/* * linux/drivers/char/atmel_serial.c * * Driver for Atmel AT91 / AT32 Serial ports * Copyright (C) 2003 Rick Bronson * * 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 * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include <linux/module.h> #include <linux/tty.h> #include <linux/ioport.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/serial.h> #include <linux/clk.h> #include <linux/console.h> #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 <mach/board.h> #ifdef CONFIG_ARM #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 #include <linux/serial_core.h> #ifdef CONFIG_SERIAL_ATMEL_TTYAT /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we * should coexist with the 8250 driver, such as if we have an external 16C550 * UART. */ #define SERIAL_ATMEL_MAJOR 204 #define MINOR_START 154 #define ATMEL_DEVICENAME "ttyAT" #else /* Use device name ttyS, major 4, minor 64-68. This is the usual serial port * name, but it is legally reserved for the 8250 driver. */ #define SERIAL_ATMEL_MAJOR TTY_MAJOR #define MINOR_START 64 #define ATMEL_DEVICENAME "ttyS" #endif #define ATMEL_ISR_PASS_LIMIT 256 /* UART registers. CR is write-only, hence no GET macro */ #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) /* 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_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_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 */ 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]; #ifdef SUPPORT_SYSRQ 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 u_int atmel_tx_empty(struct uart_port *port) { return (UART_GET_CSR(port) & ATMEL_US_TXEMPTY) ? TIOCSER_TEMT : 0; } /* * Set state of the modem control output lines */ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) { unsigned int control = 0; unsigned int mode; #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. */ if (port->mapbase == AT91RM9200_BASE_US0) { if (mctrl & TIOCM_RTS) at91_set_gpio_value(AT91_PIN_PA21, 0); else at91_set_gpio_value(AT91_PIN_PA21, 1); } } #endif if (mctrl & TIOCM_RTS) control |= ATMEL_US_RTSEN; else control |= ATMEL_US_RTSDIS; if (mctrl & TIOCM_DTR) control |= ATMEL_US_DTREN; else control |= ATMEL_US_DTRDIS; UART_PUT_CR(port, control); /* Local loopback mode? */ mode = UART_GET_MR(port) & ~ATMEL_US_CHMODE; if (mctrl & TIOCM_LOOP) mode |= ATMEL_US_CHMODE_LOC_LOOP; else mode |= ATMEL_US_CHMODE_NORMAL; UART_PUT_MR(port, mode); } /* * Get state of the modem control input lines */ static u_int atmel_get_mctrl(struct uart_port *port) { unsigned int status, ret = 0; status = UART_GET_CSR(port); /* * The control signals are active low. */ if (!(status & ATMEL_US_DCD)) ret |= TIOCM_CD; if (!(status & ATMEL_US_CTS)) ret |= TIOCM_CTS; if (!(status & ATMEL_US_DSR)) ret |= TIOCM_DSR; if (!(status & ATMEL_US_RI)) ret |= TIOCM_RI; return ret; } /* * Stop transmitting. */ static void atmel_stop_tx(struct uart_port *port) { if (atmel_use_dma_tx(port)) { /* disable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS); UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); } else UART_PUT_IDR(port, ATMEL_US_TXRDY); } /* * Start transmitting. */ static void atmel_start_tx(struct uart_port *port) { if (atmel_use_dma_tx(port)) { if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN) /* The transmitter is already running. Yes, we really need this.*/ return; UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); } else UART_PUT_IER(port, ATMEL_US_TXRDY); } /* * Stop receiving - port is in process of being closed. */ static void atmel_stop_rx(struct uart_port *port) { if (atmel_use_dma_rx(port)) { /* disable PDC receive */ UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS); UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT); } else UART_PUT_IDR(port, ATMEL_US_RXRDY); } /* * Enable modem status interrupts */ 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); } /* * Control the transmission of a break signal */ static void atmel_break_ctl(struct uart_port *port, int break_state) { if (break_state != 0) UART_PUT_CR(port, ATMEL_US_STTBRK); /* start break */ else UART_PUT_CR(port, ATMEL_US_STPBRK); /* stop break */ } /* * 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 = to_atmel_uart_port(port); unsigned int status, ch; status = UART_GET_CSR(port); while (status & ATMEL_US_RXRDY) { ch = UART_GET_CHAR(port); /* * 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) { atmel_port->break_active = 1; UART_PUT_IER(port, ATMEL_US_RXBRK); } else { /* * This is either the end-of-break * condition or we've received at * least one character without RXBRK * being set. In both cases, the next * RXBRK will indicate start-of-break. */ UART_PUT_IDR(port, ATMEL_US_RXBRK); status &= ~ATMEL_US_RXBRK; atmel_port->break_active = 0; } } atmel_buffer_rx_char(port, status, ch); status = UART_GET_CSR(port); } tasklet_schedule(&atmel_port->tasklet); } /* * 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; 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; } 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]); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); port->icount.tx++; if (uart_circ_empty(xmit)) break; } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); if (!uart_circ_empty(xmit)) UART_PUT_IER(port, ATMEL_US_TXRDY); } /* * receive interrupt handler. */ static void atmel_handle_receive(struct uart_port *port, unsigned int pending) { 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) 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. (Transmit is IRQF_NODELAY safe) */ static void atmel_handle_transmit(struct uart_port *port, unsigned int pending) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); if (atmel_use_dma_tx(port)) { /* PDC transmit */ if (pending & (ATMEL_US_ENDTX | ATMEL_US_TXBUFE)) { UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); tasklet_schedule(&atmel_port->tasklet); } } else { /* Interrupt transmit */ if (pending & ATMEL_US_TXRDY) { UART_PUT_IDR(port, ATMEL_US_TXRDY); tasklet_schedule(&atmel_port->tasklet); } } } /* * status flags interrupt handler. */ static void atmel_handle_status(struct uart_port *port, unsigned int pending, unsigned int status) { 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)) { atmel_port->irq_status = status; tasklet_schedule(&atmel_port->tasklet); } } /* * Interrupt handler */ static irqreturn_t atmel_interrupt(int irq, void *dev_id) { struct uart_port *port = dev_id; unsigned int status, pending, pass_counter = 0; 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); return pass_counter ? IRQ_HANDLED : IRQ_NONE; } /* * 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->info->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); } 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->info->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->info->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->info->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); } /* * Perform initialization and enable port for reception */ static int atmel_startup(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); struct tty_struct *tty = port->info->port.tty; int retval; /* * Ensure that no interrupts are enabled otherwise when * request_irq() is called we could get stuck trying to * handle an unexpected interrupt */ UART_PUT_IDR(port, -1); /* * Allocate the IRQ */ retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED, 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->info->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) */ if (atmel_open_hook) { retval = atmel_open_hook(port); if (retval) { free_irq(port->irq, port); return retval; } } /* 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 */ UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); /* enable xmit & rcvr */ UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN); 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; } /* * Disable the port */ 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. */ UART_PUT_CR(port, ATMEL_US_RSTSTA); UART_PUT_IDR(port, -1); /* * Free the interrupt */ free_irq(port->irq, port); /* * If there is a specific "close" function (to unregister * control line interrupts) */ if (atmel_close_hook) atmel_close_hook(port); } /* * 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 = to_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); /* 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. */ 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) { 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 | ATMEL_US_USMODE); 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 */ quot /= 8; mode |= ATMEL_US_USCLKS_MCK_DIV8; } /* byte size */ switch (termios->c_cflag & CSIZE) { case CS5: mode |= ATMEL_US_CHRL_5; break; case CS6: mode |= ATMEL_US_CHRL_6; break; case CS7: mode |= ATMEL_US_CHRL_7; break; default: mode |= ATMEL_US_CHRL_8; break; } /* stop bits */ if (termios->c_cflag & CSTOPB) mode |= ATMEL_US_NBSTOP_2; /* parity */ if (termios->c_cflag & PARENB) { /* 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) mode |= ATMEL_US_PAR_ODD; else mode |= ATMEL_US_PAR_EVEN; } 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 & INPCK) port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE); 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 */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE); if (termios->c_iflag & IGNBRK) { port->ignore_status_mask |= ATMEL_US_RXBRK; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= ATMEL_US_OVRE; } /* TODO: Ignore all characters if CREAD is set.*/ /* update the per-port timeout */ uart_update_timeout(port, termios->c_cflag, baud); /* save/disable interrupts and drain transmitter */ 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); /* set the parity, stop bits and data size */ UART_PUT_MR(port, mode); /* set the baud rate */ UART_PUT_BRGR(port, quot); UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN); /* restore interrupts */ UART_PUT_IER(port, imr); /* CTS flow-control and modem-status interrupts */ if (UART_ENABLE_MS(port, termios->c_cflag)) port->ops->enable_ms(port); spin_unlock_irqrestore(&port->lock, flags); } /* * Return string describing the specified port */ static const char *atmel_type(struct uart_port *port) { return (port->type == PORT_ATMEL) ? "ATMEL_SERIAL" : NULL; } /* * Release the memory region(s) being used by 'port'. */ static void atmel_release_port(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); int size = pdev->resource[0].end - pdev->resource[0].start + 1; release_mem_region(port->mapbase, size); if (port->flags & UPF_IOREMAP) { iounmap(port->membase); port->membase = NULL; } } /* * Request the memory region(s) being used by 'port'. */ static int atmel_request_port(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); int size = pdev->resource[0].end - pdev->resource[0].start + 1; if (!request_mem_region(port->mapbase, size, "atmel_serial")) return -EBUSY; if (port->flags & UPF_IOREMAP) { port->membase = ioremap(port->mapbase, size); if (port->membase == NULL) { release_mem_region(port->mapbase, size); return -ENOMEM; } } return 0; } /* * Configure/autoconfigure the port. */ static void atmel_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) { port->type = PORT_ATMEL; atmel_request_port(port); } } /* * Verify the new serial_struct (for TIOCSSERIAL). */ static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser) { int ret = 0; if (ser->type != PORT_UNKNOWN && ser->type != PORT_ATMEL) ret = -EINVAL; if (port->irq != ser->irq) ret = -EINVAL; if (ser->io_type != SERIAL_IO_MEM) ret = -EINVAL; if (port->uartclk / 16 != ser->baud_base) ret = -EINVAL; if ((void *)port->mapbase != ser->iomem_base) ret = -EINVAL; if (port->iobase != ser->port) ret = -EINVAL; if (ser->hub6 != 0) ret = -EINVAL; return ret; } static struct uart_ops atmel_pops = { .tx_empty = atmel_tx_empty, .set_mctrl = atmel_set_mctrl, .get_mctrl = atmel_get_mctrl, .stop_tx = atmel_stop_tx, .start_tx = atmel_start_tx, .stop_rx = atmel_stop_rx, .enable_ms = atmel_enable_ms, .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, .request_port = atmel_request_port, .config_port = atmel_config_port, .verify_port = atmel_verify_port, .pm = atmel_serial_pm, }; /* * 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) { struct uart_port *port = &atmel_port->uart; struct atmel_uart_data *data = pdev->dev.platform_data; port->iotype = UPIO_MEM; port->flags = UPF_BOOT_AUTOCONF; port->ops = &atmel_pops; port->fifosize = 1; port->line = pdev->id; port->dev = &pdev->dev; port->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; else { port->flags |= UPF_IOREMAP; port->membase = NULL; } /* 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); 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; } /* * Register board-specific modem-control line handlers. */ void __init atmel_register_uart_fns(struct atmel_port_fns *fns) { if (fns->enable_ms) atmel_pops.enable_ms = fns->enable_ms; if (fns->get_mctrl) atmel_pops.get_mctrl = fns->get_mctrl; if (fns->set_mctrl) atmel_pops.set_mctrl = fns->set_mctrl; atmel_open_hook = fns->open; atmel_close_hook = fns->close; atmel_pops.pm = fns->pm; atmel_pops.set_wake = fns->set_wake; } #ifdef CONFIG_SERIAL_ATMEL_CONSOLE static void atmel_console_putchar(struct uart_port *port, int ch) { while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY)) cpu_relax(); UART_PUT_CHAR(port, ch); } /* * Interrupts are disabled on entering */ static void atmel_console_write(struct console *co, const char *s, u_int count) { 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); /* * Finally, wait for transmitter to become empty * and restore IMR */ 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 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) { unsigned int mr, quot; /* * If the baud rate generator isn't running, the port wasn't * initialized by the boot loader. */ quot = UART_GET_BRGR(port) & ATMEL_US_CD; if (!quot) return; mr = UART_GET_MR(port) & ATMEL_US_CHRL; if (mr == ATMEL_US_CHRL_8) *bits = 8; else *bits = 7; mr = UART_GET_MR(port) & ATMEL_US_PAR; if (mr == ATMEL_US_PAR_EVEN) *parity = 'e'; else if (mr == ATMEL_US_PAR_ODD) *parity = 'o'; /* * The serial core only rounds down when matching this to a * supported baud rate. Make sure we don't end up slightly * lower than one of those, as it would make us fall through * to a much lower baud rate than we really want. */ *baud = port->uartclk / (16 * (quot - 1)); } static int __init atmel_console_setup(struct console *co, char *options) { struct uart_port *port = &atmel_ports[co->index].uart; int baud = 115200; int bits = 8; int parity = 'n'; int flow = 'n'; if (port->membase == NULL) { /* Port not initialized yet - delay setup */ 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); if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else atmel_console_get_options(port, &baud, &parity, &bits); return uart_set_options(port, co, baud, parity, bits, flow); } 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, }; #define ATMEL_CONSOLE_DEVICE (&atmel_console) /* * Early console initialization (before VM subsystem initialized). */ 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); register_console(&atmel_console); } return 0; } console_initcall(atmel_console_init); /* * Late console initialization. */ static int __init atmel_late_console_init(void) { if (atmel_default_console_device && !(atmel_console.flags & CON_ENABLED)) register_console(&atmel_console); return 0; } core_initcall(atmel_late_console_init); static inline bool atmel_is_console_port(struct uart_port *port) { return port->cons && port->cons->index == port->line; } #else #define ATMEL_CONSOLE_DEVICE NULL static inline bool atmel_is_console_port(struct uart_port *port) { return false; } #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, }; #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 = to_atmel_uart_port(port); 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 = to_atmel_uart_port(port); uart_resume_port(&atmel_uart, port); device_set_wakeup_enable(&pdev->dev, atmel_port->may_wakeup); return 0; } #else #define atmel_serial_suspend NULL #define atmel_serial_resume NULL #endif static int __devinit atmel_serial_probe(struct platform_device *pdev) { struct atmel_uart_port *port; void *data; int ret; BUILD_BUG_ON(!is_power_of_2(ATMEL_SERIAL_RINGSIZE)); 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; 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); } 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_put(port->clk); port->clk = NULL; } return ret; } static int __devexit atmel_serial_remove(struct platform_device *pdev) { struct uart_port *port = platform_get_drvdata(pdev); struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); int ret = 0; device_init_wakeup(&pdev->dev, 0); platform_set_drvdata(pdev, NULL); 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_put(atmel_port->clk); return ret; } static struct platform_driver atmel_serial_driver = { .probe = atmel_serial_probe, .remove = __devexit_p(atmel_serial_remove), .suspend = atmel_serial_suspend, .resume = atmel_serial_resume, .driver = { .name = "atmel_usart", .owner = THIS_MODULE, }, }; static int __init atmel_serial_init(void) { int ret; ret = uart_register_driver(&atmel_uart); if (ret) return ret; ret = platform_driver_register(&atmel_serial_driver); if (ret) uart_unregister_driver(&atmel_uart); return ret; } static void __exit atmel_serial_exit(void) { platform_driver_unregister(&atmel_serial_driver); uart_unregister_driver(&atmel_uart); } module_init(atmel_serial_init); module_exit(atmel_serial_exit); MODULE_AUTHOR("Rick Bronson"); MODULE_DESCRIPTION("Atmel AT91 / AT32 serial port driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:atmel_usart");