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driver: uart_npcx: Fix uart to use PM constrain

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The device PM callback needs to be used only to suspend/resume devices.
If the system cannot be suspended because UART is in a particular
state, the pm_constraint_set/release API should be used. For NPCX UART,
the chip can't enter low power idle state until UART completes the data
transmission.
This commit changes NPCX UART to use pm_constraint_set/release & fixes
UART lost data from low power idle.

Fix #40621

Signed-off-by: Wealian Liao <WHLIAO@nuvoton.com>
Signed-off-by: Jun Lin <CHLin56@nuvoton.com>
This commit is contained in:
Wealian Liao 2021-11-30 12:03:00 +08:00 • committed by Maureen Helm
commit 230378aebe
2 changed files with 42 additions and 39 deletions
Download patch file Download diff file Expand all files Collapse all files

79
drivers/serial/uart_npcx.c
View file

@ -12,6 +12,7 @@
#include <drivers/clock_control.h>
#include <kernel.h>
#include <pm/device.h>
#include <pm/pm.h>
#include <soc.h>
#include "soc_miwu.h"
#include "soc_power.h"
@ -40,6 +41,9 @@ struct uart_npcx_data {
uart_irq_callback_user_data_t user_cb;
void *user_data;
#endif
#ifdef CONFIG_PM
atomic_t pm_constraint_on;
#endif
};
/* Driver convenience defines */
@ -52,6 +56,26 @@ struct uart_npcx_data {
#define HAL_INSTANCE(dev) \
(struct uart_reg *)(DRV_CONFIG(dev)->uconf.base)
#if defined(CONFIG_PM) && defined(CONFIG_UART_INTERRUPT_DRIVEN)
static void uart_npcx_pm_constraint_set(const struct device *dev)
{
struct uart_npcx_data *data = DRV_DATA(dev);
if (atomic_set(&data->pm_constraint_on, 1) == 0) {
pm_constraint_set(PM_STATE_SUSPEND_TO_IDLE);
}
}
static void uart_npcx_pm_constraint_release(const struct device *dev)
{
struct uart_npcx_data *data = DRV_DATA(dev);
if (atomic_clear(&data->pm_constraint_on) == 1) {
pm_constraint_release(PM_STATE_SUSPEND_TO_IDLE);
}
}
#endif /* defined(CONFIG_PM) && defined(CONFIG_UART_INTERRUPT_DRIVEN) */
/* UART local functions */
static int uart_set_npcx_baud_rate(struct uart_reg *const inst, int baud_rate,
int src_clk)
@ -98,7 +122,7 @@ static void uart_npcx_dis_all_tx_interrupts(const struct device *dev)
/* Disable all Tx interrupts */
inst->UFTCTL &= ~(BIT(NPCX_UFTCTL_TEMPTY_LVL_EN) |
BIT(NPCX_UFTCTL_TEMPTY_EN) |
BIT(NPCX_UFTCTL_NXMIPEN));
BIT(NPCX_UFTCTL_NXMIP_EN));
}
static void uart_npcx_clear_rx_fifo(const struct device *dev)
@ -121,7 +145,13 @@ static int uart_npcx_fifo_fill(const struct device *dev,
/* If Tx FIFO is still ready to send */
while ((size - tx_bytes > 0) && uart_npcx_tx_fifo_ready(dev)) {
/* Put a character into Tx FIFO */
#ifdef CONFIG_PM
uart_npcx_pm_constraint_set(dev);
inst->UTBUF = tx_data[tx_bytes++];
inst->UFTCTL |= BIT(NPCX_UFTCTL_NXMIP_EN);
#else
inst->UTBUF = tx_data[tx_bytes++];
#endif /* CONFIG_PM */
}
return tx_bytes;
@ -238,6 +268,15 @@ static void uart_npcx_isr(const struct device *dev)
if (data->user_cb) {
data->user_cb(dev, data->user_data);
}
#ifdef CONFIG_PM
struct uart_reg *const inst = HAL_INSTANCE(dev);
if (IS_BIT_SET(inst->UFTCTL, NPCX_UFTCTL_NXMIP_EN) &&
IS_BIT_SET(inst->UFTSTS, NPCX_UFTSTS_NXMIP)) {
uart_npcx_pm_constraint_release(dev);
inst->UFTCTL &= ~BIT(NPCX_UFTCTL_NXMIP_EN);
}
#endif /* CONFIG_PM */
}
/*
@ -426,40 +465,6 @@ static int uart_npcx_init(const struct device *dev)
return 0;
}
#ifdef CONFIG_PM_DEVICE
static inline bool uart_npcx_device_is_transmitting(const struct device *dev)
{
if (IS_ENABLED(CONFIG_UART_INTERRUPT_DRIVEN)) {
/* The transmitted transaction is completed? */
return !uart_npcx_irq_tx_complete(dev);
}
/* No need for polling mode */
return 0;
}
static int uart_npcx_pm_action(const struct device *dev,
enum pm_device_action action)
{
/* If next device power state is SUSPEND power state */
switch (action) {
case PM_DEVICE_ACTION_SUSPEND:
/*
* If uart device is busy with transmitting, the driver will
* stay in while loop and wait for the transaction is completed.
*/
while (uart_npcx_device_is_transmitting(dev)) {
continue;
}
break;
default:
return -ENOTSUP;
}
return 0;
}
#endif /* CONFIG_PM_DEVICE */
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
#define NPCX_UART_IRQ_CONFIG_FUNC_DECL(inst) \
static void uart_npcx_irq_config_##inst(const struct device *dev)
@ -502,11 +507,9 @@ static int uart_npcx_pm_action(const struct device *dev,
.baud_rate = DT_INST_PROP(inst, current_speed) \
}; \
\
PM_DEVICE_DT_INST_DEFINE(inst, uart_npcx_pm_action); \
\
DEVICE_DT_INST_DEFINE(inst, \
&uart_npcx_init, \
PM_DEVICE_DT_INST_REF(inst), \
NULL, \
&uart_npcx_data_##inst, &uart_npcx_cfg_##inst, \
PRE_KERNEL_1, CONFIG_SERIAL_INIT_PRIORITY, \
&uart_npcx_driver_api); \

2
soc/arm/nuvoton_npcx/common/reg/reg_def.h
View file

@ -329,7 +329,7 @@ struct uart_reg {
#define NPCX_UFTCTL_TEMPTY_LVL_SEL FIELD(0, 5)
#define NPCX_UFTCTL_TEMPTY_LVL_EN 5
#define NPCX_UFTCTL_TEMPTY_EN 6
#define NPCX_UFTCTL_NXMIPEN 7
#define NPCX_UFTCTL_NXMIP_EN 7
#define NPCX_UFRCTL_RFULL_LVL_SEL FIELD(0, 5)
#define NPCX_UFRCTL_RFULL_LVL_EN 5
#define NPCX_UFRCTL_RNEMPTY_EN 6