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()
131    devices can exist on the same bus. Normal devices should ignore the MDIO_ADDR
138 	/* send the turnaround (10) */  in mdiobb_cmd_addr()
144 	ctrl->ops->set_mdio_dir(ctrl, 0);  in mdiobb_cmd_addr()
148 static int mdiobb_read_common(struct mii_bus *bus, int phy)  in mdiobb_read_common()  argument
150 	struct mdiobb_ctrl *ctrl = bus->priv;  in mdiobb_read_common()
153 	ctrl->ops->set_mdio_dir(ctrl, 0);  in mdiobb_read_common()
155 	/* check the turnaround bit: the PHY should be driving it to zero, if this  in mdiobb_read_common()
159 	    !(bus->phy_ignore_ta_mask & (1 << phy))) {  in mdiobb_read_common()
160 		/* PHY didn't drive TA low -- flush any bits it  in mdiobb_read_common()
174 int mdiobb_read_c22(struct mii_bus *bus, int phy, int reg)  in mdiobb_read_c22()  argument
176 	struct mdiobb_ctrl *ctrl = bus->priv;  in mdiobb_read_c22()
178 	mdiobb_cmd(ctrl, ctrl->op_c22_read, phy, reg);  in mdiobb_read_c22()
180 	return mdiobb_read_common(bus, phy);  in mdiobb_read_c22()
184 int mdiobb_read_c45(struct mii_bus *bus, int phy, int devad, int reg)  in mdiobb_read_c45()  argument
186 	struct mdiobb_ctrl *ctrl = bus->priv;  in mdiobb_read_c45()
191 	return mdiobb_read_common(bus, phy);  in mdiobb_read_c45()
195 static int mdiobb_write_common(struct mii_bus *bus, u16 val)  in mdiobb_write_common()  argument
197 	struct mdiobb_ctrl *ctrl = bus->priv;  in mdiobb_write_common()
199 	/* send the turnaround (10) */  in mdiobb_write_common()
205 	ctrl->ops->set_mdio_dir(ctrl, 0);  in mdiobb_write_common()
210 int mdiobb_write_c22(struct mii_bus *bus, int phy, int reg, u16 val)  in mdiobb_write_c22()  argument
212 	struct mdiobb_ctrl *ctrl = bus->priv;  in mdiobb_write_c22()
214 	mdiobb_cmd(ctrl, ctrl->op_c22_write, phy, reg);  in mdiobb_write_c22()
216 	return mdiobb_write_common(bus, val);  in mdiobb_write_c22()
220 int mdiobb_write_c45(struct mii_bus *bus, int phy, int devad, int reg, u16 val)  in mdiobb_write_c45()  argument
222 	struct mdiobb_ctrl *ctrl = bus->priv;  in mdiobb_write_c45()
227 	return mdiobb_write_common(bus, val);  in mdiobb_write_c45()
233 	struct mii_bus *bus;  in alloc_mdio_bitbang()  local
235 	bus = mdiobus_alloc();  in alloc_mdio_bitbang()
236 	if (!bus)  in alloc_mdio_bitbang()
239 	__module_get(ctrl->ops->owner);  in alloc_mdio_bitbang()
241 	bus->read = mdiobb_read_c22;  in alloc_mdio_bitbang()
242 	bus->write = mdiobb_write_c22;  in alloc_mdio_bitbang()
243 	bus->read_c45 = mdiobb_read_c45;  in alloc_mdio_bitbang()
244 	bus->write_c45 = mdiobb_write_c45;  in alloc_mdio_bitbang()
246 	bus->priv = ctrl;  in alloc_mdio_bitbang()
247 	if (!ctrl->override_op_c22) {  in alloc_mdio_bitbang()
248 		ctrl->op_c22_read = MDIO_READ;  in alloc_mdio_bitbang()
249 		ctrl->op_c22_write = MDIO_WRITE;  in alloc_mdio_bitbang()
252 	return bus;  in alloc_mdio_bitbang()
256 void free_mdio_bitbang(struct mii_bus *bus)  in free_mdio_bitbang()  argument
258 	struct mdiobb_ctrl *ctrl = bus->priv;  in free_mdio_bitbang()
260 	module_put(ctrl->ops->owner);  in free_mdio_bitbang()
261 	mdiobus_free(bus);  in free_mdio_bitbang()