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| author | Björn Ardö <bjorn.ardo@axis.com> | 2019-09-06 17:06:09 +0300 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2019-09-28 21:44:12 +0300 |
| commit | 11af27f494086188620e7768e421894af93c126a (patch) | |
| tree | 4678ba6525f599857ac3303766d5999164c834f2 /drivers/i2c | |
| parent | fd4b204a0971854c35795ab60b3673a5b57dfebc (diff) | |
| download | linux-11af27f494086188620e7768e421894af93c126a.tar.xz | |
i2c: slave-eeprom: Add read only mode
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@axis.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/i2c-slave-eeprom.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/i2c/i2c-slave-eeprom.c b/drivers/i2c/i2c-slave-eeprom.c index 92ff9991bae8..db9763cb4dae 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, @@ -53,9 +55,11 @@ static int i2c_slave_eeprom_slave_cb(struct i2c_client *client, eeprom->buffer_idx = *val | (eeprom->buffer_idx << 8); eeprom->idx_write_cnt++; } else { - spin_lock(&eeprom->buffer_lock); - eeprom->buffer[eeprom->buffer_idx++ & eeprom->address_mask] = *val; - spin_unlock(&eeprom->buffer_lock); + if (!eeprom->read_only) { + spin_lock(&eeprom->buffer_lock); + eeprom->buffer[eeprom->buffer_idx++ & eeprom->address_mask] = *val; + spin_unlock(&eeprom->buffer_lock); + } } break; @@ -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); |