* [PATCH] atmel_serial: Atmel RS485 support
@ 2010-03-19 8:28 ` Claudio Scordino
0 siblings, 0 replies; 8+ messages in thread
From: Claudio Scordino @ 2010-03-19 8:28 UTC (permalink / raw)
To: Linux Kernel
Cc: linux-arm-kernel, John Nicholls, Rick Bronson, Sebastian Heutling,
michael trimarchi, alan, kernel
[-- Attachment #1: Type: text/plain, Size: 247 bytes --]
Hi all,
this is a patch to add RS485 support to the atmel_serial driver.
The patch has been successfully tested by Sebastian Heutling (CC:-ed).
Feedback (comments, suggestions, further testing) is welcome.
Many thanks,
Claudio
[-- Attachment #2: atmel_serial_rs485.patch --]
[-- Type: text/x-patch, Size: 15692 bytes --]
atmel_serial: RS485 support
Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Signed-off-by: Michael Trimarchi <michael@evidence.eu.com>
Signed-off-by: Rick Bronson <rick@efn.org>
Signed-off-by: Sebastian Heutling <Sebastian.Heutling@who-ing.de>
---
arch/arm/include/asm/ioctls.h | 2 +
arch/arm/mach-at91/include/mach/board.h | 4 +
drivers/serial/atmel_serial.c | 247 ++++++++++++++++++++++++++-----
3 files changed, 218 insertions(+), 35 deletions(-)
diff --git a/arch/arm/include/asm/ioctls.h b/arch/arm/include/asm/ioctls.h
index a91d8a1..82f2177 100644
--- a/arch/arm/include/asm/ioctls.h
+++ b/arch/arm/include/asm/ioctls.h
@@ -70,6 +70,8 @@
#define TIOCGICOUNT 0x545D /* read serial port inline interrupt counts */
#define FIOQSIZE 0x545E
+#define TIOCSRS485 0x5461
+
/* Used for packet mode */
#define TIOCPKT_DATA 0
#define TIOCPKT_FLUSHREAD 1
diff --git a/arch/arm/mach-at91/include/mach/board.h b/arch/arm/mach-at91/include/mach/board.h
index ceaec6c..21f1308 100644
--- a/arch/arm/mach-at91/include/mach/board.h
+++ b/arch/arm/mach-at91/include/mach/board.h
@@ -39,6 +39,7 @@
#include <linux/usb/atmel_usba_udc.h>
#include <linux/atmel-mci.h>
#include <sound/atmel-ac97c.h>
+#include <linux/serial.h>
/* USB Device */
struct at91_udc_data {
@@ -146,6 +147,9 @@ struct atmel_uart_data {
short use_dma_tx; /* use transmit DMA? */
short use_dma_rx; /* use receive DMA? */
void __iomem *regs; /* virtual base address, if any */
+ struct serial_rs485 rs485; /* this flag specifies
+ if the uart must be used
+ as RS485 */
};
extern void __init at91_add_device_serial(void);
diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index 2c9bf9b..21bf3a8 100644
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -38,6 +38,7 @@
#include <linux/dma-mapping.h>
#include <linux/atmel_pdc.h>
#include <linux/atmel_serial.h>
+#include <linux/uaccess.h>
#include <asm/io.h>
@@ -59,6 +60,9 @@
#include <linux/serial_core.h>
+static void atmel_start_rx(struct uart_port *port);
+static void atmel_stop_rx(struct uart_port *port);
+
#ifdef CONFIG_SERIAL_ATMEL_TTYAT
/* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we
@@ -93,6 +97,7 @@
#define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR)
#define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR)
#define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR)
+#define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR)
/* PDC registers */
#define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR)
@@ -147,6 +152,16 @@ struct atmel_uart_port {
unsigned int irq_status_prev;
struct circ_buf rx_ring;
+
+ struct serial_rs485 rs485; /* this flag specifies
+ if the uart must be used
+ as RS485 */
+ /* Fields related to interrupts:
+ if (rs485) = ATMEL_US_TXEMPTY
+ else if (use_dma_tx) = ATMEL_US_ENDTX | ATMEL_US_TXBUFE
+ else = ATMEL_US_TXRDY;
+ */
+ unsigned int tx_done_mask;
};
static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
@@ -187,6 +202,85 @@ static bool atmel_use_dma_tx(struct uart_port *port)
}
#endif
+/* Enable or disable the rs485 support */
+void atmel_enable_disable_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ unsigned long flags;
+ unsigned int mode;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ mode = UART_GET_MR(port);
+
+ /* Resetting serial mode to RS232 (0x0) */
+ mode &= ~ATMEL_US_USMODE;
+
+ atmel_port->rs485 = *rs485conf;
+
+ if (!(rs485conf->flags & SER_RS485_ENABLED)) {
+ dev_dbg(port->dev, "Setting UART to RS232\n");
+ if (atmel_use_dma_tx(port))
+ atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
+ else
+ atmel_port->tx_done_mask = ATMEL_US_TXRDY;
+ } else {
+ dev_dbg(port->dev, "Setting UART to RS485\n");
+ atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
+ UART_PUT_TTGR(port, rs485conf->delay_rts_before_send);
+ mode |= ATMEL_US_USMODE_RS485;
+ }
+ UART_PUT_MR(port, mode);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+
+static ssize_t show_rs485(struct device *dev, struct device_attribute *attr, \
+ char *buf)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct uart_port *port = platform_get_drvdata(pdev);
+ unsigned int current_mode;
+
+ current_mode = UART_GET_MR(port);
+ current_mode &= ATMEL_US_USMODE;
+ return snprintf(buf, PAGE_SIZE, "%u\n", current_mode);
+}
+
+static ssize_t set_rs485(struct device *dev, struct device_attribute *attr, \
+ const char *buf, size_t len)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct uart_port *port = platform_get_drvdata(pdev);
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ struct serial_rs485 rs485conf = atmel_port->rs485;
+ unsigned int value;
+
+ if (buf == NULL)
+ goto err;
+
+ value = simple_strtoul(buf, NULL, 10);
+
+ if ((value != 0) && (value != 1))
+ goto err;
+
+ if (!value) {
+ rs485conf.flags &= ~(SER_RS485_ENABLED);
+ } else {
+ rs485conf.flags |= SER_RS485_ENABLED;
+ /* 0x4 is the normal reset value. */
+ rs485conf.delay_rts_before_send = 0x00000004;
+ }
+
+ atmel_enable_disable_rs485(port, &rs485conf);
+
+err:
+ return strnlen(buf, PAGE_SIZE);
+}
+
+static DEVICE_ATTR(rs485, 0644, show_rs485, set_rs485);
+
/*
* Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
*/
@@ -202,6 +296,7 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
{
unsigned int control = 0;
unsigned int mode;
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
#ifdef CONFIG_ARCH_AT91RM9200
if (cpu_is_at91rm9200()) {
@@ -236,6 +331,16 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
mode |= ATMEL_US_CHMODE_LOC_LOOP;
else
mode |= ATMEL_US_CHMODE_NORMAL;
+
+ /* Resetting serial mode to RS232 (0x0) */
+ mode &= ~ATMEL_US_USMODE;
+
+ if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
+ dev_dbg(port->dev, "Keeping UART to RS485\n");
+ UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send);
+ mode |= ATMEL_US_USMODE_RS485;
+ } else
+ dev_dbg(port->dev, "Keeping UART to RS232\n");
UART_PUT_MR(port, mode);
}
@@ -268,12 +373,17 @@ static u_int atmel_get_mctrl(struct uart_port *port)
*/
static void atmel_stop_tx(struct uart_port *port)
{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
if (atmel_use_dma_tx(port)) {
/* disable PDC transmit */
UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
- UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
- } else
- UART_PUT_IDR(port, ATMEL_US_TXRDY);
+ }
+ /* Disable interrupts */
+ UART_PUT_IDR(port, atmel_port->tx_done_mask);
+
+ if (atmel_port->rs485.flags & SER_RS485_ENABLED)
+ atmel_start_rx(port);
}
/*
@@ -281,17 +391,22 @@ static void atmel_stop_tx(struct uart_port *port)
*/
static void atmel_start_tx(struct uart_port *port)
{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
if (atmel_use_dma_tx(port)) {
if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN)
/* The transmitter is already running. Yes, we
really need this.*/
return;
- UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
+ if (atmel_port->rs485.flags & SER_RS485_ENABLED)
+ atmel_stop_rx(port);
+
/* re-enable PDC transmit */
UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
- } else
- UART_PUT_IER(port, ATMEL_US_TXRDY);
+ }
+ /* Enable interrupts */
+ UART_PUT_IER(port, atmel_port->tx_done_mask);
}
/*
@@ -302,12 +417,28 @@ static void atmel_stop_rx(struct uart_port *port)
if (atmel_use_dma_rx(port)) {
/* disable PDC receive */
UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS);
- UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
+ UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | port->read_status_mask);
} else
UART_PUT_IDR(port, ATMEL_US_RXRDY);
}
/*
+ * start receiving - port is in process of being opened.
+ */
+static void atmel_start_rx(struct uart_port *port)
+{
+ UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */
+
+ if (atmel_use_dma_rx(port)) {
+ /* enable PDC controller */
+ UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | port->read_status_mask);
+ UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
+ } else
+ UART_PUT_IER(port, ATMEL_US_RXRDY);
+}
+
+
+/*
* Enable modem status interrupts
*/
static void atmel_enable_ms(struct uart_port *port)
@@ -428,8 +559,9 @@ static void atmel_rx_chars(struct uart_port *port)
static void atmel_tx_chars(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
- if (port->x_char && UART_GET_CSR(port) & ATMEL_US_TXRDY) {
+ if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) {
UART_PUT_CHAR(port, port->x_char);
port->icount.tx++;
port->x_char = 0;
@@ -437,7 +569,7 @@ static void atmel_tx_chars(struct uart_port *port)
if (uart_circ_empty(xmit) || uart_tx_stopped(port))
return;
- while (UART_GET_CSR(port) & ATMEL_US_TXRDY) {
+ while (UART_GET_CSR(port) & atmel_port->tx_done_mask) {
UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
@@ -449,7 +581,8 @@ static void atmel_tx_chars(struct uart_port *port)
uart_write_wakeup(port);
if (!uart_circ_empty(xmit))
- UART_PUT_IER(port, ATMEL_US_TXRDY);
+ /* Enable interrupts */
+ UART_PUT_IER(port, atmel_port->tx_done_mask);
}
/*
@@ -501,18 +634,10 @@ atmel_handle_transmit(struct uart_port *port, unsigned int pending)
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
- if (atmel_use_dma_tx(port)) {
- /* PDC transmit */
- if (pending & (ATMEL_US_ENDTX | ATMEL_US_TXBUFE)) {
- UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
- tasklet_schedule(&atmel_port->tasklet);
- }
- } else {
- /* Interrupt transmit */
- if (pending & ATMEL_US_TXRDY) {
- UART_PUT_IDR(port, ATMEL_US_TXRDY);
- tasklet_schedule(&atmel_port->tasklet);
- }
+ if (pending & atmel_port->tx_done_mask) {
+ /* Either PDC or interrupt transmission */
+ UART_PUT_IDR(port, atmel_port->tx_done_mask);
+ tasklet_schedule(&atmel_port->tasklet);
}
}
@@ -590,9 +715,15 @@ static void atmel_tx_dma(struct uart_port *port)
UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
UART_PUT_TCR(port, count);
- /* re-enable PDC transmit and interrupts */
+ /* re-enable PDC transmit */
UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
- UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
+ /* Enable interrupts */
+ UART_PUT_IER(port, atmel_port->tx_done_mask);
+ } else {
+ if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
+ /* DMA done, stop TX, start RX for RS485 */
+ atmel_start_rx(port);
+ }
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
@@ -1017,6 +1148,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
{
unsigned long flags;
unsigned int mode, imr, quot, baud;
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
/* Get current mode register */
mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL
@@ -1115,6 +1247,16 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
/* disable receiver and transmitter */
UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
+ /* Resetting serial mode to RS232 (0x0) */
+ mode &= ~ATMEL_US_USMODE;
+
+ if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
+ dev_dbg(port->dev, "Keeping UART to RS485\n");
+ UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send);
+ mode |= ATMEL_US_USMODE_RS485;
+ } else
+ dev_dbg(port->dev, "Keeping UART to RS232\n");
+
/* set the parity, stop bits and data size */
UART_PUT_MR(port, mode);
@@ -1231,6 +1373,31 @@ static void atmel_poll_put_char(struct uart_port *port, unsigned char ch)
}
#endif
+static int atmel_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg)
+{
+
+ switch (cmd) {
+ case TIOCSRS485:
+ {
+ struct serial_rs485 rs485conf;
+ if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg,
+ sizeof(rs485conf)))
+ return -EFAULT;
+
+ dev_dbg(port->dev, "enable e/o disable rs485\n");
+
+ atmel_enable_disable_rs485(port, &rs485conf);
+ }
+ break;
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+ return 0;
+}
+
+
+
static struct uart_ops atmel_pops = {
.tx_empty = atmel_tx_empty,
.set_mctrl = atmel_set_mctrl,
@@ -1250,6 +1417,7 @@ static struct uart_ops atmel_pops = {
.config_port = atmel_config_port,
.verify_port = atmel_verify_port,
.pm = atmel_serial_pm,
+ .ioctl = atmel_ioctl,
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = atmel_poll_get_char,
.poll_put_char = atmel_poll_put_char,
@@ -1265,13 +1433,12 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
struct uart_port *port = &atmel_port->uart;
struct atmel_uart_data *data = pdev->dev.platform_data;
- port->iotype = UPIO_MEM;
- port->flags = UPF_BOOT_AUTOCONF;
- port->ops = &atmel_pops;
- port->fifosize = 1;
- port->line = pdev->id;
- port->dev = &pdev->dev;
-
+ port->iotype = UPIO_MEM;
+ port->flags = UPF_BOOT_AUTOCONF;
+ port->ops = &atmel_pops;
+ port->fifosize = 1;
+ port->line = pdev->id;
+ port->dev = &pdev->dev;
port->mapbase = pdev->resource[0].start;
port->irq = pdev->resource[1].start;
@@ -1299,8 +1466,15 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
atmel_port->use_dma_rx = data->use_dma_rx;
atmel_port->use_dma_tx = data->use_dma_tx;
- if (atmel_use_dma_tx(port))
+ atmel_port->rs485 = data->rs485;
+ /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
+ if (atmel_port->rs485.flags & SER_RS485_ENABLED)
+ atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
+ else if (atmel_use_dma_tx(port)) {
port->fifosize = PDC_BUFFER_SIZE;
+ atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
+ } else
+ atmel_port->tx_done_mask = ATMEL_US_TXRDY;
}
/*
@@ -1334,6 +1508,7 @@ static void atmel_console_putchar(struct uart_port *port, int ch)
static void atmel_console_write(struct console *co, const char *s, u_int count)
{
struct uart_port *port = &atmel_ports[co->index].uart;
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
unsigned int status, imr;
unsigned int pdc_tx;
@@ -1341,7 +1516,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count)
* First, save IMR and then disable interrupts
*/
imr = UART_GET_IMR(port);
- UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY);
+ UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask);
/* Store PDC transmit status and disable it */
pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN;
@@ -1355,7 +1530,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count)
*/
do {
status = UART_GET_CSR(port);
- } while (!(status & ATMEL_US_TXRDY));
+ } while (!(status & atmel_port->tx_done_mask));
/* Restore PDC transmit status */
if (pdc_tx)
@@ -1587,7 +1762,7 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev)
device_init_wakeup(&pdev->dev, 1);
platform_set_drvdata(pdev, port);
- return 0;
+ return device_create_file(&(pdev->dev), &dev_attr_rs485);
err_add_port:
kfree(port->rx_ring.buf);
@@ -1619,6 +1794,8 @@ static int __devexit atmel_serial_remove(struct platform_device *pdev)
clk_put(atmel_port->clk);
+ device_remove_file(&(pdev->dev), &dev_attr_rs485);
+
return ret;
}
--
1.6.0.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH] atmel_serial: Atmel RS485 support
2010-03-19 8:28 ` Claudio Scordino
@ 2010-03-21 20:15 ` Ryan Mallon
-1 siblings, 0 replies; 8+ messages in thread
From: Ryan Mallon @ 2010-03-21 20:15 UTC (permalink / raw)
To: linux-arm-kernel
Claudio Scordino wrote:
> Hi all,
>
> this is a patch to add RS485 support to the atmel_serial driver.
>
> The patch has been successfully tested by Sebastian Heutling (CC:-ed).
>
> Feedback (comments, suggestions, further testing) is welcome.
>
> Many thanks,
>
> Claudio
>
Please post patches inline in the message body as it makes them easier
to reply to. Some comments below:
> atmel_serial: RS485 support Signed-off-by: Claudio Scordino
> <claudio@evidence.eu.com> Signed-off-by: Michael Trimarchi
> <michael@evidence.eu.com> Signed-off-by: Rick Bronson <rick@efn.org>
> Signed-off-by: Sebastian Heutling <Sebastian.Heutling@who-ing.de> ---
> arch/arm/include/asm/ioctls.h | 2 +
> arch/arm/mach-at91/include/mach/board.h | 4 +
> drivers/serial/atmel_serial.c | 247 ++++++++++++++++++++++++++----- 3
> files changed, 218 insertions(+), 35 deletions(-) diff --git
> a/arch/arm/include/asm/ioctls.h b/arch/arm/include/asm/ioctls.h index
> a91d8a1..82f2177 100644 --- a/arch/arm/include/asm/ioctls.h +++
> b/arch/arm/include/asm/ioctls.h @@ -70,6 +70,8 @@ #define TIOCGICOUNT
> 0x545D /* read serial port inline interrupt counts */ #define FIOQSIZE
> 0x545E +#define TIOCSRS485 0x5461 + /* Used for packet mode */ #define
> TIOCPKT_DATA 0 #define TIOCPKT_FLUSHREAD 1 diff --git
> a/arch/arm/mach-at91/include/mach/board.h
> b/arch/arm/mach-at91/include/mach/board.h index ceaec6c..21f1308
> 100644 --- a/arch/arm/mach-at91/include/mach/board.h +++
> b/arch/arm/mach-at91/include/mach/board.h @@ -39,6 +39,7 @@ #include
> <linux/usb/atmel_usba_udc.h> #include <linux/atmel-mci.h> #include
> <sound/atmel-ac97c.h> +#include <linux/serial.h> /* USB Device */
> struct at91_udc_data { @@ -146,6 +147,9 @@ struct atmel_uart_data {
> short use_dma_tx; /* use transmit DMA? */ short use_dma_rx; /* use
> receive DMA? */ void __iomem *regs; /* virtual base address, if any */
> + struct serial_rs485 rs485; /* this flag specifies + if the uart must
> be used + as RS485 */
This comment is misleading, it is a struct not a flag. The comment should
say that it is the rs485 settings for the uart.
> }; extern void __init at91_add_device_serial(void); diff --git
> a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c index
> 2c9bf9b..21bf3a8 100644 --- a/drivers/serial/atmel_serial.c +++
> b/drivers/serial/atmel_serial.c @@ -38,6 +38,7 @@ #include
> <linux/dma-mapping.h> #include <linux/atmel_pdc.h> #include
> <linux/atmel_serial.h> +#include <linux/uaccess.h> #include <asm/io.h>
> @@ -59,6 +60,9 @@ #include <linux/serial_core.h> +static void
> atmel_start_rx(struct uart_port *port); +static void
> atmel_stop_rx(struct uart_port *port);
Can you move these functions, so that these declarations are not needed?
> #ifdef CONFIG_SERIAL_ATMEL_TTYAT /* Use device name ttyAT, major 204
> and minor 154-169. This is necessary if we @@ -93,6 +97,7 @@ #define
> UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR)
> #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase +
> ATMEL_US_BRGR) #define UART_PUT_RTOR(port,v) __raw_writel(v,
> (port)->membase + ATMEL_US_RTOR) +#define UART_PUT_TTGR(port, v)
> __raw_writel(v, (port)->membase + ATMEL_US_TTGR) /* PDC registers */
> #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase +
> ATMEL_PDC_PTCR) @@ -147,6 +152,16 @@ struct atmel_uart_port { unsigned
> int irq_status_prev; struct circ_buf rx_ring; + + struct serial_rs485
> rs485; /* this flag specifies + if the uart must be used + as RS485 */
Same here.
> + /* Fields related to interrupts: + if (rs485) = ATMEL_US_TXEMPTY +
> else if (use_dma_tx) = ATMEL_US_ENDTX | ATMEL_US_TXBUFE + else =
> ATMEL_US_TXRDY; + */
This comment doesn't really belong here. Also, please use *s as the beginning
of each line in a multi-line comment.
> + unsigned int tx_done_mask; }; static struct atmel_uart_port
> atmel_ports[ATMEL_MAX_UART]; @@ -187,6 +202,85 @@ static bool
> atmel_use_dma_tx(struct uart_port *port) } #endif +/* Enable or
> disable the rs485 support */ +void atmel_enable_disable_rs485(struct
> uart_port *port, struct serial_rs485 *rs485conf)
Please change the name of this function, something like atmel_config_rs485
would be better.
> +{ + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); +
> unsigned long flags; + unsigned int mode; + +
> spin_lock_irqsave(&port->lock, flags); + + mode = UART_GET_MR(port); +
> + /* Resetting serial mode to RS232 (0x0) */ + mode &=
> ~ATMEL_US_USMODE; + + atmel_port->rs485 = *rs485conf; + + if
> (!(rs485conf->flags & SER_RS485_ENABLED)) {
Reversing the logic of this if statement will make it slightly easier to read.
> + dev_dbg(port->dev, "Setting UART to RS232\n"); + if
> (atmel_use_dma_tx(port)) + atmel_port->tx_done_mask = ATMEL_US_ENDTX |
> ATMEL_US_TXBUFE; + else + atmel_port->tx_done_mask = ATMEL_US_TXRDY; +
> } else { + dev_dbg(port->dev, "Setting UART to RS485\n"); +
> atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; + UART_PUT_TTGR(port,
> rs485conf->delay_rts_before_send); + mode |= ATMEL_US_USMODE_RS485; +
> } + UART_PUT_MR(port, mode); + + spin_unlock_irqrestore(&port->lock,
> flags); +} + + +static ssize_t show_rs485(struct device *dev, struct
> device_attribute *attr, \ + char *buf) +{ + struct platform_device
> *pdev = to_platform_device(dev); + struct uart_port *port =
> platform_get_drvdata(pdev); + unsigned int current_mode; + +
> current_mode = UART_GET_MR(port); + current_mode &= ATMEL_US_USMODE;
current_mode = UART_GET_MR(port) & ATMEL_US_USMODE;
> + return snprintf(buf, PAGE_SIZE, "%u\n", current_mode); +} + +static
> ssize_t set_rs485(struct device *dev, struct device_attribute *attr, \
> + const char *buf, size_t len) +{ + struct platform_device *pdev =
> to_platform_device(dev); + struct uart_port *port =
> platform_get_drvdata(pdev); + struct atmel_uart_port *atmel_port =
> to_atmel_uart_port(port); + struct serial_rs485 rs485conf =
> atmel_port->rs485; + unsigned int value; + + if (buf == NULL) + goto err;
if (!buf)
goto -EINVAL;
> + + value = simple_strtoul(buf, NULL, 10); + + if ((value != 0) &&
> (value != 1)) + goto err;
Is there any reason to be so strict on the values, you could just do this:
value = !!(simple_strtoul(buf, NULL, 0));
which will allow the user to use values in any base, and will convert any
non-zero values to 1.
> + if (!value) { + rs485conf.flags &= ~(SER_RS485_ENABLED);
Again, I would revert the logic of this if statement.
> + } else { + rs485conf.flags |= SER_RS485_ENABLED; + /* 0x4 is the
> normal reset value. */ + rs485conf.delay_rts_before_send = 0x00000004;
> + } + + atmel_enable_disable_rs485(port, &rs485conf); + +err: + return
> strnlen(buf, PAGE_SIZE); +} + +static DEVICE_ATTR(rs485, 0644,
> show_rs485, set_rs485); + /* * Return TIOCSER_TEMT when transmitter
> FIFO and Shift register is empty. */ @@ -202,6 +296,7 @@ static void
> atmel_set_mctrl(struct uart_port *port, u_int mctrl) { unsigned int
> control = 0; unsigned int mode; + struct atmel_uart_port *atmel_port =
> to_atmel_uart_port(port); #ifdef CONFIG_ARCH_AT91RM9200 if
> (cpu_is_at91rm9200()) { @@ -236,6 +331,16 @@ static void
> atmel_set_mctrl(struct uart_port *port, u_int mctrl) mode |=
> ATMEL_US_CHMODE_LOC_LOOP; else mode |= ATMEL_US_CHMODE_NORMAL; + + /*
> Resetting serial mode to RS232 (0x0) */ + mode &= ~ATMEL_US_USMODE; +
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { +
> dev_dbg(port->dev, "Keeping UART to RS485\n"); + UART_PUT_TTGR(port,
> atmel_port->rs485.delay_rts_before_send); + mode |=
> ATMEL_US_USMODE_RS485; + } else + dev_dbg(port->dev, "Keeping UART to
> RS232\n"); UART_PUT_MR(port, mode); } @@ -268,12 +373,17 @@ static
> u_int atmel_get_mctrl(struct uart_port *port) */ static void
> atmel_stop_tx(struct uart_port *port) { + struct atmel_uart_port
> *atmel_port = to_atmel_uart_port(port); + if (atmel_use_dma_tx(port))
> { /* disable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS); -
> UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); - } else -
> UART_PUT_IDR(port, ATMEL_US_TXRDY); + } + /* Disable interrupts */ +
> UART_PUT_IDR(port, atmel_port->tx_done_mask); + + if
> (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_start_rx(port);
> } /* @@ -281,17 +391,22 @@ static void atmel_stop_tx(struct uart_port
> *port) */ static void atmel_start_tx(struct uart_port *port) { +
> struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + if
> (atmel_use_dma_tx(port)) { if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN)
> /* The transmitter is already running. Yes, we really need this.*/
> return; - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); + if
> (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_stop_rx(port); +
> /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - }
> else - UART_PUT_IER(port, ATMEL_US_TXRDY); + } + /* Enable interrupts
> */ + UART_PUT_IER(port, atmel_port->tx_done_mask); } /* @@ -302,12
> +417,28 @@ static void atmel_stop_rx(struct uart_port *port) if
> (atmel_use_dma_rx(port)) { /* disable PDC receive */
> UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS); - UART_PUT_IDR(port,
> ATMEL_US_ENDRX | ATMEL_US_TIMEOUT); + UART_PUT_IDR(port,
> ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | port->read_status_mask);
This line, and a couple of others extend over 80 characters, can you please
reformat, ie:
UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
port->read_status_mask);
> } else UART_PUT_IDR(port, ATMEL_US_RXRDY);
Please use braces even on single line else statements in the case where the
if statement has braces.
> } /* + * start receiving - port is in process of being opened. + */
> +static void atmel_start_rx(struct uart_port *port) +{ +
> UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */ +
> + if (atmel_use_dma_rx(port)) { + /* enable PDC controller */ +
> UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
> port->read_status_mask); + UART_PUT_PTCR(port, ATMEL_PDC_RXTEN); + }
> else + UART_PUT_IER(port, ATMEL_US_RXRDY); +} + + +/* * Enable modem
> status interrupts */ static void atmel_enable_ms(struct uart_port
> *port) @@ -428,8 +559,9 @@ static void atmel_rx_chars(struct uart_port
> *port) static void atmel_tx_chars(struct uart_port *port) { struct
> circ_buf *xmit = &port->state->xmit; + struct atmel_uart_port
> *atmel_port = to_atmel_uart_port(port); - if (port->x_char &&
> UART_GET_CSR(port) & ATMEL_US_TXRDY) { + if (port->x_char &&
> UART_GET_CSR(port) & atmel_port->tx_done_mask) { UART_PUT_CHAR(port,
> port->x_char); port->icount.tx++; port->x_char = 0; @@ -437,7 +569,7
> @@ static void atmel_tx_chars(struct uart_port *port) if
> (uart_circ_empty(xmit) || uart_tx_stopped(port)) return; - while
> (UART_GET_CSR(port) & ATMEL_US_TXRDY) { + while (UART_GET_CSR(port) &
> atmel_port->tx_done_mask) { UART_PUT_CHAR(port,
> xmit->buf[xmit->tail]); xmit->tail = (xmit->tail + 1) &
> (UART_XMIT_SIZE - 1); port->icount.tx++; @@ -449,7 +581,8 @@ static
> void atmel_tx_chars(struct uart_port *port) uart_write_wakeup(port);
> if (!uart_circ_empty(xmit)) - UART_PUT_IER(port, ATMEL_US_TXRDY); + /*
> Enable interrupts */ + UART_PUT_IER(port, atmel_port->tx_done_mask); }
> /* @@ -501,18 +634,10 @@ atmel_handle_transmit(struct uart_port *port,
> unsigned int pending) { struct atmel_uart_port *atmel_port =
> to_atmel_uart_port(port); - if (atmel_use_dma_tx(port)) { - /* PDC
> transmit */ - if (pending & (ATMEL_US_ENDTX | ATMEL_US_TXBUFE)) { -
> UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); -
> tasklet_schedule(&atmel_port->tasklet); - } - } else { - /* Interrupt
> transmit */ - if (pending & ATMEL_US_TXRDY) { - UART_PUT_IDR(port,
> ATMEL_US_TXRDY); - tasklet_schedule(&atmel_port->tasklet); - } + if
> (pending & atmel_port->tx_done_mask) { + /* Either PDC or interrupt
> transmission */ + UART_PUT_IDR(port, atmel_port->tx_done_mask); +
> tasklet_schedule(&atmel_port->tasklet); } } @@ -590,9 +715,15 @@
> static void atmel_tx_dma(struct uart_port *port) UART_PUT_TPR(port,
> pdc->dma_addr + xmit->tail); UART_PUT_TCR(port, count); - /* re-enable
> PDC transmit and interrupts */ + /* re-enable PDC transmit */
> UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - UART_PUT_IER(port,
> ATMEL_US_ENDTX | ATMEL_US_TXBUFE); + /* Enable interrupts */ +
> UART_PUT_IER(port, atmel_port->tx_done_mask); + } else { + if
> (atmel_port->rs485.flags & SER_RS485_ENABLED) { + /* DMA done, stop
> TX, start RX for RS485 */ + atmel_start_rx(port); + } } if
> (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) @@ -1017,6 +1148,7 @@
> static void atmel_set_termios(struct uart_port *port, struct ktermios
> *termios, { unsigned long flags; unsigned int mode, imr, quot, baud; +
> struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); /* Get
> current mode register */ mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS
> | ATMEL_US_CHRL @@ -1115,6 +1247,16 @@ static void
> atmel_set_termios(struct uart_port *port, struct ktermios *termios, /*
> disable receiver and transmitter */ UART_PUT_CR(port, ATMEL_US_TXDIS |
> ATMEL_US_RXDIS); + /* Resetting serial mode to RS232 (0x0) */ + mode
> &= ~ATMEL_US_USMODE; + + if (atmel_port->rs485.flags &
> SER_RS485_ENABLED) { + dev_dbg(port->dev, "Keeping UART to RS485\n");
> + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); + mode
> |= ATMEL_US_USMODE_RS485; + } else + dev_dbg(port->dev, "Keeping UART
> to RS232\n"); + /* set the parity, stop bits and data size */
> UART_PUT_MR(port, mode); @@ -1231,6 +1373,31 @@ static void
> atmel_poll_put_char(struct uart_port *port, unsigned char ch) } #endif
> +static int atmel_ioctl(struct uart_port *port, unsigned int cmd,
> unsigned long arg) +{ + + switch (cmd) { + case TIOCSRS485: + { +
> struct serial_rs485 rs485conf;
Moving this declaration to the top of the function will remove two
indentation levels.
Is it necessary to have both an ioctl and a sysfs control for putting the
uart into rs485 mode? The ioctl is more standardised, so perhaps drop the
sysfs control?
> + if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg, +
> sizeof(rs485conf))) + return -EFAULT; + + dev_dbg(port->dev, "enable
> e/o disable rs485\n"); + + atmel_enable_disable_rs485(port,
> &rs485conf); + } + break; + + default: + return -ENOIOCTLCMD; + } +
> return 0; +} + + + static struct uart_ops atmel_pops = { .tx_empty =
> atmel_tx_empty, .set_mctrl = atmel_set_mctrl, @@ -1250,6 +1417,7 @@
> static struct uart_ops atmel_pops = { .config_port =
> atmel_config_port, .verify_port = atmel_verify_port, .pm =
> atmel_serial_pm, + .ioctl = atmel_ioctl, #ifdef CONFIG_CONSOLE_POLL
> .poll_get_char = atmel_poll_get_char, .poll_put_char =
> atmel_poll_put_char, @@ -1265,13 +1433,12 @@ static void __devinit
> atmel_init_port(struct atmel_uart_port *atmel_port, struct uart_port
> *port = &atmel_port->uart; struct atmel_uart_data *data =
> pdev->dev.platform_data; - port->iotype = UPIO_MEM; - port->flags =
> UPF_BOOT_AUTOCONF; - port->ops = &atmel_pops; - port->fifosize = 1; -
> port->line = pdev->id; - port->dev = &pdev->dev; - + port->iotype =
> UPIO_MEM; + port->flags = UPF_BOOT_AUTOCONF; + port->ops =
> &atmel_pops; + port->fifosize = 1; + port->line = pdev->id; +
> port->dev = &pdev->dev; port->mapbase = pdev->resource[0].start;
> port->irq = pdev->resource[1].start; @@ -1299,8 +1466,15 @@ static
> void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
> atmel_port->use_dma_rx = data->use_dma_rx; atmel_port->use_dma_tx =
> data->use_dma_tx; - if (atmel_use_dma_tx(port)) + atmel_port->rs485 =
> data->rs485; + /* Use TXEMPTY for interrupt when rs485 else TXRDY or
> ENDTX|TXBUFE */ + if (atmel_port->rs485.flags & SER_RS485_ENABLED) +
> atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; + else if
> (atmel_use_dma_tx(port)) { port->fifosize = PDC_BUFFER_SIZE; +
> atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE; + } else
> + atmel_port->tx_done_mask = ATMEL_US_TXRDY; } /* @@ -1334,6 +1508,7
> @@ static void atmel_console_putchar(struct uart_port *port, int ch)
> static void atmel_console_write(struct console *co, const char *s,
> u_int count) { struct uart_port *port = &atmel_ports[co->index].uart;
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> unsigned int status, imr; unsigned int pdc_tx; @@ -1341,7 +1516,7 @@
> static void atmel_console_write(struct console *co, const char *s,
> u_int count) * First, save IMR and then disable interrupts */ imr =
> UART_GET_IMR(port); - UART_PUT_IDR(port, ATMEL_US_RXRDY |
> ATMEL_US_TXRDY); + UART_PUT_IDR(port, ATMEL_US_RXRDY |
> atmel_port->tx_done_mask); /* Store PDC transmit status and disable it
> */ pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN; @@ -1355,7 +1530,7
> @@ static void atmel_console_write(struct console *co, const char *s,
> u_int count) */ do { status = UART_GET_CSR(port); - } while (!(status
> & ATMEL_US_TXRDY)); + } while (!(status & atmel_port->tx_done_mask));
> /* Restore PDC transmit status */ if (pdc_tx) @@ -1587,7 +1762,7 @@
> static int __devinit atmel_serial_probe(struct platform_device *pdev)
> device_init_wakeup(&pdev->dev, 1); platform_set_drvdata(pdev, port); -
> return 0; + return device_create_file(&(pdev->dev), &dev_attr_rs485);
> err_add_port: kfree(port->rx_ring.buf); @@ -1619,6 +1794,8 @@ static
> int __devexit atmel_serial_remove(struct platform_device *pdev)
> clk_put(atmel_port->clk); + device_remove_file(&(pdev->dev),
> &dev_attr_rs485); + return ret; } -- 1.6.0.4
~Ryan
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] atmel_serial: Atmel RS485 support
@ 2010-03-21 20:15 ` Ryan Mallon
0 siblings, 0 replies; 8+ messages in thread
From: Ryan Mallon @ 2010-03-21 20:15 UTC (permalink / raw)
To: Claudio Scordino
Cc: Linux Kernel, kernel, Rick Bronson, John Nicholls,
Sebastian Heutling, linux-arm-kernel, michael trimarchi, alan
Claudio Scordino wrote:
> Hi all,
>
> this is a patch to add RS485 support to the atmel_serial driver.
>
> The patch has been successfully tested by Sebastian Heutling (CC:-ed).
>
> Feedback (comments, suggestions, further testing) is welcome.
>
> Many thanks,
>
> Claudio
>
Please post patches inline in the message body as it makes them easier
to reply to. Some comments below:
> atmel_serial: RS485 support Signed-off-by: Claudio Scordino
> <claudio@evidence.eu.com> Signed-off-by: Michael Trimarchi
> <michael@evidence.eu.com> Signed-off-by: Rick Bronson <rick@efn.org>
> Signed-off-by: Sebastian Heutling <Sebastian.Heutling@who-ing.de> ---
> arch/arm/include/asm/ioctls.h | 2 +
> arch/arm/mach-at91/include/mach/board.h | 4 +
> drivers/serial/atmel_serial.c | 247 ++++++++++++++++++++++++++----- 3
> files changed, 218 insertions(+), 35 deletions(-) diff --git
> a/arch/arm/include/asm/ioctls.h b/arch/arm/include/asm/ioctls.h index
> a91d8a1..82f2177 100644 --- a/arch/arm/include/asm/ioctls.h +++
> b/arch/arm/include/asm/ioctls.h @@ -70,6 +70,8 @@ #define TIOCGICOUNT
> 0x545D /* read serial port inline interrupt counts */ #define FIOQSIZE
> 0x545E +#define TIOCSRS485 0x5461 + /* Used for packet mode */ #define
> TIOCPKT_DATA 0 #define TIOCPKT_FLUSHREAD 1 diff --git
> a/arch/arm/mach-at91/include/mach/board.h
> b/arch/arm/mach-at91/include/mach/board.h index ceaec6c..21f1308
> 100644 --- a/arch/arm/mach-at91/include/mach/board.h +++
> b/arch/arm/mach-at91/include/mach/board.h @@ -39,6 +39,7 @@ #include
> <linux/usb/atmel_usba_udc.h> #include <linux/atmel-mci.h> #include
> <sound/atmel-ac97c.h> +#include <linux/serial.h> /* USB Device */
> struct at91_udc_data { @@ -146,6 +147,9 @@ struct atmel_uart_data {
> short use_dma_tx; /* use transmit DMA? */ short use_dma_rx; /* use
> receive DMA? */ void __iomem *regs; /* virtual base address, if any */
> + struct serial_rs485 rs485; /* this flag specifies + if the uart must
> be used + as RS485 */
This comment is misleading, it is a struct not a flag. The comment should
say that it is the rs485 settings for the uart.
> }; extern void __init at91_add_device_serial(void); diff --git
> a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c index
> 2c9bf9b..21bf3a8 100644 --- a/drivers/serial/atmel_serial.c +++
> b/drivers/serial/atmel_serial.c @@ -38,6 +38,7 @@ #include
> <linux/dma-mapping.h> #include <linux/atmel_pdc.h> #include
> <linux/atmel_serial.h> +#include <linux/uaccess.h> #include <asm/io.h>
> @@ -59,6 +60,9 @@ #include <linux/serial_core.h> +static void
> atmel_start_rx(struct uart_port *port); +static void
> atmel_stop_rx(struct uart_port *port);
Can you move these functions, so that these declarations are not needed?
> #ifdef CONFIG_SERIAL_ATMEL_TTYAT /* Use device name ttyAT, major 204
> and minor 154-169. This is necessary if we @@ -93,6 +97,7 @@ #define
> UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR)
> #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase +
> ATMEL_US_BRGR) #define UART_PUT_RTOR(port,v) __raw_writel(v,
> (port)->membase + ATMEL_US_RTOR) +#define UART_PUT_TTGR(port, v)
> __raw_writel(v, (port)->membase + ATMEL_US_TTGR) /* PDC registers */
> #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase +
> ATMEL_PDC_PTCR) @@ -147,6 +152,16 @@ struct atmel_uart_port { unsigned
> int irq_status_prev; struct circ_buf rx_ring; + + struct serial_rs485
> rs485; /* this flag specifies + if the uart must be used + as RS485 */
Same here.
> + /* Fields related to interrupts: + if (rs485) = ATMEL_US_TXEMPTY +
> else if (use_dma_tx) = ATMEL_US_ENDTX | ATMEL_US_TXBUFE + else =
> ATMEL_US_TXRDY; + */
This comment doesn't really belong here. Also, please use *s as the beginning
of each line in a multi-line comment.
> + unsigned int tx_done_mask; }; static struct atmel_uart_port
> atmel_ports[ATMEL_MAX_UART]; @@ -187,6 +202,85 @@ static bool
> atmel_use_dma_tx(struct uart_port *port) } #endif +/* Enable or
> disable the rs485 support */ +void atmel_enable_disable_rs485(struct
> uart_port *port, struct serial_rs485 *rs485conf)
Please change the name of this function, something like atmel_config_rs485
would be better.
> +{ + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); +
> unsigned long flags; + unsigned int mode; + +
> spin_lock_irqsave(&port->lock, flags); + + mode = UART_GET_MR(port); +
> + /* Resetting serial mode to RS232 (0x0) */ + mode &=
> ~ATMEL_US_USMODE; + + atmel_port->rs485 = *rs485conf; + + if
> (!(rs485conf->flags & SER_RS485_ENABLED)) {
Reversing the logic of this if statement will make it slightly easier to read.
> + dev_dbg(port->dev, "Setting UART to RS232\n"); + if
> (atmel_use_dma_tx(port)) + atmel_port->tx_done_mask = ATMEL_US_ENDTX |
> ATMEL_US_TXBUFE; + else + atmel_port->tx_done_mask = ATMEL_US_TXRDY; +
> } else { + dev_dbg(port->dev, "Setting UART to RS485\n"); +
> atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; + UART_PUT_TTGR(port,
> rs485conf->delay_rts_before_send); + mode |= ATMEL_US_USMODE_RS485; +
> } + UART_PUT_MR(port, mode); + + spin_unlock_irqrestore(&port->lock,
> flags); +} + + +static ssize_t show_rs485(struct device *dev, struct
> device_attribute *attr, \ + char *buf) +{ + struct platform_device
> *pdev = to_platform_device(dev); + struct uart_port *port =
> platform_get_drvdata(pdev); + unsigned int current_mode; + +
> current_mode = UART_GET_MR(port); + current_mode &= ATMEL_US_USMODE;
current_mode = UART_GET_MR(port) & ATMEL_US_USMODE;
> + return snprintf(buf, PAGE_SIZE, "%u\n", current_mode); +} + +static
> ssize_t set_rs485(struct device *dev, struct device_attribute *attr, \
> + const char *buf, size_t len) +{ + struct platform_device *pdev =
> to_platform_device(dev); + struct uart_port *port =
> platform_get_drvdata(pdev); + struct atmel_uart_port *atmel_port =
> to_atmel_uart_port(port); + struct serial_rs485 rs485conf =
> atmel_port->rs485; + unsigned int value; + + if (buf == NULL) + goto err;
if (!buf)
goto -EINVAL;
> + + value = simple_strtoul(buf, NULL, 10); + + if ((value != 0) &&
> (value != 1)) + goto err;
Is there any reason to be so strict on the values, you could just do this:
value = !!(simple_strtoul(buf, NULL, 0));
which will allow the user to use values in any base, and will convert any
non-zero values to 1.
> + if (!value) { + rs485conf.flags &= ~(SER_RS485_ENABLED);
Again, I would revert the logic of this if statement.
> + } else { + rs485conf.flags |= SER_RS485_ENABLED; + /* 0x4 is the
> normal reset value. */ + rs485conf.delay_rts_before_send = 0x00000004;
> + } + + atmel_enable_disable_rs485(port, &rs485conf); + +err: + return
> strnlen(buf, PAGE_SIZE); +} + +static DEVICE_ATTR(rs485, 0644,
> show_rs485, set_rs485); + /* * Return TIOCSER_TEMT when transmitter
> FIFO and Shift register is empty. */ @@ -202,6 +296,7 @@ static void
> atmel_set_mctrl(struct uart_port *port, u_int mctrl) { unsigned int
> control = 0; unsigned int mode; + struct atmel_uart_port *atmel_port =
> to_atmel_uart_port(port); #ifdef CONFIG_ARCH_AT91RM9200 if
> (cpu_is_at91rm9200()) { @@ -236,6 +331,16 @@ static void
> atmel_set_mctrl(struct uart_port *port, u_int mctrl) mode |=
> ATMEL_US_CHMODE_LOC_LOOP; else mode |= ATMEL_US_CHMODE_NORMAL; + + /*
> Resetting serial mode to RS232 (0x0) */ + mode &= ~ATMEL_US_USMODE; +
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { +
> dev_dbg(port->dev, "Keeping UART to RS485\n"); + UART_PUT_TTGR(port,
> atmel_port->rs485.delay_rts_before_send); + mode |=
> ATMEL_US_USMODE_RS485; + } else + dev_dbg(port->dev, "Keeping UART to
> RS232\n"); UART_PUT_MR(port, mode); } @@ -268,12 +373,17 @@ static
> u_int atmel_get_mctrl(struct uart_port *port) */ static void
> atmel_stop_tx(struct uart_port *port) { + struct atmel_uart_port
> *atmel_port = to_atmel_uart_port(port); + if (atmel_use_dma_tx(port))
> { /* disable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS); -
> UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); - } else -
> UART_PUT_IDR(port, ATMEL_US_TXRDY); + } + /* Disable interrupts */ +
> UART_PUT_IDR(port, atmel_port->tx_done_mask); + + if
> (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_start_rx(port);
> } /* @@ -281,17 +391,22 @@ static void atmel_stop_tx(struct uart_port
> *port) */ static void atmel_start_tx(struct uart_port *port) { +
> struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + if
> (atmel_use_dma_tx(port)) { if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN)
> /* The transmitter is already running. Yes, we really need this.*/
> return; - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); + if
> (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_stop_rx(port); +
> /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - }
> else - UART_PUT_IER(port, ATMEL_US_TXRDY); + } + /* Enable interrupts
> */ + UART_PUT_IER(port, atmel_port->tx_done_mask); } /* @@ -302,12
> +417,28 @@ static void atmel_stop_rx(struct uart_port *port) if
> (atmel_use_dma_rx(port)) { /* disable PDC receive */
> UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS); - UART_PUT_IDR(port,
> ATMEL_US_ENDRX | ATMEL_US_TIMEOUT); + UART_PUT_IDR(port,
> ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | port->read_status_mask);
This line, and a couple of others extend over 80 characters, can you please
reformat, ie:
UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
port->read_status_mask);
> } else UART_PUT_IDR(port, ATMEL_US_RXRDY);
Please use braces even on single line else statements in the case where the
if statement has braces.
> } /* + * start receiving - port is in process of being opened. + */
> +static void atmel_start_rx(struct uart_port *port) +{ +
> UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */ +
> + if (atmel_use_dma_rx(port)) { + /* enable PDC controller */ +
> UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
> port->read_status_mask); + UART_PUT_PTCR(port, ATMEL_PDC_RXTEN); + }
> else + UART_PUT_IER(port, ATMEL_US_RXRDY); +} + + +/* * Enable modem
> status interrupts */ static void atmel_enable_ms(struct uart_port
> *port) @@ -428,8 +559,9 @@ static void atmel_rx_chars(struct uart_port
> *port) static void atmel_tx_chars(struct uart_port *port) { struct
> circ_buf *xmit = &port->state->xmit; + struct atmel_uart_port
> *atmel_port = to_atmel_uart_port(port); - if (port->x_char &&
> UART_GET_CSR(port) & ATMEL_US_TXRDY) { + if (port->x_char &&
> UART_GET_CSR(port) & atmel_port->tx_done_mask) { UART_PUT_CHAR(port,
> port->x_char); port->icount.tx++; port->x_char = 0; @@ -437,7 +569,7
> @@ static void atmel_tx_chars(struct uart_port *port) if
> (uart_circ_empty(xmit) || uart_tx_stopped(port)) return; - while
> (UART_GET_CSR(port) & ATMEL_US_TXRDY) { + while (UART_GET_CSR(port) &
> atmel_port->tx_done_mask) { UART_PUT_CHAR(port,
> xmit->buf[xmit->tail]); xmit->tail = (xmit->tail + 1) &
> (UART_XMIT_SIZE - 1); port->icount.tx++; @@ -449,7 +581,8 @@ static
> void atmel_tx_chars(struct uart_port *port) uart_write_wakeup(port);
> if (!uart_circ_empty(xmit)) - UART_PUT_IER(port, ATMEL_US_TXRDY); + /*
> Enable interrupts */ + UART_PUT_IER(port, atmel_port->tx_done_mask); }
> /* @@ -501,18 +634,10 @@ atmel_handle_transmit(struct uart_port *port,
> unsigned int pending) { struct atmel_uart_port *atmel_port =
> to_atmel_uart_port(port); - if (atmel_use_dma_tx(port)) { - /* PDC
> transmit */ - if (pending & (ATMEL_US_ENDTX | ATMEL_US_TXBUFE)) { -
> UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); -
> tasklet_schedule(&atmel_port->tasklet); - } - } else { - /* Interrupt
> transmit */ - if (pending & ATMEL_US_TXRDY) { - UART_PUT_IDR(port,
> ATMEL_US_TXRDY); - tasklet_schedule(&atmel_port->tasklet); - } + if
> (pending & atmel_port->tx_done_mask) { + /* Either PDC or interrupt
> transmission */ + UART_PUT_IDR(port, atmel_port->tx_done_mask); +
> tasklet_schedule(&atmel_port->tasklet); } } @@ -590,9 +715,15 @@
> static void atmel_tx_dma(struct uart_port *port) UART_PUT_TPR(port,
> pdc->dma_addr + xmit->tail); UART_PUT_TCR(port, count); - /* re-enable
> PDC transmit and interrupts */ + /* re-enable PDC transmit */
> UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - UART_PUT_IER(port,
> ATMEL_US_ENDTX | ATMEL_US_TXBUFE); + /* Enable interrupts */ +
> UART_PUT_IER(port, atmel_port->tx_done_mask); + } else { + if
> (atmel_port->rs485.flags & SER_RS485_ENABLED) { + /* DMA done, stop
> TX, start RX for RS485 */ + atmel_start_rx(port); + } } if
> (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) @@ -1017,6 +1148,7 @@
> static void atmel_set_termios(struct uart_port *port, struct ktermios
> *termios, { unsigned long flags; unsigned int mode, imr, quot, baud; +
> struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); /* Get
> current mode register */ mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS
> | ATMEL_US_CHRL @@ -1115,6 +1247,16 @@ static void
> atmel_set_termios(struct uart_port *port, struct ktermios *termios, /*
> disable receiver and transmitter */ UART_PUT_CR(port, ATMEL_US_TXDIS |
> ATMEL_US_RXDIS); + /* Resetting serial mode to RS232 (0x0) */ + mode
> &= ~ATMEL_US_USMODE; + + if (atmel_port->rs485.flags &
> SER_RS485_ENABLED) { + dev_dbg(port->dev, "Keeping UART to RS485\n");
> + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); + mode
> |= ATMEL_US_USMODE_RS485; + } else + dev_dbg(port->dev, "Keeping UART
> to RS232\n"); + /* set the parity, stop bits and data size */
> UART_PUT_MR(port, mode); @@ -1231,6 +1373,31 @@ static void
> atmel_poll_put_char(struct uart_port *port, unsigned char ch) } #endif
> +static int atmel_ioctl(struct uart_port *port, unsigned int cmd,
> unsigned long arg) +{ + + switch (cmd) { + case TIOCSRS485: + { +
> struct serial_rs485 rs485conf;
Moving this declaration to the top of the function will remove two
indentation levels.
Is it necessary to have both an ioctl and a sysfs control for putting the
uart into rs485 mode? The ioctl is more standardised, so perhaps drop the
sysfs control?
> + if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg, +
> sizeof(rs485conf))) + return -EFAULT; + + dev_dbg(port->dev, "enable
> e/o disable rs485\n"); + + atmel_enable_disable_rs485(port,
> &rs485conf); + } + break; + + default: + return -ENOIOCTLCMD; + } +
> return 0; +} + + + static struct uart_ops atmel_pops = { .tx_empty =
> atmel_tx_empty, .set_mctrl = atmel_set_mctrl, @@ -1250,6 +1417,7 @@
> static struct uart_ops atmel_pops = { .config_port =
> atmel_config_port, .verify_port = atmel_verify_port, .pm =
> atmel_serial_pm, + .ioctl = atmel_ioctl, #ifdef CONFIG_CONSOLE_POLL
> .poll_get_char = atmel_poll_get_char, .poll_put_char =
> atmel_poll_put_char, @@ -1265,13 +1433,12 @@ static void __devinit
> atmel_init_port(struct atmel_uart_port *atmel_port, struct uart_port
> *port = &atmel_port->uart; struct atmel_uart_data *data =
> pdev->dev.platform_data; - port->iotype = UPIO_MEM; - port->flags =
> UPF_BOOT_AUTOCONF; - port->ops = &atmel_pops; - port->fifosize = 1; -
> port->line = pdev->id; - port->dev = &pdev->dev; - + port->iotype =
> UPIO_MEM; + port->flags = UPF_BOOT_AUTOCONF; + port->ops =
> &atmel_pops; + port->fifosize = 1; + port->line = pdev->id; +
> port->dev = &pdev->dev; port->mapbase = pdev->resource[0].start;
> port->irq = pdev->resource[1].start; @@ -1299,8 +1466,15 @@ static
> void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
> atmel_port->use_dma_rx = data->use_dma_rx; atmel_port->use_dma_tx =
> data->use_dma_tx; - if (atmel_use_dma_tx(port)) + atmel_port->rs485 =
> data->rs485; + /* Use TXEMPTY for interrupt when rs485 else TXRDY or
> ENDTX|TXBUFE */ + if (atmel_port->rs485.flags & SER_RS485_ENABLED) +
> atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; + else if
> (atmel_use_dma_tx(port)) { port->fifosize = PDC_BUFFER_SIZE; +
> atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE; + } else
> + atmel_port->tx_done_mask = ATMEL_US_TXRDY; } /* @@ -1334,6 +1508,7
> @@ static void atmel_console_putchar(struct uart_port *port, int ch)
> static void atmel_console_write(struct console *co, const char *s,
> u_int count) { struct uart_port *port = &atmel_ports[co->index].uart;
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> unsigned int status, imr; unsigned int pdc_tx; @@ -1341,7 +1516,7 @@
> static void atmel_console_write(struct console *co, const char *s,
> u_int count) * First, save IMR and then disable interrupts */ imr =
> UART_GET_IMR(port); - UART_PUT_IDR(port, ATMEL_US_RXRDY |
> ATMEL_US_TXRDY); + UART_PUT_IDR(port, ATMEL_US_RXRDY |
> atmel_port->tx_done_mask); /* Store PDC transmit status and disable it
> */ pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN; @@ -1355,7 +1530,7
> @@ static void atmel_console_write(struct console *co, const char *s,
> u_int count) */ do { status = UART_GET_CSR(port); - } while (!(status
> & ATMEL_US_TXRDY)); + } while (!(status & atmel_port->tx_done_mask));
> /* Restore PDC transmit status */ if (pdc_tx) @@ -1587,7 +1762,7 @@
> static int __devinit atmel_serial_probe(struct platform_device *pdev)
> device_init_wakeup(&pdev->dev, 1); platform_set_drvdata(pdev, port); -
> return 0; + return device_create_file(&(pdev->dev), &dev_attr_rs485);
> err_add_port: kfree(port->rx_ring.buf); @@ -1619,6 +1794,8 @@ static
> int __devexit atmel_serial_remove(struct platform_device *pdev)
> clk_put(atmel_port->clk); + device_remove_file(&(pdev->dev),
> &dev_attr_rs485); + return ret; } -- 1.6.0.4
~Ryan
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH] atmel_serial: Atmel RS485 support
2010-03-19 8:28 ` Claudio Scordino
@ 2010-03-21 21:55 ` Ryan Mallon
-1 siblings, 0 replies; 8+ messages in thread
From: Ryan Mallon @ 2010-03-21 21:55 UTC (permalink / raw)
To: linux-arm-kernel
Claudio Scordino wrote:
> Hi all,
>
> this is a patch to add RS485 support to the atmel_serial driver.
>
> The patch has been successfully tested by Sebastian Heutling (CC:-ed).
>
> Feedback (comments, suggestions, further testing) is welcome.
>
> Many thanks,
>
Ugh, not sure what happened to my previous email. It looked fine in
Thunderbird before I sent it. Hopefully this works a bit better:
> atmel_serial: RS485 support
>
> Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
> Signed-off-by: Michael Trimarchi <michael@evidence.eu.com>
> Signed-off-by: Rick Bronson <rick@efn.org>
> Signed-off-by: Sebastian Heutling <Sebastian.Heutling@who-ing.de>
> ---
> arch/arm/include/asm/ioctls.h | 2 +
> arch/arm/mach-at91/include/mach/board.h | 4 +
> drivers/serial/atmel_serial.c | 247
> ++++++++++++++++++++++++++-----
> 3 files changed, 218 insertions(+), 35 deletions(-)
>
> diff --git a/arch/arm/include/asm/ioctls.h b/arch/arm/include/asm/ioctls.h
> index a91d8a1..82f2177 100644
> --- a/arch/arm/include/asm/ioctls.h
> +++ b/arch/arm/include/asm/ioctls.h
> @@ -70,6 +70,8 @@
> #define TIOCGICOUNT 0x545D /* read serial port inline interrupt
> counts */
> #define FIOQSIZE 0x545E
>
> +#define TIOCSRS485 0x5461
> +
> /* Used for packet mode */
> #define TIOCPKT_DATA 0
> #define TIOCPKT_FLUSHREAD 1
> diff --git a/arch/arm/mach-at91/include/mach/board.h
> b/arch/arm/mach-at91/include/mach/board.h
> index ceaec6c..21f1308 100644
> --- a/arch/arm/mach-at91/include/mach/board.h
> +++ b/arch/arm/mach-at91/include/mach/board.h
> @@ -39,6 +39,7 @@
> #include <linux/usb/atmel_usba_udc.h>
> #include <linux/atmel-mci.h>
> #include <sound/atmel-ac97c.h>
> +#include <linux/serial.h>
>
> /* USB Device */
> struct at91_udc_data {
> @@ -146,6 +147,9 @@ struct atmel_uart_data {
> short use_dma_tx; /* use transmit DMA? */
> short use_dma_rx; /* use receive DMA? */
> void __iomem *regs; /* virtual base address, if any */
> + struct serial_rs485 rs485; /* this flag specifies
> + if the uart must be used
> + as RS485 */
> };
This comment is misleading, it is a struct not a flag. The comment should
say that it is the rs485 settings for the uart.
> extern void __init at91_add_device_serial(void);
>
> diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
> index 2c9bf9b..21bf3a8 100644
> --- a/drivers/serial/atmel_serial.c
> +++ b/drivers/serial/atmel_serial.c
> @@ -38,6 +38,7 @@
> #include <linux/dma-mapping.h>
> #include <linux/atmel_pdc.h>
> #include <linux/atmel_serial.h>
> +#include <linux/uaccess.h>
>
> #include <asm/io.h>
>
> @@ -59,6 +60,9 @@
>
> #include <linux/serial_core.h>
>
> +static void atmel_start_rx(struct uart_port *port);
> +static void atmel_stop_rx(struct uart_port *port);
Can you move these functions, so that these declarations are not needed?
> #ifdef CONFIG_SERIAL_ATMEL_TTYAT
>
> /* Use device name ttyAT, major 204 and minor 154-169. This is
> necessary if we
> @@ -93,6 +97,7 @@
> #define UART_GET_BRGR(port) __raw_readl((port)->membase +
> ATMEL_US_BRGR)
> #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase +
> ATMEL_US_BRGR)
> #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase +
> ATMEL_US_RTOR)
> +#define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase +
> ATMEL_US_TTGR)
>
> /* PDC registers */
> #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase +
> ATMEL_PDC_PTCR)
> @@ -147,6 +152,16 @@ struct atmel_uart_port {
> unsigned int irq_status_prev;
>
> struct circ_buf rx_ring;
> +
> + struct serial_rs485 rs485; /* this flag specifies
> + if the uart must be used
> + as RS485 */
> + /* Fields related to interrupts:
> + if (rs485) = ATMEL_US_TXEMPTY
> + else if (use_dma_tx) = ATMEL_US_ENDTX | ATMEL_US_TXBUFE
> + else = ATMEL_US_TXRDY;
> + */
This comment doesn't really belong here. Also, please use *s at the
beginning of each line in a multiline comment.
> + unsigned int tx_done_mask;
> };
>
> static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
> @@ -187,6 +202,85 @@ static bool atmel_use_dma_tx(struct uart_port *port)
> }
> #endif
>
> +/* Enable or disable the rs485 support */
> +void atmel_enable_disable_rs485(struct uart_port *port, struct
> serial_rs485 *rs485conf)
> +{
Please change the name of this function. Something like
atmel_config_rs485 would be better.
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> + unsigned long flags;
> + unsigned int mode;
> +
> + spin_lock_irqsave(&port->lock, flags);
> +
> + mode = UART_GET_MR(port);
> +
> + /* Resetting serial mode to RS232 (0x0) */
> + mode &= ~ATMEL_US_USMODE;
> +
> + atmel_port->rs485 = *rs485conf;
> +
> + if (!(rs485conf->flags & SER_RS485_ENABLED)) {
Reversing the logic of this if statement will make it slightly easier to
read.
> + dev_dbg(port->dev, "Setting UART to RS232\n");
> + if (atmel_use_dma_tx(port))
> + atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
> + else
> + atmel_port->tx_done_mask = ATMEL_US_TXRDY;
> + } else {
> + dev_dbg(port->dev, "Setting UART to RS485\n");
> + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
> + UART_PUT_TTGR(port, rs485conf->delay_rts_before_send);
> + mode |= ATMEL_US_USMODE_RS485;
> + }
> + UART_PUT_MR(port, mode);
> +
> + spin_unlock_irqrestore(&port->lock, flags);
> +}
> +
> +
> +static ssize_t show_rs485(struct device *dev, struct device_attribute
> *attr, \
> + char *buf)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct uart_port *port = platform_get_drvdata(pdev);
> + unsigned int current_mode;
> +
> + current_mode = UART_GET_MR(port);
> + current_mode &= ATMEL_US_USMODE;
current_mode = UART_GET_MR(port) & ATMEL_US_USMODE;
> + return snprintf(buf, PAGE_SIZE, "%u\n", current_mode);
> +}
> +
> +static ssize_t set_rs485(struct device *dev, struct device_attribute
> *attr, \
> + const char *buf, size_t len)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct uart_port *port = platform_get_drvdata(pdev);
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> + struct serial_rs485 rs485conf = atmel_port->rs485;
> + unsigned int value;
> +
> + if (buf == NULL)
> + goto err;
if (!buf)
return -EINVAL;
> +
> + value = simple_strtoul(buf, NULL, 10);
> +
> + if ((value != 0) && (value != 1))
> + goto err;
Is there any reason to be so strict on the values, you could just do this:
value = !!(simple_strtoul(buf, NULL, 0));
which will allow the user to use values in any base, and will convert any
non-zero values to 1.
> +
> + if (!value) {
Again, I would revert the logic of this if statement.
> + rs485conf.flags &= ~(SER_RS485_ENABLED);
> + } else {
> + rs485conf.flags |= SER_RS485_ENABLED;
> + /* 0x4 is the normal reset value. */
> + rs485conf.delay_rts_before_send = 0x00000004;
> + }
> +
> + atmel_enable_disable_rs485(port, &rs485conf);
> +
> +err:
> + return strnlen(buf, PAGE_SIZE);
> +}
> +
> +static DEVICE_ATTR(rs485, 0644, show_rs485, set_rs485);
> +
> /*
> * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
> */
> @@ -202,6 +296,7 @@ static void atmel_set_mctrl(struct uart_port
> *port, u_int mctrl)
> {
> unsigned int control = 0;
> unsigned int mode;
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
>
> #ifdef CONFIG_ARCH_AT91RM9200
> if (cpu_is_at91rm9200()) {
> @@ -236,6 +331,16 @@ static void atmel_set_mctrl(struct uart_port
> *port, u_int mctrl)
> mode |= ATMEL_US_CHMODE_LOC_LOOP;
> else
> mode |= ATMEL_US_CHMODE_NORMAL;
> +
> + /* Resetting serial mode to RS232 (0x0) */
> + mode &= ~ATMEL_US_USMODE;
> +
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
> + dev_dbg(port->dev, "Keeping UART to RS485\n");
> + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send);
> + mode |= ATMEL_US_USMODE_RS485;
> + } else
> + dev_dbg(port->dev, "Keeping UART to RS232\n");
> UART_PUT_MR(port, mode);
> }
>
> @@ -268,12 +373,17 @@ static u_int atmel_get_mctrl(struct uart_port *port)
> */
> static void atmel_stop_tx(struct uart_port *port)
> {
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> +
> if (atmel_use_dma_tx(port)) {
> /* disable PDC transmit */
> UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
> - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
> - } else
> - UART_PUT_IDR(port, ATMEL_US_TXRDY);
> + }
> + /* Disable interrupts */
> + UART_PUT_IDR(port, atmel_port->tx_done_mask);
> +
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED)
> + atmel_start_rx(port);
> }
>
> /*
> @@ -281,17 +391,22 @@ static void atmel_stop_tx(struct uart_port *port)
> */
> static void atmel_start_tx(struct uart_port *port)
> {
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> +
> if (atmel_use_dma_tx(port)) {
> if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN)
> /* The transmitter is already running. Yes, we
> really need this.*/
> return;
>
> - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED)
> + atmel_stop_rx(port);
> +
> /* re-enable PDC transmit */
> UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
> - } else
> - UART_PUT_IER(port, ATMEL_US_TXRDY);
> + }
> + /* Enable interrupts */
> + UART_PUT_IER(port, atmel_port->tx_done_mask);
> }
>
> /*
> @@ -302,12 +417,28 @@ static void atmel_stop_rx(struct uart_port *port)
> if (atmel_use_dma_rx(port)) {
> /* disable PDC receive */
> UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS);
> - UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
> + UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
> port->read_status_mask);
This line, and a couple of others, extend over 80 characters. Could you
please split them up.
> } else
> UART_PUT_IDR(port, ATMEL_US_RXRDY);
Please use braces for single line else statements when the if clause has
braces.
> }
>
> /*
> + * start receiving - port is in process of being opened.
> + */
> +static void atmel_start_rx(struct uart_port *port)
> +{
> + UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */
> +
> + if (atmel_use_dma_rx(port)) {
> + /* enable PDC controller */
> + UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
> port->read_status_mask);
> + UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
> + } else
> + UART_PUT_IER(port, ATMEL_US_RXRDY);
> +}
> +
> +
> +/*
> * Enable modem status interrupts
> */
> static void atmel_enable_ms(struct uart_port *port)
> @@ -428,8 +559,9 @@ static void atmel_rx_chars(struct uart_port *port)
> static void atmel_tx_chars(struct uart_port *port)
> {
> struct circ_buf *xmit = &port->state->xmit;
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
>
> - if (port->x_char && UART_GET_CSR(port) & ATMEL_US_TXRDY) {
> + if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) {
> UART_PUT_CHAR(port, port->x_char);
> port->icount.tx++;
> port->x_char = 0;
> @@ -437,7 +569,7 @@ static void atmel_tx_chars(struct uart_port *port)
> if (uart_circ_empty(xmit) || uart_tx_stopped(port))
> return;
>
> - while (UART_GET_CSR(port) & ATMEL_US_TXRDY) {
> + while (UART_GET_CSR(port) & atmel_port->tx_done_mask) {
> UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
> xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
> port->icount.tx++;
> @@ -449,7 +581,8 @@ static void atmel_tx_chars(struct uart_port *port)
> uart_write_wakeup(port);
>
> if (!uart_circ_empty(xmit))
> - UART_PUT_IER(port, ATMEL_US_TXRDY);
> + /* Enable interrupts */
> + UART_PUT_IER(port, atmel_port->tx_done_mask);
> }
>
> /*
> @@ -501,18 +634,10 @@ atmel_handle_transmit(struct uart_port *port,
> unsigned int pending)
> {
> struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
>
> - if (atmel_use_dma_tx(port)) {
> - /* PDC transmit */
> - if (pending & (ATMEL_US_ENDTX | ATMEL_US_TXBUFE)) {
> - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
> - tasklet_schedule(&atmel_port->tasklet);
> - }
> - } else {
> - /* Interrupt transmit */
> - if (pending & ATMEL_US_TXRDY) {
> - UART_PUT_IDR(port, ATMEL_US_TXRDY);
> - tasklet_schedule(&atmel_port->tasklet);
> - }
> + if (pending & atmel_port->tx_done_mask) {
> + /* Either PDC or interrupt transmission */
> + UART_PUT_IDR(port, atmel_port->tx_done_mask);
> + tasklet_schedule(&atmel_port->tasklet);
> }
> }
>
> @@ -590,9 +715,15 @@ static void atmel_tx_dma(struct uart_port *port)
>
> UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
> UART_PUT_TCR(port, count);
> - /* re-enable PDC transmit and interrupts */
> + /* re-enable PDC transmit */
> UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
> - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
> + /* Enable interrupts */
> + UART_PUT_IER(port, atmel_port->tx_done_mask);
> + } else {
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
> + /* DMA done, stop TX, start RX for RS485 */
> + atmel_start_rx(port);
> + }
> }
>
> if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
> @@ -1017,6 +1148,7 @@ static void atmel_set_termios(struct uart_port
> *port, struct ktermios *termios,
> {
> unsigned long flags;
> unsigned int mode, imr, quot, baud;
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
>
> /* Get current mode register */
> mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL
> @@ -1115,6 +1247,16 @@ static void atmel_set_termios(struct uart_port
> *port, struct ktermios *termios,
> /* disable receiver and transmitter */
> UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
>
> + /* Resetting serial mode to RS232 (0x0) */
> + mode &= ~ATMEL_US_USMODE;
> +
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
> + dev_dbg(port->dev, "Keeping UART to RS485\n");
> + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send);
> + mode |= ATMEL_US_USMODE_RS485;
> + } else
> + dev_dbg(port->dev, "Keeping UART to RS232\n");
> +
> /* set the parity, stop bits and data size */
> UART_PUT_MR(port, mode);
>
> @@ -1231,6 +1373,31 @@ static void atmel_poll_put_char(struct
> uart_port *port, unsigned char ch)
> }
> #endif
>
> +static int atmel_ioctl(struct uart_port *port, unsigned int cmd,
> unsigned long arg)
> +{
> +
> + switch (cmd) {
> + case TIOCSRS485:
> + {
> + struct serial_rs485 rs485conf;
If you move this declaration to the top of the function you will save
two levels of indentation.
Is it necessary to have both an ioctl and a sysfs control for putting
the uart into rs485 mode? The ioctl is more standardised, so perhaps
drop the sysfs control?
> + if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg,
> + sizeof(rs485conf)))
> + return -EFAULT;
> +
> + dev_dbg(port->dev, "enable e/o disable rs485\n");
> +
> + atmel_enable_disable_rs485(port, &rs485conf);
> + }
> + break;
> +
> + default:
> + return -ENOIOCTLCMD;
> + }
> + return 0;
> +}
> +
> +
> +
> static struct uart_ops atmel_pops = {
> .tx_empty = atmel_tx_empty,
> .set_mctrl = atmel_set_mctrl,
> @@ -1250,6 +1417,7 @@ static struct uart_ops atmel_pops = {
> .config_port = atmel_config_port,
> .verify_port = atmel_verify_port,
> .pm = atmel_serial_pm,
> + .ioctl = atmel_ioctl,
> #ifdef CONFIG_CONSOLE_POLL
> .poll_get_char = atmel_poll_get_char,
> .poll_put_char = atmel_poll_put_char,
> @@ -1265,13 +1433,12 @@ static void __devinit atmel_init_port(struct
> atmel_uart_port *atmel_port,
> struct uart_port *port = &atmel_port->uart;
> struct atmel_uart_data *data = pdev->dev.platform_data;
>
> - port->iotype = UPIO_MEM;
> - port->flags = UPF_BOOT_AUTOCONF;
> - port->ops = &atmel_pops;
> - port->fifosize = 1;
> - port->line = pdev->id;
> - port->dev = &pdev->dev;
> -
> + port->iotype = UPIO_MEM;
> + port->flags = UPF_BOOT_AUTOCONF;
> + port->ops = &atmel_pops;
> + port->fifosize = 1;
> + port->line = pdev->id;
> + port->dev = &pdev->dev;
> port->mapbase = pdev->resource[0].start;
> port->irq = pdev->resource[1].start;
>
> @@ -1299,8 +1466,15 @@ static void __devinit atmel_init_port(struct
> atmel_uart_port *atmel_port,
>
> atmel_port->use_dma_rx = data->use_dma_rx;
> atmel_port->use_dma_tx = data->use_dma_tx;
> - if (atmel_use_dma_tx(port))
> + atmel_port->rs485 = data->rs485;
> + /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED)
> + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
> + else if (atmel_use_dma_tx(port)) {
> port->fifosize = PDC_BUFFER_SIZE;
> + atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
> + } else
> + atmel_port->tx_done_mask = ATMEL_US_TXRDY;
> }
>
> /*
> @@ -1334,6 +1508,7 @@ static void atmel_console_putchar(struct
> uart_port *port, int ch)
> static void atmel_console_write(struct console *co, const char *s,
> u_int count)
> {
> struct uart_port *port = &atmel_ports[co->index].uart;
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> unsigned int status, imr;
> unsigned int pdc_tx;
>
> @@ -1341,7 +1516,7 @@ static void atmel_console_write(struct console
> *co, const char *s, u_int count)
> * First, save IMR and then disable interrupts
> */
> imr = UART_GET_IMR(port);
> - UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY);
> + UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask);
>
> /* Store PDC transmit status and disable it */
> pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN;
> @@ -1355,7 +1530,7 @@ static void atmel_console_write(struct console
> *co, const char *s, u_int count)
> */
> do {
> status = UART_GET_CSR(port);
> - } while (!(status & ATMEL_US_TXRDY));
> + } while (!(status & atmel_port->tx_done_mask));
>
> /* Restore PDC transmit status */
> if (pdc_tx)
> @@ -1587,7 +1762,7 @@ static int __devinit atmel_serial_probe(struct
> platform_device *pdev)
> device_init_wakeup(&pdev->dev, 1);
> platform_set_drvdata(pdev, port);
>
> - return 0;
> + return device_create_file(&(pdev->dev), &dev_attr_rs485);
>
> err_add_port:
> kfree(port->rx_ring.buf);
> @@ -1619,6 +1794,8 @@ static int __devexit atmel_serial_remove(struct
> platform_device *pdev)
>
> clk_put(atmel_port->clk);
>
> + device_remove_file(&(pdev->dev), &dev_attr_rs485);
> +
> return ret;
> }
>
> --
> 1.6.0.4
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] atmel_serial: Atmel RS485 support
@ 2010-03-21 21:55 ` Ryan Mallon
0 siblings, 0 replies; 8+ messages in thread
From: Ryan Mallon @ 2010-03-21 21:55 UTC (permalink / raw)
To: Claudio Scordino
Cc: Linux Kernel, kernel, Rick Bronson, John Nicholls,
Sebastian Heutling, linux-arm-kernel, michael trimarchi, alan
Claudio Scordino wrote:
> Hi all,
>
> this is a patch to add RS485 support to the atmel_serial driver.
>
> The patch has been successfully tested by Sebastian Heutling (CC:-ed).
>
> Feedback (comments, suggestions, further testing) is welcome.
>
> Many thanks,
>
Ugh, not sure what happened to my previous email. It looked fine in
Thunderbird before I sent it. Hopefully this works a bit better:
> atmel_serial: RS485 support
>
> Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
> Signed-off-by: Michael Trimarchi <michael@evidence.eu.com>
> Signed-off-by: Rick Bronson <rick@efn.org>
> Signed-off-by: Sebastian Heutling <Sebastian.Heutling@who-ing.de>
> ---
> arch/arm/include/asm/ioctls.h | 2 +
> arch/arm/mach-at91/include/mach/board.h | 4 +
> drivers/serial/atmel_serial.c | 247
> ++++++++++++++++++++++++++-----
> 3 files changed, 218 insertions(+), 35 deletions(-)
>
> diff --git a/arch/arm/include/asm/ioctls.h b/arch/arm/include/asm/ioctls.h
> index a91d8a1..82f2177 100644
> --- a/arch/arm/include/asm/ioctls.h
> +++ b/arch/arm/include/asm/ioctls.h
> @@ -70,6 +70,8 @@
> #define TIOCGICOUNT 0x545D /* read serial port inline interrupt
> counts */
> #define FIOQSIZE 0x545E
>
> +#define TIOCSRS485 0x5461
> +
> /* Used for packet mode */
> #define TIOCPKT_DATA 0
> #define TIOCPKT_FLUSHREAD 1
> diff --git a/arch/arm/mach-at91/include/mach/board.h
> b/arch/arm/mach-at91/include/mach/board.h
> index ceaec6c..21f1308 100644
> --- a/arch/arm/mach-at91/include/mach/board.h
> +++ b/arch/arm/mach-at91/include/mach/board.h
> @@ -39,6 +39,7 @@
> #include <linux/usb/atmel_usba_udc.h>
> #include <linux/atmel-mci.h>
> #include <sound/atmel-ac97c.h>
> +#include <linux/serial.h>
>
> /* USB Device */
> struct at91_udc_data {
> @@ -146,6 +147,9 @@ struct atmel_uart_data {
> short use_dma_tx; /* use transmit DMA? */
> short use_dma_rx; /* use receive DMA? */
> void __iomem *regs; /* virtual base address, if any */
> + struct serial_rs485 rs485; /* this flag specifies
> + if the uart must be used
> + as RS485 */
> };
This comment is misleading, it is a struct not a flag. The comment should
say that it is the rs485 settings for the uart.
> extern void __init at91_add_device_serial(void);
>
> diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
> index 2c9bf9b..21bf3a8 100644
> --- a/drivers/serial/atmel_serial.c
> +++ b/drivers/serial/atmel_serial.c
> @@ -38,6 +38,7 @@
> #include <linux/dma-mapping.h>
> #include <linux/atmel_pdc.h>
> #include <linux/atmel_serial.h>
> +#include <linux/uaccess.h>
>
> #include <asm/io.h>
>
> @@ -59,6 +60,9 @@
>
> #include <linux/serial_core.h>
>
> +static void atmel_start_rx(struct uart_port *port);
> +static void atmel_stop_rx(struct uart_port *port);
Can you move these functions, so that these declarations are not needed?
> #ifdef CONFIG_SERIAL_ATMEL_TTYAT
>
> /* Use device name ttyAT, major 204 and minor 154-169. This is
> necessary if we
> @@ -93,6 +97,7 @@
> #define UART_GET_BRGR(port) __raw_readl((port)->membase +
> ATMEL_US_BRGR)
> #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase +
> ATMEL_US_BRGR)
> #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase +
> ATMEL_US_RTOR)
> +#define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase +
> ATMEL_US_TTGR)
>
> /* PDC registers */
> #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase +
> ATMEL_PDC_PTCR)
> @@ -147,6 +152,16 @@ struct atmel_uart_port {
> unsigned int irq_status_prev;
>
> struct circ_buf rx_ring;
> +
> + struct serial_rs485 rs485; /* this flag specifies
> + if the uart must be used
> + as RS485 */
> + /* Fields related to interrupts:
> + if (rs485) = ATMEL_US_TXEMPTY
> + else if (use_dma_tx) = ATMEL_US_ENDTX | ATMEL_US_TXBUFE
> + else = ATMEL_US_TXRDY;
> + */
This comment doesn't really belong here. Also, please use *s at the
beginning of each line in a multiline comment.
> + unsigned int tx_done_mask;
> };
>
> static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
> @@ -187,6 +202,85 @@ static bool atmel_use_dma_tx(struct uart_port *port)
> }
> #endif
>
> +/* Enable or disable the rs485 support */
> +void atmel_enable_disable_rs485(struct uart_port *port, struct
> serial_rs485 *rs485conf)
> +{
Please change the name of this function. Something like
atmel_config_rs485 would be better.
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> + unsigned long flags;
> + unsigned int mode;
> +
> + spin_lock_irqsave(&port->lock, flags);
> +
> + mode = UART_GET_MR(port);
> +
> + /* Resetting serial mode to RS232 (0x0) */
> + mode &= ~ATMEL_US_USMODE;
> +
> + atmel_port->rs485 = *rs485conf;
> +
> + if (!(rs485conf->flags & SER_RS485_ENABLED)) {
Reversing the logic of this if statement will make it slightly easier to
read.
> + dev_dbg(port->dev, "Setting UART to RS232\n");
> + if (atmel_use_dma_tx(port))
> + atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
> + else
> + atmel_port->tx_done_mask = ATMEL_US_TXRDY;
> + } else {
> + dev_dbg(port->dev, "Setting UART to RS485\n");
> + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
> + UART_PUT_TTGR(port, rs485conf->delay_rts_before_send);
> + mode |= ATMEL_US_USMODE_RS485;
> + }
> + UART_PUT_MR(port, mode);
> +
> + spin_unlock_irqrestore(&port->lock, flags);
> +}
> +
> +
> +static ssize_t show_rs485(struct device *dev, struct device_attribute
> *attr, \
> + char *buf)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct uart_port *port = platform_get_drvdata(pdev);
> + unsigned int current_mode;
> +
> + current_mode = UART_GET_MR(port);
> + current_mode &= ATMEL_US_USMODE;
current_mode = UART_GET_MR(port) & ATMEL_US_USMODE;
> + return snprintf(buf, PAGE_SIZE, "%u\n", current_mode);
> +}
> +
> +static ssize_t set_rs485(struct device *dev, struct device_attribute
> *attr, \
> + const char *buf, size_t len)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct uart_port *port = platform_get_drvdata(pdev);
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> + struct serial_rs485 rs485conf = atmel_port->rs485;
> + unsigned int value;
> +
> + if (buf == NULL)
> + goto err;
if (!buf)
return -EINVAL;
> +
> + value = simple_strtoul(buf, NULL, 10);
> +
> + if ((value != 0) && (value != 1))
> + goto err;
Is there any reason to be so strict on the values, you could just do this:
value = !!(simple_strtoul(buf, NULL, 0));
which will allow the user to use values in any base, and will convert any
non-zero values to 1.
> +
> + if (!value) {
Again, I would revert the logic of this if statement.
> + rs485conf.flags &= ~(SER_RS485_ENABLED);
> + } else {
> + rs485conf.flags |= SER_RS485_ENABLED;
> + /* 0x4 is the normal reset value. */
> + rs485conf.delay_rts_before_send = 0x00000004;
> + }
> +
> + atmel_enable_disable_rs485(port, &rs485conf);
> +
> +err:
> + return strnlen(buf, PAGE_SIZE);
> +}
> +
> +static DEVICE_ATTR(rs485, 0644, show_rs485, set_rs485);
> +
> /*
> * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
> */
> @@ -202,6 +296,7 @@ static void atmel_set_mctrl(struct uart_port
> *port, u_int mctrl)
> {
> unsigned int control = 0;
> unsigned int mode;
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
>
> #ifdef CONFIG_ARCH_AT91RM9200
> if (cpu_is_at91rm9200()) {
> @@ -236,6 +331,16 @@ static void atmel_set_mctrl(struct uart_port
> *port, u_int mctrl)
> mode |= ATMEL_US_CHMODE_LOC_LOOP;
> else
> mode |= ATMEL_US_CHMODE_NORMAL;
> +
> + /* Resetting serial mode to RS232 (0x0) */
> + mode &= ~ATMEL_US_USMODE;
> +
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
> + dev_dbg(port->dev, "Keeping UART to RS485\n");
> + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send);
> + mode |= ATMEL_US_USMODE_RS485;
> + } else
> + dev_dbg(port->dev, "Keeping UART to RS232\n");
> UART_PUT_MR(port, mode);
> }
>
> @@ -268,12 +373,17 @@ static u_int atmel_get_mctrl(struct uart_port *port)
> */
> static void atmel_stop_tx(struct uart_port *port)
> {
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> +
> if (atmel_use_dma_tx(port)) {
> /* disable PDC transmit */
> UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
> - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
> - } else
> - UART_PUT_IDR(port, ATMEL_US_TXRDY);
> + }
> + /* Disable interrupts */
> + UART_PUT_IDR(port, atmel_port->tx_done_mask);
> +
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED)
> + atmel_start_rx(port);
> }
>
> /*
> @@ -281,17 +391,22 @@ static void atmel_stop_tx(struct uart_port *port)
> */
> static void atmel_start_tx(struct uart_port *port)
> {
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> +
> if (atmel_use_dma_tx(port)) {
> if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN)
> /* The transmitter is already running. Yes, we
> really need this.*/
> return;
>
> - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED)
> + atmel_stop_rx(port);
> +
> /* re-enable PDC transmit */
> UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
> - } else
> - UART_PUT_IER(port, ATMEL_US_TXRDY);
> + }
> + /* Enable interrupts */
> + UART_PUT_IER(port, atmel_port->tx_done_mask);
> }
>
> /*
> @@ -302,12 +417,28 @@ static void atmel_stop_rx(struct uart_port *port)
> if (atmel_use_dma_rx(port)) {
> /* disable PDC receive */
> UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS);
> - UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
> + UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
> port->read_status_mask);
This line, and a couple of others, extend over 80 characters. Could you
please split them up.
> } else
> UART_PUT_IDR(port, ATMEL_US_RXRDY);
Please use braces for single line else statements when the if clause has
braces.
> }
>
> /*
> + * start receiving - port is in process of being opened.
> + */
> +static void atmel_start_rx(struct uart_port *port)
> +{
> + UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */
> +
> + if (atmel_use_dma_rx(port)) {
> + /* enable PDC controller */
> + UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
> port->read_status_mask);
> + UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
> + } else
> + UART_PUT_IER(port, ATMEL_US_RXRDY);
> +}
> +
> +
> +/*
> * Enable modem status interrupts
> */
> static void atmel_enable_ms(struct uart_port *port)
> @@ -428,8 +559,9 @@ static void atmel_rx_chars(struct uart_port *port)
> static void atmel_tx_chars(struct uart_port *port)
> {
> struct circ_buf *xmit = &port->state->xmit;
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
>
> - if (port->x_char && UART_GET_CSR(port) & ATMEL_US_TXRDY) {
> + if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) {
> UART_PUT_CHAR(port, port->x_char);
> port->icount.tx++;
> port->x_char = 0;
> @@ -437,7 +569,7 @@ static void atmel_tx_chars(struct uart_port *port)
> if (uart_circ_empty(xmit) || uart_tx_stopped(port))
> return;
>
> - while (UART_GET_CSR(port) & ATMEL_US_TXRDY) {
> + while (UART_GET_CSR(port) & atmel_port->tx_done_mask) {
> UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
> xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
> port->icount.tx++;
> @@ -449,7 +581,8 @@ static void atmel_tx_chars(struct uart_port *port)
> uart_write_wakeup(port);
>
> if (!uart_circ_empty(xmit))
> - UART_PUT_IER(port, ATMEL_US_TXRDY);
> + /* Enable interrupts */
> + UART_PUT_IER(port, atmel_port->tx_done_mask);
> }
>
> /*
> @@ -501,18 +634,10 @@ atmel_handle_transmit(struct uart_port *port,
> unsigned int pending)
> {
> struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
>
> - if (atmel_use_dma_tx(port)) {
> - /* PDC transmit */
> - if (pending & (ATMEL_US_ENDTX | ATMEL_US_TXBUFE)) {
> - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
> - tasklet_schedule(&atmel_port->tasklet);
> - }
> - } else {
> - /* Interrupt transmit */
> - if (pending & ATMEL_US_TXRDY) {
> - UART_PUT_IDR(port, ATMEL_US_TXRDY);
> - tasklet_schedule(&atmel_port->tasklet);
> - }
> + if (pending & atmel_port->tx_done_mask) {
> + /* Either PDC or interrupt transmission */
> + UART_PUT_IDR(port, atmel_port->tx_done_mask);
> + tasklet_schedule(&atmel_port->tasklet);
> }
> }
>
> @@ -590,9 +715,15 @@ static void atmel_tx_dma(struct uart_port *port)
>
> UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
> UART_PUT_TCR(port, count);
> - /* re-enable PDC transmit and interrupts */
> + /* re-enable PDC transmit */
> UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
> - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
> + /* Enable interrupts */
> + UART_PUT_IER(port, atmel_port->tx_done_mask);
> + } else {
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
> + /* DMA done, stop TX, start RX for RS485 */
> + atmel_start_rx(port);
> + }
> }
>
> if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
> @@ -1017,6 +1148,7 @@ static void atmel_set_termios(struct uart_port
> *port, struct ktermios *termios,
> {
> unsigned long flags;
> unsigned int mode, imr, quot, baud;
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
>
> /* Get current mode register */
> mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL
> @@ -1115,6 +1247,16 @@ static void atmel_set_termios(struct uart_port
> *port, struct ktermios *termios,
> /* disable receiver and transmitter */
> UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
>
> + /* Resetting serial mode to RS232 (0x0) */
> + mode &= ~ATMEL_US_USMODE;
> +
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
> + dev_dbg(port->dev, "Keeping UART to RS485\n");
> + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send);
> + mode |= ATMEL_US_USMODE_RS485;
> + } else
> + dev_dbg(port->dev, "Keeping UART to RS232\n");
> +
> /* set the parity, stop bits and data size */
> UART_PUT_MR(port, mode);
>
> @@ -1231,6 +1373,31 @@ static void atmel_poll_put_char(struct
> uart_port *port, unsigned char ch)
> }
> #endif
>
> +static int atmel_ioctl(struct uart_port *port, unsigned int cmd,
> unsigned long arg)
> +{
> +
> + switch (cmd) {
> + case TIOCSRS485:
> + {
> + struct serial_rs485 rs485conf;
If you move this declaration to the top of the function you will save
two levels of indentation.
Is it necessary to have both an ioctl and a sysfs control for putting
the uart into rs485 mode? The ioctl is more standardised, so perhaps
drop the sysfs control?
> + if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg,
> + sizeof(rs485conf)))
> + return -EFAULT;
> +
> + dev_dbg(port->dev, "enable e/o disable rs485\n");
> +
> + atmel_enable_disable_rs485(port, &rs485conf);
> + }
> + break;
> +
> + default:
> + return -ENOIOCTLCMD;
> + }
> + return 0;
> +}
> +
> +
> +
> static struct uart_ops atmel_pops = {
> .tx_empty = atmel_tx_empty,
> .set_mctrl = atmel_set_mctrl,
> @@ -1250,6 +1417,7 @@ static struct uart_ops atmel_pops = {
> .config_port = atmel_config_port,
> .verify_port = atmel_verify_port,
> .pm = atmel_serial_pm,
> + .ioctl = atmel_ioctl,
> #ifdef CONFIG_CONSOLE_POLL
> .poll_get_char = atmel_poll_get_char,
> .poll_put_char = atmel_poll_put_char,
> @@ -1265,13 +1433,12 @@ static void __devinit atmel_init_port(struct
> atmel_uart_port *atmel_port,
> struct uart_port *port = &atmel_port->uart;
> struct atmel_uart_data *data = pdev->dev.platform_data;
>
> - port->iotype = UPIO_MEM;
> - port->flags = UPF_BOOT_AUTOCONF;
> - port->ops = &atmel_pops;
> - port->fifosize = 1;
> - port->line = pdev->id;
> - port->dev = &pdev->dev;
> -
> + port->iotype = UPIO_MEM;
> + port->flags = UPF_BOOT_AUTOCONF;
> + port->ops = &atmel_pops;
> + port->fifosize = 1;
> + port->line = pdev->id;
> + port->dev = &pdev->dev;
> port->mapbase = pdev->resource[0].start;
> port->irq = pdev->resource[1].start;
>
> @@ -1299,8 +1466,15 @@ static void __devinit atmel_init_port(struct
> atmel_uart_port *atmel_port,
>
> atmel_port->use_dma_rx = data->use_dma_rx;
> atmel_port->use_dma_tx = data->use_dma_tx;
> - if (atmel_use_dma_tx(port))
> + atmel_port->rs485 = data->rs485;
> + /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
> + if (atmel_port->rs485.flags & SER_RS485_ENABLED)
> + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
> + else if (atmel_use_dma_tx(port)) {
> port->fifosize = PDC_BUFFER_SIZE;
> + atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
> + } else
> + atmel_port->tx_done_mask = ATMEL_US_TXRDY;
> }
>
> /*
> @@ -1334,6 +1508,7 @@ static void atmel_console_putchar(struct
> uart_port *port, int ch)
> static void atmel_console_write(struct console *co, const char *s,
> u_int count)
> {
> struct uart_port *port = &atmel_ports[co->index].uart;
> + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> unsigned int status, imr;
> unsigned int pdc_tx;
>
> @@ -1341,7 +1516,7 @@ static void atmel_console_write(struct console
> *co, const char *s, u_int count)
> * First, save IMR and then disable interrupts
> */
> imr = UART_GET_IMR(port);
> - UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY);
> + UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask);
>
> /* Store PDC transmit status and disable it */
> pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN;
> @@ -1355,7 +1530,7 @@ static void atmel_console_write(struct console
> *co, const char *s, u_int count)
> */
> do {
> status = UART_GET_CSR(port);
> - } while (!(status & ATMEL_US_TXRDY));
> + } while (!(status & atmel_port->tx_done_mask));
>
> /* Restore PDC transmit status */
> if (pdc_tx)
> @@ -1587,7 +1762,7 @@ static int __devinit atmel_serial_probe(struct
> platform_device *pdev)
> device_init_wakeup(&pdev->dev, 1);
> platform_set_drvdata(pdev, port);
>
> - return 0;
> + return device_create_file(&(pdev->dev), &dev_attr_rs485);
>
> err_add_port:
> kfree(port->rx_ring.buf);
> @@ -1619,6 +1794,8 @@ static int __devexit atmel_serial_remove(struct
> platform_device *pdev)
>
> clk_put(atmel_port->clk);
>
> + device_remove_file(&(pdev->dev), &dev_attr_rs485);
> +
> return ret;
> }
>
> --
> 1.6.0.4
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH] atmel_serial: Atmel RS485 support
2010-03-21 21:55 ` Ryan Mallon
@ 2010-03-22 11:15 ` Claudio Scordino
-1 siblings, 0 replies; 8+ messages in thread
From: Claudio Scordino @ 2010-03-22 11:15 UTC (permalink / raw)
To: linux-arm-kernel
Hi Ryan,
first of all, thank you for your feedback.
To me, all comments seem to be reasonable, except maybe the following one:
>>
>> +static void atmel_start_rx(struct uart_port *port);
>> +static void atmel_stop_rx(struct uart_port *port);
>
> Can you move these functions, so that these declarations are not needed?
Actually, atmel_stop_rx is already defined, and I prefer to not move it
(since I change it, people may get confused by the diff...).
I also think that atmel_start_rx (which is added by the patch) should be
near to atmel_stop_rx...
>> + UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
>> port->read_status_mask);
>
> This line, and a couple of others, extend over 80 characters. Could you
> please split them up.
Of course. I'm going to split them up and use a backslash at the end of
the original lines.
I will create a new patch according to your comments, test it and submit
again to the mailing list.
Many thanks again,
Claudio
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] atmel_serial: Atmel RS485 support
@ 2010-03-22 11:15 ` Claudio Scordino
0 siblings, 0 replies; 8+ messages in thread
From: Claudio Scordino @ 2010-03-22 11:15 UTC (permalink / raw)
To: Ryan Mallon
Cc: Linux Kernel, Rick Bronson, John Nicholls, Sebastian Heutling,
linux-arm-kernel, michael trimarchi, alan
Hi Ryan,
first of all, thank you for your feedback.
To me, all comments seem to be reasonable, except maybe the following one:
>>
>> +static void atmel_start_rx(struct uart_port *port);
>> +static void atmel_stop_rx(struct uart_port *port);
>
> Can you move these functions, so that these declarations are not needed?
Actually, atmel_stop_rx is already defined, and I prefer to not move it
(since I change it, people may get confused by the diff...).
I also think that atmel_start_rx (which is added by the patch) should be
near to atmel_stop_rx...
>> + UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
>> port->read_status_mask);
>
> This line, and a couple of others, extend over 80 characters. Could you
> please split them up.
Of course. I'm going to split them up and use a backslash at the end of
the original lines.
I will create a new patch according to your comments, test it and submit
again to the mailing list.
Many thanks again,
Claudio
^ permalink raw reply [flat|nested] 8+ messages in thread