1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | // |
3 | // Copyright 2008 Openmoko, Inc. |
4 | // Copyright 2008 Simtec Electronics |
5 | // Ben Dooks <ben@simtec.co.uk> |
6 | // http://armlinux.simtec.co.uk/ |
7 | // |
8 | // S3C series GPIO PM code |
9 | |
10 | #include <linux/kernel.h> |
11 | #include <linux/device.h> |
12 | #include <linux/init.h> |
13 | #include <linux/io.h> |
14 | #include <linux/gpio.h> |
15 | |
16 | #include "gpio-samsung.h" |
17 | |
18 | #include "gpio-core.h" |
19 | #include "pm.h" |
20 | |
21 | /* PM GPIO helpers */ |
22 | |
23 | #define OFFS_CON (0x00) |
24 | #define OFFS_DAT (0x04) |
25 | #define OFFS_UP (0x08) |
26 | |
27 | static void samsung_gpio_pm_1bit_save(struct samsung_gpio_chip *chip) |
28 | { |
29 | chip->pm_save[0] = __raw_readl(addr: chip->base + OFFS_CON); |
30 | chip->pm_save[1] = __raw_readl(addr: chip->base + OFFS_DAT); |
31 | } |
32 | |
33 | static void samsung_gpio_pm_1bit_resume(struct samsung_gpio_chip *chip) |
34 | { |
35 | void __iomem *base = chip->base; |
36 | u32 old_gpcon = __raw_readl(addr: base + OFFS_CON); |
37 | u32 old_gpdat = __raw_readl(addr: base + OFFS_DAT); |
38 | u32 gps_gpcon = chip->pm_save[0]; |
39 | u32 gps_gpdat = chip->pm_save[1]; |
40 | u32 gpcon; |
41 | |
42 | /* GPACON only has one bit per control / data and no PULLUPs. |
43 | * GPACON[x] = 0 => Output, 1 => SFN */ |
44 | |
45 | /* first set all SFN bits to SFN */ |
46 | |
47 | gpcon = old_gpcon | gps_gpcon; |
48 | __raw_writel(val: gpcon, addr: base + OFFS_CON); |
49 | |
50 | /* now set all the other bits */ |
51 | |
52 | __raw_writel(val: gps_gpdat, addr: base + OFFS_DAT); |
53 | __raw_writel(val: gps_gpcon, addr: base + OFFS_CON); |
54 | |
55 | S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n" , |
56 | chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat); |
57 | } |
58 | |
59 | struct samsung_gpio_pm samsung_gpio_pm_1bit = { |
60 | .save = samsung_gpio_pm_1bit_save, |
61 | .resume = samsung_gpio_pm_1bit_resume, |
62 | }; |
63 | |
64 | static void samsung_gpio_pm_2bit_save(struct samsung_gpio_chip *chip) |
65 | { |
66 | chip->pm_save[0] = __raw_readl(addr: chip->base + OFFS_CON); |
67 | chip->pm_save[1] = __raw_readl(addr: chip->base + OFFS_DAT); |
68 | chip->pm_save[2] = __raw_readl(addr: chip->base + OFFS_UP); |
69 | } |
70 | |
71 | /* Test whether the given masked+shifted bits of an GPIO configuration |
72 | * are one of the SFN (special function) modes. */ |
73 | |
74 | static inline int is_sfn(unsigned long con) |
75 | { |
76 | return con >= 2; |
77 | } |
78 | |
79 | /* Test if the given masked+shifted GPIO configuration is an input */ |
80 | |
81 | static inline int is_in(unsigned long con) |
82 | { |
83 | return con == 0; |
84 | } |
85 | |
86 | /* Test if the given masked+shifted GPIO configuration is an output */ |
87 | |
88 | static inline int is_out(unsigned long con) |
89 | { |
90 | return con == 1; |
91 | } |
92 | |
93 | /** |
94 | * samsung_gpio_pm_2bit_resume() - restore the given GPIO bank |
95 | * @chip: The chip information to resume. |
96 | * |
97 | * Restore one of the GPIO banks that was saved during suspend. This is |
98 | * not as simple as once thought, due to the possibility of glitches |
99 | * from the order that the CON and DAT registers are set in. |
100 | * |
101 | * The three states the pin can be are {IN,OUT,SFN} which gives us 9 |
102 | * combinations of changes to check. Three of these, if the pin stays |
103 | * in the same configuration can be discounted. This leaves us with |
104 | * the following: |
105 | * |
106 | * { IN => OUT } Change DAT first |
107 | * { IN => SFN } Change CON first |
108 | * { OUT => SFN } Change CON first, so new data will not glitch |
109 | * { OUT => IN } Change CON first, so new data will not glitch |
110 | * { SFN => IN } Change CON first |
111 | * { SFN => OUT } Change DAT first, so new data will not glitch [1] |
112 | * |
113 | * We do not currently deal with the UP registers as these control |
114 | * weak resistors, so a small delay in change should not need to bring |
115 | * these into the calculations. |
116 | * |
117 | * [1] this assumes that writing to a pin DAT whilst in SFN will set the |
118 | * state for when it is next output. |
119 | */ |
120 | static void samsung_gpio_pm_2bit_resume(struct samsung_gpio_chip *chip) |
121 | { |
122 | void __iomem *base = chip->base; |
123 | u32 old_gpcon = __raw_readl(addr: base + OFFS_CON); |
124 | u32 old_gpdat = __raw_readl(addr: base + OFFS_DAT); |
125 | u32 gps_gpcon = chip->pm_save[0]; |
126 | u32 gps_gpdat = chip->pm_save[1]; |
127 | u32 gpcon, old, new, mask; |
128 | u32 change_mask = 0x0; |
129 | int nr; |
130 | |
131 | /* restore GPIO pull-up settings */ |
132 | __raw_writel(val: chip->pm_save[2], addr: base + OFFS_UP); |
133 | |
134 | /* Create a change_mask of all the items that need to have |
135 | * their CON value changed before their DAT value, so that |
136 | * we minimise the work between the two settings. |
137 | */ |
138 | |
139 | for (nr = 0, mask = 0x03; nr < 32; nr += 2, mask <<= 2) { |
140 | old = (old_gpcon & mask) >> nr; |
141 | new = (gps_gpcon & mask) >> nr; |
142 | |
143 | /* If there is no change, then skip */ |
144 | |
145 | if (old == new) |
146 | continue; |
147 | |
148 | /* If both are special function, then skip */ |
149 | |
150 | if (is_sfn(con: old) && is_sfn(con: new)) |
151 | continue; |
152 | |
153 | /* Change is IN => OUT, do not change now */ |
154 | |
155 | if (is_in(con: old) && is_out(con: new)) |
156 | continue; |
157 | |
158 | /* Change is SFN => OUT, do not change now */ |
159 | |
160 | if (is_sfn(con: old) && is_out(con: new)) |
161 | continue; |
162 | |
163 | /* We should now be at the case of IN=>SFN, |
164 | * OUT=>SFN, OUT=>IN, SFN=>IN. */ |
165 | |
166 | change_mask |= mask; |
167 | } |
168 | |
169 | |
170 | /* Write the new CON settings */ |
171 | |
172 | gpcon = old_gpcon & ~change_mask; |
173 | gpcon |= gps_gpcon & change_mask; |
174 | |
175 | __raw_writel(val: gpcon, addr: base + OFFS_CON); |
176 | |
177 | /* Now change any items that require DAT,CON */ |
178 | |
179 | __raw_writel(val: gps_gpdat, addr: base + OFFS_DAT); |
180 | __raw_writel(val: gps_gpcon, addr: base + OFFS_CON); |
181 | |
182 | S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n" , |
183 | chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat); |
184 | } |
185 | |
186 | struct samsung_gpio_pm samsung_gpio_pm_2bit = { |
187 | .save = samsung_gpio_pm_2bit_save, |
188 | .resume = samsung_gpio_pm_2bit_resume, |
189 | }; |
190 | |
191 | #if defined(CONFIG_ARCH_S3C64XX) |
192 | static void samsung_gpio_pm_4bit_save(struct samsung_gpio_chip *chip) |
193 | { |
194 | chip->pm_save[1] = __raw_readl(chip->base + OFFS_CON); |
195 | chip->pm_save[2] = __raw_readl(chip->base + OFFS_DAT); |
196 | chip->pm_save[3] = __raw_readl(chip->base + OFFS_UP); |
197 | |
198 | if (chip->chip.ngpio > 8) |
199 | chip->pm_save[0] = __raw_readl(chip->base - 4); |
200 | } |
201 | |
202 | static u32 samsung_gpio_pm_4bit_mask(u32 old_gpcon, u32 gps_gpcon) |
203 | { |
204 | u32 old, new, mask; |
205 | u32 change_mask = 0x0; |
206 | int nr; |
207 | |
208 | for (nr = 0, mask = 0x0f; nr < 16; nr += 4, mask <<= 4) { |
209 | old = (old_gpcon & mask) >> nr; |
210 | new = (gps_gpcon & mask) >> nr; |
211 | |
212 | /* If there is no change, then skip */ |
213 | |
214 | if (old == new) |
215 | continue; |
216 | |
217 | /* If both are special function, then skip */ |
218 | |
219 | if (is_sfn(old) && is_sfn(new)) |
220 | continue; |
221 | |
222 | /* Change is IN => OUT, do not change now */ |
223 | |
224 | if (is_in(old) && is_out(new)) |
225 | continue; |
226 | |
227 | /* Change is SFN => OUT, do not change now */ |
228 | |
229 | if (is_sfn(old) && is_out(new)) |
230 | continue; |
231 | |
232 | /* We should now be at the case of IN=>SFN, |
233 | * OUT=>SFN, OUT=>IN, SFN=>IN. */ |
234 | |
235 | change_mask |= mask; |
236 | } |
237 | |
238 | return change_mask; |
239 | } |
240 | |
241 | static void samsung_gpio_pm_4bit_con(struct samsung_gpio_chip *chip, int index) |
242 | { |
243 | void __iomem *con = chip->base + (index * 4); |
244 | u32 old_gpcon = __raw_readl(con); |
245 | u32 gps_gpcon = chip->pm_save[index + 1]; |
246 | u32 gpcon, mask; |
247 | |
248 | mask = samsung_gpio_pm_4bit_mask(old_gpcon, gps_gpcon); |
249 | |
250 | gpcon = old_gpcon & ~mask; |
251 | gpcon |= gps_gpcon & mask; |
252 | |
253 | __raw_writel(gpcon, con); |
254 | } |
255 | |
256 | static void samsung_gpio_pm_4bit_resume(struct samsung_gpio_chip *chip) |
257 | { |
258 | void __iomem *base = chip->base; |
259 | u32 old_gpcon[2]; |
260 | u32 old_gpdat = __raw_readl(base + OFFS_DAT); |
261 | u32 gps_gpdat = chip->pm_save[2]; |
262 | |
263 | /* First, modify the CON settings */ |
264 | |
265 | old_gpcon[0] = 0; |
266 | old_gpcon[1] = __raw_readl(base + OFFS_CON); |
267 | |
268 | samsung_gpio_pm_4bit_con(chip, 0); |
269 | if (chip->chip.ngpio > 8) { |
270 | old_gpcon[0] = __raw_readl(base - 4); |
271 | samsung_gpio_pm_4bit_con(chip, -1); |
272 | } |
273 | |
274 | /* Now change the configurations that require DAT,CON */ |
275 | |
276 | __raw_writel(chip->pm_save[2], base + OFFS_DAT); |
277 | __raw_writel(chip->pm_save[1], base + OFFS_CON); |
278 | if (chip->chip.ngpio > 8) |
279 | __raw_writel(chip->pm_save[0], base - 4); |
280 | |
281 | __raw_writel(chip->pm_save[2], base + OFFS_DAT); |
282 | __raw_writel(chip->pm_save[3], base + OFFS_UP); |
283 | |
284 | if (chip->chip.ngpio > 8) { |
285 | S3C_PMDBG("%s: CON4 %08x,%08x => %08x,%08x, DAT %08x => %08x\n" , |
286 | chip->chip.label, old_gpcon[0], old_gpcon[1], |
287 | __raw_readl(base - 4), |
288 | __raw_readl(base + OFFS_CON), |
289 | old_gpdat, gps_gpdat); |
290 | } else |
291 | S3C_PMDBG("%s: CON4 %08x => %08x, DAT %08x => %08x\n" , |
292 | chip->chip.label, old_gpcon[1], |
293 | __raw_readl(base + OFFS_CON), |
294 | old_gpdat, gps_gpdat); |
295 | } |
296 | |
297 | struct samsung_gpio_pm samsung_gpio_pm_4bit = { |
298 | .save = samsung_gpio_pm_4bit_save, |
299 | .resume = samsung_gpio_pm_4bit_resume, |
300 | }; |
301 | #endif /* CONFIG_ARCH_S3C64XX */ |
302 | |
303 | /** |
304 | * samsung_pm_save_gpio() - save gpio chip data for suspend |
305 | * @ourchip: The chip for suspend. |
306 | */ |
307 | static void samsung_pm_save_gpio(struct samsung_gpio_chip *ourchip) |
308 | { |
309 | struct samsung_gpio_pm *pm = ourchip->pm; |
310 | |
311 | if (pm == NULL || pm->save == NULL) |
312 | S3C_PMDBG("%s: no pm for %s\n" , __func__, ourchip->chip.label); |
313 | else |
314 | pm->save(ourchip); |
315 | } |
316 | |
317 | /** |
318 | * samsung_pm_save_gpios() - Save the state of the GPIO banks. |
319 | * |
320 | * For all the GPIO banks, save the state of each one ready for going |
321 | * into a suspend mode. |
322 | */ |
323 | void samsung_pm_save_gpios(void) |
324 | { |
325 | struct samsung_gpio_chip *ourchip; |
326 | unsigned int gpio_nr; |
327 | |
328 | for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) { |
329 | ourchip = samsung_gpiolib_getchip(pin: gpio_nr); |
330 | if (!ourchip) { |
331 | gpio_nr++; |
332 | continue; |
333 | } |
334 | |
335 | samsung_pm_save_gpio(ourchip); |
336 | |
337 | S3C_PMDBG("%s: save %08x,%08x,%08x,%08x\n" , |
338 | ourchip->chip.label, |
339 | ourchip->pm_save[0], |
340 | ourchip->pm_save[1], |
341 | ourchip->pm_save[2], |
342 | ourchip->pm_save[3]); |
343 | |
344 | gpio_nr += ourchip->chip.ngpio; |
345 | gpio_nr += CONFIG_S3C_GPIO_SPACE; |
346 | } |
347 | } |
348 | |
349 | /** |
350 | * samsung_pm_resume_gpio() - restore gpio chip data after suspend |
351 | * @ourchip: The suspended chip. |
352 | */ |
353 | static void samsung_pm_resume_gpio(struct samsung_gpio_chip *ourchip) |
354 | { |
355 | struct samsung_gpio_pm *pm = ourchip->pm; |
356 | |
357 | if (pm == NULL || pm->resume == NULL) |
358 | S3C_PMDBG("%s: no pm for %s\n" , __func__, ourchip->chip.label); |
359 | else |
360 | pm->resume(ourchip); |
361 | } |
362 | |
363 | void samsung_pm_restore_gpios(void) |
364 | { |
365 | struct samsung_gpio_chip *ourchip; |
366 | unsigned int gpio_nr; |
367 | |
368 | for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) { |
369 | ourchip = samsung_gpiolib_getchip(pin: gpio_nr); |
370 | if (!ourchip) { |
371 | gpio_nr++; |
372 | continue; |
373 | } |
374 | |
375 | samsung_pm_resume_gpio(ourchip); |
376 | |
377 | gpio_nr += ourchip->chip.ngpio; |
378 | gpio_nr += CONFIG_S3C_GPIO_SPACE; |
379 | } |
380 | } |
381 | |