linux-kernel - [PATCH] clk: mediatek: Don't check HW status for mt8192/5's imp_iic

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Date:   Mon, 11 Jul 2022 16:57:33 -0400
From:   Nícolas F. R. A. Prado 
        <nfraprado@...labora.com>
To:     Stephen Boyd <sboyd@...nel.org>
Cc:     kernel@...labora.com,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>,
        Nícolas F. R. A. Prado 
        <nfraprado@...labora.com>, Chen-Yu Tsai <wenst@...omium.org>,
        Chun-Jie Chen <chun-jie.chen@...iatek.com>,
        Ikjoon Jang <ikjn@...omium.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Michael Turquette <mturquette@...libre.com>,
        Miles Chen <miles.chen@...iatek.com>,
        Ran Jianping <ran.jianping@....com.cn>,
        Weiyi Lu <weiyi.lu@...iatek.com>,
        linux-arm-kernel@...ts.infradead.org, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-mediatek@...ts.infradead.org
Subject: [PATCH] clk: mediatek: Don't check HW status for mt8192/5's imp_iic_wrap clocks

The imp_iic_wrap clocks on mt8192/mt8195 require that the i2c_sel parent
clock be enabled before their hardware status can be checked. Since this
wasn't taken into account, reading from the clk_summary debugfs file
would cause the system to completely freeze.

Assuming that this clock is managed only by the kernel, and not by any
firmware, simply drop the is_enabled() optional callback and instead
rely on the enable count for the imp_iic_wrap clocks.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@...labora.com>

---

 drivers/clk/mediatek/clk-gate.c                | 6 ++++++
 drivers/clk/mediatek/clk-gate.h                | 1 +
 drivers/clk/mediatek/clk-mt8192-imp_iic_wrap.c | 2 +-
 drivers/clk/mediatek/clk-mt8195-imp_iic_wrap.c | 2 +-
 4 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/mediatek/clk-gate.c b/drivers/clk/mediatek/clk-gate.c
index 421806236228..8e7c719a69b3 100644
--- a/drivers/clk/mediatek/clk-gate.c
+++ b/drivers/clk/mediatek/clk-gate.c
@@ -124,6 +124,12 @@ static void mtk_cg_disable_inv_no_setclr(struct clk_hw *hw)
 	mtk_cg_clr_bit_no_setclr(hw);
 }
 
+const struct clk_ops mtk_clk_gate_ops_setclr_counted = {
+	.enable		= mtk_cg_enable,
+	.disable	= mtk_cg_disable,
+};
+EXPORT_SYMBOL_GPL(mtk_clk_gate_ops_setclr_counted);
+
 const struct clk_ops mtk_clk_gate_ops_setclr = {
 	.is_enabled	= mtk_cg_bit_is_cleared,
 	.enable		= mtk_cg_enable,
diff --git a/drivers/clk/mediatek/clk-gate.h b/drivers/clk/mediatek/clk-gate.h
index d9897ef53528..b5502b2911f5 100644
--- a/drivers/clk/mediatek/clk-gate.h
+++ b/drivers/clk/mediatek/clk-gate.h
@@ -19,6 +19,7 @@ extern const struct clk_ops mtk_clk_gate_ops_setclr;
 extern const struct clk_ops mtk_clk_gate_ops_setclr_inv;
 extern const struct clk_ops mtk_clk_gate_ops_no_setclr;
 extern const struct clk_ops mtk_clk_gate_ops_no_setclr_inv;
+extern const struct clk_ops mtk_clk_gate_ops_setclr_counted;
 
 struct mtk_gate_regs {
 	u32 sta_ofs;
diff --git a/drivers/clk/mediatek/clk-mt8192-imp_iic_wrap.c b/drivers/clk/mediatek/clk-mt8192-imp_iic_wrap.c
index 700356ac6a58..900ee601169c 100644
--- a/drivers/clk/mediatek/clk-mt8192-imp_iic_wrap.c
+++ b/drivers/clk/mediatek/clk-mt8192-imp_iic_wrap.c
@@ -20,7 +20,7 @@ static const struct mtk_gate_regs imp_iic_wrap_cg_regs = {
 
 #define GATE_IMP_IIC_WRAP(_id, _name, _parent, _shift)			\
 	GATE_MTK_FLAGS(_id, _name, _parent, &imp_iic_wrap_cg_regs, _shift,	\
-		&mtk_clk_gate_ops_setclr, CLK_OPS_PARENT_ENABLE)
+		&mtk_clk_gate_ops_setclr_counted, CLK_OPS_PARENT_ENABLE)
 
 static const struct mtk_gate imp_iic_wrap_c_clks[] = {
 	GATE_IMP_IIC_WRAP(CLK_IMP_IIC_WRAP_C_I2C10, "imp_iic_wrap_c_i2c10", "infra_i2c0", 0),
diff --git a/drivers/clk/mediatek/clk-mt8195-imp_iic_wrap.c b/drivers/clk/mediatek/clk-mt8195-imp_iic_wrap.c
index fbc809d05072..e50a77b844f4 100644
--- a/drivers/clk/mediatek/clk-mt8195-imp_iic_wrap.c
+++ b/drivers/clk/mediatek/clk-mt8195-imp_iic_wrap.c
@@ -18,7 +18,7 @@ static const struct mtk_gate_regs imp_iic_wrap_cg_regs = {
 
 #define GATE_IMP_IIC_WRAP(_id, _name, _parent, _shift)				\
 	GATE_MTK_FLAGS(_id, _name, _parent, &imp_iic_wrap_cg_regs, _shift,	\
-		&mtk_clk_gate_ops_setclr, CLK_OPS_PARENT_ENABLE)
+		&mtk_clk_gate_ops_setclr_counted, CLK_OPS_PARENT_ENABLE)
 
 static const struct mtk_gate imp_iic_wrap_s_clks[] = {
 	GATE_IMP_IIC_WRAP(CLK_IMP_IIC_WRAP_S_I2C5, "imp_iic_wrap_s_i2c5", "top_i2c", 0),
-- 
2.37.0