1/* SPDX-License-Identifier: GPL-2.0-only */
2/*******************************************************************************
3  Header File to describe Normal/enhanced descriptor functions used for RING
4  and CHAINED modes.
5
6  Copyright(C) 2011  STMicroelectronics Ltd
7
8  It defines all the functions used to handle the normal/enhanced
9  descriptors in case of the DMA is configured to work in chained or
10  in ring mode.
11
12
13  Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
14*******************************************************************************/
15
16#ifndef __DESC_COM_H__
17#define __DESC_COM_H__
18
19/* Specific functions used for Ring mode */
20
21/* Enhanced descriptors */
22static inline void ehn_desc_rx_set_on_ring(struct dma_desc *p, int end,
23					   int bfsize)
24{
25	if (bfsize == BUF_SIZE_16KiB)
26		p->des1 |= cpu_to_le32((BUF_SIZE_8KiB
27				<< ERDES1_BUFFER2_SIZE_SHIFT)
28			   & ERDES1_BUFFER2_SIZE_MASK);
29
30	if (end)
31		p->des1 |= cpu_to_le32(ERDES1_END_RING);
32}
33
34static inline void enh_desc_end_tx_desc_on_ring(struct dma_desc *p, int end)
35{
36	if (end)
37		p->des0 |= cpu_to_le32(ETDES0_END_RING);
38	else
39		p->des0 &= cpu_to_le32(~ETDES0_END_RING);
40}
41
42static inline void enh_set_tx_desc_len_on_ring(struct dma_desc *p, int len)
43{
44	if (unlikely(len > BUF_SIZE_4KiB)) {
45		p->des1 |= cpu_to_le32((((len - BUF_SIZE_4KiB)
46					<< ETDES1_BUFFER2_SIZE_SHIFT)
47			    & ETDES1_BUFFER2_SIZE_MASK) | (BUF_SIZE_4KiB
48			    & ETDES1_BUFFER1_SIZE_MASK));
49	} else
50		p->des1 |= cpu_to_le32((len & ETDES1_BUFFER1_SIZE_MASK));
51}
52
53/* Normal descriptors */
54static inline void ndesc_rx_set_on_ring(struct dma_desc *p, int end, int bfsize)
55{
56	if (bfsize >= BUF_SIZE_2KiB) {
57		int bfsize2;
58
59		bfsize2 = min(bfsize - BUF_SIZE_2KiB + 1, BUF_SIZE_2KiB - 1);
60		p->des1 |= cpu_to_le32((bfsize2 << RDES1_BUFFER2_SIZE_SHIFT)
61			    & RDES1_BUFFER2_SIZE_MASK);
62	}
63
64	if (end)
65		p->des1 |= cpu_to_le32(RDES1_END_RING);
66}
67
68static inline void ndesc_end_tx_desc_on_ring(struct dma_desc *p, int end)
69{
70	if (end)
71		p->des1 |= cpu_to_le32(TDES1_END_RING);
72	else
73		p->des1 &= cpu_to_le32(~TDES1_END_RING);
74}
75
76static inline void norm_set_tx_desc_len_on_ring(struct dma_desc *p, int len)
77{
78	if (unlikely(len > BUF_SIZE_2KiB)) {
79		unsigned int buffer1 = (BUF_SIZE_2KiB - 1)
80					& TDES1_BUFFER1_SIZE_MASK;
81		p->des1 |= cpu_to_le32((((len - buffer1)
82					<< TDES1_BUFFER2_SIZE_SHIFT)
83				& TDES1_BUFFER2_SIZE_MASK) | buffer1);
84	} else
85		p->des1 |= cpu_to_le32((len & TDES1_BUFFER1_SIZE_MASK));
86}
87
88/* Specific functions used for Chain mode */
89
90/* Enhanced descriptors */
91static inline void ehn_desc_rx_set_on_chain(struct dma_desc *p)
92{
93	p->des1 |= cpu_to_le32(ERDES1_SECOND_ADDRESS_CHAINED);
94}
95
96static inline void enh_desc_end_tx_desc_on_chain(struct dma_desc *p)
97{
98	p->des0 |= cpu_to_le32(ETDES0_SECOND_ADDRESS_CHAINED);
99}
100
101static inline void enh_set_tx_desc_len_on_chain(struct dma_desc *p, int len)
102{
103	p->des1 |= cpu_to_le32(len & ETDES1_BUFFER1_SIZE_MASK);
104}
105
106/* Normal descriptors */
107static inline void ndesc_rx_set_on_chain(struct dma_desc *p, int end)
108{
109	p->des1 |= cpu_to_le32(RDES1_SECOND_ADDRESS_CHAINED);
110}
111
112static inline void ndesc_tx_set_on_chain(struct dma_desc *p)
113{
114	p->des1 |= cpu_to_le32(TDES1_SECOND_ADDRESS_CHAINED);
115}
116
117static inline void norm_set_tx_desc_len_on_chain(struct dma_desc *p, int len)
118{
119	p->des1 |= cpu_to_le32(len & TDES1_BUFFER1_SIZE_MASK);
120}
121#endif /* __DESC_COM_H__ */
122