/* * Driver for Motorola IMX serial ports * * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * * Author: Sascha Hauer * Copyright (C) 2004 Pengutronix * * Copyright (C) 2009 emlix GmbH * Author: Fabian Godehardt (added IrDA support for iMX) * * 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 * * [29-Mar-2005] Mike Lee * Added hardware handshake */ #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) #define SUPPORT_SYSRQ #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Register definitions */ #define URXD0 0x0 /* Receiver Register */ #define URTX0 0x40 /* Transmitter Register */ #define UCR1 0x80 /* Control Register 1 */ #define UCR2 0x84 /* Control Register 2 */ #define UCR3 0x88 /* Control Register 3 */ #define UCR4 0x8c /* Control Register 4 */ #define UFCR 0x90 /* FIFO Control Register */ #define USR1 0x94 /* Status Register 1 */ #define USR2 0x98 /* Status Register 2 */ #define UESC 0x9c /* Escape Character Register */ #define UTIM 0xa0 /* Escape Timer Register */ #define UBIR 0xa4 /* BRM Incremental Register */ #define UBMR 0xa8 /* BRM Modulator Register */ #define UBRC 0xac /* Baud Rate Count Register */ #define IMX21_ONEMS 0xb0 /* One Millisecond register */ #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */ #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/ /* UART Control Register Bit Fields.*/ #define URXD_CHARRDY (1<<15) #define URXD_ERR (1<<14) #define URXD_OVRRUN (1<<13) #define URXD_FRMERR (1<<12) #define URXD_BRK (1<<11) #define URXD_PRERR (1<<10) #define UCR1_ADEN (1<<15) /* Auto detect interrupt */ #define UCR1_ADBR (1<<14) /* Auto detect baud rate */ #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */ #define UCR1_IDEN (1<<12) /* Idle condition interrupt */ #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */ #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */ #define UCR1_RDMAEN (1<<8) /* Recv ready DMA enable */ #define UCR1_IREN (1<<7) /* Infrared interface enable */ #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */ #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */ #define UCR1_SNDBRK (1<<4) /* Send break */ #define UCR1_TDMAEN (1<<3) /* Transmitter ready DMA enable */ #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */ #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */ #define UCR1_DOZE (1<<1) /* Doze */ #define UCR1_UARTEN (1<<0) /* UART enabled */ #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */ #define UCR2_IRTS (1<<14) /* Ignore RTS pin */ #define UCR2_CTSC (1<<13) /* CTS pin control */ #define UCR2_CTS (1<<12) /* Clear to send */ #define UCR2_ESCEN (1<<11) /* Escape enable */ #define UCR2_PREN (1<<8) /* Parity enable */ #define UCR2_PROE (1<<7) /* Parity odd/even */ #define UCR2_STPB (1<<6) /* Stop */ #define UCR2_WS (1<<5) /* Word size */ #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */ #define UCR2_ATEN (1<<3) /* Aging Timer Enable */ #define UCR2_TXEN (1<<2) /* Transmitter enabled */ #define UCR2_RXEN (1<<1) /* Receiver enabled */ #define UCR2_SRST (1<<0) /* SW reset */ #define UCR3_DTREN (1<<13) /* DTR interrupt enable */ #define UCR3_PARERREN (1<<12) /* Parity enable */ #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */ #define UCR3_DSR (1<<10) /* Data set ready */ #define UCR3_DCD (1<<9) /* Data carrier detect */ #define UCR3_RI (1<<8) /* Ring indicator */ #define UCR3_TIMEOUTEN (1<<7) /* Timeout interrupt enable */ #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */ #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */ #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */ #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */ #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */ #define UCR3_BPEN (1<<0) /* Preset registers enable */ #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */ #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */ #define UCR4_INVR (1<<9) /* Inverted infrared reception */ #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */ #define UCR4_WKEN (1<<7) /* Wake interrupt enable */ #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */ #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */ #define UCR4_IRSC (1<<5) /* IR special case */ #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */ #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */ #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */ #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */ #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */ #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */ #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */ #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7) #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */ #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */ #define USR1_RTSS (1<<14) /* RTS pin status */ #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */ #define USR1_RTSD (1<<12) /* RTS delta */ #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */ #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */ #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */ #define USR1_TIMEOUT (1<<7) /* Receive timeout interrupt status */ #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */ #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */ #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */ #define USR2_ADET (1<<15) /* Auto baud rate detect complete */ #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */ #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */ #define USR2_IDLE (1<<12) /* Idle condition */ #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */ #define USR2_WAKE (1<<7) /* Wake */ #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */ #define USR2_TXDC (1<<3) /* Transmitter complete */ #define USR2_BRCD (1<<2) /* Break condition */ #define USR2_ORE (1<<1) /* Overrun error */ #define USR2_RDR (1<<0) /* Recv data ready */ #define UTS_FRCPERR (1<<13) /* Force parity error */ #define UTS_LOOP (1<<12) /* Loop tx and rx */ #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */ #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */ #define UTS_TXFULL (1<<4) /* TxFIFO full */ #define UTS_RXFULL (1<<3) /* RxFIFO full */ #define UTS_SOFTRST (1<<0) /* Software reset */ /* We've been assigned a range on the "Low-density serial ports" major */ #define SERIAL_IMX_MAJOR 207 #define MINOR_START 16 #define DEV_NAME "ttymxc" /* * This determines how often we check the modem status signals * for any change. They generally aren't connected to an IRQ * so we have to poll them. We also check immediately before * filling the TX fifo incase CTS has been dropped. */ #define MCTRL_TIMEOUT (250*HZ/1000) #define DRIVER_NAME "IMX-uart" #define UART_NR 8 /* i.mx21 type uart runs on all i.mx except i.mx1 */ enum imx_uart_type { IMX1_UART, IMX21_UART, IMX6Q_UART, }; /* device type dependent stuff */ struct imx_uart_data { unsigned uts_reg; enum imx_uart_type devtype; }; struct imx_port { struct uart_port port; struct timer_list timer; unsigned int old_status; int txirq, rxirq, rtsirq; unsigned int have_rtscts:1; unsigned int dte_mode:1; unsigned int use_irda:1; unsigned int irda_inv_rx:1; unsigned int irda_inv_tx:1; unsigned short trcv_delay; /* transceiver delay */ struct clk *clk_ipg; struct clk *clk_per; const struct imx_uart_data *devdata; /* DMA fields */ unsigned int dma_is_inited:1; unsigned int dma_is_enabled:1; unsigned int dma_is_rxing:1; unsigned int dma_is_txing:1; struct dma_chan *dma_chan_rx, *dma_chan_tx; struct scatterlist rx_sgl, tx_sgl[2]; void *rx_buf; unsigned int rx_bytes, tx_bytes; struct work_struct tsk_dma_rx, tsk_dma_tx; unsigned int dma_tx_nents; wait_queue_head_t dma_wait; }; struct imx_port_ucrs { unsigned int ucr1; unsigned int ucr2; unsigned int ucr3; }; #ifdef CONFIG_IRDA #define USE_IRDA(sport) ((sport)->use_irda) #else #define USE_IRDA(sport) (0) #endif static struct imx_uart_data imx_uart_devdata[] = { [IMX1_UART] = { .uts_reg = IMX1_UTS, .devtype = IMX1_UART, }, [IMX21_UART] = { .uts_reg = IMX21_UTS, .devtype = IMX21_UART, }, [IMX6Q_UART] = { .uts_reg = IMX21_UTS, .devtype = IMX6Q_UART, }, }; static struct platform_device_id imx_uart_devtype[] = { { .name = "imx1-uart", .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART], }, { .name = "imx21-uart", .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART], }, { .name = "imx6q-uart", .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART], }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(platform, imx_uart_devtype); static struct of_device_id imx_uart_dt_ids[] = { { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], }, { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], }, { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, imx_uart_dt_ids); static inline unsigned uts_reg(struct imx_port *sport) { return sport->devdata->uts_reg; } static inline int is_imx1_uart(struct imx_port *sport) { return sport->devdata->devtype == IMX1_UART; } static inline int is_imx21_uart(struct imx_port *sport) { return sport->devdata->devtype == IMX21_UART; } static inline int is_imx6q_uart(struct imx_port *sport) { return sport->devdata->devtype == IMX6Q_UART; } /* * Save and restore functions for UCR1, UCR2 and UCR3 registers */ #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_IMX_CONSOLE) static void imx_port_ucrs_save(struct uart_port *port, struct imx_port_ucrs *ucr) { /* save control registers */ ucr->ucr1 = readl(port->membase + UCR1); ucr->ucr2 = readl(port->membase + UCR2); ucr->ucr3 = readl(port->membase + UCR3); } static void imx_port_ucrs_restore(struct uart_port *port, struct imx_port_ucrs *ucr) { /* restore control registers */ writel(ucr->ucr1, port->membase + UCR1); writel(ucr->ucr2, port->membase + UCR2); writel(ucr->ucr3, port->membase + UCR3); } #endif /* * Handle any change of modem status signal since we were last called. */ static void imx_mctrl_check(struct imx_port *sport) { unsigned int status, changed; status = sport->port.ops->get_mctrl(&sport->port); changed = status ^ sport->old_status; if (changed == 0) return; sport->old_status = status; if (changed & TIOCM_RI) sport->port.icount.rng++; if (changed & TIOCM_DSR) sport->port.icount.dsr++; if (changed & TIOCM_CAR) uart_handle_dcd_change(&sport->port, status & TIOCM_CAR); if (changed & TIOCM_CTS) uart_handle_cts_change(&sport->port, status & TIOCM_CTS); wake_up_interruptible(&sport->port.state->port.delta_msr_wait); } /* * This is our per-port timeout handler, for checking the * modem status signals. */ static void imx_timeout(unsigned long data) { struct imx_port *sport = (struct imx_port *)data; unsigned long flags; if (sport->port.state) { spin_lock_irqsave(&sport->port.lock, flags); imx_mctrl_check(sport); spin_unlock_irqrestore(&sport->port.lock, flags); mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT); } } /* * interrupts disabled on entry */ static void imx_stop_tx(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; unsigned long temp; if (USE_IRDA(sport)) { /* half duplex - wait for end of transmission */ int n = 256; while ((--n > 0) && !(readl(sport->port.membase + USR2) & USR2_TXDC)) { udelay(5); barrier(); } /* * irda transceiver - wait a bit more to avoid * cutoff, hardware dependent */ udelay(sport->trcv_delay); /* * half duplex - reactivate receive mode, * flush receive pipe echo crap */ if (readl(sport->port.membase + USR2) & USR2_TXDC) { temp = readl(sport->port.membase + UCR1); temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN); writel(temp, sport->port.membase + UCR1); temp = readl(sport->port.membase + UCR4); temp &= ~(UCR4_TCEN); writel(temp, sport->port.membase + UCR4); while (readl(sport->port.membase + URXD0) & URXD_CHARRDY) barrier(); temp = readl(sport->port.membase + UCR1); temp |= UCR1_RRDYEN; writel(temp, sport->port.membase + UCR1); temp = readl(sport->port.membase + UCR4); temp |= UCR4_DREN; writel(temp, sport->port.membase + UCR4); } return; } /* * We are maybe in the SMP context, so if the DMA TX thread is running * on other cpu, we have to wait for it to finish. */ if (sport->dma_is_enabled && sport->dma_is_txing) return; temp = readl(sport->port.membase + UCR1); writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1); } /* * interrupts disabled on entry */ static void imx_stop_rx(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; unsigned long temp; /* * We are maybe in the SMP context, so if the DMA TX thread is running * on other cpu, we have to wait for it to finish. */ if (sport->dma_is_enabled && sport->dma_is_rxing) return; temp = readl(sport->port.membase + UCR2); writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2); } /* * Set the modem control timer to fire immediately. */ static void imx_enable_ms(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; mod_timer(&sport->timer, jiffies); } static inline void imx_transmit_buffer(struct imx_port *sport) { struct circ_buf *xmit = &sport->port.state->xmit; while (!uart_circ_empty(xmit) && !(readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)) { /* send xmit->buf[xmit->tail] * out the port here */ writel(xmit->buf[xmit->tail], sport->port.membase + URTX0); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); sport->port.icount.tx++; } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&sport->port); if (uart_circ_empty(xmit)) imx_stop_tx(&sport->port); } static void dma_tx_callback(void *data) { struct imx_port *sport = data; struct scatterlist *sgl = &sport->tx_sgl[0]; struct circ_buf *xmit = &sport->port.state->xmit; unsigned long flags; dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); sport->dma_is_txing = 0; /* update the stat */ spin_lock_irqsave(&sport->port.lock, flags); xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1); sport->port.icount.tx += sport->tx_bytes; spin_unlock_irqrestore(&sport->port.lock, flags); dev_dbg(sport->port.dev, "we finish the TX DMA.\n"); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&sport->port); if (waitqueue_active(&sport->dma_wait)) { wake_up(&sport->dma_wait); dev_dbg(sport->port.dev, "exit in %s.\n", __func__); return; } schedule_work(&sport->tsk_dma_tx); } static void dma_tx_work(struct work_struct *w) { struct imx_port *sport = container_of(w, struct imx_port, tsk_dma_tx); struct circ_buf *xmit = &sport->port.state->xmit; struct scatterlist *sgl = sport->tx_sgl; struct dma_async_tx_descriptor *desc; struct dma_chan *chan = sport->dma_chan_tx; struct device *dev = sport->port.dev; enum dma_status status; unsigned long flags; int ret; status = dmaengine_tx_status(chan, (dma_cookie_t)0, NULL); if (DMA_IN_PROGRESS == status) return; spin_lock_irqsave(&sport->port.lock, flags); sport->tx_bytes = uart_circ_chars_pending(xmit); if (sport->tx_bytes == 0) { spin_unlock_irqrestore(&sport->port.lock, flags); return; } if (xmit->tail > xmit->head && xmit->head > 0) { sport->dma_tx_nents = 2; sg_init_table(sgl, 2); sg_set_buf(sgl, xmit->buf + xmit->tail, UART_XMIT_SIZE - xmit->tail); sg_set_buf(sgl + 1, xmit->buf, xmit->head); } else { sport->dma_tx_nents = 1; sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes); } spin_unlock_irqrestore(&sport->port.lock, flags); ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); if (ret == 0) { dev_err(dev, "DMA mapping error for TX.\n"); return; } desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT); if (!desc) { dev_err(dev, "We cannot prepare for the TX slave dma!\n"); return; } desc->callback = dma_tx_callback; desc->callback_param = sport; dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n", uart_circ_chars_pending(xmit)); /* fire it */ sport->dma_is_txing = 1; dmaengine_submit(desc); dma_async_issue_pending(chan); return; } /* * interrupts disabled on entry */ static void imx_start_tx(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; unsigned long temp; if (USE_IRDA(sport)) { /* half duplex in IrDA mode; have to disable receive mode */ temp = readl(sport->port.membase + UCR4); temp &= ~(UCR4_DREN); writel(temp, sport->port.membase + UCR4); temp = readl(sport->port.membase + UCR1); temp &= ~(UCR1_RRDYEN); writel(temp, sport->port.membase + UCR1); } /* Clear any pending ORE flag before enabling interrupt */ temp = readl(sport->port.membase + USR2); writel(temp | USR2_ORE, sport->port.membase + USR2); temp = readl(sport->port.membase + UCR4); temp |= UCR4_OREN; writel(temp, sport->port.membase + UCR4); if (!sport->dma_is_enabled) { temp = readl(sport->port.membase + UCR1); writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1); } if (USE_IRDA(sport)) { temp = readl(sport->port.membase + UCR1); temp |= UCR1_TRDYEN; writel(temp, sport->port.membase + UCR1); temp = readl(sport->port.membase + UCR4); temp |= UCR4_TCEN; writel(temp, sport->port.membase + UCR4); } if (sport->dma_is_enabled) { /* * We may in the interrupt context, so arise a work_struct to * do the real job. */ schedule_work(&sport->tsk_dma_tx); return; } if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY) imx_transmit_buffer(sport); } static irqreturn_t imx_rtsint(int irq, void *dev_id) { struct imx_port *sport = dev_id; unsigned int val; unsigned long flags; spin_lock_irqsave(&sport->port.lock, flags); writel(USR1_RTSD, sport->port.membase + USR1); val = readl(sport->port.membase + USR1) & USR1_RTSS; uart_handle_cts_change(&sport->port, !!val); wake_up_interruptible(&sport->port.state->port.delta_msr_wait); spin_unlock_irqrestore(&sport->port.lock, flags); return IRQ_HANDLED; } static irqreturn_t imx_txint(int irq, void *dev_id) { struct imx_port *sport = dev_id; struct circ_buf *xmit = &sport->port.state->xmit; unsigned long flags; spin_lock_irqsave(&sport->port.lock, flags); if (sport->port.x_char) { /* Send next char */ writel(sport->port.x_char, sport->port.membase + URTX0); goto out; } if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) { imx_stop_tx(&sport->port); goto out; } imx_transmit_buffer(sport); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&sport->port); out: spin_unlock_irqrestore(&sport->port.lock, flags); return IRQ_HANDLED; } static irqreturn_t imx_rxint(int irq, void *dev_id) { struct imx_port *sport = dev_id; unsigned int rx, flg, ignored = 0; struct tty_port *port = &sport->port.state->port; unsigned long flags, temp; spin_lock_irqsave(&sport->port.lock, flags); while (readl(sport->port.membase + USR2) & USR2_RDR) { flg = TTY_NORMAL; sport->port.icount.rx++; rx = readl(sport->port.membase + URXD0); temp = readl(sport->port.membase + USR2); if (temp & USR2_BRCD) { writel(USR2_BRCD, sport->port.membase + USR2); if (uart_handle_break(&sport->port)) continue; } if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx)) continue; if (unlikely(rx & URXD_ERR)) { if (rx & URXD_BRK) sport->port.icount.brk++; else if (rx & URXD_PRERR) sport->port.icount.parity++; else if (rx & URXD_FRMERR) sport->port.icount.frame++; if (rx & URXD_OVRRUN) sport->port.icount.overrun++; if (rx & sport->port.ignore_status_mask) { if (++ignored > 100) goto out; continue; } rx &= sport->port.read_status_mask; if (rx & URXD_BRK) flg = TTY_BREAK; else if (rx & URXD_PRERR) flg = TTY_PARITY; else if (rx & URXD_FRMERR) flg = TTY_FRAME; if (rx & URXD_OVRRUN) flg = TTY_OVERRUN; #ifdef SUPPORT_SYSRQ sport->port.sysrq = 0; #endif } tty_insert_flip_char(port, rx, flg); } out: spin_unlock_irqrestore(&sport->port.lock, flags); tty_flip_buffer_push(port); return IRQ_HANDLED; } /* * If the RXFIFO is filled with some data, and then we * arise a DMA operation to receive them. */ static void imx_dma_rxint(struct imx_port *sport) { unsigned long temp; temp = readl(sport->port.membase + USR2); if ((temp & USR2_RDR) && !sport->dma_is_rxing) { sport->dma_is_rxing = 1; /* disable the `Recerver Ready Interrrupt` */ temp = readl(sport->port.membase + UCR1); temp &= ~(UCR1_RRDYEN); writel(temp, sport->port.membase + UCR1); /* tell the DMA to receive the data. */ schedule_work(&sport->tsk_dma_rx); } } static irqreturn_t imx_int(int irq, void *dev_id) { struct imx_port *sport = dev_id; unsigned int sts; unsigned int sts2; sts = readl(sport->port.membase + USR1); if (sts & USR1_RRDY) { if (sport->dma_is_enabled) imx_dma_rxint(sport); else imx_rxint(irq, dev_id); } if (sts & USR1_TRDY && readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN) imx_txint(irq, dev_id); if (sts & USR1_RTSD) imx_rtsint(irq, dev_id); if (sts & USR1_AWAKE) writel(USR1_AWAKE, sport->port.membase + USR1); sts2 = readl(sport->port.membase + USR2); if (sts2 & USR2_ORE) { dev_err(sport->port.dev, "Rx FIFO overrun\n"); sport->port.icount.overrun++; writel(sts2 | USR2_ORE, sport->port.membase + USR2); } return IRQ_HANDLED; } /* * Return TIOCSER_TEMT when transmitter is not busy. */ static unsigned int imx_tx_empty(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; unsigned int ret; ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0; /* If the TX DMA is working, return 0. */ if (sport->dma_is_enabled && sport->dma_is_txing) ret = 0; return ret; } /* * We have a modem side uart, so the meanings of RTS and CTS are inverted. */ static unsigned int imx_get_mctrl(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; unsigned int tmp = TIOCM_DSR | TIOCM_CAR; if (readl(sport->port.membase + USR1) & USR1_RTSS) tmp |= TIOCM_CTS; if (readl(sport->port.membase + UCR2) & UCR2_CTS) tmp |= TIOCM_RTS; return tmp; } static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct imx_port *sport = (struct imx_port *)port; unsigned long temp; temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS; if (mctrl & TIOCM_RTS) if (!sport->dma_is_enabled) temp |= UCR2_CTS; writel(temp, sport->port.membase + UCR2); } /* * Interrupts always disabled. */ static void imx_break_ctl(struct uart_port *port, int break_state) { struct imx_port *sport = (struct imx_port *)port; unsigned long flags, temp; spin_lock_irqsave(&sport->port.lock, flags); temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK; if (break_state != 0) temp |= UCR1_SNDBRK; writel(temp, sport->port.membase + UCR1); spin_unlock_irqrestore(&sport->port.lock, flags); } #define TXTL 2 /* reset default */ #define RXTL 1 /* reset default */ static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode) { unsigned int val; /* set receiver / transmitter trigger level */ val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE); val |= TXTL << UFCR_TXTL_SHF | RXTL; writel(val, sport->port.membase + UFCR); return 0; } #define RX_BUF_SIZE (PAGE_SIZE) static int start_rx_dma(struct imx_port *sport); static void dma_rx_work(struct work_struct *w) { struct imx_port *sport = container_of(w, struct imx_port, tsk_dma_rx); struct tty_port *port = &sport->port.state->port; if (sport->rx_bytes) { tty_insert_flip_string(port, sport->rx_buf, sport->rx_bytes); tty_flip_buffer_push(port); sport->rx_bytes = 0; } if (sport->dma_is_rxing) start_rx_dma(sport); } static void imx_rx_dma_done(struct imx_port *sport) { unsigned long temp; /* Enable this interrupt when the RXFIFO is empty. */ temp = readl(sport->port.membase + UCR1); temp |= UCR1_RRDYEN; writel(temp, sport->port.membase + UCR1); sport->dma_is_rxing = 0; /* Is the shutdown waiting for us? */ if (waitqueue_active(&sport->dma_wait)) wake_up(&sport->dma_wait); } /* * There are three kinds of RX DMA interrupts(such as in the MX6Q): * [1] the RX DMA buffer is full. * [2] the Aging timer expires(wait for 8 bytes long) * [3] the Idle Condition Detect(enabled the UCR4_IDDMAEN). * * The [2] is trigger when a character was been sitting in the FIFO * meanwhile [3] can wait for 32 bytes long when the RX line is * on IDLE state and RxFIFO is empty. */ static void dma_rx_callback(void *data) { struct imx_port *sport = data; struct dma_chan *chan = sport->dma_chan_rx; struct scatterlist *sgl = &sport->rx_sgl; struct dma_tx_state state; enum dma_status status; unsigned int count; /* unmap it first */ dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE); status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state); count = RX_BUF_SIZE - state.residue; dev_dbg(sport->port.dev, "We get %d bytes.\n", count); if (count) { sport->rx_bytes = count; schedule_work(&sport->tsk_dma_rx); } else imx_rx_dma_done(sport); } static int start_rx_dma(struct imx_port *sport) { struct scatterlist *sgl = &sport->rx_sgl; struct dma_chan *chan = sport->dma_chan_rx; struct device *dev = sport->port.dev; struct dma_async_tx_descriptor *desc; int ret; sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE); ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE); if (ret == 0) { dev_err(dev, "DMA mapping error for RX.\n"); return -EINVAL; } desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); if (!desc) { dev_err(dev, "We cannot prepare for the RX slave dma!\n"); return -EINVAL; } desc->callback = dma_rx_callback; desc->callback_param = sport; dev_dbg(dev, "RX: prepare for the DMA.\n"); dmaengine_submit(desc); dma_async_issue_pending(chan); return 0; } static void imx_uart_dma_exit(struct imx_port *sport) { if (sport->dma_chan_rx) { dma_release_channel(sport->dma_chan_rx); sport->dma_chan_rx = NULL; kfree(sport->rx_buf); sport->rx_buf = NULL; } if (sport->dma_chan_tx) { dma_release_channel(sport->dma_chan_tx); sport->dma_chan_tx = NULL; } sport->dma_is_inited = 0; } static int imx_uart_dma_init(struct imx_port *sport) { struct dma_slave_config slave_config = {}; struct device *dev = sport->port.dev; int ret; /* Prepare for RX : */ sport->dma_chan_rx = dma_request_slave_channel(dev, "rx"); if (!sport->dma_chan_rx) { dev_dbg(dev, "cannot get the DMA channel.\n"); ret = -EINVAL; goto err; } slave_config.direction = DMA_DEV_TO_MEM; slave_config.src_addr = sport->port.mapbase + URXD0; slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; slave_config.src_maxburst = RXTL; ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config); if (ret) { dev_err(dev, "error in RX dma configuration.\n"); goto err; } sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); if (!sport->rx_buf) { dev_err(dev, "cannot alloc DMA buffer.\n"); ret = -ENOMEM; goto err; } sport->rx_bytes = 0; /* Prepare for TX : */ sport->dma_chan_tx = dma_request_slave_channel(dev, "tx"); if (!sport->dma_chan_tx) { dev_err(dev, "cannot get the TX DMA channel!\n"); ret = -EINVAL; goto err; } slave_config.direction = DMA_MEM_TO_DEV; slave_config.dst_addr = sport->port.mapbase + URTX0; slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; slave_config.dst_maxburst = TXTL; ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config); if (ret) { dev_err(dev, "error in TX dma configuration."); goto err; } sport->dma_is_inited = 1; return 0; err: imx_uart_dma_exit(sport); return ret; } static void imx_enable_dma(struct imx_port *sport) { unsigned long temp; struct tty_port *port = &sport->port.state->port; port->low_latency = 1; INIT_WORK(&sport->tsk_dma_tx, dma_tx_work); INIT_WORK(&sport->tsk_dma_rx, dma_rx_work); init_waitqueue_head(&sport->dma_wait); /* set UCR1 */ temp = readl(sport->port.membase + UCR1); temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN | /* wait for 32 idle frames for IDDMA interrupt */ UCR1_ICD_REG(3); writel(temp, sport->port.membase + UCR1); /* set UCR4 */ temp = readl(sport->port.membase + UCR4); temp |= UCR4_IDDMAEN; writel(temp, sport->port.membase + UCR4); sport->dma_is_enabled = 1; } static void imx_disable_dma(struct imx_port *sport) { unsigned long temp; struct tty_port *port = &sport->port.state->port; /* clear UCR1 */ temp = readl(sport->port.membase + UCR1); temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN); writel(temp, sport->port.membase + UCR1); /* clear UCR2 */ temp = readl(sport->port.membase + UCR2); temp &= ~(UCR2_CTSC | UCR2_CTS); writel(temp, sport->port.membase + UCR2); /* clear UCR4 */ temp = readl(sport->port.membase + UCR4); temp &= ~UCR4_IDDMAEN; writel(temp, sport->port.membase + UCR4); sport->dma_is_enabled = 0; port->low_latency = 0; } /* half the RX buffer size */ #define CTSTL 16 static int imx_startup(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; int retval; unsigned long flags, temp; retval = clk_prepare_enable(sport->clk_per); if (retval) goto error_out1; retval = clk_prepare_enable(sport->clk_ipg); if (retval) { clk_disable_unprepare(sport->clk_per); goto error_out1; } imx_setup_ufcr(sport, 0); /* disable the DREN bit (Data Ready interrupt enable) before * requesting IRQs */ temp = readl(sport->port.membase + UCR4); if (USE_IRDA(sport)) temp |= UCR4_IRSC; /* set the trigger level for CTS */ temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF); temp |= CTSTL << UCR4_CTSTL_SHF; writel(temp & ~UCR4_DREN, sport->port.membase + UCR4); if (USE_IRDA(sport)) { /* reset fifo's and state machines */ int i = 100; temp = readl(sport->port.membase + UCR2); temp &= ~UCR2_SRST; writel(temp, sport->port.membase + UCR2); while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0)) { udelay(1); } } /* * Allocate the IRQ(s) i.MX1 has three interrupts whereas later * chips only have one interrupt. */ if (sport->txirq > 0) { retval = request_irq(sport->rxirq, imx_rxint, 0, DRIVER_NAME, sport); if (retval) goto error_out1; retval = request_irq(sport->txirq, imx_txint, 0, DRIVER_NAME, sport); if (retval) goto error_out2; /* do not use RTS IRQ on IrDA */ if (!USE_IRDA(sport)) { retval = request_irq(sport->rtsirq, imx_rtsint, 0, DRIVER_NAME, sport); if (retval) goto error_out3; } } else { retval = request_irq(sport->port.irq, imx_int, 0, DRIVER_NAME, sport); if (retval) { free_irq(sport->port.irq, sport); goto error_out1; } } spin_lock_irqsave(&sport->port.lock, flags); /* * Finally, clear and enable interrupts */ writel(USR1_RTSD, sport->port.membase + USR1); temp = readl(sport->port.membase + UCR1); temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN; if (USE_IRDA(sport)) { temp |= UCR1_IREN; temp &= ~(UCR1_RTSDEN); } writel(temp, sport->port.membase + UCR1); temp = readl(sport->port.membase + UCR2); temp |= (UCR2_RXEN | UCR2_TXEN); if (!sport->have_rtscts) temp |= UCR2_IRTS; writel(temp, sport->port.membase + UCR2); if (USE_IRDA(sport)) { /* clear RX-FIFO */ int i = 64; while ((--i > 0) && (readl(sport->port.membase + URXD0) & URXD_CHARRDY)) { barrier(); } } if (!is_imx1_uart(sport)) { temp = readl(sport->port.membase + UCR3); temp |= IMX21_UCR3_RXDMUXSEL; writel(temp, sport->port.membase + UCR3); } if (USE_IRDA(sport)) { temp = readl(sport->port.membase + UCR4); if (sport->irda_inv_rx) temp |= UCR4_INVR; else temp &= ~(UCR4_INVR); writel(temp | UCR4_DREN, sport->port.membase + UCR4); temp = readl(sport->port.membase + UCR3); if (sport->irda_inv_tx) temp |= UCR3_INVT; else temp &= ~(UCR3_INVT); writel(temp, sport->port.membase + UCR3); } /* * Enable modem status interrupts */ imx_enable_ms(&sport->port); spin_unlock_irqrestore(&sport->port.lock, flags); if (USE_IRDA(sport)) { struct imxuart_platform_data *pdata; pdata = dev_get_platdata(sport->port.dev); sport->irda_inv_rx = pdata->irda_inv_rx; sport->irda_inv_tx = pdata->irda_inv_tx; sport->trcv_delay = pdata->transceiver_delay; if (pdata->irda_enable) pdata->irda_enable(1); } return 0; error_out3: if (sport->txirq) free_irq(sport->txirq, sport); error_out2: if (sport->rxirq) free_irq(sport->rxirq, sport); error_out1: return retval; } static void imx_shutdown(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; unsigned long temp; unsigned long flags; if (sport->dma_is_enabled) { /* We have to wait for the DMA to finish. */ wait_event(sport->dma_wait, !sport->dma_is_rxing && !sport->dma_is_txing); imx_stop_rx(port); imx_disable_dma(sport); imx_uart_dma_exit(sport); } spin_lock_irqsave(&sport->port.lock, flags); temp = readl(sport->port.membase + UCR2); temp &= ~(UCR2_TXEN); writel(temp, sport->port.membase + UCR2); spin_unlock_irqrestore(&sport->port.lock, flags); if (USE_IRDA(sport)) { struct imxuart_platform_data *pdata; pdata = dev_get_platdata(sport->port.dev); if (pdata->irda_enable) pdata->irda_enable(0); } /* * Stop our timer. */ del_timer_sync(&sport->timer); /* * Free the interrupts */ if (sport->txirq > 0) { if (!USE_IRDA(sport)) free_irq(sport->rtsirq, sport); free_irq(sport->txirq, sport); free_irq(sport->rxirq, sport); } else free_irq(sport->port.irq, sport); /* * Disable all interrupts, port and break condition. */ spin_lock_irqsave(&sport->port.lock, flags); temp = readl(sport->port.membase + UCR1); temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN); if (USE_IRDA(sport)) temp &= ~(UCR1_IREN); writel(temp, sport->port.membase + UCR1); spin_unlock_irqrestore(&sport->port.lock, flags); clk_disable_unprepare(sport->clk_per); clk_disable_unprepare(sport->clk_ipg); } static void imx_flush_buffer(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; if (sport->dma_is_enabled) { sport->tx_bytes = 0; dmaengine_terminate_all(sport->dma_chan_tx); } } static void imx_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct imx_port *sport = (struct imx_port *)port; unsigned long flags; unsigned int ucr2, old_ucr1, old_txrxen, baud, quot; unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8; unsigned int div, ufcr; unsigned long num, denom; uint64_t tdiv64; /* * If we don't support modem control lines, don't allow * these to be set. */ if (0) { termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR); termios->c_cflag |= CLOCAL; } /* * We only support CS7 and CS8. */ while ((termios->c_cflag & CSIZE) != CS7 && (termios->c_cflag & CSIZE) != CS8) { termios->c_cflag &= ~CSIZE; termios->c_cflag |= old_csize; old_csize = CS8; } if ((termios->c_cflag & CSIZE) == CS8) ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS; else ucr2 = UCR2_SRST | UCR2_IRTS; if (termios->c_cflag & CRTSCTS) { if (sport->have_rtscts) { ucr2 &= ~UCR2_IRTS; ucr2 |= UCR2_CTSC; /* Can we enable the DMA support? */ if (is_imx6q_uart(sport) && !uart_console(port) && !sport->dma_is_inited) imx_uart_dma_init(sport); } else { termios->c_cflag &= ~CRTSCTS; } } if (termios->c_cflag & CSTOPB) ucr2 |= UCR2_STPB; if (termios->c_cflag & PARENB) { ucr2 |= UCR2_PREN; if (termios->c_cflag & PARODD) ucr2 |= UCR2_PROE; } del_timer_sync(&sport->timer); /* * Ask the core to calculate the divisor for us. */ baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16); quot = uart_get_divisor(port, baud); spin_lock_irqsave(&sport->port.lock, flags); sport->port.read_status_mask = 0; if (termios->c_iflag & INPCK) sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR); if (termios->c_iflag & (BRKINT | PARMRK)) sport->port.read_status_mask |= URXD_BRK; /* * Characters to ignore */ sport->port.ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) sport->port.ignore_status_mask |= URXD_PRERR; if (termios->c_iflag & IGNBRK) { sport->port.ignore_status_mask |= URXD_BRK; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) sport->port.ignore_status_mask |= URXD_OVRRUN; } /* * Update the per-port timeout. */ uart_update_timeout(port, termios->c_cflag, baud); /* * disable interrupts and drain transmitter */ old_ucr1 = readl(sport->port.membase + UCR1); writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN), sport->port.membase + UCR1); while (!(readl(sport->port.membase + USR2) & USR2_TXDC)) barrier(); /* then, disable everything */ old_txrxen = readl(sport->port.membase + UCR2); writel(old_txrxen & ~(UCR2_TXEN | UCR2_RXEN), sport->port.membase + UCR2); old_txrxen &= (UCR2_TXEN | UCR2_RXEN); if (USE_IRDA(sport)) { /* * use maximum available submodule frequency to * avoid missing short pulses due to low sampling rate */ div = 1; } else { /* custom-baudrate handling */ div = sport->port.uartclk / (baud * 16); if (baud == 38400 && quot != div) baud = sport->port.uartclk / (quot * 16); div = sport->port.uartclk / (baud * 16); if (div > 7) div = 7; if (!div) div = 1; } rational_best_approximation(16 * div * baud, sport->port.uartclk, 1 << 16, 1 << 16, &num, &denom); tdiv64 = sport->port.uartclk; tdiv64 *= num; do_div(tdiv64, denom * 16 * div); tty_termios_encode_baud_rate(termios, (speed_t)tdiv64, (speed_t)tdiv64); num -= 1; denom -= 1; ufcr = readl(sport->port.membase + UFCR); ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div); if (sport->dte_mode) ufcr |= UFCR_DCEDTE; writel(ufcr, sport->port.membase + UFCR); writel(num, sport->port.membase + UBIR); writel(denom, sport->port.membase + UBMR); if (!is_imx1_uart(sport)) writel(sport->port.uartclk / div / 1000, sport->port.membase + IMX21_ONEMS); writel(old_ucr1, sport->port.membase + UCR1); /* set the parity, stop bits and data size */ writel(ucr2 | old_txrxen, sport->port.membase + UCR2); if (UART_ENABLE_MS(&sport->port, termios->c_cflag)) imx_enable_ms(&sport->port); if (sport->dma_is_inited && !sport->dma_is_enabled) imx_enable_dma(sport); spin_unlock_irqrestore(&sport->port.lock, flags); } static const char *imx_type(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; return sport->port.type == PORT_IMX ? "IMX" : NULL; } /* * Release the memory region(s) being used by 'port'. */ static void imx_release_port(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); struct resource *mmres; mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0); release_mem_region(mmres->start, resource_size(mmres)); } /* * Request the memory region(s) being used by 'port'. */ static int imx_request_port(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); struct resource *mmres; void *ret; mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!mmres) return -ENODEV; ret = request_mem_region(mmres->start, resource_size(mmres), "imx-uart"); return ret ? 0 : -EBUSY; } /* * Configure/autoconfigure the port. */ static void imx_config_port(struct uart_port *port, int flags) { struct imx_port *sport = (struct imx_port *)port; if (flags & UART_CONFIG_TYPE && imx_request_port(&sport->port) == 0) sport->port.type = PORT_IMX; } /* * Verify the new serial_struct (for TIOCSSERIAL). * The only change we allow are to the flags and type, and * even then only between PORT_IMX and PORT_UNKNOWN */ static int imx_verify_port(struct uart_port *port, struct serial_struct *ser) { struct imx_port *sport = (struct imx_port *)port; int ret = 0; if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX) ret = -EINVAL; if (sport->port.irq != ser->irq) ret = -EINVAL; if (ser->io_type != UPIO_MEM) ret = -EINVAL; if (sport->port.uartclk / 16 != ser->baud_base) ret = -EINVAL; if (sport->port.mapbase != (unsigned long)ser->iomem_base) ret = -EINVAL; if (sport->port.iobase != ser->port) ret = -EINVAL; if (ser->hub6 != 0) ret = -EINVAL; return ret; } #if defined(CONFIG_CONSOLE_POLL) static int imx_poll_get_char(struct uart_port *port) { struct imx_port_ucrs old_ucr; unsigned int status; unsigned char c; /* save control registers */ imx_port_ucrs_save(port, &old_ucr); /* disable interrupts */ writel(UCR1_UARTEN, port->membase + UCR1); writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI), port->membase + UCR2); writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN), port->membase + UCR3); /* poll */ do { status = readl(port->membase + USR2); } while (~status & USR2_RDR); /* read */ c = readl(port->membase + URXD0); /* restore control registers */ imx_port_ucrs_restore(port, &old_ucr); return c; } static void imx_poll_put_char(struct uart_port *port, unsigned char c) { struct imx_port_ucrs old_ucr; unsigned int status; /* save control registers */ imx_port_ucrs_save(port, &old_ucr); /* disable interrupts */ writel(UCR1_UARTEN, port->membase + UCR1); writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI), port->membase + UCR2); writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN), port->membase + UCR3); /* drain */ do { status = readl(port->membase + USR1); } while (~status & USR1_TRDY); /* write */ writel(c, port->membase + URTX0); /* flush */ do { status = readl(port->membase + USR2); } while (~status & USR2_TXDC); /* restore control registers */ imx_port_ucrs_restore(port, &old_ucr); } #endif static struct uart_ops imx_pops = { .tx_empty = imx_tx_empty, .set_mctrl = imx_set_mctrl, .get_mctrl = imx_get_mctrl, .stop_tx = imx_stop_tx, .start_tx = imx_start_tx, .stop_rx = imx_stop_rx, .enable_ms = imx_enable_ms, .break_ctl = imx_break_ctl, .startup = imx_startup, .shutdown = imx_shutdown, .flush_buffer = imx_flush_buffer, .set_termios = imx_set_termios, .type = imx_type, .release_port = imx_release_port, .request_port = imx_request_port, .config_port = imx_config_port, .verify_port = imx_verify_port, #if defined(CONFIG_CONSOLE_POLL) .poll_get_char = imx_poll_get_char, .poll_put_char = imx_poll_put_char, #endif }; static struct imx_port *imx_ports[UART_NR]; #ifdef CONFIG_SERIAL_IMX_CONSOLE static void imx_console_putchar(struct uart_port *port, int ch) { struct imx_port *sport = (struct imx_port *)port; while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL) barrier(); writel(ch, sport->port.membase + URTX0); } /* * Interrupts are disabled on entering */ static void imx_console_write(struct console *co, const char *s, unsigned int count) { struct imx_port *sport = imx_ports[co->index]; struct imx_port_ucrs old_ucr; unsigned int ucr1; unsigned long flags = 0; int locked = 1; int retval; retval = clk_enable(sport->clk_per); if (retval) return; retval = clk_enable(sport->clk_ipg); if (retval) { clk_disable(sport->clk_per); return; } if (sport->port.sysrq) locked = 0; else if (oops_in_progress) locked = spin_trylock_irqsave(&sport->port.lock, flags); else spin_lock_irqsave(&sport->port.lock, flags); /* * First, save UCR1/2/3 and then disable interrupts */ imx_port_ucrs_save(&sport->port, &old_ucr); ucr1 = old_ucr.ucr1; if (is_imx1_uart(sport)) ucr1 |= IMX1_UCR1_UARTCLKEN; ucr1 |= UCR1_UARTEN; ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN); writel(ucr1, sport->port.membase + UCR1); writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2); uart_console_write(&sport->port, s, count, imx_console_putchar); /* * Finally, wait for transmitter to become empty * and restore UCR1/2/3 */ while (!(readl(sport->port.membase + USR2) & USR2_TXDC)); imx_port_ucrs_restore(&sport->port, &old_ucr); if (locked) spin_unlock_irqrestore(&sport->port.lock, flags); clk_disable(sport->clk_ipg); clk_disable(sport->clk_per); } /* * If the port was already initialised (eg, by a boot loader), * try to determine the current setup. */ static void __init imx_console_get_options(struct imx_port *sport, int *baud, int *parity, int *bits) { if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) { /* ok, the port was enabled */ unsigned int ucr2, ubir, ubmr, uartclk; unsigned int baud_raw; unsigned int ucfr_rfdiv; ucr2 = readl(sport->port.membase + UCR2); *parity = 'n'; if (ucr2 & UCR2_PREN) { if (ucr2 & UCR2_PROE) *parity = 'o'; else *parity = 'e'; } if (ucr2 & UCR2_WS) *bits = 8; else *bits = 7; ubir = readl(sport->port.membase + UBIR) & 0xffff; ubmr = readl(sport->port.membase + UBMR) & 0xffff; ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7; if (ucfr_rfdiv == 6) ucfr_rfdiv = 7; else ucfr_rfdiv = 6 - ucfr_rfdiv; uartclk = clk_get_rate(sport->clk_per); uartclk /= ucfr_rfdiv; { /* * The next code provides exact computation of * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1)) * without need of float support or long long division, * which would be required to prevent 32bit arithmetic overflow */ unsigned int mul = ubir + 1; unsigned int div = 16 * (ubmr + 1); unsigned int rem = uartclk % div; baud_raw = (uartclk / div) * mul; baud_raw += (rem * mul + div / 2) / div; *baud = (baud_raw + 50) / 100 * 100; } if (*baud != baud_raw) pr_info("Console IMX rounded baud rate from %d to %d\n", baud_raw, *baud); } } static int __init imx_console_setup(struct console *co, char *options) { struct imx_port *sport; int baud = 9600; int bits = 8; int parity = 'n'; int flow = 'n'; int retval; /* * Check whether an invalid uart number has been specified, and * if so, search for the first available port that does have * console support. */ if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports)) co->index = 0; sport = imx_ports[co->index]; if (sport == NULL) return -ENODEV; /* For setting the registers, we only need to enable the ipg clock. */ retval = clk_prepare_enable(sport->clk_ipg); if (retval) goto error_console; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else imx_console_get_options(sport, &baud, &parity, &bits); imx_setup_ufcr(sport, 0); retval = uart_set_options(&sport->port, co, baud, parity, bits, flow); clk_disable(sport->clk_ipg); if (retval) { clk_unprepare(sport->clk_ipg); goto error_console; } retval = clk_prepare(sport->clk_per); if (retval) clk_disable_unprepare(sport->clk_ipg); error_console: return retval; } static struct uart_driver imx_reg; static struct console imx_console = { .name = DEV_NAME, .write = imx_console_write, .device = uart_console_device, .setup = imx_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &imx_reg, }; #define IMX_CONSOLE &imx_console #else #define IMX_CONSOLE NULL #endif static struct uart_driver imx_reg = { .owner = THIS_MODULE, .driver_name = DRIVER_NAME, .dev_name = DEV_NAME, .major = SERIAL_IMX_MAJOR, .minor = MINOR_START, .nr = ARRAY_SIZE(imx_ports), .cons = IMX_CONSOLE, }; static int serial_imx_suspend(struct platform_device *dev, pm_message_t state) { struct imx_port *sport = platform_get_drvdata(dev); unsigned int val; /* enable wakeup from i.MX UART */ val = readl(sport->port.membase + UCR3); val |= UCR3_AWAKEN; writel(val, sport->port.membase + UCR3); uart_suspend_port(&imx_reg, &sport->port); return 0; } static int serial_imx_resume(struct platform_device *dev) { struct imx_port *sport = platform_get_drvdata(dev); unsigned int val; /* disable wakeup from i.MX UART */ val = readl(sport->port.membase + UCR3); val &= ~UCR3_AWAKEN; writel(val, sport->port.membase + UCR3); uart_resume_port(&imx_reg, &sport->port); return 0; } #ifdef CONFIG_OF /* * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it * could successfully get all information from dt or a negative errno. */ static int serial_imx_probe_dt(struct imx_port *sport, struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; const struct of_device_id *of_id = of_match_device(imx_uart_dt_ids, &pdev->dev); int ret; if (!np) /* no device tree device */ return 1; ret = of_alias_get_id(np, "serial"); if (ret < 0) { dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret); return ret; } sport->port.line = ret; if (of_get_property(np, "fsl,uart-has-rtscts", NULL)) sport->have_rtscts = 1; if (of_get_property(np, "fsl,irda-mode", NULL)) sport->use_irda = 1; if (of_get_property(np, "fsl,dte-mode", NULL)) sport->dte_mode = 1; sport->devdata = of_id->data; if (of_device_is_stdout_path(np)) add_preferred_console(imx_reg.cons->name, sport->port.line, NULL); return 0; } #else static inline int serial_imx_probe_dt(struct imx_port *sport, struct platform_device *pdev) { return 1; } #endif static void serial_imx_probe_pdata(struct imx_port *sport, struct platform_device *pdev) { struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev); sport->port.line = pdev->id; sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data; if (!pdata) return; if (pdata->flags & IMXUART_HAVE_RTSCTS) sport->have_rtscts = 1; if (pdata->flags & IMXUART_IRDA) sport->use_irda = 1; } static int serial_imx_probe(struct platform_device *pdev) { struct imx_port *sport; struct imxuart_platform_data *pdata; void __iomem *base; int ret = 0; struct resource *res; sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); if (!sport) return -ENOMEM; ret = serial_imx_probe_dt(sport, pdev); if (ret > 0) serial_imx_probe_pdata(sport, pdev); else if (ret < 0) return ret; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) return -ENODEV; base = devm_ioremap(&pdev->dev, res->start, PAGE_SIZE); if (!base) return -ENOMEM; sport->port.dev = &pdev->dev; sport->port.mapbase = res->start; sport->port.membase = base; sport->port.type = PORT_IMX, sport->port.iotype = UPIO_MEM; sport->port.irq = platform_get_irq(pdev, 0); sport->rxirq = platform_get_irq(pdev, 0); sport->txirq = platform_get_irq(pdev, 1); sport->rtsirq = platform_get_irq(pdev, 2); sport->port.fifosize = 32; sport->port.ops = &imx_pops; sport->port.flags = UPF_BOOT_AUTOCONF; init_timer(&sport->timer); sport->timer.function = imx_timeout; sport->timer.data = (unsigned long)sport; sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); if (IS_ERR(sport->clk_ipg)) { ret = PTR_ERR(sport->clk_ipg); dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret); return ret; } sport->clk_per = devm_clk_get(&pdev->dev, "per"); if (IS_ERR(sport->clk_per)) { ret = PTR_ERR(sport->clk_per); dev_err(&pdev->dev, "failed to get per clk: %d\n", ret); return ret; } sport->port.uartclk = clk_get_rate(sport->clk_per); imx_ports[sport->port.line] = sport; pdata = dev_get_platdata(&pdev->dev); if (pdata && pdata->init) { ret = pdata->init(pdev); if (ret) return ret; } ret = uart_add_one_port(&imx_reg, &sport->port); if (ret) goto deinit; platform_set_drvdata(pdev, sport); return 0; deinit: if (pdata && pdata->exit) pdata->exit(pdev); return ret; } static int serial_imx_remove(struct platform_device *pdev) { struct imxuart_platform_data *pdata; struct imx_port *sport = platform_get_drvdata(pdev); pdata = dev_get_platdata(&pdev->dev); uart_remove_one_port(&imx_reg, &sport->port); if (pdata && pdata->exit) pdata->exit(pdev); return 0; } static struct platform_driver serial_imx_driver = { .probe = serial_imx_probe, .remove = serial_imx_remove, .suspend = serial_imx_suspend, .resume = serial_imx_resume, .id_table = imx_uart_devtype, .driver = { .name = "imx-uart", .owner = THIS_MODULE, .of_match_table = imx_uart_dt_ids, }, }; static int __init imx_serial_init(void) { int ret; pr_info("Serial: IMX driver\n"); ret = uart_register_driver(&imx_reg); if (ret) return ret; ret = platform_driver_register(&serial_imx_driver); if (ret != 0) uart_unregister_driver(&imx_reg); return ret; } static void __exit imx_serial_exit(void) { platform_driver_unregister(&serial_imx_driver); uart_unregister_driver(&imx_reg); } module_init(imx_serial_init); module_exit(imx_serial_exit); MODULE_AUTHOR("Sascha Hauer"); MODULE_DESCRIPTION("IMX generic serial port driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:imx-uart");