out_base,311 chip->shmem_size);312 if (WARN_ON(!fw->sm_shmem_out_base))313 goto unmap_in_base;314 }315 316 fw->chip = chip;317 318 platform_set_drvdata(pdev, fw);319 320 if (devm_of_platform_populate(dev))321 goto unmap_out_base;322 323 pr_info("secure-monitor enabled\n");324 325 return 0;326 327unmap_out_base:328 iounmap(fw->sm_shmem_out_base);329unmap_in_base:330 iounmap(fw->sm_shmem_in_base);331out:332 return -EINVAL;333}334 335static struct platform_driver meson_sm_driver = {336 .driver = {337 .name = "meson-sm",338 .of_match_table = of_match_ptr(meson_sm_ids),339 .dev_groups = meson_sm_sysfs_groups,340 },341};342module_platform_driver_probe(meson_sm_driver, meson_sm_probe);343MODULE_DESCRIPTION("Amlogic Secure Monitor driver");344MODULE_LICENSE("GPL v2");345