diff mbox series

[RFC,next,v1,3/5] net: stmmac: use GPIO descriptors in stmmac_mdio_reset

Message ID 20190609180621.7607-4-martin.blumenstingl@googlemail.com (mailing list archive)
State Not Applicable
Headers show
Series stmmac: honor the GPIO flags for the PHY reset GPIO | expand

Commit Message

Martin Blumenstingl June 9, 2019, 6:06 p.m. UTC
Switch stmmac_mdio_reset to use GPIO descriptors. GPIO core handles the
"snps,reset-gpio" for GPIO descriptors so we don't need to take care of
it inside the driver anymore.

The advantage of this is that we now preserve the GPIO flags which are
passed via devicetree. This is required on some newer Amlogic boards
which use an Open Drain pin for the reset GPIO. This pin can only output
a LOW signal or switch to input mode but it cannot output a HIGH signal.
There are already devicetree bindings for these special cases and GPIO
core already takes care of them but only if we use GPIO descriptors
instead of GPIO numbers.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 .../net/ethernet/stmicro/stmmac/stmmac_mdio.c | 27 +++++++++----------
 1 file changed, 13 insertions(+), 14 deletions(-)

Comments

Andrew Lunn June 9, 2019, 8:52 p.m. UTC | #1
> +		struct gpio_desc *reset_gpio;
> +
>  		if (data->reset_gpio < 0) {
>  			struct device_node *np = priv->device->of_node;
>  
> -			data->reset_gpio = of_get_named_gpio(np,
> -						"snps,reset-gpio", 0);
> -			if (data->reset_gpio < 0)
> -				return 0;
> +			reset_gpio = devm_gpiod_get_optional(priv->device,
> +							     "snps,reset",
> +							     GPIOD_OUT_LOW);
> +			if (IS_ERR(reset_gpio))
> +				return PTR_ERR(reset_gpio);
>  
> -			data->active_low = of_property_read_bool(np,
> -						"snps,reset-active-low");

Hi Martin

I think you need to keep this here. You can then use it to decide how
to change gpio_desc to remove flags that should be ignored.

   Andrew
Linus Walleij June 9, 2019, 9:50 p.m. UTC | #2
On Sun, Jun 9, 2019 at 8:06 PM Martin Blumenstingl
<martin.blumenstingl@googlemail.com> wrote:

> Switch stmmac_mdio_reset to use GPIO descriptors. GPIO core handles the
> "snps,reset-gpio" for GPIO descriptors so we don't need to take care of
> it inside the driver anymore.
>
> The advantage of this is that we now preserve the GPIO flags which are
> passed via devicetree. This is required on some newer Amlogic boards
> which use an Open Drain pin for the reset GPIO. This pin can only output
> a LOW signal or switch to input mode but it cannot output a HIGH signal.
> There are already devicetree bindings for these special cases and GPIO
> core already takes care of them but only if we use GPIO descriptors
> instead of GPIO numbers.
>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

This is in line with how I want the gpiolib to just swallow all quirks,
so:
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij
diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index cb9aad090cc9..21bbe3ba3e8e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -20,11 +20,11 @@ 
   Maintainer: Giuseppe Cavallaro <peppe.cavallaro@st.com>
 *******************************************************************************/
 
+#include <linux/gpio/consumer.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/mii.h>
 #include <linux/of.h>
-#include <linux/of_gpio.h>
 #include <linux/of_mdio.h>
 #include <linux/phy.h>
 #include <linux/slab.h>
@@ -251,34 +251,33 @@  int stmmac_mdio_reset(struct mii_bus *bus)
 
 #ifdef CONFIG_OF
 	if (priv->device->of_node) {
+		struct gpio_desc *reset_gpio;
+
 		if (data->reset_gpio < 0) {
 			struct device_node *np = priv->device->of_node;
 
-			data->reset_gpio = of_get_named_gpio(np,
-						"snps,reset-gpio", 0);
-			if (data->reset_gpio < 0)
-				return 0;
+			reset_gpio = devm_gpiod_get_optional(priv->device,
+							     "snps,reset",
+							     GPIOD_OUT_LOW);
+			if (IS_ERR(reset_gpio))
+				return PTR_ERR(reset_gpio);
 
-			data->active_low = of_property_read_bool(np,
-						"snps,reset-active-low");
 			of_property_read_u32_array(np,
 				"snps,reset-delays-us", data->delays, 3);
+		} else {
+			reset_gpio = gpio_to_desc(data->reset_gpio);
 
-			if (devm_gpio_request(priv->device, data->reset_gpio,
-					      "mdio-reset"))
-				return 0;
+			gpiod_direction_output(reset_gpio, 0);
 		}
 
-		gpio_direction_output(data->reset_gpio,
-				      data->active_low ? 1 : 0);
 		if (data->delays[0])
 			msleep(DIV_ROUND_UP(data->delays[0], 1000));
 
-		gpio_set_value(data->reset_gpio, data->active_low ? 0 : 1);
+		gpiod_set_value_cansleep(reset_gpio, 1);
 		if (data->delays[1])
 			msleep(DIV_ROUND_UP(data->delays[1], 1000));
 
-		gpio_set_value(data->reset_gpio, data->active_low ? 1 : 0);
+		gpiod_set_value_cansleep(reset_gpio, 0);
 		if (data->delays[2])
 			msleep(DIV_ROUND_UP(data->delays[2], 1000));
 	}