From 6bcbe5749b9f1a82004299bb63fba7e99b8ed358 Mon Sep 17 00:00:00 2001 From: Lee Leahy Date: Sat, 23 Apr 2016 07:58:27 -0700 Subject: lib/regscript: Add exclusive-or (xor) support Add xor support which enables toggling of a bit: * REG_SCRIPT_COMMAND_RXW enum value * REG_*_RXW* macros to support using REG_SCRIPT_COMMAND_RXW * REG_*_XOR* macros to support using REG_SCRIPT_COMMAND_RXW * reg_script_rxw routine to perform and/xor operation * case in reg_script_run_step to call reg_script_rxw TEST=Build and run on Galileo Gen2 Change-Id: I50a492c7c2643df5dc2d2fa7113e3722c1e480c7 Signed-off-by: Lee Leahy Reviewed-on: https://review.coreboot.org/14495 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin --- src/lib/reg_script.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'src/lib/reg_script.c') diff --git a/src/lib/reg_script.c b/src/lib/reg_script.c index 7f8200006e..7530dc32b8 100644 --- a/src/lib/reg_script.c +++ b/src/lib/reg_script.c @@ -521,6 +521,41 @@ static void reg_script_rmw(struct reg_script_context *ctx) reg_script_set_step(ctx, step); } +static void reg_script_rxw(struct reg_script_context *ctx) +{ + uint64_t value; + const struct reg_script *step = reg_script_get_step(ctx); + struct reg_script write_step = *step; + +/* + * XOR logic table + * Input XOR Value + * 0 0 0 + * 0 1 1 + * 1 0 1 + * 1 1 0 + * + * Supported operations + * + * Input Mask Temp XOR Value Operation + * 0 0 0 0 0 Clear bit + * 1 0 0 0 0 + * 0 0 0 1 1 Set bit + * 1 0 0 1 1 + * 0 1 0 0 0 Preserve bit + * 1 1 1 0 1 + * 0 1 0 1 1 Toggle bit + * 1 1 1 1 0 + */ + value = reg_script_read(ctx); + value &= step->mask; + value ^= step->value; + write_step.value = value; + reg_script_set_step(ctx, &write_step); + reg_script_write(ctx); + reg_script_set_step(ctx, step); +} + /* In order to easily chain scripts together handle the REG_SCRIPT_COMMAND_NEXT * as recursive call with a new context that has the same dev and resource * as the previous one. That will run to completion and then move on to the @@ -544,6 +579,9 @@ static void reg_script_run_step(struct reg_script_context *ctx, case REG_SCRIPT_COMMAND_RMW: reg_script_rmw(ctx); break; + case REG_SCRIPT_COMMAND_RXW: + reg_script_rxw(ctx); + break; case REG_SCRIPT_COMMAND_POLL: for (try = 0; try < step->timeout; try += POLL_DELAY) { value = reg_script_read(ctx) & step->mask; -- cgit v1.2.3