xref: /openbmc/linux/arch/arm/mach-omap2/cm33xx.c (revision 7e035230)
1 /*
2  * AM33XX CM functions
3  *
4  * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
5  * Vaibhav Hiremath <hvaibhav@ti.com>
6  *
7  * Reference taken from from OMAP4 cminst44xx.c
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation version 2.
12  *
13  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
14  * kind, whether express or implied; without even the implied warranty
15  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/types.h>
21 #include <linux/errno.h>
22 #include <linux/err.h>
23 #include <linux/io.h>
24 
25 #include <plat/common.h>
26 
27 #include "cm.h"
28 #include "cm33xx.h"
29 #include "cm-regbits-34xx.h"
30 #include "cm-regbits-33xx.h"
31 #include "prm33xx.h"
32 
33 /*
34  * CLKCTRL_IDLEST_*: possible values for the CM_*_CLKCTRL.IDLEST bitfield:
35  *
36  *   0x0 func:     Module is fully functional, including OCP
37  *   0x1 trans:    Module is performing transition: wakeup, or sleep, or sleep
38  *                 abortion
39  *   0x2 idle:     Module is in Idle mode (only OCP part). It is functional if
40  *                 using separate functional clock
41  *   0x3 disabled: Module is disabled and cannot be accessed
42  *
43  */
44 #define CLKCTRL_IDLEST_FUNCTIONAL		0x0
45 #define CLKCTRL_IDLEST_INTRANSITION		0x1
46 #define CLKCTRL_IDLEST_INTERFACE_IDLE		0x2
47 #define CLKCTRL_IDLEST_DISABLED			0x3
48 
49 /* Private functions */
50 
51 /* Read a register in a CM instance */
52 static inline u32 am33xx_cm_read_reg(s16 inst, u16 idx)
53 {
54 	return __raw_readl(cm_base + inst + idx);
55 }
56 
57 /* Write into a register in a CM */
58 static inline void am33xx_cm_write_reg(u32 val, s16 inst, u16 idx)
59 {
60 	__raw_writel(val, cm_base + inst + idx);
61 }
62 
63 /* Read-modify-write a register in CM */
64 static inline u32 am33xx_cm_rmw_reg_bits(u32 mask, u32 bits, s16 inst, s16 idx)
65 {
66 	u32 v;
67 
68 	v = am33xx_cm_read_reg(inst, idx);
69 	v &= ~mask;
70 	v |= bits;
71 	am33xx_cm_write_reg(v, inst, idx);
72 
73 	return v;
74 }
75 
76 static inline u32 am33xx_cm_set_reg_bits(u32 bits, s16 inst, s16 idx)
77 {
78 	return am33xx_cm_rmw_reg_bits(bits, bits, inst, idx);
79 }
80 
81 static inline u32 am33xx_cm_clear_reg_bits(u32 bits, s16 inst, s16 idx)
82 {
83 	return am33xx_cm_rmw_reg_bits(bits, 0x0, inst, idx);
84 }
85 
86 static inline u32 am33xx_cm_read_reg_bits(u16 inst, s16 idx, u32 mask)
87 {
88 	u32 v;
89 
90 	v = am33xx_cm_read_reg(inst, idx);
91 	v &= mask;
92 	v >>= __ffs(mask);
93 
94 	return v;
95 }
96 
97 /**
98  * _clkctrl_idlest - read a CM_*_CLKCTRL register; mask & shift IDLEST bitfield
99  * @inst: CM instance register offset (*_INST macro)
100  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
101  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
102  *
103  * Return the IDLEST bitfield of a CM_*_CLKCTRL register, shifted down to
104  * bit 0.
105  */
106 static u32 _clkctrl_idlest(u16 inst, s16 cdoffs, u16 clkctrl_offs)
107 {
108 	u32 v = am33xx_cm_read_reg(inst, clkctrl_offs);
109 	v &= AM33XX_IDLEST_MASK;
110 	v >>= AM33XX_IDLEST_SHIFT;
111 	return v;
112 }
113 
114 /**
115  * _is_module_ready - can module registers be accessed without causing an abort?
116  * @inst: CM instance register offset (*_INST macro)
117  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
118  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
119  *
120  * Returns true if the module's CM_*_CLKCTRL.IDLEST bitfield is either
121  * *FUNCTIONAL or *INTERFACE_IDLE; false otherwise.
122  */
123 static bool _is_module_ready(u16 inst, s16 cdoffs, u16 clkctrl_offs)
124 {
125 	u32 v;
126 
127 	v = _clkctrl_idlest(inst, cdoffs, clkctrl_offs);
128 
129 	return (v == CLKCTRL_IDLEST_FUNCTIONAL ||
130 		v == CLKCTRL_IDLEST_INTERFACE_IDLE) ? true : false;
131 }
132 
133 /**
134  * _clktrctrl_write - write @c to a CM_CLKSTCTRL.CLKTRCTRL register bitfield
135  * @c: CLKTRCTRL register bitfield (LSB = bit 0, i.e., unshifted)
136  * @inst: CM instance register offset (*_INST macro)
137  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
138  *
139  * @c must be the unshifted value for CLKTRCTRL - i.e., this function
140  * will handle the shift itself.
141  */
142 static void _clktrctrl_write(u8 c, s16 inst, u16 cdoffs)
143 {
144 	u32 v;
145 
146 	v = am33xx_cm_read_reg(inst, cdoffs);
147 	v &= ~AM33XX_CLKTRCTRL_MASK;
148 	v |= c << AM33XX_CLKTRCTRL_SHIFT;
149 	am33xx_cm_write_reg(v, inst, cdoffs);
150 }
151 
152 /* Public functions */
153 
154 /**
155  * am33xx_cm_is_clkdm_in_hwsup - is a clockdomain in hwsup idle mode?
156  * @inst: CM instance register offset (*_INST macro)
157  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
158  *
159  * Returns true if the clockdomain referred to by (@inst, @cdoffs)
160  * is in hardware-supervised idle mode, or 0 otherwise.
161  */
162 bool am33xx_cm_is_clkdm_in_hwsup(s16 inst, u16 cdoffs)
163 {
164 	u32 v;
165 
166 	v = am33xx_cm_read_reg(inst, cdoffs);
167 	v &= AM33XX_CLKTRCTRL_MASK;
168 	v >>= AM33XX_CLKTRCTRL_SHIFT;
169 
170 	return (v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ? true : false;
171 }
172 
173 /**
174  * am33xx_cm_clkdm_enable_hwsup - put a clockdomain in hwsup-idle mode
175  * @inst: CM instance register offset (*_INST macro)
176  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
177  *
178  * Put a clockdomain referred to by (@inst, @cdoffs) into
179  * hardware-supervised idle mode.  No return value.
180  */
181 void am33xx_cm_clkdm_enable_hwsup(s16 inst, u16 cdoffs)
182 {
183 	_clktrctrl_write(OMAP34XX_CLKSTCTRL_ENABLE_AUTO, inst, cdoffs);
184 }
185 
186 /**
187  * am33xx_cm_clkdm_disable_hwsup - put a clockdomain in swsup-idle mode
188  * @inst: CM instance register offset (*_INST macro)
189  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
190  *
191  * Put a clockdomain referred to by (@inst, @cdoffs) into
192  * software-supervised idle mode, i.e., controlled manually by the
193  * Linux OMAP clockdomain code.  No return value.
194  */
195 void am33xx_cm_clkdm_disable_hwsup(s16 inst, u16 cdoffs)
196 {
197 	_clktrctrl_write(OMAP34XX_CLKSTCTRL_DISABLE_AUTO, inst, cdoffs);
198 }
199 
200 /**
201  * am33xx_cm_clkdm_force_sleep - try to put a clockdomain into idle
202  * @inst: CM instance register offset (*_INST macro)
203  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
204  *
205  * Put a clockdomain referred to by (@inst, @cdoffs) into idle
206  * No return value.
207  */
208 void am33xx_cm_clkdm_force_sleep(s16 inst, u16 cdoffs)
209 {
210 	_clktrctrl_write(OMAP34XX_CLKSTCTRL_FORCE_SLEEP, inst, cdoffs);
211 }
212 
213 /**
214  * am33xx_cm_clkdm_force_wakeup - try to take a clockdomain out of idle
215  * @inst: CM instance register offset (*_INST macro)
216  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
217  *
218  * Take a clockdomain referred to by (@inst, @cdoffs) out of idle,
219  * waking it up.  No return value.
220  */
221 void am33xx_cm_clkdm_force_wakeup(s16 inst, u16 cdoffs)
222 {
223 	_clktrctrl_write(OMAP34XX_CLKSTCTRL_FORCE_WAKEUP, inst, cdoffs);
224 }
225 
226 /*
227  *
228  */
229 
230 /**
231  * am33xx_cm_wait_module_ready - wait for a module to be in 'func' state
232  * @inst: CM instance register offset (*_INST macro)
233  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
234  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
235  *
236  * Wait for the module IDLEST to be functional. If the idle state is in any
237  * the non functional state (trans, idle or disabled), module and thus the
238  * sysconfig cannot be accessed and will probably lead to an "imprecise
239  * external abort"
240  */
241 int am33xx_cm_wait_module_ready(u16 inst, s16 cdoffs, u16 clkctrl_offs)
242 {
243 	int i = 0;
244 
245 	if (!clkctrl_offs)
246 		return 0;
247 
248 	omap_test_timeout(_is_module_ready(inst, cdoffs, clkctrl_offs),
249 			  MAX_MODULE_READY_TIME, i);
250 
251 	return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
252 }
253 
254 /**
255  * am33xx_cm_wait_module_idle - wait for a module to be in 'disabled'
256  * state
257  * @inst: CM instance register offset (*_INST macro)
258  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
259  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
260  *
261  * Wait for the module IDLEST to be disabled. Some PRCM transition,
262  * like reset assertion or parent clock de-activation must wait the
263  * module to be fully disabled.
264  */
265 int am33xx_cm_wait_module_idle(u16 inst, s16 cdoffs, u16 clkctrl_offs)
266 {
267 	int i = 0;
268 
269 	if (!clkctrl_offs)
270 		return 0;
271 
272 	omap_test_timeout((_clkctrl_idlest(inst, cdoffs, clkctrl_offs) ==
273 				CLKCTRL_IDLEST_DISABLED),
274 				MAX_MODULE_READY_TIME, i);
275 
276 	return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
277 }
278 
279 /**
280  * am33xx_cm_module_enable - Enable the modulemode inside CLKCTRL
281  * @mode: Module mode (SW or HW)
282  * @inst: CM instance register offset (*_INST macro)
283  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
284  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
285  *
286  * No return value.
287  */
288 void am33xx_cm_module_enable(u8 mode, u16 inst, s16 cdoffs, u16 clkctrl_offs)
289 {
290 	u32 v;
291 
292 	v = am33xx_cm_read_reg(inst, clkctrl_offs);
293 	v &= ~AM33XX_MODULEMODE_MASK;
294 	v |= mode << AM33XX_MODULEMODE_SHIFT;
295 	am33xx_cm_write_reg(v, inst, clkctrl_offs);
296 }
297 
298 /**
299  * am33xx_cm_module_disable - Disable the module inside CLKCTRL
300  * @inst: CM instance register offset (*_INST macro)
301  * @cdoffs: Clockdomain register offset (*_CDOFFS macro)
302  * @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
303  *
304  * No return value.
305  */
306 void am33xx_cm_module_disable(u16 inst, s16 cdoffs, u16 clkctrl_offs)
307 {
308 	u32 v;
309 
310 	v = am33xx_cm_read_reg(inst, clkctrl_offs);
311 	v &= ~AM33XX_MODULEMODE_MASK;
312 	am33xx_cm_write_reg(v, inst, clkctrl_offs);
313 }
314