diff options
Diffstat (limited to 'drivers/w1/w1_io.c')
| -rw-r--r-- | drivers/w1/w1_io.c | 37 |
1 files changed, 25 insertions, 12 deletions
diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c index db3c9522a8a2..b495624984bd 100644 --- a/drivers/w1/w1_io.c +++ b/drivers/w1/w1_io.c @@ -6,6 +6,7 @@ #include <asm/io.h> #include <linux/delay.h> +#include <linux/ktime.h> #include <linux/moduleparam.h> #include <linux/module.h> @@ -36,9 +37,21 @@ static u8 w1_crc8_table[] = { 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53 }; -static void w1_delay(unsigned long tm) +static void w1_delay(struct w1_master *dev, unsigned long tm) { - udelay(tm * w1_delay_parm); + ktime_t start, delta; + + if (!dev->bus_master->delay_needs_poll) { + udelay(tm * w1_delay_parm); + return; + } + + start = ktime_get(); + delta = ktime_add(start, ns_to_ktime(1000 * tm * w1_delay_parm)); + do { + dev->bus_master->read_bit(dev->bus_master->data); + udelay(1); + } while (ktime_before(ktime_get(), delta)); } static void w1_write_bit(struct w1_master *dev, int bit); @@ -77,14 +90,14 @@ static void w1_write_bit(struct w1_master *dev, int bit) if (bit) { dev->bus_master->write_bit(dev->bus_master->data, 0); - w1_delay(6); + w1_delay(dev, 6); dev->bus_master->write_bit(dev->bus_master->data, 1); - w1_delay(64); + w1_delay(dev, 64); } else { dev->bus_master->write_bit(dev->bus_master->data, 0); - w1_delay(60); + w1_delay(dev, 60); dev->bus_master->write_bit(dev->bus_master->data, 1); - w1_delay(10); + w1_delay(dev, 10); } if(w1_disable_irqs) local_irq_restore(flags); @@ -164,14 +177,14 @@ static u8 w1_read_bit(struct w1_master *dev) /* sample timing is critical here */ local_irq_save(flags); dev->bus_master->write_bit(dev->bus_master->data, 0); - w1_delay(6); + w1_delay(dev, 6); dev->bus_master->write_bit(dev->bus_master->data, 1); - w1_delay(9); + w1_delay(dev, 9); result = dev->bus_master->read_bit(dev->bus_master->data); local_irq_restore(flags); - w1_delay(55); + w1_delay(dev, 55); return result & 0x1; } @@ -333,16 +346,16 @@ int w1_reset_bus(struct w1_master *dev) * cpu for such a short amount of time AND get it back in * the maximum amount of time. */ - w1_delay(500); + w1_delay(dev, 500); dev->bus_master->write_bit(dev->bus_master->data, 1); - w1_delay(70); + w1_delay(dev, 70); result = dev->bus_master->read_bit(dev->bus_master->data) & 0x1; /* minimum 70 (above) + 430 = 500 us * There aren't any timing requirements between a reset and * the following transactions. Sleeping is safe here. */ - /* w1_delay(430); min required time */ + /* w1_delay(dev, 430); min required time */ msleep(1); } |