| 1 | /* |
| 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. |
| 6 | * |
| 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. |
| 11 | * |
| 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 |
| 15 | * |
| 16 | * Copyright (c) 2008,2009 Andy Green <andy@openmoko.com> |
| 17 | */ |
| 18 | |
| 19 | #include <linux/kernel.h> |
| 20 | #include <linux/device.h> |
| 21 | |
| 22 | #include <linux/touchscreen/ts_filter_chain.h> |
| 23 | #include <linux/touchscreen/ts_filter.h> |
| 24 | |
| 25 | /* |
| 26 | * Tux, would you like the following function in /lib? |
| 27 | * It helps us avoid silly code. |
| 28 | */ |
| 29 | |
| 30 | /** |
| 31 | * sptrlen - Count how many non-null pointers are in a pointer array |
| 32 | * @arr: The array of pointers |
| 33 | */ |
| 34 | static int sptrlen(const void *arr) |
| 35 | { |
| 36 | /* All pointers have the same size. */ |
| 37 | const int **p = (const int **)arr; |
| 38 | int len = 0; |
| 39 | |
| 40 | while (*(p++)) |
| 41 | len++; |
| 42 | |
| 43 | return len; |
| 44 | } |
| 45 | |
| 46 | |
| 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. */ |
| 53 | int pchain_len; |
| 54 | /* FIXME: Add a spinlock and use it. */ |
| 55 | }; |
| 56 | |
| 57 | struct ts_filter_chain *ts_filter_chain_create( |
| 58 | struct platform_device *pdev, |
| 59 | const struct ts_filter_chain_configuration conf[], |
| 60 | int count_coords) |
| 61 | { |
| 62 | struct ts_filter_chain *c; |
| 63 | int count = 0; |
| 64 | int len; |
| 65 | |
| 66 | BUG_ON((count_coords < 1)); |
| 67 | BUG_ON(count_coords > MAX_TS_FILTER_COORDS); |
| 68 | |
| 69 | c = kzalloc(sizeof(struct ts_filter_chain), GFP_KERNEL); |
| 70 | if (!c) |
| 71 | goto create_err_1; |
| 72 | |
| 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); |
| 76 | if (!c->arr) |
| 77 | goto create_err_1; |
| 78 | c->pchain = c->arr + len; |
| 79 | |
| 80 | while (conf->api) { |
| 81 | /* TODO: Can we get away with only sending pdev->dev? */ |
| 82 | struct ts_filter *f = |
| 83 | (conf->api->create)(pdev, conf->config, count_coords); |
| 84 | if (!f) { |
| 85 | dev_info(&pdev->dev, "Filter %d creation failed\n", |
| 86 | count); |
| 87 | goto create_err_2; |
| 88 | } |
| 89 | |
| 90 | f->api = conf->api; |
| 91 | c->arr[count++] = f; |
| 92 | |
| 93 | if (f->api->haspoint && f->api->getpoint && f->api->process) |
| 94 | c->pchain[c->pchain_len++] = f; |
| 95 | |
| 96 | conf++; |
| 97 | } |
| 98 | |
| 99 | dev_info(&pdev->dev, "%d filter(s) initialized\n", count); |
| 100 | |
| 101 | return c; |
| 102 | |
| 103 | create_err_2: |
| 104 | ts_filter_chain_destroy(c); /* Also frees c. */ |
| 105 | create_err_1: |
| 106 | dev_info(&pdev->dev, "Error in filter chain initialization\n"); |
| 107 | /* |
| 108 | * FIXME: Individual filters have to return errors this way. |
| 109 | * We only have to forward the errors we find. |
| 110 | */ |
| 111 | return ERR_PTR(-ENOMEM); |
| 112 | } |
| 113 | EXPORT_SYMBOL_GPL(ts_filter_chain_create); |
| 114 | |
| 115 | void ts_filter_chain_destroy(struct ts_filter_chain *c) |
| 116 | { |
| 117 | if (c->arr) { |
| 118 | struct ts_filter **a = c->arr; |
| 119 | while (*a) { |
| 120 | ((*a)->api->destroy)(*a); |
| 121 | a++; |
| 122 | } |
| 123 | kfree(c->arr); |
| 124 | } |
| 125 | kfree(c); |
| 126 | } |
| 127 | EXPORT_SYMBOL_GPL(ts_filter_chain_destroy); |
| 128 | |
| 129 | void ts_filter_chain_clear(struct ts_filter_chain *c) |
| 130 | { |
| 131 | struct ts_filter **a = c->arr; |
| 132 | |
| 133 | while (*a) { |
| 134 | if ((*a)->api->clear) |
| 135 | ((*a)->api->clear)(*a); |
| 136 | a++; |
| 137 | } |
| 138 | } |
| 139 | EXPORT_SYMBOL_GPL(ts_filter_chain_clear); |
| 140 | |
| 141 | static void ts_filter_chain_scale(struct ts_filter_chain *c, int *coords) |
| 142 | { |
| 143 | struct ts_filter **a = c->arr; |
| 144 | while (*a) { |
| 145 | if ((*a)->api->scale) |
| 146 | ((*a)->api->scale)(*a, coords); |
| 147 | a++; |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | int ts_filter_chain_feed(struct ts_filter_chain *c, int *coords) |
| 152 | { |
| 153 | int len = c->pchain_len; |
| 154 | int i = len - 1; |
| 155 | |
| 156 | if (!c->pchain[0]) |
| 157 | return 1; /* Nothing to do. */ |
| 158 | |
| 159 | BUG_ON(c->pchain[0]->api->haspoint(c->pchain[0])); |
| 160 | |
| 161 | if (c->pchain[0]->api->process(c->pchain[0], coords)) |
| 162 | return -1; |
| 163 | |
| 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); |
| 167 | if (++i < len && |
| 168 | c->pchain[i]->api->process(c->pchain[i], coords)) |
| 169 | return -1; /* Error. */ |
| 170 | } else { |
| 171 | i--; |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | if (i >= 0) { /* Same as i == len. */ |
| 176 | ts_filter_chain_scale(c, coords); |
| 177 | return 1; |
| 178 | } |
| 179 | |
| 180 | return 0; |
| 181 | } |
| 182 | EXPORT_SYMBOL_GPL(ts_filter_chain_feed); |
| 183 | |
| 184 | |
