i2c: riic: Enable runtime PM autosuspend support

Enable runtime PM autosuspend support for the RIIC driver. With this, in
case there are consecutive xfer requests the device wouldn't be runtime
enabled/disabled after each consecutive xfer but after the
the delay configured by user. With this, we can avoid touching hardware
registers involved in runtime PM suspend/resume saving in this way some
cycles. The default chosen autosuspend delay is zero to keep the
previous driver behavior.

Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>

diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index 6fc41bde2ec2b116c5c631b824bcfd85608b832b..ec854a525a0b6e923844e558b42777f510987f76 100644 (file)
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -171,7 +171,8 @@ static int riic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
        }
 
  out:
-       pm_runtime_put(dev);
+       pm_runtime_mark_last_busy(dev);
+       pm_runtime_put_autosuspend(dev);
 
        return riic->err ?: num;
 }
@@ -399,7 +400,8 @@ static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
 
        riic_clear_set_bit(riic, ICCR1_IICRST, 0, RIIC_ICCR1);
 
-       pm_runtime_put(dev);
+       pm_runtime_mark_last_busy(dev);
+       pm_runtime_put_autosuspend(dev);
        return 0;
 }
 
@@ -479,6 +481,9 @@ static int riic_i2c_probe(struct platform_device *pdev)
 
        i2c_parse_fw_timings(dev, &i2c_t, true);
 
+       /* Default 0 to save power. Can be overridden via sysfs for lower latency. */
+       pm_runtime_set_autosuspend_delay(dev, 0);
+       pm_runtime_use_autosuspend(dev);
        pm_runtime_enable(dev);
 
        ret = riic_init_hw(riic, &i2c_t);
@@ -496,6 +501,7 @@ static int riic_i2c_probe(struct platform_device *pdev)
 
 out:
        pm_runtime_disable(dev);
+       pm_runtime_dont_use_autosuspend(dev);
        return ret;
 }
 
@@ -512,6 +518,7 @@ static void riic_i2c_remove(struct platform_device *pdev)
        }
        i2c_del_adapter(&riic->adapter);
        pm_runtime_disable(dev);
+       pm_runtime_dont_use_autosuspend(dev);
 }
 
 static const struct riic_of_data riic_rz_a_info = {