diff options
Diffstat (limited to 'drivers/w1/masters/ds2482.c')
| -rw-r--r-- | drivers/w1/masters/ds2482.c | 51 |
1 files changed, 45 insertions, 6 deletions
diff --git a/drivers/w1/masters/ds2482.c b/drivers/w1/masters/ds2482.c index 6429b9e..e033491 100644 --- a/drivers/w1/masters/ds2482.c +++ b/drivers/w1/masters/ds2482.c @@ -51,10 +51,10 @@ * The top 4 bits always read 0. * To write, the top nibble must be the 1's compl. of the low nibble. */ -#define DS2482_REG_CFG_1WS 0x08 -#define DS2482_REG_CFG_SPU 0x04 -#define DS2482_REG_CFG_PPM 0x02 -#define DS2482_REG_CFG_APU 0x01 +#define DS2482_REG_CFG_1WS 0x08 /* 1-wire speed */ +#define DS2482_REG_CFG_SPU 0x04 /* strong pull-up */ +#define DS2482_REG_CFG_PPM 0x02 /* presence pulse masking */ +#define DS2482_REG_CFG_APU 0x01 /* active pull-up */ /** @@ -132,6 +132,17 @@ struct ds2482_data { /** + * Helper to calculate values for configuration register + * @param conf the raw config value + * @return the value w/ complements that can be written to register + */ +static inline u8 ds2482_calculate_config(u8 conf) +{ + return conf | ((~conf & 0x0f) << 4); +} + + +/** * Sets the read pointer. * @param pdev The ds2482 client pointer * @param read_ptr see DS2482_PTR_CODE_xxx above @@ -399,7 +410,7 @@ static u8 ds2482_w1_reset_bus(void *data) /* If the chip did reset since detect, re-config it */ if (err & DS2482_REG_STS_RST) ds2482_send_cmd_data(pdev, DS2482_CMD_WRITE_CONFIG, - 0xF0); + ds2482_calculate_config(0x00)); } mutex_unlock(&pdev->access_lock); @@ -407,6 +418,32 @@ static u8 ds2482_w1_reset_bus(void *data) return retval; } +static u8 ds2482_w1_set_pullup(void *data, int delay) +{ + struct ds2482_w1_chan *pchan = data; + struct ds2482_data *pdev = pchan->pdev; + u8 retval = 1; + + /* if delay is non-zero activate the pullup, + * the strong pullup will be automatically deactivated + * by the master, so do not explicitly deactive it + */ + if (delay) { + /* both waits are crucial, otherwise devices might not be + * powered long enough, causing e.g. a w1_therm sensor to + * provide wrong conversion results + */ + ds2482_wait_1wire_idle(pdev); + /* note: it seems like both SPU and APU have to be set! */ + retval = ds2482_send_cmd_data(pdev, DS2482_CMD_WRITE_CONFIG, + ds2482_calculate_config(DS2482_REG_CFG_SPU | + DS2482_REG_CFG_APU)); + ds2482_wait_1wire_idle(pdev); + } + + return retval; +} + static int ds2482_probe(struct i2c_client *client, const struct i2c_device_id *id) @@ -452,7 +489,8 @@ static int ds2482_probe(struct i2c_client *client, data->w1_count = 8; /* Set all config items to 0 (off) */ - ds2482_send_cmd_data(data, DS2482_CMD_WRITE_CONFIG, 0xF0); + ds2482_send_cmd_data(data, DS2482_CMD_WRITE_CONFIG, + ds2482_calculate_config(0x00)); mutex_init(&data->access_lock); @@ -468,6 +506,7 @@ static int ds2482_probe(struct i2c_client *client, data->w1_ch[idx].w1_bm.touch_bit = ds2482_w1_touch_bit; data->w1_ch[idx].w1_bm.triplet = ds2482_w1_triplet; data->w1_ch[idx].w1_bm.reset_bus = ds2482_w1_reset_bus; + data->w1_ch[idx].w1_bm.set_pullup = ds2482_w1_set_pullup; err = w1_add_master_device(&data->w1_ch[idx].w1_bm); if (err) { |
