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w1: ds2482: Added 1-Wire pull-up support to the driver 

Signed-off-by: Michael Arndt <michael@scriptkiller.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hifive-unleashed-5.1
Michael Arndt 2013-02-17 20:31:27 +01:00 committed by Greg Kroah-Hartman
parent def1820d25
commit 9c95bb6f25
1 changed files with 45 additions and 6 deletions
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51
drivers/w1/masters/ds2482.c
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@ -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 */
/**
@ -131,6 +131,17 @@ 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
@ -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) {