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drivers: serial: Add optional reset line for uart_ns16550

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If the optional hardware reset line is available, this change
will use that reset line to assert the uart module and bring
it out of reset state to use.

Signed-off-by: Girisha Dengi <girisha.dengi@intel.com>
This commit is contained in:
Girisha Dengi 2023-07-06 14:47:06 +00:00 • committed by Fabio Baltieri
commit f0ac2347da
2 changed files with 58 additions and 2 deletions
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58
drivers/serial/uart_ns16550.c
View file

@ -4,7 +4,7 @@
/*
* Copyright (c) 2010, 2012-2015 Wind River Systems, Inc.
* Copyright (c) 2020-2022 Intel Corp.
* Copyright (c) 2020-2023 Intel Corp.
*
* SPDX-License-Identifier: Apache-2.0
*/
@ -39,6 +39,9 @@
#endif
#include <zephyr/drivers/serial/uart_ns16550.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(uart_ns16550, CONFIG_UART_LOG_LEVEL);
#define INST_HAS_PCP_HELPER(inst) DT_INST_NODE_HAS_PROP(inst, pcp) ||
#define INST_HAS_DLF_HELPER(inst) DT_INST_NODE_HAS_PROP(inst, dlf) ||
@ -53,6 +56,13 @@ BUILD_ASSERT(IS_ENABLED(CONFIG_PCIE), "NS16550(s) in DT need CONFIG_PCIE");
#include <zephyr/drivers/pcie/pcie.h>
#endif
/* Is UART module 'resets' line property defined */
#define UART_NS16550_RESET_ENABLED DT_ANY_INST_HAS_PROP_STATUS_OKAY(resets)
#if UART_NS16550_RESET_ENABLED
#include <zephyr/drivers/reset.h>
#endif
/* register definitions */
#define REG_THR 0x00 /* Transmitter holding reg. */
@ -247,6 +257,9 @@ struct uart_ns16550_device_config {
#if defined(CONFIG_UART_NS16550_ACCESS_IOPORT) || defined(CONFIG_UART_NS16550_SIMULT_ACCESS)
bool io_map;
#endif
#if UART_NS16550_RESET_ENABLED
struct reset_dt_spec reset_spec;
#endif
};
/** Device data structure */
@ -580,6 +593,35 @@ static int uart_ns16550_config_get(const struct device *dev,
}
#endif /* CONFIG_UART_USE_RUNTIME_CONFIGURE */
#if UART_NS16550_RESET_ENABLED
/**
* @brief Toggle the reset UART line
*
* This routine is called to bring UART IP out of reset state.
*
* @param reset_spec Reset controller device configuration struct
*
* @return 0 if successful, failed otherwise
*/
static int uart_reset_config(const struct reset_dt_spec *reset_spec)
{
int ret;
if (!device_is_ready(reset_spec->dev)) {
LOG_ERR("Reset controller device is not ready");
return -ENODEV;
}
ret = reset_line_toggle(reset_spec->dev, reset_spec->id);
if (ret != 0) {
LOG_ERR("UART toggle reset line failed");
return ret;
}
return 0;
}
#endif /* UART_NS16550_RESET_ENABLED */
/**
* @brief Initialize individual UART port
*
@ -597,6 +639,16 @@ static int uart_ns16550_init(const struct device *dev)
ARG_UNUSED(dev_cfg);
#if UART_NS16550_RESET_ENABLED
/* Assert the UART reset line if it is defined. */
if (dev_cfg->reset_spec.dev != NULL) {
ret = uart_reset_config(&(dev_cfg->reset_spec));
if (ret != 0) {
return ret;
}
}
#endif
#if DT_ANY_INST_ON_BUS_STATUS_OKAY(pcie)
if (dev_cfg->pcie) {
struct pcie_bar mbar;
@ -1285,6 +1337,8 @@ static const struct uart_driver_api uart_ns16550_driver_api = {
#else
#define BOOT_LEVEL(n) PRE_KERNEL_1
#endif
#define UART_RESET_FUNC_INIT(n) \
.reset_spec = RESET_DT_SPEC_INST_GET(n),
#define UART_NS16550_DEVICE_INIT(n) \
UART_NS16550_IRQ_FUNC_DECLARE(n); \
@ -1310,6 +1364,8 @@ static const struct uart_driver_api uart_ns16550_driver_api = {
DEV_CONFIG_PCIE_INIT(n) \
IF_ENABLED(DT_INST_NODE_HAS_PROP(n, pinctrl_0), \
(.pincfg = PINCTRL_DT_DEV_CONFIG_GET(DT_DRV_INST(n)),)) \
IF_ENABLED(DT_INST_NODE_HAS_PROP(n, resets), \
(UART_RESET_FUNC_INIT(n))) \
}; \
static struct uart_ns16550_dev_data uart_ns16550_dev_data_##n = { \
.uart_config.baudrate = DT_INST_PROP_OR(n, current_speed, 0), \