Add read-only versions of all EEPROMs. These versions are read-only
on the i2c side, but can be written from the sysfs side.
Signed-off-by: Björn Ardö <bjorn.ardo@xxxxxxxx>
---
drivers/i2c/i2c-slave-eeprom.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/i2c/i2c-slave-eeprom.c b/drivers/i2c/i2c-slave-eeprom.c
index 92ff999..b3d271b 100644
--- a/drivers/i2c/i2c-slave-eeprom.c
+++ b/drivers/i2c/i2c-slave-eeprom.c
@@ -33,11 +33,13 @@ struct eeprom_data {
u16 address_mask;
u8 num_address_bytes;
u8 idx_write_cnt;
+ bool read_only;
u8 buffer[];
};
#define I2C_SLAVE_BYTELEN GENMASK(15, 0)
#define I2C_SLAVE_FLAG_ADDR16 BIT(16)
+#define I2C_SLAVE_FLAG_RO BIT(17)
#define I2C_SLAVE_DEVICE_MAGIC(_len, _flags) ((_flags) | (_len))
static int i2c_slave_eeprom_slave_cb(struct i2c_client *client,
@@ -53,6 +55,8 @@ static int i2c_slave_eeprom_slave_cb(struct i2c_client *client,
eeprom->buffer_idx = *val | (eeprom->buffer_idx << 8);
eeprom->idx_write_cnt++;
} else {
+ if (eeprom->read_only)
+ return 0;
spin_lock(&eeprom->buffer_lock);
eeprom->buffer[eeprom->buffer_idx++ & eeprom->address_mask] = *val;
spin_unlock(&eeprom->buffer_lock);
@@ -130,6 +134,7 @@ static int i2c_slave_eeprom_probe(struct i2c_client *client, const struct i2c_de
eeprom->idx_write_cnt = 0;
eeprom->num_address_bytes = flag_addr16 ? 2 : 1;
eeprom->address_mask = size - 1;
+ eeprom->read_only = FIELD_GET(I2C_SLAVE_FLAG_RO, id->driver_data);
spin_lock_init(&eeprom->buffer_lock);
i2c_set_clientdata(client, eeprom);
@@ -165,8 +170,11 @@ static int i2c_slave_eeprom_remove(struct i2c_client *client)
static const struct i2c_device_id i2c_slave_eeprom_id[] = {
{ "slave-24c02", I2C_SLAVE_DEVICE_MAGIC(2048 / 8, 0) },
+ { "slave-24c02ro", I2C_SLAVE_DEVICE_MAGIC(2048 / 8, I2C_SLAVE_FLAG_RO) },
{ "slave-24c32", I2C_SLAVE_DEVICE_MAGIC(32768 / 8, I2C_SLAVE_FLAG_ADDR16) },
+ { "slave-24c32ro", I2C_SLAVE_DEVICE_MAGIC(32768 / 8, I2C_SLAVE_FLAG_ADDR16 | I2C_SLAVE_FLAG_RO) },
{ "slave-24c64", I2C_SLAVE_DEVICE_MAGIC(65536 / 8, I2C_SLAVE_FLAG_ADDR16) },
+ { "slave-24c64ro", I2C_SLAVE_DEVICE_MAGIC(65536 / 8, I2C_SLAVE_FLAG_ADDR16 | I2C_SLAVE_FLAG_RO) },
{ }
};
MODULE_DEVICE_TABLE(i2c, i2c_slave_eeprom_id);
--
2.1.4
