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authorMasahiro Yamada <yamada.masahiro@socionext.com>2016-09-01 20:46:28 +0900
committerWolfram Sang <wsa@the-dreams.de>2016-09-08 22:40:32 +0200
commit4c91307ce9387519836e17482906ef0f698ea7d9 (patch)
tree059b502e466ff8e50b5142bc349365bf73b17997 /drivers/i2c
parentfbf8090b723d4df3cfe18c9491a8bc21ec15a5c0 (diff)
i2c: uniphier: avoid WARN_ON() of clk_disable() in failure path
If clk_prepare_enable() fails, clk_disable_unprepare() is called in the failure path, where the enable_count is still zero, so it hits WARN_ON(core->enable_count == 0) in the clk_core_disable(). To fix this, make the clock setting more linear in the probe function so that it can exploit "goto err" in case of error. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-uniphier.c73
1 files changed, 31 insertions, 42 deletions
diff --git a/drivers/i2c/busses/i2c-uniphier.c b/drivers/i2c/busses/i2c-uniphier.c
index d6e612a0e02a..56e92af46ddc 100644
--- a/drivers/i2c/busses/i2c-uniphier.c
+++ b/drivers/i2c/busses/i2c-uniphier.c
@@ -316,50 +316,15 @@ static struct i2c_bus_recovery_info uniphier_i2c_bus_recovery_info = {
.unprepare_recovery = uniphier_i2c_unprepare_recovery,
};
-static int uniphier_i2c_clk_init(struct device *dev,
- struct uniphier_i2c_priv *priv)
+static void uniphier_i2c_hw_init(struct uniphier_i2c_priv *priv,
+ u32 bus_speed, unsigned long clk_rate)
{
- struct device_node *np = dev->of_node;
- unsigned long clk_rate;
- u32 bus_speed;
- int ret;
-
- if (of_property_read_u32(np, "clock-frequency", &bus_speed))
- bus_speed = UNIPHIER_I2C_DEFAULT_SPEED;
-
- if (!bus_speed) {
- dev_err(dev, "clock-frequency should not be zero\n");
- return -EINVAL;
- }
-
- if (bus_speed > UNIPHIER_I2C_MAX_SPEED)
- bus_speed = UNIPHIER_I2C_MAX_SPEED;
-
- /* Get input clk rate through clk driver */
- priv->clk = devm_clk_get(dev, NULL);
- if (IS_ERR(priv->clk)) {
- dev_err(dev, "failed to get clock\n");
- return PTR_ERR(priv->clk);
- }
-
- ret = clk_prepare_enable(priv->clk);
- if (ret)
- return ret;
-
- clk_rate = clk_get_rate(priv->clk);
- if (!clk_rate) {
- dev_err(dev, "input clock rate should not be zero\n");
- return -EINVAL;
- }
-
uniphier_i2c_reset(priv, true);
writel((clk_rate / bus_speed / 2 << 16) | (clk_rate / bus_speed),
priv->membase + UNIPHIER_I2C_CLK);
uniphier_i2c_reset(priv, false);
-
- return 0;
}
static int uniphier_i2c_probe(struct platform_device *pdev)
@@ -367,8 +332,9 @@ static int uniphier_i2c_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct uniphier_i2c_priv *priv;
struct resource *regs;
- int irq;
- int ret;
+ u32 bus_speed;
+ unsigned long clk_rate;
+ int irq, ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
@@ -385,6 +351,31 @@ static int uniphier_i2c_probe(struct platform_device *pdev)
return irq;
}
+ if (of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed))
+ bus_speed = UNIPHIER_I2C_DEFAULT_SPEED;
+
+ if (!bus_speed || bus_speed > UNIPHIER_I2C_MAX_SPEED) {
+ dev_err(dev, "invalid clock-frequency %d\n", bus_speed);
+ return -EINVAL;
+ }
+
+ priv->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(priv->clk)) {
+ dev_err(dev, "failed to get clock\n");
+ return PTR_ERR(priv->clk);
+ }
+
+ ret = clk_prepare_enable(priv->clk);
+ if (ret)
+ return ret;
+
+ clk_rate = clk_get_rate(priv->clk);
+ if (!clk_rate) {
+ dev_err(dev, "input clock rate should not be zero\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
init_completion(&priv->comp);
priv->adap.owner = THIS_MODULE;
priv->adap.algo = &uniphier_i2c_algo;
@@ -395,9 +386,7 @@ static int uniphier_i2c_probe(struct platform_device *pdev)
i2c_set_adapdata(&priv->adap, priv);
platform_set_drvdata(pdev, priv);
- ret = uniphier_i2c_clk_init(dev, priv);
- if (ret)
- goto err;
+ uniphier_i2c_hw_init(priv, bus_speed, clk_rate);
ret = devm_request_irq(dev, irq, uniphier_i2c_interrupt, 0, pdev->name,
priv);