* [PATCH v2] i2c: iproc: Add suspend/resume support
2015-05-14 22:36 [PATCH v2] Add suspend/resume support to the iProc I2C driver Ray Jui
@ 2015-05-14 22:36 ` Ray Jui
[not found] ` <1431642964-6948-2-git-send-email-rjui-dY08KVG/lbpWk0Htik3J/w@public.gmane.org>
0 siblings, 1 reply; 3+ messages in thread
From: Ray Jui @ 2015-05-14 22:36 UTC (permalink / raw)
To: Wolfram Sang; +Cc: linux-i2c, linux-kernel, bcm-kernel-feedback-list, Ray Jui
Add suspend/resume support to the Broadcom iProc I2C driver
Signed-off-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
---
drivers/i2c/busses/i2c-bcm-iproc.c | 57 ++++++++++++++++++++++++++++++++++++
1 file changed, 57 insertions(+)
diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
index f9f2c20..0419f52 100644
--- a/drivers/i2c/busses/i2c-bcm-iproc.c
+++ b/drivers/i2c/busses/i2c-bcm-iproc.c
@@ -91,6 +91,7 @@ struct bcm_iproc_i2c_dev {
void __iomem *base;
struct i2c_adapter adapter;
+ unsigned int bus_speed;
struct completion done;
int xfer_is_done;
@@ -309,6 +310,7 @@ static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
bus_speed = 400000;
}
+ iproc_i2c->bus_speed = bus_speed;
val = readl(iproc_i2c->base + TIM_CFG_OFFSET);
val &= ~(1 << TIM_CFG_MODE_400_SHIFT);
val |= (bus_speed == 400000) << TIM_CFG_MODE_400_SHIFT;
@@ -439,6 +441,60 @@ static int bcm_iproc_i2c_remove(struct platform_device *pdev)
return 0;
}
+#ifdef CONFIG_PM_SLEEP
+
+static int bcm_iproc_i2c_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
+
+ /* make sure there's no pending interrupt when we go into suspend */
+ writel(0, iproc_i2c->base + IE_OFFSET);
+ readl(iproc_i2c->base + IE_OFFSET);
+ synchronize_irq(iproc_i2c->irq);
+
+ /* now disable the controller */
+ bcm_iproc_i2c_enable_disable(iproc_i2c, false);
+
+ return 0;
+}
+
+static int bcm_iproc_i2c_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
+ int ret;
+ u32 val;
+
+ /*
+ * Power domain could have been shut off completely in system deep
+ * sleep, so re-initialize the block here
+ */
+ ret = bcm_iproc_i2c_init(iproc_i2c);
+ if (ret)
+ return ret;
+
+ /* configure to the desired bus speed */
+ val = readl(iproc_i2c->base + TIM_CFG_OFFSET);
+ val &= ~(1 << TIM_CFG_MODE_400_SHIFT);
+ val |= (iproc_i2c->bus_speed == 400000) << TIM_CFG_MODE_400_SHIFT;
+ writel(val, iproc_i2c->base + TIM_CFG_OFFSET);
+
+ bcm_iproc_i2c_enable_disable(iproc_i2c, true);
+
+ return 0;
+}
+
+static const struct dev_pm_ops bcm_iproc_i2c_pm_ops = {
+ .suspend_late = &bcm_iproc_i2c_suspend,
+ .resume_early = &bcm_iproc_i2c_resume
+};
+
+#define BCM_IPROC_I2C_PM_OPS (&bcm_iproc_i2c_pm_ops)
+#else
+#define BCM_IPROC_I2C_PM_OPS NULL
+#endif /* CONFIG_PM_SLEEP */
+
static const struct of_device_id bcm_iproc_i2c_of_match[] = {
{ .compatible = "brcm,iproc-i2c" },
{ /* sentinel */ }
@@ -449,6 +505,7 @@ static struct platform_driver bcm_iproc_i2c_driver = {
.driver = {
.name = "bcm-iproc-i2c",
.of_match_table = bcm_iproc_i2c_of_match,
+ .pm = BCM_IPROC_I2C_PM_OPS,
},
.probe = bcm_iproc_i2c_probe,
.remove = bcm_iproc_i2c_remove,
--
1.7.9.5
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