2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16 * Copyright (c) 2008,2009 Andy Green <andy@openmoko.com>
19 #include <linux/kernel.h>
20 #include <linux/device.h>
22 #include <linux/touchscreen/ts_filter_chain.h>
23 #include <linux/touchscreen/ts_filter.h>
26 * Tux, would you like the following function in /lib?
27 * It helps us avoid silly code.
31 * sptrlen - Count how many non-null pointers are in a pointer array
32 * @arr: The array of pointers
34 static int sptrlen(const void *arr
)
36 /* All pointers have the same size. */
37 const int **p
= (const int **)arr
;
47 struct ts_filter_chain
{
48 /* All of the filters. */
49 struct ts_filter
**arr
;
50 /* Filters that can propagate values in the chain. */
51 struct ts_filter
**pchain
;
52 /* Length of the pchain array. */
54 /* FIXME: Add a spinlock and use it. */
57 struct ts_filter_chain
*ts_filter_chain_create(
58 struct platform_device
*pdev
,
59 const struct ts_filter_chain_configuration conf
[],
62 struct ts_filter_chain
*c
;
66 BUG_ON((count_coords
< 1));
67 BUG_ON(count_coords
> MAX_TS_FILTER_COORDS
);
69 c
= kzalloc(sizeof(struct ts_filter_chain
), GFP_KERNEL
);
73 len
= (sptrlen(conf
) + 1);
74 /* Memory for two null-terminated arrays of filters. */
75 c
->arr
= kzalloc(2 * sizeof(struct ts_filter
*) * len
, GFP_KERNEL
);
78 c
->pchain
= c
->arr
+ len
;
81 /* TODO: Can we get away with only sending pdev->dev? */
83 (conf
->api
->create
)(pdev
, conf
->config
, count_coords
);
85 dev_info(&pdev
->dev
, "Filter %d creation failed\n",
93 if (f
->api
->haspoint
&& f
->api
->getpoint
&& f
->api
->process
)
94 c
->pchain
[c
->pchain_len
++] = f
;
99 dev_info(&pdev
->dev
, "%d filter(s) initialized\n", count
);
104 ts_filter_chain_destroy(c
); /* Also frees c. */
106 dev_info(&pdev
->dev
, "Error in filter chain initialization\n");
108 * FIXME: Individual filters have to return errors this way.
109 * We only have to forward the errors we find.
111 return ERR_PTR(-ENOMEM
);
113 EXPORT_SYMBOL_GPL(ts_filter_chain_create
);
115 void ts_filter_chain_destroy(struct ts_filter_chain
*c
)
118 struct ts_filter
**a
= c
->arr
;
120 ((*a
)->api
->destroy
)(*a
);
127 EXPORT_SYMBOL_GPL(ts_filter_chain_destroy
);
129 void ts_filter_chain_clear(struct ts_filter_chain
*c
)
131 struct ts_filter
**a
= c
->arr
;
134 if ((*a
)->api
->clear
)
135 ((*a
)->api
->clear
)(*a
);
139 EXPORT_SYMBOL_GPL(ts_filter_chain_clear
);
141 static void ts_filter_chain_scale(struct ts_filter_chain
*c
, int *coords
)
143 struct ts_filter
**a
= c
->arr
;
145 if ((*a
)->api
->scale
)
146 ((*a
)->api
->scale
)(*a
, coords
);
151 int ts_filter_chain_feed(struct ts_filter_chain
*c
, int *coords
)
153 int len
= c
->pchain_len
;
157 return 1; /* Nothing to do. */
159 BUG_ON(c
->pchain
[0]->api
->haspoint(c
->pchain
[0]));
161 if (c
->pchain
[0]->api
->process(c
->pchain
[0], coords
))
164 while (i
>= 0 && i
< len
) {
165 if (c
->pchain
[i
]->api
->haspoint(c
->pchain
[i
])) {
166 c
->pchain
[i
]->api
->getpoint(c
->pchain
[i
], coords
);
168 c
->pchain
[i
]->api
->process(c
->pchain
[i
], coords
))
169 return -1; /* Error. */
175 if (i
>= 0) { /* Same as i == len. */
176 ts_filter_chain_scale(c
, coords
);
182 EXPORT_SYMBOL_GPL(ts_filter_chain_feed
);