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1/* SPDX-License-Identifier: BSD-3-Clause */
2/*
3 * Copyright (C) 2023 OpenSynergy GmbH
4 * Copyright (C) 2025 Qualcomm Innovation Center, Inc. All rights reserved.
5 */
6#ifndef _LINUX_VIRTIO_VIRTIO_SPI_H
7#define _LINUX_VIRTIO_VIRTIO_SPI_H
8
9#include <linux/types.h>
10#include <linux/virtio_config.h>
11#include <linux/virtio_ids.h>
12#include <linux/virtio_types.h>
13
14/* Sample data on trailing clock edge */
15#define VIRTIO_SPI_CPHA _BITUL(0)
16/* Clock is high when IDLE */
17#define VIRTIO_SPI_CPOL _BITUL(1)
18/* Chip Select is active high */
19#define VIRTIO_SPI_CS_HIGH _BITUL(2)
20/* Transmit LSB first */
21#define VIRTIO_SPI_MODE_LSB_FIRST _BITUL(3)
22/* Loopback mode */
23#define VIRTIO_SPI_MODE_LOOP _BITUL(4)
24
25/**
26 * struct virtio_spi_config - All config fields are read-only for the
27 * Virtio SPI driver
28 * @cs_max_number: maximum number of chipselect the host SPI controller
29 * supports.
30 * @cs_change_supported: indicates if the host SPI controller supports to toggle
31 * chipselect after each transfer in one message:
32 * 0: unsupported, chipselect will be kept in active state throughout the
33 * message transaction;
34 * 1: supported.
35 * Note: Message here contains a sequence of SPI transfers.
36 * @tx_nbits_supported: indicates the supported number of bit for writing:
37 * bit 0: DUAL (2-bit transfer), 1 for supported
38 * bit 1: QUAD (4-bit transfer), 1 for supported
39 * bit 2: OCTAL (8-bit transfer), 1 for supported
40 * other bits are reserved as 0, 1-bit transfer is always supported.
41 * @rx_nbits_supported: indicates the supported number of bit for reading:
42 * bit 0: DUAL (2-bit transfer), 1 for supported
43 * bit 1: QUAD (4-bit transfer), 1 for supported
44 * bit 2: OCTAL (8-bit transfer), 1 for supported
45 * other bits are reserved as 0, 1-bit transfer is always supported.
46 * @bits_per_word_mask: mask indicating which values of bits_per_word are
47 * supported. If not set, no limitation for bits_per_word.
48 * @mode_func_supported: indicates the following features are supported or not:
49 * bit 0-1: CPHA feature
50 * 0b00: invalid, should support as least one CPHA setting
51 * 0b01: supports CPHA=0 only
52 * 0b10: supports CPHA=1 only
53 * 0b11: supports CPHA=0 and CPHA=1.
54 * bit 2-3: CPOL feature
55 * 0b00: invalid, should support as least one CPOL setting
56 * 0b01: supports CPOL=0 only
57 * 0b10: supports CPOL=1 only
58 * 0b11: supports CPOL=0 and CPOL=1.
59 * bit 4: chipselect active high feature, 0 for unsupported and 1 for
60 * supported, chipselect active low is supported by default.
61 * bit 5: LSB first feature, 0 for unsupported and 1 for supported,
62 * MSB first is supported by default.
63 * bit 6: loopback mode feature, 0 for unsupported and 1 for supported,
64 * normal mode is supported by default.
65 * @max_freq_hz: the maximum clock rate supported in Hz unit, 0 means no
66 * limitation for transfer speed.
67 * @max_word_delay_ns: the maximum word delay supported, in nanoseconds.
68 * A value of 0 indicates that word delay is unsupported.
69 * Each transfer may consist of a sequence of words.
70 * @max_cs_setup_ns: the maximum delay supported after chipselect is asserted,
71 * in ns unit, 0 means delay is not supported to introduce after chipselect is
72 * asserted.
73 * @max_cs_hold_ns: the maximum delay supported before chipselect is deasserted,
74 * in ns unit, 0 means delay is not supported to introduce before chipselect
75 * is deasserted.
76 * @max_cs_incative_ns: maximum delay supported after chipselect is deasserted,
77 * in ns unit, 0 means delay is not supported to introduce after chipselect is
78 * deasserted.
79 */
80struct virtio_spi_config {
81 __u8 cs_max_number;
82 __u8 cs_change_supported;
83#define VIRTIO_SPI_RX_TX_SUPPORT_DUAL _BITUL(0)
84#define VIRTIO_SPI_RX_TX_SUPPORT_QUAD _BITUL(1)
85#define VIRTIO_SPI_RX_TX_SUPPORT_OCTAL _BITUL(2)
86 __u8 tx_nbits_supported;
87 __u8 rx_nbits_supported;
88 __le32 bits_per_word_mask;
89#define VIRTIO_SPI_MF_SUPPORT_CPHA_0 _BITUL(0)
90#define VIRTIO_SPI_MF_SUPPORT_CPHA_1 _BITUL(1)
91#define VIRTIO_SPI_MF_SUPPORT_CPOL_0 _BITUL(2)
92#define VIRTIO_SPI_MF_SUPPORT_CPOL_1 _BITUL(3)
93#define VIRTIO_SPI_MF_SUPPORT_CS_HIGH _BITUL(4)
94#define VIRTIO_SPI_MF_SUPPORT_LSB_FIRST _BITUL(5)
95#define VIRTIO_SPI_MF_SUPPORT_LOOPBACK _BITUL(6)
96 __le32 mode_func_supported;
97 __le32 max_freq_hz;
98 __le32 max_word_delay_ns;
99 __le32 max_cs_setup_ns;
100 __le32 max_cs_hold_ns;
101 __le32 max_cs_inactive_ns;
102};
103
104/**
105 * struct spi_transfer_head - virtio SPI transfer descriptor
106 * @chip_select_id: chipselect index the SPI transfer used.
107 * @bits_per_word: the number of bits in each SPI transfer word.
108 * @cs_change: whether to deselect device after finishing this transfer
109 * before starting the next transfer, 0 means cs keep asserted and
110 * 1 means cs deasserted then asserted again.
111 * @tx_nbits: bus width for write transfer.
112 * 0,1: bus width is 1, also known as SINGLE
113 * 2 : bus width is 2, also known as DUAL
114 * 4 : bus width is 4, also known as QUAD
115 * 8 : bus width is 8, also known as OCTAL
116 * other values are invalid.
117 * @rx_nbits: bus width for read transfer.
118 * 0,1: bus width is 1, also known as SINGLE
119 * 2 : bus width is 2, also known as DUAL
120 * 4 : bus width is 4, also known as QUAD
121 * 8 : bus width is 8, also known as OCTAL
122 * other values are invalid.
123 * @reserved: for future use.
124 * @mode: SPI transfer mode.
125 * bit 0: CPHA, determines the timing (i.e. phase) of the data
126 * bits relative to the clock pulses.For CPHA=0, the
127 * "out" side changes the data on the trailing edge of the
128 * preceding clock cycle, while the "in" side captures the data
129 * on (or shortly after) the leading edge of the clock cycle.
130 * For CPHA=1, the "out" side changes the data on the leading
131 * edge of the current clock cycle, while the "in" side
132 * captures the data on (or shortly after) the trailing edge of
133 * the clock cycle.
134 * bit 1: CPOL, determines the polarity of the clock. CPOL=0 is a
135 * clock which idles at 0, and each cycle consists of a pulse
136 * of 1. CPOL=1 is a clock which idles at 1, and each cycle
137 * consists of a pulse of 0.
138 * bit 2: CS_HIGH, if 1, chip select active high, else active low.
139 * bit 3: LSB_FIRST, determines per-word bits-on-wire, if 0, MSB
140 * first, else LSB first.
141 * bit 4: LOOP, loopback mode.
142 * @freq: the transfer speed in Hz.
143 * @word_delay_ns: delay to be inserted between consecutive words of a
144 * transfer, in ns unit.
145 * @cs_setup_ns: delay to be introduced after CS is asserted, in ns
146 * unit.
147 * @cs_delay_hold_ns: delay to be introduced before CS is deasserted
148 * for each transfer, in ns unit.
149 * @cs_change_delay_inactive_ns: delay to be introduced after CS is
150 * deasserted and before next asserted, in ns unit.
151 */
152struct spi_transfer_head {
153 __u8 chip_select_id;
154 __u8 bits_per_word;
155 __u8 cs_change;
156 __u8 tx_nbits;
157 __u8 rx_nbits;
158 __u8 reserved[3];
159 __le32 mode;
160 __le32 freq;
161 __le32 word_delay_ns;
162 __le32 cs_setup_ns;
163 __le32 cs_delay_hold_ns;
164 __le32 cs_change_delay_inactive_ns;
165};
166
167/**
168 * struct spi_transfer_result - virtio SPI transfer result
169 * @result: Transfer result code.
170 * VIRTIO_SPI_TRANS_OK: Transfer successful.
171 * VIRTIO_SPI_PARAM_ERR: Parameter error.
172 * VIRTIO_SPI_TRANS_ERR: Transfer error.
173 */
174struct spi_transfer_result {
175#define VIRTIO_SPI_TRANS_OK 0
176#define VIRTIO_SPI_PARAM_ERR 1
177#define VIRTIO_SPI_TRANS_ERR 2
178 __u8 result;
179};
180
181#endif /* #ifndef _LINUX_VIRTIO_VIRTIO_SPI_H */
182

source code of linux/include/uapi/linux/virtio_spi.h