board: ti: j721s2: Add support to detect daughtercards

Add support to detect daughtercards (GESI Ethernet card) in-order
to set the MAC address of the main CPSW2G interface.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>

diff --git a/board/ti/j721s2/evm.c b/board/ti/j721s2/evm.c
index 09d2688..8eaca9d 100644 (file)
--- a/board/ti/j721s2/evm.c
+++ b/board/ti/j721s2/evm.c
@@ -153,6 +153,135 @@ static void setup_serial(void)
        snprintf(serial_string, sizeof(serial_string), "%016lx", board_serial);
        env_set("serial#", serial_string);
 }
+
+/*
+ * Declaration of daughtercards to probe. Note that when adding more
+ * cards they should be grouped by the 'i2c_addr' field to allow for a
+ * more efficient probing process.
+ */
+static const struct {
+       u8 i2c_addr;            /* I2C address of card EEPROM */
+       char *card_name;        /* EEPROM-programmed card name */
+       char *dtbo_name;        /* Device tree overlay to apply */
+       u8 eth_offset;          /* ethXaddr MAC address index offset */
+} ext_cards[] = {
+       {
+               0x52,
+               "J7X-GESI-EXP",
+               "k3-j721s2-gesi-exp-board.dtbo",
+               1,              /* Start populating from eth1addr */
+       },
+};
+
+#define DAUGHTER_CARD_NO_OF_MAC_ADDR   5
+static bool daughter_card_detect_flags[ARRAY_SIZE(ext_cards)];
+
+static int probe_daughtercards(void)
+{
+       char mac_addr[DAUGHTER_CARD_NO_OF_MAC_ADDR][TI_EEPROM_HDR_ETH_ALEN];
+       bool eeprom_read_success;
+       struct ti_am6_eeprom ep;
+       u8 previous_i2c_addr;
+       u8 mac_addr_cnt;
+       int i;
+       int ret;
+
+       /* Mark previous I2C address variable as not populated */
+       previous_i2c_addr = 0xff;
+
+       /* No EEPROM data was read yet */
+       eeprom_read_success = false;
+
+       /* Iterate through list of daughtercards */
+       for (i = 0; i < ARRAY_SIZE(ext_cards); i++) {
+               /* Obtain card-specific I2C address */
+               u8 i2c_addr = ext_cards[i].i2c_addr;
+
+               /* Read card EEPROM if not already read previously */
+               if (i2c_addr != previous_i2c_addr) {
+                       /* Store I2C address so we can avoid reading twice */
+                       previous_i2c_addr = i2c_addr;
+
+                       /* Get and parse the daughter card EEPROM record */
+                       ret = ti_i2c_eeprom_am6_get(CONFIG_EEPROM_BUS_ADDRESS,
+                                                   i2c_addr,
+                                                   &ep,
+                                                   (char **)mac_addr,
+                                                   DAUGHTER_CARD_NO_OF_MAC_ADDR,
+                                                   &mac_addr_cnt);
+                       if (ret) {
+                               debug("%s: No daughtercard EEPROM at 0x%02x found %d\n",
+                                     __func__, i2c_addr, ret);
+                               eeprom_read_success = false;
+                               /* Skip to the next daughtercard to probe */
+                               continue;
+                       }
+
+                       /* EEPROM read successful, okay to further process. */
+                       eeprom_read_success = true;
+               }
+
+               /* Only continue processing if EEPROM data was read */
+               if (!eeprom_read_success)
+                       continue;
+
+               /* Only process the parsed data if we found a match */
+               if (strncmp(ep.name, ext_cards[i].card_name, sizeof(ep.name)))
+                       continue;
+
+               printf("Detected: %s rev %s\n", ep.name, ep.version);
+               daughter_card_detect_flags[i] = true;
+
+               if (!IS_ENABLED(CONFIG_SPL_BUILD)) {
+                       int j;
+                       /*
+                        * Populate any MAC addresses from daughtercard into the U-Boot
+                        * environment, starting with a card-specific offset so we can
+                        * have multiple ext_cards contribute to the MAC pool in a well-
+                        * defined manner.
+                        */
+                       for (j = 0; j < mac_addr_cnt; j++) {
+                               if (!is_valid_ethaddr((u8 *)mac_addr[j]))
+                                       continue;
+
+                               eth_env_set_enetaddr_by_index("eth", ext_cards[i].eth_offset + j,
+                                                             (uchar *)mac_addr[j]);
+                       }
+               }
+       }
+
+       if (!IS_ENABLED(CONFIG_SPL_BUILD)) {
+               char name_overlays[1024] = { 0 };
+
+               for (i = 0; i < ARRAY_SIZE(ext_cards); i++) {
+                       if (!daughter_card_detect_flags[i])
+                               continue;
+
+                       /* Skip if no overlays are to be added */
+                       if (!strlen(ext_cards[i].dtbo_name))
+                               continue;
+
+                       /*
+                        * Make sure we are not running out of buffer space by checking
+                        * if we can fit the new overlay, a trailing space to be used
+                        * as a separator, plus the terminating zero.
+                        */
+                       if (strlen(name_overlays) + strlen(ext_cards[i].dtbo_name) + 2 >
+                           sizeof(name_overlays))
+                               return -ENOMEM;
+
+                       /* Append to our list of overlays */
+                       strcat(name_overlays, ext_cards[i].dtbo_name);
+                       strcat(name_overlays, " ");
+               }
+
+               /* Apply device tree overlay(s) to the U-Boot environment, if any */
+               if (strlen(name_overlays))
+                       return env_set("name_overlays", name_overlays);
+       }
+
+       return 0;
+}
 #endif
 
 /*
@@ -182,6 +311,7 @@ int board_late_init(void)
        if (IS_ENABLED(CONFIG_TI_I2C_BOARD_DETECT)) {
                setup_board_eeprom_env();
                setup_serial();
+               probe_daughtercards();
        }
 
        return 0;