diff options
| author | Aaron Durbin <adurbin@chromium.org> | 2014-08-29 09:14:25 -0500 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2015-03-27 08:04:34 +0100 |
| commit | 19902e9d9bce730ed6cda4f7c934d6c08f783635 (patch) | |
| tree | 199f1b78ab763871c08bcec872a138cf903ec7f1 /src/soc | |
| parent | 7565f7b00073b9bb618550cabcec438f81d6175a (diff) | |
tegra132: return actual plld frequency
Depending on the requested frequency the plld cannot
necessarily obtain the exact clock. Therefore provide the
closest configured frequency as a return value. This is
equivalent to the t124 patch.
BUG=chrome-os-partner:31640
BRANCH=None
TEST=Built and noted plld actual value close to requested.
Change-Id: I9aaba81222fb97d9fbbb4156af3a7476ba654c10
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: fc928db8197b465220e53b4d0ba5896b3c06a863
Original-Change-Id: I94b94a1bf01087ff0d0e4b1ef3fb59eec2a8ba15
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/214843
Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Tom Warren <twarren@nvidia.com>
Reviewed-on: http://review.coreboot.org/9025
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/soc')
| -rw-r--r-- | src/soc/nvidia/tegra132/clock.c | 26 | ||||
| -rw-r--r-- | src/soc/nvidia/tegra132/include/soc/clock.h | 2 |
2 files changed, 18 insertions, 10 deletions
diff --git a/src/soc/nvidia/tegra132/clock.c b/src/soc/nvidia/tegra132/clock.c index caeb24a9a1..6640505b34 100644 --- a/src/soc/nvidia/tegra132/clock.c +++ b/src/soc/nvidia/tegra132/clock.c @@ -298,8 +298,14 @@ static void graphics_pll(void) */ } -/* Init PLLD clock source. */ -int +/* + * Init PLLD clock source. + * + * @frequency: the requested plld frequency + * + * Return the plld frequency if success, otherwise return 0. + */ +u32 clock_display(u32 frequency) { /** @@ -318,7 +324,7 @@ clock_display(u32 frequency) */ struct pllpad_dividers plld = { 0 }; u32 ref = clock_get_pll_input_khz() * 1000, m, n, p = 0; - u32 cf, vco; + u32 cf, vco, rounded_rate = frequency; u32 diff, best_diff; const u32 max_m = 1 << 5, max_n = 1 << 10, max_p = 1 << 3, mhz = 1000 * 1000, min_vco = 500 * mhz, max_vco = 1000 * mhz, @@ -330,7 +336,7 @@ clock_display(u32 frequency) if (vco < min_vco || vco > max_vco) { printk(BIOS_ERR, "%s: Cannot find out a supported VCO" " for Frequency (%u).\n", __func__, frequency); - return -1; + return 0; } plld.p = p; @@ -370,18 +376,20 @@ clock_display(u32 frequency) else plld.cpcon = 12; - if (best_diff) - printk(BIOS_ERR, "%s: Failed to match output frequency %u, " + if (best_diff) { + printk(BIOS_WARNING, "%s: Failed to match output frequency %u, " "best difference is %u.\n", __func__, frequency, best_diff); + rounded_rate = (ref / plld.m * plld.n) >> plld.p; + } printk(BIOS_DEBUG, "%s: PLLD=%u ref=%u, m/n/p/cpcon=%u/%u/%u/%u\n", - __func__, (ref / plld.m * plld.n) >> plld.p, ref, plld.m, plld.n, - plld.p, plld.cpcon); + __func__, rounded_rate, ref, plld.m, plld.n, plld.p, plld.cpcon); init_pll(&clk_rst->plld_base, &clk_rst->plld_misc, plld, (PLLUD_MISC_LOCK_ENABLE | PLLD_MISC_CLK_ENABLE)); - return 0; + + return rounded_rate; } /* Initialize the UART and put it on CLK_M so we can use it during clock_init(). diff --git a/src/soc/nvidia/tegra132/include/soc/clock.h b/src/soc/nvidia/tegra132/include/soc/clock.h index eecb735672..711741ba9e 100644 --- a/src/soc/nvidia/tegra132/include/soc/clock.h +++ b/src/soc/nvidia/tegra132/include/soc/clock.h @@ -285,7 +285,7 @@ enum clock_source { /* Careful: Not true for all sources, always check TRM! */ int clock_get_osc_khz(void); int clock_get_pll_input_khz(void); -int clock_display(u32 frequency); +u32 clock_display(u32 frequency); void clock_early_uart(void); void clock_external_output(int clk_id); void clock_sdram(u32 m, u32 n, u32 p, u32 setup, u32 ph45, u32 ph90, |