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// SPDX-License-Identifier: GPL-2.0+
/*
* Sample SPMI bus driver
*
* It emulates bus with single pm8916-like pmic that has only GPIO reigsters.
*
* (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <spmi/spmi.h>
#include <asm/gpio.h>
#include <asm/io.h>
#define EMUL_GPIO_PID_START 0xC0
#define EMUL_GPIO_PID_END 0xC3
#define EMUL_GPIO_COUNT 4
#define EMUL_GPIO_REG_END 0x46 /* Last valid register */
#define EMUL_PERM_R 0x1
#define EMUL_PERM_W 0x2
#define EMUL_PERM_RW (EMUL_PERM_R | EMUL_PERM_W)
struct sandbox_emul_fake_regs {
u8 value;
u8 access_mask;
u8 perms; /* Access permissions */
};
struct sandbox_emul_gpio {
/* Fake registers - need one more entry as REG_END is valid address. */
struct sandbox_emul_fake_regs r[EMUL_GPIO_REG_END + 1];
};
struct sandbox_spmi_priv {
struct sandbox_emul_gpio gpios[EMUL_GPIO_COUNT];
};
/* Check if valid register was requested */
static bool check_address_valid(int usid, int pid, int off)
{
if (usid != 0)
return false;
if (pid < EMUL_GPIO_PID_START || pid > EMUL_GPIO_PID_END)
return false;
if (off > EMUL_GPIO_REG_END)
return false;
return true;
}
static int sandbox_spmi_write(struct udevice *dev, int usid, int pid, int off,
uint8_t val)
{
struct sandbox_spmi_priv *priv = dev_get_priv(dev);
struct sandbox_emul_fake_regs *regs;
if (!check_address_valid(usid, pid, off))
return -EIO;
regs = priv->gpios[pid & 0x3].r; /* Last 3 bits of pid are gpio # */
switch (off) {
case 0x40: /* Control */
val &= regs[off].access_mask;
if (((val & 0x30) == 0x10) || ((val & 0x30) == 0x20)) {
/* out/inout - set status register */
regs[0x8].value &= ~0x1;
regs[0x8].value |= val & 0x1;
}
break;
default:
if (regs[off].perms & EMUL_PERM_W)
regs[off].value = val & regs[off].access_mask;
}
return 0;
}
static int sandbox_spmi_read(struct udevice *dev, int usid, int pid, int off)
{
struct sandbox_spmi_priv *priv = dev_get_priv(dev);
struct sandbox_emul_fake_regs *regs;
if (!check_address_valid(usid, pid, off))
return -EIO;
regs = priv->gpios[pid & 0x3].r; /* Last 3 bits of pid are gpio # */
if (regs[0x46].value == 0) /* Block disabled */
return 0;
switch (off) {
case 0x8: /* Status */
if (regs[0x46].value == 0) /* Block disabled */
return 0;
return regs[off].value;
default:
if (regs[off].perms & EMUL_PERM_R)
return regs[off].value;
else
return 0;
}
}
static struct dm_spmi_ops sandbox_spmi_ops = {
.read = sandbox_spmi_read,
.write = sandbox_spmi_write,
};
static int sandbox_spmi_probe(struct udevice *dev)
{
struct sandbox_spmi_priv *priv = dev_get_priv(dev);
int i;
for (i = 0; i < EMUL_GPIO_COUNT; ++i) {
struct sandbox_emul_fake_regs *regs = priv->gpios[i].r;
regs[4].perms = EMUL_PERM_R;
regs[4].value = 0x10;
regs[5].perms = EMUL_PERM_R;
regs[5].value = 0x5;
regs[8].access_mask = 0x81;
regs[8].perms = EMUL_PERM_RW;
regs[0x40].access_mask = 0x7F;
regs[0x40].perms = EMUL_PERM_RW;
regs[0x41].access_mask = 7;
regs[0x41].perms = EMUL_PERM_RW;
regs[0x42].access_mask = 7;
regs[0x42].perms = EMUL_PERM_RW;
regs[0x42].value = 0x4;
regs[0x45].access_mask = 0x3F;
regs[0x45].perms = EMUL_PERM_RW;
regs[0x45].value = 0x1;
regs[0x46].access_mask = 0x80;
regs[0x46].perms = EMUL_PERM_RW;
regs[0x46].value = 0x80;
}
return 0;
}
static const struct udevice_id sandbox_spmi_ids[] = {
{ .compatible = "sandbox,spmi" },
{ }
};
U_BOOT_DRIVER(msm_spmi) = {
.name = "sandbox_spmi",
.id = UCLASS_SPMI,
.of_match = sandbox_spmi_ids,
.ops = &sandbox_spmi_ops,
.probe = sandbox_spmi_probe,
.priv_auto = sizeof(struct sandbox_spmi_priv),
};