@@ -37,6 +37,8 @@
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of.h>
+#include <linux/clk.h>
+#include <linux/pm_runtime.h>
#define DRIVER_NAME "xiic-i2c"
@@ -66,6 +68,7 @@ enum xiic_endian {
* @endianness: big/little-endian byte order
*/
struct xiic_i2c {
+ struct device *dev;
void __iomem *base;
wait_queue_head_t wait;
struct i2c_adapter adap;
@@ -77,6 +80,7 @@ struct xiic_i2c {
struct i2c_msg *rx_msg;
int rx_pos;
enum xiic_endian endianness;
+ struct clk *clk;
};
@@ -164,6 +168,7 @@ struct xiic_i2c {
#define XIIC_RESET_MASK 0xAUL
+#define XIIC_PM_TIMEOUT 1000 /* ms */
/*
* The following constant is used for the device global interrupt enable
* register, to enable all interrupts for the device, this is the only bit
@@ -676,9 +681,13 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
dev_dbg(adap->dev.parent, "%s entry SR: 0x%x\n", __func__,
xiic_getreg8(i2c, XIIC_SR_REG_OFFSET));
+ err = pm_runtime_get_sync(i2c->dev);
+ if (err < 0)
+ return err;
+
err = xiic_busy(i2c);
if (err)
- return err;
+ goto out;
i2c->tx_msg = msgs;
i2c->nmsgs = num;
@@ -686,14 +695,20 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
xiic_start_xfer(i2c);
if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) ||
- (i2c->state == STATE_DONE), HZ))
- return (i2c->state == STATE_DONE) ? num : -EIO;
- else {
+ (i2c->state == STATE_DONE), HZ)) {
+ err = (i2c->state == STATE_DONE) ? num : -EIO;
+ goto out;
+ } else {
i2c->tx_msg = NULL;
i2c->rx_msg = NULL;
i2c->nmsgs = 0;
- return -ETIMEDOUT;
+ err = -ETIMEDOUT;
+ goto out;
}
+out:
+ pm_runtime_mark_last_busy(i2c->dev);
+ pm_runtime_put_autosuspend(i2c->dev);
+ return err;
}
static u32 xiic_func(struct i2c_adapter *adap)
@@ -748,13 +763,28 @@ static int xiic_i2c_probe(struct platform_device *pdev)
mutex_init(&i2c->lock);
init_waitqueue_head(&i2c->wait);
+ i2c->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(i2c->clk)) {
+ dev_err(&pdev->dev, "input clock not found.\n");
+ return PTR_ERR(i2c->clk);
+ }
+ ret = clk_prepare_enable(i2c->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Unable to enable clock.\n");
+ return ret;
+ }
+ i2c->dev = &pdev->dev;
+ pm_runtime_enable(i2c->dev);
+ pm_runtime_set_autosuspend_delay(i2c->dev, XIIC_PM_TIMEOUT);
+ pm_runtime_use_autosuspend(i2c->dev);
+ pm_runtime_set_active(i2c->dev);
ret = devm_request_threaded_irq(&pdev->dev, irq, xiic_isr,
xiic_process, IRQF_ONESHOT,
pdev->name, i2c);
if (ret < 0) {
dev_err(&pdev->dev, "Cannot claim IRQ\n");
- return ret;
+ goto err_clk_dis;
}
/*
@@ -776,7 +806,7 @@ static int xiic_i2c_probe(struct platform_device *pdev)
if (ret) {
dev_err(&pdev->dev, "Failed to add adapter\n");
xiic_deinit(i2c);
- return ret;
+ goto err_clk_dis;
}
if (pdata) {
@@ -786,16 +816,30 @@ static int xiic_i2c_probe(struct platform_device *pdev)
}
return 0;
+
+err_clk_dis:
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+ clk_disable_unprepare(i2c->clk);
+ return ret;
}
static int xiic_i2c_remove(struct platform_device *pdev)
{
struct xiic_i2c *i2c = platform_get_drvdata(pdev);
+ int ret;
/* remove adapter & data */
i2c_del_adapter(&i2c->adap);
+ ret = clk_prepare_enable(i2c->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Unable to enable clock.\n");
+ return ret;
+ }
xiic_deinit(i2c);
+ clk_disable_unprepare(i2c->clk);
+ pm_runtime_disable(&pdev->dev);
return 0;
}
@@ -808,12 +852,42 @@ static const struct of_device_id xiic_of_match[] = {
MODULE_DEVICE_TABLE(of, xiic_of_match);
#endif
+static int __maybe_unused cdns_i2c_runtime_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct xiic_i2c *i2c = platform_get_drvdata(pdev);
+
+ clk_disable(i2c->clk);
+
+ return 0;
+}
+
+static int __maybe_unused cdns_i2c_runtime_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct xiic_i2c *i2c = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = clk_enable(i2c->clk);
+ if (ret) {
+ dev_err(dev, "Cannot enable clock.\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct dev_pm_ops xiic_dev_pm_ops = {
+ SET_RUNTIME_PM_OPS(cdns_i2c_runtime_suspend,
+ cdns_i2c_runtime_resume, NULL)
+};
static struct platform_driver xiic_i2c_driver = {
.probe = xiic_i2c_probe,
.remove = xiic_i2c_remove,
.driver = {
.name = DRIVER_NAME,
.of_match_table = of_match_ptr(xiic_of_match),
+ .pm = &xiic_dev_pm_ops,
},
};
Enable power management. This patch enables the clocks before transfer and disables after the transfer. Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com> --- drivers/i2c/busses/i2c-xiic.c | 88 +++++++++++++++++++++++++++++++++++++--- 1 files changed, 81 insertions(+), 7 deletions(-)