diff options
Diffstat (limited to 'test')
| -rw-r--r-- | test/dm/Makefile | 1 | ||||
| -rw-r--r-- | test/dm/k210_pll.c | 96 |
2 files changed, 97 insertions, 0 deletions
diff --git a/test/dm/Makefile b/test/dm/Makefile index 6c18fd04ce1..5094a7866af 100644 --- a/test/dm/Makefile +++ b/test/dm/Makefile @@ -73,4 +73,5 @@ obj-$(CONFIG_DMA) += dma.o obj-$(CONFIG_DM_MDIO) += mdio.o obj-$(CONFIG_DM_MDIO_MUX) += mdio_mux.o obj-$(CONFIG_DM_RNG) += rng.o +obj-$(CONFIG_CLK_K210_SET_RATE) += k210_pll.o endif diff --git a/test/dm/k210_pll.c b/test/dm/k210_pll.c new file mode 100644 index 00000000000..54764f269c5 --- /dev/null +++ b/test/dm/k210_pll.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Sean Anderson <seanga2@gmail.com> + */ + +#include <common.h> +/* For DIV_ROUND_DOWN_ULL, defined in linux/kernel.h */ +#include <div64.h> +#include <dm/test.h> +#include <kendryte/pll.h> +#include <test/ut.h> + +static int dm_test_k210_pll_calc_config(u32 rate, u32 rate_in, + struct k210_pll_config *best) +{ + u64 f, r, od, max_r, inv_ratio; + s64 error, best_error; + + best_error = S64_MAX; + error = best_error; + max_r = min(16ULL, DIV_ROUND_DOWN_ULL(rate_in, 13300000)); + inv_ratio = DIV_ROUND_CLOSEST_ULL((u64)rate_in << 32, rate); + + /* Brute force it */ + for (r = 1; r <= max_r; r++) { + for (f = 1; f <= 64; f++) { + for (od = 1; od <= 16; od++) { + u64 vco = DIV_ROUND_CLOSEST_ULL(rate_in * f, r); + + if (vco > 1750000000 || vco < 340000000) + continue; + + error = DIV_ROUND_CLOSEST_ULL(f * inv_ratio, + r * od); + /* The lower 16 bits are spurious */ + error = abs((error - BIT(32))) >> 16; + if (error < best_error) { + best->r = r; + best->f = f; + best->od = od; + best_error = error; + } + } + } + } + + if (best_error == S64_MAX) + return -EINVAL; + return 0; +} + +static int dm_test_k210_pll_compare(struct k210_pll_config *ours, + struct k210_pll_config *theirs) +{ + return (u32)ours->f * theirs->r * theirs->od != + (u32)theirs->f * ours->r * ours->od; +} + +static int dm_test_k210_pll(struct unit_test_state *uts) +{ + struct k210_pll_config ours, theirs; + + /* General range checks */ + ut_asserteq(-EINVAL, k210_pll_calc_config(0, 26000000, &theirs)); + ut_asserteq(-EINVAL, k210_pll_calc_config(390000000, 0, &theirs)); + ut_asserteq(-EINVAL, k210_pll_calc_config(2000000000, 26000000, + &theirs)); + ut_asserteq(-EINVAL, k210_pll_calc_config(390000000, 2000000000, + &theirs)); + ut_asserteq(-EINVAL, k210_pll_calc_config(1500000000, 20000000, + &theirs)); + + /* Verify we get the same output with brute-force */ + ut_assertok(dm_test_k210_pll_calc_config(390000000, 26000000, &ours)); + ut_assertok(k210_pll_calc_config(390000000, 26000000, &theirs)); + ut_assertok(dm_test_k210_pll_compare(&ours, &theirs)); + + ut_assertok(dm_test_k210_pll_calc_config(26000000, 390000000, &ours)); + ut_assertok(k210_pll_calc_config(26000000, 390000000, &theirs)); + ut_assertok(dm_test_k210_pll_compare(&ours, &theirs)); + + ut_assertok(dm_test_k210_pll_calc_config(400000000, 26000000, &ours)); + ut_assertok(k210_pll_calc_config(400000000, 26000000, &theirs)); + ut_assertok(dm_test_k210_pll_compare(&ours, &theirs)); + + ut_assertok(dm_test_k210_pll_calc_config(27000000, 26000000, &ours)); + ut_assertok(k210_pll_calc_config(27000000, 26000000, &theirs)); + ut_assertok(dm_test_k210_pll_compare(&ours, &theirs)); + + ut_assertok(dm_test_k210_pll_calc_config(26000000, 27000000, &ours)); + ut_assertok(k210_pll_calc_config(26000000, 27000000, &theirs)); + ut_assertok(dm_test_k210_pll_compare(&ours, &theirs)); + + return 0; +} +DM_TEST(dm_test_k210_pll, 0); |