[2/4] ravb: Add optional PHY reset during system resume

Commit Message

Sergei Shtylyov Oct. 9, 2017, 12:50 p.m. UTC

On 10/09/2017 12:37 PM, Sergei Shtylyov wrote:

>>>>>>> If the optional "reset-gpios" property is specified in DT, the generic
>>>>>>> MDIO bus code takes care of resetting the PHY during device probe.
>>>>>>> However, the PHY may still have to be reset explicitly after system
>>>>>>> resume.
>>>>>>>
>>>>>>> This allows to restore Ethernet operation after resume from s2ram on
>>>>>>> Salvator-XS, where the enable pin of the regulator providing PHY power
>>>>>>> is connected to PRESETn, and PSCI suspend powers down the SoC.
>>>>>>>
>>>>>>> Signed-off-by: Geert Uytterhoeven <[e-mail]>
>>>>>>> ---
>>>>>>>    drivers/net/ethernet/renesas/ravb_main.c | 9 +++++++++
>>>>>>>    1 file changed, 9 insertions(+)
>>>>>>>
>>>>>>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c
>>>>>>> b/drivers/net/ethernet/renesas/ravb_main.c
>>>>>>> index fdf30bfa403bf416..96d1d48e302f8c9a 100644
>>>>>>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>>>>>>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>>> [...]
>>>>>>> @@ -2302,6 +2304,13 @@ static int __maybe_unused ravb_resume(struct
>>>>>>> device *dev)he patches
>>>>>>>          * reopen device if it was running before system suspended.
>>>>>>>          */
>>>>>>>
>>>>>>> +     /* PHY reset */
>>>>>>> +     if (bus->reset_gpiod) {
>>>>>>> +             gpiod_set_value_cansleep(bus->reset_gpiod, 1);
>>>>>>> +             udelay(bus->reset_delay_us);
>>>>>>> +             gpiod_set_value_cansleep(bus->reset_gpiod, 0);
>>>>>>> +     }
>>>>>>
>>>>>> This is a clever hack, but unfortunately this is also misusing the MDIO
>>>>>> bus reset line into a PHY reset line. As commented in patch 3, if this
>>>>>> reset line is tied to the PHY, then this should be a PHY property and
>>>>>
>>>>> OK.
>>>>>
>>>>>> you cannot (ab)use the MDIO bus GPIO reset logic anymore...
>>>>>
>>>>> And then I should add reset-gpios support to drivers/net/phy/micrel.c?
>>>>> Or is there already generic code to handle per-PHY reset? I couldn't
>>>>> find it.
>>>>
>>>> There is not such a thing unfortunately, but it would presumably be
>>>
>>>     It's strange you don't remember about my (abandoned) patches to
>>> handle per=PHY reset GPIOs -- perhaps it's time to unearth them. Here
>>> they are:
>>>
>>> http://patchwork.ozlabs.org/patch/616495/
>>> http://patchwork.ozlabs.org/patch/616501/
>>>
>>>     I had v3 in the works before abandoning this series -- it doesn't
>>> apply now.
>>
>> Should Geert pick-up where you left and address the feedback given in
>> v2, or do you plan to post a rebased v3?
> 
>     I was going to address the rejects in v3 and give the patchset to Geert... 
> unfortunately, this took so-o-o long. I'm going to do it today, at last.

    Here you are! Attaching both the patches against net-next.git...
Perhaps I also will be able to return to this subject in the near future...

MBR, Sergei

Patch

Subject: macb: kill PHY reset code

With  the phylib now  being aware of the "reset-gpios"  PHY node property,
there should  be no need to frob the PHY  reset in this driver anymore...

Signed-off-by: Sergei Shtylyov <[e-mail]>

---
Changes in version 3:
- resolved rejects due to the file being renamed, refreshed the patch;
- added the code to reset PHY on a probe error;
- edited the patch description.

 drivers/net/ethernet/cadence/macb.h      |    1 -
 drivers/net/ethernet/cadence/macb_main.c |   21 ---------------------
 2 files changed, 22 deletions(-)

Index: net-next/drivers/net/ethernet/cadence/macb.h
===================================================================
--- net-next.orig/drivers/net/ethernet/cadence/macb.h
+++ net-next/drivers/net/ethernet/cadence/macb.h
@@ -1032,7 +1032,6 @@  struct macb {
 	unsigned int		dma_burst_length;
 
 	phy_interface_t		phy_interface;
-	struct gpio_desc	*reset_gpio;
 
 	/* AT91RM9200 transmit */
 	struct sk_buff *skb;			/* holds skb until xmit interrupt completes */
Index: net-next/drivers/net/ethernet/cadence/macb_main.c
===================================================================
--- net-next.orig/drivers/net/ethernet/cadence/macb_main.c
+++ net-next/drivers/net/ethernet/cadence/macb_main.c
@@ -3393,7 +3393,6 @@  static int macb_probe(struct platform_de
 					      = macb_config->clk_init;
 	int (*init)(struct platform_device *) = macb_config->init;
 	struct device_node *np = pdev->dev.of_node;
-	struct device_node *phy_node;
 	struct clk *pclk, *hclk = NULL, *tx_clk = NULL, *rx_clk = NULL;
 	unsigned int queue_mask, num_queues;
 	struct macb_platform_data *pdata;
@@ -3499,18 +3498,6 @@  static int macb_probe(struct platform_de
 	else
 		macb_get_hwaddr(bp);
 
-	/* Power up the PHY if there is a GPIO reset */
-	phy_node =  of_get_next_available_child(np, NULL);
-	if (phy_node) {
-		int gpio = of_get_named_gpio(phy_node, "reset-gpios", 0);
-
-		if (gpio_is_valid(gpio)) {
-			bp->reset_gpio = gpio_to_desc(gpio);
-			gpiod_direction_output(bp->reset_gpio, 1);
-		}
-	}
-	of_node_put(phy_node);
-
 	err = of_get_phy_mode(np);
 	if (err < 0) {
 		pdata = dev_get_platdata(&pdev->dev);
@@ -3554,10 +3541,6 @@  err_out_unregister_mdio:
 	mdiobus_unregister(bp->mii_bus);
 	mdiobus_free(bp->mii_bus);
 
-	/* Shutdown the PHY if there is a GPIO reset */
-	if (bp->reset_gpio)
-		gpiod_set_value(bp->reset_gpio, 0);
-
 err_out_free_netdev:
 	free_netdev(dev);
 
@@ -3585,10 +3568,6 @@  static int macb_remove(struct platform_d
 		dev->phydev = NULL;
 		mdiobus_free(bp->mii_bus);
 
-		/* Shutdown the PHY if there is a GPIO reset */
-		if (bp->reset_gpio)
-			gpiod_set_value(bp->reset_gpio, 0);
-
 		unregister_netdev(dev);
 		clk_disable_unprepare(bp->tx_clk);
 		clk_disable_unprepare(bp->hclk);