arm: mvebu: turris_omnia: Read DDR speed from EEPROM

Some Turris Omnia boards experience memory issues, and by
experimentation we found that some of these issues can be solved by
slowing DDR speed.

Add a new field in the extended EEPROM information structure, ddr_speed.
Support several values in this field (for now 1066F, 1333H, and the
default, 1600K) and use it to overwrite the DDR topology parameters
used by the DDR training algorithm.

Signed-off-by: Marek Behún <kabel@kernel.org>

diff --git a/board/CZ.NIC/turris_omnia/eeprom.c b/board/CZ.NIC/turris_omnia/eeprom.c
index ea13e95b376af7d5442faf354a908466110798a9..32572481ce9cc63d929df0d409d5f5e8fcf03c01 100644 (file)
--- a/board/CZ.NIC/turris_omnia/eeprom.c
+++ b/board/CZ.NIC/turris_omnia/eeprom.c
@@ -55,12 +55,49 @@ static int eeprom_field_update_region(struct eeprom_field *field, char *value)
        return 0;
 }
 
+static void eeprom_field_print_ddr_speed(const struct eeprom_field *field)
+{
+       printf(PRINT_FIELD_SEGMENT, field->name);
+
+       if (field->buf[0] == '\0' || field->buf[0] == 0xff)
+               puts("(empty, defaults to 1600K)\n");
+       else
+               printf("%.5s\n", field->buf);
+}
+
+bool omnia_valid_ddr_speed(const char *name);
+void omnia_print_ddr_speeds(void);
+
+static int eeprom_field_update_ddr_speed(struct eeprom_field *field,
+                                        char *value)
+{
+       if (value[0] == '\0') {
+               /* setting default value */
+               memset(field->buf, 0xff, field->size);
+
+               return 0;
+       }
+
+       if (!omnia_valid_ddr_speed(value)) {
+               printf("%s: invalid setting, supported values are:\n  ",
+                      field->name);
+               omnia_print_ddr_speeds();
+
+               return -1;
+       }
+
+       strncpy(field->buf, value, field->size);
+
+       return 0;
+}
+
 static struct eeprom_field omnia_layout[] = {
        _DEF_FIELD("Magic constant", 4, bin),
        _DEF_FIELD("RAM size in GB", 4, ramsz),
        _DEF_FIELD("Wi-Fi Region", 4, region),
        _DEF_FIELD("CRC32 checksum", 4, bin),
-       _DEF_FIELD("Extended reserved fields", 44, reserved),
+       _DEF_FIELD("DDR speed", 5, ddr_speed),
+       _DEF_FIELD("Extended reserved fields", 39, reserved),
        _DEF_FIELD("Extended CRC32 checksum", 4, bin),
 };
 
@@ -96,7 +133,7 @@ static int omnia_update_field(struct eeprom_layout *layout, char *field_name,
        }
 
        if (field < ext_crc_field) {
-               u32 crc = crc32(0, layout->data, 44);
+               u32 crc = crc32(0, layout->data, 60);
                put_unaligned_le32(crc, ext_crc_field->buf);
        }
 

diff --git a/board/CZ.NIC/turris_omnia/turris_omnia.c b/board/CZ.NIC/turris_omnia/turris_omnia.c
index c2f91b762f52fa010642865b3e52d866e6fe8824..544784e860e1e6cba488d577648ba9e3e0631f89 100644 (file)
--- a/board/CZ.NIC/turris_omnia/turris_omnia.c
+++ b/board/CZ.NIC/turris_omnia/turris_omnia.c
@@ -431,7 +431,8 @@ struct omnia_eeprom {
        u32 crc;
 
        /* second part (only considered if crc2 is not all-ones) */
-       u8 reserved[44];
+       char ddr_speed[5];
+       u8 reserved[39];
        u32 crc2;
 };
 
@@ -520,6 +521,26 @@ static int omnia_get_ram_size_gb(void)
        return ram_size;
 }
 
+static const char *omnia_get_ddr_speed(void)
+{
+       struct omnia_eeprom oep;
+       static char speed[sizeof(oep.ddr_speed) + 1];
+
+       if (!omnia_read_eeprom(&oep))
+               return NULL;
+
+       if (!is_omnia_eeprom_second_part_valid(&oep))
+               return NULL;
+
+       if (!oep.ddr_speed[0] || oep.ddr_speed[0] == 0xff)
+               return NULL;
+
+       memcpy(&speed, &oep.ddr_speed, sizeof(oep.ddr_speed));
+       speed[sizeof(speed) - 1] = '\0';
+
+       return speed;
+}
+
 static const char * const omnia_get_mcu_type(void)
 {
        static char result[] = "xxxxxxx (with peripheral resets)";
@@ -634,12 +655,84 @@ static struct mv_ddr_topology_map board_topology_map_2g = {
        {0}                             /* timing parameters */
 };
 
+static const struct omnia_ddr_speed {
+       char name[5];
+       u8 speed_bin;
+       u8 freq;
+} omnia_ddr_speeds[] = {
+       { "1066F", SPEED_BIN_DDR_1066F, MV_DDR_FREQ_533 },
+       { "1333H", SPEED_BIN_DDR_1333H, MV_DDR_FREQ_667 },
+       { "1600K", SPEED_BIN_DDR_1600K, MV_DDR_FREQ_800 },
+};
+
+static const struct omnia_ddr_speed *find_ddr_speed_setting(const char *name)
+{
+       for (int i = 0; i < ARRAY_SIZE(omnia_ddr_speeds); ++i)
+               if (!strncmp(name, omnia_ddr_speeds[i].name, 5))
+                       return &omnia_ddr_speeds[i];
+
+       return NULL;
+}
+
+bool omnia_valid_ddr_speed(const char *name)
+{
+       return find_ddr_speed_setting(name) != NULL;
+}
+
+void omnia_print_ddr_speeds(void)
+{
+       for (int i = 0; i < ARRAY_SIZE(omnia_ddr_speeds); ++i)
+               printf("%.5s%s", omnia_ddr_speeds[i].name,
+                      i == ARRAY_SIZE(omnia_ddr_speeds) - 1 ? "\n" : ", ");
+}
+
+static void fixup_speed_in_ddr_topology(struct mv_ddr_topology_map *topology)
+{
+       typeof(topology->interface_params[0]) *params;
+       const struct omnia_ddr_speed *setting;
+       const char *speed;
+       static bool done;
+
+       if (done)
+               return;
+
+       done = true;
+
+       speed = omnia_get_ddr_speed();
+       if (!speed)
+               return;
+
+       setting = find_ddr_speed_setting(speed);
+       if (!setting) {
+               printf("Unsupported value %s for DDR3 speed in EEPROM!\n",
+                      speed);
+               return;
+       }
+
+       params = &topology->interface_params[0];
+
+       /* don't inform if we are not changing the speed from the default one */
+       if (params->speed_bin_index == setting->speed_bin)
+               return;
+
+       printf("Fixing up DDR3 speed (EEPROM defines %s)\n", speed);
+
+       params->speed_bin_index = setting->speed_bin;
+       params->memory_freq = setting->freq;
+}
+
 struct mv_ddr_topology_map *mv_ddr_topology_map_get(void)
 {
+       struct mv_ddr_topology_map *topology;
+
        if (omnia_get_ram_size_gb() == 2)
-               return &board_topology_map_2g;
+               topology = &board_topology_map_2g;
        else
-               return &board_topology_map_1g;
+               topology = &board_topology_map_1g;
+
+       fixup_speed_in_ddr_topology(topology);
+
+       return topology;
 }
 
 static int set_regdomain(void)