Commit facb87ad75 ("clk: at91: sama7g5: remove prescaler part of master
clock") removed the master clock's prescaler from clock tree of SAMA7G5
as it has been discovered that there is a hardware bug when trying to
change it at run-time (bug is described in description of
commit facb87ad75 ("clk: at91: sama7g5: remove prescaler part of master
clock")). This was previously changed at CPUFreq driver request. Thus, with
commit facb87ad75 ("clk: at91: sama7g5: remove prescaler part of master
clock") there is no need of code that handles run-time changes of master
clock's prescaler, thus remove this code.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20220203110202.18329-1-claudiu.beznea@microchip.com
SAMA7G5 supports DVFS by changing cpuck. On SAMA7G5 mck0 shares the same
parent with cpuck as seen in the following clock tree:
+----------> cpuck
|
FRAC PLL ---> DIV PLL -+-> DIV ---> mck0
mck0 could go b/w 32KHz and 200MHz on SAMA7G5. To avoid mck0 overclocking
while changing FRAC PLL or DIV PLL the commit implements a notifier for
mck0 which applies a safe divider to register (maximum value of the divider
which is 5) on PRE_RATE_CHANGE events (such that changes on PLL to not
overclock mck0) and sets the maximum allowed rate on POST_RATE_CHANGE
events.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20211011112719.3951784-13-claudiu.beznea@microchip.com
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
These are all "early clocks" that require initialization just at
of_clk_init() time. Use CLK_OF_DECLARE() to declare them.
This also fixes a problem that was spotted when fw_devlink was
set to 'on' by default: the boards failed to boot. The reason is
that CLK_OF_DECLARE_DRIVER() clears the OF_POPULATED and causes
the consumers of the clock to be postponed by fw_devlink until
the second initialization routine of the clock has been completed.
One of the consumers of the clock is the timer, which is used as a
clocksource, and needs the clock initialized early. Postponing the
timers caused the fail at boot.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20210203154332.470587-1-tudor.ambarus@microchip.com
Acked-by: Saravana Kannan <saravanak@google.com>
Tested-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Pass the ID of changeable parent at registration. This will allow
the scalability of this clock driver with regards to the changeable
parent ID for versions of this IP where changeable parent is not the
last one in the parents list (e.g. SAMA7G5). With this the clock flags
are set to zero in case we have no changeable parent. Also in
clk_generated_best_diff() the *best_diff variable is check against
tmp_diff variable using ">=" operator instead of ">" so that in case
the requested frequency could be obtained using fix parents + gck
dividers but the clock also supports changeable parent to be able
to force the usage of the changeable parent.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/1595403506-8209-11-git-send-email-claudiu.beznea@microchip.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Lockdep warns about a possible circular locking dependency because using
syscon_node_to_regmap() will make the created regmap get and enable the
first clock it can parse from the device tree. This clock is not needed to
access the registers and should not be enabled at that time.
Use the recently introduced device_node_to_regmap to solve that as it looks
up the regmap in the same list but doesn't care about the clocks.
Reported-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lkml.kernel.org/r/20191128102531.817549-1-alexandre.belloni@bootlin.com
Tested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
It's just some static data that doesn't get changed after being used.
Mark it const everywhere.
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The PCR register layout for GCLKCSS is changing for the future SoCs, allow
configuring it.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The PCR register actually changed layout for each SoC. By chance, this
didn't have impact on sama5d[2-4] support but since sama5d3, PID is seven
bits wide and sama5d4 and sama5d2 don't have DIV.
For the DT backward compatibility, keep the layout as is.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The master clock is actually named masterck earlier in the driver. Having
"mck" in the parent list means that it can never be selected.
Fixes: 1eabdc2f9d ("clk: at91: add at91sam9x5 PMCs driver")
Fixes: a2038077de ("clk: at91: add sama5d2 PMC driver")
Fixes: 084b696bb5 ("clk: at91: add sama5d4 pmc driver")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Add a driver for the PMC clocks of the sama5d2
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
[sboyd@kernel.org: Make i signed to fix signedness bug]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
