1 // SPDX-License-Identifier: GPL-2.0
18 #include <linux/mdio-bitbang.h>
33 /* Minimum MDC period is 400 ns, plus some margin for error.  MDIO_DELAY
38 /* The PHY may take up to 300 ns to produce data, plus some margin
46 	const struct mdiobb_ops *ops = ctrl->ops;  in mdiobb_send_bit()
48 	ops->set_mdio_data(ctrl, val);  in mdiobb_send_bit()
50 	ops->set_mdc(ctrl, 1);  in mdiobb_send_bit()
52 	ops->set_mdc(ctrl, 0);  in mdiobb_send_bit()
58 	const struct mdiobb_ops *ops = ctrl->ops;  in mdiobb_get_bit()
61 	ops->set_mdc(ctrl, 1);  in mdiobb_get_bit()
63 	ops->set_mdc(ctrl, 0);  in mdiobb_get_bit()
65 	return ops->get_mdio_data(ctrl);  in mdiobb_get_bit()
73 	for (i = bits - 1; i >= 0; i--)  in mdiobb_send_num()
83 	for (i = bits - 1; i >= 0; i--) {  in mdiobb_get_num()
96 	const struct mdiobb_ops *ops = ctrl->ops;  in mdiobb_cmd()
99 	ops->set_mdio_dir(ctrl, 1);  in mdiobb_cmd()
132    can exist on the same bus. Normal devices should ignore the MDIO_ADDR
140 	/* send the turnaround (10) */  in mdiobb_cmd_addr()
146 	ctrl->ops->set_mdio_dir(ctrl, 0);  in mdiobb_cmd_addr()
152 static int mdiobb_read(struct mii_bus *bus, int phy, int reg)  in mdiobb_read()  argument
154 	struct mdiobb_ctrl *ctrl = bus->priv;  in mdiobb_read()
163 	ctrl->ops->set_mdio_dir(ctrl, 0);  in mdiobb_read()
165 	/* check the turnaround bit: the PHY should be driving it to zero, if this  in mdiobb_read()
169 	    !(bus->phy_ignore_ta_mask & (1 << phy))) {  in mdiobb_read()
170 		/* PHY didn't drive TA low -- flush any bits it  in mdiobb_read()
184 static int mdiobb_write(struct mii_bus *bus, int phy, int reg, u16 val)  in mdiobb_write()  argument
186 	struct mdiobb_ctrl *ctrl = bus->priv;  in mdiobb_write()
194 	/* send the turnaround (10) */  in mdiobb_write()
200 	ctrl->ops->set_mdio_dir(ctrl, 0);  in mdiobb_write()
207 	struct mii_bus *bus;  in alloc_mdio_bitbang()  local
209 	bus = mdiobus_alloc();  in alloc_mdio_bitbang()
210 	if (!bus)  in alloc_mdio_bitbang()
213 	__module_get(ctrl->ops->owner);  in alloc_mdio_bitbang()
215 	bus->read = mdiobb_read;  in alloc_mdio_bitbang()
216 	bus->write = mdiobb_write;  in alloc_mdio_bitbang()
217 	bus->priv = ctrl;  in alloc_mdio_bitbang()
219 	return bus;  in alloc_mdio_bitbang()
223 void free_mdio_bitbang(struct mii_bus *bus)  in free_mdio_bitbang()  argument
225 	struct mdiobb_ctrl *ctrl = bus->priv;  in free_mdio_bitbang()
227 	module_put(ctrl->ops->owner);  in free_mdio_bitbang()
228 	mdiobus_free(bus);  in free_mdio_bitbang()