The current driver calculates the clock divider with
fractional support enabled.
But it does not enable fractional support in the
control register itself resulting in an integer only divider,
but in clk_set_rate responds back the fractionally divided
clock frequency.
This patch enables fractional support in the control register
whenever there is a fractional bit set in the requested clock divider.
Mash clock limits are are also handled for the PWM clock
applying the correct divider limits (2 and max_int) applicable to
basic fractional divider support (mash order of 1).
It also adds locking to protect the read/modify/write cycle of
the register modification.
Fixes: 41691b8862 ("clk: bcm2835: Add support for programming the
audio domain clocks")
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Current clamping of a normal divider allows a value < 1 to be valid.
A divider of < 1 would actually only be possible if we had a PLL...
So this patch clamps the divider to 1.
Fixes: 41691b8862 ("clk: bcm2835: Add support for programming the
audio domain clocks")
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Add missing locking to:
* bcm2835_pll_divider_on
* bcm2835_pll_divider_off
to protect the read modify write cycle for the
register access protecting both cm_reg and a2w_reg
registers.
Fixes: 41691b8862 ("clk: bcm2835: Add support for programming the
audio domain clocks")
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
bcm2835_pll_off is currently assigning CM_PLL_ANARST to the control
register, which may lose the other bits that are currently set by the
clock dividers.
It also now locks during the read/modify/write cycle of both
registers.
Fixes: 41691b8862 ("clk: bcm2835: Add support for programming the
audio domain clocks")
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
This flag is a no-op now. Remove usage of the flag.
Cc: Lee Jones <lee@kernel.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
We were rolling this ourselves, but clk-divider can do it now.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Our dividers weren't being set successfully because CM_PASSWORD wasn't
included in the register write. It looks easier to just compute the
divider to write ourselves than to update clk-divider for the ability
to OR in some arbitrary bits on write.
Fixes about half of the video modes on my HDMI monitor (everything
except 720x400).
Cc: stable@vger.kernel.org
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Register the pwm clock for bcm2835.
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Some bcm2835 clocks used by hardware (like "PWM" or "H264") can have multiple
parent clocks. These clocks divide the rate of a parent which can be selected by
setting the proper bits in the clock control register.
Previously all these parents where handled by a mux clock. But a mux clock
cannot be used because updating clock control register to select parent needs a
password to be xor'd with the parent index.
This patch get rid of mux clock and make these clocks handle their own parent,
allowing them to select the one to use.
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Make bcm2835_clock_choose_div to optionally round up the chosen MASH divisor
so that the resulting average rate will not be higher than the requested one.
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
This adds support for enabling, disabling, and setting the rate of the
audio domain clocks. It will be necessary for setting the pixel clock
for HDMI in the VC4 driver and let us write a cpufreq driver. It will
also improve compatibility with user changes to the firmware's
config.txt, since our previous fixed clocks are unaware of it.
The firmware also has support for configuring the clocks through the
mailbox channel, but the pixel clock setup by the firmware doesn't
work, and it's Raspberry Pi specific anyway. The only conflicts we
should have with the firmware would be if we made firmware calls that
result in clock management (like opening firmware V3D or ISP access,
which we don't support in upstream), or on hardware over-thermal or
under-voltage (when the firmware would rewrite PLLB to take the ARM
out of overclock). If that happens, our cached .recalc_rate() results
would be incorrect, but that's no worse than our current state where
we used fixed clocks.
The existing fixed clocks in the code are left in place to provide
backwards compatibility with old device tree files.
Signed-off-by: Eric Anholt <eric@anholt.net>
Tested-by: Martin Sperl <kernel@martin.sperl.org>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
clk-bcm2835.c predates the drivers under bcm/, but all the new BCM
drivers are going in there so let's follow them.
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Martin Sperl