From: Xingyu Wu <xingyu.wu@starfivetech.com>
To: Michael Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@kernel.org>, Conor Dooley <conor@kernel.org>,
Emil Renner Berthing <emil.renner.berthing@canonical.com>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc: Emil Renner Berthing <kernel@esmil.dk>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Hal Feng <hal.feng@starfivetech.com>,
Xingyu Wu <xingyu.wu@starfivetech.com>,
linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org,
linux-riscv@lists.infradead.org, devicetree@vger.kernel.org
Subject: [PATCH v4 1/2] clk: starfive: jh7110-sys: Add notifier for PLL clock
Date: Wed, 10 Apr 2024 11:31:47 +0800 [thread overview]
Message-ID: <20240410033148.213991-2-xingyu.wu@starfivetech.com> (raw)
In-Reply-To: <20240410033148.213991-1-xingyu.wu@starfivetech.com>
Add notifier function for PLL clock. In the function, the cpu_root clock
should be operated by saving its current parent and setting a new safe
parent (osc clock) before setting the PLL clock rate. After setting PLL
rate, it should be switched back to the original parent clock.
Signed-off-by: Xingyu Wu <xingyu.wu@starfivetech.com>
---
.../clk/starfive/clk-starfive-jh7110-sys.c | 31 ++++++++++++++++++-
drivers/clk/starfive/clk-starfive-jh71x0.h | 2 ++
2 files changed, 32 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/starfive/clk-starfive-jh7110-sys.c b/drivers/clk/starfive/clk-starfive-jh7110-sys.c
index 8f5e5abfa178..adf62e4d94e4 100644
--- a/drivers/clk/starfive/clk-starfive-jh7110-sys.c
+++ b/drivers/clk/starfive/clk-starfive-jh7110-sys.c
@@ -385,6 +385,32 @@ int jh7110_reset_controller_register(struct jh71x0_clk_priv *priv,
}
EXPORT_SYMBOL_GPL(jh7110_reset_controller_register);
+/*
+ * This clock notifier is called when the rate of PLL0 clock is to be change,
+ * The cpu_root clock should save curent parent clock and swicth its parent
+ * clock to osc before PLL0 rate will be changed. And switch its parent clock
+ * back after PLL rate finished.
+ */
+static int jh7110_pll_clk_notifier_cb(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct jh71x0_clk_priv *priv = container_of(nb, struct jh71x0_clk_priv, pll_clk_nb);
+ struct clk *cpu_root = priv->reg[JH7110_SYSCLK_CPU_ROOT].hw.clk;
+ int ret = 0;
+
+ if (action == PRE_RATE_CHANGE) {
+ struct clk *osc = clk_get(priv->dev, "osc");
+
+ priv->original_clk = clk_get_parent(cpu_root);
+ ret = clk_set_parent(cpu_root, osc);
+ clk_put(osc);
+ } else if (action == POST_RATE_CHANGE) {
+ ret = clk_set_parent(cpu_root, priv->original_clk);
+ }
+
+ return notifier_from_errno(ret);
+}
+
static int __init jh7110_syscrg_probe(struct platform_device *pdev)
{
struct jh71x0_clk_priv *priv;
@@ -413,7 +439,10 @@ static int __init jh7110_syscrg_probe(struct platform_device *pdev)
if (IS_ERR(priv->pll[0]))
return PTR_ERR(priv->pll[0]);
} else {
- clk_put(pllclk);
+ priv->pll_clk_nb.notifier_call = jh7110_pll_clk_notifier_cb;
+ ret = clk_notifier_register(pllclk, &priv->pll_clk_nb);
+ if (ret)
+ return ret;
priv->pll[0] = NULL;
}
diff --git a/drivers/clk/starfive/clk-starfive-jh71x0.h b/drivers/clk/starfive/clk-starfive-jh71x0.h
index 23e052fc1549..e3f441393e48 100644
--- a/drivers/clk/starfive/clk-starfive-jh71x0.h
+++ b/drivers/clk/starfive/clk-starfive-jh71x0.h
@@ -114,6 +114,8 @@ struct jh71x0_clk_priv {
spinlock_t rmw_lock;
struct device *dev;
void __iomem *base;
+ struct clk *original_clk;
+ struct notifier_block pll_clk_nb;
struct clk_hw *pll[3];
struct jh71x0_clk reg[];
};
--
2.25.1
next prev parent reply other threads:[~2024-04-10 10:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-10 3:31 [PATCH v4 0/2] Add notifier for PLL0 clock and set it 1.5GHz on Xingyu Wu
2024-04-10 3:31 ` Xingyu Wu [this message]
2024-04-10 7:58 ` [PATCH v4 1/2] clk: starfive: jh7110-sys: Add notifier for PLL clock Stephen Boyd
2024-04-12 8:48 ` Xingyu Wu
2024-04-10 3:31 ` [PATCH v4 2/2] riscv: dts: starfive: visionfive-2: Fix lower rate of CPUfreq by setting PLL0 rate to 1.5GHz Xingyu Wu
2024-04-24 20:32 ` [PATCH v4 0/2] Add notifier for PLL0 clock and set it 1.5GHz on Alexandre Ghiti
2024-04-25 9:08 ` Xingyu Wu
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