drivers: net: davinci_mdio: implement pm runtime auto mode
Davinci MDIO is always used as slave device which services
read/write requests from MDIO/PHY core. It doesn't use IRQ also.
As result, It's possible to relax PM runtime constraints for Davinci
MDIO and enable it on demand, instead of powering it during probe
and powering off during removal.
Hence, implement PM runtime autosuspend for Davinci MDIO, but keep it
disabled by default, because Davinci MDIO is integrated in big set of
TI devices and not all of them expected to work corectly with RPM
autosuspend enabled:
- expected to work on SoCs where MDIO is part of TI CPSW
(cpsw.c DRA7/am57x, am437x, am335x, dm814x)
- not verified on Keystone 2 and other SoCs where MDIO is used with TI EMAC IP
(davinci_emac.c: dm6467-emac, am3517-emac, dm816-emac).
Davinci MDIO RPM autosuspend can be enabled through sysfs:
echo 100 > /sys/devices/../48484000.ethernet/48485000.mdio/power/autosuspend_delay_ms
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
index 13f5080..ce3ec42 100644
--- a/drivers/net/ethernet/ti/davinci_mdio.c
+++ b/drivers/net/ethernet/ti/davinci_mdio.c
@@ -93,6 +93,7 @@
struct clk *clk;
struct device *dev;
struct mii_bus *bus;
+ bool active_in_suspend;
unsigned long access_time; /* jiffies */
/* Indicates that driver shouldn't modify phy_mask in case
* if MDIO bus is registered from DT.
@@ -141,8 +142,13 @@
{
struct davinci_mdio_data *data = bus->priv;
u32 phy_mask, ver;
+ int ret;
- davinci_mdio_enable(data);
+ ret = pm_runtime_get_sync(data->dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(data->dev);
+ return ret;
+ }
/* wait for scan logic to settle */
msleep(PHY_MAX_ADDR * data->access_time);
@@ -153,7 +159,7 @@
(ver >> 8) & 0xff, ver & 0xff);
if (data->skip_scan)
- return 0;
+ goto done;
/* get phy mask from the alive register */
phy_mask = __raw_readl(&data->regs->alive);
@@ -168,6 +174,10 @@
}
data->bus->phy_mask = phy_mask;
+done:
+ pm_runtime_mark_last_busy(data->dev);
+ pm_runtime_put_autosuspend(data->dev);
+
return 0;
}
@@ -228,6 +238,12 @@
if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
return -EINVAL;
+ ret = pm_runtime_get_sync(data->dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(data->dev);
+ return ret;
+ }
+
reg = (USERACCESS_GO | USERACCESS_READ | (phy_reg << 21) |
(phy_id << 16));
@@ -251,6 +267,8 @@
break;
}
+ pm_runtime_mark_last_busy(data->dev);
+ pm_runtime_put_autosuspend(data->dev);
return ret;
}
@@ -264,6 +282,12 @@
if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
return -EINVAL;
+ ret = pm_runtime_get_sync(data->dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(data->dev);
+ return ret;
+ }
+
reg = (USERACCESS_GO | USERACCESS_WRITE | (phy_reg << 21) |
(phy_id << 16) | (phy_data & USERACCESS_DATA));
@@ -282,7 +306,10 @@
break;
}
- return 0;
+ pm_runtime_mark_last_busy(data->dev);
+ pm_runtime_put_autosuspend(data->dev);
+
+ return ret;
}
#if IS_ENABLED(CONFIG_OF)
@@ -357,8 +384,9 @@
davinci_mdio_init_clk(data);
+ pm_runtime_set_autosuspend_delay(&pdev->dev, -1);
+ pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_enable(&pdev->dev);
- pm_runtime_get_sync(&pdev->dev);
/* register the mii bus
* Create PHYs from DT only in case if PHY child nodes are explicitly
@@ -387,9 +415,8 @@
return 0;
bail_out:
- pm_runtime_put_sync(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
pm_runtime_disable(&pdev->dev);
-
return ret;
}
@@ -400,7 +427,7 @@
if (data->bus)
mdiobus_unregister(data->bus);
- pm_runtime_put_sync(&pdev->dev);
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return 0;
@@ -436,7 +463,9 @@
struct davinci_mdio_data *data = dev_get_drvdata(dev);
int ret = 0;
- ret = pm_runtime_force_suspend(dev);
+ data->active_in_suspend = !pm_runtime_status_suspended(dev);
+ if (data->active_in_suspend)
+ ret = pm_runtime_force_suspend(dev);
if (ret < 0)
return ret;
@@ -453,7 +482,8 @@
/* Select default pin state */
pinctrl_pm_select_default_state(dev);
- pm_runtime_force_resume(dev);
+ if (data->active_in_suspend)
+ pm_runtime_force_resume(dev);
return 0;
}