Commit Graph

5 Commits

Author SHA1 Message Date
Remi Pommarel
cfbab8fbab clk: bcm2835: Add PWM clock support
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>
2015-12-24 20:38:38 -08:00
Remi Pommarel
6d18b8adbe clk: bcm2835: Support for clock parent selection
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>
2015-12-24 20:38:30 -08:00
Remi Pommarel
9c95b32ca0 clk: bcm2835: add a round up ability to the clock divisor
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>
2015-12-24 20:38:06 -08:00
Eric Anholt
41691b8862 clk: bcm2835: Add support for programming the audio domain clocks
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>
2015-10-12 11:32:02 -07:00
Eric Anholt
4f61d8e220 clk: bcm2835: Move under bcm/ with other Broadcom SoC clk drivers.
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>
2015-10-01 17:12:03 -07:00