This driver add support for Ambarella's uart, which
can be used for console and etc.
Signed-off-by: Li Chen <lchen@xxxxxxxxxxxxx>
Change-Id: Ie68af7ad2187e21853e58d52cd97fd7145303730
---
MAINTAINERS | 1 +
drivers/tty/serial/Kconfig | 16 +
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/ambarella_uart.c | 1581 +++++++++++++++++++++++++++
drivers/tty/serial/ambarella_uart.h | 120 ++
5 files changed, 1719 insertions(+)
create mode 100644 drivers/tty/serial/ambarella_uart.c
create mode 100644 drivers/tty/serial/ambarella_uart.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 080412535e26..ee1d201dd89a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1909,6 +1909,7 @@ F: drivers/clk/ambarella/clk-pll-common.h
F: drivers/clk/ambarella/clk-pll-normal.c
F: drivers/soc/ambarella/Makefile
F: drivers/soc/ambarella/soc.c
+F: drivers/tty/serial/ambarella_uart.c
F: include/soc/ambarella/misc.h
ARM/Amlogic Meson SoC CLOCK FRAMEWORK
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index c55b947f3cdb..27216ecc3161 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -18,6 +18,22 @@ source "drivers/tty/serial/8250/Kconfig"
comment "Non-8250 serial port support"
+config SERIAL_AMBARELLA
+ tristate "Ambarella Media Soc serial port support"
+ depends on ARCH_AMBARELLA
+ select SERIAL_CORE
+ help
+ If you have a machine based on an Ambarella Media SoC you
+ can enable its onboard serial ports by enabling this option.
+
+config SERIAL_AMBARELLA_CONSOLE
+ bool "Console on Ambarella Media SoC serial port"
+ depends on SERIAL_AMBARELLA=y
+ select SERIAL_CORE_CONSOLE
+ help
+ If you have enabled the serial port on the Ambarella Media SoC
+ you can make it the console by answering Y to this option.
+
config SERIAL_AMBA_PL010
tristate "ARM AMBA PL010 serial port support"
depends on ARM_AMBA || COMPILE_TEST
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 238a9557b487..00e454e06976 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -3,6 +3,7 @@
# Makefile for the kernel serial device drivers.
#
+obj-$(CONFIG_SERIAL_AMBARELLA) += ambarella_uart.o
obj-$(CONFIG_SERIAL_CORE) += serial_core.o
obj-$(CONFIG_SERIAL_EARLYCON) += earlycon.o
diff --git a/drivers/tty/serial/ambarella_uart.c b/drivers/tty/serial/ambarella_uart.c
new file mode 100644
index 000000000000..54de84fbb623
--- /dev/null
+++ b/drivers/tty/serial/ambarella_uart.c
@@ -0,0 +1,1581 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Author: Anthony Ginger <hfjiang@xxxxxxxxxxxxx>
+ *
+ * Copyright (C) 2023, Ambarella, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#if defined(CONFIG_SERIAL_AMBARELLA_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <asm-generic/types.h>
+#include "ambarella_uart.h"
+#include <asm-generic/errno-base.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/clk.h>
+#include <linux/syscore_ops.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/slab.h>
+#include <linux/serial_reg.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+
+#define AMBA_UART_MAX_NUM 8
+
+#define AMBA_UART_RX_DMA_BUFFER_SIZE PAGE_SIZE
+#define AMBA_UART_MIN_DMA 16
+#define AMBA_UART_LSR_ANY \
+ (UART_LSR_OE | UART_LSR_BI | UART_LSR_PE | UART_LSR_FE)
+
+#define AMBA_UART_RESET_FLAG 0 /* bit 0 */
+
+struct ambarella_uart_port {
+ struct uart_port port;
+ struct clk *uart_pll;
+ struct clk *parent_pll;
+ unsigned long flags;
+ u32 msr_used : 1;
+ u32 tx_fifo_fix : 1;
+ u32 less_reg : 1;
+ u32 txdma_used:1;
+ u32 rxdma_used:1;
+ u32 mcr;
+ u32 c_cflag;
+ /* following are for dma transfer */
+ struct dma_chan *rx_dma_chan;
+ struct dma_chan *tx_dma_chan;
+ unsigned char *rx_dma_buf_virt;
+ unsigned char *tx_dma_buf_virt;
+ dma_addr_t rx_dma_buf_phys;
+ dma_addr_t tx_dma_buf_phys;
+ struct dma_async_tx_descriptor *tx_dma_desc;
+ struct dma_async_tx_descriptor *rx_dma_desc;
+ dma_cookie_t tx_cookie;
+ dma_cookie_t rx_cookie;
+ int tx_bytes_requested;
+ int rx_bytes_requested;
+ bool tx_in_progress;
+ bool rx_in_progress;
+ bool ignore_fe;
+#ifdef CONFIG_PM
+ u32 clk_rate;
+#endif
+};
+
+static struct ambarella_uart_port ambarella_port[AMBA_UART_MAX_NUM];
+
+static void __serial_ambarella_stop_tx(struct uart_port *port, u32 tx_fifo_fix)
+{
+ struct ambarella_uart_port *amb_port;
+ struct circ_buf *xmit = &port->state->xmit;
+ struct dma_tx_state state;
+ u32 ier, iir;
+ int count;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+
+ if (tx_fifo_fix) {
+ ier = readl_relaxed(port->membase + UART_IE_OFFSET);
+ if ((ier & UART_IE_PTIME) != UART_IE_PTIME)
+ writel_relaxed(ier | UART_IE_PTIME | UART_IE_ETBEI,
+ port->membase + UART_IE_OFFSET);
+
+ iir = readl_relaxed(port->membase + UART_II_OFFSET);
+ writel_relaxed(ier & ~(UART_IE_PTIME | UART_IE_ETBEI),
+ port->membase + UART_IE_OFFSET);
+ (void)(iir);
+ } else {
+ ier = readl_relaxed(port->membase + UART_IE_OFFSET);
+ writel_relaxed(ier & ~UART_IE_ETBEI, port->membase + UART_IE_OFFSET);
+ }
+
+ if (amb_port->txdma_used && amb_port->tx_in_progress) {
+ dmaengine_tx_status(amb_port->tx_dma_chan, amb_port->tx_cookie, &state);
+ dmaengine_terminate_all(amb_port->tx_dma_chan);
+ count = amb_port->tx_bytes_requested - state.residue;
+ xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
+ port->icount.tx += count;
+ amb_port->tx_in_progress = false;
+ }
+}
+
+static u32 __serial_ambarella_read_ms(struct uart_port *port, u32 tx_fifo_fix)
+{
+ u32 ier, ms;
+
+ if (tx_fifo_fix) {
+ ier = readl_relaxed(port->membase + UART_IE_OFFSET);
+ if ((ier & UART_IE_EDSSI) != UART_IE_EDSSI)
+ writel_relaxed(ier | UART_IE_EDSSI,
+ port->membase + UART_IE_OFFSET);
+
+ ms = readl_relaxed(port->membase + UART_MS_OFFSET);
+ if ((ier & UART_IE_EDSSI) != UART_IE_EDSSI)
+ writel_relaxed(ier, port->membase + UART_IE_OFFSET);
+ } else {
+ ms = readl_relaxed(port->membase + UART_MS_OFFSET);
+ }
+
+ return ms;
+}
+
+static void __serial_ambarella_enable_ms(struct uart_port *port)
+{
+ u32 ier = readl_relaxed(port->membase + UART_IE_OFFSET);
+
+ writel_relaxed(ier | UART_IE_EDSSI, port->membase + UART_IE_OFFSET);
+}
+
+static void __serial_ambarella_disable_ms(struct uart_port *port)
+{
+ u32 ier = readl_relaxed(port->membase + UART_IE_OFFSET);
+
+ writel_relaxed(ier & ~UART_IE_EDSSI, port->membase + UART_IE_OFFSET);
+}
+
+static inline void wait_for_tx(struct uart_port *port)
+{
+ u32 ls;
+
+ ls = readl_relaxed(port->membase + UART_LS_OFFSET);
+ while ((ls & UART_LS_TEMT) != UART_LS_TEMT) {
+ cpu_relax();
+ ls = readl_relaxed(port->membase + UART_LS_OFFSET);
+ }
+}
+
+static inline void wait_for_rx(struct uart_port *port)
+{
+ u32 ls;
+
+ ls = readl_relaxed(port->membase + UART_LS_OFFSET);
+ while ((ls & UART_LS_DR) != UART_LS_DR) {
+ cpu_relax();
+ ls = readl_relaxed(port->membase + UART_LS_OFFSET);
+ }
+}
+
+static inline int tx_fifo_is_full(struct uart_port *port)
+{
+ return !(readl_relaxed(port->membase + UART_US_OFFSET) & UART_US_TFNF);
+}
+
+/* ==========================================================================*/
+static void serial_ambarella_hw_setup(struct uart_port *port)
+{
+ struct ambarella_uart_port *amb_port;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+
+ if (!test_and_set_bit(AMBA_UART_RESET_FLAG, &amb_port->flags)) {
+ port->uartclk = clk_get_rate(amb_port->uart_pll);
+ /* reset the whole UART only once */
+ writel_relaxed(0x01, port->membase + UART_SRR_OFFSET);
+ mdelay(1);
+ writel_relaxed(0x00, port->membase + UART_SRR_OFFSET);
+ }
+
+ writel_relaxed(DEFAULT_AMBARELLA_UART_IER | UART_IE_PTIME,
+ port->membase + UART_IE_OFFSET);
+ writel_relaxed(UART_FC_FIFOE | UART_FC_RX_2_TO_FULL | UART_FC_TX_EMPTY |
+ UART_FC_XMITR | UART_FC_RCVRR, port->membase + UART_FC_OFFSET);
+ writel_relaxed(DEFAULT_AMBARELLA_UART_IER, port->membase + UART_IE_OFFSET);
+
+ if (amb_port->txdma_used || amb_port->rxdma_used) {
+ /*
+ * we must use 14bytes as trigger, because if we use 8bytes, FIFO may
+ * be empty due to dma burst size is also set to 8bytes before dma complete,
+ * in this case, if FIFO is empty, but no more data is received, timeout irq
+ * can't be trigged after, we don't have chance to push the data that dma has
+ * transferred any more.
+ */
+ writel_relaxed(UART_FC_FIFOE | UART_FC_RX_2_TO_FULL |
+ UART_FC_TX_EMPTY | UART_FC_XMITR | UART_FC_RCVRR |
+ UART_FCR_DMA_SELECT, port->membase + UART_FC_OFFSET);
+ writel_relaxed((amb_port->txdma_used << 1) | amb_port->rxdma_used,
+ port->membase + UART_DMAE_OFFSET);
+
+ writel_relaxed(UART_IE_ETOI, port->membase + UART_IE_OFFSET);
+ }
+}
+
+static inline void serial_ambarella_receive_chars(struct uart_port *port,
+ u32 tmo)
+{
+ struct ambarella_uart_port *amb_port;
+ u32 ch, flag, ls;
+ int max_count;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+
+ ls = readl_relaxed(port->membase + UART_LS_OFFSET);
+ max_count = port->fifosize;
+
+ do {
+ flag = TTY_NORMAL;
+ if (unlikely(ls & (UART_LS_BI | UART_LS_PE |
+ UART_LS_FE | UART_LS_OE))) {
+ if (ls & UART_LS_BI) {
+ ls &= ~(UART_LS_FE | UART_LS_PE);
+ port->icount.brk++;
+
+ if (uart_handle_break(port))
+ goto ignore_char;
+ }
+ if ((ls & UART_LS_FE) && !amb_port->ignore_fe)
+ port->icount.frame++;
+ if (ls & UART_LS_PE)
+ port->icount.parity++;
+ if (ls & UART_LS_OE)
+ port->icount.overrun++;
+
+ ls &= port->read_status_mask;
+
+ if (ls & UART_LS_BI)
+ flag = TTY_BREAK;
+ else if (ls & UART_LS_FE && !amb_port->ignore_fe)
+ flag = TTY_FRAME;
+ else if (ls & UART_LS_PE)
+ flag = TTY_PARITY;
+ else if (ls & UART_LS_OE)
+ flag = TTY_OVERRUN;
+
+ if (ls & UART_LS_OE)
+ pr_debug("%s: OVERFLOW\n", __func__);
+ }
+
+ if (likely(ls & UART_LS_DR)) {
+ ch = readl_relaxed(port->membase + UART_RB_OFFSET);
+ port->icount.rx++;
+ tmo = 0;
+
+ if (uart_handle_sysrq_char(port, ch))
+ goto ignore_char;
+
+ uart_insert_char(port, ls, UART_LS_OE, ch, flag);
+ } else {
+ if (tmo) {
+ ch = readl_relaxed(port->membase + UART_RB_OFFSET);
+ /* printk(KERN_DEBUG "False TMO get %d\n", ch); */
+ }
+ }
+
+ignore_char:
+ ls = readl_relaxed(port->membase + UART_LS_OFFSET);
+ } while ((ls & (UART_LS_DR | UART_LSR_BI)) && (max_count-- > 0));
+
+ tty_flip_buffer_push(&port->state->port);
+}
+
+static void serial_ambarella_transmit_chars(struct uart_port *port)
+{
+ struct circ_buf *xmit = &port->state->xmit;
+ struct ambarella_uart_port *amb_port;
+ int count;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+
+ if (port->x_char) {
+ writel_relaxed(port->x_char, port->membase + UART_TH_OFFSET);
+ port->icount.tx++;
+ port->x_char = 0;
+ return;
+ }
+
+ if (uart_tx_stopped(port) || uart_circ_empty(xmit)) {
+ __serial_ambarella_stop_tx(port, amb_port->tx_fifo_fix);
+ return;
+ }
+
+ count = port->fifosize;
+ while (count-- > 0) {
+ if (!amb_port->less_reg && tx_fifo_is_full(port))
+ break;
+ writel_relaxed(xmit->buf[xmit->tail], port->membase + UART_TH_OFFSET);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ port->icount.tx++;
+ if (uart_circ_empty(xmit))
+ break;
+ }
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+ if (uart_circ_empty(xmit))
+ __serial_ambarella_stop_tx(port, amb_port->tx_fifo_fix);
+}
+
+static inline void serial_ambarella_check_modem_status(struct uart_port *port)
+{
+ struct ambarella_uart_port *amb_port;
+ u32 ms;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+
+ if (amb_port->msr_used) {
+ ms = __serial_ambarella_read_ms(port, amb_port->tx_fifo_fix);
+
+ if (ms & UART_MS_RI)
+ port->icount.rng++;
+ if (ms & UART_MS_DSR)
+ port->icount.dsr++;
+ if (ms & UART_MS_DCTS)
+ uart_handle_cts_change(port, (ms & UART_MS_CTS));
+ if (ms & UART_MS_DDCD)
+ uart_handle_dcd_change(port, (ms & UART_MS_DCD));
+
+ wake_up_interruptible(&port->state->port.delta_msr_wait);
+ }
+}
+
+static char serial_ambarella_decode_rx_error(struct ambarella_uart_port *amb_port,
+ unsigned long lsr)
+{
+ char flag = TTY_NORMAL;
+
+ if (unlikely(lsr & AMBA_UART_LSR_ANY)) {
+ if (lsr & UART_LSR_OE) {
+ /* Overrun error */
+ flag |= TTY_OVERRUN;
+ amb_port->port.icount.overrun++;
+ }
+ if (lsr & UART_LSR_PE) {
+ /* Parity error */
+ flag |= TTY_PARITY;
+ amb_port->port.icount.parity++;
+ }
+ if ((lsr & UART_LSR_FE) && !amb_port->ignore_fe) {
+ flag |= TTY_FRAME;
+ amb_port->port.icount.frame++;
+ }
+ if (lsr & UART_LSR_BI) {
+ amb_port->port.icount.brk++;
+ /* If FIFO read error without any data, reset Rx FIFO */
+ if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE))
+ writel_relaxed(UART_FCR_CLEAR_RCVR,
+ amb_port->port.membase + UART_SRR_OFFSET);
+ }
+ }
+ return flag;
+}
+
+static void serial_ambarella_handle_rx_pio(struct ambarella_uart_port *amb_port,
+ struct tty_port *tty)
+{
+ int cnt;
+
+ for (cnt = 0; cnt < amb_port->port.fifosize; cnt++) {
+ char flag = TTY_NORMAL;
+ unsigned long lsr = 0;
+ unsigned char ch;
+
+ lsr = readl_relaxed(amb_port->port.membase + UART_LS_OFFSET);
+ if (!(lsr & UART_LS_DR))
+ break;
+
+ flag = serial_ambarella_decode_rx_error(amb_port, lsr);
+ ch = (unsigned char) readl_relaxed(amb_port->port.membase + UART_RB_OFFSET);
+ amb_port->port.icount.rx++;
+
+ if (!uart_handle_sysrq_char(&amb_port->port, ch) && tty)
+ tty_insert_flip_char(tty, ch, flag);
+ }
+
+ /* do a dummy read to clear interrupt */
+ if (!cnt)
+ readl_relaxed(amb_port->port.membase + UART_RB_OFFSET);
+}
+
+static void serial_ambarella_copy_rx_to_tty(struct ambarella_uart_port *amb_port,
+ struct tty_port *tty, int count);
+static int serial_ambarella_start_rx_dma(struct ambarella_uart_port *amb_port);
+
+static void serial_ambarella_dma_rx_irq(struct ambarella_uart_port *amb_port)
+{
+ struct tty_port *port = &amb_port->port.state->port;
+ struct dma_tx_state state;
+ size_t pending;
+ u32 value;
+
+ dmaengine_pause(amb_port->rx_dma_chan);
+ value = readl_relaxed(amb_port->port.membase + UART_DMAE_OFFSET);
+ writel_relaxed(value & ~0x1, amb_port->port.membase + UART_DMAE_OFFSET);
+
+ dmaengine_tx_status(amb_port->rx_dma_chan, amb_port->rx_cookie, &state);
+ dmaengine_terminate_async(amb_port->rx_dma_chan);
+
+ pending = amb_port->rx_bytes_requested - state.residue;
+ BUG_ON(pending > AMBA_UART_RX_DMA_BUFFER_SIZE);
+
+ serial_ambarella_copy_rx_to_tty(amb_port, port, pending);
+ serial_ambarella_handle_rx_pio(amb_port, port);
+
+ tty_flip_buffer_push(port);
+
+ writel_relaxed(value, amb_port->port.membase + UART_DMAE_OFFSET);
+ dmaengine_resume(amb_port->rx_dma_chan);
+
+ serial_ambarella_start_rx_dma(amb_port);
+}
+
+static irqreturn_t serial_ambarella_irq(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+ struct ambarella_uart_port *amb_port;
+ int rval = IRQ_HANDLED;
+ unsigned long flags;
+ u32 ii;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ ii = readl_relaxed(port->membase + UART_II_OFFSET);
+ switch (ii & 0x0F) {
+ case UART_II_MODEM_STATUS_CHANGED:
+ serial_ambarella_check_modem_status(port);
+ break;
+
+ case UART_II_THR_EMPTY:
+ serial_ambarella_transmit_chars(port);
+ break;
+
+ case UART_II_RCV_STATUS:
+ case UART_II_RCV_DATA_AVAIL:
+ serial_ambarella_receive_chars(port, 0);
+ break;
+ case UART_II_CHAR_TIMEOUT:
+ if (amb_port->rxdma_used && amb_port->rx_dma_chan)
+ serial_ambarella_dma_rx_irq(amb_port);
+ else
+ serial_ambarella_receive_chars(port, 1);
+ break;
+
+ case UART_II_NO_INT_PENDING:
+ break;
+ default:
+ pr_debug("%s: 0x%x\n", __func__, ii);
+ break;
+ }
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return rval;
+}
+
+/* ==========================================================================*/
+static void serial_ambarella_enable_ms(struct uart_port *port)
+{
+ __serial_ambarella_enable_ms(port);
+}
+
+static void serial_ambarella_start_next_tx(struct ambarella_uart_port *amb_port);
+
+static void serial_ambarella_tx_dma_complete(void *args)
+{
+ struct ambarella_uart_port *amb_port = args;
+ struct circ_buf *xmit = &amb_port->port.state->xmit;
+ struct dma_tx_state state;
+ unsigned long flags;
+ int count;
+
+ dmaengine_tx_status(amb_port->tx_dma_chan, amb_port->tx_cookie, &state);
+ count = amb_port->tx_bytes_requested - state.residue;
+ spin_lock_irqsave(&amb_port->port.lock, flags);
+ xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
+ amb_port->tx_in_progress = false;
+ amb_port->port.icount.tx += count;
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&amb_port->port);
+ serial_ambarella_start_next_tx(amb_port);
+ spin_unlock_irqrestore(&amb_port->port.lock, flags);
+}
+
+static int serial_ambarella_start_tx_dma(struct ambarella_uart_port *amb_port,
+ unsigned long count)
+{
+ struct circ_buf *xmit = &amb_port->port.state->xmit;
+ dma_addr_t tx_phys_addr;
+ int tx_bytes;
+
+ dma_sync_single_for_device(amb_port->port.dev, amb_port->tx_dma_buf_phys,
+ UART_XMIT_SIZE, DMA_TO_DEVICE);
+
+ tx_bytes = count & ~(0xF);
+ tx_phys_addr = amb_port->tx_dma_buf_phys + xmit->tail;
+ amb_port->tx_dma_desc = dmaengine_prep_slave_single(amb_port->tx_dma_chan,
+ tx_phys_addr, tx_bytes, DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!amb_port->tx_dma_desc) {
+ dev_err(amb_port->port.dev, "Not able to get desc for Tx\n");
+ return -EIO;
+ }
+
+ amb_port->tx_dma_desc->callback = serial_ambarella_tx_dma_complete;
+ amb_port->tx_dma_desc->callback_param = amb_port;
+ amb_port->tx_bytes_requested = tx_bytes;
+ amb_port->tx_in_progress = true;
+ amb_port->tx_cookie = dmaengine_submit(amb_port->tx_dma_desc);
+ dma_async_issue_pending(amb_port->tx_dma_chan);
+
+ return 0;
+}
+
+static void serial_ambarella_start_next_tx(struct ambarella_uart_port *amb_port)
+{
+ struct circ_buf *xmit = &amb_port->port.state->xmit;
+ struct uart_port *port;
+ unsigned long tail, count;
+
+ port = &amb_port->port;
+
+ tail = (unsigned long)&xmit->buf[xmit->tail];
+ count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+ if (!count)
+ return;
+
+ if (count < AMBA_UART_MIN_DMA) {
+ wait_for_tx(port);
+ serial_ambarella_transmit_chars(port);
+ serial_ambarella_start_next_tx(amb_port);
+ } else {
+ serial_ambarella_start_tx_dma(amb_port, count);
+ }
+}
+
+static void serial_ambarella_start_tx(struct uart_port *port)
+{
+ struct ambarella_uart_port *amb_port;
+ u32 ier;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+
+ if (amb_port->txdma_used) {
+ if (uart_tx_stopped(port) || amb_port->tx_in_progress)
+ return;
+ serial_ambarella_start_next_tx(amb_port);
+ } else {
+ ier = readl_relaxed(port->membase + UART_IE_OFFSET);
+ writel_relaxed(ier | UART_IE_ETBEI, port->membase + UART_IE_OFFSET);
+
+ /*
+ * if FIFO status register is not provided, we have no idea about
+ * the Tx FIFO is full or not, so we need to wait for the Tx Empty
+ * Interrupt coming, then we can start to transfer data.
+ */
+ if (amb_port->less_reg)
+ return;
+
+ serial_ambarella_transmit_chars(port);
+ }
+}
+
+static void serial_ambarella_copy_rx_to_tty(struct ambarella_uart_port *amb_port,
+ struct tty_port *tty, int count)
+{
+ int copied;
+
+ amb_port->port.icount.rx += count;
+ if (!tty) {
+ dev_err(amb_port->port.dev, "No tty port\n");
+ return;
+ }
+
+ dma_sync_single_for_cpu(amb_port->port.dev, amb_port->rx_dma_buf_phys,
+ AMBA_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
+ copied = tty_insert_flip_string(tty, amb_port->rx_dma_buf_virt, count);
+ if (copied != count)
+ pr_warn_ratelimited("%s:Unable to push data ret %d_bytes %d\n",
+ __func__, copied, count);
+}
+
+static void serial_ambarella_rx_dma_complete(void *args)
+{
+ struct ambarella_uart_port *amb_port = args;
+ struct uart_port *u = &amb_port->port;
+ struct tty_port *port = &u->state->port;
+ int count = amb_port->rx_bytes_requested;
+ unsigned long flags;
+
+ spin_lock_irqsave(&u->lock, flags);
+ serial_ambarella_copy_rx_to_tty(amb_port, port, count);
+ tty_flip_buffer_push(port);
+ serial_ambarella_start_rx_dma(amb_port);
+ spin_unlock_irqrestore(&u->lock, flags);
+}
+
+static int serial_ambarella_start_rx_dma(struct ambarella_uart_port *amb_port)
+{
+ unsigned int count = AMBA_UART_RX_DMA_BUFFER_SIZE;
+
+ amb_port->rx_dma_desc = dmaengine_prep_slave_single(amb_port->rx_dma_chan,
+ amb_port->rx_dma_buf_phys, count, DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+
+ if (!amb_port->rx_dma_desc) {
+ dev_err(amb_port->port.dev, "Not able to get desc for Rx\n");
+ return -EIO;
+ }
+
+ amb_port->rx_dma_desc->callback = serial_ambarella_rx_dma_complete;
+ amb_port->rx_dma_desc->callback_param = amb_port;
+ dma_sync_single_for_device(amb_port->port.dev, amb_port->rx_dma_buf_phys,
+ count, DMA_FROM_DEVICE);
+ amb_port->rx_bytes_requested = count;
+ amb_port->rx_cookie = dmaengine_submit(amb_port->rx_dma_desc);
+ dma_async_issue_pending(amb_port->rx_dma_chan);
+
+ return 0;
+}
+
+static void serial_ambarella_stop_tx(struct uart_port *port)
+{
+ struct ambarella_uart_port *amb_port;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+ __serial_ambarella_stop_tx(port, amb_port->tx_fifo_fix);
+}
+
+static void serial_ambarella_stop_rx(struct uart_port *port)
+{
+ struct ambarella_uart_port *amb_port = (struct ambarella_uart_port *)(port->private_data);
+ struct tty_port *tty_port = &port->state->port;
+ struct dma_tx_state state;
+ size_t pending;
+ u32 ier;
+
+ if (amb_port->rxdma_used) {
+ if (!amb_port->rx_in_progress)
+ return;
+
+ ier = readl_relaxed(port->membase + UART_IE_OFFSET);
+ writel_relaxed(ier & ~UART_IE_ETOI, port->membase + UART_IE_OFFSET);
+
+ amb_port->rx_in_progress = false;
+ dmaengine_tx_status(amb_port->rx_dma_chan, amb_port->rx_cookie, &state);
+ dmaengine_terminate_async(amb_port->rx_dma_chan);
+
+ pending = amb_port->rx_bytes_requested - state.residue;
+ BUG_ON(pending > AMBA_UART_RX_DMA_BUFFER_SIZE);
+
+ serial_ambarella_copy_rx_to_tty(amb_port, tty_port, pending);
+ serial_ambarella_handle_rx_pio(amb_port, tty_port);
+
+ tty_flip_buffer_push(tty_port);
+ } else {
+ ier = readl_relaxed(port->membase + UART_IE_OFFSET);
+ writel_relaxed(ier & ~UART_IE_ERBFI, port->membase + UART_IE_OFFSET);
+ }
+
+}
+
+static unsigned int serial_ambarella_tx_empty(struct uart_port *port)
+{
+ unsigned int lsr;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ lsr = readl_relaxed(port->membase + UART_LS_OFFSET);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return ((lsr & (UART_LS_TEMT | UART_LS_THRE)) ==
+ (UART_LS_TEMT | UART_LS_THRE)) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int serial_ambarella_get_mctrl(struct uart_port *port)
+{
+ struct ambarella_uart_port *amb_port;
+ u32 ms, mctrl = 0;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+
+ if (amb_port->msr_used) {
+ ms = __serial_ambarella_read_ms(port, amb_port->tx_fifo_fix);
+
+ if (ms & UART_MS_CTS)
+ mctrl |= TIOCM_CTS;
+ if (ms & UART_MS_DSR)
+ mctrl |= TIOCM_DSR;
+ if (ms & UART_MS_RI)
+ mctrl |= TIOCM_RI;
+ if (ms & UART_MS_DCD)
+ mctrl |= TIOCM_CD;
+ }
+
+ return mctrl;
+}
+
+static void serial_ambarella_set_mctrl(struct uart_port *port,
+ unsigned int mctrl)
+{
+ struct ambarella_uart_port *amb_port;
+ u32 mcr, mcr_new = 0;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+
+ if (amb_port->msr_used) {
+ mcr = readl_relaxed(port->membase + UART_MC_OFFSET);
+
+ if (mctrl & TIOCM_DTR)
+ mcr_new |= UART_MC_DTR;
+ if (mctrl & TIOCM_RTS)
+ mcr_new |= UART_MC_RTS;
+ if (mctrl & TIOCM_OUT1)
+ mcr_new |= UART_MC_OUT1;
+ if (mctrl & TIOCM_OUT2)
+ mcr_new |= UART_MC_OUT2;
+ if (mctrl & TIOCM_LOOP)
+ mcr_new |= UART_MC_LB;
+
+ mcr_new |= amb_port->mcr;
+ if (mcr_new != mcr) {
+ if ((mcr & UART_MC_AFCE) == UART_MC_AFCE) {
+ mcr &= ~UART_MC_AFCE;
+ writel_relaxed(mcr, port->membase + UART_MC_OFFSET);
+ }
+ writel_relaxed(mcr_new, port->membase + UART_MC_OFFSET);
+ }
+ }
+}
+
+static void serial_ambarella_break_ctl(struct uart_port *port, int break_state)
+{
+ u32 lcr = readl_relaxed(port->membase + UART_LC_OFFSET);
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ if (break_state != 0)
+ writel_relaxed(lcr | UART_LC_BRK, port->membase + UART_LC_OFFSET);
+ else
+ writel_relaxed(lcr & ~UART_LC_BRK, port->membase + UART_LC_OFFSET);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void serial_ambarella_dma_channel_free(struct ambarella_uart_port *amb_port,
+ bool dma_to_memory)
+{
+ struct dma_chan *dma_chan;
+
+ if (dma_to_memory) {
+ kfree(amb_port->rx_dma_buf_virt);
+
+ dma_chan = amb_port->rx_dma_chan;
+ amb_port->rx_dma_chan = NULL;
+ amb_port->rx_dma_buf_phys = 0;
+ amb_port->rx_dma_buf_virt = NULL;
+ } else {
+ dma_unmap_single(amb_port->port.dev, amb_port->tx_dma_buf_phys,
+ UART_XMIT_SIZE, DMA_TO_DEVICE);
+ dma_chan = amb_port->tx_dma_chan;
+ amb_port->tx_dma_chan = NULL;
+ amb_port->tx_dma_buf_phys = 0;
+ amb_port->tx_dma_buf_virt = NULL;
+ }
+ dma_release_channel(dma_chan);
+}
+
+static int serial_ambarella_dma_channel_allocate(struct ambarella_uart_port *amb_port,
+ bool dma_to_memory)
+{
+ struct dma_chan *dma_chan;
+ struct dma_slave_config dma_sconfig;
+ dma_addr_t dma_phys;
+ unsigned char *dma_buf;
+ int ret;
+
+ dma_chan = dma_request_slave_channel(amb_port->port.dev,
+ dma_to_memory ? "rx" : "tx");
+ if (!dma_chan) {
+ ret = PTR_ERR(dma_chan);
+ if (ret != -EPROBE_DEFER)
+ dev_err(amb_port->port.dev,
+ "Dma channel is not available: %d\n", ret);
+ return ret;
+ }
+
+ if (dma_to_memory) {
+ /* use double buffer to handle rx */
+ dma_buf = kmalloc(AMBA_UART_RX_DMA_BUFFER_SIZE, GFP_KERNEL);
+ if (!dma_buf) {
+ dma_release_channel(dma_chan);
+ return -ENOMEM;
+ }
+ dma_phys = dma_map_single(dma_chan->device->dev,
+ dma_buf, AMBA_UART_RX_DMA_BUFFER_SIZE,
+ DMA_FROM_DEVICE);
+ if (dma_mapping_error(dma_chan->device->dev, dma_phys)) {
+ dev_err(dma_chan->device->dev,
+ "failed mapping rx dma buffer\n");
+ dma_release_channel(dma_chan);
+ return -ENOMEM;
+ }
+ } else {
+ dma_phys = dma_map_single(dma_chan->device->dev,
+ amb_port->port.state->xmit.buf, UART_XMIT_SIZE,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(dma_chan->device->dev, dma_phys)) {
+ dev_err(dma_chan->device->dev,
+ "failed mapping tx dma buffer\n");
+ dma_release_channel(dma_chan);
+ return -ENOMEM;
+ }
+ dma_buf = amb_port->port.state->xmit.buf;
+ }
+
+ if (dma_to_memory) {
+ dma_sconfig.src_addr = amb_port->port.mapbase + UART_DMAF_OFFSET;
+ dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconfig.src_maxburst = 8;
+ dma_sconfig.direction = DMA_DEV_TO_MEM;
+ } else {
+ dma_sconfig.dst_addr = amb_port->port.mapbase + UART_DMAF_OFFSET;
+ dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconfig.dst_maxburst = 16;
+ dma_sconfig.direction = DMA_MEM_TO_DEV;
+ }
+
+ ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
+ if (ret < 0) {
+ dev_err(amb_port->port.dev,
+ "Dma slave config failed, err = %d\n", ret);
+ goto scrub;
+ }
+
+ if (dma_to_memory) {
+ amb_port->rx_dma_chan = dma_chan;
+ amb_port->rx_dma_buf_virt = dma_buf;
+ amb_port->rx_dma_buf_phys = dma_phys;
+ } else {
+ amb_port->tx_dma_chan = dma_chan;
+ amb_port->tx_dma_buf_virt = dma_buf;
+ amb_port->tx_dma_buf_phys = dma_phys;
+ }
+ return 0;
+
+scrub:
+ serial_ambarella_dma_channel_free(amb_port, dma_to_memory);
+ return ret;
+}
+
+static int serial_ambarella_startup(struct uart_port *port)
+{
+ int rval = 0;
+ struct ambarella_uart_port *amb_port;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+
+ if (amb_port->txdma_used) {
+ rval = serial_ambarella_dma_channel_allocate(amb_port, false);
+ if (rval < 0) {
+ dev_err(amb_port->port.dev, "Tx Dma allocation failed, err = %d\n", rval);
+ return -EBUSY;
+ }
+ }
+
+ if (amb_port->rxdma_used) {
+ rval = serial_ambarella_dma_channel_allocate(amb_port, true);
+ if (rval < 0) {
+ dev_err(amb_port->port.dev, "Rx Dma allocation failed, err = %d\n", rval);
+ return -EBUSY;
+ }
+
+ rval = serial_ambarella_start_rx_dma(amb_port);
+ if (rval < 0) {
+ dev_err(amb_port->port.dev, "Not able to start Rx DMA\n");
+ return rval;
+ }
+ amb_port->rx_in_progress = true;
+ }
+
+ serial_ambarella_hw_setup(port);
+
+ return rval;
+}
+
+static void serial_ambarella_hw_deinit(struct ambarella_uart_port *amb_port)
+{
+ struct uart_port *port = &amb_port->port;
+
+ /* Disable interrupts */
+ writel_relaxed(0, port->membase + UART_IE_OFFSET);
+ /* Disable DMA */
+ writel_relaxed(0, port->membase + UART_DMAE_OFFSET);
+ /* Reset the Rx and Tx FIFOs */
+ writel_relaxed(UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR,
+ port->membase + UART_SRR_OFFSET);
+}
+
+static void serial_ambarella_shutdown(struct uart_port *port)
+{
+ struct ambarella_uart_port *amb_port;
+ u32 lcr;
+ unsigned long flags;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ if (amb_port->txdma_used || amb_port->rxdma_used) {
+ serial_ambarella_hw_deinit(amb_port);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ if (amb_port->txdma_used) {
+ dmaengine_terminate_all(amb_port->tx_dma_chan);
+ serial_ambarella_dma_channel_free(amb_port, false);
+ amb_port->tx_in_progress = false;
+ }
+ if (amb_port->rxdma_used) {
+ dmaengine_terminate_all(amb_port->rx_dma_chan);
+ serial_ambarella_dma_channel_free(amb_port, true);
+ amb_port->rx_in_progress = false;
+ }
+
+ spin_lock_irqsave(&port->lock, flags);
+ }
+
+ lcr = readl_relaxed(port->membase + UART_LC_OFFSET);
+ writel_relaxed(lcr & ~UART_LC_BRK, port->membase + UART_LC_OFFSET);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void serial_ambarella_set_termios(struct uart_port *port,
+ struct ktermios *termios, const struct ktermios *old)
+{
+ struct ambarella_uart_port *amb_port;
+ unsigned int baud, quot;
+ u32 lc = 0x0;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+ amb_port->c_cflag = termios->c_cflag;
+
+ port->uartclk = clk_get_rate(amb_port->uart_pll);
+ switch (termios->c_cflag & CSIZE) {
+ case CS5:
+ lc |= UART_LC_CLS_5_BITS;
+ break;
+ case CS6:
+ lc |= UART_LC_CLS_6_BITS;
+ break;
+ case CS7:
+ lc |= UART_LC_CLS_7_BITS;
+ break;
+ case CS8:
+ default:
+ lc |= UART_LC_CLS_8_BITS;
+ break;
+ }
+
+ if (termios->c_cflag & CSTOPB)
+ lc |= UART_LC_STOP_2BIT;
+ else
+ lc |= UART_LC_STOP_1BIT;
+
+ if (termios->c_cflag & PARENB) {
+ if (termios->c_cflag & PARODD)
+ lc |= (UART_LC_PEN | UART_LC_ODD_PARITY);
+ else
+ lc |= (UART_LC_PEN | UART_LC_EVEN_PARITY);
+ }
+
+ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+ quot = uart_get_divisor(port, baud);
+
+ disable_irq(port->irq);
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
+ if (termios->c_iflag & INPCK)
+ port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+ if (termios->c_iflag & (BRKINT | PARMRK))
+ port->read_status_mask |= UART_LSR_BI;
+
+ port->ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+ if (termios->c_iflag & IGNBRK) {
+ port->ignore_status_mask |= UART_LSR_BI;
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= UART_LSR_OE;
+ }
+ if ((termios->c_cflag & CREAD) == 0)
+ port->ignore_status_mask |= UART_LSR_DR;
+
+ if ((termios->c_cflag & CRTSCTS) == 0) {
+ amb_port->mcr &= ~UART_MC_AFCE;
+ port->status &= ~UPSTAT_AUTOCTS;
+ } else {
+ amb_port->mcr |= UART_MC_AFCE;
+ port->status |= UPSTAT_AUTOCTS;
+ }
+
+ writel_relaxed(UART_LC_DLAB, port->membase + UART_LC_OFFSET);
+ writel_relaxed(quot & 0xff, port->membase + UART_DLL_OFFSET);
+ writel_relaxed((quot >> 8) & 0xff, port->membase + UART_DLH_OFFSET);
+ writel_relaxed(lc, port->membase + UART_LC_OFFSET);
+ if (UART_ENABLE_MS(port, termios->c_cflag))
+ __serial_ambarella_enable_ms(port);
+ else
+ __serial_ambarella_disable_ms(port);
+ serial_ambarella_set_mctrl(port, port->mctrl);
+
+ enable_irq(port->irq);
+}
+
+static void serial_ambarella_pm(struct uart_port *port,
+ unsigned int state, unsigned int oldstate)
+{
+}
+
+static void serial_ambarella_release_port(struct uart_port *port)
+{
+}
+
+static int serial_ambarella_request_port(struct uart_port *port)
+{
+ return 0;
+}
+
+static void serial_ambarella_config_port(struct uart_port *port, int flags)
+{
+}
+
+static int serial_ambarella_verify_port(struct uart_port *port,
+ struct serial_struct *ser)
+{
+ int rval = 0;
+
+ if (ser->type != PORT_UNKNOWN && ser->type != PORT_UART00)
+ rval = -EINVAL;
+ if (port->irq != ser->irq)
+ rval = -EINVAL;
+ if (ser->io_type != SERIAL_IO_MEM)
+ rval = -EINVAL;
+
+ return rval;
+}
+
+static const char *serial_ambarella_type(struct uart_port *port)
+{
+ return "ambuart";
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static void serial_ambarella_poll_put_char(struct uart_port *port,
+ unsigned char chr)
+{
+ struct ambarella_uart_port *amb_port;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+ if (!port->suspended) {
+ wait_for_tx(port);
+ writel_relaxed(chr, port->membase + UART_TH_OFFSET);
+ }
+}
+
+static int serial_ambarella_poll_get_char(struct uart_port *port)
+{
+ struct ambarella_uart_port *amb_port;
+
+ amb_port = (struct ambarella_uart_port *)(port->private_data);
+ if (!port->suspended) {
+ wait_for_rx(port);
+ return readl_relaxed(port->membase + UART_RB_OFFSET);
+ }
+ return 0;
+}
+#endif
+
+static const struct uart_ops serial_ambarella_pops = {
+ .tx_empty = serial_ambarella_tx_empty,
+ .set_mctrl = serial_ambarella_set_mctrl,
+ .get_mctrl = serial_ambarella_get_mctrl,
+ .stop_tx = serial_ambarella_stop_tx,
+ .start_tx = serial_ambarella_start_tx,
+ .stop_rx = serial_ambarella_stop_rx,
+ .enable_ms = serial_ambarella_enable_ms,
+ .break_ctl = serial_ambarella_break_ctl,
+ .startup = serial_ambarella_startup,
+ .shutdown = serial_ambarella_shutdown,
+ .set_termios = serial_ambarella_set_termios,
+ .pm = serial_ambarella_pm,
+ .type = serial_ambarella_type,
+ .release_port = serial_ambarella_release_port,
+ .request_port = serial_ambarella_request_port,
+ .config_port = serial_ambarella_config_port,
+ .verify_port = serial_ambarella_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_put_char = serial_ambarella_poll_put_char,
+ .poll_get_char = serial_ambarella_poll_get_char,
+#endif
+};
+
+/* ==========================================================================*/
+#if defined(CONFIG_SERIAL_AMBARELLA_CONSOLE)
+
+static struct uart_driver serial_ambarella_reg;
+static void ambarella_uart_of_enumerate(void);
+
+static void serial_ambarella_console_putchar(struct uart_port *port, unsigned char ch)
+{
+ wait_for_tx(port);
+ writel_relaxed(ch, port->membase + UART_TH_OFFSET);
+}
+
+static void serial_ambarella_console_write(struct console *co,
+ const char *s, unsigned int count)
+{
+ struct uart_port *port;
+ int locked = 1;
+ unsigned long flags;
+
+ port = &ambarella_port[co->index].port;
+
+ if (!port->suspended) {
+ local_irq_save(flags);
+ if (port->sysrq) {
+ locked = 0;
+ } else if (oops_in_progress) {
+ locked = spin_trylock(&port->lock);
+ } else {
+ spin_lock(&port->lock);
+ locked = 1;
+ }
+
+ uart_console_write(port, s, count,
+ serial_ambarella_console_putchar);
+ wait_for_tx(port);
+
+ if (locked)
+ spin_unlock(&port->lock);
+ local_irq_restore(flags);
+ }
+}
+
+static int __init serial_ambarella_console_setup(struct console *co,
+ char *options)
+{
+ struct uart_port *port;
+ int baud = 115200, bits = 8, parity = 'n', flow = 'n';
+
+ if (co->index < 0 || co->index >= serial_ambarella_reg.nr)
+ co->index = 0;
+
+ port = &ambarella_port[co->index].port;
+ if (!port->membase) {
+ pr_err("No device available for serial console\n");
+ return -ENODEV;
+ }
+
+ port->ops = &serial_ambarella_pops;
+ port->private_data = &ambarella_port[co->index];
+ port->line = co->index;
+
+ serial_ambarella_hw_setup(port);
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+ return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console serial_ambarella_console = {
+ .name = "ttyS",
+ .write = serial_ambarella_console_write,
+ .device = uart_console_device,
+ .setup = serial_ambarella_console_setup,
+ .flags = CON_PRINTBUFFER | CON_ANYTIME,
+ .index = -1,
+ .data = &serial_ambarella_reg,
+};
+
+#ifdef CONFIG_PM
+/* when no_console_suspend is specified in cmdline, Linux thought the console
+ * would never suspend. But actually we may put system into STR and power off
+ * the SoC, so the console must be initialized when system exit STR.
+ *
+ * NOTE: We MUST ensure that no information will be output via UART until
+ * syscore_resume() is completed, otherwise the UART may be in deadloop.
+ */
+static void serial_ambarella_console_resume(void)
+{
+ struct console *co = &serial_ambarella_console;
+ struct ambarella_uart_port *amb_port;
+ struct uart_port *port;
+ struct ktermios termios;
+
+ if (console_suspend_enabled)
+ return;
+
+ if (co->index < 0 || co->index >= serial_ambarella_reg.nr)
+ return;
+
+ amb_port = &ambarella_port[co->index];
+
+ port = &ambarella_port[co->index].port;
+ if (!port->membase)
+ return;
+
+ clk_set_parent(amb_port->uart_pll, amb_port->parent_pll);
+ clk_set_rate(amb_port->uart_pll, amb_port->clk_rate);
+
+ clear_bit(AMBA_UART_RESET_FLAG, &amb_port->flags);
+ serial_ambarella_hw_setup(port);
+
+ memset(&termios, 0, sizeof(struct ktermios));
+ termios.c_cflag = amb_port->c_cflag;
+ port->ops->set_termios(port, &termios, NULL);
+}
+
+static int serial_ambarella_console_suspend(void)
+{
+ struct console *co = &serial_ambarella_console;
+ struct ambarella_uart_port *amb_port;
+
+ if (console_suspend_enabled)
+ return 0;
+
+ if (co->index < 0 || co->index >= serial_ambarella_reg.nr)
+ return 0;
+
+ amb_port = &ambarella_port[co->index];
+
+ clk_set_parent(amb_port->uart_pll, NULL);
+
+ return 0;
+}
+
+static struct syscore_ops ambarella_console_syscore_ops = {
+ .resume = serial_ambarella_console_resume,
+ .suspend = serial_ambarella_console_suspend,
+};
+#endif
+
+static int __init serial_ambarella_console_init(void)
+{
+ struct device_node *np;
+ const char *name;
+ int id;
+
+ ambarella_uart_of_enumerate();
+
+ name = of_get_property(of_chosen, "linux,stdout-path", NULL);
+ if (name == NULL)
+ return -ENODEV;
+
+ np = of_find_node_by_path(name);
+ if (!np)
+ return -ENODEV;
+
+ id = of_alias_get_id(np, "serial");
+ if (id < 0 || id >= serial_ambarella_reg.nr)
+ return -ENODEV;
+
+ ambarella_port[id].port.membase = of_iomap(np, 0);
+
+ ambarella_port[id].uart_pll = of_clk_get(np, 0);
+ if (IS_ERR(ambarella_port[id].uart_pll)) {
+ pr_err("No clock available for serial console\n");
+ return -ENODEV;
+ }
+ ambarella_port[id].parent_pll = clk_get_parent(ambarella_port[id].uart_pll);
+
+ register_console(&serial_ambarella_console);
+
+#ifdef CONFIG_PM
+ register_syscore_ops(&ambarella_console_syscore_ops);
+#endif
+
+ return 0;
+}
+
+console_initcall(serial_ambarella_console_init);
+
+static void serial_ambarella_console_early_write(struct console *con, const char *s,
+ unsigned int count)
+{
+ struct earlycon_device *dev = con->data;
+
+ uart_console_write(&dev->port, s, count, serial_ambarella_console_putchar);
+}
+
+static int __init serial_ambarella_console_early_setup(struct earlycon_device *dev,
+ const char *opt)
+{
+ if (!dev->port.membase)
+ return -ENODEV;
+
+ dev->con->write = serial_ambarella_console_early_write;
+
+ return 0;
+}
+OF_EARLYCON_DECLARE(ambarella_uart, "ambarella,uart", serial_ambarella_console_early_setup);
+
+#define AMBARELLA_CONSOLE (&serial_ambarella_console)
+#else
+#define AMBARELLA_CONSOLE NULL
+#endif
+
+/* ==========================================================================*/
+static struct uart_driver serial_ambarella_reg = {
+ .owner = THIS_MODULE,
+ .driver_name = "ambarella-uart",
+ .dev_name = "ttyS",
+ .major = TTY_MAJOR,
+ .minor = 64,
+ .nr = 0,
+ .cons = AMBARELLA_CONSOLE,
+};
+
+static int serial_ambarella_probe(struct platform_device *pdev)
+{
+ struct ambarella_uart_port *amb_port;
+ struct resource *mem;
+ struct pinctrl *pinctrl;
+ int irq, id, rval = 0;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!mem) {
+ dev_err(&pdev->dev, "no mem resource!\n");
+ return -ENODEV;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "no irq resource!\n");
+ return -ENODEV;
+ }
+
+ id = of_alias_get_id(pdev->dev.of_node, "serial");
+ if (id < 0 || id >= serial_ambarella_reg.nr) {
+ dev_err(&pdev->dev, "Invalid uart ID %d!\n", id);
+ return -ENXIO;
+ }
+
+ pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
+ if (IS_ERR(pinctrl)) {
+ dev_err(&pdev->dev, "Failed to request pinctrl\n");
+ return PTR_ERR(pinctrl);
+ }
+
+ amb_port = &ambarella_port[id];
+
+ amb_port->uart_pll = of_clk_get(pdev->dev.of_node, 0);
+ if (IS_ERR(amb_port->uart_pll)) {
+ dev_err(&pdev->dev, "Get uart clk failed!\n");
+ return PTR_ERR(amb_port->uart_pll);
+ }
+ amb_port->parent_pll = clk_get_parent(amb_port->uart_pll);
+
+ amb_port->mcr = DEFAULT_AMBARELLA_UART_MCR;
+ /* check if using modem status register, available for non-uart0. */
+ if (of_find_property(pdev->dev.of_node, "amb,msr-used", NULL))
+ amb_port->msr_used = 1;
+ else
+ amb_port->msr_used = 0;
+ /* check if workaround for tx fifo is needed */
+ if (of_find_property(pdev->dev.of_node, "amb,tx-fifo-fix", NULL))
+ amb_port->tx_fifo_fix = 1;
+ else
+ amb_port->tx_fifo_fix = 0;
+ /* check if registers like FIFO status register are NOT provided. */
+ if (of_find_property(pdev->dev.of_node, "amb,less-reg", NULL))
+ amb_port->less_reg = 1;
+ else
+ amb_port->less_reg = 0;
+ /* check if using tx dma */
+ if (of_find_property(pdev->dev.of_node, "amb,txdma-used", NULL)) {
+ amb_port->txdma_used = 1;
+ dev_info(&pdev->dev, "Serial[%d] use txdma\n", id);
+ } else
+ amb_port->txdma_used = 0;
+ /* check if using rx dma */
+ if (of_find_property(pdev->dev.of_node, "amb,rxdma-used", NULL)) {
+ amb_port->rxdma_used = 1;
+ dev_info(&pdev->dev, "Serial[%d] use rxdma\n", id);
+ } else {
+ amb_port->rxdma_used = 0;
+ }
+ /* check if ignore frame error */
+ if (of_find_property(pdev->dev.of_node, "amb,ignore-fe", NULL)) {
+ amb_port->ignore_fe = 1;
+ dev_info(&pdev->dev, "Serial[%d] ignores FE\n", id);
+ } else {
+ amb_port->ignore_fe = 0;
+ }
+
+ amb_port->port.dev = &pdev->dev;
+ amb_port->port.type = PORT_UART00;
+ amb_port->port.iotype = UPIO_MEM;
+ amb_port->port.fifosize = UART_FIFO_SIZE;
+ amb_port->port.uartclk = clk_get_rate(amb_port->uart_pll);
+ amb_port->port.ops = &serial_ambarella_pops;
+ amb_port->port.private_data = amb_port;
+ amb_port->port.irq = irq;
+ amb_port->port.line = id;
+ amb_port->port.mapbase = mem->start;
+ amb_port->port.membase =
+ devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
+ if (!amb_port->port.membase) {
+ dev_err(&pdev->dev, "can't ioremap UART\n");
+ return -ENOMEM;
+ }
+
+ rval = uart_add_one_port(&serial_ambarella_reg, &amb_port->port);
+ if (rval < 0)
+ dev_err(&pdev->dev, "failed to add port: %d, %d!\n", id, rval);
+
+ rval = request_irq(irq, serial_ambarella_irq, IRQF_TRIGGER_HIGH,
+ dev_name(amb_port->port.dev), &amb_port->port);
+
+ platform_set_drvdata(pdev, amb_port);
+
+ return rval;
+}
+
+static int serial_ambarella_remove(struct platform_device *pdev)
+{
+ struct ambarella_uart_port *amb_port;
+ int rval = 0;
+
+ amb_port = platform_get_drvdata(pdev);
+ rval = uart_remove_one_port(&serial_ambarella_reg, &amb_port->port);
+ if (rval < 0)
+ dev_err(&pdev->dev, "uart_remove_one_port fail %d!\n", rval);
+ free_irq(amb_port->port.irq, &amb_port->port);
+
+ dev_notice(&pdev->dev,
+ "Remove Ambarella Media Processor UART.\n");
+
+ return rval;
+}
+
+#ifdef CONFIG_PM
+static int serial_ambarella_suspend(struct platform_device *pdev,
+ pm_message_t state)
+{
+ struct ambarella_uart_port *amb_port;
+ int rval = 0;
+
+ amb_port = platform_get_drvdata(pdev);
+ rval = uart_suspend_port(&serial_ambarella_reg, &amb_port->port);
+
+ amb_port->clk_rate = clk_get_rate(amb_port->uart_pll);
+ clk_set_parent(amb_port->uart_pll, NULL);
+
+ dev_dbg(&pdev->dev, "%s exit with %d @ %d\n",
+ __func__, rval, state.event);
+
+ return rval;
+}
+
+static int serial_ambarella_resume(struct platform_device *pdev)
+{
+ struct ambarella_uart_port *amb_port;
+ int rval = 0;
+
+ amb_port = platform_get_drvdata(pdev);
+
+ clk_set_parent(amb_port->uart_pll, amb_port->parent_pll);
+ clk_set_rate(amb_port->uart_pll, amb_port->clk_rate);
+
+ clear_bit(AMBA_UART_RESET_FLAG, &amb_port->flags);
+ serial_ambarella_hw_setup(&amb_port->port);
+
+ rval = uart_resume_port(&serial_ambarella_reg, &amb_port->port);
+
+ dev_dbg(&pdev->dev, "%s exit with %d\n", __func__, rval);
+
+ return rval;
+}
+#endif
+
+static const struct of_device_id ambarella_serial_of_match[] = {
+ { .compatible = "ambarella,uart" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ambarella_serial_of_match);
+
+static void ambarella_uart_of_enumerate(void)
+{
+ struct device_node *np;
+ int nr = 0;
+
+ if (serial_ambarella_reg.nr <= 0) {
+ for_each_matching_node(np, ambarella_serial_of_match) {
+ nr++;
+ }
+
+ if (nr > AMBA_UART_MAX_NUM)
+ nr = AMBA_UART_MAX_NUM;
+
+ serial_ambarella_reg.nr = nr;
+ }
+}
+
+
+static struct platform_driver serial_ambarella_driver = {
+ .probe = serial_ambarella_probe,
+ .remove = serial_ambarella_remove,
+#ifdef CONFIG_PM
+ .suspend = serial_ambarella_suspend,
+ .resume = serial_ambarella_resume,
+#endif
+ .driver = {
+ .name = "ambarella-uart",
+ .of_match_table = ambarella_serial_of_match,
+ },
+};
+
+static int __init serial_ambarella_init(void)
+{
+ int rval;
+
+ ambarella_uart_of_enumerate();
+
+ rval = uart_register_driver(&serial_ambarella_reg);
+ if (rval < 0)
+ return rval;
+
+ rval = platform_driver_register(&serial_ambarella_driver);
+ if (rval < 0)
+ uart_unregister_driver(&serial_ambarella_reg);
+
+ return rval;
+}
+
+static void __exit serial_ambarella_exit(void)
+{
+ platform_driver_unregister(&serial_ambarella_driver);
+ uart_unregister_driver(&serial_ambarella_reg);
+}
+
+module_init(serial_ambarella_init);
+module_exit(serial_ambarella_exit);
+
+MODULE_AUTHOR("Anthony Ginger");
+MODULE_DESCRIPTION("Ambarella Media Processor UART driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ambarella-uart");
diff --git a/drivers/tty/serial/ambarella_uart.h b/drivers/tty/serial/ambarella_uart.h
new file mode 100644
index 000000000000..991fee680e16
--- /dev/null
+++ b/drivers/tty/serial/ambarella_uart.h
@@ -0,0 +1,120 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2023, Ambarella, Inc.
+ */
+
+#ifndef __AMBARELLA_UART_H__
+#define __AMBARELLA_UART_H__
+
+/* ==========================================================================*/
+#define UART_RB_OFFSET 0x00
+#define UART_TH_OFFSET 0x00
+#define UART_DLL_OFFSET 0x00
+#define UART_IE_OFFSET 0x04
+#define UART_DLH_OFFSET 0x04
+#define UART_II_OFFSET 0x08
+#define UART_FC_OFFSET 0x08
+#define UART_LC_OFFSET 0x0c
+#define UART_MC_OFFSET 0x10
+#define UART_LS_OFFSET 0x14
+#define UART_MS_OFFSET 0x18
+#define UART_SC_OFFSET 0x1c /* Byte */
+#define UART_DMAE_OFFSET 0x28
+#define UART_DMAF_OFFSET 0x40 /* DMA fifo */
+#define UART_US_OFFSET 0x7c
+#define UART_TFL_OFFSET 0x80
+#define UART_RFL_OFFSET 0x84
+#define UART_SRR_OFFSET 0x88
+#define UART_RTR_OFFSET 0xac
+#define UART_TTR_OFFSET 0xb0
+
+/* UART[x]_IE_REG */
+#define UART_IE_PTIME 0x80
+#define UART_IE_ETOI 0x20
+#define UART_IE_EBDI 0x10
+#define UART_IE_EDSSI 0x08
+#define UART_IE_ELSI 0x04
+#define UART_IE_ETBEI 0x02
+#define UART_IE_ERBFI 0x01
+
+/* UART[x]_II_REG */
+#define UART_II_MODEM_STATUS_CHANGED 0x00
+#define UART_II_NO_INT_PENDING 0x01
+#define UART_II_THR_EMPTY 0x02
+#define UART_II_RCV_DATA_AVAIL 0x04
+#define UART_II_RCV_STATUS 0x06
+#define UART_II_CHAR_TIMEOUT 0x0c
+
+/* UART[x]_FC_REG */
+#define UART_FC_RX_ONECHAR 0x00
+#define UART_FC_RX_QUARTER_FULL 0x40
+#define UART_FC_RX_HALF_FULL 0x80
+#define UART_FC_RX_2_TO_FULL 0xc0
+#define UART_FC_TX_EMPTY 0x00
+#define UART_FC_TX_2_IN_FIFO 0x10
+#define UART_FC_TX_QUATER_IN_FIFO 0x20
+#define UART_FC_TX_HALF_IN_FIFO 0x30
+#define UART_FC_DMA_SELECT 0x08
+#define UART_FC_XMITR 0x04
+#define UART_FC_RCVRR 0x02
+#define UART_FC_FIFOE 0x01
+
+/* UART[x]_LC_REG */
+#define UART_LC_DLAB 0x80
+#define UART_LC_BRK 0x40
+#define UART_LC_EVEN_PARITY 0x10
+#define UART_LC_ODD_PARITY 0x00
+#define UART_LC_PEN 0x08
+#define UART_LC_STOP_2BIT 0x04
+#define UART_LC_STOP_1BIT 0x00
+#define UART_LC_CLS_8_BITS 0x03
+#define UART_LC_CLS_7_BITS 0x02
+#define UART_LC_CLS_6_BITS 0x01
+#define UART_LC_CLS_5_BITS 0x00
+/* quick defs */
+#define UART_LC_8N1 0x03
+#define UART_LC_7E1 0x0a
+
+/* UART[x]_MC_REG */
+#define UART_MC_SIRE 0x40
+#define UART_MC_AFCE 0x20
+#define UART_MC_LB 0x10
+#define UART_MC_OUT2 0x08
+#define UART_MC_OUT1 0x04
+#define UART_MC_RTS 0x02
+#define UART_MC_DTR 0x01
+
+/* UART[x]_LS_REG */
+#define UART_LS_FERR 0x80
+#define UART_LS_TEMT 0x40
+#define UART_LS_THRE 0x20
+#define UART_LS_BI 0x10
+#define UART_LS_FE 0x08
+#define UART_LS_PE 0x04
+#define UART_LS_OE 0x02
+#define UART_LS_DR 0x01
+
+/* UART[x]_MS_REG */
+#define UART_MS_DCD 0x80
+#define UART_MS_RI 0x40
+#define UART_MS_DSR 0x20
+#define UART_MS_CTS 0x10
+#define UART_MS_DDCD 0x08
+#define UART_MS_TERI 0x04
+#define UART_MS_DDSR 0x02
+#define UART_MS_DCTS 0x01
+
+/* UART[x]_US_REG */
+#define UART_US_RFF 0x10
+#define UART_US_RFNE 0x08
+#define UART_US_TFE 0x04
+#define UART_US_TFNF 0x02
+#define UART_US_BUSY 0x01
+
+/* ==========================================================================*/
+#define UART_FIFO_SIZE (16)
+
+#define DEFAULT_AMBARELLA_UART_MCR (0)
+#define DEFAULT_AMBARELLA_UART_IER (UART_IE_ELSI | UART_IE_ERBFI | UART_IE_ETOI)
+
+#endif /* __AMBARELLA_UART_H__ */
--
2.34.1
