drivers: serial: add LiteUART driver
Add LiteX UART driver with bindings for this device.
Signed-off-by: Filip Kokosinski <fkokosinski@internships.antmicro.com>
Signed-off-by: Mateusz Holenko <mholenko@antmicro.com>
diff --git a/CODEOWNERS b/CODEOWNERS
index 62e06fa..4689dc7 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -137,6 +137,8 @@
/drivers/sensor/lsm*/ @avisconti
/drivers/serial/uart_altera_jtag_hal.c @wentongwu
/drivers/serial/*ns16550* @gnuless
+/drivers/serial/Kconfig.litex @mateusz-holenko @kgugala @pgielda
+/drivers/serial/uart_liteuart.c @mateusz-holenko @kgugala @pgielda
/drivers/net/ @jukkar @tbursztyka
/drivers/ptp_clock/ @jukkar
/drivers/spi/ @tbursztyka
@@ -170,6 +172,7 @@
/dts/bindings/*/st* @erwango
/dts/bindings/sensor/ams* @alexanderwachter
/dts/bindings/*/sifive* @mateusz-holenko @kgugala @pgielda @nategraff-sifive
+/dts/bindings/*/litex* @mateusz-holenko @kgugala @pgielda
/ext/fs/ @nashif @wentongwu
/ext/hal/atmel/asf/sam/include/same70*/ @aurel32
/ext/hal/atmel/asf/sam0/include/samr21/ @benpicco
diff --git a/drivers/serial/CMakeLists.txt b/drivers/serial/CMakeLists.txt
index 4128acd..7473c51 100644
--- a/drivers/serial/CMakeLists.txt
+++ b/drivers/serial/CMakeLists.txt
@@ -28,6 +28,7 @@
zephyr_library_sources_if_kconfig(uart_psoc6.c)
zephyr_library_sources_if_kconfig(uart_pl011.c)
zephyr_library_sources_if_kconfig(uart_rv32m1_lpuart.c)
+zephyr_library_sources_if_kconfig(uart_liteuart.c)
zephyr_library_sources_ifdef(CONFIG_USERSPACE uart_handlers.c)
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index d190610..4e9bb4c 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -116,4 +116,6 @@
source "drivers/serial/Kconfig.rv32m1_lpuart"
+source "drivers/serial/Kconfig.litex"
+
endif # SERIAL
diff --git a/drivers/serial/Kconfig.litex b/drivers/serial/Kconfig.litex
new file mode 100644
index 0000000..d649adf
--- /dev/null
+++ b/drivers/serial/Kconfig.litex
@@ -0,0 +1,22 @@
+# Kconfig.litex - LiteX UART (LiteUART) configuration option
+#
+# Copyright (c) 2018 - 2019 Antmicro <www.antmicro.com>
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+menuconfig UART_LITEUART
+ bool "LiteUART serial driver"
+ depends on SOC_RISCV32_LITEX_VEXRISCV
+ # currently not supporting interrupts due to a bug in LiteUART Tx IRQ
+ depends on !SERIAL_SUPPORT_INTERRUPT
+ select SERIAL_HAS_DRIVER
+ help
+ This option enables LiteUART serial driver.
+
+menuconfig UART_LITEUART_PORT_0
+ bool "Enable LiteX Port 0"
+ depends on UART_LITEUART
+ help
+ This tells the driver to configure the UART port at boot, depending on
+ the additional configuration options below.
diff --git a/drivers/serial/uart_liteuart.c b/drivers/serial/uart_liteuart.c
new file mode 100644
index 0000000..7b2c1fd
--- /dev/null
+++ b/drivers/serial/uart_liteuart.c
@@ -0,0 +1,337 @@
+/*
+ * Copyright (c) 2018 - 2019 Antmicro <www.antmicro.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <kernel.h>
+#include <arch/cpu.h>
+#include <init.h>
+#include <irq.h>
+#include <device.h>
+#include <uart.h>
+#include <zephyr/types.h>
+
+#define UART_EV_TX (1 << 0)
+#define UART_EV_RX (1 << 1)
+#define UART_BASE_ADDR DT_LITEX_UART0_E0001800_BASE_ADDRESS
+#define UART_RXTX ((UART_BASE_ADDR) + 0x00)
+#define UART_TXFULL ((UART_BASE_ADDR) + 0x04)
+#define UART_RXEMPTY ((UART_BASE_ADDR) + 0x08)
+#define UART_EV_STATUS ((UART_BASE_ADDR) + 0x0c)
+#define UART_EV_PENDING ((UART_BASE_ADDR) + 0x10)
+#define UART_EV_ENABLE ((UART_BASE_ADDR) + 0x14)
+#define UART_IRQ DT_LITEX_UART0_E0001800_IRQ_0
+
+#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+typedef void (*irq_cfg_func_t)(void);
+#endif
+
+struct uart_liteuart_device_config {
+ u32_t port;
+ u32_t sys_clk_freq;
+ u32_t baud_rate;
+#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+ irq_cfg_func_t cfg_func;
+#endif
+};
+
+struct uart_liteuart_data {
+#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+ uart_irq_callback_user_data_t callback;
+ void *cb_data;
+#endif
+};
+
+/**
+ * @brief Output a character in polled mode.
+ *
+ * Writes data to tx register. Waits for space if transmitter is full.
+ *
+ * @param dev UART device struct
+ * @param c Character to send
+ */
+static void uart_liteuart_poll_out(struct device *dev, unsigned char c)
+{
+ /* wait for space */
+ while (sys_read8(UART_TXFULL))
+ ;
+
+ sys_write8(c, UART_RXTX);
+}
+
+/**
+ * @brief Poll the device for input.
+ *
+ * @param dev UART device struct
+ * @param c Pointer to character
+ *
+ * @return 0 if a character arrived, -1 if the input buffer if empty.
+ */
+static int uart_liteuart_poll_in(struct device *dev, unsigned char *c)
+{
+ if (!sys_read8(UART_RXEMPTY)) {
+ *c = sys_read8(UART_RXTX);
+
+ /* refresh UART_RXEMPTY by writing UART_EV_RX
+ * to UART_EV_PENDING
+ */
+ sys_write8(UART_EV_RX, UART_EV_PENDING);
+ return 0;
+ } else {
+ return -1;
+ }
+}
+
+#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+/**
+ * @brief Enable TX interrupt in event register
+ *
+ * @param dev UART device struct
+ *
+ * @return N/A
+ */
+static void uart_liteuart_irq_tx_enable(struct device *dev)
+{
+ u8_t enable = sys_read8(UART_EV_ENABLE);
+
+ sys_write8(enable | UART_EV_TX, UART_EV_ENABLE);
+}
+
+/**
+ * @brief Disable TX interrupt in event register
+ *
+ * @param dev UART device struct
+ *
+ * @return N/A
+ */
+static void uart_liteuart_irq_tx_disable(struct device *dev)
+{
+ u8_t enable = sys_read8(UART_EV_ENABLE);
+
+ sys_write8(enable & ~(UART_EV_TX), UART_EV_ENABLE);
+}
+
+/**
+ * @brief Enable RX interrupt in event register
+ *
+ * @param dev UART device struct
+ *
+ * @return N/A
+ */
+static void uart_liteuart_irq_rx_enable(struct device *dev)
+{
+ u8_t enable = sys_read8(UART_EV_ENABLE);
+
+ sys_write8(enable | UART_EV_RX, UART_EV_ENABLE);
+}
+
+/**
+ * @brief Disable RX interrupt in event register
+ *
+ * @param dev UART device struct
+ *
+ * @return N/A
+ */
+static void uart_liteuart_irq_rx_disable(struct device *dev)
+{
+ u8_t enable = sys_read8(UART_EV_ENABLE);
+
+ sys_write8(enable & ~(UART_EV_RX), UART_EV_ENABLE);
+}
+
+/**
+ * @brief Check if Tx IRQ has been raised and UART is ready to accept new data
+ *
+ * @param dev UART device struct
+ *
+ * @return 1 if an IRQ has been raised, 0 otherwise
+ */
+static int uart_liteuart_irq_tx_ready(struct device *dev)
+{
+ u8_t val = sys_read8(UART_TXFULL);
+
+ return !val;
+}
+
+/**
+ * @brief Check if Rx IRQ has been raised and there's data to be read from UART
+ *
+ * @param dev UART device struct
+ *
+ * @return 1 if an IRQ has been raised, 0 otherwise
+ */
+static int uart_liteuart_irq_rx_ready(struct device *dev)
+{
+ u8_t pending;
+
+ pending = sys_read8(UART_EV_PENDING);
+
+ if (pending & UART_EV_RX) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+/**
+ * @brief Fill FIFO with data
+ *
+ * @param dev UART device struct
+ * @param tx_data Data to transmit
+ * @param size Number of bytes to send
+ *
+ * @return Number of bytes sent
+ */
+static int uart_liteuart_fifo_fill(struct device *dev,
+ const u8_t *tx_data, int size)
+{
+ int i;
+
+ for (i = 0; i < size && !sys_read8(UART_TXFULL); i++) {
+ sys_write8(tx_data[i], UART_RXTX);
+ }
+
+ return i;
+}
+
+/**
+ * @brief Read data from FIFO
+ *
+ * @param dev UART device struct
+ * @param rxData Data container
+ * @param size Container size
+ *
+ * @return Number of bytes read
+ */
+static int uart_liteuart_fifo_read(struct device *dev,
+ u8_t *rx_data, const int size)
+{
+ int i;
+
+ for (i = 0; i < size && !sys_read8(UART_RXEMPTY); i++) {
+ rx_data[i] = sys_read8(UART_RXTX);
+
+ /* refresh UART_RXEMPTY by writing UART_EV_RX
+ * to UART_EV_PENDING
+ */
+ sys_write8(UART_EV_RX, UART_EV_PENDING);
+ }
+
+ return i;
+}
+
+static void uart_liteuart_irq_err(struct device *dev)
+{
+ ARG_UNUSED(dev);
+}
+
+/**
+ * @brief Check if any IRQ is pending
+ *
+ * @param dev UART device struct
+ *
+ * @return 1 if an IRQ is pending, 0 otherwise
+ */
+static int uart_liteuart_irq_is_pending(struct device *dev)
+{
+ u8_t pending;
+
+ pending = sys_read8(UART_EV_PENDING);
+
+ if (pending & (UART_EV_TX | UART_EV_RX)) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+static int uart_liteuart_irq_update(struct device *dev)
+{
+ return 1;
+}
+
+/**
+ * @brief Set the callback function pointer for IRQ.
+ *
+ * @param dev UART device struct
+ * @param cb Callback function pointer.
+ *
+ * @return N/A
+ */
+static void uart_liteuart_irq_callback_set(struct device *dev,
+ uart_irq_callback_user_data_t cb,
+ void *cb_data)
+{
+ struct uart_liteuart_data *data;
+
+ data = (struct uart_liteuart_data *)dev->driver_data;
+ data->callback = cb;
+ data->cb_data = cb_data;
+}
+
+static void liteuart_uart_irq_handler(void *arg)
+{
+ struct device *dev = (struct device *)arg;
+ struct uart_liteuart_data *data = DEV_DATA(dev);
+ int key = irq_lock();
+
+ if (data->callback) {
+ data->callback(data->cb_data);
+ }
+
+ /* clear events */
+ sys_write8(UART_EV_TX | UART_EV_RX, UART_EV_PENDING);
+
+ irq_unlock(key);
+}
+#endif /* CONFIG_UART_INTERRUPT_DRIVEN */
+
+static const struct uart_driver_api uart_liteuart_driver_api = {
+ .poll_in = uart_liteuart_poll_in,
+ .poll_out = uart_liteuart_poll_out,
+ .err_check = NULL,
+#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+ .fifo_fill = uart_liteuart_fifo_fill,
+ .fifo_read = uart_liteuart_fifo_read,
+ .irq_tx_enable = uart_liteuart_irq_tx_enable,
+ .irq_tx_disable = uart_liteuart_irq_tx_disable,
+ .irq_tx_ready = uart_liteuart_irq_tx_ready,
+ .irq_rx_enable = uart_liteuart_irq_rx_enable,
+ .irq_rx_disable = uart_liteuart_irq_rx_disable,
+ .irq_rx_ready = uart_liteuart_irq_rx_ready,
+ .irq_err_enable = uart_liteuart_irq_err,
+ .irq_err_disable = uart_liteuart_irq_err,
+ .irq_is_pending = uart_liteuart_irq_is_pending,
+ .irq_update = uart_liteuart_irq_update,
+ .irq_callback_set = uart_liteuart_irq_callback_set
+#endif
+};
+
+static struct uart_liteuart_data uart_liteuart_data_0;
+static int uart_liteuart_init(struct device *dev);
+
+static const struct uart_liteuart_device_config uart_liteuart_dev_cfg_0 = {
+ .port = UART_BASE_ADDR,
+ .baud_rate = DT_LITEX_UART0_E0001800_CURRENT_SPEED
+};
+
+DEVICE_AND_API_INIT(uart_liteuart_0, DT_LITEX_UART0_E0001800_LABEL,
+ uart_liteuart_init,
+ &uart_liteuart_data_0, &uart_liteuart_dev_cfg_0,
+ PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
+ (void *)&uart_liteuart_driver_api);
+
+static int uart_liteuart_init(struct device *dev)
+{
+ sys_write8(UART_EV_TX | UART_EV_RX, UART_EV_PENDING);
+
+#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+ IRQ_CONNECT(UART_IRQ, DT_LITEX_UART0_E0001800_IRQ_0_PRIORITY,
+ liteuart_uart_irq_handler, DEVICE_GET(uart_liteuart_0),
+ 0);
+ irq_enable(UART_IRQ);
+#endif
+
+ return 0;
+}
diff --git a/dts/bindings/serial/litex,uart0.yaml b/dts/bindings/serial/litex,uart0.yaml
new file mode 100644
index 0000000..bc3e3db
--- /dev/null
+++ b/dts/bindings/serial/litex,uart0.yaml
@@ -0,0 +1,36 @@
+#
+# Copyright (c) 2018 - 2019 Antmicro <www.antmicro.com>
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+---
+title: LiteX UART
+version: 0.1
+
+description: >
+ This binding gives a base representation of the LiteX UART
+
+inherits:
+ !include uart.yaml
+
+properties:
+ compatible:
+ type: string
+ category: required
+ description: compatible strings
+ constraint: "litex,uart0"
+ generation: define
+
+ reg:
+ type: array
+ description: mmio register space
+ generation: define
+ category: required
+
+ interrupts:
+ type: array
+ category: required
+ description: required interrupts
+ generation: define
+
+...
