On 03/02/2017 01:10 PM, Felipe Balbi wrote:
Hi,
Franklin S Cooper Jr fcooper@ti.com writes:
From: Nishanth Menon nm@ti.com
In some situations the EEPROM used for board detection may not be programmed or simply programmed incorrectly. Therefore, it may be necessary to "simulate" reading the contents of the EEPROM to set appropriate variables used in the board detection code.
This may also be helpful in certain boot modes where doing i2c reads may be costly and the config supports running only a specific board.
Signed-off-by: Nishanth Menon nm@ti.com Signed-off-by: Tero Kristo t-kristo@ti.com Signed-off-by: Keerthy j-keerthy@ti.com Signed-off-by: Franklin S Cooper Jr. fcooper@ti.com
board/ti/common/board_detect.c | 24 ++++++++++++++++++++++++ board/ti/common/board_detect.h | 17 +++++++++++++++++ 2 files changed, 41 insertions(+)
diff --git a/board/ti/common/board_detect.c b/board/ti/common/board_detect.c index a5dba94..5aaf884 100644 --- a/board/ti/common/board_detect.c +++ b/board/ti/common/board_detect.c @@ -116,6 +116,30 @@ static int __maybe_unused ti_i2c_eeprom_get(int bus_addr, int dev_addr, return 0; }
+int __maybe_unused ti_i2c_eeprom_am_set(const char *name, const char *rev) +{
- struct ti_common_eeprom *ep;
- if (!name || !rev)
return -1;- ep = TI_EEPROM_DATA;
- if (ep->header == TI_EEPROM_HEADER_MAGIC)
goto already_set;- /* Set to 0 all fields */
- memset(ep, 0, sizeof(*ep));
- strncpy(ep->name, name, TI_EEPROM_HDR_NAME_LEN);
- strncpy(ep->version, rev, TI_EEPROM_HDR_REV_LEN);
- /* Some dummy serial number to identify the platform */
- strncpy(ep->serial, "0000", TI_EEPROM_HDR_SERIAL_LEN);
- /* Mark it with a valid header */
- ep->header = TI_EEPROM_HEADER_MAGIC;
+already_set:
- return 0;
+}
int __maybe_unused ti_i2c_eeprom_am_get(int bus_addr, int dev_addr) { int rc; diff --git a/board/ti/common/board_detect.h b/board/ti/common/board_detect.h index 343fcb4..eeeacd3 100644 --- a/board/ti/common/board_detect.h +++ b/board/ti/common/board_detect.h @@ -193,4 +193,21 @@ u64 board_ti_get_emif2_size(void); */ void set_board_info_env(char *name);
+/**
- ti_i2c_eeprom_am_set() - Setup the eeprom data with predefined values
- @name: Name of the board
- @rev: Revision of the board
- In some cases such as in RTC-only mode, we are able to skip reading eeprom
- and wasting i2c based initialization time by using predefined flags for
- detecting what platform we are booting on. For those platforms, provide
- a handy function to pre-program information.
there's a micro-optimization for some cases here. You can try to read i2c only on first time and save the result to environment. Something like:
if (!getenv("serial#")) { read_serial_from_eeprom(&serial); setenv("serial#", serial); saveenv(); }
Of course, this assumes i2c is available and eeprom is properly programmed. For bogus eeprom data, well, can't do much.
Atleast for the purposes I'm using it for I have to deal with non programmed eeprom. The other usecase I've seen was wanting to avoid touching the EEPROM at all.