Tegra I2C driver enables the fast clock during initialization
and does not disable till driver removed.
Enable this clock before transfer and disable after transfer done.
Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
---
This patch is on top of the clock chnages which is in Tegra sub system and
based on
i2c: tegra: I2_M_NOSTART functionality not supported in Tegra20
So recommend to go on tegra sub-system.
drivers/i2c/busses/i2c-tegra.c | 35 ++++++++++++++++++++++++++++-------
1 files changed, 28 insertions(+), 7 deletions(-)
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 554f713..24f7cee 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -362,12 +362,36 @@ static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
}
+static inline int tegra_i2c_clock_enable(struct tegra_i2c_dev *i2c_dev)
+{
+ int ret;
+ ret = clk_prepare_enable(i2c_dev->fast_clk);
+ if (ret < 0) {
+ dev_err(i2c_dev->dev,
+ "Enabling fast clk failed, err %d\n", ret);
+ return ret;
+ }
+ ret = clk_prepare_enable(i2c_dev->div_clk);
+ if (ret < 0) {
+ dev_err(i2c_dev->dev,
+ "Enabling div clk failed, err %d\n", ret);
+ clk_disable_unprepare(i2c_dev->fast_clk);
+ }
+ return ret;
+}
+
+static inline void tegra_i2c_clock_disable(struct tegra_i2c_dev *i2c_dev)
+{
+ clk_disable_unprepare(i2c_dev->div_clk);
+ clk_disable_unprepare(i2c_dev->fast_clk);
+}
+
static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
{
u32 val;
int err = 0;
- clk_prepare_enable(i2c_dev->div_clk);
+ tegra_i2c_clock_enable(i2c_dev);
tegra_periph_reset_assert(i2c_dev->div_clk);
udelay(2);
@@ -398,7 +422,7 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
if (tegra_i2c_flush_fifos(i2c_dev))
err = -ETIMEDOUT;
- clk_disable_unprepare(i2c_dev->div_clk);
+ tegra_i2c_clock_disable(i2c_dev);
if (i2c_dev->irq_disabled) {
i2c_dev->irq_disabled = 0;
@@ -584,7 +608,7 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
}
}
- clk_prepare_enable(i2c_dev->clk);
+ tegra_i2c_clock_enable(i2c_dev);
for (i = 0; i < num; i++) {
enum msg_end_type end_type = MSG_END_STOP;
if (i < (num - 1)) {
@@ -597,7 +621,7 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
if (ret)
break;
}
- clk_disable_unprepare(i2c_dev->div_clk);
+ tegra_i2c_clock_disable(i2c_dev);
return ret ?: i;
}
@@ -734,8 +758,6 @@ static int __devinit tegra_i2c_probe(struct platform_device *pdev)
return ret;
}
- clk_prepare_enable(i2c_dev->fast_clk);
-
i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
i2c_dev->adapter.owner = THIS_MODULE;
i2c_dev->adapter.class = I2C_CLASS_HWMON;
@@ -749,7 +771,6 @@ static int __devinit tegra_i2c_probe(struct platform_device *pdev)
ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
if (ret) {
dev_err(&pdev->dev, "Failed to add I2C adapter\n");
- clk_disable_unprepare(i2c_dev->fast_clk);
return ret;
}
--
1.7.1.1
--
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