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  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Driver for the Synopsys DesignWare AHB DMA Controller
  4 *
  5 * Copyright (C) 2005-2007 Atmel Corporation
  6 * Copyright (C) 2010-2011 ST Microelectronics
  7 * Copyright (C) 2016 Intel Corporation
  8 */
  9
 10#include <linux/bitops.h>
 11#include <linux/interrupt.h>
 12#include <linux/dmaengine.h>
 13
 14#include <linux/io-64-nonatomic-hi-lo.h>
 15
 16#include "internal.h"
 17
 18#define DW_DMA_MAX_NR_REQUESTS	16
 19
 20/* flow controller */
 21enum dw_dma_fc {
 22	DW_DMA_FC_D_M2M,
 23	DW_DMA_FC_D_M2P,
 24	DW_DMA_FC_D_P2M,
 25	DW_DMA_FC_D_P2P,
 26	DW_DMA_FC_P_P2M,
 27	DW_DMA_FC_SP_P2P,
 28	DW_DMA_FC_P_M2P,
 29	DW_DMA_FC_DP_P2P,
 30};
 31
 32/*
 33 * Redefine this macro to handle differences between 32- and 64-bit
 34 * addressing, big vs. little endian, etc.
 35 */
 36#define DW_REG(name)		u32 name; u32 __pad_##name
 37
 38/* Hardware register definitions. */
 39struct dw_dma_chan_regs {
 40	DW_REG(SAR);		/* Source Address Register */
 41	DW_REG(DAR);		/* Destination Address Register */
 42	DW_REG(LLP);		/* Linked List Pointer */
 43	u32	CTL_LO;		/* Control Register Low */
 44	u32	CTL_HI;		/* Control Register High */
 45	DW_REG(SSTAT);
 46	DW_REG(DSTAT);
 47	DW_REG(SSTATAR);
 48	DW_REG(DSTATAR);
 49	u32	CFG_LO;		/* Configuration Register Low */
 50	u32	CFG_HI;		/* Configuration Register High */
 51	DW_REG(SGR);
 52	DW_REG(DSR);
 53};
 54
 55struct dw_dma_irq_regs {
 56	DW_REG(XFER);
 57	DW_REG(BLOCK);
 58	DW_REG(SRC_TRAN);
 59	DW_REG(DST_TRAN);
 60	DW_REG(ERROR);
 61};
 62
 63struct dw_dma_regs {
 64	/* per-channel registers */
 65	struct dw_dma_chan_regs	CHAN[DW_DMA_MAX_NR_CHANNELS];
 66
 67	/* irq handling */
 68	struct dw_dma_irq_regs	RAW;		/* r */
 69	struct dw_dma_irq_regs	STATUS;		/* r (raw & mask) */
 70	struct dw_dma_irq_regs	MASK;		/* rw (set = irq enabled) */
 71	struct dw_dma_irq_regs	CLEAR;		/* w (ack, affects "raw") */
 72
 73	DW_REG(STATUS_INT);			/* r */
 74
 75	/* software handshaking */
 76	DW_REG(REQ_SRC);
 77	DW_REG(REQ_DST);
 78	DW_REG(SGL_REQ_SRC);
 79	DW_REG(SGL_REQ_DST);
 80	DW_REG(LAST_SRC);
 81	DW_REG(LAST_DST);
 82
 83	/* miscellaneous */
 84	DW_REG(CFG);
 85	DW_REG(CH_EN);
 86	DW_REG(ID);
 87	DW_REG(TEST);
 88
 89	/* iDMA 32-bit support */
 90	DW_REG(CLASS_PRIORITY0);
 91	DW_REG(CLASS_PRIORITY1);
 92
 93	/* optional encoded params, 0x3c8..0x3f7 */
 94	u32	__reserved;
 95
 96	/* per-channel configuration registers */
 97	u32	DWC_PARAMS[DW_DMA_MAX_NR_CHANNELS];
 98	u32	MULTI_BLK_TYPE;
 99	u32	MAX_BLK_SIZE;
100
101	/* top-level parameters */
102	u32	DW_PARAMS;
103
104	/* component ID */
105	u32	COMP_TYPE;
106	u32	COMP_VERSION;
107
108	/* iDMA 32-bit support */
109	DW_REG(FIFO_PARTITION0);
110	DW_REG(FIFO_PARTITION1);
111
112	DW_REG(SAI_ERR);
113	DW_REG(GLOBAL_CFG);
114};
115
116/* Bitfields in DW_PARAMS */
117#define DW_PARAMS_NR_CHAN	8		/* number of channels */
118#define DW_PARAMS_NR_MASTER	11		/* number of AHB masters */
119#define DW_PARAMS_DATA_WIDTH(n)	(15 + 2 * (n))
120#define DW_PARAMS_DATA_WIDTH1	15		/* master 1 data width */
121#define DW_PARAMS_DATA_WIDTH2	17		/* master 2 data width */
122#define DW_PARAMS_DATA_WIDTH3	19		/* master 3 data width */
123#define DW_PARAMS_DATA_WIDTH4	21		/* master 4 data width */
124#define DW_PARAMS_EN		28		/* encoded parameters */
125
126/* Bitfields in DWC_PARAMS */
127#define DWC_PARAMS_MBLK_EN	11		/* multi block transfer */
128#define DWC_PARAMS_HC_LLP	13		/* set LLP register to zero */
129#define DWC_PARAMS_MSIZE	16		/* max group transaction size */
130
131/* bursts size */
132enum dw_dma_msize {
133	DW_DMA_MSIZE_1,
134	DW_DMA_MSIZE_4,
135	DW_DMA_MSIZE_8,
136	DW_DMA_MSIZE_16,
137	DW_DMA_MSIZE_32,
138	DW_DMA_MSIZE_64,
139	DW_DMA_MSIZE_128,
140	DW_DMA_MSIZE_256,
141};
142
143/* Bitfields in LLP */
144#define DWC_LLP_LMS(x)		((x) & 3)	/* list master select */
145#define DWC_LLP_LOC(x)		((x) & ~3)	/* next lli */
146
147/* Bitfields in CTL_LO */
148#define DWC_CTLL_INT_EN		(1 << 0)	/* irqs enabled? */
149#define DWC_CTLL_DST_WIDTH(n)	((n)<<1)	/* bytes per element */
150#define DWC_CTLL_SRC_WIDTH(n)	((n)<<4)
151#define DWC_CTLL_DST_INC	(0<<7)		/* DAR update/not */
152#define DWC_CTLL_DST_DEC	(1<<7)
153#define DWC_CTLL_DST_FIX	(2<<7)
154#define DWC_CTLL_SRC_INC	(0<<9)		/* SAR update/not */
155#define DWC_CTLL_SRC_DEC	(1<<9)
156#define DWC_CTLL_SRC_FIX	(2<<9)
157#define DWC_CTLL_DST_MSIZE(n)	((n)<<11)	/* burst, #elements */
158#define DWC_CTLL_SRC_MSIZE(n)	((n)<<14)
159#define DWC_CTLL_S_GATH_EN	(1 << 17)	/* src gather, !FIX */
160#define DWC_CTLL_D_SCAT_EN	(1 << 18)	/* dst scatter, !FIX */
161#define DWC_CTLL_FC(n)		((n) << 20)
162#define DWC_CTLL_FC_M2M		(0 << 20)	/* mem-to-mem */
163#define DWC_CTLL_FC_M2P		(1 << 20)	/* mem-to-periph */
164#define DWC_CTLL_FC_P2M		(2 << 20)	/* periph-to-mem */
165#define DWC_CTLL_FC_P2P		(3 << 20)	/* periph-to-periph */
166/* plus 4 transfer types for peripheral-as-flow-controller */
167#define DWC_CTLL_DMS(n)		((n)<<23)	/* dst master select */
168#define DWC_CTLL_SMS(n)		((n)<<25)	/* src master select */
169#define DWC_CTLL_LLP_D_EN	(1 << 27)	/* dest block chain */
170#define DWC_CTLL_LLP_S_EN	(1 << 28)	/* src block chain */
171
172/* Bitfields in CTL_HI */
173#define DWC_CTLH_BLOCK_TS_MASK	GENMASK(11, 0)
174#define DWC_CTLH_BLOCK_TS(x)	((x) & DWC_CTLH_BLOCK_TS_MASK)
175#define DWC_CTLH_DONE		(1 << 12)
176
177/* Bitfields in CFG_LO */
178#define DWC_CFGL_CH_PRIOR_MASK	(0x7 << 5)	/* priority mask */
179#define DWC_CFGL_CH_PRIOR(x)	((x) << 5)	/* priority */
180#define DWC_CFGL_CH_SUSP	(1 << 8)	/* pause xfer */
181#define DWC_CFGL_FIFO_EMPTY	(1 << 9)	/* pause xfer */
182#define DWC_CFGL_HS_DST		(1 << 10)	/* handshake w/dst */
183#define DWC_CFGL_HS_SRC		(1 << 11)	/* handshake w/src */
184#define DWC_CFGL_LOCK_CH_XFER	(0 << 12)	/* scope of LOCK_CH */
185#define DWC_CFGL_LOCK_CH_BLOCK	(1 << 12)
186#define DWC_CFGL_LOCK_CH_XACT	(2 << 12)
187#define DWC_CFGL_LOCK_BUS_XFER	(0 << 14)	/* scope of LOCK_BUS */
188#define DWC_CFGL_LOCK_BUS_BLOCK	(1 << 14)
189#define DWC_CFGL_LOCK_BUS_XACT	(2 << 14)
190#define DWC_CFGL_LOCK_CH	(1 << 15)	/* channel lockout */
191#define DWC_CFGL_LOCK_BUS	(1 << 16)	/* busmaster lockout */
192#define DWC_CFGL_HS_DST_POL	(1 << 18)	/* dst handshake active low */
193#define DWC_CFGL_HS_SRC_POL	(1 << 19)	/* src handshake active low */
194#define DWC_CFGL_MAX_BURST(x)	((x) << 20)
195#define DWC_CFGL_RELOAD_SAR	(1 << 30)
196#define DWC_CFGL_RELOAD_DAR	(1 << 31)
197
198/* Bitfields in CFG_HI */
199#define DWC_CFGH_FCMODE		(1 << 0)
200#define DWC_CFGH_FIFO_MODE	(1 << 1)
201#define DWC_CFGH_PROTCTL(x)	((x) << 2)
202#define DWC_CFGH_PROTCTL_DATA	(0 << 2)	/* data access - always set */
203#define DWC_CFGH_PROTCTL_PRIV	(1 << 2)	/* privileged -> AHB HPROT[1] */
204#define DWC_CFGH_PROTCTL_BUFFER	(2 << 2)	/* bufferable -> AHB HPROT[2] */
205#define DWC_CFGH_PROTCTL_CACHE	(4 << 2)	/* cacheable  -> AHB HPROT[3] */
206#define DWC_CFGH_DS_UPD_EN	(1 << 5)
207#define DWC_CFGH_SS_UPD_EN	(1 << 6)
208#define DWC_CFGH_SRC_PER(x)	((x) << 7)
209#define DWC_CFGH_DST_PER(x)	((x) << 11)
210
211/* Bitfields in SGR */
212#define DWC_SGR_SGI(x)		((x) << 0)
213#define DWC_SGR_SGC(x)		((x) << 20)
214
215/* Bitfields in DSR */
216#define DWC_DSR_DSI(x)		((x) << 0)
217#define DWC_DSR_DSC(x)		((x) << 20)
218
219/* Bitfields in CFG */
220#define DW_CFG_DMA_EN		(1 << 0)
221
222/* iDMA 32-bit support */
223
224/* bursts size */
225enum idma32_msize {
226	IDMA32_MSIZE_1,
227	IDMA32_MSIZE_2,
228	IDMA32_MSIZE_4,
229	IDMA32_MSIZE_8,
230	IDMA32_MSIZE_16,
231	IDMA32_MSIZE_32,
232};
233
234/* Bitfields in CTL_HI */
235#define IDMA32C_CTLH_BLOCK_TS_MASK	GENMASK(16, 0)
236#define IDMA32C_CTLH_BLOCK_TS(x)	((x) & IDMA32C_CTLH_BLOCK_TS_MASK)
237#define IDMA32C_CTLH_DONE		(1 << 17)
238
239/* Bitfields in CFG_LO */
240#define IDMA32C_CFGL_DST_BURST_ALIGN	(1 << 0)	/* dst burst align */
241#define IDMA32C_CFGL_SRC_BURST_ALIGN	(1 << 1)	/* src burst align */
242#define IDMA32C_CFGL_CH_DRAIN		(1 << 10)	/* drain FIFO */
243#define IDMA32C_CFGL_DST_OPT_BL		(1 << 20)	/* optimize dst burst length */
244#define IDMA32C_CFGL_SRC_OPT_BL		(1 << 21)	/* optimize src burst length */
245
246/* Bitfields in CFG_HI */
247#define IDMA32C_CFGH_SRC_PER(x)		((x) << 0)
248#define IDMA32C_CFGH_DST_PER(x)		((x) << 4)
249#define IDMA32C_CFGH_RD_ISSUE_THD(x)	((x) << 8)
250#define IDMA32C_CFGH_RW_ISSUE_THD(x)	((x) << 18)
251#define IDMA32C_CFGH_SRC_PER_EXT(x)	((x) << 28)	/* src peripheral extension */
252#define IDMA32C_CFGH_DST_PER_EXT(x)	((x) << 30)	/* dst peripheral extension */
253
254/* Bitfields in FIFO_PARTITION */
255#define IDMA32C_FP_PSIZE_CH0(x)		((x) << 0)
256#define IDMA32C_FP_PSIZE_CH1(x)		((x) << 13)
257#define IDMA32C_FP_UPDATE		(1 << 26)
258
259enum dw_dmac_flags {
260	DW_DMA_IS_CYCLIC = 0,
261	DW_DMA_IS_SOFT_LLP = 1,
262	DW_DMA_IS_PAUSED = 2,
263	DW_DMA_IS_INITIALIZED = 3,
264};
265
266struct dw_dma_chan {
267	struct dma_chan			chan;
268	void __iomem			*ch_regs;
269	u8				mask;
270	u8				priority;
271	enum dma_transfer_direction	direction;
272
273	/* software emulation of the LLP transfers */
274	struct list_head	*tx_node_active;
275
276	spinlock_t		lock;
277
278	/* these other elements are all protected by lock */
279	unsigned long		flags;
280	struct list_head	active_list;
281	struct list_head	queue;
282
283	unsigned int		descs_allocated;
284
285	/* hardware configuration */
286	unsigned int		block_size;
287	bool			nollp;
288	u32			max_burst;
289
290	/* custom slave configuration */
291	struct dw_dma_slave	dws;
292
293	/* configuration passed via .device_config */
294	struct dma_slave_config dma_sconfig;
295};
296
297static inline struct dw_dma_chan_regs __iomem *
298__dwc_regs(struct dw_dma_chan *dwc)
299{
300	return dwc->ch_regs;
301}
302
303#define channel_readl(dwc, name) \
304	readl(&(__dwc_regs(dwc)->name))
305#define channel_writel(dwc, name, val) \
306	writel((val), &(__dwc_regs(dwc)->name))
307
308static inline struct dw_dma_chan *to_dw_dma_chan(struct dma_chan *chan)
309{
310	return container_of(chan, struct dw_dma_chan, chan);
311}
312
313struct dw_dma {
314	struct dma_device	dma;
315	char			name[20];
316	void __iomem		*regs;
317	struct dma_pool		*desc_pool;
318	struct tasklet_struct	tasklet;
319
320	/* channels */
321	struct dw_dma_chan	*chan;
322	u8			all_chan_mask;
323	u8			in_use;
324
325	/* Channel operations */
326	void	(*initialize_chan)(struct dw_dma_chan *dwc);
327	void	(*suspend_chan)(struct dw_dma_chan *dwc, bool drain);
328	void	(*resume_chan)(struct dw_dma_chan *dwc, bool drain);
329	u32	(*prepare_ctllo)(struct dw_dma_chan *dwc);
330	void	(*encode_maxburst)(struct dw_dma_chan *dwc, u32 *maxburst);
331	u32	(*bytes2block)(struct dw_dma_chan *dwc, size_t bytes,
332			       unsigned int width, size_t *len);
333	size_t	(*block2bytes)(struct dw_dma_chan *dwc, u32 block, u32 width);
334
335	/* Device operations */
336	void (*set_device_name)(struct dw_dma *dw, int id);
337	void (*disable)(struct dw_dma *dw);
338	void (*enable)(struct dw_dma *dw);
339
340	/* platform data */
341	struct dw_dma_platform_data	*pdata;
342};
343
344static inline struct dw_dma_regs __iomem *__dw_regs(struct dw_dma *dw)
345{
346	return dw->regs;
347}
348
349#define dma_readl(dw, name) \
350	readl(&(__dw_regs(dw)->name))
351#define dma_writel(dw, name, val) \
352	writel((val), &(__dw_regs(dw)->name))
353
354#define idma32_readq(dw, name)				\
355	hi_lo_readq(&(__dw_regs(dw)->name))
356#define idma32_writeq(dw, name, val)			\
357	hi_lo_writeq((val), &(__dw_regs(dw)->name))
358
359#define channel_set_bit(dw, reg, mask) \
360	dma_writel(dw, reg, ((mask) << 8) | (mask))
361#define channel_clear_bit(dw, reg, mask) \
362	dma_writel(dw, reg, ((mask) << 8) | 0)
363
364static inline struct dw_dma *to_dw_dma(struct dma_device *ddev)
365{
366	return container_of(ddev, struct dw_dma, dma);
367}
368
369/* LLI == Linked List Item; a.k.a. DMA block descriptor */
370struct dw_lli {
371	/* values that are not changed by hardware */
372	__le32		sar;
373	__le32		dar;
374	__le32		llp;		/* chain to next lli */
375	__le32		ctllo;
376	/* values that may get written back: */
377	__le32		ctlhi;
378	/* sstat and dstat can snapshot peripheral register state.
379	 * silicon config may discard either or both...
380	 */
381	__le32		sstat;
382	__le32		dstat;
383};
384
385struct dw_desc {
386	/* FIRST values the hardware uses */
387	struct dw_lli			lli;
388
389#define lli_set(d, reg, v)		((d)->lli.reg |= cpu_to_le32(v))
390#define lli_clear(d, reg, v)		((d)->lli.reg &= ~cpu_to_le32(v))
391#define lli_read(d, reg)		le32_to_cpu((d)->lli.reg)
392#define lli_write(d, reg, v)		((d)->lli.reg = cpu_to_le32(v))
393
394	/* THEN values for driver housekeeping */
395	struct list_head		desc_node;
396	struct list_head		tx_list;
397	struct dma_async_tx_descriptor	txd;
398	size_t				len;
399	size_t				total_len;
400	u32				residue;
401};
402
403#define to_dw_desc(h)	list_entry(h, struct dw_desc, desc_node)
404
405static inline struct dw_desc *
406txd_to_dw_desc(struct dma_async_tx_descriptor *txd)
407{
408	return container_of(txd, struct dw_desc, txd);
409}