xref: /openbmc/linux/drivers/dma/qcom/bam_dma.c (revision 901181b7)
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/kernel.h>
27 #include <linux/io.h>
28 #include <linux/init.h>
29 #include <linux/slab.h>
30 #include <linux/module.h>
31 #include <linux/interrupt.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/scatterlist.h>
34 #include <linux/device.h>
35 #include <linux/platform_device.h>
36 #include <linux/of.h>
37 #include <linux/of_address.h>
38 #include <linux/of_irq.h>
39 #include <linux/of_dma.h>
40 #include <linux/circ_buf.h>
41 #include <linux/clk.h>
42 #include <linux/dmaengine.h>
43 #include <linux/pm_runtime.h>
44 
45 #include "../dmaengine.h"
46 #include "../virt-dma.h"
47 
48 struct bam_desc_hw {
49 	__le32 addr;		/* Buffer physical address */
50 	__le16 size;		/* Buffer size in bytes */
51 	__le16 flags;
52 };
53 
54 #define BAM_DMA_AUTOSUSPEND_DELAY 100
55 
56 #define DESC_FLAG_INT BIT(15)
57 #define DESC_FLAG_EOT BIT(14)
58 #define DESC_FLAG_EOB BIT(13)
59 #define DESC_FLAG_NWD BIT(12)
60 #define DESC_FLAG_CMD BIT(11)
61 
62 struct bam_async_desc {
63 	struct virt_dma_desc vd;
64 
65 	u32 num_desc;
66 	u32 xfer_len;
67 
68 	/* transaction flags, EOT|EOB|NWD */
69 	u16 flags;
70 
71 	struct bam_desc_hw *curr_desc;
72 
73 	/* list node for the desc in the bam_chan list of descriptors */
74 	struct list_head desc_node;
75 	enum dma_transfer_direction dir;
76 	size_t length;
77 	struct bam_desc_hw desc[];
78 };
79 
80 enum bam_reg {
81 	BAM_CTRL,
82 	BAM_REVISION,
83 	BAM_NUM_PIPES,
84 	BAM_DESC_CNT_TRSHLD,
85 	BAM_IRQ_SRCS,
86 	BAM_IRQ_SRCS_MSK,
87 	BAM_IRQ_SRCS_UNMASKED,
88 	BAM_IRQ_STTS,
89 	BAM_IRQ_CLR,
90 	BAM_IRQ_EN,
91 	BAM_CNFG_BITS,
92 	BAM_IRQ_SRCS_EE,
93 	BAM_IRQ_SRCS_MSK_EE,
94 	BAM_P_CTRL,
95 	BAM_P_RST,
96 	BAM_P_HALT,
97 	BAM_P_IRQ_STTS,
98 	BAM_P_IRQ_CLR,
99 	BAM_P_IRQ_EN,
100 	BAM_P_EVNT_DEST_ADDR,
101 	BAM_P_EVNT_REG,
102 	BAM_P_SW_OFSTS,
103 	BAM_P_DATA_FIFO_ADDR,
104 	BAM_P_DESC_FIFO_ADDR,
105 	BAM_P_EVNT_GEN_TRSHLD,
106 	BAM_P_FIFO_SIZES,
107 };
108 
109 struct reg_offset_data {
110 	u32 base_offset;
111 	unsigned int pipe_mult, evnt_mult, ee_mult;
112 };
113 
114 static const struct reg_offset_data bam_v1_3_reg_info[] = {
115 	[BAM_CTRL]		= { 0x0F80, 0x00, 0x00, 0x00 },
116 	[BAM_REVISION]		= { 0x0F84, 0x00, 0x00, 0x00 },
117 	[BAM_NUM_PIPES]		= { 0x0FBC, 0x00, 0x00, 0x00 },
118 	[BAM_DESC_CNT_TRSHLD]	= { 0x0F88, 0x00, 0x00, 0x00 },
119 	[BAM_IRQ_SRCS]		= { 0x0F8C, 0x00, 0x00, 0x00 },
120 	[BAM_IRQ_SRCS_MSK]	= { 0x0F90, 0x00, 0x00, 0x00 },
121 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0FB0, 0x00, 0x00, 0x00 },
122 	[BAM_IRQ_STTS]		= { 0x0F94, 0x00, 0x00, 0x00 },
123 	[BAM_IRQ_CLR]		= { 0x0F98, 0x00, 0x00, 0x00 },
124 	[BAM_IRQ_EN]		= { 0x0F9C, 0x00, 0x00, 0x00 },
125 	[BAM_CNFG_BITS]		= { 0x0FFC, 0x00, 0x00, 0x00 },
126 	[BAM_IRQ_SRCS_EE]	= { 0x1800, 0x00, 0x00, 0x80 },
127 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x1804, 0x00, 0x00, 0x80 },
128 	[BAM_P_CTRL]		= { 0x0000, 0x80, 0x00, 0x00 },
129 	[BAM_P_RST]		= { 0x0004, 0x80, 0x00, 0x00 },
130 	[BAM_P_HALT]		= { 0x0008, 0x80, 0x00, 0x00 },
131 	[BAM_P_IRQ_STTS]	= { 0x0010, 0x80, 0x00, 0x00 },
132 	[BAM_P_IRQ_CLR]		= { 0x0014, 0x80, 0x00, 0x00 },
133 	[BAM_P_IRQ_EN]		= { 0x0018, 0x80, 0x00, 0x00 },
134 	[BAM_P_EVNT_DEST_ADDR]	= { 0x102C, 0x00, 0x40, 0x00 },
135 	[BAM_P_EVNT_REG]	= { 0x1018, 0x00, 0x40, 0x00 },
136 	[BAM_P_SW_OFSTS]	= { 0x1000, 0x00, 0x40, 0x00 },
137 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1024, 0x00, 0x40, 0x00 },
138 	[BAM_P_DESC_FIFO_ADDR]	= { 0x101C, 0x00, 0x40, 0x00 },
139 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1028, 0x00, 0x40, 0x00 },
140 	[BAM_P_FIFO_SIZES]	= { 0x1020, 0x00, 0x40, 0x00 },
141 };
142 
143 static const struct reg_offset_data bam_v1_4_reg_info[] = {
144 	[BAM_CTRL]		= { 0x0000, 0x00, 0x00, 0x00 },
145 	[BAM_REVISION]		= { 0x0004, 0x00, 0x00, 0x00 },
146 	[BAM_NUM_PIPES]		= { 0x003C, 0x00, 0x00, 0x00 },
147 	[BAM_DESC_CNT_TRSHLD]	= { 0x0008, 0x00, 0x00, 0x00 },
148 	[BAM_IRQ_SRCS]		= { 0x000C, 0x00, 0x00, 0x00 },
149 	[BAM_IRQ_SRCS_MSK]	= { 0x0010, 0x00, 0x00, 0x00 },
150 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0030, 0x00, 0x00, 0x00 },
151 	[BAM_IRQ_STTS]		= { 0x0014, 0x00, 0x00, 0x00 },
152 	[BAM_IRQ_CLR]		= { 0x0018, 0x00, 0x00, 0x00 },
153 	[BAM_IRQ_EN]		= { 0x001C, 0x00, 0x00, 0x00 },
154 	[BAM_CNFG_BITS]		= { 0x007C, 0x00, 0x00, 0x00 },
155 	[BAM_IRQ_SRCS_EE]	= { 0x0800, 0x00, 0x00, 0x80 },
156 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x0804, 0x00, 0x00, 0x80 },
157 	[BAM_P_CTRL]		= { 0x1000, 0x1000, 0x00, 0x00 },
158 	[BAM_P_RST]		= { 0x1004, 0x1000, 0x00, 0x00 },
159 	[BAM_P_HALT]		= { 0x1008, 0x1000, 0x00, 0x00 },
160 	[BAM_P_IRQ_STTS]	= { 0x1010, 0x1000, 0x00, 0x00 },
161 	[BAM_P_IRQ_CLR]		= { 0x1014, 0x1000, 0x00, 0x00 },
162 	[BAM_P_IRQ_EN]		= { 0x1018, 0x1000, 0x00, 0x00 },
163 	[BAM_P_EVNT_DEST_ADDR]	= { 0x182C, 0x00, 0x1000, 0x00 },
164 	[BAM_P_EVNT_REG]	= { 0x1818, 0x00, 0x1000, 0x00 },
165 	[BAM_P_SW_OFSTS]	= { 0x1800, 0x00, 0x1000, 0x00 },
166 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1824, 0x00, 0x1000, 0x00 },
167 	[BAM_P_DESC_FIFO_ADDR]	= { 0x181C, 0x00, 0x1000, 0x00 },
168 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1828, 0x00, 0x1000, 0x00 },
169 	[BAM_P_FIFO_SIZES]	= { 0x1820, 0x00, 0x1000, 0x00 },
170 };
171 
172 static const struct reg_offset_data bam_v1_7_reg_info[] = {
173 	[BAM_CTRL]		= { 0x00000, 0x00, 0x00, 0x00 },
174 	[BAM_REVISION]		= { 0x01000, 0x00, 0x00, 0x00 },
175 	[BAM_NUM_PIPES]		= { 0x01008, 0x00, 0x00, 0x00 },
176 	[BAM_DESC_CNT_TRSHLD]	= { 0x00008, 0x00, 0x00, 0x00 },
177 	[BAM_IRQ_SRCS]		= { 0x03010, 0x00, 0x00, 0x00 },
178 	[BAM_IRQ_SRCS_MSK]	= { 0x03014, 0x00, 0x00, 0x00 },
179 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x03018, 0x00, 0x00, 0x00 },
180 	[BAM_IRQ_STTS]		= { 0x00014, 0x00, 0x00, 0x00 },
181 	[BAM_IRQ_CLR]		= { 0x00018, 0x00, 0x00, 0x00 },
182 	[BAM_IRQ_EN]		= { 0x0001C, 0x00, 0x00, 0x00 },
183 	[BAM_CNFG_BITS]		= { 0x0007C, 0x00, 0x00, 0x00 },
184 	[BAM_IRQ_SRCS_EE]	= { 0x03000, 0x00, 0x00, 0x1000 },
185 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x03004, 0x00, 0x00, 0x1000 },
186 	[BAM_P_CTRL]		= { 0x13000, 0x1000, 0x00, 0x00 },
187 	[BAM_P_RST]		= { 0x13004, 0x1000, 0x00, 0x00 },
188 	[BAM_P_HALT]		= { 0x13008, 0x1000, 0x00, 0x00 },
189 	[BAM_P_IRQ_STTS]	= { 0x13010, 0x1000, 0x00, 0x00 },
190 	[BAM_P_IRQ_CLR]		= { 0x13014, 0x1000, 0x00, 0x00 },
191 	[BAM_P_IRQ_EN]		= { 0x13018, 0x1000, 0x00, 0x00 },
192 	[BAM_P_EVNT_DEST_ADDR]	= { 0x1382C, 0x00, 0x1000, 0x00 },
193 	[BAM_P_EVNT_REG]	= { 0x13818, 0x00, 0x1000, 0x00 },
194 	[BAM_P_SW_OFSTS]	= { 0x13800, 0x00, 0x1000, 0x00 },
195 	[BAM_P_DATA_FIFO_ADDR]	= { 0x13824, 0x00, 0x1000, 0x00 },
196 	[BAM_P_DESC_FIFO_ADDR]	= { 0x1381C, 0x00, 0x1000, 0x00 },
197 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x13828, 0x00, 0x1000, 0x00 },
198 	[BAM_P_FIFO_SIZES]	= { 0x13820, 0x00, 0x1000, 0x00 },
199 };
200 
201 /* BAM CTRL */
202 #define BAM_SW_RST			BIT(0)
203 #define BAM_EN				BIT(1)
204 #define BAM_EN_ACCUM			BIT(4)
205 #define BAM_TESTBUS_SEL_SHIFT		5
206 #define BAM_TESTBUS_SEL_MASK		0x3F
207 #define BAM_DESC_CACHE_SEL_SHIFT	13
208 #define BAM_DESC_CACHE_SEL_MASK		0x3
209 #define BAM_CACHED_DESC_STORE		BIT(15)
210 #define IBC_DISABLE			BIT(16)
211 
212 /* BAM REVISION */
213 #define REVISION_SHIFT		0
214 #define REVISION_MASK		0xFF
215 #define NUM_EES_SHIFT		8
216 #define NUM_EES_MASK		0xF
217 #define CE_BUFFER_SIZE		BIT(13)
218 #define AXI_ACTIVE		BIT(14)
219 #define USE_VMIDMT		BIT(15)
220 #define SECURED			BIT(16)
221 #define BAM_HAS_NO_BYPASS	BIT(17)
222 #define HIGH_FREQUENCY_BAM	BIT(18)
223 #define INACTIV_TMRS_EXST	BIT(19)
224 #define NUM_INACTIV_TMRS	BIT(20)
225 #define DESC_CACHE_DEPTH_SHIFT	21
226 #define DESC_CACHE_DEPTH_1	(0 << DESC_CACHE_DEPTH_SHIFT)
227 #define DESC_CACHE_DEPTH_2	(1 << DESC_CACHE_DEPTH_SHIFT)
228 #define DESC_CACHE_DEPTH_3	(2 << DESC_CACHE_DEPTH_SHIFT)
229 #define DESC_CACHE_DEPTH_4	(3 << DESC_CACHE_DEPTH_SHIFT)
230 #define CMD_DESC_EN		BIT(23)
231 #define INACTIV_TMR_BASE_SHIFT	24
232 #define INACTIV_TMR_BASE_MASK	0xFF
233 
234 /* BAM NUM PIPES */
235 #define BAM_NUM_PIPES_SHIFT		0
236 #define BAM_NUM_PIPES_MASK		0xFF
237 #define PERIPH_NON_PIPE_GRP_SHIFT	16
238 #define PERIPH_NON_PIP_GRP_MASK		0xFF
239 #define BAM_NON_PIPE_GRP_SHIFT		24
240 #define BAM_NON_PIPE_GRP_MASK		0xFF
241 
242 /* BAM CNFG BITS */
243 #define BAM_PIPE_CNFG		BIT(2)
244 #define BAM_FULL_PIPE		BIT(11)
245 #define BAM_NO_EXT_P_RST	BIT(12)
246 #define BAM_IBC_DISABLE		BIT(13)
247 #define BAM_SB_CLK_REQ		BIT(14)
248 #define BAM_PSM_CSW_REQ		BIT(15)
249 #define BAM_PSM_P_RES		BIT(16)
250 #define BAM_AU_P_RES		BIT(17)
251 #define BAM_SI_P_RES		BIT(18)
252 #define BAM_WB_P_RES		BIT(19)
253 #define BAM_WB_BLK_CSW		BIT(20)
254 #define BAM_WB_CSW_ACK_IDL	BIT(21)
255 #define BAM_WB_RETR_SVPNT	BIT(22)
256 #define BAM_WB_DSC_AVL_P_RST	BIT(23)
257 #define BAM_REG_P_EN		BIT(24)
258 #define BAM_PSM_P_HD_DATA	BIT(25)
259 #define BAM_AU_ACCUMED		BIT(26)
260 #define BAM_CMD_ENABLE		BIT(27)
261 
262 #define BAM_CNFG_BITS_DEFAULT	(BAM_PIPE_CNFG |	\
263 				 BAM_NO_EXT_P_RST |	\
264 				 BAM_IBC_DISABLE |	\
265 				 BAM_SB_CLK_REQ |	\
266 				 BAM_PSM_CSW_REQ |	\
267 				 BAM_PSM_P_RES |	\
268 				 BAM_AU_P_RES |		\
269 				 BAM_SI_P_RES |		\
270 				 BAM_WB_P_RES |		\
271 				 BAM_WB_BLK_CSW |	\
272 				 BAM_WB_CSW_ACK_IDL |	\
273 				 BAM_WB_RETR_SVPNT |	\
274 				 BAM_WB_DSC_AVL_P_RST |	\
275 				 BAM_REG_P_EN |		\
276 				 BAM_PSM_P_HD_DATA |	\
277 				 BAM_AU_ACCUMED |	\
278 				 BAM_CMD_ENABLE)
279 
280 /* PIPE CTRL */
281 #define P_EN			BIT(1)
282 #define P_DIRECTION		BIT(3)
283 #define P_SYS_STRM		BIT(4)
284 #define P_SYS_MODE		BIT(5)
285 #define P_AUTO_EOB		BIT(6)
286 #define P_AUTO_EOB_SEL_SHIFT	7
287 #define P_AUTO_EOB_SEL_512	(0 << P_AUTO_EOB_SEL_SHIFT)
288 #define P_AUTO_EOB_SEL_256	(1 << P_AUTO_EOB_SEL_SHIFT)
289 #define P_AUTO_EOB_SEL_128	(2 << P_AUTO_EOB_SEL_SHIFT)
290 #define P_AUTO_EOB_SEL_64	(3 << P_AUTO_EOB_SEL_SHIFT)
291 #define P_PREFETCH_LIMIT_SHIFT	9
292 #define P_PREFETCH_LIMIT_32	(0 << P_PREFETCH_LIMIT_SHIFT)
293 #define P_PREFETCH_LIMIT_16	(1 << P_PREFETCH_LIMIT_SHIFT)
294 #define P_PREFETCH_LIMIT_4	(2 << P_PREFETCH_LIMIT_SHIFT)
295 #define P_WRITE_NWD		BIT(11)
296 #define P_LOCK_GROUP_SHIFT	16
297 #define P_LOCK_GROUP_MASK	0x1F
298 
299 /* BAM_DESC_CNT_TRSHLD */
300 #define CNT_TRSHLD		0xffff
301 #define DEFAULT_CNT_THRSHLD	0x4
302 
303 /* BAM_IRQ_SRCS */
304 #define BAM_IRQ			BIT(31)
305 #define P_IRQ			0x7fffffff
306 
307 /* BAM_IRQ_SRCS_MSK */
308 #define BAM_IRQ_MSK		BAM_IRQ
309 #define P_IRQ_MSK		P_IRQ
310 
311 /* BAM_IRQ_STTS */
312 #define BAM_TIMER_IRQ		BIT(4)
313 #define BAM_EMPTY_IRQ		BIT(3)
314 #define BAM_ERROR_IRQ		BIT(2)
315 #define BAM_HRESP_ERR_IRQ	BIT(1)
316 
317 /* BAM_IRQ_CLR */
318 #define BAM_TIMER_CLR		BIT(4)
319 #define BAM_EMPTY_CLR		BIT(3)
320 #define BAM_ERROR_CLR		BIT(2)
321 #define BAM_HRESP_ERR_CLR	BIT(1)
322 
323 /* BAM_IRQ_EN */
324 #define BAM_TIMER_EN		BIT(4)
325 #define BAM_EMPTY_EN		BIT(3)
326 #define BAM_ERROR_EN		BIT(2)
327 #define BAM_HRESP_ERR_EN	BIT(1)
328 
329 /* BAM_P_IRQ_EN */
330 #define P_PRCSD_DESC_EN		BIT(0)
331 #define P_TIMER_EN		BIT(1)
332 #define P_WAKE_EN		BIT(2)
333 #define P_OUT_OF_DESC_EN	BIT(3)
334 #define P_ERR_EN		BIT(4)
335 #define P_TRNSFR_END_EN		BIT(5)
336 #define P_DEFAULT_IRQS_EN	(P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
337 
338 /* BAM_P_SW_OFSTS */
339 #define P_SW_OFSTS_MASK		0xffff
340 
341 #define BAM_DESC_FIFO_SIZE	SZ_32K
342 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
343 #define BAM_FIFO_SIZE	(SZ_32K - 8)
344 #define IS_BUSY(chan)	(CIRC_SPACE(bchan->tail, bchan->head,\
345 			 MAX_DESCRIPTORS + 1) == 0)
346 
347 struct bam_chan {
348 	struct virt_dma_chan vc;
349 
350 	struct bam_device *bdev;
351 
352 	/* configuration from device tree */
353 	u32 id;
354 
355 	/* runtime configuration */
356 	struct dma_slave_config slave;
357 
358 	/* fifo storage */
359 	struct bam_desc_hw *fifo_virt;
360 	dma_addr_t fifo_phys;
361 
362 	/* fifo markers */
363 	unsigned short head;		/* start of active descriptor entries */
364 	unsigned short tail;		/* end of active descriptor entries */
365 
366 	unsigned int initialized;	/* is the channel hw initialized? */
367 	unsigned int paused;		/* is the channel paused? */
368 	unsigned int reconfigure;	/* new slave config? */
369 	/* list of descriptors currently processed */
370 	struct list_head desc_list;
371 
372 	struct list_head node;
373 };
374 
375 static inline struct bam_chan *to_bam_chan(struct dma_chan *common)
376 {
377 	return container_of(common, struct bam_chan, vc.chan);
378 }
379 
380 struct bam_device {
381 	void __iomem *regs;
382 	struct device *dev;
383 	struct dma_device common;
384 	struct bam_chan *channels;
385 	u32 num_channels;
386 	u32 num_ees;
387 
388 	/* execution environment ID, from DT */
389 	u32 ee;
390 	bool controlled_remotely;
391 	bool powered_remotely;
392 	u32 active_channels;
393 
394 	const struct reg_offset_data *layout;
395 
396 	struct clk *bamclk;
397 	int irq;
398 
399 	/* dma start transaction tasklet */
400 	struct tasklet_struct task;
401 };
402 
403 /**
404  * bam_addr - returns BAM register address
405  * @bdev: bam device
406  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
407  * @reg:  register enum
408  */
409 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
410 		enum bam_reg reg)
411 {
412 	const struct reg_offset_data r = bdev->layout[reg];
413 
414 	return bdev->regs + r.base_offset +
415 		r.pipe_mult * pipe +
416 		r.evnt_mult * pipe +
417 		r.ee_mult * bdev->ee;
418 }
419 
420 /**
421  * bam_reset() - reset and initialize BAM registers
422  * @bdev: bam device
423  */
424 static void bam_reset(struct bam_device *bdev)
425 {
426 	u32 val;
427 
428 	/* s/w reset bam */
429 	/* after reset all pipes are disabled and idle */
430 	val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
431 	val |= BAM_SW_RST;
432 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
433 	val &= ~BAM_SW_RST;
434 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
435 
436 	/* make sure previous stores are visible before enabling BAM */
437 	wmb();
438 
439 	/* enable bam */
440 	val |= BAM_EN;
441 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
442 
443 	/* set descriptor threshhold, start with 4 bytes */
444 	writel_relaxed(DEFAULT_CNT_THRSHLD,
445 			bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
446 
447 	/* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
448 	writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
449 
450 	/* enable irqs for errors */
451 	writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
452 			bam_addr(bdev, 0, BAM_IRQ_EN));
453 
454 	/* unmask global bam interrupt */
455 	writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
456 }
457 
458 /**
459  * bam_reset_channel - Reset individual BAM DMA channel
460  * @bchan: bam channel
461  *
462  * This function resets a specific BAM channel
463  */
464 static void bam_reset_channel(struct bam_chan *bchan)
465 {
466 	struct bam_device *bdev = bchan->bdev;
467 
468 	lockdep_assert_held(&bchan->vc.lock);
469 
470 	/* reset channel */
471 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
472 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
473 
474 	/* don't allow cpu to reorder BAM register accesses done after this */
475 	wmb();
476 
477 	/* make sure hw is initialized when channel is used the first time  */
478 	bchan->initialized = 0;
479 }
480 
481 /**
482  * bam_chan_init_hw - Initialize channel hardware
483  * @bchan: bam channel
484  * @dir: DMA transfer direction
485  *
486  * This function resets and initializes the BAM channel
487  */
488 static void bam_chan_init_hw(struct bam_chan *bchan,
489 	enum dma_transfer_direction dir)
490 {
491 	struct bam_device *bdev = bchan->bdev;
492 	u32 val;
493 
494 	/* Reset the channel to clear internal state of the FIFO */
495 	bam_reset_channel(bchan);
496 
497 	/*
498 	 * write out 8 byte aligned address.  We have enough space for this
499 	 * because we allocated 1 more descriptor (8 bytes) than we can use
500 	 */
501 	writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
502 			bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
503 	writel_relaxed(BAM_FIFO_SIZE,
504 			bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
505 
506 	/* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
507 	writel_relaxed(P_DEFAULT_IRQS_EN,
508 			bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
509 
510 	/* unmask the specific pipe and EE combo */
511 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
512 	val |= BIT(bchan->id);
513 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
514 
515 	/* don't allow cpu to reorder the channel enable done below */
516 	wmb();
517 
518 	/* set fixed direction and mode, then enable channel */
519 	val = P_EN | P_SYS_MODE;
520 	if (dir == DMA_DEV_TO_MEM)
521 		val |= P_DIRECTION;
522 
523 	writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
524 
525 	bchan->initialized = 1;
526 
527 	/* init FIFO pointers */
528 	bchan->head = 0;
529 	bchan->tail = 0;
530 }
531 
532 /**
533  * bam_alloc_chan - Allocate channel resources for DMA channel.
534  * @chan: specified channel
535  *
536  * This function allocates the FIFO descriptor memory
537  */
538 static int bam_alloc_chan(struct dma_chan *chan)
539 {
540 	struct bam_chan *bchan = to_bam_chan(chan);
541 	struct bam_device *bdev = bchan->bdev;
542 
543 	if (bchan->fifo_virt)
544 		return 0;
545 
546 	/* allocate FIFO descriptor space, but only if necessary */
547 	bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
548 					&bchan->fifo_phys, GFP_KERNEL);
549 
550 	if (!bchan->fifo_virt) {
551 		dev_err(bdev->dev, "Failed to allocate desc fifo\n");
552 		return -ENOMEM;
553 	}
554 
555 	if (bdev->active_channels++ == 0 && bdev->powered_remotely)
556 		bam_reset(bdev);
557 
558 	return 0;
559 }
560 
561 static int bam_pm_runtime_get_sync(struct device *dev)
562 {
563 	if (pm_runtime_enabled(dev))
564 		return pm_runtime_get_sync(dev);
565 
566 	return 0;
567 }
568 
569 /**
570  * bam_free_chan - Frees dma resources associated with specific channel
571  * @chan: specified channel
572  *
573  * Free the allocated fifo descriptor memory and channel resources
574  *
575  */
576 static void bam_free_chan(struct dma_chan *chan)
577 {
578 	struct bam_chan *bchan = to_bam_chan(chan);
579 	struct bam_device *bdev = bchan->bdev;
580 	u32 val;
581 	unsigned long flags;
582 	int ret;
583 
584 	ret = bam_pm_runtime_get_sync(bdev->dev);
585 	if (ret < 0)
586 		return;
587 
588 	vchan_free_chan_resources(to_virt_chan(chan));
589 
590 	if (!list_empty(&bchan->desc_list)) {
591 		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
592 		goto err;
593 	}
594 
595 	spin_lock_irqsave(&bchan->vc.lock, flags);
596 	bam_reset_channel(bchan);
597 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
598 
599 	dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
600 		    bchan->fifo_phys);
601 	bchan->fifo_virt = NULL;
602 
603 	/* mask irq for pipe/channel */
604 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
605 	val &= ~BIT(bchan->id);
606 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
607 
608 	/* disable irq */
609 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
610 
611 	if (--bdev->active_channels == 0 && bdev->powered_remotely) {
612 		/* s/w reset bam */
613 		val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
614 		val |= BAM_SW_RST;
615 		writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
616 	}
617 
618 err:
619 	pm_runtime_mark_last_busy(bdev->dev);
620 	pm_runtime_put_autosuspend(bdev->dev);
621 }
622 
623 /**
624  * bam_slave_config - set slave configuration for channel
625  * @chan: dma channel
626  * @cfg: slave configuration
627  *
628  * Sets slave configuration for channel
629  *
630  */
631 static int bam_slave_config(struct dma_chan *chan,
632 			    struct dma_slave_config *cfg)
633 {
634 	struct bam_chan *bchan = to_bam_chan(chan);
635 	unsigned long flag;
636 
637 	spin_lock_irqsave(&bchan->vc.lock, flag);
638 	memcpy(&bchan->slave, cfg, sizeof(*cfg));
639 	bchan->reconfigure = 1;
640 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
641 
642 	return 0;
643 }
644 
645 /**
646  * bam_prep_slave_sg - Prep slave sg transaction
647  *
648  * @chan: dma channel
649  * @sgl: scatter gather list
650  * @sg_len: length of sg
651  * @direction: DMA transfer direction
652  * @flags: DMA flags
653  * @context: transfer context (unused)
654  */
655 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
656 	struct scatterlist *sgl, unsigned int sg_len,
657 	enum dma_transfer_direction direction, unsigned long flags,
658 	void *context)
659 {
660 	struct bam_chan *bchan = to_bam_chan(chan);
661 	struct bam_device *bdev = bchan->bdev;
662 	struct bam_async_desc *async_desc;
663 	struct scatterlist *sg;
664 	u32 i;
665 	struct bam_desc_hw *desc;
666 	unsigned int num_alloc = 0;
667 
668 
669 	if (!is_slave_direction(direction)) {
670 		dev_err(bdev->dev, "invalid dma direction\n");
671 		return NULL;
672 	}
673 
674 	/* calculate number of required entries */
675 	for_each_sg(sgl, sg, sg_len, i)
676 		num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE);
677 
678 	/* allocate enough room to accomodate the number of entries */
679 	async_desc = kzalloc(struct_size(async_desc, desc, num_alloc),
680 			     GFP_NOWAIT);
681 
682 	if (!async_desc)
683 		return NULL;
684 
685 	if (flags & DMA_PREP_FENCE)
686 		async_desc->flags |= DESC_FLAG_NWD;
687 
688 	if (flags & DMA_PREP_INTERRUPT)
689 		async_desc->flags |= DESC_FLAG_EOT;
690 
691 	async_desc->num_desc = num_alloc;
692 	async_desc->curr_desc = async_desc->desc;
693 	async_desc->dir = direction;
694 
695 	/* fill in temporary descriptors */
696 	desc = async_desc->desc;
697 	for_each_sg(sgl, sg, sg_len, i) {
698 		unsigned int remainder = sg_dma_len(sg);
699 		unsigned int curr_offset = 0;
700 
701 		do {
702 			if (flags & DMA_PREP_CMD)
703 				desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
704 
705 			desc->addr = cpu_to_le32(sg_dma_address(sg) +
706 						 curr_offset);
707 
708 			if (remainder > BAM_FIFO_SIZE) {
709 				desc->size = cpu_to_le16(BAM_FIFO_SIZE);
710 				remainder -= BAM_FIFO_SIZE;
711 				curr_offset += BAM_FIFO_SIZE;
712 			} else {
713 				desc->size = cpu_to_le16(remainder);
714 				remainder = 0;
715 			}
716 
717 			async_desc->length += le16_to_cpu(desc->size);
718 			desc++;
719 		} while (remainder > 0);
720 	}
721 
722 	return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
723 }
724 
725 /**
726  * bam_dma_terminate_all - terminate all transactions on a channel
727  * @chan: bam dma channel
728  *
729  * Dequeues and frees all transactions
730  * No callbacks are done
731  *
732  */
733 static int bam_dma_terminate_all(struct dma_chan *chan)
734 {
735 	struct bam_chan *bchan = to_bam_chan(chan);
736 	struct bam_async_desc *async_desc, *tmp;
737 	unsigned long flag;
738 	LIST_HEAD(head);
739 
740 	/* remove all transactions, including active transaction */
741 	spin_lock_irqsave(&bchan->vc.lock, flag);
742 	/*
743 	 * If we have transactions queued, then some might be committed to the
744 	 * hardware in the desc fifo.  The only way to reset the desc fifo is
745 	 * to do a hardware reset (either by pipe or the entire block).
746 	 * bam_chan_init_hw() will trigger a pipe reset, and also reinit the
747 	 * pipe.  If the pipe is left disabled (default state after pipe reset)
748 	 * and is accessed by a connected hardware engine, a fatal error in
749 	 * the BAM will occur.  There is a small window where this could happen
750 	 * with bam_chan_init_hw(), but it is assumed that the caller has
751 	 * stopped activity on any attached hardware engine.  Make sure to do
752 	 * this first so that the BAM hardware doesn't cause memory corruption
753 	 * by accessing freed resources.
754 	 */
755 	if (!list_empty(&bchan->desc_list)) {
756 		async_desc = list_first_entry(&bchan->desc_list,
757 					      struct bam_async_desc, desc_node);
758 		bam_chan_init_hw(bchan, async_desc->dir);
759 	}
760 
761 	list_for_each_entry_safe(async_desc, tmp,
762 				 &bchan->desc_list, desc_node) {
763 		list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
764 		list_del(&async_desc->desc_node);
765 	}
766 
767 	vchan_get_all_descriptors(&bchan->vc, &head);
768 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
769 
770 	vchan_dma_desc_free_list(&bchan->vc, &head);
771 
772 	return 0;
773 }
774 
775 /**
776  * bam_pause - Pause DMA channel
777  * @chan: dma channel
778  *
779  */
780 static int bam_pause(struct dma_chan *chan)
781 {
782 	struct bam_chan *bchan = to_bam_chan(chan);
783 	struct bam_device *bdev = bchan->bdev;
784 	unsigned long flag;
785 	int ret;
786 
787 	ret = bam_pm_runtime_get_sync(bdev->dev);
788 	if (ret < 0)
789 		return ret;
790 
791 	spin_lock_irqsave(&bchan->vc.lock, flag);
792 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
793 	bchan->paused = 1;
794 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
795 	pm_runtime_mark_last_busy(bdev->dev);
796 	pm_runtime_put_autosuspend(bdev->dev);
797 
798 	return 0;
799 }
800 
801 /**
802  * bam_resume - Resume DMA channel operations
803  * @chan: dma channel
804  *
805  */
806 static int bam_resume(struct dma_chan *chan)
807 {
808 	struct bam_chan *bchan = to_bam_chan(chan);
809 	struct bam_device *bdev = bchan->bdev;
810 	unsigned long flag;
811 	int ret;
812 
813 	ret = bam_pm_runtime_get_sync(bdev->dev);
814 	if (ret < 0)
815 		return ret;
816 
817 	spin_lock_irqsave(&bchan->vc.lock, flag);
818 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
819 	bchan->paused = 0;
820 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
821 	pm_runtime_mark_last_busy(bdev->dev);
822 	pm_runtime_put_autosuspend(bdev->dev);
823 
824 	return 0;
825 }
826 
827 /**
828  * process_channel_irqs - processes the channel interrupts
829  * @bdev: bam controller
830  *
831  * This function processes the channel interrupts
832  *
833  */
834 static u32 process_channel_irqs(struct bam_device *bdev)
835 {
836 	u32 i, srcs, pipe_stts, offset, avail;
837 	unsigned long flags;
838 	struct bam_async_desc *async_desc, *tmp;
839 
840 	srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
841 
842 	/* return early if no pipe/channel interrupts are present */
843 	if (!(srcs & P_IRQ))
844 		return srcs;
845 
846 	for (i = 0; i < bdev->num_channels; i++) {
847 		struct bam_chan *bchan = &bdev->channels[i];
848 
849 		if (!(srcs & BIT(i)))
850 			continue;
851 
852 		/* clear pipe irq */
853 		pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
854 
855 		writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
856 
857 		spin_lock_irqsave(&bchan->vc.lock, flags);
858 
859 		offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) &
860 				       P_SW_OFSTS_MASK;
861 		offset /= sizeof(struct bam_desc_hw);
862 
863 		/* Number of bytes available to read */
864 		avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
865 
866 		if (offset < bchan->head)
867 			avail--;
868 
869 		list_for_each_entry_safe(async_desc, tmp,
870 					 &bchan->desc_list, desc_node) {
871 			/* Not enough data to read */
872 			if (avail < async_desc->xfer_len)
873 				break;
874 
875 			/* manage FIFO */
876 			bchan->head += async_desc->xfer_len;
877 			bchan->head %= MAX_DESCRIPTORS;
878 
879 			async_desc->num_desc -= async_desc->xfer_len;
880 			async_desc->curr_desc += async_desc->xfer_len;
881 			avail -= async_desc->xfer_len;
882 
883 			/*
884 			 * if complete, process cookie. Otherwise
885 			 * push back to front of desc_issued so that
886 			 * it gets restarted by the tasklet
887 			 */
888 			if (!async_desc->num_desc) {
889 				vchan_cookie_complete(&async_desc->vd);
890 			} else {
891 				list_add(&async_desc->vd.node,
892 					 &bchan->vc.desc_issued);
893 			}
894 			list_del(&async_desc->desc_node);
895 		}
896 
897 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
898 	}
899 
900 	return srcs;
901 }
902 
903 /**
904  * bam_dma_irq - irq handler for bam controller
905  * @irq: IRQ of interrupt
906  * @data: callback data
907  *
908  * IRQ handler for the bam controller
909  */
910 static irqreturn_t bam_dma_irq(int irq, void *data)
911 {
912 	struct bam_device *bdev = data;
913 	u32 clr_mask = 0, srcs = 0;
914 	int ret;
915 
916 	srcs |= process_channel_irqs(bdev);
917 
918 	/* kick off tasklet to start next dma transfer */
919 	if (srcs & P_IRQ)
920 		tasklet_schedule(&bdev->task);
921 
922 	ret = bam_pm_runtime_get_sync(bdev->dev);
923 	if (ret < 0)
924 		return IRQ_NONE;
925 
926 	if (srcs & BAM_IRQ) {
927 		clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
928 
929 		/*
930 		 * don't allow reorder of the various accesses to the BAM
931 		 * registers
932 		 */
933 		mb();
934 
935 		writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
936 	}
937 
938 	pm_runtime_mark_last_busy(bdev->dev);
939 	pm_runtime_put_autosuspend(bdev->dev);
940 
941 	return IRQ_HANDLED;
942 }
943 
944 /**
945  * bam_tx_status - returns status of transaction
946  * @chan: dma channel
947  * @cookie: transaction cookie
948  * @txstate: DMA transaction state
949  *
950  * Return status of dma transaction
951  */
952 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
953 		struct dma_tx_state *txstate)
954 {
955 	struct bam_chan *bchan = to_bam_chan(chan);
956 	struct bam_async_desc *async_desc;
957 	struct virt_dma_desc *vd;
958 	int ret;
959 	size_t residue = 0;
960 	unsigned int i;
961 	unsigned long flags;
962 
963 	ret = dma_cookie_status(chan, cookie, txstate);
964 	if (ret == DMA_COMPLETE)
965 		return ret;
966 
967 	if (!txstate)
968 		return bchan->paused ? DMA_PAUSED : ret;
969 
970 	spin_lock_irqsave(&bchan->vc.lock, flags);
971 	vd = vchan_find_desc(&bchan->vc, cookie);
972 	if (vd) {
973 		residue = container_of(vd, struct bam_async_desc, vd)->length;
974 	} else {
975 		list_for_each_entry(async_desc, &bchan->desc_list, desc_node) {
976 			if (async_desc->vd.tx.cookie != cookie)
977 				continue;
978 
979 			for (i = 0; i < async_desc->num_desc; i++)
980 				residue += le16_to_cpu(
981 						async_desc->curr_desc[i].size);
982 		}
983 	}
984 
985 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
986 
987 	dma_set_residue(txstate, residue);
988 
989 	if (ret == DMA_IN_PROGRESS && bchan->paused)
990 		ret = DMA_PAUSED;
991 
992 	return ret;
993 }
994 
995 /**
996  * bam_apply_new_config
997  * @bchan: bam dma channel
998  * @dir: DMA direction
999  */
1000 static void bam_apply_new_config(struct bam_chan *bchan,
1001 	enum dma_transfer_direction dir)
1002 {
1003 	struct bam_device *bdev = bchan->bdev;
1004 	u32 maxburst;
1005 
1006 	if (!bdev->controlled_remotely) {
1007 		if (dir == DMA_DEV_TO_MEM)
1008 			maxburst = bchan->slave.src_maxburst;
1009 		else
1010 			maxburst = bchan->slave.dst_maxburst;
1011 
1012 		writel_relaxed(maxburst,
1013 			       bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1014 	}
1015 
1016 	bchan->reconfigure = 0;
1017 }
1018 
1019 /**
1020  * bam_start_dma - start next transaction
1021  * @bchan: bam dma channel
1022  */
1023 static void bam_start_dma(struct bam_chan *bchan)
1024 {
1025 	struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
1026 	struct bam_device *bdev = bchan->bdev;
1027 	struct bam_async_desc *async_desc = NULL;
1028 	struct bam_desc_hw *desc;
1029 	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
1030 					sizeof(struct bam_desc_hw));
1031 	int ret;
1032 	unsigned int avail;
1033 	struct dmaengine_desc_callback cb;
1034 
1035 	lockdep_assert_held(&bchan->vc.lock);
1036 
1037 	if (!vd)
1038 		return;
1039 
1040 	ret = bam_pm_runtime_get_sync(bdev->dev);
1041 	if (ret < 0)
1042 		return;
1043 
1044 	while (vd && !IS_BUSY(bchan)) {
1045 		list_del(&vd->node);
1046 
1047 		async_desc = container_of(vd, struct bam_async_desc, vd);
1048 
1049 		/* on first use, initialize the channel hardware */
1050 		if (!bchan->initialized)
1051 			bam_chan_init_hw(bchan, async_desc->dir);
1052 
1053 		/* apply new slave config changes, if necessary */
1054 		if (bchan->reconfigure)
1055 			bam_apply_new_config(bchan, async_desc->dir);
1056 
1057 		desc = async_desc->curr_desc;
1058 		avail = CIRC_SPACE(bchan->tail, bchan->head,
1059 				   MAX_DESCRIPTORS + 1);
1060 
1061 		if (async_desc->num_desc > avail)
1062 			async_desc->xfer_len = avail;
1063 		else
1064 			async_desc->xfer_len = async_desc->num_desc;
1065 
1066 		/* set any special flags on the last descriptor */
1067 		if (async_desc->num_desc == async_desc->xfer_len)
1068 			desc[async_desc->xfer_len - 1].flags |=
1069 						cpu_to_le16(async_desc->flags);
1070 
1071 		vd = vchan_next_desc(&bchan->vc);
1072 
1073 		dmaengine_desc_get_callback(&async_desc->vd.tx, &cb);
1074 
1075 		/*
1076 		 * An interrupt is generated at this desc, if
1077 		 *  - FIFO is FULL.
1078 		 *  - No more descriptors to add.
1079 		 *  - If a callback completion was requested for this DESC,
1080 		 *     In this case, BAM will deliver the completion callback
1081 		 *     for this desc and continue processing the next desc.
1082 		 */
1083 		if (((avail <= async_desc->xfer_len) || !vd ||
1084 		     dmaengine_desc_callback_valid(&cb)) &&
1085 		    !(async_desc->flags & DESC_FLAG_EOT))
1086 			desc[async_desc->xfer_len - 1].flags |=
1087 				cpu_to_le16(DESC_FLAG_INT);
1088 
1089 		if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
1090 			u32 partial = MAX_DESCRIPTORS - bchan->tail;
1091 
1092 			memcpy(&fifo[bchan->tail], desc,
1093 			       partial * sizeof(struct bam_desc_hw));
1094 			memcpy(fifo, &desc[partial],
1095 			       (async_desc->xfer_len - partial) *
1096 				sizeof(struct bam_desc_hw));
1097 		} else {
1098 			memcpy(&fifo[bchan->tail], desc,
1099 			       async_desc->xfer_len *
1100 			       sizeof(struct bam_desc_hw));
1101 		}
1102 
1103 		bchan->tail += async_desc->xfer_len;
1104 		bchan->tail %= MAX_DESCRIPTORS;
1105 		list_add_tail(&async_desc->desc_node, &bchan->desc_list);
1106 	}
1107 
1108 	/* ensure descriptor writes and dma start not reordered */
1109 	wmb();
1110 	writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
1111 			bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
1112 
1113 	pm_runtime_mark_last_busy(bdev->dev);
1114 	pm_runtime_put_autosuspend(bdev->dev);
1115 }
1116 
1117 /**
1118  * dma_tasklet - DMA IRQ tasklet
1119  * @t: tasklet argument (bam controller structure)
1120  *
1121  * Sets up next DMA operation and then processes all completed transactions
1122  */
1123 static void dma_tasklet(struct tasklet_struct *t)
1124 {
1125 	struct bam_device *bdev = from_tasklet(bdev, t, task);
1126 	struct bam_chan *bchan;
1127 	unsigned long flags;
1128 	unsigned int i;
1129 
1130 	/* go through the channels and kick off transactions */
1131 	for (i = 0; i < bdev->num_channels; i++) {
1132 		bchan = &bdev->channels[i];
1133 		spin_lock_irqsave(&bchan->vc.lock, flags);
1134 
1135 		if (!list_empty(&bchan->vc.desc_issued) && !IS_BUSY(bchan))
1136 			bam_start_dma(bchan);
1137 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
1138 	}
1139 
1140 }
1141 
1142 /**
1143  * bam_issue_pending - starts pending transactions
1144  * @chan: dma channel
1145  *
1146  * Calls tasklet directly which in turn starts any pending transactions
1147  */
1148 static void bam_issue_pending(struct dma_chan *chan)
1149 {
1150 	struct bam_chan *bchan = to_bam_chan(chan);
1151 	unsigned long flags;
1152 
1153 	spin_lock_irqsave(&bchan->vc.lock, flags);
1154 
1155 	/* if work pending and idle, start a transaction */
1156 	if (vchan_issue_pending(&bchan->vc) && !IS_BUSY(bchan))
1157 		bam_start_dma(bchan);
1158 
1159 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
1160 }
1161 
1162 /**
1163  * bam_dma_free_desc - free descriptor memory
1164  * @vd: virtual descriptor
1165  *
1166  */
1167 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1168 {
1169 	struct bam_async_desc *async_desc = container_of(vd,
1170 			struct bam_async_desc, vd);
1171 
1172 	kfree(async_desc);
1173 }
1174 
1175 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1176 		struct of_dma *of)
1177 {
1178 	struct bam_device *bdev = container_of(of->of_dma_data,
1179 					struct bam_device, common);
1180 	unsigned int request;
1181 
1182 	if (dma_spec->args_count != 1)
1183 		return NULL;
1184 
1185 	request = dma_spec->args[0];
1186 	if (request >= bdev->num_channels)
1187 		return NULL;
1188 
1189 	return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1190 }
1191 
1192 /**
1193  * bam_init
1194  * @bdev: bam device
1195  *
1196  * Initialization helper for global bam registers
1197  */
1198 static int bam_init(struct bam_device *bdev)
1199 {
1200 	u32 val;
1201 
1202 	/* read revision and configuration information */
1203 	if (!bdev->num_ees) {
1204 		val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
1205 		bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
1206 	}
1207 
1208 	/* check that configured EE is within range */
1209 	if (bdev->ee >= bdev->num_ees)
1210 		return -EINVAL;
1211 
1212 	if (!bdev->num_channels) {
1213 		val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1214 		bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1215 	}
1216 
1217 	/* Reset BAM now if fully controlled locally */
1218 	if (!bdev->controlled_remotely && !bdev->powered_remotely)
1219 		bam_reset(bdev);
1220 
1221 	return 0;
1222 }
1223 
1224 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1225 	u32 index)
1226 {
1227 	bchan->id = index;
1228 	bchan->bdev = bdev;
1229 
1230 	vchan_init(&bchan->vc, &bdev->common);
1231 	bchan->vc.desc_free = bam_dma_free_desc;
1232 	INIT_LIST_HEAD(&bchan->desc_list);
1233 }
1234 
1235 static const struct of_device_id bam_of_match[] = {
1236 	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1237 	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1238 	{ .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1239 	{}
1240 };
1241 
1242 MODULE_DEVICE_TABLE(of, bam_of_match);
1243 
1244 static int bam_dma_probe(struct platform_device *pdev)
1245 {
1246 	struct bam_device *bdev;
1247 	const struct of_device_id *match;
1248 	struct resource *iores;
1249 	int ret, i;
1250 
1251 	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1252 	if (!bdev)
1253 		return -ENOMEM;
1254 
1255 	bdev->dev = &pdev->dev;
1256 
1257 	match = of_match_node(bam_of_match, pdev->dev.of_node);
1258 	if (!match) {
1259 		dev_err(&pdev->dev, "Unsupported BAM module\n");
1260 		return -ENODEV;
1261 	}
1262 
1263 	bdev->layout = match->data;
1264 
1265 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1266 	bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
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 		ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
1287 					   &bdev->num_channels);
1288 		if (ret)
1289 			dev_err(bdev->dev, "num-channels unspecified in dt\n");
1290 
1291 		ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",
1292 					   &bdev->num_ees);
1293 		if (ret)
1294 			dev_err(bdev->dev, "num-ees unspecified in dt\n");
1295 	}
1296 
1297 	if (bdev->controlled_remotely || bdev->powered_remotely)
1298 		bdev->bamclk = devm_clk_get_optional(bdev->dev, "bam_clk");
1299 	else
1300 		bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1301 
1302 	if (IS_ERR(bdev->bamclk))
1303 		return PTR_ERR(bdev->bamclk);
1304 
1305 	ret = clk_prepare_enable(bdev->bamclk);
1306 	if (ret) {
1307 		dev_err(bdev->dev, "failed to prepare/enable clock\n");
1308 		return ret;
1309 	}
1310 
1311 	ret = bam_init(bdev);
1312 	if (ret)
1313 		goto err_disable_clk;
1314 
1315 	tasklet_setup(&bdev->task, dma_tasklet);
1316 
1317 	bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1318 				sizeof(*bdev->channels), GFP_KERNEL);
1319 
1320 	if (!bdev->channels) {
1321 		ret = -ENOMEM;
1322 		goto err_tasklet_kill;
1323 	}
1324 
1325 	/* allocate and initialize channels */
1326 	INIT_LIST_HEAD(&bdev->common.channels);
1327 
1328 	for (i = 0; i < bdev->num_channels; i++)
1329 		bam_channel_init(bdev, &bdev->channels[i], i);
1330 
1331 	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1332 			IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1333 	if (ret)
1334 		goto err_bam_channel_exit;
1335 
1336 	/* set max dma segment size */
1337 	bdev->common.dev = bdev->dev;
1338 	ret = dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1339 	if (ret) {
1340 		dev_err(bdev->dev, "cannot set maximum segment size\n");
1341 		goto err_bam_channel_exit;
1342 	}
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 	if (!bdev->bamclk) {
1378 		pm_runtime_disable(&pdev->dev);
1379 		return 0;
1380 	}
1381 
1382 	pm_runtime_irq_safe(&pdev->dev);
1383 	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
1384 	pm_runtime_use_autosuspend(&pdev->dev);
1385 	pm_runtime_mark_last_busy(&pdev->dev);
1386 	pm_runtime_set_active(&pdev->dev);
1387 	pm_runtime_enable(&pdev->dev);
1388 
1389 	return 0;
1390 
1391 err_unregister_dma:
1392 	dma_async_device_unregister(&bdev->common);
1393 err_bam_channel_exit:
1394 	for (i = 0; i < bdev->num_channels; i++)
1395 		tasklet_kill(&bdev->channels[i].vc.task);
1396 err_tasklet_kill:
1397 	tasklet_kill(&bdev->task);
1398 err_disable_clk:
1399 	clk_disable_unprepare(bdev->bamclk);
1400 
1401 	return ret;
1402 }
1403 
1404 static int bam_dma_remove(struct platform_device *pdev)
1405 {
1406 	struct bam_device *bdev = platform_get_drvdata(pdev);
1407 	u32 i;
1408 
1409 	pm_runtime_force_suspend(&pdev->dev);
1410 
1411 	of_dma_controller_free(pdev->dev.of_node);
1412 	dma_async_device_unregister(&bdev->common);
1413 
1414 	/* mask all interrupts for this execution environment */
1415 	writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1416 
1417 	devm_free_irq(bdev->dev, bdev->irq, bdev);
1418 
1419 	for (i = 0; i < bdev->num_channels; i++) {
1420 		bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1421 		tasklet_kill(&bdev->channels[i].vc.task);
1422 
1423 		if (!bdev->channels[i].fifo_virt)
1424 			continue;
1425 
1426 		dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1427 			    bdev->channels[i].fifo_virt,
1428 			    bdev->channels[i].fifo_phys);
1429 	}
1430 
1431 	tasklet_kill(&bdev->task);
1432 
1433 	clk_disable_unprepare(bdev->bamclk);
1434 
1435 	return 0;
1436 }
1437 
1438 static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
1439 {
1440 	struct bam_device *bdev = dev_get_drvdata(dev);
1441 
1442 	clk_disable(bdev->bamclk);
1443 
1444 	return 0;
1445 }
1446 
1447 static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
1448 {
1449 	struct bam_device *bdev = dev_get_drvdata(dev);
1450 	int ret;
1451 
1452 	ret = clk_enable(bdev->bamclk);
1453 	if (ret < 0) {
1454 		dev_err(dev, "clk_enable failed: %d\n", ret);
1455 		return ret;
1456 	}
1457 
1458 	return 0;
1459 }
1460 
1461 static int __maybe_unused bam_dma_suspend(struct device *dev)
1462 {
1463 	struct bam_device *bdev = dev_get_drvdata(dev);
1464 
1465 	if (bdev->bamclk) {
1466 		pm_runtime_force_suspend(dev);
1467 		clk_unprepare(bdev->bamclk);
1468 	}
1469 
1470 	return 0;
1471 }
1472 
1473 static int __maybe_unused bam_dma_resume(struct device *dev)
1474 {
1475 	struct bam_device *bdev = dev_get_drvdata(dev);
1476 	int ret;
1477 
1478 	if (bdev->bamclk) {
1479 		ret = clk_prepare(bdev->bamclk);
1480 		if (ret)
1481 			return ret;
1482 
1483 		pm_runtime_force_resume(dev);
1484 	}
1485 
1486 	return 0;
1487 }
1488 
1489 static const struct dev_pm_ops bam_dma_pm_ops = {
1490 	SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
1491 	SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
1492 				NULL)
1493 };
1494 
1495 static struct platform_driver bam_dma_driver = {
1496 	.probe = bam_dma_probe,
1497 	.remove = bam_dma_remove,
1498 	.driver = {
1499 		.name = "bam-dma-engine",
1500 		.pm = &bam_dma_pm_ops,
1501 		.of_match_table = bam_of_match,
1502 	},
1503 };
1504 
1505 module_platform_driver(bam_dma_driver);
1506 
1507 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1508 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1509 MODULE_LICENSE("GPL v2");
1510