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optoe: Add CMIS Bank support for transceivers with >8 lanes
Signed-off-by: Wataru Ishida <[email protected]>
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‎patch/driver-support-optoe-bank-support.patch‎

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From d654fd07f90bda8565ebbb18979dfee8d8fff3da Mon Sep 17 00:00:00 2001
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From: Wataru Ishida <[email protected]>
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Date: Wed, 2 Apr 2025 07:10:10 +0000
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Subject: [PATCH] optoe: Add CMIS Bank support for transceivers with >8 lanes
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This patch adds CMIS Bank support to the 'optoe3' device class in order
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to enable access to CMIS transceivers with more than 8 lanes (e.g., OSFP-XD, CPO OEs).
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- Bank support is enabled only for the 'optoe3' dev class.
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- The default bank size is set to 4, and can be modified via the 'bank_size' sysfs entry.
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- For 'optoe3', the 'write_max' value is updated to 2 to comply with CMIS requirements,
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which mandate that both bank and page values be updated in a single WRITE operation.
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Signed-off-by: Wataru Ishida <[email protected]>
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---
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drivers/misc/eeprom/optoe.c | 142 ++++++++++++++++++++++++++++--------
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1 file changed, 112 insertions(+), 30 deletions(-)
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diff --git a/drivers/misc/eeprom/optoe.c b/drivers/misc/eeprom/optoe.c
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index 22d2c0cd4..f5be0d9b7 100644
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--- a/drivers/misc/eeprom/optoe.c
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+++ b/drivers/misc/eeprom/optoe.c
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@@ -150,6 +150,12 @@ struct optoe_platform_data {
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/* fundamental unit of addressing for EEPROM */
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#define OPTOE_PAGE_SIZE 128
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+
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+#define OPTOE_DEFAULT_BANK_SIZE 4
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+#define OPTOE_MAX_SUPPORTED_BANK_SIZE 8
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+#define OPTOE_NON_BANKED_PAGE_SIZE 16 /* page 00h-0Fh are not banked */
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+#define OPTOE_BANKED_PAGE_SIZE 240 /* page 10h-FFh are banked */
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+
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/*
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* Single address devices (eg QSFP) have 256 pages, plus the unpaged
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* low 128 bytes. If the device does not support paging, it is
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@@ -168,6 +174,7 @@ struct optoe_platform_data {
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#define TWO_ADDR_NO_0X51_SIZE (2 * OPTOE_PAGE_SIZE)
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/* a few constants to find our way around the EEPROM */
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+#define OPTOE_BANK_SELECT_REG 0x7E
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#define OPTOE_PAGE_SELECT_REG 0x7F
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#define ONE_ADDR_PAGEABLE_REG 0x02
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#define QSFP_NOT_PAGEABLE (1<<2)
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@@ -195,6 +202,7 @@ struct optoe_data {
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u8 *writebuf;
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unsigned int write_max;
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unsigned int write_timeout;
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+ unsigned int bank_size; /* 0 means bank is not supported */
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unsigned int num_addresses;
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@@ -245,13 +253,19 @@ static const struct i2c_device_id optoe_ids[] = {
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};
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MODULE_DEVICE_TABLE(i2c, optoe_ids);
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+static uint32_t one_addr_eeprom_size_with_bank(uint32_t bank_size)
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+{
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+ bank_size = bank_size == 0 ? 1 : bank_size;
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+ return (bank_size * OPTOE_BANKED_PAGE_SIZE + OPTOE_NON_BANKED_PAGE_SIZE + 1) * OPTOE_PAGE_SIZE;
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+}
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+
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/*-------------------------------------------------------------------------*/
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/*
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* This routine computes the addressing information to be used for
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* a given r/w request.
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*
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* Task is to calculate the client (0 = i2c addr 50, 1 = i2c addr 51),
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- * the page, and the offset.
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+ * the bank, the page, and the offset.
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*
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* Handles both single address (eg QSFP) and two address (eg SFP).
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* For SFP, offset 0-255 are on client[0], >255 is on client[1]
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@@ -274,7 +288,7 @@ MODULE_DEVICE_TABLE(i2c, optoe_ids);
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*/
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static uint8_t optoe_translate_offset(struct optoe_data *optoe,
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- loff_t *offset, struct i2c_client **client)
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+ loff_t *offset, struct i2c_client **client, uint8_t *bank)
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{
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unsigned int page = 0;
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@@ -301,8 +315,9 @@ static uint8_t optoe_translate_offset(struct optoe_data *optoe,
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page = (*offset >> 7)-1;
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/* 0x80 places the offset in the top half, offset is last 7 bits */
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*offset = OPTOE_PAGE_SIZE + (*offset & 0x7f);
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-
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- return page; /* note also returning client and offset */
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+ *bank = page < OPTOE_PAGE_SIZE ? 0 : (page - OPTOE_NON_BANKED_PAGE_SIZE) / OPTOE_BANKED_PAGE_SIZE;
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+ page = page - *bank * OPTOE_BANKED_PAGE_SIZE;
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+ return page; /* note also returning client, bank and offset */
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}
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static ssize_t optoe_eeprom_read(struct optoe_data *optoe,
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@@ -511,21 +526,38 @@ static ssize_t optoe_eeprom_update_client(struct optoe_data *optoe,
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{
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struct i2c_client *client;
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ssize_t retval = 0;
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- uint8_t page = 0;
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+ uint8_t page = 0, bank = 0;
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loff_t phy_offset = off;
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int ret = 0;
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- page = optoe_translate_offset(optoe, &phy_offset, &client);
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+ page = optoe_translate_offset(optoe, &phy_offset, &client, &bank);
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dev_dbg(&client->dev,
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- "%s off %lld page:%d phy_offset:%lld, count:%ld, opcode:%d\n",
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- __func__, off, page, phy_offset, (long int) count, opcode);
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+ "%s off %lld bank:%d page:%d phy_offset:%lld, count:%ld, opcode:%d\n",
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+ __func__, off, bank, page, phy_offset, (long int) count, opcode);
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if (page > 0) {
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- ret = optoe_eeprom_write(optoe, client, &page,
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- OPTOE_PAGE_SELECT_REG, 1);
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+ /*
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+ * CMIS 5.3 8.2.15 Page Mapping
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+ *
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+ * For an arbitrary Page Address change or for just a Bank Index change,
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+ * a host must write both BankSelect and PageSelect in one WRITE access,
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+ * even if the PageSelect value does not change.
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+ * The module does not begin processing the BankSelect value until after the PageSelect register has been written.
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+ *
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+ * For just a Page Index change (mapping another Page in the current Bank),
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+ * or for mapping an arbitrary unbanked Page to Upper Memory, a host may WRITE only the PageSelect Byte.
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+ */
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+ if (bank > 0) {
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+ char buf[2] = {bank, page};
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+ ret = optoe_eeprom_write(optoe, client, buf,
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+ OPTOE_BANK_SELECT_REG, 2);
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+ } else {
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+ ret = optoe_eeprom_write(optoe, client, &page,
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+ OPTOE_PAGE_SELECT_REG, 1);
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+ }
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if (ret < 0) {
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dev_dbg(&client->dev,
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- "Write page register for page %d failed ret:%d!\n",
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- page, ret);
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+ "Write page register for bank %d, page %d failed ret:%d!\n",
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+ bank, page, ret);
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return ret;
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}
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}
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@@ -552,14 +584,14 @@ static ssize_t optoe_eeprom_update_client(struct optoe_data *optoe,
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}
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- if (page > 0) {
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- /* return the page register to page 0 (why?) */
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- page = 0;
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- ret = optoe_eeprom_write(optoe, client, &page,
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- OPTOE_PAGE_SELECT_REG, 1);
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+ if (page > 0 || bank > 0) {
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+ /* return the page register to bank 0, page 0 (why?) */
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+ char buf[2] = {0, 0};
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+ ret = optoe_eeprom_write(optoe, client, buf,
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+ OPTOE_BANK_SELECT_REG, 2);
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if (ret < 0) {
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dev_err(&client->dev,
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- "Restore page register to 0 failed:%d!\n", ret);
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+ "Restore bank, page register to (0, 0) failed:%d!\n", ret);
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/* error only if nothing has been transferred */
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if (retval == 0)
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retval = ret;
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@@ -622,8 +654,10 @@ static ssize_t optoe_page_legal(struct optoe_data *optoe,
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/* if no pages needed, we're good */
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if ((off + len) <= ONE_ADDR_EEPROM_UNPAGED_SIZE)
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return len;
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+
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+ maxlen = one_addr_eeprom_size_with_bank(optoe->bank_size);
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/* if offset exceeds possible pages, we're not good */
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- if (off >= ONE_ADDR_EEPROM_SIZE)
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+ if (off >= maxlen)
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return OPTOE_EOF;
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/* in between, are pages supported? */
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status = optoe_eeprom_read(optoe, client, &regval,
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@@ -665,7 +699,7 @@ static ssize_t optoe_page_legal(struct optoe_data *optoe,
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maxlen = ONE_ADDR_EEPROM_UNPAGED_SIZE - off;
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} else {
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/* Pages supported, trim len to the end of pages */
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- maxlen = ONE_ADDR_EEPROM_SIZE - off;
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+ maxlen = maxlen - off;
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}
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len = (len > maxlen) ? maxlen : len;
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dev_dbg(&client->dev,
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@@ -995,6 +1029,44 @@ static ssize_t set_port_name(struct device *dev,
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return count;
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}
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+static ssize_t show_bank_size(struct device *dev,
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+ struct device_attribute *dattr, char *buf)
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+{
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+ struct i2c_client *client = to_i2c_client(dev);
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+ struct optoe_data *optoe = i2c_get_clientdata(client);
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+ ssize_t count;
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+
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+ mutex_lock(&optoe->lock);
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+ count = sprintf(buf, "%u\n", optoe->bank_size);
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+ mutex_unlock(&optoe->lock);
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+
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+ return count;
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+}
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+
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+static ssize_t set_bank_size(struct device *dev,
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+ struct device_attribute *attr,
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+ const char *buf, size_t count)
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+{
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+ struct i2c_client *client = to_i2c_client(dev);
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+ struct optoe_data *optoe = i2c_get_clientdata(client);
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+ unsigned int bank_size;
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+
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+ // setting bank size is only supported for the CMIS device
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+ if (optoe->dev_class != CMIS_ADDR) {
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+ return -EINVAL;
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+ }
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+
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+ if (kstrtouint(buf, 0, &bank_size) != 0 ||
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+ bank_size < 0 || bank_size > OPTOE_MAX_SUPPORTED_BANK_SIZE)
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+ return -EINVAL;
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+
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+ mutex_lock(&optoe->lock);
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+ optoe->bank_size = bank_size;
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+ mutex_unlock(&optoe->lock);
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+
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+ return count;
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+}
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+
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static DEVICE_ATTR(port_name, 0644, show_port_name, set_port_name);
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#endif /* if NOT defined EEPROM_CLASS, the common case */
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@@ -1003,6 +1075,7 @@ static DEVICE_ATTR(write_timeout, 0644, show_dev_write_timeout_size,
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static DEVICE_ATTR(write_max, 0644, show_dev_write_max_size,
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set_dev_write_max_size);
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static DEVICE_ATTR(dev_class, 0644, show_dev_class, set_dev_class);
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+static DEVICE_ATTR(bank_size, 0644, show_bank_size, set_bank_size);
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static struct attribute *optoe_attrs[] = {
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#ifndef EEPROM_CLASS
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@@ -1011,6 +1084,7 @@ static struct attribute *optoe_attrs[] = {
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&dev_attr_write_timeout.attr,
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&dev_attr_write_max.attr,
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&dev_attr_dev_class.attr,
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+ &dev_attr_bank_size.attr,
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NULL,
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};
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@@ -1027,6 +1101,17 @@ static int optoe_probe(struct i2c_client *client,
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struct optoe_data *optoe;
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int num_addresses = 0;
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char port_name[MAX_PORT_NAME_LEN];
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+ /*
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+ * NOTE: AN-2079
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+ * Finisar recommends that the host implement 1 byte writes
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+ * only since this module only supports 32 byte page boundaries.
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+ * 2 byte writes are acceptable for PE and Vout changes per
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+ * Application Note AN-2071.
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+ *
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+ * use 2 bytes for CMIS devices since CMIS 5.3 requires write both BankSelect and PageSlect in one WRITE acess.
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+ * see the comment in optoe_eeprom_update_client().
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+ */
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+ unsigned int write_max;
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if (client->addr != 0x50) {
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dev_dbg(&client->dev, "probe, bad i2c addr: 0x%x\n",
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@@ -1097,19 +1182,25 @@ static int optoe_probe(struct i2c_client *client,
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(strcmp(client->name, "sff8436") == 0)) {
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/* one-address (eg QSFP) family */
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optoe->dev_class = ONE_ADDR;
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+ optoe->bank_size = 0;
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chip.byte_len = ONE_ADDR_EEPROM_SIZE;
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num_addresses = 1;
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+ write_max = 1;
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} else if ((strcmp(client->name, "optoe2") == 0) ||
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(strcmp(client->name, "24c04") == 0)) {
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/* SFP family */
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optoe->dev_class = TWO_ADDR;
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+ optoe->bank_size = 0;
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chip.byte_len = TWO_ADDR_EEPROM_SIZE;
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num_addresses = 2;
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+ write_max = 1;
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} else if (strcmp(client->name, "optoe3") == 0) {
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/* CMIS spec */
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optoe->dev_class = CMIS_ADDR;
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- chip.byte_len = ONE_ADDR_EEPROM_SIZE;
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+ optoe->bank_size = OPTOE_DEFAULT_BANK_SIZE;
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+ chip.byte_len = one_addr_eeprom_size_with_bank(OPTOE_MAX_SUPPORTED_BANK_SIZE);
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num_addresses = 1;
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+ write_max = 2;
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} else { /* those were the only choices */
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err = -EINVAL;
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goto exit;
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@@ -1139,15 +1230,6 @@ static int optoe_probe(struct i2c_client *client,
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I2C_FUNC_SMBUS_WRITE_WORD_DATA) ||
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i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
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- /*
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- * NOTE: AN-2079
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- * Finisar recommends that the host implement 1 byte writes
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- * only since this module only supports 32 byte page boundaries.
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- * 2 byte writes are acceptable for PE and Vout changes per
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- * Application Note AN-2071.
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- */
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- unsigned int write_max = 1;
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-
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optoe->bin.write = optoe_bin_write;
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optoe->bin.attr.mode |= 0200;
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--
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2.25.1
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‎patch/series‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -34,6 +34,7 @@ driver-support-optoe-twoaddr-a2h-access.patch
3434
driver-support-optoe-oneaddr-pageable.patch
3535
driver-support-optoe-update-to-linux-6.1.patch
3636
driver-support-optoe-dynamic-write-timeout.patch
37+
driver-support-optoe-bank-support.patch
3738
driver-net-tg3-add-param-short-preamble-and-reset.patch
3839
driver-net-tg3-change-dma-mask-for-57766.patch
3940
0004-dt-bindings-hwmon-Add-missing-documentation-for-lm75.patch

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