xref: /linux/drivers/dma/qcom/bam_dma.c (revision ca220141fa8ebae09765a242076b2b77338106b0)
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 /* BAM CTRL */
203 #define BAM_SW_RST			BIT(0)
204 #define BAM_EN				BIT(1)
205 #define BAM_EN_ACCUM			BIT(4)
206 #define BAM_TESTBUS_SEL_SHIFT		5
207 #define BAM_TESTBUS_SEL_MASK		0x3F
208 #define BAM_DESC_CACHE_SEL_SHIFT	13
209 #define BAM_DESC_CACHE_SEL_MASK		0x3
210 #define BAM_CACHED_DESC_STORE		BIT(15)
211 #define IBC_DISABLE			BIT(16)
212 
213 /* BAM REVISION */
214 #define REVISION_SHIFT		0
215 #define REVISION_MASK		0xFF
216 #define NUM_EES_SHIFT		8
217 #define NUM_EES_MASK		0xF
218 #define CE_BUFFER_SIZE		BIT(13)
219 #define AXI_ACTIVE		BIT(14)
220 #define USE_VMIDMT		BIT(15)
221 #define SECURED			BIT(16)
222 #define BAM_HAS_NO_BYPASS	BIT(17)
223 #define HIGH_FREQUENCY_BAM	BIT(18)
224 #define INACTIV_TMRS_EXST	BIT(19)
225 #define NUM_INACTIV_TMRS	BIT(20)
226 #define DESC_CACHE_DEPTH_SHIFT	21
227 #define DESC_CACHE_DEPTH_1	(0 << DESC_CACHE_DEPTH_SHIFT)
228 #define DESC_CACHE_DEPTH_2	(1 << DESC_CACHE_DEPTH_SHIFT)
229 #define DESC_CACHE_DEPTH_3	(2 << DESC_CACHE_DEPTH_SHIFT)
230 #define DESC_CACHE_DEPTH_4	(3 << DESC_CACHE_DEPTH_SHIFT)
231 #define CMD_DESC_EN		BIT(23)
232 #define INACTIV_TMR_BASE_SHIFT	24
233 #define INACTIV_TMR_BASE_MASK	0xFF
234 
235 /* BAM NUM PIPES */
236 #define BAM_NUM_PIPES_SHIFT		0
237 #define BAM_NUM_PIPES_MASK		0xFF
238 #define PERIPH_NON_PIPE_GRP_SHIFT	16
239 #define PERIPH_NON_PIP_GRP_MASK		0xFF
240 #define BAM_NON_PIPE_GRP_SHIFT		24
241 #define BAM_NON_PIPE_GRP_MASK		0xFF
242 
243 /* BAM CNFG BITS */
244 #define BAM_PIPE_CNFG		BIT(2)
245 #define BAM_FULL_PIPE		BIT(11)
246 #define BAM_NO_EXT_P_RST	BIT(12)
247 #define BAM_IBC_DISABLE		BIT(13)
248 #define BAM_SB_CLK_REQ		BIT(14)
249 #define BAM_PSM_CSW_REQ		BIT(15)
250 #define BAM_PSM_P_RES		BIT(16)
251 #define BAM_AU_P_RES		BIT(17)
252 #define BAM_SI_P_RES		BIT(18)
253 #define BAM_WB_P_RES		BIT(19)
254 #define BAM_WB_BLK_CSW		BIT(20)
255 #define BAM_WB_CSW_ACK_IDL	BIT(21)
256 #define BAM_WB_RETR_SVPNT	BIT(22)
257 #define BAM_WB_DSC_AVL_P_RST	BIT(23)
258 #define BAM_REG_P_EN		BIT(24)
259 #define BAM_PSM_P_HD_DATA	BIT(25)
260 #define BAM_AU_ACCUMED		BIT(26)
261 #define BAM_CMD_ENABLE		BIT(27)
262 
263 #define BAM_CNFG_BITS_DEFAULT	(BAM_PIPE_CNFG |	\
264 				 BAM_NO_EXT_P_RST |	\
265 				 BAM_IBC_DISABLE |	\
266 				 BAM_SB_CLK_REQ |	\
267 				 BAM_PSM_CSW_REQ |	\
268 				 BAM_PSM_P_RES |	\
269 				 BAM_AU_P_RES |		\
270 				 BAM_SI_P_RES |		\
271 				 BAM_WB_P_RES |		\
272 				 BAM_WB_BLK_CSW |	\
273 				 BAM_WB_CSW_ACK_IDL |	\
274 				 BAM_WB_RETR_SVPNT |	\
275 				 BAM_WB_DSC_AVL_P_RST |	\
276 				 BAM_REG_P_EN |		\
277 				 BAM_PSM_P_HD_DATA |	\
278 				 BAM_AU_ACCUMED |	\
279 				 BAM_CMD_ENABLE)
280 
281 /* PIPE CTRL */
282 #define P_EN			BIT(1)
283 #define P_DIRECTION		BIT(3)
284 #define P_SYS_STRM		BIT(4)
285 #define P_SYS_MODE		BIT(5)
286 #define P_AUTO_EOB		BIT(6)
287 #define P_AUTO_EOB_SEL_SHIFT	7
288 #define P_AUTO_EOB_SEL_512	(0 << P_AUTO_EOB_SEL_SHIFT)
289 #define P_AUTO_EOB_SEL_256	(1 << P_AUTO_EOB_SEL_SHIFT)
290 #define P_AUTO_EOB_SEL_128	(2 << P_AUTO_EOB_SEL_SHIFT)
291 #define P_AUTO_EOB_SEL_64	(3 << P_AUTO_EOB_SEL_SHIFT)
292 #define P_PREFETCH_LIMIT_SHIFT	9
293 #define P_PREFETCH_LIMIT_32	(0 << P_PREFETCH_LIMIT_SHIFT)
294 #define P_PREFETCH_LIMIT_16	(1 << P_PREFETCH_LIMIT_SHIFT)
295 #define P_PREFETCH_LIMIT_4	(2 << P_PREFETCH_LIMIT_SHIFT)
296 #define P_WRITE_NWD		BIT(11)
297 #define P_LOCK_GROUP_SHIFT	16
298 #define P_LOCK_GROUP_MASK	0x1F
299 
300 /* BAM_DESC_CNT_TRSHLD */
301 #define CNT_TRSHLD		0xffff
302 #define DEFAULT_CNT_THRSHLD	0x4
303 
304 /* BAM_IRQ_SRCS */
305 #define BAM_IRQ			BIT(31)
306 #define P_IRQ			0x7fffffff
307 
308 /* BAM_IRQ_SRCS_MSK */
309 #define BAM_IRQ_MSK		BAM_IRQ
310 #define P_IRQ_MSK		P_IRQ
311 
312 /* BAM_IRQ_STTS */
313 #define BAM_TIMER_IRQ		BIT(4)
314 #define BAM_EMPTY_IRQ		BIT(3)
315 #define BAM_ERROR_IRQ		BIT(2)
316 #define BAM_HRESP_ERR_IRQ	BIT(1)
317 
318 /* BAM_IRQ_CLR */
319 #define BAM_TIMER_CLR		BIT(4)
320 #define BAM_EMPTY_CLR		BIT(3)
321 #define BAM_ERROR_CLR		BIT(2)
322 #define BAM_HRESP_ERR_CLR	BIT(1)
323 
324 /* BAM_IRQ_EN */
325 #define BAM_TIMER_EN		BIT(4)
326 #define BAM_EMPTY_EN		BIT(3)
327 #define BAM_ERROR_EN		BIT(2)
328 #define BAM_HRESP_ERR_EN	BIT(1)
329 
330 /* BAM_P_IRQ_EN */
331 #define P_PRCSD_DESC_EN		BIT(0)
332 #define P_TIMER_EN		BIT(1)
333 #define P_WAKE_EN		BIT(2)
334 #define P_OUT_OF_DESC_EN	BIT(3)
335 #define P_ERR_EN		BIT(4)
336 #define P_TRNSFR_END_EN		BIT(5)
337 #define P_DEFAULT_IRQS_EN	(P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
338 
339 /* BAM_P_SW_OFSTS */
340 #define P_SW_OFSTS_MASK		0xffff
341 
342 #define BAM_DESC_FIFO_SIZE	SZ_32K
343 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
344 #define BAM_FIFO_SIZE	(SZ_32K - 8)
345 #define IS_BUSY(chan)	(CIRC_SPACE(bchan->tail, bchan->head,\
346 			 MAX_DESCRIPTORS + 1) == 0)
347 
348 struct bam_chan {
349 	struct virt_dma_chan vc;
350 
351 	struct bam_device *bdev;
352 
353 	/* configuration from device tree */
354 	u32 id;
355 
356 	/* runtime configuration */
357 	struct dma_slave_config slave;
358 
359 	/* fifo storage */
360 	struct bam_desc_hw *fifo_virt;
361 	dma_addr_t fifo_phys;
362 
363 	/* fifo markers */
364 	unsigned short head;		/* start of active descriptor entries */
365 	unsigned short tail;		/* end of active descriptor entries */
366 
367 	unsigned int initialized;	/* is the channel hw initialized? */
368 	unsigned int paused;		/* is the channel paused? */
369 	unsigned int reconfigure;	/* new slave config? */
370 	/* list of descriptors currently processed */
371 	struct list_head desc_list;
372 
373 	struct list_head node;
374 };
375 
376 static inline struct bam_chan *to_bam_chan(struct dma_chan *common)
377 {
378 	return container_of(common, struct bam_chan, vc.chan);
379 }
380 
381 struct bam_device {
382 	void __iomem *regs;
383 	struct device *dev;
384 	struct dma_device common;
385 	struct bam_chan *channels;
386 	u32 num_channels;
387 	u32 num_ees;
388 
389 	/* execution environment ID, from DT */
390 	u32 ee;
391 	bool controlled_remotely;
392 	bool powered_remotely;
393 	u32 active_channels;
394 
395 	const struct reg_offset_data *layout;
396 
397 	struct clk *bamclk;
398 	int irq;
399 
400 	/* dma start transaction tasklet */
401 	struct tasklet_struct task;
402 };
403 
404 /**
405  * bam_addr - returns BAM register address
406  * @bdev: bam device
407  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
408  * @reg:  register enum
409  */
410 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
411 		enum bam_reg reg)
412 {
413 	const struct reg_offset_data r = bdev->layout[reg];
414 
415 	return bdev->regs + r.base_offset +
416 		r.pipe_mult * pipe +
417 		r.evnt_mult * pipe +
418 		r.ee_mult * bdev->ee;
419 }
420 
421 /**
422  * bam_reset() - reset and initialize BAM registers
423  * @bdev: bam device
424  */
425 static void bam_reset(struct bam_device *bdev)
426 {
427 	u32 val;
428 
429 	/* s/w reset bam */
430 	/* after reset all pipes are disabled and idle */
431 	val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
432 	val |= BAM_SW_RST;
433 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
434 	val &= ~BAM_SW_RST;
435 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
436 
437 	/* make sure previous stores are visible before enabling BAM */
438 	wmb();
439 
440 	/* enable bam */
441 	val |= BAM_EN;
442 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
443 
444 	/* set descriptor threshold, start with 4 bytes */
445 	writel_relaxed(DEFAULT_CNT_THRSHLD,
446 			bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
447 
448 	/* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
449 	writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
450 
451 	/* enable irqs for errors */
452 	writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
453 			bam_addr(bdev, 0, BAM_IRQ_EN));
454 
455 	/* unmask global bam interrupt */
456 	writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
457 }
458 
459 /**
460  * bam_reset_channel - Reset individual BAM DMA channel
461  * @bchan: bam channel
462  *
463  * This function resets a specific BAM channel
464  */
465 static void bam_reset_channel(struct bam_chan *bchan)
466 {
467 	struct bam_device *bdev = bchan->bdev;
468 
469 	lockdep_assert_held(&bchan->vc.lock);
470 
471 	/* reset channel */
472 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
473 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
474 
475 	/* don't allow cpu to reorder BAM register accesses done after this */
476 	wmb();
477 
478 	/* make sure hw is initialized when channel is used the first time  */
479 	bchan->initialized = 0;
480 }
481 
482 /**
483  * bam_chan_init_hw - Initialize channel hardware
484  * @bchan: bam channel
485  * @dir: DMA transfer direction
486  *
487  * This function resets and initializes the BAM channel
488  */
489 static void bam_chan_init_hw(struct bam_chan *bchan,
490 	enum dma_transfer_direction dir)
491 {
492 	struct bam_device *bdev = bchan->bdev;
493 	u32 val;
494 
495 	/* Reset the channel to clear internal state of the FIFO */
496 	bam_reset_channel(bchan);
497 
498 	/*
499 	 * write out 8 byte aligned address.  We have enough space for this
500 	 * because we allocated 1 more descriptor (8 bytes) than we can use
501 	 */
502 	writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
503 			bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
504 	writel_relaxed(BAM_FIFO_SIZE,
505 			bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
506 
507 	/* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
508 	writel_relaxed(P_DEFAULT_IRQS_EN,
509 			bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
510 
511 	/* unmask the specific pipe and EE combo */
512 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
513 	val |= BIT(bchan->id);
514 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
515 
516 	/* don't allow cpu to reorder the channel enable done below */
517 	wmb();
518 
519 	/* set fixed direction and mode, then enable channel */
520 	val = P_EN | P_SYS_MODE;
521 	if (dir == DMA_DEV_TO_MEM)
522 		val |= P_DIRECTION;
523 
524 	writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
525 
526 	bchan->initialized = 1;
527 
528 	/* init FIFO pointers */
529 	bchan->head = 0;
530 	bchan->tail = 0;
531 }
532 
533 /**
534  * bam_alloc_chan - Allocate channel resources for DMA channel.
535  * @chan: specified channel
536  *
537  * This function allocates the FIFO descriptor memory
538  */
539 static int bam_alloc_chan(struct dma_chan *chan)
540 {
541 	struct bam_chan *bchan = to_bam_chan(chan);
542 	struct bam_device *bdev = bchan->bdev;
543 
544 	if (bchan->fifo_virt)
545 		return 0;
546 
547 	/* allocate FIFO descriptor space, but only if necessary */
548 	bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
549 					&bchan->fifo_phys, GFP_KERNEL);
550 
551 	if (!bchan->fifo_virt) {
552 		dev_err(bdev->dev, "Failed to allocate desc fifo\n");
553 		return -ENOMEM;
554 	}
555 
556 	if (bdev->active_channels++ == 0 && bdev->powered_remotely)
557 		bam_reset(bdev);
558 
559 	return 0;
560 }
561 
562 /**
563  * bam_free_chan - Frees dma resources associated with specific channel
564  * @chan: specified channel
565  *
566  * Free the allocated fifo descriptor memory and channel resources
567  *
568  */
569 static void bam_free_chan(struct dma_chan *chan)
570 {
571 	struct bam_chan *bchan = to_bam_chan(chan);
572 	struct bam_device *bdev = bchan->bdev;
573 	u32 val;
574 	int ret;
575 
576 	ret = pm_runtime_get_sync(bdev->dev);
577 	if (ret < 0)
578 		return;
579 
580 	vchan_free_chan_resources(to_virt_chan(chan));
581 
582 	if (!list_empty(&bchan->desc_list)) {
583 		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
584 		goto err;
585 	}
586 
587 	scoped_guard(spinlock_irqsave, &bchan->vc.lock)
588 		bam_reset_channel(bchan);
589 
590 	dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
591 		    bchan->fifo_phys);
592 	bchan->fifo_virt = NULL;
593 
594 	/* mask irq for pipe/channel */
595 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
596 	val &= ~BIT(bchan->id);
597 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
598 
599 	/* disable irq */
600 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
601 
602 	if (--bdev->active_channels == 0 && bdev->powered_remotely) {
603 		/* s/w reset bam */
604 		val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
605 		val |= BAM_SW_RST;
606 		writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
607 	}
608 
609 err:
610 	pm_runtime_mark_last_busy(bdev->dev);
611 	pm_runtime_put_autosuspend(bdev->dev);
612 }
613 
614 /**
615  * bam_slave_config - set slave configuration for channel
616  * @chan: dma channel
617  * @cfg: slave configuration
618  *
619  * Sets slave configuration for channel
620  *
621  */
622 static int bam_slave_config(struct dma_chan *chan,
623 			    struct dma_slave_config *cfg)
624 {
625 	struct bam_chan *bchan = to_bam_chan(chan);
626 
627 	guard(spinlock_irqsave)(&bchan->vc.lock);
628 
629 	memcpy(&bchan->slave, cfg, sizeof(*cfg));
630 	bchan->reconfigure = 1;
631 
632 	return 0;
633 }
634 
635 /**
636  * bam_prep_slave_sg - Prep slave sg transaction
637  *
638  * @chan: dma channel
639  * @sgl: scatter gather list
640  * @sg_len: length of sg
641  * @direction: DMA transfer direction
642  * @flags: DMA flags
643  * @context: transfer context (unused)
644  */
645 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
646 	struct scatterlist *sgl, unsigned int sg_len,
647 	enum dma_transfer_direction direction, unsigned long flags,
648 	void *context)
649 {
650 	struct bam_chan *bchan = to_bam_chan(chan);
651 	struct bam_device *bdev = bchan->bdev;
652 	struct bam_async_desc *async_desc;
653 	struct scatterlist *sg;
654 	u32 i;
655 	struct bam_desc_hw *desc;
656 	unsigned int num_alloc;
657 
658 	if (!is_slave_direction(direction)) {
659 		dev_err(bdev->dev, "invalid dma direction\n");
660 		return NULL;
661 	}
662 
663 	/* allocate enough room to accommodate the number of entries */
664 	num_alloc = sg_nents_for_dma(sgl, sg_len, BAM_FIFO_SIZE);
665 	async_desc = kzalloc(struct_size(async_desc, desc, num_alloc),
666 			     GFP_NOWAIT);
667 	if (!async_desc)
668 		return NULL;
669 
670 	if (flags & DMA_PREP_FENCE)
671 		async_desc->flags |= DESC_FLAG_NWD;
672 
673 	if (flags & DMA_PREP_INTERRUPT)
674 		async_desc->flags |= DESC_FLAG_EOT;
675 
676 	async_desc->num_desc = num_alloc;
677 	async_desc->curr_desc = async_desc->desc;
678 	async_desc->dir = direction;
679 
680 	/* fill in temporary descriptors */
681 	desc = async_desc->desc;
682 	for_each_sg(sgl, sg, sg_len, i) {
683 		unsigned int remainder = sg_dma_len(sg);
684 		unsigned int curr_offset = 0;
685 
686 		do {
687 			if (flags & DMA_PREP_CMD)
688 				desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
689 
690 			desc->addr = cpu_to_le32(sg_dma_address(sg) +
691 						 curr_offset);
692 
693 			if (remainder > BAM_FIFO_SIZE) {
694 				desc->size = cpu_to_le16(BAM_FIFO_SIZE);
695 				remainder -= BAM_FIFO_SIZE;
696 				curr_offset += BAM_FIFO_SIZE;
697 			} else {
698 				desc->size = cpu_to_le16(remainder);
699 				remainder = 0;
700 			}
701 
702 			async_desc->length += le16_to_cpu(desc->size);
703 			desc++;
704 		} while (remainder > 0);
705 	}
706 
707 	return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
708 }
709 
710 /**
711  * bam_dma_terminate_all - terminate all transactions on a channel
712  * @chan: bam dma channel
713  *
714  * Dequeues and frees all transactions
715  * No callbacks are done
716  *
717  */
718 static int bam_dma_terminate_all(struct dma_chan *chan)
719 {
720 	struct bam_chan *bchan = to_bam_chan(chan);
721 	struct bam_async_desc *async_desc, *tmp;
722 	LIST_HEAD(head);
723 
724 	/* remove all transactions, including active transaction */
725 	scoped_guard(spinlock_irqsave, &bchan->vc.lock) {
726 		/*
727 		 * If we have transactions queued, then some might be committed to the
728 		 * hardware in the desc fifo.  The only way to reset the desc fifo is
729 		 * to do a hardware reset (either by pipe or the entire block).
730 		 * bam_chan_init_hw() will trigger a pipe reset, and also reinit the
731 		 * pipe.  If the pipe is left disabled (default state after pipe reset)
732 		 * and is accessed by a connected hardware engine, a fatal error in
733 		 * the BAM will occur.  There is a small window where this could happen
734 		 * with bam_chan_init_hw(), but it is assumed that the caller has
735 		 * stopped activity on any attached hardware engine.  Make sure to do
736 		 * this first so that the BAM hardware doesn't cause memory corruption
737 		 * by accessing freed resources.
738 		 */
739 		if (!list_empty(&bchan->desc_list)) {
740 			async_desc = list_first_entry(&bchan->desc_list,
741 						      struct bam_async_desc, desc_node);
742 			bam_chan_init_hw(bchan, async_desc->dir);
743 		}
744 
745 		list_for_each_entry_safe(async_desc, tmp,
746 					 &bchan->desc_list, desc_node) {
747 			list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
748 			list_del(&async_desc->desc_node);
749 		}
750 
751 		vchan_get_all_descriptors(&bchan->vc, &head);
752 	}
753 
754 	vchan_dma_desc_free_list(&bchan->vc, &head);
755 
756 	return 0;
757 }
758 
759 /**
760  * bam_pause - Pause DMA channel
761  * @chan: dma channel
762  *
763  */
764 static int bam_pause(struct dma_chan *chan)
765 {
766 	struct bam_chan *bchan = to_bam_chan(chan);
767 	struct bam_device *bdev = bchan->bdev;
768 	int ret;
769 
770 	ret = pm_runtime_get_sync(bdev->dev);
771 	if (ret < 0)
772 		return ret;
773 
774 	scoped_guard(spinlock_irqsave, &bchan->vc.lock) {
775 		writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
776 		bchan->paused = 1;
777 	}
778 	pm_runtime_mark_last_busy(bdev->dev);
779 	pm_runtime_put_autosuspend(bdev->dev);
780 
781 	return 0;
782 }
783 
784 /**
785  * bam_resume - Resume DMA channel operations
786  * @chan: dma channel
787  *
788  */
789 static int bam_resume(struct dma_chan *chan)
790 {
791 	struct bam_chan *bchan = to_bam_chan(chan);
792 	struct bam_device *bdev = bchan->bdev;
793 	int ret;
794 
795 	ret = pm_runtime_get_sync(bdev->dev);
796 	if (ret < 0)
797 		return ret;
798 
799 	scoped_guard(spinlock_irqsave, &bchan->vc.lock) {
800 		writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
801 		bchan->paused = 0;
802 	}
803 	pm_runtime_mark_last_busy(bdev->dev);
804 	pm_runtime_put_autosuspend(bdev->dev);
805 
806 	return 0;
807 }
808 
809 /**
810  * process_channel_irqs - processes the channel interrupts
811  * @bdev: bam controller
812  *
813  * This function processes the channel interrupts
814  *
815  */
816 static u32 process_channel_irqs(struct bam_device *bdev)
817 {
818 	u32 i, srcs, pipe_stts, offset, avail;
819 	struct bam_async_desc *async_desc, *tmp;
820 
821 	srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
822 
823 	/* return early if no pipe/channel interrupts are present */
824 	if (!(srcs & P_IRQ))
825 		return srcs;
826 
827 	for (i = 0; i < bdev->num_channels; i++) {
828 		struct bam_chan *bchan = &bdev->channels[i];
829 
830 		if (!(srcs & BIT(i)))
831 			continue;
832 
833 		/* clear pipe irq */
834 		pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
835 
836 		writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
837 
838 		guard(spinlock_irqsave)(&bchan->vc.lock);
839 
840 		offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) &
841 				       P_SW_OFSTS_MASK;
842 		offset /= sizeof(struct bam_desc_hw);
843 
844 		/* Number of bytes available to read */
845 		avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
846 
847 		if (offset < bchan->head)
848 			avail--;
849 
850 		list_for_each_entry_safe(async_desc, tmp,
851 					 &bchan->desc_list, desc_node) {
852 			/* Not enough data to read */
853 			if (avail < async_desc->xfer_len)
854 				break;
855 
856 			/* manage FIFO */
857 			bchan->head += async_desc->xfer_len;
858 			bchan->head %= MAX_DESCRIPTORS;
859 
860 			async_desc->num_desc -= async_desc->xfer_len;
861 			async_desc->curr_desc += async_desc->xfer_len;
862 			avail -= async_desc->xfer_len;
863 
864 			/*
865 			 * if complete, process cookie. Otherwise
866 			 * push back to front of desc_issued so that
867 			 * it gets restarted by the tasklet
868 			 */
869 			if (!async_desc->num_desc) {
870 				vchan_cookie_complete(&async_desc->vd);
871 			} else {
872 				list_add(&async_desc->vd.node,
873 					 &bchan->vc.desc_issued);
874 			}
875 			list_del(&async_desc->desc_node);
876 		}
877 	}
878 
879 	return srcs;
880 }
881 
882 /**
883  * bam_dma_irq - irq handler for bam controller
884  * @irq: IRQ of interrupt
885  * @data: callback data
886  *
887  * IRQ handler for the bam controller
888  */
889 static irqreturn_t bam_dma_irq(int irq, void *data)
890 {
891 	struct bam_device *bdev = data;
892 	u32 clr_mask = 0, srcs = 0;
893 	int ret;
894 
895 	srcs |= process_channel_irqs(bdev);
896 
897 	/* kick off tasklet to start next dma transfer */
898 	if (srcs & P_IRQ)
899 		tasklet_schedule(&bdev->task);
900 
901 	ret = pm_runtime_get_sync(bdev->dev);
902 	if (ret < 0)
903 		return IRQ_NONE;
904 
905 	if (srcs & BAM_IRQ) {
906 		clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
907 
908 		/*
909 		 * don't allow reorder of the various accesses to the BAM
910 		 * registers
911 		 */
912 		mb();
913 
914 		writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
915 	}
916 
917 	pm_runtime_mark_last_busy(bdev->dev);
918 	pm_runtime_put_autosuspend(bdev->dev);
919 
920 	return IRQ_HANDLED;
921 }
922 
923 /**
924  * bam_tx_status - returns status of transaction
925  * @chan: dma channel
926  * @cookie: transaction cookie
927  * @txstate: DMA transaction state
928  *
929  * Return status of dma transaction
930  */
931 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
932 		struct dma_tx_state *txstate)
933 {
934 	struct bam_chan *bchan = to_bam_chan(chan);
935 	struct bam_async_desc *async_desc;
936 	struct virt_dma_desc *vd;
937 	int ret;
938 	size_t residue = 0;
939 	unsigned int i;
940 
941 	ret = dma_cookie_status(chan, cookie, txstate);
942 	if (ret == DMA_COMPLETE)
943 		return ret;
944 
945 	if (!txstate)
946 		return bchan->paused ? DMA_PAUSED : ret;
947 
948 	scoped_guard(spinlock_irqsave, &bchan->vc.lock) {
949 		vd = vchan_find_desc(&bchan->vc, cookie);
950 		if (vd) {
951 			residue = container_of(vd, struct bam_async_desc, vd)->length;
952 		} else {
953 			list_for_each_entry(async_desc, &bchan->desc_list, desc_node) {
954 				if (async_desc->vd.tx.cookie != cookie)
955 					continue;
956 
957 				for (i = 0; i < async_desc->num_desc; i++)
958 					residue += le16_to_cpu(
959 							async_desc->curr_desc[i].size);
960 			}
961 		}
962 	}
963 
964 	dma_set_residue(txstate, residue);
965 
966 	if (ret == DMA_IN_PROGRESS && bchan->paused)
967 		ret = DMA_PAUSED;
968 
969 	return ret;
970 }
971 
972 /**
973  * bam_apply_new_config
974  * @bchan: bam dma channel
975  * @dir: DMA direction
976  */
977 static void bam_apply_new_config(struct bam_chan *bchan,
978 	enum dma_transfer_direction dir)
979 {
980 	struct bam_device *bdev = bchan->bdev;
981 	u32 maxburst;
982 
983 	if (!bdev->controlled_remotely) {
984 		if (dir == DMA_DEV_TO_MEM)
985 			maxburst = bchan->slave.src_maxburst;
986 		else
987 			maxburst = bchan->slave.dst_maxburst;
988 
989 		writel_relaxed(maxburst,
990 			       bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
991 	}
992 
993 	bchan->reconfigure = 0;
994 }
995 
996 /**
997  * bam_start_dma - start next transaction
998  * @bchan: bam dma channel
999  */
1000 static void bam_start_dma(struct bam_chan *bchan)
1001 {
1002 	struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
1003 	struct bam_device *bdev = bchan->bdev;
1004 	struct bam_async_desc *async_desc = NULL;
1005 	struct bam_desc_hw *desc;
1006 	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
1007 					sizeof(struct bam_desc_hw));
1008 	int ret;
1009 	unsigned int avail;
1010 	struct dmaengine_desc_callback cb;
1011 
1012 	lockdep_assert_held(&bchan->vc.lock);
1013 
1014 	if (!vd)
1015 		return;
1016 
1017 	ret = pm_runtime_get_sync(bdev->dev);
1018 	if (ret < 0)
1019 		return;
1020 
1021 	while (vd && !IS_BUSY(bchan)) {
1022 		list_del(&vd->node);
1023 
1024 		async_desc = container_of(vd, struct bam_async_desc, vd);
1025 
1026 		/* on first use, initialize the channel hardware */
1027 		if (!bchan->initialized)
1028 			bam_chan_init_hw(bchan, async_desc->dir);
1029 
1030 		/* apply new slave config changes, if necessary */
1031 		if (bchan->reconfigure)
1032 			bam_apply_new_config(bchan, async_desc->dir);
1033 
1034 		desc = async_desc->curr_desc;
1035 		avail = CIRC_SPACE(bchan->tail, bchan->head,
1036 				   MAX_DESCRIPTORS + 1);
1037 
1038 		if (async_desc->num_desc > avail)
1039 			async_desc->xfer_len = avail;
1040 		else
1041 			async_desc->xfer_len = async_desc->num_desc;
1042 
1043 		/* set any special flags on the last descriptor */
1044 		if (async_desc->num_desc == async_desc->xfer_len)
1045 			desc[async_desc->xfer_len - 1].flags |=
1046 						cpu_to_le16(async_desc->flags);
1047 
1048 		vd = vchan_next_desc(&bchan->vc);
1049 
1050 		dmaengine_desc_get_callback(&async_desc->vd.tx, &cb);
1051 
1052 		/*
1053 		 * An interrupt is generated at this desc, if
1054 		 *  - FIFO is FULL.
1055 		 *  - No more descriptors to add.
1056 		 *  - If a callback completion was requested for this DESC,
1057 		 *     In this case, BAM will deliver the completion callback
1058 		 *     for this desc and continue processing the next desc.
1059 		 */
1060 		if (((avail <= async_desc->xfer_len) || !vd ||
1061 		     dmaengine_desc_callback_valid(&cb)) &&
1062 		    !(async_desc->flags & DESC_FLAG_EOT))
1063 			desc[async_desc->xfer_len - 1].flags |=
1064 				cpu_to_le16(DESC_FLAG_INT);
1065 
1066 		if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
1067 			u32 partial = MAX_DESCRIPTORS - bchan->tail;
1068 
1069 			memcpy(&fifo[bchan->tail], desc,
1070 			       partial * sizeof(struct bam_desc_hw));
1071 			memcpy(fifo, &desc[partial],
1072 			       (async_desc->xfer_len - partial) *
1073 				sizeof(struct bam_desc_hw));
1074 		} else {
1075 			memcpy(&fifo[bchan->tail], desc,
1076 			       async_desc->xfer_len *
1077 			       sizeof(struct bam_desc_hw));
1078 		}
1079 
1080 		bchan->tail += async_desc->xfer_len;
1081 		bchan->tail %= MAX_DESCRIPTORS;
1082 		list_add_tail(&async_desc->desc_node, &bchan->desc_list);
1083 	}
1084 
1085 	/* ensure descriptor writes and dma start not reordered */
1086 	wmb();
1087 	writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
1088 			bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
1089 
1090 	pm_runtime_mark_last_busy(bdev->dev);
1091 	pm_runtime_put_autosuspend(bdev->dev);
1092 }
1093 
1094 /**
1095  * dma_tasklet - DMA IRQ tasklet
1096  * @t: tasklet argument (bam controller structure)
1097  *
1098  * Sets up next DMA operation and then processes all completed transactions
1099  */
1100 static void dma_tasklet(struct tasklet_struct *t)
1101 {
1102 	struct bam_device *bdev = from_tasklet(bdev, t, task);
1103 	struct bam_chan *bchan;
1104 	unsigned int i;
1105 
1106 	/* go through the channels and kick off transactions */
1107 	for (i = 0; i < bdev->num_channels; i++) {
1108 		bchan = &bdev->channels[i];
1109 
1110 		guard(spinlock_irqsave)(&bchan->vc.lock);
1111 
1112 		if (!list_empty(&bchan->vc.desc_issued) && !IS_BUSY(bchan))
1113 			bam_start_dma(bchan);
1114 	}
1115 
1116 }
1117 
1118 /**
1119  * bam_issue_pending - starts pending transactions
1120  * @chan: dma channel
1121  *
1122  * Calls tasklet directly which in turn starts any pending transactions
1123  */
1124 static void bam_issue_pending(struct dma_chan *chan)
1125 {
1126 	struct bam_chan *bchan = to_bam_chan(chan);
1127 
1128 	guard(spinlock_irqsave)(&bchan->vc.lock);
1129 
1130 	/* if work pending and idle, start a transaction */
1131 	if (vchan_issue_pending(&bchan->vc) && !IS_BUSY(bchan))
1132 		bam_start_dma(bchan);
1133 }
1134 
1135 /**
1136  * bam_dma_free_desc - free descriptor memory
1137  * @vd: virtual descriptor
1138  *
1139  */
1140 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1141 {
1142 	struct bam_async_desc *async_desc = container_of(vd,
1143 			struct bam_async_desc, vd);
1144 
1145 	kfree(async_desc);
1146 }
1147 
1148 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1149 		struct of_dma *of)
1150 {
1151 	struct bam_device *bdev = container_of(of->of_dma_data,
1152 					struct bam_device, common);
1153 	unsigned int request;
1154 
1155 	if (dma_spec->args_count != 1)
1156 		return NULL;
1157 
1158 	request = dma_spec->args[0];
1159 	if (request >= bdev->num_channels)
1160 		return NULL;
1161 
1162 	return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1163 }
1164 
1165 /**
1166  * bam_init
1167  * @bdev: bam device
1168  *
1169  * Initialization helper for global bam registers
1170  */
1171 static int bam_init(struct bam_device *bdev)
1172 {
1173 	u32 val;
1174 
1175 	/* read revision and configuration information */
1176 	if (!bdev->num_ees) {
1177 		val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
1178 		bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
1179 	}
1180 
1181 	/* check that configured EE is within range */
1182 	if (bdev->ee >= bdev->num_ees)
1183 		return -EINVAL;
1184 
1185 	if (!bdev->num_channels) {
1186 		val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1187 		bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1188 	}
1189 
1190 	/* Reset BAM now if fully controlled locally */
1191 	if (!bdev->controlled_remotely && !bdev->powered_remotely)
1192 		bam_reset(bdev);
1193 
1194 	return 0;
1195 }
1196 
1197 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1198 	u32 index)
1199 {
1200 	bchan->id = index;
1201 	bchan->bdev = bdev;
1202 
1203 	vchan_init(&bchan->vc, &bdev->common);
1204 	bchan->vc.desc_free = bam_dma_free_desc;
1205 	INIT_LIST_HEAD(&bchan->desc_list);
1206 }
1207 
1208 static const struct of_device_id bam_of_match[] = {
1209 	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1210 	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1211 	{ .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1212 	{}
1213 };
1214 
1215 MODULE_DEVICE_TABLE(of, bam_of_match);
1216 
1217 static int bam_dma_probe(struct platform_device *pdev)
1218 {
1219 	struct bam_device *bdev;
1220 	const struct of_device_id *match;
1221 	int ret, i;
1222 
1223 	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1224 	if (!bdev)
1225 		return -ENOMEM;
1226 
1227 	bdev->dev = &pdev->dev;
1228 
1229 	match = of_match_node(bam_of_match, pdev->dev.of_node);
1230 	if (!match) {
1231 		dev_err(&pdev->dev, "Unsupported BAM module\n");
1232 		return -ENODEV;
1233 	}
1234 
1235 	bdev->layout = match->data;
1236 
1237 	bdev->regs = devm_platform_ioremap_resource(pdev, 0);
1238 	if (IS_ERR(bdev->regs))
1239 		return PTR_ERR(bdev->regs);
1240 
1241 	bdev->irq = platform_get_irq(pdev, 0);
1242 	if (bdev->irq < 0)
1243 		return bdev->irq;
1244 
1245 	ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1246 	if (ret) {
1247 		dev_err(bdev->dev, "Execution environment unspecified\n");
1248 		return ret;
1249 	}
1250 
1251 	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
1252 						"qcom,controlled-remotely");
1253 	bdev->powered_remotely = of_property_read_bool(pdev->dev.of_node,
1254 						"qcom,powered-remotely");
1255 
1256 	if (bdev->controlled_remotely || bdev->powered_remotely)
1257 		bdev->bamclk = devm_clk_get_optional(bdev->dev, "bam_clk");
1258 	else
1259 		bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1260 
1261 	if (IS_ERR(bdev->bamclk))
1262 		return PTR_ERR(bdev->bamclk);
1263 
1264 	if (!bdev->bamclk) {
1265 		ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
1266 					   &bdev->num_channels);
1267 		if (ret) {
1268 			dev_err(bdev->dev, "num-channels unspecified in dt\n");
1269 			return ret;
1270 		}
1271 
1272 		ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",
1273 					   &bdev->num_ees);
1274 		if (ret) {
1275 			dev_err(bdev->dev, "num-ees unspecified in dt\n");
1276 			return ret;
1277 		}
1278 	}
1279 
1280 	ret = clk_prepare_enable(bdev->bamclk);
1281 	if (ret) {
1282 		dev_err(bdev->dev, "failed to prepare/enable clock\n");
1283 		return ret;
1284 	}
1285 
1286 	ret = bam_init(bdev);
1287 	if (ret)
1288 		goto err_disable_clk;
1289 
1290 	tasklet_setup(&bdev->task, dma_tasklet);
1291 
1292 	bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1293 				sizeof(*bdev->channels), GFP_KERNEL);
1294 
1295 	if (!bdev->channels) {
1296 		ret = -ENOMEM;
1297 		goto err_tasklet_kill;
1298 	}
1299 
1300 	/* allocate and initialize channels */
1301 	INIT_LIST_HEAD(&bdev->common.channels);
1302 
1303 	for (i = 0; i < bdev->num_channels; i++)
1304 		bam_channel_init(bdev, &bdev->channels[i], i);
1305 
1306 	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1307 			IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1308 	if (ret)
1309 		goto err_bam_channel_exit;
1310 
1311 	/* set max dma segment size */
1312 	bdev->common.dev = bdev->dev;
1313 	dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1314 
1315 	platform_set_drvdata(pdev, bdev);
1316 
1317 	/* set capabilities */
1318 	dma_cap_zero(bdev->common.cap_mask);
1319 	dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1320 
1321 	/* initialize dmaengine apis */
1322 	bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1323 	bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1324 	bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1325 	bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1326 	bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1327 	bdev->common.device_free_chan_resources = bam_free_chan;
1328 	bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1329 	bdev->common.device_config = bam_slave_config;
1330 	bdev->common.device_pause = bam_pause;
1331 	bdev->common.device_resume = bam_resume;
1332 	bdev->common.device_terminate_all = bam_dma_terminate_all;
1333 	bdev->common.device_issue_pending = bam_issue_pending;
1334 	bdev->common.device_tx_status = bam_tx_status;
1335 	bdev->common.dev = bdev->dev;
1336 
1337 	ret = dma_async_device_register(&bdev->common);
1338 	if (ret) {
1339 		dev_err(bdev->dev, "failed to register dma async device\n");
1340 		goto err_bam_channel_exit;
1341 	}
1342 
1343 	ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1344 					&bdev->common);
1345 	if (ret)
1346 		goto err_unregister_dma;
1347 
1348 	pm_runtime_irq_safe(&pdev->dev);
1349 	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
1350 	pm_runtime_use_autosuspend(&pdev->dev);
1351 	pm_runtime_mark_last_busy(&pdev->dev);
1352 	pm_runtime_set_active(&pdev->dev);
1353 	pm_runtime_enable(&pdev->dev);
1354 
1355 	return 0;
1356 
1357 err_unregister_dma:
1358 	dma_async_device_unregister(&bdev->common);
1359 err_bam_channel_exit:
1360 	for (i = 0; i < bdev->num_channels; i++)
1361 		tasklet_kill(&bdev->channels[i].vc.task);
1362 err_tasklet_kill:
1363 	tasklet_kill(&bdev->task);
1364 err_disable_clk:
1365 	clk_disable_unprepare(bdev->bamclk);
1366 
1367 	return ret;
1368 }
1369 
1370 static void bam_dma_remove(struct platform_device *pdev)
1371 {
1372 	struct bam_device *bdev = platform_get_drvdata(pdev);
1373 	u32 i;
1374 
1375 	pm_runtime_force_suspend(&pdev->dev);
1376 
1377 	of_dma_controller_free(pdev->dev.of_node);
1378 	dma_async_device_unregister(&bdev->common);
1379 
1380 	/* mask all interrupts for this execution environment */
1381 	writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1382 
1383 	devm_free_irq(bdev->dev, bdev->irq, bdev);
1384 
1385 	for (i = 0; i < bdev->num_channels; i++) {
1386 		bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1387 		tasklet_kill(&bdev->channels[i].vc.task);
1388 
1389 		if (!bdev->channels[i].fifo_virt)
1390 			continue;
1391 
1392 		dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1393 			    bdev->channels[i].fifo_virt,
1394 			    bdev->channels[i].fifo_phys);
1395 	}
1396 
1397 	tasklet_kill(&bdev->task);
1398 
1399 	clk_disable_unprepare(bdev->bamclk);
1400 }
1401 
1402 static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
1403 {
1404 	struct bam_device *bdev = dev_get_drvdata(dev);
1405 
1406 	clk_disable(bdev->bamclk);
1407 
1408 	return 0;
1409 }
1410 
1411 static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
1412 {
1413 	struct bam_device *bdev = dev_get_drvdata(dev);
1414 	int ret;
1415 
1416 	ret = clk_enable(bdev->bamclk);
1417 	if (ret < 0) {
1418 		dev_err(dev, "clk_enable failed: %d\n", ret);
1419 		return ret;
1420 	}
1421 
1422 	return 0;
1423 }
1424 
1425 static int __maybe_unused bam_dma_suspend(struct device *dev)
1426 {
1427 	struct bam_device *bdev = dev_get_drvdata(dev);
1428 
1429 	pm_runtime_force_suspend(dev);
1430 	clk_unprepare(bdev->bamclk);
1431 
1432 	return 0;
1433 }
1434 
1435 static int __maybe_unused bam_dma_resume(struct device *dev)
1436 {
1437 	struct bam_device *bdev = dev_get_drvdata(dev);
1438 	int ret;
1439 
1440 	ret = clk_prepare(bdev->bamclk);
1441 	if (ret)
1442 		return ret;
1443 
1444 	pm_runtime_force_resume(dev);
1445 
1446 	return 0;
1447 }
1448 
1449 static const struct dev_pm_ops bam_dma_pm_ops = {
1450 	SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
1451 	SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
1452 				NULL)
1453 };
1454 
1455 static struct platform_driver bam_dma_driver = {
1456 	.probe = bam_dma_probe,
1457 	.remove = bam_dma_remove,
1458 	.driver = {
1459 		.name = "bam-dma-engine",
1460 		.pm = &bam_dma_pm_ops,
1461 		.of_match_table = bam_of_match,
1462 	},
1463 };
1464 
1465 module_platform_driver(bam_dma_driver);
1466 
1467 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1468 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1469 MODULE_LICENSE("GPL v2");
1470