2 /* linux/arch/arm/plat-s3c/pm-gpio.c
4 * Copyright 2008 Openmoko, Inc.
5 * Copyright 2008 Simtec Electronics
6 * Ben Dooks <ben@simtec.co.uk>
7 * http://armlinux.simtec.co.uk/
9 * S3C series GPIO PM code
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.
16 #include <linux/kernel.h>
17 #include <linux/device.h>
18 #include <linux/init.h>
20 #include <linux/gpio.h>
22 #include <mach/gpio-samsung.h>
24 #include <plat/gpio-core.h>
29 #define OFFS_CON (0x00)
30 #define OFFS_DAT (0x04)
31 #define OFFS_UP (0x08)
33 static void samsung_gpio_pm_1bit_save(struct samsung_gpio_chip
*chip
)
35 chip
->pm_save
[0] = __raw_readl(chip
->base
+ OFFS_CON
);
36 chip
->pm_save
[1] = __raw_readl(chip
->base
+ OFFS_DAT
);
39 static void samsung_gpio_pm_1bit_resume(struct samsung_gpio_chip
*chip
)
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];
48 /* GPACON only has one bit per control / data and no PULLUPs.
49 * GPACON[x] = 0 => Output, 1 => SFN */
51 /* first set all SFN bits to SFN */
53 gpcon
= old_gpcon
| gps_gpcon
;
54 __raw_writel(gpcon
, base
+ OFFS_CON
);
56 /* now set all the other bits */
58 __raw_writel(gps_gpdat
, base
+ OFFS_DAT
);
59 __raw_writel(gps_gpcon
, base
+ OFFS_CON
);
61 S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n",
62 chip
->chip
.label
, old_gpcon
, gps_gpcon
, old_gpdat
, gps_gpdat
);
65 struct samsung_gpio_pm samsung_gpio_pm_1bit
= {
66 .save
= samsung_gpio_pm_1bit_save
,
67 .resume
= samsung_gpio_pm_1bit_resume
,
70 static void samsung_gpio_pm_2bit_save(struct samsung_gpio_chip
*chip
)
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
);
77 /* Test whether the given masked+shifted bits of an GPIO configuration
78 * are one of the SFN (special function) modes. */
80 static inline int is_sfn(unsigned long con
)
85 /* Test if the given masked+shifted GPIO configuration is an input */
87 static inline int is_in(unsigned long con
)
92 /* Test if the given masked+shifted GPIO configuration is an output */
94 static inline int is_out(unsigned long con
)
100 * samsung_gpio_pm_2bit_resume() - restore the given GPIO bank
101 * @chip: The chip information to resume.
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.
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
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]
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.
123 * [1] this assumes that writing to a pin DAT whilst in SFN will set the
124 * state for when it is next output.
126 static void samsung_gpio_pm_2bit_resume(struct samsung_gpio_chip
*chip
)
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;
137 /* restore GPIO pull-up settings */
138 __raw_writel(chip
->pm_save
[2], base
+ OFFS_UP
);
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.
145 for (nr
= 0, mask
= 0x03; nr
< 32; nr
+= 2, mask
<<= 2) {
146 old
= (old_gpcon
& mask
) >> nr
;
147 new = (gps_gpcon
& mask
) >> nr
;
149 /* If there is no change, then skip */
154 /* If both are special function, then skip */
156 if (is_sfn(old
) && is_sfn(new))
159 /* Change is IN => OUT, do not change now */
161 if (is_in(old
) && is_out(new))
164 /* Change is SFN => OUT, do not change now */
166 if (is_sfn(old
) && is_out(new))
169 /* We should now be at the case of IN=>SFN,
170 * OUT=>SFN, OUT=>IN, SFN=>IN. */
176 /* Write the new CON settings */
178 gpcon
= old_gpcon
& ~change_mask
;
179 gpcon
|= gps_gpcon
& change_mask
;
181 __raw_writel(gpcon
, base
+ OFFS_CON
);
183 /* Now change any items that require DAT,CON */
185 __raw_writel(gps_gpdat
, base
+ OFFS_DAT
);
186 __raw_writel(gps_gpcon
, base
+ OFFS_CON
);
188 S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n",
189 chip
->chip
.label
, old_gpcon
, gps_gpcon
, old_gpdat
, gps_gpdat
);
192 struct samsung_gpio_pm samsung_gpio_pm_2bit
= {
193 .save
= samsung_gpio_pm_2bit_save
,
194 .resume
= samsung_gpio_pm_2bit_resume
,
197 #if defined(CONFIG_ARCH_S3C64XX)
198 static void samsung_gpio_pm_4bit_save(struct samsung_gpio_chip
*chip
)
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
);
204 if (chip
->chip
.ngpio
> 8)
205 chip
->pm_save
[0] = __raw_readl(chip
->base
- 4);
208 static u32
samsung_gpio_pm_4bit_mask(u32 old_gpcon
, u32 gps_gpcon
)
211 u32 change_mask
= 0x0;
214 for (nr
= 0, mask
= 0x0f; nr
< 16; nr
+= 4, mask
<<= 4) {
215 old
= (old_gpcon
& mask
) >> nr
;
216 new = (gps_gpcon
& mask
) >> nr
;
218 /* If there is no change, then skip */
223 /* If both are special function, then skip */
225 if (is_sfn(old
) && is_sfn(new))
228 /* Change is IN => OUT, do not change now */
230 if (is_in(old
) && is_out(new))
233 /* Change is SFN => OUT, do not change now */
235 if (is_sfn(old
) && is_out(new))
238 /* We should now be at the case of IN=>SFN,
239 * OUT=>SFN, OUT=>IN, SFN=>IN. */
247 static void samsung_gpio_pm_4bit_con(struct samsung_gpio_chip
*chip
, int index
)
249 void __iomem
*con
= chip
->base
+ (index
* 4);
250 u32 old_gpcon
= __raw_readl(con
);
251 u32 gps_gpcon
= chip
->pm_save
[index
+ 1];
254 mask
= samsung_gpio_pm_4bit_mask(old_gpcon
, gps_gpcon
);
256 gpcon
= old_gpcon
& ~mask
;
257 gpcon
|= gps_gpcon
& mask
;
259 __raw_writel(gpcon
, con
);
262 static void samsung_gpio_pm_4bit_resume(struct samsung_gpio_chip
*chip
)
264 void __iomem
*base
= chip
->base
;
266 u32 old_gpdat
= __raw_readl(base
+ OFFS_DAT
);
267 u32 gps_gpdat
= chip
->pm_save
[2];
269 /* First, modify the CON settings */
272 old_gpcon
[1] = __raw_readl(base
+ OFFS_CON
);
274 samsung_gpio_pm_4bit_con(chip
, 0);
275 if (chip
->chip
.ngpio
> 8) {
276 old_gpcon
[0] = __raw_readl(base
- 4);
277 samsung_gpio_pm_4bit_con(chip
, -1);
280 /* Now change the configurations that require DAT,CON */
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);
287 __raw_writel(chip
->pm_save
[2], base
+ OFFS_DAT
);
288 __raw_writel(chip
->pm_save
[3], base
+ OFFS_UP
);
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
);
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
);
303 struct samsung_gpio_pm samsung_gpio_pm_4bit
= {
304 .save
= samsung_gpio_pm_4bit_save
,
305 .resume
= samsung_gpio_pm_4bit_resume
,
307 #endif /* CONFIG_ARCH_S3C64XX */
310 * samsung_pm_save_gpio() - save gpio chip data for suspend
311 * @ourchip: The chip for suspend.
313 static void samsung_pm_save_gpio(struct samsung_gpio_chip
*ourchip
)
315 struct samsung_gpio_pm
*pm
= ourchip
->pm
;
317 if (pm
== NULL
|| pm
->save
== NULL
)
318 S3C_PMDBG("%s: no pm for %s\n", __func__
, ourchip
->chip
.label
);
324 * samsung_pm_save_gpios() - Save the state of the GPIO banks.
326 * For all the GPIO banks, save the state of each one ready for going
327 * into a suspend mode.
329 void samsung_pm_save_gpios(void)
331 struct samsung_gpio_chip
*ourchip
;
332 unsigned int gpio_nr
;
334 for (gpio_nr
= 0; gpio_nr
< S3C_GPIO_END
;) {
335 ourchip
= samsung_gpiolib_getchip(gpio_nr
);
341 samsung_pm_save_gpio(ourchip
);
343 S3C_PMDBG("%s: save %08x,%08x,%08x,%08x\n",
348 ourchip
->pm_save
[3]);
350 gpio_nr
+= ourchip
->chip
.ngpio
;
351 gpio_nr
+= CONFIG_S3C_GPIO_SPACE
;
356 * samsung_pm_resume_gpio() - restore gpio chip data after suspend
357 * @ourchip: The suspended chip.
359 static void samsung_pm_resume_gpio(struct samsung_gpio_chip
*ourchip
)
361 struct samsung_gpio_pm
*pm
= ourchip
->pm
;
363 if (pm
== NULL
|| pm
->resume
== NULL
)
364 S3C_PMDBG("%s: no pm for %s\n", __func__
, ourchip
->chip
.label
);
369 void samsung_pm_restore_gpios(void)
371 struct samsung_gpio_chip
*ourchip
;
372 unsigned int gpio_nr
;
374 for (gpio_nr
= 0; gpio_nr
< S3C_GPIO_END
;) {
375 ourchip
= samsung_gpiolib_getchip(gpio_nr
);
381 samsung_pm_resume_gpio(ourchip
);
383 gpio_nr
+= ourchip
->chip
.ngpio
;
384 gpio_nr
+= CONFIG_S3C_GPIO_SPACE
;