xref: /freebsd/sys/dev/enetc/enetc_mdio.c (revision d0b2dbfa)
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/cdefs.h>
29 #include <sys/param.h>
30 #include <sys/bus.h>
31 #include <sys/endian.h>
32 #include <sys/kernel.h>
33 #include <sys/module.h>
34 #include <sys/rman.h>
35 
36 #include <machine/bus.h>
37 #include <machine/resource.h>
38 
39 #include <dev/enetc/enetc_hw.h>
40 #include <dev/enetc/enetc_mdio.h>
41 
42 #define ENETC_MDIO_RD4(regs, base, off) \
43 	bus_read_4((regs), (base) + (off))
44 #define ENETC_MDIO_WR4(regs, base, off, value) \
45 	bus_write_4((regs), (base) + (off), (value))
46 
47 static int
48 enetc_mdio_wait(struct resource *regs, int mdio_base)
49 {
50 	int i;
51 	uint32_t val;
52 
53 	i = 0;
54 	do {
55 		DELAY(100);
56 		val = ENETC_MDIO_RD4(regs, mdio_base, ENETC_MDIO_CFG);
57 		if ((val & MDIO_CFG_BSY) == 0)
58 			return (0);
59 	} while (i++ < ENETC_TIMEOUT);
60 
61 	return (ETIMEDOUT);
62 }
63 
64 int
65 enetc_mdio_read(struct resource *regs, int mdio_base, int phy, int reg)
66 {
67 	uint32_t mdio_cfg, mdio_ctl;
68 	uint16_t dev_addr;
69 
70 	mdio_cfg = MDIO_CFG_CLKDIV(ENETC_MDC_DIV) | MDIO_CFG_NEG;
71 	if (reg & MII_ADDR_C45) {
72 		/* clause 45 */
73 		dev_addr = (reg >> 16) & 0x1f;
74 		mdio_cfg |= MDIO_CFG_ENC45;
75 	} else {
76 		/* clause 22 */
77 		dev_addr = reg & 0x1f;
78 		mdio_cfg &= ~MDIO_CFG_ENC45;
79 	}
80 
81 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CFG, mdio_cfg);
82 
83 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
84 		return (EIO);
85 
86 	/* Set port and device addr. */
87 	mdio_ctl = MDIO_CTL_PORT_ADDR(phy) | MDIO_CTL_DEV_ADDR(dev_addr);
88 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CTL, mdio_ctl);
89 
90 	/* Set the register address. */
91 	if (reg & MII_ADDR_C45) {
92 		ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_ADDR, reg & 0xffff);
93 
94 		if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
95 			return (EIO);
96 	}
97 
98 	/* Initiate the read. */
99 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CTL, mdio_ctl | MDIO_CTL_READ);
100 
101 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
102 		return (EIO);
103 
104 	/* Check if any error occurred while reading PHY register. */
105 	if (ENETC_MDIO_RD4(regs, mdio_base, ENETC_MDIO_CFG) & MDIO_CFG_RD_ER)
106 		return (ENXIO);
107 
108 	return (MDIO_DATA(ENETC_MDIO_RD4(regs, mdio_base, ENETC_MDIO_DATA)));
109 }
110 
111 int
112 enetc_mdio_write(struct resource *regs, int mdio_base, int phy, int reg,
113     int data)
114 {
115 	uint32_t mdio_cfg, mdio_ctl;
116 	uint16_t dev_addr;
117 
118 	mdio_cfg = MDIO_CFG_CLKDIV(ENETC_MDC_DIV) | MDIO_CFG_NEG;
119 	if (reg & MII_ADDR_C45) {
120 		/* clause 45 */
121 		dev_addr = (reg >> 16) & 0x1f;
122 		mdio_cfg |= MDIO_CFG_ENC45;
123 	} else {
124 		/* clause 22 */
125 		dev_addr = reg & 0x1f;
126 		mdio_cfg &= ~MDIO_CFG_ENC45;
127 	}
128 
129 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CFG, mdio_cfg);
130 
131 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
132 		return (EIO);
133 
134 	/* Set port and device addr. */
135 	mdio_ctl = MDIO_CTL_PORT_ADDR(phy) | MDIO_CTL_DEV_ADDR(dev_addr);
136 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_CTL, mdio_ctl);
137 
138 	/* Set the register address. */
139 	if (reg & MII_ADDR_C45) {
140 		ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_ADDR, reg & 0xffff);
141 
142 		if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
143 			return (EIO);
144 	}
145 
146 	/* Write the value. */
147 	ENETC_MDIO_WR4(regs, mdio_base, ENETC_MDIO_DATA, MDIO_DATA(data));
148 
149 	if (enetc_mdio_wait(regs, mdio_base) == ETIMEDOUT)
150 		return (EIO);
151 
152 	return (0);
153 }
154