On 9/3/24 10:04, Marek Behún wrote:
On Tue, Sep 03, 2024 at 08:57:24AM +0200, Stefan Roese wrote:
On 8/29/24 10:08, Marek Behún wrote:
Use the i2c_eeprom miscellaneous driver for reading Turris Omnia EEPROM
in U-Boot proper. Keep using dm_i2c_read() in SPL build, since adding
the i2c_eeprom driver to SPL build increases the image by 1.5 KiB.

Signed-off-by: Marek Behún <ka...@kernel.org>
---
   arch/arm/mach-mvebu/Kconfig              | 1 +
   board/CZ.NIC/turris_omnia/turris_omnia.c | 9 +++++++--
   configs/turris_omnia_defconfig           | 1 -
   3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-mvebu/Kconfig b/arch/arm/mach-mvebu/Kconfig
index 4a8328760eb..c1a1a333e6c 100644
--- a/arch/arm/mach-mvebu/Kconfig
+++ b/arch/arm/mach-mvebu/Kconfig
@@ -149,6 +149,7 @@ config TARGET_TURRIS_OMNIA
        select SPL_SYS_MALLOC_SIMPLE
        select SYS_I2C_MVTWSI
        select ATSHA204A
+       select I2C_EEPROM
        select ARMADA_38X_SUPPORT_OLD_DDR3_TRAINING
   config TARGET_TURRIS_MOX
diff --git a/board/CZ.NIC/turris_omnia/turris_omnia.c 
b/board/CZ.NIC/turris_omnia/turris_omnia.c
index 392df53a6d8..46f20f05c05 100644
--- a/board/CZ.NIC/turris_omnia/turris_omnia.c
+++ b/board/CZ.NIC/turris_omnia/turris_omnia.c
@@ -23,6 +23,7 @@
   #include <dt-bindings/gpio/gpio.h>
   #include <fdt_support.h>
   #include <hexdump.h>
+#include <i2c_eeprom.h>
   #include <time.h>
   #include <turris-omnia-mcu-interface.h>
   #include <linux/bitops.h>
@@ -473,9 +474,13 @@ static bool omnia_read_eeprom(struct omnia_eeprom *oep)
        if (!eeprom)
                return false;
-       ret = dm_i2c_read(eeprom, 0, (void *)oep, sizeof(*oep));
+       if (IS_ENABLED(CONFIG_SPL_BUILD))
+               ret = dm_i2c_read(eeprom, 0, (void *)oep, sizeof(*oep));
+       else
+               ret = i2c_eeprom_read(eeprom, 0, (void *)oep, sizeof(*oep));

So whats the advantage using i2c_eeprom_read() here in U-Boot proper?
The only thing that stands out to me is that the code get more complex
because of the SPL/non-SPL distinction.

The reasons are as follows:
- it's "more correct" semantically

- the i2c_eeprom driver was already enabled for U-Boot proper in
   defconfig (with this commit selected by the board), because of the
   `eeprom` commmand, so I thought "why not use it?"
   (looking at the code now, it goes
      i2c_eeprom_read()
        dereference of i2c_eeprom_ops->read method
        i2c_eeprom_std_read()
          dm_i2c_read()
    so the complication is trivial, IMO)

- the following commit adds code that writes the eeprom, and this cannot
   be done with simple dm_i2c_write(), because each eeprom page has to be
   written by another transaction, which is what i2c_eeprom_write()
   does.

   So I knew that I was going to add i2c_eeprom_write(), and I thought
   that it would seem weird writing with i2c_eeprom_write() but reading
   with dm_i2c_read().

That's what I thought after reviewing patch 3/3. Okay, makes sense.
Let's see, if we can pull this into the upcoming release.

Reviewed-by: Stefan Roese <s...@denx.de>

Thanks,
Stefan

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