xref: /openbmc/linux/sound/soc/atmel/atmel-pcm.h (revision d9fd5a71)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * at91-pcm.h - ALSA PCM interface for the Atmel AT91 SoC.
4  *
5  *  Copyright (C) 2005 SAN People
6  *  Copyright (C) 2008 Atmel
7  *
8  * Authors: Sedji Gaouaou <sedji.gaouaou@atmel.com>
9  *
10  * Based on at91-pcm. by:
11  * Frank Mandarino <fmandarino@endrelia.com>
12  * Copyright 2006 Endrelia Technologies Inc.
13  *
14  * Based on pxa2xx-pcm.c by:
15  *
16  * Author:	Nicolas Pitre
17  * Created:	Nov 30, 2004
18  * Copyright:	(C) 2004 MontaVista Software, Inc.
19  */
20 
21 #ifndef _ATMEL_PCM_H
22 #define _ATMEL_PCM_H
23 
24 #include <linux/atmel-ssc.h>
25 
26 #define ATMEL_SSC_DMABUF_SIZE	(64 * 1024)
27 
28 /*
29  * Registers and status bits that are required by the PCM driver.
30  */
31 struct atmel_pdc_regs {
32 	unsigned int	xpr;		/* PDC recv/trans pointer */
33 	unsigned int	xcr;		/* PDC recv/trans counter */
34 	unsigned int	xnpr;		/* PDC next recv/trans pointer */
35 	unsigned int	xncr;		/* PDC next recv/trans counter */
36 	unsigned int	ptcr;		/* PDC transfer control */
37 };
38 
39 struct atmel_ssc_mask {
40 	u32	ssc_enable;		/* SSC recv/trans enable */
41 	u32	ssc_disable;		/* SSC recv/trans disable */
42 	u32	ssc_error;		/* SSC error conditions */
43 	u32	ssc_endx;		/* SSC ENDTX or ENDRX */
44 	u32	ssc_endbuf;		/* SSC TXBUFE or RXBUFF */
45 	u32	pdc_enable;		/* PDC recv/trans enable */
46 	u32	pdc_disable;		/* PDC recv/trans disable */
47 };
48 
49 /*
50  * This structure, shared between the PCM driver and the interface,
51  * contains all information required by the PCM driver to perform the
52  * PDC DMA operation.  All fields except dma_intr_handler() are initialized
53  * by the interface.  The dma_intr_handler() pointer is set by the PCM
54  * driver and called by the interface SSC interrupt handler if it is
55  * non-NULL.
56  */
57 struct atmel_pcm_dma_params {
58 	char *name;			/* stream identifier */
59 	int pdc_xfer_size;		/* PDC counter increment in bytes */
60 	struct ssc_device *ssc;		/* SSC device for stream */
61 	struct atmel_pdc_regs *pdc;	/* PDC receive or transmit registers */
62 	struct atmel_ssc_mask *mask;	/* SSC & PDC status bits */
63 	struct snd_pcm_substream *substream;
64 	void (*dma_intr_handler)(u32, struct snd_pcm_substream *);
65 };
66 
67 /*
68  * SSC register access (since ssc_writel() / ssc_readl() require literal name)
69  */
70 #define ssc_readx(base, reg)            (__raw_readl((base) + (reg)))
71 #define ssc_writex(base, reg, value)    __raw_writel((value), (base) + (reg))
72 
73 #if IS_ENABLED(CONFIG_SND_ATMEL_SOC_PDC)
74 int atmel_pcm_pdc_platform_register(struct device *dev);
75 #else
76 static inline int atmel_pcm_pdc_platform_register(struct device *dev)
77 {
78 	return 0;
79 }
80 #endif
81 
82 #if IS_ENABLED(CONFIG_SND_ATMEL_SOC_DMA)
83 int atmel_pcm_dma_platform_register(struct device *dev);
84 #else
85 static inline int atmel_pcm_dma_platform_register(struct device *dev)
86 {
87 	return 0;
88 }
89 #endif
90 
91 #endif /* _ATMEL_PCM_H */
92