redonkable
/
remarkable-linux
1
0
Fork 0
Code Releases Activity

hwmon: lis3: use block read to access data registers 

Add optional blockread function to interface driver. If available
the chip driver uses it for data register access. For 12 bit device
it reads 6 bytes to get 3*16bit data. For 8 bit device it reads out
5 bytes since every second byte is dummy.
This optimizes bus usage and reduces number of operations and
interrupts needed for one data update.

Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Acked-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
wifi-calibration
Samu Onkalo 2010-10-22 07:57:31 -04:00 committed by Guenter Roeck
parent 477bc918c2
commit f10a5407b5
4 changed files with 33 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
drivers/hwmon/lis3lv02d.c
View File

@ -154,9 +154,24 @@ static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z)
int position[3];
int i;
position[0] = lis3->read_data(lis3, OUTX);
position[1] = lis3->read_data(lis3, OUTY);
position[2] = lis3->read_data(lis3, OUTZ);
if (lis3->blkread) {
if (lis3_dev.whoami == WAI_12B) {
u16 data[3];
lis3->blkread(lis3, OUTX_L, 6, (u8 *)data);
for (i = 0; i < 3; i++)
position[i] = (s16)le16_to_cpu(data[i]);
} else {
u8 data[5];
/* Data: x, dummy, y, dummy, z */
lis3->blkread(lis3, OUTX, 5, data);
for (i = 0; i < 3; i++)
position[i] = (s8)data[i * 2];
}
} else {
position[0] = lis3->read_data(lis3, OUTX);
position[1] = lis3->read_data(lis3, OUTY);
position[2] = lis3->read_data(lis3, OUTZ);
}
for (i = 0; i < 3; i++)
position[i] = (position[i] * lis3->scale) / LIS3_ACCURACY;

1
drivers/hwmon/lis3lv02d.h
View File

@ -244,6 +244,7 @@ struct lis3lv02d {
int (*init) (struct lis3lv02d *lis3);
int (*write) (struct lis3lv02d *lis3, int reg, u8 val);
int (*read) (struct lis3lv02d *lis3, int reg, u8 *ret);
int (*blkread) (struct lis3lv02d *lis3, int reg, int len, u8 *ret);
int (*reg_ctrl) (struct lis3lv02d *lis3, bool state);
int *odrs; /* Supported output data rates */

13
drivers/hwmon/lis3lv02d_i2c.c
View File

@ -66,6 +66,14 @@ static inline s32 lis3_i2c_read(struct lis3lv02d *lis3, int reg, u8 *v)
return 0;
}
static inline s32 lis3_i2c_blockread(struct lis3lv02d *lis3, int reg, int len,
u8 *v)
{
struct i2c_client *c = lis3->bus_priv;
reg |= (1 << 7); /* 7th bit enables address auto incrementation */
return i2c_smbus_read_i2c_block_data(c, reg, len, v);
}
static int lis3_i2c_init(struct lis3lv02d *lis3)
{
u8 reg;
@ -102,6 +110,11 @@ static int __devinit lis3lv02d_i2c_probe(struct i2c_client *client,
if (pdata->driver_features & LIS3_USE_REGULATOR_CTRL)
lis3_dev.reg_ctrl = lis3_reg_ctrl;
if ((pdata->driver_features & LIS3_USE_BLOCK_READ) &&
(i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_I2C_BLOCK)))
lis3_dev.blkread = lis3_i2c_blockread;
if (pdata->axis_x)
lis3lv02d_axis_map.x = pdata->axis_x;

1
include/linux/lis3lv02d.h
View File

@ -68,6 +68,7 @@ struct lis3lv02d_platform_data {
s8 axis_y;
s8 axis_z;
#define LIS3_USE_REGULATOR_CTRL 0x01
#define LIS3_USE_BLOCK_READ 0x02
u16 driver_features;
int default_rate;
int (*setup_resources)(void);