Hi everyone,
This is the serial driver supports Blackfin processors. It is designed for the serial core framework.
Thanks Alan and Aubrey. Aubrey update the patch according Alan's review.
Sorry for start a new thread, because I change a new email client.
Signed-off-by: Bryan Wu <[email protected]>
---
drivers/serial/Kconfig | 94 ++++
drivers/serial/Makefile | 1
drivers/serial/bfin_5xx.c | 1027 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/serial_core.h | 3
4 files changed, 1125 insertions(+)
Index: linux-2.6/drivers/serial/Kconfig
===================================================================
--- linux-2.6.orig/drivers/serial/Kconfig 2007-02-06 01:13:42.000000000 +0800
+++ linux-2.6/drivers/serial/Kconfig 2007-02-06 01:20:13.000000000 +0800
@@ -498,6 +498,100 @@
your boot loader (lilo or loadlin) about how to pass options to the
kernel at boot time.)
+config SERIAL_BFIN
+ tristate "Blackfin serial port support (EXPERIMENTAL)"
+ depends on BFIN && EXPERIMENTAL
+ select SERIAL_CORE
+ select SERIAL_BFIN_UART0 if (BF531 || BF532 || BF533 || BF561)
+ help
+ Add support for the built-in UARTs on the Blackfin.
+
+ To compile this driver as a module, choose M here: the
+ module will be called bfin_5xx.
+
+config SERIAL_BFIN_CONSOLE
+ bool "Console on Blackfin serial port"
+ depends on SERIAL_BFIN
+ select SERIAL_CORE_CONSOLE
+
+choice
+ prompt "Blackfin UART Mode"
+ depends on SERIAL_BFIN
+ default SERIAL_BFIN_DMA
+ help
+ This driver supports the built-in serial ports of the Blackfin family
+ of CPUs
+
+config SERIAL_BFIN_DMA
+ bool "Blackfin UART DMA mode"
+ depends on DMA_UNCACHED_1M
+ help
+ This driver works under DMA mode. If this option is selected, the
+ blackfin simple dma driver is also enabled.
+
+config SERIAL_BFIN_PIO
+ bool "Blackfin UART PIO mode"
+ help
+ This driver works under PIO mode.
+
+endchoice
+
+config SERIAL_BFIN_UART0
+ bool "Enable UART0"
+ depends on SERIAL_BFIN
+ help
+ Enable UART0
+
+config BFIN_UART0_CTSRTS
+ bool "Enable UART0 hardware flow control"
+ depends on SERIAL_BFIN_UART0
+ help
+ Enable hardware flow control in the driver. Using GPIO emulate the CTS/RTS
+ signal.
+
+config UART0_CTS_PIN
+ int "UART0 CTS pin"
+ depends on BFIN_UART0_CTSRTS
+ default 23
+ help
+ The default pin is GPIO_GP7.
+ Refer to ./include/asm-blackfin/gpio.h to see the GPIO map.
+
+config UART0_RTS_PIN
+ int "UART0 RTS pin"
+ depends on BFIN_UART0_CTSRTS
+ default 22
+ help
+ The default pin is GPIO_GP6.
+ Refer to ./include/asm-blackfin/gpio.h to see the GPIO map.
+
+config SERIAL_BFIN_UART1
+ bool "Enable UART1"
+ depends on SERIAL_BFIN && BF537
+ help
+ Enable UART1
+
+config BFIN_UART1_CTSRTS
+ bool "Enable UART1 hardware flow control"
+ depends on SERIAL_BFIN_UART1
+ help
+ Enable hardware flow control in the driver. Using GPIO emulate the CTS/RTS
+ signal.
+
+config UART1_CTS_PIN
+ int "UART1 CTS pin"
+ depends on BFIN_UART1_CTSRTS
+ default -1
+ help
+ Refer to ./include/asm-blackfin/gpio.h to see the GPIO map.
+
+config UART1_RTS_PIN
+ int "UART1 RTS pin"
+ depends on BFIN_UART1_CTSRTS
+ default -1
+ help
+ Refer to ./include/asm-blackfin/gpio.h to see the GPIO map.
+
config SERIAL_IMX
bool "IMX serial port support"
depends on ARM && ARCH_IMX
Index: linux-2.6/drivers/serial/Makefile
===================================================================
--- linux-2.6.orig/drivers/serial/Makefile 2007-02-06 01:13:42.000000000 +0800
+++ linux-2.6/drivers/serial/Makefile 2007-02-06 01:20:13.000000000 +0800
@@ -26,6 +26,7 @@
obj-$(CONFIG_SERIAL_CLPS711X) += clps711x.o
obj-$(CONFIG_SERIAL_PXA) += pxa.o
obj-$(CONFIG_SERIAL_SA1100) += sa1100.o
+obj-$(CONFIG_SERIAL_BFIN) += bfin_5xx.o
obj-$(CONFIG_SERIAL_S3C2410) += s3c2410.o
obj-$(CONFIG_SERIAL_SUNCORE) += suncore.o
obj-$(CONFIG_SERIAL_SUNHV) += sunhv.o
Index: linux-2.6/drivers/serial/bfin_5xx.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/drivers/serial/bfin_5xx.c 2007-02-06 11:12:47.000000000 +0800
@@ -0,0 +1,1027 @@
+/*
+ * File: drivers/serial/bfin_5xx.c
+ * Based on: Based on drivers/serial/sa1100.c
+ * Author: Aubrey Li <[email protected]>
+ *
+ * Created:
+ * Description: Driver for blackfin 5xx serial ports
+ *
+ * Rev: $Id: bfin_5xx.c,v 1.19 2006/09/24 02:33:53 aubrey Exp $
+ *
+ * Modified:
+ * Copyright 2006 Analog Devices Inc.
+ *
+ * Bugs: Enter bugs at http://blackfin.uclinux.org/
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#if defined(CONFIG_SERIAL_BFIN_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+
+#include <asm/gpio.h>
+#include <asm/mach/bfin_serial_5xx.h>
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+#include <linux/dma-mapping.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/cacheflush.h>
+#endif
+
+/* We've been assigned a range on the "Low-density serial ports" major */
+#define SERIAL_BFIN_MAJOR TTY_MAJOR
+#define MINOR_START 64
+
+/*
+ * Setup for console. Argument comes from the menuconfig
+ */
+
+#if defined(CONFIG_BAUD_9600)
+#define CONSOLE_BAUD_RATE 9600
+#elif defined(CONFIG_BAUD_19200)
+#define CONSOLE_BAUD_RATE 19200
+#elif defined(CONFIG_BAUD_38400)
+#define CONSOLE_BAUD_RATE 38400
+#elif defined(CONFIG_BAUD_57600)
+#define CONSOLE_BAUD_RATE 57600
+#elif defined(CONFIG_BAUD_115200)
+#define CONSOLE_BAUD_RATE 115200
+#endif
+
+#define DMA_RX_XCOUNT 512
+#define DMA_RX_YCOUNT (PAGE_SIZE / DMA_RX_XCOUNT)
+
+#define DMA_RX_FLUSH_JIFFIES 5
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
+#else
+static void bfin_serial_do_work(struct work_struct *work);
+static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
+static void local_put_char(struct bfin_serial_port *uart, char ch);
+#endif
+
+static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
+static int bfin_serial_calc_baud(unsigned int uartclk, unsigned int baud);
+
+/*
+ * interrupts are disabled on entry
+ */
+static void bfin_serial_stop_tx(struct uart_port *port)
+{
+ struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+ disable_dma(uart->tx_dma_channel);
+#else
+ unsigned short ier;
+
+ ier = UART_GET_IER(uart);
+ ier &= ~ETBEI;
+ UART_PUT_IER(uart, ier);
+#endif
+}
+
+/*
+ * port is locked and interrupts are disabled
+ */
+static void bfin_serial_start_tx(struct uart_port *port)
+{
+ struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+ bfin_serial_dma_tx_chars(uart);
+#else
+ unsigned short ier;
+ ier = UART_GET_IER(uart);
+ ier |= ETBEI;
+ UART_PUT_IER(uart, ier);
+ bfin_serial_tx_chars(uart);
+#endif
+}
+
+/*
+ * Interrupts are enabled
+ */
+static void bfin_serial_stop_rx(struct uart_port *port)
+{
+ struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+ unsigned short ier;
+
+ ier = UART_GET_IER(uart);
+ ier &= ERBFI;
+ UART_PUT_IER(uart, ier);
+}
+
+/*
+ * Set the modem control timer to fire immediately.
+ */
+static void bfin_serial_enable_ms(struct uart_port *port)
+{
+}
+
+#ifdef CONFIG_SERIAL_BFIN_PIO
+static void local_put_char(struct bfin_serial_port *uart, char ch)
+{
+ unsigned short status;
+ int flags = 0;
+
+ spin_lock_irqsave(&uart->port.lock, flags);
+
+ do {
+ status = UART_GET_LSR(uart);
+ } while (!(status & THRE));
+
+ UART_PUT_CHAR(uart, ch);
+
+ spin_unlock_irqrestore(&uart->port.lock, flags);
+}
+
+static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
+{
+ struct tty_struct *tty = uart->port.info?uart->port.info->tty:0;
+ unsigned int status, ch, flg;
+#if defined(CONFIG_BF531) || defined(CONFIG_BF532) || defined(CONFIG_BF533)
+ static int in_break = 0;
+#endif
+
+ status = UART_GET_LSR(uart);
+ ch = UART_GET_CHAR(uart);
+ uart->port.icount.rx++;
+
+#if defined(CONFIG_BF531) || defined(CONFIG_BF532) || defined(CONFIG_BF533)
+ if (in_break) {
+ if (ch != 0) {
+ in_break = 0;
+ ch = UART_GET_CHAR(uart);
+ }
+ return;
+ }
+#endif
+
+ if (status & BI) {
+#if defined(CONFIG_BF531) || defined(CONFIG_BF532) || defined(CONFIG_BF533)
+ in_break = 1;
+#endif
+ uart->port.icount.brk++;
+ if (uart_handle_break(&uart->port))
+ goto ignore_char;
+ flg = TTY_BREAK;
+ } else if (status & PE) {
+ flg = TTY_PARITY;
+ uart->port.icount.parity++;
+ } else if (status & OE) {
+ flg = TTY_OVERRUN;
+ uart->port.icount.overrun++;
+ } else if (status & FE) {
+ flg = TTY_FRAME;
+ uart->port.icount.frame++;
+ } else
+ flg = TTY_NORMAL;
+
+ if (uart_handle_sysrq_char(&uart->port, ch))
+ goto ignore_char;
+ if (tty)
+ uart_insert_char(&uart->port, status, 2, ch, flg);
+
+ignore_char:
+ if (tty)
+ tty_flip_buffer_push(tty);
+}
+
+static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
+{
+ struct circ_buf *xmit = &uart->port.info->xmit;
+
+ if (uart->port.x_char) {
+ UART_PUT_CHAR(uart, uart->port.x_char);
+ uart->port.icount.tx++;
+ uart->port.x_char = 0;
+ return;
+ }
+ /*
+ * Check the modem control lines before
+ * transmitting anything.
+ */
+ bfin_serial_mctrl_check(uart);
+
+ if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
+ bfin_serial_stop_tx(&uart->port);
+ return;
+ }
+
+ local_put_char(uart, xmit->buf[xmit->tail]);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ uart->port.icount.tx++;
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&uart->port);
+
+ if (uart_circ_empty(xmit))
+ bfin_serial_stop_tx(&uart->port);
+}
+
+static irqreturn_t bfin_serial_int(int irq, void *dev_id)
+{
+ struct bfin_serial_port *uart = dev_id;
+ unsigned short status;
+
+ spin_lock(&uart->port.lock);
+ status = UART_GET_IIR(uart);
+ do {
+ if ((status & IIR_STATUS) == IIR_TX_READY)
+ bfin_serial_tx_chars(uart);
+ if ((status & IIR_STATUS) == IIR_RX_READY)
+ bfin_serial_rx_chars(uart);
+ status = UART_GET_IIR(uart);
+ } while (status &(IIR_TX_READY | IIR_RX_READY));
+ spin_unlock(&uart->port.lock);
+ return IRQ_HANDLED;
+}
+
+static void bfin_serial_do_work(struct work_struct *work)
+{
+ struct bfin_serial_port *uart = container_of(work, struct bfin_serial_port, cts_workqueue);
+
+ bfin_serial_mctrl_check(uart);
+}
+
+#endif
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
+{
+ struct circ_buf *xmit = &uart->port.info->xmit;
+ unsigned short ier;
+ int flags = 0;
+
+ if (!uart->tx_done)
+ return;
+
+ uart->tx_done = 0;
+
+ if (uart->port.x_char) {
+ UART_PUT_CHAR(uart, uart->port.x_char);
+ uart->port.icount.tx++;
+ uart->port.x_char = 0;
+ uart->tx_done = 1;
+ return;
+ }
+ /*
+ * Check the modem control lines before
+ * transmitting anything.
+ */
+ bfin_serial_mctrl_check(uart);
+
+ if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
+ bfin_serial_stop_tx(&uart->port);
+ uart->tx_done = 1;
+ return;
+ }
+
+ spin_lock_irqsave(&uart->port.lock, flags);
+ uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
+ if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))
+ uart->tx_count = UART_XMIT_SIZE - xmit->tail;
+ blackfin_dcache_flush_range((unsigned long)(xmit->buf+xmit->tail),
+ (unsigned long)(xmit->buf+xmit->tail+uart->tx_count));
+ set_dma_config(uart->tx_dma_channel,
+ set_bfin_dma_config(DIR_READ, DMA_FLOW_STOP,
+ INTR_ON_BUF,
+ DIMENSION_LINEAR,
+ DATA_SIZE_8));
+ set_dma_start_addr(uart->tx_dma_channel, (unsigned long)(xmit->buf+xmit->tail));
+ set_dma_x_count(uart->tx_dma_channel, uart->tx_count);
+ set_dma_x_modify(uart->tx_dma_channel, 1);
+ enable_dma(uart->tx_dma_channel);
+ ier = UART_GET_IER(uart);
+ ier |= ETBEI;
+ UART_PUT_IER(uart, ier);
+ spin_unlock_irqrestore(&uart->port.lock, flags);
+}
+
+static void bfin_serial_dma_rx_chars(struct bfin_serial_port * uart)
+{
+ struct tty_struct *tty = uart->port.info->tty;
+ int i, flg, status;
+
+ status = UART_GET_LSR(uart);
+ uart->port.icount.rx += CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail, UART_XMIT_SIZE);;
+
+ if (status & BI) {
+ uart->port.icount.brk++;
+ if (uart_handle_break(&uart->port))
+ goto dma_ignore_char;
+ flg = TTY_BREAK;
+ } else if (status & PE) {
+ flg = TTY_PARITY;
+ uart->port.icount.parity++;
+ } else if (status & OE) {
+ flg = TTY_OVERRUN;
+ uart->port.icount.overrun++;
+ } else if (status & FE) {
+ flg = TTY_FRAME;
+ uart->port.icount.frame++;
+ } else
+ flg = TTY_NORMAL;
+
+ for (i = uart->rx_dma_buf.head; i < uart->rx_dma_buf.tail; i++) {
+ if (uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
+ goto dma_ignore_char;
+ uart_insert_char(&uart->port, status, 2, uart->rx_dma_buf.buf[i], flg);
+ }
+dma_ignore_char:
+ tty_flip_buffer_push(tty);
+}
+
+void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
+{
+ int x_pos, pos;
+ int flags = 0;
+
+ bfin_serial_dma_tx_chars(uart);
+
+ spin_lock_irqsave(&uart->port.lock, flags);
+ x_pos = DMA_RX_XCOUNT - get_dma_curr_xcount(uart->rx_dma_channel);
+ if (x_pos == DMA_RX_XCOUNT)
+ x_pos = 0;
+
+ pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
+
+ if (pos>uart->rx_dma_buf.tail) {
+ uart->rx_dma_buf.tail = pos;
+ bfin_serial_dma_rx_chars(uart);
+ uart->rx_dma_buf.head = uart->rx_dma_buf.tail;
+ }
+ spin_unlock_irqrestore(&uart->port.lock, flags);
+ uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
+ add_timer(&(uart->rx_dma_timer));
+}
+
+static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
+{
+ struct bfin_serial_port *uart = dev_id;
+ struct circ_buf *xmit = &uart->port.info->xmit;
+ unsigned short ier;
+
+ spin_lock(&uart->port.lock);
+ if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
+ clear_dma_irqstat(uart->tx_dma_channel);
+ disable_dma(uart->tx_dma_channel);
+ ier = UART_GET_IER(uart);
+ ier &= ~ETBEI;
+ UART_PUT_IER(uart, ier);
+ xmit->tail = (xmit->tail+uart->tx_count) &(UART_XMIT_SIZE -1);
+ uart->port.icount.tx+=uart->tx_count;
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&uart->port);
+
+ if (uart_circ_empty(xmit))
+ bfin_serial_stop_tx(&uart->port);
+ uart->tx_done = 1;
+ }
+
+ spin_unlock(&uart->port.lock);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id)
+{
+ struct bfin_serial_port *uart = dev_id;
+ unsigned short irqstat;
+
+ uart->rx_dma_nrows++;
+ if (uart->rx_dma_nrows == DMA_RX_YCOUNT) {
+ uart->rx_dma_nrows = 0;
+ uart->rx_dma_buf.tail = DMA_RX_XCOUNT*DMA_RX_YCOUNT;
+ bfin_serial_dma_rx_chars(uart);
+ uart->rx_dma_buf.head = uart->rx_dma_buf.tail = 0;
+ }
+ spin_lock(&uart->port.lock);
+ irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
+ clear_dma_irqstat(uart->rx_dma_channel);
+
+ spin_unlock(&uart->port.lock);
+ return IRQ_HANDLED;
+}
+#endif
+
+/*
+ * Return TIOCSER_TEMT when transmitter is not busy.
+ */
+static unsigned int bfin_serial_tx_empty(struct uart_port *port)
+{
+ struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+ unsigned short lsr;
+
+ lsr = UART_GET_LSR(uart);
+ if (lsr & THRE)
+ return TIOCSER_TEMT;
+ else
+ return 0;
+}
+
+static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
+{
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+ struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+ if (uart->cts_pin < 0)
+ return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+
+ if (gpio_get_value(uart->cts_pin))
+ return TIOCM_DSR | TIOCM_CAR;
+ else
+#endif
+ return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+}
+
+static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+ struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+ if (uart->rts_pin < 0)
+ return;
+
+ if (mctrl & TIOCM_RTS)
+ gpio_set_value(uart->rts_pin, 0);
+ else
+ gpio_set_value(uart->rts_pin, 1);
+#endif
+}
+
+/*
+ * Handle any change of modem status signal since we were last called.
+ */
+static void bfin_serial_mctrl_check(struct bfin_serial_port *uart)
+{
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+ unsigned int status;
+# ifdef CONFIG_SERIAL_BFIN_DMA
+ struct uart_info *info = uart->port.info;
+ struct tty_struct *tty = info->tty;
+
+ status = bfin_serial_get_mctrl(&uart->port);
+ if (!(status & TIOCM_CTS)) {
+ tty->hw_stopped = 1;
+ } else {
+ tty->hw_stopped = 0;
+ }
+# else
+ status = bfin_serial_get_mctrl(&uart->port);
+ uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
+ if (!(status & TIOCM_CTS))
+ schedule_work(&uart->cts_workqueue);
+# endif
+#endif
+}
+
+/*
+ * Interrupts are always disabled.
+ */
+static void bfin_serial_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static int bfin_serial_startup(struct uart_port *port)
+{
+ struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+ dma_addr_t dma_handle;
+
+ if (request_dma(uart->rx_dma_channel, "BFIN_UART_RX") < 0) {
+ printk(KERN_NOTICE "Unable to attach Blackfin UART RX DMA channel\n");
+ return -EBUSY;
+ }
+
+ if (request_dma(uart->tx_dma_channel, "BFIN_UART_TX") < 0) {
+ printk(KERN_NOTICE "Unable to attach Blackfin UART TX DMA channel\n");
+ free_dma(uart->rx_dma_channel);
+ return -EBUSY;
+ }
+
+ set_dma_callback(uart->rx_dma_channel, bfin_serial_dma_rx_int, uart);
+ set_dma_callback(uart->tx_dma_channel, bfin_serial_dma_tx_int, uart);
+
+ uart->rx_dma_buf.buf = (unsigned char *)dma_alloc_coherent(NULL, PAGE_SIZE, &dma_handle, GFP_DMA);
+ uart->rx_dma_buf.head = 0;
+ uart->rx_dma_buf.tail = 0;
+ uart->rx_dma_nrows = 0;
+
+ set_dma_config(uart->rx_dma_channel,
+ set_bfin_dma_config(DIR_WRITE, DMA_FLOW_AUTO,
+ INTR_ON_ROW, DIMENSION_2D,
+ DATA_SIZE_8));
+ set_dma_x_count(uart->rx_dma_channel, DMA_RX_XCOUNT);
+ set_dma_x_modify(uart->rx_dma_channel, 1);
+ set_dma_y_count(uart->rx_dma_channel, DMA_RX_YCOUNT);
+ set_dma_y_modify(uart->rx_dma_channel, 1);
+ set_dma_start_addr(uart->rx_dma_channel, (unsigned long)uart->rx_dma_buf.buf);
+ enable_dma(uart->rx_dma_channel);
+
+ uart->rx_dma_timer.data = (unsigned long)(uart);
+ uart->rx_dma_timer.function = (void *)bfin_serial_rx_dma_timeout;
+ uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
+ add_timer(&(uart->rx_dma_timer));
+#else
+ if (request_irq
+ (uart->port.irq, bfin_serial_int, SA_INTERRUPT | SA_SHIRQ,
+ "BFIN_UART0_RX", uart)) {
+ printk(KERN_NOTICE "Unable to attach BlackFin UART RX interrupt\n");
+ return -EBUSY;
+ }
+
+ if (request_irq
+ (uart->port.irq+1, bfin_serial_int, SA_INTERRUPT | SA_SHIRQ,
+ "BFIN_UART0_TX", uart)) {
+ printk(KERN_NOTICE "Unable to attach BlackFin UART TX interrupt\n");
+ free_irq(uart->port.irq, uart);
+ return -EBUSY;
+ }
+#endif
+ UART_PUT_IER(uart, UART_GET_IER(uart) | ERBFI);
+ return 0;
+}
+
+static void bfin_serial_shutdown(struct uart_port *port)
+{
+ struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+ disable_dma(uart->tx_dma_channel);
+ free_dma(uart->tx_dma_channel);
+ disable_dma(uart->rx_dma_channel);
+ free_dma(uart->rx_dma_channel);
+ del_timer(&(uart->rx_dma_timer));
+#else
+ free_irq(uart->port.irq, uart);
+ free_irq(uart->port.irq+1, uart);
+#endif
+}
+
+static void
+bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
+ struct ktermios *old)
+{
+ struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+ unsigned long flags;
+ unsigned int baud, quot;
+ unsigned short val, ier;
+
+ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
+ quot = bfin_serial_calc_baud(port->uartclk, baud);
+ spin_lock_irqsave(&uart->port.lock, flags);
+
+ /* Disable UART */
+ ier = UART_GET_IER(uart);
+ UART_PUT_IER(uart, 0);
+
+ /* Set DLAB in LCR to Access DLL and DLH */
+ val = UART_GET_LCR(uart);
+ val |= DLAB;
+ UART_PUT_LCR(uart, val);
+ __builtin_bfin_ssync();
+
+ UART_PUT_DLL(uart, quot & 0xFF);
+ __builtin_bfin_ssync();
+ UART_PUT_DLH(uart, (quot >> 8) & 0xFF);
+ __builtin_bfin_ssync();
+
+ /* Clear DLAB in LCR to Access THR RBR IER */
+ val = UART_GET_LCR(uart);
+ val &= ~DLAB;
+ UART_PUT_LCR(uart, val);
+ __builtin_bfin_ssync();
+
+ /* Enable UART */
+ UART_PUT_IER(uart, ier);
+
+ val = UART_GET_GCTL(uart);
+ val |= UCEN;
+ UART_PUT_GCTL(uart, val);
+
+ spin_unlock_irqrestore(&uart->port.lock, flags);
+}
+
+static const char *bfin_serial_type(struct uart_port *port)
+{
+ struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+ return uart->port.type == PORT_BFIN ? "BFIN-UART" : NULL;
+}
+
+/*
+ * Release the memory region(s) being used by 'port'.
+ */
+static void bfin_serial_release_port(struct uart_port *port)
+{
+}
+
+/*
+ * Request the memory region(s) being used by 'port'.
+ */
+static int bfin_serial_request_port(struct uart_port *port)
+{
+ return 0;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void bfin_serial_config_port(struct uart_port *port, int flags)
+{
+ struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+ if (flags & UART_CONFIG_TYPE &&
+ bfin_serial_request_port(&uart->port) == 0)
+ uart->port.type = PORT_BFIN;
+}
+
+/*
+ * Verify the new serial_struct (for TIOCSSERIAL).
+ * The only change we allow are to the flags and type, and
+ * even then only between PORT_BFIN and PORT_UNKNOWN
+ */
+static int
+bfin_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+ return 0;
+}
+
+static struct uart_ops bfin_serial_pops = {
+ .tx_empty = bfin_serial_tx_empty,
+ .set_mctrl = bfin_serial_set_mctrl,
+ .get_mctrl = bfin_serial_get_mctrl,
+ .stop_tx = bfin_serial_stop_tx,
+ .start_tx = bfin_serial_start_tx,
+ .stop_rx = bfin_serial_stop_rx,
+ .enable_ms = bfin_serial_enable_ms,
+ .break_ctl = bfin_serial_break_ctl,
+ .startup = bfin_serial_startup,
+ .shutdown = bfin_serial_shutdown,
+ .set_termios = bfin_serial_set_termios,
+ .type = bfin_serial_type,
+ .release_port = bfin_serial_release_port,
+ .request_port = bfin_serial_request_port,
+ .config_port = bfin_serial_config_port,
+ .verify_port = bfin_serial_verify_port,
+};
+
+static int bfin_serial_calc_baud(unsigned int uartclk, unsigned int baud)
+{
+ int quot;
+
+ quot = uartclk / (baud * 8);
+ if ((quot & 0x1) == 1) {
+ quot++;
+ }
+ return quot/2;
+}
+
+static void __init bfin_serial_init_ports(void)
+{
+ static int first = 1;
+ int i;
+ unsigned short val;
+ int quot;
+
+ if (!first)
+ return;
+ first = 0;
+
+ for (i = 0; i < nr_ports; i++) {
+ bfin_serial_ports[i].port.uartclk = get_sclk();
+ bfin_serial_ports[i].port.ops = &bfin_serial_pops;
+ bfin_serial_ports[i].port.line = i;
+ bfin_serial_ports[i].port.iotype = UPIO_MEM;
+ bfin_serial_ports[i].port.membase =
+ (void __iomem *)bfin_serial_resource[i].uart_base_addr;
+ bfin_serial_ports[i].port.mapbase =
+ bfin_serial_resource[i].uart_base_addr;
+ bfin_serial_ports[i].port.irq =
+ bfin_serial_resource[i].uart_irq;
+ bfin_serial_ports[i].port.flags = UPF_BOOT_AUTOCONF;
+#ifdef CONFIG_SERIAL_BFIN_DMA
+ bfin_serial_ports[i].tx_done = 1;
+ bfin_serial_ports[i].tx_count = 0;
+ bfin_serial_ports[i].tx_dma_channel =
+ bfin_serial_resource[i].uart_tx_dma_channel;
+ bfin_serial_ports[i].rx_dma_channel =
+ bfin_serial_resource[i].uart_rx_dma_channel;
+ init_timer(&(bfin_serial_ports[i].rx_dma_timer));
+#else
+ INIT_WORK(&bfin_serial_ports[i].cts_workqueue,
+ bfin_serial_do_work, &bfin_serial_ports[i]);
+#endif
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+ bfin_serial_ports[i].cts_pin =
+ bfin_serial_resource[i].uart_cts_pin;
+ bfin_serial_ports[i].rts_pin =
+ bfin_serial_resource[i].uart_rts_pin;
+#endif
+ bfin_serial_hw_init(&bfin_serial_ports[i]);
+
+ quot = bfin_serial_calc_baud(bfin_serial_ports[i].port.uartclk,
+ CONSOLE_BAUD_RATE);
+
+ /* Disable UART */
+ UART_PUT_GCTL(&bfin_serial_ports[i], 0);
+
+ /* Set DLAB in LCR to Access DLL and DLH */
+ val = UART_GET_LCR(&bfin_serial_ports[i]);
+ val |= DLAB;
+ UART_PUT_LCR(&bfin_serial_ports[i], val);
+
+ UART_PUT_DLL(&bfin_serial_ports[i], quot & 0xFF);
+ UART_PUT_DLH(&bfin_serial_ports[i], (quot >> 8) & 0xFF);
+
+ /* Clear DLAB in LCR to Access THR RBR IER */
+ val = UART_GET_LCR(&bfin_serial_ports[i]);
+ val &= ~DLAB;
+ UART_PUT_LCR(&bfin_serial_ports[i], val);
+
+ /* Set LCR to Word Lengh 8-bit word select */
+ val = WLS(8);
+ UART_PUT_LCR(&bfin_serial_ports[i], val);
+
+ /* Enable UART */
+ val = UART_GET_GCTL(&bfin_serial_ports[i]);
+ val |= UCEN;
+ UART_PUT_GCTL(&bfin_serial_ports[i], val);
+ }
+}
+
+#ifdef CONFIG_SERIAL_BFIN_CONSOLE
+/*
+ * Interrupts are disabled on entering
+ */
+static void
+bfin_serial_console_write(struct console *co, const char *s, unsigned int count)
+{
+ struct bfin_serial_port *uart = &bfin_serial_ports[co->index];
+ int flags = 0;
+ unsigned short status, tmp;
+ int i;
+
+ spin_lock_irqsave(&uart->port.lock, flags);
+ for (i = 0; i < count; i++) {
+ do {
+ status = UART_GET_LSR(uart);
+ } while (!(status & THRE));
+
+ tmp = UART_GET_LCR(uart);
+ tmp &= ~DLAB;
+ UART_PUT_LCR(uart, tmp);
+
+ UART_PUT_CHAR(uart, s[i]);
+ if (s[i] == '\n') {
+ do {
+ status = UART_GET_LSR(uart);
+ } while(!(status & THRE));
+ UART_PUT_CHAR(uart, '\r');
+ }
+ }
+ spin_unlock_irqrestore(&uart->port.lock, flags);
+
+}
+
+/*
+ * If the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
+ */
+static void __init
+bfin_serial_console_get_options(struct bfin_serial_port *uart, int *baud,
+ int *parity, int *bits)
+{
+ unsigned short status;
+
+ status = UART_GET_IER(uart) & (ERBFI | ETBEI);
+ if (status == (ERBFI | ETBEI)) {
+ /* ok, the port was enabled */
+ unsigned short lcr, val;
+ unsigned short dlh, dll;
+
+ lcr = UART_GET_LCR(uart);
+
+ *parity = 'n';
+ if (lcr & PEN) {
+ if (lcr & EPS)
+ *parity = 'e';
+ else
+ *parity = 'o';
+ }
+ switch (lcr & 0x03) {
+ case 0: *bits = 5; break;
+ case 1: *bits = 6; break;
+ case 2: *bits = 7; break;
+ case 3: *bits = 8; break;
+ }
+ /* Set DLAB in LCR to Access DLL and DLH */
+ val = UART_GET_LCR(uart);
+ val |= DLAB;
+ UART_PUT_LCR(uart, val);
+
+ dll = UART_GET_DLL(uart);
+ dlh = UART_GET_DLH(uart);
+
+ /* Clear DLAB in LCR to Access THR RBR IER */
+ val = UART_GET_LCR(uart);
+ val &= ~DLAB;
+ UART_PUT_LCR(uart, val);
+
+ *baud = get_sclk() / (16*(dll | dlh << 8));
+ }
+ pr_debug("%s:baud = %d, parity = %c, bits= %d\n", __FUNCTION__, *baud, *parity, *bits);
+}
+
+static int __init
+bfin_serial_console_setup(struct console *co, char *options)
+{
+ struct bfin_serial_port *uart;
+ int baud = CONSOLE_BAUD_RATE;
+ int bits = 8;
+ int parity = 'n';
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+ int flow = 'r';
+#else
+ int flow = 'n';
+#endif
+
+ /*
+ * Check whether an invalid uart number has been specified, and
+ * if so, search for the first available port that does have
+ * console support.
+ */
+ if (co->index == -1 || co->index >= nr_ports)
+ co->index = 0;
+ uart = &bfin_serial_ports[co->index];
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+ else
+ bfin_serial_console_get_options(uart, &baud, &parity, &bits);
+
+ return uart_set_options(&uart->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver bfin_serial_reg;
+static struct console bfin_serial_console = {
+ .name = "ttyS",
+ .write = bfin_serial_console_write,
+ .device = uart_console_device,
+ .setup = bfin_serial_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &bfin_serial_reg,
+};
+
+static int __init bfin_serial_rs_console_init(void)
+{
+ bfin_serial_init_ports();
+ register_console(&bfin_serial_console);
+ return 0;
+}
+console_initcall(bfin_serial_rs_console_init);
+
+#define BFIN_SERIAL_CONSOLE &bfin_serial_console
+#else
+#define BFIN_SERIAL_CONSOLE NULL
+#endif
+
+static struct uart_driver bfin_serial_reg = {
+ .owner = THIS_MODULE,
+ .driver_name = "bfin-uart",
+ .dev_name = "ttyS",
+ .major = SERIAL_BFIN_MAJOR,
+ .minor = MINOR_START,
+ .nr = NR_PORTS,
+ .cons = BFIN_SERIAL_CONSOLE,
+};
+
+static int bfin_serial_suspend(struct platform_device *dev, pm_message_t state)
+{
+ struct bfin_serial_port *uart = platform_get_drvdata(dev);
+
+ if (uart)
+ uart_suspend_port(&bfin_serial_reg, &uart->port);
+
+ return 0;
+}
+
+static int bfin_serial_resume(struct platform_device *dev)
+{
+ struct bfin_serial_port *uart = platform_get_drvdata(dev);
+
+ if (uart)
+ uart_resume_port(&bfin_serial_reg, &uart->port);
+
+ return 0;
+}
+
+static int bfin_serial_probe(struct platform_device *dev)
+{
+ struct resource *res = dev->resource;
+ int i;
+
+ for (i = 0; i < dev->num_resources; i++, res++)
+ if (res->flags & IORESOURCE_MEM)
+ break;
+
+ if (i < dev->num_resources) {
+ for (i = 0; i < nr_ports; i++, res++) {
+ if (bfin_serial_ports[i].port.mapbase != res->start)
+ continue;
+ bfin_serial_ports[i].port.dev = &dev->dev;
+ uart_add_one_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
+ platform_set_drvdata(dev, &bfin_serial_ports[i]);
+ }
+ }
+
+ return 0;
+}
+
+static int bfin_serial_remove(struct platform_device *pdev)
+{
+ struct bfin_serial_port *uart = platform_get_drvdata(pdev);
+
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+ gpio_free(uart->cts_pin);
+ gpio_free(uart->rts_pin);
+#endif
+
+ platform_set_drvdata(pdev, NULL);
+
+ if (uart)
+ uart_remove_one_port(&bfin_serial_reg, &uart->port);
+
+ return 0;
+}
+
+static struct platform_driver bfin_serial_driver = {
+ .probe = bfin_serial_probe,
+ .remove = bfin_serial_remove,
+ .suspend = bfin_serial_suspend,
+ .resume = bfin_serial_resume,
+ .driver = {
+ .name = "bfin-uart",
+ },
+};
+
+static int __init bfin_serial_init(void)
+{
+ int ret;
+
+ pr_info("Serial: Blackfin serial driver\n");
+
+ bfin_serial_init_ports();
+
+ ret = uart_register_driver(&bfin_serial_reg);
+ if (ret == 0) {
+ ret = platform_driver_register(&bfin_serial_driver);
+ if (ret) {
+ pr_debug("uart register failed\n");
+ uart_unregister_driver(&bfin_serial_reg);
+ }
+ }
+ return ret;
+}
+
+static void __exit bfin_serial_exit(void)
+{
+ platform_driver_unregister(&bfin_serial_driver);
+ uart_unregister_driver(&bfin_serial_reg);
+}
+
+module_init(bfin_serial_init);
+module_exit(bfin_serial_exit);
+
+MODULE_AUTHOR("Aubrey.Li <[email protected]>");
+MODULE_DESCRIPTION("Blackfin generic serial port driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_BFIN_MAJOR);
Index: linux-2.6/include/linux/serial_core.h
===================================================================
--- linux-2.6.orig/include/linux/serial_core.h 2007-02-06 01:13:42.000000000 +0800
+++ linux-2.6/include/linux/serial_core.h 2007-02-06 01:20:13.000000000 +0800
@@ -135,6 +135,9 @@
/* Xilinx uartlite */
#define PORT_UARTLITE 74
+/* Blackfin bf5xx */
+#define PORT_BFIN 75
+
#ifdef __KERNEL__
#include <linux/compiler.h>
---
Thanks a lot
Best Regards
Bryan Wu <[email protected]>
I think you have a bit of work to do on this driver; it seems to be
missing all termios handling apart from setting the baud rate.
Moreover, it's re-using the 8250 driver port range despite claiming
to have a proper allocation.
(I don't maintain serial anymore but I do reserve the right to
occasionally review serial code.)
On Tue, Feb 06, 2007 at 11:20:11AM +0800, Wu, Bryan wrote:
> +/* We've been assigned a range on the "Low-density serial ports" major */
> +#define SERIAL_BFIN_MAJOR TTY_MAJOR
> +#define MINOR_START 64
If you've been assigned a range in the low density serial ports major,
why aren't you using it instead of taking the 8250 drivers range (thereby
preventing PCMCIA cards from ever being used) ?
> +#if defined(CONFIG_BAUD_9600)
> +#define CONSOLE_BAUD_RATE 9600
> +#elif defined(CONFIG_BAUD_19200)
> +#define CONSOLE_BAUD_RATE 19200
> +#elif defined(CONFIG_BAUD_38400)
> +#define CONSOLE_BAUD_RATE 38400
> +#elif defined(CONFIG_BAUD_57600)
> +#define CONSOLE_BAUD_RATE 57600
> +#elif defined(CONFIG_BAUD_115200)
> +#define CONSOLE_BAUD_RATE 115200
> +#endif
What's wrong with passing console=ttyblackfin0,115200 to the kernel or
via some default command line?
> +/*
> + * interrupts are disabled on entry
> + */
> +static void bfin_serial_stop_tx(struct uart_port *port)
> +{
> + struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
> +
> +#ifdef CONFIG_SERIAL_BFIN_DMA
> + disable_dma(uart->tx_dma_channel);
It's far better to stop transmission as soon as possible to prevent
overruns at the remote end. I doubt disabling DMA achieves that.
> +#else
> + unsigned short ier;
> +
> + ier = UART_GET_IER(uart);
> + ier &= ~ETBEI;
> + UART_PUT_IER(uart, ier);
> +#endif
> +}
...
> +static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
> +{
> + struct tty_struct *tty = uart->port.info?uart->port.info->tty:0;
> + unsigned int status, ch, flg;
> +#if defined(CONFIG_BF531) || defined(CONFIG_BF532) || defined(CONFIG_BF533)
> + static int in_break = 0;
> +#endif
> +
> + status = UART_GET_LSR(uart);
> + ch = UART_GET_CHAR(uart);
> + uart->port.icount.rx++;
> +
> +#if defined(CONFIG_BF531) || defined(CONFIG_BF532) || defined(CONFIG_BF533)
> + if (in_break) {
> + if (ch != 0) {
> + in_break = 0;
> + ch = UART_GET_CHAR(uart);
> + }
> + return;
> + }
> +#endif
> +
> + if (status & BI) {
> +#if defined(CONFIG_BF531) || defined(CONFIG_BF532) || defined(CONFIG_BF533)
> + in_break = 1;
> +#endif
> + uart->port.icount.brk++;
> + if (uart_handle_break(&uart->port))
> + goto ignore_char;
> + flg = TTY_BREAK;
> + } else if (status & PE) {
> + flg = TTY_PARITY;
> + uart->port.icount.parity++;
> + } else if (status & OE) {
> + flg = TTY_OVERRUN;
> + uart->port.icount.overrun++;
> + } else if (status & FE) {
> + flg = TTY_FRAME;
> + uart->port.icount.frame++;
> + } else
> + flg = TTY_NORMAL;
Why do many serial drivers when they're first written utterly ignore
termios modes in their reception path by not using port.read_status_mask?
It's broken as stands.
> +
> + if (uart_handle_sysrq_char(&uart->port, ch))
> + goto ignore_char;
> + if (tty)
> + uart_insert_char(&uart->port, status, 2, ch, flg);
> +
> +ignore_char:
> + if (tty)
> + tty_flip_buffer_push(tty);
> +}
...
> +static irqreturn_t bfin_serial_int(int irq, void *dev_id)
> +{
> + struct bfin_serial_port *uart = dev_id;
> + unsigned short status;
> +
> + spin_lock(&uart->port.lock);
> + status = UART_GET_IIR(uart);
> + do {
> + if ((status & IIR_STATUS) == IIR_TX_READY)
> + bfin_serial_tx_chars(uart);
> + if ((status & IIR_STATUS) == IIR_RX_READY)
> + bfin_serial_rx_chars(uart);
> + status = UART_GET_IIR(uart);
> + } while (status &(IIR_TX_READY | IIR_RX_READY));
Space between '&' and '(' please.
> + spin_unlock(&uart->port.lock);
> + return IRQ_HANDLED;
> +}
...
> +static void bfin_serial_dma_rx_chars(struct bfin_serial_port * uart)
> +{
> + struct tty_struct *tty = uart->port.info->tty;
> + int i, flg, status;
> +
> + status = UART_GET_LSR(uart);
> + uart->port.icount.rx += CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail, UART_XMIT_SIZE);;
> +
> + if (status & BI) {
> + uart->port.icount.brk++;
> + if (uart_handle_break(&uart->port))
> + goto dma_ignore_char;
> + flg = TTY_BREAK;
> + } else if (status & PE) {
> + flg = TTY_PARITY;
> + uart->port.icount.parity++;
> + } else if (status & OE) {
> + flg = TTY_OVERRUN;
> + uart->port.icount.overrun++;
> + } else if (status & FE) {
> + flg = TTY_FRAME;
> + uart->port.icount.frame++;
> + } else
> + flg = TTY_NORMAL;
No termios handling.
> +
> + for (i = uart->rx_dma_buf.head; i < uart->rx_dma_buf.tail; i++) {
> + if (uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
> + goto dma_ignore_char;
> + uart_insert_char(&uart->port, status, 2, uart->rx_dma_buf.buf[i], flg);
> + }
> +dma_ignore_char:
> + tty_flip_buffer_push(tty);
> +}
...
> +/*
> + * Handle any change of modem status signal since we were last called.
> + */
> +static void bfin_serial_mctrl_check(struct bfin_serial_port *uart)
> +{
> +#ifdef CONFIG_SERIAL_BFIN_CTSRTS
> + unsigned int status;
> +# ifdef CONFIG_SERIAL_BFIN_DMA
> + struct uart_info *info = uart->port.info;
> + struct tty_struct *tty = info->tty;
> +
> + status = bfin_serial_get_mctrl(&uart->port);
> + if (!(status & TIOCM_CTS)) {
> + tty->hw_stopped = 1;
> + } else {
> + tty->hw_stopped = 0;
> + }
A change of CTS doesn't always mean transmission has to stop.
uart_handle_cts_change() knows when this has to happen. Use it.
> +# else
> + status = bfin_serial_get_mctrl(&uart->port);
> + uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
> + if (!(status & TIOCM_CTS))
> + schedule_work(&uart->cts_workqueue);
> +# endif
> +#endif
> +}
...
> +static void
> +bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
> + struct ktermios *old)
> +{
> + struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
> + unsigned long flags;
> + unsigned int baud, quot;
> + unsigned short val, ier;
> +
> + baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
> + quot = bfin_serial_calc_baud(port->uartclk, baud);
> + spin_lock_irqsave(&uart->port.lock, flags);
Doesn't set port.ignore_status_mask nor port.read_status_mask, so *NONE*
of the termios modes to do with error handling will work with this driver.
In fact, I doubt it's possible to even change the parity, length or stop
bit settings as this code stands.
> +
> + /* Disable UART */
> + ier = UART_GET_IER(uart);
> + UART_PUT_IER(uart, 0);
> +
> + /* Set DLAB in LCR to Access DLL and DLH */
> + val = UART_GET_LCR(uart);
> + val |= DLAB;
> + UART_PUT_LCR(uart, val);
> + __builtin_bfin_ssync();
> +
> + UART_PUT_DLL(uart, quot & 0xFF);
> + __builtin_bfin_ssync();
> + UART_PUT_DLH(uart, (quot >> 8) & 0xFF);
> + __builtin_bfin_ssync();
> +
> + /* Clear DLAB in LCR to Access THR RBR IER */
> + val = UART_GET_LCR(uart);
> + val &= ~DLAB;
> + UART_PUT_LCR(uart, val);
> + __builtin_bfin_ssync();
> +
> + /* Enable UART */
> + UART_PUT_IER(uart, ier);
> +
> + val = UART_GET_GCTL(uart);
> + val |= UCEN;
> + UART_PUT_GCTL(uart, val);
> +
> + spin_unlock_irqrestore(&uart->port.lock, flags);
> +}
...
> +static int bfin_serial_calc_baud(unsigned int uartclk, unsigned int baud)
> +{
> + int quot;
> +
> + quot = uartclk / (baud * 8);
> + if ((quot & 0x1) == 1) {
> + quot++;
> + }
> + return quot/2;
Something wrong with the standard function (uart_get_divisor)? If so, what?
> +}
...
> +#ifdef CONFIG_SERIAL_BFIN_CONSOLE
> +/*
> + * Interrupts are disabled on entering
> + */
> +static void
> +bfin_serial_console_write(struct console *co, const char *s, unsigned int count)
> +{
> + struct bfin_serial_port *uart = &bfin_serial_ports[co->index];
> + int flags = 0;
> + unsigned short status, tmp;
> + int i;
> +
> + spin_lock_irqsave(&uart->port.lock, flags);
> + for (i = 0; i < count; i++) {
> + do {
> + status = UART_GET_LSR(uart);
> + } while (!(status & THRE));
> +
> + tmp = UART_GET_LCR(uart);
> + tmp &= ~DLAB;
> + UART_PUT_LCR(uart, tmp);
> +
> + UART_PUT_CHAR(uart, s[i]);
> + if (s[i] == '\n') {
> + do {
> + status = UART_GET_LSR(uart);
> + } while(!(status & THRE));
> + UART_PUT_CHAR(uart, '\r');
> + }
Use uart_console_write()
> + }
> + spin_unlock_irqrestore(&uart->port.lock, flags);
> +
> +}
> +
> +/*
> + * If the port was already initialised (eg, by a boot loader),
> + * try to determine the current setup.
> + */
> +static void __init
> +bfin_serial_console_get_options(struct bfin_serial_port *uart, int *baud,
> + int *parity, int *bits)
> +{
> + unsigned short status;
> +
> + status = UART_GET_IER(uart) & (ERBFI | ETBEI);
> + if (status == (ERBFI | ETBEI)) {
> + /* ok, the port was enabled */
> + unsigned short lcr, val;
> + unsigned short dlh, dll;
> +
> + lcr = UART_GET_LCR(uart);
> +
> + *parity = 'n';
> + if (lcr & PEN) {
> + if (lcr & EPS)
> + *parity = 'e';
> + else
> + *parity = 'o';
> + }
> + switch (lcr & 0x03) {
> + case 0: *bits = 5; break;
> + case 1: *bits = 6; break;
> + case 2: *bits = 7; break;
> + case 3: *bits = 8; break;
> + }
You do have length and parity settings on this port, yet you don't
have code in your set_termios method to set them from the termios...
> + /* Set DLAB in LCR to Access DLL and DLH */
> + val = UART_GET_LCR(uart);
> + val |= DLAB;
> + UART_PUT_LCR(uart, val);
> +
> + dll = UART_GET_DLL(uart);
> + dlh = UART_GET_DLH(uart);
> +
> + /* Clear DLAB in LCR to Access THR RBR IER */
> + val = UART_GET_LCR(uart);
> + val &= ~DLAB;
> + UART_PUT_LCR(uart, val);
> +
> + *baud = get_sclk() / (16*(dll | dlh << 8));
> + }
> + pr_debug("%s:baud = %d, parity = %c, bits= %d\n", __FUNCTION__, *baud, *parity, *bits);
> +}
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of:
On 2/6/07, Russell King <[email protected]> wrote:
> I think you have a bit of work to do on this driver; it seems to be
> missing all termios handling apart from setting the baud rate.
Yes, only baud rate setting is enabled. We'll implement others in future.
> Moreover, it's re-using the 8250 driver port range despite claiming
> to have a proper allocation.
Thanks to point this out, although 8250 driver and bfin serial driver
will never be enabled at the same time.
Is there a port map to show which ports are used? Or how do I know
which port is available?
>
> (I don't maintain serial anymore but I do reserve the right to
> occasionally review serial code.)
>
> On Tue, Feb 06, 2007 at 11:20:11AM +0800, Wu, Bryan wrote:
> > +/* We've been assigned a range on the "Low-density serial ports" major */
> > +#define SERIAL_BFIN_MAJOR TTY_MAJOR
> > +#define MINOR_START 64
>
> If you've been assigned a range in the low density serial ports major,
> why aren't you using it instead of taking the 8250 drivers range (thereby
> preventing PCMCIA cards from ever being used) ?
>
> > +#if defined(CONFIG_BAUD_9600)
> > +#define CONSOLE_BAUD_RATE 9600
> > +#elif defined(CONFIG_BAUD_19200)
> > +#define CONSOLE_BAUD_RATE 19200
> > +#elif defined(CONFIG_BAUD_38400)
> > +#define CONSOLE_BAUD_RATE 38400
> > +#elif defined(CONFIG_BAUD_57600)
> > +#define CONSOLE_BAUD_RATE 57600
> > +#elif defined(CONFIG_BAUD_115200)
> > +#define CONSOLE_BAUD_RATE 115200
> > +#endif
>
> What's wrong with passing console=ttyblackfin0,115200 to the kernel or
> via some default command line?
We are not used to pass parameter like that. Put it in Kconfig option
is more friendly to our customer.
> > +/*
> > + * interrupts are disabled on entry
> > + */
> > +static void bfin_serial_stop_tx(struct uart_port *port)
> > +{
> > + struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
> > +
> > +#ifdef CONFIG_SERIAL_BFIN_DMA
> > + disable_dma(uart->tx_dma_channel);
>
> It's far better to stop transmission as soon as possible to prevent
> overruns at the remote end. I doubt disabling DMA achieves that.
UART peripheral on blackfin has two work mode, one is PIO, the other is DMA.
The driver enables two mode. If overruns at the remote end is critical
for someone, PIO is a better choice.
>
> > +#else
> > + unsigned short ier;
> > +
> > + ier = UART_GET_IER(uart);
> > + ier &= ~ETBEI;
> > + UART_PUT_IER(uart, ier);
> > +#endif
> > +}
> ...
> > +static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
> > +{
> > + struct tty_struct *tty = uart->port.info?uart->port.info->tty:0;
> > + unsigned int status, ch, flg;
> > +#if defined(CONFIG_BF531) || defined(CONFIG_BF532) || defined(CONFIG_BF533)
> > + static int in_break = 0;
> > +#endif
> > +
> > + status = UART_GET_LSR(uart);
> > + ch = UART_GET_CHAR(uart);
> > + uart->port.icount.rx++;
> > +
> > +#if defined(CONFIG_BF531) || defined(CONFIG_BF532) || defined(CONFIG_BF533)
> > + if (in_break) {
> > + if (ch != 0) {
> > + in_break = 0;
> > + ch = UART_GET_CHAR(uart);
> > + }
> > + return;
> > + }
> > +#endif
> > +
> > + if (status & BI) {
> > +#if defined(CONFIG_BF531) || defined(CONFIG_BF532) || defined(CONFIG_BF533)
> > + in_break = 1;
> > +#endif
> > + uart->port.icount.brk++;
> > + if (uart_handle_break(&uart->port))
> > + goto ignore_char;
> > + flg = TTY_BREAK;
> > + } else if (status & PE) {
> > + flg = TTY_PARITY;
> > + uart->port.icount.parity++;
> > + } else if (status & OE) {
> > + flg = TTY_OVERRUN;
> > + uart->port.icount.overrun++;
> > + } else if (status & FE) {
> > + flg = TTY_FRAME;
> > + uart->port.icount.frame++;
> > + } else
> > + flg = TTY_NORMAL;
>
> Why do many serial drivers when they're first written utterly ignore
> termios modes in their reception path by not using port.read_status_mask?
> It's broken as stands.
>
> > +
> > + if (uart_handle_sysrq_char(&uart->port, ch))
> > + goto ignore_char;
> > + if (tty)
> > + uart_insert_char(&uart->port, status, 2, ch, flg);
> > +
> > +ignore_char:
> > + if (tty)
> > + tty_flip_buffer_push(tty);
> > +}
> ...
> > +static irqreturn_t bfin_serial_int(int irq, void *dev_id)
> > +{
> > + struct bfin_serial_port *uart = dev_id;
> > + unsigned short status;
> > +
> > + spin_lock(&uart->port.lock);
> > + status = UART_GET_IIR(uart);
> > + do {
> > + if ((status & IIR_STATUS) == IIR_TX_READY)
> > + bfin_serial_tx_chars(uart);
> > + if ((status & IIR_STATUS) == IIR_RX_READY)
> > + bfin_serial_rx_chars(uart);
> > + status = UART_GET_IIR(uart);
> > + } while (status &(IIR_TX_READY | IIR_RX_READY));
>
> Space between '&' and '(' please.
>
> > + spin_unlock(&uart->port.lock);
> > + return IRQ_HANDLED;
> > +}
> ...
> > +static void bfin_serial_dma_rx_chars(struct bfin_serial_port * uart)
> > +{
> > + struct tty_struct *tty = uart->port.info->tty;
> > + int i, flg, status;
> > +
> > + status = UART_GET_LSR(uart);
> > + uart->port.icount.rx += CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail, UART_XMIT_SIZE);;
> > +
> > + if (status & BI) {
> > + uart->port.icount.brk++;
> > + if (uart_handle_break(&uart->port))
> > + goto dma_ignore_char;
> > + flg = TTY_BREAK;
> > + } else if (status & PE) {
> > + flg = TTY_PARITY;
> > + uart->port.icount.parity++;
> > + } else if (status & OE) {
> > + flg = TTY_OVERRUN;
> > + uart->port.icount.overrun++;
> > + } else if (status & FE) {
> > + flg = TTY_FRAME;
> > + uart->port.icount.frame++;
> > + } else
> > + flg = TTY_NORMAL;
>
> No termios handling.
>
> > +
> > + for (i = uart->rx_dma_buf.head; i < uart->rx_dma_buf.tail; i++) {
> > + if (uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
> > + goto dma_ignore_char;
> > + uart_insert_char(&uart->port, status, 2, uart->rx_dma_buf.buf[i], flg);
> > + }
> > +dma_ignore_char:
> > + tty_flip_buffer_push(tty);
> > +}
> ...
> > +/*
> > + * Handle any change of modem status signal since we were last called.
> > + */
> > +static void bfin_serial_mctrl_check(struct bfin_serial_port *uart)
> > +{
> > +#ifdef CONFIG_SERIAL_BFIN_CTSRTS
> > + unsigned int status;
> > +# ifdef CONFIG_SERIAL_BFIN_DMA
> > + struct uart_info *info = uart->port.info;
> > + struct tty_struct *tty = info->tty;
> > +
> > + status = bfin_serial_get_mctrl(&uart->port);
> > + if (!(status & TIOCM_CTS)) {
> > + tty->hw_stopped = 1;
> > + } else {
> > + tty->hw_stopped = 0;
> > + }
>
> A change of CTS doesn't always mean transmission has to stop.
> uart_handle_cts_change() knows when this has to happen. Use it.
If I recall correctly, uart_handle_cts_change can't handle DMA case on blackfin.
>
> > +# else
> > + status = bfin_serial_get_mctrl(&uart->port);
> > + uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
> > + if (!(status & TIOCM_CTS))
> > + schedule_work(&uart->cts_workqueue);
> > +# endif
> > +#endif
> > +}
> ...
> > +static void
> > +bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
> > + struct ktermios *old)
> > +{
> > + struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
> > + unsigned long flags;
> > + unsigned int baud, quot;
> > + unsigned short val, ier;
> > +
> > + baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
> > + quot = bfin_serial_calc_baud(port->uartclk, baud);
> > + spin_lock_irqsave(&uart->port.lock, flags);
>
> Doesn't set port.ignore_status_mask nor port.read_status_mask, so *NONE*
> of the termios modes to do with error handling will work with this driver.
> In fact, I doubt it's possible to even change the parity, length or stop
> bit settings as this code stands.
Yes, not implemented, I'll do in future.
>
> > +
> > + /* Disable UART */
> > + ier = UART_GET_IER(uart);
> > + UART_PUT_IER(uart, 0);
> > +
> > + /* Set DLAB in LCR to Access DLL and DLH */
> > + val = UART_GET_LCR(uart);
> > + val |= DLAB;
> > + UART_PUT_LCR(uart, val);
> > + __builtin_bfin_ssync();
> > +
> > + UART_PUT_DLL(uart, quot & 0xFF);
> > + __builtin_bfin_ssync();
> > + UART_PUT_DLH(uart, (quot >> 8) & 0xFF);
> > + __builtin_bfin_ssync();
> > +
> > + /* Clear DLAB in LCR to Access THR RBR IER */
> > + val = UART_GET_LCR(uart);
> > + val &= ~DLAB;
> > + UART_PUT_LCR(uart, val);
> > + __builtin_bfin_ssync();
> > +
> > + /* Enable UART */
> > + UART_PUT_IER(uart, ier);
> > +
> > + val = UART_GET_GCTL(uart);
> > + val |= UCEN;
> > + UART_PUT_GCTL(uart, val);
> > +
> > + spin_unlock_irqrestore(&uart->port.lock, flags);
> > +}
> ...
> > +static int bfin_serial_calc_baud(unsigned int uartclk, unsigned int baud)
> > +{
> > + int quot;
> > +
> > + quot = uartclk / (baud * 8);
> > + if ((quot & 0x1) == 1) {
> > + quot++;
> > + }
> > + return quot/2;
>
> Something wrong with the standard function (uart_get_divisor)? If so, what?
No problem, will change to use it.
>
> > +}
> ...
> > +#ifdef CONFIG_SERIAL_BFIN_CONSOLE
> > +/*
> > + * Interrupts are disabled on entering
> > + */
> > +static void
> > +bfin_serial_console_write(struct console *co, const char *s, unsigned int count)
> > +{
> > + struct bfin_serial_port *uart = &bfin_serial_ports[co->index];
> > + int flags = 0;
> > + unsigned short status, tmp;
> > + int i;
> > +
> > + spin_lock_irqsave(&uart->port.lock, flags);
> > + for (i = 0; i < count; i++) {
> > + do {
> > + status = UART_GET_LSR(uart);
> > + } while (!(status & THRE));
> > +
> > + tmp = UART_GET_LCR(uart);
> > + tmp &= ~DLAB;
> > + UART_PUT_LCR(uart, tmp);
> > +
> > + UART_PUT_CHAR(uart, s[i]);
> > + if (s[i] == '\n') {
> > + do {
> > + status = UART_GET_LSR(uart);
> > + } while(!(status & THRE));
> > + UART_PUT_CHAR(uart, '\r');
> > + }
>
> Use uart_console_write()
>
> > + }
> > + spin_unlock_irqrestore(&uart->port.lock, flags);
> > +
> > +}
> > +
> > +/*
> > + * If the port was already initialised (eg, by a boot loader),
> > + * try to determine the current setup.
> > + */
> > +static void __init
> > +bfin_serial_console_get_options(struct bfin_serial_port *uart, int *baud,
> > + int *parity, int *bits)
> > +{
> > + unsigned short status;
> > +
> > + status = UART_GET_IER(uart) & (ERBFI | ETBEI);
> > + if (status == (ERBFI | ETBEI)) {
> > + /* ok, the port was enabled */
> > + unsigned short lcr, val;
> > + unsigned short dlh, dll;
> > +
> > + lcr = UART_GET_LCR(uart);
> > +
> > + *parity = 'n';
> > + if (lcr & PEN) {
> > + if (lcr & EPS)
> > + *parity = 'e';
> > + else
> > + *parity = 'o';
> > + }
> > + switch (lcr & 0x03) {
> > + case 0: *bits = 5; break;
> > + case 1: *bits = 6; break;
> > + case 2: *bits = 7; break;
> > + case 3: *bits = 8; break;
> > + }
>
> You do have length and parity settings on this port, yet you don't
> have code in your set_termios method to set them from the termios...
That means termios can't be changed on the fly. it will be enabled in future.
>
> > + /* Set DLAB in LCR to Access DLL and DLH */
> > + val = UART_GET_LCR(uart);
> > + val |= DLAB;
> > + UART_PUT_LCR(uart, val);
> > +
> > + dll = UART_GET_DLL(uart);
> > + dlh = UART_GET_DLH(uart);
> > +
> > + /* Clear DLAB in LCR to Access THR RBR IER */
> > + val = UART_GET_LCR(uart);
> > + val &= ~DLAB;
> > + UART_PUT_LCR(uart, val);
> > +
> > + *baud = get_sclk() / (16*(dll | dlh << 8));
> > + }
> > + pr_debug("%s:baud = %d, parity = %c, bits= %d\n", __FUNCTION__, *baud, *parity, *bits);
> > +}
>
Thanks for your comment and suggestion.
I'll get back to you soon.
-Aubrey