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i3c: dw: Add apb reset support

PATCH Superseded Jisheng Zhang 3 participants 3 messages Nov 2, 2025 – Nov 3, 2025

Subsystems (2)
I3C I3C driver for synopsys DesignWare

v1 of 4 Superseded Latest is v4 →

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Jisheng Zhang

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#0 lore raw

PATCH 1/1 i3c: dw: Add apb reset support

Add support of apb reset which is to reset the APB interface.

Signed-off-by Jisheng Zhang <[email protected]>
---
 drivers/i3c/master/dw-i3c-master.c | 9 +++++++++
 drivers/i3c/master/dw-i3c-master.h | 1 +
 2 files changed, 10 insertions(+)
drivers/i3c/master/dw-i3c-master.c +9 -0
index 9ceedf09c3b6..ca2863d2b2b7 100644
@@ -1558,7 +1558,13 @@ int dw_i3c_common_probe(struct dw_i3c_master *master,
 	if (IS_ERR(master->core_rst))
 		return PTR_ERR(master->core_rst);
 
+	master->apb_rst = devm_reset_control_get_optional_exclusive(&pdev->dev,
+								    "apb_rst");
+	if (IS_ERR(master->apb_rst))
+		return PTR_ERR(master->apb_rst);
+
 	reset_control_deassert(master->core_rst);
+	reset_control_deassert(master->apb_rst);
 
 	spin_lock_init(&master->xferqueue.lock);
 	INIT_LIST_HEAD(&master->xferqueue.list);

@@ -1607,6 +1613,7 @@ int dw_i3c_common_probe(struct dw_i3c_master *master,
 
 err_assert_rst:
 	reset_control_assert(master->core_rst);
+	reset_control_assert(master->apb_rst);
 
 	return ret;
 }

@@ -1711,6 +1718,7 @@ static int __maybe_unused dw_i3c_master_runtime_suspend(struct device *dev)
 	dw_i3c_master_disable(master);
 
 	reset_control_assert(master->core_rst);
+	reset_control_assert(master->apb_rst);
 	dw_i3c_master_disable_clks(master);
 	pinctrl_pm_select_sleep_state(dev);
 	return 0;

@@ -1723,6 +1731,7 @@ static int __maybe_unused dw_i3c_master_runtime_resume(struct device *dev)
 	pinctrl_pm_select_default_state(dev);
 	dw_i3c_master_enable_clks(master);
 	reset_control_deassert(master->core_rst);
+	reset_control_deassert(master->apb_rst);
 
 	dw_i3c_master_set_intr_regs(master);
 	dw_i3c_master_restore_timing_regs(master);
drivers/i3c/master/dw-i3c-master.h +1 -0
index c5cb695c16ab..a4ba60043288 100644
@@ -37,6 +37,7 @@ struct dw_i3c_master {
 	struct dw_i3c_master_caps caps;
 	void __iomem *regs;
 	struct reset_control *core_rst;
+	struct reset_control *apb_rst;
 	struct clk *core_clk;
 	struct clk *pclk;
 	char version[5];
Signature · 1 line
2.51.0
reviewer
#1 lore raw
Quoted 13 lines · Jisheng Zhang

Add support of apb reset which is to reset the APB interface.

Signed-off-by Jisheng Zhang <[email protected]>
---
 drivers/i3c/master/dw-i3c-master.c | 9 +++++++++
 drivers/i3c/master/dw-i3c-master.h | 1 +
 2 files changed, 10 insertions(+)
drivers/i3c/master/dw-i3c-master.c +0 -0
index 9ceedf09c3b6..ca2863d2b2b7 100644

drivers/i3c/master/dw-i3c-master.c int dw_i3c_common_probe(struct dw_i3c_master *master, · line 1562

Quoted 5 lines
drivers/i3c/master/dw-i3c-master.c +2 -0
@@ -1558,7 +1558,13 @@ int dw_i3c_common_probe(struct dw_i3c_master *master,
 	if (IS_ERR(master->core_rst))
 		return PTR_ERR(master->core_rst);
 
+	master->apb_rst = devm_reset_control_get_optional_exclusive(&pdev->dev,
+								    "apb_rst");

Does binding already add "app_rst"? The name "app" should be enough.

Frank

Quoted 47 lines
drivers/i3c/master/dw-i3c-master.c +7 -0
+	if (IS_ERR(master->apb_rst))
+		return PTR_ERR(master->apb_rst);
+
 	reset_control_deassert(master->core_rst);
+	reset_control_deassert(master->apb_rst);
 
 	spin_lock_init(&master->xferqueue.lock);
 	INIT_LIST_HEAD(&master->xferqueue.list);

@@ -1607,6 +1613,7 @@ int dw_i3c_common_probe(struct dw_i3c_master *master,
 
 err_assert_rst:
 	reset_control_assert(master->core_rst);
+	reset_control_assert(master->apb_rst);
 
 	return ret;
 }

@@ -1711,6 +1718,7 @@ static int __maybe_unused dw_i3c_master_runtime_suspend(struct device *dev)
 	dw_i3c_master_disable(master);
 
 	reset_control_assert(master->core_rst);
+	reset_control_assert(master->apb_rst);
 	dw_i3c_master_disable_clks(master);
 	pinctrl_pm_select_sleep_state(dev);
 	return 0;

@@ -1723,6 +1731,7 @@ static int __maybe_unused dw_i3c_master_runtime_resume(struct device *dev)
 	pinctrl_pm_select_default_state(dev);
 	dw_i3c_master_enable_clks(master);
 	reset_control_deassert(master->core_rst);
+	reset_control_deassert(master->apb_rst);
 
 	dw_i3c_master_set_intr_regs(master);
 	dw_i3c_master_restore_timing_regs(master);
drivers/i3c/master/dw-i3c-master.h +1 -1
index c5cb695c16ab..a4ba60043288 100644
@@ -37,6 +37,7 @@ struct dw_i3c_master {
 	struct dw_i3c_master_caps caps;
 	void __iomem *regs;
 	struct reset_control *core_rst;
+	struct reset_control *apb_rst;
 	struct clk *core_clk;
 	struct clk *pclk;
 	char version[5];
--

2.51.0

#2 lore raw
Quoted 17 lines · Frank Li
Quoted 16 lines · Jisheng Zhang

Add support of apb reset which is to reset the APB interface.

Signed-off-by Jisheng Zhang <[email protected]>
---
 drivers/i3c/master/dw-i3c-master.c | 9 +++++++++
 drivers/i3c/master/dw-i3c-master.h | 1 +
 2 files changed, 10 insertions(+)
drivers/i3c/master/dw-i3c-master.c +0 -0
index 9ceedf09c3b6..ca2863d2b2b7 100644
@@ -1558,7 +1558,13 @@ int dw_i3c_common_probe(struct dw_i3c_master *master,
 	if (IS_ERR(master->core_rst))
 		return PTR_ERR(master->core_rst);
Quoted 4 lines

drivers/i3c/master/dw-i3c-master.c int dw_i3c_common_probe(struct dw_i3c_master *master, · line 1562

Quoted 2 lines
drivers/i3c/master/dw-i3c-master.c +2 -0
+	master->apb_rst = devm_reset_control_get_optional_exclusive(&pdev->dev,
+								    "apb_rst");

Does binding already add "app_rst"? The name "app" should be enough.

The binding defines no resets at all, so there's a missing patch here.