RE: [PATCH 2/3] net: mdio-gpio: Add support for active low gpio pins

From: Chris Healy
Date: Tue Apr 15 2014 - 22:50:33 EST


Some systems using mdio-gpio may use active-low gpio pins
(eg with inverters or FETs connected to all or some of the
gpio pins).

Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Tested-by: Chris Healy <cphealy@xxxxxxxxx>
---
drivers/net/phy/mdio-gpio.c | 19 +++++++++++++------
include/linux/mdio-gpio.h | 3 +++
2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/net/phy/mdio-gpio.c b/drivers/net/phy/mdio-gpio.c
index e853066..fac211a 100644
--- a/drivers/net/phy/mdio-gpio.c
+++ b/drivers/net/phy/mdio-gpio.c
@@ -33,28 +33,32 @@
struct mdio_gpio_info {
struct mdiobb_ctrl ctrl;
int mdc, mdio;
+ int mdc_active_low, mdio_active_low;
};

static void *mdio_gpio_of_get_data(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct mdio_gpio_platform_data *pdata;
+ enum of_gpio_flags flags;
int ret;

pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return NULL;

- ret = of_get_gpio(np, 0);
+ ret = of_get_gpio_flags(np, 0, &flags);
if (ret < 0)
return NULL;

pdata->mdc = ret;
+ pdata->mdc_active_low = flags & OF_GPIO_ACTIVE_LOW;

- ret = of_get_gpio(np, 1);
+ ret = of_get_gpio_flags(np, 1, &flags);
if (ret < 0)
return NULL;
pdata->mdio = ret;
+ pdata->mdio_active_low = flags & OF_GPIO_ACTIVE_LOW;

return pdata;
}
@@ -65,7 +69,8 @@ static void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
container_of(ctrl, struct mdio_gpio_info, ctrl);

if (dir)
- gpio_direction_output(bitbang->mdio, 1);
+ gpio_direction_output(bitbang->mdio,
+ 1 ^ bitbang->mdio_active_low);
else
gpio_direction_input(bitbang->mdio);
}
@@ -75,7 +80,7 @@ static int mdio_get(struct mdiobb_ctrl *ctrl)
struct mdio_gpio_info *bitbang =
container_of(ctrl, struct mdio_gpio_info, ctrl);

- return gpio_get_value(bitbang->mdio);
+ return gpio_get_value(bitbang->mdio) ^ bitbang->mdio_active_low;
}

static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
@@ -83,7 +88,7 @@ static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
struct mdio_gpio_info *bitbang =
container_of(ctrl, struct mdio_gpio_info, ctrl);

- gpio_set_value(bitbang->mdio, what);
+ gpio_set_value(bitbang->mdio, what ^ bitbang->mdio_active_low);
}

static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
@@ -91,7 +96,7 @@ static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
struct mdio_gpio_info *bitbang =
container_of(ctrl, struct mdio_gpio_info, ctrl);

- gpio_set_value(bitbang->mdc, what);
+ gpio_set_value(bitbang->mdc, what ^ bitbang->mdc_active_low);
}

static struct mdiobb_ops mdio_gpio_ops = {
@@ -117,7 +122,9 @@ static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
bitbang->ctrl.ops = &mdio_gpio_ops;
bitbang->ctrl.reset = pdata->reset;
bitbang->mdc = pdata->mdc;
+ bitbang->mdc_active_low = pdata->mdc_active_low;
bitbang->mdio = pdata->mdio;
+ bitbang->mdio_active_low = pdata->mdio_active_low;

new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
if (!new_bus)
diff --git a/include/linux/mdio-gpio.h b/include/linux/mdio-gpio.h
index 7c9fe3c..57e57fe 100644
--- a/include/linux/mdio-gpio.h
+++ b/include/linux/mdio-gpio.h
@@ -18,6 +18,9 @@ struct mdio_gpio_platform_data {
unsigned int mdc;
unsigned int mdio;

+ bool mdc_active_low;
+ bool mdio_active_low;
+
unsigned int phy_mask;
int irqs[PHY_MAX_ADDR];
/* reset callback */
--
1.7.9.7


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