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* [PATCH v5 1/1] i2c: mediatek: add runtime PM operations and bus regulator control
@ 2025-03-14 14:53 Zoie Lin
  2025-03-18 23:34 ` Andi Shyti
  0 siblings, 1 reply; 6+ messages in thread
From: Zoie Lin @ 2025-03-14 14:53 UTC (permalink / raw)
  To: Qii Wang, Andi Shyti, Matthias Brugger,
	AngeloGioacchino Del Regno
  Cc: Project_Global_Chrome_Upstream_Group, linux-i2c, linux-kernel,
	linux-arm-kernel, linux-mediatek, teddy.chen, joseph-cc.chang,
	leilk.liu, Zoie Lin

Introduce support for runtime PM operations in
the I2C driver, enabling runtime suspend and resume functionality.

Although in most platforms, the bus power of i2c is always
on, some platforms disable the i2c bus power in order to meet
low power request.

This implementation includes bus regulator control to facilitate
proper handling of the bus power based on platform requirements.

Signed-off-by: Zoie Lin <zoie.lin@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 74 ++++++++++++++++++++++++++++-----
 1 file changed, 63 insertions(+), 11 deletions(-)

This series is based on linux-next, tag: next-20250314

Changes in v5:
- Add pm runtime autosuspend setting to 250ms
- Add error message for clock enable failure

Changes in v4:
- Removed unnecessary variable initialization.
- Removed unnecessary brackets.
- Corrected grammar issues in the commit message.
- Confirmed autosuspend delay is not necessary.

Changes in v3:
- Removed the autosuspend functionality
- Resumed the I2C bus in mtk_i2c_resume_noirq() 

Changes in v2:
- Author name modification
- Replacement of pm runtime API
- Removal of redundant error messages
- Return value adjustment
- Add runtime pm status check

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 5bd342047d59..a630733a8890 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -21,6 +21,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/scatterlist.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
@@ -1245,8 +1246,8 @@ static int mtk_i2c_transfer(struct i2c_adapter *adap,
 	int left_num = num;
 	struct mtk_i2c *i2c = i2c_get_adapdata(adap);
 
-	ret = clk_bulk_enable(I2C_MT65XX_CLK_MAX, i2c->clocks);
-	if (ret)
+	ret = pm_runtime_resume_and_get(i2c->dev);
+	if (ret < 0)
 		return ret;
 
 	i2c->auto_restart = i2c->dev_comp->auto_restart;
@@ -1299,7 +1300,9 @@ static int mtk_i2c_transfer(struct i2c_adapter *adap,
 	ret = num;
 
 err_exit:
-	clk_bulk_disable(I2C_MT65XX_CLK_MAX, i2c->clocks);
+	pm_runtime_mark_last_busy(i2c->dev);
+	pm_runtime_put_autosuspend(i2c->dev);
+
 	return ret;
 }
 
@@ -1370,6 +1373,38 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c)
 	return 0;
 }
 
+static int mtk_i2c_runtime_suspend(struct device *dev)
+{
+	struct mtk_i2c *i2c = dev_get_drvdata(dev);
+
+	clk_bulk_disable(I2C_MT65XX_CLK_MAX, i2c->clocks);
+	if (i2c->adap.bus_regulator)
+		regulator_disable(i2c->adap.bus_regulator);
+
+	return 0;
+}
+
+static int mtk_i2c_runtime_resume(struct device *dev)
+{
+	int ret;
+	struct mtk_i2c *i2c = dev_get_drvdata(dev);
+
+	if (i2c->adap.bus_regulator) {
+		ret = regulator_enable(i2c->adap.bus_regulator);
+		if (ret) {
+			dev_err(dev, "enable regulator failed!\n");
+			return ret;
+		}
+	}
+
+	ret = clk_bulk_enable(I2C_MT65XX_CLK_MAX, i2c->clocks);
+	if (ret)
+		if (i2c->adap.bus_regulator)
+			regulator_disable(i2c->adap.bus_regulator);
+
+	return ret;
+}
+
 static int mtk_i2c_probe(struct platform_device *pdev)
 {
 	int ret = 0;
@@ -1472,13 +1507,19 @@ static int mtk_i2c_probe(struct platform_device *pdev)
 		}
 	}
 
-	ret = clk_bulk_prepare_enable(I2C_MT65XX_CLK_MAX, i2c->clocks);
+	ret = clk_bulk_prepare(I2C_MT65XX_CLK_MAX, i2c->clocks);
 	if (ret) {
 		dev_err(&pdev->dev, "clock enable failed!\n");
 		return ret;
 	}
+
+	platform_set_drvdata(pdev, i2c);
+
+	ret = mtk_i2c_runtime_resume(i2c->dev);
+	if (ret < 0)
+		goto err_clk_bulk_unprepare;
 	mtk_i2c_init_hw(i2c);
-	clk_bulk_disable(I2C_MT65XX_CLK_MAX, i2c->clocks);
+	mtk_i2c_runtime_suspend(i2c->dev);
 
 	ret = devm_request_irq(&pdev->dev, irq, mtk_i2c_irq,
 			       IRQF_NO_SUSPEND | IRQF_TRIGGER_NONE,
@@ -1486,19 +1527,22 @@ static int mtk_i2c_probe(struct platform_device *pdev)
 	if (ret < 0) {
 		dev_err(&pdev->dev,
 			"Request I2C IRQ %d fail\n", irq);
-		goto err_bulk_unprepare;
+		goto err_clk_bulk_unprepare;
 	}
+	pm_runtime_set_autosuspend_delay(&pdev->dev, 250);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
 
 	i2c_set_adapdata(&i2c->adap, i2c);
 	ret = i2c_add_adapter(&i2c->adap);
 	if (ret)
-		goto err_bulk_unprepare;
-
-	platform_set_drvdata(pdev, i2c);
+		goto err_pm_runtime_disable;
 
 	return 0;
 
-err_bulk_unprepare:
+err_pm_runtime_disable:
+	pm_runtime_disable(&pdev->dev);
+err_clk_bulk_unprepare:
 	clk_bulk_unprepare(I2C_MT65XX_CLK_MAX, i2c->clocks);
 
 	return ret;
@@ -1510,6 +1554,7 @@ static void mtk_i2c_remove(struct platform_device *pdev)
 
 	i2c_del_adapter(&i2c->adap);
 
+	pm_runtime_disable(&pdev->dev);
 	clk_bulk_unprepare(I2C_MT65XX_CLK_MAX, i2c->clocks);
 }
 
@@ -1518,6 +1563,10 @@ static int mtk_i2c_suspend_noirq(struct device *dev)
 	struct mtk_i2c *i2c = dev_get_drvdata(dev);
 
 	i2c_mark_adapter_suspended(&i2c->adap);
+
+	if (!pm_runtime_status_suspended(dev))
+		mtk_i2c_runtime_suspend(dev);
+
 	clk_bulk_unprepare(I2C_MT65XX_CLK_MAX, i2c->clocks);
 
 	return 0;
@@ -1536,7 +1585,8 @@ static int mtk_i2c_resume_noirq(struct device *dev)
 
 	mtk_i2c_init_hw(i2c);
 
-	clk_bulk_disable(I2C_MT65XX_CLK_MAX, i2c->clocks);
+	if (pm_runtime_status_suspended(dev))
+		mtk_i2c_runtime_resume(dev);
 
 	i2c_mark_adapter_resumed(&i2c->adap);
 
@@ -1546,6 +1596,8 @@ static int mtk_i2c_resume_noirq(struct device *dev)
 static const struct dev_pm_ops mtk_i2c_pm = {
 	NOIRQ_SYSTEM_SLEEP_PM_OPS(mtk_i2c_suspend_noirq,
 				  mtk_i2c_resume_noirq)
+	SET_RUNTIME_PM_OPS(mtk_i2c_runtime_suspend, mtk_i2c_runtime_resume,
+			   NULL)
 };
 
 static struct platform_driver mtk_i2c_driver = {
-- 
2.45.2


^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2025-08-19 14:33 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-03-14 14:53 [PATCH v5 1/1] i2c: mediatek: add runtime PM operations and bus regulator control Zoie Lin
2025-03-18 23:34 ` Andi Shyti
2025-03-20 22:08   ` Daniel Golle
2025-03-21  0:34     ` Andi Shyti
2025-05-19 13:26       ` Zoie Lin (林禹妡)
2025-08-19 14:33         ` Zoie Lin (林禹妡)

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