xref: /linux/drivers/dma/qcom/bam_dma.c (revision 3331fc194b129582fa21cb3a7e5cc68aaac1081f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
4  */
5 /*
6  * QCOM BAM DMA engine driver
7  *
8  * QCOM BAM DMA blocks are distributed amongst a number of the on-chip
9  * peripherals on the MSM 8x74.  The configuration of the channels are dependent
10  * on the way they are hard wired to that specific peripheral.  The peripheral
11  * device tree entries specify the configuration of each channel.
12  *
13  * The DMA controller requires the use of external memory for storage of the
14  * hardware descriptors for each channel.  The descriptor FIFO is accessed as a
15  * circular buffer and operations are managed according to the offset within the
16  * FIFO.  After pipe/channel reset, all of the pipe registers and internal state
17  * are back to defaults.
18  *
19  * During DMA operations, we write descriptors to the FIFO, being careful to
20  * handle wrapping and then write the last FIFO offset to that channel's
21  * P_EVNT_REG register to kick off the transaction.  The P_SW_OFSTS register
22  * indicates the current FIFO offset that is being processed, so there is some
23  * indication of where the hardware is currently working.
24  */
25 
26 #include <linux/circ_buf.h>
27 #include <linux/cleanup.h>
28 #include <linux/clk.h>
29 #include <linux/device.h>
30 #include <linux/dma-mapping.h>
31 #include <linux/dmaengine.h>
32 #include <linux/init.h>
33 #include <linux/interrupt.h>
34 #include <linux/io.h>
35 #include <linux/kernel.h>
36 #include <linux/module.h>
37 #include <linux/of_address.h>
38 #include <linux/of_dma.h>
39 #include <linux/of_irq.h>
40 #include <linux/of.h>
41 #include <linux/platform_device.h>
42 #include <linux/pm_runtime.h>
43 #include <linux/scatterlist.h>
44 #include <linux/slab.h>
45 
46 #include "../dmaengine.h"
47 #include "../virt-dma.h"
48 
49 struct bam_desc_hw {
50 	__le32 addr;		/* Buffer physical address */
51 	__le16 size;		/* Buffer size in bytes */
52 	__le16 flags;
53 };
54 
55 #define BAM_DMA_AUTOSUSPEND_DELAY 100
56 
57 #define DESC_FLAG_INT BIT(15)
58 #define DESC_FLAG_EOT BIT(14)
59 #define DESC_FLAG_EOB BIT(13)
60 #define DESC_FLAG_NWD BIT(12)
61 #define DESC_FLAG_CMD BIT(11)
62 
63 struct bam_async_desc {
64 	struct virt_dma_desc vd;
65 
66 	u32 num_desc;
67 	u32 xfer_len;
68 
69 	/* transaction flags, EOT|EOB|NWD */
70 	u16 flags;
71 
72 	struct bam_desc_hw *curr_desc;
73 
74 	/* list node for the desc in the bam_chan list of descriptors */
75 	struct list_head desc_node;
76 	enum dma_transfer_direction dir;
77 	size_t length;
78 	struct bam_desc_hw desc[] __counted_by(num_desc);
79 };
80 
81 enum bam_reg {
82 	BAM_CTRL,
83 	BAM_REVISION,
84 	BAM_NUM_PIPES,
85 	BAM_DESC_CNT_TRSHLD,
86 	BAM_IRQ_SRCS,
87 	BAM_IRQ_SRCS_MSK,
88 	BAM_IRQ_SRCS_UNMASKED,
89 	BAM_IRQ_STTS,
90 	BAM_IRQ_CLR,
91 	BAM_IRQ_EN,
92 	BAM_CNFG_BITS,
93 	BAM_IRQ_SRCS_EE,
94 	BAM_IRQ_SRCS_MSK_EE,
95 	BAM_P_CTRL,
96 	BAM_P_RST,
97 	BAM_P_HALT,
98 	BAM_P_IRQ_STTS,
99 	BAM_P_IRQ_CLR,
100 	BAM_P_IRQ_EN,
101 	BAM_P_EVNT_DEST_ADDR,
102 	BAM_P_EVNT_REG,
103 	BAM_P_SW_OFSTS,
104 	BAM_P_DATA_FIFO_ADDR,
105 	BAM_P_DESC_FIFO_ADDR,
106 	BAM_P_EVNT_GEN_TRSHLD,
107 	BAM_P_FIFO_SIZES,
108 };
109 
110 struct reg_offset_data {
111 	u32 base_offset;
112 	unsigned int pipe_mult, evnt_mult, ee_mult;
113 };
114 
115 static const struct reg_offset_data bam_v1_3_reg_info[] = {
116 	[BAM_CTRL]		= { 0x0F80, 0x00, 0x00, 0x00 },
117 	[BAM_REVISION]		= { 0x0F84, 0x00, 0x00, 0x00 },
118 	[BAM_NUM_PIPES]		= { 0x0FBC, 0x00, 0x00, 0x00 },
119 	[BAM_DESC_CNT_TRSHLD]	= { 0x0F88, 0x00, 0x00, 0x00 },
120 	[BAM_IRQ_SRCS]		= { 0x0F8C, 0x00, 0x00, 0x00 },
121 	[BAM_IRQ_SRCS_MSK]	= { 0x0F90, 0x00, 0x00, 0x00 },
122 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0FB0, 0x00, 0x00, 0x00 },
123 	[BAM_IRQ_STTS]		= { 0x0F94, 0x00, 0x00, 0x00 },
124 	[BAM_IRQ_CLR]		= { 0x0F98, 0x00, 0x00, 0x00 },
125 	[BAM_IRQ_EN]		= { 0x0F9C, 0x00, 0x00, 0x00 },
126 	[BAM_CNFG_BITS]		= { 0x0FFC, 0x00, 0x00, 0x00 },
127 	[BAM_IRQ_SRCS_EE]	= { 0x1800, 0x00, 0x00, 0x80 },
128 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x1804, 0x00, 0x00, 0x80 },
129 	[BAM_P_CTRL]		= { 0x0000, 0x80, 0x00, 0x00 },
130 	[BAM_P_RST]		= { 0x0004, 0x80, 0x00, 0x00 },
131 	[BAM_P_HALT]		= { 0x0008, 0x80, 0x00, 0x00 },
132 	[BAM_P_IRQ_STTS]	= { 0x0010, 0x80, 0x00, 0x00 },
133 	[BAM_P_IRQ_CLR]		= { 0x0014, 0x80, 0x00, 0x00 },
134 	[BAM_P_IRQ_EN]		= { 0x0018, 0x80, 0x00, 0x00 },
135 	[BAM_P_EVNT_DEST_ADDR]	= { 0x102C, 0x00, 0x40, 0x00 },
136 	[BAM_P_EVNT_REG]	= { 0x1018, 0x00, 0x40, 0x00 },
137 	[BAM_P_SW_OFSTS]	= { 0x1000, 0x00, 0x40, 0x00 },
138 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1024, 0x00, 0x40, 0x00 },
139 	[BAM_P_DESC_FIFO_ADDR]	= { 0x101C, 0x00, 0x40, 0x00 },
140 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1028, 0x00, 0x40, 0x00 },
141 	[BAM_P_FIFO_SIZES]	= { 0x1020, 0x00, 0x40, 0x00 },
142 };
143 
144 static const struct reg_offset_data bam_v1_4_reg_info[] = {
145 	[BAM_CTRL]		= { 0x0000, 0x00, 0x00, 0x00 },
146 	[BAM_REVISION]		= { 0x0004, 0x00, 0x00, 0x00 },
147 	[BAM_NUM_PIPES]		= { 0x003C, 0x00, 0x00, 0x00 },
148 	[BAM_DESC_CNT_TRSHLD]	= { 0x0008, 0x00, 0x00, 0x00 },
149 	[BAM_IRQ_SRCS]		= { 0x000C, 0x00, 0x00, 0x00 },
150 	[BAM_IRQ_SRCS_MSK]	= { 0x0010, 0x00, 0x00, 0x00 },
151 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0030, 0x00, 0x00, 0x00 },
152 	[BAM_IRQ_STTS]		= { 0x0014, 0x00, 0x00, 0x00 },
153 	[BAM_IRQ_CLR]		= { 0x0018, 0x00, 0x00, 0x00 },
154 	[BAM_IRQ_EN]		= { 0x001C, 0x00, 0x00, 0x00 },
155 	[BAM_CNFG_BITS]		= { 0x007C, 0x00, 0x00, 0x00 },
156 	[BAM_IRQ_SRCS_EE]	= { 0x0800, 0x00, 0x00, 0x80 },
157 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x0804, 0x00, 0x00, 0x80 },
158 	[BAM_P_CTRL]		= { 0x1000, 0x1000, 0x00, 0x00 },
159 	[BAM_P_RST]		= { 0x1004, 0x1000, 0x00, 0x00 },
160 	[BAM_P_HALT]		= { 0x1008, 0x1000, 0x00, 0x00 },
161 	[BAM_P_IRQ_STTS]	= { 0x1010, 0x1000, 0x00, 0x00 },
162 	[BAM_P_IRQ_CLR]		= { 0x1014, 0x1000, 0x00, 0x00 },
163 	[BAM_P_IRQ_EN]		= { 0x1018, 0x1000, 0x00, 0x00 },
164 	[BAM_P_EVNT_DEST_ADDR]	= { 0x182C, 0x00, 0x1000, 0x00 },
165 	[BAM_P_EVNT_REG]	= { 0x1818, 0x00, 0x1000, 0x00 },
166 	[BAM_P_SW_OFSTS]	= { 0x1800, 0x00, 0x1000, 0x00 },
167 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1824, 0x00, 0x1000, 0x00 },
168 	[BAM_P_DESC_FIFO_ADDR]	= { 0x181C, 0x00, 0x1000, 0x00 },
169 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1828, 0x00, 0x1000, 0x00 },
170 	[BAM_P_FIFO_SIZES]	= { 0x1820, 0x00, 0x1000, 0x00 },
171 };
172 
173 static const struct reg_offset_data bam_v1_7_reg_info[] = {
174 	[BAM_CTRL]		= { 0x00000, 0x00, 0x00, 0x00 },
175 	[BAM_REVISION]		= { 0x01000, 0x00, 0x00, 0x00 },
176 	[BAM_NUM_PIPES]		= { 0x01008, 0x00, 0x00, 0x00 },
177 	[BAM_DESC_CNT_TRSHLD]	= { 0x00008, 0x00, 0x00, 0x00 },
178 	[BAM_IRQ_SRCS]		= { 0x03010, 0x00, 0x00, 0x00 },
179 	[BAM_IRQ_SRCS_MSK]	= { 0x03014, 0x00, 0x00, 0x00 },
180 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x03018, 0x00, 0x00, 0x00 },
181 	[BAM_IRQ_STTS]		= { 0x00014, 0x00, 0x00, 0x00 },
182 	[BAM_IRQ_CLR]		= { 0x00018, 0x00, 0x00, 0x00 },
183 	[BAM_IRQ_EN]		= { 0x0001C, 0x00, 0x00, 0x00 },
184 	[BAM_CNFG_BITS]		= { 0x0007C, 0x00, 0x00, 0x00 },
185 	[BAM_IRQ_SRCS_EE]	= { 0x03000, 0x00, 0x00, 0x1000 },
186 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x03004, 0x00, 0x00, 0x1000 },
187 	[BAM_P_CTRL]		= { 0x13000, 0x1000, 0x00, 0x00 },
188 	[BAM_P_RST]		= { 0x13004, 0x1000, 0x00, 0x00 },
189 	[BAM_P_HALT]		= { 0x13008, 0x1000, 0x00, 0x00 },
190 	[BAM_P_IRQ_STTS]	= { 0x13010, 0x1000, 0x00, 0x00 },
191 	[BAM_P_IRQ_CLR]		= { 0x13014, 0x1000, 0x00, 0x00 },
192 	[BAM_P_IRQ_EN]		= { 0x13018, 0x1000, 0x00, 0x00 },
193 	[BAM_P_EVNT_DEST_ADDR]	= { 0x1382C, 0x00, 0x1000, 0x00 },
194 	[BAM_P_EVNT_REG]	= { 0x13818, 0x00, 0x1000, 0x00 },
195 	[BAM_P_SW_OFSTS]	= { 0x13800, 0x00, 0x1000, 0x00 },
196 	[BAM_P_DATA_FIFO_ADDR]	= { 0x13824, 0x00, 0x1000, 0x00 },
197 	[BAM_P_DESC_FIFO_ADDR]	= { 0x1381C, 0x00, 0x1000, 0x00 },
198 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x13828, 0x00, 0x1000, 0x00 },
199 	[BAM_P_FIFO_SIZES]	= { 0x13820, 0x00, 0x1000, 0x00 },
200 };
201 
202 static const struct reg_offset_data bam_v2_0_reg_info[] = {
203 	[BAM_CTRL]		= { 0x0000, 0x00, 0x00, 0x00 },
204 	[BAM_REVISION]		= { 0x1000, 0x00, 0x00, 0x00 },
205 	[BAM_NUM_PIPES]		= { 0x1008, 0x00, 0x00, 0x00 },
206 	[BAM_DESC_CNT_TRSHLD]	= { 0x0008, 0x00, 0x00, 0x00 },
207 	[BAM_IRQ_SRCS]		= { 0x3010, 0x00, 0x00, 0x00 },
208 	[BAM_IRQ_SRCS_MSK]	= { 0x3014, 0x00, 0x00, 0x00 },
209 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x3018, 0x00, 0x00, 0x00 },
210 	[BAM_IRQ_STTS]		= { 0x0014, 0x00, 0x00, 0x00 },
211 	[BAM_IRQ_CLR]		= { 0x0018, 0x00, 0x00, 0x00 },
212 	[BAM_IRQ_EN]		= { 0x001C, 0x00, 0x00, 0x00 },
213 	[BAM_CNFG_BITS]		= { 0x007C, 0x00, 0x00, 0x00 },
214 	[BAM_IRQ_SRCS_EE]	= { 0x3000, 0x00, 0x00, 0x1000 },
215 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x3004, 0x00, 0x00, 0x1000 },
216 	[BAM_P_CTRL]		= { 0xC000, 0x1000, 0x00, 0x00 },
217 	[BAM_P_RST]		= { 0xC004, 0x1000, 0x00, 0x00 },
218 	[BAM_P_HALT]		= { 0xC008, 0x1000, 0x00, 0x00 },
219 	[BAM_P_IRQ_STTS]	= { 0xC010, 0x1000, 0x00, 0x00 },
220 	[BAM_P_IRQ_CLR]		= { 0xC014, 0x1000, 0x00, 0x00 },
221 	[BAM_P_IRQ_EN]		= { 0xC018, 0x1000, 0x00, 0x00 },
222 	[BAM_P_EVNT_DEST_ADDR]	= { 0xC82C, 0x00, 0x1000, 0x00 },
223 	[BAM_P_EVNT_REG]	= { 0xC818, 0x00, 0x1000, 0x00 },
224 	[BAM_P_SW_OFSTS]	= { 0xC800, 0x00, 0x1000, 0x00 },
225 	[BAM_P_DATA_FIFO_ADDR]	= { 0xC824, 0x00, 0x1000, 0x00 },
226 	[BAM_P_DESC_FIFO_ADDR]	= { 0xC81C, 0x00, 0x1000, 0x00 },
227 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0xC828, 0x00, 0x1000, 0x00 },
228 	[BAM_P_FIFO_SIZES]	= { 0xC820, 0x00, 0x1000, 0x00 },
229 };
230 
231 /* BAM CTRL */
232 #define BAM_SW_RST			BIT(0)
233 #define BAM_EN				BIT(1)
234 #define BAM_EN_ACCUM			BIT(4)
235 #define BAM_TESTBUS_SEL_SHIFT		5
236 #define BAM_TESTBUS_SEL_MASK		0x3F
237 #define BAM_DESC_CACHE_SEL_SHIFT	13
238 #define BAM_DESC_CACHE_SEL_MASK		0x3
239 #define BAM_CACHED_DESC_STORE		BIT(15)
240 #define IBC_DISABLE			BIT(16)
241 
242 /* BAM REVISION */
243 #define REVISION_SHIFT		0
244 #define REVISION_MASK		0xFF
245 #define NUM_EES_SHIFT		8
246 #define NUM_EES_MASK		0xF
247 #define CE_BUFFER_SIZE		BIT(13)
248 #define AXI_ACTIVE		BIT(14)
249 #define USE_VMIDMT		BIT(15)
250 #define SECURED			BIT(16)
251 #define BAM_HAS_NO_BYPASS	BIT(17)
252 #define HIGH_FREQUENCY_BAM	BIT(18)
253 #define INACTIV_TMRS_EXST	BIT(19)
254 #define NUM_INACTIV_TMRS	BIT(20)
255 #define DESC_CACHE_DEPTH_SHIFT	21
256 #define DESC_CACHE_DEPTH_1	(0 << DESC_CACHE_DEPTH_SHIFT)
257 #define DESC_CACHE_DEPTH_2	(1 << DESC_CACHE_DEPTH_SHIFT)
258 #define DESC_CACHE_DEPTH_3	(2 << DESC_CACHE_DEPTH_SHIFT)
259 #define DESC_CACHE_DEPTH_4	(3 << DESC_CACHE_DEPTH_SHIFT)
260 #define CMD_DESC_EN		BIT(23)
261 #define INACTIV_TMR_BASE_SHIFT	24
262 #define INACTIV_TMR_BASE_MASK	0xFF
263 
264 /* BAM NUM PIPES */
265 #define BAM_NUM_PIPES_SHIFT		0
266 #define BAM_NUM_PIPES_MASK		0xFF
267 #define PERIPH_NON_PIPE_GRP_SHIFT	16
268 #define PERIPH_NON_PIP_GRP_MASK		0xFF
269 #define BAM_NON_PIPE_GRP_SHIFT		24
270 #define BAM_NON_PIPE_GRP_MASK		0xFF
271 
272 /* BAM CNFG BITS */
273 #define BAM_PIPE_CNFG		BIT(2)
274 #define BAM_FULL_PIPE		BIT(11)
275 #define BAM_NO_EXT_P_RST	BIT(12)
276 #define BAM_IBC_DISABLE		BIT(13)
277 #define BAM_SB_CLK_REQ		BIT(14)
278 #define BAM_PSM_CSW_REQ		BIT(15)
279 #define BAM_PSM_P_RES		BIT(16)
280 #define BAM_AU_P_RES		BIT(17)
281 #define BAM_SI_P_RES		BIT(18)
282 #define BAM_WB_P_RES		BIT(19)
283 #define BAM_WB_BLK_CSW		BIT(20)
284 #define BAM_WB_CSW_ACK_IDL	BIT(21)
285 #define BAM_WB_RETR_SVPNT	BIT(22)
286 #define BAM_WB_DSC_AVL_P_RST	BIT(23)
287 #define BAM_REG_P_EN		BIT(24)
288 #define BAM_PSM_P_HD_DATA	BIT(25)
289 #define BAM_AU_ACCUMED		BIT(26)
290 #define BAM_CMD_ENABLE		BIT(27)
291 
292 #define BAM_CNFG_BITS_DEFAULT	(BAM_PIPE_CNFG |	\
293 				 BAM_NO_EXT_P_RST |	\
294 				 BAM_IBC_DISABLE |	\
295 				 BAM_SB_CLK_REQ |	\
296 				 BAM_PSM_CSW_REQ |	\
297 				 BAM_PSM_P_RES |	\
298 				 BAM_AU_P_RES |		\
299 				 BAM_SI_P_RES |		\
300 				 BAM_WB_P_RES |		\
301 				 BAM_WB_BLK_CSW |	\
302 				 BAM_WB_CSW_ACK_IDL |	\
303 				 BAM_WB_RETR_SVPNT |	\
304 				 BAM_WB_DSC_AVL_P_RST |	\
305 				 BAM_REG_P_EN |		\
306 				 BAM_PSM_P_HD_DATA |	\
307 				 BAM_AU_ACCUMED |	\
308 				 BAM_CMD_ENABLE)
309 
310 /* PIPE CTRL */
311 #define P_EN			BIT(1)
312 #define P_DIRECTION		BIT(3)
313 #define P_SYS_STRM		BIT(4)
314 #define P_SYS_MODE		BIT(5)
315 #define P_AUTO_EOB		BIT(6)
316 #define P_AUTO_EOB_SEL_SHIFT	7
317 #define P_AUTO_EOB_SEL_512	(0 << P_AUTO_EOB_SEL_SHIFT)
318 #define P_AUTO_EOB_SEL_256	(1 << P_AUTO_EOB_SEL_SHIFT)
319 #define P_AUTO_EOB_SEL_128	(2 << P_AUTO_EOB_SEL_SHIFT)
320 #define P_AUTO_EOB_SEL_64	(3 << P_AUTO_EOB_SEL_SHIFT)
321 #define P_PREFETCH_LIMIT_SHIFT	9
322 #define P_PREFETCH_LIMIT_32	(0 << P_PREFETCH_LIMIT_SHIFT)
323 #define P_PREFETCH_LIMIT_16	(1 << P_PREFETCH_LIMIT_SHIFT)
324 #define P_PREFETCH_LIMIT_4	(2 << P_PREFETCH_LIMIT_SHIFT)
325 #define P_WRITE_NWD		BIT(11)
326 #define P_LOCK_GROUP_SHIFT	16
327 #define P_LOCK_GROUP_MASK	0x1F
328 
329 /* BAM_DESC_CNT_TRSHLD */
330 #define CNT_TRSHLD		0xffff
331 #define DEFAULT_CNT_THRSHLD	0x4
332 
333 /* BAM_IRQ_SRCS */
334 #define BAM_IRQ			BIT(31)
335 #define P_IRQ			0x7fffffff
336 
337 /* BAM_IRQ_SRCS_MSK */
338 #define BAM_IRQ_MSK		BAM_IRQ
339 #define P_IRQ_MSK		P_IRQ
340 
341 /* BAM_IRQ_STTS */
342 #define BAM_TIMER_IRQ		BIT(4)
343 #define BAM_EMPTY_IRQ		BIT(3)
344 #define BAM_ERROR_IRQ		BIT(2)
345 #define BAM_HRESP_ERR_IRQ	BIT(1)
346 
347 /* BAM_IRQ_CLR */
348 #define BAM_TIMER_CLR		BIT(4)
349 #define BAM_EMPTY_CLR		BIT(3)
350 #define BAM_ERROR_CLR		BIT(2)
351 #define BAM_HRESP_ERR_CLR	BIT(1)
352 
353 /* BAM_IRQ_EN */
354 #define BAM_TIMER_EN		BIT(4)
355 #define BAM_EMPTY_EN		BIT(3)
356 #define BAM_ERROR_EN		BIT(2)
357 #define BAM_HRESP_ERR_EN	BIT(1)
358 
359 /* BAM_P_IRQ_EN */
360 #define P_PRCSD_DESC_EN		BIT(0)
361 #define P_TIMER_EN		BIT(1)
362 #define P_WAKE_EN		BIT(2)
363 #define P_OUT_OF_DESC_EN	BIT(3)
364 #define P_ERR_EN		BIT(4)
365 #define P_TRNSFR_END_EN		BIT(5)
366 #define P_DEFAULT_IRQS_EN	(P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
367 
368 /* BAM_P_SW_OFSTS */
369 #define P_SW_OFSTS_MASK		0xffff
370 
371 #define BAM_DESC_FIFO_SIZE	SZ_32K
372 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
373 #define BAM_FIFO_SIZE	(SZ_32K - 8)
374 #define IS_BUSY(chan)	(CIRC_SPACE(bchan->tail, bchan->head,\
375 			 MAX_DESCRIPTORS + 1) == 0)
376 
377 struct bam_chan {
378 	struct virt_dma_chan vc;
379 
380 	struct bam_device *bdev;
381 
382 	/* configuration from device tree */
383 	u32 id;
384 
385 	/* runtime configuration */
386 	struct dma_slave_config slave;
387 
388 	/* fifo storage */
389 	struct bam_desc_hw *fifo_virt;
390 	dma_addr_t fifo_phys;
391 
392 	/* fifo markers */
393 	unsigned short head;		/* start of active descriptor entries */
394 	unsigned short tail;		/* end of active descriptor entries */
395 
396 	unsigned int initialized;	/* is the channel hw initialized? */
397 	unsigned int paused;		/* is the channel paused? */
398 	unsigned int reconfigure;	/* new slave config? */
399 	/* list of descriptors currently processed */
400 	struct list_head desc_list;
401 
402 	struct list_head node;
403 };
404 
405 static inline struct bam_chan *to_bam_chan(struct dma_chan *common)
406 {
407 	return container_of(common, struct bam_chan, vc.chan);
408 }
409 
410 struct bam_device {
411 	void __iomem *regs;
412 	struct device *dev;
413 	struct dma_device common;
414 	struct bam_chan *channels;
415 	u32 num_channels;
416 	u32 num_ees;
417 
418 	/* execution environment ID, from DT */
419 	u32 ee;
420 	bool controlled_remotely;
421 	bool powered_remotely;
422 	u32 active_channels;
423 
424 	const struct reg_offset_data *layout;
425 
426 	struct clk *bamclk;
427 	int irq;
428 
429 	/* dma start transaction tasklet */
430 	struct tasklet_struct task;
431 };
432 
433 /**
434  * bam_addr - returns BAM register address
435  * @bdev: bam device
436  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
437  * @reg:  register enum
438  */
439 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
440 		enum bam_reg reg)
441 {
442 	const struct reg_offset_data r = bdev->layout[reg];
443 
444 	return bdev->regs + r.base_offset +
445 		r.pipe_mult * pipe +
446 		r.evnt_mult * pipe +
447 		r.ee_mult * bdev->ee;
448 }
449 
450 /**
451  * bam_reset() - reset and initialize BAM registers
452  * @bdev: bam device
453  */
454 static void bam_reset(struct bam_device *bdev)
455 {
456 	u32 val;
457 
458 	/* s/w reset bam */
459 	/* after reset all pipes are disabled and idle */
460 	val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
461 	val |= BAM_SW_RST;
462 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
463 	val &= ~BAM_SW_RST;
464 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
465 
466 	/* make sure previous stores are visible before enabling BAM */
467 	wmb();
468 
469 	/* enable bam */
470 	val |= BAM_EN;
471 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
472 
473 	/* set descriptor threshold, start with 4 bytes */
474 	writel_relaxed(DEFAULT_CNT_THRSHLD,
475 			bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
476 
477 	/* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
478 	writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
479 
480 	/* enable irqs for errors */
481 	writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
482 			bam_addr(bdev, 0, BAM_IRQ_EN));
483 
484 	/* unmask global bam interrupt */
485 	writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
486 }
487 
488 /**
489  * bam_reset_channel - Reset individual BAM DMA channel
490  * @bchan: bam channel
491  *
492  * This function resets a specific BAM channel
493  */
494 static void bam_reset_channel(struct bam_chan *bchan)
495 {
496 	struct bam_device *bdev = bchan->bdev;
497 
498 	lockdep_assert_held(&bchan->vc.lock);
499 
500 	/* reset channel */
501 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
502 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
503 
504 	/* don't allow cpu to reorder BAM register accesses done after this */
505 	wmb();
506 
507 	/* make sure hw is initialized when channel is used the first time  */
508 	bchan->initialized = 0;
509 }
510 
511 /**
512  * bam_chan_init_hw - Initialize channel hardware
513  * @bchan: bam channel
514  * @dir: DMA transfer direction
515  *
516  * This function resets and initializes the BAM channel
517  */
518 static void bam_chan_init_hw(struct bam_chan *bchan,
519 	enum dma_transfer_direction dir)
520 {
521 	struct bam_device *bdev = bchan->bdev;
522 	u32 val;
523 
524 	/* Reset the channel to clear internal state of the FIFO */
525 	bam_reset_channel(bchan);
526 
527 	/*
528 	 * write out 8 byte aligned address.  We have enough space for this
529 	 * because we allocated 1 more descriptor (8 bytes) than we can use
530 	 */
531 	writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
532 			bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
533 	writel_relaxed(BAM_FIFO_SIZE,
534 			bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
535 
536 	/* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
537 	writel_relaxed(P_DEFAULT_IRQS_EN,
538 			bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
539 
540 	/* unmask the specific pipe and EE combo */
541 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
542 	val |= BIT(bchan->id);
543 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
544 
545 	/* don't allow cpu to reorder the channel enable done below */
546 	wmb();
547 
548 	/* set fixed direction and mode, then enable channel */
549 	val = P_EN | P_SYS_MODE;
550 	if (dir == DMA_DEV_TO_MEM)
551 		val |= P_DIRECTION;
552 
553 	writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
554 
555 	bchan->initialized = 1;
556 
557 	/* init FIFO pointers */
558 	bchan->head = 0;
559 	bchan->tail = 0;
560 }
561 
562 /**
563  * bam_alloc_chan - Allocate channel resources for DMA channel.
564  * @chan: specified channel
565  *
566  * This function allocates the FIFO descriptor memory
567  */
568 static int bam_alloc_chan(struct dma_chan *chan)
569 {
570 	struct bam_chan *bchan = to_bam_chan(chan);
571 	struct bam_device *bdev = bchan->bdev;
572 
573 	if (bchan->fifo_virt)
574 		return 0;
575 
576 	/* allocate FIFO descriptor space, but only if necessary */
577 	bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
578 					&bchan->fifo_phys, GFP_KERNEL);
579 
580 	if (!bchan->fifo_virt) {
581 		dev_err(bdev->dev, "Failed to allocate desc fifo\n");
582 		return -ENOMEM;
583 	}
584 
585 	if (bdev->active_channels++ == 0 && bdev->powered_remotely)
586 		bam_reset(bdev);
587 
588 	return 0;
589 }
590 
591 /**
592  * bam_free_chan - Frees dma resources associated with specific channel
593  * @chan: specified channel
594  *
595  * Free the allocated fifo descriptor memory and channel resources
596  *
597  */
598 static void bam_free_chan(struct dma_chan *chan)
599 {
600 	struct bam_chan *bchan = to_bam_chan(chan);
601 	struct bam_device *bdev = bchan->bdev;
602 	u32 val;
603 	int ret;
604 
605 	ret = pm_runtime_get_sync(bdev->dev);
606 	if (ret < 0)
607 		return;
608 
609 	vchan_free_chan_resources(to_virt_chan(chan));
610 
611 	if (!list_empty(&bchan->desc_list)) {
612 		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
613 		goto err;
614 	}
615 
616 	scoped_guard(spinlock_irqsave, &bchan->vc.lock)
617 		bam_reset_channel(bchan);
618 
619 	dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
620 		    bchan->fifo_phys);
621 	bchan->fifo_virt = NULL;
622 
623 	/* mask irq for pipe/channel */
624 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
625 	val &= ~BIT(bchan->id);
626 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
627 
628 	/* disable irq */
629 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
630 
631 	if (--bdev->active_channels == 0 && bdev->powered_remotely) {
632 		/* s/w reset bam */
633 		val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
634 		val |= BAM_SW_RST;
635 		writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
636 	}
637 
638 err:
639 	pm_runtime_mark_last_busy(bdev->dev);
640 	pm_runtime_put_autosuspend(bdev->dev);
641 }
642 
643 /**
644  * bam_slave_config - set slave configuration for channel
645  * @chan: dma channel
646  * @cfg: slave configuration
647  *
648  * Sets slave configuration for channel
649  *
650  */
651 static int bam_slave_config(struct dma_chan *chan,
652 			    struct dma_slave_config *cfg)
653 {
654 	struct bam_chan *bchan = to_bam_chan(chan);
655 
656 	guard(spinlock_irqsave)(&bchan->vc.lock);
657 
658 	memcpy(&bchan->slave, cfg, sizeof(*cfg));
659 	bchan->reconfigure = 1;
660 
661 	return 0;
662 }
663 
664 /**
665  * bam_prep_slave_sg - Prep slave sg transaction
666  *
667  * @chan: dma channel
668  * @sgl: scatter gather list
669  * @sg_len: length of sg
670  * @direction: DMA transfer direction
671  * @flags: DMA flags
672  * @context: transfer context (unused)
673  */
674 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
675 	struct scatterlist *sgl, unsigned int sg_len,
676 	enum dma_transfer_direction direction, unsigned long flags,
677 	void *context)
678 {
679 	struct bam_chan *bchan = to_bam_chan(chan);
680 	struct bam_device *bdev = bchan->bdev;
681 	struct bam_async_desc *async_desc;
682 	struct scatterlist *sg;
683 	u32 i;
684 	struct bam_desc_hw *desc;
685 	unsigned int num_alloc;
686 
687 	if (!is_slave_direction(direction)) {
688 		dev_err(bdev->dev, "invalid dma direction\n");
689 		return NULL;
690 	}
691 
692 	/* allocate enough room to accommodate the number of entries */
693 	num_alloc = sg_nents_for_dma(sgl, sg_len, BAM_FIFO_SIZE);
694 	async_desc = kzalloc_flex(*async_desc, desc, num_alloc, GFP_NOWAIT);
695 	if (!async_desc)
696 		return NULL;
697 
698 	if (flags & DMA_PREP_FENCE)
699 		async_desc->flags |= DESC_FLAG_NWD;
700 
701 	if (flags & DMA_PREP_INTERRUPT)
702 		async_desc->flags |= DESC_FLAG_EOT;
703 
704 	async_desc->num_desc = num_alloc;
705 	async_desc->curr_desc = async_desc->desc;
706 	async_desc->dir = direction;
707 
708 	/* fill in temporary descriptors */
709 	desc = async_desc->desc;
710 	for_each_sg(sgl, sg, sg_len, i) {
711 		unsigned int remainder = sg_dma_len(sg);
712 		unsigned int curr_offset = 0;
713 
714 		do {
715 			if (flags & DMA_PREP_CMD)
716 				desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
717 
718 			desc->addr = cpu_to_le32(sg_dma_address(sg) +
719 						 curr_offset);
720 
721 			if (remainder > BAM_FIFO_SIZE) {
722 				desc->size = cpu_to_le16(BAM_FIFO_SIZE);
723 				remainder -= BAM_FIFO_SIZE;
724 				curr_offset += BAM_FIFO_SIZE;
725 			} else {
726 				desc->size = cpu_to_le16(remainder);
727 				remainder = 0;
728 			}
729 
730 			async_desc->length += le16_to_cpu(desc->size);
731 			desc++;
732 		} while (remainder > 0);
733 	}
734 
735 	return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
736 }
737 
738 /**
739  * bam_dma_terminate_all - terminate all transactions on a channel
740  * @chan: bam dma channel
741  *
742  * Dequeues and frees all transactions
743  * No callbacks are done
744  *
745  */
746 static int bam_dma_terminate_all(struct dma_chan *chan)
747 {
748 	struct bam_chan *bchan = to_bam_chan(chan);
749 	struct bam_async_desc *async_desc, *tmp;
750 	LIST_HEAD(head);
751 
752 	/* remove all transactions, including active transaction */
753 	scoped_guard(spinlock_irqsave, &bchan->vc.lock) {
754 		/*
755 		 * If we have transactions queued, then some might be committed to the
756 		 * hardware in the desc fifo.  The only way to reset the desc fifo is
757 		 * to do a hardware reset (either by pipe or the entire block).
758 		 * bam_chan_init_hw() will trigger a pipe reset, and also reinit the
759 		 * pipe.  If the pipe is left disabled (default state after pipe reset)
760 		 * and is accessed by a connected hardware engine, a fatal error in
761 		 * the BAM will occur.  There is a small window where this could happen
762 		 * with bam_chan_init_hw(), but it is assumed that the caller has
763 		 * stopped activity on any attached hardware engine.  Make sure to do
764 		 * this first so that the BAM hardware doesn't cause memory corruption
765 		 * by accessing freed resources.
766 		 */
767 		if (!list_empty(&bchan->desc_list)) {
768 			async_desc = list_first_entry(&bchan->desc_list,
769 						      struct bam_async_desc, desc_node);
770 			bam_chan_init_hw(bchan, async_desc->dir);
771 		}
772 
773 		list_for_each_entry_safe(async_desc, tmp,
774 					 &bchan->desc_list, desc_node) {
775 			list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
776 			list_del(&async_desc->desc_node);
777 		}
778 
779 		vchan_get_all_descriptors(&bchan->vc, &head);
780 	}
781 
782 	vchan_dma_desc_free_list(&bchan->vc, &head);
783 
784 	return 0;
785 }
786 
787 /**
788  * bam_pause - Pause DMA channel
789  * @chan: dma channel
790  *
791  */
792 static int bam_pause(struct dma_chan *chan)
793 {
794 	struct bam_chan *bchan = to_bam_chan(chan);
795 	struct bam_device *bdev = bchan->bdev;
796 	int ret;
797 
798 	ret = pm_runtime_get_sync(bdev->dev);
799 	if (ret < 0)
800 		return ret;
801 
802 	scoped_guard(spinlock_irqsave, &bchan->vc.lock) {
803 		writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
804 		bchan->paused = 1;
805 	}
806 	pm_runtime_mark_last_busy(bdev->dev);
807 	pm_runtime_put_autosuspend(bdev->dev);
808 
809 	return 0;
810 }
811 
812 /**
813  * bam_resume - Resume DMA channel operations
814  * @chan: dma channel
815  *
816  */
817 static int bam_resume(struct dma_chan *chan)
818 {
819 	struct bam_chan *bchan = to_bam_chan(chan);
820 	struct bam_device *bdev = bchan->bdev;
821 	int ret;
822 
823 	ret = pm_runtime_get_sync(bdev->dev);
824 	if (ret < 0)
825 		return ret;
826 
827 	scoped_guard(spinlock_irqsave, &bchan->vc.lock) {
828 		writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
829 		bchan->paused = 0;
830 	}
831 	pm_runtime_mark_last_busy(bdev->dev);
832 	pm_runtime_put_autosuspend(bdev->dev);
833 
834 	return 0;
835 }
836 
837 /**
838  * process_channel_irqs - processes the channel interrupts
839  * @bdev: bam controller
840  *
841  * This function processes the channel interrupts
842  *
843  */
844 static u32 process_channel_irqs(struct bam_device *bdev)
845 {
846 	u32 i, srcs, pipe_stts, offset, avail;
847 	struct bam_async_desc *async_desc, *tmp;
848 
849 	srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
850 
851 	/* return early if no pipe/channel interrupts are present */
852 	if (!(srcs & P_IRQ))
853 		return srcs;
854 
855 	for (i = 0; i < bdev->num_channels; i++) {
856 		struct bam_chan *bchan = &bdev->channels[i];
857 
858 		if (!(srcs & BIT(i)))
859 			continue;
860 
861 		/* clear pipe irq */
862 		pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
863 
864 		writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
865 
866 		guard(spinlock_irqsave)(&bchan->vc.lock);
867 
868 		offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) &
869 				       P_SW_OFSTS_MASK;
870 		offset /= sizeof(struct bam_desc_hw);
871 
872 		/* Number of bytes available to read */
873 		avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
874 
875 		if (offset < bchan->head)
876 			avail--;
877 
878 		list_for_each_entry_safe(async_desc, tmp,
879 					 &bchan->desc_list, desc_node) {
880 			/* Not enough data to read */
881 			if (avail < async_desc->xfer_len)
882 				break;
883 
884 			/* manage FIFO */
885 			bchan->head += async_desc->xfer_len;
886 			bchan->head %= MAX_DESCRIPTORS;
887 
888 			async_desc->num_desc -= async_desc->xfer_len;
889 			async_desc->curr_desc += async_desc->xfer_len;
890 			avail -= async_desc->xfer_len;
891 
892 			/*
893 			 * if complete, process cookie. Otherwise
894 			 * push back to front of desc_issued so that
895 			 * it gets restarted by the tasklet
896 			 */
897 			if (!async_desc->num_desc) {
898 				vchan_cookie_complete(&async_desc->vd);
899 			} else {
900 				list_add(&async_desc->vd.node,
901 					 &bchan->vc.desc_issued);
902 			}
903 			list_del(&async_desc->desc_node);
904 		}
905 	}
906 
907 	return srcs;
908 }
909 
910 /**
911  * bam_dma_irq - irq handler for bam controller
912  * @irq: IRQ of interrupt
913  * @data: callback data
914  *
915  * IRQ handler for the bam controller
916  */
917 static irqreturn_t bam_dma_irq(int irq, void *data)
918 {
919 	struct bam_device *bdev = data;
920 	u32 clr_mask = 0, srcs = 0;
921 	int ret;
922 
923 	srcs |= process_channel_irqs(bdev);
924 
925 	/* kick off tasklet to start next dma transfer */
926 	if (srcs & P_IRQ)
927 		tasklet_schedule(&bdev->task);
928 
929 	ret = pm_runtime_get_sync(bdev->dev);
930 	if (ret < 0)
931 		return IRQ_NONE;
932 
933 	if (srcs & BAM_IRQ) {
934 		clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
935 
936 		/*
937 		 * don't allow reorder of the various accesses to the BAM
938 		 * registers
939 		 */
940 		mb();
941 
942 		writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
943 	}
944 
945 	pm_runtime_mark_last_busy(bdev->dev);
946 	pm_runtime_put_autosuspend(bdev->dev);
947 
948 	return IRQ_HANDLED;
949 }
950 
951 /**
952  * bam_tx_status - returns status of transaction
953  * @chan: dma channel
954  * @cookie: transaction cookie
955  * @txstate: DMA transaction state
956  *
957  * Return status of dma transaction
958  */
959 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
960 		struct dma_tx_state *txstate)
961 {
962 	struct bam_chan *bchan = to_bam_chan(chan);
963 	struct bam_async_desc *async_desc;
964 	struct virt_dma_desc *vd;
965 	int ret;
966 	size_t residue = 0;
967 	unsigned int i;
968 
969 	ret = dma_cookie_status(chan, cookie, txstate);
970 	if (ret == DMA_COMPLETE)
971 		return ret;
972 
973 	if (!txstate)
974 		return bchan->paused ? DMA_PAUSED : ret;
975 
976 	scoped_guard(spinlock_irqsave, &bchan->vc.lock) {
977 		vd = vchan_find_desc(&bchan->vc, cookie);
978 		if (vd) {
979 			residue = container_of(vd, struct bam_async_desc, vd)->length;
980 		} else {
981 			list_for_each_entry(async_desc, &bchan->desc_list, desc_node) {
982 				if (async_desc->vd.tx.cookie != cookie)
983 					continue;
984 
985 				for (i = 0; i < async_desc->num_desc; i++)
986 					residue += le16_to_cpu(
987 							async_desc->curr_desc[i].size);
988 			}
989 		}
990 	}
991 
992 	dma_set_residue(txstate, residue);
993 
994 	if (ret == DMA_IN_PROGRESS && bchan->paused)
995 		ret = DMA_PAUSED;
996 
997 	return ret;
998 }
999 
1000 /**
1001  * bam_apply_new_config
1002  * @bchan: bam dma channel
1003  * @dir: DMA direction
1004  */
1005 static void bam_apply_new_config(struct bam_chan *bchan,
1006 	enum dma_transfer_direction dir)
1007 {
1008 	struct bam_device *bdev = bchan->bdev;
1009 	u32 maxburst;
1010 
1011 	if (!bdev->controlled_remotely) {
1012 		if (dir == DMA_DEV_TO_MEM)
1013 			maxburst = bchan->slave.src_maxburst;
1014 		else
1015 			maxburst = bchan->slave.dst_maxburst;
1016 
1017 		writel_relaxed(maxburst,
1018 			       bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1019 	}
1020 
1021 	bchan->reconfigure = 0;
1022 }
1023 
1024 /**
1025  * bam_start_dma - start next transaction
1026  * @bchan: bam dma channel
1027  */
1028 static void bam_start_dma(struct bam_chan *bchan)
1029 {
1030 	struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
1031 	struct bam_device *bdev = bchan->bdev;
1032 	struct bam_async_desc *async_desc = NULL;
1033 	struct bam_desc_hw *desc;
1034 	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
1035 					sizeof(struct bam_desc_hw));
1036 	int ret;
1037 	unsigned int avail;
1038 	struct dmaengine_desc_callback cb;
1039 
1040 	lockdep_assert_held(&bchan->vc.lock);
1041 
1042 	if (!vd)
1043 		return;
1044 
1045 	ret = pm_runtime_get_sync(bdev->dev);
1046 	if (ret < 0)
1047 		return;
1048 
1049 	while (vd && !IS_BUSY(bchan)) {
1050 		list_del(&vd->node);
1051 
1052 		async_desc = container_of(vd, struct bam_async_desc, vd);
1053 
1054 		/* on first use, initialize the channel hardware */
1055 		if (!bchan->initialized)
1056 			bam_chan_init_hw(bchan, async_desc->dir);
1057 
1058 		/* apply new slave config changes, if necessary */
1059 		if (bchan->reconfigure)
1060 			bam_apply_new_config(bchan, async_desc->dir);
1061 
1062 		desc = async_desc->curr_desc;
1063 		avail = CIRC_SPACE(bchan->tail, bchan->head,
1064 				   MAX_DESCRIPTORS + 1);
1065 
1066 		if (async_desc->num_desc > avail)
1067 			async_desc->xfer_len = avail;
1068 		else
1069 			async_desc->xfer_len = async_desc->num_desc;
1070 
1071 		/* set any special flags on the last descriptor */
1072 		if (async_desc->num_desc == async_desc->xfer_len)
1073 			desc[async_desc->xfer_len - 1].flags |=
1074 						cpu_to_le16(async_desc->flags);
1075 
1076 		vd = vchan_next_desc(&bchan->vc);
1077 
1078 		dmaengine_desc_get_callback(&async_desc->vd.tx, &cb);
1079 
1080 		/*
1081 		 * An interrupt is generated at this desc, if
1082 		 *  - FIFO is FULL.
1083 		 *  - No more descriptors to add.
1084 		 *  - If a callback completion was requested for this DESC,
1085 		 *     In this case, BAM will deliver the completion callback
1086 		 *     for this desc and continue processing the next desc.
1087 		 */
1088 		if (((avail <= async_desc->xfer_len) || !vd ||
1089 		     dmaengine_desc_callback_valid(&cb)) &&
1090 		    !(async_desc->flags & DESC_FLAG_EOT))
1091 			desc[async_desc->xfer_len - 1].flags |=
1092 				cpu_to_le16(DESC_FLAG_INT);
1093 
1094 		if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
1095 			u32 partial = MAX_DESCRIPTORS - bchan->tail;
1096 
1097 			memcpy(&fifo[bchan->tail], desc,
1098 			       partial * sizeof(struct bam_desc_hw));
1099 			memcpy(fifo, &desc[partial],
1100 			       (async_desc->xfer_len - partial) *
1101 				sizeof(struct bam_desc_hw));
1102 		} else {
1103 			memcpy(&fifo[bchan->tail], desc,
1104 			       async_desc->xfer_len *
1105 			       sizeof(struct bam_desc_hw));
1106 		}
1107 
1108 		bchan->tail += async_desc->xfer_len;
1109 		bchan->tail %= MAX_DESCRIPTORS;
1110 		list_add_tail(&async_desc->desc_node, &bchan->desc_list);
1111 	}
1112 
1113 	/* ensure descriptor writes and dma start not reordered */
1114 	wmb();
1115 	writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
1116 			bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
1117 
1118 	pm_runtime_mark_last_busy(bdev->dev);
1119 	pm_runtime_put_autosuspend(bdev->dev);
1120 }
1121 
1122 /**
1123  * dma_tasklet - DMA IRQ tasklet
1124  * @t: tasklet argument (bam controller structure)
1125  *
1126  * Sets up next DMA operation and then processes all completed transactions
1127  */
1128 static void dma_tasklet(struct tasklet_struct *t)
1129 {
1130 	struct bam_device *bdev = from_tasklet(bdev, t, task);
1131 	struct bam_chan *bchan;
1132 	unsigned int i;
1133 
1134 	/* go through the channels and kick off transactions */
1135 	for (i = 0; i < bdev->num_channels; i++) {
1136 		bchan = &bdev->channels[i];
1137 
1138 		guard(spinlock_irqsave)(&bchan->vc.lock);
1139 
1140 		if (!list_empty(&bchan->vc.desc_issued) && !IS_BUSY(bchan))
1141 			bam_start_dma(bchan);
1142 	}
1143 
1144 }
1145 
1146 /**
1147  * bam_issue_pending - starts pending transactions
1148  * @chan: dma channel
1149  *
1150  * Calls tasklet directly which in turn starts any pending transactions
1151  */
1152 static void bam_issue_pending(struct dma_chan *chan)
1153 {
1154 	struct bam_chan *bchan = to_bam_chan(chan);
1155 
1156 	guard(spinlock_irqsave)(&bchan->vc.lock);
1157 
1158 	/* if work pending and idle, start a transaction */
1159 	if (vchan_issue_pending(&bchan->vc) && !IS_BUSY(bchan))
1160 		bam_start_dma(bchan);
1161 }
1162 
1163 /**
1164  * bam_dma_free_desc - free descriptor memory
1165  * @vd: virtual descriptor
1166  *
1167  */
1168 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1169 {
1170 	struct bam_async_desc *async_desc = container_of(vd,
1171 			struct bam_async_desc, vd);
1172 
1173 	kfree(async_desc);
1174 }
1175 
1176 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1177 		struct of_dma *of)
1178 {
1179 	struct bam_device *bdev = container_of(of->of_dma_data,
1180 					struct bam_device, common);
1181 	unsigned int request;
1182 
1183 	if (dma_spec->args_count != 1)
1184 		return NULL;
1185 
1186 	request = dma_spec->args[0];
1187 	if (request >= bdev->num_channels)
1188 		return NULL;
1189 
1190 	return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1191 }
1192 
1193 /**
1194  * bam_init
1195  * @bdev: bam device
1196  *
1197  * Initialization helper for global bam registers
1198  */
1199 static int bam_init(struct bam_device *bdev)
1200 {
1201 	u32 val;
1202 
1203 	/* read revision and configuration information */
1204 	if (!bdev->num_ees) {
1205 		val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
1206 		bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
1207 	}
1208 
1209 	/* check that configured EE is within range */
1210 	if (bdev->ee >= bdev->num_ees)
1211 		return -EINVAL;
1212 
1213 	if (!bdev->num_channels) {
1214 		val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1215 		bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1216 	}
1217 
1218 	/* Reset BAM now if fully controlled locally */
1219 	if (!bdev->controlled_remotely && !bdev->powered_remotely)
1220 		bam_reset(bdev);
1221 
1222 	return 0;
1223 }
1224 
1225 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1226 	u32 index)
1227 {
1228 	bchan->id = index;
1229 	bchan->bdev = bdev;
1230 
1231 	vchan_init(&bchan->vc, &bdev->common);
1232 	bchan->vc.desc_free = bam_dma_free_desc;
1233 	INIT_LIST_HEAD(&bchan->desc_list);
1234 }
1235 
1236 static const struct of_device_id bam_of_match[] = {
1237 	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1238 	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1239 	{ .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1240 	{ .compatible = "qcom,bam-v2.0.0", .data = &bam_v2_0_reg_info },
1241 	{}
1242 };
1243 
1244 MODULE_DEVICE_TABLE(of, bam_of_match);
1245 
1246 static int bam_dma_probe(struct platform_device *pdev)
1247 {
1248 	struct bam_device *bdev;
1249 	const struct of_device_id *match;
1250 	int ret, i;
1251 
1252 	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1253 	if (!bdev)
1254 		return -ENOMEM;
1255 
1256 	bdev->dev = &pdev->dev;
1257 
1258 	match = of_match_node(bam_of_match, pdev->dev.of_node);
1259 	if (!match) {
1260 		dev_err(&pdev->dev, "Unsupported BAM module\n");
1261 		return -ENODEV;
1262 	}
1263 
1264 	bdev->layout = match->data;
1265 
1266 	bdev->regs = devm_platform_ioremap_resource(pdev, 0);
1267 	if (IS_ERR(bdev->regs))
1268 		return PTR_ERR(bdev->regs);
1269 
1270 	bdev->irq = platform_get_irq(pdev, 0);
1271 	if (bdev->irq < 0)
1272 		return bdev->irq;
1273 
1274 	ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1275 	if (ret) {
1276 		dev_err(bdev->dev, "Execution environment unspecified\n");
1277 		return ret;
1278 	}
1279 
1280 	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
1281 						"qcom,controlled-remotely");
1282 	bdev->powered_remotely = of_property_read_bool(pdev->dev.of_node,
1283 						"qcom,powered-remotely");
1284 
1285 	if (bdev->controlled_remotely || bdev->powered_remotely)
1286 		bdev->bamclk = devm_clk_get_optional(bdev->dev, "bam_clk");
1287 	else
1288 		bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1289 
1290 	if (IS_ERR(bdev->bamclk))
1291 		return PTR_ERR(bdev->bamclk);
1292 
1293 	if (!bdev->bamclk) {
1294 		ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
1295 					   &bdev->num_channels);
1296 		if (ret) {
1297 			dev_err(bdev->dev, "num-channels unspecified in dt\n");
1298 			return ret;
1299 		}
1300 
1301 		ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",
1302 					   &bdev->num_ees);
1303 		if (ret) {
1304 			dev_err(bdev->dev, "num-ees unspecified in dt\n");
1305 			return ret;
1306 		}
1307 	}
1308 
1309 	ret = clk_prepare_enable(bdev->bamclk);
1310 	if (ret) {
1311 		dev_err(bdev->dev, "failed to prepare/enable clock\n");
1312 		return ret;
1313 	}
1314 
1315 	ret = bam_init(bdev);
1316 	if (ret)
1317 		goto err_disable_clk;
1318 
1319 	tasklet_setup(&bdev->task, dma_tasklet);
1320 
1321 	bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1322 				sizeof(*bdev->channels), GFP_KERNEL);
1323 
1324 	if (!bdev->channels) {
1325 		ret = -ENOMEM;
1326 		goto err_tasklet_kill;
1327 	}
1328 
1329 	/* allocate and initialize channels */
1330 	INIT_LIST_HEAD(&bdev->common.channels);
1331 
1332 	for (i = 0; i < bdev->num_channels; i++)
1333 		bam_channel_init(bdev, &bdev->channels[i], i);
1334 
1335 	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1336 			IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1337 	if (ret)
1338 		goto err_bam_channel_exit;
1339 
1340 	/* set max dma segment size */
1341 	bdev->common.dev = bdev->dev;
1342 	dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1343 
1344 	platform_set_drvdata(pdev, bdev);
1345 
1346 	/* set capabilities */
1347 	dma_cap_zero(bdev->common.cap_mask);
1348 	dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1349 
1350 	/* initialize dmaengine apis */
1351 	bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1352 	bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1353 	bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1354 	bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1355 	bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1356 	bdev->common.device_free_chan_resources = bam_free_chan;
1357 	bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1358 	bdev->common.device_config = bam_slave_config;
1359 	bdev->common.device_pause = bam_pause;
1360 	bdev->common.device_resume = bam_resume;
1361 	bdev->common.device_terminate_all = bam_dma_terminate_all;
1362 	bdev->common.device_issue_pending = bam_issue_pending;
1363 	bdev->common.device_tx_status = bam_tx_status;
1364 	bdev->common.dev = bdev->dev;
1365 
1366 	ret = dma_async_device_register(&bdev->common);
1367 	if (ret) {
1368 		dev_err(bdev->dev, "failed to register dma async device\n");
1369 		goto err_bam_channel_exit;
1370 	}
1371 
1372 	ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1373 					&bdev->common);
1374 	if (ret)
1375 		goto err_unregister_dma;
1376 
1377 	pm_runtime_irq_safe(&pdev->dev);
1378 	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
1379 	pm_runtime_use_autosuspend(&pdev->dev);
1380 	pm_runtime_mark_last_busy(&pdev->dev);
1381 	pm_runtime_set_active(&pdev->dev);
1382 	pm_runtime_enable(&pdev->dev);
1383 
1384 	return 0;
1385 
1386 err_unregister_dma:
1387 	dma_async_device_unregister(&bdev->common);
1388 err_bam_channel_exit:
1389 	for (i = 0; i < bdev->num_channels; i++)
1390 		tasklet_kill(&bdev->channels[i].vc.task);
1391 err_tasklet_kill:
1392 	tasklet_kill(&bdev->task);
1393 err_disable_clk:
1394 	clk_disable_unprepare(bdev->bamclk);
1395 
1396 	return ret;
1397 }
1398 
1399 static void bam_dma_remove(struct platform_device *pdev)
1400 {
1401 	struct bam_device *bdev = platform_get_drvdata(pdev);
1402 	u32 i;
1403 
1404 	pm_runtime_force_suspend(&pdev->dev);
1405 
1406 	of_dma_controller_free(pdev->dev.of_node);
1407 	dma_async_device_unregister(&bdev->common);
1408 
1409 	/* mask all interrupts for this execution environment */
1410 	writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1411 
1412 	devm_free_irq(bdev->dev, bdev->irq, bdev);
1413 
1414 	for (i = 0; i < bdev->num_channels; i++) {
1415 		bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1416 		tasklet_kill(&bdev->channels[i].vc.task);
1417 
1418 		if (!bdev->channels[i].fifo_virt)
1419 			continue;
1420 
1421 		dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1422 			    bdev->channels[i].fifo_virt,
1423 			    bdev->channels[i].fifo_phys);
1424 	}
1425 
1426 	tasklet_kill(&bdev->task);
1427 
1428 	clk_disable_unprepare(bdev->bamclk);
1429 }
1430 
1431 static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
1432 {
1433 	struct bam_device *bdev = dev_get_drvdata(dev);
1434 
1435 	clk_disable(bdev->bamclk);
1436 
1437 	return 0;
1438 }
1439 
1440 static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
1441 {
1442 	struct bam_device *bdev = dev_get_drvdata(dev);
1443 	int ret;
1444 
1445 	ret = clk_enable(bdev->bamclk);
1446 	if (ret < 0) {
1447 		dev_err(dev, "clk_enable failed: %d\n", ret);
1448 		return ret;
1449 	}
1450 
1451 	return 0;
1452 }
1453 
1454 static int __maybe_unused bam_dma_suspend(struct device *dev)
1455 {
1456 	struct bam_device *bdev = dev_get_drvdata(dev);
1457 
1458 	pm_runtime_force_suspend(dev);
1459 	clk_unprepare(bdev->bamclk);
1460 
1461 	return 0;
1462 }
1463 
1464 static int __maybe_unused bam_dma_resume(struct device *dev)
1465 {
1466 	struct bam_device *bdev = dev_get_drvdata(dev);
1467 	int ret;
1468 
1469 	ret = clk_prepare(bdev->bamclk);
1470 	if (ret)
1471 		return ret;
1472 
1473 	pm_runtime_force_resume(dev);
1474 
1475 	return 0;
1476 }
1477 
1478 static const struct dev_pm_ops bam_dma_pm_ops = {
1479 	SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
1480 	SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
1481 				NULL)
1482 };
1483 
1484 static struct platform_driver bam_dma_driver = {
1485 	.probe = bam_dma_probe,
1486 	.remove = bam_dma_remove,
1487 	.driver = {
1488 		.name = "bam-dma-engine",
1489 		.pm = &bam_dma_pm_ops,
1490 		.of_match_table = bam_of_match,
1491 	},
1492 };
1493 
1494 module_platform_driver(bam_dma_driver);
1495 
1496 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1497 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1498 MODULE_LICENSE("GPL v2");
1499