Hello Steven and Andrew,
Attached I have put a patchset that is independant from the patchset at:
http://maxim.org.za/AT91RM9200/2.6/2.6.23-at91.patch.gz
These patches should go to mainline:
* atmel_serial_cleanup_no_at91.patch
* atmel_serial_irq_splitup_no_at91.patch
And this one into the RT-patch:
* atmel_serial_irqf_nodelay.patch
I hope this set is easier to integrate.
Kind Regards,
Remy
2007/12/12, Remy Bohmer <linux@xxxxxxxxxx>:
> Hello Steven,
>
> > > So, I have here 3 patches:
> > > * atmel_serial_cleanup -> This patch adapts the driver to the coding
> > > rules, splits the interrupt handler into 3 routines (cuts the routine
> > > in more readable pieces) , but there is no functional change involved.
> > > * atmel_serial_irq_splitup -> This patch splits up the interrupt handler.
> > > * atmel_serial_irqf_nodelay -> This patch is additionally required to
> > > get it properly working on Preempt-RT. (This patch should thus go into
> > > the RT-patch, AFTER integration of the other 2 patches into mainline)
> > >
> > > BUT: I based the patch on the 2.6.23.1 + Andrews patch collection at
> > > http://maxim.org.za/AT91RM9200/2.6/2.6.23-at91.patch.gz
> >
> > I could pull all the patches into RT (although I would like Thomas to take
> > a look first and give an OK).
>
> Instead of pulling the complete patchset, we can also pull the minimal
> set of patches to make Preempt-RT to work properly on AT91; Preempt-RT
> depends on:
> 1) ClockSource & ClockEvents for AT91RM9200. [David Brownell, and others]
> 2) Support configurable HZ. [David Brownell]
> 3) The Serial port interrupt handler splitup patchset.
> 4) And of course, the
> use-edge-irq-instead-of-simple-irq-interrupt-handler patch for AT91, I
> posted last week.
>
> Maybe, Andrew can provide the patches 1 and 2 separate from his
> patchset, so you can add them to RT for 2.6.23 only? patch 1 seems to
> be in 2.6.24-rc4 already.
>
> > And then apply your patches on top. I'm
> > assuming that this only affects the ARM architecture and the AT91 device?
>
> The complete patchset from Andrew also effects other Atmel cores, and
> I only focussed on AT91sam/at91rm. Andrew mentioned that the DMA patch
> for Serial in his set did not work on AVR32, so, we probably do not
> want to have that change until it is really stable.
> Tomorrow, I can easily make my set separate from that DMA part, so
> that the patches 1-4 can be mainlined without other dependencies,
> including the irqf_nodelay-patch which can be put in the RT-patchset.
> I can post this mainline-able patch (3) tomorrow.
>
> > I'm leaving this out for -rt13 and for the next cut of 2.6.24-rc-rt. But
> > if Thomas is OK with pulling in the external patch queue, I'll do it for
> > -rt14.
>
> OK.
>
> > It is best if the patch queue in question makes it into mainline.
>
> Agree.
>
>
> Kind Regards,
>
> Remy
>
This patch cleans up the atmel_serial driver to conform the coding rules.
It contains no functional change.
Signed-off-by: Remy Bohmer <linux@xxxxxxxxxx>
---
drivers/serial/atmel_serial.c | 348 +++++++++++++++++++++++-------------------
1 file changed, 196 insertions(+), 152 deletions(-)
Index: linux-2.6.23/drivers/serial/atmel_serial.c
===================================================================
--- linux-2.6.23.orig/drivers/serial/atmel_serial.c 2007-12-13 17:30:46.000000000 +0100
+++ linux-2.6.23/drivers/serial/atmel_serial.c 2007-12-13 17:30:48.000000000 +0100
@@ -74,47 +74,51 @@
#define ATMEL_ISR_PASS_LIMIT 256
-#define UART_PUT_CR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_CR)
-#define UART_GET_MR(port) __raw_readl((port)->membase + ATMEL_US_MR)
-#define UART_PUT_MR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_MR)
-#define UART_PUT_IER(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IER)
-#define UART_PUT_IDR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IDR)
-#define UART_GET_IMR(port) __raw_readl((port)->membase + ATMEL_US_IMR)
-#define UART_GET_CSR(port) __raw_readl((port)->membase + ATMEL_US_CSR)
-#define UART_GET_CHAR(port) __raw_readl((port)->membase + ATMEL_US_RHR)
-#define UART_PUT_CHAR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_THR)
-#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 lread(port) __raw_readl(port)
+#define lwrite(v, port) __raw_writel(v, port)
-// #define UART_GET_CR(port) __raw_readl((port)->membase + ATMEL_US_CR) // is write-only
+#define UART_PUT_CR(port, v) lwrite(v, (port)->membase + ATMEL_US_CR)
+#define UART_PUT_MR(port, v) lwrite(v, (port)->membase + ATMEL_US_MR)
+#define UART_PUT_IER(port, v) lwrite(v, (port)->membase + ATMEL_US_IER)
+#define UART_PUT_IDR(port, v) lwrite(v, (port)->membase + ATMEL_US_IDR)
+#define UART_PUT_CHAR(port, v) lwrite(v, (port)->membase + ATMEL_US_THR)
+#define UART_PUT_BRGR(port, v) lwrite(v, (port)->membase + ATMEL_US_BRGR)
+#define UART_PUT_RTOR(port, v) lwrite(v, (port)->membase + ATMEL_US_RTOR)
+
+#define UART_GET_MR(port) lread((port)->membase + ATMEL_US_MR)
+#define UART_GET_IMR(port) lread((port)->membase + ATMEL_US_IMR)
+#define UART_GET_CSR(port) lread((port)->membase + ATMEL_US_CSR)
+#define UART_GET_CHAR(port) lread((port)->membase + ATMEL_US_RHR)
+#define UART_GET_BRGR(port) lread((port)->membase + ATMEL_US_BRGR)
+
+/* is write-only */
+/* #define UART_GET_CR(port) lread((port)->membase + ATMEL_US_CR) */
/* PDC registers */
-#define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR)
-#define UART_GET_PTSR(port) __raw_readl((port)->membase + ATMEL_PDC_PTSR)
+#define UART_PUT_PTCR(port, v) lwrite(v, (port)->membase + ATMEL_PDC_PTCR)
+#define UART_PUT_RPR(port, v) lwrite(v, (port)->membase + ATMEL_PDC_RPR)
+#define UART_PUT_RCR(port, v) lwrite(v, (port)->membase + ATMEL_PDC_RCR)
+#define UART_PUT_RNPR(port, v) lwrite(v, (port)->membase + ATMEL_PDC_RNPR)
+#define UART_PUT_RNCR(port, v) lwrite(v, (port)->membase + ATMEL_PDC_RNCR)
+#define UART_PUT_TPR(port, v) lwrite(v, (port)->membase + ATMEL_PDC_TPR)
+#define UART_PUT_TCR(port, v) lwrite(v, (port)->membase + ATMEL_PDC_TCR)
+/*#define UART_PUT_TNPR(port, v) lwrite(v, (port)->membase + ATMEL_PDC_TNPR) */
+/*#define UART_PUT_TNCR(port, v) lwrite(v, (port)->membase + ATMEL_PDC_TNCR) */
-#define UART_PUT_RPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RPR)
-#define UART_GET_RPR(port) __raw_readl((port)->membase + ATMEL_PDC_RPR)
-#define UART_PUT_RCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RCR)
-#define UART_PUT_RNPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNPR)
-#define UART_PUT_RNCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNCR)
-
-#define UART_PUT_TPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TPR)
-#define UART_PUT_TCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TCR)
-//#define UART_PUT_TNPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TNPR)
-//#define UART_PUT_TNCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TNCR)
+#define UART_GET_PTSR(port) lread((port)->membase + ATMEL_PDC_PTSR)
+#define UART_GET_RPR(port) lread((port)->membase + ATMEL_PDC_RPR)
-static int (*atmel_open_hook)(struct uart_port *);
-static void (*atmel_close_hook)(struct uart_port *);
+static int (*atmel_open_hook) (struct uart_port *);
+static void (*atmel_close_hook) (struct uart_port *);
/*
* We wrap our port structure around the generic uart_port.
*/
struct atmel_uart_port {
- struct uart_port uart; /* uart */
- struct clk *clk; /* uart clock */
- unsigned short suspended; /* is port suspended? */
- int break_active; /* break being received */
+ struct uart_port uart; /* uart */
+ struct clk *clk; /* uart clock */
+ unsigned short suspended; /* is port suspended? */
+ int break_active; /* break being received */
};
static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
@@ -142,8 +146,8 @@ static void atmel_set_mctrl(struct uart_
#ifdef CONFIG_ARCH_AT91RM9200
if (cpu_is_at91rm9200()) {
/*
- * AT91RM9200 Errata #39: RTS0 is not internally connected to PA21.
- * We need to drive the pin manually.
+ * AT91RM9200 Errata #39: RTS0 is not internally connected
+ * to PA21. We need to drive the pin manually.
*/
if (port->mapbase == AT91RM9200_BASE_US0) {
if (mctrl & TIOCM_RTS)
@@ -204,8 +208,6 @@ static u_int atmel_get_mctrl(struct uart
*/
static void atmel_stop_tx(struct uart_port *port)
{
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
-
UART_PUT_IDR(port, ATMEL_US_TXRDY);
}
@@ -214,8 +216,6 @@ static void atmel_stop_tx(struct uart_po
*/
static void atmel_start_tx(struct uart_port *port)
{
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
-
UART_PUT_IER(port, ATMEL_US_TXRDY);
}
@@ -224,8 +224,6 @@ static void atmel_start_tx(struct uart_p
*/
static void atmel_stop_rx(struct uart_port *port)
{
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
-
UART_PUT_IDR(port, ATMEL_US_RXRDY);
}
@@ -234,7 +232,9 @@ static void atmel_stop_rx(struct uart_po
*/
static void atmel_enable_ms(struct uart_port *port)
{
- UART_PUT_IER(port, ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC | ATMEL_US_CTSIC);
+ UART_PUT_IER(port,
+ ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC |
+ ATMEL_US_CTSIC);
}
/*
@@ -253,7 +253,7 @@ static void atmel_break_ctl(struct uart_
*/
static void atmel_rx_chars(struct uart_port *port)
{
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
struct tty_struct *tty = port->info->tty;
unsigned int status, ch, flg;
@@ -272,10 +272,12 @@ static void atmel_rx_chars(struct uart_p
if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
| ATMEL_US_OVRE | ATMEL_US_RXBRK)
|| atmel_port->break_active)) {
- UART_PUT_CR(port, ATMEL_US_RSTSTA); /* clear error */
+ /* clear error */
+ UART_PUT_CR(port, ATMEL_US_RSTSTA);
if (status & ATMEL_US_RXBRK
&& !atmel_port->break_active) {
- status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME); /* ignore side-effect */
+ /* ignore side-effect */
+ status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
port->icount.brk++;
atmel_port->break_active = 1;
UART_PUT_IER(port, ATMEL_US_RXBRK);
@@ -315,7 +317,7 @@ static void atmel_rx_chars(struct uart_p
uart_insert_char(port, status, ATMEL_US_OVRE, ch, flg);
- ignore_char:
+ignore_char:
status = UART_GET_CSR(port);
}
@@ -356,44 +358,72 @@ static void atmel_tx_chars(struct uart_p
}
/*
+ * receive interrupt handler.
+ */
+static void atmel_handle_receive(struct uart_port *port, unsigned int pending)
+{
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
+
+ /* Interrupt receive */
+ if (pending & ATMEL_US_RXRDY)
+ atmel_rx_chars(port);
+ else if (pending & ATMEL_US_RXBRK) {
+ /*
+ * End of break detected. If it came along
+ * with a character, atmel_rx_chars will
+ * handle it.
+ */
+ UART_PUT_CR(port, ATMEL_US_RSTSTA);
+ UART_PUT_IDR(port, ATMEL_US_RXBRK);
+ atmel_port->break_active = 0;
+ }
+}
+
+/*
+ * transmit interrupt handler.
+ */
+static void atmel_handle_transmit(struct uart_port *port, unsigned int pending)
+{
+ /* Interrupt transmit */
+ if (pending & ATMEL_US_TXRDY)
+ atmel_tx_chars(port);
+}
+
+/*
+ * status flags interrupt handler.
+ */
+static void atmel_handle_status(struct uart_port *port, unsigned int pending,
+ unsigned int status)
+{
+ /* TODO: All reads to CSR will clear these interrupts! */
+ if (pending & ATMEL_US_RIIC)
+ port->icount.rng++;
+ if (pending & ATMEL_US_DSRIC)
+ port->icount.dsr++;
+ if (pending & ATMEL_US_DCDIC)
+ uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
+ if (pending & ATMEL_US_CTSIC)
+ uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
+ if (pending &
+ (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC |
+ ATMEL_US_CTSIC))
+ wake_up_interruptible(&port->info->delta_msr_wait);
+}
+
+/*
* Interrupt handler
*/
static irqreturn_t atmel_interrupt(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
unsigned int status, pending, pass_counter = 0;
status = UART_GET_CSR(port);
pending = status & UART_GET_IMR(port);
while (pending) {
- /* Interrupt receive */
- if (pending & ATMEL_US_RXRDY)
- atmel_rx_chars(port);
- else if (pending & ATMEL_US_RXBRK) {
- /*
- * End of break detected. If it came along
- * with a character, atmel_rx_chars will
- * handle it.
- */
- UART_PUT_CR(port, ATMEL_US_RSTSTA);
- UART_PUT_IDR(port, ATMEL_US_RXBRK);
- atmel_port->break_active = 0;
- }
-
- // TODO: All reads to CSR will clear these interrupts!
- if (pending & ATMEL_US_RIIC) port->icount.rng++;
- if (pending & ATMEL_US_DSRIC) port->icount.dsr++;
- if (pending & ATMEL_US_DCDIC)
- uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
- if (pending & ATMEL_US_CTSIC)
- uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
- if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC | ATMEL_US_CTSIC))
- wake_up_interruptible(&port->info->delta_msr_wait);
-
- /* Interrupt transmit */
- if (pending & ATMEL_US_TXRDY)
- atmel_tx_chars(port);
+ atmel_handle_receive(port, pending);
+ atmel_handle_status(port, pending, status);
+ atmel_handle_transmit(port, pending);
if (pass_counter++ > ATMEL_ISR_PASS_LIMIT)
break;
@@ -409,7 +439,6 @@ static irqreturn_t atmel_interrupt(int i
*/
static int atmel_startup(struct uart_port *port)
{
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
int retval;
/*
@@ -422,7 +451,9 @@ static int atmel_startup(struct uart_por
/*
* Allocate the IRQ
*/
- retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED, "atmel_serial", port);
+ retval =
+ request_irq(port->irq, atmel_interrupt, IRQF_SHARED,
+ "atmel_serial", port);
if (retval) {
printk("atmel_serial: atmel_startup - Can't get irq\n");
return retval;
@@ -444,9 +475,11 @@ static int atmel_startup(struct uart_por
* Finally, enable the serial port
*/
UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
- UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN); /* enable xmit & rcvr */
+ /* enable xmit & rcvr */
+ UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
- UART_PUT_IER(port, ATMEL_US_RXRDY); /* enable receive only */
+ /* enable receive only */
+ UART_PUT_IER(port, ATMEL_US_RXRDY);
return 0;
}
@@ -456,8 +489,6 @@ static int atmel_startup(struct uart_por
*/
static void atmel_shutdown(struct uart_port *port)
{
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
-
/*
* Disable all interrupts, port and break condition.
*/
@@ -480,45 +511,49 @@ static void atmel_shutdown(struct uart_p
/*
* Power / Clock management.
*/
-static void atmel_serial_pm(struct uart_port *port, unsigned int state, unsigned int oldstate)
+static void atmel_serial_pm(struct uart_port *port, unsigned int state,
+ unsigned int oldstate)
{
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
switch (state) {
- case 0:
- /*
- * Enable the peripheral clock for this serial port.
- * This is called on uart_open() or a resume event.
- */
- clk_enable(atmel_port->clk);
- break;
- case 3:
- /*
- * Disable the peripheral clock for this serial port.
- * This is called on uart_close() or a suspend event.
- */
- clk_disable(atmel_port->clk);
- break;
- default:
- printk(KERN_ERR "atmel_serial: unknown pm %d\n", state);
+ case 0:
+ /*
+ * Enable the peripheral clock for this serial port.
+ * This is called on uart_open() or a resume event.
+ */
+ clk_enable(atmel_port->clk);
+ break;
+ case 3:
+ /*
+ * Disable the peripheral clock for this serial port.
+ * This is called on uart_close() or a suspend event.
+ */
+ clk_disable(atmel_port->clk);
+ break;
+ default:
+ printk(KERN_ERR "atmel_serial: unknown pm %d\n", state);
}
}
/*
* Change the port parameters
*/
-static void atmel_set_termios(struct uart_port *port, struct ktermios * termios, struct ktermios * old)
+static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
+ struct ktermios *old)
{
unsigned long flags;
unsigned int mode, imr, quot, baud;
/* Get current mode register */
- mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL | ATMEL_US_NBSTOP | ATMEL_US_PAR);
+ mode =
+ UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL |
+ ATMEL_US_NBSTOP | ATMEL_US_PAR);
- baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
+ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
quot = uart_get_divisor(port, baud);
- if (quot > 65535) { /* BRGR is 16-bit, so switch to slower clock */
+ if (quot > 65535) { /* BRGR is 16-bit, so switch to slower clock */
quot /= 8;
mode |= ATMEL_US_USCLKS_MCK_DIV8;
}
@@ -545,18 +580,17 @@ static void atmel_set_termios(struct uar
/* parity */
if (termios->c_cflag & PARENB) {
- if (termios->c_cflag & CMSPAR) { /* Mark or Space parity */
+ /* Mark or Space parity */
+ if (termios->c_cflag & CMSPAR) {
if (termios->c_cflag & PARODD)
mode |= ATMEL_US_PAR_MARK;
else
mode |= ATMEL_US_PAR_SPACE;
- }
- else if (termios->c_cflag & PARODD)
+ } else if (termios->c_cflag & PARODD)
mode |= ATMEL_US_PAR_ODD;
else
mode |= ATMEL_US_PAR_EVEN;
- }
- else
+ } else
mode |= ATMEL_US_PAR_NONE;
spin_lock_irqsave(&port->lock, flags);
@@ -582,16 +616,16 @@ static void atmel_set_termios(struct uar
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= ATMEL_US_OVRE;
}
-
- // TODO: Ignore all characters if CREAD is set.
+ /* TODO: Ignore all characters if CREAD is set.*/
/* update the per-port timeout */
uart_update_timeout(port, termios->c_cflag, baud);
/* disable interrupts and drain transmitter */
- imr = UART_GET_IMR(port); /* get interrupt mask */
- UART_PUT_IDR(port, -1); /* disable all interrupts */
- while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY)) { barrier(); }
+ imr = UART_GET_IMR(port); /* get interrupt mask */
+ UART_PUT_IDR(port, -1); /* disable all interrupts */
+ while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY))
+ barrier();
/* disable receiver and transmitter */
UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
@@ -717,7 +751,8 @@ static struct uart_ops atmel_pops = {
/*
* Configure the port from the platform device resource info.
*/
-static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, struct platform_device *pdev)
+static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
+ struct platform_device *pdev)
{
struct uart_port *port = &atmel_port->uart;
struct atmel_uart_data *data = pdev->dev.platform_data;
@@ -740,7 +775,8 @@ static void __devinit atmel_init_port(st
port->membase = NULL;
}
- if (!atmel_port->clk) { /* for console, the clock could already be configured */
+ /* for console, the clock could already be configured */
+ if (!atmel_port->clk) {
atmel_port->clk = clk_get(&pdev->dev, "usart");
clk_enable(atmel_port->clk);
port->uartclk = clk_get_rate(atmel_port->clk);
@@ -764,7 +800,6 @@ void __init atmel_register_uart_fns(stru
atmel_pops.set_wake = fns->set_wake;
}
-
#ifdef CONFIG_SERIAL_ATMEL_CONSOLE
static void atmel_console_putchar(struct uart_port *port, int ch)
{
@@ -782,7 +817,7 @@ static void atmel_console_write(struct c
unsigned int status, imr;
/*
- * First, save IMR and then disable interrupts
+ * First, save IMR and then disable interrupts
*/
imr = UART_GET_IMR(port); /* get interrupt mask */
UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY);
@@ -790,30 +825,32 @@ static void atmel_console_write(struct c
uart_console_write(port, s, count, atmel_console_putchar);
/*
- * Finally, wait for transmitter to become empty
- * and restore IMR
+ * Finally, wait for transmitter to become empty
+ * and restore IMR
*/
do {
status = UART_GET_CSR(port);
} while (!(status & ATMEL_US_TXRDY));
- UART_PUT_IER(port, imr); /* set interrupts back the way they were */
+ /* set interrupts back the way they were */
+ UART_PUT_IER(port, imr);
}
/*
- * If the port was already initialised (eg, by a boot loader), try to determine
- * the current setup.
+ * If the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
*/
-static void __init atmel_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits)
+static void __init atmel_console_get_options(struct uart_port *port, int *baud,
+ int *parity, int *bits)
{
unsigned int mr, quot;
-// TODO: CR is a write-only register
-// unsigned int cr;
+/* TODO: CR is a write-only register
+// unsigned int cr;
//
-// cr = UART_GET_CR(port) & (ATMEL_US_RXEN | ATMEL_US_TXEN);
-// if (cr == (ATMEL_US_RXEN | ATMEL_US_TXEN)) {
-// /* ok, the port was enabled */
-// }
+// cr = UART_GET_CR(port) & (ATMEL_US_RXEN | ATMEL_US_TXEN);
+// if (cr == (ATMEL_US_RXEN | ATMEL_US_TXEN)) {
+// / * ok, the port was enabled * /
+// }*/
mr = UART_GET_MR(port) & ATMEL_US_CHRL;
if (mr == ATMEL_US_CHRL_8)
@@ -845,10 +882,10 @@ static int __init atmel_console_setup(st
int parity = 'n';
int flow = 'n';
- if (port->membase == 0) /* Port not initialized yet - delay setup */
+ if (port->membase == 0) /* Port not initialized yet - delay setup */
return -ENODEV;
- UART_PUT_IDR(port, -1); /* disable interrupts */
+ UART_PUT_IDR(port, -1); /* disable interrupts */
UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
@@ -863,13 +900,13 @@ static int __init atmel_console_setup(st
static struct uart_driver atmel_uart;
static struct console atmel_console = {
- .name = ATMEL_DEVICENAME,
- .write = atmel_console_write,
- .device = uart_console_device,
- .setup = atmel_console_setup,
- .flags = CON_PRINTBUFFER,
- .index = -1,
- .data = &atmel_uart,
+ .name = ATMEL_DEVICENAME,
+ .write = atmel_console_write,
+ .device = uart_console_device,
+ .setup = atmel_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &atmel_uart,
};
#define ATMEL_CONSOLE_DEVICE &atmel_console
@@ -880,13 +917,17 @@ static struct console atmel_console = {
static int __init atmel_console_init(void)
{
if (atmel_default_console_device) {
- add_preferred_console(ATMEL_DEVICENAME, atmel_default_console_device->id, NULL);
- atmel_init_port(&(atmel_ports[atmel_default_console_device->id]), atmel_default_console_device);
+ add_preferred_console(ATMEL_DEVICENAME,
+ atmel_default_console_device->id, NULL);
+ atmel_init_port(
+ &(atmel_ports[atmel_default_console_device->id]),
+ atmel_default_console_device);
register_console(&atmel_console);
}
return 0;
}
+
console_initcall(atmel_console_init);
/*
@@ -894,11 +935,13 @@ console_initcall(atmel_console_init);
*/
static int __init atmel_late_console_init(void)
{
- if (atmel_default_console_device && !(atmel_console.flags & CON_ENABLED))
+ if (atmel_default_console_device
+ && !(atmel_console.flags & CON_ENABLED))
register_console(&atmel_console);
return 0;
}
+
core_initcall(atmel_late_console_init);
#else
@@ -906,22 +949,24 @@ core_initcall(atmel_late_console_init);
#endif
static struct uart_driver atmel_uart = {
- .owner = THIS_MODULE,
- .driver_name = "atmel_serial",
- .dev_name = ATMEL_DEVICENAME,
- .major = SERIAL_ATMEL_MAJOR,
- .minor = MINOR_START,
- .nr = ATMEL_MAX_UART,
- .cons = ATMEL_CONSOLE_DEVICE,
+ .owner = THIS_MODULE,
+ .driver_name = "atmel_serial",
+ .dev_name = ATMEL_DEVICENAME,
+ .major = SERIAL_ATMEL_MAJOR,
+ .minor = MINOR_START,
+ .nr = ATMEL_MAX_UART,
+ .cons = ATMEL_CONSOLE_DEVICE,
};
#ifdef CONFIG_PM
-static int atmel_serial_suspend(struct platform_device *pdev, pm_message_t state)
+static int atmel_serial_suspend(struct platform_device *pdev,
+ pm_message_t state)
{
struct uart_port *port = platform_get_drvdata(pdev);
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
- if (device_may_wakeup(&pdev->dev) && !at91_suspend_entering_slow_clock())
+ if (device_may_wakeup(&pdev->dev)
+ && !at91_suspend_entering_slow_clock())
enable_irq_wake(port->irq);
else {
uart_suspend_port(&atmel_uart, port);
@@ -934,13 +979,12 @@ static int atmel_serial_suspend(struct p
static int atmel_serial_resume(struct platform_device *pdev)
{
struct uart_port *port = platform_get_drvdata(pdev);
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
if (atmel_port->suspended) {
uart_resume_port(&atmel_uart, port);
atmel_port->suspended = 0;
- }
- else
+ } else
disable_irq_wake(port->irq);
return 0;
@@ -970,7 +1014,7 @@ static int __devinit atmel_serial_probe(
static int __devexit atmel_serial_remove(struct platform_device *pdev)
{
struct uart_port *port = platform_get_drvdata(pdev);
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
int ret = 0;
clk_disable(atmel_port->clk);
This patch splits up the interrupt handler of the serial port
into a interrupt top-half and some tasklets.
The goal is to get the interrupt top-half as short as possible to
minimize latencies on interrupts. But the old code also does some
calls in the interrupt handler that are not allowed on preempt-RT
in IRQF_NODELAY context. This handler is executed in this context
because of the interrupt sharing with the timer interrupt.
The timer interrupt on Preempt-RT runs in IRQF_NODELAY context.
2 tasklets are used:
* one for handling the error statuses
* one for pushing the incoming characters into the tty-layer.
The Transmit path was IRQF_NODELAY safe by itself, and is not adapted.
The read path for DMA(PDC) is also not adapted, because that code
does not run in IRQF_NODELAY context due to irq-sharing. The DBGU
which is shared with the timer-irq does not work with DMA, so
therefor this is no problem.
Reading the complete receive queue is still done in the top-half
because we never want to miss any incoming character.
This patch demands the following patches to be installed first:
* atmel_serial_cleanup.patch
Signed-off-by: Remy Bohmer <linux@xxxxxxxxxx>
---
drivers/serial/atmel_serial.c | 150 +++++++++++++++++++++++++++++++++++++-----
1 file changed, 133 insertions(+), 17 deletions(-)
Index: linux-2.6.23/drivers/serial/atmel_serial.c
===================================================================
--- linux-2.6.23.orig/drivers/serial/atmel_serial.c 2007-12-13 17:30:48.000000000 +0100
+++ linux-2.6.23/drivers/serial/atmel_serial.c 2007-12-13 17:32:12.000000000 +0100
@@ -111,6 +111,22 @@
static int (*atmel_open_hook) (struct uart_port *);
static void (*atmel_close_hook) (struct uart_port *);
+struct atmel_uart_char {
+ unsigned int status;
+ unsigned int overrun;
+ unsigned int ch;
+ unsigned int flg;
+};
+
+#define ATMEL_SERIAL_RINGSIZE 1024
+
+struct atmel_uart_ring {
+ unsigned int head;
+ unsigned int tail;
+ unsigned int count;
+ struct atmel_uart_char data[ATMEL_SERIAL_RINGSIZE];
+};
+
/*
* We wrap our port structure around the generic uart_port.
*/
@@ -119,6 +135,13 @@ struct atmel_uart_port {
struct clk *clk; /* uart clock */
unsigned short suspended; /* is port suspended? */
int break_active; /* break being received */
+
+ struct tasklet_struct rx_task;
+ struct tasklet_struct status_task;
+ unsigned int irq_pending;
+ unsigned int irq_status;
+
+ struct atmel_uart_ring rx_ring;
};
static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
@@ -249,12 +272,41 @@ static void atmel_break_ctl(struct uart_
}
/*
+ * Stores the incoming character in the ring buffer
+ */
+static void
+atmel_buffer_rx_char(struct uart_port *port, unsigned int status,
+ unsigned int overrun, unsigned int ch,
+ unsigned int flg)
+{
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
+ struct atmel_uart_ring *ring = &atmel_port->rx_ring;
+ struct atmel_uart_char *c;
+
+ spin_lock(&port->lock);
+
+ if (ring->count == ATMEL_SERIAL_RINGSIZE)
+ goto out; /* Buffer overflow, ignore char */
+
+ c = &ring->data[ring->head];
+ c->status = status;
+ c->overrun = overrun;
+ c->ch = ch;
+ c->flg = flg;
+
+ ring->head++;
+ ring->head %= ATMEL_SERIAL_RINGSIZE;
+ ring->count++;
+out:
+ spin_unlock(&port->lock);
+}
+
+/*
* Characters received (called from interrupt handler)
*/
static void atmel_rx_chars(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
- struct tty_struct *tty = port->info->tty;
unsigned int status, ch, flg;
status = UART_GET_CSR(port);
@@ -315,13 +367,13 @@ static void atmel_rx_chars(struct uart_p
if (uart_handle_sysrq_char(port, ch))
goto ignore_char;
- uart_insert_char(port, status, ATMEL_US_OVRE, ch, flg);
+ atmel_buffer_rx_char(port, status, ATMEL_US_OVRE, ch, flg);
ignore_char:
status = UART_GET_CSR(port);
}
- tty_flip_buffer_push(tty);
+ tasklet_schedule(&atmel_port->rx_task);
}
/*
@@ -380,7 +432,7 @@ static void atmel_handle_receive(struct
}
/*
- * transmit interrupt handler.
+ * transmit interrupt handler. (Transmit is IRQF_NODELAY safe)
*/
static void atmel_handle_transmit(struct uart_port *port, unsigned int pending)
{
@@ -395,19 +447,16 @@ static void atmel_handle_transmit(struct
static void atmel_handle_status(struct uart_port *port, unsigned int pending,
unsigned int status)
{
- /* TODO: All reads to CSR will clear these interrupts! */
- if (pending & ATMEL_US_RIIC)
- port->icount.rng++;
- if (pending & ATMEL_US_DSRIC)
- port->icount.dsr++;
- if (pending & ATMEL_US_DCDIC)
- uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
- if (pending & ATMEL_US_CTSIC)
- uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
- if (pending &
- (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC |
- ATMEL_US_CTSIC))
- wake_up_interruptible(&port->info->delta_msr_wait);
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
+
+ spin_lock(&port->lock);
+
+ atmel_port->irq_pending = pending;
+ atmel_port->irq_status = status;
+
+ spin_unlock(&port->lock);
+
+ tasklet_schedule(&atmel_port->status_task);
}
/*
@@ -435,6 +484,66 @@ static irqreturn_t atmel_interrupt(int i
}
/*
+ * tasklet handling tty stuff outside the interrupt handler.
+ */
+static void atmel_rx_handler_task(unsigned long data)
+{
+ struct uart_port *port = (struct uart_port *)data;
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
+ struct atmel_uart_ring *ring = &atmel_port->rx_ring;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ while (ring->count) {
+ struct atmel_uart_char c = ring->data[ring->tail];
+
+ ring->tail++;
+ ring->tail %= ATMEL_SERIAL_RINGSIZE;
+ ring->count--;
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ uart_insert_char(port, c.status, c.overrun, c.ch, c.flg);
+
+ spin_lock_irqsave(&port->lock, flags);
+ }
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ tty_flip_buffer_push(port->info->tty);
+}
+
+static void atmel_status_handler_task(unsigned long data)
+{
+ struct uart_port *port = (struct uart_port *)data;
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
+ unsigned long flags;
+ unsigned int pending, status;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ pending = atmel_port->irq_pending;
+ status = atmel_port->irq_status;
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ /* TODO: All reads to CSR will clear these interrupts! */
+ if (pending & ATMEL_US_RIIC)
+ port->icount.rng++;
+ if (pending & ATMEL_US_DSRIC)
+ port->icount.dsr++;
+ if (pending & ATMEL_US_DCDIC)
+ uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
+ if (pending & ATMEL_US_CTSIC)
+ uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
+ if (pending &
+ (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC |
+ ATMEL_US_CTSIC))
+ wake_up_interruptible(&port->info->delta_msr_wait);
+}
+
+/*
* Perform initialization and enable port for reception
*/
static int atmel_startup(struct uart_port *port)
@@ -767,6 +876,13 @@ static void __devinit atmel_init_port(st
port->mapbase = pdev->resource[0].start;
port->irq = pdev->resource[1].start;
+ tasklet_init(&atmel_port->rx_task, atmel_rx_handler_task,
+ (unsigned long)port);
+ tasklet_init(&atmel_port->status_task, atmel_status_handler_task,
+ (unsigned long)port);
+
+ memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
+
if (data->regs)
/* Already mapped by setup code */
port->membase = data->regs;
On PREEMPT-RT we may not block on a normal spinlock in IRQ/IRQF_NODELAY-context.
This patch fixes this by making the lock a raw_spinlock_t for the
Atmel serial console.
This patch demands the following patches to be installed first:
* atmel_serial_cleanup.patch
* atmel_serial_irq_splitup.patch
Signed-off-by: Remy Bohmer <linux@xxxxxxxxxx>
---
include/linux/serial_core.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
Index: linux-2.6.23/include/linux/serial_core.h
===================================================================
--- linux-2.6.23.orig/include/linux/serial_core.h 2007-12-13 13:31:27.000000000 +0100
+++ linux-2.6.23/include/linux/serial_core.h 2007-12-13 16:32:22.000000000 +0100
@@ -226,7 +226,12 @@ struct uart_icount {
typedef unsigned int __bitwise__ upf_t;
struct uart_port {
- spinlock_t lock; /* port lock */
+
+#ifdef CONFIG_SERIAL_ATMEL
+ raw_spinlock_t lock; /* port lock */
+#else
+ spinlock_t lock; /* port lock */
+#endif
unsigned int iobase; /* in/out[bwl] */
unsigned char __iomem *membase; /* read/write[bwl] */
unsigned int irq; /* irq number */
