diff options
Diffstat (limited to 'drivers/thunderbolt/switch.c')
| -rw-r--r-- | drivers/thunderbolt/switch.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c index 8e232ce615e9..c242a027698d 100644 --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -1457,6 +1457,40 @@ int tb_switch_reset(struct tb_switch *sw) return res.err; } +/** + * tb_switch_wait_for_bit() - Wait for specified value of bits in offset + * @sw: Router to read the offset value from + * @offset: Offset in the router config space to read from + * @bit: Bit mask in the offset to wait for + * @value: Value of the bits to wait for + * @timeout_msec: Timeout in ms how long to wait + * + * Wait till the specified bits in specified offset reach specified value. + * Returns %0 in case of success, %-ETIMEDOUT if the @value was not reached + * within the given timeout or a negative errno in case of failure. + */ +int tb_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit, + u32 value, int timeout_msec) +{ + ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec); + + do { + u32 val; + int ret; + + ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, offset, 1); + if (ret) + return ret; + + if ((val & bit) == value) + return 0; + + usleep_range(50, 100); + } while (ktime_before(ktime_get(), timeout)); + + return -ETIMEDOUT; +} + /* * tb_plug_events_active() - enable/disable plug events on a switch * |