xref: /openbmc/linux/drivers/dma/bestcomm/ata.c (revision a1117495)
1 /*
2  * Bestcomm ATA task driver
3  *
4  *
5  * Patterned after bestcomm/fec.c by Dale Farnsworth <dfarnsworth@mvista.com>
6  *                                   2003-2004 (c) MontaVista, Software, Inc.
7  *
8  * Copyright (C) 2006-2007 Sylvain Munaut <tnt@246tNt.com>
9  * Copyright (C) 2006      Freescale - John Rigby
10  *
11  * This file is licensed under the terms of the GNU General Public License
12  * version 2. This program is licensed "as is" without any warranty of any
13  * kind, whether express or implied.
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/types.h>
19 #include <asm/io.h>
20 
21 #include <linux/fsl/bestcomm/bestcomm.h>
22 #include <linux/fsl/bestcomm/bestcomm_priv.h>
23 #include <linux/fsl/bestcomm/ata.h>
24 
25 
26 /* ======================================================================== */
27 /* Task image/var/inc                                                       */
28 /* ======================================================================== */
29 
30 /* ata task image */
31 extern u32 bcom_ata_task[];
32 
33 /* ata task vars that need to be set before enabling the task */
34 struct bcom_ata_var {
35 	u32 enable;		/* (u16*) address of task's control register */
36 	u32 bd_base;		/* (struct bcom_bd*) beginning of ring buffer */
37 	u32 bd_last;		/* (struct bcom_bd*) end of ring buffer */
38 	u32 bd_start;		/* (struct bcom_bd*) current bd */
39 	u32 buffer_size;	/* size of receive buffer */
40 };
41 
42 /* ata task incs that need to be set before enabling the task */
43 struct bcom_ata_inc {
44 	u16 pad0;
45 	s16 incr_bytes;
46 	u16 pad1;
47 	s16 incr_dst;
48 	u16 pad2;
49 	s16 incr_src;
50 };
51 
52 
53 /* ======================================================================== */
54 /* Task support code                                                        */
55 /* ======================================================================== */
56 
57 struct bcom_task *
58 bcom_ata_init(int queue_len, int maxbufsize)
59 {
60 	struct bcom_task *tsk;
61 	struct bcom_ata_var *var;
62 	struct bcom_ata_inc *inc;
63 
64 	/* Prefetch breaks ATA DMA.  Turn it off for ATA DMA */
65 	bcom_disable_prefetch();
66 
67 	tsk = bcom_task_alloc(queue_len, sizeof(struct bcom_ata_bd), 0);
68 	if (!tsk)
69 		return NULL;
70 
71 	tsk->flags = BCOM_FLAGS_NONE;
72 
73 	bcom_ata_reset_bd(tsk);
74 
75 	var = (struct bcom_ata_var *) bcom_task_var(tsk->tasknum);
76 	inc = (struct bcom_ata_inc *) bcom_task_inc(tsk->tasknum);
77 
78 	if (bcom_load_image(tsk->tasknum, bcom_ata_task)) {
79 		bcom_task_free(tsk);
80 		return NULL;
81 	}
82 
83 	var->enable	= bcom_eng->regs_base +
84 				offsetof(struct mpc52xx_sdma, tcr[tsk->tasknum]);
85 	var->bd_base	= tsk->bd_pa;
86 	var->bd_last	= tsk->bd_pa + ((tsk->num_bd-1) * tsk->bd_size);
87 	var->bd_start	= tsk->bd_pa;
88 	var->buffer_size = maxbufsize;
89 
90 	/* Configure some stuff */
91 	bcom_set_task_pragma(tsk->tasknum, BCOM_ATA_PRAGMA);
92 	bcom_set_task_auto_start(tsk->tasknum, tsk->tasknum);
93 
94 	out_8(&bcom_eng->regs->ipr[BCOM_INITIATOR_ATA_RX], BCOM_IPR_ATA_RX);
95 	out_8(&bcom_eng->regs->ipr[BCOM_INITIATOR_ATA_TX], BCOM_IPR_ATA_TX);
96 
97 	out_be32(&bcom_eng->regs->IntPend, 1<<tsk->tasknum); /* Clear ints */
98 
99 	return tsk;
100 }
101 EXPORT_SYMBOL_GPL(bcom_ata_init);
102 
103 void bcom_ata_rx_prepare(struct bcom_task *tsk)
104 {
105 	struct bcom_ata_inc *inc;
106 
107 	inc = (struct bcom_ata_inc *) bcom_task_inc(tsk->tasknum);
108 
109 	inc->incr_bytes	= -(s16)sizeof(u32);
110 	inc->incr_src	= 0;
111 	inc->incr_dst	= sizeof(u32);
112 
113 	bcom_set_initiator(tsk->tasknum, BCOM_INITIATOR_ATA_RX);
114 }
115 EXPORT_SYMBOL_GPL(bcom_ata_rx_prepare);
116 
117 void bcom_ata_tx_prepare(struct bcom_task *tsk)
118 {
119 	struct bcom_ata_inc *inc;
120 
121 	inc = (struct bcom_ata_inc *) bcom_task_inc(tsk->tasknum);
122 
123 	inc->incr_bytes	= -(s16)sizeof(u32);
124 	inc->incr_src	= sizeof(u32);
125 	inc->incr_dst	= 0;
126 
127 	bcom_set_initiator(tsk->tasknum, BCOM_INITIATOR_ATA_TX);
128 }
129 EXPORT_SYMBOL_GPL(bcom_ata_tx_prepare);
130 
131 void bcom_ata_reset_bd(struct bcom_task *tsk)
132 {
133 	struct bcom_ata_var *var;
134 
135 	/* Reset all BD */
136 	memset_io(tsk->bd, 0x00, tsk->num_bd * tsk->bd_size);
137 
138 	tsk->index = 0;
139 	tsk->outdex = 0;
140 
141 	var = (struct bcom_ata_var *) bcom_task_var(tsk->tasknum);
142 	var->bd_start = var->bd_base;
143 }
144 EXPORT_SYMBOL_GPL(bcom_ata_reset_bd);
145 
146 void bcom_ata_release(struct bcom_task *tsk)
147 {
148 	/* Nothing special for the ATA tasks */
149 	bcom_task_free(tsk);
150 }
151 EXPORT_SYMBOL_GPL(bcom_ata_release);
152 
153 
154 MODULE_DESCRIPTION("BestComm ATA task driver");
155 MODULE_AUTHOR("John Rigby");
156 MODULE_LICENSE("GPL v2");
157 
158