/*
* Copyright (C) Maxime Coquelin 2015
* Copyright (C) STMicroelectronics SA 2017
* Authors: Maxime Coquelin <mcoquelin.stm32@gmail.com>
* Gerald Baeza <gerald.baeza@st.com>
* License terms: GNU General Public License (GPL), version 2
*
* Inspired by st-asc.c from STMicroelectronics (c)
*/
#if defined(CONFIG_SERIAL_STM32_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/clk.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/dma-direction.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/pm_wakeirq.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/spinlock.h>
#include <linux/sysrq.h>
#include <linux/tty_flip.h>
#include <linux/tty.h>
#include "stm32-usart.h"
static void stm32_stop_tx(struct uart_port *port);
static void stm32_transmit_chars(struct uart_port *port);
static inline struct stm32_port *to_stm32_port(struct uart_port *port)
{
return container_of(port, struct stm32_port, port);
}
static void stm32_set_bits(struct uart_port *port, u32 reg, u32 bits)
{
u32 val;
val = readl_relaxed(port->membase + reg);
val |= bits;
writel_relaxed(val, port->membase + reg);
}
static void stm32_clr_bits(struct uart_port *port, u32 reg, u32 bits)
{
u32 val;
val = readl_relaxed(port->membase + reg);
val &= ~bits;
writel_relaxed(val, port->membase + reg);
}
static int stm32_pending_rx(struct uart_port *port, u32 *sr, int *last_res,
bool threaded)
{
struct stm32_port *stm32_port = to_stm32_port(port);
struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
enum dma_status status;
struct dma_tx_state state;
*sr = readl_relaxed(port->membase + ofs->isr);
if (threaded && stm32_port->rx_ch) {
status = dmaengine_tx_status(stm32_port->rx_ch,
stm32_port->rx_ch->cookie,
&state);
if ((status == DMA_IN_PROGRESS) &&
(*last_res != state.residue))
return 1;
else
return 0;
} else if (*sr & USART_SR_RXNE) {
return 1;
}
return 0;
}
static unsigned long
stm32_get_char(struct uart_port *port, u32 *sr, int *last_res)
{
struct stm32_port *stm32_port = to_stm32_port(port);
struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
unsigned long c;
if (stm32_port->rx_ch) {
c = stm32_port->rx_buf[RX_BUF_L - (*last_res)--];
if ((*last_res) == 0)
*last_res = RX_BUF_L;
return c;
} else {
return readl_relaxed(port->membase + ofs->rdr);
}
}
static void stm32_receive_chars(struct