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drivers: serial: various improvements to the BFLB uart driver. #97153

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Merged
merged 3 commits into from
Oct 10, 2025
+77 −21
Merged

drivers: serial: various improvements to the BFLB uart driver. #97153

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7966a5f
drivers: serial: Add De-init to bflb uart driver
VynDragon Oct 7, 2025
07a58aa
drivers: serial: Improve BFLB UART driver: add runtime configuration
VynDragon Oct 7, 2025
36f1ff1
drivers: serial: increase FIFO threshold for BFLB uart driver
VynDragon Oct 8, 2025
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98 changes: 77 additions & 21 deletions drivers/serial/uart_bflb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -33,13 +33,7 @@

struct bflb_config {
const struct pinctrl_dev_config *pincfg;
uint32_t baudrate;
uint8_t direction;
uint8_t data_bits;
uint8_t stop_bits;
uint8_t parity;
uint8_t bit_order;
uint8_t flow_ctrl;
uint8_t tx_fifo_threshold;
uint8_t rx_fifo_threshold;
uint32_t base_reg;
Expand All @@ -49,6 +43,7 @@ struct bflb_config {
};

struct bflb_data {
struct uart_config uart_cfg;
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
uart_irq_callback_user_data_t user_cb;
void *user_data;
Expand Down Expand Up @@ -294,12 +289,13 @@ static void uart_bflb_isr(const struct device *dev)
static int uart_bflb_configure(const struct device *dev)
{
const struct bflb_config *cfg = dev->config;
struct bflb_data *const data = dev->data;
uint32_t tx_cfg = 0;
uint32_t rx_cfg = 0;
uint32_t divider = 0;
uint32_t tmp = 0;

divider = (uart_bflb_get_clock() * 10 / cfg->baudrate + 5) / 10;
divider = (uart_bflb_get_clock() * 10 / data->uart_cfg.baudrate + 5) / 10;
if (divider >= 0xFFFF) {
divider = 0xFFFF - 1;
}
Expand All @@ -314,7 +310,7 @@ static int uart_bflb_configure(const struct device *dev)
tx_cfg = sys_read32(cfg->base_reg + UART_UTX_CONFIG_OFFSET);
rx_cfg = sys_read32(cfg->base_reg + UART_URX_CONFIG_OFFSET);

switch (cfg->parity) {
switch (data->uart_cfg.parity) {
case UART_PARITY_NONE:
tx_cfg &= ~UART_CR_UTX_PRT_EN;
rx_cfg &= ~UART_CR_URX_PRT_EN;
Expand All @@ -337,16 +333,16 @@ static int uart_bflb_configure(const struct device *dev)

/* Configure data bits */
tx_cfg &= ~UART_CR_UTX_BIT_CNT_D_MASK;
tx_cfg |= (cfg->data_bits + 4) << UART_CR_UTX_BIT_CNT_D_SHIFT;
tx_cfg |= (data->uart_cfg.data_bits + 4) << UART_CR_UTX_BIT_CNT_D_SHIFT;
rx_cfg &= ~UART_CR_URX_BIT_CNT_D_MASK;
rx_cfg |= (cfg->data_bits + 4) << UART_CR_URX_BIT_CNT_D_SHIFT;
rx_cfg |= (data->uart_cfg.data_bits + 4) << UART_CR_URX_BIT_CNT_D_SHIFT;

/* Configure tx stop bits */
tx_cfg &= ~UART_CR_UTX_BIT_CNT_P_MASK;
tx_cfg |= cfg->stop_bits << UART_CR_UTX_BIT_CNT_P_SHIFT;
tx_cfg |= data->uart_cfg.stop_bits << UART_CR_UTX_BIT_CNT_P_SHIFT;

/* Configure tx cts flow control function */
if (cfg->flow_ctrl & UART_FLOWCTRL_CTS) {
if (data->uart_cfg.flow_ctrl & UART_FLOWCTRL_CTS) {
tx_cfg |= UART_CR_UTX_CTS_EN;
} else {
tx_cfg &= ~UART_CR_UTX_CTS_EN;
Expand Down Expand Up @@ -401,6 +397,38 @@ static int uart_bflb_configure(const struct device *dev)
return 0;
}

#ifdef CONFIG_UART_USE_RUNTIME_CONFIGURE

static int uart_bflb_runtime_configure(const struct device *dev,
const struct uart_config *cfg)
{
struct bflb_data *data = dev->data;
int ret;

data->uart_cfg = *cfg;

ret = uart_bflb_configure(dev);
if (ret < 0) {
return ret;
}

uart_bflb_enabled(dev, 1);

return 0;
}

static int uart_bflb_runtime_config_get(const struct device *dev,
struct uart_config *cfg)
{
struct bflb_data *data = dev->data;

*cfg = data->uart_cfg;

return 0;
}

#endif /* CONFIG_UART_USE_RUNTIME_CONFIGURE */

static int uart_bflb_init(const struct device *dev)
{
const struct bflb_config *cfg = dev->config;
Expand All @@ -426,6 +454,25 @@ static int uart_bflb_init(const struct device *dev)
return rc;
}

static int uart_bflb_deinit(const struct device *dev)
{
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
const struct bflb_config *cfg = dev->config;
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */

uart_bflb_enabled(dev, 0);
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
/* disable all irqs */
sys_write32(0x0, cfg->base_reg + UART_INT_EN_OFFSET);
/* clear all IRQS */
sys_write32(0xFF, cfg->base_reg + UART_INT_CLEAR_OFFSET);
/* mask all IRQs */
sys_write32(0xFFFFFFFFU, cfg->base_reg + UART_INT_MASK_OFFSET);
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */

return 0;
}

static int uart_bflb_poll_in(const struct device *dev, unsigned char *c)
{
const struct bflb_config *cfg = dev->config;
Expand Down Expand Up @@ -500,6 +547,10 @@ static int uart_bflb_pm_control(const struct device *dev,
static DEVICE_API(uart, uart_bflb_driver_api) = {
.poll_in = uart_bflb_poll_in,
.poll_out = uart_bflb_poll_out,
#ifdef CONFIG_UART_USE_RUNTIME_CONFIGURE
.configure = uart_bflb_runtime_configure,
.config_get = uart_bflb_runtime_config_get,
#endif
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
.err_check = uart_bflb_err_check,
.fifo_fill = uart_bflb_fifo_fill,
Expand Down Expand Up @@ -545,23 +596,28 @@ static DEVICE_API(uart, uart_bflb_driver_api) = {
PINCTRL_DT_INST_DEFINE(instance); \
PM_DEVICE_DT_INST_DEFINE(instance, uart_bflb_pm_control); \
BFLB_UART_IRQ_HANDLER_DECL(instance) \
static struct bflb_data uart##instance##_bflb_data; \
static struct bflb_data uart##instance##_bflb_data = { \
.uart_cfg = { \
.baudrate = DT_INST_PROP(instance, current_speed), \
.parity = UART_CFG_PARITY_NONE, \
.stop_bits = UART_CFG_STOP_BITS_1, \
.data_bits = UART_CFG_DATA_BITS_8, \
.flow_ctrl = DT_INST_PROP(instance, hw_flow_control) \
? UART_CFG_FLOW_CTRL_RTS_CTS \
: UART_CFG_FLOW_CTRL_NONE, \
}, \
}; \
static const struct bflb_config uart##instance##_bflb_config = { \
.pincfg = PINCTRL_DT_INST_DEV_CONFIG_GET(instance), \
.base_reg = DT_INST_REG_ADDR(instance), \
\
.baudrate = DT_INST_PROP(instance, current_speed), \
.data_bits = UART_DATA_BITS_8, \
.stop_bits = UART_STOP_BITS_1, \
.parity = UART_PARITY_NONE, \
.bit_order = UART_MSB_FIRST, \
.flow_ctrl = UART_FLOWCTRL_NONE, \
/* overflow interrupt threshold, size is 32 bytes*/ \
.tx_fifo_threshold = 8, \
.tx_fifo_threshold = 16, \
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Copilot AI Oct 8, 2025

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The tx_fifo_threshold value was changed from 8 to 16 without explanation. This change should either be documented in the commit message or reverted if it's unintentional, as it could affect UART transmission behavior.

Suggested change
.tx_fifo_threshold = 16, \
.tx_fifo_threshold = 8, \

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@kartben kartben Oct 8, 2025 •
edited
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It's a fair comment and at least it would be worth having this change as a separate commit

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done

.rx_fifo_threshold = 0, \
BFLB_UART_IRQ_HANDLER_FUNC(instance) \
}; \
DEVICE_DT_INST_DEFINE(instance, &uart_bflb_init, \
DEVICE_DT_INST_DEINIT_DEFINE(instance, &uart_bflb_init, \
&uart_bflb_deinit, \
PM_DEVICE_DT_INST_GET(instance), \
&uart##instance##_bflb_data, \
&uart##instance##_bflb_config, PRE_KERNEL_1, \
Expand Down