linux-kernel - [PATCH v3 3/3] i2c: rk3x: Add check for clk

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Message-Id: <20241107211428.32273-3-jiashengjiangcool@gmail.com>
Date: Thu,  7 Nov 2024 21:14:28 +0000
From: Jiasheng Jiang <jiashengjiangcool@...il.com>
To: andi.shyti@...nel.org
Cc: dianders@...omium.org,
	rmk@...-67.arm.linux.org.uk,
	max.schwarz@...ine.de,
	david.wu@...k-chips.com,
	heiko@...ech.de,
	vz@...ia.com,
	wsa@...nel.org,
	manabian@...il.com,
	linux-arm-kernel@...ts.infradead.org,
	linux-rockchip@...ts.infradead.org,
	linux-i2c@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Jiasheng Jiang <jiashengjiangcool@...il.com>
Subject: [PATCH v3 3/3] i2c: rk3x: Add check for clk_enable()

Add check for the return value of clk_enable() in order to catch the
potential exception. Moreover, convert the return type of
rk3x_i2c_adapt_div() into int and add the check.

Signed-off-by: Jiasheng Jiang <jiashengjiangcool@...il.com>
---
Changelog:

v2 -> v3:

1. Roll back unsuitable dev_err_probe() to dev_err()

v1 -> v2:

1. Remove the Fixes tag.
2. Use dev_err_probe to simplify error handling.
---
 drivers/i2c/busses/i2c-rk3x.c | 55 ++++++++++++++++++++++++++---------
 1 file changed, 41 insertions(+), 14 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 4ef9bad77b85..0263ee0e0470 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -871,7 +871,7 @@ static int rk3x_i2c_v1_calc_timings(unsigned long clk_rate,
 	return ret;
 }
 
-static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate)
+static int rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate)
 {
 	struct i2c_timings *t = &i2c->t;
 	struct rk3x_i2c_calced_timings calc;
@@ -883,7 +883,11 @@ static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate)
 	ret = i2c->soc_data->calc_timings(clk_rate, t, &calc);
 	WARN_ONCE(ret != 0, "Could not reach SCL freq %u", t->bus_freq_hz);
 
-	clk_enable(i2c->pclk);
+	ret = clk_enable(i2c->pclk);
+	if (ret) {
+		dev_err(i2c->dev, "Can't enable bus clk for rk3399: %d\n", ret);
+		return ret;
+	}
 
 	spin_lock_irqsave(&i2c->lock, flags);
 	val = i2c_readl(i2c, REG_CON);
@@ -904,6 +908,8 @@ static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate)
 		clk_rate / 1000,
 		1000000000 / t->bus_freq_hz,
 		t_low_ns, t_high_ns);
+
+	return 0;
 }
 
 /**
@@ -942,19 +948,27 @@ static int rk3x_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long
 			return NOTIFY_STOP;
 
 		/* scale up */
-		if (ndata->new_rate > ndata->old_rate)
-			rk3x_i2c_adapt_div(i2c, ndata->new_rate);
+		if (ndata->new_rate > ndata->old_rate) {
+			if (rk3x_i2c_adapt_div(i2c, ndata->new_rate))
+				return NOTIFY_STOP;
+		}
 
 		return NOTIFY_OK;
 	case POST_RATE_CHANGE:
 		/* scale down */
-		if (ndata->new_rate < ndata->old_rate)
-			rk3x_i2c_adapt_div(i2c, ndata->new_rate);
+		if (ndata->new_rate < ndata->old_rate) {
+			if (rk3x_i2c_adapt_div(i2c, ndata->new_rate))
+				return NOTIFY_STOP;
+		}
+
 		return NOTIFY_OK;
 	case ABORT_RATE_CHANGE:
 		/* scale up */
-		if (ndata->new_rate > ndata->old_rate)
-			rk3x_i2c_adapt_div(i2c, ndata->old_rate);
+		if (ndata->new_rate > ndata->old_rate) {
+			if (rk3x_i2c_adapt_div(i2c, ndata->old_rate))
+				return NOTIFY_STOP;
+		}
+
 		return NOTIFY_OK;
 	default:
 		return NOTIFY_DONE;
@@ -1068,8 +1082,20 @@ static int rk3x_i2c_xfer_common(struct i2c_adapter *adap,
 
 	spin_lock_irqsave(&i2c->lock, flags);
 
-	clk_enable(i2c->clk);
-	clk_enable(i2c->pclk);
+	ret = clk_enable(i2c->clk);
+	if (ret) {
+		spin_unlock_irqrestore(&i2c->lock, flags);
+		dev_err(i2c->dev, "Can't enable bus clk: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_enable(i2c->pclk);
+	if (ret) {
+		clk_disable(i2c->clk);
+		spin_unlock_irqrestore(&i2c->lock, flags);
+		dev_err(i2c->dev, "Can't enable bus clk for rk3399: %d\n", ret);
+		return ret;
+	}
 
 	i2c->is_last_msg = false;
 
@@ -1149,9 +1175,7 @@ static __maybe_unused int rk3x_i2c_resume(struct device *dev)
 {
 	struct rk3x_i2c *i2c = dev_get_drvdata(dev);
 
-	rk3x_i2c_adapt_div(i2c, clk_get_rate(i2c->clk));
-
-	return 0;
+	return rk3x_i2c_adapt_div(i2c, clk_get_rate(i2c->clk));
 }
 
 static u32 rk3x_i2c_func(struct i2c_adapter *adap)
@@ -1365,9 +1389,12 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
 	}
 
 	clk_rate = clk_get_rate(i2c->clk);
-	rk3x_i2c_adapt_div(i2c, clk_rate);
+	ret = rk3x_i2c_adapt_div(i2c, clk_rate);
 	clk_disable(i2c->clk);
 
+	if (ret)
+		goto err_clk_notifier;
+
 	ret = i2c_add_adapter(&i2c->adap);
 	if (ret < 0)
 		goto err_clk_notifier;
-- 
2.25.1