xref: /openbmc/linux/drivers/dma/dw/idma32.c (revision e65e175b)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2013,2018,2020-2021 Intel Corporation
3 
4 #include <linux/bitops.h>
5 #include <linux/dmaengine.h>
6 #include <linux/errno.h>
7 #include <linux/io.h>
8 #include <linux/pci.h>
9 #include <linux/slab.h>
10 #include <linux/types.h>
11 
12 #include "internal.h"
13 
14 #define DMA_CTL_CH(x)			(0x1000 + (x) * 4)
15 #define DMA_SRC_ADDR_FILLIN(x)		(0x1100 + (x) * 4)
16 #define DMA_DST_ADDR_FILLIN(x)		(0x1200 + (x) * 4)
17 #define DMA_XBAR_SEL(x)			(0x1300 + (x) * 4)
18 #define DMA_REGACCESS_CHID_CFG		(0x1400)
19 
20 #define CTL_CH_TRANSFER_MODE_MASK	GENMASK(1, 0)
21 #define CTL_CH_TRANSFER_MODE_S2S	0
22 #define CTL_CH_TRANSFER_MODE_S2D	1
23 #define CTL_CH_TRANSFER_MODE_D2S	2
24 #define CTL_CH_TRANSFER_MODE_D2D	3
25 #define CTL_CH_RD_RS_MASK		GENMASK(4, 3)
26 #define CTL_CH_WR_RS_MASK		GENMASK(6, 5)
27 #define CTL_CH_RD_NON_SNOOP_BIT		BIT(8)
28 #define CTL_CH_WR_NON_SNOOP_BIT		BIT(9)
29 
30 #define XBAR_SEL_DEVID_MASK		GENMASK(15, 0)
31 #define XBAR_SEL_RX_TX_BIT		BIT(16)
32 #define XBAR_SEL_RX_TX_SHIFT		16
33 
34 #define REGACCESS_CHID_MASK		GENMASK(2, 0)
35 
36 static unsigned int idma32_get_slave_devfn(struct dw_dma_chan *dwc)
37 {
38 	struct device *slave = dwc->chan.slave;
39 
40 	if (!slave || !dev_is_pci(slave))
41 		return 0;
42 
43 	return to_pci_dev(slave)->devfn;
44 }
45 
46 static void idma32_initialize_chan_xbar(struct dw_dma_chan *dwc)
47 {
48 	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
49 	void __iomem *misc = __dw_regs(dw);
50 	u32 cfghi = 0, cfglo = 0;
51 	u8 dst_id, src_id;
52 	u32 value;
53 
54 	/* DMA Channel ID Configuration register must be programmed first */
55 	value = readl(misc + DMA_REGACCESS_CHID_CFG);
56 
57 	value &= ~REGACCESS_CHID_MASK;
58 	value |= dwc->chan.chan_id;
59 
60 	writel(value, misc + DMA_REGACCESS_CHID_CFG);
61 
62 	/* Configure channel attributes */
63 	value = readl(misc + DMA_CTL_CH(dwc->chan.chan_id));
64 
65 	value &= ~(CTL_CH_RD_NON_SNOOP_BIT | CTL_CH_WR_NON_SNOOP_BIT);
66 	value &= ~(CTL_CH_RD_RS_MASK | CTL_CH_WR_RS_MASK);
67 	value &= ~CTL_CH_TRANSFER_MODE_MASK;
68 
69 	switch (dwc->direction) {
70 	case DMA_MEM_TO_DEV:
71 		value |= CTL_CH_TRANSFER_MODE_D2S;
72 		value |= CTL_CH_WR_NON_SNOOP_BIT;
73 		break;
74 	case DMA_DEV_TO_MEM:
75 		value |= CTL_CH_TRANSFER_MODE_S2D;
76 		value |= CTL_CH_RD_NON_SNOOP_BIT;
77 		break;
78 	default:
79 		/*
80 		 * Memory-to-Memory and Device-to-Device are ignored for now.
81 		 *
82 		 * For Memory-to-Memory transfers we would need to set mode
83 		 * and disable snooping on both sides.
84 		 */
85 		return;
86 	}
87 
88 	writel(value, misc + DMA_CTL_CH(dwc->chan.chan_id));
89 
90 	/* Configure crossbar selection */
91 	value = readl(misc + DMA_XBAR_SEL(dwc->chan.chan_id));
92 
93 	/* DEVFN selection */
94 	value &= ~XBAR_SEL_DEVID_MASK;
95 	value |= idma32_get_slave_devfn(dwc);
96 
97 	switch (dwc->direction) {
98 	case DMA_MEM_TO_DEV:
99 		value |= XBAR_SEL_RX_TX_BIT;
100 		break;
101 	case DMA_DEV_TO_MEM:
102 		value &= ~XBAR_SEL_RX_TX_BIT;
103 		break;
104 	default:
105 		/* Memory-to-Memory and Device-to-Device are ignored for now */
106 		return;
107 	}
108 
109 	writel(value, misc + DMA_XBAR_SEL(dwc->chan.chan_id));
110 
111 	/* Configure DMA channel low and high registers */
112 	switch (dwc->direction) {
113 	case DMA_MEM_TO_DEV:
114 		dst_id = dwc->chan.chan_id;
115 		src_id = dwc->dws.src_id;
116 		break;
117 	case DMA_DEV_TO_MEM:
118 		dst_id = dwc->dws.dst_id;
119 		src_id = dwc->chan.chan_id;
120 		break;
121 	default:
122 		/* Memory-to-Memory and Device-to-Device are ignored for now */
123 		return;
124 	}
125 
126 	/* Set default burst alignment */
127 	cfglo |= IDMA32C_CFGL_DST_BURST_ALIGN | IDMA32C_CFGL_SRC_BURST_ALIGN;
128 
129 	/* Low 4 bits of the request lines */
130 	cfghi |= IDMA32C_CFGH_DST_PER(dst_id & 0xf);
131 	cfghi |= IDMA32C_CFGH_SRC_PER(src_id & 0xf);
132 
133 	/* Request line extension (2 bits) */
134 	cfghi |= IDMA32C_CFGH_DST_PER_EXT(dst_id >> 4 & 0x3);
135 	cfghi |= IDMA32C_CFGH_SRC_PER_EXT(src_id >> 4 & 0x3);
136 
137 	channel_writel(dwc, CFG_LO, cfglo);
138 	channel_writel(dwc, CFG_HI, cfghi);
139 }
140 
141 static void idma32_initialize_chan_generic(struct dw_dma_chan *dwc)
142 {
143 	u32 cfghi = 0;
144 	u32 cfglo = 0;
145 
146 	/* Set default burst alignment */
147 	cfglo |= IDMA32C_CFGL_DST_BURST_ALIGN | IDMA32C_CFGL_SRC_BURST_ALIGN;
148 
149 	/* Low 4 bits of the request lines */
150 	cfghi |= IDMA32C_CFGH_DST_PER(dwc->dws.dst_id & 0xf);
151 	cfghi |= IDMA32C_CFGH_SRC_PER(dwc->dws.src_id & 0xf);
152 
153 	/* Request line extension (2 bits) */
154 	cfghi |= IDMA32C_CFGH_DST_PER_EXT(dwc->dws.dst_id >> 4 & 0x3);
155 	cfghi |= IDMA32C_CFGH_SRC_PER_EXT(dwc->dws.src_id >> 4 & 0x3);
156 
157 	channel_writel(dwc, CFG_LO, cfglo);
158 	channel_writel(dwc, CFG_HI, cfghi);
159 }
160 
161 static void idma32_suspend_chan(struct dw_dma_chan *dwc, bool drain)
162 {
163 	u32 cfglo = channel_readl(dwc, CFG_LO);
164 
165 	if (drain)
166 		cfglo |= IDMA32C_CFGL_CH_DRAIN;
167 
168 	channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
169 }
170 
171 static void idma32_resume_chan(struct dw_dma_chan *dwc, bool drain)
172 {
173 	u32 cfglo = channel_readl(dwc, CFG_LO);
174 
175 	if (drain)
176 		cfglo &= ~IDMA32C_CFGL_CH_DRAIN;
177 
178 	channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
179 }
180 
181 static u32 idma32_bytes2block(struct dw_dma_chan *dwc,
182 			      size_t bytes, unsigned int width, size_t *len)
183 {
184 	u32 block;
185 
186 	if (bytes > dwc->block_size) {
187 		block = dwc->block_size;
188 		*len = dwc->block_size;
189 	} else {
190 		block = bytes;
191 		*len = bytes;
192 	}
193 
194 	return block;
195 }
196 
197 static size_t idma32_block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
198 {
199 	return IDMA32C_CTLH_BLOCK_TS(block);
200 }
201 
202 static u32 idma32_prepare_ctllo(struct dw_dma_chan *dwc)
203 {
204 	struct dma_slave_config	*sconfig = &dwc->dma_sconfig;
205 	u8 smsize = (dwc->direction == DMA_DEV_TO_MEM) ? sconfig->src_maxburst : 0;
206 	u8 dmsize = (dwc->direction == DMA_MEM_TO_DEV) ? sconfig->dst_maxburst : 0;
207 
208 	return DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN |
209 	       DWC_CTLL_DST_MSIZE(dmsize) | DWC_CTLL_SRC_MSIZE(smsize);
210 }
211 
212 static void idma32_encode_maxburst(struct dw_dma_chan *dwc, u32 *maxburst)
213 {
214 	*maxburst = *maxburst > 1 ? fls(*maxburst) - 1 : 0;
215 }
216 
217 static void idma32_set_device_name(struct dw_dma *dw, int id)
218 {
219 	snprintf(dw->name, sizeof(dw->name), "idma32:dmac%d", id);
220 }
221 
222 /*
223  * Program FIFO size of channels.
224  *
225  * By default full FIFO (512 bytes) is assigned to channel 0. Here we
226  * slice FIFO on equal parts between channels.
227  */
228 static void idma32_fifo_partition(struct dw_dma *dw)
229 {
230 	u64 value = IDMA32C_FP_PSIZE_CH0(64) | IDMA32C_FP_PSIZE_CH1(64) |
231 		    IDMA32C_FP_UPDATE;
232 	u64 fifo_partition = 0;
233 
234 	/* Fill FIFO_PARTITION low bits (Channels 0..1, 4..5) */
235 	fifo_partition |= value << 0;
236 
237 	/* Fill FIFO_PARTITION high bits (Channels 2..3, 6..7) */
238 	fifo_partition |= value << 32;
239 
240 	/* Program FIFO Partition registers - 64 bytes per channel */
241 	idma32_writeq(dw, FIFO_PARTITION1, fifo_partition);
242 	idma32_writeq(dw, FIFO_PARTITION0, fifo_partition);
243 }
244 
245 static void idma32_disable(struct dw_dma *dw)
246 {
247 	do_dw_dma_off(dw);
248 	idma32_fifo_partition(dw);
249 }
250 
251 static void idma32_enable(struct dw_dma *dw)
252 {
253 	idma32_fifo_partition(dw);
254 	do_dw_dma_on(dw);
255 }
256 
257 int idma32_dma_probe(struct dw_dma_chip *chip)
258 {
259 	struct dw_dma *dw;
260 
261 	dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
262 	if (!dw)
263 		return -ENOMEM;
264 
265 	/* Channel operations */
266 	if (chip->pdata->quirks & DW_DMA_QUIRK_XBAR_PRESENT)
267 		dw->initialize_chan = idma32_initialize_chan_xbar;
268 	else
269 		dw->initialize_chan = idma32_initialize_chan_generic;
270 	dw->suspend_chan = idma32_suspend_chan;
271 	dw->resume_chan = idma32_resume_chan;
272 	dw->prepare_ctllo = idma32_prepare_ctllo;
273 	dw->encode_maxburst = idma32_encode_maxburst;
274 	dw->bytes2block = idma32_bytes2block;
275 	dw->block2bytes = idma32_block2bytes;
276 
277 	/* Device operations */
278 	dw->set_device_name = idma32_set_device_name;
279 	dw->disable = idma32_disable;
280 	dw->enable = idma32_enable;
281 
282 	chip->dw = dw;
283 	return do_dma_probe(chip);
284 }
285 EXPORT_SYMBOL_GPL(idma32_dma_probe);
286 
287 int idma32_dma_remove(struct dw_dma_chip *chip)
288 {
289 	return do_dma_remove(chip);
290 }
291 EXPORT_SYMBOL_GPL(idma32_dma_remove);
292