drivers: esp32: Add UART Driver with FIFO/Interrupt support

- Fixes #3981
- Implement UART Polling functions
- Implement UART Interrupt APIs
- Remove dependency on esp32_rom_uart_xxx functions
- Update Device tree with UART addresses and pin config
- Update ESP32 UART KConfig

Notes about implementation:
- Interrupts now defined as a local macros, and should be removed
later on, when interrupts for esp32 are supported in dts

- Threshold interrupts are used for TX/RX
- Reseting FIFOs using _RST bit will corrupt FIFO of UART2 when used for
UART1 and vice-versa, so a generic way is used for all three UARTs

- Old Silicon rev is not supported

Signed-off-by: Mohamed ElShahawi <ExtremeGTX@hotmail.com>
This commit is contained in:
Mohamed ElShahawi 2019-08-21 23:54:00 +02:00 committed by Kumar Gala
commit 2d035c4191
6 changed files with 582 additions and 39 deletions

View file

@ -18,6 +18,7 @@
chosen {
zephyr,sram = &sram0;
zephyr,console = &uart0;
zephyr,shell-uart = &uart0;
};
};
@ -32,4 +33,24 @@
&uart0 {
status = "okay";
current-speed = <115200>;
tx-pin = <1>;
rx-pin = <3>;
rts-pin = <22>;
cts-pin = <19>;
};
&uart1 {
current-speed = <115200>;
tx-pin = <10>;
rx-pin = <9>;
rts-pin = <11>;
cts-pin = <6>;
};
&uart2 {
current-speed = <115200>;
tx-pin = <17>;
rx-pin = <16>;
rts-pin = <7>;
cts-pin = <8>;
};

View file

@ -2,7 +2,10 @@
menuconfig UART_ESP32
bool "ESP32 UART driver"
default y
select SERIAL_HAS_DRIVER
select SERIAL_SUPPORT_INTERRUPT
select GPIO_ESP32
depends on SOC_ESP32
help
Enable the ESP32 UART using ROM routines.

View file

@ -1,58 +1,540 @@
/*
* Copyright (c) 2017 Intel Corporation
* Copyright (c) 2019 Mohamed ElShahawi (extremegtx@hotmail.com)
*
* SPDX-License-Identifier: Apache-2.0
*/
/* Include esp-idf headers first to avoid redefining BIT() macro */
#include <rom/ets_sys.h>
#include <soc/dport_reg.h>
#include <rom/gpio.h>
#include <soc/gpio_sig_map.h>
#include <device.h>
#include <soc.h>
#include <drivers/uart.h>
#include <errno.h>
#include <sys/util.h>
static void esp32_uart_tx(struct device *dev,
unsigned char c)
{
ARG_UNUSED(dev);
esp32_rom_uart_tx_one_char(c);
}
static int esp32_uart_rx(struct device *dev, unsigned char *p_char)
{
ARG_UNUSED(dev);
switch (esp32_rom_uart_rx_one_char(p_char)) {
case OK:
return 0;
case PENDING:
return -EINPROGRESS;
case BUSY:
return -EBUSY;
case CANCEL:
return -ECANCELED;
default:
return -EIO;
}
}
static int esp32_uart_init(struct device *dev)
{
ARG_UNUSED(dev);
esp32_rom_uart_attach();
return 0;
}
static const struct uart_driver_api esp32_uart_api = {
.poll_in = &esp32_uart_rx,
.poll_out = &esp32_uart_tx,
.err_check = NULL,
/*
* ESP32 UARTx register map structure
*/
struct uart_esp32_regs_t {
u32_t fifo;
u32_t int_raw;
u32_t int_st;
u32_t int_ena;
u32_t int_clr;
u32_t clk_div;
u32_t auto_baud;
u32_t status;
u32_t conf0;
u32_t conf1;
u32_t lowpulse;
u32_t highpulse;
u32_t rxd_cnt;
u32_t flow_conf;
u32_t sleep_conf;
u32_t swfc_conf;
u32_t idle_conf;
u32_t rs485_conf;
u32_t at_cmd_precnt;
u32_t at_cmd_postcnt;
u32_t at_cmd_gaptout;
u32_t at_cmd_char;
u32_t mem_conf;
u32_t mem_tx_status;
u32_t mem_rx_status;
u32_t mem_cnt_status;
u32_t pospulse;
u32_t negpulse;
u32_t reserved_0;
u32_t reserved_1;
u32_t date;
u32_t id;
};
DEVICE_AND_API_INIT(esp32_uart, "ROMUART",
esp32_uart_init, NULL, NULL,
PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
&esp32_uart_api);
struct uart_esp32_config {
struct uart_device_config dev_conf;
const struct {
int tx_out;
int rx_in;
int rts_out;
int cts_in;
} signals;
const struct {
int tx;
int rx;
int rts;
int cts;
} pins;
const struct esp32_peripheral peripheral;
const struct {
int source;
int line;
} irq;
};
/* driver data */
struct uart_esp32_data {
struct uart_config uart_config;
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
uart_irq_callback_user_data_t irq_cb;
void *irq_cb_data;
#endif
};
#define DEV_CFG(dev) \
((const struct uart_esp32_config *const)(dev)->config->config_info)
#define DEV_DATA(dev) \
((struct uart_esp32_data *)(dev)->driver_data)
#define DEV_BASE(dev) \
((volatile struct uart_esp32_regs_t *)(DEV_CFG(dev))->dev_conf.base)
#define UART_TXFIFO_COUNT(status_reg) ((status_reg >> 16) & 0xFF)
#define UART_RXFIFO_COUNT(status_reg) ((status_reg >> 0) & 0xFF)
#define UART_FIFO_LIMIT 127U
#define UART_TX_FIFO_THRESH 0x1
#define UART_RX_FIFO_THRESH 0x1
#define UART_GET_PARITY_ERR(reg) ((reg >> 2) & 0x1)
#define UART_GET_FRAME_ERR(reg) ((reg >> 3) & 0x1)
#define UART_GET_PARITY(conf0_reg) ((conf0_reg >> 0) & 0x1)
#define UART_GET_PARITY_EN(conf0_reg) ((conf0_reg >> 1) & 0x1)
#define UART_GET_DATA_BITS(conf0_reg) ((conf0_reg >> 2) & 0x3)
#define UART_GET_STOP_BITS(conf0_reg) ((conf0_reg >> 4) & 0x3)
#define UART_GET_TX_FLOW(conf0_reg) ((conf0_reg >> 15) & 0x1)
#define UART_GET_RX_FLOW(conf1_reg) ((conf1_reg >> 23) & 0x1)
/* FIXME: This should be removed when interrupt support added to ESP32 dts */
#define DT_UART_ESP32_PORT_0_IRQ_0 12
#define DT_UART_ESP32_PORT_1_IRQ_0 17
#define DT_UART_ESP32_PORT_2_IRQ_0 18
/* ESP-IDF Naming is not consistent for UART0 with UART1/2 */
#define DPORT_UART0_CLK_EN DPORT_UART_CLK_EN
#define DPORT_UART0_RST DPORT_UART_RST
static int uart_esp32_poll_in(struct device *dev, unsigned char *p_char)
{
if (UART_RXFIFO_COUNT(DEV_BASE(dev)->status) == 0) {
return -1;
}
*p_char = DEV_BASE(dev)->fifo;
return 0;
}
static void uart_esp32_poll_out(struct device *dev,
unsigned char c)
{
/* Wait for space in FIFO */
while (UART_TXFIFO_COUNT(DEV_BASE(dev)->status) >= UART_FIFO_LIMIT) {
; /* Wait */
}
/* Send a character */
DEV_BASE(dev)->fifo = (u32_t)c;
}
static int uart_esp32_err_check(struct device *dev)
{
u32_t err = UART_GET_PARITY_ERR(DEV_BASE(dev)->int_st)
| UART_GET_FRAME_ERR(DEV_BASE(dev)->int_st);
return err;
}
static int uart_esp32_config_get(struct device *dev, struct uart_config *cfg)
{
struct uart_esp32_data *data = DEV_DATA(dev);
cfg->baudrate = data->uart_config.baudrate;
if (UART_GET_PARITY_EN(DEV_BASE(dev)->conf0)) {
cfg->parity = UART_GET_PARITY(DEV_BASE(dev)->conf0);
} else {
cfg->parity = UART_CFG_PARITY_NONE;
}
cfg->stop_bits = UART_GET_STOP_BITS(DEV_BASE(dev)->conf0);
cfg->data_bits = UART_GET_DATA_BITS(DEV_BASE(dev)->conf0);
if (UART_GET_TX_FLOW(DEV_BASE(dev)->conf0)) {
cfg->flow_ctrl = UART_CFG_FLOW_CTRL_RTS_CTS;
}
if (UART_GET_RX_FLOW(DEV_BASE(dev)->conf1)) {
cfg->flow_ctrl = UART_CFG_FLOW_CTRL_DTR_DSR;
}
return 0;
}
static int uart_esp32_set_baudrate(struct device *dev, int baudrate)
{
u32_t sys_clk_freq = DEV_CFG(dev)->dev_conf.sys_clk_freq;
u32_t clk_div = (((sys_clk_freq) << 4) / baudrate);
while (UART_TXFIFO_COUNT(DEV_BASE(dev)->status)) {
; /* Wait */
}
if (clk_div < 16) {
return -EINVAL;
}
DEV_BASE(dev)->clk_div = ((clk_div >> 4) | (clk_div & 0xf));
return 1;
}
static int uart_esp32_configure_pins(struct device *dev)
{
const struct uart_esp32_config *const cfg = DEV_CFG(dev);
esp32_rom_gpio_matrix_out(cfg->pins.tx,
cfg->signals.tx_out,
false,
false);
esp32_rom_gpio_matrix_in(cfg->pins.rx,
cfg->signals.rx_in,
false);
esp32_rom_gpio_matrix_out(cfg->pins.cts,
cfg->signals.cts_in,
false,
false);
esp32_rom_gpio_matrix_in(cfg->pins.rts,
cfg->signals.rts_out,
false);
return 0;
}
static int uart_esp32_configure(struct device *dev,
const struct uart_config *cfg)
{
u32_t conf0 = UART_TICK_REF_ALWAYS_ON;
u32_t conf1 = (UART_RX_FIFO_THRESH << UART_RXFIFO_FULL_THRHD_S)
| (UART_TX_FIFO_THRESH << UART_TXFIFO_EMPTY_THRHD_S);
uart_esp32_configure_pins(dev);
esp32_enable_peripheral(&DEV_CFG(dev)->peripheral);
/*
* Reset RX Buffer by reading all received bytes
* Hardware Reset functionality can't be used with UART 1/2
*/
while (UART_RXFIFO_COUNT(DEV_BASE(dev)->status) != 0) {
(void) DEV_BASE(dev)->fifo;
}
switch (cfg->parity) {
case UART_CFG_PARITY_NONE:
conf0 &= ~(UART_PARITY_EN);
conf0 &= ~(UART_PARITY);
break;
case UART_CFG_PARITY_EVEN:
conf0 &= ~(UART_PARITY);
break;
case UART_CFG_PARITY_ODD:
conf0 |= UART_PARITY;
break;
default:
return -ENOTSUP;
}
switch (cfg->stop_bits) {
case UART_CFG_STOP_BITS_1:
case UART_CFG_STOP_BITS_1_5:
case UART_CFG_STOP_BITS_2:
conf0 |= cfg->stop_bits << UART_STOP_BIT_NUM_S;
break;
default:
return -ENOTSUP;
}
if (cfg->data_bits <= UART_CFG_DATA_BITS_8) {
conf0 |= cfg->data_bits << UART_BIT_NUM_S;
} else {
return -ENOTSUP;
}
switch (cfg->flow_ctrl) {
case UART_CFG_FLOW_CTRL_NONE:
conf0 &= ~(UART_TX_FLOW_EN);
conf1 &= ~(UART_RX_FLOW_EN);
break;
case UART_CFG_FLOW_CTRL_RTS_CTS:
conf0 |= UART_TX_FLOW_EN;
conf1 |= UART_RX_FLOW_EN;
break;
default:
return -ENOTSUP;
}
if (uart_esp32_set_baudrate(dev, cfg->baudrate)) {
DEV_DATA(dev)->uart_config.baudrate = cfg->baudrate;
} else {
return -ENOTSUP;
}
DEV_BASE(dev)->conf0 = conf0;
DEV_BASE(dev)->conf1 = conf1;
return 0;
}
static int uart_esp32_init(struct device *dev)
{
uart_esp32_configure(dev, &DEV_DATA(dev)->uart_config);
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
DEV_CFG(dev)->dev_conf.irq_config_func(dev);
#endif
return 0;
}
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
static int uart_esp32_fifo_fill(struct device *dev,
const u8_t *tx_data, int len)
{
u8_t num_tx = 0U;
while ((len - num_tx > 0) &&
UART_TXFIFO_COUNT(DEV_BASE(dev)->status) < UART_FIFO_LIMIT) {
DEV_BASE(dev)->fifo = (u32_t)tx_data[num_tx++];
}
return num_tx;
}
static int uart_esp32_fifo_read(struct device *dev,
u8_t *rx_data, const int len)
{
u8_t num_rx = 0U;
while ((len - num_rx > 0) &&
(UART_RXFIFO_COUNT(DEV_BASE(dev)->status) != 0)) {
rx_data[num_rx++] = DEV_BASE(dev)->fifo;
}
return num_rx;
}
static void uart_esp32_irq_tx_enable(struct device *dev)
{
DEV_BASE(dev)->int_clr |= UART_TXFIFO_EMPTY_INT_ENA;
DEV_BASE(dev)->int_ena |= UART_TXFIFO_EMPTY_INT_ENA;
}
static void uart_esp32_irq_tx_disable(struct device *dev)
{
DEV_BASE(dev)->int_ena &= ~(UART_TXFIFO_EMPTY_INT_ENA);
}
static int uart_esp32_irq_tx_ready(struct device *dev)
{
return (UART_TXFIFO_COUNT(DEV_BASE(dev)->status) < UART_FIFO_LIMIT);
}
static void uart_esp32_irq_rx_enable(struct device *dev)
{
DEV_BASE(dev)->int_clr |= UART_RXFIFO_FULL_INT_ENA;
DEV_BASE(dev)->int_ena |= UART_RXFIFO_FULL_INT_ENA;
}
static void uart_esp32_irq_rx_disable(struct device *dev)
{
DEV_BASE(dev)->int_ena &= ~(UART_RXFIFO_FULL_INT_ENA);
}
static int uart_esp32_irq_tx_complete(struct device *dev)
{
/* check if TX FIFO is empty */
return (UART_TXFIFO_COUNT(DEV_BASE(dev)->status) == 0 ? 1 : 0);
}
static int uart_esp32_irq_rx_ready(struct device *dev)
{
return (UART_RXFIFO_COUNT(DEV_BASE(dev)->status) > 0);
}
static void uart_esp32_irq_err_enable(struct device *dev)
{
/* enable framing, parity */
DEV_BASE(dev)->int_ena |= UART_FRM_ERR_INT_ENA
| UART_PARITY_ERR_INT_ENA;
}
static void uart_esp32_irq_err_disable(struct device *dev)
{
DEV_BASE(dev)->int_ena &= ~(UART_FRM_ERR_INT_ENA);
DEV_BASE(dev)->int_ena &= ~(UART_PARITY_ERR_INT_ENA);
}
static int uart_esp32_irq_is_pending(struct device *dev)
{
return uart_esp32_irq_rx_ready(dev) || uart_esp32_irq_tx_ready(dev);
}
static int uart_esp32_irq_update(struct device *dev)
{
DEV_BASE(dev)->int_clr |= UART_RXFIFO_FULL_INT_ENA;
DEV_BASE(dev)->int_clr |= UART_TXFIFO_EMPTY_INT_ENA;
return 1;
}
static void uart_esp32_irq_callback_set(struct device *dev,
uart_irq_callback_user_data_t cb,
void *cb_data)
{
DEV_DATA(dev)->irq_cb = cb;
DEV_DATA(dev)->irq_cb_data = cb_data;
}
void uart_esp32_isr(void *arg)
{
struct device *dev = arg;
struct uart_esp32_data *data = DEV_DATA(dev);
/* Verify if the callback has been registered */
if (data->irq_cb) {
data->irq_cb(data->irq_cb_data);
}
}
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
static const struct uart_driver_api uart_esp32_api = {
.poll_in = uart_esp32_poll_in,
.poll_out = uart_esp32_poll_out,
.err_check = uart_esp32_err_check,
.configure = uart_esp32_configure,
.config_get = uart_esp32_config_get,
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
.fifo_fill = uart_esp32_fifo_fill,
.fifo_read = uart_esp32_fifo_read,
.irq_tx_enable = uart_esp32_irq_tx_enable,
.irq_tx_disable = uart_esp32_irq_tx_disable,
.irq_tx_ready = uart_esp32_irq_tx_ready,
.irq_rx_enable = uart_esp32_irq_rx_enable,
.irq_rx_disable = uart_esp32_irq_rx_disable,
.irq_tx_complete = uart_esp32_irq_tx_complete,
.irq_rx_ready = uart_esp32_irq_rx_ready,
.irq_err_enable = uart_esp32_irq_err_enable,
.irq_err_disable = uart_esp32_irq_err_disable,
.irq_is_pending = uart_esp32_irq_is_pending,
.irq_update = uart_esp32_irq_update,
.irq_callback_set = uart_esp32_irq_callback_set,
#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
};
#ifdef CONFIG_UART_INTERRUPT_DRIVEN
#define ESP32_UART_IRQ_HANDLER_DECL(idx) \
static void uart_esp32_irq_config_func_##idx(struct device *dev)
#define ESP32_UART_IRQ_HANDLER_FUNC(idx) \
.irq_config_func = uart_esp32_irq_config_func_##idx,
#define ESP32_UART_IRQ_HANDLER(idx) \
static void uart_esp32_irq_config_func_##idx(struct device *dev) \
{ \
esp32_rom_intr_matrix_set(0, ETS_UART##idx##_INTR_SOURCE, \
DT_UART_ESP32_PORT_##idx##_IRQ_0); \
IRQ_CONNECT(DT_UART_ESP32_PORT_##idx##_IRQ_0, \
1, \
uart_esp32_isr, \
DEVICE_GET(uart_esp32_##idx), \
0); \
irq_enable(DT_UART_ESP32_PORT_##idx##_IRQ_0); \
}
#else
#define ESP32_UART_IRQ_HANDLER_DECL(idx)
#define ESP32_UART_IRQ_HANDLER_FUNC(idx)
#define ESP32_UART_IRQ_HANDLER(idx)
#endif
#define ESP32_UART_INIT(idx) \
ESP32_UART_IRQ_HANDLER_DECL(idx); \
static const struct uart_esp32_config uart_esp32_cfg_port_##idx = { \
.dev_conf = { \
.base = (u8_t *)DT_INST_##idx##_XTENSA_ESP32_UART_BASE_ADDRESS, \
.sys_clk_freq = DT_INST_0_CADENCE_TENSILICA_XTENSA_LX6_CLOCK_FREQUENCY, \
ESP32_UART_IRQ_HANDLER_FUNC(idx) \
}, \
\
.peripheral = { \
.clk = DPORT_UART##idx##_CLK_EN, \
.rst = DPORT_UART##idx##_RST, \
}, \
\
.signals = { \
.tx_out = U##idx##TXD_OUT_IDX, \
.rx_in = U##idx##RXD_IN_IDX, \
.rts_out = U##idx##RTS_OUT_IDX, \
.cts_in = U##idx##CTS_IN_IDX, \
}, \
\
.pins = { \
.tx = DT_INST_##idx##_XTENSA_ESP32_UART_TX_PIN, \
.rx = DT_INST_##idx##_XTENSA_ESP32_UART_RX_PIN, \
.rts = DT_INST_##idx##_XTENSA_ESP32_UART_RTS_PIN, \
.cts = DT_INST_##idx##_XTENSA_ESP32_UART_CTS_PIN, \
}, \
\
.irq = { \
.source = ETS_UART##idx##_INTR_SOURCE, \
.line = DT_UART_ESP32_PORT_##idx##_IRQ_0, \
} \
}; \
\
static struct uart_esp32_data uart_esp32_data_##idx = { \
.uart_config = { \
.baudrate = DT_INST_##idx##_XTENSA_ESP32_UART_CURRENT_SPEED, \
.parity = UART_CFG_PARITY_NONE, \
.stop_bits = UART_CFG_STOP_BITS_1, \
.data_bits = UART_CFG_DATA_BITS_8, \
.flow_ctrl = UART_CFG_FLOW_CTRL_NONE \
} \
}; \
\
DEVICE_AND_API_INIT(uart_esp32_##idx, \
DT_INST_##idx##_XTENSA_ESP32_UART_LABEL, \
uart_esp32_init, \
&uart_esp32_data_##idx, \
&uart_esp32_cfg_port_##idx, \
PRE_KERNEL_1, \
CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
&uart_esp32_api); \
\
ESP32_UART_IRQ_HANDLER(idx)
#ifdef DT_INST_0_XTENSA_ESP32_UART
ESP32_UART_INIT(0);
#endif
#ifdef DT_INST_1_XTENSA_ESP32_UART
ESP32_UART_INIT(1);
#endif
#ifdef DT_INST_2_XTENSA_ESP32_UART
ESP32_UART_INIT(2);
#endif

View file

@ -12,7 +12,27 @@ properties:
required: true
interrupts:
required: true
category: optional
clocks:
required: true
category: required
tx-pin:
type: int
description: TX pin
category: required
rx-pin:
type: int
description: RX pin
category: required
rts-pin:
type: int
description: RTS pin
category: optional
cts-pin:
type: int
description: CTS pin
category: optional

View file

@ -454,6 +454,7 @@ x-powers X-Powers
xes Extreme Engineering Solutions (X-ES)
xillybus Xillybus Ltd.
xlnx Xilinx
xtensa The Tensilica Xtensa processor architecture
xunlong Shenzhen Xunlong Software CO.,Limited
ysoft Y Soft Corporation a.s.
zarlink Zarlink Semiconductor

View file

@ -31,11 +31,27 @@
};
soc {
uart0: uart@40008fd0 {
compatible = "espressif,esp32-uart";
reg = <0x40008fd0 0x400>;
label = "ROMUART";
uart0: uart@3ff40000 {
compatible = "xtensa,esp32-uart";
reg = <0x3ff40000 0x400>;
/* interrupts = <12>; - FIXME: Enable interrupts when interrupt-controller got supported in device tree */
label = "UART_0";
status = "disabled";
};
uart1: uart@3ff50000 {
compatible = "xtensa,esp32-uart";
reg = <0x3ff50000 0x400>;
/* interrupts = <17>; - FIXME: Enable interrupts when interrupt-controller got supported in device tree */
label = "UART_1";
status = "disabled";
};
uart2: uart@3ff6e000 {
compatible = "xtensa,esp32-uart";
reg = <0x3ff6E000 0x400>;
/* interrupts = <18>; - FIXME: Enable interrupts when interrupt-controller got supported in device tree */
label = "UART_2";
status = "disabled";
};