xref: /openbmc/u-boot/arch/arm/mach-imx/rdc-sema.c (revision 0649cd0d)
1 /*
2  * Copyright (C) 2016 Freescale Semiconductor, Inc.
3  *
4  * SPDX-License-Identifier:  GPL-2.0+
5  */
6 #include <common.h>
7 #include <asm/io.h>
8 #include <asm/arch/imx-regs.h>
9 #include <asm/mach-imx/rdc-sema.h>
10 #include <asm/arch/imx-rdc.h>
11 #include <linux/errno.h>
12 
13 /*
14  * Check if the RDC Semaphore is required for this peripheral.
15  */
16 static inline int imx_rdc_check_sema_required(int per_id)
17 {
18 	struct rdc_regs *imx_rdc = (struct rdc_regs *)RDC_BASE_ADDR;
19 	u32 reg;
20 
21 	reg = readl(&imx_rdc->pdap[per_id]);
22 	/*
23 	 * No semaphore:
24 	 * Intial value or this peripheral is assigned to only one domain
25 	 */
26 	if (!(reg & RDC_PDAP_SREQ_MASK))
27 		return -ENOENT;
28 
29 	return 0;
30 }
31 
32 /*
33  * Check the peripheral read / write access permission on Domain [dom_id].
34  */
35 int imx_rdc_check_permission(int per_id, int dom_id)
36 {
37 	struct rdc_regs *imx_rdc = (struct rdc_regs *)RDC_BASE_ADDR;
38 	u32 reg;
39 
40 	reg = readl(&imx_rdc->pdap[per_id]);
41 	if (!(reg & RDC_PDAP_DRW_MASK(dom_id)))
42 		return -EACCES;  /*No access*/
43 
44 	return 0;
45 }
46 
47 /*
48  * Lock up the RDC semaphore for this peripheral if semaphore is required.
49  */
50 int imx_rdc_sema_lock(int per_id)
51 {
52 	struct rdc_sema_regs *imx_rdc_sema;
53 	int ret;
54 	u8 reg;
55 
56 	ret = imx_rdc_check_sema_required(per_id);
57 	if (ret)
58 		return ret;
59 
60 	if (per_id < SEMA_GATES_NUM)
61 		imx_rdc_sema  = (struct rdc_sema_regs *)SEMAPHORE1_BASE_ADDR;
62 	else
63 		imx_rdc_sema  = (struct rdc_sema_regs *)SEMAPHORE2_BASE_ADDR;
64 
65 	do {
66 		writeb(RDC_SEMA_PROC_ID,
67 		       &imx_rdc_sema->gate[per_id % SEMA_GATES_NUM]);
68 		reg = readb(&imx_rdc_sema->gate[per_id % SEMA_GATES_NUM]);
69 		if ((reg & RDC_SEMA_GATE_GTFSM_MASK) == RDC_SEMA_PROC_ID)
70 			break;  /* Get the Semaphore*/
71 	} while (1);
72 
73 	return 0;
74 }
75 
76 /*
77  * Unlock the RDC semaphore for this peripheral if main CPU is the
78  * semaphore owner.
79  */
80 int imx_rdc_sema_unlock(int per_id)
81 {
82 	struct rdc_sema_regs *imx_rdc_sema;
83 	int ret;
84 	u8 reg;
85 
86 	ret = imx_rdc_check_sema_required(per_id);
87 	if (ret)
88 		return ret;
89 
90 	if (per_id < SEMA_GATES_NUM)
91 		imx_rdc_sema  = (struct rdc_sema_regs *)SEMAPHORE1_BASE_ADDR;
92 	else
93 		imx_rdc_sema  = (struct rdc_sema_regs *)SEMAPHORE2_BASE_ADDR;
94 
95 	reg = readb(&imx_rdc_sema->gate[per_id % SEMA_GATES_NUM]);
96 	if ((reg & RDC_SEMA_GATE_GTFSM_MASK) != RDC_SEMA_PROC_ID)
97 		return -EACCES;	/*Not the semaphore owner */
98 
99 	writeb(0x0, &imx_rdc_sema->gate[per_id % SEMA_GATES_NUM]);
100 
101 	return 0;
102 }
103 
104 /*
105  * Setup RDC setting for one peripheral
106  */
107 int imx_rdc_setup_peri(rdc_peri_cfg_t p)
108 {
109 	struct rdc_regs *imx_rdc = (struct rdc_regs *)RDC_BASE_ADDR;
110 	u32 reg = 0;
111 	u32 share_count = 0;
112 	u32 peri_id = p & RDC_PERI_MASK;
113 	u32 domain = (p & RDC_DOMAIN_MASK) >> RDC_DOMAIN_SHIFT_BASE;
114 
115 	/* No domain assigned */
116 	if (domain == 0)
117 		return -EINVAL;
118 
119 	reg |= domain;
120 
121 	share_count = (domain & 0x3)
122 		+ ((domain >> 2) & 0x3)
123 		+ ((domain >> 4) & 0x3)
124 		+ ((domain >> 6) & 0x3);
125 
126 	if (share_count > 0x3)
127 		reg |= RDC_PDAP_SREQ_MASK;
128 
129 	writel(reg, &imx_rdc->pdap[peri_id]);
130 
131 	return 0;
132 }
133 
134 /*
135  * Setup RDC settings for multiple peripherals
136  */
137 int imx_rdc_setup_peripherals(rdc_peri_cfg_t const *peripherals_list,
138 				     unsigned count)
139 {
140 	rdc_peri_cfg_t const *p = peripherals_list;
141 	int i, ret;
142 
143 	for (i = 0; i < count; i++) {
144 		ret = imx_rdc_setup_peri(*p);
145 		if (ret)
146 			return ret;
147 		p++;
148 	}
149 
150 	return 0;
151 }
152 
153 /*
154  * Setup RDC setting for one master
155  */
156 int imx_rdc_setup_ma(rdc_ma_cfg_t p)
157 {
158 	struct rdc_regs *imx_rdc = (struct rdc_regs *)RDC_BASE_ADDR;
159 	u32 master_id = (p & RDC_MASTER_MASK) >> RDC_MASTER_SHIFT;
160 	u32 domain = (p & RDC_DOMAIN_MASK) >> RDC_DOMAIN_SHIFT_BASE;
161 
162 	writel((domain & RDC_MDA_DID_MASK), &imx_rdc->mda[master_id]);
163 
164 	return 0;
165 }
166 
167 /*
168  * Setup RDC settings for multiple masters
169  */
170 int imx_rdc_setup_masters(rdc_ma_cfg_t const *masters_list, unsigned count)
171 {
172 	rdc_ma_cfg_t const *p = masters_list;
173 	int i, ret;
174 
175 	for (i = 0; i < count; i++) {
176 		ret = imx_rdc_setup_ma(*p);
177 		if (ret)
178 			return ret;
179 		p++;
180 	}
181 
182 	return 0;
183 }
184