2 * Sample SPMI bus driver
4 * It emulates bus with single pm8916-like pmic that has only GPIO reigsters.
6 * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
8 * SPDX-License-Identifier: GPL-2.0+
14 #include <spmi/spmi.h>
18 #define EMUL_GPIO_PID_START 0xC0
19 #define EMUL_GPIO_PID_END 0xC3
21 #define EMUL_GPIO_COUNT 4
23 #define EMUL_GPIO_REG_END 0x46 /* Last valid register */
25 #define EMUL_PERM_R 0x1
26 #define EMUL_PERM_W 0x2
27 #define EMUL_PERM_RW (EMUL_PERM_R | EMUL_PERM_W)
29 struct sandbox_emul_fake_regs {
32 u8 perms; /* Access permissions */
35 struct sandbox_emul_gpio {
36 /* Fake registers - need one more entry as REG_END is valid address. */
37 struct sandbox_emul_fake_regs r[EMUL_GPIO_REG_END + 1];
40 struct sandbox_spmi_priv {
41 struct sandbox_emul_gpio gpios[EMUL_GPIO_COUNT];
44 /* Check if valid register was requested */
45 static bool check_address_valid(int usid, int pid, int off)
49 if (pid < EMUL_GPIO_PID_START || pid > EMUL_GPIO_PID_END)
51 if (off > EMUL_GPIO_REG_END)
56 static int sandbox_spmi_write(struct udevice *dev, int usid, int pid, int off,
59 struct sandbox_spmi_priv *priv = dev_get_priv(dev);
60 struct sandbox_emul_fake_regs *regs;
62 if (!check_address_valid(usid, pid, off))
65 regs = priv->gpios[pid & 0x3].r; /* Last 3 bits of pid are gpio # */
68 case 0x40: /* Control */
69 val &= regs[off].access_mask;
70 if (((val & 0x30) == 0x10) || ((val & 0x30) == 0x20)) {
71 /* out/inout - set status register */
72 regs[0x8].value &= ~0x1;
73 regs[0x8].value |= val & 0x1;
77 if (regs[off].perms & EMUL_PERM_W)
78 regs[off].value = val & regs[off].access_mask;
83 static int sandbox_spmi_read(struct udevice *dev, int usid, int pid, int off)
85 struct sandbox_spmi_priv *priv = dev_get_priv(dev);
86 struct sandbox_emul_fake_regs *regs;
88 if (!check_address_valid(usid, pid, off))
91 regs = priv->gpios[pid & 0x3].r; /* Last 3 bits of pid are gpio # */
93 if (regs[0x46].value == 0) /* Block disabled */
97 case 0x8: /* Status */
98 if (regs[0x46].value == 0) /* Block disabled */
100 return regs[off].value;
102 if (regs[off].perms & EMUL_PERM_R)
103 return regs[off].value;
109 static struct dm_spmi_ops sandbox_spmi_ops = {
110 .read = sandbox_spmi_read,
111 .write = sandbox_spmi_write,
114 static int sandbox_spmi_probe(struct udevice *dev)
116 struct sandbox_spmi_priv *priv = dev_get_priv(dev);
119 for (i = 0; i < EMUL_GPIO_COUNT; ++i) {
120 struct sandbox_emul_fake_regs *regs = priv->gpios[i].r;
121 regs[4].perms = EMUL_PERM_R;
122 regs[4].value = 0x10;
123 regs[5].perms = EMUL_PERM_R;
125 regs[8].access_mask = 0x81;
126 regs[8].perms = EMUL_PERM_RW;
127 regs[0x40].access_mask = 0x7F;
128 regs[0x40].perms = EMUL_PERM_RW;
129 regs[0x41].access_mask = 7;
130 regs[0x41].perms = EMUL_PERM_RW;
131 regs[0x42].access_mask = 7;
132 regs[0x42].perms = EMUL_PERM_RW;
133 regs[0x42].value = 0x4;
134 regs[0x45].access_mask = 0x3F;
135 regs[0x45].perms = EMUL_PERM_RW;
136 regs[0x45].value = 0x1;
137 regs[0x46].access_mask = 0x80;
138 regs[0x46].perms = EMUL_PERM_RW;
139 regs[0x46].value = 0x80;
144 static const struct udevice_id sandbox_spmi_ids[] = {
145 { .compatible = "sandbox,spmi" },
149 U_BOOT_DRIVER(msm_spmi) = {
150 .name = "sandbox_spmi",
152 .of_match = sandbox_spmi_ids,
153 .ops = &sandbox_spmi_ops,
154 .probe = sandbox_spmi_probe,
155 .priv_auto_alloc_size = sizeof(struct sandbox_spmi_priv),