Hello Andrew,
So, to come to a conclusion about this complex patch series, I
attached all the latest versions to this mail. The latest patches from
yesterday including inline are also included to make the set complete.
So, this is the order in which the patches should be installed:
1) atmel_serial_cleanup.patch
2) atmel_serial_irq_splitup.patch
3) NEW: optional: add-atmel-serial-dma.patch, this merged the DMA
code (from Chip Coldwell) in your 2.6.23 patch back on top of this
series. Because the AT32 bug is not been fixed for a very long time, I
do not expect it to be fixed soon, so I think a reordering is better
to make preempt-RT work on AT91.
4) For RT only: atmel_serial_irqf_nodelay.patch can be applied
anywhere after 1 and 2
Steven, for the RT-patch, patches 1,2 and 4 are the _only_ patches
needed to make RT work stable on AT91 (based on 2.6.23.9-rt13), where
I think that 1 and 2 should go to mainline during time. I tested this
and it works properly, so we can, at least create a working/bootable
preempt-RT system on AT91. Notice that without the other patches from
Andrew the clock granularity is bound to 10ms. (Partly solved in
2.6.24-rc* by mainlining of the clocksource/events patches form David
Brownell)
If any of you have any comments, or suggestions, please let me know.
Kind Regards,
Remy Bohmer
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 | 351 +++++++++++++++++++++++-------------------
1 file changed, 199 insertions(+), 152 deletions(-)
Index: linux-2.6.23.1-rt5/drivers/serial/atmel_serial.c
===================================================================
--- linux-2.6.23.1-rt5.orig/drivers/serial/atmel_serial.c 2007-10-09 22:31:38.000000000 +0200
+++ linux-2.6.23.1-rt5/drivers/serial/atmel_serial.c 2007-12-13 20:59:16.000000000 +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 +358,75 @@ static void atmel_tx_chars(struct uart_p
}
/*
+ * receive interrupt handler.
+ */
+static inline 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 inline 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 inline 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 +442,6 @@ 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 +454,9 @@ 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 +478,11 @@ 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 +492,6 @@ 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 +514,49 @@ 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 +583,17 @@ 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 +619,16 @@ 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 +754,8 @@ 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 +778,8 @@ 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 +803,6 @@ 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 +820,7 @@ 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 +828,32 @@ 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 +885,10 @@ 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 +903,13 @@ 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 +920,17 @@ 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 +938,13 @@ 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 +952,24 @@ 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 +982,12 @@ 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 +1017,7 @@ 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-2.6.23.1-rt5/drivers/serial/atmel_serial.c
===================================================================
--- linux-2.6.23.1-rt5.orig/drivers/serial/atmel_serial.c 2007-12-13 21:33:08.000000000 +0100
+++ linux-2.6.23.1-rt5/drivers/serial/atmel_serial.c 2007-12-13 21:33:10.000000000 +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);
}
/*
@@ -381,7 +433,7 @@ atmel_handle_receive(struct uart_port *p
}
/*
- * transmit interrupt handler.
+ * transmit interrupt handler. (Transmit is IRQF_NODELAY safe)
*/
static inline void
atmel_handle_transmit(struct uart_port *port, unsigned int pending)
@@ -398,19 +450,16 @@ static inline 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);
}
/*
@@ -438,6 +487,66 @@ 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)
@@ -770,6 +879,13 @@ 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;
This patch adds the DMA-patch build by Chip Coldwell for the AT91/AT32
serial USARTS to the patch stack, but the order of the patches
has been changed.
Because the DMA-patch does not seem to work on AT32 and has not
been fixed since months and several kernel releases, this DMA
patch is holding things up. Currently the DBGU and the USART does
not work on Preempt-RT, and needs a splitup of the interrupt handler.
The biggest part of the interrupt handler splitup patch is not related
to RT, and can therefor be integrated in mainline seperately.
When that is done, the RT-patch can be fixed. Due to the bug in the
DMA-patch this integration gets too complicated, and a reorder of
patches is required.
Previously this order was valid:
* http://maxim.org.za/AT91RM9200/2.6/2.6.23-at91.patch.gz
* Serial-port interrupt handler splitup patches
With this patch, the order needs to be:
* Serial-port splitup patches.
* This patch for adding DMA-support.
The older DMA-patch has to be removed from the patch at:
http://maxim.org.za/AT91RM9200/2.6/2.6.23-at91.patch.gz
Signed-off-by: Remy Bohmer <linux@xxxxxxxxxx>
---
drivers/serial/atmel_serial.c | 325 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 319 insertions(+), 6 deletions(-)
Index: linux-2.6.23/drivers/serial/atmel_serial.c
===================================================================
--- linux-2.6.23.orig/drivers/serial/atmel_serial.c 2007-12-14 12:00:20.000000000 +0100
+++ linux-2.6.23/drivers/serial/atmel_serial.c 2007-12-14 12:00:23.000000000 +0100
@@ -7,6 +7,8 @@
* Based on drivers/char/serial_sa1100.c, by Deep Blue Solutions Ltd.
* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
*
+ * DMA support added by Chip Coldwell.
+ *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
@@ -33,6 +35,7 @@
#include <linux/sysrq.h>
#include <linux/tty_flip.h>
#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
#include <linux/atmel_pdc.h>
#include <asm/io.h>
@@ -47,6 +50,11 @@
#include "atmel_serial.h"
+#define SUPPORT_PDC
+#define PDC_BUFFER_SIZE (L1_CACHE_BYTES << 3)
+#warning "Revisit"
+#define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */
+
#if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
@@ -111,6 +119,13 @@
static int (*atmel_open_hook) (struct uart_port *);
static void (*atmel_close_hook) (struct uart_port *);
+struct atmel_dma_buffer {
+ unsigned char *buf;
+ dma_addr_t dma_addr;
+ size_t dma_size;
+ unsigned int ofs;
+};
+
struct atmel_uart_char {
unsigned int status;
unsigned int overrun;
@@ -136,6 +151,13 @@ struct atmel_uart_port {
unsigned short suspended; /* is port suspended? */
int break_active; /* break being received */
+ short use_dma_rx; /* enable PDC receiver */
+ short pdc_rx_idx; /* current PDC RX buffer */
+ struct atmel_dma_buffer pdc_rx[2]; /* PDC receier */
+
+ short use_dma_tx; /* enable PDC transmitter */
+ struct atmel_dma_buffer pdc_tx; /* PDC transmitter */
+
struct tasklet_struct rx_task;
struct tasklet_struct status_task;
unsigned int irq_pending;
@@ -146,6 +168,9 @@ struct atmel_uart_port {
static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
+#define PDC_RX_BUF(port) &(port)->pdc_rx[(port)->pdc_rx_idx]
+#define PDC_RX_SWITCH(port) (port)->pdc_rx_idx = !(port)->pdc_rx_idx
+
#ifdef SUPPORT_SYSRQ
static struct console atmel_console;
#endif
@@ -231,7 +256,14 @@ static u_int atmel_get_mctrl(struct uart
*/
static void atmel_stop_tx(struct uart_port *port)
{
- UART_PUT_IDR(port, ATMEL_US_TXRDY);
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+
+ if (atmel_port->use_dma_tx) {
+ /* 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);
}
/*
@@ -239,7 +271,19 @@ static void atmel_stop_tx(struct uart_po
*/
static void atmel_start_tx(struct uart_port *port)
{
- UART_PUT_IER(port, ATMEL_US_TXRDY);
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+
+ if (atmel_port->use_dma_tx) {
+ 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);
+ /* re-enable PDC transmit */
+ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
+ } else
+ UART_PUT_IER(port, ATMEL_US_TXRDY);
}
/*
@@ -247,7 +291,14 @@ static void atmel_start_tx(struct uart_p
*/
static void atmel_stop_rx(struct uart_port *port)
{
- UART_PUT_IDR(port, ATMEL_US_RXRDY);
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+
+ if (atmel_port->use_dma_rx) {
+ /* disable PDC receive */
+ UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS);
+ UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
+ } else
+ UART_PUT_IDR(port, ATMEL_US_RXRDY);
}
/*
@@ -302,6 +353,148 @@ out:
}
/*
+ * Receive data via the PDC. A buffer has been fulled.
+ */
+static void atmel_pdc_endrx(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+ struct tty_struct *tty = port->info->tty;
+ struct atmel_dma_buffer *pdc = PDC_RX_BUF(atmel_port);
+ unsigned int count;
+
+ count = pdc->dma_size - pdc->ofs;
+ if (likely(count > 0)) {
+ dma_sync_single_for_cpu(port->dev,
+ pdc->dma_addr,
+ pdc->dma_size,
+ DMA_FROM_DEVICE);
+ tty_insert_flip_string(tty, pdc->buf + pdc->ofs, count);
+ tty_flip_buffer_push(tty);
+
+ port->icount.rx += count;
+ }
+
+ /* Set this buffer as the next receive buffer */
+ pdc->ofs = 0;
+ UART_PUT_RNPR(port, pdc->dma_addr);
+ UART_PUT_RNCR(port, pdc->dma_size);
+
+ /* Switch to next buffer */
+ PDC_RX_SWITCH(atmel_port); /* next PDC buffer */
+}
+
+/*
+ * Receive data via the PDC. At least one byte was received, but the
+ * buffer was not full when the inter-character timeout expired.
+ */
+static void atmel_pdc_timeout(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+ struct tty_struct *tty = port->info->tty;
+ struct atmel_dma_buffer *pdc = PDC_RX_BUF(atmel_port);
+ /* unsigned */ int ofs, count;
+
+ ofs = UART_GET_RPR(port) - pdc->dma_addr; /* current DMA adress */
+ count = ofs - pdc->ofs;
+
+ if (likely(count > 0)) {
+ dma_sync_single_for_cpu(port->dev,
+ pdc->dma_addr,
+ pdc->dma_size,
+ DMA_FROM_DEVICE);
+ tty_insert_flip_string(tty, pdc->buf + pdc->ofs, count);
+ tty_flip_buffer_push(tty);
+
+ pdc->ofs = ofs;
+ port->icount.rx += count;
+ }
+
+ /* reset the UART timeout */
+ UART_PUT_CR(port, ATMEL_US_STTTO);
+}
+
+/*
+ * Deal with parity, framing and overrun errors.
+ */
+static void atmel_pdc_rxerr(struct uart_port *port, unsigned int status)
+{
+ /* clear error */
+ UART_PUT_CR(port, ATMEL_US_RSTSTA);
+
+ if (status & ATMEL_US_RXBRK) {
+ /* ignore side-effect */
+ status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
+ port->icount.brk++;
+ }
+ if (status & ATMEL_US_PARE)
+ port->icount.parity++;
+ if (status & ATMEL_US_FRAME)
+ port->icount.frame++;
+ if (status & ATMEL_US_OVRE)
+ port->icount.overrun++;
+}
+
+/*
+ * A transmission via the PDC is complete.
+ */
+static void atmel_pdc_endtx(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+ struct circ_buf *xmit = &port->info->xmit;
+ struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
+
+ xmit->tail += pdc->ofs;
+ if (xmit->tail >= SERIAL_XMIT_SIZE)
+ xmit->tail -= SERIAL_XMIT_SIZE;
+
+ port->icount.tx += pdc->ofs;
+ pdc->ofs = 0;
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+}
+
+/*
+ * The PDC transmitter is idle, so either start the next transfer or
+ * disable the transmitter.
+ */
+static void atmel_pdc_txbufe(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
+ struct circ_buf *xmit = &port->info->xmit;
+ struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
+ int count;
+
+ if (!uart_circ_empty(xmit)) {
+ /* more to transmit - setup next transfer */
+
+ /* disable PDC transmit */
+ UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
+ dma_sync_single_for_device(port->dev,
+ pdc->dma_addr,
+ pdc->dma_size,
+ DMA_TO_DEVICE);
+
+ if (xmit->tail < xmit->head)
+ count = xmit->head - xmit->tail;
+ else
+ count = SERIAL_XMIT_SIZE - xmit->tail;
+ pdc->ofs = count;
+
+ UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
+ UART_PUT_TCR(port, count);
+ /* re-enable PDC transmit */
+ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
+ } else {
+ /* nothing left to transmit - disable the transmitter */
+
+ /* disable PDC transmit */
+ UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
+ UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
+ }
+}
+
+/*
* Characters received (called from interrupt handler)
*/
static void atmel_rx_chars(struct uart_port *port)
@@ -417,6 +610,16 @@ atmel_handle_receive(struct uart_port *p
{
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
+ /* PDC receive */
+ if (pending & ATMEL_US_ENDRX)
+ atmel_pdc_endrx(port);
+ if (pending & ATMEL_US_TIMEOUT)
+ atmel_pdc_timeout(port);
+ if (atmel_port->use_dma_rx &&
+ (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE |
+ ATMEL_US_FRAME | ATMEL_US_PARE)))
+ atmel_pdc_rxerr(port, pending);
+
/* Interrupt receive */
if (pending & ATMEL_US_RXRDY)
atmel_rx_chars(port);
@@ -438,6 +641,12 @@ atmel_handle_receive(struct uart_port *p
static inline void
atmel_handle_transmit(struct uart_port *port, unsigned int pending)
{
+ /* PDC transmit */
+ if (pending & ATMEL_US_ENDTX)
+ atmel_pdc_endtx(port);
+ if (pending & ATMEL_US_TXBUFE)
+ atmel_pdc_txbufe(port);
+
/* Interrupt transmit */
if (pending & ATMEL_US_TXRDY)
atmel_tx_chars(port);
@@ -551,6 +760,7 @@ static void atmel_status_handler_task(un
*/
static int atmel_startup(struct uart_port *port)
{
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
int retval;
/*
@@ -572,6 +782,56 @@ static int atmel_startup(struct uart_por
}
/*
+ * Initialize DMA (if necessary)
+ */
+ if (atmel_port->use_dma_rx) {
+ int i;
+
+ for (i = 0; i < 2; i++) {
+ struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
+
+ pdc->buf = kmalloc(PDC_BUFFER_SIZE, GFP_KERNEL);
+ if (pdc->buf == NULL) {
+ if (i != 0) {
+ dma_unmap_single(port->dev,
+ atmel_port->pdc_rx[0].dma_addr,
+ PDC_BUFFER_SIZE,
+ DMA_FROM_DEVICE);
+ kfree(atmel_port->pdc_rx[0].buf);
+ }
+ free_irq(port->irq, port);
+ return -ENOMEM;
+ }
+ pdc->dma_addr = dma_map_single(port->dev,
+ pdc->buf,
+ PDC_BUFFER_SIZE,
+ DMA_FROM_DEVICE);
+ pdc->dma_size = PDC_BUFFER_SIZE;
+ pdc->ofs = 0;
+ }
+
+ atmel_port->pdc_rx_idx = 0;
+
+ UART_PUT_RPR(port, atmel_port->pdc_rx[0].dma_addr);
+ UART_PUT_RCR(port, PDC_BUFFER_SIZE);
+
+ UART_PUT_RNPR(port, atmel_port->pdc_rx[1].dma_addr);
+ UART_PUT_RNCR(port, PDC_BUFFER_SIZE);
+ }
+ if (atmel_port->use_dma_tx) {
+ struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
+ struct circ_buf *xmit = &port->info->xmit;
+
+ pdc->buf = xmit->buf;
+ pdc->dma_addr = dma_map_single(port->dev,
+ pdc->buf,
+ SERIAL_XMIT_SIZE,
+ DMA_TO_DEVICE);
+ pdc->dma_size = SERIAL_XMIT_SIZE;
+ pdc->ofs = 0;
+ }
+
+ /*
* If there is a specific "open" function (to register
* control line interrupts)
*/
@@ -590,8 +850,18 @@ static int atmel_startup(struct uart_por
/* enable xmit & rcvr */
UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
- /* enable receive only */
- UART_PUT_IER(port, ATMEL_US_RXRDY);
+ if (atmel_port->use_dma_rx) {
+ /* set UART timeout */
+ UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
+ UART_PUT_CR(port, ATMEL_US_STTTO);
+
+ UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
+ /* enable PDC controller */
+ UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
+ } else {
+ /* enable receive only */
+ UART_PUT_IER(port, ATMEL_US_RXRDY);
+ }
return 0;
}
@@ -601,6 +871,38 @@ 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;
+ /*
+ * Ensure everything is stopped.
+ */
+ atmel_stop_rx(port);
+ atmel_stop_tx(port);
+
+ /*
+ * Shut-down the DMA.
+ */
+ if (atmel_port->use_dma_rx) {
+ int i;
+
+ for (i = 0; i < 2; i++) {
+ struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
+
+ dma_unmap_single(port->dev,
+ pdc->dma_addr,
+ pdc->dma_size,
+ DMA_FROM_DEVICE);
+ kfree(pdc->buf);
+ }
+ }
+ if (atmel_port->use_dma_tx) {
+ struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
+
+ dma_unmap_single(port->dev,
+ pdc->dma_addr,
+ pdc->dma_size,
+ DMA_TO_DEVICE);
+ }
+
/*
* Disable all interrupts, port and break condition.
*/
@@ -654,6 +956,7 @@ static void atmel_serial_pm(struct uart_
static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
+ struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
unsigned long flags;
unsigned int mode, imr, quot, baud;
@@ -713,6 +1016,9 @@ static void atmel_set_termios(struct uar
if (termios->c_iflag & (BRKINT | PARMRK))
port->read_status_mask |= ATMEL_US_RXBRK;
+ if (atmel_port->use_dma_rx) /* need to enable error interrupts */
+ UART_PUT_IER(port, port->read_status_mask);
+
/*
* Characters to ignore
*/
@@ -900,6 +1206,13 @@ static void __devinit atmel_init_port(st
clk_enable(atmel_port->clk);
port->uartclk = clk_get_rate(atmel_port->clk);
}
+
+#ifdef SUPPORT_PDC
+ atmel_port->use_dma_rx = data->use_dma_rx;
+ atmel_port->use_dma_tx = data->use_dma_tx;
+ if (atmel_port->use_dma_tx)
+ port->fifosize = PDC_BUFFER_SIZE;
+#endif
}
/*
@@ -1085,7 +1398,7 @@ static int atmel_serial_suspend(struct p
struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
if (device_may_wakeup(&pdev->dev)
- && !at91_suspend_entering_slow_clock())
+ && !clk_must_disable(atmel_port->clk))
enable_irq_wake(port->irq);
else {
uart_suspend_port(&atmel_uart, port);
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 */
