1 /*
2  * Copyright (C) ST-Ericsson AB 2010
3  * Author:	Daniel Martensson / Daniel.Martensson@stericsson.com
4  * License terms: GNU General Public License (GPL) version 2
5  */
6 
7 #ifndef CAIF_SPI_H_
8 #define CAIF_SPI_H_
9 
10 #include <net/caif/caif_device.h>
11 
12 #define SPI_CMD_WR			0x00
13 #define SPI_CMD_RD			0x01
14 #define SPI_CMD_EOT			0x02
15 #define SPI_CMD_IND			0x04
16 
17 #define SPI_DMA_BUF_LEN			8192
18 
19 #define WL_SZ				2	/* 16 bits. */
20 #define SPI_CMD_SZ			4	/* 32 bits. */
21 #define SPI_IND_SZ			4	/* 32 bits. */
22 
23 #define SPI_XFER			0
24 #define SPI_SS_ON			1
25 #define SPI_SS_OFF			2
26 #define SPI_TERMINATE			3
27 
28 /* Minimum time between different levels is 50 microseconds. */
29 #define MIN_TRANSITION_TIME_USEC	50
30 
31 /* Defines for calculating duration of SPI transfers for a particular
32  * number of bytes.
33  */
34 #define SPI_MASTER_CLK_MHZ		13
35 #define SPI_XFER_TIME_USEC(bytes, clk) (((bytes) * 8) / clk)
36 
37 /* Normally this should be aligned on the modem in order to benefit from full
38  * duplex transfers. However a size of 8188 provokes errors when running with
39  * the modem. These errors occur when packet sizes approaches 4 kB of data.
40  */
41 #define CAIF_MAX_SPI_FRAME 4092
42 
43 /* Maximum number of uplink CAIF frames that can reside in the same SPI frame.
44  * This number should correspond with the modem setting. The application side
45  * CAIF accepts any number of embedded downlink CAIF frames.
46  */
47 #define CAIF_MAX_SPI_PKTS 9
48 
49 /* Decides if SPI buffers should be prefilled with 0xFF pattern for easier
50  * debugging. Both TX and RX buffers will be filled before the transfer.
51  */
52 #define CFSPI_DBG_PREFILL		0
53 
54 /* Structure describing a SPI transfer. */
55 struct cfspi_xfer {
56 	u16 tx_dma_len;
57 	u16 rx_dma_len;
58 	void *va_tx[2];
59 	dma_addr_t pa_tx[2];
60 	void *va_rx;
61 	dma_addr_t pa_rx;
62 };
63 
64 /* Structure implemented by the SPI interface. */
65 struct cfspi_ifc {
66 	void (*ss_cb) (bool assert, struct cfspi_ifc *ifc);
67 	void (*xfer_done_cb) (struct cfspi_ifc *ifc);
68 	void *priv;
69 };
70 
71 /* Structure implemented by SPI clients. */
72 struct cfspi_dev {
73 	int (*init_xfer) (struct cfspi_xfer *xfer, struct cfspi_dev *dev);
74 	void (*sig_xfer) (bool xfer, struct cfspi_dev *dev);
75 	struct cfspi_ifc *ifc;
76 	char *name;
77 	u32 clk_mhz;
78 	void *priv;
79 };
80 
81 /* Enumeration describing the CAIF SPI state. */
82 enum cfspi_state {
83 	CFSPI_STATE_WAITING = 0,
84 	CFSPI_STATE_AWAKE,
85 	CFSPI_STATE_FETCH_PKT,
86 	CFSPI_STATE_GET_NEXT,
87 	CFSPI_STATE_INIT_XFER,
88 	CFSPI_STATE_WAIT_ACTIVE,
89 	CFSPI_STATE_SIG_ACTIVE,
90 	CFSPI_STATE_WAIT_XFER_DONE,
91 	CFSPI_STATE_XFER_DONE,
92 	CFSPI_STATE_WAIT_INACTIVE,
93 	CFSPI_STATE_SIG_INACTIVE,
94 	CFSPI_STATE_DELIVER_PKT,
95 	CFSPI_STATE_MAX,
96 };
97 
98 /* Structure implemented by SPI physical interfaces. */
99 struct cfspi {
100 	struct caif_dev_common cfdev;
101 	struct net_device *ndev;
102 	struct platform_device *pdev;
103 	struct sk_buff_head qhead;
104 	struct sk_buff_head chead;
105 	u16 cmd;
106 	u16 tx_cpck_len;
107 	u16 tx_npck_len;
108 	u16 rx_cpck_len;
109 	u16 rx_npck_len;
110 	struct cfspi_ifc ifc;
111 	struct cfspi_xfer xfer;
112 	struct cfspi_dev *dev;
113 	unsigned long state;
114 	struct work_struct work;
115 	struct workqueue_struct *wq;
116 	struct list_head list;
117 	int    flow_off_sent;
118 	u32 qd_low_mark;
119 	u32 qd_high_mark;
120 	struct completion comp;
121 	wait_queue_head_t wait;
122 	spinlock_t lock;
123 	bool flow_stop;
124 	bool slave;
125 	bool slave_talked;
126 #ifdef CONFIG_DEBUG_FS
127 	enum cfspi_state dbg_state;
128 	u16 pcmd;
129 	u16 tx_ppck_len;
130 	u16 rx_ppck_len;
131 	struct dentry *dbgfs_dir;
132 	struct dentry *dbgfs_state;
133 	struct dentry *dbgfs_frame;
134 #endif				/* CONFIG_DEBUG_FS */
135 };
136 
137 extern int spi_frm_align;
138 extern int spi_up_head_align;
139 extern int spi_up_tail_align;
140 extern int spi_down_head_align;
141 extern int spi_down_tail_align;
142 extern struct platform_driver cfspi_spi_driver;
143 
144 void cfspi_dbg_state(struct cfspi *cfspi, int state);
145 int cfspi_xmitfrm(struct cfspi *cfspi, u8 *buf, size_t len);
146 int cfspi_xmitlen(struct cfspi *cfspi);
147 int cfspi_rxfrm(struct cfspi *cfspi, u8 *buf, size_t len);
148 int cfspi_spi_remove(struct platform_device *pdev);
149 int cfspi_spi_probe(struct platform_device *pdev);
150 int cfspi_xmitfrm(struct cfspi *cfspi, u8 *buf, size_t len);
151 int cfspi_xmitlen(struct cfspi *cfspi);
152 int cfspi_rxfrm(struct cfspi *cfspi, u8 *buf, size_t len);
153 void cfspi_xfer(struct work_struct *work);
154 
155 #endif				/* CAIF_SPI_H_ */
156