aboutsummaryrefslogtreecommitdiff
path: root/drivers/i2c/busses/i2c-sh_mobile.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/i2c/busses/i2c-sh_mobile.c')
-rw-r--r--drivers/i2c/busses/i2c-sh_mobile.c39
1 files changed, 37 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index 820487d0d5c..86a9d4e8147 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -28,6 +28,7 @@
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/err.h>
+#include <linux/pm_runtime.h>
#include <linux/clk.h>
#include <linux/io.h>
@@ -165,7 +166,8 @@ static void activate_ch(struct sh_mobile_i2c_data *pd)
u_int32_t denom;
u_int32_t tmp;
- /* Make sure the clock is enabled */
+ /* Wake up device and enable clock */
+ pm_runtime_get_sync(pd->dev);
clk_enable(pd->clk);
/* Get clock rate after clock is enabled */
@@ -213,8 +215,9 @@ static void deactivate_ch(struct sh_mobile_i2c_data *pd)
/* Disable channel */
iowrite8(ioread8(ICCR(pd)) & ~ICCR_ICE, ICCR(pd));
- /* Disable clock */
+ /* Disable clock and mark device as idle */
clk_disable(pd->clk);
+ pm_runtime_put_sync(pd->dev);
}
static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
@@ -572,6 +575,19 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
goto err_irq;
}
+ /* Enable Runtime PM for this device.
+ *
+ * Also tell the Runtime PM core to ignore children
+ * for this device since it is valid for us to suspend
+ * this I2C master driver even though the slave devices
+ * on the I2C bus may not be suspended.
+ *
+ * The state of the I2C hardware bus is unaffected by
+ * the Runtime PM state.
+ */
+ pm_suspend_ignore_children(&dev->dev, true);
+ pm_runtime_enable(&dev->dev);
+
/* setup the private data */
adap = &pd->adap;
i2c_set_adapdata(adap, pd);
@@ -614,14 +630,33 @@ static int sh_mobile_i2c_remove(struct platform_device *dev)
iounmap(pd->reg);
sh_mobile_i2c_hook_irqs(dev, 0);
clk_put(pd->clk);
+ pm_runtime_disable(&dev->dev);
kfree(pd);
return 0;
}
+static int sh_mobile_i2c_runtime_nop(struct device *dev)
+{
+ /* Runtime PM callback shared between ->runtime_suspend()
+ * and ->runtime_resume(). Simply returns success.
+ *
+ * This driver re-initializes all registers after
+ * pm_runtime_get_sync() anyway so there is no need
+ * to save and restore registers here.
+ */
+ return 0;
+}
+
+static struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = {
+ .runtime_suspend = sh_mobile_i2c_runtime_nop,
+ .runtime_resume = sh_mobile_i2c_runtime_nop,
+};
+
static struct platform_driver sh_mobile_i2c_driver = {
.driver = {
.name = "i2c-sh_mobile",
.owner = THIS_MODULE,
+ .pm = &sh_mobile_i2c_dev_pm_ops,
},
.probe = sh_mobile_i2c_probe,
.remove = sh_mobile_i2c_remove,