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Joachim Foerster03d67e12011-10-21 15:48:50 +02001/*
2 * Driver for Altera's PIO ip core
3 *
4 * Copyright (C) 2011 Missing Link Electronics
5 * Joachim Foerster <joachim@missinglinkelectronics.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
20 * MA 02111-1307 USA
21 *
22 * To use this driver, in your board's config. header:
23 * #define CONFIG_ALTERA_PIO
24 * #define CONFIG_SYS_ALTERA_PIO_NUM <number-of-pio-cores>
25 * #define CONFIG_SYS_ALTERA_PIO_GPIO_NUM <total-number-of-gpios>
26 * And in your board's early setup routine:
27 * altera_pio_init(<baseaddr>, <width>, 'i'|'o'|'t',
28 * <reset-value>, <neg-mask>, "label");
29 * - 'i'|'o'|'t': PIO is input-only/output-only/tri-state
30 * - <reset-value>: for correct initial status display, output-only
31 * - <neg-mask> is meant to be used to in cases of active-low
32 * GPIOs, such as LEDs and buttons (on/pressed == 0). Each bit
33 * which is 1 in <neg-mask> inverts the corresponding GPIO's value
34 * before set/after get. So: gpio_set_value(gpio, 1) => LED on .
35 *
36 * Do NOT define CONFIG_SYS_GPIO_BASE !
37 *
38 * Optionally, in your board's config. header:
39 * - To force a GPIO numbering scheme like in Linux ...
40 * #define CONFIG_GPIO_DOWNTO_NUMBERING
41 * ... starting with 255 (default)
42 * #define CONFIG_GPIO_DOWNTO_MAX 255
43 */
44#include <common.h>
45#include <asm/io.h>
46#include <asm/gpio.h>
47
48#ifdef CONFIG_GPIO_DOWNTO_NUMBERING
49#ifndef CONFIG_GPIO_DOWNTO_MAX
50#define CONFIG_GPIO_DOWNTO_MAX 255
51#endif
52#endif
53
54#define ALTERA_PIO_DATA 0x0
55#define ALTERA_PIO_DIR 0x4
56
57#define GPIO_LABEL_SIZE 9
58
59
60static struct altera_pio {
61 u32 base;
62 u8 width;
63 char iot;
64 u32 negmask;
65 u32 sh_data;
66 u32 sh_dir;
67 int gidx;
68 char label[GPIO_LABEL_SIZE];
69} pios[CONFIG_SYS_ALTERA_PIO_NUM];
70
71static int pio_num;
72
73static struct altera_pio_gpio {
74 unsigned num;
75 struct altera_pio *pio;
76 char reqlabel[GPIO_LABEL_SIZE];
77} gpios[CONFIG_SYS_ALTERA_PIO_GPIO_NUM];
78
79static int pio_gpio_num;
80
81
82static int altera_pio_gidx(unsigned gpio)
83{
84 int i;
85
86 for (i = 0; i < pio_gpio_num; ++i) {
87 if (gpio == gpios[i].num)
88 break;
89 }
90 if (i >= pio_gpio_num)
91 return -1;
92 return i;
93}
94
95static struct altera_pio *altera_pio_get_and_mask(unsigned gpio, u32 *mask)
96{
97 int gidx = altera_pio_gidx(gpio);
98 if (gidx < 0)
99 return NULL;
100 if (mask)
101 *mask = 1 << (gidx - gpios[gidx].pio->gidx);
102 return gpios[gidx].pio;
103}
104
105#define altera_pio_use_gidx(_gidx, _reqlabel) \
106 { strncpy(gpios[_gidx].reqlabel, _reqlabel, GPIO_LABEL_SIZE); }
107#define altera_pio_unuse_gidx(_gidx) { gpios[_gidx].reqlabel[0] = '\0'; }
108#define altera_pio_is_gidx_used(_gidx) (gpios[_gidx].reqlabel[0] != '\0')
109
110static int altera_pio_gpio_init(struct altera_pio *pio, u8 width)
111{
112 u8 gidx = pio_gpio_num;
113 int i;
114
115 if (!width)
116 return -1;
117 if ((pio_gpio_num + width) > CONFIG_SYS_ALTERA_PIO_GPIO_NUM)
118 return -1;
119
120 for (i = 0; i < width; ++i) {
121#ifdef CONFIG_GPIO_DOWNTO_NUMBERING
122 gpios[pio_gpio_num + i].num = \
123 CONFIG_GPIO_DOWNTO_MAX + 1 - gidx - width + i;
124#else
125 gpios[pio_gpio_num + i].num = pio_gpio_num + i;
126#endif
127 gpios[pio_gpio_num + i].pio = pio;
128 altera_pio_unuse_gidx(pio_gpio_num + i);
129 }
130 pio_gpio_num += width;
131 return gidx;
132}
133
134int altera_pio_init(u32 base, u8 width, char iot, u32 rstval, u32 negmask,
135 const char *label)
136{
137 if (pio_num >= CONFIG_SYS_ALTERA_PIO_NUM)
138 return -1;
139
140 pios[pio_num].base = base;
141 pios[pio_num].width = width;
142 pios[pio_num].iot = iot;
143 switch (iot) {
144 case 'i':
145 /* input only */
146 pios[pio_num].sh_dir = 0;
147 pios[pio_num].sh_data = readl(base + ALTERA_PIO_DATA);
148 break;
149 case 'o':
150 /* output only */
151 pios[pio_num].sh_dir = 0xffffffff & ((1 << width) - 1);
152 pios[pio_num].sh_data = rstval;
153 break;
154 case 't':
155 /* bidir, tri-state */
156 pios[pio_num].sh_dir = readl(base + ALTERA_PIO_DIR);
157 pios[pio_num].sh_data = readl(base + ALTERA_PIO_DATA);
158 break;
159 default:
160 return -1;
161 }
162 pios[pio_num].negmask = negmask & ((1 << width) - 1);
163 pios[pio_num].gidx = altera_pio_gpio_init(&pios[pio_num], width);
164 if (pios[pio_num].gidx < 0)
165 return -1;
166 strncpy(pios[pio_num].label, label, GPIO_LABEL_SIZE);
167 return pio_num++;
168}
169
170void altera_pio_info(void)
171{
172 int i;
173 int j;
174 int gidx;
175 u32 mask;
176
177 for (i = 0; i < pio_num; ++i) {
178 printf("Altera PIO % 2d, @0x%08x, "
179 "width: %u, label: %s\n",
180 i, pios[i].base, pios[i].width, pios[i].label);
181 gidx = pios[i].gidx;
182 for (j = gidx; j < (gidx + pios[i].width); ++j) {
183 mask = 1 << (j - gidx);
184 printf("\tGPIO % 4d: %s %s [%c] %s\n",
185 gpios[j].num,
186 gpios[j].pio->sh_dir & mask ? "out" : " in",
187 gpio_get_value(gpios[j].num) ? "set" : "clr",
188 altera_pio_is_gidx_used(j) ? 'x' : ' ',
189 gpios[j].reqlabel);
190 }
191 }
192}
193
194
195int gpio_request(unsigned gpio, const char *label)
196{
197 int gidx = altera_pio_gidx(gpio);
198 if (gidx < 0)
199 return gidx;
200 if (altera_pio_is_gidx_used(gidx))
201 return -1;
202
203 altera_pio_use_gidx(gidx, label);
204 return 0;
205}
206
207int gpio_free(unsigned gpio)
208{
209 int gidx = altera_pio_gidx(gpio);
210 if (gidx < 0)
211 return gidx;
212 if (!altera_pio_is_gidx_used(gidx))
213 return -1;
214
215 altera_pio_unuse_gidx(gidx);
216 return 0;
217}
218
219int gpio_direction_input(unsigned gpio)
220{
221 u32 mask;
222 struct altera_pio *pio;
223
224 pio = altera_pio_get_and_mask(gpio, &mask);
225 if (!pio)
226 return -1;
227 if (pio->iot == 'o')
228 return -1;
229
230 writel(pio->sh_dir &= ~mask, pio->base + ALTERA_PIO_DIR);
231 return 0;
232}
233
234int gpio_direction_output(unsigned gpio, int value)
235{
236 u32 mask;
237 struct altera_pio *pio;
238
239 pio = altera_pio_get_and_mask(gpio, &mask);
240 if (!pio)
241 return -1;
242 if (pio->iot == 'i')
243 return -1;
244
245 value = (pio->negmask & mask) ? !value : value;
246 if (value)
247 pio->sh_data |= mask;
248 else
249 pio->sh_data &= ~mask;
250 writel(pio->sh_data, pio->base + ALTERA_PIO_DATA);
251 writel(pio->sh_dir |= mask, pio->base + ALTERA_PIO_DIR);
252 return 0;
253}
254
255int gpio_get_value(unsigned gpio)
256{
257 u32 mask;
258 struct altera_pio *pio;
259 u32 val;
260
261 pio = altera_pio_get_and_mask(gpio, &mask);
262 if (!pio)
263 return -1;
264
265 if ((pio->sh_dir & mask) || (pio->iot == 'o'))
266 val = pio->sh_data & mask;
267 else
268 val = readl(pio->base + ALTERA_PIO_DATA) & mask;
269 return (pio->negmask & mask) ? !val : val;
270}
271
272void gpio_set_value(unsigned gpio, int value)
273{
274 u32 mask;
275 struct altera_pio *pio;
276
277 pio = altera_pio_get_and_mask(gpio, &mask);
278 if (!pio)
279 return;
280 if (pio->iot == 'i')
281 return;
282
283 value = (pio->negmask & mask) ? !value : value;
284 if (value)
285 pio->sh_data |= mask;
286 else
287 pio->sh_data &= ~mask;
288 writel(pio->sh_data, pio->base + ALTERA_PIO_DATA);
289 return;
290}
291
292int gpio_is_valid(int number)
293{
294 int gidx = altera_pio_gidx(number);
295
296 if (gidx < 0)
297 return 1;
298 return 0;
299}