diff options
| author | Vadim Bendebury <vbendeb@chromium.org> | 2014-05-23 14:18:35 -0700 |
|---|---|---|
| committer | Marc Jones <marc.jones@se-eng.com> | 2015-01-04 00:27:50 +0100 |
| commit | 11aaf1f42ad8035c2870dc50852437f5e8863061 (patch) | |
| tree | 5b39011faeed8d3601e5449f9a9c62093cd06a81 /payloads/libpayload/drivers/timer | |
| parent | 66fdbced5e61ad2387bfae2db7caf507fef88f37 (diff) | |
ipq8064: Add work around for slow timer clock
Libpayload libc requires timer clock frequency to be at least 1MHz.
Ipq8064 code presently provides a single option of 32kHz. Pretend to
be running at 1 MHz without additional accuracy.
This is a hack which will be reverted as soon as the SOC is configured
to supply a faster running clock.
BUG=chrome-os-partner:27784, chrome-os-partner:28880
TEST=with other changes depthcharge boots to the CLI console
Original-Change-Id: I80ec6652bc5693a549668cd6e824e9cf5c26b182
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/201342
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 466a59967b13986099106f8b44924648c1e6e6cd)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Change-Id: I113689191db70710e7a45ccd02d672f482343e35
Reviewed-on: http://review.coreboot.org/8004
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)
Diffstat (limited to 'payloads/libpayload/drivers/timer')
| -rw-r--r-- | payloads/libpayload/drivers/timer/ipq806x.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/payloads/libpayload/drivers/timer/ipq806x.c b/payloads/libpayload/drivers/timer/ipq806x.c index 4edbf8eda0..0d70a86813 100644 --- a/payloads/libpayload/drivers/timer/ipq806x.c +++ b/payloads/libpayload/drivers/timer/ipq806x.c @@ -29,13 +29,31 @@ #include <libpayload.h> +/* + * TODO(vbendeb): reverted this hack once proper timer code is in place (see + * http://crosbug.com/p/28880 for details. + */ +#define MIN_TIMER_FREQ 1000000 + uint64_t timer_hz(void) { - return CONFIG_LP_IPQ806X_TIMER_FREQ; + return (CONFIG_LP_IPQ806X_TIMER_FREQ >= MIN_TIMER_FREQ) ? + CONFIG_LP_IPQ806X_TIMER_FREQ : MIN_TIMER_FREQ; } uint64_t timer_raw_value(void) { - return readl((void *)CONFIG_LP_IPQ806X_TIMER_REG); + uint64_t rawv = readl((void *)CONFIG_LP_IPQ806X_TIMER_REG); + + /* + * This is extremely crude, but it kicks in only for the case when the + * timer clock frequency is below 1MHz, which should never be the case + * on a properly configured system. The compiler will eliminate the + * check as long as config value exceeds 1MHz. + */ + if (CONFIG_LP_IPQ806X_TIMER_FREQ < MIN_TIMER_FREQ) + rawv *= (MIN_TIMER_FREQ / CONFIG_LP_IPQ806X_TIMER_FREQ); + + return rawv; } |