xref: /freebsd/sys/dev/enetc/enetc_mdio.c (revision fdafd315ad0d0f28a11b9fb4476a9ab059c62b92)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2021 Alstom Group.
5  * Copyright (c) 2021 Semihalf.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/param.h>
29 #include <sys/bus.h>
30 #include <sys/endian.h>
31 #include <sys/kernel.h>
32 #include <sys/module.h>
33 #include <sys/rman.h>
34 
35 #include <machine/bus.h>
36 #include <machine/resource.h>
37 
38 #include <dev/enetc/enetc_hw.h>
39 #include <dev/enetc/enetc_mdio.h>
40 
41 #define ENETC_MDIO_RD4(regs, base, off) \
42 	bus_read_4((regs), (base) + (off))
43 #define ENETC_MDIO_WR4(regs, base, off, value) \
44 	bus_write_4((regs), (base) + (off), (value))
45 
46 static int
enetc_mdio_wait(struct resource * regs,int mdio_base)47 enetc_mdio_wait(struct resource *regs, int mdio_base)
48 {
49 	int i;
50 	uint32_t val;
51 
52 	i = 0;
53 	do {
54 		DELAY(100);
55 		val = ENETC_MDIO_RD4(regs, mdio_base, ENETC_MDIO_CFG);
56 		if ((val & MDIO_CFG_BSY) == 0)
57 			return (0);
58 	} while (i++ < ENETC_TIMEOUT);
59 
60 	return (ETIMEDOUT);
61 }
62 
63 int
enetc_mdio_read(struct resource * regs,int mdio_base,int phy,int reg)64 enetc_mdio_read(struct resource *regs, int mdio_base, int phy, int reg)
65 {
66 	uint32_t mdio_cfg, mdio_ctl;
67 	uint16_t dev_addr;
68 
69 	mdio_cfg = MDIO_CFG_CLKDIV(ENETC_MDC_DIV) | MDIO_CFG_NEG;
70 	if (reg & MII_ADDR_C45) {
71 		/* clause 45 */
72 		dev_addr = (reg >> 16) & 0x1f;
73 		mdio_cfg |= MDIO_CFG_ENC45;
74 	} else {
75 		/* clause 22 */
76 		dev_addr = reg & 0x1f;
77 		mdio_cfg &= ~MDIO_CFG_ENC45;
78 	}
79 
80 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CFG, mdio_cfg);
81 
82 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
83 		return (EIO);
84 
85 	/* Set port and device addr. */
86 	mdio_ctl = MDIO_CTL_PORT_ADDR(phy) | MDIO_CTL_DEV_ADDR(dev_addr);
87 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CTL, mdio_ctl);
88 
89 	/* Set the register address. */
90 	if (reg & MII_ADDR_C45) {
91 		ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_ADDR, reg & 0xffff);
92 
93 		if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
94 			return (EIO);
95 	}
96 
97 	/* Initiate the read. */
98 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CTL, mdio_ctl | MDIO_CTL_READ);
99 
100 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
101 		return (EIO);
102 
103 	/* Check if any error occurred while reading PHY register. */
104 	if (ENETC_MDIO_RD4(regs, mdio_base, ENETC_MDIO_CFG) & MDIO_CFG_RD_ER)
105 		return (ENXIO);
106 
107 	return (MDIO_DATA(ENETC_MDIO_RD4(regs, mdio_base, ENETC_MDIO_DATA)));
108 }
109 
110 int
enetc_mdio_write(struct resource * regs,int mdio_base,int phy,int reg,int data)111 enetc_mdio_write(struct resource *regs, int mdio_base, int phy, int reg,
112     int data)
113 {
114 	uint32_t mdio_cfg, mdio_ctl;
115 	uint16_t dev_addr;
116 
117 	mdio_cfg = MDIO_CFG_CLKDIV(ENETC_MDC_DIV) | MDIO_CFG_NEG;
118 	if (reg & MII_ADDR_C45) {
119 		/* clause 45 */
120 		dev_addr = (reg >> 16) & 0x1f;
121 		mdio_cfg |= MDIO_CFG_ENC45;
122 	} else {
123 		/* clause 22 */
124 		dev_addr = reg & 0x1f;
125 		mdio_cfg &= ~MDIO_CFG_ENC45;
126 	}
127 
128 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CFG, mdio_cfg);
129 
130 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
131 		return (EIO);
132 
133 	/* Set port and device addr. */
134 	mdio_ctl = MDIO_CTL_PORT_ADDR(phy) | MDIO_CTL_DEV_ADDR(dev_addr);
135 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CTL, mdio_ctl);
136 
137 	/* Set the register address. */
138 	if (reg & MII_ADDR_C45) {
139 		ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_ADDR, reg & 0xffff);
140 
141 		if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
142 			return (EIO);
143 	}
144 
145 	/* Write the value. */
146 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_DATA, MDIO_DATA(data));
147 
148 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
149 		return (EIO);
150 
151 	return (0);
152 }
153