xref: /freebsd/sys/dev/enetc/enetc_mdio.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/bus.h>
33 #include <sys/endian.h>
34 #include <sys/kernel.h>
35 #include <sys/module.h>
36 #include <sys/rman.h>
37 
38 #include <machine/bus.h>
39 #include <machine/resource.h>
40 
41 #include <dev/enetc/enetc_hw.h>
42 #include <dev/enetc/enetc_mdio.h>
43 
44 #define ENETC_MDIO_RD4(regs, base, off) \
45 	bus_read_4((regs), (base) + (off))
46 #define ENETC_MDIO_WR4(regs, base, off, value) \
47 	bus_write_4((regs), (base) + (off), (value))
48 
49 static int
50 enetc_mdio_wait(struct resource *regs, int mdio_base)
51 {
52 	int i;
53 	uint32_t val;
54 
55 	i = 0;
56 	do {
57 		DELAY(100);
58 		val = ENETC_MDIO_RD4(regs, mdio_base, ENETC_MDIO_CFG);
59 		if ((val & MDIO_CFG_BSY) == 0)
60 			return (0);
61 	} while (i++ < ENETC_TIMEOUT);
62 
63 	return (ETIMEDOUT);
64 }
65 
66 int
67 enetc_mdio_read(struct resource *regs, int mdio_base, int phy, int reg)
68 {
69 	uint32_t mdio_cfg, mdio_ctl;
70 	uint16_t dev_addr;
71 
72 	mdio_cfg = MDIO_CFG_CLKDIV(ENETC_MDC_DIV) | MDIO_CFG_NEG;
73 	if (reg & MII_ADDR_C45) {
74 		/* clause 45 */
75 		dev_addr = (reg >> 16) & 0x1f;
76 		mdio_cfg |= MDIO_CFG_ENC45;
77 	} else {
78 		/* clause 22 */
79 		dev_addr = reg & 0x1f;
80 		mdio_cfg &= ~MDIO_CFG_ENC45;
81 	}
82 
83 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CFG, mdio_cfg);
84 
85 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
86 		return (EIO);
87 
88 	/* Set port and device addr. */
89 	mdio_ctl = MDIO_CTL_PORT_ADDR(phy) | MDIO_CTL_DEV_ADDR(dev_addr);
90 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CTL, mdio_ctl);
91 
92 	/* Set the register address. */
93 	if (reg & MII_ADDR_C45) {
94 		ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_ADDR, reg & 0xffff);
95 
96 		if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
97 			return (EIO);
98 	}
99 
100 	/* Initiate the read. */
101 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CTL, mdio_ctl | MDIO_CTL_READ);
102 
103 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
104 		return (EIO);
105 
106 	/* Check if any error occurred while reading PHY register. */
107 	if (ENETC_MDIO_RD4(regs, mdio_base, ENETC_MDIO_CFG) & MDIO_CFG_RD_ER)
108 		return (ENXIO);
109 
110 	return (MDIO_DATA(ENETC_MDIO_RD4(regs, mdio_base, ENETC_MDIO_DATA)));
111 }
112 
113 int
114 enetc_mdio_write(struct resource *regs, int mdio_base, int phy, int reg,
115     int data)
116 {
117 	uint32_t mdio_cfg, mdio_ctl;
118 	uint16_t dev_addr;
119 
120 	mdio_cfg = MDIO_CFG_CLKDIV(ENETC_MDC_DIV) | MDIO_CFG_NEG;
121 	if (reg & MII_ADDR_C45) {
122 		/* clause 45 */
123 		dev_addr = (reg >> 16) & 0x1f;
124 		mdio_cfg |= MDIO_CFG_ENC45;
125 	} else {
126 		/* clause 22 */
127 		dev_addr = reg & 0x1f;
128 		mdio_cfg &= ~MDIO_CFG_ENC45;
129 	}
130 
131 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CFG, mdio_cfg);
132 
133 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
134 		return (EIO);
135 
136 	/* Set port and device addr. */
137 	mdio_ctl = MDIO_CTL_PORT_ADDR(phy) | MDIO_CTL_DEV_ADDR(dev_addr);
138 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CTL, mdio_ctl);
139 
140 	/* Set the register address. */
141 	if (reg & MII_ADDR_C45) {
142 		ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_ADDR, reg & 0xffff);
143 
144 		if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
145 			return (EIO);
146 	}
147 
148 	/* Write the value. */
149 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_DATA, MDIO_DATA(data));
150 
151 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
152 		return (EIO);
153 
154 	return (0);
155 }
156