From: Jonas Aberg <jonas.aberg@xxxxxxxxxxxxxx>
This on-chip I2C controller needs to fetch the regulator
representing its voltage domain so that it won't be switched off.
Signed-off-by: Jonas Aberg <jonas.aberg@xxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-nomadik.c | 73 ++++++++++++++++++++++++++++++--------
1 files changed, 58 insertions(+), 15 deletions(-)
diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index e10e5cf..182761e 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -22,6 +22,7 @@
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
+#include <linux/regulator/consumer.h>
#include <plat/i2c.h>
@@ -151,6 +152,7 @@ struct i2c_nmk_client {
* @stop: stop condition
* @xfer_complete: acknowledge completion for a I2C message
* @result: controller propogated result
+ * @busy: Busy doing transfer
*/
struct nmk_i2c_dev {
struct platform_device *pdev;
@@ -163,6 +165,8 @@ struct nmk_i2c_dev {
int stop;
struct completion xfer_complete;
int result;
+ struct regulator *regulator;
+ bool busy;
};
/* controller's abort causes */
@@ -257,7 +261,7 @@ static int init_hw(struct nmk_i2c_dev *dev)
stat = flush_i2c_fifo(dev);
if (stat)
- return stat;
+ goto exit;
/* disable the controller */
i2c_clr_bit(dev->virtbase + I2C_CR , I2C_CR_PE);
@@ -268,10 +272,16 @@ static int init_hw(struct nmk_i2c_dev *dev)
dev->cli.operation = I2C_NO_OPERATION;
+exit:
+ /* TODO: Why disable clocks after init hw? */
clk_disable(dev->clk);
-
+ /*
+ * TODO: What is this delay for?
+ * Must be pretty pointless since the hw block
+ * is frozen. Or?
+ */
udelay(I2C_DELAY);
- return 0;
+ return stat;
}
/* enable peripheral, master mode operation */
@@ -562,9 +572,14 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
u32 cause;
struct nmk_i2c_dev *dev = i2c_get_adapdata(i2c_adap);
+ dev->busy = true;
+
+ if (dev->regulator)
+ regulator_enable(dev->regulator);
+
status = init_hw(dev);
if (status)
- return status;
+ goto out2;
clk_enable(dev->clk);
@@ -575,7 +590,9 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
if (unlikely(msgs[i].flags & I2C_M_TEN)) {
dev_err(&dev->pdev->dev, "10 bit addressing"
"not supported\n");
- return -EINVAL;
+
+ status = -EINVAL;
+ goto out;
}
dev->cli.slave_adr = msgs[i].addr;
dev->cli.buffer = msgs[i].buf;
@@ -600,12 +617,19 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
dev_err(&dev->pdev->dev, "%s\n",
cause >= ARRAY_SIZE(abort_causes)
? "unknown reason" : abort_causes[cause]);
- clk_disable(dev->clk);
- return status;
+
+ goto out;
}
udelay(I2C_DELAY);
}
+
+out:
clk_disable(dev->clk);
+out2:
+ if (dev->regulator)
+ regulator_disable(dev->regulator);
+
+ dev->busy = false;
/* return the no. messages processed */
if (status)
@@ -805,6 +829,21 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
return IRQ_HANDLED;
}
+
+#ifdef CONFIG_PM
+static int nmk_i2c_suspend(struct platform_device *pdev, pm_message_t mesg)
+{
+ struct nmk_i2c_dev *dev = platform_get_drvdata(pdev);
+
+ if (dev->busy)
+ return -EBUSY;
+ else
+ return 0;
+}
+#else
+#define nmk_i2c_suspend NULL
+#endif
+
static unsigned int nmk_i2c_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
@@ -830,7 +869,7 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
ret = -ENOMEM;
goto err_no_mem;
}
-
+ dev->busy = false;
dev->pdev = pdev;
platform_set_drvdata(pdev, dev);
@@ -860,6 +899,12 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
goto err_irq;
}
+ dev->regulator = regulator_get(&pdev->dev, "v-i2c");
+ if (IS_ERR(dev->regulator)) {
+ dev_warn(&pdev->dev, "could not get i2c regulator\n");
+ dev->regulator = NULL;
+ }
+
dev->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(dev->clk)) {
dev_err(&pdev->dev, "could not get i2c clock\n");
@@ -887,12 +932,6 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
i2c_set_adapdata(adap, dev);
- ret = init_hw(dev);
- if (ret != 0) {
- dev_err(&pdev->dev, "error in initializing i2c hardware\n");
- goto err_init_hw;
- }
-
dev_info(&pdev->dev, "initialize %s on virtual "
"base %p\n", adap->name, dev->virtbase);
@@ -904,10 +943,11 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
return 0;
- err_init_hw:
err_add_adap:
clk_put(dev->clk);
err_no_clk:
+ if (dev->regulator)
+ regulator_put(dev->regulator);
free_irq(dev->irq, dev);
err_irq:
iounmap(dev->virtbase);
@@ -938,6 +978,8 @@ static int __devexit nmk_i2c_remove(struct platform_device *pdev)
if (res)
release_mem_region(res->start, resource_size(res));
clk_put(dev->clk);
+ if (dev->regulator)
+ regulator_put(dev->regulator);
platform_set_drvdata(pdev, NULL);
kfree(dev);
@@ -951,6 +993,7 @@ static struct platform_driver nmk_i2c_driver = {
},
.probe = nmk_i2c_probe,
.remove = __devexit_p(nmk_i2c_remove),
+ .suspend = nmk_i2c_suspend,
};
static int __init nmk_i2c_init(void)
--
1.7.5.1
--
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