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path: root/drivers/i2c/busses/i2c-omap.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-omap.c')
-rw-r--r--drivers/i2c/busses/i2c-omap.c36
1 files changed, 28 insertions, 8 deletions
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index da6639707ea..7ba31770d77 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -128,6 +128,8 @@ struct omap_i2c_dev {
size_t buf_len;
struct i2c_adapter adapter;
unsigned rev1:1;
+ unsigned idle:1;
+ u16 iestate; /* Saved interrupt register */
};
static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
@@ -174,18 +176,30 @@ static void omap_i2c_put_clocks(struct omap_i2c_dev *dev)
}
}
-static void omap_i2c_enable_clocks(struct omap_i2c_dev *dev)
+static void omap_i2c_unidle(struct omap_i2c_dev *dev)
{
if (dev->iclk != NULL)
clk_enable(dev->iclk);
clk_enable(dev->fclk);
+ if (dev->iestate)
+ omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
+ dev->idle = 0;
}
-static void omap_i2c_disable_clocks(struct omap_i2c_dev *dev)
+static void omap_i2c_idle(struct omap_i2c_dev *dev)
{
+ u16 iv;
+
+ dev->idle = 1;
+ dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
+ omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0);
+ if (dev->rev1)
+ iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); /* Read clears */
+ else
+ omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate);
+ clk_disable(dev->fclk);
if (dev->iclk != NULL)
clk_disable(dev->iclk);
- clk_disable(dev->fclk);
}
static int omap_i2c_init(struct omap_i2c_dev *dev)
@@ -360,7 +374,7 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
int i;
int r;
- omap_i2c_enable_clocks(dev);
+ omap_i2c_unidle(dev);
if ((r = omap_i2c_wait_for_bb(dev)) < 0)
goto out;
@@ -374,7 +388,7 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
if (r == 0)
r = num;
out:
- omap_i2c_disable_clocks(dev);
+ omap_i2c_idle(dev);
return r;
}
@@ -403,6 +417,9 @@ omap_i2c_rev1_isr(int this_irq, void *dev_id)
struct omap_i2c_dev *dev = dev_id;
u16 iv, w;
+ if (dev->idle)
+ return IRQ_NONE;
+
iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
switch (iv) {
case 0x00: /* None */
@@ -457,6 +474,9 @@ omap_i2c_isr(int this_irq, void *dev_id)
u16 stat, w;
int count = 0;
+ if (dev->idle)
+ return IRQ_NONE;
+
bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
@@ -575,7 +595,7 @@ omap_i2c_probe(struct platform_device *pdev)
if ((r = omap_i2c_get_clocks(dev)) != 0)
goto err_free_mem;
- omap_i2c_enable_clocks(dev);
+ omap_i2c_unidle(dev);
if (cpu_is_omap15xx())
dev->rev1 = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) < 0x20;
@@ -610,7 +630,7 @@ omap_i2c_probe(struct platform_device *pdev)
goto err_free_irq;
}
- omap_i2c_disable_clocks(dev);
+ omap_i2c_idle(dev);
return 0;
@@ -618,7 +638,7 @@ err_free_irq:
free_irq(dev->irq, dev);
err_unuse_clocks:
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
- omap_i2c_disable_clocks(dev);
+ omap_i2c_idle(dev);
omap_i2c_put_clocks(dev);
err_free_mem:
platform_set_drvdata(pdev, NULL);