xref: /openbmc/linux/drivers/dma/qcom/bam_dma.c (revision 5a244f48)
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 #define DESC_FLAG_CMD BIT(11)
69 
70 struct bam_async_desc {
71 	struct virt_dma_desc vd;
72 
73 	u32 num_desc;
74 	u32 xfer_len;
75 
76 	/* transaction flags, EOT|EOB|NWD */
77 	u16 flags;
78 
79 	struct bam_desc_hw *curr_desc;
80 
81 	enum dma_transfer_direction dir;
82 	size_t length;
83 	struct bam_desc_hw desc[0];
84 };
85 
86 enum bam_reg {
87 	BAM_CTRL,
88 	BAM_REVISION,
89 	BAM_NUM_PIPES,
90 	BAM_DESC_CNT_TRSHLD,
91 	BAM_IRQ_SRCS,
92 	BAM_IRQ_SRCS_MSK,
93 	BAM_IRQ_SRCS_UNMASKED,
94 	BAM_IRQ_STTS,
95 	BAM_IRQ_CLR,
96 	BAM_IRQ_EN,
97 	BAM_CNFG_BITS,
98 	BAM_IRQ_SRCS_EE,
99 	BAM_IRQ_SRCS_MSK_EE,
100 	BAM_P_CTRL,
101 	BAM_P_RST,
102 	BAM_P_HALT,
103 	BAM_P_IRQ_STTS,
104 	BAM_P_IRQ_CLR,
105 	BAM_P_IRQ_EN,
106 	BAM_P_EVNT_DEST_ADDR,
107 	BAM_P_EVNT_REG,
108 	BAM_P_SW_OFSTS,
109 	BAM_P_DATA_FIFO_ADDR,
110 	BAM_P_DESC_FIFO_ADDR,
111 	BAM_P_EVNT_GEN_TRSHLD,
112 	BAM_P_FIFO_SIZES,
113 };
114 
115 struct reg_offset_data {
116 	u32 base_offset;
117 	unsigned int pipe_mult, evnt_mult, ee_mult;
118 };
119 
120 static const struct reg_offset_data bam_v1_3_reg_info[] = {
121 	[BAM_CTRL]		= { 0x0F80, 0x00, 0x00, 0x00 },
122 	[BAM_REVISION]		= { 0x0F84, 0x00, 0x00, 0x00 },
123 	[BAM_NUM_PIPES]		= { 0x0FBC, 0x00, 0x00, 0x00 },
124 	[BAM_DESC_CNT_TRSHLD]	= { 0x0F88, 0x00, 0x00, 0x00 },
125 	[BAM_IRQ_SRCS]		= { 0x0F8C, 0x00, 0x00, 0x00 },
126 	[BAM_IRQ_SRCS_MSK]	= { 0x0F90, 0x00, 0x00, 0x00 },
127 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0FB0, 0x00, 0x00, 0x00 },
128 	[BAM_IRQ_STTS]		= { 0x0F94, 0x00, 0x00, 0x00 },
129 	[BAM_IRQ_CLR]		= { 0x0F98, 0x00, 0x00, 0x00 },
130 	[BAM_IRQ_EN]		= { 0x0F9C, 0x00, 0x00, 0x00 },
131 	[BAM_CNFG_BITS]		= { 0x0FFC, 0x00, 0x00, 0x00 },
132 	[BAM_IRQ_SRCS_EE]	= { 0x1800, 0x00, 0x00, 0x80 },
133 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x1804, 0x00, 0x00, 0x80 },
134 	[BAM_P_CTRL]		= { 0x0000, 0x80, 0x00, 0x00 },
135 	[BAM_P_RST]		= { 0x0004, 0x80, 0x00, 0x00 },
136 	[BAM_P_HALT]		= { 0x0008, 0x80, 0x00, 0x00 },
137 	[BAM_P_IRQ_STTS]	= { 0x0010, 0x80, 0x00, 0x00 },
138 	[BAM_P_IRQ_CLR]		= { 0x0014, 0x80, 0x00, 0x00 },
139 	[BAM_P_IRQ_EN]		= { 0x0018, 0x80, 0x00, 0x00 },
140 	[BAM_P_EVNT_DEST_ADDR]	= { 0x102C, 0x00, 0x40, 0x00 },
141 	[BAM_P_EVNT_REG]	= { 0x1018, 0x00, 0x40, 0x00 },
142 	[BAM_P_SW_OFSTS]	= { 0x1000, 0x00, 0x40, 0x00 },
143 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1024, 0x00, 0x40, 0x00 },
144 	[BAM_P_DESC_FIFO_ADDR]	= { 0x101C, 0x00, 0x40, 0x00 },
145 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1028, 0x00, 0x40, 0x00 },
146 	[BAM_P_FIFO_SIZES]	= { 0x1020, 0x00, 0x40, 0x00 },
147 };
148 
149 static const struct reg_offset_data bam_v1_4_reg_info[] = {
150 	[BAM_CTRL]		= { 0x0000, 0x00, 0x00, 0x00 },
151 	[BAM_REVISION]		= { 0x0004, 0x00, 0x00, 0x00 },
152 	[BAM_NUM_PIPES]		= { 0x003C, 0x00, 0x00, 0x00 },
153 	[BAM_DESC_CNT_TRSHLD]	= { 0x0008, 0x00, 0x00, 0x00 },
154 	[BAM_IRQ_SRCS]		= { 0x000C, 0x00, 0x00, 0x00 },
155 	[BAM_IRQ_SRCS_MSK]	= { 0x0010, 0x00, 0x00, 0x00 },
156 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0030, 0x00, 0x00, 0x00 },
157 	[BAM_IRQ_STTS]		= { 0x0014, 0x00, 0x00, 0x00 },
158 	[BAM_IRQ_CLR]		= { 0x0018, 0x00, 0x00, 0x00 },
159 	[BAM_IRQ_EN]		= { 0x001C, 0x00, 0x00, 0x00 },
160 	[BAM_CNFG_BITS]		= { 0x007C, 0x00, 0x00, 0x00 },
161 	[BAM_IRQ_SRCS_EE]	= { 0x0800, 0x00, 0x00, 0x80 },
162 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x0804, 0x00, 0x00, 0x80 },
163 	[BAM_P_CTRL]		= { 0x1000, 0x1000, 0x00, 0x00 },
164 	[BAM_P_RST]		= { 0x1004, 0x1000, 0x00, 0x00 },
165 	[BAM_P_HALT]		= { 0x1008, 0x1000, 0x00, 0x00 },
166 	[BAM_P_IRQ_STTS]	= { 0x1010, 0x1000, 0x00, 0x00 },
167 	[BAM_P_IRQ_CLR]		= { 0x1014, 0x1000, 0x00, 0x00 },
168 	[BAM_P_IRQ_EN]		= { 0x1018, 0x1000, 0x00, 0x00 },
169 	[BAM_P_EVNT_DEST_ADDR]	= { 0x182C, 0x00, 0x1000, 0x00 },
170 	[BAM_P_EVNT_REG]	= { 0x1818, 0x00, 0x1000, 0x00 },
171 	[BAM_P_SW_OFSTS]	= { 0x1800, 0x00, 0x1000, 0x00 },
172 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1824, 0x00, 0x1000, 0x00 },
173 	[BAM_P_DESC_FIFO_ADDR]	= { 0x181C, 0x00, 0x1000, 0x00 },
174 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1828, 0x00, 0x1000, 0x00 },
175 	[BAM_P_FIFO_SIZES]	= { 0x1820, 0x00, 0x1000, 0x00 },
176 };
177 
178 static const struct reg_offset_data bam_v1_7_reg_info[] = {
179 	[BAM_CTRL]		= { 0x00000, 0x00, 0x00, 0x00 },
180 	[BAM_REVISION]		= { 0x01000, 0x00, 0x00, 0x00 },
181 	[BAM_NUM_PIPES]		= { 0x01008, 0x00, 0x00, 0x00 },
182 	[BAM_DESC_CNT_TRSHLD]	= { 0x00008, 0x00, 0x00, 0x00 },
183 	[BAM_IRQ_SRCS]		= { 0x03010, 0x00, 0x00, 0x00 },
184 	[BAM_IRQ_SRCS_MSK]	= { 0x03014, 0x00, 0x00, 0x00 },
185 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x03018, 0x00, 0x00, 0x00 },
186 	[BAM_IRQ_STTS]		= { 0x00014, 0x00, 0x00, 0x00 },
187 	[BAM_IRQ_CLR]		= { 0x00018, 0x00, 0x00, 0x00 },
188 	[BAM_IRQ_EN]		= { 0x0001C, 0x00, 0x00, 0x00 },
189 	[BAM_CNFG_BITS]		= { 0x0007C, 0x00, 0x00, 0x00 },
190 	[BAM_IRQ_SRCS_EE]	= { 0x03000, 0x00, 0x00, 0x1000 },
191 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x03004, 0x00, 0x00, 0x1000 },
192 	[BAM_P_CTRL]		= { 0x13000, 0x1000, 0x00, 0x00 },
193 	[BAM_P_RST]		= { 0x13004, 0x1000, 0x00, 0x00 },
194 	[BAM_P_HALT]		= { 0x13008, 0x1000, 0x00, 0x00 },
195 	[BAM_P_IRQ_STTS]	= { 0x13010, 0x1000, 0x00, 0x00 },
196 	[BAM_P_IRQ_CLR]		= { 0x13014, 0x1000, 0x00, 0x00 },
197 	[BAM_P_IRQ_EN]		= { 0x13018, 0x1000, 0x00, 0x00 },
198 	[BAM_P_EVNT_DEST_ADDR]	= { 0x1382C, 0x00, 0x1000, 0x00 },
199 	[BAM_P_EVNT_REG]	= { 0x13818, 0x00, 0x1000, 0x00 },
200 	[BAM_P_SW_OFSTS]	= { 0x13800, 0x00, 0x1000, 0x00 },
201 	[BAM_P_DATA_FIFO_ADDR]	= { 0x13824, 0x00, 0x1000, 0x00 },
202 	[BAM_P_DESC_FIFO_ADDR]	= { 0x1381C, 0x00, 0x1000, 0x00 },
203 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x13828, 0x00, 0x1000, 0x00 },
204 	[BAM_P_FIFO_SIZES]	= { 0x13820, 0x00, 0x1000, 0x00 },
205 };
206 
207 /* BAM CTRL */
208 #define BAM_SW_RST			BIT(0)
209 #define BAM_EN				BIT(1)
210 #define BAM_EN_ACCUM			BIT(4)
211 #define BAM_TESTBUS_SEL_SHIFT		5
212 #define BAM_TESTBUS_SEL_MASK		0x3F
213 #define BAM_DESC_CACHE_SEL_SHIFT	13
214 #define BAM_DESC_CACHE_SEL_MASK		0x3
215 #define BAM_CACHED_DESC_STORE		BIT(15)
216 #define IBC_DISABLE			BIT(16)
217 
218 /* BAM REVISION */
219 #define REVISION_SHIFT		0
220 #define REVISION_MASK		0xFF
221 #define NUM_EES_SHIFT		8
222 #define NUM_EES_MASK		0xF
223 #define CE_BUFFER_SIZE		BIT(13)
224 #define AXI_ACTIVE		BIT(14)
225 #define USE_VMIDMT		BIT(15)
226 #define SECURED			BIT(16)
227 #define BAM_HAS_NO_BYPASS	BIT(17)
228 #define HIGH_FREQUENCY_BAM	BIT(18)
229 #define INACTIV_TMRS_EXST	BIT(19)
230 #define NUM_INACTIV_TMRS	BIT(20)
231 #define DESC_CACHE_DEPTH_SHIFT	21
232 #define DESC_CACHE_DEPTH_1	(0 << DESC_CACHE_DEPTH_SHIFT)
233 #define DESC_CACHE_DEPTH_2	(1 << DESC_CACHE_DEPTH_SHIFT)
234 #define DESC_CACHE_DEPTH_3	(2 << DESC_CACHE_DEPTH_SHIFT)
235 #define DESC_CACHE_DEPTH_4	(3 << DESC_CACHE_DEPTH_SHIFT)
236 #define CMD_DESC_EN		BIT(23)
237 #define INACTIV_TMR_BASE_SHIFT	24
238 #define INACTIV_TMR_BASE_MASK	0xFF
239 
240 /* BAM NUM PIPES */
241 #define BAM_NUM_PIPES_SHIFT		0
242 #define BAM_NUM_PIPES_MASK		0xFF
243 #define PERIPH_NON_PIPE_GRP_SHIFT	16
244 #define PERIPH_NON_PIP_GRP_MASK		0xFF
245 #define BAM_NON_PIPE_GRP_SHIFT		24
246 #define BAM_NON_PIPE_GRP_MASK		0xFF
247 
248 /* BAM CNFG BITS */
249 #define BAM_PIPE_CNFG		BIT(2)
250 #define BAM_FULL_PIPE		BIT(11)
251 #define BAM_NO_EXT_P_RST	BIT(12)
252 #define BAM_IBC_DISABLE		BIT(13)
253 #define BAM_SB_CLK_REQ		BIT(14)
254 #define BAM_PSM_CSW_REQ		BIT(15)
255 #define BAM_PSM_P_RES		BIT(16)
256 #define BAM_AU_P_RES		BIT(17)
257 #define BAM_SI_P_RES		BIT(18)
258 #define BAM_WB_P_RES		BIT(19)
259 #define BAM_WB_BLK_CSW		BIT(20)
260 #define BAM_WB_CSW_ACK_IDL	BIT(21)
261 #define BAM_WB_RETR_SVPNT	BIT(22)
262 #define BAM_WB_DSC_AVL_P_RST	BIT(23)
263 #define BAM_REG_P_EN		BIT(24)
264 #define BAM_PSM_P_HD_DATA	BIT(25)
265 #define BAM_AU_ACCUMED		BIT(26)
266 #define BAM_CMD_ENABLE		BIT(27)
267 
268 #define BAM_CNFG_BITS_DEFAULT	(BAM_PIPE_CNFG |	\
269 				 BAM_NO_EXT_P_RST |	\
270 				 BAM_IBC_DISABLE |	\
271 				 BAM_SB_CLK_REQ |	\
272 				 BAM_PSM_CSW_REQ |	\
273 				 BAM_PSM_P_RES |	\
274 				 BAM_AU_P_RES |		\
275 				 BAM_SI_P_RES |		\
276 				 BAM_WB_P_RES |		\
277 				 BAM_WB_BLK_CSW |	\
278 				 BAM_WB_CSW_ACK_IDL |	\
279 				 BAM_WB_RETR_SVPNT |	\
280 				 BAM_WB_DSC_AVL_P_RST |	\
281 				 BAM_REG_P_EN |		\
282 				 BAM_PSM_P_HD_DATA |	\
283 				 BAM_AU_ACCUMED |	\
284 				 BAM_CMD_ENABLE)
285 
286 /* PIPE CTRL */
287 #define P_EN			BIT(1)
288 #define P_DIRECTION		BIT(3)
289 #define P_SYS_STRM		BIT(4)
290 #define P_SYS_MODE		BIT(5)
291 #define P_AUTO_EOB		BIT(6)
292 #define P_AUTO_EOB_SEL_SHIFT	7
293 #define P_AUTO_EOB_SEL_512	(0 << P_AUTO_EOB_SEL_SHIFT)
294 #define P_AUTO_EOB_SEL_256	(1 << P_AUTO_EOB_SEL_SHIFT)
295 #define P_AUTO_EOB_SEL_128	(2 << P_AUTO_EOB_SEL_SHIFT)
296 #define P_AUTO_EOB_SEL_64	(3 << P_AUTO_EOB_SEL_SHIFT)
297 #define P_PREFETCH_LIMIT_SHIFT	9
298 #define P_PREFETCH_LIMIT_32	(0 << P_PREFETCH_LIMIT_SHIFT)
299 #define P_PREFETCH_LIMIT_16	(1 << P_PREFETCH_LIMIT_SHIFT)
300 #define P_PREFETCH_LIMIT_4	(2 << P_PREFETCH_LIMIT_SHIFT)
301 #define P_WRITE_NWD		BIT(11)
302 #define P_LOCK_GROUP_SHIFT	16
303 #define P_LOCK_GROUP_MASK	0x1F
304 
305 /* BAM_DESC_CNT_TRSHLD */
306 #define CNT_TRSHLD		0xffff
307 #define DEFAULT_CNT_THRSHLD	0x4
308 
309 /* BAM_IRQ_SRCS */
310 #define BAM_IRQ			BIT(31)
311 #define P_IRQ			0x7fffffff
312 
313 /* BAM_IRQ_SRCS_MSK */
314 #define BAM_IRQ_MSK		BAM_IRQ
315 #define P_IRQ_MSK		P_IRQ
316 
317 /* BAM_IRQ_STTS */
318 #define BAM_TIMER_IRQ		BIT(4)
319 #define BAM_EMPTY_IRQ		BIT(3)
320 #define BAM_ERROR_IRQ		BIT(2)
321 #define BAM_HRESP_ERR_IRQ	BIT(1)
322 
323 /* BAM_IRQ_CLR */
324 #define BAM_TIMER_CLR		BIT(4)
325 #define BAM_EMPTY_CLR		BIT(3)
326 #define BAM_ERROR_CLR		BIT(2)
327 #define BAM_HRESP_ERR_CLR	BIT(1)
328 
329 /* BAM_IRQ_EN */
330 #define BAM_TIMER_EN		BIT(4)
331 #define BAM_EMPTY_EN		BIT(3)
332 #define BAM_ERROR_EN		BIT(2)
333 #define BAM_HRESP_ERR_EN	BIT(1)
334 
335 /* BAM_P_IRQ_EN */
336 #define P_PRCSD_DESC_EN		BIT(0)
337 #define P_TIMER_EN		BIT(1)
338 #define P_WAKE_EN		BIT(2)
339 #define P_OUT_OF_DESC_EN	BIT(3)
340 #define P_ERR_EN		BIT(4)
341 #define P_TRNSFR_END_EN		BIT(5)
342 #define P_DEFAULT_IRQS_EN	(P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
343 
344 /* BAM_P_SW_OFSTS */
345 #define P_SW_OFSTS_MASK		0xffff
346 
347 #define BAM_DESC_FIFO_SIZE	SZ_32K
348 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
349 #define BAM_FIFO_SIZE	(SZ_32K - 8)
350 
351 struct bam_chan {
352 	struct virt_dma_chan vc;
353 
354 	struct bam_device *bdev;
355 
356 	/* configuration from device tree */
357 	u32 id;
358 
359 	struct bam_async_desc *curr_txd;	/* current running dma */
360 
361 	/* runtime configuration */
362 	struct dma_slave_config slave;
363 
364 	/* fifo storage */
365 	struct bam_desc_hw *fifo_virt;
366 	dma_addr_t fifo_phys;
367 
368 	/* fifo markers */
369 	unsigned short head;		/* start of active descriptor entries */
370 	unsigned short tail;		/* end of active descriptor entries */
371 
372 	unsigned int initialized;	/* is the channel hw initialized? */
373 	unsigned int paused;		/* is the channel paused? */
374 	unsigned int reconfigure;	/* new slave config? */
375 
376 	struct list_head node;
377 };
378 
379 static inline struct bam_chan *to_bam_chan(struct dma_chan *common)
380 {
381 	return container_of(common, struct bam_chan, vc.chan);
382 }
383 
384 struct bam_device {
385 	void __iomem *regs;
386 	struct device *dev;
387 	struct dma_device common;
388 	struct device_dma_parameters dma_parms;
389 	struct bam_chan *channels;
390 	u32 num_channels;
391 
392 	/* execution environment ID, from DT */
393 	u32 ee;
394 	bool controlled_remotely;
395 
396 	const struct reg_offset_data *layout;
397 
398 	struct clk *bamclk;
399 	int irq;
400 
401 	/* dma start transaction tasklet */
402 	struct tasklet_struct task;
403 };
404 
405 /**
406  * bam_addr - returns BAM register address
407  * @bdev: bam device
408  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
409  * @reg:  register enum
410  */
411 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
412 		enum bam_reg reg)
413 {
414 	const struct reg_offset_data r = bdev->layout[reg];
415 
416 	return bdev->regs + r.base_offset +
417 		r.pipe_mult * pipe +
418 		r.evnt_mult * pipe +
419 		r.ee_mult * bdev->ee;
420 }
421 
422 /**
423  * bam_reset_channel - Reset individual BAM DMA channel
424  * @bchan: bam channel
425  *
426  * This function resets a specific BAM channel
427  */
428 static void bam_reset_channel(struct bam_chan *bchan)
429 {
430 	struct bam_device *bdev = bchan->bdev;
431 
432 	lockdep_assert_held(&bchan->vc.lock);
433 
434 	/* reset channel */
435 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
436 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
437 
438 	/* don't allow cpu to reorder BAM register accesses done after this */
439 	wmb();
440 
441 	/* make sure hw is initialized when channel is used the first time  */
442 	bchan->initialized = 0;
443 }
444 
445 /**
446  * bam_chan_init_hw - Initialize channel hardware
447  * @bchan: bam channel
448  *
449  * This function resets and initializes the BAM channel
450  */
451 static void bam_chan_init_hw(struct bam_chan *bchan,
452 	enum dma_transfer_direction dir)
453 {
454 	struct bam_device *bdev = bchan->bdev;
455 	u32 val;
456 
457 	/* Reset the channel to clear internal state of the FIFO */
458 	bam_reset_channel(bchan);
459 
460 	/*
461 	 * write out 8 byte aligned address.  We have enough space for this
462 	 * because we allocated 1 more descriptor (8 bytes) than we can use
463 	 */
464 	writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
465 			bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
466 	writel_relaxed(BAM_FIFO_SIZE,
467 			bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
468 
469 	/* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
470 	writel_relaxed(P_DEFAULT_IRQS_EN,
471 			bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
472 
473 	/* unmask the specific pipe and EE combo */
474 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
475 	val |= BIT(bchan->id);
476 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
477 
478 	/* don't allow cpu to reorder the channel enable done below */
479 	wmb();
480 
481 	/* set fixed direction and mode, then enable channel */
482 	val = P_EN | P_SYS_MODE;
483 	if (dir == DMA_DEV_TO_MEM)
484 		val |= P_DIRECTION;
485 
486 	writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
487 
488 	bchan->initialized = 1;
489 
490 	/* init FIFO pointers */
491 	bchan->head = 0;
492 	bchan->tail = 0;
493 }
494 
495 /**
496  * bam_alloc_chan - Allocate channel resources for DMA channel.
497  * @chan: specified channel
498  *
499  * This function allocates the FIFO descriptor memory
500  */
501 static int bam_alloc_chan(struct dma_chan *chan)
502 {
503 	struct bam_chan *bchan = to_bam_chan(chan);
504 	struct bam_device *bdev = bchan->bdev;
505 
506 	if (bchan->fifo_virt)
507 		return 0;
508 
509 	/* allocate FIFO descriptor space, but only if necessary */
510 	bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
511 					&bchan->fifo_phys, GFP_KERNEL);
512 
513 	if (!bchan->fifo_virt) {
514 		dev_err(bdev->dev, "Failed to allocate desc fifo\n");
515 		return -ENOMEM;
516 	}
517 
518 	return 0;
519 }
520 
521 /**
522  * bam_free_chan - Frees dma resources associated with specific channel
523  * @chan: specified channel
524  *
525  * Free the allocated fifo descriptor memory and channel resources
526  *
527  */
528 static void bam_free_chan(struct dma_chan *chan)
529 {
530 	struct bam_chan *bchan = to_bam_chan(chan);
531 	struct bam_device *bdev = bchan->bdev;
532 	u32 val;
533 	unsigned long flags;
534 	int ret;
535 
536 	ret = pm_runtime_get_sync(bdev->dev);
537 	if (ret < 0)
538 		return;
539 
540 	vchan_free_chan_resources(to_virt_chan(chan));
541 
542 	if (bchan->curr_txd) {
543 		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
544 		goto err;
545 	}
546 
547 	spin_lock_irqsave(&bchan->vc.lock, flags);
548 	bam_reset_channel(bchan);
549 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
550 
551 	dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
552 		    bchan->fifo_phys);
553 	bchan->fifo_virt = NULL;
554 
555 	/* mask irq for pipe/channel */
556 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
557 	val &= ~BIT(bchan->id);
558 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
559 
560 	/* disable irq */
561 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
562 
563 err:
564 	pm_runtime_mark_last_busy(bdev->dev);
565 	pm_runtime_put_autosuspend(bdev->dev);
566 }
567 
568 /**
569  * bam_slave_config - set slave configuration for channel
570  * @chan: dma channel
571  * @cfg: slave configuration
572  *
573  * Sets slave configuration for channel
574  *
575  */
576 static int bam_slave_config(struct dma_chan *chan,
577 			    struct dma_slave_config *cfg)
578 {
579 	struct bam_chan *bchan = to_bam_chan(chan);
580 	unsigned long flag;
581 
582 	spin_lock_irqsave(&bchan->vc.lock, flag);
583 	memcpy(&bchan->slave, cfg, sizeof(*cfg));
584 	bchan->reconfigure = 1;
585 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
586 
587 	return 0;
588 }
589 
590 /**
591  * bam_prep_slave_sg - Prep slave sg transaction
592  *
593  * @chan: dma channel
594  * @sgl: scatter gather list
595  * @sg_len: length of sg
596  * @direction: DMA transfer direction
597  * @flags: DMA flags
598  * @context: transfer context (unused)
599  */
600 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
601 	struct scatterlist *sgl, unsigned int sg_len,
602 	enum dma_transfer_direction direction, unsigned long flags,
603 	void *context)
604 {
605 	struct bam_chan *bchan = to_bam_chan(chan);
606 	struct bam_device *bdev = bchan->bdev;
607 	struct bam_async_desc *async_desc;
608 	struct scatterlist *sg;
609 	u32 i;
610 	struct bam_desc_hw *desc;
611 	unsigned int num_alloc = 0;
612 
613 
614 	if (!is_slave_direction(direction)) {
615 		dev_err(bdev->dev, "invalid dma direction\n");
616 		return NULL;
617 	}
618 
619 	/* calculate number of required entries */
620 	for_each_sg(sgl, sg, sg_len, i)
621 		num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE);
622 
623 	/* allocate enough room to accomodate the number of entries */
624 	async_desc = kzalloc(sizeof(*async_desc) +
625 			(num_alloc * sizeof(struct bam_desc_hw)), GFP_NOWAIT);
626 
627 	if (!async_desc)
628 		goto err_out;
629 
630 	if (flags & DMA_PREP_FENCE)
631 		async_desc->flags |= DESC_FLAG_NWD;
632 
633 	if (flags & DMA_PREP_INTERRUPT)
634 		async_desc->flags |= DESC_FLAG_EOT;
635 	else
636 		async_desc->flags |= DESC_FLAG_INT;
637 
638 	async_desc->num_desc = num_alloc;
639 	async_desc->curr_desc = async_desc->desc;
640 	async_desc->dir = direction;
641 
642 	/* fill in temporary descriptors */
643 	desc = async_desc->desc;
644 	for_each_sg(sgl, sg, sg_len, i) {
645 		unsigned int remainder = sg_dma_len(sg);
646 		unsigned int curr_offset = 0;
647 
648 		do {
649 			if (flags & DMA_PREP_CMD)
650 				desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
651 
652 			desc->addr = cpu_to_le32(sg_dma_address(sg) +
653 						 curr_offset);
654 
655 			if (remainder > BAM_FIFO_SIZE) {
656 				desc->size = cpu_to_le16(BAM_FIFO_SIZE);
657 				remainder -= BAM_FIFO_SIZE;
658 				curr_offset += BAM_FIFO_SIZE;
659 			} else {
660 				desc->size = cpu_to_le16(remainder);
661 				remainder = 0;
662 			}
663 
664 			async_desc->length += desc->size;
665 			desc++;
666 		} while (remainder > 0);
667 	}
668 
669 	return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
670 
671 err_out:
672 	kfree(async_desc);
673 	return NULL;
674 }
675 
676 /**
677  * bam_dma_terminate_all - terminate all transactions on a channel
678  * @bchan: bam dma channel
679  *
680  * Dequeues and frees all transactions
681  * No callbacks are done
682  *
683  */
684 static int bam_dma_terminate_all(struct dma_chan *chan)
685 {
686 	struct bam_chan *bchan = to_bam_chan(chan);
687 	unsigned long flag;
688 	LIST_HEAD(head);
689 
690 	/* remove all transactions, including active transaction */
691 	spin_lock_irqsave(&bchan->vc.lock, flag);
692 	if (bchan->curr_txd) {
693 		list_add(&bchan->curr_txd->vd.node, &bchan->vc.desc_issued);
694 		bchan->curr_txd = NULL;
695 	}
696 
697 	vchan_get_all_descriptors(&bchan->vc, &head);
698 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
699 
700 	vchan_dma_desc_free_list(&bchan->vc, &head);
701 
702 	return 0;
703 }
704 
705 /**
706  * bam_pause - Pause DMA channel
707  * @chan: dma channel
708  *
709  */
710 static int bam_pause(struct dma_chan *chan)
711 {
712 	struct bam_chan *bchan = to_bam_chan(chan);
713 	struct bam_device *bdev = bchan->bdev;
714 	unsigned long flag;
715 	int ret;
716 
717 	ret = pm_runtime_get_sync(bdev->dev);
718 	if (ret < 0)
719 		return ret;
720 
721 	spin_lock_irqsave(&bchan->vc.lock, flag);
722 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
723 	bchan->paused = 1;
724 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
725 	pm_runtime_mark_last_busy(bdev->dev);
726 	pm_runtime_put_autosuspend(bdev->dev);
727 
728 	return 0;
729 }
730 
731 /**
732  * bam_resume - Resume DMA channel operations
733  * @chan: dma channel
734  *
735  */
736 static int bam_resume(struct dma_chan *chan)
737 {
738 	struct bam_chan *bchan = to_bam_chan(chan);
739 	struct bam_device *bdev = bchan->bdev;
740 	unsigned long flag;
741 	int ret;
742 
743 	ret = pm_runtime_get_sync(bdev->dev);
744 	if (ret < 0)
745 		return ret;
746 
747 	spin_lock_irqsave(&bchan->vc.lock, flag);
748 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
749 	bchan->paused = 0;
750 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
751 	pm_runtime_mark_last_busy(bdev->dev);
752 	pm_runtime_put_autosuspend(bdev->dev);
753 
754 	return 0;
755 }
756 
757 /**
758  * process_channel_irqs - processes the channel interrupts
759  * @bdev: bam controller
760  *
761  * This function processes the channel interrupts
762  *
763  */
764 static u32 process_channel_irqs(struct bam_device *bdev)
765 {
766 	u32 i, srcs, pipe_stts;
767 	unsigned long flags;
768 	struct bam_async_desc *async_desc;
769 
770 	srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
771 
772 	/* return early if no pipe/channel interrupts are present */
773 	if (!(srcs & P_IRQ))
774 		return srcs;
775 
776 	for (i = 0; i < bdev->num_channels; i++) {
777 		struct bam_chan *bchan = &bdev->channels[i];
778 
779 		if (!(srcs & BIT(i)))
780 			continue;
781 
782 		/* clear pipe irq */
783 		pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
784 
785 		writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
786 
787 		spin_lock_irqsave(&bchan->vc.lock, flags);
788 		async_desc = bchan->curr_txd;
789 
790 		if (async_desc) {
791 			async_desc->num_desc -= async_desc->xfer_len;
792 			async_desc->curr_desc += async_desc->xfer_len;
793 			bchan->curr_txd = NULL;
794 
795 			/* manage FIFO */
796 			bchan->head += async_desc->xfer_len;
797 			bchan->head %= MAX_DESCRIPTORS;
798 
799 			/*
800 			 * if complete, process cookie.  Otherwise
801 			 * push back to front of desc_issued so that
802 			 * it gets restarted by the tasklet
803 			 */
804 			if (!async_desc->num_desc)
805 				vchan_cookie_complete(&async_desc->vd);
806 			else
807 				list_add(&async_desc->vd.node,
808 					&bchan->vc.desc_issued);
809 		}
810 
811 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
812 	}
813 
814 	return srcs;
815 }
816 
817 /**
818  * bam_dma_irq - irq handler for bam controller
819  * @irq: IRQ of interrupt
820  * @data: callback data
821  *
822  * IRQ handler for the bam controller
823  */
824 static irqreturn_t bam_dma_irq(int irq, void *data)
825 {
826 	struct bam_device *bdev = data;
827 	u32 clr_mask = 0, srcs = 0;
828 	int ret;
829 
830 	srcs |= process_channel_irqs(bdev);
831 
832 	/* kick off tasklet to start next dma transfer */
833 	if (srcs & P_IRQ)
834 		tasklet_schedule(&bdev->task);
835 
836 	ret = pm_runtime_get_sync(bdev->dev);
837 	if (ret < 0)
838 		return ret;
839 
840 	if (srcs & BAM_IRQ) {
841 		clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
842 
843 		/*
844 		 * don't allow reorder of the various accesses to the BAM
845 		 * registers
846 		 */
847 		mb();
848 
849 		writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
850 	}
851 
852 	pm_runtime_mark_last_busy(bdev->dev);
853 	pm_runtime_put_autosuspend(bdev->dev);
854 
855 	return IRQ_HANDLED;
856 }
857 
858 /**
859  * bam_tx_status - returns status of transaction
860  * @chan: dma channel
861  * @cookie: transaction cookie
862  * @txstate: DMA transaction state
863  *
864  * Return status of dma transaction
865  */
866 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
867 		struct dma_tx_state *txstate)
868 {
869 	struct bam_chan *bchan = to_bam_chan(chan);
870 	struct virt_dma_desc *vd;
871 	int ret;
872 	size_t residue = 0;
873 	unsigned int i;
874 	unsigned long flags;
875 
876 	ret = dma_cookie_status(chan, cookie, txstate);
877 	if (ret == DMA_COMPLETE)
878 		return ret;
879 
880 	if (!txstate)
881 		return bchan->paused ? DMA_PAUSED : ret;
882 
883 	spin_lock_irqsave(&bchan->vc.lock, flags);
884 	vd = vchan_find_desc(&bchan->vc, cookie);
885 	if (vd)
886 		residue = container_of(vd, struct bam_async_desc, vd)->length;
887 	else if (bchan->curr_txd && bchan->curr_txd->vd.tx.cookie == cookie)
888 		for (i = 0; i < bchan->curr_txd->num_desc; i++)
889 			residue += bchan->curr_txd->curr_desc[i].size;
890 
891 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
892 
893 	dma_set_residue(txstate, residue);
894 
895 	if (ret == DMA_IN_PROGRESS && bchan->paused)
896 		ret = DMA_PAUSED;
897 
898 	return ret;
899 }
900 
901 /**
902  * bam_apply_new_config
903  * @bchan: bam dma channel
904  * @dir: DMA direction
905  */
906 static void bam_apply_new_config(struct bam_chan *bchan,
907 	enum dma_transfer_direction dir)
908 {
909 	struct bam_device *bdev = bchan->bdev;
910 	u32 maxburst;
911 
912 	if (dir == DMA_DEV_TO_MEM)
913 		maxburst = bchan->slave.src_maxburst;
914 	else
915 		maxburst = bchan->slave.dst_maxburst;
916 
917 	writel_relaxed(maxburst, bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
918 
919 	bchan->reconfigure = 0;
920 }
921 
922 /**
923  * bam_start_dma - start next transaction
924  * @bchan - bam dma channel
925  */
926 static void bam_start_dma(struct bam_chan *bchan)
927 {
928 	struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
929 	struct bam_device *bdev = bchan->bdev;
930 	struct bam_async_desc *async_desc;
931 	struct bam_desc_hw *desc;
932 	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
933 					sizeof(struct bam_desc_hw));
934 	int ret;
935 
936 	lockdep_assert_held(&bchan->vc.lock);
937 
938 	if (!vd)
939 		return;
940 
941 	list_del(&vd->node);
942 
943 	async_desc = container_of(vd, struct bam_async_desc, vd);
944 	bchan->curr_txd = async_desc;
945 
946 	ret = pm_runtime_get_sync(bdev->dev);
947 	if (ret < 0)
948 		return;
949 
950 	/* on first use, initialize the channel hardware */
951 	if (!bchan->initialized)
952 		bam_chan_init_hw(bchan, async_desc->dir);
953 
954 	/* apply new slave config changes, if necessary */
955 	if (bchan->reconfigure)
956 		bam_apply_new_config(bchan, async_desc->dir);
957 
958 	desc = bchan->curr_txd->curr_desc;
959 
960 	if (async_desc->num_desc > MAX_DESCRIPTORS)
961 		async_desc->xfer_len = MAX_DESCRIPTORS;
962 	else
963 		async_desc->xfer_len = async_desc->num_desc;
964 
965 	/* set any special flags on the last descriptor */
966 	if (async_desc->num_desc == async_desc->xfer_len)
967 		desc[async_desc->xfer_len - 1].flags |=
968 					cpu_to_le16(async_desc->flags);
969 	else
970 		desc[async_desc->xfer_len - 1].flags |=
971 					cpu_to_le16(DESC_FLAG_INT);
972 
973 	if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
974 		u32 partial = MAX_DESCRIPTORS - bchan->tail;
975 
976 		memcpy(&fifo[bchan->tail], desc,
977 				partial * sizeof(struct bam_desc_hw));
978 		memcpy(fifo, &desc[partial], (async_desc->xfer_len - partial) *
979 				sizeof(struct bam_desc_hw));
980 	} else {
981 		memcpy(&fifo[bchan->tail], desc,
982 			async_desc->xfer_len * sizeof(struct bam_desc_hw));
983 	}
984 
985 	bchan->tail += async_desc->xfer_len;
986 	bchan->tail %= MAX_DESCRIPTORS;
987 
988 	/* ensure descriptor writes and dma start not reordered */
989 	wmb();
990 	writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
991 			bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
992 
993 	pm_runtime_mark_last_busy(bdev->dev);
994 	pm_runtime_put_autosuspend(bdev->dev);
995 }
996 
997 /**
998  * dma_tasklet - DMA IRQ tasklet
999  * @data: tasklet argument (bam controller structure)
1000  *
1001  * Sets up next DMA operation and then processes all completed transactions
1002  */
1003 static void dma_tasklet(unsigned long data)
1004 {
1005 	struct bam_device *bdev = (struct bam_device *)data;
1006 	struct bam_chan *bchan;
1007 	unsigned long flags;
1008 	unsigned int i;
1009 
1010 	/* go through the channels and kick off transactions */
1011 	for (i = 0; i < bdev->num_channels; i++) {
1012 		bchan = &bdev->channels[i];
1013 		spin_lock_irqsave(&bchan->vc.lock, flags);
1014 
1015 		if (!list_empty(&bchan->vc.desc_issued) && !bchan->curr_txd)
1016 			bam_start_dma(bchan);
1017 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
1018 	}
1019 
1020 }
1021 
1022 /**
1023  * bam_issue_pending - starts pending transactions
1024  * @chan: dma channel
1025  *
1026  * Calls tasklet directly which in turn starts any pending transactions
1027  */
1028 static void bam_issue_pending(struct dma_chan *chan)
1029 {
1030 	struct bam_chan *bchan = to_bam_chan(chan);
1031 	unsigned long flags;
1032 
1033 	spin_lock_irqsave(&bchan->vc.lock, flags);
1034 
1035 	/* if work pending and idle, start a transaction */
1036 	if (vchan_issue_pending(&bchan->vc) && !bchan->curr_txd)
1037 		bam_start_dma(bchan);
1038 
1039 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
1040 }
1041 
1042 /**
1043  * bam_dma_free_desc - free descriptor memory
1044  * @vd: virtual descriptor
1045  *
1046  */
1047 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1048 {
1049 	struct bam_async_desc *async_desc = container_of(vd,
1050 			struct bam_async_desc, vd);
1051 
1052 	kfree(async_desc);
1053 }
1054 
1055 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1056 		struct of_dma *of)
1057 {
1058 	struct bam_device *bdev = container_of(of->of_dma_data,
1059 					struct bam_device, common);
1060 	unsigned int request;
1061 
1062 	if (dma_spec->args_count != 1)
1063 		return NULL;
1064 
1065 	request = dma_spec->args[0];
1066 	if (request >= bdev->num_channels)
1067 		return NULL;
1068 
1069 	return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1070 }
1071 
1072 /**
1073  * bam_init
1074  * @bdev: bam device
1075  *
1076  * Initialization helper for global bam registers
1077  */
1078 static int bam_init(struct bam_device *bdev)
1079 {
1080 	u32 val;
1081 
1082 	/* read revision and configuration information */
1083 	val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)) >> NUM_EES_SHIFT;
1084 	val &= NUM_EES_MASK;
1085 
1086 	/* check that configured EE is within range */
1087 	if (bdev->ee >= val)
1088 		return -EINVAL;
1089 
1090 	val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1091 	bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1092 
1093 	if (bdev->controlled_remotely)
1094 		return 0;
1095 
1096 	/* s/w reset bam */
1097 	/* after reset all pipes are disabled and idle */
1098 	val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
1099 	val |= BAM_SW_RST;
1100 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1101 	val &= ~BAM_SW_RST;
1102 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1103 
1104 	/* make sure previous stores are visible before enabling BAM */
1105 	wmb();
1106 
1107 	/* enable bam */
1108 	val |= BAM_EN;
1109 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1110 
1111 	/* set descriptor threshhold, start with 4 bytes */
1112 	writel_relaxed(DEFAULT_CNT_THRSHLD,
1113 			bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1114 
1115 	/* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
1116 	writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
1117 
1118 	/* enable irqs for errors */
1119 	writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
1120 			bam_addr(bdev, 0, BAM_IRQ_EN));
1121 
1122 	/* unmask global bam interrupt */
1123 	writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
1124 
1125 	return 0;
1126 }
1127 
1128 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1129 	u32 index)
1130 {
1131 	bchan->id = index;
1132 	bchan->bdev = bdev;
1133 
1134 	vchan_init(&bchan->vc, &bdev->common);
1135 	bchan->vc.desc_free = bam_dma_free_desc;
1136 }
1137 
1138 static const struct of_device_id bam_of_match[] = {
1139 	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1140 	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1141 	{ .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1142 	{}
1143 };
1144 
1145 MODULE_DEVICE_TABLE(of, bam_of_match);
1146 
1147 static int bam_dma_probe(struct platform_device *pdev)
1148 {
1149 	struct bam_device *bdev;
1150 	const struct of_device_id *match;
1151 	struct resource *iores;
1152 	int ret, i;
1153 
1154 	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1155 	if (!bdev)
1156 		return -ENOMEM;
1157 
1158 	bdev->dev = &pdev->dev;
1159 
1160 	match = of_match_node(bam_of_match, pdev->dev.of_node);
1161 	if (!match) {
1162 		dev_err(&pdev->dev, "Unsupported BAM module\n");
1163 		return -ENODEV;
1164 	}
1165 
1166 	bdev->layout = match->data;
1167 
1168 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1169 	bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
1170 	if (IS_ERR(bdev->regs))
1171 		return PTR_ERR(bdev->regs);
1172 
1173 	bdev->irq = platform_get_irq(pdev, 0);
1174 	if (bdev->irq < 0)
1175 		return bdev->irq;
1176 
1177 	ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1178 	if (ret) {
1179 		dev_err(bdev->dev, "Execution environment unspecified\n");
1180 		return ret;
1181 	}
1182 
1183 	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
1184 						"qcom,controlled-remotely");
1185 
1186 	bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1187 	if (IS_ERR(bdev->bamclk))
1188 		return PTR_ERR(bdev->bamclk);
1189 
1190 	ret = clk_prepare_enable(bdev->bamclk);
1191 	if (ret) {
1192 		dev_err(bdev->dev, "failed to prepare/enable clock\n");
1193 		return ret;
1194 	}
1195 
1196 	ret = bam_init(bdev);
1197 	if (ret)
1198 		goto err_disable_clk;
1199 
1200 	tasklet_init(&bdev->task, dma_tasklet, (unsigned long)bdev);
1201 
1202 	bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1203 				sizeof(*bdev->channels), GFP_KERNEL);
1204 
1205 	if (!bdev->channels) {
1206 		ret = -ENOMEM;
1207 		goto err_tasklet_kill;
1208 	}
1209 
1210 	/* allocate and initialize channels */
1211 	INIT_LIST_HEAD(&bdev->common.channels);
1212 
1213 	for (i = 0; i < bdev->num_channels; i++)
1214 		bam_channel_init(bdev, &bdev->channels[i], i);
1215 
1216 	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1217 			IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1218 	if (ret)
1219 		goto err_bam_channel_exit;
1220 
1221 	/* set max dma segment size */
1222 	bdev->common.dev = bdev->dev;
1223 	bdev->common.dev->dma_parms = &bdev->dma_parms;
1224 	ret = dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1225 	if (ret) {
1226 		dev_err(bdev->dev, "cannot set maximum segment size\n");
1227 		goto err_bam_channel_exit;
1228 	}
1229 
1230 	platform_set_drvdata(pdev, bdev);
1231 
1232 	/* set capabilities */
1233 	dma_cap_zero(bdev->common.cap_mask);
1234 	dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1235 
1236 	/* initialize dmaengine apis */
1237 	bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1238 	bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1239 	bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1240 	bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1241 	bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1242 	bdev->common.device_free_chan_resources = bam_free_chan;
1243 	bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1244 	bdev->common.device_config = bam_slave_config;
1245 	bdev->common.device_pause = bam_pause;
1246 	bdev->common.device_resume = bam_resume;
1247 	bdev->common.device_terminate_all = bam_dma_terminate_all;
1248 	bdev->common.device_issue_pending = bam_issue_pending;
1249 	bdev->common.device_tx_status = bam_tx_status;
1250 	bdev->common.dev = bdev->dev;
1251 
1252 	ret = dma_async_device_register(&bdev->common);
1253 	if (ret) {
1254 		dev_err(bdev->dev, "failed to register dma async device\n");
1255 		goto err_bam_channel_exit;
1256 	}
1257 
1258 	ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1259 					&bdev->common);
1260 	if (ret)
1261 		goto err_unregister_dma;
1262 
1263 	pm_runtime_irq_safe(&pdev->dev);
1264 	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
1265 	pm_runtime_use_autosuspend(&pdev->dev);
1266 	pm_runtime_mark_last_busy(&pdev->dev);
1267 	pm_runtime_set_active(&pdev->dev);
1268 	pm_runtime_enable(&pdev->dev);
1269 
1270 	return 0;
1271 
1272 err_unregister_dma:
1273 	dma_async_device_unregister(&bdev->common);
1274 err_bam_channel_exit:
1275 	for (i = 0; i < bdev->num_channels; i++)
1276 		tasklet_kill(&bdev->channels[i].vc.task);
1277 err_tasklet_kill:
1278 	tasklet_kill(&bdev->task);
1279 err_disable_clk:
1280 	clk_disable_unprepare(bdev->bamclk);
1281 
1282 	return ret;
1283 }
1284 
1285 static int bam_dma_remove(struct platform_device *pdev)
1286 {
1287 	struct bam_device *bdev = platform_get_drvdata(pdev);
1288 	u32 i;
1289 
1290 	pm_runtime_force_suspend(&pdev->dev);
1291 
1292 	of_dma_controller_free(pdev->dev.of_node);
1293 	dma_async_device_unregister(&bdev->common);
1294 
1295 	/* mask all interrupts for this execution environment */
1296 	writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1297 
1298 	devm_free_irq(bdev->dev, bdev->irq, bdev);
1299 
1300 	for (i = 0; i < bdev->num_channels; i++) {
1301 		bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1302 		tasklet_kill(&bdev->channels[i].vc.task);
1303 
1304 		if (!bdev->channels[i].fifo_virt)
1305 			continue;
1306 
1307 		dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1308 			    bdev->channels[i].fifo_virt,
1309 			    bdev->channels[i].fifo_phys);
1310 	}
1311 
1312 	tasklet_kill(&bdev->task);
1313 
1314 	clk_disable_unprepare(bdev->bamclk);
1315 
1316 	return 0;
1317 }
1318 
1319 static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
1320 {
1321 	struct bam_device *bdev = dev_get_drvdata(dev);
1322 
1323 	clk_disable(bdev->bamclk);
1324 
1325 	return 0;
1326 }
1327 
1328 static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
1329 {
1330 	struct bam_device *bdev = dev_get_drvdata(dev);
1331 	int ret;
1332 
1333 	ret = clk_enable(bdev->bamclk);
1334 	if (ret < 0) {
1335 		dev_err(dev, "clk_enable failed: %d\n", ret);
1336 		return ret;
1337 	}
1338 
1339 	return 0;
1340 }
1341 
1342 static int __maybe_unused bam_dma_suspend(struct device *dev)
1343 {
1344 	struct bam_device *bdev = dev_get_drvdata(dev);
1345 
1346 	pm_runtime_force_suspend(dev);
1347 
1348 	clk_unprepare(bdev->bamclk);
1349 
1350 	return 0;
1351 }
1352 
1353 static int __maybe_unused bam_dma_resume(struct device *dev)
1354 {
1355 	struct bam_device *bdev = dev_get_drvdata(dev);
1356 	int ret;
1357 
1358 	ret = clk_prepare(bdev->bamclk);
1359 	if (ret)
1360 		return ret;
1361 
1362 	pm_runtime_force_resume(dev);
1363 
1364 	return 0;
1365 }
1366 
1367 static const struct dev_pm_ops bam_dma_pm_ops = {
1368 	SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
1369 	SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
1370 				NULL)
1371 };
1372 
1373 static struct platform_driver bam_dma_driver = {
1374 	.probe = bam_dma_probe,
1375 	.remove = bam_dma_remove,
1376 	.driver = {
1377 		.name = "bam-dma-engine",
1378 		.pm = &bam_dma_pm_ops,
1379 		.of_match_table = bam_of_match,
1380 	},
1381 };
1382 
1383 module_platform_driver(bam_dma_driver);
1384 
1385 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1386 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1387 MODULE_LICENSE("GPL v2");
1388