xref: /openbmc/linux/drivers/net/mdio/mdio-cavium.c (revision 0bf49ffb)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2009-2016 Cavium, Inc.
4  */
5 
6 #include <linux/delay.h>
7 #include <linux/module.h>
8 #include <linux/phy.h>
9 #include <linux/io.h>
10 
11 #include "mdio-cavium.h"
12 
13 static void cavium_mdiobus_set_mode(struct cavium_mdiobus *p,
14 				    enum cavium_mdiobus_mode m)
15 {
16 	union cvmx_smix_clk smi_clk;
17 
18 	if (m == p->mode)
19 		return;
20 
21 	smi_clk.u64 = oct_mdio_readq(p->register_base + SMI_CLK);
22 	smi_clk.s.mode = (m == C45) ? 1 : 0;
23 	smi_clk.s.preamble = 1;
24 	oct_mdio_writeq(smi_clk.u64, p->register_base + SMI_CLK);
25 	p->mode = m;
26 }
27 
28 static int cavium_mdiobus_c45_addr(struct cavium_mdiobus *p,
29 				   int phy_id, int regnum)
30 {
31 	union cvmx_smix_cmd smi_cmd;
32 	union cvmx_smix_wr_dat smi_wr;
33 	int timeout = 1000;
34 
35 	cavium_mdiobus_set_mode(p, C45);
36 
37 	smi_wr.u64 = 0;
38 	smi_wr.s.dat = regnum & 0xffff;
39 	oct_mdio_writeq(smi_wr.u64, p->register_base + SMI_WR_DAT);
40 
41 	regnum = (regnum >> 16) & 0x1f;
42 
43 	smi_cmd.u64 = 0;
44 	smi_cmd.s.phy_op = 0; /* MDIO_CLAUSE_45_ADDRESS */
45 	smi_cmd.s.phy_adr = phy_id;
46 	smi_cmd.s.reg_adr = regnum;
47 	oct_mdio_writeq(smi_cmd.u64, p->register_base + SMI_CMD);
48 
49 	do {
50 		/* Wait 1000 clocks so we don't saturate the RSL bus
51 		 * doing reads.
52 		 */
53 		__delay(1000);
54 		smi_wr.u64 = oct_mdio_readq(p->register_base + SMI_WR_DAT);
55 	} while (smi_wr.s.pending && --timeout);
56 
57 	if (timeout <= 0)
58 		return -EIO;
59 	return 0;
60 }
61 
62 int cavium_mdiobus_read(struct mii_bus *bus, int phy_id, int regnum)
63 {
64 	struct cavium_mdiobus *p = bus->priv;
65 	union cvmx_smix_cmd smi_cmd;
66 	union cvmx_smix_rd_dat smi_rd;
67 	unsigned int op = 1; /* MDIO_CLAUSE_22_READ */
68 	int timeout = 1000;
69 
70 	if (regnum & MII_ADDR_C45) {
71 		int r = cavium_mdiobus_c45_addr(p, phy_id, regnum);
72 
73 		if (r < 0)
74 			return r;
75 
76 		regnum = (regnum >> 16) & 0x1f;
77 		op = 3; /* MDIO_CLAUSE_45_READ */
78 	} else {
79 		cavium_mdiobus_set_mode(p, C22);
80 	}
81 
82 	smi_cmd.u64 = 0;
83 	smi_cmd.s.phy_op = op;
84 	smi_cmd.s.phy_adr = phy_id;
85 	smi_cmd.s.reg_adr = regnum;
86 	oct_mdio_writeq(smi_cmd.u64, p->register_base + SMI_CMD);
87 
88 	do {
89 		/* Wait 1000 clocks so we don't saturate the RSL bus
90 		 * doing reads.
91 		 */
92 		__delay(1000);
93 		smi_rd.u64 = oct_mdio_readq(p->register_base + SMI_RD_DAT);
94 	} while (smi_rd.s.pending && --timeout);
95 
96 	if (smi_rd.s.val)
97 		return smi_rd.s.dat;
98 	else
99 		return -EIO;
100 }
101 EXPORT_SYMBOL(cavium_mdiobus_read);
102 
103 int cavium_mdiobus_write(struct mii_bus *bus, int phy_id, int regnum, u16 val)
104 {
105 	struct cavium_mdiobus *p = bus->priv;
106 	union cvmx_smix_cmd smi_cmd;
107 	union cvmx_smix_wr_dat smi_wr;
108 	unsigned int op = 0; /* MDIO_CLAUSE_22_WRITE */
109 	int timeout = 1000;
110 
111 	if (regnum & MII_ADDR_C45) {
112 		int r = cavium_mdiobus_c45_addr(p, phy_id, regnum);
113 
114 		if (r < 0)
115 			return r;
116 
117 		regnum = (regnum >> 16) & 0x1f;
118 		op = 1; /* MDIO_CLAUSE_45_WRITE */
119 	} else {
120 		cavium_mdiobus_set_mode(p, C22);
121 	}
122 
123 	smi_wr.u64 = 0;
124 	smi_wr.s.dat = val;
125 	oct_mdio_writeq(smi_wr.u64, p->register_base + SMI_WR_DAT);
126 
127 	smi_cmd.u64 = 0;
128 	smi_cmd.s.phy_op = op;
129 	smi_cmd.s.phy_adr = phy_id;
130 	smi_cmd.s.reg_adr = regnum;
131 	oct_mdio_writeq(smi_cmd.u64, p->register_base + SMI_CMD);
132 
133 	do {
134 		/* Wait 1000 clocks so we don't saturate the RSL bus
135 		 * doing reads.
136 		 */
137 		__delay(1000);
138 		smi_wr.u64 = oct_mdio_readq(p->register_base + SMI_WR_DAT);
139 	} while (smi_wr.s.pending && --timeout);
140 
141 	if (timeout <= 0)
142 		return -EIO;
143 
144 	return 0;
145 }
146 EXPORT_SYMBOL(cavium_mdiobus_write);
147 
148 MODULE_DESCRIPTION("Common code for OCTEON and Thunder MDIO bus drivers");
149 MODULE_AUTHOR("David Daney");
150 MODULE_LICENSE("GPL v2");
151