Unlike the system clocks there are audio clocks that combine both
multiplexer/divider and gate/multiplexer/divider, so add support for
that.
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Link: https://lore.kernel.org/r/20220126173953.1016706-7-kernel@esmil.dk
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The JH7100 has additional audio and video clocks at different memory
ranges, but they use the same register layout. Add a header and export
the starfive_jh7100_clk_ops function so the clock implementation can be
reused by drivers handling these clocks.
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Link: https://lore.kernel.org/r/20220126173953.1016706-6-kernel@esmil.dk
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
It turns out the audio_div clock is a fractional divider where the
lowest byte of the ctrl register is the integer part of the divider and
the 2nd byte is the number of 100th added to the divider.
The children of this clock is used by the audio peripherals for their
sample rate clock, so round to the closest possible rate rather than
always rounding down like regular dividers.
Fixes: 4210be668a ("clk: starfive: Add JH7100 clock generator driver")
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Link: https://lore.kernel.org/r/20220126173953.1016706-3-kernel@esmil.dk
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The problem is best illustrated by an example. Suppose a consumer wants
a 4MHz clock rate from a divider with a 10MHz parent. It would then
call
clk_round_rate(clk, 4000000)
which would call into our determine_rate() callback that correctly
rounds up and finds that a divisor of 3 gives the highest possible
frequency below the requested 4MHz and returns 10000000 / 3 = 3333333Hz.
However the consumer would then call
clk_set_rate(clk, 3333333)
but since 3333333 doesn't divide 10000000 evenly our set_rate() callback
would again round the divisor up and set it to 4 which results in an
unnecessarily low rate of 2.5MHz.
Fix it by using DIV_ROUND_CLOSEST in the set_rate() callback.
Fixes: 4210be668a ("clk: starfive: Add JH7100 clock generator driver")
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Link: https://lore.kernel.org/r/20220126173953.1016706-2-kernel@esmil.dk
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Add a driver for the StarFive JH7100 clock generator.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Co-developed-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
