Commit graph

4 commits

Author SHA1 Message Date
Jorge Ramirez-Ortiz
8a7729abec clk: qcom: hfpll: use clk_parent_data to specify the parent
This permits extending the driver to other platforms without having to
modify its source code.

Co-developed-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Link: https://lkml.kernel.org/r/20191125135910.679310-6-niklas.cassel@linaro.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-12-18 22:07:52 -08:00
Jorge Ramirez-Ortiz
b455dc3510 clk: qcom: hfpll: CLK_IGNORE_UNUSED
When COMMON_CLK_DISABLED_UNUSED is set, in an effort to save power and
to keep the software model of the clock in line with reality, the
framework transverses the clock tree and disables those clocks that
were enabled by the firmware but have not been enabled by any device
driver.

If CPUFREQ is enabled, early during the system boot, it might attempt
to change the CPU frequency ("set_rate"). If the HFPLL is selected as
a provider, it will then change the rate for this clock.

As boot continues, clk_disable_unused_subtree will run. Since it wont
find a valid counter (enable_count) for a clock that is actually
enabled it will attempt to disable it which will cause the CPU to
stop. Notice that in this driver, calls to check whether the clock is
enabled are routed via the is_enabled callback which queries the
hardware.

The following commit, rather than marking the clock critical and
forcing the clock to be always enabled, addresses the above scenario
making sure the clock is not disabled but it continues to rely on the
firmware to enable the clock.

Co-developed-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lkml.kernel.org/r/20191125135910.679310-5-niklas.cassel@linaro.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-12-18 22:07:52 -08:00
Jorge Ramirez-Ortiz
9e4066748b clk: qcom: hfpll: register as clock provider
Make the output of the high frequency pll a clock provider.
On the QCS404 this PLL controls cpu frequency scaling.

Co-developed-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lkml.kernel.org/r/20191125135910.679310-4-niklas.cassel@linaro.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-12-18 22:07:52 -08:00
Stephen Boyd
cb546b797a clk: qcom: Add HFPLL driver
On some devices (MSM8974 for example), the HFPLLs are
instantiated within the Krait processor subsystem as separate
register regions. Add a driver for these PLLs so that we can
provide HFPLL clocks for use by the system.

Cc: <devicetree@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Tested-by: Craig Tatlor <ctatlor97@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2018-10-17 13:14:40 -07:00