diff options
Diffstat (limited to 'drivers/tty/serial/imx.c')
| -rw-r--r-- | drivers/tty/serial/imx.c | 2036 |
1 files changed, 2036 insertions, 0 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c new file mode 100644 index 000000000..88250395b --- /dev/null +++ b/drivers/tty/serial/imx.c @@ -0,0 +1,2036 @@ +/* + * Driver for Motorola/Freescale IMX serial ports + * + * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. + * + * Author: Sascha Hauer <sascha@saschahauer.de> + * Copyright (C) 2004 Pengutronix + * + * 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. + */ + +#if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) +#define SUPPORT_SYSRQ +#endif + +#include <linux/module.h> +#include <linux/ioport.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/sysrq.h> +#include <linux/platform_device.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/serial_core.h> +#include <linux/serial.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/rational.h> +#include <linux/slab.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/io.h> +#include <linux/dma-mapping.h> + +#include <asm/irq.h> +#include <linux/platform_data/serial-imx.h> +#include <linux/platform_data/dma-imx.h> + +/* 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_DUMMY_READ (1<<16) +#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 URXD_RX_DATA (0xFF<<0) +#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_ADNIMP (1<<7) /* Autobaud Detection Not Improved */ +#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 and i.MX6q */ +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; + unsigned int have_rtscts:1; + unsigned int dte_mode: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 tx_bytes; + unsigned int dma_tx_nents; + wait_queue_head_t dma_wait; +}; + +struct imx_port_ucrs { + unsigned int ucr1; + unsigned int ucr2; + unsigned int ucr3; +}; + +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 const 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_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; + + /* + * 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(port->membase + UCR1); + writel(temp & ~UCR1_TXMPTYEN, port->membase + UCR1); + + /* in rs485 mode disable transmitter if shifter is empty */ + if (port->rs485.flags & SER_RS485_ENABLED && + readl(port->membase + USR2) & USR2_TXDC) { + temp = readl(port->membase + UCR2); + if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) + temp &= ~UCR2_CTS; + else + temp |= UCR2_CTS; + writel(temp, port->membase + UCR2); + + temp = readl(port->membase + UCR4); + temp &= ~UCR4_TCEN; + writel(temp, port->membase + UCR4); + } +} + +/* + * interrupts disabled on entry + */ +static void imx_stop_rx(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + unsigned long temp; + + if (sport->dma_is_enabled && sport->dma_is_rxing) { + if (sport->port.suspended) { + dmaengine_terminate_all(sport->dma_chan_rx); + sport->dma_is_rxing = 0; + } else { + return; + } + } + + temp = readl(sport->port.membase + UCR2); + writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2); + + /* disable the `Receiver Ready Interrrupt` */ + temp = readl(sport->port.membase + UCR1); + writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1); +} + +/* + * 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 void imx_dma_tx(struct imx_port *sport); +static inline void imx_transmit_buffer(struct imx_port *sport) +{ + struct circ_buf *xmit = &sport->port.state->xmit; + unsigned long temp; + + if (sport->port.x_char) { + /* Send next char */ + writel(sport->port.x_char, sport->port.membase + URTX0); + sport->port.icount.tx++; + sport->port.x_char = 0; + return; + } + + if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) { + imx_stop_tx(&sport->port); + return; + } + + if (sport->dma_is_enabled) { + /* + * We've just sent a X-char Ensure the TX DMA is enabled + * and the TX IRQ is disabled. + **/ + temp = readl(sport->port.membase + UCR1); + temp &= ~UCR1_TXMPTYEN; + if (sport->dma_is_txing) { + temp |= UCR1_TDMAEN; + writel(temp, sport->port.membase + UCR1); + } else { + writel(temp, sport->port.membase + UCR1); + imx_dma_tx(sport); + } + } + + 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; + unsigned long temp; + + spin_lock_irqsave(&sport->port.lock, flags); + + dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); + + temp = readl(sport->port.membase + UCR1); + temp &= ~UCR1_TDMAEN; + writel(temp, sport->port.membase + UCR1); + + /* update the stat */ + xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1); + sport->port.icount.tx += sport->tx_bytes; + + dev_dbg(sport->port.dev, "we finish the TX DMA.\n"); + + sport->dma_is_txing = 0; + + spin_unlock_irqrestore(&sport->port.lock, flags); + + 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; + } + + spin_lock_irqsave(&sport->port.lock, flags); + if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port)) + imx_dma_tx(sport); + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +static void imx_dma_tx(struct imx_port *sport) +{ + 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; + unsigned long temp; + int ret; + + if (sport->dma_is_txing) + return; + + sport->tx_bytes = uart_circ_chars_pending(xmit); + + if (xmit->tail < xmit->head) { + sport->dma_tx_nents = 1; + sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes); + } else { + 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); + } + + 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) { + dma_unmap_sg(dev, sgl, sport->dma_tx_nents, + DMA_TO_DEVICE); + 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)); + + temp = readl(sport->port.membase + UCR1); + temp |= UCR1_TDMAEN; + writel(temp, sport->port.membase + UCR1); + + /* 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 (port->rs485.flags & SER_RS485_ENABLED) { + /* enable transmitter and shifter empty irq */ + temp = readl(port->membase + UCR2); + if (port->rs485.flags & SER_RS485_RTS_ON_SEND) + temp &= ~UCR2_CTS; + else + temp |= UCR2_CTS; + writel(temp, port->membase + UCR2); + + temp = readl(port->membase + UCR4); + temp |= UCR4_TCEN; + writel(temp, port->membase + UCR4); + } + + if (!sport->dma_is_enabled) { + temp = readl(sport->port.membase + UCR1); + writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1); + } + + if (sport->dma_is_enabled) { + if (sport->port.x_char) { + /* We have X-char to send, so enable TX IRQ and + * disable TX DMA to let TX interrupt to send X-char */ + temp = readl(sport->port.membase + UCR1); + temp &= ~UCR1_TDMAEN; + temp |= UCR1_TXMPTYEN; + writel(temp, sport->port.membase + UCR1); + return; + } + + if (!uart_circ_empty(&port->state->xmit) && + !uart_tx_stopped(port)) + imx_dma_tx(sport); + return; + } +} + +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; + unsigned long flags; + + spin_lock_irqsave(&sport->port.lock, flags); + imx_transmit_buffer(sport); + 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 | 0xFF); + + 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 + } + + if (sport->port.ignore_status_mask & URXD_DUMMY_READ) + goto out; + + tty_insert_flip_char(port, rx, flg); + } + +out: + spin_unlock_irqrestore(&sport->port.lock, flags); + tty_flip_buffer_push(port); + return IRQ_HANDLED; +} + +static int start_rx_dma(struct imx_port *sport); +/* + * 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; + unsigned long flags; + + spin_lock_irqsave(&sport->port.lock, flags); + + 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. */ + start_rx_dma(sport); + } + + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +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); + sts2 = readl(sport->port.membase + USR2); + + 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) || + (sts2 & USR2_TXDC && + readl(sport->port.membase + UCR4) & UCR4_TCEN)) + 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); + + if (sts2 & USR2_ORE) { + dev_err(sport->port.dev, "Rx FIFO overrun\n"); + sport->port.icount.overrun++; + writel(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; + + if (readl(sport->port.membase + uts_reg(sport)) & UTS_LOOP) + tmp |= TIOCM_LOOP; + + 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; + + if (!(port->rs485.flags & SER_RS485_ENABLED)) { + temp = readl(sport->port.membase + UCR2); + temp &= ~(UCR2_CTS | UCR2_CTSC); + if (mctrl & TIOCM_RTS) + temp |= UCR2_CTS | UCR2_CTSC; + writel(temp, sport->port.membase + UCR2); + } + + temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP; + if (mctrl & TIOCM_LOOP) + temp |= UTS_LOOP; + writel(temp, sport->port.membase + uts_reg(sport)); +} + +/* + * 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 void imx_rx_dma_done(struct imx_port *sport) +{ + unsigned long temp; + unsigned long flags; + + spin_lock_irqsave(&sport->port.lock, flags); + + /* 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); + + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +/* + * 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 tty_port *port = &sport->port.state->port; + 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; + + if (readl(sport->port.membase + USR2) & USR2_IDLE) { + /* In condition [3] the SDMA counted up too early */ + count--; + + writel(USR2_IDLE, sport->port.membase + USR2); + } + + dev_dbg(sport->port.dev, "We get %d bytes.\n", count); + + if (count) { + if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) + tty_insert_flip_string(port, sport->rx_buf, count); + tty_flip_buffer_push(port); + + start_rx_dma(sport); + } else if (readl(sport->port.membase + USR2) & USR2_RDR) { + /* + * start rx_dma directly once data in RXFIFO, more efficient + * than before: + * 1. call imx_rx_dma_done to stop dma if no data received + * 2. wait next RDR interrupt to start dma transfer. + */ + start_rx_dma(sport); + } else { + /* + * stop dma to prevent too many IDLE event trigged if no data + * in RXFIFO + */ + 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) { + dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE); + 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) { + ret = -ENOMEM; + goto err; + } + + /* 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; + + 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; + + /* 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; +} + +/* 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, i; + unsigned long flags, temp; + + retval = clk_prepare_enable(sport->clk_per); + if (retval) + return retval; + retval = clk_prepare_enable(sport->clk_ipg); + if (retval) { + clk_disable_unprepare(sport->clk_per); + return retval; + } + + imx_setup_ufcr(sport, 0); + + /* disable the DREN bit (Data Ready interrupt enable) before + * requesting IRQs + */ + temp = readl(sport->port.membase + UCR4); + + /* 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); + + /* Reset fifo's and state machines */ + 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); + + /* Can we enable the DMA support? */ + if (is_imx6q_uart(sport) && !uart_console(port) && + !sport->dma_is_inited) + imx_uart_dma_init(sport); + + spin_lock_irqsave(&sport->port.lock, flags); + + /* + * Finally, clear and enable interrupts + */ + writel(USR1_RTSD, sport->port.membase + USR1); + writel(USR2_ORE, sport->port.membase + USR2); + + if (sport->dma_is_inited && !sport->dma_is_enabled) + imx_enable_dma(sport); + + temp = readl(sport->port.membase + UCR1); + temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN; + + writel(temp, sport->port.membase + UCR1); + + temp = readl(sport->port.membase + UCR4); + temp |= UCR4_OREN; + writel(temp, sport->port.membase + UCR4); + + 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 (!is_imx1_uart(sport)) { + temp = readl(sport->port.membase + UCR3); + temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP; + writel(temp, sport->port.membase + UCR3); + } + + /* + * Enable modem status interrupts + */ + imx_enable_ms(&sport->port); + spin_unlock_irqrestore(&sport->port.lock, flags); + + return 0; +} + +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) { + int ret; + + /* We have to wait for the DMA to finish. */ + ret = wait_event_interruptible(sport->dma_wait, + !sport->dma_is_rxing && !sport->dma_is_txing); + if (ret != 0) { + sport->dma_is_rxing = 0; + sport->dma_is_txing = 0; + dmaengine_terminate_all(sport->dma_chan_tx); + dmaengine_terminate_all(sport->dma_chan_rx); + } + spin_lock_irqsave(&sport->port.lock, flags); + imx_stop_tx(port); + imx_stop_rx(port); + imx_disable_dma(sport); + spin_unlock_irqrestore(&sport->port.lock, flags); + 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); + + /* + * Stop our timer. + */ + del_timer_sync(&sport->timer); + + /* + * 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); + + 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; + struct scatterlist *sgl = &sport->tx_sgl[0]; + unsigned long temp; + int i = 100, ubir, ubmr, uts; + + if (!sport->dma_chan_tx) + return; + + sport->tx_bytes = 0; + dmaengine_terminate_all(sport->dma_chan_tx); + if (sport->dma_is_txing) { + dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, + DMA_TO_DEVICE); + temp = readl(sport->port.membase + UCR1); + temp &= ~UCR1_TDMAEN; + writel(temp, sport->port.membase + UCR1); + sport->dma_is_txing = false; + } + + /* + * According to the Reference Manual description of the UART SRST bit: + * "Reset the transmit and receive state machines, + * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD + * and UTS[6-3]". As we don't need to restore the old values from + * USR1, USR2, URXD, UTXD, only save/restore the other four registers + */ + ubir = readl(sport->port.membase + UBIR); + ubmr = readl(sport->port.membase + UBMR); + uts = readl(sport->port.membase + IMX21_UTS); + + 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); + + /* Restore the registers */ + writel(ubir, sport->port.membase + UBIR); + writel(ubmr, sport->port.membase + UBMR); + writel(uts, sport->port.membase + IMX21_UTS); +} + +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; + + /* + * 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; + + if (port->rs485.flags & SER_RS485_ENABLED) { + /* + * RTS is mandatory for rs485 operation, so keep + * it under manual control and keep transmitter + * disabled. + */ + if (!(port->rs485.flags & + SER_RS485_RTS_AFTER_SEND)) + ucr2 |= UCR2_CTS; + } else { + ucr2 |= UCR2_CTSC; + } + } else { + termios->c_cflag &= ~CRTSCTS; + } + } else if (port->rs485.flags & SER_RS485_ENABLED) + /* disable transmitter */ + if (!(port->rs485.flags & SER_RS485_RTS_AFTER_SEND)) + ucr2 |= UCR2_CTS; + + 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 | URXD_FRMERR; + 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; + } + + if ((termios->c_cflag & CREAD) == 0) + sport->port.ignore_status_mask |= URXD_DUMMY_READ; + + /* + * 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); + + /* 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); + + 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; +} + +/* + * 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) + 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_init(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + unsigned long flags; + unsigned long temp; + int retval; + + retval = clk_prepare_enable(sport->clk_ipg); + if (retval) + return retval; + retval = clk_prepare_enable(sport->clk_per); + if (retval) + clk_disable_unprepare(sport->clk_ipg); + + imx_setup_ufcr(sport, 0); + + spin_lock_irqsave(&sport->port.lock, flags); + + temp = readl(sport->port.membase + UCR1); + if (is_imx1_uart(sport)) + temp |= IMX1_UCR1_UARTCLKEN; + temp |= UCR1_UARTEN | UCR1_RRDYEN; + temp &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN); + writel(temp, sport->port.membase + UCR1); + + temp = readl(sport->port.membase + UCR2); + temp |= UCR2_RXEN; + writel(temp, sport->port.membase + UCR2); + + spin_unlock_irqrestore(&sport->port.lock, flags); + + return 0; +} + +static int imx_poll_get_char(struct uart_port *port) +{ + if (!(readl_relaxed(port->membase + USR2) & USR2_RDR)) + return NO_POLL_CHAR; + + return readl_relaxed(port->membase + URXD0) & URXD_RX_DATA; +} + +static void imx_poll_put_char(struct uart_port *port, unsigned char c) +{ + unsigned int status; + + /* drain */ + do { + status = readl_relaxed(port->membase + USR1); + } while (~status & USR1_TRDY); + + /* write */ + writel_relaxed(c, port->membase + URTX0); + + /* flush */ + do { + status = readl_relaxed(port->membase + USR2); + } while (~status & USR2_TXDC); +} +#endif + +static int imx_rs485_config(struct uart_port *port, + struct serial_rs485 *rs485conf) +{ + struct imx_port *sport = (struct imx_port *)port; + + /* unimplemented */ + rs485conf->delay_rts_before_send = 0; + rs485conf->delay_rts_after_send = 0; + rs485conf->flags |= SER_RS485_RX_DURING_TX; + + /* RTS is required to control the transmitter */ + if (!sport->have_rtscts) + rs485conf->flags &= ~SER_RS485_ENABLED; + + if (rs485conf->flags & SER_RS485_ENABLED) { + unsigned long temp; + + /* disable transmitter */ + temp = readl(sport->port.membase + UCR2); + temp &= ~UCR2_CTSC; + if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND) + temp &= ~UCR2_CTS; + else + temp |= UCR2_CTS; + writel(temp, sport->port.membase + UCR2); + } + + port->rs485 = *rs485conf; + + return 0; +} + +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, + .config_port = imx_config_port, + .verify_port = imx_verify_port, +#if defined(CONFIG_CONSOLE_POLL) + .poll_init = imx_poll_init, + .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,dte-mode", NULL)) + sport->dte_mode = 1; + + sport->devdata = of_id->data; + + 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; +} + +static int serial_imx_probe(struct platform_device *pdev) +{ + struct imx_port *sport; + void __iomem *base; + int ret = 0; + struct resource *res; + int txirq, rxirq, rtsirq; + + 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); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + rxirq = platform_get_irq(pdev, 0); + txirq = platform_get_irq(pdev, 1); + rtsirq = platform_get_irq(pdev, 2); + + 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 = rxirq; + sport->port.fifosize = 32; + sport->port.ops = &imx_pops; + sport->port.rs485_config = imx_rs485_config; + sport->port.rs485.flags = + SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX; + 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); + + /* + * Allocate the IRQ(s) i.MX1 has three interrupts whereas later + * chips only have one interrupt. + */ + if (txirq > 0) { + ret = devm_request_irq(&pdev->dev, rxirq, imx_rxint, 0, + dev_name(&pdev->dev), sport); + if (ret) + return ret; + + ret = devm_request_irq(&pdev->dev, txirq, imx_txint, 0, + dev_name(&pdev->dev), sport); + if (ret) + return ret; + } else { + ret = devm_request_irq(&pdev->dev, rxirq, imx_int, 0, + dev_name(&pdev->dev), sport); + if (ret) + return ret; + } + + imx_ports[sport->port.line] = sport; + + platform_set_drvdata(pdev, sport); + + return uart_add_one_port(&imx_reg, &sport->port); +} + +static int serial_imx_remove(struct platform_device *pdev) +{ + struct imx_port *sport = platform_get_drvdata(pdev); + + return uart_remove_one_port(&imx_reg, &sport->port); +} + +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", + .of_match_table = imx_uart_dt_ids, + }, +}; + +static int __init imx_serial_init(void) +{ + int 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"); |