1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
4 */
5 /*
6 * QCOM BAM DMA engine driver
7 *
8 * QCOM BAM DMA blocks are distributed amongst a number of the on-chip
9 * peripherals on the MSM 8x74. The configuration of the channels are dependent
10 * on the way they are hard wired to that specific peripheral. The peripheral
11 * device tree entries specify the configuration of each channel.
12 *
13 * The DMA controller requires the use of external memory for storage of the
14 * hardware descriptors for each channel. The descriptor FIFO is accessed as a
15 * circular buffer and operations are managed according to the offset within the
16 * FIFO. After pipe/channel reset, all of the pipe registers and internal state
17 * are back to defaults.
18 *
19 * During DMA operations, we write descriptors to the FIFO, being careful to
20 * handle wrapping and then write the last FIFO offset to that channel's
21 * P_EVNT_REG register to kick off the transaction. The P_SW_OFSTS register
22 * indicates the current FIFO offset that is being processed, so there is some
23 * indication of where the hardware is currently working.
24 */
25
26 #include <linux/kernel.h>
27 #include <linux/io.h>
28 #include <linux/init.h>
29 #include <linux/slab.h>
30 #include <linux/module.h>
31 #include <linux/interrupt.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/scatterlist.h>
34 #include <linux/device.h>
35 #include <linux/platform_device.h>
36 #include <linux/of.h>
37 #include <linux/of_address.h>
38 #include <linux/of_irq.h>
39 #include <linux/of_dma.h>
40 #include <linux/circ_buf.h>
41 #include <linux/clk.h>
42 #include <linux/dmaengine.h>
43 #include <linux/pm_runtime.h>
44
45 #include "../dmaengine.h"
46 #include "../virt-dma.h"
47
48 struct bam_desc_hw {
49 __le32 addr; /* Buffer physical address */
50 __le16 size; /* Buffer size in bytes */
51 __le16 flags;
52 };
53
54 #define BAM_DMA_AUTOSUSPEND_DELAY 100
55
56 #define DESC_FLAG_INT BIT(15)
57 #define DESC_FLAG_EOT BIT(14)
58 #define DESC_FLAG_EOB BIT(13)
59 #define DESC_FLAG_NWD BIT(12)
60 #define DESC_FLAG_CMD BIT(11)
61
62 struct bam_async_desc {
63 struct virt_dma_desc vd;
64
65 u32 num_desc;
66 u32 xfer_len;
67
68 /* transaction flags, EOT|EOB|NWD */
69 u16 flags;
70
71 struct bam_desc_hw *curr_desc;
72
73 /* list node for the desc in the bam_chan list of descriptors */
74 struct list_head desc_node;
75 enum dma_transfer_direction dir;
76 size_t length;
77 struct bam_desc_hw desc[] __counted_by(num_desc);
78 };
79
80 enum bam_reg {
81 BAM_CTRL,
82 BAM_REVISION,
83 BAM_NUM_PIPES,
84 BAM_DESC_CNT_TRSHLD,
85 BAM_IRQ_SRCS,
86 BAM_IRQ_SRCS_MSK,
87 BAM_IRQ_SRCS_UNMASKED,
88 BAM_IRQ_STTS,
89 BAM_IRQ_CLR,
90 BAM_IRQ_EN,
91 BAM_CNFG_BITS,
92 BAM_IRQ_SRCS_EE,
93 BAM_IRQ_SRCS_MSK_EE,
94 BAM_P_CTRL,
95 BAM_P_RST,
96 BAM_P_HALT,
97 BAM_P_IRQ_STTS,
98 BAM_P_IRQ_CLR,
99 BAM_P_IRQ_EN,
100 BAM_P_EVNT_DEST_ADDR,
101 BAM_P_EVNT_REG,
102 BAM_P_SW_OFSTS,
103 BAM_P_DATA_FIFO_ADDR,
104 BAM_P_DESC_FIFO_ADDR,
105 BAM_P_EVNT_GEN_TRSHLD,
106 BAM_P_FIFO_SIZES,
107 };
108
109 struct reg_offset_data {
110 u32 base_offset;
111 unsigned int pipe_mult, evnt_mult, ee_mult;
112 };
113
114 static const struct reg_offset_data bam_v1_3_reg_info[] = {
115 [BAM_CTRL] = { 0x0F80, 0x00, 0x00, 0x00 },
116 [BAM_REVISION] = { 0x0F84, 0x00, 0x00, 0x00 },
117 [BAM_NUM_PIPES] = { 0x0FBC, 0x00, 0x00, 0x00 },
118 [BAM_DESC_CNT_TRSHLD] = { 0x0F88, 0x00, 0x00, 0x00 },
119 [BAM_IRQ_SRCS] = { 0x0F8C, 0x00, 0x00, 0x00 },
120 [BAM_IRQ_SRCS_MSK] = { 0x0F90, 0x00, 0x00, 0x00 },
121 [BAM_IRQ_SRCS_UNMASKED] = { 0x0FB0, 0x00, 0x00, 0x00 },
122 [BAM_IRQ_STTS] = { 0x0F94, 0x00, 0x00, 0x00 },
123 [BAM_IRQ_CLR] = { 0x0F98, 0x00, 0x00, 0x00 },
124 [BAM_IRQ_EN] = { 0x0F9C, 0x00, 0x00, 0x00 },
125 [BAM_CNFG_BITS] = { 0x0FFC, 0x00, 0x00, 0x00 },
126 [BAM_IRQ_SRCS_EE] = { 0x1800, 0x00, 0x00, 0x80 },
127 [BAM_IRQ_SRCS_MSK_EE] = { 0x1804, 0x00, 0x00, 0x80 },
128 [BAM_P_CTRL] = { 0x0000, 0x80, 0x00, 0x00 },
129 [BAM_P_RST] = { 0x0004, 0x80, 0x00, 0x00 },
130 [BAM_P_HALT] = { 0x0008, 0x80, 0x00, 0x00 },
131 [BAM_P_IRQ_STTS] = { 0x0010, 0x80, 0x00, 0x00 },
132 [BAM_P_IRQ_CLR] = { 0x0014, 0x80, 0x00, 0x00 },
133 [BAM_P_IRQ_EN] = { 0x0018, 0x80, 0x00, 0x00 },
134 [BAM_P_EVNT_DEST_ADDR] = { 0x102C, 0x00, 0x40, 0x00 },
135 [BAM_P_EVNT_REG] = { 0x1018, 0x00, 0x40, 0x00 },
136 [BAM_P_SW_OFSTS] = { 0x1000, 0x00, 0x40, 0x00 },
137 [BAM_P_DATA_FIFO_ADDR] = { 0x1024, 0x00, 0x40, 0x00 },
138 [BAM_P_DESC_FIFO_ADDR] = { 0x101C, 0x00, 0x40, 0x00 },
139 [BAM_P_EVNT_GEN_TRSHLD] = { 0x1028, 0x00, 0x40, 0x00 },
140 [BAM_P_FIFO_SIZES] = { 0x1020, 0x00, 0x40, 0x00 },
141 };
142
143 static const struct reg_offset_data bam_v1_4_reg_info[] = {
144 [BAM_CTRL] = { 0x0000, 0x00, 0x00, 0x00 },
145 [BAM_REVISION] = { 0x0004, 0x00, 0x00, 0x00 },
146 [BAM_NUM_PIPES] = { 0x003C, 0x00, 0x00, 0x00 },
147 [BAM_DESC_CNT_TRSHLD] = { 0x0008, 0x00, 0x00, 0x00 },
148 [BAM_IRQ_SRCS] = { 0x000C, 0x00, 0x00, 0x00 },
149 [BAM_IRQ_SRCS_MSK] = { 0x0010, 0x00, 0x00, 0x00 },
150 [BAM_IRQ_SRCS_UNMASKED] = { 0x0030, 0x00, 0x00, 0x00 },
151 [BAM_IRQ_STTS] = { 0x0014, 0x00, 0x00, 0x00 },
152 [BAM_IRQ_CLR] = { 0x0018, 0x00, 0x00, 0x00 },
153 [BAM_IRQ_EN] = { 0x001C, 0x00, 0x00, 0x00 },
154 [BAM_CNFG_BITS] = { 0x007C, 0x00, 0x00, 0x00 },
155 [BAM_IRQ_SRCS_EE] = { 0x0800, 0x00, 0x00, 0x80 },
156 [BAM_IRQ_SRCS_MSK_EE] = { 0x0804, 0x00, 0x00, 0x80 },
157 [BAM_P_CTRL] = { 0x1000, 0x1000, 0x00, 0x00 },
158 [BAM_P_RST] = { 0x1004, 0x1000, 0x00, 0x00 },
159 [BAM_P_HALT] = { 0x1008, 0x1000, 0x00, 0x00 },
160 [BAM_P_IRQ_STTS] = { 0x1010, 0x1000, 0x00, 0x00 },
161 [BAM_P_IRQ_CLR] = { 0x1014, 0x1000, 0x00, 0x00 },
162 [BAM_P_IRQ_EN] = { 0x1018, 0x1000, 0x00, 0x00 },
163 [BAM_P_EVNT_DEST_ADDR] = { 0x182C, 0x00, 0x1000, 0x00 },
164 [BAM_P_EVNT_REG] = { 0x1818, 0x00, 0x1000, 0x00 },
165 [BAM_P_SW_OFSTS] = { 0x1800, 0x00, 0x1000, 0x00 },
166 [BAM_P_DATA_FIFO_ADDR] = { 0x1824, 0x00, 0x1000, 0x00 },
167 [BAM_P_DESC_FIFO_ADDR] = { 0x181C, 0x00, 0x1000, 0x00 },
168 [BAM_P_EVNT_GEN_TRSHLD] = { 0x1828, 0x00, 0x1000, 0x00 },
169 [BAM_P_FIFO_SIZES] = { 0x1820, 0x00, 0x1000, 0x00 },
170 };
171
172 static const struct reg_offset_data bam_v1_7_reg_info[] = {
173 [BAM_CTRL] = { 0x00000, 0x00, 0x00, 0x00 },
174 [BAM_REVISION] = { 0x01000, 0x00, 0x00, 0x00 },
175 [BAM_NUM_PIPES] = { 0x01008, 0x00, 0x00, 0x00 },
176 [BAM_DESC_CNT_TRSHLD] = { 0x00008, 0x00, 0x00, 0x00 },
177 [BAM_IRQ_SRCS] = { 0x03010, 0x00, 0x00, 0x00 },
178 [BAM_IRQ_SRCS_MSK] = { 0x03014, 0x00, 0x00, 0x00 },
179 [BAM_IRQ_SRCS_UNMASKED] = { 0x03018, 0x00, 0x00, 0x00 },
180 [BAM_IRQ_STTS] = { 0x00014, 0x00, 0x00, 0x00 },
181 [BAM_IRQ_CLR] = { 0x00018, 0x00, 0x00, 0x00 },
182 [BAM_IRQ_EN] = { 0x0001C, 0x00, 0x00, 0x00 },
183 [BAM_CNFG_BITS] = { 0x0007C, 0x00, 0x00, 0x00 },
184 [BAM_IRQ_SRCS_EE] = { 0x03000, 0x00, 0x00, 0x1000 },
185 [BAM_IRQ_SRCS_MSK_EE] = { 0x03004, 0x00, 0x00, 0x1000 },
186 [BAM_P_CTRL] = { 0x13000, 0x1000, 0x00, 0x00 },
187 [BAM_P_RST] = { 0x13004, 0x1000, 0x00, 0x00 },
188 [BAM_P_HALT] = { 0x13008, 0x1000, 0x00, 0x00 },
189 [BAM_P_IRQ_STTS] = { 0x13010, 0x1000, 0x00, 0x00 },
190 [BAM_P_IRQ_CLR] = { 0x13014, 0x1000, 0x00, 0x00 },
191 [BAM_P_IRQ_EN] = { 0x13018, 0x1000, 0x00, 0x00 },
192 [BAM_P_EVNT_DEST_ADDR] = { 0x1382C, 0x00, 0x1000, 0x00 },
193 [BAM_P_EVNT_REG] = { 0x13818, 0x00, 0x1000, 0x00 },
194 [BAM_P_SW_OFSTS] = { 0x13800, 0x00, 0x1000, 0x00 },
195 [BAM_P_DATA_FIFO_ADDR] = { 0x13824, 0x00, 0x1000, 0x00 },
196 [BAM_P_DESC_FIFO_ADDR] = { 0x1381C, 0x00, 0x1000, 0x00 },
197 [BAM_P_EVNT_GEN_TRSHLD] = { 0x13828, 0x00, 0x1000, 0x00 },
198 [BAM_P_FIFO_SIZES] = { 0x13820, 0x00, 0x1000, 0x00 },
199 };
200
201 /* BAM CTRL */
202 #define BAM_SW_RST BIT(0)
203 #define BAM_EN BIT(1)
204 #define BAM_EN_ACCUM BIT(4)
205 #define BAM_TESTBUS_SEL_SHIFT 5
206 #define BAM_TESTBUS_SEL_MASK 0x3F
207 #define BAM_DESC_CACHE_SEL_SHIFT 13
208 #define BAM_DESC_CACHE_SEL_MASK 0x3
209 #define BAM_CACHED_DESC_STORE BIT(15)
210 #define IBC_DISABLE BIT(16)
211
212 /* BAM REVISION */
213 #define REVISION_SHIFT 0
214 #define REVISION_MASK 0xFF
215 #define NUM_EES_SHIFT 8
216 #define NUM_EES_MASK 0xF
217 #define CE_BUFFER_SIZE BIT(13)
218 #define AXI_ACTIVE BIT(14)
219 #define USE_VMIDMT BIT(15)
220 #define SECURED BIT(16)
221 #define BAM_HAS_NO_BYPASS BIT(17)
222 #define HIGH_FREQUENCY_BAM BIT(18)
223 #define INACTIV_TMRS_EXST BIT(19)
224 #define NUM_INACTIV_TMRS BIT(20)
225 #define DESC_CACHE_DEPTH_SHIFT 21
226 #define DESC_CACHE_DEPTH_1 (0 << DESC_CACHE_DEPTH_SHIFT)
227 #define DESC_CACHE_DEPTH_2 (1 << DESC_CACHE_DEPTH_SHIFT)
228 #define DESC_CACHE_DEPTH_3 (2 << DESC_CACHE_DEPTH_SHIFT)
229 #define DESC_CACHE_DEPTH_4 (3 << DESC_CACHE_DEPTH_SHIFT)
230 #define CMD_DESC_EN BIT(23)
231 #define INACTIV_TMR_BASE_SHIFT 24
232 #define INACTIV_TMR_BASE_MASK 0xFF
233
234 /* BAM NUM PIPES */
235 #define BAM_NUM_PIPES_SHIFT 0
236 #define BAM_NUM_PIPES_MASK 0xFF
237 #define PERIPH_NON_PIPE_GRP_SHIFT 16
238 #define PERIPH_NON_PIP_GRP_MASK 0xFF
239 #define BAM_NON_PIPE_GRP_SHIFT 24
240 #define BAM_NON_PIPE_GRP_MASK 0xFF
241
242 /* BAM CNFG BITS */
243 #define BAM_PIPE_CNFG BIT(2)
244 #define BAM_FULL_PIPE BIT(11)
245 #define BAM_NO_EXT_P_RST BIT(12)
246 #define BAM_IBC_DISABLE BIT(13)
247 #define BAM_SB_CLK_REQ BIT(14)
248 #define BAM_PSM_CSW_REQ BIT(15)
249 #define BAM_PSM_P_RES BIT(16)
250 #define BAM_AU_P_RES BIT(17)
251 #define BAM_SI_P_RES BIT(18)
252 #define BAM_WB_P_RES BIT(19)
253 #define BAM_WB_BLK_CSW BIT(20)
254 #define BAM_WB_CSW_ACK_IDL BIT(21)
255 #define BAM_WB_RETR_SVPNT BIT(22)
256 #define BAM_WB_DSC_AVL_P_RST BIT(23)
257 #define BAM_REG_P_EN BIT(24)
258 #define BAM_PSM_P_HD_DATA BIT(25)
259 #define BAM_AU_ACCUMED BIT(26)
260 #define BAM_CMD_ENABLE BIT(27)
261
262 #define BAM_CNFG_BITS_DEFAULT (BAM_PIPE_CNFG | \
263 BAM_NO_EXT_P_RST | \
264 BAM_IBC_DISABLE | \
265 BAM_SB_CLK_REQ | \
266 BAM_PSM_CSW_REQ | \
267 BAM_PSM_P_RES | \
268 BAM_AU_P_RES | \
269 BAM_SI_P_RES | \
270 BAM_WB_P_RES | \
271 BAM_WB_BLK_CSW | \
272 BAM_WB_CSW_ACK_IDL | \
273 BAM_WB_RETR_SVPNT | \
274 BAM_WB_DSC_AVL_P_RST | \
275 BAM_REG_P_EN | \
276 BAM_PSM_P_HD_DATA | \
277 BAM_AU_ACCUMED | \
278 BAM_CMD_ENABLE)
279
280 /* PIPE CTRL */
281 #define P_EN BIT(1)
282 #define P_DIRECTION BIT(3)
283 #define P_SYS_STRM BIT(4)
284 #define P_SYS_MODE BIT(5)
285 #define P_AUTO_EOB BIT(6)
286 #define P_AUTO_EOB_SEL_SHIFT 7
287 #define P_AUTO_EOB_SEL_512 (0 << P_AUTO_EOB_SEL_SHIFT)
288 #define P_AUTO_EOB_SEL_256 (1 << P_AUTO_EOB_SEL_SHIFT)
289 #define P_AUTO_EOB_SEL_128 (2 << P_AUTO_EOB_SEL_SHIFT)
290 #define P_AUTO_EOB_SEL_64 (3 << P_AUTO_EOB_SEL_SHIFT)
291 #define P_PREFETCH_LIMIT_SHIFT 9
292 #define P_PREFETCH_LIMIT_32 (0 << P_PREFETCH_LIMIT_SHIFT)
293 #define P_PREFETCH_LIMIT_16 (1 << P_PREFETCH_LIMIT_SHIFT)
294 #define P_PREFETCH_LIMIT_4 (2 << P_PREFETCH_LIMIT_SHIFT)
295 #define P_WRITE_NWD BIT(11)
296 #define P_LOCK_GROUP_SHIFT 16
297 #define P_LOCK_GROUP_MASK 0x1F
298
299 /* BAM_DESC_CNT_TRSHLD */
300 #define CNT_TRSHLD 0xffff
301 #define DEFAULT_CNT_THRSHLD 0x4
302
303 /* BAM_IRQ_SRCS */
304 #define BAM_IRQ BIT(31)
305 #define P_IRQ 0x7fffffff
306
307 /* BAM_IRQ_SRCS_MSK */
308 #define BAM_IRQ_MSK BAM_IRQ
309 #define P_IRQ_MSK P_IRQ
310
311 /* BAM_IRQ_STTS */
312 #define BAM_TIMER_IRQ BIT(4)
313 #define BAM_EMPTY_IRQ BIT(3)
314 #define BAM_ERROR_IRQ BIT(2)
315 #define BAM_HRESP_ERR_IRQ BIT(1)
316
317 /* BAM_IRQ_CLR */
318 #define BAM_TIMER_CLR BIT(4)
319 #define BAM_EMPTY_CLR BIT(3)
320 #define BAM_ERROR_CLR BIT(2)
321 #define BAM_HRESP_ERR_CLR BIT(1)
322
323 /* BAM_IRQ_EN */
324 #define BAM_TIMER_EN BIT(4)
325 #define BAM_EMPTY_EN BIT(3)
326 #define BAM_ERROR_EN BIT(2)
327 #define BAM_HRESP_ERR_EN BIT(1)
328
329 /* BAM_P_IRQ_EN */
330 #define P_PRCSD_DESC_EN BIT(0)
331 #define P_TIMER_EN BIT(1)
332 #define P_WAKE_EN BIT(2)
333 #define P_OUT_OF_DESC_EN BIT(3)
334 #define P_ERR_EN BIT(4)
335 #define P_TRNSFR_END_EN BIT(5)
336 #define P_DEFAULT_IRQS_EN (P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
337
338 /* BAM_P_SW_OFSTS */
339 #define P_SW_OFSTS_MASK 0xffff
340
341 #define BAM_DESC_FIFO_SIZE SZ_32K
342 #define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
343 #define BAM_FIFO_SIZE (SZ_32K - 8)
344 #define IS_BUSY(chan) (CIRC_SPACE(bchan->tail, bchan->head,\
345 MAX_DESCRIPTORS + 1) == 0)
346
347 struct bam_chan {
348 struct virt_dma_chan vc;
349
350 struct bam_device *bdev;
351
352 /* configuration from device tree */
353 u32 id;
354
355 /* runtime configuration */
356 struct dma_slave_config slave;
357
358 /* fifo storage */
359 struct bam_desc_hw *fifo_virt;
360 dma_addr_t fifo_phys;
361
362 /* fifo markers */
363 unsigned short head; /* start of active descriptor entries */
364 unsigned short tail; /* end of active descriptor entries */
365
366 unsigned int initialized; /* is the channel hw initialized? */
367 unsigned int paused; /* is the channel paused? */
368 unsigned int reconfigure; /* new slave config? */
369 /* list of descriptors currently processed */
370 struct list_head desc_list;
371
372 struct list_head node;
373 };
374
to_bam_chan(struct dma_chan * common)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 bam_chan *channels;
385 u32 num_channels;
386 u32 num_ees;
387
388 /* execution environment ID, from DT */
389 u32 ee;
390 bool controlled_remotely;
391 bool powered_remotely;
392 u32 active_channels;
393
394 const struct reg_offset_data *layout;
395
396 struct clk *bamclk;
397 int irq;
398
399 /* dma start transaction tasklet */
400 struct tasklet_struct task;
401 };
402
403 /**
404 * bam_addr - returns BAM register address
405 * @bdev: bam device
406 * @pipe: pipe instance (ignored when register doesn't have multiple instances)
407 * @reg: register enum
408 */
bam_addr(struct bam_device * bdev,u32 pipe,enum bam_reg reg)409 static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
410 enum bam_reg reg)
411 {
412 const struct reg_offset_data r = bdev->layout[reg];
413
414 return bdev->regs + r.base_offset +
415 r.pipe_mult * pipe +
416 r.evnt_mult * pipe +
417 r.ee_mult * bdev->ee;
418 }
419
420 /**
421 * bam_reset() - reset and initialize BAM registers
422 * @bdev: bam device
423 */
bam_reset(struct bam_device * bdev)424 static void bam_reset(struct bam_device *bdev)
425 {
426 u32 val;
427
428 /* s/w reset bam */
429 /* after reset all pipes are disabled and idle */
430 val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
431 val |= BAM_SW_RST;
432 writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
433 val &= ~BAM_SW_RST;
434 writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
435
436 /* make sure previous stores are visible before enabling BAM */
437 wmb();
438
439 /* enable bam */
440 val |= BAM_EN;
441 writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
442
443 /* set descriptor threshold, start with 4 bytes */
444 writel_relaxed(DEFAULT_CNT_THRSHLD,
445 bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
446
447 /* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
448 writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
449
450 /* enable irqs for errors */
451 writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
452 bam_addr(bdev, 0, BAM_IRQ_EN));
453
454 /* unmask global bam interrupt */
455 writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
456 }
457
458 /**
459 * bam_reset_channel - Reset individual BAM DMA channel
460 * @bchan: bam channel
461 *
462 * This function resets a specific BAM channel
463 */
bam_reset_channel(struct bam_chan * bchan)464 static void bam_reset_channel(struct bam_chan *bchan)
465 {
466 struct bam_device *bdev = bchan->bdev;
467
468 lockdep_assert_held(&bchan->vc.lock);
469
470 /* reset channel */
471 writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
472 writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
473
474 /* don't allow cpu to reorder BAM register accesses done after this */
475 wmb();
476
477 /* make sure hw is initialized when channel is used the first time */
478 bchan->initialized = 0;
479 }
480
481 /**
482 * bam_chan_init_hw - Initialize channel hardware
483 * @bchan: bam channel
484 * @dir: DMA transfer direction
485 *
486 * This function resets and initializes the BAM channel
487 */
bam_chan_init_hw(struct bam_chan * bchan,enum dma_transfer_direction dir)488 static void bam_chan_init_hw(struct bam_chan *bchan,
489 enum dma_transfer_direction dir)
490 {
491 struct bam_device *bdev = bchan->bdev;
492 u32 val;
493
494 /* Reset the channel to clear internal state of the FIFO */
495 bam_reset_channel(bchan);
496
497 /*
498 * write out 8 byte aligned address. We have enough space for this
499 * because we allocated 1 more descriptor (8 bytes) than we can use
500 */
501 writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
502 bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
503 writel_relaxed(BAM_FIFO_SIZE,
504 bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
505
506 /* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
507 writel_relaxed(P_DEFAULT_IRQS_EN,
508 bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
509
510 /* unmask the specific pipe and EE combo */
511 val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
512 val |= BIT(bchan->id);
513 writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
514
515 /* don't allow cpu to reorder the channel enable done below */
516 wmb();
517
518 /* set fixed direction and mode, then enable channel */
519 val = P_EN | P_SYS_MODE;
520 if (dir == DMA_DEV_TO_MEM)
521 val |= P_DIRECTION;
522
523 writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
524
525 bchan->initialized = 1;
526
527 /* init FIFO pointers */
528 bchan->head = 0;
529 bchan->tail = 0;
530 }
531
532 /**
533 * bam_alloc_chan - Allocate channel resources for DMA channel.
534 * @chan: specified channel
535 *
536 * This function allocates the FIFO descriptor memory
537 */
bam_alloc_chan(struct dma_chan * chan)538 static int bam_alloc_chan(struct dma_chan *chan)
539 {
540 struct bam_chan *bchan = to_bam_chan(chan);
541 struct bam_device *bdev = bchan->bdev;
542
543 if (bchan->fifo_virt)
544 return 0;
545
546 /* allocate FIFO descriptor space, but only if necessary */
547 bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
548 &bchan->fifo_phys, GFP_KERNEL);
549
550 if (!bchan->fifo_virt) {
551 dev_err(bdev->dev, "Failed to allocate desc fifo\n");
552 return -ENOMEM;
553 }
554
555 if (bdev->active_channels++ == 0 && bdev->powered_remotely)
556 bam_reset(bdev);
557
558 return 0;
559 }
560
561 /**
562 * bam_free_chan - Frees dma resources associated with specific channel
563 * @chan: specified channel
564 *
565 * Free the allocated fifo descriptor memory and channel resources
566 *
567 */
bam_free_chan(struct dma_chan * chan)568 static void bam_free_chan(struct dma_chan *chan)
569 {
570 struct bam_chan *bchan = to_bam_chan(chan);
571 struct bam_device *bdev = bchan->bdev;
572 u32 val;
573 unsigned long flags;
574 int ret;
575
576 ret = pm_runtime_get_sync(bdev->dev);
577 if (ret < 0)
578 return;
579
580 vchan_free_chan_resources(to_virt_chan(chan));
581
582 if (!list_empty(&bchan->desc_list)) {
583 dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
584 goto err;
585 }
586
587 spin_lock_irqsave(&bchan->vc.lock, flags);
588 bam_reset_channel(bchan);
589 spin_unlock_irqrestore(&bchan->vc.lock, flags);
590
591 dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
592 bchan->fifo_phys);
593 bchan->fifo_virt = NULL;
594
595 /* mask irq for pipe/channel */
596 val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
597 val &= ~BIT(bchan->id);
598 writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
599
600 /* disable irq */
601 writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
602
603 if (--bdev->active_channels == 0 && bdev->powered_remotely) {
604 /* s/w reset bam */
605 val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
606 val |= BAM_SW_RST;
607 writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
608 }
609
610 err:
611 pm_runtime_mark_last_busy(bdev->dev);
612 pm_runtime_put_autosuspend(bdev->dev);
613 }
614
615 /**
616 * bam_slave_config - set slave configuration for channel
617 * @chan: dma channel
618 * @cfg: slave configuration
619 *
620 * Sets slave configuration for channel
621 *
622 */
bam_slave_config(struct dma_chan * chan,struct dma_slave_config * cfg)623 static int bam_slave_config(struct dma_chan *chan,
624 struct dma_slave_config *cfg)
625 {
626 struct bam_chan *bchan = to_bam_chan(chan);
627 unsigned long flag;
628
629 spin_lock_irqsave(&bchan->vc.lock, flag);
630 memcpy(&bchan->slave, cfg, sizeof(*cfg));
631 bchan->reconfigure = 1;
632 spin_unlock_irqrestore(&bchan->vc.lock, flag);
633
634 return 0;
635 }
636
637 /**
638 * bam_prep_slave_sg - Prep slave sg transaction
639 *
640 * @chan: dma channel
641 * @sgl: scatter gather list
642 * @sg_len: length of sg
643 * @direction: DMA transfer direction
644 * @flags: DMA flags
645 * @context: transfer context (unused)
646 */
bam_prep_slave_sg(struct dma_chan * chan,struct scatterlist * sgl,unsigned int sg_len,enum dma_transfer_direction direction,unsigned long flags,void * context)647 static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
648 struct scatterlist *sgl, unsigned int sg_len,
649 enum dma_transfer_direction direction, unsigned long flags,
650 void *context)
651 {
652 struct bam_chan *bchan = to_bam_chan(chan);
653 struct bam_device *bdev = bchan->bdev;
654 struct bam_async_desc *async_desc;
655 struct scatterlist *sg;
656 u32 i;
657 struct bam_desc_hw *desc;
658 unsigned int num_alloc = 0;
659
660
661 if (!is_slave_direction(direction)) {
662 dev_err(bdev->dev, "invalid dma direction\n");
663 return NULL;
664 }
665
666 /* calculate number of required entries */
667 for_each_sg(sgl, sg, sg_len, i)
668 num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE);
669
670 /* allocate enough room to accommodate the number of entries */
671 async_desc = kzalloc(struct_size(async_desc, desc, num_alloc),
672 GFP_NOWAIT);
673
674 if (!async_desc)
675 return NULL;
676
677 if (flags & DMA_PREP_FENCE)
678 async_desc->flags |= DESC_FLAG_NWD;
679
680 if (flags & DMA_PREP_INTERRUPT)
681 async_desc->flags |= DESC_FLAG_EOT;
682
683 async_desc->num_desc = num_alloc;
684 async_desc->curr_desc = async_desc->desc;
685 async_desc->dir = direction;
686
687 /* fill in temporary descriptors */
688 desc = async_desc->desc;
689 for_each_sg(sgl, sg, sg_len, i) {
690 unsigned int remainder = sg_dma_len(sg);
691 unsigned int curr_offset = 0;
692
693 do {
694 if (flags & DMA_PREP_CMD)
695 desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
696
697 desc->addr = cpu_to_le32(sg_dma_address(sg) +
698 curr_offset);
699
700 if (remainder > BAM_FIFO_SIZE) {
701 desc->size = cpu_to_le16(BAM_FIFO_SIZE);
702 remainder -= BAM_FIFO_SIZE;
703 curr_offset += BAM_FIFO_SIZE;
704 } else {
705 desc->size = cpu_to_le16(remainder);
706 remainder = 0;
707 }
708
709 async_desc->length += le16_to_cpu(desc->size);
710 desc++;
711 } while (remainder > 0);
712 }
713
714 return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
715 }
716
717 /**
718 * bam_dma_terminate_all - terminate all transactions on a channel
719 * @chan: bam dma channel
720 *
721 * Dequeues and frees all transactions
722 * No callbacks are done
723 *
724 */
bam_dma_terminate_all(struct dma_chan * chan)725 static int bam_dma_terminate_all(struct dma_chan *chan)
726 {
727 struct bam_chan *bchan = to_bam_chan(chan);
728 struct bam_async_desc *async_desc, *tmp;
729 unsigned long flag;
730 LIST_HEAD(head);
731
732 /* remove all transactions, including active transaction */
733 spin_lock_irqsave(&bchan->vc.lock, flag);
734 /*
735 * If we have transactions queued, then some might be committed to the
736 * hardware in the desc fifo. The only way to reset the desc fifo is
737 * to do a hardware reset (either by pipe or the entire block).
738 * bam_chan_init_hw() will trigger a pipe reset, and also reinit the
739 * pipe. If the pipe is left disabled (default state after pipe reset)
740 * and is accessed by a connected hardware engine, a fatal error in
741 * the BAM will occur. There is a small window where this could happen
742 * with bam_chan_init_hw(), but it is assumed that the caller has
743 * stopped activity on any attached hardware engine. Make sure to do
744 * this first so that the BAM hardware doesn't cause memory corruption
745 * by accessing freed resources.
746 */
747 if (!list_empty(&bchan->desc_list)) {
748 async_desc = list_first_entry(&bchan->desc_list,
749 struct bam_async_desc, desc_node);
750 bam_chan_init_hw(bchan, async_desc->dir);
751 }
752
753 list_for_each_entry_safe(async_desc, tmp,
754 &bchan->desc_list, desc_node) {
755 list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
756 list_del(&async_desc->desc_node);
757 }
758
759 vchan_get_all_descriptors(&bchan->vc, &head);
760 spin_unlock_irqrestore(&bchan->vc.lock, flag);
761
762 vchan_dma_desc_free_list(&bchan->vc, &head);
763
764 return 0;
765 }
766
767 /**
768 * bam_pause - Pause DMA channel
769 * @chan: dma channel
770 *
771 */
bam_pause(struct dma_chan * chan)772 static int bam_pause(struct dma_chan *chan)
773 {
774 struct bam_chan *bchan = to_bam_chan(chan);
775 struct bam_device *bdev = bchan->bdev;
776 unsigned long flag;
777 int ret;
778
779 ret = pm_runtime_get_sync(bdev->dev);
780 if (ret < 0)
781 return ret;
782
783 spin_lock_irqsave(&bchan->vc.lock, flag);
784 writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
785 bchan->paused = 1;
786 spin_unlock_irqrestore(&bchan->vc.lock, flag);
787 pm_runtime_mark_last_busy(bdev->dev);
788 pm_runtime_put_autosuspend(bdev->dev);
789
790 return 0;
791 }
792
793 /**
794 * bam_resume - Resume DMA channel operations
795 * @chan: dma channel
796 *
797 */
bam_resume(struct dma_chan * chan)798 static int bam_resume(struct dma_chan *chan)
799 {
800 struct bam_chan *bchan = to_bam_chan(chan);
801 struct bam_device *bdev = bchan->bdev;
802 unsigned long flag;
803 int ret;
804
805 ret = pm_runtime_get_sync(bdev->dev);
806 if (ret < 0)
807 return ret;
808
809 spin_lock_irqsave(&bchan->vc.lock, flag);
810 writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
811 bchan->paused = 0;
812 spin_unlock_irqrestore(&bchan->vc.lock, flag);
813 pm_runtime_mark_last_busy(bdev->dev);
814 pm_runtime_put_autosuspend(bdev->dev);
815
816 return 0;
817 }
818
819 /**
820 * process_channel_irqs - processes the channel interrupts
821 * @bdev: bam controller
822 *
823 * This function processes the channel interrupts
824 *
825 */
process_channel_irqs(struct bam_device * bdev)826 static u32 process_channel_irqs(struct bam_device *bdev)
827 {
828 u32 i, srcs, pipe_stts, offset, avail;
829 unsigned long flags;
830 struct bam_async_desc *async_desc, *tmp;
831
832 srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
833
834 /* return early if no pipe/channel interrupts are present */
835 if (!(srcs & P_IRQ))
836 return srcs;
837
838 for (i = 0; i < bdev->num_channels; i++) {
839 struct bam_chan *bchan = &bdev->channels[i];
840
841 if (!(srcs & BIT(i)))
842 continue;
843
844 /* clear pipe irq */
845 pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
846
847 writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
848
849 spin_lock_irqsave(&bchan->vc.lock, flags);
850
851 offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) &
852 P_SW_OFSTS_MASK;
853 offset /= sizeof(struct bam_desc_hw);
854
855 /* Number of bytes available to read */
856 avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
857
858 if (offset < bchan->head)
859 avail--;
860
861 list_for_each_entry_safe(async_desc, tmp,
862 &bchan->desc_list, desc_node) {
863 /* Not enough data to read */
864 if (avail < async_desc->xfer_len)
865 break;
866
867 /* manage FIFO */
868 bchan->head += async_desc->xfer_len;
869 bchan->head %= MAX_DESCRIPTORS;
870
871 async_desc->num_desc -= async_desc->xfer_len;
872 async_desc->curr_desc += async_desc->xfer_len;
873 avail -= async_desc->xfer_len;
874
875 /*
876 * if complete, process cookie. Otherwise
877 * push back to front of desc_issued so that
878 * it gets restarted by the tasklet
879 */
880 if (!async_desc->num_desc) {
881 vchan_cookie_complete(&async_desc->vd);
882 } else {
883 list_add(&async_desc->vd.node,
884 &bchan->vc.desc_issued);
885 }
886 list_del(&async_desc->desc_node);
887 }
888
889 spin_unlock_irqrestore(&bchan->vc.lock, flags);
890 }
891
892 return srcs;
893 }
894
895 /**
896 * bam_dma_irq - irq handler for bam controller
897 * @irq: IRQ of interrupt
898 * @data: callback data
899 *
900 * IRQ handler for the bam controller
901 */
bam_dma_irq(int irq,void * data)902 static irqreturn_t bam_dma_irq(int irq, void *data)
903 {
904 struct bam_device *bdev = data;
905 u32 clr_mask = 0, srcs = 0;
906 int ret;
907
908 srcs |= process_channel_irqs(bdev);
909
910 /* kick off tasklet to start next dma transfer */
911 if (srcs & P_IRQ)
912 tasklet_schedule(&bdev->task);
913
914 ret = pm_runtime_get_sync(bdev->dev);
915 if (ret < 0)
916 return IRQ_NONE;
917
918 if (srcs & BAM_IRQ) {
919 clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
920
921 /*
922 * don't allow reorder of the various accesses to the BAM
923 * registers
924 */
925 mb();
926
927 writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
928 }
929
930 pm_runtime_mark_last_busy(bdev->dev);
931 pm_runtime_put_autosuspend(bdev->dev);
932
933 return IRQ_HANDLED;
934 }
935
936 /**
937 * bam_tx_status - returns status of transaction
938 * @chan: dma channel
939 * @cookie: transaction cookie
940 * @txstate: DMA transaction state
941 *
942 * Return status of dma transaction
943 */
bam_tx_status(struct dma_chan * chan,dma_cookie_t cookie,struct dma_tx_state * txstate)944 static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
945 struct dma_tx_state *txstate)
946 {
947 struct bam_chan *bchan = to_bam_chan(chan);
948 struct bam_async_desc *async_desc;
949 struct virt_dma_desc *vd;
950 int ret;
951 size_t residue = 0;
952 unsigned int i;
953 unsigned long flags;
954
955 ret = dma_cookie_status(chan, cookie, txstate);
956 if (ret == DMA_COMPLETE)
957 return ret;
958
959 if (!txstate)
960 return bchan->paused ? DMA_PAUSED : ret;
961
962 spin_lock_irqsave(&bchan->vc.lock, flags);
963 vd = vchan_find_desc(&bchan->vc, cookie);
964 if (vd) {
965 residue = container_of(vd, struct bam_async_desc, vd)->length;
966 } else {
967 list_for_each_entry(async_desc, &bchan->desc_list, desc_node) {
968 if (async_desc->vd.tx.cookie != cookie)
969 continue;
970
971 for (i = 0; i < async_desc->num_desc; i++)
972 residue += le16_to_cpu(
973 async_desc->curr_desc[i].size);
974 }
975 }
976
977 spin_unlock_irqrestore(&bchan->vc.lock, flags);
978
979 dma_set_residue(txstate, residue);
980
981 if (ret == DMA_IN_PROGRESS && bchan->paused)
982 ret = DMA_PAUSED;
983
984 return ret;
985 }
986
987 /**
988 * bam_apply_new_config
989 * @bchan: bam dma channel
990 * @dir: DMA direction
991 */
bam_apply_new_config(struct bam_chan * bchan,enum dma_transfer_direction dir)992 static void bam_apply_new_config(struct bam_chan *bchan,
993 enum dma_transfer_direction dir)
994 {
995 struct bam_device *bdev = bchan->bdev;
996 u32 maxburst;
997
998 if (!bdev->controlled_remotely) {
999 if (dir == DMA_DEV_TO_MEM)
1000 maxburst = bchan->slave.src_maxburst;
1001 else
1002 maxburst = bchan->slave.dst_maxburst;
1003
1004 writel_relaxed(maxburst,
1005 bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
1006 }
1007
1008 bchan->reconfigure = 0;
1009 }
1010
1011 /**
1012 * bam_start_dma - start next transaction
1013 * @bchan: bam dma channel
1014 */
bam_start_dma(struct bam_chan * bchan)1015 static void bam_start_dma(struct bam_chan *bchan)
1016 {
1017 struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
1018 struct bam_device *bdev = bchan->bdev;
1019 struct bam_async_desc *async_desc = NULL;
1020 struct bam_desc_hw *desc;
1021 struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
1022 sizeof(struct bam_desc_hw));
1023 int ret;
1024 unsigned int avail;
1025 struct dmaengine_desc_callback cb;
1026
1027 lockdep_assert_held(&bchan->vc.lock);
1028
1029 if (!vd)
1030 return;
1031
1032 ret = pm_runtime_get_sync(bdev->dev);
1033 if (ret < 0)
1034 return;
1035
1036 while (vd && !IS_BUSY(bchan)) {
1037 list_del(&vd->node);
1038
1039 async_desc = container_of(vd, struct bam_async_desc, vd);
1040
1041 /* on first use, initialize the channel hardware */
1042 if (!bchan->initialized)
1043 bam_chan_init_hw(bchan, async_desc->dir);
1044
1045 /* apply new slave config changes, if necessary */
1046 if (bchan->reconfigure)
1047 bam_apply_new_config(bchan, async_desc->dir);
1048
1049 desc = async_desc->curr_desc;
1050 avail = CIRC_SPACE(bchan->tail, bchan->head,
1051 MAX_DESCRIPTORS + 1);
1052
1053 if (async_desc->num_desc > avail)
1054 async_desc->xfer_len = avail;
1055 else
1056 async_desc->xfer_len = async_desc->num_desc;
1057
1058 /* set any special flags on the last descriptor */
1059 if (async_desc->num_desc == async_desc->xfer_len)
1060 desc[async_desc->xfer_len - 1].flags |=
1061 cpu_to_le16(async_desc->flags);
1062
1063 vd = vchan_next_desc(&bchan->vc);
1064
1065 dmaengine_desc_get_callback(&async_desc->vd.tx, &cb);
1066
1067 /*
1068 * An interrupt is generated at this desc, if
1069 * - FIFO is FULL.
1070 * - No more descriptors to add.
1071 * - If a callback completion was requested for this DESC,
1072 * In this case, BAM will deliver the completion callback
1073 * for this desc and continue processing the next desc.
1074 */
1075 if (((avail <= async_desc->xfer_len) || !vd ||
1076 dmaengine_desc_callback_valid(&cb)) &&
1077 !(async_desc->flags & DESC_FLAG_EOT))
1078 desc[async_desc->xfer_len - 1].flags |=
1079 cpu_to_le16(DESC_FLAG_INT);
1080
1081 if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
1082 u32 partial = MAX_DESCRIPTORS - bchan->tail;
1083
1084 memcpy(&fifo[bchan->tail], desc,
1085 partial * sizeof(struct bam_desc_hw));
1086 memcpy(fifo, &desc[partial],
1087 (async_desc->xfer_len - partial) *
1088 sizeof(struct bam_desc_hw));
1089 } else {
1090 memcpy(&fifo[bchan->tail], desc,
1091 async_desc->xfer_len *
1092 sizeof(struct bam_desc_hw));
1093 }
1094
1095 bchan->tail += async_desc->xfer_len;
1096 bchan->tail %= MAX_DESCRIPTORS;
1097 list_add_tail(&async_desc->desc_node, &bchan->desc_list);
1098 }
1099
1100 /* ensure descriptor writes and dma start not reordered */
1101 wmb();
1102 writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
1103 bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
1104
1105 pm_runtime_mark_last_busy(bdev->dev);
1106 pm_runtime_put_autosuspend(bdev->dev);
1107 }
1108
1109 /**
1110 * dma_tasklet - DMA IRQ tasklet
1111 * @t: tasklet argument (bam controller structure)
1112 *
1113 * Sets up next DMA operation and then processes all completed transactions
1114 */
dma_tasklet(struct tasklet_struct * t)1115 static void dma_tasklet(struct tasklet_struct *t)
1116 {
1117 struct bam_device *bdev = from_tasklet(bdev, t, task);
1118 struct bam_chan *bchan;
1119 unsigned long flags;
1120 unsigned int i;
1121
1122 /* go through the channels and kick off transactions */
1123 for (i = 0; i < bdev->num_channels; i++) {
1124 bchan = &bdev->channels[i];
1125 spin_lock_irqsave(&bchan->vc.lock, flags);
1126
1127 if (!list_empty(&bchan->vc.desc_issued) && !IS_BUSY(bchan))
1128 bam_start_dma(bchan);
1129 spin_unlock_irqrestore(&bchan->vc.lock, flags);
1130 }
1131
1132 }
1133
1134 /**
1135 * bam_issue_pending - starts pending transactions
1136 * @chan: dma channel
1137 *
1138 * Calls tasklet directly which in turn starts any pending transactions
1139 */
bam_issue_pending(struct dma_chan * chan)1140 static void bam_issue_pending(struct dma_chan *chan)
1141 {
1142 struct bam_chan *bchan = to_bam_chan(chan);
1143 unsigned long flags;
1144
1145 spin_lock_irqsave(&bchan->vc.lock, flags);
1146
1147 /* if work pending and idle, start a transaction */
1148 if (vchan_issue_pending(&bchan->vc) && !IS_BUSY(bchan))
1149 bam_start_dma(bchan);
1150
1151 spin_unlock_irqrestore(&bchan->vc.lock, flags);
1152 }
1153
1154 /**
1155 * bam_dma_free_desc - free descriptor memory
1156 * @vd: virtual descriptor
1157 *
1158 */
bam_dma_free_desc(struct virt_dma_desc * vd)1159 static void bam_dma_free_desc(struct virt_dma_desc *vd)
1160 {
1161 struct bam_async_desc *async_desc = container_of(vd,
1162 struct bam_async_desc, vd);
1163
1164 kfree(async_desc);
1165 }
1166
bam_dma_xlate(struct of_phandle_args * dma_spec,struct of_dma * of)1167 static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
1168 struct of_dma *of)
1169 {
1170 struct bam_device *bdev = container_of(of->of_dma_data,
1171 struct bam_device, common);
1172 unsigned int request;
1173
1174 if (dma_spec->args_count != 1)
1175 return NULL;
1176
1177 request = dma_spec->args[0];
1178 if (request >= bdev->num_channels)
1179 return NULL;
1180
1181 return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
1182 }
1183
1184 /**
1185 * bam_init
1186 * @bdev: bam device
1187 *
1188 * Initialization helper for global bam registers
1189 */
bam_init(struct bam_device * bdev)1190 static int bam_init(struct bam_device *bdev)
1191 {
1192 u32 val;
1193
1194 /* read revision and configuration information */
1195 if (!bdev->num_ees) {
1196 val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
1197 bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
1198 }
1199
1200 /* check that configured EE is within range */
1201 if (bdev->ee >= bdev->num_ees)
1202 return -EINVAL;
1203
1204 if (!bdev->num_channels) {
1205 val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
1206 bdev->num_channels = val & BAM_NUM_PIPES_MASK;
1207 }
1208
1209 /* Reset BAM now if fully controlled locally */
1210 if (!bdev->controlled_remotely && !bdev->powered_remotely)
1211 bam_reset(bdev);
1212
1213 return 0;
1214 }
1215
bam_channel_init(struct bam_device * bdev,struct bam_chan * bchan,u32 index)1216 static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
1217 u32 index)
1218 {
1219 bchan->id = index;
1220 bchan->bdev = bdev;
1221
1222 vchan_init(&bchan->vc, &bdev->common);
1223 bchan->vc.desc_free = bam_dma_free_desc;
1224 INIT_LIST_HEAD(&bchan->desc_list);
1225 }
1226
1227 static const struct of_device_id bam_of_match[] = {
1228 { .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
1229 { .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
1230 { .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
1231 {}
1232 };
1233
1234 MODULE_DEVICE_TABLE(of, bam_of_match);
1235
bam_dma_probe(struct platform_device * pdev)1236 static int bam_dma_probe(struct platform_device *pdev)
1237 {
1238 struct bam_device *bdev;
1239 const struct of_device_id *match;
1240 int ret, i;
1241
1242 bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
1243 if (!bdev)
1244 return -ENOMEM;
1245
1246 bdev->dev = &pdev->dev;
1247
1248 match = of_match_node(bam_of_match, pdev->dev.of_node);
1249 if (!match) {
1250 dev_err(&pdev->dev, "Unsupported BAM module\n");
1251 return -ENODEV;
1252 }
1253
1254 bdev->layout = match->data;
1255
1256 bdev->regs = devm_platform_ioremap_resource(pdev, 0);
1257 if (IS_ERR(bdev->regs))
1258 return PTR_ERR(bdev->regs);
1259
1260 bdev->irq = platform_get_irq(pdev, 0);
1261 if (bdev->irq < 0)
1262 return bdev->irq;
1263
1264 ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
1265 if (ret) {
1266 dev_err(bdev->dev, "Execution environment unspecified\n");
1267 return ret;
1268 }
1269
1270 bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
1271 "qcom,controlled-remotely");
1272 bdev->powered_remotely = of_property_read_bool(pdev->dev.of_node,
1273 "qcom,powered-remotely");
1274
1275 if (bdev->controlled_remotely || bdev->powered_remotely)
1276 bdev->bamclk = devm_clk_get_optional(bdev->dev, "bam_clk");
1277 else
1278 bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
1279
1280 if (IS_ERR(bdev->bamclk))
1281 return PTR_ERR(bdev->bamclk);
1282
1283 if (!bdev->bamclk) {
1284 ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
1285 &bdev->num_channels);
1286 if (ret)
1287 dev_err(bdev->dev, "num-channels unspecified in dt\n");
1288
1289 ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",
1290 &bdev->num_ees);
1291 if (ret)
1292 dev_err(bdev->dev, "num-ees unspecified in dt\n");
1293 }
1294
1295 ret = clk_prepare_enable(bdev->bamclk);
1296 if (ret) {
1297 dev_err(bdev->dev, "failed to prepare/enable clock\n");
1298 return ret;
1299 }
1300
1301 ret = bam_init(bdev);
1302 if (ret)
1303 goto err_disable_clk;
1304
1305 tasklet_setup(&bdev->task, dma_tasklet);
1306
1307 bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
1308 sizeof(*bdev->channels), GFP_KERNEL);
1309
1310 if (!bdev->channels) {
1311 ret = -ENOMEM;
1312 goto err_tasklet_kill;
1313 }
1314
1315 /* allocate and initialize channels */
1316 INIT_LIST_HEAD(&bdev->common.channels);
1317
1318 for (i = 0; i < bdev->num_channels; i++)
1319 bam_channel_init(bdev, &bdev->channels[i], i);
1320
1321 ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
1322 IRQF_TRIGGER_HIGH, "bam_dma", bdev);
1323 if (ret)
1324 goto err_bam_channel_exit;
1325
1326 /* set max dma segment size */
1327 bdev->common.dev = bdev->dev;
1328 dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
1329
1330 platform_set_drvdata(pdev, bdev);
1331
1332 /* set capabilities */
1333 dma_cap_zero(bdev->common.cap_mask);
1334 dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
1335
1336 /* initialize dmaengine apis */
1337 bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1338 bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1339 bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1340 bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
1341 bdev->common.device_alloc_chan_resources = bam_alloc_chan;
1342 bdev->common.device_free_chan_resources = bam_free_chan;
1343 bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
1344 bdev->common.device_config = bam_slave_config;
1345 bdev->common.device_pause = bam_pause;
1346 bdev->common.device_resume = bam_resume;
1347 bdev->common.device_terminate_all = bam_dma_terminate_all;
1348 bdev->common.device_issue_pending = bam_issue_pending;
1349 bdev->common.device_tx_status = bam_tx_status;
1350 bdev->common.dev = bdev->dev;
1351
1352 ret = dma_async_device_register(&bdev->common);
1353 if (ret) {
1354 dev_err(bdev->dev, "failed to register dma async device\n");
1355 goto err_bam_channel_exit;
1356 }
1357
1358 ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
1359 &bdev->common);
1360 if (ret)
1361 goto err_unregister_dma;
1362
1363 pm_runtime_irq_safe(&pdev->dev);
1364 pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
1365 pm_runtime_use_autosuspend(&pdev->dev);
1366 pm_runtime_mark_last_busy(&pdev->dev);
1367 pm_runtime_set_active(&pdev->dev);
1368 pm_runtime_enable(&pdev->dev);
1369
1370 return 0;
1371
1372 err_unregister_dma:
1373 dma_async_device_unregister(&bdev->common);
1374 err_bam_channel_exit:
1375 for (i = 0; i < bdev->num_channels; i++)
1376 tasklet_kill(&bdev->channels[i].vc.task);
1377 err_tasklet_kill:
1378 tasklet_kill(&bdev->task);
1379 err_disable_clk:
1380 clk_disable_unprepare(bdev->bamclk);
1381
1382 return ret;
1383 }
1384
bam_dma_remove(struct platform_device * pdev)1385 static void bam_dma_remove(struct platform_device *pdev)
1386 {
1387 struct bam_device *bdev = platform_get_drvdata(pdev);
1388 u32 i;
1389
1390 pm_runtime_force_suspend(&pdev->dev);
1391
1392 of_dma_controller_free(pdev->dev.of_node);
1393 dma_async_device_unregister(&bdev->common);
1394
1395 /* mask all interrupts for this execution environment */
1396 writel_relaxed(0, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
1397
1398 devm_free_irq(bdev->dev, bdev->irq, bdev);
1399
1400 for (i = 0; i < bdev->num_channels; i++) {
1401 bam_dma_terminate_all(&bdev->channels[i].vc.chan);
1402 tasklet_kill(&bdev->channels[i].vc.task);
1403
1404 if (!bdev->channels[i].fifo_virt)
1405 continue;
1406
1407 dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
1408 bdev->channels[i].fifo_virt,
1409 bdev->channels[i].fifo_phys);
1410 }
1411
1412 tasklet_kill(&bdev->task);
1413
1414 clk_disable_unprepare(bdev->bamclk);
1415 }
1416
bam_dma_runtime_suspend(struct device * dev)1417 static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
1418 {
1419 struct bam_device *bdev = dev_get_drvdata(dev);
1420
1421 clk_disable(bdev->bamclk);
1422
1423 return 0;
1424 }
1425
bam_dma_runtime_resume(struct device * dev)1426 static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
1427 {
1428 struct bam_device *bdev = dev_get_drvdata(dev);
1429 int ret;
1430
1431 ret = clk_enable(bdev->bamclk);
1432 if (ret < 0) {
1433 dev_err(dev, "clk_enable failed: %d\n", ret);
1434 return ret;
1435 }
1436
1437 return 0;
1438 }
1439
bam_dma_suspend(struct device * dev)1440 static int __maybe_unused bam_dma_suspend(struct device *dev)
1441 {
1442 struct bam_device *bdev = dev_get_drvdata(dev);
1443
1444 pm_runtime_force_suspend(dev);
1445 clk_unprepare(bdev->bamclk);
1446
1447 return 0;
1448 }
1449
bam_dma_resume(struct device * dev)1450 static int __maybe_unused bam_dma_resume(struct device *dev)
1451 {
1452 struct bam_device *bdev = dev_get_drvdata(dev);
1453 int ret;
1454
1455 ret = clk_prepare(bdev->bamclk);
1456 if (ret)
1457 return ret;
1458
1459 pm_runtime_force_resume(dev);
1460
1461 return 0;
1462 }
1463
1464 static const struct dev_pm_ops bam_dma_pm_ops = {
1465 SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
1466 SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
1467 NULL)
1468 };
1469
1470 static struct platform_driver bam_dma_driver = {
1471 .probe = bam_dma_probe,
1472 .remove_new = bam_dma_remove,
1473 .driver = {
1474 .name = "bam-dma-engine",
1475 .pm = &bam_dma_pm_ops,
1476 .of_match_table = bam_of_match,
1477 },
1478 };
1479
1480 module_platform_driver(bam_dma_driver);
1481
1482 MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
1483 MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
1484 MODULE_LICENSE("GPL v2");
1485