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drivers: reset: added Reset Controller for Raspberry Pi Pico

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added Reset Controller driver for Raspberry Pi Pico board

Signed-off-by: Andrei-Edward Popa <andrei.popa105@yahoo.com>
This commit is contained in:
Andrei-Edward Popa 2022-03-22 02:25:39 +02:00 • committed by Carles Cufí
commit 3d24f62c05
4 changed files with 171 additions and 0 deletions
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1
drivers/reset/CMakeLists.txt
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@ -1,3 +1,4 @@
# SPDX-License-Identifier: Apache-2.0
zephyr_library()
zephyr_library_sources_ifdef(CONFIG_RESET_RPI_PICO reset_rpi_pico.c)

2
drivers/reset/Kconfig
View file

@ -27,4 +27,6 @@ config RESET_INIT_PRIORITY
comment "Reset Controller Drivers"
rsource "Kconfig.rpi_pico"
endif # RESET

9
drivers/reset/Kconfig.rpi_pico Normal file
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@ -0,0 +1,9 @@
# Copyright (c) 2022 Andrei-Edward Popa
# SPDX-License-Identifier: Apache-2.0
# Workaround for not being able to have commas in macro arguments
DT_COMPAT_RPI_PICO_RESET := raspberrypi,pico-reset
config RESET_RPI_PICO
bool "Raspberry Pi Reset Controller driver"
default $(dt_compat_enabled,$(DT_COMPAT_RPI_PICO_RESET))

159
drivers/reset/reset_rpi_pico.c Normal file
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@ -0,0 +1,159 @@
/*
* Copyright (c) 2022 Andrei-Edward Popa
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT raspberrypi_pico_reset
#include <device.h>
#include <drivers/reset.h>
struct reset_rpi_config {
DEVICE_MMIO_ROM;
uint8_t reg_width;
uint8_t active_low;
uintptr_t base_address;
};
static int reset_rpi_read_register(const struct device *dev, uint16_t offset, uint32_t *value)
{
const struct reset_rpi_config *config = dev->config;
uint32_t base_address = config->base_address;
switch (config->reg_width) {
case 1:
*value = sys_read8(base_address + offset);
break;
case 2:
*value = sys_read16(base_address + offset);
break;
case 4:
*value = sys_read32(base_address + offset);
break;
default:
return -EINVAL;
}
return 0;
}
static int reset_rpi_write_register(const struct device *dev, uint16_t offset, uint32_t value)
{
const struct reset_rpi_config *config = dev->config;
uint32_t base_address = config->base_address;
switch (config->reg_width) {
case 1:
sys_write8(value, base_address + offset);
break;
case 2:
sys_write16(value, base_address + offset);
break;
case 4:
sys_write32(value, base_address + offset);
break;
default:
return -EINVAL;
}
return 0;
}
static int reset_rpi_status(const struct device *dev, uint32_t id, uint8_t *status)
{
const struct reset_rpi_config *config = dev->config;
uint16_t offset;
uint32_t value;
uint8_t regbit;
int ret;
offset = id / (config->reg_width * CHAR_BIT);
regbit = id % (config->reg_width * CHAR_BIT);
ret = reset_rpi_read_register(dev, offset, &value);
if (ret) {
return ret;
}
*status = !(value & BIT(regbit)) ^ !config->active_low;
return ret;
}
static int reset_rpi_update(const struct device *dev, uint32_t id, uint8_t assert)
{
const struct reset_rpi_config *config = dev->config;
uint16_t offset;
uint32_t value;
uint8_t regbit;
int ret;
offset = id / (config->reg_width * CHAR_BIT);
regbit = id % (config->reg_width * CHAR_BIT);
ret = reset_rpi_read_register(dev, offset, &value);
if (ret) {
return ret;
}
if (assert ^ config->active_low) {
value |= BIT(regbit);
} else {
value &= ~BIT(regbit);
}
return reset_rpi_write_register(dev, offset, value);
}
static int reset_rpi_assert(const struct device *dev, uint32_t id)
{
return reset_rpi_update(dev, id, 1);
}
static int reset_rpi_deassert(const struct device *dev, uint32_t id)
{
return reset_rpi_update(dev, id, 0);
}
static int reset_rpi_toggle(const struct device *dev, uint32_t id)
{
int ret;
ret = reset_rpi_assert(dev, id);
if (ret) {
return ret;
}
return reset_rpi_deassert(dev, id);
}
static int reset_rpi_init(const struct device *dev)
{
DEVICE_MMIO_MAP(dev, K_MEM_CACHE_NONE);
return 0;
}
static const struct reset_driver_api reset_rpi_driver_api = {
.status = reset_rpi_status,
.assert = reset_rpi_assert,
.deassert = reset_rpi_deassert,
.toggle = reset_rpi_toggle,
};
#define RPI_RESET_INIT(idx) \
static const struct reset_rpi_config reset_rpi_config_##idx = { \
DEVICE_MMIO_ROM_INIT(DT_DRV_INST(idx)), \
.reg_width = DT_INST_PROP_OR(idx, reg_width, 4), \
.active_low = DT_INST_PROP_OR(idx, active_low, 0), \
.base_address = DT_INST_REG_ADDR(idx), \
}; \
\
DEVICE_DT_INST_DEFINE(idx, reset_rpi_init, \
NULL, NULL, \
&reset_rpi_config_##idx, PRE_KERNEL_1, \
CONFIG_RESET_INIT_PRIORITY, \
&reset_rpi_driver_api);
DT_INST_FOREACH_STATUS_OKAY(RPI_RESET_INIT);