Re: [PATCH v2] eeprom: at24: Add support for 24c1025 EEPROM

[Maxim Kochetkov <fido_max@xxxxxxxx>]

On 04.12.2021 01:37, Maxim Kochetkov wrote:
> Microchip EEPROM 24xx1025 is like a 24c1024. The only difference
> between them is that the I2C address bit used to select between the
> two banks is bit 2 for the 1025 and not bit 0 as in the 1024.
>
> Signed-off-by: Maxim Kochetkov <fido_max@xxxxxxxx>

Adding Bartosz' new email to CC...

> ---
> v2: rebased on git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git/at24/for-next
>
>   drivers/misc/eeprom/at24.c | 15 ++++++++++++++-
>   1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> index 4d91c71c42cd..633e1cf08d6e 100644
> --- a/drivers/misc/eeprom/at24.c
> +++ b/drivers/misc/eeprom/at24.c
> @@ -91,6 +91,7 @@ struct at24_data {
>   	 * Some chips tie up multiple I2C addresses; dummy devices reserve
>   	 * them for us.
>   	 */
> +	u8 bank_addr_shift;
>   	struct regmap *client_regmaps[];
>   };
>   
> @@ -118,6 +119,7 @@ MODULE_PARM_DESC(at24_write_timeout, "Time (in ms) to try writes (default 25)");
>   struct at24_chip_data {
>   	u32 byte_len;
>   	u8 flags;
> +	u8 bank_addr_shift;
>   	void (*read_post)(unsigned int off, char *buf, size_t count);
>   };
>   
> @@ -132,6 +134,12 @@ struct at24_chip_data {
>   		.read_post = _read_post,				\
>   	}
>   
> +#define AT24_CHIP_DATA_BS(_name, _len, _flags, _bank_addr_shift)	\
> +	static const struct at24_chip_data _name = {			\
> +		.byte_len = _len, .flags = _flags,			\
> +		.bank_addr_shift = _bank_addr_shift			\
> +	}
> +
>   static void at24_read_post_vaio(unsigned int off, char *buf, size_t count)
>   {
>   	int i;
> @@ -192,6 +200,7 @@ AT24_CHIP_DATA(at24_data_24c128, 131072 / 8, AT24_FLAG_ADDR16);
>   AT24_CHIP_DATA(at24_data_24c256, 262144 / 8, AT24_FLAG_ADDR16);
>   AT24_CHIP_DATA(at24_data_24c512, 524288 / 8, AT24_FLAG_ADDR16);
>   AT24_CHIP_DATA(at24_data_24c1024, 1048576 / 8, AT24_FLAG_ADDR16);
> +AT24_CHIP_DATA_BS(at24_data_24c1025, 1048576 / 8, AT24_FLAG_ADDR16, 2);
>   AT24_CHIP_DATA(at24_data_24c2048, 2097152 / 8, AT24_FLAG_ADDR16);
>   /* identical to 24c08 ? */
>   AT24_CHIP_DATA(at24_data_INT3499, 8192 / 8, 0);
> @@ -220,6 +229,7 @@ static const struct i2c_device_id at24_ids[] = {
>   	{ "24c256",	(kernel_ulong_t)&at24_data_24c256 },
>   	{ "24c512",	(kernel_ulong_t)&at24_data_24c512 },
>   	{ "24c1024",	(kernel_ulong_t)&at24_data_24c1024 },
> +	{ "24c1025",	(kernel_ulong_t)&at24_data_24c1025 },
>   	{ "24c2048",    (kernel_ulong_t)&at24_data_24c2048 },
>   	{ "at24",	0 },
>   	{ /* END OF LIST */ }
> @@ -249,6 +259,7 @@ static const struct of_device_id at24_of_match[] = {
>   	{ .compatible = "atmel,24c256",		.data = &at24_data_24c256 },
>   	{ .compatible = "atmel,24c512",		.data = &at24_data_24c512 },
>   	{ .compatible = "atmel,24c1024",	.data = &at24_data_24c1024 },
> +	{ .compatible = "atmel,24c1025",	.data = &at24_data_24c1025 },
>   	{ .compatible = "atmel,24c2048",	.data = &at24_data_24c2048 },
>   	{ /* END OF LIST */ },
>   };
> @@ -533,7 +544,8 @@ static int at24_make_dummy_client(struct at24_data *at24, unsigned int index,
>   
>   	dummy_client = devm_i2c_new_dummy_device(&base_client->dev,
>   						 base_client->adapter,
> -						 base_client->addr + index);
> +						 base_client->addr +
> +						 (index << at24->bank_addr_shift));
>   	if (IS_ERR(dummy_client))
>   		return PTR_ERR(dummy_client);
>   
> @@ -674,6 +686,7 @@ static int at24_probe(struct i2c_client *client)
>   	at24->page_size = page_size;
>   	at24->flags = flags;
>   	at24->read_post = cdata->read_post;
> +	at24->bank_addr_shift = cdata->bank_addr_shift;
>   	at24->num_addresses = num_addresses;
>   	at24->offset_adj = at24_get_offset_adj(flags, byte_len);
>   	at24->client_regmaps[0] = regmap;