diff options
| -rw-r--r-- | drivers/net/can/c_can/c_can_platform.c | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c index f363972cd77d..e36d10520e24 100644 --- a/drivers/net/can/c_can/c_can_platform.c +++ b/drivers/net/can/c_can/c_can_platform.c @@ -103,27 +103,34 @@ static void c_can_hw_raminit_syscon(const struct c_can_priv *priv, bool enable) mask = 1 << raminit->bits.start | 1 << raminit->bits.done; regmap_read(raminit->syscon, raminit->reg, &ctrl); - /* We clear the done and start bit first. The start bit is + /* We clear the start bit first. The start bit is * looking at the 0 -> transition, but is not self clearing; - * And we clear the init done bit as well. * NOTE: DONE must be written with 1 to clear it. + * We can't clear the DONE bit here using regmap_update_bits() + * as it will bypass the write if initial condition is START:0 DONE:1 + * e.g. on DRA7 which needs START pulse. */ - ctrl &= ~(1 << raminit->bits.start); - ctrl |= 1 << raminit->bits.done; - regmap_write(raminit->syscon, raminit->reg, ctrl); + ctrl &= ~mask; /* START = 0, DONE = 0 */ + regmap_update_bits(raminit->syscon, raminit->reg, mask, ctrl); - ctrl &= ~(1 << raminit->bits.done); - c_can_hw_raminit_wait_syscon(priv, mask, ctrl); + /* check if START bit is 0. Ignore DONE bit for now + * as it can be either 0 or 1. + */ + c_can_hw_raminit_wait_syscon(priv, 1 << raminit->bits.start, ctrl); if (enable) { - /* Set start bit and wait for the done bit. */ + /* Clear DONE bit & set START bit. */ ctrl |= 1 << raminit->bits.start; - regmap_write(raminit->syscon, raminit->reg, ctrl); - + /* DONE must be written with 1 to clear it */ + ctrl |= 1 << raminit->bits.done; + regmap_update_bits(raminit->syscon, raminit->reg, mask, ctrl); + /* prevent further clearing of DONE bit */ + ctrl &= ~(1 << raminit->bits.done); /* clear START bit if start pulse is needed */ if (raminit->needs_pulse) { ctrl &= ~(1 << raminit->bits.start); - regmap_write(raminit->syscon, raminit->reg, ctrl); + regmap_update_bits(raminit->syscon, raminit->reg, + mask, ctrl); } ctrl |= 1 << raminit->bits.done; |