You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
216 lines
6.8 KiB
216 lines
6.8 KiB
"""
|
|
This is an auxiliary script that is used to compute valid PLL values to set
|
|
the CPU frequency to a given value. The algorithm here appears as C code
|
|
for the machine.freq() function.
|
|
"""
|
|
|
|
from __future__ import print_function
|
|
import re
|
|
|
|
def close_int(x):
|
|
return abs(x - round(x)) < 0.01
|
|
|
|
# original version that requires N/M to be an integer (for simplicity)
|
|
def compute_pll(hse, sys):
|
|
for P in (2, 4, 6, 8): # allowed values of P
|
|
Q = sys * P / 48
|
|
NbyM = sys * P / hse
|
|
# N/M and Q must be integers
|
|
if not (close_int(NbyM) and close_int(Q)):
|
|
continue
|
|
# VCO_OUT must be between 192MHz and 432MHz
|
|
if not (192 <= hse * NbyM <= 432):
|
|
continue
|
|
# compute M
|
|
M = int(192 // NbyM)
|
|
while hse > 2 * M or NbyM * M < 192:
|
|
M += 1
|
|
# VCO_IN must be between 1MHz and 2MHz (2MHz recommended)
|
|
if not (M <= hse):
|
|
continue
|
|
# compute N
|
|
N = NbyM * M
|
|
# N and Q are restricted
|
|
if not (192 <= N <= 432 and 2 <= Q <= 15):
|
|
continue
|
|
# found valid values
|
|
assert NbyM == N // M
|
|
return (M, N, P, Q)
|
|
# no valid values found
|
|
return None
|
|
|
|
# improved version that doesn't require N/M to be an integer
|
|
def compute_pll2(hse, sys, relax_pll48):
|
|
# Loop over the allowed values of P, looking for a valid PLL configuration
|
|
# that gives the desired "sys" frequency. We use floats for P to force
|
|
# floating point arithmetic on Python 2.
|
|
fallback = None
|
|
for P in (2.0, 4.0, 6.0, 8.0):
|
|
NbyM = sys * P / hse
|
|
# VCO_OUT must be between 192MHz and 432MHz
|
|
if not (192 <= hse * NbyM <= 432):
|
|
continue
|
|
# scan M
|
|
M = int(192 // NbyM) # starting value
|
|
while 2 * M < hse:
|
|
M += 1
|
|
# VCO_IN must be between 1MHz and 2MHz (2MHz recommended)
|
|
for M in range(M, hse + 1):
|
|
if NbyM * M < 191.99 or not close_int(NbyM * M):
|
|
continue
|
|
# compute N
|
|
N = NbyM * M
|
|
# N must be an integer
|
|
if not close_int(N):
|
|
continue
|
|
# N is restricted
|
|
if not (192 <= N <= 432):
|
|
continue
|
|
Q = (sys * P / 48)
|
|
# Q must be an integer in a set range
|
|
if not (2 <= Q <= 15):
|
|
continue
|
|
if not close_int(Q):
|
|
if int(M) == int(hse) and fallback is None:
|
|
# the values don't give 48MHz on PLL48 but are otherwise OK
|
|
fallback = M, N, P, int(Q)
|
|
continue
|
|
# found valid values
|
|
return (M, N, P, Q)
|
|
if relax_pll48:
|
|
# might have found values which don't give 48MHz on PLL48
|
|
return fallback
|
|
else:
|
|
# no valid values found which give 48MHz on PLL48
|
|
return None
|
|
|
|
def compute_derived(hse, pll):
|
|
M, N, P, Q = pll
|
|
vco_in = hse / M
|
|
vco_out = hse * N / M
|
|
pllck = hse / M * N / P
|
|
pll48ck = hse / M * N / Q
|
|
return (vco_in, vco_out, pllck, pll48ck)
|
|
|
|
def verify_pll(hse, pll):
|
|
M, N, P, Q = pll
|
|
vco_in, vco_out, pllck, pll48ck = compute_derived(hse, pll)
|
|
|
|
# verify ints
|
|
assert close_int(M)
|
|
assert close_int(N)
|
|
assert close_int(P)
|
|
assert close_int(Q)
|
|
|
|
# verify range
|
|
assert 2 <= M <= 63
|
|
assert 192 <= N <= 432
|
|
assert P in (2, 4, 6, 8)
|
|
assert 2 <= Q <= 15
|
|
assert 1 <= vco_in <= 2
|
|
assert 192 <= vco_out <= 432
|
|
|
|
def compute_pll_table(source_clk, relax_pll48):
|
|
valid_plls = []
|
|
for sysclk in range(2, 217, 2):
|
|
pll = compute_pll2(source_clk, sysclk, relax_pll48)
|
|
if pll is not None:
|
|
verify_pll(source_clk, pll)
|
|
valid_plls.append((sysclk, pll))
|
|
return valid_plls
|
|
|
|
def generate_c_table(hse, valid_plls):
|
|
valid_plls.sort()
|
|
print("// (M, P/2-1, SYS) values for %u MHz source" % hse)
|
|
print("static const uint16_t pll_freq_table[%u] = {" % len(valid_plls))
|
|
for sys, (M, N, P, Q) in valid_plls:
|
|
print(" (%u << 10) | (%u << 8) | %u," % (M, P // 2 - 1, sys))
|
|
print("};")
|
|
|
|
def print_table(hse, valid_plls):
|
|
print("HSE =", hse, "MHz")
|
|
print("sys : M N P Q : VCO_IN VCO_OUT PLLCK PLL48CK")
|
|
out_format = "%3u : %2u %.1f %.2f %.2f : %5.2f %6.2f %6.2f %6.2f"
|
|
for sys, pll in valid_plls:
|
|
print(out_format % ((sys,) + pll + compute_derived(hse, pll)))
|
|
print("found %u valid configurations" % len(valid_plls))
|
|
|
|
def search_header_for_hsx_values(filename, vals):
|
|
regex_inc = re.compile(r'#include "(boards/[A-Za-z0-9_./]+)"')
|
|
regex_def = re.compile(r'#define +(HSE_VALUE|HSI_VALUE) +\((\(uint32_t\))?([0-9]+)\)')
|
|
with open(filename) as f:
|
|
for line in f:
|
|
line = line.strip()
|
|
m = regex_inc.match(line)
|
|
if m:
|
|
# Search included file
|
|
search_header_for_hsx_values(m.group(1), vals)
|
|
continue
|
|
m = regex_def.match(line)
|
|
if m:
|
|
# Found HSE_VALUE or HSI_VALUE
|
|
val = int(m.group(3)) // 1000000
|
|
if m.group(1) == 'HSE_VALUE':
|
|
vals[0] = val
|
|
else:
|
|
vals[1] = val
|
|
return vals
|
|
|
|
def main():
|
|
global out_format
|
|
|
|
# parse input args
|
|
import sys
|
|
argv = sys.argv[1:]
|
|
|
|
c_table = False
|
|
relax_pll48 = False
|
|
hse = None
|
|
hsi = None
|
|
|
|
while True:
|
|
if argv[0] == '-c':
|
|
c_table = True
|
|
argv.pop(0)
|
|
elif argv[0] == '--relax-pll48':
|
|
relax_pll48 = True
|
|
argv.pop(0)
|
|
else:
|
|
break
|
|
|
|
if len(argv) != 1:
|
|
print("usage: pllvalues.py [-c] <hse in MHz>")
|
|
sys.exit(1)
|
|
|
|
if argv[0].startswith("file:"):
|
|
# extract HSE_VALUE, and optionally HSI_VALUE, from header file
|
|
hse, hsi = search_header_for_hsx_values(argv[0][5:], [None, None])
|
|
if hse is None:
|
|
raise ValueError("%s does not contain a definition of HSE_VALUE" % argv[0])
|
|
if hsi is not None and hsi > 16:
|
|
# Currently, a HSI value greater than 16MHz is not supported
|
|
hsi = None
|
|
else:
|
|
# HSE given directly as an integer
|
|
hse = int(argv[0])
|
|
|
|
hse_valid_plls = compute_pll_table(hse, relax_pll48)
|
|
if hsi is not None:
|
|
hsi_valid_plls = compute_pll_table(hsi, relax_pll48)
|
|
|
|
if c_table:
|
|
print('#if MICROPY_HW_CLK_USE_HSI')
|
|
if hsi is not None:
|
|
hsi_valid_plls.append((hsi, (0, 0, 2, 0)))
|
|
generate_c_table(hsi, hsi_valid_plls)
|
|
print('#else')
|
|
if hsi is not None:
|
|
hse_valid_plls.append((hsi, (0, 0, 2, 0)))
|
|
hse_valid_plls.append((hse, (1, 0, 2, 0)))
|
|
generate_c_table(hse, hse_valid_plls)
|
|
print('#endif')
|
|
else:
|
|
print_table(hse, hse_valid_plls)
|
|
|
|
if __name__ == "__main__":
|
|
main()
|
|
|