xref: /openbmc/linux/drivers/dma/dw/idma32.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2013,2018 Intel Corporation
3 
4 #include <linux/bitops.h>
5 #include <linux/dmaengine.h>
6 #include <linux/errno.h>
7 #include <linux/slab.h>
8 #include <linux/types.h>
9 
10 #include "internal.h"
11 
12 static void idma32_initialize_chan(struct dw_dma_chan *dwc)
13 {
14 	u32 cfghi = 0;
15 	u32 cfglo = 0;
16 
17 	/* Set default burst alignment */
18 	cfglo |= IDMA32C_CFGL_DST_BURST_ALIGN | IDMA32C_CFGL_SRC_BURST_ALIGN;
19 
20 	/* Low 4 bits of the request lines */
21 	cfghi |= IDMA32C_CFGH_DST_PER(dwc->dws.dst_id & 0xf);
22 	cfghi |= IDMA32C_CFGH_SRC_PER(dwc->dws.src_id & 0xf);
23 
24 	/* Request line extension (2 bits) */
25 	cfghi |= IDMA32C_CFGH_DST_PER_EXT(dwc->dws.dst_id >> 4 & 0x3);
26 	cfghi |= IDMA32C_CFGH_SRC_PER_EXT(dwc->dws.src_id >> 4 & 0x3);
27 
28 	channel_writel(dwc, CFG_LO, cfglo);
29 	channel_writel(dwc, CFG_HI, cfghi);
30 }
31 
32 static void idma32_suspend_chan(struct dw_dma_chan *dwc, bool drain)
33 {
34 	u32 cfglo = channel_readl(dwc, CFG_LO);
35 
36 	if (drain)
37 		cfglo |= IDMA32C_CFGL_CH_DRAIN;
38 
39 	channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
40 }
41 
42 static void idma32_resume_chan(struct dw_dma_chan *dwc, bool drain)
43 {
44 	u32 cfglo = channel_readl(dwc, CFG_LO);
45 
46 	if (drain)
47 		cfglo &= ~IDMA32C_CFGL_CH_DRAIN;
48 
49 	channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
50 }
51 
52 static u32 idma32_bytes2block(struct dw_dma_chan *dwc,
53 			      size_t bytes, unsigned int width, size_t *len)
54 {
55 	u32 block;
56 
57 	if (bytes > dwc->block_size) {
58 		block = dwc->block_size;
59 		*len = dwc->block_size;
60 	} else {
61 		block = bytes;
62 		*len = bytes;
63 	}
64 
65 	return block;
66 }
67 
68 static size_t idma32_block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
69 {
70 	return IDMA32C_CTLH_BLOCK_TS(block);
71 }
72 
73 static u32 idma32_prepare_ctllo(struct dw_dma_chan *dwc)
74 {
75 	struct dma_slave_config	*sconfig = &dwc->dma_sconfig;
76 	bool is_slave = is_slave_direction(dwc->direction);
77 	u8 smsize = is_slave ? sconfig->src_maxburst : IDMA32_MSIZE_8;
78 	u8 dmsize = is_slave ? sconfig->dst_maxburst : IDMA32_MSIZE_8;
79 
80 	return DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN |
81 	       DWC_CTLL_DST_MSIZE(dmsize) | DWC_CTLL_SRC_MSIZE(smsize);
82 }
83 
84 static void idma32_encode_maxburst(struct dw_dma_chan *dwc, u32 *maxburst)
85 {
86 	*maxburst = *maxburst > 1 ? fls(*maxburst) - 1 : 0;
87 }
88 
89 static void idma32_set_device_name(struct dw_dma *dw, int id)
90 {
91 	snprintf(dw->name, sizeof(dw->name), "idma32:dmac%d", id);
92 }
93 
94 /*
95  * Program FIFO size of channels.
96  *
97  * By default full FIFO (512 bytes) is assigned to channel 0. Here we
98  * slice FIFO on equal parts between channels.
99  */
100 static void idma32_fifo_partition(struct dw_dma *dw)
101 {
102 	u64 value = IDMA32C_FP_PSIZE_CH0(64) | IDMA32C_FP_PSIZE_CH1(64) |
103 		    IDMA32C_FP_UPDATE;
104 	u64 fifo_partition = 0;
105 
106 	/* Fill FIFO_PARTITION low bits (Channels 0..1, 4..5) */
107 	fifo_partition |= value << 0;
108 
109 	/* Fill FIFO_PARTITION high bits (Channels 2..3, 6..7) */
110 	fifo_partition |= value << 32;
111 
112 	/* Program FIFO Partition registers - 64 bytes per channel */
113 	idma32_writeq(dw, FIFO_PARTITION1, fifo_partition);
114 	idma32_writeq(dw, FIFO_PARTITION0, fifo_partition);
115 }
116 
117 static void idma32_disable(struct dw_dma *dw)
118 {
119 	do_dw_dma_off(dw);
120 	idma32_fifo_partition(dw);
121 }
122 
123 static void idma32_enable(struct dw_dma *dw)
124 {
125 	idma32_fifo_partition(dw);
126 	do_dw_dma_on(dw);
127 }
128 
129 int idma32_dma_probe(struct dw_dma_chip *chip)
130 {
131 	struct dw_dma *dw;
132 
133 	dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
134 	if (!dw)
135 		return -ENOMEM;
136 
137 	/* Channel operations */
138 	dw->initialize_chan = idma32_initialize_chan;
139 	dw->suspend_chan = idma32_suspend_chan;
140 	dw->resume_chan = idma32_resume_chan;
141 	dw->prepare_ctllo = idma32_prepare_ctllo;
142 	dw->encode_maxburst = idma32_encode_maxburst;
143 	dw->bytes2block = idma32_bytes2block;
144 	dw->block2bytes = idma32_block2bytes;
145 
146 	/* Device operations */
147 	dw->set_device_name = idma32_set_device_name;
148 	dw->disable = idma32_disable;
149 	dw->enable = idma32_enable;
150 
151 	chip->dw = dw;
152 	return do_dma_probe(chip);
153 }
154 EXPORT_SYMBOL_GPL(idma32_dma_probe);
155 
156 int idma32_dma_remove(struct dw_dma_chip *chip)
157 {
158 	return do_dma_remove(chip);
159 }
160 EXPORT_SYMBOL_GPL(idma32_dma_remove);
161