From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
To: "Andy Gross" <agross@kernel.org>,
"Bjorn Andersson" <bjorn.andersson@linaro.org>,
"Stephen Boyd" <swboyd@chromium.org>,
"Michael Turquette" <mturquette@baylibre.com>,
"Taniya Das" <tdas@codeaurora.org>,
"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Bjorn Helgaas" <bhelgaas@google.com>
Cc: Prasad Malisetty <quic_pmaliset@quicinc.com>,
linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org,
linux-pci@vger.kernel.org
Subject: [PATCH v2 1/5] clk: qcom: regmap-mux: add pipe clk implementation
Date: Tue, 12 Apr 2022 22:38:35 +0300 [thread overview]
Message-ID: <20220412193839.2545814-2-dmitry.baryshkov@linaro.org> (raw)
In-Reply-To: <20220412193839.2545814-1-dmitry.baryshkov@linaro.org>
On recent Qualcomm platforms the QMP PIPE clocks feed into a set of
muxes which must be parked to the "safe" source (bi_tcxo) when
corresponding GDSC is turned off and on again. Currently this is
handcoded in the PCIe driver by reparenting the gcc_pipe_N_clk_src
clock. However the same code sequence should be applied in the
pcie-qcom endpoint, USB3 and UFS drivers.
Rather than copying this sequence over and over again, follow the
example of clk_rcg2_shared_ops and implement this parking in the
enable() and disable() clock operations. As we are changing the parent
behind the back of the clock framework, also implement custom
set_parent() and get_parent() operations behaving accroding to the clock
framework expectations (cache the new parent if the clock is in disabled
state, return cached parent).
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
drivers/clk/qcom/clk-regmap-mux.c | 78 +++++++++++++++++++++++++++++++
drivers/clk/qcom/clk-regmap-mux.h | 3 ++
2 files changed, 81 insertions(+)
diff --git a/drivers/clk/qcom/clk-regmap-mux.c b/drivers/clk/qcom/clk-regmap-mux.c
index 45d9cca28064..c39ee783ee83 100644
--- a/drivers/clk/qcom/clk-regmap-mux.c
+++ b/drivers/clk/qcom/clk-regmap-mux.c
@@ -49,9 +49,87 @@ static int mux_set_parent(struct clk_hw *hw, u8 index)
return regmap_update_bits(clkr->regmap, mux->reg, mask, val);
}
+static u8 mux_safe_get_parent(struct clk_hw *hw)
+{
+ struct clk_regmap_mux *mux = to_clk_regmap_mux(hw);
+ unsigned int val;
+
+ if (clk_hw_is_enabled(hw))
+ return mux_get_parent(hw);
+
+ val = mux->stored_parent_cfg;
+
+ if (mux->parent_map)
+ return qcom_find_cfg_index(hw, mux->parent_map, val);
+
+ return val;
+}
+
+static int mux_safe_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct clk_regmap_mux *mux = to_clk_regmap_mux(hw);
+
+ if (clk_hw_is_enabled(hw))
+ return mux_set_parent(hw, index);
+
+ if (mux->parent_map)
+ index = mux->parent_map[index].cfg;
+
+ mux->stored_parent_cfg = index;
+
+ return 0;
+}
+
+static void mux_safe_disable(struct clk_hw *hw)
+{
+ struct clk_regmap_mux *mux = to_clk_regmap_mux(hw);
+ struct clk_regmap *clkr = to_clk_regmap(hw);
+ unsigned int mask = GENMASK(mux->width + mux->shift - 1, mux->shift);
+ unsigned int val;
+
+ regmap_read(clkr->regmap, mux->reg, &val);
+
+ mux->stored_parent_cfg = (val & mask) >> mux->shift;
+
+ val = mux->safe_src_parent;
+ if (mux->parent_map) {
+ int index = qcom_find_src_index(hw, mux->parent_map, val);
+
+ if (WARN_ON(index < 0))
+ return;
+
+ val = mux->parent_map[index].cfg;
+ }
+ val <<= mux->shift;
+
+ regmap_update_bits(clkr->regmap, mux->reg, mask, val);
+}
+
+static int mux_safe_enable(struct clk_hw *hw)
+{
+ struct clk_regmap_mux *mux = to_clk_regmap_mux(hw);
+ struct clk_regmap *clkr = to_clk_regmap(hw);
+ unsigned int mask = GENMASK(mux->width + mux->shift - 1, mux->shift);
+ unsigned int val;
+
+ val = mux->stored_parent_cfg;
+ val <<= mux->shift;
+
+ return regmap_update_bits(clkr->regmap, mux->reg, mask, val);
+}
+
const struct clk_ops clk_regmap_mux_closest_ops = {
.get_parent = mux_get_parent,
.set_parent = mux_set_parent,
.determine_rate = __clk_mux_determine_rate_closest,
};
EXPORT_SYMBOL_GPL(clk_regmap_mux_closest_ops);
+
+const struct clk_ops clk_regmap_mux_safe_ops = {
+ .enable = mux_safe_enable,
+ .disable = mux_safe_disable,
+ .get_parent = mux_safe_get_parent,
+ .set_parent = mux_safe_set_parent,
+ .determine_rate = __clk_mux_determine_rate_closest,
+};
+EXPORT_SYMBOL_GPL(clk_regmap_mux_safe_ops);
diff --git a/drivers/clk/qcom/clk-regmap-mux.h b/drivers/clk/qcom/clk-regmap-mux.h
index db6f4cdd9586..f86c674ce139 100644
--- a/drivers/clk/qcom/clk-regmap-mux.h
+++ b/drivers/clk/qcom/clk-regmap-mux.h
@@ -14,10 +14,13 @@ struct clk_regmap_mux {
u32 reg;
u32 shift;
u32 width;
+ u8 safe_src_parent;
+ u8 stored_parent_cfg;
const struct parent_map *parent_map;
struct clk_regmap clkr;
};
extern const struct clk_ops clk_regmap_mux_closest_ops;
+extern const struct clk_ops clk_regmap_mux_safe_ops;
#endif
--
2.35.1
next prev parent reply other threads:[~2022-04-12 19:38 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-12 19:38 [PATCH v2 0/5] PCI: qcom: rework pipe_clk/pipe_clk_src handling Dmitry Baryshkov
2022-04-12 19:38 ` Dmitry Baryshkov [this message]
2022-04-13 9:15 ` [PATCH v2 1/5] clk: qcom: regmap-mux: add pipe clk implementation Johan Hovold
2022-04-13 17:57 ` Dmitry Baryshkov
2022-04-14 12:17 ` Johan Hovold
2022-04-13 22:21 ` Dmitry Baryshkov
2022-04-14 12:26 ` Johan Hovold
2022-04-12 19:38 ` [PATCH v2 2/5] clk: qcom: gcc-sm8450: use new clk_regmap_mux_safe_ops for PCIe pipe clocks Dmitry Baryshkov
2022-04-12 19:38 ` [PATCH v2 3/5] clk: qcom: gcc-sc7280: " Dmitry Baryshkov
2022-04-12 19:38 ` [PATCH v2 4/5] PCI: qcom: Remove unnecessary pipe_clk handling Dmitry Baryshkov
2022-04-12 19:38 ` [PATCH v2 5/5] PCI: qcom: Drop manual pipe_clk_src handling Dmitry Baryshkov
2022-04-13 9:20 ` [PATCH v2 0/5] PCI: qcom: rework pipe_clk/pipe_clk_src handling Johan Hovold
2022-04-13 17:58 ` Dmitry Baryshkov
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