diff mbox

[v4,0/1] i2c: mediatek: add runtime PM operations and bus regulator control

Message ID 20250211144016.488001-1-zoie.lin@mediatek.com
State New
Headers show

Commit Message

Zoie Lin Feb. 11, 2025, 2:39 p.m. UTC 
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 | 73 +++++++++++++++++++++++++++------
 1 file changed, 61 insertions(+), 12 deletions(-)

This series is based on linux-next, tag: next-20250210

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

Comments

Andi Shyti Feb. 12, 2025, 6:37 p.m. UTC | #1 
Hi Zoie,

my comment was on the [PATCH v3 ...], this should have been
[PATCH v4 1/1]. If you use git-format-patch, most probably you
will get it right.

If you have more than one patch, you can use the --cover-letter.
option to get the patch 0/X.

On Tue, Feb 11, 2025 at 10:39:37PM +0800, Zoie Lin wrote:
> 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>

Is it possible to have an ack from Qii?

> ---
>  drivers/i2c/busses/i2c-mt65xx.c | 73 +++++++++++++++++++++++++++------
>  1 file changed, 61 insertions(+), 12 deletions(-)
> 
> This series is based on linux-next, tag: next-20250210
> 
> Changes in v4:

what about the previous versions?

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

...

> @@ -1472,13 +1507,18 @@ 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");

Why have you removed this dev_err? You coulde have rather changed
it to match the error. While at it you could also replace it with
dev_err_probe()

The rest looks good to me, I'll be happy if you can have an ack
from Qii.

Andi

>  		return ret;
diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 5bd342047d59..1979b46d75f0 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_sync(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 +1507,18 @@  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 +1526,20 @@  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_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 +1551,7 @@  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 +1560,10 @@  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 +1582,8 @@  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 +1593,8 @@  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 = {