diff options
Diffstat (limited to 'drivers/net/wireless/intel/iwlwifi/iwl-eeprom-read.c')
| -rw-r--r-- | drivers/net/wireless/intel/iwlwifi/iwl-eeprom-read.c | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-eeprom-read.c b/drivers/net/wireless/intel/iwlwifi/iwl-eeprom-read.c new file mode 100644 index 000000000..5f386bb1a --- /dev/null +++ b/drivers/net/wireless/intel/iwlwifi/iwl-eeprom-read.c @@ -0,0 +1,394 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause +/* + * Copyright (C) 2005-2014, 2018-2019, 2021 Intel Corporation + */ +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/export.h> + +#include "iwl-drv.h" +#include "iwl-debug.h" +#include "iwl-eeprom-read.h" +#include "iwl-io.h" +#include "iwl-prph.h" +#include "iwl-csr.h" + +/* + * EEPROM access time values: + * + * Driver initiates EEPROM read by writing byte address << 1 to CSR_EEPROM_REG. + * Driver then polls CSR_EEPROM_REG for CSR_EEPROM_REG_READ_VALID_MSK (0x1). + * When polling, wait 10 uSec between polling loops, up to a maximum 5000 uSec. + * Driver reads 16-bit value from bits 31-16 of CSR_EEPROM_REG. + */ +#define IWL_EEPROM_ACCESS_TIMEOUT 5000 /* uSec */ + +/* + * The device's EEPROM semaphore prevents conflicts between driver and uCode + * when accessing the EEPROM; each access is a series of pulses to/from the + * EEPROM chip, not a single event, so even reads could conflict if they + * weren't arbitrated by the semaphore. + */ +#define IWL_EEPROM_SEM_TIMEOUT 10 /* microseconds */ +#define IWL_EEPROM_SEM_RETRY_LIMIT 1000 /* number of attempts (not time) */ + + +static int iwl_eeprom_acquire_semaphore(struct iwl_trans *trans) +{ + u16 count; + int ret; + + for (count = 0; count < IWL_EEPROM_SEM_RETRY_LIMIT; count++) { + /* Request semaphore */ + iwl_set_bit(trans, CSR_HW_IF_CONFIG_REG, + CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM); + + /* See if we got it */ + ret = iwl_poll_bit(trans, CSR_HW_IF_CONFIG_REG, + CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM, + CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM, + IWL_EEPROM_SEM_TIMEOUT); + if (ret >= 0) { + IWL_DEBUG_EEPROM(trans->dev, + "Acquired semaphore after %d tries.\n", + count+1); + return ret; + } + } + + return ret; +} + +static void iwl_eeprom_release_semaphore(struct iwl_trans *trans) +{ + iwl_clear_bit(trans, CSR_HW_IF_CONFIG_REG, + CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM); +} + +static int iwl_eeprom_verify_signature(struct iwl_trans *trans, bool nvm_is_otp) +{ + u32 gp = iwl_read32(trans, CSR_EEPROM_GP) & CSR_EEPROM_GP_VALID_MSK; + + IWL_DEBUG_EEPROM(trans->dev, "EEPROM signature=0x%08x\n", gp); + + switch (gp) { + case CSR_EEPROM_GP_BAD_SIG_EEP_GOOD_SIG_OTP: + if (!nvm_is_otp) { + IWL_ERR(trans, "EEPROM with bad signature: 0x%08x\n", + gp); + return -ENOENT; + } + return 0; + case CSR_EEPROM_GP_GOOD_SIG_EEP_LESS_THAN_4K: + case CSR_EEPROM_GP_GOOD_SIG_EEP_MORE_THAN_4K: + if (nvm_is_otp) { + IWL_ERR(trans, "OTP with bad signature: 0x%08x\n", gp); + return -ENOENT; + } + return 0; + case CSR_EEPROM_GP_BAD_SIGNATURE_BOTH_EEP_AND_OTP: + default: + IWL_ERR(trans, + "bad EEPROM/OTP signature, type=%s, EEPROM_GP=0x%08x\n", + nvm_is_otp ? "OTP" : "EEPROM", gp); + return -ENOENT; + } +} + +/****************************************************************************** + * + * OTP related functions + * +******************************************************************************/ + +static void iwl_set_otp_access_absolute(struct iwl_trans *trans) +{ + iwl_read32(trans, CSR_OTP_GP_REG); + + iwl_clear_bit(trans, CSR_OTP_GP_REG, + CSR_OTP_GP_REG_OTP_ACCESS_MODE); +} + +static int iwl_nvm_is_otp(struct iwl_trans *trans) +{ + u32 otpgp; + + /* OTP only valid for CP/PP and after */ + switch (trans->hw_rev & CSR_HW_REV_TYPE_MSK) { + case CSR_HW_REV_TYPE_NONE: + IWL_ERR(trans, "Unknown hardware type\n"); + return -EIO; + case CSR_HW_REV_TYPE_5300: + case CSR_HW_REV_TYPE_5350: + case CSR_HW_REV_TYPE_5100: + case CSR_HW_REV_TYPE_5150: + return 0; + default: + otpgp = iwl_read32(trans, CSR_OTP_GP_REG); + if (otpgp & CSR_OTP_GP_REG_DEVICE_SELECT) + return 1; + return 0; + } +} + +static int iwl_init_otp_access(struct iwl_trans *trans) +{ + int ret; + + ret = iwl_finish_nic_init(trans); + if (ret) + return ret; + + iwl_set_bits_prph(trans, APMG_PS_CTRL_REG, + APMG_PS_CTRL_VAL_RESET_REQ); + udelay(5); + iwl_clear_bits_prph(trans, APMG_PS_CTRL_REG, + APMG_PS_CTRL_VAL_RESET_REQ); + + /* + * CSR auto clock gate disable bit - + * this is only applicable for HW with OTP shadow RAM + */ + if (trans->trans_cfg->base_params->shadow_ram_support) + iwl_set_bit(trans, CSR_DBG_LINK_PWR_MGMT_REG, + CSR_RESET_LINK_PWR_MGMT_DISABLED); + + return 0; +} + +static int iwl_read_otp_word(struct iwl_trans *trans, u16 addr, + __le16 *eeprom_data) +{ + int ret = 0; + u32 r; + u32 otpgp; + + iwl_write32(trans, CSR_EEPROM_REG, + CSR_EEPROM_REG_MSK_ADDR & (addr << 1)); + ret = iwl_poll_bit(trans, CSR_EEPROM_REG, + CSR_EEPROM_REG_READ_VALID_MSK, + CSR_EEPROM_REG_READ_VALID_MSK, + IWL_EEPROM_ACCESS_TIMEOUT); + if (ret < 0) { + IWL_ERR(trans, "Time out reading OTP[%d]\n", addr); + return ret; + } + r = iwl_read32(trans, CSR_EEPROM_REG); + /* check for ECC errors: */ + otpgp = iwl_read32(trans, CSR_OTP_GP_REG); + if (otpgp & CSR_OTP_GP_REG_ECC_UNCORR_STATUS_MSK) { + /* stop in this case */ + /* set the uncorrectable OTP ECC bit for acknowledgment */ + iwl_set_bit(trans, CSR_OTP_GP_REG, + CSR_OTP_GP_REG_ECC_UNCORR_STATUS_MSK); + IWL_ERR(trans, "Uncorrectable OTP ECC error, abort OTP read\n"); + return -EINVAL; + } + if (otpgp & CSR_OTP_GP_REG_ECC_CORR_STATUS_MSK) { + /* continue in this case */ + /* set the correctable OTP ECC bit for acknowledgment */ + iwl_set_bit(trans, CSR_OTP_GP_REG, + CSR_OTP_GP_REG_ECC_CORR_STATUS_MSK); + IWL_ERR(trans, "Correctable OTP ECC error, continue read\n"); + } + *eeprom_data = cpu_to_le16(r >> 16); + return 0; +} + +/* + * iwl_is_otp_empty: check for empty OTP + */ +static bool iwl_is_otp_empty(struct iwl_trans *trans) +{ + u16 next_link_addr = 0; + __le16 link_value; + bool is_empty = false; + + /* locate the beginning of OTP link list */ + if (!iwl_read_otp_word(trans, next_link_addr, &link_value)) { + if (!link_value) { + IWL_ERR(trans, "OTP is empty\n"); + is_empty = true; + } + } else { + IWL_ERR(trans, "Unable to read first block of OTP list.\n"); + is_empty = true; + } + + return is_empty; +} + + +/* + * iwl_find_otp_image: find EEPROM image in OTP + * finding the OTP block that contains the EEPROM image. + * the last valid block on the link list (the block _before_ the last block) + * is the block we should read and used to configure the device. + * If all the available OTP blocks are full, the last block will be the block + * we should read and used to configure the device. + * only perform this operation if shadow RAM is disabled + */ +static int iwl_find_otp_image(struct iwl_trans *trans, + u16 *validblockaddr) +{ + u16 next_link_addr = 0, valid_addr; + __le16 link_value = 0; + int usedblocks = 0; + + /* set addressing mode to absolute to traverse the link list */ + iwl_set_otp_access_absolute(trans); + + /* checking for empty OTP or error */ + if (iwl_is_otp_empty(trans)) + return -EINVAL; + + /* + * start traverse link list + * until reach the max number of OTP blocks + * different devices have different number of OTP blocks + */ + do { + /* save current valid block address + * check for more block on the link list + */ + valid_addr = next_link_addr; + next_link_addr = le16_to_cpu(link_value) * sizeof(u16); + IWL_DEBUG_EEPROM(trans->dev, "OTP blocks %d addr 0x%x\n", + usedblocks, next_link_addr); + if (iwl_read_otp_word(trans, next_link_addr, &link_value)) + return -EINVAL; + if (!link_value) { + /* + * reach the end of link list, return success and + * set address point to the starting address + * of the image + */ + *validblockaddr = valid_addr; + /* skip first 2 bytes (link list pointer) */ + *validblockaddr += 2; + return 0; + } + /* more in the link list, continue */ + usedblocks++; + } while (usedblocks <= trans->trans_cfg->base_params->max_ll_items); + + /* OTP has no valid blocks */ + IWL_DEBUG_EEPROM(trans->dev, "OTP has no valid blocks\n"); + return -EINVAL; +} + +/* + * iwl_read_eeprom - read EEPROM contents + * + * Load the EEPROM contents from adapter and return it + * and its size. + * + * NOTE: This routine uses the non-debug IO access functions. + */ +int iwl_read_eeprom(struct iwl_trans *trans, u8 **eeprom, size_t *eeprom_size) +{ + __le16 *e; + u32 gp = iwl_read32(trans, CSR_EEPROM_GP); + int sz; + int ret; + u16 addr; + u16 validblockaddr = 0; + u16 cache_addr = 0; + int nvm_is_otp; + + if (!eeprom || !eeprom_size) + return -EINVAL; + + nvm_is_otp = iwl_nvm_is_otp(trans); + if (nvm_is_otp < 0) + return nvm_is_otp; + + sz = trans->trans_cfg->base_params->eeprom_size; + IWL_DEBUG_EEPROM(trans->dev, "NVM size = %d\n", sz); + + e = kmalloc(sz, GFP_KERNEL); + if (!e) + return -ENOMEM; + + ret = iwl_eeprom_verify_signature(trans, nvm_is_otp); + if (ret < 0) { + IWL_ERR(trans, "EEPROM not found, EEPROM_GP=0x%08x\n", gp); + goto err_free; + } + + /* Make sure driver (instead of uCode) is allowed to read EEPROM */ + ret = iwl_eeprom_acquire_semaphore(trans); + if (ret < 0) { + IWL_ERR(trans, "Failed to acquire EEPROM semaphore.\n"); + goto err_free; + } + + if (nvm_is_otp) { + ret = iwl_init_otp_access(trans); + if (ret) { + IWL_ERR(trans, "Failed to initialize OTP access.\n"); + goto err_unlock; + } + + iwl_write32(trans, CSR_EEPROM_GP, + iwl_read32(trans, CSR_EEPROM_GP) & + ~CSR_EEPROM_GP_IF_OWNER_MSK); + + iwl_set_bit(trans, CSR_OTP_GP_REG, + CSR_OTP_GP_REG_ECC_CORR_STATUS_MSK | + CSR_OTP_GP_REG_ECC_UNCORR_STATUS_MSK); + /* traversing the linked list if no shadow ram supported */ + if (!trans->trans_cfg->base_params->shadow_ram_support) { + ret = iwl_find_otp_image(trans, &validblockaddr); + if (ret) + goto err_unlock; + } + for (addr = validblockaddr; addr < validblockaddr + sz; + addr += sizeof(u16)) { + __le16 eeprom_data; + + ret = iwl_read_otp_word(trans, addr, &eeprom_data); + if (ret) + goto err_unlock; + e[cache_addr / 2] = eeprom_data; + cache_addr += sizeof(u16); + } + } else { + /* eeprom is an array of 16bit values */ + for (addr = 0; addr < sz; addr += sizeof(u16)) { + u32 r; + + iwl_write32(trans, CSR_EEPROM_REG, + CSR_EEPROM_REG_MSK_ADDR & (addr << 1)); + + ret = iwl_poll_bit(trans, CSR_EEPROM_REG, + CSR_EEPROM_REG_READ_VALID_MSK, + CSR_EEPROM_REG_READ_VALID_MSK, + IWL_EEPROM_ACCESS_TIMEOUT); + if (ret < 0) { + IWL_ERR(trans, + "Time out reading EEPROM[%d]\n", addr); + goto err_unlock; + } + r = iwl_read32(trans, CSR_EEPROM_REG); + e[addr / 2] = cpu_to_le16(r >> 16); + } + } + + IWL_DEBUG_EEPROM(trans->dev, "NVM Type: %s\n", + nvm_is_otp ? "OTP" : "EEPROM"); + + iwl_eeprom_release_semaphore(trans); + + *eeprom_size = sz; + *eeprom = (u8 *)e; + return 0; + + err_unlock: + iwl_eeprom_release_semaphore(trans); + err_free: + kfree(e); + + return ret; +} +IWL_EXPORT_SYMBOL(iwl_read_eeprom); |