1 /*
2  * OMAP4 PRM instance functions
3  *
4  * Copyright (C) 2009 Nokia Corporation
5  * Copyright (C) 2011 Texas Instruments, Inc.
6  * Paul Walmsley
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/types.h>
15 #include <linux/errno.h>
16 #include <linux/err.h>
17 #include <linux/io.h>
18 
19 #include "iomap.h"
20 #include "common.h"
21 #include "prcm-common.h"
22 #include "prm44xx.h"
23 #include "prm54xx.h"
24 #include "prm7xx.h"
25 #include "prminst44xx.h"
26 #include "prm-regbits-44xx.h"
27 #include "prcm44xx.h"
28 #include "prcm_mpu44xx.h"
29 #include "soc.h"
30 
31 static void __iomem *_prm_bases[OMAP4_MAX_PRCM_PARTITIONS];
32 
33 /**
34  * omap_prm_base_init - Populates the prm partitions
35  *
36  * Populates the base addresses of the _prm_bases
37  * array used for read/write of prm module registers.
38  */
39 void omap_prm_base_init(void)
40 {
41 	_prm_bases[OMAP4430_PRM_PARTITION] = prm_base;
42 	_prm_bases[OMAP4430_PRCM_MPU_PARTITION] = prcm_mpu_base;
43 }
44 
45 /* Read a register in a PRM instance */
46 u32 omap4_prminst_read_inst_reg(u8 part, s16 inst, u16 idx)
47 {
48 	BUG_ON(part >= OMAP4_MAX_PRCM_PARTITIONS ||
49 	       part == OMAP4430_INVALID_PRCM_PARTITION ||
50 	       !_prm_bases[part]);
51 	return __raw_readl(_prm_bases[part] + inst + idx);
52 }
53 
54 /* Write into a register in a PRM instance */
55 void omap4_prminst_write_inst_reg(u32 val, u8 part, s16 inst, u16 idx)
56 {
57 	BUG_ON(part >= OMAP4_MAX_PRCM_PARTITIONS ||
58 	       part == OMAP4430_INVALID_PRCM_PARTITION ||
59 	       !_prm_bases[part]);
60 	__raw_writel(val, _prm_bases[part] + inst + idx);
61 }
62 
63 /* Read-modify-write a register in PRM. Caller must lock */
64 u32 omap4_prminst_rmw_inst_reg_bits(u32 mask, u32 bits, u8 part, s16 inst,
65 				    u16 idx)
66 {
67 	u32 v;
68 
69 	v = omap4_prminst_read_inst_reg(part, inst, idx);
70 	v &= ~mask;
71 	v |= bits;
72 	omap4_prminst_write_inst_reg(v, part, inst, idx);
73 
74 	return v;
75 }
76 
77 /*
78  * Address offset (in bytes) between the reset control and the reset
79  * status registers: 4 bytes on OMAP4
80  */
81 #define OMAP4_RST_CTRL_ST_OFFSET		4
82 
83 /**
84  * omap4_prminst_is_hardreset_asserted - read the HW reset line state of
85  * submodules contained in the hwmod module
86  * @rstctrl_reg: RM_RSTCTRL register address for this module
87  * @shift: register bit shift corresponding to the reset line to check
88  *
89  * Returns 1 if the (sub)module hardreset line is currently asserted,
90  * 0 if the (sub)module hardreset line is not currently asserted, or
91  * -EINVAL upon parameter error.
92  */
93 int omap4_prminst_is_hardreset_asserted(u8 shift, u8 part, s16 inst,
94 					u16 rstctrl_offs)
95 {
96 	u32 v;
97 
98 	v = omap4_prminst_read_inst_reg(part, inst, rstctrl_offs);
99 	v &= 1 << shift;
100 	v >>= shift;
101 
102 	return v;
103 }
104 
105 /**
106  * omap4_prminst_assert_hardreset - assert the HW reset line of a submodule
107  * @rstctrl_reg: RM_RSTCTRL register address for this module
108  * @shift: register bit shift corresponding to the reset line to assert
109  *
110  * Some IPs like dsp, ipu or iva contain processors that require an HW
111  * reset line to be asserted / deasserted in order to fully enable the
112  * IP.  These modules may have multiple hard-reset lines that reset
113  * different 'submodules' inside the IP block.  This function will
114  * place the submodule into reset.  Returns 0 upon success or -EINVAL
115  * upon an argument error.
116  */
117 int omap4_prminst_assert_hardreset(u8 shift, u8 part, s16 inst,
118 				   u16 rstctrl_offs)
119 {
120 	u32 mask = 1 << shift;
121 
122 	omap4_prminst_rmw_inst_reg_bits(mask, mask, part, inst, rstctrl_offs);
123 
124 	return 0;
125 }
126 
127 /**
128  * omap4_prminst_deassert_hardreset - deassert a submodule hardreset line and
129  * wait
130  * @rstctrl_reg: RM_RSTCTRL register address for this module
131  * @shift: register bit shift corresponding to the reset line to deassert
132  *
133  * Some IPs like dsp, ipu or iva contain processors that require an HW
134  * reset line to be asserted / deasserted in order to fully enable the
135  * IP.  These modules may have multiple hard-reset lines that reset
136  * different 'submodules' inside the IP block.  This function will
137  * take the submodule out of reset and wait until the PRCM indicates
138  * that the reset has completed before returning.  Returns 0 upon success or
139  * -EINVAL upon an argument error, -EEXIST if the submodule was already out
140  * of reset, or -EBUSY if the submodule did not exit reset promptly.
141  */
142 int omap4_prminst_deassert_hardreset(u8 shift, u8 part, s16 inst,
143 				     u16 rstctrl_offs)
144 {
145 	int c;
146 	u32 mask = 1 << shift;
147 	u16 rstst_offs = rstctrl_offs + OMAP4_RST_CTRL_ST_OFFSET;
148 
149 	/* Check the current status to avoid de-asserting the line twice */
150 	if (omap4_prminst_is_hardreset_asserted(shift, part, inst,
151 						rstctrl_offs) == 0)
152 		return -EEXIST;
153 
154 	/* Clear the reset status by writing 1 to the status bit */
155 	omap4_prminst_rmw_inst_reg_bits(0xffffffff, mask, part, inst,
156 					rstst_offs);
157 	/* de-assert the reset control line */
158 	omap4_prminst_rmw_inst_reg_bits(mask, 0, part, inst, rstctrl_offs);
159 	/* wait the status to be set */
160 	omap_test_timeout(omap4_prminst_is_hardreset_asserted(shift, part, inst,
161 							      rstst_offs),
162 			  MAX_MODULE_HARDRESET_WAIT, c);
163 
164 	return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
165 }
166 
167 
168 void omap4_prminst_global_warm_sw_reset(void)
169 {
170 	u32 v;
171 	s16 dev_inst;
172 
173 	if (cpu_is_omap44xx())
174 		dev_inst = OMAP4430_PRM_DEVICE_INST;
175 	else if (soc_is_omap54xx())
176 		dev_inst = OMAP54XX_PRM_DEVICE_INST;
177 	else if (soc_is_dra7xx())
178 		dev_inst = DRA7XX_PRM_DEVICE_INST;
179 	else
180 		return;
181 
182 	v = omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION, dev_inst,
183 					OMAP4_PRM_RSTCTRL_OFFSET);
184 	v |= OMAP4430_RST_GLOBAL_WARM_SW_MASK;
185 	omap4_prminst_write_inst_reg(v, OMAP4430_PRM_PARTITION,
186 				 OMAP4430_PRM_DEVICE_INST,
187 				 OMAP4_PRM_RSTCTRL_OFFSET);
188 
189 	/* OCP barrier */
190 	v = omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
191 				    OMAP4430_PRM_DEVICE_INST,
192 				    OMAP4_PRM_RSTCTRL_OFFSET);
193 }
194