1 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
2 /*
3 * Copyright (c) 2018 Microsemi Corporation
4 */
5
6 #include <log.h>
7 #include <linux/bitops.h>
8 #include <linux/delay.h>
9 #include <linux/io.h>
10 #include "mscc_xfer.h"
11
12 #define QS_XTR_FLUSH_FLUSH GENMASK(1, 0)
13 #define QS_INJ_CTRL_GAP_SIZE(x) ((x) << 21)
14 #define QS_INJ_CTRL_EOF BIT(19)
15 #define QS_INJ_CTRL_SOF BIT(18)
16 #define QS_INJ_CTRL_VLD_BYTES(x) ((x) << 16)
17
18 #define XTR_EOF_0 ntohl(0x80000000u)
19 #define XTR_EOF_1 ntohl(0x80000001u)
20 #define XTR_EOF_2 ntohl(0x80000002u)
21 #define XTR_EOF_3 ntohl(0x80000003u)
22 #define XTR_PRUNED ntohl(0x80000004u)
23 #define XTR_ABORT ntohl(0x80000005u)
24 #define XTR_ESCAPE ntohl(0x80000006u)
25 #define XTR_NOT_READY ntohl(0x80000007u)
26
27 #define BUF_CELL_SZ 60
28 #define XTR_VALID_BYTES(x) (4 - ((x) & 3))
29
mscc_send(void __iomem * regs,const unsigned long * mscc_qs_offset,u32 * ifh,size_t ifh_len,u32 * buff,size_t buff_len)30 int mscc_send(void __iomem *regs, const unsigned long *mscc_qs_offset,
31 u32 *ifh, size_t ifh_len, u32 *buff, size_t buff_len)
32 {
33 int i, count = (buff_len + 3) / 4, last = buff_len % 4;
34
35 writel(QS_INJ_CTRL_GAP_SIZE(1) | QS_INJ_CTRL_SOF,
36 regs + mscc_qs_offset[MSCC_QS_INJ_CTRL]);
37
38 for (i = 0; i < ifh_len; i++)
39 writel(ifh[i], regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
40
41 for (i = 0; i < count; i++)
42 writel(buff[i], regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
43
44 /* Add padding */
45 while (i < (BUF_CELL_SZ / 4)) {
46 writel(0, regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
47 i++;
48 }
49
50 /* Indicate EOF and valid bytes in last word */
51 writel(QS_INJ_CTRL_GAP_SIZE(1) |
52 QS_INJ_CTRL_VLD_BYTES(buff_len < BUF_CELL_SZ ? 0 : last) |
53 QS_INJ_CTRL_EOF, regs + mscc_qs_offset[MSCC_QS_INJ_CTRL]);
54
55 /* Add dummy CRC */
56 writel(0, regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
57
58 return 0;
59 }
60
mscc_recv(void __iomem * regs,const unsigned long * mscc_qs_offset,u32 * rxbuf,size_t ifh_len,bool byte_swap)61 int mscc_recv(void __iomem *regs, const unsigned long *mscc_qs_offset,
62 u32 *rxbuf, size_t ifh_len, bool byte_swap)
63 {
64 u8 grp = 0; /* Recv everything on CPU group 0 */
65 int i, byte_cnt = 0;
66 bool eof_flag = false, pruned_flag = false, abort_flag = false;
67
68 if (!(readl(regs + mscc_qs_offset[MSCC_QS_XTR_DATA_PRESENT]) &
69 BIT(grp)))
70 return -EAGAIN;
71
72 /* skip IFH */
73 for (i = 0; i < ifh_len; i++)
74 readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
75
76 while (!eof_flag) {
77 u32 val = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
78 u32 cmp = val;
79
80 if (byte_swap)
81 cmp = ntohl(val);
82
83 switch (cmp) {
84 case XTR_NOT_READY:
85 debug("%d NOT_READY...?\n", byte_cnt);
86 break;
87 case XTR_ABORT:
88 *rxbuf = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
89 abort_flag = true;
90 eof_flag = true;
91 debug("XTR_ABORT\n");
92 break;
93 case XTR_EOF_0:
94 case XTR_EOF_1:
95 case XTR_EOF_2:
96 case XTR_EOF_3:
97 byte_cnt += XTR_VALID_BYTES(val);
98 *rxbuf = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
99 eof_flag = true;
100 debug("EOF\n");
101 break;
102 case XTR_PRUNED:
103 /* But get the last 4 bytes as well */
104 eof_flag = true;
105 pruned_flag = true;
106 debug("PRUNED\n");
107 /* fallthrough */
108 case XTR_ESCAPE:
109 *rxbuf = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
110 byte_cnt += 4;
111 rxbuf++;
112 debug("ESCAPED\n");
113 break;
114 default:
115 *rxbuf = val;
116 byte_cnt += 4;
117 rxbuf++;
118 }
119 }
120
121 if (abort_flag || pruned_flag || !eof_flag) {
122 debug("Discarded frame: abort:%d pruned:%d eof:%d\n",
123 abort_flag, pruned_flag, eof_flag);
124 return -EAGAIN;
125 }
126
127 return byte_cnt;
128 }
129
mscc_flush(void __iomem * regs,const unsigned long * mscc_qs_offset)130 void mscc_flush(void __iomem *regs, const unsigned long *mscc_qs_offset)
131 {
132 /* All Queues flush */
133 setbits_le32(regs + mscc_qs_offset[MSCC_QS_XTR_FLUSH],
134 QS_XTR_FLUSH_FLUSH);
135
136 /* Allow to drain */
137 mdelay(1);
138
139 /* All Queues normal */
140 clrbits_le32(regs + mscc_qs_offset[MSCC_QS_XTR_FLUSH],
141 QS_XTR_FLUSH_FLUSH);
142 }
143