* 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
#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 <linux/atmel_serial.h>
#include <asm/io.h>
#include <asm/mach/serial_at91.h>
-#include <asm/arch/board.h>
+#include <mach/board.h>
#ifdef CONFIG_ARM
-#include <asm/arch/cpu.h>
-#include <asm/arch/gpio.h>
+#include <mach/cpu.h>
+#include <mach/gpio.h>
#endif
+#define PDC_BUFFER_SIZE 512
+/* Revisit: We should calculate this based on the actual port settings */
+#define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */
+
#if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#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_GET_TCR(port) __raw_readl((port)->membase + ATMEL_PDC_TCR)
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;
+ unsigned int dma_size;
+ unsigned int ofs;
+};
+
+struct atmel_uart_char {
+ u16 status;
+ u16 ch;
+};
+
+#define ATMEL_SERIAL_RINGSIZE 1024
+
/*
* 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 may_wakeup; /* cached value of device_may_wakeup for times we need to disable it */
+ u32 backup_imr; /* IMR saved during suspend */
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 tasklet;
+ unsigned int irq_status;
+ unsigned int irq_status_prev;
+
+ struct circ_buf rx_ring;
};
static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
static struct console atmel_console;
#endif
+static inline struct atmel_uart_port *
+to_atmel_uart_port(struct uart_port *uart)
+{
+ return container_of(uart, struct atmel_uart_port, uart);
+}
+
+#ifdef CONFIG_SERIAL_ATMEL_PDC
+static bool atmel_use_dma_rx(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+ return atmel_port->use_dma_rx;
+}
+
+static bool atmel_use_dma_tx(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+ return atmel_port->use_dma_tx;
+}
+#else
+static bool atmel_use_dma_rx(struct uart_port *port)
+{
+ return false;
+}
+
+static bool atmel_use_dma_tx(struct uart_port *port)
+{
+ return false;
+}
+#endif
+
/*
* Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
*/
*/
static void atmel_stop_tx(struct uart_port *port)
{
- UART_PUT_IDR(port, ATMEL_US_TXRDY);
+ 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);
}
/*
*/
static void atmel_start_tx(struct uart_port *port)
{
- UART_PUT_IER(port, ATMEL_US_TXRDY);
+ 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);
+ /* re-enable PDC transmit */
+ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
+ } else
+ UART_PUT_IER(port, ATMEL_US_TXRDY);
}
/*
*/
static void atmel_stop_rx(struct uart_port *port)
{
- UART_PUT_IDR(port, ATMEL_US_RXRDY);
+ 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);
+ } else
+ UART_PUT_IDR(port, ATMEL_US_RXRDY);
}
/*
}
/*
+ * Stores the incoming character in the ring buffer
+ */
+static void
+atmel_buffer_rx_char(struct uart_port *port, unsigned int status,
+ unsigned int ch)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ struct circ_buf *ring = &atmel_port->rx_ring;
+ struct atmel_uart_char *c;
+
+ if (!CIRC_SPACE(ring->head, ring->tail, ATMEL_SERIAL_RINGSIZE))
+ /* Buffer overflow, ignore char */
+ return;
+
+ c = &((struct atmel_uart_char *)ring->buf)[ring->head];
+ c->status = status;
+ c->ch = ch;
+
+ /* Make sure the character is stored before we update head. */
+ smp_wmb();
+
+ ring->head = (ring->head + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
+}
+
+/*
+ * 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++;
+}
+
+/*
* 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;
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ unsigned int status, ch;
status = UART_GET_CSR(port);
while (status & ATMEL_US_RXRDY) {
ch = UART_GET_CHAR(port);
- port->icount.rx++;
-
- flg = TTY_NORMAL;
-
/*
* note that the error handling code is
* out of the main execution path
if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
| ATMEL_US_OVRE | ATMEL_US_RXBRK)
|| atmel_port->break_active)) {
+
/* clear error */
UART_PUT_CR(port, ATMEL_US_RSTSTA);
+
if (status & ATMEL_US_RXBRK
&& !atmel_port->break_active) {
- /* 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);
- if (uart_handle_break(port))
- goto ignore_char;
} else {
/*
* This is either the end-of-break
status &= ~ATMEL_US_RXBRK;
atmel_port->break_active = 0;
}
- if (status & ATMEL_US_PARE)
- port->icount.parity++;
- if (status & ATMEL_US_FRAME)
- port->icount.frame++;
- if (status & ATMEL_US_OVRE)
- port->icount.overrun++;
-
- status &= port->read_status_mask;
-
- if (status & ATMEL_US_RXBRK)
- flg = TTY_BREAK;
- else if (status & ATMEL_US_PARE)
- flg = TTY_PARITY;
- else if (status & ATMEL_US_FRAME)
- flg = TTY_FRAME;
}
- if (uart_handle_sysrq_char(port, ch))
- goto ignore_char;
-
- uart_insert_char(port, status, ATMEL_US_OVRE, ch, flg);
-
-ignore_char:
+ atmel_buffer_rx_char(port, status, ch);
status = UART_GET_CSR(port);
}
- tty_flip_buffer_push(tty);
+ tasklet_schedule(&atmel_port->tasklet);
}
/*
- * Transmit characters (called from interrupt handler)
+ * Transmit characters (called from tasklet with TXRDY interrupt
+ * disabled)
*/
static void atmel_tx_chars(struct uart_port *port)
{
- struct circ_buf *xmit = &port->info->xmit;
+ struct circ_buf *xmit = &port->state->xmit;
- if (port->x_char) {
+ if (port->x_char && UART_GET_CSR(port) & ATMEL_US_TXRDY) {
UART_PUT_CHAR(port, port->x_char);
port->icount.tx++;
port->x_char = 0;
- return;
}
- if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
- atmel_stop_tx(port);
+ if (uart_circ_empty(xmit) || uart_tx_stopped(port))
return;
- }
while (UART_GET_CSR(port) & ATMEL_US_TXRDY) {
UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
- if (uart_circ_empty(xmit))
- atmel_stop_tx(port);
+ if (!uart_circ_empty(xmit))
+ UART_PUT_IER(port, ATMEL_US_TXRDY);
}
/*
static void
atmel_handle_receive(struct uart_port *port, unsigned int pending)
{
- struct atmel_uart_port *atmel_port = (struct atmel_uart_port *)port;
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+ if (atmel_use_dma_rx(port)) {
+ /*
+ * PDC receive. Just schedule the tasklet and let it
+ * figure out the details.
+ *
+ * TODO: We're not handling error flags correctly at
+ * the moment.
+ */
+ if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) {
+ UART_PUT_IDR(port, (ATMEL_US_ENDRX
+ | ATMEL_US_TIMEOUT));
+ tasklet_schedule(&atmel_port->tasklet);
+ }
+
+ if (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)
}
/*
- * transmit interrupt handler.
+ * transmit interrupt handler. (Transmit is IRQF_NODELAY safe)
*/
static void
atmel_handle_transmit(struct uart_port *port, unsigned int pending)
{
- /* Interrupt transmit */
- if (pending & ATMEL_US_TXRDY)
- atmel_tx_chars(port);
+ 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);
+ }
+ }
}
/*
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));
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC
- | ATMEL_US_CTSIC))
- wake_up_interruptible(&port->info->delta_msr_wait);
+ | ATMEL_US_CTSIC)) {
+ atmel_port->irq_status = status;
+ tasklet_schedule(&atmel_port->tasklet);
+ }
}
/*
struct uart_port *port = dev_id;
unsigned int status, pending, pass_counter = 0;
- status = UART_GET_CSR(port);
- pending = status & UART_GET_IMR(port);
- while (pending) {
+ do {
+ status = UART_GET_CSR(port);
+ pending = status & UART_GET_IMR(port);
+ if (!pending)
+ break;
+
atmel_handle_receive(port, pending);
atmel_handle_status(port, pending, status);
atmel_handle_transmit(port, pending);
+ } while (pass_counter++ < ATMEL_ISR_PASS_LIMIT);
- if (pass_counter++ > ATMEL_ISR_PASS_LIMIT)
- break;
+ return pass_counter ? IRQ_HANDLED : IRQ_NONE;
+}
- status = UART_GET_CSR(port);
- pending = status & UART_GET_IMR(port);
+/*
+ * Called from tasklet with ENDTX and TXBUFE interrupts disabled.
+ */
+static void atmel_tx_dma(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ struct circ_buf *xmit = &port->state->xmit;
+ struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
+ int count;
+
+ /* nothing left to transmit? */
+ if (UART_GET_TCR(port))
+ return;
+
+ xmit->tail += pdc->ofs;
+ xmit->tail &= UART_XMIT_SIZE - 1;
+
+ port->icount.tx += pdc->ofs;
+ pdc->ofs = 0;
+
+ /* more to transmit - setup next transfer */
+
+ /* disable PDC transmit */
+ UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
+
+ if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
+ dma_sync_single_for_device(port->dev,
+ pdc->dma_addr,
+ pdc->dma_size,
+ DMA_TO_DEVICE);
+
+ count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+ pdc->ofs = count;
+
+ UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
+ UART_PUT_TCR(port, count);
+ /* re-enable PDC transmit and interrupts */
+ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
+ UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
}
- return IRQ_HANDLED;
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+}
+
+static void atmel_rx_from_ring(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ struct circ_buf *ring = &atmel_port->rx_ring;
+ unsigned int flg;
+ unsigned int status;
+
+ while (ring->head != ring->tail) {
+ struct atmel_uart_char c;
+
+ /* Make sure c is loaded after head. */
+ smp_rmb();
+
+ c = ((struct atmel_uart_char *)ring->buf)[ring->tail];
+
+ ring->tail = (ring->tail + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
+
+ port->icount.rx++;
+ status = c.status;
+ flg = TTY_NORMAL;
+
+ /*
+ * note that the error handling code is
+ * out of the main execution path
+ */
+ if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
+ | ATMEL_US_OVRE | ATMEL_US_RXBRK))) {
+ if (status & ATMEL_US_RXBRK) {
+ /* ignore side-effect */
+ status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
+
+ port->icount.brk++;
+ if (uart_handle_break(port))
+ continue;
+ }
+ if (status & ATMEL_US_PARE)
+ port->icount.parity++;
+ if (status & ATMEL_US_FRAME)
+ port->icount.frame++;
+ if (status & ATMEL_US_OVRE)
+ port->icount.overrun++;
+
+ status &= port->read_status_mask;
+
+ if (status & ATMEL_US_RXBRK)
+ flg = TTY_BREAK;
+ else if (status & ATMEL_US_PARE)
+ flg = TTY_PARITY;
+ else if (status & ATMEL_US_FRAME)
+ flg = TTY_FRAME;
+ }
+
+
+ if (uart_handle_sysrq_char(port, c.ch))
+ continue;
+
+ uart_insert_char(port, status, ATMEL_US_OVRE, c.ch, flg);
+ }
+
+ /*
+ * Drop the lock here since it might end up calling
+ * uart_start(), which takes the lock.
+ */
+ spin_unlock(&port->lock);
+ tty_flip_buffer_push(port->state->port.tty);
+ spin_lock(&port->lock);
+}
+
+static void atmel_rx_from_dma(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ struct tty_struct *tty = port->state->port.tty;
+ struct atmel_dma_buffer *pdc;
+ int rx_idx = atmel_port->pdc_rx_idx;
+ unsigned int head;
+ unsigned int tail;
+ unsigned int count;
+
+ do {
+ /* Reset the UART timeout early so that we don't miss one */
+ UART_PUT_CR(port, ATMEL_US_STTTO);
+
+ pdc = &atmel_port->pdc_rx[rx_idx];
+ head = UART_GET_RPR(port) - pdc->dma_addr;
+ tail = pdc->ofs;
+
+ /* If the PDC has switched buffers, RPR won't contain
+ * any address within the current buffer. Since head
+ * is unsigned, we just need a one-way comparison to
+ * find out.
+ *
+ * In this case, we just need to consume the entire
+ * buffer and resubmit it for DMA. This will clear the
+ * ENDRX bit as well, so that we can safely re-enable
+ * all interrupts below.
+ */
+ head = min(head, pdc->dma_size);
+
+ if (likely(head != tail)) {
+ dma_sync_single_for_cpu(port->dev, pdc->dma_addr,
+ pdc->dma_size, DMA_FROM_DEVICE);
+
+ /*
+ * head will only wrap around when we recycle
+ * the DMA buffer, and when that happens, we
+ * explicitly set tail to 0. So head will
+ * always be greater than tail.
+ */
+ count = head - tail;
+
+ tty_insert_flip_string(tty, pdc->buf + pdc->ofs, count);
+
+ dma_sync_single_for_device(port->dev, pdc->dma_addr,
+ pdc->dma_size, DMA_FROM_DEVICE);
+
+ port->icount.rx += count;
+ pdc->ofs = head;
+ }
+
+ /*
+ * If the current buffer is full, we need to check if
+ * the next one contains any additional data.
+ */
+ if (head >= pdc->dma_size) {
+ pdc->ofs = 0;
+ UART_PUT_RNPR(port, pdc->dma_addr);
+ UART_PUT_RNCR(port, pdc->dma_size);
+
+ rx_idx = !rx_idx;
+ atmel_port->pdc_rx_idx = rx_idx;
+ }
+ } while (head >= pdc->dma_size);
+
+ /*
+ * Drop the lock here since it might end up calling
+ * uart_start(), which takes the lock.
+ */
+ spin_unlock(&port->lock);
+ tty_flip_buffer_push(tty);
+ spin_lock(&port->lock);
+
+ UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
+}
+
+/*
+ * tasklet handling tty stuff outside the interrupt handler.
+ */
+static void atmel_tasklet_func(unsigned long data)
+{
+ struct uart_port *port = (struct uart_port *)data;
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ unsigned int status;
+ unsigned int status_change;
+
+ /* The interrupt handler does not take the lock */
+ spin_lock(&port->lock);
+
+ if (atmel_use_dma_tx(port))
+ atmel_tx_dma(port);
+ else
+ atmel_tx_chars(port);
+
+ status = atmel_port->irq_status;
+ status_change = status ^ atmel_port->irq_status_prev;
+
+ if (status_change & (ATMEL_US_RI | ATMEL_US_DSR
+ | ATMEL_US_DCD | ATMEL_US_CTS)) {
+ /* TODO: All reads to CSR will clear these interrupts! */
+ if (status_change & ATMEL_US_RI)
+ port->icount.rng++;
+ if (status_change & ATMEL_US_DSR)
+ port->icount.dsr++;
+ if (status_change & ATMEL_US_DCD)
+ uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
+ if (status_change & ATMEL_US_CTS)
+ uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
+
+ wake_up_interruptible(&port->state->port.delta_msr_wait);
+
+ atmel_port->irq_status_prev = status;
+ }
+
+ if (atmel_use_dma_rx(port))
+ atmel_rx_from_dma(port);
+ else
+ atmel_rx_from_ring(port);
+
+ spin_unlock(&port->lock);
}
/*
*/
static int atmel_startup(struct uart_port *port)
{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ struct tty_struct *tty = port->state->port.tty;
int retval;
/*
* Allocate the IRQ
*/
retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED,
- "atmel_serial", port);
+ tty ? tty->name : "atmel_serial", port);
if (retval) {
printk("atmel_serial: atmel_startup - Can't get irq\n");
return retval;
}
/*
+ * Initialize DMA (if necessary)
+ */
+ if (atmel_use_dma_rx(port)) {
+ 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_use_dma_tx(port)) {
+ struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
+ struct circ_buf *xmit = &port->state->xmit;
+
+ pdc->buf = xmit->buf;
+ pdc->dma_addr = dma_map_single(port->dev,
+ pdc->buf,
+ UART_XMIT_SIZE,
+ DMA_TO_DEVICE);
+ pdc->dma_size = UART_XMIT_SIZE;
+ pdc->ofs = 0;
+ }
+
+ /*
* If there is a specific "open" function (to register
* control line interrupts)
*/
}
}
+ /* Save current CSR for comparison in atmel_tasklet_func() */
+ atmel_port->irq_status_prev = UART_GET_CSR(port);
+ atmel_port->irq_status = atmel_port->irq_status_prev;
+
/*
* Finally, enable the serial port
*/
/* 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_use_dma_rx(port)) {
+ /* 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;
}
*/
static void atmel_shutdown(struct uart_port *port)
{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ /*
+ * Ensure everything is stopped.
+ */
+ atmel_stop_rx(port);
+ atmel_stop_tx(port);
+
+ /*
+ * Shut-down the DMA.
+ */
+ if (atmel_use_dma_rx(port)) {
+ 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_use_dma_tx(port)) {
+ 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.
*/
}
/*
+ * Flush any TX data submitted for DMA. Called when the TX circular
+ * buffer is reset.
+ */
+static void atmel_flush_buffer(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+ if (atmel_use_dma_tx(port)) {
+ UART_PUT_TCR(port, 0);
+ atmel_port->pdc_tx.ofs = 0;
+ }
+}
+
+/*
* Power / Clock management.
*/
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 = to_atmel_uart_port(port);
switch (state) {
case 0:
* This is called on uart_open() or a resume event.
*/
clk_enable(atmel_port->clk);
+
+ /* re-enable interrupts if we disabled some on suspend */
+ UART_PUT_IER(port, atmel_port->backup_imr);
break;
case 3:
+ /* Back up the interrupt mask and disable all interrupts */
+ atmel_port->backup_imr = UART_GET_IMR(port);
+ UART_PUT_IDR(port, -1);
+
/*
* Disable the peripheral clock for this serial port.
* This is called on uart_close() or a suspend event.
/* Get current mode register */
mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL
- | ATMEL_US_NBSTOP | ATMEL_US_PAR);
+ | ATMEL_US_NBSTOP | ATMEL_US_PAR
+ | ATMEL_US_USMODE);
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
quot = uart_get_divisor(port, baud);
} else
mode |= ATMEL_US_PAR_NONE;
+ /* hardware handshake (RTS/CTS) */
+ if (termios->c_cflag & CRTSCTS)
+ mode |= ATMEL_US_USMODE_HWHS;
+ else
+ mode |= ATMEL_US_USMODE_NORMAL;
+
spin_lock_irqsave(&port->lock, flags);
port->read_status_mask = ATMEL_US_OVRE;
if (termios->c_iflag & (BRKINT | PARMRK))
port->read_status_mask |= ATMEL_US_RXBRK;
+ if (atmel_use_dma_rx(port))
+ /* need to enable error interrupts */
+ UART_PUT_IER(port, port->read_status_mask);
+
/*
* Characters to ignore
*/
/* update the per-port timeout */
uart_update_timeout(port, termios->c_cflag, baud);
- /* save/disable interrupts and drain transmitter */
+ /*
+ * save/disable interrupts. The tty layer will ensure that the
+ * transmitter is empty if requested by the caller, so there's
+ * no need to wait for it here.
+ */
imr = UART_GET_IMR(port);
UART_PUT_IDR(port, -1);
- while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY))
- cpu_relax();
/* disable receiver and transmitter */
UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
return ret;
}
+#ifdef CONFIG_CONSOLE_POLL
+static int atmel_poll_get_char(struct uart_port *port)
+{
+ while (!(UART_GET_CSR(port) & ATMEL_US_RXRDY))
+ cpu_relax();
+
+ return UART_GET_CHAR(port);
+}
+
+static void atmel_poll_put_char(struct uart_port *port, unsigned char ch)
+{
+ while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
+ cpu_relax();
+
+ UART_PUT_CHAR(port, ch);
+}
+#endif
+
static struct uart_ops atmel_pops = {
.tx_empty = atmel_tx_empty,
.set_mctrl = atmel_set_mctrl,
.break_ctl = atmel_break_ctl,
.startup = atmel_startup,
.shutdown = atmel_shutdown,
+ .flush_buffer = atmel_flush_buffer,
.set_termios = atmel_set_termios,
.type = atmel_type,
.release_port = atmel_release_port,
.config_port = atmel_config_port,
.verify_port = atmel_verify_port,
.pm = atmel_serial_pm,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_get_char = atmel_poll_get_char,
+ .poll_put_char = atmel_poll_put_char,
+#endif
};
/*
port->mapbase = pdev->resource[0].start;
port->irq = pdev->resource[1].start;
+ tasklet_init(&atmel_port->tasklet, atmel_tasklet_func,
+ (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;
atmel_port->clk = clk_get(&pdev->dev, "usart");
clk_enable(atmel_port->clk);
port->uartclk = clk_get_rate(atmel_port->clk);
+ clk_disable(atmel_port->clk);
+ /* only enable clock when USART is in use */
}
+
+ atmel_port->use_dma_rx = data->use_dma_rx;
+ atmel_port->use_dma_tx = data->use_dma_tx;
+ if (atmel_use_dma_tx(port))
+ port->fifosize = PDC_BUFFER_SIZE;
}
/*
{
struct uart_port *port = &atmel_ports[co->index].uart;
unsigned int status, imr;
+ unsigned int pdc_tx;
/*
* First, save IMR and then disable interrupts
imr = UART_GET_IMR(port);
UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY);
+ /* Store PDC transmit status and disable it */
+ pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN;
+ UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
+
uart_console_write(port, s, count, atmel_console_putchar);
/*
do {
status = UART_GET_CSR(port);
} while (!(status & ATMEL_US_TXRDY));
+
+ /* Restore PDC transmit status */
+ if (pdc_tx)
+ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
+
/* set interrupts back the way they were */
UART_PUT_IER(port, imr);
}
* If the baud rate generator isn't running, the port wasn't
* initialized by the boot loader.
*/
- quot = UART_GET_BRGR(port);
+ quot = UART_GET_BRGR(port) & ATMEL_US_CD;
if (!quot)
return;
return -ENODEV;
}
+ clk_enable(atmel_ports[co->index].clk);
+
UART_PUT_IDR(port, -1);
UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
.data = &atmel_uart,
};
-#define ATMEL_CONSOLE_DEVICE &atmel_console
+#define ATMEL_CONSOLE_DEVICE (&atmel_console)
/*
* Early console initialization (before VM subsystem initialized).
};
#ifdef CONFIG_PM
+static bool atmel_serial_clk_will_stop(void)
+{
+#ifdef CONFIG_ARCH_AT91
+ return at91_suspend_entering_slow_clock();
+#else
+ return false;
+#endif
+}
+
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 = to_atmel_uart_port(port);
- if (device_may_wakeup(&pdev->dev)
- && !at91_suspend_entering_slow_clock())
- enable_irq_wake(port->irq);
- else {
- uart_suspend_port(&atmel_uart, port);
- atmel_port->suspended = 1;
+ if (atmel_is_console_port(port) && console_suspend_enabled) {
+ /* Drain the TX shifter */
+ while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY))
+ cpu_relax();
}
+ /* we can not wake up if we're running on slow clock */
+ atmel_port->may_wakeup = device_may_wakeup(&pdev->dev);
+ if (atmel_serial_clk_will_stop())
+ device_set_wakeup_enable(&pdev->dev, 0);
+
+ uart_suspend_port(&atmel_uart, port);
+
return 0;
}
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 = to_atmel_uart_port(port);
- if (atmel_port->suspended) {
- uart_resume_port(&atmel_uart, port);
- atmel_port->suspended = 0;
- } else
- disable_irq_wake(port->irq);
+ uart_resume_port(&atmel_uart, port);
+ device_set_wakeup_enable(&pdev->dev, atmel_port->may_wakeup);
return 0;
}
static int __devinit atmel_serial_probe(struct platform_device *pdev)
{
struct atmel_uart_port *port;
+ void *data;
int ret;
+ BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
+
port = &atmel_ports[pdev->id];
+ port->backup_imr = 0;
+
atmel_init_port(port, pdev);
+ if (!atmel_use_dma_rx(&port->uart)) {
+ ret = -ENOMEM;
+ data = kmalloc(sizeof(struct atmel_uart_char)
+ * ATMEL_SERIAL_RINGSIZE, GFP_KERNEL);
+ if (!data)
+ goto err_alloc_ring;
+ port->rx_ring.buf = data;
+ }
+
ret = uart_add_one_port(&atmel_uart, &port->uart);
if (ret)
goto err_add_port;
+#ifdef CONFIG_SERIAL_ATMEL_CONSOLE
+ if (atmel_is_console_port(&port->uart)
+ && ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
+ /*
+ * The serial core enabled the clock for us, so undo
+ * the clk_enable() in atmel_console_setup()
+ */
+ clk_disable(port->clk);
+ }
+#endif
+
device_init_wakeup(&pdev->dev, 1);
platform_set_drvdata(pdev, port);
return 0;
err_add_port:
+ kfree(port->rx_ring.buf);
+ port->rx_ring.buf = NULL;
+err_alloc_ring:
if (!atmel_is_console_port(&port->uart)) {
- clk_disable(port->clk);
clk_put(port->clk);
port->clk = NULL;
}
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 = to_atmel_uart_port(port);
int ret = 0;
device_init_wakeup(&pdev->dev, 0);
ret = uart_remove_one_port(&atmel_uart, port);
+ tasklet_kill(&atmel_port->tasklet);
+ kfree(atmel_port->rx_ring.buf);
+
/* "port" is allocated statically, so we shouldn't free it */
- clk_disable(atmel_port->clk);
clk_put(atmel_port->clk);
return ret;
MODULE_AUTHOR("Rick Bronson");
MODULE_DESCRIPTION("Atmel AT91 / AT32 serial port driver");
MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:atmel_usart");
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff