xref: /openbmc/linux/drivers/dma/qcom/bam_dma.c (revision feac8c8b)
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/circ_buf.h>
50 #include <linux/clk.h>
51 #include <linux/dmaengine.h>
52 #include <linux/pm_runtime.h>
53 
54 #include "../dmaengine.h"
55 #include "../virt-dma.h"
56 
57 struct bam_desc_hw {
58 	__le32 addr;		/* Buffer physical address */
59 	__le16 size;		/* Buffer size in bytes */
60 	__le16 flags;
61 };
62 
63 #define BAM_DMA_AUTOSUSPEND_DELAY 100
64 
65 #define DESC_FLAG_INT BIT(15)
66 #define DESC_FLAG_EOT BIT(14)
67 #define DESC_FLAG_EOB BIT(13)
68 #define DESC_FLAG_NWD BIT(12)
69 #define DESC_FLAG_CMD BIT(11)
70 
71 struct bam_async_desc {
72 	struct virt_dma_desc vd;
73 
74 	u32 num_desc;
75 	u32 xfer_len;
76 
77 	/* transaction flags, EOT|EOB|NWD */
78 	u16 flags;
79 
80 	struct bam_desc_hw *curr_desc;
81 
82 	/* list node for the desc in the bam_chan list of descriptors */
83 	struct list_head desc_node;
84 	enum dma_transfer_direction dir;
85 	size_t length;
86 	struct bam_desc_hw desc[0];
87 };
88 
89 enum bam_reg {
90 	BAM_CTRL,
91 	BAM_REVISION,
92 	BAM_NUM_PIPES,
93 	BAM_DESC_CNT_TRSHLD,
94 	BAM_IRQ_SRCS,
95 	BAM_IRQ_SRCS_MSK,
96 	BAM_IRQ_SRCS_UNMASKED,
97 	BAM_IRQ_STTS,
98 	BAM_IRQ_CLR,
99 	BAM_IRQ_EN,
100 	BAM_CNFG_BITS,
101 	BAM_IRQ_SRCS_EE,
102 	BAM_IRQ_SRCS_MSK_EE,
103 	BAM_P_CTRL,
104 	BAM_P_RST,
105 	BAM_P_HALT,
106 	BAM_P_IRQ_STTS,
107 	BAM_P_IRQ_CLR,
108 	BAM_P_IRQ_EN,
109 	BAM_P_EVNT_DEST_ADDR,
110 	BAM_P_EVNT_REG,
111 	BAM_P_SW_OFSTS,
112 	BAM_P_DATA_FIFO_ADDR,
113 	BAM_P_DESC_FIFO_ADDR,
114 	BAM_P_EVNT_GEN_TRSHLD,
115 	BAM_P_FIFO_SIZES,
116 };
117 
118 struct reg_offset_data {
119 	u32 base_offset;
120 	unsigned int pipe_mult, evnt_mult, ee_mult;
121 };
122 
123 static const struct reg_offset_data bam_v1_3_reg_info[] = {
124 	[BAM_CTRL]		= { 0x0F80, 0x00, 0x00, 0x00 },
125 	[BAM_REVISION]		= { 0x0F84, 0x00, 0x00, 0x00 },
126 	[BAM_NUM_PIPES]		= { 0x0FBC, 0x00, 0x00, 0x00 },
127 	[BAM_DESC_CNT_TRSHLD]	= { 0x0F88, 0x00, 0x00, 0x00 },
128 	[BAM_IRQ_SRCS]		= { 0x0F8C, 0x00, 0x00, 0x00 },
129 	[BAM_IRQ_SRCS_MSK]	= { 0x0F90, 0x00, 0x00, 0x00 },
130 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0FB0, 0x00, 0x00, 0x00 },
131 	[BAM_IRQ_STTS]		= { 0x0F94, 0x00, 0x00, 0x00 },
132 	[BAM_IRQ_CLR]		= { 0x0F98, 0x00, 0x00, 0x00 },
133 	[BAM_IRQ_EN]		= { 0x0F9C, 0x00, 0x00, 0x00 },
134 	[BAM_CNFG_BITS]		= { 0x0FFC, 0x00, 0x00, 0x00 },
135 	[BAM_IRQ_SRCS_EE]	= { 0x1800, 0x00, 0x00, 0x80 },
136 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x1804, 0x00, 0x00, 0x80 },
137 	[BAM_P_CTRL]		= { 0x0000, 0x80, 0x00, 0x00 },
138 	[BAM_P_RST]		= { 0x0004, 0x80, 0x00, 0x00 },
139 	[BAM_P_HALT]		= { 0x0008, 0x80, 0x00, 0x00 },
140 	[BAM_P_IRQ_STTS]	= { 0x0010, 0x80, 0x00, 0x00 },
141 	[BAM_P_IRQ_CLR]		= { 0x0014, 0x80, 0x00, 0x00 },
142 	[BAM_P_IRQ_EN]		= { 0x0018, 0x80, 0x00, 0x00 },
143 	[BAM_P_EVNT_DEST_ADDR]	= { 0x102C, 0x00, 0x40, 0x00 },
144 	[BAM_P_EVNT_REG]	= { 0x1018, 0x00, 0x40, 0x00 },
145 	[BAM_P_SW_OFSTS]	= { 0x1000, 0x00, 0x40, 0x00 },
146 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1024, 0x00, 0x40, 0x00 },
147 	[BAM_P_DESC_FIFO_ADDR]	= { 0x101C, 0x00, 0x40, 0x00 },
148 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1028, 0x00, 0x40, 0x00 },
149 	[BAM_P_FIFO_SIZES]	= { 0x1020, 0x00, 0x40, 0x00 },
150 };
151 
152 static const struct reg_offset_data bam_v1_4_reg_info[] = {
153 	[BAM_CTRL]		= { 0x0000, 0x00, 0x00, 0x00 },
154 	[BAM_REVISION]		= { 0x0004, 0x00, 0x00, 0x00 },
155 	[BAM_NUM_PIPES]		= { 0x003C, 0x00, 0x00, 0x00 },
156 	[BAM_DESC_CNT_TRSHLD]	= { 0x0008, 0x00, 0x00, 0x00 },
157 	[BAM_IRQ_SRCS]		= { 0x000C, 0x00, 0x00, 0x00 },
158 	[BAM_IRQ_SRCS_MSK]	= { 0x0010, 0x00, 0x00, 0x00 },
159 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0030, 0x00, 0x00, 0x00 },
160 	[BAM_IRQ_STTS]		= { 0x0014, 0x00, 0x00, 0x00 },
161 	[BAM_IRQ_CLR]		= { 0x0018, 0x00, 0x00, 0x00 },
162 	[BAM_IRQ_EN]		= { 0x001C, 0x00, 0x00, 0x00 },
163 	[BAM_CNFG_BITS]		= { 0x007C, 0x00, 0x00, 0x00 },
164 	[BAM_IRQ_SRCS_EE]	= { 0x0800, 0x00, 0x00, 0x80 },
165 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x0804, 0x00, 0x00, 0x80 },
166 	[BAM_P_CTRL]		= { 0x1000, 0x1000, 0x00, 0x00 },
167 	[BAM_P_RST]		= { 0x1004, 0x1000, 0x00, 0x00 },
168 	[BAM_P_HALT]		= { 0x1008, 0x1000, 0x00, 0x00 },
169 	[BAM_P_IRQ_STTS]	= { 0x1010, 0x1000, 0x00, 0x00 },
170 	[BAM_P_IRQ_CLR]		= { 0x1014, 0x1000, 0x00, 0x00 },
171 	[BAM_P_IRQ_EN]		= { 0x1018, 0x1000, 0x00, 0x00 },
172 	[BAM_P_EVNT_DEST_ADDR]	= { 0x182C, 0x00, 0x1000, 0x00 },
173 	[BAM_P_EVNT_REG]	= { 0x1818, 0x00, 0x1000, 0x00 },
174 	[BAM_P_SW_OFSTS]	= { 0x1800, 0x00, 0x1000, 0x00 },
175 	[BAM_P_DATA_FIFO_ADDR]	= { 0x1824, 0x00, 0x1000, 0x00 },
176 	[BAM_P_DESC_FIFO_ADDR]	= { 0x181C, 0x00, 0x1000, 0x00 },
177 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1828, 0x00, 0x1000, 0x00 },
178 	[BAM_P_FIFO_SIZES]	= { 0x1820, 0x00, 0x1000, 0x00 },
179 };
180 
181 static const struct reg_offset_data bam_v1_7_reg_info[] = {
182 	[BAM_CTRL]		= { 0x00000, 0x00, 0x00, 0x00 },
183 	[BAM_REVISION]		= { 0x01000, 0x00, 0x00, 0x00 },
184 	[BAM_NUM_PIPES]		= { 0x01008, 0x00, 0x00, 0x00 },
185 	[BAM_DESC_CNT_TRSHLD]	= { 0x00008, 0x00, 0x00, 0x00 },
186 	[BAM_IRQ_SRCS]		= { 0x03010, 0x00, 0x00, 0x00 },
187 	[BAM_IRQ_SRCS_MSK]	= { 0x03014, 0x00, 0x00, 0x00 },
188 	[BAM_IRQ_SRCS_UNMASKED]	= { 0x03018, 0x00, 0x00, 0x00 },
189 	[BAM_IRQ_STTS]		= { 0x00014, 0x00, 0x00, 0x00 },
190 	[BAM_IRQ_CLR]		= { 0x00018, 0x00, 0x00, 0x00 },
191 	[BAM_IRQ_EN]		= { 0x0001C, 0x00, 0x00, 0x00 },
192 	[BAM_CNFG_BITS]		= { 0x0007C, 0x00, 0x00, 0x00 },
193 	[BAM_IRQ_SRCS_EE]	= { 0x03000, 0x00, 0x00, 0x1000 },
194 	[BAM_IRQ_SRCS_MSK_EE]	= { 0x03004, 0x00, 0x00, 0x1000 },
195 	[BAM_P_CTRL]		= { 0x13000, 0x1000, 0x00, 0x00 },
196 	[BAM_P_RST]		= { 0x13004, 0x1000, 0x00, 0x00 },
197 	[BAM_P_HALT]		= { 0x13008, 0x1000, 0x00, 0x00 },
198 	[BAM_P_IRQ_STTS]	= { 0x13010, 0x1000, 0x00, 0x00 },
199 	[BAM_P_IRQ_CLR]		= { 0x13014, 0x1000, 0x00, 0x00 },
200 	[BAM_P_IRQ_EN]		= { 0x13018, 0x1000, 0x00, 0x00 },
201 	[BAM_P_EVNT_DEST_ADDR]	= { 0x1382C, 0x00, 0x1000, 0x00 },
202 	[BAM_P_EVNT_REG]	= { 0x13818, 0x00, 0x1000, 0x00 },
203 	[BAM_P_SW_OFSTS]	= { 0x13800, 0x00, 0x1000, 0x00 },
204 	[BAM_P_DATA_FIFO_ADDR]	= { 0x13824, 0x00, 0x1000, 0x00 },
205 	[BAM_P_DESC_FIFO_ADDR]	= { 0x1381C, 0x00, 0x1000, 0x00 },
206 	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x13828, 0x00, 0x1000, 0x00 },
207 	[BAM_P_FIFO_SIZES]	= { 0x13820, 0x00, 0x1000, 0x00 },
208 };
209 
210 /* BAM CTRL */
211 #define BAM_SW_RST			BIT(0)
212 #define BAM_EN				BIT(1)
213 #define BAM_EN_ACCUM			BIT(4)
214 #define BAM_TESTBUS_SEL_SHIFT		5
215 #define BAM_TESTBUS_SEL_MASK		0x3F
216 #define BAM_DESC_CACHE_SEL_SHIFT	13
217 #define BAM_DESC_CACHE_SEL_MASK		0x3
218 #define BAM_CACHED_DESC_STORE		BIT(15)
219 #define IBC_DISABLE			BIT(16)
220 
221 /* BAM REVISION */
222 #define REVISION_SHIFT		0
223 #define REVISION_MASK		0xFF
224 #define NUM_EES_SHIFT		8
225 #define NUM_EES_MASK		0xF
226 #define CE_BUFFER_SIZE		BIT(13)
227 #define AXI_ACTIVE		BIT(14)
228 #define USE_VMIDMT		BIT(15)
229 #define SECURED			BIT(16)
230 #define BAM_HAS_NO_BYPASS	BIT(17)
231 #define HIGH_FREQUENCY_BAM	BIT(18)
232 #define INACTIV_TMRS_EXST	BIT(19)
233 #define NUM_INACTIV_TMRS	BIT(20)
234 #define DESC_CACHE_DEPTH_SHIFT	21
235 #define DESC_CACHE_DEPTH_1	(0 << DESC_CACHE_DEPTH_SHIFT)
236 #define DESC_CACHE_DEPTH_2	(1 << DESC_CACHE_DEPTH_SHIFT)
237 #define DESC_CACHE_DEPTH_3	(2 << DESC_CACHE_DEPTH_SHIFT)
238 #define DESC_CACHE_DEPTH_4	(3 << DESC_CACHE_DEPTH_SHIFT)
239 #define CMD_DESC_EN		BIT(23)
240 #define INACTIV_TMR_BASE_SHIFT	24
241 #define INACTIV_TMR_BASE_MASK	0xFF
242 
243 /* BAM NUM PIPES */
244 #define BAM_NUM_PIPES_SHIFT		0
245 #define BAM_NUM_PIPES_MASK		0xFF
246 #define PERIPH_NON_PIPE_GRP_SHIFT	16
247 #define PERIPH_NON_PIP_GRP_MASK		0xFF
248 #define BAM_NON_PIPE_GRP_SHIFT		24
249 #define BAM_NON_PIPE_GRP_MASK		0xFF
250 
251 /* BAM CNFG BITS */
252 #define BAM_PIPE_CNFG		BIT(2)
253 #define BAM_FULL_PIPE		BIT(11)
254 #define BAM_NO_EXT_P_RST	BIT(12)
255 #define BAM_IBC_DISABLE		BIT(13)
256 #define BAM_SB_CLK_REQ		BIT(14)
257 #define BAM_PSM_CSW_REQ		BIT(15)
258 #define BAM_PSM_P_RES		BIT(16)
259 #define BAM_AU_P_RES		BIT(17)
260 #define BAM_SI_P_RES		BIT(18)
261 #define BAM_WB_P_RES		BIT(19)
262 #define BAM_WB_BLK_CSW		BIT(20)
263 #define BAM_WB_CSW_ACK_IDL	BIT(21)
264 #define BAM_WB_RETR_SVPNT	BIT(22)
265 #define BAM_WB_DSC_AVL_P_RST	BIT(23)
266 #define BAM_REG_P_EN		BIT(24)
267 #define BAM_PSM_P_HD_DATA	BIT(25)
268 #define BAM_AU_ACCUMED		BIT(26)
269 #define BAM_CMD_ENABLE		BIT(27)
270 
271 #define BAM_CNFG_BITS_DEFAULT	(BAM_PIPE_CNFG |	\
272 				 BAM_NO_EXT_P_RST |	\
273 				 BAM_IBC_DISABLE |	\
274 				 BAM_SB_CLK_REQ |	\
275 				 BAM_PSM_CSW_REQ |	\
276 				 BAM_PSM_P_RES |	\
277 				 BAM_AU_P_RES |		\
278 				 BAM_SI_P_RES |		\
279 				 BAM_WB_P_RES |		\
280 				 BAM_WB_BLK_CSW |	\
281 				 BAM_WB_CSW_ACK_IDL |	\
282 				 BAM_WB_RETR_SVPNT |	\
283 				 BAM_WB_DSC_AVL_P_RST |	\
284 				 BAM_REG_P_EN |		\
285 				 BAM_PSM_P_HD_DATA |	\
286 				 BAM_AU_ACCUMED |	\
287 				 BAM_CMD_ENABLE)
288 
289 /* PIPE CTRL */
290 #define P_EN			BIT(1)
291 #define P_DIRECTION		BIT(3)
292 #define P_SYS_STRM		BIT(4)
293 #define P_SYS_MODE		BIT(5)
294 #define P_AUTO_EOB		BIT(6)
295 #define P_AUTO_EOB_SEL_SHIFT	7
296 #define P_AUTO_EOB_SEL_512	(0 << P_AUTO_EOB_SEL_SHIFT)
297 #define P_AUTO_EOB_SEL_256	(1 << P_AUTO_EOB_SEL_SHIFT)
298 #define P_AUTO_EOB_SEL_128	(2 << P_AUTO_EOB_SEL_SHIFT)
299 #define P_AUTO_EOB_SEL_64	(3 << P_AUTO_EOB_SEL_SHIFT)
300 #define P_PREFETCH_LIMIT_SHIFT	9
301 #define P_PREFETCH_LIMIT_32	(0 << P_PREFETCH_LIMIT_SHIFT)
302 #define P_PREFETCH_LIMIT_16	(1 << P_PREFETCH_LIMIT_SHIFT)
303 #define P_PREFETCH_LIMIT_4	(2 << P_PREFETCH_LIMIT_SHIFT)
304 #define P_WRITE_NWD		BIT(11)
305 #define P_LOCK_GROUP_SHIFT	16
306 #define P_LOCK_GROUP_MASK	0x1F
307 
308 /* BAM_DESC_CNT_TRSHLD */
309 #define CNT_TRSHLD		0xffff
310 #define DEFAULT_CNT_THRSHLD	0x4
311 
312 /* BAM_IRQ_SRCS */
313 #define BAM_IRQ			BIT(31)
314 #define P_IRQ			0x7fffffff
315 
316 /* BAM_IRQ_SRCS_MSK */
317 #define BAM_IRQ_MSK		BAM_IRQ
318 #define P_IRQ_MSK		P_IRQ
319 
320 /* BAM_IRQ_STTS */
321 #define BAM_TIMER_IRQ		BIT(4)
322 #define BAM_EMPTY_IRQ		BIT(3)
323 #define BAM_ERROR_IRQ		BIT(2)
324 #define BAM_HRESP_ERR_IRQ	BIT(1)
325 
326 /* BAM_IRQ_CLR */
327 #define BAM_TIMER_CLR		BIT(4)
328 #define BAM_EMPTY_CLR		BIT(3)
329 #define BAM_ERROR_CLR		BIT(2)
330 #define BAM_HRESP_ERR_CLR	BIT(1)
331 
332 /* BAM_IRQ_EN */
333 #define BAM_TIMER_EN		BIT(4)
334 #define BAM_EMPTY_EN		BIT(3)
335 #define BAM_ERROR_EN		BIT(2)
336 #define BAM_HRESP_ERR_EN	BIT(1)
337 
338 /* BAM_P_IRQ_EN */
339 #define P_PRCSD_DESC_EN		BIT(0)
340 #define P_TIMER_EN		BIT(1)
341 #define P_WAKE_EN		BIT(2)
342 #define P_OUT_OF_DESC_EN	BIT(3)
343 #define P_ERR_EN		BIT(4)
344 #define P_TRNSFR_END_EN		BIT(5)
345 #define P_DEFAULT_IRQS_EN	(P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
346 
347 /* BAM_P_SW_OFSTS */
348 #define P_SW_OFSTS_MASK		0xffff
349 
350 #define BAM_DESC_FIFO_SIZE	SZ_32K
351 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
352 #define BAM_FIFO_SIZE	(SZ_32K - 8)
353 #define IS_BUSY(chan)	(CIRC_SPACE(bchan->tail, bchan->head,\
354 			 MAX_DESCRIPTORS + 1) == 0)
355 
356 struct bam_chan {
357 	struct virt_dma_chan vc;
358 
359 	struct bam_device *bdev;
360 
361 	/* configuration from device tree */
362 	u32 id;
363 
364 	/* runtime configuration */
365 	struct dma_slave_config slave;
366 
367 	/* fifo storage */
368 	struct bam_desc_hw *fifo_virt;
369 	dma_addr_t fifo_phys;
370 
371 	/* fifo markers */
372 	unsigned short head;		/* start of active descriptor entries */
373 	unsigned short tail;		/* end of active descriptor entries */
374 
375 	unsigned int initialized;	/* is the channel hw initialized? */
376 	unsigned int paused;		/* is the channel paused? */
377 	unsigned int reconfigure;	/* new slave config? */
378 	/* list of descriptors currently processed */
379 	struct list_head desc_list;
380 
381 	struct list_head node;
382 };
383 
384 static inline struct bam_chan *to_bam_chan(struct dma_chan *common)
385 {
386 	return container_of(common, struct bam_chan, vc.chan);
387 }
388 
389 struct bam_device {
390 	void __iomem *regs;
391 	struct device *dev;
392 	struct dma_device common;
393 	struct device_dma_parameters dma_parms;
394 	struct bam_chan *channels;
395 	u32 num_channels;
396 
397 	/* execution environment ID, from DT */
398 	u32 ee;
399 	bool controlled_remotely;
400 
401 	const struct reg_offset_data *layout;
402 
403 	struct clk *bamclk;
404 	int irq;
405 
406 	/* dma start transaction tasklet */
407 	struct tasklet_struct task;
408 };
409 
410 /**
411  * bam_addr - returns BAM register address
412  * @bdev: bam device
413  * @pipe: pipe instance (ignored when register doesn't have multiple instances)
414  * @reg:  register enum
415  */
416 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
417 		enum bam_reg reg)
418 {
419 	const struct reg_offset_data r = bdev->layout[reg];
420 
421 	return bdev->regs + r.base_offset +
422 		r.pipe_mult * pipe +
423 		r.evnt_mult * pipe +
424 		r.ee_mult * bdev->ee;
425 }
426 
427 /**
428  * bam_reset_channel - Reset individual BAM DMA channel
429  * @bchan: bam channel
430  *
431  * This function resets a specific BAM channel
432  */
433 static void bam_reset_channel(struct bam_chan *bchan)
434 {
435 	struct bam_device *bdev = bchan->bdev;
436 
437 	lockdep_assert_held(&bchan->vc.lock);
438 
439 	/* reset channel */
440 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
441 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
442 
443 	/* don't allow cpu to reorder BAM register accesses done after this */
444 	wmb();
445 
446 	/* make sure hw is initialized when channel is used the first time  */
447 	bchan->initialized = 0;
448 }
449 
450 /**
451  * bam_chan_init_hw - Initialize channel hardware
452  * @bchan: bam channel
453  *
454  * This function resets and initializes the BAM channel
455  */
456 static void bam_chan_init_hw(struct bam_chan *bchan,
457 	enum dma_transfer_direction dir)
458 {
459 	struct bam_device *bdev = bchan->bdev;
460 	u32 val;
461 
462 	/* Reset the channel to clear internal state of the FIFO */
463 	bam_reset_channel(bchan);
464 
465 	/*
466 	 * write out 8 byte aligned address.  We have enough space for this
467 	 * because we allocated 1 more descriptor (8 bytes) than we can use
468 	 */
469 	writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
470 			bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
471 	writel_relaxed(BAM_FIFO_SIZE,
472 			bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
473 
474 	/* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
475 	writel_relaxed(P_DEFAULT_IRQS_EN,
476 			bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
477 
478 	/* unmask the specific pipe and EE combo */
479 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
480 	val |= BIT(bchan->id);
481 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
482 
483 	/* don't allow cpu to reorder the channel enable done below */
484 	wmb();
485 
486 	/* set fixed direction and mode, then enable channel */
487 	val = P_EN | P_SYS_MODE;
488 	if (dir == DMA_DEV_TO_MEM)
489 		val |= P_DIRECTION;
490 
491 	writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
492 
493 	bchan->initialized = 1;
494 
495 	/* init FIFO pointers */
496 	bchan->head = 0;
497 	bchan->tail = 0;
498 }
499 
500 /**
501  * bam_alloc_chan - Allocate channel resources for DMA channel.
502  * @chan: specified channel
503  *
504  * This function allocates the FIFO descriptor memory
505  */
506 static int bam_alloc_chan(struct dma_chan *chan)
507 {
508 	struct bam_chan *bchan = to_bam_chan(chan);
509 	struct bam_device *bdev = bchan->bdev;
510 
511 	if (bchan->fifo_virt)
512 		return 0;
513 
514 	/* allocate FIFO descriptor space, but only if necessary */
515 	bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
516 					&bchan->fifo_phys, GFP_KERNEL);
517 
518 	if (!bchan->fifo_virt) {
519 		dev_err(bdev->dev, "Failed to allocate desc fifo\n");
520 		return -ENOMEM;
521 	}
522 
523 	return 0;
524 }
525 
526 /**
527  * bam_free_chan - Frees dma resources associated with specific channel
528  * @chan: specified channel
529  *
530  * Free the allocated fifo descriptor memory and channel resources
531  *
532  */
533 static void bam_free_chan(struct dma_chan *chan)
534 {
535 	struct bam_chan *bchan = to_bam_chan(chan);
536 	struct bam_device *bdev = bchan->bdev;
537 	u32 val;
538 	unsigned long flags;
539 	int ret;
540 
541 	ret = pm_runtime_get_sync(bdev->dev);
542 	if (ret < 0)
543 		return;
544 
545 	vchan_free_chan_resources(to_virt_chan(chan));
546 
547 	if (!list_empty(&bchan->desc_list)) {
548 		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
549 		goto err;
550 	}
551 
552 	spin_lock_irqsave(&bchan->vc.lock, flags);
553 	bam_reset_channel(bchan);
554 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
555 
556 	dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
557 		    bchan->fifo_phys);
558 	bchan->fifo_virt = NULL;
559 
560 	/* mask irq for pipe/channel */
561 	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
562 	val &= ~BIT(bchan->id);
563 	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
564 
565 	/* disable irq */
566 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
567 
568 err:
569 	pm_runtime_mark_last_busy(bdev->dev);
570 	pm_runtime_put_autosuspend(bdev->dev);
571 }
572 
573 /**
574  * bam_slave_config - set slave configuration for channel
575  * @chan: dma channel
576  * @cfg: slave configuration
577  *
578  * Sets slave configuration for channel
579  *
580  */
581 static int bam_slave_config(struct dma_chan *chan,
582 			    struct dma_slave_config *cfg)
583 {
584 	struct bam_chan *bchan = to_bam_chan(chan);
585 	unsigned long flag;
586 
587 	spin_lock_irqsave(&bchan->vc.lock, flag);
588 	memcpy(&bchan->slave, cfg, sizeof(*cfg));
589 	bchan->reconfigure = 1;
590 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
591 
592 	return 0;
593 }
594 
595 /**
596  * bam_prep_slave_sg - Prep slave sg transaction
597  *
598  * @chan: dma channel
599  * @sgl: scatter gather list
600  * @sg_len: length of sg
601  * @direction: DMA transfer direction
602  * @flags: DMA flags
603  * @context: transfer context (unused)
604  */
605 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
606 	struct scatterlist *sgl, unsigned int sg_len,
607 	enum dma_transfer_direction direction, unsigned long flags,
608 	void *context)
609 {
610 	struct bam_chan *bchan = to_bam_chan(chan);
611 	struct bam_device *bdev = bchan->bdev;
612 	struct bam_async_desc *async_desc;
613 	struct scatterlist *sg;
614 	u32 i;
615 	struct bam_desc_hw *desc;
616 	unsigned int num_alloc = 0;
617 
618 
619 	if (!is_slave_direction(direction)) {
620 		dev_err(bdev->dev, "invalid dma direction\n");
621 		return NULL;
622 	}
623 
624 	/* calculate number of required entries */
625 	for_each_sg(sgl, sg, sg_len, i)
626 		num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE);
627 
628 	/* allocate enough room to accomodate the number of entries */
629 	async_desc = kzalloc(sizeof(*async_desc) +
630 			(num_alloc * sizeof(struct bam_desc_hw)), GFP_NOWAIT);
631 
632 	if (!async_desc)
633 		goto err_out;
634 
635 	if (flags & DMA_PREP_FENCE)
636 		async_desc->flags |= DESC_FLAG_NWD;
637 
638 	if (flags & DMA_PREP_INTERRUPT)
639 		async_desc->flags |= DESC_FLAG_EOT;
640 
641 	async_desc->num_desc = num_alloc;
642 	async_desc->curr_desc = async_desc->desc;
643 	async_desc->dir = direction;
644 
645 	/* fill in temporary descriptors */
646 	desc = async_desc->desc;
647 	for_each_sg(sgl, sg, sg_len, i) {
648 		unsigned int remainder = sg_dma_len(sg);
649 		unsigned int curr_offset = 0;
650 
651 		do {
652 			if (flags & DMA_PREP_CMD)
653 				desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
654 
655 			desc->addr = cpu_to_le32(sg_dma_address(sg) +
656 						 curr_offset);
657 
658 			if (remainder > BAM_FIFO_SIZE) {
659 				desc->size = cpu_to_le16(BAM_FIFO_SIZE);
660 				remainder -= BAM_FIFO_SIZE;
661 				curr_offset += BAM_FIFO_SIZE;
662 			} else {
663 				desc->size = cpu_to_le16(remainder);
664 				remainder = 0;
665 			}
666 
667 			async_desc->length += desc->size;
668 			desc++;
669 		} while (remainder > 0);
670 	}
671 
672 	return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
673 
674 err_out:
675 	kfree(async_desc);
676 	return NULL;
677 }
678 
679 /**
680  * bam_dma_terminate_all - terminate all transactions on a channel
681  * @bchan: bam dma channel
682  *
683  * Dequeues and frees all transactions
684  * No callbacks are done
685  *
686  */
687 static int bam_dma_terminate_all(struct dma_chan *chan)
688 {
689 	struct bam_chan *bchan = to_bam_chan(chan);
690 	struct bam_async_desc *async_desc, *tmp;
691 	unsigned long flag;
692 	LIST_HEAD(head);
693 
694 	/* remove all transactions, including active transaction */
695 	spin_lock_irqsave(&bchan->vc.lock, flag);
696 	list_for_each_entry_safe(async_desc, tmp,
697 				 &bchan->desc_list, desc_node) {
698 		list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
699 		list_del(&async_desc->desc_node);
700 	}
701 
702 	vchan_get_all_descriptors(&bchan->vc, &head);
703 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
704 
705 	vchan_dma_desc_free_list(&bchan->vc, &head);
706 
707 	return 0;
708 }
709 
710 /**
711  * bam_pause - Pause DMA channel
712  * @chan: dma channel
713  *
714  */
715 static int bam_pause(struct dma_chan *chan)
716 {
717 	struct bam_chan *bchan = to_bam_chan(chan);
718 	struct bam_device *bdev = bchan->bdev;
719 	unsigned long flag;
720 	int ret;
721 
722 	ret = pm_runtime_get_sync(bdev->dev);
723 	if (ret < 0)
724 		return ret;
725 
726 	spin_lock_irqsave(&bchan->vc.lock, flag);
727 	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
728 	bchan->paused = 1;
729 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
730 	pm_runtime_mark_last_busy(bdev->dev);
731 	pm_runtime_put_autosuspend(bdev->dev);
732 
733 	return 0;
734 }
735 
736 /**
737  * bam_resume - Resume DMA channel operations
738  * @chan: dma channel
739  *
740  */
741 static int bam_resume(struct dma_chan *chan)
742 {
743 	struct bam_chan *bchan = to_bam_chan(chan);
744 	struct bam_device *bdev = bchan->bdev;
745 	unsigned long flag;
746 	int ret;
747 
748 	ret = pm_runtime_get_sync(bdev->dev);
749 	if (ret < 0)
750 		return ret;
751 
752 	spin_lock_irqsave(&bchan->vc.lock, flag);
753 	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
754 	bchan->paused = 0;
755 	spin_unlock_irqrestore(&bchan->vc.lock, flag);
756 	pm_runtime_mark_last_busy(bdev->dev);
757 	pm_runtime_put_autosuspend(bdev->dev);
758 
759 	return 0;
760 }
761 
762 /**
763  * process_channel_irqs - processes the channel interrupts
764  * @bdev: bam controller
765  *
766  * This function processes the channel interrupts
767  *
768  */
769 static u32 process_channel_irqs(struct bam_device *bdev)
770 {
771 	u32 i, srcs, pipe_stts, offset, avail;
772 	unsigned long flags;
773 	struct bam_async_desc *async_desc, *tmp;
774 
775 	srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
776 
777 	/* return early if no pipe/channel interrupts are present */
778 	if (!(srcs & P_IRQ))
779 		return srcs;
780 
781 	for (i = 0; i < bdev->num_channels; i++) {
782 		struct bam_chan *bchan = &bdev->channels[i];
783 
784 		if (!(srcs & BIT(i)))
785 			continue;
786 
787 		/* clear pipe irq */
788 		pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
789 
790 		writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
791 
792 		spin_lock_irqsave(&bchan->vc.lock, flags);
793 
794 		offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) &
795 				       P_SW_OFSTS_MASK;
796 		offset /= sizeof(struct bam_desc_hw);
797 
798 		/* Number of bytes available to read */
799 		avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
800 
801 		list_for_each_entry_safe(async_desc, tmp,
802 					 &bchan->desc_list, desc_node) {
803 			/* Not enough data to read */
804 			if (avail < async_desc->xfer_len)
805 				break;
806 
807 			/* manage FIFO */
808 			bchan->head += async_desc->xfer_len;
809 			bchan->head %= MAX_DESCRIPTORS;
810 
811 			async_desc->num_desc -= async_desc->xfer_len;
812 			async_desc->curr_desc += async_desc->xfer_len;
813 			avail -= async_desc->xfer_len;
814 
815 			/*
816 			 * if complete, process cookie. Otherwise
817 			 * push back to front of desc_issued so that
818 			 * it gets restarted by the tasklet
819 			 */
820 			if (!async_desc->num_desc) {
821 				vchan_cookie_complete(&async_desc->vd);
822 			} else {
823 				list_add(&async_desc->vd.node,
824 					 &bchan->vc.desc_issued);
825 			}
826 			list_del(&async_desc->desc_node);
827 		}
828 
829 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
830 	}
831 
832 	return srcs;
833 }
834 
835 /**
836  * bam_dma_irq - irq handler for bam controller
837  * @irq: IRQ of interrupt
838  * @data: callback data
839  *
840  * IRQ handler for the bam controller
841  */
842 static irqreturn_t bam_dma_irq(int irq, void *data)
843 {
844 	struct bam_device *bdev = data;
845 	u32 clr_mask = 0, srcs = 0;
846 	int ret;
847 
848 	srcs |= process_channel_irqs(bdev);
849 
850 	/* kick off tasklet to start next dma transfer */
851 	if (srcs & P_IRQ)
852 		tasklet_schedule(&bdev->task);
853 
854 	ret = pm_runtime_get_sync(bdev->dev);
855 	if (ret < 0)
856 		return ret;
857 
858 	if (srcs & BAM_IRQ) {
859 		clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
860 
861 		/*
862 		 * don't allow reorder of the various accesses to the BAM
863 		 * registers
864 		 */
865 		mb();
866 
867 		writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
868 	}
869 
870 	pm_runtime_mark_last_busy(bdev->dev);
871 	pm_runtime_put_autosuspend(bdev->dev);
872 
873 	return IRQ_HANDLED;
874 }
875 
876 /**
877  * bam_tx_status - returns status of transaction
878  * @chan: dma channel
879  * @cookie: transaction cookie
880  * @txstate: DMA transaction state
881  *
882  * Return status of dma transaction
883  */
884 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
885 		struct dma_tx_state *txstate)
886 {
887 	struct bam_chan *bchan = to_bam_chan(chan);
888 	struct bam_async_desc *async_desc;
889 	struct virt_dma_desc *vd;
890 	int ret;
891 	size_t residue = 0;
892 	unsigned int i;
893 	unsigned long flags;
894 
895 	ret = dma_cookie_status(chan, cookie, txstate);
896 	if (ret == DMA_COMPLETE)
897 		return ret;
898 
899 	if (!txstate)
900 		return bchan->paused ? DMA_PAUSED : ret;
901 
902 	spin_lock_irqsave(&bchan->vc.lock, flags);
903 	vd = vchan_find_desc(&bchan->vc, cookie);
904 	if (vd) {
905 		residue = container_of(vd, struct bam_async_desc, vd)->length;
906 	} else {
907 		list_for_each_entry(async_desc, &bchan->desc_list, desc_node) {
908 			if (async_desc->vd.tx.cookie != cookie)
909 				continue;
910 
911 			for (i = 0; i < async_desc->num_desc; i++)
912 				residue += async_desc->curr_desc[i].size;
913 		}
914 	}
915 
916 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
917 
918 	dma_set_residue(txstate, residue);
919 
920 	if (ret == DMA_IN_PROGRESS && bchan->paused)
921 		ret = DMA_PAUSED;
922 
923 	return ret;
924 }
925 
926 /**
927  * bam_apply_new_config
928  * @bchan: bam dma channel
929  * @dir: DMA direction
930  */
931 static void bam_apply_new_config(struct bam_chan *bchan,
932 	enum dma_transfer_direction dir)
933 {
934 	struct bam_device *bdev = bchan->bdev;
935 	u32 maxburst;
936 
937 	if (dir == DMA_DEV_TO_MEM)
938 		maxburst = bchan->slave.src_maxburst;
939 	else
940 		maxburst = bchan->slave.dst_maxburst;
941 
942 	writel_relaxed(maxburst, bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
943 
944 	bchan->reconfigure = 0;
945 }
946 
947 /**
948  * bam_start_dma - start next transaction
949  * @bchan - bam dma channel
950  */
951 static void bam_start_dma(struct bam_chan *bchan)
952 {
953 	struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
954 	struct bam_device *bdev = bchan->bdev;
955 	struct bam_async_desc *async_desc = NULL;
956 	struct bam_desc_hw *desc;
957 	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
958 					sizeof(struct bam_desc_hw));
959 	int ret;
960 	unsigned int avail;
961 	struct dmaengine_desc_callback cb;
962 
963 	lockdep_assert_held(&bchan->vc.lock);
964 
965 	if (!vd)
966 		return;
967 
968 	ret = pm_runtime_get_sync(bdev->dev);
969 	if (ret < 0)
970 		return;
971 
972 	while (vd && !IS_BUSY(bchan)) {
973 		list_del(&vd->node);
974 
975 		async_desc = container_of(vd, struct bam_async_desc, vd);
976 
977 		/* on first use, initialize the channel hardware */
978 		if (!bchan->initialized)
979 			bam_chan_init_hw(bchan, async_desc->dir);
980 
981 		/* apply new slave config changes, if necessary */
982 		if (bchan->reconfigure)
983 			bam_apply_new_config(bchan, async_desc->dir);
984 
985 		desc = async_desc->curr_desc;
986 		avail = CIRC_SPACE(bchan->tail, bchan->head,
987 				   MAX_DESCRIPTORS + 1);
988 
989 		if (async_desc->num_desc > avail)
990 			async_desc->xfer_len = avail;
991 		else
992 			async_desc->xfer_len = async_desc->num_desc;
993 
994 		/* set any special flags on the last descriptor */
995 		if (async_desc->num_desc == async_desc->xfer_len)
996 			desc[async_desc->xfer_len - 1].flags |=
997 						cpu_to_le16(async_desc->flags);
998 
999 		vd = vchan_next_desc(&bchan->vc);
1000 
1001 		dmaengine_desc_get_callback(&async_desc->vd.tx, &cb);
1002 
1003 		/*
1004 		 * An interrupt is generated at this desc, if
1005 		 *  - FIFO is FULL.
1006 		 *  - No more descriptors to add.
1007 		 *  - If a callback completion was requested for this DESC,
1008 		 *     In this case, BAM will deliver the completion callback
1009 		 *     for this desc and continue processing the next desc.
1010 		 */
1011 		if (((avail <= async_desc->xfer_len) || !vd ||
1012 		     dmaengine_desc_callback_valid(&cb)) &&
1013 		    !(async_desc->flags & DESC_FLAG_EOT))
1014 			desc[async_desc->xfer_len - 1].flags |=
1015 				cpu_to_le16(DESC_FLAG_INT);
1016 
1017 		if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
1018 			u32 partial = MAX_DESCRIPTORS - bchan->tail;
1019 
1020 			memcpy(&fifo[bchan->tail], desc,
1021 			       partial * sizeof(struct bam_desc_hw));
1022 			memcpy(fifo, &desc[partial],
1023 			       (async_desc->xfer_len - partial) *
1024 				sizeof(struct bam_desc_hw));
1025 		} else {
1026 			memcpy(&fifo[bchan->tail], desc,
1027 			       async_desc->xfer_len *
1028 			       sizeof(struct bam_desc_hw));
1029 		}
1030 
1031 		bchan->tail += async_desc->xfer_len;
1032 		bchan->tail %= MAX_DESCRIPTORS;
1033 		list_add_tail(&async_desc->desc_node, &bchan->desc_list);
1034 	}
1035 
1036 	/* ensure descriptor writes and dma start not reordered */
1037 	wmb();
1038 	writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
1039 			bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
1040 
1041 	pm_runtime_mark_last_busy(bdev->dev);
1042 	pm_runtime_put_autosuspend(bdev->dev);
1043 }
1044 
1045 /**
1046  * dma_tasklet - DMA IRQ tasklet
1047  * @data: tasklet argument (bam controller structure)
1048  *
1049  * Sets up next DMA operation and then processes all completed transactions
1050  */
1051 static void dma_tasklet(unsigned long data)
1052 {
1053 	struct bam_device *bdev = (struct bam_device *)data;
1054 	struct bam_chan *bchan;
1055 	unsigned long flags;
1056 	unsigned int i;
1057 
1058 	/* go through the channels and kick off transactions */
1059 	for (i = 0; i < bdev->num_channels; i++) {
1060 		bchan = &bdev->channels[i];
1061 		spin_lock_irqsave(&bchan->vc.lock, flags);
1062 
1063 		if (!list_empty(&bchan->vc.desc_issued) && !IS_BUSY(bchan))
1064 			bam_start_dma(bchan);
1065 		spin_unlock_irqrestore(&bchan->vc.lock, flags);
1066 	}
1067 
1068 }
1069 
1070 /**
1071  * bam_issue_pending - starts pending transactions
1072  * @chan: dma channel
1073  *
1074  * Calls tasklet directly which in turn starts any pending transactions
1075  */
1076 static void bam_issue_pending(struct dma_chan *chan)
1077 {
1078 	struct bam_chan *bchan = to_bam_chan(chan);
1079 	unsigned long flags;
1080 
1081 	spin_lock_irqsave(&bchan->vc.lock, flags);
1082 
1083 	/* if work pending and idle, start a transaction */
1084 	if (vchan_issue_pending(&bchan->vc) && !IS_BUSY(bchan))
1085 		bam_start_dma(bchan);
1086 
1087 	spin_unlock_irqrestore(&bchan->vc.lock, flags);
1088 }
1089 
1090 /**
1091  * bam_dma_free_desc - free descriptor memory
1092  * @vd: virtual descriptor
1093  *
1094  */
1095 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1096 {
1097 	struct bam_async_desc *async_desc = container_of(vd,
1098 			struct bam_async_desc, vd);
1099 
1100 	kfree(async_desc);
1101 }
1102 
1103 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1104 		struct of_dma *of)
1105 {
1106 	struct bam_device *bdev = container_of(of->of_dma_data,
1107 					struct bam_device, common);
1108 	unsigned int request;
1109 
1110 	if (dma_spec->args_count != 1)
1111 		return NULL;
1112 
1113 	request = dma_spec->args[0];
1114 	if (request >= bdev->num_channels)
1115 		return NULL;
1116 
1117 	return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1118 }
1119 
1120 /**
1121  * bam_init
1122  * @bdev: bam device
1123  *
1124  * Initialization helper for global bam registers
1125  */
1126 static int bam_init(struct bam_device *bdev)
1127 {
1128 	u32 val;
1129 
1130 	/* read revision and configuration information */
1131 	val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)) >> NUM_EES_SHIFT;
1132 	val &= NUM_EES_MASK;
1133 
1134 	/* check that configured EE is within range */
1135 	if (bdev->ee >= val)
1136 		return -EINVAL;
1137 
1138 	val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1139 	bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1140 
1141 	if (bdev->controlled_remotely)
1142 		return 0;
1143 
1144 	/* s/w reset bam */
1145 	/* after reset all pipes are disabled and idle */
1146 	val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
1147 	val |= BAM_SW_RST;
1148 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1149 	val &= ~BAM_SW_RST;
1150 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1151 
1152 	/* make sure previous stores are visible before enabling BAM */
1153 	wmb();
1154 
1155 	/* enable bam */
1156 	val |= BAM_EN;
1157 	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
1158 
1159 	/* set descriptor threshhold, start with 4 bytes */
1160 	writel_relaxed(DEFAULT_CNT_THRSHLD,
1161 			bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1162 
1163 	/* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
1164 	writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
1165 
1166 	/* enable irqs for errors */
1167 	writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
1168 			bam_addr(bdev, 0, BAM_IRQ_EN));
1169 
1170 	/* unmask global bam interrupt */
1171 	writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
1172 
1173 	return 0;
1174 }
1175 
1176 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1177 	u32 index)
1178 {
1179 	bchan->id = index;
1180 	bchan->bdev = bdev;
1181 
1182 	vchan_init(&bchan->vc, &bdev->common);
1183 	bchan->vc.desc_free = bam_dma_free_desc;
1184 	INIT_LIST_HEAD(&bchan->desc_list);
1185 }
1186 
1187 static const struct of_device_id bam_of_match[] = {
1188 	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1189 	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1190 	{ .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1191 	{}
1192 };
1193 
1194 MODULE_DEVICE_TABLE(of, bam_of_match);
1195 
1196 static int bam_dma_probe(struct platform_device *pdev)
1197 {
1198 	struct bam_device *bdev;
1199 	const struct of_device_id *match;
1200 	struct resource *iores;
1201 	int ret, i;
1202 
1203 	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1204 	if (!bdev)
1205 		return -ENOMEM;
1206 
1207 	bdev->dev = &pdev->dev;
1208 
1209 	match = of_match_node(bam_of_match, pdev->dev.of_node);
1210 	if (!match) {
1211 		dev_err(&pdev->dev, "Unsupported BAM module\n");
1212 		return -ENODEV;
1213 	}
1214 
1215 	bdev->layout = match->data;
1216 
1217 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1218 	bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
1219 	if (IS_ERR(bdev->regs))
1220 		return PTR_ERR(bdev->regs);
1221 
1222 	bdev->irq = platform_get_irq(pdev, 0);
1223 	if (bdev->irq < 0)
1224 		return bdev->irq;
1225 
1226 	ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1227 	if (ret) {
1228 		dev_err(bdev->dev, "Execution environment unspecified\n");
1229 		return ret;
1230 	}
1231 
1232 	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
1233 						"qcom,controlled-remotely");
1234 
1235 	bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1236 	if (IS_ERR(bdev->bamclk))
1237 		return PTR_ERR(bdev->bamclk);
1238 
1239 	ret = clk_prepare_enable(bdev->bamclk);
1240 	if (ret) {
1241 		dev_err(bdev->dev, "failed to prepare/enable clock\n");
1242 		return ret;
1243 	}
1244 
1245 	ret = bam_init(bdev);
1246 	if (ret)
1247 		goto err_disable_clk;
1248 
1249 	tasklet_init(&bdev->task, dma_tasklet, (unsigned long)bdev);
1250 
1251 	bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1252 				sizeof(*bdev->channels), GFP_KERNEL);
1253 
1254 	if (!bdev->channels) {
1255 		ret = -ENOMEM;
1256 		goto err_tasklet_kill;
1257 	}
1258 
1259 	/* allocate and initialize channels */
1260 	INIT_LIST_HEAD(&bdev->common.channels);
1261 
1262 	for (i = 0; i < bdev->num_channels; i++)
1263 		bam_channel_init(bdev, &bdev->channels[i], i);
1264 
1265 	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1266 			IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1267 	if (ret)
1268 		goto err_bam_channel_exit;
1269 
1270 	/* set max dma segment size */
1271 	bdev->common.dev = bdev->dev;
1272 	bdev->common.dev->dma_parms = &bdev->dma_parms;
1273 	ret = dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1274 	if (ret) {
1275 		dev_err(bdev->dev, "cannot set maximum segment size\n");
1276 		goto err_bam_channel_exit;
1277 	}
1278 
1279 	platform_set_drvdata(pdev, bdev);
1280 
1281 	/* set capabilities */
1282 	dma_cap_zero(bdev->common.cap_mask);
1283 	dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1284 
1285 	/* initialize dmaengine apis */
1286 	bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1287 	bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1288 	bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1289 	bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1290 	bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1291 	bdev->common.device_free_chan_resources = bam_free_chan;
1292 	bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1293 	bdev->common.device_config = bam_slave_config;
1294 	bdev->common.device_pause = bam_pause;
1295 	bdev->common.device_resume = bam_resume;
1296 	bdev->common.device_terminate_all = bam_dma_terminate_all;
1297 	bdev->common.device_issue_pending = bam_issue_pending;
1298 	bdev->common.device_tx_status = bam_tx_status;
1299 	bdev->common.dev = bdev->dev;
1300 
1301 	ret = dma_async_device_register(&bdev->common);
1302 	if (ret) {
1303 		dev_err(bdev->dev, "failed to register dma async device\n");
1304 		goto err_bam_channel_exit;
1305 	}
1306 
1307 	ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1308 					&bdev->common);
1309 	if (ret)
1310 		goto err_unregister_dma;
1311 
1312 	pm_runtime_irq_safe(&pdev->dev);
1313 	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
1314 	pm_runtime_use_autosuspend(&pdev->dev);
1315 	pm_runtime_mark_last_busy(&pdev->dev);
1316 	pm_runtime_set_active(&pdev->dev);
1317 	pm_runtime_enable(&pdev->dev);
1318 
1319 	return 0;
1320 
1321 err_unregister_dma:
1322 	dma_async_device_unregister(&bdev->common);
1323 err_bam_channel_exit:
1324 	for (i = 0; i < bdev->num_channels; i++)
1325 		tasklet_kill(&bdev->channels[i].vc.task);
1326 err_tasklet_kill:
1327 	tasklet_kill(&bdev->task);
1328 err_disable_clk:
1329 	clk_disable_unprepare(bdev->bamclk);
1330 
1331 	return ret;
1332 }
1333 
1334 static int bam_dma_remove(struct platform_device *pdev)
1335 {
1336 	struct bam_device *bdev = platform_get_drvdata(pdev);
1337 	u32 i;
1338 
1339 	pm_runtime_force_suspend(&pdev->dev);
1340 
1341 	of_dma_controller_free(pdev->dev.of_node);
1342 	dma_async_device_unregister(&bdev->common);
1343 
1344 	/* mask all interrupts for this execution environment */
1345 	writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
1346 
1347 	devm_free_irq(bdev->dev, bdev->irq, bdev);
1348 
1349 	for (i = 0; i < bdev->num_channels; i++) {
1350 		bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1351 		tasklet_kill(&bdev->channels[i].vc.task);
1352 
1353 		if (!bdev->channels[i].fifo_virt)
1354 			continue;
1355 
1356 		dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1357 			    bdev->channels[i].fifo_virt,
1358 			    bdev->channels[i].fifo_phys);
1359 	}
1360 
1361 	tasklet_kill(&bdev->task);
1362 
1363 	clk_disable_unprepare(bdev->bamclk);
1364 
1365 	return 0;
1366 }
1367 
1368 static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
1369 {
1370 	struct bam_device *bdev = dev_get_drvdata(dev);
1371 
1372 	clk_disable(bdev->bamclk);
1373 
1374 	return 0;
1375 }
1376 
1377 static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
1378 {
1379 	struct bam_device *bdev = dev_get_drvdata(dev);
1380 	int ret;
1381 
1382 	ret = clk_enable(bdev->bamclk);
1383 	if (ret < 0) {
1384 		dev_err(dev, "clk_enable failed: %d\n", ret);
1385 		return ret;
1386 	}
1387 
1388 	return 0;
1389 }
1390 
1391 static int __maybe_unused bam_dma_suspend(struct device *dev)
1392 {
1393 	struct bam_device *bdev = dev_get_drvdata(dev);
1394 
1395 	pm_runtime_force_suspend(dev);
1396 
1397 	clk_unprepare(bdev->bamclk);
1398 
1399 	return 0;
1400 }
1401 
1402 static int __maybe_unused bam_dma_resume(struct device *dev)
1403 {
1404 	struct bam_device *bdev = dev_get_drvdata(dev);
1405 	int ret;
1406 
1407 	ret = clk_prepare(bdev->bamclk);
1408 	if (ret)
1409 		return ret;
1410 
1411 	pm_runtime_force_resume(dev);
1412 
1413 	return 0;
1414 }
1415 
1416 static const struct dev_pm_ops bam_dma_pm_ops = {
1417 	SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
1418 	SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
1419 				NULL)
1420 };
1421 
1422 static struct platform_driver bam_dma_driver = {
1423 	.probe = bam_dma_probe,
1424 	.remove = bam_dma_remove,
1425 	.driver = {
1426 		.name = "bam-dma-engine",
1427 		.pm = &bam_dma_pm_ops,
1428 		.of_match_table = bam_of_match,
1429 	},
1430 };
1431 
1432 module_platform_driver(bam_dma_driver);
1433 
1434 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1435 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1436 MODULE_LICENSE("GPL v2");
1437