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path: root/drivers/net/wireless/intel/iwlwifi/iwl-eeprom-read.c
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Diffstat (limited to 'drivers/net/wireless/intel/iwlwifi/iwl-eeprom-read.c')
-rw-r--r--drivers/net/wireless/intel/iwlwifi/iwl-eeprom-read.c394
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);