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d87964c4 BD |
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2 | /* linux/arch/arm/plat-s3c/pm-gpio.c | |
3 | * | |
4 | * Copyright 2008 Openmoko, Inc. | |
5 | * Copyright 2008 Simtec Electronics | |
6 | * Ben Dooks <ben@simtec.co.uk> | |
7 | * http://armlinux.simtec.co.uk/ | |
8 | * | |
9 | * S3C series GPIO PM code | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License version 2 as | |
13 | * published by the Free Software Foundation. | |
14 | */ | |
15 | ||
16 | #include <linux/kernel.h> | |
edbaa603 | 17 | #include <linux/device.h> |
d87964c4 BD |
18 | #include <linux/init.h> |
19 | #include <linux/io.h> | |
20 | #include <linux/gpio.h> | |
21 | ||
b0161caa | 22 | #include <mach/gpio-samsung.h> |
785acec3 | 23 | |
e856bb1f | 24 | #include <plat/gpio-core.h> |
d87964c4 BD |
25 | #include <plat/pm.h> |
26 | ||
27 | /* PM GPIO helpers */ | |
28 | ||
29 | #define OFFS_CON (0x00) | |
30 | #define OFFS_DAT (0x04) | |
31 | #define OFFS_UP (0x08) | |
32 | ||
782d8a3c | 33 | static void samsung_gpio_pm_1bit_save(struct samsung_gpio_chip *chip) |
d87964c4 BD |
34 | { |
35 | chip->pm_save[0] = __raw_readl(chip->base + OFFS_CON); | |
36 | chip->pm_save[1] = __raw_readl(chip->base + OFFS_DAT); | |
37 | } | |
38 | ||
782d8a3c | 39 | static void samsung_gpio_pm_1bit_resume(struct samsung_gpio_chip *chip) |
d87964c4 BD |
40 | { |
41 | void __iomem *base = chip->base; | |
42 | u32 old_gpcon = __raw_readl(base + OFFS_CON); | |
43 | u32 old_gpdat = __raw_readl(base + OFFS_DAT); | |
44 | u32 gps_gpcon = chip->pm_save[0]; | |
45 | u32 gps_gpdat = chip->pm_save[1]; | |
46 | u32 gpcon; | |
47 | ||
48 | /* GPACON only has one bit per control / data and no PULLUPs. | |
49 | * GPACON[x] = 0 => Output, 1 => SFN */ | |
50 | ||
51 | /* first set all SFN bits to SFN */ | |
52 | ||
53 | gpcon = old_gpcon | gps_gpcon; | |
54 | __raw_writel(gpcon, base + OFFS_CON); | |
55 | ||
56 | /* now set all the other bits */ | |
57 | ||
58 | __raw_writel(gps_gpdat, base + OFFS_DAT); | |
59 | __raw_writel(gps_gpcon, base + OFFS_CON); | |
60 | ||
61 | S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n", | |
62 | chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat); | |
63 | } | |
64 | ||
782d8a3c KK |
65 | struct samsung_gpio_pm samsung_gpio_pm_1bit = { |
66 | .save = samsung_gpio_pm_1bit_save, | |
67 | .resume = samsung_gpio_pm_1bit_resume, | |
d87964c4 BD |
68 | }; |
69 | ||
782d8a3c | 70 | static void samsung_gpio_pm_2bit_save(struct samsung_gpio_chip *chip) |
d87964c4 BD |
71 | { |
72 | chip->pm_save[0] = __raw_readl(chip->base + OFFS_CON); | |
73 | chip->pm_save[1] = __raw_readl(chip->base + OFFS_DAT); | |
74 | chip->pm_save[2] = __raw_readl(chip->base + OFFS_UP); | |
75 | } | |
76 | ||
77 | /* Test whether the given masked+shifted bits of an GPIO configuration | |
78 | * are one of the SFN (special function) modes. */ | |
79 | ||
80 | static inline int is_sfn(unsigned long con) | |
81 | { | |
82 | return con >= 2; | |
83 | } | |
84 | ||
85 | /* Test if the given masked+shifted GPIO configuration is an input */ | |
86 | ||
87 | static inline int is_in(unsigned long con) | |
88 | { | |
89 | return con == 0; | |
90 | } | |
91 | ||
92 | /* Test if the given masked+shifted GPIO configuration is an output */ | |
93 | ||
94 | static inline int is_out(unsigned long con) | |
95 | { | |
96 | return con == 1; | |
97 | } | |
98 | ||
99 | /** | |
782d8a3c | 100 | * samsung_gpio_pm_2bit_resume() - restore the given GPIO bank |
d87964c4 BD |
101 | * @chip: The chip information to resume. |
102 | * | |
103 | * Restore one of the GPIO banks that was saved during suspend. This is | |
104 | * not as simple as once thought, due to the possibility of glitches | |
105 | * from the order that the CON and DAT registers are set in. | |
106 | * | |
107 | * The three states the pin can be are {IN,OUT,SFN} which gives us 9 | |
108 | * combinations of changes to check. Three of these, if the pin stays | |
109 | * in the same configuration can be discounted. This leaves us with | |
110 | * the following: | |
111 | * | |
112 | * { IN => OUT } Change DAT first | |
113 | * { IN => SFN } Change CON first | |
114 | * { OUT => SFN } Change CON first, so new data will not glitch | |
115 | * { OUT => IN } Change CON first, so new data will not glitch | |
116 | * { SFN => IN } Change CON first | |
117 | * { SFN => OUT } Change DAT first, so new data will not glitch [1] | |
118 | * | |
119 | * We do not currently deal with the UP registers as these control | |
120 | * weak resistors, so a small delay in change should not need to bring | |
121 | * these into the calculations. | |
122 | * | |
123 | * [1] this assumes that writing to a pin DAT whilst in SFN will set the | |
124 | * state for when it is next output. | |
125 | */ | |
782d8a3c | 126 | static void samsung_gpio_pm_2bit_resume(struct samsung_gpio_chip *chip) |
d87964c4 BD |
127 | { |
128 | void __iomem *base = chip->base; | |
129 | u32 old_gpcon = __raw_readl(base + OFFS_CON); | |
130 | u32 old_gpdat = __raw_readl(base + OFFS_DAT); | |
131 | u32 gps_gpcon = chip->pm_save[0]; | |
132 | u32 gps_gpdat = chip->pm_save[1]; | |
133 | u32 gpcon, old, new, mask; | |
134 | u32 change_mask = 0x0; | |
135 | int nr; | |
136 | ||
137 | /* restore GPIO pull-up settings */ | |
138 | __raw_writel(chip->pm_save[2], base + OFFS_UP); | |
139 | ||
140 | /* Create a change_mask of all the items that need to have | |
141 | * their CON value changed before their DAT value, so that | |
142 | * we minimise the work between the two settings. | |
143 | */ | |
144 | ||
145 | for (nr = 0, mask = 0x03; nr < 32; nr += 2, mask <<= 2) { | |
146 | old = (old_gpcon & mask) >> nr; | |
147 | new = (gps_gpcon & mask) >> nr; | |
148 | ||
149 | /* If there is no change, then skip */ | |
150 | ||
151 | if (old == new) | |
152 | continue; | |
153 | ||
154 | /* If both are special function, then skip */ | |
155 | ||
156 | if (is_sfn(old) && is_sfn(new)) | |
157 | continue; | |
158 | ||
159 | /* Change is IN => OUT, do not change now */ | |
160 | ||
161 | if (is_in(old) && is_out(new)) | |
162 | continue; | |
163 | ||
164 | /* Change is SFN => OUT, do not change now */ | |
165 | ||
166 | if (is_sfn(old) && is_out(new)) | |
167 | continue; | |
168 | ||
169 | /* We should now be at the case of IN=>SFN, | |
170 | * OUT=>SFN, OUT=>IN, SFN=>IN. */ | |
171 | ||
172 | change_mask |= mask; | |
173 | } | |
174 | ||
175 | ||
176 | /* Write the new CON settings */ | |
177 | ||
178 | gpcon = old_gpcon & ~change_mask; | |
179 | gpcon |= gps_gpcon & change_mask; | |
180 | ||
181 | __raw_writel(gpcon, base + OFFS_CON); | |
182 | ||
183 | /* Now change any items that require DAT,CON */ | |
184 | ||
185 | __raw_writel(gps_gpdat, base + OFFS_DAT); | |
186 | __raw_writel(gps_gpcon, base + OFFS_CON); | |
187 | ||
188 | S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n", | |
189 | chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat); | |
190 | } | |
191 | ||
782d8a3c KK |
192 | struct samsung_gpio_pm samsung_gpio_pm_2bit = { |
193 | .save = samsung_gpio_pm_2bit_save, | |
194 | .resume = samsung_gpio_pm_2bit_resume, | |
d87964c4 BD |
195 | }; |
196 | ||
d78c16cc | 197 | #if defined(CONFIG_ARCH_S3C64XX) |
782d8a3c | 198 | static void samsung_gpio_pm_4bit_save(struct samsung_gpio_chip *chip) |
d87964c4 BD |
199 | { |
200 | chip->pm_save[1] = __raw_readl(chip->base + OFFS_CON); | |
201 | chip->pm_save[2] = __raw_readl(chip->base + OFFS_DAT); | |
202 | chip->pm_save[3] = __raw_readl(chip->base + OFFS_UP); | |
203 | ||
204 | if (chip->chip.ngpio > 8) | |
205 | chip->pm_save[0] = __raw_readl(chip->base - 4); | |
206 | } | |
207 | ||
782d8a3c | 208 | static u32 samsung_gpio_pm_4bit_mask(u32 old_gpcon, u32 gps_gpcon) |
d87964c4 BD |
209 | { |
210 | u32 old, new, mask; | |
211 | u32 change_mask = 0x0; | |
212 | int nr; | |
213 | ||
214 | for (nr = 0, mask = 0x0f; nr < 16; nr += 4, mask <<= 4) { | |
215 | old = (old_gpcon & mask) >> nr; | |
216 | new = (gps_gpcon & mask) >> nr; | |
217 | ||
218 | /* If there is no change, then skip */ | |
219 | ||
220 | if (old == new) | |
221 | continue; | |
222 | ||
223 | /* If both are special function, then skip */ | |
224 | ||
225 | if (is_sfn(old) && is_sfn(new)) | |
226 | continue; | |
227 | ||
228 | /* Change is IN => OUT, do not change now */ | |
229 | ||
230 | if (is_in(old) && is_out(new)) | |
231 | continue; | |
232 | ||
233 | /* Change is SFN => OUT, do not change now */ | |
234 | ||
235 | if (is_sfn(old) && is_out(new)) | |
236 | continue; | |
237 | ||
238 | /* We should now be at the case of IN=>SFN, | |
239 | * OUT=>SFN, OUT=>IN, SFN=>IN. */ | |
240 | ||
241 | change_mask |= mask; | |
242 | } | |
243 | ||
244 | return change_mask; | |
245 | } | |
246 | ||
782d8a3c | 247 | static void samsung_gpio_pm_4bit_con(struct samsung_gpio_chip *chip, int index) |
d87964c4 BD |
248 | { |
249 | void __iomem *con = chip->base + (index * 4); | |
250 | u32 old_gpcon = __raw_readl(con); | |
251 | u32 gps_gpcon = chip->pm_save[index + 1]; | |
252 | u32 gpcon, mask; | |
253 | ||
782d8a3c | 254 | mask = samsung_gpio_pm_4bit_mask(old_gpcon, gps_gpcon); |
d87964c4 BD |
255 | |
256 | gpcon = old_gpcon & ~mask; | |
257 | gpcon |= gps_gpcon & mask; | |
258 | ||
259 | __raw_writel(gpcon, con); | |
260 | } | |
261 | ||
782d8a3c | 262 | static void samsung_gpio_pm_4bit_resume(struct samsung_gpio_chip *chip) |
d87964c4 BD |
263 | { |
264 | void __iomem *base = chip->base; | |
265 | u32 old_gpcon[2]; | |
266 | u32 old_gpdat = __raw_readl(base + OFFS_DAT); | |
267 | u32 gps_gpdat = chip->pm_save[2]; | |
268 | ||
269 | /* First, modify the CON settings */ | |
270 | ||
271 | old_gpcon[0] = 0; | |
272 | old_gpcon[1] = __raw_readl(base + OFFS_CON); | |
273 | ||
782d8a3c | 274 | samsung_gpio_pm_4bit_con(chip, 0); |
d87964c4 BD |
275 | if (chip->chip.ngpio > 8) { |
276 | old_gpcon[0] = __raw_readl(base - 4); | |
782d8a3c | 277 | samsung_gpio_pm_4bit_con(chip, -1); |
d87964c4 BD |
278 | } |
279 | ||
280 | /* Now change the configurations that require DAT,CON */ | |
281 | ||
282 | __raw_writel(chip->pm_save[2], base + OFFS_DAT); | |
283 | __raw_writel(chip->pm_save[1], base + OFFS_CON); | |
284 | if (chip->chip.ngpio > 8) | |
285 | __raw_writel(chip->pm_save[0], base - 4); | |
286 | ||
287 | __raw_writel(chip->pm_save[2], base + OFFS_DAT); | |
288 | __raw_writel(chip->pm_save[3], base + OFFS_UP); | |
289 | ||
290 | if (chip->chip.ngpio > 8) { | |
291 | S3C_PMDBG("%s: CON4 %08x,%08x => %08x,%08x, DAT %08x => %08x\n", | |
292 | chip->chip.label, old_gpcon[0], old_gpcon[1], | |
293 | __raw_readl(base - 4), | |
294 | __raw_readl(base + OFFS_CON), | |
295 | old_gpdat, gps_gpdat); | |
296 | } else | |
297 | S3C_PMDBG("%s: CON4 %08x => %08x, DAT %08x => %08x\n", | |
298 | chip->chip.label, old_gpcon[1], | |
299 | __raw_readl(base + OFFS_CON), | |
300 | old_gpdat, gps_gpdat); | |
301 | } | |
302 | ||
782d8a3c KK |
303 | struct samsung_gpio_pm samsung_gpio_pm_4bit = { |
304 | .save = samsung_gpio_pm_4bit_save, | |
305 | .resume = samsung_gpio_pm_4bit_resume, | |
d87964c4 | 306 | }; |
d78c16cc | 307 | #endif /* CONFIG_ARCH_S3C64XX */ |
d87964c4 BD |
308 | |
309 | /** | |
782d8a3c | 310 | * samsung_pm_save_gpio() - save gpio chip data for suspend |
d87964c4 BD |
311 | * @ourchip: The chip for suspend. |
312 | */ | |
782d8a3c | 313 | static void samsung_pm_save_gpio(struct samsung_gpio_chip *ourchip) |
d87964c4 | 314 | { |
782d8a3c | 315 | struct samsung_gpio_pm *pm = ourchip->pm; |
d87964c4 BD |
316 | |
317 | if (pm == NULL || pm->save == NULL) | |
318 | S3C_PMDBG("%s: no pm for %s\n", __func__, ourchip->chip.label); | |
319 | else | |
320 | pm->save(ourchip); | |
321 | } | |
322 | ||
323 | /** | |
782d8a3c | 324 | * samsung_pm_save_gpios() - Save the state of the GPIO banks. |
d87964c4 BD |
325 | * |
326 | * For all the GPIO banks, save the state of each one ready for going | |
327 | * into a suspend mode. | |
328 | */ | |
782d8a3c | 329 | void samsung_pm_save_gpios(void) |
d87964c4 | 330 | { |
782d8a3c | 331 | struct samsung_gpio_chip *ourchip; |
d87964c4 BD |
332 | unsigned int gpio_nr; |
333 | ||
32b6cb38 | 334 | for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) { |
782d8a3c | 335 | ourchip = samsung_gpiolib_getchip(gpio_nr); |
91dc74e4 P |
336 | if (!ourchip) { |
337 | gpio_nr++; | |
d87964c4 | 338 | continue; |
91dc74e4 | 339 | } |
d87964c4 | 340 | |
782d8a3c | 341 | samsung_pm_save_gpio(ourchip); |
d87964c4 BD |
342 | |
343 | S3C_PMDBG("%s: save %08x,%08x,%08x,%08x\n", | |
344 | ourchip->chip.label, | |
345 | ourchip->pm_save[0], | |
346 | ourchip->pm_save[1], | |
347 | ourchip->pm_save[2], | |
348 | ourchip->pm_save[3]); | |
349 | ||
350 | gpio_nr += ourchip->chip.ngpio; | |
351 | gpio_nr += CONFIG_S3C_GPIO_SPACE; | |
352 | } | |
353 | } | |
354 | ||
355 | /** | |
782d8a3c | 356 | * samsung_pm_resume_gpio() - restore gpio chip data after suspend |
d87964c4 BD |
357 | * @ourchip: The suspended chip. |
358 | */ | |
782d8a3c | 359 | static void samsung_pm_resume_gpio(struct samsung_gpio_chip *ourchip) |
d87964c4 | 360 | { |
782d8a3c | 361 | struct samsung_gpio_pm *pm = ourchip->pm; |
d87964c4 BD |
362 | |
363 | if (pm == NULL || pm->resume == NULL) | |
364 | S3C_PMDBG("%s: no pm for %s\n", __func__, ourchip->chip.label); | |
365 | else | |
366 | pm->resume(ourchip); | |
367 | } | |
368 | ||
782d8a3c | 369 | void samsung_pm_restore_gpios(void) |
d87964c4 | 370 | { |
782d8a3c | 371 | struct samsung_gpio_chip *ourchip; |
d87964c4 BD |
372 | unsigned int gpio_nr; |
373 | ||
32b6cb38 | 374 | for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) { |
782d8a3c | 375 | ourchip = samsung_gpiolib_getchip(gpio_nr); |
91dc74e4 P |
376 | if (!ourchip) { |
377 | gpio_nr++; | |
d87964c4 | 378 | continue; |
91dc74e4 | 379 | } |
d87964c4 | 380 | |
782d8a3c | 381 | samsung_pm_resume_gpio(ourchip); |
d87964c4 BD |
382 | |
383 | gpio_nr += ourchip->chip.ngpio; | |
384 | gpio_nr += CONFIG_S3C_GPIO_SPACE; | |
385 | } | |
386 | } |