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Mateusz Kulikowskid33776e2016-03-31 23:12:28 +02001/*
2 * Sample SPMI bus driver
3 *
4 * It emulates bus with single pm8916-like pmic that has only GPIO reigsters.
5 *
6 * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
7 *
8 * SPDX-License-Identifier: GPL-2.0+
9 */
10
11#include <common.h>
12#include <dm.h>
13#include <errno.h>
14#include <spmi/spmi.h>
15#include <asm/gpio.h>
16#include <asm/io.h>
17
18DECLARE_GLOBAL_DATA_PTR;
19
20#define EMUL_GPIO_PID_START 0xC0
21#define EMUL_GPIO_PID_END 0xC3
22
23#define EMUL_GPIO_COUNT 4
24
25#define EMUL_GPIO_REG_END 0x46 /* Last valid register */
26
27#define EMUL_PERM_R 0x1
28#define EMUL_PERM_W 0x2
29#define EMUL_PERM_RW (EMUL_PERM_R | EMUL_PERM_W)
30
31struct sandbox_emul_fake_regs {
32 u8 value;
33 u8 access_mask;
34 u8 perms; /* Access permissions */
35};
36
37struct sandbox_emul_gpio {
Mateusz Kulikowskiaafa6482016-04-04 19:55:58 +020038 /* Fake registers - need one more entry as REG_END is valid address. */
39 struct sandbox_emul_fake_regs r[EMUL_GPIO_REG_END + 1];
Mateusz Kulikowskid33776e2016-03-31 23:12:28 +020040};
41
42struct sandbox_spmi_priv {
43 struct sandbox_emul_gpio gpios[EMUL_GPIO_COUNT];
44};
45
46/* Check if valid register was requested */
47static bool check_address_valid(int usid, int pid, int off)
48{
49 if (usid != 0)
50 return false;
51 if (pid < EMUL_GPIO_PID_START || pid > EMUL_GPIO_PID_END)
52 return false;
53 if (off > EMUL_GPIO_REG_END)
54 return false;
55 return true;
56}
57
58static int sandbox_spmi_write(struct udevice *dev, int usid, int pid, int off,
59 uint8_t val)
60{
61 struct sandbox_spmi_priv *priv = dev_get_priv(dev);
62 struct sandbox_emul_fake_regs *regs;
63
64 if (!check_address_valid(usid, pid, off))
65 return -EIO;
66
67 regs = priv->gpios[pid & 0x3].r; /* Last 3 bits of pid are gpio # */
68
69 switch (off) {
70 case 0x40: /* Control */
71 val &= regs[off].access_mask;
72 if (((val & 0x30) == 0x10) || ((val & 0x30) == 0x20)) {
73 /* out/inout - set status register */
74 regs[0x8].value &= ~0x1;
75 regs[0x8].value |= val & 0x1;
76 }
77 break;
78 default:
79 if (regs[off].perms & EMUL_PERM_W)
80 regs[off].value = val & regs[off].access_mask;
81 }
82 return 0;
83}
84
85static int sandbox_spmi_read(struct udevice *dev, int usid, int pid, int off)
86{
87 struct sandbox_spmi_priv *priv = dev_get_priv(dev);
88 struct sandbox_emul_fake_regs *regs;
89
90 if (!check_address_valid(usid, pid, off))
91 return -EIO;
92
93 regs = priv->gpios[pid & 0x3].r; /* Last 3 bits of pid are gpio # */
94
95 if (regs[0x46].value == 0) /* Block disabled */
96 return 0;
97
98 switch (off) {
99 case 0x8: /* Status */
100 if (regs[0x46].value == 0) /* Block disabled */
101 return 0;
102 return regs[off].value;
103 default:
104 if (regs[off].perms & EMUL_PERM_R)
105 return regs[off].value;
106 else
107 return 0;
108 }
109}
110
111static struct dm_spmi_ops sandbox_spmi_ops = {
112 .read = sandbox_spmi_read,
113 .write = sandbox_spmi_write,
114};
115
116static int sandbox_spmi_probe(struct udevice *dev)
117{
118 struct sandbox_spmi_priv *priv = dev_get_priv(dev);
119 int i;
120
121 for (i = 0; i < EMUL_GPIO_COUNT; ++i) {
122 struct sandbox_emul_fake_regs *regs = priv->gpios[i].r;
123 regs[4].perms = EMUL_PERM_R;
124 regs[4].value = 0x10;
125 regs[5].perms = EMUL_PERM_R;
126 regs[5].value = 0x5;
127 regs[8].access_mask = 0x81;
128 regs[8].perms = EMUL_PERM_RW;
129 regs[0x40].access_mask = 0x7F;
130 regs[0x40].perms = EMUL_PERM_RW;
131 regs[0x41].access_mask = 7;
132 regs[0x41].perms = EMUL_PERM_RW;
133 regs[0x42].access_mask = 7;
134 regs[0x42].perms = EMUL_PERM_RW;
135 regs[0x42].value = 0x4;
136 regs[0x45].access_mask = 0x3F;
137 regs[0x45].perms = EMUL_PERM_RW;
138 regs[0x45].value = 0x1;
139 regs[0x46].access_mask = 0x80;
140 regs[0x46].perms = EMUL_PERM_RW;
141 regs[0x46].value = 0x80;
142 }
143 return 0;
144}
145
146static const struct udevice_id sandbox_spmi_ids[] = {
147 { .compatible = "sandbox,spmi" },
148 { }
149};
150
151U_BOOT_DRIVER(msm_spmi) = {
152 .name = "sandbox_spmi",
153 .id = UCLASS_SPMI,
154 .of_match = sandbox_spmi_ids,
155 .ops = &sandbox_spmi_ops,
156 .probe = sandbox_spmi_probe,
157 .priv_auto_alloc_size = sizeof(struct sandbox_spmi_priv),
158};