1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2012
4 * Dirk Eibach, Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
5 */
6
7 #include <common.h>
8 #include <asm/io.h>
9 #include <errno.h>
10
11 #include <gdsys_fpga.h>
12
13 enum {
14 MCINT_SLAVE_LINK_CHANGED_EV = 1 << 7,
15 MCINT_TX_ERROR_EV = 1 << 9,
16 MCINT_TX_BUFFER_FREE = 1 << 10,
17 MCINT_TX_PACKET_TRANSMITTED_EV = 1 << 11,
18 MCINT_RX_ERROR_EV = 1 << 13,
19 MCINT_RX_CONTENT_AVAILABLE = 1 << 14,
20 MCINT_RX_PACKET_RECEIVED_EV = 1 << 15,
21 };
22
mclink_probe(void)23 int mclink_probe(void)
24 {
25 unsigned int k;
26 int slaves = 0;
27
28 for (k = 0; k < CONFIG_SYS_MCLINK_MAX; ++k) {
29 int timeout = 0;
30 unsigned int ctr = 0;
31 u16 mc_status;
32
33 FPGA_GET_REG(k, mc_status, &mc_status);
34
35 if (!(mc_status & (1 << 15)))
36 break;
37
38 FPGA_SET_REG(k, mc_control, 0x8000);
39
40 FPGA_GET_REG(k, mc_status, &mc_status);
41 while (!(mc_status & (1 << 14))) {
42 udelay(100);
43 if (ctr++ > 500) {
44 timeout = 1;
45 break;
46 }
47 FPGA_GET_REG(k, mc_status, &mc_status);
48 }
49 if (timeout)
50 break;
51
52 printf("waited %d us for mclink %d to come up\n", ctr * 100, k);
53
54 slaves++;
55 }
56
57 return slaves;
58 }
59
mclink_send(u8 slave,u16 addr,u16 data)60 int mclink_send(u8 slave, u16 addr, u16 data)
61 {
62 unsigned int ctr = 0;
63 u16 int_status;
64 u16 rx_cmd_status;
65 u16 rx_cmd;
66
67 /* reset interrupt status */
68 FPGA_GET_REG(0, mc_int, &int_status);
69 FPGA_SET_REG(0, mc_int, int_status);
70
71 /* send */
72 FPGA_SET_REG(0, mc_tx_address, addr);
73 FPGA_SET_REG(0, mc_tx_data, data);
74 FPGA_SET_REG(0, mc_tx_cmd, (slave & 0x03) << 14);
75 FPGA_SET_REG(0, mc_control, 0x8001);
76
77 /* wait for reply */
78 FPGA_GET_REG(0, mc_int, &int_status);
79 while (!(int_status & MCINT_RX_PACKET_RECEIVED_EV)) {
80 udelay(100);
81 if (ctr++ > 3)
82 return -ETIMEDOUT;
83 FPGA_GET_REG(0, mc_int, &int_status);
84 }
85
86 FPGA_GET_REG(0, mc_rx_cmd_status, &rx_cmd_status);
87 rx_cmd = (rx_cmd_status >> 12) & 0x03;
88 if (rx_cmd != 0)
89 printf("mclink_send: received cmd %d, expected %d\n", rx_cmd,
90 0);
91
92 return 0;
93 }
94
mclink_receive(u8 slave,u16 addr,u16 * data)95 int mclink_receive(u8 slave, u16 addr, u16 *data)
96 {
97 u16 rx_cmd_status;
98 u16 rx_cmd;
99 u16 int_status;
100 unsigned int ctr = 0;
101
102 /* send read request */
103 FPGA_SET_REG(0, mc_tx_address, addr);
104 FPGA_SET_REG(0, mc_tx_cmd,
105 ((slave & 0x03) << 14) | (1 << 12) | (1 << 0));
106 FPGA_SET_REG(0, mc_control, 0x8001);
107
108
109 /* wait for reply */
110 FPGA_GET_REG(0, mc_int, &int_status);
111 while (!(int_status & MCINT_RX_CONTENT_AVAILABLE)) {
112 udelay(100);
113 if (ctr++ > 3)
114 return -ETIMEDOUT;
115 FPGA_GET_REG(0, mc_int, &int_status);
116 }
117
118 /* check reply */
119 FPGA_GET_REG(0, mc_rx_cmd_status, &rx_cmd_status);
120 if ((rx_cmd_status >> 14) != slave) {
121 printf("mclink_receive: reply from slave %d, expected %d\n",
122 rx_cmd_status >> 14, slave);
123 return -EINVAL;
124 }
125
126 rx_cmd = (rx_cmd_status >> 12) & 0x03;
127 if (rx_cmd != 1) {
128 printf("mclink_send: received cmd %d, expected %d\n",
129 rx_cmd, 1);
130 return -EIO;
131 }
132
133 FPGA_GET_REG(0, mc_rx_data, data);
134
135 return 0;
136 }
137