1 // SPDX-License-Identifier: GPL-2.0
17 #include <linux/module.h>
18 #include <linux/mdio-bitbang.h>
44 static void mdiobb_send_bit(struct mdiobb_ctrl *ctrl, int val)  in mdiobb_send_bit()  argument
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()
56 static int mdiobb_get_bit(struct mdiobb_ctrl *ctrl)  in mdiobb_get_bit()  argument
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()
69 static void mdiobb_send_num(struct mdiobb_ctrl *ctrl, u16 val, int bits)  in mdiobb_send_num()  argument
73 	for (i = bits - 1; i >= 0; i--)  in mdiobb_send_num()
74 		mdiobb_send_bit(ctrl, (val >> i) & 1);  in mdiobb_send_num()
78 static u16 mdiobb_get_num(struct mdiobb_ctrl *ctrl, int bits)  in mdiobb_get_num()  argument
83 	for (i = bits - 1; i >= 0; i--) {  in mdiobb_get_num()
85 		ret |= mdiobb_get_bit(ctrl);  in mdiobb_get_num()
94 static void mdiobb_cmd(struct mdiobb_ctrl *ctrl, int op, u8 phy, u8 reg)  in mdiobb_cmd()  argument
96 	const struct mdiobb_ops *ops = ctrl->ops;  in mdiobb_cmd()
99 	ops->set_mdio_dir(ctrl, 1);  in mdiobb_cmd()
111 		mdiobb_send_bit(ctrl, 1);  in mdiobb_cmd()
116 	mdiobb_send_bit(ctrl, 0);  in mdiobb_cmd()
118 		mdiobb_send_bit(ctrl, 0);  in mdiobb_cmd()
120 		mdiobb_send_bit(ctrl, 1);  in mdiobb_cmd()
121 	mdiobb_send_bit(ctrl, (op >> 1) & 1);  in mdiobb_cmd()
122 	mdiobb_send_bit(ctrl, (op >> 0) & 1);  in mdiobb_cmd()
124 	mdiobb_send_num(ctrl, phy, 5);  in mdiobb_cmd()
125 	mdiobb_send_num(ctrl, reg, 5);  in mdiobb_cmd()
134 static int mdiobb_cmd_addr(struct mdiobb_ctrl *ctrl, int phy, u32 addr)  in mdiobb_cmd_addr()  argument
138 	mdiobb_cmd(ctrl, MDIO_C45_ADDR, phy, dev_addr);  in mdiobb_cmd_addr()
141 	mdiobb_send_bit(ctrl, 1);  in mdiobb_cmd_addr()
142 	mdiobb_send_bit(ctrl, 0);  in mdiobb_cmd_addr()
144 	mdiobb_send_num(ctrl, reg, 16);  in mdiobb_cmd_addr()
146 	ctrl->ops->set_mdio_dir(ctrl, 0);  in mdiobb_cmd_addr()
147 	mdiobb_get_bit(ctrl);  in mdiobb_cmd_addr()
154 	struct mdiobb_ctrl *ctrl = bus->priv;  in mdiobb_read()  local
158 		reg = mdiobb_cmd_addr(ctrl, phy, reg);  in mdiobb_read()
159 		mdiobb_cmd(ctrl, MDIO_C45_READ, phy, reg);  in mdiobb_read()
161 		mdiobb_cmd(ctrl, MDIO_READ, phy, reg);  in mdiobb_read()
163 	ctrl->ops->set_mdio_dir(ctrl, 0);  in mdiobb_read()
168 	if (mdiobb_get_bit(ctrl) != 0 &&  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()
174 			mdiobb_get_bit(ctrl);  in mdiobb_read()
179 	ret = mdiobb_get_num(ctrl, 16);  in mdiobb_read()
180 	mdiobb_get_bit(ctrl);  in mdiobb_read()
186 	struct mdiobb_ctrl *ctrl = bus->priv;  in mdiobb_write()  local
189 		reg = mdiobb_cmd_addr(ctrl, phy, reg);  in mdiobb_write()
190 		mdiobb_cmd(ctrl, MDIO_C45_WRITE, phy, reg);  in mdiobb_write()
192 		mdiobb_cmd(ctrl, MDIO_WRITE, phy, reg);  in mdiobb_write()
195 	mdiobb_send_bit(ctrl, 1);  in mdiobb_write()
196 	mdiobb_send_bit(ctrl, 0);  in mdiobb_write()
198 	mdiobb_send_num(ctrl, val, 16);  in mdiobb_write()
200 	ctrl->ops->set_mdio_dir(ctrl, 0);  in mdiobb_write()
201 	mdiobb_get_bit(ctrl);  in mdiobb_write()
205 struct mii_bus *alloc_mdio_bitbang(struct mdiobb_ctrl *ctrl)  in alloc_mdio_bitbang()  argument
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()
225 	struct mdiobb_ctrl *ctrl = bus->priv;  in free_mdio_bitbang()  local
227 	module_put(ctrl->ops->owner);  in free_mdio_bitbang()