xref: /linux/drivers/dma/qcom/bam_dma.c (revision 6b72cd9ef062702390fc96c469beea1729a5dffe)
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 #define BAM_NDP_REVISION_START	0x20
63 #define BAM_NDP_REVISION_END	0x27
64 
65 struct bam_async_desc {
66 	struct virt_dma_desc vd;
67 
68 	u32 num_desc;
69 	u32 xfer_len;
70 
71 	/* transaction flags, EOT|EOB|NWD */
72 	u16 flags;
73 
74 	struct bam_desc_hw *curr_desc;
75 
76 	/* list node for the desc in the bam_chan list of descriptors */
77 	struct list_head desc_node;
78 	enum dma_transfer_direction dir;
79 	size_t length;
80 	struct bam_desc_hw desc[] __counted_by(num_desc);
81 };
82 
83 enum bam_reg {
84 	BAM_CTRL,
85 	BAM_REVISION,
86 	BAM_NUM_PIPES,
87 	BAM_DESC_CNT_TRSHLD,
88 	BAM_IRQ_SRCS,
89 	BAM_IRQ_SRCS_MSK,
90 	BAM_IRQ_SRCS_UNMASKED,
91 	BAM_IRQ_STTS,
92 	BAM_IRQ_CLR,
93 	BAM_IRQ_EN,
94 	BAM_CNFG_BITS,
95 	BAM_IRQ_SRCS_EE,
96 	BAM_IRQ_SRCS_MSK_EE,
97 	BAM_P_CTRL,
98 	BAM_P_RST,
99 	BAM_P_HALT,
100 	BAM_P_IRQ_STTS,
101 	BAM_P_IRQ_CLR,
102 	BAM_P_IRQ_EN,
103 	BAM_P_EVNT_DEST_ADDR,
104 	BAM_P_EVNT_REG,
105 	BAM_P_SW_OFSTS,
106 	BAM_P_DATA_FIFO_ADDR,
107 	BAM_P_DESC_FIFO_ADDR,
108 	BAM_P_EVNT_GEN_TRSHLD,
109 	BAM_P_FIFO_SIZES,
110 };
111 
112 struct reg_offset_data {
113 	u32 base_offset;
114 	unsigned int pipe_mult, evnt_mult, ee_mult;
115 };
116 
117 static const struct reg_offset_data bam_v1_3_reg_info[] = {
118 	[BAM_CTRL]		= { 0x0F80, 0x00, 0x00, 0x00 },
119 	[BAM_REVISION]		= { 0x0F84, 0x00, 0x00, 0x00 },
120 	[BAM_NUM_PIPES]		= { 0x0FBC, 0x00, 0x00, 0x00 },
121 	[BAM_DESC_CNT_TRSHLD]	= { 0x0F88, 0x00, 0x00, 0x00 },
122 	[BAM_IRQ_SRCS]		= { 0x0F8C, 0x00, 0x00, 0x00 },
123 	[BAM_IRQ_SRCS_MSK]	= { 0x0F90, 0x00, 0x00, 0x00 },
124 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0FB0, 0x00, 0x00, 0x00 },
125 	[BAM_IRQ_STTS]		= { 0x0F94, 0x00, 0x00, 0x00 },
126 	[BAM_IRQ_CLR]		= { 0x0F98, 0x00, 0x00, 0x00 },
127 	[BAM_IRQ_EN]		= { 0x0F9C, 0x00, 0x00, 0x00 },
128 	[BAM_CNFG_BITS]		= { 0x0FFC, 0x00, 0x00, 0x00 },
129 	[BAM_IRQ_SRCS_EE]	= { 0x1800, 0x00, 0x00, 0x80 },
130 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x1804, 0x00, 0x00, 0x80 },
131 	[BAM_P_CTRL]		= { 0x0000, 0x80, 0x00, 0x00 },
132 	[BAM_P_RST]		= { 0x0004, 0x80, 0x00, 0x00 },
133 	[BAM_P_HALT]		= { 0x0008, 0x80, 0x00, 0x00 },
134 	[BAM_P_IRQ_STTS]	= { 0x0010, 0x80, 0x00, 0x00 },
135 	[BAM_P_IRQ_CLR]		= { 0x0014, 0x80, 0x00, 0x00 },
136 	[BAM_P_IRQ_EN]		= { 0x0018, 0x80, 0x00, 0x00 },
137 	[BAM_P_EVNT_DEST_ADDR]	= { 0x102C, 0x00, 0x40, 0x00 },
138 	[BAM_P_EVNT_REG]	= { 0x1018, 0x00, 0x40, 0x00 },
139 	[BAM_P_SW_OFSTS]	= { 0x1000, 0x00, 0x40, 0x00 },
140 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1024, 0x00, 0x40, 0x00 },
141 	[BAM_P_DESC_FIFO_ADDR]	= { 0x101C, 0x00, 0x40, 0x00 },
142 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1028, 0x00, 0x40, 0x00 },
143 	[BAM_P_FIFO_SIZES]	= { 0x1020, 0x00, 0x40, 0x00 },
144 };
145 
146 static const struct reg_offset_data bam_v1_4_reg_info[] = {
147 	[BAM_CTRL]		= { 0x0000, 0x00, 0x00, 0x00 },
148 	[BAM_REVISION]		= { 0x0004, 0x00, 0x00, 0x00 },
149 	[BAM_NUM_PIPES]		= { 0x003C, 0x00, 0x00, 0x00 },
150 	[BAM_DESC_CNT_TRSHLD]	= { 0x0008, 0x00, 0x00, 0x00 },
151 	[BAM_IRQ_SRCS]		= { 0x000C, 0x00, 0x00, 0x00 },
152 	[BAM_IRQ_SRCS_MSK]	= { 0x0010, 0x00, 0x00, 0x00 },
153 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0030, 0x00, 0x00, 0x00 },
154 	[BAM_IRQ_STTS]		= { 0x0014, 0x00, 0x00, 0x00 },
155 	[BAM_IRQ_CLR]		= { 0x0018, 0x00, 0x00, 0x00 },
156 	[BAM_IRQ_EN]		= { 0x001C, 0x00, 0x00, 0x00 },
157 	[BAM_CNFG_BITS]		= { 0x007C, 0x00, 0x00, 0x00 },
158 	[BAM_IRQ_SRCS_EE]	= { 0x0800, 0x00, 0x00, 0x80 },
159 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x0804, 0x00, 0x00, 0x80 },
160 	[BAM_P_CTRL]		= { 0x1000, 0x1000, 0x00, 0x00 },
161 	[BAM_P_RST]		= { 0x1004, 0x1000, 0x00, 0x00 },
162 	[BAM_P_HALT]		= { 0x1008, 0x1000, 0x00, 0x00 },
163 	[BAM_P_IRQ_STTS]	= { 0x1010, 0x1000, 0x00, 0x00 },
164 	[BAM_P_IRQ_CLR]		= { 0x1014, 0x1000, 0x00, 0x00 },
165 	[BAM_P_IRQ_EN]		= { 0x1018, 0x1000, 0x00, 0x00 },
166 	[BAM_P_EVNT_DEST_ADDR]	= { 0x182C, 0x00, 0x1000, 0x00 },
167 	[BAM_P_EVNT_REG]	= { 0x1818, 0x00, 0x1000, 0x00 },
168 	[BAM_P_SW_OFSTS]	= { 0x1800, 0x00, 0x1000, 0x00 },
169 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1824, 0x00, 0x1000, 0x00 },
170 	[BAM_P_DESC_FIFO_ADDR]	= { 0x181C, 0x00, 0x1000, 0x00 },
171 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1828, 0x00, 0x1000, 0x00 },
172 	[BAM_P_FIFO_SIZES]	= { 0x1820, 0x00, 0x1000, 0x00 },
173 };
174 
175 static const struct reg_offset_data bam_v1_7_reg_info[] = {
176 	[BAM_CTRL]		= { 0x00000, 0x00, 0x00, 0x00 },
177 	[BAM_REVISION]		= { 0x01000, 0x00, 0x00, 0x00 },
178 	[BAM_NUM_PIPES]		= { 0x01008, 0x00, 0x00, 0x00 },
179 	[BAM_DESC_CNT_TRSHLD]	= { 0x00008, 0x00, 0x00, 0x00 },
180 	[BAM_IRQ_SRCS]		= { 0x03010, 0x00, 0x00, 0x00 },
181 	[BAM_IRQ_SRCS_MSK]	= { 0x03014, 0x00, 0x00, 0x00 },
182 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x03018, 0x00, 0x00, 0x00 },
183 	[BAM_IRQ_STTS]		= { 0x00014, 0x00, 0x00, 0x00 },
184 	[BAM_IRQ_CLR]		= { 0x00018, 0x00, 0x00, 0x00 },
185 	[BAM_IRQ_EN]		= { 0x0001C, 0x00, 0x00, 0x00 },
186 	[BAM_CNFG_BITS]		= { 0x0007C, 0x00, 0x00, 0x00 },
187 	[BAM_IRQ_SRCS_EE]	= { 0x03000, 0x00, 0x00, 0x1000 },
188 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x03004, 0x00, 0x00, 0x1000 },
189 	[BAM_P_CTRL]		= { 0x13000, 0x1000, 0x00, 0x00 },
190 	[BAM_P_RST]		= { 0x13004, 0x1000, 0x00, 0x00 },
191 	[BAM_P_HALT]		= { 0x13008, 0x1000, 0x00, 0x00 },
192 	[BAM_P_IRQ_STTS]	= { 0x13010, 0x1000, 0x00, 0x00 },
193 	[BAM_P_IRQ_CLR]		= { 0x13014, 0x1000, 0x00, 0x00 },
194 	[BAM_P_IRQ_EN]		= { 0x13018, 0x1000, 0x00, 0x00 },
195 	[BAM_P_EVNT_DEST_ADDR]	= { 0x1382C, 0x00, 0x1000, 0x00 },
196 	[BAM_P_EVNT_REG]	= { 0x13818, 0x00, 0x1000, 0x00 },
197 	[BAM_P_SW_OFSTS]	= { 0x13800, 0x00, 0x1000, 0x00 },
198 	[BAM_P_DATA_FIFO_ADDR]	= { 0x13824, 0x00, 0x1000, 0x00 },
199 	[BAM_P_DESC_FIFO_ADDR]	= { 0x1381C, 0x00, 0x1000, 0x00 },
200 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x13828, 0x00, 0x1000, 0x00 },
201 	[BAM_P_FIFO_SIZES]	= { 0x13820, 0x00, 0x1000, 0x00 },
202 };
203 
204 /* BAM CTRL */
205 #define BAM_SW_RST			BIT(0)
206 #define BAM_EN				BIT(1)
207 #define BAM_EN_ACCUM			BIT(4)
208 #define BAM_TESTBUS_SEL_SHIFT		5
209 #define BAM_TESTBUS_SEL_MASK		0x3F
210 #define BAM_DESC_CACHE_SEL_SHIFT	13
211 #define BAM_DESC_CACHE_SEL_MASK		0x3
212 #define BAM_CACHED_DESC_STORE		BIT(15)
213 #define IBC_DISABLE			BIT(16)
214 
215 /* BAM REVISION */
216 #define REVISION_SHIFT		0
217 #define REVISION_MASK		0xFF
218 #define NUM_EES_SHIFT		8
219 #define NUM_EES_MASK		0xF
220 #define CE_BUFFER_SIZE		BIT(13)
221 #define AXI_ACTIVE		BIT(14)
222 #define USE_VMIDMT		BIT(15)
223 #define SECURED			BIT(16)
224 #define BAM_HAS_NO_BYPASS	BIT(17)
225 #define HIGH_FREQUENCY_BAM	BIT(18)
226 #define INACTIV_TMRS_EXST	BIT(19)
227 #define NUM_INACTIV_TMRS	BIT(20)
228 #define DESC_CACHE_DEPTH_SHIFT	21
229 #define DESC_CACHE_DEPTH_1	(0 << DESC_CACHE_DEPTH_SHIFT)
230 #define DESC_CACHE_DEPTH_2	(1 << DESC_CACHE_DEPTH_SHIFT)
231 #define DESC_CACHE_DEPTH_3	(2 << DESC_CACHE_DEPTH_SHIFT)
232 #define DESC_CACHE_DEPTH_4	(3 << DESC_CACHE_DEPTH_SHIFT)
233 #define CMD_DESC_EN		BIT(23)
234 #define INACTIV_TMR_BASE_SHIFT	24
235 #define INACTIV_TMR_BASE_MASK	0xFF
236 
237 /* BAM NUM PIPES */
238 #define BAM_NUM_PIPES_SHIFT		0
239 #define BAM_NUM_PIPES_MASK		0xFF
240 #define PERIPH_NON_PIPE_GRP_SHIFT	16
241 #define PERIPH_NON_PIP_GRP_MASK		0xFF
242 #define BAM_NON_PIPE_GRP_SHIFT		24
243 #define BAM_NON_PIPE_GRP_MASK		0xFF
244 
245 /* BAM CNFG BITS */
246 #define BAM_PIPE_CNFG		BIT(2)
247 #define BAM_FULL_PIPE		BIT(11)
248 #define BAM_NO_EXT_P_RST	BIT(12)
249 #define BAM_IBC_DISABLE		BIT(13)
250 #define BAM_SB_CLK_REQ		BIT(14)
251 #define BAM_PSM_CSW_REQ		BIT(15)
252 #define BAM_PSM_P_RES		BIT(16)
253 #define BAM_AU_P_RES		BIT(17)
254 #define BAM_SI_P_RES		BIT(18)
255 #define BAM_WB_P_RES		BIT(19)
256 #define BAM_WB_BLK_CSW		BIT(20)
257 #define BAM_WB_CSW_ACK_IDL	BIT(21)
258 #define BAM_WB_RETR_SVPNT	BIT(22)
259 #define BAM_WB_DSC_AVL_P_RST	BIT(23)
260 #define BAM_REG_P_EN		BIT(24)
261 #define BAM_PSM_P_HD_DATA	BIT(25)
262 #define BAM_AU_ACCUMED		BIT(26)
263 #define BAM_CMD_ENABLE		BIT(27)
264 
265 #define BAM_CNFG_BITS_DEFAULT	(BAM_PIPE_CNFG |	\
266 				 BAM_NO_EXT_P_RST |	\
267 				 BAM_IBC_DISABLE |	\
268 				 BAM_SB_CLK_REQ |	\
269 				 BAM_PSM_CSW_REQ |	\
270 				 BAM_PSM_P_RES |	\
271 				 BAM_AU_P_RES |		\
272 				 BAM_SI_P_RES |		\
273 				 BAM_WB_P_RES |		\
274 				 BAM_WB_BLK_CSW |	\
275 				 BAM_WB_CSW_ACK_IDL |	\
276 				 BAM_WB_RETR_SVPNT |	\
277 				 BAM_WB_DSC_AVL_P_RST |	\
278 				 BAM_REG_P_EN |		\
279 				 BAM_PSM_P_HD_DATA |	\
280 				 BAM_AU_ACCUMED |	\
281 				 BAM_CMD_ENABLE)
282 
283 /* PIPE CTRL */
284 #define P_EN			BIT(1)
285 #define P_DIRECTION		BIT(3)
286 #define P_SYS_STRM		BIT(4)
287 #define P_SYS_MODE		BIT(5)
288 #define P_AUTO_EOB		BIT(6)
289 #define P_AUTO_EOB_SEL_SHIFT	7
290 #define P_AUTO_EOB_SEL_512	(0 << P_AUTO_EOB_SEL_SHIFT)
291 #define P_AUTO_EOB_SEL_256	(1 << P_AUTO_EOB_SEL_SHIFT)
292 #define P_AUTO_EOB_SEL_128	(2 << P_AUTO_EOB_SEL_SHIFT)
293 #define P_AUTO_EOB_SEL_64	(3 << P_AUTO_EOB_SEL_SHIFT)
294 #define P_PREFETCH_LIMIT_SHIFT	9
295 #define P_PREFETCH_LIMIT_32	(0 << P_PREFETCH_LIMIT_SHIFT)
296 #define P_PREFETCH_LIMIT_16	(1 << P_PREFETCH_LIMIT_SHIFT)
297 #define P_PREFETCH_LIMIT_4	(2 << P_PREFETCH_LIMIT_SHIFT)
298 #define P_WRITE_NWD		BIT(11)
299 #define P_LOCK_GROUP_SHIFT	16
300 #define P_LOCK_GROUP_MASK	0x1F
301 
302 /* BAM_DESC_CNT_TRSHLD */
303 #define CNT_TRSHLD		0xffff
304 #define DEFAULT_CNT_THRSHLD	0x4
305 
306 /* BAM_IRQ_SRCS */
307 #define BAM_IRQ			BIT(31)
308 #define P_IRQ			0x7fffffff
309 
310 /* BAM_IRQ_SRCS_MSK */
311 #define BAM_IRQ_MSK		BAM_IRQ
312 #define P_IRQ_MSK		P_IRQ
313 
314 /* BAM_IRQ_STTS */
315 #define BAM_TIMER_IRQ		BIT(4)
316 #define BAM_EMPTY_IRQ		BIT(3)
317 #define BAM_ERROR_IRQ		BIT(2)
318 #define BAM_HRESP_ERR_IRQ	BIT(1)
319 
320 /* BAM_IRQ_CLR */
321 #define BAM_TIMER_CLR		BIT(4)
322 #define BAM_EMPTY_CLR		BIT(3)
323 #define BAM_ERROR_CLR		BIT(2)
324 #define BAM_HRESP_ERR_CLR	BIT(1)
325 
326 /* BAM_IRQ_EN */
327 #define BAM_TIMER_EN		BIT(4)
328 #define BAM_EMPTY_EN		BIT(3)
329 #define BAM_ERROR_EN		BIT(2)
330 #define BAM_HRESP_ERR_EN	BIT(1)
331 
332 /* BAM_P_IRQ_EN */
333 #define P_PRCSD_DESC_EN		BIT(0)
334 #define P_TIMER_EN		BIT(1)
335 #define P_WAKE_EN		BIT(2)
336 #define P_OUT_OF_DESC_EN	BIT(3)
337 #define P_ERR_EN		BIT(4)
338 #define P_TRNSFR_END_EN		BIT(5)
339 #define P_DEFAULT_IRQS_EN	(P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
340 
341 /* BAM_P_SW_OFSTS */
342 #define P_SW_OFSTS_MASK		0xffff
343 
344 #define BAM_DESC_FIFO_SIZE	SZ_32K
345 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
346 #define BAM_FIFO_SIZE	(SZ_32K - 8)
347 #define IS_BUSY(chan)	(CIRC_SPACE(bchan->tail, bchan->head,\
348 			 MAX_DESCRIPTORS + 1) == 0)
349 
350 struct bam_chan {
351 	struct virt_dma_chan vc;
352 
353 	struct bam_device *bdev;
354 
355 	/* configuration from device tree */
356 	u32 id;
357 
358 	/* runtime configuration */
359 	struct dma_slave_config slave;
360 
361 	/* fifo storage */
362 	struct bam_desc_hw *fifo_virt;
363 	dma_addr_t fifo_phys;
364 
365 	/* fifo markers */
366 	unsigned short head;		/* start of active descriptor entries */
367 	unsigned short tail;		/* end of active descriptor entries */
368 
369 	unsigned int initialized;	/* is the channel hw initialized? */
370 	unsigned int paused;		/* is the channel paused? */
371 	unsigned int reconfigure;	/* new slave config? */
372 	/* list of descriptors currently processed */
373 	struct list_head desc_list;
374 
375 	struct list_head node;
376 };
377 
378 static inline struct bam_chan *to_bam_chan(struct dma_chan *common)
379 {
380 	return container_of(common, struct bam_chan, vc.chan);
381 }
382 
383 struct bam_device {
384 	void __iomem *regs;
385 	struct device *dev;
386 	struct dma_device common;
387 	struct bam_chan *channels;
388 	u32 num_channels;
389 	u32 num_ees;
390 
391 	/* execution environment ID, from DT */
392 	u32 ee;
393 	bool controlled_remotely;
394 	bool powered_remotely;
395 	u32 active_channels;
396 
397 	const struct reg_offset_data *layout;
398 
399 	struct clk *bamclk;
400 	int irq;
401 
402 	/* dma start transaction tasklet */
403 	struct tasklet_struct task;
404 	u32 bam_revision;
405 };
406 
407 /**
408  * bam_addr - returns BAM register address
409  * @bdev: bam device
410  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
411  * @reg:  register enum
412  */
413 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
414 		enum bam_reg reg)
415 {
416 	const struct reg_offset_data r = bdev->layout[reg];
417 
418 	return bdev->regs + r.base_offset +
419 		r.pipe_mult * pipe +
420 		r.evnt_mult * pipe +
421 		r.ee_mult * bdev->ee;
422 }
423 
424 /**
425  * bam_reset() - reset and initialize BAM registers
426  * @bdev: bam device
427  */
428 static void bam_reset(struct bam_device *bdev)
429 {
430 	u32 val;
431 
432 	/* s/w reset bam */
433 	/* after reset all pipes are disabled and idle */
434 	val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
435 	val |= BAM_SW_RST;
436 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
437 	val &= ~BAM_SW_RST;
438 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
439 
440 	/* make sure previous stores are visible before enabling BAM */
441 	wmb();
442 
443 	/* enable bam */
444 	val |= BAM_EN;
445 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
446 
447 	/* set descriptor threshold, start with 4 bytes */
448 	if (in_range(bdev->bam_revision, BAM_NDP_REVISION_START,
449 		     BAM_NDP_REVISION_END))
450 		writel_relaxed(DEFAULT_CNT_THRSHLD,
451 			       bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
452 
453 	/* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
454 	writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
455 
456 	/* enable irqs for errors */
457 	writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
458 			bam_addr(bdev, 0, BAM_IRQ_EN));
459 
460 	/* unmask global bam interrupt */
461 	writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
462 }
463 
464 /**
465  * bam_reset_channel - Reset individual BAM DMA channel
466  * @bchan: bam channel
467  *
468  * This function resets a specific BAM channel
469  */
470 static void bam_reset_channel(struct bam_chan *bchan)
471 {
472 	struct bam_device *bdev = bchan->bdev;
473 
474 	lockdep_assert_held(&bchan->vc.lock);
475 
476 	/* reset channel */
477 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
478 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
479 
480 	/* don't allow cpu to reorder BAM register accesses done after this */
481 	wmb();
482 
483 	/* make sure hw is initialized when channel is used the first time  */
484 	bchan->initialized = 0;
485 }
486 
487 /**
488  * bam_chan_init_hw - Initialize channel hardware
489  * @bchan: bam channel
490  * @dir: DMA transfer direction
491  *
492  * This function resets and initializes the BAM channel
493  */
494 static void bam_chan_init_hw(struct bam_chan *bchan,
495 	enum dma_transfer_direction dir)
496 {
497 	struct bam_device *bdev = bchan->bdev;
498 	u32 val;
499 
500 	/* Reset the channel to clear internal state of the FIFO */
501 	bam_reset_channel(bchan);
502 
503 	/*
504 	 * write out 8 byte aligned address.  We have enough space for this
505 	 * because we allocated 1 more descriptor (8 bytes) than we can use
506 	 */
507 	writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
508 			bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
509 	writel_relaxed(BAM_FIFO_SIZE,
510 			bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
511 
512 	/* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
513 	writel_relaxed(P_DEFAULT_IRQS_EN,
514 			bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
515 
516 	/* unmask the specific pipe and EE combo */
517 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
518 	val |= BIT(bchan->id);
519 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
520 
521 	/* don't allow cpu to reorder the channel enable done below */
522 	wmb();
523 
524 	/* set fixed direction and mode, then enable channel */
525 	val = P_EN | P_SYS_MODE;
526 	if (dir == DMA_DEV_TO_MEM)
527 		val |= P_DIRECTION;
528 
529 	writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
530 
531 	bchan->initialized = 1;
532 
533 	/* init FIFO pointers */
534 	bchan->head = 0;
535 	bchan->tail = 0;
536 }
537 
538 /**
539  * bam_alloc_chan - Allocate channel resources for DMA channel.
540  * @chan: specified channel
541  *
542  * This function allocates the FIFO descriptor memory
543  */
544 static int bam_alloc_chan(struct dma_chan *chan)
545 {
546 	struct bam_chan *bchan = to_bam_chan(chan);
547 	struct bam_device *bdev = bchan->bdev;
548 
549 	if (bchan->fifo_virt)
550 		return 0;
551 
552 	/* allocate FIFO descriptor space, but only if necessary */
553 	bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
554 					&bchan->fifo_phys, GFP_KERNEL);
555 
556 	if (!bchan->fifo_virt) {
557 		dev_err(bdev->dev, "Failed to allocate desc fifo\n");
558 		return -ENOMEM;
559 	}
560 
561 	if (bdev->active_channels++ == 0 && bdev->powered_remotely)
562 		bam_reset(bdev);
563 
564 	return 0;
565 }
566 
567 /**
568  * bam_free_chan - Frees dma resources associated with specific channel
569  * @chan: specified channel
570  *
571  * Free the allocated fifo descriptor memory and channel resources
572  *
573  */
574 static void bam_free_chan(struct dma_chan *chan)
575 {
576 	struct bam_chan *bchan = to_bam_chan(chan);
577 	struct bam_device *bdev = bchan->bdev;
578 	u32 val;
579 	unsigned long flags;
580 	int ret;
581 
582 	ret = pm_runtime_get_sync(bdev->dev);
583 	if (ret < 0)
584 		return;
585 
586 	vchan_free_chan_resources(to_virt_chan(chan));
587 
588 	if (!list_empty(&bchan->desc_list)) {
589 		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
590 		goto err;
591 	}
592 
593 	spin_lock_irqsave(&bchan->vc.lock, flags);
594 	bam_reset_channel(bchan);
595 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
596 
597 	dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
598 		    bchan->fifo_phys);
599 	bchan->fifo_virt = NULL;
600 
601 	/* mask irq for pipe/channel */
602 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
603 	val &= ~BIT(bchan->id);
604 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
605 
606 	/* disable irq */
607 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
608 
609 	if (--bdev->active_channels == 0 && bdev->powered_remotely) {
610 		/* s/w reset bam */
611 		val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
612 		val |= BAM_SW_RST;
613 		writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
614 	}
615 
616 err:
617 	pm_runtime_mark_last_busy(bdev->dev);
618 	pm_runtime_put_autosuspend(bdev->dev);
619 }
620 
621 /**
622  * bam_slave_config - set slave configuration for channel
623  * @chan: dma channel
624  * @cfg: slave configuration
625  *
626  * Sets slave configuration for channel
627  *
628  */
629 static int bam_slave_config(struct dma_chan *chan,
630 			    struct dma_slave_config *cfg)
631 {
632 	struct bam_chan *bchan = to_bam_chan(chan);
633 	unsigned long flag;
634 
635 	spin_lock_irqsave(&bchan->vc.lock, flag);
636 	memcpy(&bchan->slave, cfg, sizeof(*cfg));
637 	bchan->reconfigure = 1;
638 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
639 
640 	return 0;
641 }
642 
643 /**
644  * bam_prep_slave_sg - Prep slave sg transaction
645  *
646  * @chan: dma channel
647  * @sgl: scatter gather list
648  * @sg_len: length of sg
649  * @direction: DMA transfer direction
650  * @flags: DMA flags
651  * @context: transfer context (unused)
652  */
653 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
654 	struct scatterlist *sgl, unsigned int sg_len,
655 	enum dma_transfer_direction direction, unsigned long flags,
656 	void *context)
657 {
658 	struct bam_chan *bchan = to_bam_chan(chan);
659 	struct bam_device *bdev = bchan->bdev;
660 	struct bam_async_desc *async_desc;
661 	struct scatterlist *sg;
662 	u32 i;
663 	struct bam_desc_hw *desc;
664 	unsigned int num_alloc = 0;
665 
666 
667 	if (!is_slave_direction(direction)) {
668 		dev_err(bdev->dev, "invalid dma direction\n");
669 		return NULL;
670 	}
671 
672 	/* calculate number of required entries */
673 	for_each_sg(sgl, sg, sg_len, i)
674 		num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE);
675 
676 	/* allocate enough room to accommodate the number of entries */
677 	async_desc = kzalloc(struct_size(async_desc, desc, num_alloc),
678 			     GFP_NOWAIT);
679 
680 	if (!async_desc)
681 		return NULL;
682 
683 	if (flags & DMA_PREP_FENCE)
684 		async_desc->flags |= DESC_FLAG_NWD;
685 
686 	if (flags & DMA_PREP_INTERRUPT)
687 		async_desc->flags |= DESC_FLAG_EOT;
688 
689 	async_desc->num_desc = num_alloc;
690 	async_desc->curr_desc = async_desc->desc;
691 	async_desc->dir = direction;
692 
693 	/* fill in temporary descriptors */
694 	desc = async_desc->desc;
695 	for_each_sg(sgl, sg, sg_len, i) {
696 		unsigned int remainder = sg_dma_len(sg);
697 		unsigned int curr_offset = 0;
698 
699 		do {
700 			if (flags & DMA_PREP_CMD)
701 				desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
702 
703 			desc->addr = cpu_to_le32(sg_dma_address(sg) +
704 						 curr_offset);
705 
706 			if (remainder > BAM_FIFO_SIZE) {
707 				desc->size = cpu_to_le16(BAM_FIFO_SIZE);
708 				remainder -= BAM_FIFO_SIZE;
709 				curr_offset += BAM_FIFO_SIZE;
710 			} else {
711 				desc->size = cpu_to_le16(remainder);
712 				remainder = 0;
713 			}
714 
715 			async_desc->length += le16_to_cpu(desc->size);
716 			desc++;
717 		} while (remainder > 0);
718 	}
719 
720 	return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
721 }
722 
723 /**
724  * bam_dma_terminate_all - terminate all transactions on a channel
725  * @chan: bam dma channel
726  *
727  * Dequeues and frees all transactions
728  * No callbacks are done
729  *
730  */
731 static int bam_dma_terminate_all(struct dma_chan *chan)
732 {
733 	struct bam_chan *bchan = to_bam_chan(chan);
734 	struct bam_async_desc *async_desc, *tmp;
735 	unsigned long flag;
736 	LIST_HEAD(head);
737 
738 	/* remove all transactions, including active transaction */
739 	spin_lock_irqsave(&bchan->vc.lock, flag);
740 	/*
741 	 * If we have transactions queued, then some might be committed to the
742 	 * hardware in the desc fifo.  The only way to reset the desc fifo is
743 	 * to do a hardware reset (either by pipe or the entire block).
744 	 * bam_chan_init_hw() will trigger a pipe reset, and also reinit the
745 	 * pipe.  If the pipe is left disabled (default state after pipe reset)
746 	 * and is accessed by a connected hardware engine, a fatal error in
747 	 * the BAM will occur.  There is a small window where this could happen
748 	 * with bam_chan_init_hw(), but it is assumed that the caller has
749 	 * stopped activity on any attached hardware engine.  Make sure to do
750 	 * this first so that the BAM hardware doesn't cause memory corruption
751 	 * by accessing freed resources.
752 	 */
753 	if (!list_empty(&bchan->desc_list)) {
754 		async_desc = list_first_entry(&bchan->desc_list,
755 					      struct bam_async_desc, desc_node);
756 		bam_chan_init_hw(bchan, async_desc->dir);
757 	}
758 
759 	list_for_each_entry_safe(async_desc, tmp,
760 				 &bchan->desc_list, desc_node) {
761 		list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
762 		list_del(&async_desc->desc_node);
763 	}
764 
765 	vchan_get_all_descriptors(&bchan->vc, &head);
766 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
767 
768 	vchan_dma_desc_free_list(&bchan->vc, &head);
769 
770 	return 0;
771 }
772 
773 /**
774  * bam_pause - Pause DMA channel
775  * @chan: dma channel
776  *
777  */
778 static int bam_pause(struct dma_chan *chan)
779 {
780 	struct bam_chan *bchan = to_bam_chan(chan);
781 	struct bam_device *bdev = bchan->bdev;
782 	unsigned long flag;
783 	int ret;
784 
785 	ret = pm_runtime_get_sync(bdev->dev);
786 	if (ret < 0)
787 		return ret;
788 
789 	spin_lock_irqsave(&bchan->vc.lock, flag);
790 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
791 	bchan->paused = 1;
792 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
793 	pm_runtime_mark_last_busy(bdev->dev);
794 	pm_runtime_put_autosuspend(bdev->dev);
795 
796 	return 0;
797 }
798 
799 /**
800  * bam_resume - Resume DMA channel operations
801  * @chan: dma channel
802  *
803  */
804 static int bam_resume(struct dma_chan *chan)
805 {
806 	struct bam_chan *bchan = to_bam_chan(chan);
807 	struct bam_device *bdev = bchan->bdev;
808 	unsigned long flag;
809 	int ret;
810 
811 	ret = pm_runtime_get_sync(bdev->dev);
812 	if (ret < 0)
813 		return ret;
814 
815 	spin_lock_irqsave(&bchan->vc.lock, flag);
816 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
817 	bchan->paused = 0;
818 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
819 	pm_runtime_mark_last_busy(bdev->dev);
820 	pm_runtime_put_autosuspend(bdev->dev);
821 
822 	return 0;
823 }
824 
825 /**
826  * process_channel_irqs - processes the channel interrupts
827  * @bdev: bam controller
828  *
829  * This function processes the channel interrupts
830  *
831  */
832 static u32 process_channel_irqs(struct bam_device *bdev)
833 {
834 	u32 i, srcs, pipe_stts, offset, avail;
835 	unsigned long flags;
836 	struct bam_async_desc *async_desc, *tmp;
837 
838 	srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
839 
840 	/* return early if no pipe/channel interrupts are present */
841 	if (!(srcs & P_IRQ))
842 		return srcs;
843 
844 	for (i = 0; i < bdev->num_channels; i++) {
845 		struct bam_chan *bchan = &bdev->channels[i];
846 
847 		if (!(srcs & BIT(i)))
848 			continue;
849 
850 		/* clear pipe irq */
851 		pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
852 
853 		writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
854 
855 		spin_lock_irqsave(&bchan->vc.lock, flags);
856 
857 		offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) &
858 				       P_SW_OFSTS_MASK;
859 		offset /= sizeof(struct bam_desc_hw);
860 
861 		/* Number of bytes available to read */
862 		avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
863 
864 		if (offset < bchan->head)
865 			avail--;
866 
867 		list_for_each_entry_safe(async_desc, tmp,
868 					 &bchan->desc_list, desc_node) {
869 			/* Not enough data to read */
870 			if (avail < async_desc->xfer_len)
871 				break;
872 
873 			/* manage FIFO */
874 			bchan->head += async_desc->xfer_len;
875 			bchan->head %= MAX_DESCRIPTORS;
876 
877 			async_desc->num_desc -= async_desc->xfer_len;
878 			async_desc->curr_desc += async_desc->xfer_len;
879 			avail -= async_desc->xfer_len;
880 
881 			/*
882 			 * if complete, process cookie. Otherwise
883 			 * push back to front of desc_issued so that
884 			 * it gets restarted by the tasklet
885 			 */
886 			if (!async_desc->num_desc) {
887 				vchan_cookie_complete(&async_desc->vd);
888 			} else {
889 				list_add(&async_desc->vd.node,
890 					 &bchan->vc.desc_issued);
891 			}
892 			list_del(&async_desc->desc_node);
893 		}
894 
895 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
896 	}
897 
898 	return srcs;
899 }
900 
901 /**
902  * bam_dma_irq - irq handler for bam controller
903  * @irq: IRQ of interrupt
904  * @data: callback data
905  *
906  * IRQ handler for the bam controller
907  */
908 static irqreturn_t bam_dma_irq(int irq, void *data)
909 {
910 	struct bam_device *bdev = data;
911 	u32 clr_mask = 0, srcs = 0;
912 	int ret;
913 
914 	srcs |= process_channel_irqs(bdev);
915 
916 	/* kick off tasklet to start next dma transfer */
917 	if (srcs & P_IRQ)
918 		tasklet_schedule(&bdev->task);
919 
920 	ret = pm_runtime_get_sync(bdev->dev);
921 	if (ret < 0)
922 		return IRQ_NONE;
923 
924 	if (srcs & BAM_IRQ) {
925 		clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
926 
927 		/*
928 		 * don't allow reorder of the various accesses to the BAM
929 		 * registers
930 		 */
931 		mb();
932 
933 		writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
934 	}
935 
936 	pm_runtime_mark_last_busy(bdev->dev);
937 	pm_runtime_put_autosuspend(bdev->dev);
938 
939 	return IRQ_HANDLED;
940 }
941 
942 /**
943  * bam_tx_status - returns status of transaction
944  * @chan: dma channel
945  * @cookie: transaction cookie
946  * @txstate: DMA transaction state
947  *
948  * Return status of dma transaction
949  */
950 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
951 		struct dma_tx_state *txstate)
952 {
953 	struct bam_chan *bchan = to_bam_chan(chan);
954 	struct bam_async_desc *async_desc;
955 	struct virt_dma_desc *vd;
956 	int ret;
957 	size_t residue = 0;
958 	unsigned int i;
959 	unsigned long flags;
960 
961 	ret = dma_cookie_status(chan, cookie, txstate);
962 	if (ret == DMA_COMPLETE)
963 		return ret;
964 
965 	if (!txstate)
966 		return bchan->paused ? DMA_PAUSED : ret;
967 
968 	spin_lock_irqsave(&bchan->vc.lock, flags);
969 	vd = vchan_find_desc(&bchan->vc, cookie);
970 	if (vd) {
971 		residue = container_of(vd, struct bam_async_desc, vd)->length;
972 	} else {
973 		list_for_each_entry(async_desc, &bchan->desc_list, desc_node) {
974 			if (async_desc->vd.tx.cookie != cookie)
975 				continue;
976 
977 			for (i = 0; i < async_desc->num_desc; i++)
978 				residue += le16_to_cpu(
979 						async_desc->curr_desc[i].size);
980 		}
981 	}
982 
983 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
984 
985 	dma_set_residue(txstate, residue);
986 
987 	if (ret == DMA_IN_PROGRESS && bchan->paused)
988 		ret = DMA_PAUSED;
989 
990 	return ret;
991 }
992 
993 /**
994  * bam_apply_new_config
995  * @bchan: bam dma channel
996  * @dir: DMA direction
997  */
998 static void bam_apply_new_config(struct bam_chan *bchan,
999 	enum dma_transfer_direction dir)
1000 {
1001 	struct bam_device *bdev = bchan->bdev;
1002 	u32 maxburst;
1003 
1004 	if (!bdev->controlled_remotely) {
1005 		if (dir == DMA_DEV_TO_MEM)
1006 			maxburst = bchan->slave.src_maxburst;
1007 		else
1008 			maxburst = bchan->slave.dst_maxburst;
1009 		if (in_range(bdev->bam_revision, BAM_NDP_REVISION_START,
1010 			     BAM_NDP_REVISION_END))
1011 			writel_relaxed(maxburst,
1012 				       bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1013 	}
1014 
1015 	bchan->reconfigure = 0;
1016 }
1017 
1018 /**
1019  * bam_start_dma - start next transaction
1020  * @bchan: bam dma channel
1021  */
1022 static void bam_start_dma(struct bam_chan *bchan)
1023 {
1024 	struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
1025 	struct bam_device *bdev = bchan->bdev;
1026 	struct bam_async_desc *async_desc = NULL;
1027 	struct bam_desc_hw *desc;
1028 	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
1029 					sizeof(struct bam_desc_hw));
1030 	int ret;
1031 	unsigned int avail;
1032 	struct dmaengine_desc_callback cb;
1033 
1034 	lockdep_assert_held(&bchan->vc.lock);
1035 
1036 	if (!vd)
1037 		return;
1038 
1039 	ret = pm_runtime_get_sync(bdev->dev);
1040 	if (ret < 0)
1041 		return;
1042 
1043 	while (vd && !IS_BUSY(bchan)) {
1044 		list_del(&vd->node);
1045 
1046 		async_desc = container_of(vd, struct bam_async_desc, vd);
1047 
1048 		/* on first use, initialize the channel hardware */
1049 		if (!bchan->initialized)
1050 			bam_chan_init_hw(bchan, async_desc->dir);
1051 
1052 		/* apply new slave config changes, if necessary */
1053 		if (bchan->reconfigure)
1054 			bam_apply_new_config(bchan, async_desc->dir);
1055 
1056 		desc = async_desc->curr_desc;
1057 		avail = CIRC_SPACE(bchan->tail, bchan->head,
1058 				   MAX_DESCRIPTORS + 1);
1059 
1060 		if (async_desc->num_desc > avail)
1061 			async_desc->xfer_len = avail;
1062 		else
1063 			async_desc->xfer_len = async_desc->num_desc;
1064 
1065 		/* set any special flags on the last descriptor */
1066 		if (async_desc->num_desc == async_desc->xfer_len)
1067 			desc[async_desc->xfer_len - 1].flags |=
1068 						cpu_to_le16(async_desc->flags);
1069 
1070 		vd = vchan_next_desc(&bchan->vc);
1071 
1072 		dmaengine_desc_get_callback(&async_desc->vd.tx, &cb);
1073 
1074 		/*
1075 		 * An interrupt is generated at this desc, if
1076 		 *  - FIFO is FULL.
1077 		 *  - No more descriptors to add.
1078 		 *  - If a callback completion was requested for this DESC,
1079 		 *     In this case, BAM will deliver the completion callback
1080 		 *     for this desc and continue processing the next desc.
1081 		 */
1082 		if (((avail <= async_desc->xfer_len) || !vd ||
1083 		     dmaengine_desc_callback_valid(&cb)) &&
1084 		    !(async_desc->flags & DESC_FLAG_EOT))
1085 			desc[async_desc->xfer_len - 1].flags |=
1086 				cpu_to_le16(DESC_FLAG_INT);
1087 
1088 		if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
1089 			u32 partial = MAX_DESCRIPTORS - bchan->tail;
1090 
1091 			memcpy(&fifo[bchan->tail], desc,
1092 			       partial * sizeof(struct bam_desc_hw));
1093 			memcpy(fifo, &desc[partial],
1094 			       (async_desc->xfer_len - partial) *
1095 				sizeof(struct bam_desc_hw));
1096 		} else {
1097 			memcpy(&fifo[bchan->tail], desc,
1098 			       async_desc->xfer_len *
1099 			       sizeof(struct bam_desc_hw));
1100 		}
1101 
1102 		bchan->tail += async_desc->xfer_len;
1103 		bchan->tail %= MAX_DESCRIPTORS;
1104 		list_add_tail(&async_desc->desc_node, &bchan->desc_list);
1105 	}
1106 
1107 	/* ensure descriptor writes and dma start not reordered */
1108 	wmb();
1109 	writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
1110 			bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
1111 
1112 	pm_runtime_mark_last_busy(bdev->dev);
1113 	pm_runtime_put_autosuspend(bdev->dev);
1114 }
1115 
1116 /**
1117  * dma_tasklet - DMA IRQ tasklet
1118  * @t: tasklet argument (bam controller structure)
1119  *
1120  * Sets up next DMA operation and then processes all completed transactions
1121  */
1122 static void dma_tasklet(struct tasklet_struct *t)
1123 {
1124 	struct bam_device *bdev = from_tasklet(bdev, t, task);
1125 	struct bam_chan *bchan;
1126 	unsigned long flags;
1127 	unsigned int i;
1128 
1129 	/* go through the channels and kick off transactions */
1130 	for (i = 0; i < bdev->num_channels; i++) {
1131 		bchan = &bdev->channels[i];
1132 		spin_lock_irqsave(&bchan->vc.lock, flags);
1133 
1134 		if (!list_empty(&bchan->vc.desc_issued) && !IS_BUSY(bchan))
1135 			bam_start_dma(bchan);
1136 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
1137 	}
1138 
1139 }
1140 
1141 /**
1142  * bam_issue_pending - starts pending transactions
1143  * @chan: dma channel
1144  *
1145  * Calls tasklet directly which in turn starts any pending transactions
1146  */
1147 static void bam_issue_pending(struct dma_chan *chan)
1148 {
1149 	struct bam_chan *bchan = to_bam_chan(chan);
1150 	unsigned long flags;
1151 
1152 	spin_lock_irqsave(&bchan->vc.lock, flags);
1153 
1154 	/* if work pending and idle, start a transaction */
1155 	if (vchan_issue_pending(&bchan->vc) && !IS_BUSY(bchan))
1156 		bam_start_dma(bchan);
1157 
1158 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
1159 }
1160 
1161 /**
1162  * bam_dma_free_desc - free descriptor memory
1163  * @vd: virtual descriptor
1164  *
1165  */
1166 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1167 {
1168 	struct bam_async_desc *async_desc = container_of(vd,
1169 			struct bam_async_desc, vd);
1170 
1171 	kfree(async_desc);
1172 }
1173 
1174 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1175 		struct of_dma *of)
1176 {
1177 	struct bam_device *bdev = container_of(of->of_dma_data,
1178 					struct bam_device, common);
1179 	unsigned int request;
1180 
1181 	if (dma_spec->args_count != 1)
1182 		return NULL;
1183 
1184 	request = dma_spec->args[0];
1185 	if (request >= bdev->num_channels)
1186 		return NULL;
1187 
1188 	return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1189 }
1190 
1191 /**
1192  * bam_init
1193  * @bdev: bam device
1194  *
1195  * Initialization helper for global bam registers
1196  */
1197 static int bam_init(struct bam_device *bdev)
1198 {
1199 	u32 val;
1200 
1201 	/* read revision and configuration information */
1202 	val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
1203 	if (!bdev->num_ees)
1204 		bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
1205 
1206 	bdev->bam_revision = val & REVISION_MASK;
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 	int ret, i;
1249 
1250 	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1251 	if (!bdev)
1252 		return -ENOMEM;
1253 
1254 	bdev->dev = &pdev->dev;
1255 
1256 	match = of_match_node(bam_of_match, pdev->dev.of_node);
1257 	if (!match) {
1258 		dev_err(&pdev->dev, "Unsupported BAM module\n");
1259 		return -ENODEV;
1260 	}
1261 
1262 	bdev->layout = match->data;
1263 
1264 	bdev->regs = devm_platform_ioremap_resource(pdev, 0);
1265 	if (IS_ERR(bdev->regs))
1266 		return PTR_ERR(bdev->regs);
1267 
1268 	bdev->irq = platform_get_irq(pdev, 0);
1269 	if (bdev->irq < 0)
1270 		return bdev->irq;
1271 
1272 	ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1273 	if (ret) {
1274 		dev_err(bdev->dev, "Execution environment unspecified\n");
1275 		return ret;
1276 	}
1277 
1278 	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
1279 						"qcom,controlled-remotely");
1280 	bdev->powered_remotely = of_property_read_bool(pdev->dev.of_node,
1281 						"qcom,powered-remotely");
1282 
1283 	if (bdev->controlled_remotely || bdev->powered_remotely)
1284 		bdev->bamclk = devm_clk_get_optional(bdev->dev, "bam_clk");
1285 	else
1286 		bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1287 
1288 	if (IS_ERR(bdev->bamclk))
1289 		return PTR_ERR(bdev->bamclk);
1290 
1291 	if (!bdev->bamclk) {
1292 		ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
1293 					   &bdev->num_channels);
1294 		if (ret)
1295 			dev_err(bdev->dev, "num-channels unspecified in dt\n");
1296 
1297 		ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",
1298 					   &bdev->num_ees);
1299 		if (ret)
1300 			dev_err(bdev->dev, "num-ees unspecified in dt\n");
1301 	}
1302 
1303 	ret = clk_prepare_enable(bdev->bamclk);
1304 	if (ret) {
1305 		dev_err(bdev->dev, "failed to prepare/enable clock\n");
1306 		return ret;
1307 	}
1308 
1309 	ret = bam_init(bdev);
1310 	if (ret)
1311 		goto err_disable_clk;
1312 
1313 	tasklet_setup(&bdev->task, dma_tasklet);
1314 
1315 	bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1316 				sizeof(*bdev->channels), GFP_KERNEL);
1317 
1318 	if (!bdev->channels) {
1319 		ret = -ENOMEM;
1320 		goto err_tasklet_kill;
1321 	}
1322 
1323 	/* allocate and initialize channels */
1324 	INIT_LIST_HEAD(&bdev->common.channels);
1325 
1326 	for (i = 0; i < bdev->num_channels; i++)
1327 		bam_channel_init(bdev, &bdev->channels[i], i);
1328 
1329 	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1330 			IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1331 	if (ret)
1332 		goto err_bam_channel_exit;
1333 
1334 	/* set max dma segment size */
1335 	bdev->common.dev = bdev->dev;
1336 	dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1337 
1338 	platform_set_drvdata(pdev, bdev);
1339 
1340 	/* set capabilities */
1341 	dma_cap_zero(bdev->common.cap_mask);
1342 	dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1343 
1344 	/* initialize dmaengine apis */
1345 	bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1346 	bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1347 	bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1348 	bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1349 	bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1350 	bdev->common.device_free_chan_resources = bam_free_chan;
1351 	bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1352 	bdev->common.device_config = bam_slave_config;
1353 	bdev->common.device_pause = bam_pause;
1354 	bdev->common.device_resume = bam_resume;
1355 	bdev->common.device_terminate_all = bam_dma_terminate_all;
1356 	bdev->common.device_issue_pending = bam_issue_pending;
1357 	bdev->common.device_tx_status = bam_tx_status;
1358 	bdev->common.dev = bdev->dev;
1359 
1360 	ret = dma_async_device_register(&bdev->common);
1361 	if (ret) {
1362 		dev_err(bdev->dev, "failed to register dma async device\n");
1363 		goto err_bam_channel_exit;
1364 	}
1365 
1366 	ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1367 					&bdev->common);
1368 	if (ret)
1369 		goto err_unregister_dma;
1370 
1371 	pm_runtime_irq_safe(&pdev->dev);
1372 	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
1373 	pm_runtime_use_autosuspend(&pdev->dev);
1374 	pm_runtime_mark_last_busy(&pdev->dev);
1375 	pm_runtime_set_active(&pdev->dev);
1376 	pm_runtime_enable(&pdev->dev);
1377 
1378 	return 0;
1379 
1380 err_unregister_dma:
1381 	dma_async_device_unregister(&bdev->common);
1382 err_bam_channel_exit:
1383 	for (i = 0; i < bdev->num_channels; i++)
1384 		tasklet_kill(&bdev->channels[i].vc.task);
1385 err_tasklet_kill:
1386 	tasklet_kill(&bdev->task);
1387 err_disable_clk:
1388 	clk_disable_unprepare(bdev->bamclk);
1389 
1390 	return ret;
1391 }
1392 
1393 static void bam_dma_remove(struct platform_device *pdev)
1394 {
1395 	struct bam_device *bdev = platform_get_drvdata(pdev);
1396 	u32 i;
1397 
1398 	pm_runtime_force_suspend(&pdev->dev);
1399 
1400 	of_dma_controller_free(pdev->dev.of_node);
1401 	dma_async_device_unregister(&bdev->common);
1402 
1403 	/* mask all interrupts for this execution environment */
1404 	writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1405 
1406 	devm_free_irq(bdev->dev, bdev->irq, bdev);
1407 
1408 	for (i = 0; i < bdev->num_channels; i++) {
1409 		bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1410 		tasklet_kill(&bdev->channels[i].vc.task);
1411 
1412 		if (!bdev->channels[i].fifo_virt)
1413 			continue;
1414 
1415 		dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1416 			    bdev->channels[i].fifo_virt,
1417 			    bdev->channels[i].fifo_phys);
1418 	}
1419 
1420 	tasklet_kill(&bdev->task);
1421 
1422 	clk_disable_unprepare(bdev->bamclk);
1423 }
1424 
1425 static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
1426 {
1427 	struct bam_device *bdev = dev_get_drvdata(dev);
1428 
1429 	clk_disable(bdev->bamclk);
1430 
1431 	return 0;
1432 }
1433 
1434 static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
1435 {
1436 	struct bam_device *bdev = dev_get_drvdata(dev);
1437 	int ret;
1438 
1439 	ret = clk_enable(bdev->bamclk);
1440 	if (ret < 0) {
1441 		dev_err(dev, "clk_enable failed: %d\n", ret);
1442 		return ret;
1443 	}
1444 
1445 	return 0;
1446 }
1447 
1448 static int __maybe_unused bam_dma_suspend(struct device *dev)
1449 {
1450 	struct bam_device *bdev = dev_get_drvdata(dev);
1451 
1452 	pm_runtime_force_suspend(dev);
1453 	clk_unprepare(bdev->bamclk);
1454 
1455 	return 0;
1456 }
1457 
1458 static int __maybe_unused bam_dma_resume(struct device *dev)
1459 {
1460 	struct bam_device *bdev = dev_get_drvdata(dev);
1461 	int ret;
1462 
1463 	ret = clk_prepare(bdev->bamclk);
1464 	if (ret)
1465 		return ret;
1466 
1467 	pm_runtime_force_resume(dev);
1468 
1469 	return 0;
1470 }
1471 
1472 static const struct dev_pm_ops bam_dma_pm_ops = {
1473 	SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
1474 	SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
1475 				NULL)
1476 };
1477 
1478 static struct platform_driver bam_dma_driver = {
1479 	.probe = bam_dma_probe,
1480 	.remove = bam_dma_remove,
1481 	.driver = {
1482 		.name = "bam-dma-engine",
1483 		.pm = &bam_dma_pm_ops,
1484 		.of_match_table = bam_of_match,
1485 	},
1486 };
1487 
1488 module_platform_driver(bam_dma_driver);
1489 
1490 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1491 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1492 MODULE_LICENSE("GPL v2");
1493