diff options
| -rw-r--r-- | drivers/nvmem/zynqmp_nvmem.c | 186 |
1 files changed, 176 insertions, 10 deletions
diff --git a/drivers/nvmem/zynqmp_nvmem.c b/drivers/nvmem/zynqmp_nvmem.c index 391d8e88b270..8682adaacd69 100644 --- a/drivers/nvmem/zynqmp_nvmem.c +++ b/drivers/nvmem/zynqmp_nvmem.c @@ -4,6 +4,7 @@ * Copyright (C) 2022 - 2023, Advanced Micro Devices, Inc. */ +#include <linux/dma-mapping.h> #include <linux/module.h> #include <linux/nvmem-provider.h> #include <linux/of.h> @@ -11,24 +12,189 @@ #include <linux/firmware/xlnx-zynqmp.h> #define SILICON_REVISION_MASK 0xF +#define P_USER_0_64_UPPER_MASK GENMASK(31, 16) +#define P_USER_127_LOWER_4_BIT_MASK GENMASK(3, 0) +#define WORD_INBYTES 4 +#define SOC_VER_SIZE 0x4 +#define EFUSE_MEMORY_SIZE 0x177 +#define UNUSED_SPACE 0x8 +#define ZYNQMP_NVMEM_SIZE (SOC_VER_SIZE + UNUSED_SPACE + \ + EFUSE_MEMORY_SIZE) +#define SOC_VERSION_OFFSET 0x0 +#define EFUSE_START_OFFSET 0xC +#define EFUSE_END_OFFSET 0xFC +#define EFUSE_PUF_START_OFFSET 0x100 +#define EFUSE_PUF_MID_OFFSET 0x140 +#define EFUSE_PUF_END_OFFSET 0x17F +#define EFUSE_NOT_ENABLED 29 +/* + * efuse access type + */ +enum efuse_access { + EFUSE_READ = 0, + EFUSE_WRITE +}; + +/** + * struct xilinx_efuse - the basic structure + * @src: address of the buffer to store the data to be write/read + * @size: read/write word count + * @offset: read/write offset + * @flag: 0 - represents efuse read and 1- represents efuse write + * @pufuserfuse:0 - represents non-puf efuses, offset is used for read/write + * 1 - represents puf user fuse row number. + * + * this structure stores all the required details to + * read/write efuse memory. + */ +struct xilinx_efuse { + u64 src; + u32 size; + u32 offset; + enum efuse_access flag; + u32 pufuserfuse; +}; + +static int zynqmp_efuse_access(void *context, unsigned int offset, + void *val, size_t bytes, enum efuse_access flag, + unsigned int pufflag) +{ + struct device *dev = context; + struct xilinx_efuse *efuse; + dma_addr_t dma_addr; + dma_addr_t dma_buf; + size_t words = bytes / WORD_INBYTES; + int ret; + int value; + char *data; + + if (bytes % WORD_INBYTES != 0) { + dev_err(dev, "Bytes requested should be word aligned\n"); + return -EOPNOTSUPP; + } + + if (pufflag == 0 && offset % WORD_INBYTES) { + dev_err(dev, "Offset requested should be word aligned\n"); + return -EOPNOTSUPP; + } + + if (pufflag == 1 && flag == EFUSE_WRITE) { + memcpy(&value, val, bytes); + if ((offset == EFUSE_PUF_START_OFFSET || + offset == EFUSE_PUF_MID_OFFSET) && + value & P_USER_0_64_UPPER_MASK) { + dev_err(dev, "Only lower 4 bytes are allowed to be programmed in P_USER_0 & P_USER_64\n"); + return -EOPNOTSUPP; + } + + if (offset == EFUSE_PUF_END_OFFSET && + (value & P_USER_127_LOWER_4_BIT_MASK)) { + dev_err(dev, "Only MSB 28 bits are allowed to be programmed for P_USER_127\n"); + return -EOPNOTSUPP; + } + } + + efuse = dma_alloc_coherent(dev, sizeof(struct xilinx_efuse), + &dma_addr, GFP_KERNEL); + if (!efuse) + return -ENOMEM; -static int zynqmp_nvmem_read(void *context, unsigned int offset, - void *val, size_t bytes) + data = dma_alloc_coherent(dev, sizeof(bytes), + &dma_buf, GFP_KERNEL); + if (!data) { + ret = -ENOMEM; + goto efuse_data_fail; + } + + if (flag == EFUSE_WRITE) { + memcpy(data, val, bytes); + efuse->flag = EFUSE_WRITE; + } else { + efuse->flag = EFUSE_READ; + } + + efuse->src = dma_buf; + efuse->size = words; + efuse->offset = offset; + efuse->pufuserfuse = pufflag; + + zynqmp_pm_efuse_access(dma_addr, (u32 *)&ret); + if (ret != 0) { + if (ret == EFUSE_NOT_ENABLED) { + dev_err(dev, "efuse access is not enabled\n"); + ret = -EOPNOTSUPP; + } else { + dev_err(dev, "Error in efuse read %x\n", ret); + ret = -EPERM; + } + goto efuse_access_err; + } + + if (flag == EFUSE_READ) + memcpy(val, data, bytes); +efuse_access_err: + dma_free_coherent(dev, sizeof(bytes), + data, dma_buf); +efuse_data_fail: + dma_free_coherent(dev, sizeof(struct xilinx_efuse), + efuse, dma_addr); + + return ret; +} + +static int zynqmp_nvmem_read(void *context, unsigned int offset, void *val, size_t bytes) { struct device *dev = context; int ret; + int pufflag = 0; int idcode; int version; - ret = zynqmp_pm_get_chipid(&idcode, &version); - if (ret < 0) - return ret; + if (offset >= EFUSE_PUF_START_OFFSET && offset <= EFUSE_PUF_END_OFFSET) + pufflag = 1; + + switch (offset) { + /* Soc version offset is zero */ + case SOC_VERSION_OFFSET: + if (bytes != SOC_VER_SIZE) + return -EOPNOTSUPP; + + ret = zynqmp_pm_get_chipid((u32 *)&idcode, (u32 *)&version); + if (ret < 0) + return ret; + + dev_dbg(dev, "Read chipid val %x %x\n", idcode, version); + *(int *)val = version & SILICON_REVISION_MASK; + break; + /* Efuse offset starts from 0xc */ + case EFUSE_START_OFFSET ... EFUSE_END_OFFSET: + case EFUSE_PUF_START_OFFSET ... EFUSE_PUF_END_OFFSET: + ret = zynqmp_efuse_access(context, offset, val, + bytes, EFUSE_READ, pufflag); + break; + default: + *(u32 *)val = 0xDEADBEEF; + ret = 0; + break; + } + + return ret; +} + +static int zynqmp_nvmem_write(void *context, + unsigned int offset, void *val, size_t bytes) +{ + int pufflag = 0; + + if (offset < EFUSE_START_OFFSET || offset > EFUSE_PUF_END_OFFSET) + return -EOPNOTSUPP; - dev_dbg(dev, "Read chipid val %x %x\n", idcode, version); - *(int *)val = version & SILICON_REVISION_MASK; + if (offset >= EFUSE_PUF_START_OFFSET && offset <= EFUSE_PUF_END_OFFSET) + pufflag = 1; - return 0; + return zynqmp_efuse_access(context, offset, + val, bytes, EFUSE_WRITE, pufflag); } static const struct of_device_id zynqmp_nvmem_match[] = { @@ -45,11 +211,11 @@ static int zynqmp_nvmem_probe(struct platform_device *pdev) econfig.name = "zynqmp-nvmem"; econfig.owner = THIS_MODULE; econfig.word_size = 1; - econfig.size = 1; + econfig.size = ZYNQMP_NVMEM_SIZE; econfig.dev = dev; econfig.add_legacy_fixed_of_cells = true; - econfig.read_only = true; econfig.reg_read = zynqmp_nvmem_read; + econfig.reg_write = zynqmp_nvmem_write; return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &econfig)); } |