xref: /linux/drivers/dma/qcom/bam_dma.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 /*
2  * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 and
6  * only version 2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14 /*
15  * QCOM BAM DMA engine driver
16  *
17  * QCOM BAM DMA blocks are distributed amongst a number of the on-chip
18  * peripherals on the MSM 8x74.  The configuration of the channels are dependent
19  * on the way they are hard wired to that specific peripheral.  The peripheral
20  * device tree entries specify the configuration of each channel.
21  *
22  * The DMA controller requires the use of external memory for storage of the
23  * hardware descriptors for each channel.  The descriptor FIFO is accessed as a
24  * circular buffer and operations are managed according to the offset within the
25  * FIFO.  After pipe/channel reset, all of the pipe registers and internal state
26  * are back to defaults.
27  *
28  * During DMA operations, we write descriptors to the FIFO, being careful to
29  * handle wrapping and then write the last FIFO offset to that channel's
30  * P_EVNT_REG register to kick off the transaction.  The P_SW_OFSTS register
31  * indicates the current FIFO offset that is being processed, so there is some
32  * indication of where the hardware is currently working.
33  */
34 
35 #include <linux/kernel.h>
36 #include <linux/io.h>
37 #include <linux/init.h>
38 #include <linux/slab.h>
39 #include <linux/module.h>
40 #include <linux/interrupt.h>
41 #include <linux/dma-mapping.h>
42 #include <linux/scatterlist.h>
43 #include <linux/device.h>
44 #include <linux/platform_device.h>
45 #include <linux/of.h>
46 #include <linux/of_address.h>
47 #include <linux/of_irq.h>
48 #include <linux/of_dma.h>
49 #include <linux/clk.h>
50 #include <linux/dmaengine.h>
51 #include <linux/pm_runtime.h>
52 
53 #include "../dmaengine.h"
54 #include "../virt-dma.h"
55 
56 struct bam_desc_hw {
57 	__le32 addr;		/* Buffer physical address */
58 	__le16 size;		/* Buffer size in bytes */
59 	__le16 flags;
60 };
61 
62 #define BAM_DMA_AUTOSUSPEND_DELAY 100
63 
64 #define DESC_FLAG_INT BIT(15)
65 #define DESC_FLAG_EOT BIT(14)
66 #define DESC_FLAG_EOB BIT(13)
67 #define DESC_FLAG_NWD BIT(12)
68 
69 struct bam_async_desc {
70 	struct virt_dma_desc vd;
71 
72 	u32 num_desc;
73 	u32 xfer_len;
74 
75 	/* transaction flags, EOT|EOB|NWD */
76 	u16 flags;
77 
78 	struct bam_desc_hw *curr_desc;
79 
80 	enum dma_transfer_direction dir;
81 	size_t length;
82 	struct bam_desc_hw desc[0];
83 };
84 
85 enum bam_reg {
86 	BAM_CTRL,
87 	BAM_REVISION,
88 	BAM_NUM_PIPES,
89 	BAM_DESC_CNT_TRSHLD,
90 	BAM_IRQ_SRCS,
91 	BAM_IRQ_SRCS_MSK,
92 	BAM_IRQ_SRCS_UNMASKED,
93 	BAM_IRQ_STTS,
94 	BAM_IRQ_CLR,
95 	BAM_IRQ_EN,
96 	BAM_CNFG_BITS,
97 	BAM_IRQ_SRCS_EE,
98 	BAM_IRQ_SRCS_MSK_EE,
99 	BAM_P_CTRL,
100 	BAM_P_RST,
101 	BAM_P_HALT,
102 	BAM_P_IRQ_STTS,
103 	BAM_P_IRQ_CLR,
104 	BAM_P_IRQ_EN,
105 	BAM_P_EVNT_DEST_ADDR,
106 	BAM_P_EVNT_REG,
107 	BAM_P_SW_OFSTS,
108 	BAM_P_DATA_FIFO_ADDR,
109 	BAM_P_DESC_FIFO_ADDR,
110 	BAM_P_EVNT_GEN_TRSHLD,
111 	BAM_P_FIFO_SIZES,
112 };
113 
114 struct reg_offset_data {
115 	u32 base_offset;
116 	unsigned int pipe_mult, evnt_mult, ee_mult;
117 };
118 
119 static const struct reg_offset_data bam_v1_3_reg_info[] = {
120 	[BAM_CTRL]		= { 0x0F80, 0x00, 0x00, 0x00 },
121 	[BAM_REVISION]		= { 0x0F84, 0x00, 0x00, 0x00 },
122 	[BAM_NUM_PIPES]		= { 0x0FBC, 0x00, 0x00, 0x00 },
123 	[BAM_DESC_CNT_TRSHLD]	= { 0x0F88, 0x00, 0x00, 0x00 },
124 	[BAM_IRQ_SRCS]		= { 0x0F8C, 0x00, 0x00, 0x00 },
125 	[BAM_IRQ_SRCS_MSK]	= { 0x0F90, 0x00, 0x00, 0x00 },
126 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0FB0, 0x00, 0x00, 0x00 },
127 	[BAM_IRQ_STTS]		= { 0x0F94, 0x00, 0x00, 0x00 },
128 	[BAM_IRQ_CLR]		= { 0x0F98, 0x00, 0x00, 0x00 },
129 	[BAM_IRQ_EN]		= { 0x0F9C, 0x00, 0x00, 0x00 },
130 	[BAM_CNFG_BITS]		= { 0x0FFC, 0x00, 0x00, 0x00 },
131 	[BAM_IRQ_SRCS_EE]	= { 0x1800, 0x00, 0x00, 0x80 },
132 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x1804, 0x00, 0x00, 0x80 },
133 	[BAM_P_CTRL]		= { 0x0000, 0x80, 0x00, 0x00 },
134 	[BAM_P_RST]		= { 0x0004, 0x80, 0x00, 0x00 },
135 	[BAM_P_HALT]		= { 0x0008, 0x80, 0x00, 0x00 },
136 	[BAM_P_IRQ_STTS]	= { 0x0010, 0x80, 0x00, 0x00 },
137 	[BAM_P_IRQ_CLR]		= { 0x0014, 0x80, 0x00, 0x00 },
138 	[BAM_P_IRQ_EN]		= { 0x0018, 0x80, 0x00, 0x00 },
139 	[BAM_P_EVNT_DEST_ADDR]	= { 0x102C, 0x00, 0x40, 0x00 },
140 	[BAM_P_EVNT_REG]	= { 0x1018, 0x00, 0x40, 0x00 },
141 	[BAM_P_SW_OFSTS]	= { 0x1000, 0x00, 0x40, 0x00 },
142 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1024, 0x00, 0x40, 0x00 },
143 	[BAM_P_DESC_FIFO_ADDR]	= { 0x101C, 0x00, 0x40, 0x00 },
144 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1028, 0x00, 0x40, 0x00 },
145 	[BAM_P_FIFO_SIZES]	= { 0x1020, 0x00, 0x40, 0x00 },
146 };
147 
148 static const struct reg_offset_data bam_v1_4_reg_info[] = {
149 	[BAM_CTRL]		= { 0x0000, 0x00, 0x00, 0x00 },
150 	[BAM_REVISION]		= { 0x0004, 0x00, 0x00, 0x00 },
151 	[BAM_NUM_PIPES]		= { 0x003C, 0x00, 0x00, 0x00 },
152 	[BAM_DESC_CNT_TRSHLD]	= { 0x0008, 0x00, 0x00, 0x00 },
153 	[BAM_IRQ_SRCS]		= { 0x000C, 0x00, 0x00, 0x00 },
154 	[BAM_IRQ_SRCS_MSK]	= { 0x0010, 0x00, 0x00, 0x00 },
155 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0030, 0x00, 0x00, 0x00 },
156 	[BAM_IRQ_STTS]		= { 0x0014, 0x00, 0x00, 0x00 },
157 	[BAM_IRQ_CLR]		= { 0x0018, 0x00, 0x00, 0x00 },
158 	[BAM_IRQ_EN]		= { 0x001C, 0x00, 0x00, 0x00 },
159 	[BAM_CNFG_BITS]		= { 0x007C, 0x00, 0x00, 0x00 },
160 	[BAM_IRQ_SRCS_EE]	= { 0x0800, 0x00, 0x00, 0x80 },
161 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x0804, 0x00, 0x00, 0x80 },
162 	[BAM_P_CTRL]		= { 0x1000, 0x1000, 0x00, 0x00 },
163 	[BAM_P_RST]		= { 0x1004, 0x1000, 0x00, 0x00 },
164 	[BAM_P_HALT]		= { 0x1008, 0x1000, 0x00, 0x00 },
165 	[BAM_P_IRQ_STTS]	= { 0x1010, 0x1000, 0x00, 0x00 },
166 	[BAM_P_IRQ_CLR]		= { 0x1014, 0x1000, 0x00, 0x00 },
167 	[BAM_P_IRQ_EN]		= { 0x1018, 0x1000, 0x00, 0x00 },
168 	[BAM_P_EVNT_DEST_ADDR]	= { 0x182C, 0x00, 0x1000, 0x00 },
169 	[BAM_P_EVNT_REG]	= { 0x1818, 0x00, 0x1000, 0x00 },
170 	[BAM_P_SW_OFSTS]	= { 0x1800, 0x00, 0x1000, 0x00 },
171 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1824, 0x00, 0x1000, 0x00 },
172 	[BAM_P_DESC_FIFO_ADDR]	= { 0x181C, 0x00, 0x1000, 0x00 },
173 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1828, 0x00, 0x1000, 0x00 },
174 	[BAM_P_FIFO_SIZES]	= { 0x1820, 0x00, 0x1000, 0x00 },
175 };
176 
177 static const struct reg_offset_data bam_v1_7_reg_info[] = {
178 	[BAM_CTRL]		= { 0x00000, 0x00, 0x00, 0x00 },
179 	[BAM_REVISION]		= { 0x01000, 0x00, 0x00, 0x00 },
180 	[BAM_NUM_PIPES]		= { 0x01008, 0x00, 0x00, 0x00 },
181 	[BAM_DESC_CNT_TRSHLD]	= { 0x00008, 0x00, 0x00, 0x00 },
182 	[BAM_IRQ_SRCS]		= { 0x03010, 0x00, 0x00, 0x00 },
183 	[BAM_IRQ_SRCS_MSK]	= { 0x03014, 0x00, 0x00, 0x00 },
184 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x03018, 0x00, 0x00, 0x00 },
185 	[BAM_IRQ_STTS]		= { 0x00014, 0x00, 0x00, 0x00 },
186 	[BAM_IRQ_CLR]		= { 0x00018, 0x00, 0x00, 0x00 },
187 	[BAM_IRQ_EN]		= { 0x0001C, 0x00, 0x00, 0x00 },
188 	[BAM_CNFG_BITS]		= { 0x0007C, 0x00, 0x00, 0x00 },
189 	[BAM_IRQ_SRCS_EE]	= { 0x03000, 0x00, 0x00, 0x1000 },
190 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x03004, 0x00, 0x00, 0x1000 },
191 	[BAM_P_CTRL]		= { 0x13000, 0x1000, 0x00, 0x00 },
192 	[BAM_P_RST]		= { 0x13004, 0x1000, 0x00, 0x00 },
193 	[BAM_P_HALT]		= { 0x13008, 0x1000, 0x00, 0x00 },
194 	[BAM_P_IRQ_STTS]	= { 0x13010, 0x1000, 0x00, 0x00 },
195 	[BAM_P_IRQ_CLR]		= { 0x13014, 0x1000, 0x00, 0x00 },
196 	[BAM_P_IRQ_EN]		= { 0x13018, 0x1000, 0x00, 0x00 },
197 	[BAM_P_EVNT_DEST_ADDR]	= { 0x1382C, 0x00, 0x1000, 0x00 },
198 	[BAM_P_EVNT_REG]	= { 0x13818, 0x00, 0x1000, 0x00 },
199 	[BAM_P_SW_OFSTS]	= { 0x13800, 0x00, 0x1000, 0x00 },
200 	[BAM_P_DATA_FIFO_ADDR]	= { 0x13824, 0x00, 0x1000, 0x00 },
201 	[BAM_P_DESC_FIFO_ADDR]	= { 0x1381C, 0x00, 0x1000, 0x00 },
202 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x13828, 0x00, 0x1000, 0x00 },
203 	[BAM_P_FIFO_SIZES]	= { 0x13820, 0x00, 0x1000, 0x00 },
204 };
205 
206 /* BAM CTRL */
207 #define BAM_SW_RST			BIT(0)
208 #define BAM_EN				BIT(1)
209 #define BAM_EN_ACCUM			BIT(4)
210 #define BAM_TESTBUS_SEL_SHIFT		5
211 #define BAM_TESTBUS_SEL_MASK		0x3F
212 #define BAM_DESC_CACHE_SEL_SHIFT	13
213 #define BAM_DESC_CACHE_SEL_MASK		0x3
214 #define BAM_CACHED_DESC_STORE		BIT(15)
215 #define IBC_DISABLE			BIT(16)
216 
217 /* BAM REVISION */
218 #define REVISION_SHIFT		0
219 #define REVISION_MASK		0xFF
220 #define NUM_EES_SHIFT		8
221 #define NUM_EES_MASK		0xF
222 #define CE_BUFFER_SIZE		BIT(13)
223 #define AXI_ACTIVE		BIT(14)
224 #define USE_VMIDMT		BIT(15)
225 #define SECURED			BIT(16)
226 #define BAM_HAS_NO_BYPASS	BIT(17)
227 #define HIGH_FREQUENCY_BAM	BIT(18)
228 #define INACTIV_TMRS_EXST	BIT(19)
229 #define NUM_INACTIV_TMRS	BIT(20)
230 #define DESC_CACHE_DEPTH_SHIFT	21
231 #define DESC_CACHE_DEPTH_1	(0 << DESC_CACHE_DEPTH_SHIFT)
232 #define DESC_CACHE_DEPTH_2	(1 << DESC_CACHE_DEPTH_SHIFT)
233 #define DESC_CACHE_DEPTH_3	(2 << DESC_CACHE_DEPTH_SHIFT)
234 #define DESC_CACHE_DEPTH_4	(3 << DESC_CACHE_DEPTH_SHIFT)
235 #define CMD_DESC_EN		BIT(23)
236 #define INACTIV_TMR_BASE_SHIFT	24
237 #define INACTIV_TMR_BASE_MASK	0xFF
238 
239 /* BAM NUM PIPES */
240 #define BAM_NUM_PIPES_SHIFT		0
241 #define BAM_NUM_PIPES_MASK		0xFF
242 #define PERIPH_NON_PIPE_GRP_SHIFT	16
243 #define PERIPH_NON_PIP_GRP_MASK		0xFF
244 #define BAM_NON_PIPE_GRP_SHIFT		24
245 #define BAM_NON_PIPE_GRP_MASK		0xFF
246 
247 /* BAM CNFG BITS */
248 #define BAM_PIPE_CNFG		BIT(2)
249 #define BAM_FULL_PIPE		BIT(11)
250 #define BAM_NO_EXT_P_RST	BIT(12)
251 #define BAM_IBC_DISABLE		BIT(13)
252 #define BAM_SB_CLK_REQ		BIT(14)
253 #define BAM_PSM_CSW_REQ		BIT(15)
254 #define BAM_PSM_P_RES		BIT(16)
255 #define BAM_AU_P_RES		BIT(17)
256 #define BAM_SI_P_RES		BIT(18)
257 #define BAM_WB_P_RES		BIT(19)
258 #define BAM_WB_BLK_CSW		BIT(20)
259 #define BAM_WB_CSW_ACK_IDL	BIT(21)
260 #define BAM_WB_RETR_SVPNT	BIT(22)
261 #define BAM_WB_DSC_AVL_P_RST	BIT(23)
262 #define BAM_REG_P_EN		BIT(24)
263 #define BAM_PSM_P_HD_DATA	BIT(25)
264 #define BAM_AU_ACCUMED		BIT(26)
265 #define BAM_CMD_ENABLE		BIT(27)
266 
267 #define BAM_CNFG_BITS_DEFAULT	(BAM_PIPE_CNFG |	\
268 				 BAM_NO_EXT_P_RST |	\
269 				 BAM_IBC_DISABLE |	\
270 				 BAM_SB_CLK_REQ |	\
271 				 BAM_PSM_CSW_REQ |	\
272 				 BAM_PSM_P_RES |	\
273 				 BAM_AU_P_RES |		\
274 				 BAM_SI_P_RES |		\
275 				 BAM_WB_P_RES |		\
276 				 BAM_WB_BLK_CSW |	\
277 				 BAM_WB_CSW_ACK_IDL |	\
278 				 BAM_WB_RETR_SVPNT |	\
279 				 BAM_WB_DSC_AVL_P_RST |	\
280 				 BAM_REG_P_EN |		\
281 				 BAM_PSM_P_HD_DATA |	\
282 				 BAM_AU_ACCUMED |	\
283 				 BAM_CMD_ENABLE)
284 
285 /* PIPE CTRL */
286 #define P_EN			BIT(1)
287 #define P_DIRECTION		BIT(3)
288 #define P_SYS_STRM		BIT(4)
289 #define P_SYS_MODE		BIT(5)
290 #define P_AUTO_EOB		BIT(6)
291 #define P_AUTO_EOB_SEL_SHIFT	7
292 #define P_AUTO_EOB_SEL_512	(0 << P_AUTO_EOB_SEL_SHIFT)
293 #define P_AUTO_EOB_SEL_256	(1 << P_AUTO_EOB_SEL_SHIFT)
294 #define P_AUTO_EOB_SEL_128	(2 << P_AUTO_EOB_SEL_SHIFT)
295 #define P_AUTO_EOB_SEL_64	(3 << P_AUTO_EOB_SEL_SHIFT)
296 #define P_PREFETCH_LIMIT_SHIFT	9
297 #define P_PREFETCH_LIMIT_32	(0 << P_PREFETCH_LIMIT_SHIFT)
298 #define P_PREFETCH_LIMIT_16	(1 << P_PREFETCH_LIMIT_SHIFT)
299 #define P_PREFETCH_LIMIT_4	(2 << P_PREFETCH_LIMIT_SHIFT)
300 #define P_WRITE_NWD		BIT(11)
301 #define P_LOCK_GROUP_SHIFT	16
302 #define P_LOCK_GROUP_MASK	0x1F
303 
304 /* BAM_DESC_CNT_TRSHLD */
305 #define CNT_TRSHLD		0xffff
306 #define DEFAULT_CNT_THRSHLD	0x4
307 
308 /* BAM_IRQ_SRCS */
309 #define BAM_IRQ			BIT(31)
310 #define P_IRQ			0x7fffffff
311 
312 /* BAM_IRQ_SRCS_MSK */
313 #define BAM_IRQ_MSK		BAM_IRQ
314 #define P_IRQ_MSK		P_IRQ
315 
316 /* BAM_IRQ_STTS */
317 #define BAM_TIMER_IRQ		BIT(4)
318 #define BAM_EMPTY_IRQ		BIT(3)
319 #define BAM_ERROR_IRQ		BIT(2)
320 #define BAM_HRESP_ERR_IRQ	BIT(1)
321 
322 /* BAM_IRQ_CLR */
323 #define BAM_TIMER_CLR		BIT(4)
324 #define BAM_EMPTY_CLR		BIT(3)
325 #define BAM_ERROR_CLR		BIT(2)
326 #define BAM_HRESP_ERR_CLR	BIT(1)
327 
328 /* BAM_IRQ_EN */
329 #define BAM_TIMER_EN		BIT(4)
330 #define BAM_EMPTY_EN		BIT(3)
331 #define BAM_ERROR_EN		BIT(2)
332 #define BAM_HRESP_ERR_EN	BIT(1)
333 
334 /* BAM_P_IRQ_EN */
335 #define P_PRCSD_DESC_EN		BIT(0)
336 #define P_TIMER_EN		BIT(1)
337 #define P_WAKE_EN		BIT(2)
338 #define P_OUT_OF_DESC_EN	BIT(3)
339 #define P_ERR_EN		BIT(4)
340 #define P_TRNSFR_END_EN		BIT(5)
341 #define P_DEFAULT_IRQS_EN	(P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
342 
343 /* BAM_P_SW_OFSTS */
344 #define P_SW_OFSTS_MASK		0xffff
345 
346 #define BAM_DESC_FIFO_SIZE	SZ_32K
347 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
348 #define BAM_FIFO_SIZE	(SZ_32K - 8)
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 	struct bam_async_desc *curr_txd;	/* current running dma */
359 
360 	/* runtime configuration */
361 	struct dma_slave_config slave;
362 
363 	/* fifo storage */
364 	struct bam_desc_hw *fifo_virt;
365 	dma_addr_t fifo_phys;
366 
367 	/* fifo markers */
368 	unsigned short head;		/* start of active descriptor entries */
369 	unsigned short tail;		/* end of active descriptor entries */
370 
371 	unsigned int initialized;	/* is the channel hw initialized? */
372 	unsigned int paused;		/* is the channel paused? */
373 	unsigned int reconfigure;	/* new slave config? */
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 device_dma_parameters dma_parms;
388 	struct bam_chan *channels;
389 	u32 num_channels;
390 
391 	/* execution environment ID, from DT */
392 	u32 ee;
393 	bool controlled_remotely;
394 
395 	const struct reg_offset_data *layout;
396 
397 	struct clk *bamclk;
398 	int irq;
399 
400 	/* dma start transaction tasklet */
401 	struct tasklet_struct task;
402 };
403 
404 /**
405  * bam_addr - returns BAM register address
406  * @bdev: bam device
407  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
408  * @reg:  register enum
409  */
410 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
411 		enum bam_reg reg)
412 {
413 	const struct reg_offset_data r = bdev->layout[reg];
414 
415 	return bdev->regs + r.base_offset +
416 		r.pipe_mult * pipe +
417 		r.evnt_mult * pipe +
418 		r.ee_mult * bdev->ee;
419 }
420 
421 /**
422  * bam_reset_channel - Reset individual BAM DMA channel
423  * @bchan: bam channel
424  *
425  * This function resets a specific BAM channel
426  */
427 static void bam_reset_channel(struct bam_chan *bchan)
428 {
429 	struct bam_device *bdev = bchan->bdev;
430 
431 	lockdep_assert_held(&bchan->vc.lock);
432 
433 	/* reset channel */
434 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
435 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
436 
437 	/* don't allow cpu to reorder BAM register accesses done after this */
438 	wmb();
439 
440 	/* make sure hw is initialized when channel is used the first time  */
441 	bchan->initialized = 0;
442 }
443 
444 /**
445  * bam_chan_init_hw - Initialize channel hardware
446  * @bchan: bam channel
447  *
448  * This function resets and initializes the BAM channel
449  */
450 static void bam_chan_init_hw(struct bam_chan *bchan,
451 	enum dma_transfer_direction dir)
452 {
453 	struct bam_device *bdev = bchan->bdev;
454 	u32 val;
455 
456 	/* Reset the channel to clear internal state of the FIFO */
457 	bam_reset_channel(bchan);
458 
459 	/*
460 	 * write out 8 byte aligned address.  We have enough space for this
461 	 * because we allocated 1 more descriptor (8 bytes) than we can use
462 	 */
463 	writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
464 			bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
465 	writel_relaxed(BAM_FIFO_SIZE,
466 			bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
467 
468 	/* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
469 	writel_relaxed(P_DEFAULT_IRQS_EN,
470 			bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
471 
472 	/* unmask the specific pipe and EE combo */
473 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
474 	val |= BIT(bchan->id);
475 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
476 
477 	/* don't allow cpu to reorder the channel enable done below */
478 	wmb();
479 
480 	/* set fixed direction and mode, then enable channel */
481 	val = P_EN | P_SYS_MODE;
482 	if (dir == DMA_DEV_TO_MEM)
483 		val |= P_DIRECTION;
484 
485 	writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
486 
487 	bchan->initialized = 1;
488 
489 	/* init FIFO pointers */
490 	bchan->head = 0;
491 	bchan->tail = 0;
492 }
493 
494 /**
495  * bam_alloc_chan - Allocate channel resources for DMA channel.
496  * @chan: specified channel
497  *
498  * This function allocates the FIFO descriptor memory
499  */
500 static int bam_alloc_chan(struct dma_chan *chan)
501 {
502 	struct bam_chan *bchan = to_bam_chan(chan);
503 	struct bam_device *bdev = bchan->bdev;
504 
505 	if (bchan->fifo_virt)
506 		return 0;
507 
508 	/* allocate FIFO descriptor space, but only if necessary */
509 	bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
510 					&bchan->fifo_phys, GFP_KERNEL);
511 
512 	if (!bchan->fifo_virt) {
513 		dev_err(bdev->dev, "Failed to allocate desc fifo\n");
514 		return -ENOMEM;
515 	}
516 
517 	return 0;
518 }
519 
520 /**
521  * bam_free_chan - Frees dma resources associated with specific channel
522  * @chan: specified channel
523  *
524  * Free the allocated fifo descriptor memory and channel resources
525  *
526  */
527 static void bam_free_chan(struct dma_chan *chan)
528 {
529 	struct bam_chan *bchan = to_bam_chan(chan);
530 	struct bam_device *bdev = bchan->bdev;
531 	u32 val;
532 	unsigned long flags;
533 	int ret;
534 
535 	ret = pm_runtime_get_sync(bdev->dev);
536 	if (ret < 0)
537 		return;
538 
539 	vchan_free_chan_resources(to_virt_chan(chan));
540 
541 	if (bchan->curr_txd) {
542 		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
543 		goto err;
544 	}
545 
546 	spin_lock_irqsave(&bchan->vc.lock, flags);
547 	bam_reset_channel(bchan);
548 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
549 
550 	dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
551 		    bchan->fifo_phys);
552 	bchan->fifo_virt = NULL;
553 
554 	/* mask irq for pipe/channel */
555 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
556 	val &= ~BIT(bchan->id);
557 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
558 
559 	/* disable irq */
560 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
561 
562 err:
563 	pm_runtime_mark_last_busy(bdev->dev);
564 	pm_runtime_put_autosuspend(bdev->dev);
565 }
566 
567 /**
568  * bam_slave_config - set slave configuration for channel
569  * @chan: dma channel
570  * @cfg: slave configuration
571  *
572  * Sets slave configuration for channel
573  *
574  */
575 static int bam_slave_config(struct dma_chan *chan,
576 			    struct dma_slave_config *cfg)
577 {
578 	struct bam_chan *bchan = to_bam_chan(chan);
579 	unsigned long flag;
580 
581 	spin_lock_irqsave(&bchan->vc.lock, flag);
582 	memcpy(&bchan->slave, cfg, sizeof(*cfg));
583 	bchan->reconfigure = 1;
584 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
585 
586 	return 0;
587 }
588 
589 /**
590  * bam_prep_slave_sg - Prep slave sg transaction
591  *
592  * @chan: dma channel
593  * @sgl: scatter gather list
594  * @sg_len: length of sg
595  * @direction: DMA transfer direction
596  * @flags: DMA flags
597  * @context: transfer context (unused)
598  */
599 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
600 	struct scatterlist *sgl, unsigned int sg_len,
601 	enum dma_transfer_direction direction, unsigned long flags,
602 	void *context)
603 {
604 	struct bam_chan *bchan = to_bam_chan(chan);
605 	struct bam_device *bdev = bchan->bdev;
606 	struct bam_async_desc *async_desc;
607 	struct scatterlist *sg;
608 	u32 i;
609 	struct bam_desc_hw *desc;
610 	unsigned int num_alloc = 0;
611 
612 
613 	if (!is_slave_direction(direction)) {
614 		dev_err(bdev->dev, "invalid dma direction\n");
615 		return NULL;
616 	}
617 
618 	/* calculate number of required entries */
619 	for_each_sg(sgl, sg, sg_len, i)
620 		num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE);
621 
622 	/* allocate enough room to accomodate the number of entries */
623 	async_desc = kzalloc(sizeof(*async_desc) +
624 			(num_alloc * sizeof(struct bam_desc_hw)), GFP_NOWAIT);
625 
626 	if (!async_desc)
627 		goto err_out;
628 
629 	if (flags & DMA_PREP_FENCE)
630 		async_desc->flags |= DESC_FLAG_NWD;
631 
632 	if (flags & DMA_PREP_INTERRUPT)
633 		async_desc->flags |= DESC_FLAG_EOT;
634 	else
635 		async_desc->flags |= DESC_FLAG_INT;
636 
637 	async_desc->num_desc = num_alloc;
638 	async_desc->curr_desc = async_desc->desc;
639 	async_desc->dir = direction;
640 
641 	/* fill in temporary descriptors */
642 	desc = async_desc->desc;
643 	for_each_sg(sgl, sg, sg_len, i) {
644 		unsigned int remainder = sg_dma_len(sg);
645 		unsigned int curr_offset = 0;
646 
647 		do {
648 			desc->addr = cpu_to_le32(sg_dma_address(sg) +
649 						 curr_offset);
650 
651 			if (remainder > BAM_FIFO_SIZE) {
652 				desc->size = cpu_to_le16(BAM_FIFO_SIZE);
653 				remainder -= BAM_FIFO_SIZE;
654 				curr_offset += BAM_FIFO_SIZE;
655 			} else {
656 				desc->size = cpu_to_le16(remainder);
657 				remainder = 0;
658 			}
659 
660 			async_desc->length += desc->size;
661 			desc++;
662 		} while (remainder > 0);
663 	}
664 
665 	return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
666 
667 err_out:
668 	kfree(async_desc);
669 	return NULL;
670 }
671 
672 /**
673  * bam_dma_terminate_all - terminate all transactions on a channel
674  * @bchan: bam dma channel
675  *
676  * Dequeues and frees all transactions
677  * No callbacks are done
678  *
679  */
680 static int bam_dma_terminate_all(struct dma_chan *chan)
681 {
682 	struct bam_chan *bchan = to_bam_chan(chan);
683 	unsigned long flag;
684 	LIST_HEAD(head);
685 
686 	/* remove all transactions, including active transaction */
687 	spin_lock_irqsave(&bchan->vc.lock, flag);
688 	if (bchan->curr_txd) {
689 		list_add(&bchan->curr_txd->vd.node, &bchan->vc.desc_issued);
690 		bchan->curr_txd = NULL;
691 	}
692 
693 	vchan_get_all_descriptors(&bchan->vc, &head);
694 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
695 
696 	vchan_dma_desc_free_list(&bchan->vc, &head);
697 
698 	return 0;
699 }
700 
701 /**
702  * bam_pause - Pause DMA channel
703  * @chan: dma channel
704  *
705  */
706 static int bam_pause(struct dma_chan *chan)
707 {
708 	struct bam_chan *bchan = to_bam_chan(chan);
709 	struct bam_device *bdev = bchan->bdev;
710 	unsigned long flag;
711 	int ret;
712 
713 	ret = pm_runtime_get_sync(bdev->dev);
714 	if (ret < 0)
715 		return ret;
716 
717 	spin_lock_irqsave(&bchan->vc.lock, flag);
718 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
719 	bchan->paused = 1;
720 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
721 	pm_runtime_mark_last_busy(bdev->dev);
722 	pm_runtime_put_autosuspend(bdev->dev);
723 
724 	return 0;
725 }
726 
727 /**
728  * bam_resume - Resume DMA channel operations
729  * @chan: dma channel
730  *
731  */
732 static int bam_resume(struct dma_chan *chan)
733 {
734 	struct bam_chan *bchan = to_bam_chan(chan);
735 	struct bam_device *bdev = bchan->bdev;
736 	unsigned long flag;
737 	int ret;
738 
739 	ret = pm_runtime_get_sync(bdev->dev);
740 	if (ret < 0)
741 		return ret;
742 
743 	spin_lock_irqsave(&bchan->vc.lock, flag);
744 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
745 	bchan->paused = 0;
746 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
747 	pm_runtime_mark_last_busy(bdev->dev);
748 	pm_runtime_put_autosuspend(bdev->dev);
749 
750 	return 0;
751 }
752 
753 /**
754  * process_channel_irqs - processes the channel interrupts
755  * @bdev: bam controller
756  *
757  * This function processes the channel interrupts
758  *
759  */
760 static u32 process_channel_irqs(struct bam_device *bdev)
761 {
762 	u32 i, srcs, pipe_stts;
763 	unsigned long flags;
764 	struct bam_async_desc *async_desc;
765 
766 	srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
767 
768 	/* return early if no pipe/channel interrupts are present */
769 	if (!(srcs & P_IRQ))
770 		return srcs;
771 
772 	for (i = 0; i < bdev->num_channels; i++) {
773 		struct bam_chan *bchan = &bdev->channels[i];
774 
775 		if (!(srcs & BIT(i)))
776 			continue;
777 
778 		/* clear pipe irq */
779 		pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
780 
781 		writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
782 
783 		spin_lock_irqsave(&bchan->vc.lock, flags);
784 		async_desc = bchan->curr_txd;
785 
786 		if (async_desc) {
787 			async_desc->num_desc -= async_desc->xfer_len;
788 			async_desc->curr_desc += async_desc->xfer_len;
789 			bchan->curr_txd = NULL;
790 
791 			/* manage FIFO */
792 			bchan->head += async_desc->xfer_len;
793 			bchan->head %= MAX_DESCRIPTORS;
794 
795 			/*
796 			 * if complete, process cookie.  Otherwise
797 			 * push back to front of desc_issued so that
798 			 * it gets restarted by the tasklet
799 			 */
800 			if (!async_desc->num_desc)
801 				vchan_cookie_complete(&async_desc->vd);
802 			else
803 				list_add(&async_desc->vd.node,
804 					&bchan->vc.desc_issued);
805 		}
806 
807 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
808 	}
809 
810 	return srcs;
811 }
812 
813 /**
814  * bam_dma_irq - irq handler for bam controller
815  * @irq: IRQ of interrupt
816  * @data: callback data
817  *
818  * IRQ handler for the bam controller
819  */
820 static irqreturn_t bam_dma_irq(int irq, void *data)
821 {
822 	struct bam_device *bdev = data;
823 	u32 clr_mask = 0, srcs = 0;
824 	int ret;
825 
826 	srcs |= process_channel_irqs(bdev);
827 
828 	/* kick off tasklet to start next dma transfer */
829 	if (srcs & P_IRQ)
830 		tasklet_schedule(&bdev->task);
831 
832 	ret = pm_runtime_get_sync(bdev->dev);
833 	if (ret < 0)
834 		return ret;
835 
836 	if (srcs & BAM_IRQ) {
837 		clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
838 
839 		/*
840 		 * don't allow reorder of the various accesses to the BAM
841 		 * registers
842 		 */
843 		mb();
844 
845 		writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
846 	}
847 
848 	pm_runtime_mark_last_busy(bdev->dev);
849 	pm_runtime_put_autosuspend(bdev->dev);
850 
851 	return IRQ_HANDLED;
852 }
853 
854 /**
855  * bam_tx_status - returns status of transaction
856  * @chan: dma channel
857  * @cookie: transaction cookie
858  * @txstate: DMA transaction state
859  *
860  * Return status of dma transaction
861  */
862 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
863 		struct dma_tx_state *txstate)
864 {
865 	struct bam_chan *bchan = to_bam_chan(chan);
866 	struct virt_dma_desc *vd;
867 	int ret;
868 	size_t residue = 0;
869 	unsigned int i;
870 	unsigned long flags;
871 
872 	ret = dma_cookie_status(chan, cookie, txstate);
873 	if (ret == DMA_COMPLETE)
874 		return ret;
875 
876 	if (!txstate)
877 		return bchan->paused ? DMA_PAUSED : ret;
878 
879 	spin_lock_irqsave(&bchan->vc.lock, flags);
880 	vd = vchan_find_desc(&bchan->vc, cookie);
881 	if (vd)
882 		residue = container_of(vd, struct bam_async_desc, vd)->length;
883 	else if (bchan->curr_txd && bchan->curr_txd->vd.tx.cookie == cookie)
884 		for (i = 0; i < bchan->curr_txd->num_desc; i++)
885 			residue += bchan->curr_txd->curr_desc[i].size;
886 
887 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
888 
889 	dma_set_residue(txstate, residue);
890 
891 	if (ret == DMA_IN_PROGRESS && bchan->paused)
892 		ret = DMA_PAUSED;
893 
894 	return ret;
895 }
896 
897 /**
898  * bam_apply_new_config
899  * @bchan: bam dma channel
900  * @dir: DMA direction
901  */
902 static void bam_apply_new_config(struct bam_chan *bchan,
903 	enum dma_transfer_direction dir)
904 {
905 	struct bam_device *bdev = bchan->bdev;
906 	u32 maxburst;
907 
908 	if (dir == DMA_DEV_TO_MEM)
909 		maxburst = bchan->slave.src_maxburst;
910 	else
911 		maxburst = bchan->slave.dst_maxburst;
912 
913 	writel_relaxed(maxburst, bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
914 
915 	bchan->reconfigure = 0;
916 }
917 
918 /**
919  * bam_start_dma - start next transaction
920  * @bchan - bam dma channel
921  */
922 static void bam_start_dma(struct bam_chan *bchan)
923 {
924 	struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
925 	struct bam_device *bdev = bchan->bdev;
926 	struct bam_async_desc *async_desc;
927 	struct bam_desc_hw *desc;
928 	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
929 					sizeof(struct bam_desc_hw));
930 	int ret;
931 
932 	lockdep_assert_held(&bchan->vc.lock);
933 
934 	if (!vd)
935 		return;
936 
937 	list_del(&vd->node);
938 
939 	async_desc = container_of(vd, struct bam_async_desc, vd);
940 	bchan->curr_txd = async_desc;
941 
942 	ret = pm_runtime_get_sync(bdev->dev);
943 	if (ret < 0)
944 		return;
945 
946 	/* on first use, initialize the channel hardware */
947 	if (!bchan->initialized)
948 		bam_chan_init_hw(bchan, async_desc->dir);
949 
950 	/* apply new slave config changes, if necessary */
951 	if (bchan->reconfigure)
952 		bam_apply_new_config(bchan, async_desc->dir);
953 
954 	desc = bchan->curr_txd->curr_desc;
955 
956 	if (async_desc->num_desc > MAX_DESCRIPTORS)
957 		async_desc->xfer_len = MAX_DESCRIPTORS;
958 	else
959 		async_desc->xfer_len = async_desc->num_desc;
960 
961 	/* set any special flags on the last descriptor */
962 	if (async_desc->num_desc == async_desc->xfer_len)
963 		desc[async_desc->xfer_len - 1].flags =
964 					cpu_to_le16(async_desc->flags);
965 	else
966 		desc[async_desc->xfer_len - 1].flags |=
967 					cpu_to_le16(DESC_FLAG_INT);
968 
969 	if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
970 		u32 partial = MAX_DESCRIPTORS - bchan->tail;
971 
972 		memcpy(&fifo[bchan->tail], desc,
973 				partial * sizeof(struct bam_desc_hw));
974 		memcpy(fifo, &desc[partial], (async_desc->xfer_len - partial) *
975 				sizeof(struct bam_desc_hw));
976 	} else {
977 		memcpy(&fifo[bchan->tail], desc,
978 			async_desc->xfer_len * sizeof(struct bam_desc_hw));
979 	}
980 
981 	bchan->tail += async_desc->xfer_len;
982 	bchan->tail %= MAX_DESCRIPTORS;
983 
984 	/* ensure descriptor writes and dma start not reordered */
985 	wmb();
986 	writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
987 			bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
988 
989 	pm_runtime_mark_last_busy(bdev->dev);
990 	pm_runtime_put_autosuspend(bdev->dev);
991 }
992 
993 /**
994  * dma_tasklet - DMA IRQ tasklet
995  * @data: tasklet argument (bam controller structure)
996  *
997  * Sets up next DMA operation and then processes all completed transactions
998  */
999 static void dma_tasklet(unsigned long data)
1000 {
1001 	struct bam_device *bdev = (struct bam_device *)data;
1002 	struct bam_chan *bchan;
1003 	unsigned long flags;
1004 	unsigned int i;
1005 
1006 	/* go through the channels and kick off transactions */
1007 	for (i = 0; i < bdev->num_channels; i++) {
1008 		bchan = &bdev->channels[i];
1009 		spin_lock_irqsave(&bchan->vc.lock, flags);
1010 
1011 		if (!list_empty(&bchan->vc.desc_issued) && !bchan->curr_txd)
1012 			bam_start_dma(bchan);
1013 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
1014 	}
1015 
1016 }
1017 
1018 /**
1019  * bam_issue_pending - starts pending transactions
1020  * @chan: dma channel
1021  *
1022  * Calls tasklet directly which in turn starts any pending transactions
1023  */
1024 static void bam_issue_pending(struct dma_chan *chan)
1025 {
1026 	struct bam_chan *bchan = to_bam_chan(chan);
1027 	unsigned long flags;
1028 
1029 	spin_lock_irqsave(&bchan->vc.lock, flags);
1030 
1031 	/* if work pending and idle, start a transaction */
1032 	if (vchan_issue_pending(&bchan->vc) && !bchan->curr_txd)
1033 		bam_start_dma(bchan);
1034 
1035 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
1036 }
1037 
1038 /**
1039  * bam_dma_free_desc - free descriptor memory
1040  * @vd: virtual descriptor
1041  *
1042  */
1043 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1044 {
1045 	struct bam_async_desc *async_desc = container_of(vd,
1046 			struct bam_async_desc, vd);
1047 
1048 	kfree(async_desc);
1049 }
1050 
1051 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1052 		struct of_dma *of)
1053 {
1054 	struct bam_device *bdev = container_of(of->of_dma_data,
1055 					struct bam_device, common);
1056 	unsigned int request;
1057 
1058 	if (dma_spec->args_count != 1)
1059 		return NULL;
1060 
1061 	request = dma_spec->args[0];
1062 	if (request >= bdev->num_channels)
1063 		return NULL;
1064 
1065 	return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1066 }
1067 
1068 /**
1069  * bam_init
1070  * @bdev: bam device
1071  *
1072  * Initialization helper for global bam registers
1073  */
1074 static int bam_init(struct bam_device *bdev)
1075 {
1076 	u32 val;
1077 
1078 	/* read revision and configuration information */
1079 	val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)) >> NUM_EES_SHIFT;
1080 	val &= NUM_EES_MASK;
1081 
1082 	/* check that configured EE is within range */
1083 	if (bdev->ee >= val)
1084 		return -EINVAL;
1085 
1086 	val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1087 	bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1088 
1089 	if (bdev->controlled_remotely)
1090 		return 0;
1091 
1092 	/* s/w reset bam */
1093 	/* after reset all pipes are disabled and idle */
1094 	val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
1095 	val |= BAM_SW_RST;
1096 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1097 	val &= ~BAM_SW_RST;
1098 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1099 
1100 	/* make sure previous stores are visible before enabling BAM */
1101 	wmb();
1102 
1103 	/* enable bam */
1104 	val |= BAM_EN;
1105 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1106 
1107 	/* set descriptor threshhold, start with 4 bytes */
1108 	writel_relaxed(DEFAULT_CNT_THRSHLD,
1109 			bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1110 
1111 	/* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
1112 	writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
1113 
1114 	/* enable irqs for errors */
1115 	writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
1116 			bam_addr(bdev, 0, BAM_IRQ_EN));
1117 
1118 	/* unmask global bam interrupt */
1119 	writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
1120 
1121 	return 0;
1122 }
1123 
1124 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1125 	u32 index)
1126 {
1127 	bchan->id = index;
1128 	bchan->bdev = bdev;
1129 
1130 	vchan_init(&bchan->vc, &bdev->common);
1131 	bchan->vc.desc_free = bam_dma_free_desc;
1132 }
1133 
1134 static const struct of_device_id bam_of_match[] = {
1135 	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1136 	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1137 	{ .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1138 	{}
1139 };
1140 
1141 MODULE_DEVICE_TABLE(of, bam_of_match);
1142 
1143 static int bam_dma_probe(struct platform_device *pdev)
1144 {
1145 	struct bam_device *bdev;
1146 	const struct of_device_id *match;
1147 	struct resource *iores;
1148 	int ret, i;
1149 
1150 	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1151 	if (!bdev)
1152 		return -ENOMEM;
1153 
1154 	bdev->dev = &pdev->dev;
1155 
1156 	match = of_match_node(bam_of_match, pdev->dev.of_node);
1157 	if (!match) {
1158 		dev_err(&pdev->dev, "Unsupported BAM module\n");
1159 		return -ENODEV;
1160 	}
1161 
1162 	bdev->layout = match->data;
1163 
1164 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1165 	bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
1166 	if (IS_ERR(bdev->regs))
1167 		return PTR_ERR(bdev->regs);
1168 
1169 	bdev->irq = platform_get_irq(pdev, 0);
1170 	if (bdev->irq < 0)
1171 		return bdev->irq;
1172 
1173 	ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1174 	if (ret) {
1175 		dev_err(bdev->dev, "Execution environment unspecified\n");
1176 		return ret;
1177 	}
1178 
1179 	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
1180 						"qcom,controlled-remotely");
1181 
1182 	bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1183 	if (IS_ERR(bdev->bamclk))
1184 		return PTR_ERR(bdev->bamclk);
1185 
1186 	ret = clk_prepare_enable(bdev->bamclk);
1187 	if (ret) {
1188 		dev_err(bdev->dev, "failed to prepare/enable clock\n");
1189 		return ret;
1190 	}
1191 
1192 	ret = bam_init(bdev);
1193 	if (ret)
1194 		goto err_disable_clk;
1195 
1196 	tasklet_init(&bdev->task, dma_tasklet, (unsigned long)bdev);
1197 
1198 	bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1199 				sizeof(*bdev->channels), GFP_KERNEL);
1200 
1201 	if (!bdev->channels) {
1202 		ret = -ENOMEM;
1203 		goto err_tasklet_kill;
1204 	}
1205 
1206 	/* allocate and initialize channels */
1207 	INIT_LIST_HEAD(&bdev->common.channels);
1208 
1209 	for (i = 0; i < bdev->num_channels; i++)
1210 		bam_channel_init(bdev, &bdev->channels[i], i);
1211 
1212 	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1213 			IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1214 	if (ret)
1215 		goto err_bam_channel_exit;
1216 
1217 	/* set max dma segment size */
1218 	bdev->common.dev = bdev->dev;
1219 	bdev->common.dev->dma_parms = &bdev->dma_parms;
1220 	ret = dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1221 	if (ret) {
1222 		dev_err(bdev->dev, "cannot set maximum segment size\n");
1223 		goto err_bam_channel_exit;
1224 	}
1225 
1226 	platform_set_drvdata(pdev, bdev);
1227 
1228 	/* set capabilities */
1229 	dma_cap_zero(bdev->common.cap_mask);
1230 	dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1231 
1232 	/* initialize dmaengine apis */
1233 	bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1234 	bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1235 	bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1236 	bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1237 	bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1238 	bdev->common.device_free_chan_resources = bam_free_chan;
1239 	bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1240 	bdev->common.device_config = bam_slave_config;
1241 	bdev->common.device_pause = bam_pause;
1242 	bdev->common.device_resume = bam_resume;
1243 	bdev->common.device_terminate_all = bam_dma_terminate_all;
1244 	bdev->common.device_issue_pending = bam_issue_pending;
1245 	bdev->common.device_tx_status = bam_tx_status;
1246 	bdev->common.dev = bdev->dev;
1247 
1248 	ret = dma_async_device_register(&bdev->common);
1249 	if (ret) {
1250 		dev_err(bdev->dev, "failed to register dma async device\n");
1251 		goto err_bam_channel_exit;
1252 	}
1253 
1254 	ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1255 					&bdev->common);
1256 	if (ret)
1257 		goto err_unregister_dma;
1258 
1259 	pm_runtime_irq_safe(&pdev->dev);
1260 	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
1261 	pm_runtime_use_autosuspend(&pdev->dev);
1262 	pm_runtime_mark_last_busy(&pdev->dev);
1263 	pm_runtime_set_active(&pdev->dev);
1264 	pm_runtime_enable(&pdev->dev);
1265 
1266 	return 0;
1267 
1268 err_unregister_dma:
1269 	dma_async_device_unregister(&bdev->common);
1270 err_bam_channel_exit:
1271 	for (i = 0; i < bdev->num_channels; i++)
1272 		tasklet_kill(&bdev->channels[i].vc.task);
1273 err_tasklet_kill:
1274 	tasklet_kill(&bdev->task);
1275 err_disable_clk:
1276 	clk_disable_unprepare(bdev->bamclk);
1277 
1278 	return ret;
1279 }
1280 
1281 static int bam_dma_remove(struct platform_device *pdev)
1282 {
1283 	struct bam_device *bdev = platform_get_drvdata(pdev);
1284 	u32 i;
1285 
1286 	pm_runtime_force_suspend(&pdev->dev);
1287 
1288 	of_dma_controller_free(pdev->dev.of_node);
1289 	dma_async_device_unregister(&bdev->common);
1290 
1291 	/* mask all interrupts for this execution environment */
1292 	writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1293 
1294 	devm_free_irq(bdev->dev, bdev->irq, bdev);
1295 
1296 	for (i = 0; i < bdev->num_channels; i++) {
1297 		bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1298 		tasklet_kill(&bdev->channels[i].vc.task);
1299 
1300 		if (!bdev->channels[i].fifo_virt)
1301 			continue;
1302 
1303 		dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1304 			    bdev->channels[i].fifo_virt,
1305 			    bdev->channels[i].fifo_phys);
1306 	}
1307 
1308 	tasklet_kill(&bdev->task);
1309 
1310 	clk_disable_unprepare(bdev->bamclk);
1311 
1312 	return 0;
1313 }
1314 
1315 static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
1316 {
1317 	struct bam_device *bdev = dev_get_drvdata(dev);
1318 
1319 	clk_disable(bdev->bamclk);
1320 
1321 	return 0;
1322 }
1323 
1324 static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
1325 {
1326 	struct bam_device *bdev = dev_get_drvdata(dev);
1327 	int ret;
1328 
1329 	ret = clk_enable(bdev->bamclk);
1330 	if (ret < 0) {
1331 		dev_err(dev, "clk_enable failed: %d\n", ret);
1332 		return ret;
1333 	}
1334 
1335 	return 0;
1336 }
1337 
1338 static int __maybe_unused bam_dma_suspend(struct device *dev)
1339 {
1340 	struct bam_device *bdev = dev_get_drvdata(dev);
1341 
1342 	pm_runtime_force_suspend(dev);
1343 
1344 	clk_unprepare(bdev->bamclk);
1345 
1346 	return 0;
1347 }
1348 
1349 static int __maybe_unused bam_dma_resume(struct device *dev)
1350 {
1351 	struct bam_device *bdev = dev_get_drvdata(dev);
1352 	int ret;
1353 
1354 	ret = clk_prepare(bdev->bamclk);
1355 	if (ret)
1356 		return ret;
1357 
1358 	pm_runtime_force_resume(dev);
1359 
1360 	return 0;
1361 }
1362 
1363 static const struct dev_pm_ops bam_dma_pm_ops = {
1364 	SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
1365 	SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
1366 				NULL)
1367 };
1368 
1369 static struct platform_driver bam_dma_driver = {
1370 	.probe = bam_dma_probe,
1371 	.remove = bam_dma_remove,
1372 	.driver = {
1373 		.name = "bam-dma-engine",
1374 		.pm = &bam_dma_pm_ops,
1375 		.of_match_table = bam_of_match,
1376 	},
1377 };
1378 
1379 module_platform_driver(bam_dma_driver);
1380 
1381 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1382 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1383 MODULE_LICENSE("GPL v2");
1384