xref: /openbmc/linux/arch/arm/mach-omap2/prm44xx.c (revision 95e9fd10)
1 /*
2  * OMAP4 PRM module functions
3  *
4  * Copyright (C) 2011 Texas Instruments, Inc.
5  * Copyright (C) 2010 Nokia Corporation
6  * Benoît Cousson
7  * Paul Walmsley
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/delay.h>
16 #include <linux/errno.h>
17 #include <linux/err.h>
18 #include <linux/io.h>
19 
20 #include <plat/cpu.h>
21 #include <plat/irqs.h>
22 #include <plat/prcm.h>
23 
24 #include "iomap.h"
25 #include "common.h"
26 #include "vp.h"
27 #include "prm44xx.h"
28 #include "prm-regbits-44xx.h"
29 #include "prcm44xx.h"
30 #include "prminst44xx.h"
31 
32 static const struct omap_prcm_irq omap4_prcm_irqs[] = {
33 	OMAP_PRCM_IRQ("wkup",   0,      0),
34 	OMAP_PRCM_IRQ("io",     9,      1),
35 };
36 
37 static struct omap_prcm_irq_setup omap4_prcm_irq_setup = {
38 	.ack			= OMAP4_PRM_IRQSTATUS_MPU_OFFSET,
39 	.mask			= OMAP4_PRM_IRQENABLE_MPU_OFFSET,
40 	.nr_regs		= 2,
41 	.irqs			= omap4_prcm_irqs,
42 	.nr_irqs		= ARRAY_SIZE(omap4_prcm_irqs),
43 	.irq			= OMAP44XX_IRQ_PRCM,
44 	.read_pending_irqs	= &omap44xx_prm_read_pending_irqs,
45 	.ocp_barrier		= &omap44xx_prm_ocp_barrier,
46 	.save_and_clear_irqen	= &omap44xx_prm_save_and_clear_irqen,
47 	.restore_irqen		= &omap44xx_prm_restore_irqen,
48 };
49 
50 /* PRM low-level functions */
51 
52 /* Read a register in a CM/PRM instance in the PRM module */
53 u32 omap4_prm_read_inst_reg(s16 inst, u16 reg)
54 {
55 	return __raw_readl(OMAP44XX_PRM_REGADDR(inst, reg));
56 }
57 
58 /* Write into a register in a CM/PRM instance in the PRM module */
59 void omap4_prm_write_inst_reg(u32 val, s16 inst, u16 reg)
60 {
61 	__raw_writel(val, OMAP44XX_PRM_REGADDR(inst, reg));
62 }
63 
64 /* Read-modify-write a register in a PRM module. Caller must lock */
65 u32 omap4_prm_rmw_inst_reg_bits(u32 mask, u32 bits, s16 inst, s16 reg)
66 {
67 	u32 v;
68 
69 	v = omap4_prm_read_inst_reg(inst, reg);
70 	v &= ~mask;
71 	v |= bits;
72 	omap4_prm_write_inst_reg(v, inst, reg);
73 
74 	return v;
75 }
76 
77 /* PRM VP */
78 
79 /*
80  * struct omap4_vp - OMAP4 VP register access description.
81  * @irqstatus_mpu: offset to IRQSTATUS_MPU register for VP
82  * @tranxdone_status: VP_TRANXDONE_ST bitmask in PRM_IRQSTATUS_MPU reg
83  */
84 struct omap4_vp {
85 	u32 irqstatus_mpu;
86 	u32 tranxdone_status;
87 };
88 
89 static struct omap4_vp omap4_vp[] = {
90 	[OMAP4_VP_VDD_MPU_ID] = {
91 		.irqstatus_mpu = OMAP4_PRM_IRQSTATUS_MPU_2_OFFSET,
92 		.tranxdone_status = OMAP4430_VP_MPU_TRANXDONE_ST_MASK,
93 	},
94 	[OMAP4_VP_VDD_IVA_ID] = {
95 		.irqstatus_mpu = OMAP4_PRM_IRQSTATUS_MPU_OFFSET,
96 		.tranxdone_status = OMAP4430_VP_IVA_TRANXDONE_ST_MASK,
97 	},
98 	[OMAP4_VP_VDD_CORE_ID] = {
99 		.irqstatus_mpu = OMAP4_PRM_IRQSTATUS_MPU_OFFSET,
100 		.tranxdone_status = OMAP4430_VP_CORE_TRANXDONE_ST_MASK,
101 	},
102 };
103 
104 u32 omap4_prm_vp_check_txdone(u8 vp_id)
105 {
106 	struct omap4_vp *vp = &omap4_vp[vp_id];
107 	u32 irqstatus;
108 
109 	irqstatus = omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
110 						OMAP4430_PRM_OCP_SOCKET_INST,
111 						vp->irqstatus_mpu);
112 	return irqstatus & vp->tranxdone_status;
113 }
114 
115 void omap4_prm_vp_clear_txdone(u8 vp_id)
116 {
117 	struct omap4_vp *vp = &omap4_vp[vp_id];
118 
119 	omap4_prminst_write_inst_reg(vp->tranxdone_status,
120 				     OMAP4430_PRM_PARTITION,
121 				     OMAP4430_PRM_OCP_SOCKET_INST,
122 				     vp->irqstatus_mpu);
123 };
124 
125 u32 omap4_prm_vcvp_read(u8 offset)
126 {
127 	return omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
128 					   OMAP4430_PRM_DEVICE_INST, offset);
129 }
130 
131 void omap4_prm_vcvp_write(u32 val, u8 offset)
132 {
133 	omap4_prminst_write_inst_reg(val, OMAP4430_PRM_PARTITION,
134 				     OMAP4430_PRM_DEVICE_INST, offset);
135 }
136 
137 u32 omap4_prm_vcvp_rmw(u32 mask, u32 bits, u8 offset)
138 {
139 	return omap4_prminst_rmw_inst_reg_bits(mask, bits,
140 					       OMAP4430_PRM_PARTITION,
141 					       OMAP4430_PRM_DEVICE_INST,
142 					       offset);
143 }
144 
145 static inline u32 _read_pending_irq_reg(u16 irqen_offs, u16 irqst_offs)
146 {
147 	u32 mask, st;
148 
149 	/* XXX read mask from RAM? */
150 	mask = omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST,
151 				       irqen_offs);
152 	st = omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST, irqst_offs);
153 
154 	return mask & st;
155 }
156 
157 /**
158  * omap44xx_prm_read_pending_irqs - read pending PRM MPU IRQs into @events
159  * @events: ptr to two consecutive u32s, preallocated by caller
160  *
161  * Read PRM_IRQSTATUS_MPU* bits, AND'ed with the currently-enabled PRM
162  * MPU IRQs, and store the result into the two u32s pointed to by @events.
163  * No return value.
164  */
165 void omap44xx_prm_read_pending_irqs(unsigned long *events)
166 {
167 	events[0] = _read_pending_irq_reg(OMAP4_PRM_IRQENABLE_MPU_OFFSET,
168 					  OMAP4_PRM_IRQSTATUS_MPU_OFFSET);
169 
170 	events[1] = _read_pending_irq_reg(OMAP4_PRM_IRQENABLE_MPU_2_OFFSET,
171 					  OMAP4_PRM_IRQSTATUS_MPU_2_OFFSET);
172 }
173 
174 /**
175  * omap44xx_prm_ocp_barrier - force buffered MPU writes to the PRM to complete
176  *
177  * Force any buffered writes to the PRM IP block to complete.  Needed
178  * by the PRM IRQ handler, which reads and writes directly to the IP
179  * block, to avoid race conditions after acknowledging or clearing IRQ
180  * bits.  No return value.
181  */
182 void omap44xx_prm_ocp_barrier(void)
183 {
184 	omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST,
185 				OMAP4_REVISION_PRM_OFFSET);
186 }
187 
188 /**
189  * omap44xx_prm_save_and_clear_irqen - save/clear PRM_IRQENABLE_MPU* regs
190  * @saved_mask: ptr to a u32 array to save IRQENABLE bits
191  *
192  * Save the PRM_IRQENABLE_MPU and PRM_IRQENABLE_MPU_2 registers to
193  * @saved_mask.  @saved_mask must be allocated by the caller.
194  * Intended to be used in the PRM interrupt handler suspend callback.
195  * The OCP barrier is needed to ensure the write to disable PRM
196  * interrupts reaches the PRM before returning; otherwise, spurious
197  * interrupts might occur.  No return value.
198  */
199 void omap44xx_prm_save_and_clear_irqen(u32 *saved_mask)
200 {
201 	saved_mask[0] =
202 		omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST,
203 					OMAP4_PRM_IRQSTATUS_MPU_OFFSET);
204 	saved_mask[1] =
205 		omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST,
206 					OMAP4_PRM_IRQSTATUS_MPU_2_OFFSET);
207 
208 	omap4_prm_write_inst_reg(0, OMAP4430_PRM_OCP_SOCKET_INST,
209 				 OMAP4_PRM_IRQENABLE_MPU_OFFSET);
210 	omap4_prm_write_inst_reg(0, OMAP4430_PRM_OCP_SOCKET_INST,
211 				 OMAP4_PRM_IRQENABLE_MPU_2_OFFSET);
212 
213 	/* OCP barrier */
214 	omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST,
215 				OMAP4_REVISION_PRM_OFFSET);
216 }
217 
218 /**
219  * omap44xx_prm_restore_irqen - set PRM_IRQENABLE_MPU* registers from args
220  * @saved_mask: ptr to a u32 array of IRQENABLE bits saved previously
221  *
222  * Restore the PRM_IRQENABLE_MPU and PRM_IRQENABLE_MPU_2 registers from
223  * @saved_mask.  Intended to be used in the PRM interrupt handler resume
224  * callback to restore values saved by omap44xx_prm_save_and_clear_irqen().
225  * No OCP barrier should be needed here; any pending PRM interrupts will fire
226  * once the writes reach the PRM.  No return value.
227  */
228 void omap44xx_prm_restore_irqen(u32 *saved_mask)
229 {
230 	omap4_prm_write_inst_reg(saved_mask[0], OMAP4430_PRM_OCP_SOCKET_INST,
231 				 OMAP4_PRM_IRQENABLE_MPU_OFFSET);
232 	omap4_prm_write_inst_reg(saved_mask[1], OMAP4430_PRM_OCP_SOCKET_INST,
233 				 OMAP4_PRM_IRQENABLE_MPU_2_OFFSET);
234 }
235 
236 /**
237  * omap44xx_prm_reconfigure_io_chain - clear latches and reconfigure I/O chain
238  *
239  * Clear any previously-latched I/O wakeup events and ensure that the
240  * I/O wakeup gates are aligned with the current mux settings.  Works
241  * by asserting WUCLKIN, waiting for WUCLKOUT to be asserted, and then
242  * deasserting WUCLKIN and waiting for WUCLKOUT to be deasserted.
243  * No return value. XXX Are the final two steps necessary?
244  */
245 void omap44xx_prm_reconfigure_io_chain(void)
246 {
247 	int i = 0;
248 
249 	/* Trigger WUCLKIN enable */
250 	omap4_prm_rmw_inst_reg_bits(OMAP4430_WUCLK_CTRL_MASK,
251 				    OMAP4430_WUCLK_CTRL_MASK,
252 				    OMAP4430_PRM_DEVICE_INST,
253 				    OMAP4_PRM_IO_PMCTRL_OFFSET);
254 	omap_test_timeout(
255 		(((omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
256 					   OMAP4_PRM_IO_PMCTRL_OFFSET) &
257 		   OMAP4430_WUCLK_STATUS_MASK) >>
258 		  OMAP4430_WUCLK_STATUS_SHIFT) == 1),
259 		MAX_IOPAD_LATCH_TIME, i);
260 	if (i == MAX_IOPAD_LATCH_TIME)
261 		pr_warn("PRM: I/O chain clock line assertion timed out\n");
262 
263 	/* Trigger WUCLKIN disable */
264 	omap4_prm_rmw_inst_reg_bits(OMAP4430_WUCLK_CTRL_MASK, 0x0,
265 				    OMAP4430_PRM_DEVICE_INST,
266 				    OMAP4_PRM_IO_PMCTRL_OFFSET);
267 	omap_test_timeout(
268 		(((omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
269 					   OMAP4_PRM_IO_PMCTRL_OFFSET) &
270 		   OMAP4430_WUCLK_STATUS_MASK) >>
271 		  OMAP4430_WUCLK_STATUS_SHIFT) == 0),
272 		MAX_IOPAD_LATCH_TIME, i);
273 	if (i == MAX_IOPAD_LATCH_TIME)
274 		pr_warn("PRM: I/O chain clock line deassertion timed out\n");
275 
276 	return;
277 }
278 
279 /**
280  * omap44xx_prm_enable_io_wakeup - enable wakeup events from I/O wakeup latches
281  *
282  * Activates the I/O wakeup event latches and allows events logged by
283  * those latches to signal a wakeup event to the PRCM.  For I/O wakeups
284  * to occur, WAKEUPENABLE bits must be set in the pad mux registers, and
285  * omap44xx_prm_reconfigure_io_chain() must be called.  No return value.
286  */
287 static void __init omap44xx_prm_enable_io_wakeup(void)
288 {
289 	omap4_prm_rmw_inst_reg_bits(OMAP4430_GLOBAL_WUEN_MASK,
290 				    OMAP4430_GLOBAL_WUEN_MASK,
291 				    OMAP4430_PRM_DEVICE_INST,
292 				    OMAP4_PRM_IO_PMCTRL_OFFSET);
293 }
294 
295 static int __init omap4xxx_prcm_init(void)
296 {
297 	if (cpu_is_omap44xx()) {
298 		omap44xx_prm_enable_io_wakeup();
299 		return omap_prcm_register_chain_handler(&omap4_prcm_irq_setup);
300 	}
301 	return 0;
302 }
303 subsys_initcall(omap4xxx_prcm_init);
304