From: Andrew Lunn <and...@lunn.ch>
SMI0 is a mangled version of MDIO. The main low level difference is
the MDIO C22 OP code is always 0, not 0x2 or 0x1 for Read/Write. The
read/write information is instead encoded in the PHY address.
Extend the bit-bang code to allow the op code to be overridden, but
default to normal C22 values. Add an extra compatible to the mdio-gpio
driver, and when this compatible is present, set the op codes to 0.
A higher level driver, sitting on top of the basic MDIO bus driver can
then implement the rest of the microchip SMI0 odderties.
Signed-off-by: Andrew Lunn <and...@lunn.ch>
Signed-off-by: Michael Grzeschik <m.grzesc...@pengutronix.de>
---
drivers/net/phy/mdio-bitbang.c | 7 ++-----
drivers/net/phy/mdio-gpio.c | 13 +++++++++++++
include/linux/mdio-bitbang.h | 2 ++
3 files changed, 17 insertions(+), 5 deletions(-)
diff --git a/drivers/net/phy/mdio-bitbang.c b/drivers/net/phy/mdio-bitbang.c
index 5136275c8e7399..11255460ecb933 100644
--- a/drivers/net/phy/mdio-bitbang.c
+++ b/drivers/net/phy/mdio-bitbang.c
@@ -19,9 +19,6 @@
#include <linux/types.h>
#include <linux/delay.h>
-#define MDIO_READ 2
-#define MDIO_WRITE 1
-
#define MDIO_C45 (1<<15)
#define MDIO_C45_ADDR (MDIO_C45 | 0)
#define MDIO_C45_READ (MDIO_C45 | 3)
@@ -158,7 +155,7 @@ static int mdiobb_read(struct mii_bus *bus, int phy, int
reg)
reg = mdiobb_cmd_addr(ctrl, phy, reg);
mdiobb_cmd(ctrl, MDIO_C45_READ, phy, reg);
} else
- mdiobb_cmd(ctrl, MDIO_READ, phy, reg);
+ mdiobb_cmd(ctrl, ctrl->op_c22_read, phy, reg);
ctrl->ops->set_mdio_dir(ctrl, 0);
@@ -189,7 +186,7 @@ static int mdiobb_write(struct mii_bus *bus, int phy, int
reg, u16 val)
reg = mdiobb_cmd_addr(ctrl, phy, reg);
mdiobb_cmd(ctrl, MDIO_C45_WRITE, phy, reg);
} else
- mdiobb_cmd(ctrl, MDIO_WRITE, phy, reg);
+ mdiobb_cmd(ctrl, ctrl->op_c22_write, phy, reg);
/* send the turnaround (10) */
mdiobb_send_bit(ctrl, 1);
diff --git a/drivers/net/phy/mdio-gpio.c b/drivers/net/phy/mdio-gpio.c
index 1b00235d7dc5b5..d85bc1a98647e2 100644
--- a/drivers/net/phy/mdio-gpio.c
+++ b/drivers/net/phy/mdio-gpio.c
@@ -27,6 +27,9 @@
#include <linux/gpio/consumer.h>
#include <linux/of_mdio.h>
+#define MDIO_READ 2
+#define MDIO_WRITE 1
+
struct mdio_gpio_info {
struct mdiobb_ctrl ctrl;
struct gpio_desc *mdc, *mdio, *mdo;
@@ -132,6 +135,15 @@ static struct mii_bus *mdio_gpio_bus_init(struct device
*dev,
new_bus->phy_ignore_ta_mask = pdata->phy_ignore_ta_mask;
}
+ if (dev->of_node &&
+ of_device_is_compatible(dev->of_node, "microchip,mdio-smi0")) {
+ bitbang->ctrl.op_c22_read = 0;
+ bitbang->ctrl.op_c22_write = 0;
+ } else {
+ bitbang->ctrl.op_c22_read = MDIO_READ;
+ bitbang->ctrl.op_c22_write = MDIO_WRITE;
+ }
+
dev_set_drvdata(dev, new_bus);
return new_bus;
@@ -196,6 +208,7 @@ static int mdio_gpio_remove(struct platform_device *pdev)
static const struct of_device_id mdio_gpio_of_match[] = {
{ .compatible = "virtual,mdio-gpio", },
+ { .compatible = "microchip,mdio-smi0" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mdio_gpio_of_match);
diff --git a/include/linux/mdio-bitbang.h b/include/linux/mdio-bitbang.h
index 5d71e8a8500f5e..8ae0b383523371 100644
--- a/include/linux/mdio-bitbang.h
+++ b/include/linux/mdio-bitbang.h
@@ -33,6 +33,8 @@ struct mdiobb_ops {
struct mdiobb_ctrl {
const struct mdiobb_ops *ops;
+ u8 op_c22_read;
+ u8 op_c22_write;
};
/* The returned bus is not yet registered with the phy layer. */
--
2.26.2
