xref: /openbmc/linux/drivers/dma/qcom/bam_dma.c (revision a20eefae)
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[0];
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 device_dma_parameters dma_parms;
385 	struct bam_chan *channels;
386 	u32 num_channels;
387 	u32 num_ees;
388 
389 	/* execution environment ID, from DT */
390 	u32 ee;
391 	bool controlled_remotely;
392 
393 	const struct reg_offset_data *layout;
394 
395 	struct clk *bamclk;
396 	int irq;
397 
398 	/* dma start transaction tasklet */
399 	struct tasklet_struct task;
400 };
401 
402 /**
403  * bam_addr - returns BAM register address
404  * @bdev: bam device
405  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
406  * @reg:  register enum
407  */
408 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
409 		enum bam_reg reg)
410 {
411 	const struct reg_offset_data r = bdev->layout[reg];
412 
413 	return bdev->regs + r.base_offset +
414 		r.pipe_mult * pipe +
415 		r.evnt_mult * pipe +
416 		r.ee_mult * bdev->ee;
417 }
418 
419 /**
420  * bam_reset_channel - Reset individual BAM DMA channel
421  * @bchan: bam channel
422  *
423  * This function resets a specific BAM channel
424  */
425 static void bam_reset_channel(struct bam_chan *bchan)
426 {
427 	struct bam_device *bdev = bchan->bdev;
428 
429 	lockdep_assert_held(&bchan->vc.lock);
430 
431 	/* reset channel */
432 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
433 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
434 
435 	/* don't allow cpu to reorder BAM register accesses done after this */
436 	wmb();
437 
438 	/* make sure hw is initialized when channel is used the first time  */
439 	bchan->initialized = 0;
440 }
441 
442 /**
443  * bam_chan_init_hw - Initialize channel hardware
444  * @bchan: bam channel
445  * @dir: DMA transfer direction
446  *
447  * This function resets and initializes the BAM channel
448  */
449 static void bam_chan_init_hw(struct bam_chan *bchan,
450 	enum dma_transfer_direction dir)
451 {
452 	struct bam_device *bdev = bchan->bdev;
453 	u32 val;
454 
455 	/* Reset the channel to clear internal state of the FIFO */
456 	bam_reset_channel(bchan);
457 
458 	/*
459 	 * write out 8 byte aligned address.  We have enough space for this
460 	 * because we allocated 1 more descriptor (8 bytes) than we can use
461 	 */
462 	writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
463 			bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
464 	writel_relaxed(BAM_FIFO_SIZE,
465 			bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
466 
467 	/* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
468 	writel_relaxed(P_DEFAULT_IRQS_EN,
469 			bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
470 
471 	/* unmask the specific pipe and EE combo */
472 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
473 	val |= BIT(bchan->id);
474 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
475 
476 	/* don't allow cpu to reorder the channel enable done below */
477 	wmb();
478 
479 	/* set fixed direction and mode, then enable channel */
480 	val = P_EN | P_SYS_MODE;
481 	if (dir == DMA_DEV_TO_MEM)
482 		val |= P_DIRECTION;
483 
484 	writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
485 
486 	bchan->initialized = 1;
487 
488 	/* init FIFO pointers */
489 	bchan->head = 0;
490 	bchan->tail = 0;
491 }
492 
493 /**
494  * bam_alloc_chan - Allocate channel resources for DMA channel.
495  * @chan: specified channel
496  *
497  * This function allocates the FIFO descriptor memory
498  */
499 static int bam_alloc_chan(struct dma_chan *chan)
500 {
501 	struct bam_chan *bchan = to_bam_chan(chan);
502 	struct bam_device *bdev = bchan->bdev;
503 
504 	if (bchan->fifo_virt)
505 		return 0;
506 
507 	/* allocate FIFO descriptor space, but only if necessary */
508 	bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
509 					&bchan->fifo_phys, GFP_KERNEL);
510 
511 	if (!bchan->fifo_virt) {
512 		dev_err(bdev->dev, "Failed to allocate desc fifo\n");
513 		return -ENOMEM;
514 	}
515 
516 	return 0;
517 }
518 
519 static int bam_pm_runtime_get_sync(struct device *dev)
520 {
521 	if (pm_runtime_enabled(dev))
522 		return pm_runtime_get_sync(dev);
523 
524 	return 0;
525 }
526 
527 /**
528  * bam_free_chan - Frees dma resources associated with specific channel
529  * @chan: specified channel
530  *
531  * Free the allocated fifo descriptor memory and channel resources
532  *
533  */
534 static void bam_free_chan(struct dma_chan *chan)
535 {
536 	struct bam_chan *bchan = to_bam_chan(chan);
537 	struct bam_device *bdev = bchan->bdev;
538 	u32 val;
539 	unsigned long flags;
540 	int ret;
541 
542 	ret = bam_pm_runtime_get_sync(bdev->dev);
543 	if (ret < 0)
544 		return;
545 
546 	vchan_free_chan_resources(to_virt_chan(chan));
547 
548 	if (!list_empty(&bchan->desc_list)) {
549 		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
550 		goto err;
551 	}
552 
553 	spin_lock_irqsave(&bchan->vc.lock, flags);
554 	bam_reset_channel(bchan);
555 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
556 
557 	dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
558 		    bchan->fifo_phys);
559 	bchan->fifo_virt = NULL;
560 
561 	/* mask irq for pipe/channel */
562 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
563 	val &= ~BIT(bchan->id);
564 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
565 
566 	/* disable irq */
567 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
568 
569 err:
570 	pm_runtime_mark_last_busy(bdev->dev);
571 	pm_runtime_put_autosuspend(bdev->dev);
572 }
573 
574 /**
575  * bam_slave_config - set slave configuration for channel
576  * @chan: dma channel
577  * @cfg: slave configuration
578  *
579  * Sets slave configuration for channel
580  *
581  */
582 static int bam_slave_config(struct dma_chan *chan,
583 			    struct dma_slave_config *cfg)
584 {
585 	struct bam_chan *bchan = to_bam_chan(chan);
586 	unsigned long flag;
587 
588 	spin_lock_irqsave(&bchan->vc.lock, flag);
589 	memcpy(&bchan->slave, cfg, sizeof(*cfg));
590 	bchan->reconfigure = 1;
591 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
592 
593 	return 0;
594 }
595 
596 /**
597  * bam_prep_slave_sg - Prep slave sg transaction
598  *
599  * @chan: dma channel
600  * @sgl: scatter gather list
601  * @sg_len: length of sg
602  * @direction: DMA transfer direction
603  * @flags: DMA flags
604  * @context: transfer context (unused)
605  */
606 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
607 	struct scatterlist *sgl, unsigned int sg_len,
608 	enum dma_transfer_direction direction, unsigned long flags,
609 	void *context)
610 {
611 	struct bam_chan *bchan = to_bam_chan(chan);
612 	struct bam_device *bdev = bchan->bdev;
613 	struct bam_async_desc *async_desc;
614 	struct scatterlist *sg;
615 	u32 i;
616 	struct bam_desc_hw *desc;
617 	unsigned int num_alloc = 0;
618 
619 
620 	if (!is_slave_direction(direction)) {
621 		dev_err(bdev->dev, "invalid dma direction\n");
622 		return NULL;
623 	}
624 
625 	/* calculate number of required entries */
626 	for_each_sg(sgl, sg, sg_len, i)
627 		num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE);
628 
629 	/* allocate enough room to accomodate the number of entries */
630 	async_desc = kzalloc(struct_size(async_desc, desc, num_alloc),
631 			     GFP_NOWAIT);
632 
633 	if (!async_desc)
634 		goto err_out;
635 
636 	if (flags & DMA_PREP_FENCE)
637 		async_desc->flags |= DESC_FLAG_NWD;
638 
639 	if (flags & DMA_PREP_INTERRUPT)
640 		async_desc->flags |= DESC_FLAG_EOT;
641 
642 	async_desc->num_desc = num_alloc;
643 	async_desc->curr_desc = async_desc->desc;
644 	async_desc->dir = direction;
645 
646 	/* fill in temporary descriptors */
647 	desc = async_desc->desc;
648 	for_each_sg(sgl, sg, sg_len, i) {
649 		unsigned int remainder = sg_dma_len(sg);
650 		unsigned int curr_offset = 0;
651 
652 		do {
653 			if (flags & DMA_PREP_CMD)
654 				desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
655 
656 			desc->addr = cpu_to_le32(sg_dma_address(sg) +
657 						 curr_offset);
658 
659 			if (remainder > BAM_FIFO_SIZE) {
660 				desc->size = cpu_to_le16(BAM_FIFO_SIZE);
661 				remainder -= BAM_FIFO_SIZE;
662 				curr_offset += BAM_FIFO_SIZE;
663 			} else {
664 				desc->size = cpu_to_le16(remainder);
665 				remainder = 0;
666 			}
667 
668 			async_desc->length += le16_to_cpu(desc->size);
669 			desc++;
670 		} while (remainder > 0);
671 	}
672 
673 	return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
674 
675 err_out:
676 	kfree(async_desc);
677 	return NULL;
678 }
679 
680 /**
681  * bam_dma_terminate_all - terminate all transactions on a channel
682  * @chan: bam dma channel
683  *
684  * Dequeues and frees all transactions
685  * No callbacks are done
686  *
687  */
688 static int bam_dma_terminate_all(struct dma_chan *chan)
689 {
690 	struct bam_chan *bchan = to_bam_chan(chan);
691 	struct bam_async_desc *async_desc, *tmp;
692 	unsigned long flag;
693 	LIST_HEAD(head);
694 
695 	/* remove all transactions, including active transaction */
696 	spin_lock_irqsave(&bchan->vc.lock, flag);
697 	list_for_each_entry_safe(async_desc, tmp,
698 				 &bchan->desc_list, desc_node) {
699 		list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
700 		list_del(&async_desc->desc_node);
701 	}
702 
703 	vchan_get_all_descriptors(&bchan->vc, &head);
704 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
705 
706 	vchan_dma_desc_free_list(&bchan->vc, &head);
707 
708 	return 0;
709 }
710 
711 /**
712  * bam_pause - Pause DMA channel
713  * @chan: dma channel
714  *
715  */
716 static int bam_pause(struct dma_chan *chan)
717 {
718 	struct bam_chan *bchan = to_bam_chan(chan);
719 	struct bam_device *bdev = bchan->bdev;
720 	unsigned long flag;
721 	int ret;
722 
723 	ret = bam_pm_runtime_get_sync(bdev->dev);
724 	if (ret < 0)
725 		return ret;
726 
727 	spin_lock_irqsave(&bchan->vc.lock, flag);
728 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
729 	bchan->paused = 1;
730 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
731 	pm_runtime_mark_last_busy(bdev->dev);
732 	pm_runtime_put_autosuspend(bdev->dev);
733 
734 	return 0;
735 }
736 
737 /**
738  * bam_resume - Resume DMA channel operations
739  * @chan: dma channel
740  *
741  */
742 static int bam_resume(struct dma_chan *chan)
743 {
744 	struct bam_chan *bchan = to_bam_chan(chan);
745 	struct bam_device *bdev = bchan->bdev;
746 	unsigned long flag;
747 	int ret;
748 
749 	ret = bam_pm_runtime_get_sync(bdev->dev);
750 	if (ret < 0)
751 		return ret;
752 
753 	spin_lock_irqsave(&bchan->vc.lock, flag);
754 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
755 	bchan->paused = 0;
756 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
757 	pm_runtime_mark_last_busy(bdev->dev);
758 	pm_runtime_put_autosuspend(bdev->dev);
759 
760 	return 0;
761 }
762 
763 /**
764  * process_channel_irqs - processes the channel interrupts
765  * @bdev: bam controller
766  *
767  * This function processes the channel interrupts
768  *
769  */
770 static u32 process_channel_irqs(struct bam_device *bdev)
771 {
772 	u32 i, srcs, pipe_stts, offset, avail;
773 	unsigned long flags;
774 	struct bam_async_desc *async_desc, *tmp;
775 
776 	srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
777 
778 	/* return early if no pipe/channel interrupts are present */
779 	if (!(srcs & P_IRQ))
780 		return srcs;
781 
782 	for (i = 0; i < bdev->num_channels; i++) {
783 		struct bam_chan *bchan = &bdev->channels[i];
784 
785 		if (!(srcs & BIT(i)))
786 			continue;
787 
788 		/* clear pipe irq */
789 		pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
790 
791 		writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
792 
793 		spin_lock_irqsave(&bchan->vc.lock, flags);
794 
795 		offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) &
796 				       P_SW_OFSTS_MASK;
797 		offset /= sizeof(struct bam_desc_hw);
798 
799 		/* Number of bytes available to read */
800 		avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
801 
802 		if (offset < bchan->head)
803 			avail--;
804 
805 		list_for_each_entry_safe(async_desc, tmp,
806 					 &bchan->desc_list, desc_node) {
807 			/* Not enough data to read */
808 			if (avail < async_desc->xfer_len)
809 				break;
810 
811 			/* manage FIFO */
812 			bchan->head += async_desc->xfer_len;
813 			bchan->head %= MAX_DESCRIPTORS;
814 
815 			async_desc->num_desc -= async_desc->xfer_len;
816 			async_desc->curr_desc += async_desc->xfer_len;
817 			avail -= async_desc->xfer_len;
818 
819 			/*
820 			 * if complete, process cookie. Otherwise
821 			 * push back to front of desc_issued so that
822 			 * it gets restarted by the tasklet
823 			 */
824 			if (!async_desc->num_desc) {
825 				vchan_cookie_complete(&async_desc->vd);
826 			} else {
827 				list_add(&async_desc->vd.node,
828 					 &bchan->vc.desc_issued);
829 			}
830 			list_del(&async_desc->desc_node);
831 		}
832 
833 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
834 	}
835 
836 	return srcs;
837 }
838 
839 /**
840  * bam_dma_irq - irq handler for bam controller
841  * @irq: IRQ of interrupt
842  * @data: callback data
843  *
844  * IRQ handler for the bam controller
845  */
846 static irqreturn_t bam_dma_irq(int irq, void *data)
847 {
848 	struct bam_device *bdev = data;
849 	u32 clr_mask = 0, srcs = 0;
850 	int ret;
851 
852 	srcs |= process_channel_irqs(bdev);
853 
854 	/* kick off tasklet to start next dma transfer */
855 	if (srcs & P_IRQ)
856 		tasklet_schedule(&bdev->task);
857 
858 	ret = bam_pm_runtime_get_sync(bdev->dev);
859 	if (ret < 0)
860 		return ret;
861 
862 	if (srcs & BAM_IRQ) {
863 		clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
864 
865 		/*
866 		 * don't allow reorder of the various accesses to the BAM
867 		 * registers
868 		 */
869 		mb();
870 
871 		writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
872 	}
873 
874 	pm_runtime_mark_last_busy(bdev->dev);
875 	pm_runtime_put_autosuspend(bdev->dev);
876 
877 	return IRQ_HANDLED;
878 }
879 
880 /**
881  * bam_tx_status - returns status of transaction
882  * @chan: dma channel
883  * @cookie: transaction cookie
884  * @txstate: DMA transaction state
885  *
886  * Return status of dma transaction
887  */
888 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
889 		struct dma_tx_state *txstate)
890 {
891 	struct bam_chan *bchan = to_bam_chan(chan);
892 	struct bam_async_desc *async_desc;
893 	struct virt_dma_desc *vd;
894 	int ret;
895 	size_t residue = 0;
896 	unsigned int i;
897 	unsigned long flags;
898 
899 	ret = dma_cookie_status(chan, cookie, txstate);
900 	if (ret == DMA_COMPLETE)
901 		return ret;
902 
903 	if (!txstate)
904 		return bchan->paused ? DMA_PAUSED : ret;
905 
906 	spin_lock_irqsave(&bchan->vc.lock, flags);
907 	vd = vchan_find_desc(&bchan->vc, cookie);
908 	if (vd) {
909 		residue = container_of(vd, struct bam_async_desc, vd)->length;
910 	} else {
911 		list_for_each_entry(async_desc, &bchan->desc_list, desc_node) {
912 			if (async_desc->vd.tx.cookie != cookie)
913 				continue;
914 
915 			for (i = 0; i < async_desc->num_desc; i++)
916 				residue += le16_to_cpu(
917 						async_desc->curr_desc[i].size);
918 		}
919 	}
920 
921 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
922 
923 	dma_set_residue(txstate, residue);
924 
925 	if (ret == DMA_IN_PROGRESS && bchan->paused)
926 		ret = DMA_PAUSED;
927 
928 	return ret;
929 }
930 
931 /**
932  * bam_apply_new_config
933  * @bchan: bam dma channel
934  * @dir: DMA direction
935  */
936 static void bam_apply_new_config(struct bam_chan *bchan,
937 	enum dma_transfer_direction dir)
938 {
939 	struct bam_device *bdev = bchan->bdev;
940 	u32 maxburst;
941 
942 	if (!bdev->controlled_remotely) {
943 		if (dir == DMA_DEV_TO_MEM)
944 			maxburst = bchan->slave.src_maxburst;
945 		else
946 			maxburst = bchan->slave.dst_maxburst;
947 
948 		writel_relaxed(maxburst,
949 			       bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
950 	}
951 
952 	bchan->reconfigure = 0;
953 }
954 
955 /**
956  * bam_start_dma - start next transaction
957  * @bchan: bam dma channel
958  */
959 static void bam_start_dma(struct bam_chan *bchan)
960 {
961 	struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
962 	struct bam_device *bdev = bchan->bdev;
963 	struct bam_async_desc *async_desc = NULL;
964 	struct bam_desc_hw *desc;
965 	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
966 					sizeof(struct bam_desc_hw));
967 	int ret;
968 	unsigned int avail;
969 	struct dmaengine_desc_callback cb;
970 
971 	lockdep_assert_held(&bchan->vc.lock);
972 
973 	if (!vd)
974 		return;
975 
976 	ret = bam_pm_runtime_get_sync(bdev->dev);
977 	if (ret < 0)
978 		return;
979 
980 	while (vd && !IS_BUSY(bchan)) {
981 		list_del(&vd->node);
982 
983 		async_desc = container_of(vd, struct bam_async_desc, vd);
984 
985 		/* on first use, initialize the channel hardware */
986 		if (!bchan->initialized)
987 			bam_chan_init_hw(bchan, async_desc->dir);
988 
989 		/* apply new slave config changes, if necessary */
990 		if (bchan->reconfigure)
991 			bam_apply_new_config(bchan, async_desc->dir);
992 
993 		desc = async_desc->curr_desc;
994 		avail = CIRC_SPACE(bchan->tail, bchan->head,
995 				   MAX_DESCRIPTORS + 1);
996 
997 		if (async_desc->num_desc > avail)
998 			async_desc->xfer_len = avail;
999 		else
1000 			async_desc->xfer_len = async_desc->num_desc;
1001 
1002 		/* set any special flags on the last descriptor */
1003 		if (async_desc->num_desc == async_desc->xfer_len)
1004 			desc[async_desc->xfer_len - 1].flags |=
1005 						cpu_to_le16(async_desc->flags);
1006 
1007 		vd = vchan_next_desc(&bchan->vc);
1008 
1009 		dmaengine_desc_get_callback(&async_desc->vd.tx, &cb);
1010 
1011 		/*
1012 		 * An interrupt is generated at this desc, if
1013 		 *  - FIFO is FULL.
1014 		 *  - No more descriptors to add.
1015 		 *  - If a callback completion was requested for this DESC,
1016 		 *     In this case, BAM will deliver the completion callback
1017 		 *     for this desc and continue processing the next desc.
1018 		 */
1019 		if (((avail <= async_desc->xfer_len) || !vd ||
1020 		     dmaengine_desc_callback_valid(&cb)) &&
1021 		    !(async_desc->flags & DESC_FLAG_EOT))
1022 			desc[async_desc->xfer_len - 1].flags |=
1023 				cpu_to_le16(DESC_FLAG_INT);
1024 
1025 		if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
1026 			u32 partial = MAX_DESCRIPTORS - bchan->tail;
1027 
1028 			memcpy(&fifo[bchan->tail], desc,
1029 			       partial * sizeof(struct bam_desc_hw));
1030 			memcpy(fifo, &desc[partial],
1031 			       (async_desc->xfer_len - partial) *
1032 				sizeof(struct bam_desc_hw));
1033 		} else {
1034 			memcpy(&fifo[bchan->tail], desc,
1035 			       async_desc->xfer_len *
1036 			       sizeof(struct bam_desc_hw));
1037 		}
1038 
1039 		bchan->tail += async_desc->xfer_len;
1040 		bchan->tail %= MAX_DESCRIPTORS;
1041 		list_add_tail(&async_desc->desc_node, &bchan->desc_list);
1042 	}
1043 
1044 	/* ensure descriptor writes and dma start not reordered */
1045 	wmb();
1046 	writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
1047 			bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
1048 
1049 	pm_runtime_mark_last_busy(bdev->dev);
1050 	pm_runtime_put_autosuspend(bdev->dev);
1051 }
1052 
1053 /**
1054  * dma_tasklet - DMA IRQ tasklet
1055  * @data: tasklet argument (bam controller structure)
1056  *
1057  * Sets up next DMA operation and then processes all completed transactions
1058  */
1059 static void dma_tasklet(unsigned long data)
1060 {
1061 	struct bam_device *bdev = (struct bam_device *)data;
1062 	struct bam_chan *bchan;
1063 	unsigned long flags;
1064 	unsigned int i;
1065 
1066 	/* go through the channels and kick off transactions */
1067 	for (i = 0; i < bdev->num_channels; i++) {
1068 		bchan = &bdev->channels[i];
1069 		spin_lock_irqsave(&bchan->vc.lock, flags);
1070 
1071 		if (!list_empty(&bchan->vc.desc_issued) && !IS_BUSY(bchan))
1072 			bam_start_dma(bchan);
1073 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
1074 	}
1075 
1076 }
1077 
1078 /**
1079  * bam_issue_pending - starts pending transactions
1080  * @chan: dma channel
1081  *
1082  * Calls tasklet directly which in turn starts any pending transactions
1083  */
1084 static void bam_issue_pending(struct dma_chan *chan)
1085 {
1086 	struct bam_chan *bchan = to_bam_chan(chan);
1087 	unsigned long flags;
1088 
1089 	spin_lock_irqsave(&bchan->vc.lock, flags);
1090 
1091 	/* if work pending and idle, start a transaction */
1092 	if (vchan_issue_pending(&bchan->vc) && !IS_BUSY(bchan))
1093 		bam_start_dma(bchan);
1094 
1095 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
1096 }
1097 
1098 /**
1099  * bam_dma_free_desc - free descriptor memory
1100  * @vd: virtual descriptor
1101  *
1102  */
1103 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1104 {
1105 	struct bam_async_desc *async_desc = container_of(vd,
1106 			struct bam_async_desc, vd);
1107 
1108 	kfree(async_desc);
1109 }
1110 
1111 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1112 		struct of_dma *of)
1113 {
1114 	struct bam_device *bdev = container_of(of->of_dma_data,
1115 					struct bam_device, common);
1116 	unsigned int request;
1117 
1118 	if (dma_spec->args_count != 1)
1119 		return NULL;
1120 
1121 	request = dma_spec->args[0];
1122 	if (request >= bdev->num_channels)
1123 		return NULL;
1124 
1125 	return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1126 }
1127 
1128 /**
1129  * bam_init
1130  * @bdev: bam device
1131  *
1132  * Initialization helper for global bam registers
1133  */
1134 static int bam_init(struct bam_device *bdev)
1135 {
1136 	u32 val;
1137 
1138 	/* read revision and configuration information */
1139 	if (!bdev->num_ees) {
1140 		val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
1141 		bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
1142 	}
1143 
1144 	/* check that configured EE is within range */
1145 	if (bdev->ee >= bdev->num_ees)
1146 		return -EINVAL;
1147 
1148 	if (!bdev->num_channels) {
1149 		val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1150 		bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1151 	}
1152 
1153 	if (bdev->controlled_remotely)
1154 		return 0;
1155 
1156 	/* s/w reset bam */
1157 	/* after reset all pipes are disabled and idle */
1158 	val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
1159 	val |= BAM_SW_RST;
1160 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1161 	val &= ~BAM_SW_RST;
1162 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1163 
1164 	/* make sure previous stores are visible before enabling BAM */
1165 	wmb();
1166 
1167 	/* enable bam */
1168 	val |= BAM_EN;
1169 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1170 
1171 	/* set descriptor threshhold, start with 4 bytes */
1172 	writel_relaxed(DEFAULT_CNT_THRSHLD,
1173 			bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1174 
1175 	/* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
1176 	writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
1177 
1178 	/* enable irqs for errors */
1179 	writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
1180 			bam_addr(bdev, 0, BAM_IRQ_EN));
1181 
1182 	/* unmask global bam interrupt */
1183 	writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
1184 
1185 	return 0;
1186 }
1187 
1188 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1189 	u32 index)
1190 {
1191 	bchan->id = index;
1192 	bchan->bdev = bdev;
1193 
1194 	vchan_init(&bchan->vc, &bdev->common);
1195 	bchan->vc.desc_free = bam_dma_free_desc;
1196 	INIT_LIST_HEAD(&bchan->desc_list);
1197 }
1198 
1199 static const struct of_device_id bam_of_match[] = {
1200 	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1201 	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1202 	{ .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1203 	{}
1204 };
1205 
1206 MODULE_DEVICE_TABLE(of, bam_of_match);
1207 
1208 static int bam_dma_probe(struct platform_device *pdev)
1209 {
1210 	struct bam_device *bdev;
1211 	const struct of_device_id *match;
1212 	struct resource *iores;
1213 	int ret, i;
1214 
1215 	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1216 	if (!bdev)
1217 		return -ENOMEM;
1218 
1219 	bdev->dev = &pdev->dev;
1220 
1221 	match = of_match_node(bam_of_match, pdev->dev.of_node);
1222 	if (!match) {
1223 		dev_err(&pdev->dev, "Unsupported BAM module\n");
1224 		return -ENODEV;
1225 	}
1226 
1227 	bdev->layout = match->data;
1228 
1229 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1230 	bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
1231 	if (IS_ERR(bdev->regs))
1232 		return PTR_ERR(bdev->regs);
1233 
1234 	bdev->irq = platform_get_irq(pdev, 0);
1235 	if (bdev->irq < 0)
1236 		return bdev->irq;
1237 
1238 	ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1239 	if (ret) {
1240 		dev_err(bdev->dev, "Execution environment unspecified\n");
1241 		return ret;
1242 	}
1243 
1244 	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
1245 						"qcom,controlled-remotely");
1246 
1247 	if (bdev->controlled_remotely) {
1248 		ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
1249 					   &bdev->num_channels);
1250 		if (ret)
1251 			dev_err(bdev->dev, "num-channels unspecified in dt\n");
1252 
1253 		ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",
1254 					   &bdev->num_ees);
1255 		if (ret)
1256 			dev_err(bdev->dev, "num-ees unspecified in dt\n");
1257 	}
1258 
1259 	bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1260 	if (IS_ERR(bdev->bamclk)) {
1261 		if (!bdev->controlled_remotely)
1262 			return PTR_ERR(bdev->bamclk);
1263 
1264 		bdev->bamclk = NULL;
1265 	}
1266 
1267 	ret = clk_prepare_enable(bdev->bamclk);
1268 	if (ret) {
1269 		dev_err(bdev->dev, "failed to prepare/enable clock\n");
1270 		return ret;
1271 	}
1272 
1273 	ret = bam_init(bdev);
1274 	if (ret)
1275 		goto err_disable_clk;
1276 
1277 	tasklet_init(&bdev->task, dma_tasklet, (unsigned long)bdev);
1278 
1279 	bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1280 				sizeof(*bdev->channels), GFP_KERNEL);
1281 
1282 	if (!bdev->channels) {
1283 		ret = -ENOMEM;
1284 		goto err_tasklet_kill;
1285 	}
1286 
1287 	/* allocate and initialize channels */
1288 	INIT_LIST_HEAD(&bdev->common.channels);
1289 
1290 	for (i = 0; i < bdev->num_channels; i++)
1291 		bam_channel_init(bdev, &bdev->channels[i], i);
1292 
1293 	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1294 			IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1295 	if (ret)
1296 		goto err_bam_channel_exit;
1297 
1298 	/* set max dma segment size */
1299 	bdev->common.dev = bdev->dev;
1300 	bdev->common.dev->dma_parms = &bdev->dma_parms;
1301 	ret = dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1302 	if (ret) {
1303 		dev_err(bdev->dev, "cannot set maximum segment size\n");
1304 		goto err_bam_channel_exit;
1305 	}
1306 
1307 	platform_set_drvdata(pdev, bdev);
1308 
1309 	/* set capabilities */
1310 	dma_cap_zero(bdev->common.cap_mask);
1311 	dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1312 
1313 	/* initialize dmaengine apis */
1314 	bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1315 	bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1316 	bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1317 	bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1318 	bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1319 	bdev->common.device_free_chan_resources = bam_free_chan;
1320 	bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1321 	bdev->common.device_config = bam_slave_config;
1322 	bdev->common.device_pause = bam_pause;
1323 	bdev->common.device_resume = bam_resume;
1324 	bdev->common.device_terminate_all = bam_dma_terminate_all;
1325 	bdev->common.device_issue_pending = bam_issue_pending;
1326 	bdev->common.device_tx_status = bam_tx_status;
1327 	bdev->common.dev = bdev->dev;
1328 
1329 	ret = dma_async_device_register(&bdev->common);
1330 	if (ret) {
1331 		dev_err(bdev->dev, "failed to register dma async device\n");
1332 		goto err_bam_channel_exit;
1333 	}
1334 
1335 	ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1336 					&bdev->common);
1337 	if (ret)
1338 		goto err_unregister_dma;
1339 
1340 	if (bdev->controlled_remotely) {
1341 		pm_runtime_disable(&pdev->dev);
1342 		return 0;
1343 	}
1344 
1345 	pm_runtime_irq_safe(&pdev->dev);
1346 	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
1347 	pm_runtime_use_autosuspend(&pdev->dev);
1348 	pm_runtime_mark_last_busy(&pdev->dev);
1349 	pm_runtime_set_active(&pdev->dev);
1350 	pm_runtime_enable(&pdev->dev);
1351 
1352 	return 0;
1353 
1354 err_unregister_dma:
1355 	dma_async_device_unregister(&bdev->common);
1356 err_bam_channel_exit:
1357 	for (i = 0; i < bdev->num_channels; i++)
1358 		tasklet_kill(&bdev->channels[i].vc.task);
1359 err_tasklet_kill:
1360 	tasklet_kill(&bdev->task);
1361 err_disable_clk:
1362 	clk_disable_unprepare(bdev->bamclk);
1363 
1364 	return ret;
1365 }
1366 
1367 static int bam_dma_remove(struct platform_device *pdev)
1368 {
1369 	struct bam_device *bdev = platform_get_drvdata(pdev);
1370 	u32 i;
1371 
1372 	pm_runtime_force_suspend(&pdev->dev);
1373 
1374 	of_dma_controller_free(pdev->dev.of_node);
1375 	dma_async_device_unregister(&bdev->common);
1376 
1377 	/* mask all interrupts for this execution environment */
1378 	writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1379 
1380 	devm_free_irq(bdev->dev, bdev->irq, bdev);
1381 
1382 	for (i = 0; i < bdev->num_channels; i++) {
1383 		bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1384 		tasklet_kill(&bdev->channels[i].vc.task);
1385 
1386 		if (!bdev->channels[i].fifo_virt)
1387 			continue;
1388 
1389 		dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1390 			    bdev->channels[i].fifo_virt,
1391 			    bdev->channels[i].fifo_phys);
1392 	}
1393 
1394 	tasklet_kill(&bdev->task);
1395 
1396 	clk_disable_unprepare(bdev->bamclk);
1397 
1398 	return 0;
1399 }
1400 
1401 static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
1402 {
1403 	struct bam_device *bdev = dev_get_drvdata(dev);
1404 
1405 	clk_disable(bdev->bamclk);
1406 
1407 	return 0;
1408 }
1409 
1410 static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
1411 {
1412 	struct bam_device *bdev = dev_get_drvdata(dev);
1413 	int ret;
1414 
1415 	ret = clk_enable(bdev->bamclk);
1416 	if (ret < 0) {
1417 		dev_err(dev, "clk_enable failed: %d\n", ret);
1418 		return ret;
1419 	}
1420 
1421 	return 0;
1422 }
1423 
1424 static int __maybe_unused bam_dma_suspend(struct device *dev)
1425 {
1426 	struct bam_device *bdev = dev_get_drvdata(dev);
1427 
1428 	if (!bdev->controlled_remotely)
1429 		pm_runtime_force_suspend(dev);
1430 
1431 	clk_unprepare(bdev->bamclk);
1432 
1433 	return 0;
1434 }
1435 
1436 static int __maybe_unused bam_dma_resume(struct device *dev)
1437 {
1438 	struct bam_device *bdev = dev_get_drvdata(dev);
1439 	int ret;
1440 
1441 	ret = clk_prepare(bdev->bamclk);
1442 	if (ret)
1443 		return ret;
1444 
1445 	if (!bdev->controlled_remotely)
1446 		pm_runtime_force_resume(dev);
1447 
1448 	return 0;
1449 }
1450 
1451 static const struct dev_pm_ops bam_dma_pm_ops = {
1452 	SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
1453 	SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
1454 				NULL)
1455 };
1456 
1457 static struct platform_driver bam_dma_driver = {
1458 	.probe = bam_dma_probe,
1459 	.remove = bam_dma_remove,
1460 	.driver = {
1461 		.name = "bam-dma-engine",
1462 		.pm = &bam_dma_pm_ops,
1463 		.of_match_table = bam_of_match,
1464 	},
1465 };
1466 
1467 module_platform_driver(bam_dma_driver);
1468 
1469 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1470 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1471 MODULE_LICENSE("GPL v2");
1472