Messages in this thread | | | Date | Thu, 9 Mar 2023 02:54:36 +0200 | Subject | Re: [PATCH RFT v2 09/14] clk: qcom: smd-rpm: Add support for keepalive votes | From | Dmitry Baryshkov <> |
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On 08/03/2023 23:35, Konrad Dybcio wrote: > Some bus clock should always have a minimum (19.2 MHz) vote cast on > them, otherwise the platform will fall apart, hang and reboot. > > Add support for specifying which clocks should be kept alive and > always keep a vote on XO_A to make sure the clock tree doesn't > collapse. This removes the need to keep a maximum vote that was > previously guaranteed by clk_smd_rpm_handoff. > > This commit is a combination of existing (not-exactly-upstream) work > by Taniya Das, Shawn Guo and myself. > > Co-developed-by: Shawn Guo <shawn.guo@linaro.org> > Co-developed-by: Taniya Das <quic_tdas@quicinc.com> > Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org> > --- > drivers/clk/qcom/clk-smd-rpm.c | 29 +++++++++++++++++++++++++++-- > 1 file changed, 27 insertions(+), 2 deletions(-) > > diff --git a/drivers/clk/qcom/clk-smd-rpm.c b/drivers/clk/qcom/clk-smd-rpm.c > index eb7781e5c8c1..d89918f9ae60 100644 > --- a/drivers/clk/qcom/clk-smd-rpm.c > +++ b/drivers/clk/qcom/clk-smd-rpm.c > @@ -45,15 +45,17 @@ > }, \ > }; \ > __DEFINE_CLK_SMD_RPM_AO_PREFIX(_prefix, _name, _active, type, \ > - r_id, key, ao_flags) > + r_id, key, ao_flags, false) > > #define __DEFINE_CLK_SMD_RPM_AO_PREFIX(_prefix, _name, _active, \ > - type, r_id, key, ao_flags) \ > + type, r_id, key, ao_flags, \ > + _keep_alive) \ > static struct clk_smd_rpm clk_smd_rpm_##_prefix##_active = { \ > .rpm_res_type = (type), \ > .rpm_clk_id = (r_id), \ > .active_only = true, \ > .rpm_key = (key), \ > + .keep_alive = (_keep_alive), \ > .peer = &clk_smd_rpm_##_prefix##_name, \ > .rate = INT_MAX, \ > .hw.init = &(struct clk_init_data){ \ > @@ -170,6 +172,7 @@ struct clk_smd_rpm { > const bool active_only; > bool enabled; > bool branch; > + bool keep_alive; > struct clk_smd_rpm *peer; > struct clk_hw hw; > unsigned long rate; > @@ -198,11 +201,16 @@ static int clk_smd_rpm_handoff(struct clk_smd_rpm *r) > .value = cpu_to_le32(r->branch ? 1 : INT_MAX), > }; > > + /* Set up keepalive clocks with a minimum bus rate */ > + if (r->keep_alive) > + req.value = cpu_to_le32(19200); /* 19.2 MHz */
Should this be set to cpu_to_le32(max(19200, ...)) ?
> + > ret = qcom_rpm_smd_write(r->rpm, QCOM_SMD_RPM_ACTIVE_STATE, > r->rpm_res_type, r->rpm_clk_id, &req, > sizeof(req)); > if (ret) > return ret; > + > ret = qcom_rpm_smd_write(r->rpm, QCOM_SMD_RPM_SLEEP_STATE, > r->rpm_res_type, r->rpm_clk_id, &req, > sizeof(req)); > @@ -438,12 +446,29 @@ static int clk_smd_rpm_is_enabled(struct clk_hw *hw) > return r->enabled; > } > > +static int clk_smd_rpm_determine_rate(struct clk_hw *hw, > + struct clk_rate_request *req) > +{ > + struct clk_smd_rpm *r = to_clk_smd_rpm(hw); > + > + /* > + * RPM resolves the rates internally. All we have to do on the kernel > + * side is ensure that we don't accidentally put down the keepalive > + * clocks, which could happen if they received a vote below 19.2 MHz. > + */ > + if (r->keep_alive) > + req->rate = max(req->rate, 19200000UL); > + > + return 0; > +} > + > static const struct clk_ops clk_smd_rpm_ops = { > .prepare = clk_smd_rpm_prepare, > .unprepare = clk_smd_rpm_unprepare, > .set_rate = clk_smd_rpm_set_rate, > .round_rate = clk_smd_rpm_round_rate, > .recalc_rate = clk_smd_rpm_recalc_rate, > + .determine_rate = clk_smd_rpm_determine_rate, > .is_enabled = clk_smd_rpm_is_enabled, > .is_prepared = clk_smd_rpm_is_enabled, > }; >
-- With best wishes Dmitry
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