diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-at91-master.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-at91-master.c | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c index df80557eabfe..273bd8bda32d 100644 --- a/drivers/i2c/busses/i2c-at91-master.c +++ b/drivers/i2c/busses/i2c-at91-master.c @@ -43,6 +43,12 @@ void at91_init_twi_bus_master(struct at91_twi_dev *dev) /* enable digital filter */ if (pdata->has_dig_filtr && dev->enable_dig_filt) at91_twi_write(dev, AT91_TWI_FILTR, AT91_TWI_FILTR_FILT); + + /* enable advanced digital filter */ + if (pdata->has_adv_dig_filtr && dev->enable_dig_filt) + at91_twi_write(dev, AT91_TWI_FILTR, AT91_TWI_FILTR_FILT | + (AT91_TWI_FILTR_THRES(dev->filter_width) & + AT91_TWI_FILTR_THRES_MASK)); } /* @@ -51,7 +57,7 @@ void at91_init_twi_bus_master(struct at91_twi_dev *dev) */ static void at91_calc_twi_clock(struct at91_twi_dev *dev) { - int ckdiv, cdiv, div, hold = 0; + int ckdiv, cdiv, div, hold = 0, filter_width = 0; struct at91_twi_pdata *pdata = dev->pdata; int offset = pdata->clk_offset; int max_ckdiv = pdata->clk_max_div; @@ -90,11 +96,29 @@ static void at91_calc_twi_clock(struct at91_twi_dev *dev) } } + if (pdata->has_adv_dig_filtr) { + /* + * filter width = 0 to AT91_TWI_FILTR_THRES_MAX + * peripheral clocks + */ + filter_width = DIV_ROUND_UP(t->digital_filter_width_ns + * (clk_get_rate(dev->clk) / 1000), 1000000); + if (filter_width > AT91_TWI_FILTR_THRES_MAX) { + dev_warn(dev->dev, + "Filter threshold set to its maximum value (%d instead of %d)\n", + AT91_TWI_FILTR_THRES_MAX, filter_width); + filter_width = AT91_TWI_FILTR_THRES_MAX; + } + } + dev->twi_cwgr_reg = (ckdiv << 16) | (cdiv << 8) | cdiv | AT91_TWI_CWGR_HOLD(hold); - dev_dbg(dev->dev, "cdiv %d ckdiv %d hold %d (%d ns)\n", - cdiv, ckdiv, hold, t->sda_hold_ns); + dev->filter_width = filter_width; + + dev_dbg(dev->dev, "cdiv %d ckdiv %d hold %d (%d ns), filter_width %d (%d ns)\n", + cdiv, ckdiv, hold, t->sda_hold_ns, filter_width, + t->digital_filter_width_ns); } static void at91_twi_dma_cleanup(struct at91_twi_dev *dev) |