xref: /openbmc/linux/drivers/dma/qcom/bam_dma.c (revision 32981ea5)
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 
52 #include "../dmaengine.h"
53 #include "../virt-dma.h"
54 
55 struct bam_desc_hw {
56 	__le32 addr;		/* Buffer physical address */
57 	__le16 size;		/* Buffer size in bytes */
58 	__le16 flags;
59 };
60 
61 #define DESC_FLAG_INT BIT(15)
62 #define DESC_FLAG_EOT BIT(14)
63 #define DESC_FLAG_EOB BIT(13)
64 #define DESC_FLAG_NWD BIT(12)
65 
66 struct bam_async_desc {
67 	struct virt_dma_desc vd;
68 
69 	u32 num_desc;
70 	u32 xfer_len;
71 
72 	/* transaction flags, EOT|EOB|NWD */
73 	u16 flags;
74 
75 	struct bam_desc_hw *curr_desc;
76 
77 	enum dma_transfer_direction dir;
78 	size_t length;
79 	struct bam_desc_hw desc[0];
80 };
81 
82 enum bam_reg {
83 	BAM_CTRL,
84 	BAM_REVISION,
85 	BAM_NUM_PIPES,
86 	BAM_DESC_CNT_TRSHLD,
87 	BAM_IRQ_SRCS,
88 	BAM_IRQ_SRCS_MSK,
89 	BAM_IRQ_SRCS_UNMASKED,
90 	BAM_IRQ_STTS,
91 	BAM_IRQ_CLR,
92 	BAM_IRQ_EN,
93 	BAM_CNFG_BITS,
94 	BAM_IRQ_SRCS_EE,
95 	BAM_IRQ_SRCS_MSK_EE,
96 	BAM_P_CTRL,
97 	BAM_P_RST,
98 	BAM_P_HALT,
99 	BAM_P_IRQ_STTS,
100 	BAM_P_IRQ_CLR,
101 	BAM_P_IRQ_EN,
102 	BAM_P_EVNT_DEST_ADDR,
103 	BAM_P_EVNT_REG,
104 	BAM_P_SW_OFSTS,
105 	BAM_P_DATA_FIFO_ADDR,
106 	BAM_P_DESC_FIFO_ADDR,
107 	BAM_P_EVNT_GEN_TRSHLD,
108 	BAM_P_FIFO_SIZES,
109 };
110 
111 struct reg_offset_data {
112 	u32 base_offset;
113 	unsigned int pipe_mult, evnt_mult, ee_mult;
114 };
115 
116 static const struct reg_offset_data bam_v1_3_reg_info[] = {
117 	[BAM_CTRL]		= { 0x0F80, 0x00, 0x00, 0x00 },
118 	[BAM_REVISION]		= { 0x0F84, 0x00, 0x00, 0x00 },
119 	[BAM_NUM_PIPES]		= { 0x0FBC, 0x00, 0x00, 0x00 },
120 	[BAM_DESC_CNT_TRSHLD]	= { 0x0F88, 0x00, 0x00, 0x00 },
121 	[BAM_IRQ_SRCS]		= { 0x0F8C, 0x00, 0x00, 0x00 },
122 	[BAM_IRQ_SRCS_MSK]	= { 0x0F90, 0x00, 0x00, 0x00 },
123 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0FB0, 0x00, 0x00, 0x00 },
124 	[BAM_IRQ_STTS]		= { 0x0F94, 0x00, 0x00, 0x00 },
125 	[BAM_IRQ_CLR]		= { 0x0F98, 0x00, 0x00, 0x00 },
126 	[BAM_IRQ_EN]		= { 0x0F9C, 0x00, 0x00, 0x00 },
127 	[BAM_CNFG_BITS]		= { 0x0FFC, 0x00, 0x00, 0x00 },
128 	[BAM_IRQ_SRCS_EE]	= { 0x1800, 0x00, 0x00, 0x80 },
129 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x1804, 0x00, 0x00, 0x80 },
130 	[BAM_P_CTRL]		= { 0x0000, 0x80, 0x00, 0x00 },
131 	[BAM_P_RST]		= { 0x0004, 0x80, 0x00, 0x00 },
132 	[BAM_P_HALT]		= { 0x0008, 0x80, 0x00, 0x00 },
133 	[BAM_P_IRQ_STTS]	= { 0x0010, 0x80, 0x00, 0x00 },
134 	[BAM_P_IRQ_CLR]		= { 0x0014, 0x80, 0x00, 0x00 },
135 	[BAM_P_IRQ_EN]		= { 0x0018, 0x80, 0x00, 0x00 },
136 	[BAM_P_EVNT_DEST_ADDR]	= { 0x102C, 0x00, 0x40, 0x00 },
137 	[BAM_P_EVNT_REG]	= { 0x1018, 0x00, 0x40, 0x00 },
138 	[BAM_P_SW_OFSTS]	= { 0x1000, 0x00, 0x40, 0x00 },
139 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1024, 0x00, 0x40, 0x00 },
140 	[BAM_P_DESC_FIFO_ADDR]	= { 0x101C, 0x00, 0x40, 0x00 },
141 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1028, 0x00, 0x40, 0x00 },
142 	[BAM_P_FIFO_SIZES]	= { 0x1020, 0x00, 0x40, 0x00 },
143 };
144 
145 static const struct reg_offset_data bam_v1_4_reg_info[] = {
146 	[BAM_CTRL]		= { 0x0000, 0x00, 0x00, 0x00 },
147 	[BAM_REVISION]		= { 0x0004, 0x00, 0x00, 0x00 },
148 	[BAM_NUM_PIPES]		= { 0x003C, 0x00, 0x00, 0x00 },
149 	[BAM_DESC_CNT_TRSHLD]	= { 0x0008, 0x00, 0x00, 0x00 },
150 	[BAM_IRQ_SRCS]		= { 0x000C, 0x00, 0x00, 0x00 },
151 	[BAM_IRQ_SRCS_MSK]	= { 0x0010, 0x00, 0x00, 0x00 },
152 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0030, 0x00, 0x00, 0x00 },
153 	[BAM_IRQ_STTS]		= { 0x0014, 0x00, 0x00, 0x00 },
154 	[BAM_IRQ_CLR]		= { 0x0018, 0x00, 0x00, 0x00 },
155 	[BAM_IRQ_EN]		= { 0x001C, 0x00, 0x00, 0x00 },
156 	[BAM_CNFG_BITS]		= { 0x007C, 0x00, 0x00, 0x00 },
157 	[BAM_IRQ_SRCS_EE]	= { 0x0800, 0x00, 0x00, 0x80 },
158 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x0804, 0x00, 0x00, 0x80 },
159 	[BAM_P_CTRL]		= { 0x1000, 0x1000, 0x00, 0x00 },
160 	[BAM_P_RST]		= { 0x1004, 0x1000, 0x00, 0x00 },
161 	[BAM_P_HALT]		= { 0x1008, 0x1000, 0x00, 0x00 },
162 	[BAM_P_IRQ_STTS]	= { 0x1010, 0x1000, 0x00, 0x00 },
163 	[BAM_P_IRQ_CLR]		= { 0x1014, 0x1000, 0x00, 0x00 },
164 	[BAM_P_IRQ_EN]		= { 0x1018, 0x1000, 0x00, 0x00 },
165 	[BAM_P_EVNT_DEST_ADDR]	= { 0x182C, 0x00, 0x1000, 0x00 },
166 	[BAM_P_EVNT_REG]	= { 0x1818, 0x00, 0x1000, 0x00 },
167 	[BAM_P_SW_OFSTS]	= { 0x1800, 0x00, 0x1000, 0x00 },
168 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1824, 0x00, 0x1000, 0x00 },
169 	[BAM_P_DESC_FIFO_ADDR]	= { 0x181C, 0x00, 0x1000, 0x00 },
170 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1828, 0x00, 0x1000, 0x00 },
171 	[BAM_P_FIFO_SIZES]	= { 0x1820, 0x00, 0x1000, 0x00 },
172 };
173 
174 static const struct reg_offset_data bam_v1_7_reg_info[] = {
175 	[BAM_CTRL]		= { 0x00000, 0x00, 0x00, 0x00 },
176 	[BAM_REVISION]		= { 0x01000, 0x00, 0x00, 0x00 },
177 	[BAM_NUM_PIPES]		= { 0x01008, 0x00, 0x00, 0x00 },
178 	[BAM_DESC_CNT_TRSHLD]	= { 0x00008, 0x00, 0x00, 0x00 },
179 	[BAM_IRQ_SRCS]		= { 0x03010, 0x00, 0x00, 0x00 },
180 	[BAM_IRQ_SRCS_MSK]	= { 0x03014, 0x00, 0x00, 0x00 },
181 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x03018, 0x00, 0x00, 0x00 },
182 	[BAM_IRQ_STTS]		= { 0x00014, 0x00, 0x00, 0x00 },
183 	[BAM_IRQ_CLR]		= { 0x00018, 0x00, 0x00, 0x00 },
184 	[BAM_IRQ_EN]		= { 0x0001C, 0x00, 0x00, 0x00 },
185 	[BAM_CNFG_BITS]		= { 0x0007C, 0x00, 0x00, 0x00 },
186 	[BAM_IRQ_SRCS_EE]	= { 0x03000, 0x00, 0x00, 0x1000 },
187 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x03004, 0x00, 0x00, 0x1000 },
188 	[BAM_P_CTRL]		= { 0x13000, 0x1000, 0x00, 0x00 },
189 	[BAM_P_RST]		= { 0x13004, 0x1000, 0x00, 0x00 },
190 	[BAM_P_HALT]		= { 0x13008, 0x1000, 0x00, 0x00 },
191 	[BAM_P_IRQ_STTS]	= { 0x13010, 0x1000, 0x00, 0x00 },
192 	[BAM_P_IRQ_CLR]		= { 0x13014, 0x1000, 0x00, 0x00 },
193 	[BAM_P_IRQ_EN]		= { 0x13018, 0x1000, 0x00, 0x00 },
194 	[BAM_P_EVNT_DEST_ADDR]	= { 0x1382C, 0x00, 0x1000, 0x00 },
195 	[BAM_P_EVNT_REG]	= { 0x13818, 0x00, 0x1000, 0x00 },
196 	[BAM_P_SW_OFSTS]	= { 0x13800, 0x00, 0x1000, 0x00 },
197 	[BAM_P_DATA_FIFO_ADDR]	= { 0x13824, 0x00, 0x1000, 0x00 },
198 	[BAM_P_DESC_FIFO_ADDR]	= { 0x1381C, 0x00, 0x1000, 0x00 },
199 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x13828, 0x00, 0x1000, 0x00 },
200 	[BAM_P_FIFO_SIZES]	= { 0x13820, 0x00, 0x1000, 0x00 },
201 };
202 
203 /* BAM CTRL */
204 #define BAM_SW_RST			BIT(0)
205 #define BAM_EN				BIT(1)
206 #define BAM_EN_ACCUM			BIT(4)
207 #define BAM_TESTBUS_SEL_SHIFT		5
208 #define BAM_TESTBUS_SEL_MASK		0x3F
209 #define BAM_DESC_CACHE_SEL_SHIFT	13
210 #define BAM_DESC_CACHE_SEL_MASK		0x3
211 #define BAM_CACHED_DESC_STORE		BIT(15)
212 #define IBC_DISABLE			BIT(16)
213 
214 /* BAM REVISION */
215 #define REVISION_SHIFT		0
216 #define REVISION_MASK		0xFF
217 #define NUM_EES_SHIFT		8
218 #define NUM_EES_MASK		0xF
219 #define CE_BUFFER_SIZE		BIT(13)
220 #define AXI_ACTIVE		BIT(14)
221 #define USE_VMIDMT		BIT(15)
222 #define SECURED			BIT(16)
223 #define BAM_HAS_NO_BYPASS	BIT(17)
224 #define HIGH_FREQUENCY_BAM	BIT(18)
225 #define INACTIV_TMRS_EXST	BIT(19)
226 #define NUM_INACTIV_TMRS	BIT(20)
227 #define DESC_CACHE_DEPTH_SHIFT	21
228 #define DESC_CACHE_DEPTH_1	(0 << DESC_CACHE_DEPTH_SHIFT)
229 #define DESC_CACHE_DEPTH_2	(1 << DESC_CACHE_DEPTH_SHIFT)
230 #define DESC_CACHE_DEPTH_3	(2 << DESC_CACHE_DEPTH_SHIFT)
231 #define DESC_CACHE_DEPTH_4	(3 << DESC_CACHE_DEPTH_SHIFT)
232 #define CMD_DESC_EN		BIT(23)
233 #define INACTIV_TMR_BASE_SHIFT	24
234 #define INACTIV_TMR_BASE_MASK	0xFF
235 
236 /* BAM NUM PIPES */
237 #define BAM_NUM_PIPES_SHIFT		0
238 #define BAM_NUM_PIPES_MASK		0xFF
239 #define PERIPH_NON_PIPE_GRP_SHIFT	16
240 #define PERIPH_NON_PIP_GRP_MASK		0xFF
241 #define BAM_NON_PIPE_GRP_SHIFT		24
242 #define BAM_NON_PIPE_GRP_MASK		0xFF
243 
244 /* BAM CNFG BITS */
245 #define BAM_PIPE_CNFG		BIT(2)
246 #define BAM_FULL_PIPE		BIT(11)
247 #define BAM_NO_EXT_P_RST	BIT(12)
248 #define BAM_IBC_DISABLE		BIT(13)
249 #define BAM_SB_CLK_REQ		BIT(14)
250 #define BAM_PSM_CSW_REQ		BIT(15)
251 #define BAM_PSM_P_RES		BIT(16)
252 #define BAM_AU_P_RES		BIT(17)
253 #define BAM_SI_P_RES		BIT(18)
254 #define BAM_WB_P_RES		BIT(19)
255 #define BAM_WB_BLK_CSW		BIT(20)
256 #define BAM_WB_CSW_ACK_IDL	BIT(21)
257 #define BAM_WB_RETR_SVPNT	BIT(22)
258 #define BAM_WB_DSC_AVL_P_RST	BIT(23)
259 #define BAM_REG_P_EN		BIT(24)
260 #define BAM_PSM_P_HD_DATA	BIT(25)
261 #define BAM_AU_ACCUMED		BIT(26)
262 #define BAM_CMD_ENABLE		BIT(27)
263 
264 #define BAM_CNFG_BITS_DEFAULT	(BAM_PIPE_CNFG |	\
265 				 BAM_NO_EXT_P_RST |	\
266 				 BAM_IBC_DISABLE |	\
267 				 BAM_SB_CLK_REQ |	\
268 				 BAM_PSM_CSW_REQ |	\
269 				 BAM_PSM_P_RES |	\
270 				 BAM_AU_P_RES |		\
271 				 BAM_SI_P_RES |		\
272 				 BAM_WB_P_RES |		\
273 				 BAM_WB_BLK_CSW |	\
274 				 BAM_WB_CSW_ACK_IDL |	\
275 				 BAM_WB_RETR_SVPNT |	\
276 				 BAM_WB_DSC_AVL_P_RST |	\
277 				 BAM_REG_P_EN |		\
278 				 BAM_PSM_P_HD_DATA |	\
279 				 BAM_AU_ACCUMED |	\
280 				 BAM_CMD_ENABLE)
281 
282 /* PIPE CTRL */
283 #define P_EN			BIT(1)
284 #define P_DIRECTION		BIT(3)
285 #define P_SYS_STRM		BIT(4)
286 #define P_SYS_MODE		BIT(5)
287 #define P_AUTO_EOB		BIT(6)
288 #define P_AUTO_EOB_SEL_SHIFT	7
289 #define P_AUTO_EOB_SEL_512	(0 << P_AUTO_EOB_SEL_SHIFT)
290 #define P_AUTO_EOB_SEL_256	(1 << P_AUTO_EOB_SEL_SHIFT)
291 #define P_AUTO_EOB_SEL_128	(2 << P_AUTO_EOB_SEL_SHIFT)
292 #define P_AUTO_EOB_SEL_64	(3 << P_AUTO_EOB_SEL_SHIFT)
293 #define P_PREFETCH_LIMIT_SHIFT	9
294 #define P_PREFETCH_LIMIT_32	(0 << P_PREFETCH_LIMIT_SHIFT)
295 #define P_PREFETCH_LIMIT_16	(1 << P_PREFETCH_LIMIT_SHIFT)
296 #define P_PREFETCH_LIMIT_4	(2 << P_PREFETCH_LIMIT_SHIFT)
297 #define P_WRITE_NWD		BIT(11)
298 #define P_LOCK_GROUP_SHIFT	16
299 #define P_LOCK_GROUP_MASK	0x1F
300 
301 /* BAM_DESC_CNT_TRSHLD */
302 #define CNT_TRSHLD		0xffff
303 #define DEFAULT_CNT_THRSHLD	0x4
304 
305 /* BAM_IRQ_SRCS */
306 #define BAM_IRQ			BIT(31)
307 #define P_IRQ			0x7fffffff
308 
309 /* BAM_IRQ_SRCS_MSK */
310 #define BAM_IRQ_MSK		BAM_IRQ
311 #define P_IRQ_MSK		P_IRQ
312 
313 /* BAM_IRQ_STTS */
314 #define BAM_TIMER_IRQ		BIT(4)
315 #define BAM_EMPTY_IRQ		BIT(3)
316 #define BAM_ERROR_IRQ		BIT(2)
317 #define BAM_HRESP_ERR_IRQ	BIT(1)
318 
319 /* BAM_IRQ_CLR */
320 #define BAM_TIMER_CLR		BIT(4)
321 #define BAM_EMPTY_CLR		BIT(3)
322 #define BAM_ERROR_CLR		BIT(2)
323 #define BAM_HRESP_ERR_CLR	BIT(1)
324 
325 /* BAM_IRQ_EN */
326 #define BAM_TIMER_EN		BIT(4)
327 #define BAM_EMPTY_EN		BIT(3)
328 #define BAM_ERROR_EN		BIT(2)
329 #define BAM_HRESP_ERR_EN	BIT(1)
330 
331 /* BAM_P_IRQ_EN */
332 #define P_PRCSD_DESC_EN		BIT(0)
333 #define P_TIMER_EN		BIT(1)
334 #define P_WAKE_EN		BIT(2)
335 #define P_OUT_OF_DESC_EN	BIT(3)
336 #define P_ERR_EN		BIT(4)
337 #define P_TRNSFR_END_EN		BIT(5)
338 #define P_DEFAULT_IRQS_EN	(P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
339 
340 /* BAM_P_SW_OFSTS */
341 #define P_SW_OFSTS_MASK		0xffff
342 
343 #define BAM_DESC_FIFO_SIZE	SZ_32K
344 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
345 #define BAM_FIFO_SIZE	(SZ_32K - 8)
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 	struct bam_async_desc *curr_txd;	/* current running dma */
356 
357 	/* runtime configuration */
358 	struct dma_slave_config slave;
359 
360 	/* fifo storage */
361 	struct bam_desc_hw *fifo_virt;
362 	dma_addr_t fifo_phys;
363 
364 	/* fifo markers */
365 	unsigned short head;		/* start of active descriptor entries */
366 	unsigned short tail;		/* end of active descriptor entries */
367 
368 	unsigned int initialized;	/* is the channel hw initialized? */
369 	unsigned int paused;		/* is the channel paused? */
370 	unsigned int reconfigure;	/* new slave config? */
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 
388 	/* execution environment ID, from DT */
389 	u32 ee;
390 	bool controlled_remotely;
391 
392 	const struct reg_offset_data *layout;
393 
394 	struct clk *bamclk;
395 	int irq;
396 
397 	/* dma start transaction tasklet */
398 	struct tasklet_struct task;
399 };
400 
401 /**
402  * bam_addr - returns BAM register address
403  * @bdev: bam device
404  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
405  * @reg:  register enum
406  */
407 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
408 		enum bam_reg reg)
409 {
410 	const struct reg_offset_data r = bdev->layout[reg];
411 
412 	return bdev->regs + r.base_offset +
413 		r.pipe_mult * pipe +
414 		r.evnt_mult * pipe +
415 		r.ee_mult * bdev->ee;
416 }
417 
418 /**
419  * bam_reset_channel - Reset individual BAM DMA channel
420  * @bchan: bam channel
421  *
422  * This function resets a specific BAM channel
423  */
424 static void bam_reset_channel(struct bam_chan *bchan)
425 {
426 	struct bam_device *bdev = bchan->bdev;
427 
428 	lockdep_assert_held(&bchan->vc.lock);
429 
430 	/* reset channel */
431 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
432 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
433 
434 	/* don't allow cpu to reorder BAM register accesses done after this */
435 	wmb();
436 
437 	/* make sure hw is initialized when channel is used the first time  */
438 	bchan->initialized = 0;
439 }
440 
441 /**
442  * bam_chan_init_hw - Initialize channel hardware
443  * @bchan: bam channel
444  *
445  * This function resets and initializes the BAM channel
446  */
447 static void bam_chan_init_hw(struct bam_chan *bchan,
448 	enum dma_transfer_direction dir)
449 {
450 	struct bam_device *bdev = bchan->bdev;
451 	u32 val;
452 
453 	/* Reset the channel to clear internal state of the FIFO */
454 	bam_reset_channel(bchan);
455 
456 	/*
457 	 * write out 8 byte aligned address.  We have enough space for this
458 	 * because we allocated 1 more descriptor (8 bytes) than we can use
459 	 */
460 	writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
461 			bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
462 	writel_relaxed(BAM_FIFO_SIZE,
463 			bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
464 
465 	/* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
466 	writel_relaxed(P_DEFAULT_IRQS_EN,
467 			bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
468 
469 	/* unmask the specific pipe and EE combo */
470 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
471 	val |= BIT(bchan->id);
472 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
473 
474 	/* don't allow cpu to reorder the channel enable done below */
475 	wmb();
476 
477 	/* set fixed direction and mode, then enable channel */
478 	val = P_EN | P_SYS_MODE;
479 	if (dir == DMA_DEV_TO_MEM)
480 		val |= P_DIRECTION;
481 
482 	writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
483 
484 	bchan->initialized = 1;
485 
486 	/* init FIFO pointers */
487 	bchan->head = 0;
488 	bchan->tail = 0;
489 }
490 
491 /**
492  * bam_alloc_chan - Allocate channel resources for DMA channel.
493  * @chan: specified channel
494  *
495  * This function allocates the FIFO descriptor memory
496  */
497 static int bam_alloc_chan(struct dma_chan *chan)
498 {
499 	struct bam_chan *bchan = to_bam_chan(chan);
500 	struct bam_device *bdev = bchan->bdev;
501 
502 	if (bchan->fifo_virt)
503 		return 0;
504 
505 	/* allocate FIFO descriptor space, but only if necessary */
506 	bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
507 					&bchan->fifo_phys, GFP_KERNEL);
508 
509 	if (!bchan->fifo_virt) {
510 		dev_err(bdev->dev, "Failed to allocate desc fifo\n");
511 		return -ENOMEM;
512 	}
513 
514 	return 0;
515 }
516 
517 /**
518  * bam_free_chan - Frees dma resources associated with specific channel
519  * @chan: specified channel
520  *
521  * Free the allocated fifo descriptor memory and channel resources
522  *
523  */
524 static void bam_free_chan(struct dma_chan *chan)
525 {
526 	struct bam_chan *bchan = to_bam_chan(chan);
527 	struct bam_device *bdev = bchan->bdev;
528 	u32 val;
529 	unsigned long flags;
530 
531 	vchan_free_chan_resources(to_virt_chan(chan));
532 
533 	if (bchan->curr_txd) {
534 		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
535 		return;
536 	}
537 
538 	spin_lock_irqsave(&bchan->vc.lock, flags);
539 	bam_reset_channel(bchan);
540 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
541 
542 	dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
543 		    bchan->fifo_phys);
544 	bchan->fifo_virt = NULL;
545 
546 	/* mask irq for pipe/channel */
547 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
548 	val &= ~BIT(bchan->id);
549 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
550 
551 	/* disable irq */
552 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
553 }
554 
555 /**
556  * bam_slave_config - set slave configuration for channel
557  * @chan: dma channel
558  * @cfg: slave configuration
559  *
560  * Sets slave configuration for channel
561  *
562  */
563 static int bam_slave_config(struct dma_chan *chan,
564 			    struct dma_slave_config *cfg)
565 {
566 	struct bam_chan *bchan = to_bam_chan(chan);
567 	unsigned long flag;
568 
569 	spin_lock_irqsave(&bchan->vc.lock, flag);
570 	memcpy(&bchan->slave, cfg, sizeof(*cfg));
571 	bchan->reconfigure = 1;
572 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
573 
574 	return 0;
575 }
576 
577 /**
578  * bam_prep_slave_sg - Prep slave sg transaction
579  *
580  * @chan: dma channel
581  * @sgl: scatter gather list
582  * @sg_len: length of sg
583  * @direction: DMA transfer direction
584  * @flags: DMA flags
585  * @context: transfer context (unused)
586  */
587 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
588 	struct scatterlist *sgl, unsigned int sg_len,
589 	enum dma_transfer_direction direction, unsigned long flags,
590 	void *context)
591 {
592 	struct bam_chan *bchan = to_bam_chan(chan);
593 	struct bam_device *bdev = bchan->bdev;
594 	struct bam_async_desc *async_desc;
595 	struct scatterlist *sg;
596 	u32 i;
597 	struct bam_desc_hw *desc;
598 	unsigned int num_alloc = 0;
599 
600 
601 	if (!is_slave_direction(direction)) {
602 		dev_err(bdev->dev, "invalid dma direction\n");
603 		return NULL;
604 	}
605 
606 	/* calculate number of required entries */
607 	for_each_sg(sgl, sg, sg_len, i)
608 		num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE);
609 
610 	/* allocate enough room to accomodate the number of entries */
611 	async_desc = kzalloc(sizeof(*async_desc) +
612 			(num_alloc * sizeof(struct bam_desc_hw)), GFP_NOWAIT);
613 
614 	if (!async_desc)
615 		goto err_out;
616 
617 	if (flags & DMA_PREP_FENCE)
618 		async_desc->flags |= DESC_FLAG_NWD;
619 
620 	if (flags & DMA_PREP_INTERRUPT)
621 		async_desc->flags |= DESC_FLAG_EOT;
622 	else
623 		async_desc->flags |= DESC_FLAG_INT;
624 
625 	async_desc->num_desc = num_alloc;
626 	async_desc->curr_desc = async_desc->desc;
627 	async_desc->dir = direction;
628 
629 	/* fill in temporary descriptors */
630 	desc = async_desc->desc;
631 	for_each_sg(sgl, sg, sg_len, i) {
632 		unsigned int remainder = sg_dma_len(sg);
633 		unsigned int curr_offset = 0;
634 
635 		do {
636 			desc->addr = cpu_to_le32(sg_dma_address(sg) +
637 						 curr_offset);
638 
639 			if (remainder > BAM_FIFO_SIZE) {
640 				desc->size = cpu_to_le16(BAM_FIFO_SIZE);
641 				remainder -= BAM_FIFO_SIZE;
642 				curr_offset += BAM_FIFO_SIZE;
643 			} else {
644 				desc->size = cpu_to_le16(remainder);
645 				remainder = 0;
646 			}
647 
648 			async_desc->length += desc->size;
649 			desc++;
650 		} while (remainder > 0);
651 	}
652 
653 	return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
654 
655 err_out:
656 	kfree(async_desc);
657 	return NULL;
658 }
659 
660 /**
661  * bam_dma_terminate_all - terminate all transactions on a channel
662  * @bchan: bam dma channel
663  *
664  * Dequeues and frees all transactions
665  * No callbacks are done
666  *
667  */
668 static int bam_dma_terminate_all(struct dma_chan *chan)
669 {
670 	struct bam_chan *bchan = to_bam_chan(chan);
671 	unsigned long flag;
672 	LIST_HEAD(head);
673 
674 	/* remove all transactions, including active transaction */
675 	spin_lock_irqsave(&bchan->vc.lock, flag);
676 	if (bchan->curr_txd) {
677 		list_add(&bchan->curr_txd->vd.node, &bchan->vc.desc_issued);
678 		bchan->curr_txd = NULL;
679 	}
680 
681 	vchan_get_all_descriptors(&bchan->vc, &head);
682 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
683 
684 	vchan_dma_desc_free_list(&bchan->vc, &head);
685 
686 	return 0;
687 }
688 
689 /**
690  * bam_pause - Pause DMA channel
691  * @chan: dma channel
692  *
693  */
694 static int bam_pause(struct dma_chan *chan)
695 {
696 	struct bam_chan *bchan = to_bam_chan(chan);
697 	struct bam_device *bdev = bchan->bdev;
698 	unsigned long flag;
699 
700 	spin_lock_irqsave(&bchan->vc.lock, flag);
701 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
702 	bchan->paused = 1;
703 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
704 
705 	return 0;
706 }
707 
708 /**
709  * bam_resume - Resume DMA channel operations
710  * @chan: dma channel
711  *
712  */
713 static int bam_resume(struct dma_chan *chan)
714 {
715 	struct bam_chan *bchan = to_bam_chan(chan);
716 	struct bam_device *bdev = bchan->bdev;
717 	unsigned long flag;
718 
719 	spin_lock_irqsave(&bchan->vc.lock, flag);
720 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
721 	bchan->paused = 0;
722 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
723 
724 	return 0;
725 }
726 
727 /**
728  * process_channel_irqs - processes the channel interrupts
729  * @bdev: bam controller
730  *
731  * This function processes the channel interrupts
732  *
733  */
734 static u32 process_channel_irqs(struct bam_device *bdev)
735 {
736 	u32 i, srcs, pipe_stts;
737 	unsigned long flags;
738 	struct bam_async_desc *async_desc;
739 
740 	srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
741 
742 	/* return early if no pipe/channel interrupts are present */
743 	if (!(srcs & P_IRQ))
744 		return srcs;
745 
746 	for (i = 0; i < bdev->num_channels; i++) {
747 		struct bam_chan *bchan = &bdev->channels[i];
748 
749 		if (!(srcs & BIT(i)))
750 			continue;
751 
752 		/* clear pipe irq */
753 		pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
754 
755 		writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
756 
757 		spin_lock_irqsave(&bchan->vc.lock, flags);
758 		async_desc = bchan->curr_txd;
759 
760 		if (async_desc) {
761 			async_desc->num_desc -= async_desc->xfer_len;
762 			async_desc->curr_desc += async_desc->xfer_len;
763 			bchan->curr_txd = NULL;
764 
765 			/* manage FIFO */
766 			bchan->head += async_desc->xfer_len;
767 			bchan->head %= MAX_DESCRIPTORS;
768 
769 			/*
770 			 * if complete, process cookie.  Otherwise
771 			 * push back to front of desc_issued so that
772 			 * it gets restarted by the tasklet
773 			 */
774 			if (!async_desc->num_desc)
775 				vchan_cookie_complete(&async_desc->vd);
776 			else
777 				list_add(&async_desc->vd.node,
778 					&bchan->vc.desc_issued);
779 		}
780 
781 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
782 	}
783 
784 	return srcs;
785 }
786 
787 /**
788  * bam_dma_irq - irq handler for bam controller
789  * @irq: IRQ of interrupt
790  * @data: callback data
791  *
792  * IRQ handler for the bam controller
793  */
794 static irqreturn_t bam_dma_irq(int irq, void *data)
795 {
796 	struct bam_device *bdev = data;
797 	u32 clr_mask = 0, srcs = 0;
798 
799 	srcs |= process_channel_irqs(bdev);
800 
801 	/* kick off tasklet to start next dma transfer */
802 	if (srcs & P_IRQ)
803 		tasklet_schedule(&bdev->task);
804 
805 	if (srcs & BAM_IRQ) {
806 		clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
807 
808 		/*
809 		 * don't allow reorder of the various accesses to the BAM
810 		 * registers
811 		 */
812 		mb();
813 
814 		writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
815 	}
816 
817 	return IRQ_HANDLED;
818 }
819 
820 /**
821  * bam_tx_status - returns status of transaction
822  * @chan: dma channel
823  * @cookie: transaction cookie
824  * @txstate: DMA transaction state
825  *
826  * Return status of dma transaction
827  */
828 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
829 		struct dma_tx_state *txstate)
830 {
831 	struct bam_chan *bchan = to_bam_chan(chan);
832 	struct virt_dma_desc *vd;
833 	int ret;
834 	size_t residue = 0;
835 	unsigned int i;
836 	unsigned long flags;
837 
838 	ret = dma_cookie_status(chan, cookie, txstate);
839 	if (ret == DMA_COMPLETE)
840 		return ret;
841 
842 	if (!txstate)
843 		return bchan->paused ? DMA_PAUSED : ret;
844 
845 	spin_lock_irqsave(&bchan->vc.lock, flags);
846 	vd = vchan_find_desc(&bchan->vc, cookie);
847 	if (vd)
848 		residue = container_of(vd, struct bam_async_desc, vd)->length;
849 	else if (bchan->curr_txd && bchan->curr_txd->vd.tx.cookie == cookie)
850 		for (i = 0; i < bchan->curr_txd->num_desc; i++)
851 			residue += bchan->curr_txd->curr_desc[i].size;
852 
853 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
854 
855 	dma_set_residue(txstate, residue);
856 
857 	if (ret == DMA_IN_PROGRESS && bchan->paused)
858 		ret = DMA_PAUSED;
859 
860 	return ret;
861 }
862 
863 /**
864  * bam_apply_new_config
865  * @bchan: bam dma channel
866  * @dir: DMA direction
867  */
868 static void bam_apply_new_config(struct bam_chan *bchan,
869 	enum dma_transfer_direction dir)
870 {
871 	struct bam_device *bdev = bchan->bdev;
872 	u32 maxburst;
873 
874 	if (dir == DMA_DEV_TO_MEM)
875 		maxburst = bchan->slave.src_maxburst;
876 	else
877 		maxburst = bchan->slave.dst_maxburst;
878 
879 	writel_relaxed(maxburst, bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
880 
881 	bchan->reconfigure = 0;
882 }
883 
884 /**
885  * bam_start_dma - start next transaction
886  * @bchan - bam dma channel
887  */
888 static void bam_start_dma(struct bam_chan *bchan)
889 {
890 	struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
891 	struct bam_device *bdev = bchan->bdev;
892 	struct bam_async_desc *async_desc;
893 	struct bam_desc_hw *desc;
894 	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
895 					sizeof(struct bam_desc_hw));
896 
897 	lockdep_assert_held(&bchan->vc.lock);
898 
899 	if (!vd)
900 		return;
901 
902 	list_del(&vd->node);
903 
904 	async_desc = container_of(vd, struct bam_async_desc, vd);
905 	bchan->curr_txd = async_desc;
906 
907 	/* on first use, initialize the channel hardware */
908 	if (!bchan->initialized)
909 		bam_chan_init_hw(bchan, async_desc->dir);
910 
911 	/* apply new slave config changes, if necessary */
912 	if (bchan->reconfigure)
913 		bam_apply_new_config(bchan, async_desc->dir);
914 
915 	desc = bchan->curr_txd->curr_desc;
916 
917 	if (async_desc->num_desc > MAX_DESCRIPTORS)
918 		async_desc->xfer_len = MAX_DESCRIPTORS;
919 	else
920 		async_desc->xfer_len = async_desc->num_desc;
921 
922 	/* set any special flags on the last descriptor */
923 	if (async_desc->num_desc == async_desc->xfer_len)
924 		desc[async_desc->xfer_len - 1].flags =
925 					cpu_to_le16(async_desc->flags);
926 	else
927 		desc[async_desc->xfer_len - 1].flags |=
928 					cpu_to_le16(DESC_FLAG_INT);
929 
930 	if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
931 		u32 partial = MAX_DESCRIPTORS - bchan->tail;
932 
933 		memcpy(&fifo[bchan->tail], desc,
934 				partial * sizeof(struct bam_desc_hw));
935 		memcpy(fifo, &desc[partial], (async_desc->xfer_len - partial) *
936 				sizeof(struct bam_desc_hw));
937 	} else {
938 		memcpy(&fifo[bchan->tail], desc,
939 			async_desc->xfer_len * sizeof(struct bam_desc_hw));
940 	}
941 
942 	bchan->tail += async_desc->xfer_len;
943 	bchan->tail %= MAX_DESCRIPTORS;
944 
945 	/* ensure descriptor writes and dma start not reordered */
946 	wmb();
947 	writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
948 			bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
949 }
950 
951 /**
952  * dma_tasklet - DMA IRQ tasklet
953  * @data: tasklet argument (bam controller structure)
954  *
955  * Sets up next DMA operation and then processes all completed transactions
956  */
957 static void dma_tasklet(unsigned long data)
958 {
959 	struct bam_device *bdev = (struct bam_device *)data;
960 	struct bam_chan *bchan;
961 	unsigned long flags;
962 	unsigned int i;
963 
964 	/* go through the channels and kick off transactions */
965 	for (i = 0; i < bdev->num_channels; i++) {
966 		bchan = &bdev->channels[i];
967 		spin_lock_irqsave(&bchan->vc.lock, flags);
968 
969 		if (!list_empty(&bchan->vc.desc_issued) && !bchan->curr_txd)
970 			bam_start_dma(bchan);
971 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
972 	}
973 }
974 
975 /**
976  * bam_issue_pending - starts pending transactions
977  * @chan: dma channel
978  *
979  * Calls tasklet directly which in turn starts any pending transactions
980  */
981 static void bam_issue_pending(struct dma_chan *chan)
982 {
983 	struct bam_chan *bchan = to_bam_chan(chan);
984 	unsigned long flags;
985 
986 	spin_lock_irqsave(&bchan->vc.lock, flags);
987 
988 	/* if work pending and idle, start a transaction */
989 	if (vchan_issue_pending(&bchan->vc) && !bchan->curr_txd)
990 		bam_start_dma(bchan);
991 
992 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
993 }
994 
995 /**
996  * bam_dma_free_desc - free descriptor memory
997  * @vd: virtual descriptor
998  *
999  */
1000 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1001 {
1002 	struct bam_async_desc *async_desc = container_of(vd,
1003 			struct bam_async_desc, vd);
1004 
1005 	kfree(async_desc);
1006 }
1007 
1008 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1009 		struct of_dma *of)
1010 {
1011 	struct bam_device *bdev = container_of(of->of_dma_data,
1012 					struct bam_device, common);
1013 	unsigned int request;
1014 
1015 	if (dma_spec->args_count != 1)
1016 		return NULL;
1017 
1018 	request = dma_spec->args[0];
1019 	if (request >= bdev->num_channels)
1020 		return NULL;
1021 
1022 	return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1023 }
1024 
1025 /**
1026  * bam_init
1027  * @bdev: bam device
1028  *
1029  * Initialization helper for global bam registers
1030  */
1031 static int bam_init(struct bam_device *bdev)
1032 {
1033 	u32 val;
1034 
1035 	/* read revision and configuration information */
1036 	val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)) >> NUM_EES_SHIFT;
1037 	val &= NUM_EES_MASK;
1038 
1039 	/* check that configured EE is within range */
1040 	if (bdev->ee >= val)
1041 		return -EINVAL;
1042 
1043 	val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1044 	bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1045 
1046 	if (bdev->controlled_remotely)
1047 		return 0;
1048 
1049 	/* s/w reset bam */
1050 	/* after reset all pipes are disabled and idle */
1051 	val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
1052 	val |= BAM_SW_RST;
1053 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1054 	val &= ~BAM_SW_RST;
1055 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1056 
1057 	/* make sure previous stores are visible before enabling BAM */
1058 	wmb();
1059 
1060 	/* enable bam */
1061 	val |= BAM_EN;
1062 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1063 
1064 	/* set descriptor threshhold, start with 4 bytes */
1065 	writel_relaxed(DEFAULT_CNT_THRSHLD,
1066 			bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1067 
1068 	/* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
1069 	writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
1070 
1071 	/* enable irqs for errors */
1072 	writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
1073 			bam_addr(bdev, 0, BAM_IRQ_EN));
1074 
1075 	/* unmask global bam interrupt */
1076 	writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
1077 
1078 	return 0;
1079 }
1080 
1081 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1082 	u32 index)
1083 {
1084 	bchan->id = index;
1085 	bchan->bdev = bdev;
1086 
1087 	vchan_init(&bchan->vc, &bdev->common);
1088 	bchan->vc.desc_free = bam_dma_free_desc;
1089 }
1090 
1091 static const struct of_device_id bam_of_match[] = {
1092 	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1093 	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1094 	{ .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1095 	{}
1096 };
1097 
1098 MODULE_DEVICE_TABLE(of, bam_of_match);
1099 
1100 static int bam_dma_probe(struct platform_device *pdev)
1101 {
1102 	struct bam_device *bdev;
1103 	const struct of_device_id *match;
1104 	struct resource *iores;
1105 	int ret, i;
1106 
1107 	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1108 	if (!bdev)
1109 		return -ENOMEM;
1110 
1111 	bdev->dev = &pdev->dev;
1112 
1113 	match = of_match_node(bam_of_match, pdev->dev.of_node);
1114 	if (!match) {
1115 		dev_err(&pdev->dev, "Unsupported BAM module\n");
1116 		return -ENODEV;
1117 	}
1118 
1119 	bdev->layout = match->data;
1120 
1121 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1122 	bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
1123 	if (IS_ERR(bdev->regs))
1124 		return PTR_ERR(bdev->regs);
1125 
1126 	bdev->irq = platform_get_irq(pdev, 0);
1127 	if (bdev->irq < 0)
1128 		return bdev->irq;
1129 
1130 	ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1131 	if (ret) {
1132 		dev_err(bdev->dev, "Execution environment unspecified\n");
1133 		return ret;
1134 	}
1135 
1136 	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
1137 						"qcom,controlled-remotely");
1138 
1139 	bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1140 	if (IS_ERR(bdev->bamclk))
1141 		return PTR_ERR(bdev->bamclk);
1142 
1143 	ret = clk_prepare_enable(bdev->bamclk);
1144 	if (ret) {
1145 		dev_err(bdev->dev, "failed to prepare/enable clock\n");
1146 		return ret;
1147 	}
1148 
1149 	ret = bam_init(bdev);
1150 	if (ret)
1151 		goto err_disable_clk;
1152 
1153 	tasklet_init(&bdev->task, dma_tasklet, (unsigned long)bdev);
1154 
1155 	bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1156 				sizeof(*bdev->channels), GFP_KERNEL);
1157 
1158 	if (!bdev->channels) {
1159 		ret = -ENOMEM;
1160 		goto err_tasklet_kill;
1161 	}
1162 
1163 	/* allocate and initialize channels */
1164 	INIT_LIST_HEAD(&bdev->common.channels);
1165 
1166 	for (i = 0; i < bdev->num_channels; i++)
1167 		bam_channel_init(bdev, &bdev->channels[i], i);
1168 
1169 	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1170 			IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1171 	if (ret)
1172 		goto err_bam_channel_exit;
1173 
1174 	/* set max dma segment size */
1175 	bdev->common.dev = bdev->dev;
1176 	bdev->common.dev->dma_parms = &bdev->dma_parms;
1177 	ret = dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1178 	if (ret) {
1179 		dev_err(bdev->dev, "cannot set maximum segment size\n");
1180 		goto err_bam_channel_exit;
1181 	}
1182 
1183 	platform_set_drvdata(pdev, bdev);
1184 
1185 	/* set capabilities */
1186 	dma_cap_zero(bdev->common.cap_mask);
1187 	dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1188 
1189 	/* initialize dmaengine apis */
1190 	bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1191 	bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1192 	bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1193 	bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1194 	bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1195 	bdev->common.device_free_chan_resources = bam_free_chan;
1196 	bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1197 	bdev->common.device_config = bam_slave_config;
1198 	bdev->common.device_pause = bam_pause;
1199 	bdev->common.device_resume = bam_resume;
1200 	bdev->common.device_terminate_all = bam_dma_terminate_all;
1201 	bdev->common.device_issue_pending = bam_issue_pending;
1202 	bdev->common.device_tx_status = bam_tx_status;
1203 	bdev->common.dev = bdev->dev;
1204 
1205 	ret = dma_async_device_register(&bdev->common);
1206 	if (ret) {
1207 		dev_err(bdev->dev, "failed to register dma async device\n");
1208 		goto err_bam_channel_exit;
1209 	}
1210 
1211 	ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1212 					&bdev->common);
1213 	if (ret)
1214 		goto err_unregister_dma;
1215 
1216 	return 0;
1217 
1218 err_unregister_dma:
1219 	dma_async_device_unregister(&bdev->common);
1220 err_bam_channel_exit:
1221 	for (i = 0; i < bdev->num_channels; i++)
1222 		tasklet_kill(&bdev->channels[i].vc.task);
1223 err_tasklet_kill:
1224 	tasklet_kill(&bdev->task);
1225 err_disable_clk:
1226 	clk_disable_unprepare(bdev->bamclk);
1227 
1228 	return ret;
1229 }
1230 
1231 static int bam_dma_remove(struct platform_device *pdev)
1232 {
1233 	struct bam_device *bdev = platform_get_drvdata(pdev);
1234 	u32 i;
1235 
1236 	of_dma_controller_free(pdev->dev.of_node);
1237 	dma_async_device_unregister(&bdev->common);
1238 
1239 	/* mask all interrupts for this execution environment */
1240 	writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1241 
1242 	devm_free_irq(bdev->dev, bdev->irq, bdev);
1243 
1244 	for (i = 0; i < bdev->num_channels; i++) {
1245 		bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1246 		tasklet_kill(&bdev->channels[i].vc.task);
1247 
1248 		if (!bdev->channels[i].fifo_virt)
1249 			continue;
1250 
1251 		dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1252 			    bdev->channels[i].fifo_virt,
1253 			    bdev->channels[i].fifo_phys);
1254 	}
1255 
1256 	tasklet_kill(&bdev->task);
1257 
1258 	clk_disable_unprepare(bdev->bamclk);
1259 
1260 	return 0;
1261 }
1262 
1263 static struct platform_driver bam_dma_driver = {
1264 	.probe = bam_dma_probe,
1265 	.remove = bam_dma_remove,
1266 	.driver = {
1267 		.name = "bam-dma-engine",
1268 		.of_match_table = bam_of_match,
1269 	},
1270 };
1271 
1272 module_platform_driver(bam_dma_driver);
1273 
1274 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1275 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1276 MODULE_LICENSE("GPL v2");
1277