diff options
Diffstat (limited to 'drivers/tty/serial/imx.c')
| -rw-r--r-- | drivers/tty/serial/imx.c | 2702 |
1 files changed, 2702 insertions, 0 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c new file mode 100644 index 000000000..f8962a3d4 --- /dev/null +++ b/drivers/tty/serial/imx.c @@ -0,0 +1,2702 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * 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 + */ + +#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/ktime.h> +#include <linux/pinctrl/consumer.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/dma/imx-dma.h> + +#include "serial_mctrl_gpio.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_RXDMAEN (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_TXDMAEN (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 UCR3_DTRDEN (1<<3) /* Data Terminal Ready Delta 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_AGTIM (1<<8) /* Ageing timer interrupt flag */ +#define USR1_DTRD (1<<7) /* DTR Delta */ +#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_RIDELT (1<<10) /* Ring Interrupt Delta */ +#define USR2_RIIN (1<<9) /* Ring Indicator Input */ +#define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */ +#define USR2_WAKE (1<<7) /* Wake */ +#define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */ +#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, + IMX53_UART, + IMX6Q_UART, +}; + +/* device type dependent stuff */ +struct imx_uart_data { + unsigned uts_reg; + enum imx_uart_type devtype; +}; + +enum imx_tx_state { + OFF, + WAIT_AFTER_RTS, + SEND, + WAIT_AFTER_SEND, +}; + +struct imx_port { + struct uart_port port; + struct timer_list timer; + unsigned int old_status; + unsigned int have_rtscts:1; + unsigned int have_rtsgpio:1; + unsigned int dte_mode:1; + unsigned int inverted_tx:1; + unsigned int inverted_rx:1; + struct clk *clk_ipg; + struct clk *clk_per; + const struct imx_uart_data *devdata; + + struct mctrl_gpios *gpios; + + /* shadow registers */ + unsigned int ucr1; + unsigned int ucr2; + unsigned int ucr3; + unsigned int ucr4; + unsigned int ufcr; + + /* DMA fields */ + 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; + struct circ_buf rx_ring; + unsigned int rx_buf_size; + unsigned int rx_period_length; + unsigned int rx_periods; + dma_cookie_t rx_cookie; + unsigned int tx_bytes; + unsigned int dma_tx_nents; + unsigned int saved_reg[10]; + bool context_saved; + + enum imx_tx_state tx_state; + struct hrtimer trigger_start_tx; + struct hrtimer trigger_stop_tx; +}; + +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, + }, + [IMX53_UART] = { + .uts_reg = IMX21_UTS, + .devtype = IMX53_UART, + }, + [IMX6Q_UART] = { + .uts_reg = IMX21_UTS, + .devtype = IMX6Q_UART, + }, +}; + +static const struct of_device_id imx_uart_dt_ids[] = { + { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], }, + { .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_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 void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset) +{ + switch (offset) { + case UCR1: + sport->ucr1 = val; + break; + case UCR2: + sport->ucr2 = val; + break; + case UCR3: + sport->ucr3 = val; + break; + case UCR4: + sport->ucr4 = val; + break; + case UFCR: + sport->ufcr = val; + break; + default: + break; + } + writel(val, sport->port.membase + offset); +} + +static u32 imx_uart_readl(struct imx_port *sport, u32 offset) +{ + switch (offset) { + case UCR1: + return sport->ucr1; + break; + case UCR2: + /* + * UCR2_SRST is the only bit in the cached registers that might + * differ from the value that was last written. As it only + * automatically becomes one after being cleared, reread + * conditionally. + */ + if (!(sport->ucr2 & UCR2_SRST)) + sport->ucr2 = readl(sport->port.membase + offset); + return sport->ucr2; + break; + case UCR3: + return sport->ucr3; + break; + case UCR4: + return sport->ucr4; + break; + case UFCR: + return sport->ufcr; + break; + default: + return readl(sport->port.membase + offset); + } +} + +static inline unsigned imx_uart_uts_reg(struct imx_port *sport) +{ + return sport->devdata->uts_reg; +} + +static inline int imx_uart_is_imx1(struct imx_port *sport) +{ + return sport->devdata->devtype == IMX1_UART; +} + +static inline int imx_uart_is_imx21(struct imx_port *sport) +{ + return sport->devdata->devtype == IMX21_UART; +} + +static inline int imx_uart_is_imx53(struct imx_port *sport) +{ + return sport->devdata->devtype == IMX53_UART; +} + +static inline int imx_uart_is_imx6q(struct imx_port *sport) +{ + return sport->devdata->devtype == IMX6Q_UART; +} +/* + * Save and restore functions for UCR1, UCR2 and UCR3 registers + */ +#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE) +static void imx_uart_ucrs_save(struct imx_port *sport, + struct imx_port_ucrs *ucr) +{ + /* save control registers */ + ucr->ucr1 = imx_uart_readl(sport, UCR1); + ucr->ucr2 = imx_uart_readl(sport, UCR2); + ucr->ucr3 = imx_uart_readl(sport, UCR3); +} + +static void imx_uart_ucrs_restore(struct imx_port *sport, + struct imx_port_ucrs *ucr) +{ + /* restore control registers */ + imx_uart_writel(sport, ucr->ucr1, UCR1); + imx_uart_writel(sport, ucr->ucr2, UCR2); + imx_uart_writel(sport, ucr->ucr3, UCR3); +} +#endif + +/* called with port.lock taken and irqs caller dependent */ +static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2) +{ + *ucr2 &= ~(UCR2_CTSC | UCR2_CTS); + + mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS); +} + +/* called with port.lock taken and irqs caller dependent */ +static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2) +{ + *ucr2 &= ~UCR2_CTSC; + *ucr2 |= UCR2_CTS; + + mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS); +} + +static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec) +{ + hrtimer_start(hrt, ms_to_ktime(msec), HRTIMER_MODE_REL); +} + +static void imx_uart_disable_loopback_rs485(struct imx_port *sport) +{ + unsigned int uts; + + /* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */ + uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)); + uts &= ~UTS_LOOP; + imx_uart_writel(sport, uts, imx_uart_uts_reg(sport)); +} + +/* called with port.lock taken and irqs off */ +static void imx_uart_start_rx(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + unsigned int ucr1, ucr2; + + ucr1 = imx_uart_readl(sport, UCR1); + ucr2 = imx_uart_readl(sport, UCR2); + + ucr2 |= UCR2_RXEN; + + if (sport->dma_is_enabled) { + ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN; + } else { + ucr1 |= UCR1_RRDYEN; + ucr2 |= UCR2_ATEN; + } + + /* Write UCR2 first as it includes RXEN */ + imx_uart_writel(sport, ucr2, UCR2); + imx_uart_writel(sport, ucr1, UCR1); + imx_uart_disable_loopback_rs485(sport); +} + +/* called with port.lock taken and irqs off */ +static void imx_uart_stop_tx(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + u32 ucr1, ucr4, usr2; + + if (sport->tx_state == OFF) + 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_txing) + return; + + ucr1 = imx_uart_readl(sport, UCR1); + imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1); + + ucr4 = imx_uart_readl(sport, UCR4); + usr2 = imx_uart_readl(sport, USR2); + if ((!(usr2 & USR2_TXDC)) && (ucr4 & UCR4_TCEN)) { + /* The shifter is still busy, so retry once TC triggers */ + return; + } + + ucr4 &= ~UCR4_TCEN; + imx_uart_writel(sport, ucr4, UCR4); + + /* in rs485 mode disable transmitter */ + if (port->rs485.flags & SER_RS485_ENABLED) { + if (sport->tx_state == SEND) { + sport->tx_state = WAIT_AFTER_SEND; + + if (port->rs485.delay_rts_after_send > 0) { + start_hrtimer_ms(&sport->trigger_stop_tx, + port->rs485.delay_rts_after_send); + return; + } + + /* continue without any delay */ + } + + if (sport->tx_state == WAIT_AFTER_RTS || + sport->tx_state == WAIT_AFTER_SEND) { + u32 ucr2; + + hrtimer_try_to_cancel(&sport->trigger_start_tx); + + ucr2 = imx_uart_readl(sport, UCR2); + if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) + imx_uart_rts_active(sport, &ucr2); + else + imx_uart_rts_inactive(sport, &ucr2); + imx_uart_writel(sport, ucr2, UCR2); + + imx_uart_start_rx(port); + + sport->tx_state = OFF; + } + } else { + sport->tx_state = OFF; + } +} + +/* called with port.lock taken and irqs off */ +static void imx_uart_stop_rx(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + u32 ucr1, ucr2, ucr4, uts; + + ucr1 = imx_uart_readl(sport, UCR1); + ucr2 = imx_uart_readl(sport, UCR2); + ucr4 = imx_uart_readl(sport, UCR4); + + if (sport->dma_is_enabled) { + ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN); + } else { + ucr1 &= ~UCR1_RRDYEN; + ucr2 &= ~UCR2_ATEN; + ucr4 &= ~UCR4_OREN; + } + imx_uart_writel(sport, ucr1, UCR1); + imx_uart_writel(sport, ucr4, UCR4); + + /* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */ + if (port->rs485.flags & SER_RS485_ENABLED && + port->rs485.flags & SER_RS485_RTS_ON_SEND && + sport->have_rtscts && !sport->have_rtsgpio) { + uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)); + uts |= UTS_LOOP; + imx_uart_writel(sport, uts, imx_uart_uts_reg(sport)); + ucr2 |= UCR2_RXEN; + } else { + ucr2 &= ~UCR2_RXEN; + } + + imx_uart_writel(sport, ucr2, UCR2); +} + +/* called with port.lock taken and irqs off */ +static void imx_uart_enable_ms(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + + mod_timer(&sport->timer, jiffies); + + mctrl_gpio_enable_ms(sport->gpios); +} + +static void imx_uart_dma_tx(struct imx_port *sport); + +/* called with port.lock taken and irqs off */ +static inline void imx_uart_transmit_buffer(struct imx_port *sport) +{ + struct circ_buf *xmit = &sport->port.state->xmit; + + if (sport->port.x_char) { + /* Send next char */ + imx_uart_writel(sport, sport->port.x_char, URTX0); + sport->port.icount.tx++; + sport->port.x_char = 0; + return; + } + + if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) { + imx_uart_stop_tx(&sport->port); + return; + } + + if (sport->dma_is_enabled) { + u32 ucr1; + /* + * We've just sent a X-char Ensure the TX DMA is enabled + * and the TX IRQ is disabled. + **/ + ucr1 = imx_uart_readl(sport, UCR1); + ucr1 &= ~UCR1_TRDYEN; + if (sport->dma_is_txing) { + ucr1 |= UCR1_TXDMAEN; + imx_uart_writel(sport, ucr1, UCR1); + } else { + imx_uart_writel(sport, ucr1, UCR1); + imx_uart_dma_tx(sport); + } + + return; + } + + while (!uart_circ_empty(xmit) && + !(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) { + /* send xmit->buf[xmit->tail] + * out the port here */ + imx_uart_writel(sport, xmit->buf[xmit->tail], 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_uart_stop_tx(&sport->port); +} + +static void imx_uart_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; + u32 ucr1; + + spin_lock_irqsave(&sport->port.lock, flags); + + dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); + + ucr1 = imx_uart_readl(sport, UCR1); + ucr1 &= ~UCR1_TXDMAEN; + imx_uart_writel(sport, ucr1, 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; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&sport->port); + + if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port)) + imx_uart_dma_tx(sport); + else if (sport->port.rs485.flags & SER_RS485_ENABLED) { + u32 ucr4 = imx_uart_readl(sport, UCR4); + ucr4 |= UCR4_TCEN; + imx_uart_writel(sport, ucr4, UCR4); + } + + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +/* called with port.lock taken and irqs off */ +static void imx_uart_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; + u32 ucr1, ucr4; + int ret; + + if (sport->dma_is_txing) + return; + + ucr4 = imx_uart_readl(sport, UCR4); + ucr4 &= ~UCR4_TCEN; + imx_uart_writel(sport, ucr4, UCR4); + + sport->tx_bytes = uart_circ_chars_pending(xmit); + + if (xmit->tail < xmit->head || xmit->head == 0) { + 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, ret, + 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 = imx_uart_dma_tx_callback; + desc->callback_param = sport; + + dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n", + uart_circ_chars_pending(xmit)); + + ucr1 = imx_uart_readl(sport, UCR1); + ucr1 |= UCR1_TXDMAEN; + imx_uart_writel(sport, ucr1, UCR1); + + /* fire it */ + sport->dma_is_txing = 1; + dmaengine_submit(desc); + dma_async_issue_pending(chan); + return; +} + +/* called with port.lock taken and irqs off */ +static void imx_uart_start_tx(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + u32 ucr1; + + if (!sport->port.x_char && uart_circ_empty(&port->state->xmit)) + return; + + /* + * We cannot simply do nothing here if sport->tx_state == SEND already + * because UCR1_TXMPTYEN might already have been cleared in + * imx_uart_stop_tx(), but tx_state is still SEND. + */ + + if (port->rs485.flags & SER_RS485_ENABLED) { + if (sport->tx_state == OFF) { + u32 ucr2 = imx_uart_readl(sport, UCR2); + if (port->rs485.flags & SER_RS485_RTS_ON_SEND) + imx_uart_rts_active(sport, &ucr2); + else + imx_uart_rts_inactive(sport, &ucr2); + imx_uart_writel(sport, ucr2, UCR2); + + if (!(port->rs485.flags & SER_RS485_RX_DURING_TX)) + imx_uart_stop_rx(port); + + sport->tx_state = WAIT_AFTER_RTS; + + if (port->rs485.delay_rts_before_send > 0) { + start_hrtimer_ms(&sport->trigger_start_tx, + port->rs485.delay_rts_before_send); + return; + } + + /* continue without any delay */ + } + + if (sport->tx_state == WAIT_AFTER_SEND + || sport->tx_state == WAIT_AFTER_RTS) { + + hrtimer_try_to_cancel(&sport->trigger_stop_tx); + + /* + * Enable transmitter and shifter empty irq only if DMA + * is off. In the DMA case this is done in the + * tx-callback. + */ + if (!sport->dma_is_enabled) { + u32 ucr4 = imx_uart_readl(sport, UCR4); + ucr4 |= UCR4_TCEN; + imx_uart_writel(sport, ucr4, UCR4); + } + + sport->tx_state = SEND; + } + } else { + sport->tx_state = SEND; + } + + if (!sport->dma_is_enabled) { + ucr1 = imx_uart_readl(sport, UCR1); + imx_uart_writel(sport, ucr1 | UCR1_TRDYEN, 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 */ + ucr1 = imx_uart_readl(sport, UCR1); + ucr1 &= ~UCR1_TXDMAEN; + ucr1 |= UCR1_TRDYEN; + imx_uart_writel(sport, ucr1, UCR1); + return; + } + + if (!uart_circ_empty(&port->state->xmit) && + !uart_tx_stopped(port)) + imx_uart_dma_tx(sport); + return; + } +} + +static irqreturn_t __imx_uart_rtsint(int irq, void *dev_id) +{ + struct imx_port *sport = dev_id; + u32 usr1; + + imx_uart_writel(sport, USR1_RTSD, USR1); + usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS; + uart_handle_cts_change(&sport->port, !!usr1); + wake_up_interruptible(&sport->port.state->port.delta_msr_wait); + + return IRQ_HANDLED; +} + +static irqreturn_t imx_uart_rtsint(int irq, void *dev_id) +{ + struct imx_port *sport = dev_id; + irqreturn_t ret; + + spin_lock(&sport->port.lock); + + ret = __imx_uart_rtsint(irq, dev_id); + + spin_unlock(&sport->port.lock); + + return ret; +} + +static irqreturn_t imx_uart_txint(int irq, void *dev_id) +{ + struct imx_port *sport = dev_id; + + spin_lock(&sport->port.lock); + imx_uart_transmit_buffer(sport); + spin_unlock(&sport->port.lock); + return IRQ_HANDLED; +} + +static irqreturn_t __imx_uart_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; + + while (imx_uart_readl(sport, USR2) & USR2_RDR) { + u32 usr2; + + flg = TTY_NORMAL; + sport->port.icount.rx++; + + rx = imx_uart_readl(sport, URXD0); + + usr2 = imx_uart_readl(sport, USR2); + if (usr2 & USR2_BRCD) { + imx_uart_writel(sport, USR2_BRCD, 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; + + sport->port.sysrq = 0; + } + + if (sport->port.ignore_status_mask & URXD_DUMMY_READ) + goto out; + + if (tty_insert_flip_char(port, rx, flg) == 0) + sport->port.icount.buf_overrun++; + } + +out: + tty_flip_buffer_push(port); + + return IRQ_HANDLED; +} + +static irqreturn_t imx_uart_rxint(int irq, void *dev_id) +{ + struct imx_port *sport = dev_id; + irqreturn_t ret; + + spin_lock(&sport->port.lock); + + ret = __imx_uart_rxint(irq, dev_id); + + spin_unlock(&sport->port.lock); + + return ret; +} + +static void imx_uart_clear_rx_errors(struct imx_port *sport); + +/* + * We have a modem side uart, so the meanings of RTS and CTS are inverted. + */ +static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport) +{ + unsigned int tmp = TIOCM_DSR; + unsigned usr1 = imx_uart_readl(sport, USR1); + unsigned usr2 = imx_uart_readl(sport, USR2); + + if (usr1 & USR1_RTSS) + tmp |= TIOCM_CTS; + + /* in DCE mode DCDIN is always 0 */ + if (!(usr2 & USR2_DCDIN)) + tmp |= TIOCM_CAR; + + if (sport->dte_mode) + if (!(imx_uart_readl(sport, USR2) & USR2_RIIN)) + tmp |= TIOCM_RI; + + return tmp; +} + +/* + * Handle any change of modem status signal since we were last called. + */ +static void imx_uart_mctrl_check(struct imx_port *sport) +{ + unsigned int status, changed; + + status = imx_uart_get_hwmctrl(sport); + changed = status ^ sport->old_status; + + if (changed == 0) + return; + + sport->old_status = status; + + if (changed & TIOCM_RI && status & 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); +} + +static irqreturn_t imx_uart_int(int irq, void *dev_id) +{ + struct imx_port *sport = dev_id; + unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4; + irqreturn_t ret = IRQ_NONE; + + spin_lock(&sport->port.lock); + + usr1 = imx_uart_readl(sport, USR1); + usr2 = imx_uart_readl(sport, USR2); + ucr1 = imx_uart_readl(sport, UCR1); + ucr2 = imx_uart_readl(sport, UCR2); + ucr3 = imx_uart_readl(sport, UCR3); + ucr4 = imx_uart_readl(sport, UCR4); + + /* + * Even if a condition is true that can trigger an irq only handle it if + * the respective irq source is enabled. This prevents some undesired + * actions, for example if a character that sits in the RX FIFO and that + * should be fetched via DMA is tried to be fetched using PIO. Or the + * receiver is currently off and so reading from URXD0 results in an + * exception. So just mask the (raw) status bits for disabled irqs. + */ + if ((ucr1 & UCR1_RRDYEN) == 0) + usr1 &= ~USR1_RRDY; + if ((ucr2 & UCR2_ATEN) == 0) + usr1 &= ~USR1_AGTIM; + if ((ucr1 & UCR1_TRDYEN) == 0) + usr1 &= ~USR1_TRDY; + if ((ucr4 & UCR4_TCEN) == 0) + usr2 &= ~USR2_TXDC; + if ((ucr3 & UCR3_DTRDEN) == 0) + usr1 &= ~USR1_DTRD; + if ((ucr1 & UCR1_RTSDEN) == 0) + usr1 &= ~USR1_RTSD; + if ((ucr3 & UCR3_AWAKEN) == 0) + usr1 &= ~USR1_AWAKE; + if ((ucr4 & UCR4_OREN) == 0) + usr2 &= ~USR2_ORE; + + if (usr1 & (USR1_RRDY | USR1_AGTIM)) { + imx_uart_writel(sport, USR1_AGTIM, USR1); + + __imx_uart_rxint(irq, dev_id); + ret = IRQ_HANDLED; + } + + if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) { + imx_uart_transmit_buffer(sport); + ret = IRQ_HANDLED; + } + + if (usr1 & USR1_DTRD) { + imx_uart_writel(sport, USR1_DTRD, USR1); + + imx_uart_mctrl_check(sport); + + ret = IRQ_HANDLED; + } + + if (usr1 & USR1_RTSD) { + __imx_uart_rtsint(irq, dev_id); + ret = IRQ_HANDLED; + } + + if (usr1 & USR1_AWAKE) { + imx_uart_writel(sport, USR1_AWAKE, USR1); + ret = IRQ_HANDLED; + } + + if (usr2 & USR2_ORE) { + sport->port.icount.overrun++; + imx_uart_writel(sport, USR2_ORE, USR2); + ret = IRQ_HANDLED; + } + + spin_unlock(&sport->port.lock); + + return ret; +} + +/* + * Return TIOCSER_TEMT when transmitter is not busy. + */ +static unsigned int imx_uart_tx_empty(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + unsigned int ret; + + ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0; + + /* If the TX DMA is working, return 0. */ + if (sport->dma_is_txing) + ret = 0; + + return ret; +} + +/* called with port.lock taken and irqs off */ +static unsigned int imx_uart_get_mctrl(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + unsigned int ret = imx_uart_get_hwmctrl(sport); + + mctrl_gpio_get(sport->gpios, &ret); + + return ret; +} + +/* called with port.lock taken and irqs off */ +static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + struct imx_port *sport = (struct imx_port *)port; + u32 ucr3, uts; + + if (!(port->rs485.flags & SER_RS485_ENABLED)) { + u32 ucr2; + + /* + * Turn off autoRTS if RTS is lowered and restore autoRTS + * setting if RTS is raised. + */ + ucr2 = imx_uart_readl(sport, UCR2); + ucr2 &= ~(UCR2_CTS | UCR2_CTSC); + if (mctrl & TIOCM_RTS) { + ucr2 |= UCR2_CTS; + /* + * UCR2_IRTS is unset if and only if the port is + * configured for CRTSCTS, so we use inverted UCR2_IRTS + * to get the state to restore to. + */ + if (!(ucr2 & UCR2_IRTS)) + ucr2 |= UCR2_CTSC; + } + imx_uart_writel(sport, ucr2, UCR2); + } + + ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR; + if (!(mctrl & TIOCM_DTR)) + ucr3 |= UCR3_DSR; + imx_uart_writel(sport, ucr3, UCR3); + + uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP; + if (mctrl & TIOCM_LOOP) + uts |= UTS_LOOP; + imx_uart_writel(sport, uts, imx_uart_uts_reg(sport)); + + mctrl_gpio_set(sport->gpios, mctrl); +} + +/* + * Interrupts always disabled. + */ +static void imx_uart_break_ctl(struct uart_port *port, int break_state) +{ + struct imx_port *sport = (struct imx_port *)port; + unsigned long flags; + u32 ucr1; + + spin_lock_irqsave(&sport->port.lock, flags); + + ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK; + + if (break_state != 0) + ucr1 |= UCR1_SNDBRK; + + imx_uart_writel(sport, ucr1, UCR1); + + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +/* + * This is our per-port timeout handler, for checking the + * modem status signals. + */ +static void imx_uart_timeout(struct timer_list *t) +{ + struct imx_port *sport = from_timer(sport, t, timer); + unsigned long flags; + + if (sport->port.state) { + spin_lock_irqsave(&sport->port.lock, flags); + imx_uart_mctrl_check(sport); + spin_unlock_irqrestore(&sport->port.lock, flags); + + mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT); + } +} + +/* + * There are two kinds of RX DMA interrupts(such as in the MX6Q): + * [1] the RX DMA buffer is full. + * [2] the aging timer expires + * + * Condition [2] is triggered when a character has been sitting in the FIFO + * for at least 8 byte durations. + */ +static void imx_uart_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; + struct circ_buf *rx_ring = &sport->rx_ring; + enum dma_status status; + unsigned int w_bytes = 0; + unsigned int r_bytes; + unsigned int bd_size; + + status = dmaengine_tx_status(chan, sport->rx_cookie, &state); + + if (status == DMA_ERROR) { + imx_uart_clear_rx_errors(sport); + return; + } + + if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) { + + /* + * The state-residue variable represents the empty space + * relative to the entire buffer. Taking this in consideration + * the head is always calculated base on the buffer total + * length - DMA transaction residue. The UART script from the + * SDMA firmware will jump to the next buffer descriptor, + * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4). + * Taking this in consideration the tail is always at the + * beginning of the buffer descriptor that contains the head. + */ + + /* Calculate the head */ + rx_ring->head = sg_dma_len(sgl) - state.residue; + + /* Calculate the tail. */ + bd_size = sg_dma_len(sgl) / sport->rx_periods; + rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size; + + if (rx_ring->head <= sg_dma_len(sgl) && + rx_ring->head > rx_ring->tail) { + + /* Move data from tail to head */ + r_bytes = rx_ring->head - rx_ring->tail; + + /* CPU claims ownership of RX DMA buffer */ + dma_sync_sg_for_cpu(sport->port.dev, sgl, 1, + DMA_FROM_DEVICE); + + w_bytes = tty_insert_flip_string(port, + sport->rx_buf + rx_ring->tail, r_bytes); + + /* UART retrieves ownership of RX DMA buffer */ + dma_sync_sg_for_device(sport->port.dev, sgl, 1, + DMA_FROM_DEVICE); + + if (w_bytes != r_bytes) + sport->port.icount.buf_overrun++; + + sport->port.icount.rx += w_bytes; + } else { + WARN_ON(rx_ring->head > sg_dma_len(sgl)); + WARN_ON(rx_ring->head <= rx_ring->tail); + } + } + + if (w_bytes) { + tty_flip_buffer_push(port); + dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes); + } +} + +static int imx_uart_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; + + sport->rx_ring.head = 0; + sport->rx_ring.tail = 0; + + sg_init_one(sgl, sport->rx_buf, sport->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_dma_cyclic(chan, sg_dma_address(sgl), + sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods, + 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 = imx_uart_dma_rx_callback; + desc->callback_param = sport; + + dev_dbg(dev, "RX: prepare for the DMA.\n"); + sport->dma_is_rxing = 1; + sport->rx_cookie = dmaengine_submit(desc); + dma_async_issue_pending(chan); + return 0; +} + +static void imx_uart_clear_rx_errors(struct imx_port *sport) +{ + struct tty_port *port = &sport->port.state->port; + u32 usr1, usr2; + + usr1 = imx_uart_readl(sport, USR1); + usr2 = imx_uart_readl(sport, USR2); + + if (usr2 & USR2_BRCD) { + sport->port.icount.brk++; + imx_uart_writel(sport, USR2_BRCD, USR2); + uart_handle_break(&sport->port); + if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0) + sport->port.icount.buf_overrun++; + tty_flip_buffer_push(port); + } else { + if (usr1 & USR1_FRAMERR) { + sport->port.icount.frame++; + imx_uart_writel(sport, USR1_FRAMERR, USR1); + } else if (usr1 & USR1_PARITYERR) { + sport->port.icount.parity++; + imx_uart_writel(sport, USR1_PARITYERR, USR1); + } + } + + if (usr2 & USR2_ORE) { + sport->port.icount.overrun++; + imx_uart_writel(sport, USR2_ORE, USR2); + } + +} + +#define TXTL_DEFAULT 2 /* reset default */ +#define RXTL_DEFAULT 8 /* 8 characters or aging timer */ +#define TXTL_DMA 8 /* DMA burst setting */ +#define RXTL_DMA 9 /* DMA burst setting */ + +static void imx_uart_setup_ufcr(struct imx_port *sport, + unsigned char txwl, unsigned char rxwl) +{ + unsigned int val; + + /* set receiver / transmitter trigger level */ + val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE); + val |= txwl << UFCR_TXTL_SHF | rxwl; + imx_uart_writel(sport, val, UFCR); +} + +static void imx_uart_dma_exit(struct imx_port *sport) +{ + if (sport->dma_chan_rx) { + dmaengine_terminate_sync(sport->dma_chan_rx); + dma_release_channel(sport->dma_chan_rx); + sport->dma_chan_rx = NULL; + sport->rx_cookie = -EINVAL; + kfree(sport->rx_buf); + sport->rx_buf = NULL; + } + + if (sport->dma_chan_tx) { + dmaengine_terminate_sync(sport->dma_chan_tx); + dma_release_channel(sport->dma_chan_tx); + sport->dma_chan_tx = NULL; + } +} + +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; + /* one byte less than the watermark level to enable the aging timer */ + slave_config.src_maxburst = RXTL_DMA - 1; + 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_size = sport->rx_period_length * sport->rx_periods; + sport->rx_buf = kzalloc(sport->rx_buf_size, GFP_KERNEL); + if (!sport->rx_buf) { + ret = -ENOMEM; + goto err; + } + sport->rx_ring.buf = sport->rx_buf; + + /* 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_DMA; + ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config); + if (ret) { + dev_err(dev, "error in TX dma configuration."); + goto err; + } + + return 0; +err: + imx_uart_dma_exit(sport); + return ret; +} + +static void imx_uart_enable_dma(struct imx_port *sport) +{ + u32 ucr1; + + imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA); + + /* set UCR1 */ + ucr1 = imx_uart_readl(sport, UCR1); + ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN; + imx_uart_writel(sport, ucr1, UCR1); + + sport->dma_is_enabled = 1; +} + +static void imx_uart_disable_dma(struct imx_port *sport) +{ + u32 ucr1; + + /* clear UCR1 */ + ucr1 = imx_uart_readl(sport, UCR1); + ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN); + imx_uart_writel(sport, ucr1, UCR1); + + imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT); + + sport->dma_is_enabled = 0; +} + +/* half the RX buffer size */ +#define CTSTL 16 + +static int imx_uart_startup(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + int retval, i; + unsigned long flags; + int dma_is_inited = 0; + u32 ucr1, ucr2, ucr3, ucr4; + + 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_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT); + + /* disable the DREN bit (Data Ready interrupt enable) before + * requesting IRQs + */ + ucr4 = imx_uart_readl(sport, UCR4); + + /* set the trigger level for CTS */ + ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF); + ucr4 |= CTSTL << UCR4_CTSTL_SHF; + + imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4); + + /* Can we enable the DMA support? */ + if (!uart_console(port) && imx_uart_dma_init(sport) == 0) + dma_is_inited = 1; + + spin_lock_irqsave(&sport->port.lock, flags); + /* Reset fifo's and state machines */ + i = 100; + + ucr2 = imx_uart_readl(sport, UCR2); + ucr2 &= ~UCR2_SRST; + imx_uart_writel(sport, ucr2, UCR2); + + while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0)) + udelay(1); + + /* + * Finally, clear and enable interrupts + */ + imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1); + imx_uart_writel(sport, USR2_ORE, USR2); + + ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN; + ucr1 |= UCR1_UARTEN; + if (sport->have_rtscts) + ucr1 |= UCR1_RTSDEN; + + imx_uart_writel(sport, ucr1, UCR1); + + ucr4 = imx_uart_readl(sport, UCR4) & ~(UCR4_OREN | UCR4_INVR); + if (!dma_is_inited) + ucr4 |= UCR4_OREN; + if (sport->inverted_rx) + ucr4 |= UCR4_INVR; + imx_uart_writel(sport, ucr4, UCR4); + + ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_INVT; + /* + * configure tx polarity before enabling tx + */ + if (sport->inverted_tx) + ucr3 |= UCR3_INVT; + + if (!imx_uart_is_imx1(sport)) { + ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD; + + if (sport->dte_mode) + /* disable broken interrupts */ + ucr3 &= ~(UCR3_RI | UCR3_DCD); + } + imx_uart_writel(sport, ucr3, UCR3); + + ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN; + ucr2 |= (UCR2_RXEN | UCR2_TXEN); + if (!sport->have_rtscts) + ucr2 |= UCR2_IRTS; + /* + * make sure the edge sensitive RTS-irq is disabled, + * we're using RTSD instead. + */ + if (!imx_uart_is_imx1(sport)) + ucr2 &= ~UCR2_RTSEN; + imx_uart_writel(sport, ucr2, UCR2); + + /* + * Enable modem status interrupts + */ + imx_uart_enable_ms(&sport->port); + + if (dma_is_inited) { + imx_uart_enable_dma(sport); + imx_uart_start_rx_dma(sport); + } else { + ucr1 = imx_uart_readl(sport, UCR1); + ucr1 |= UCR1_RRDYEN; + imx_uart_writel(sport, ucr1, UCR1); + + ucr2 = imx_uart_readl(sport, UCR2); + ucr2 |= UCR2_ATEN; + imx_uart_writel(sport, ucr2, UCR2); + } + + imx_uart_disable_loopback_rs485(sport); + + spin_unlock_irqrestore(&sport->port.lock, flags); + + return 0; +} + +static void imx_uart_shutdown(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + unsigned long flags; + u32 ucr1, ucr2, ucr4, uts; + + if (sport->dma_is_enabled) { + dmaengine_terminate_sync(sport->dma_chan_tx); + if (sport->dma_is_txing) { + dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0], + sport->dma_tx_nents, DMA_TO_DEVICE); + sport->dma_is_txing = 0; + } + dmaengine_terminate_sync(sport->dma_chan_rx); + if (sport->dma_is_rxing) { + dma_unmap_sg(sport->port.dev, &sport->rx_sgl, + 1, DMA_FROM_DEVICE); + sport->dma_is_rxing = 0; + } + + spin_lock_irqsave(&sport->port.lock, flags); + imx_uart_stop_tx(port); + imx_uart_stop_rx(port); + imx_uart_disable_dma(sport); + spin_unlock_irqrestore(&sport->port.lock, flags); + imx_uart_dma_exit(sport); + } + + mctrl_gpio_disable_ms(sport->gpios); + + spin_lock_irqsave(&sport->port.lock, flags); + ucr2 = imx_uart_readl(sport, UCR2); + ucr2 &= ~(UCR2_TXEN | UCR2_ATEN); + imx_uart_writel(sport, ucr2, 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); + + ucr1 = imx_uart_readl(sport, UCR1); + ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_RXDMAEN | UCR1_ATDMAEN); + /* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */ + if (port->rs485.flags & SER_RS485_ENABLED && + port->rs485.flags & SER_RS485_RTS_ON_SEND && + sport->have_rtscts && !sport->have_rtsgpio) { + uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)); + uts |= UTS_LOOP; + imx_uart_writel(sport, uts, imx_uart_uts_reg(sport)); + ucr1 |= UCR1_UARTEN; + } else { + ucr1 &= ~UCR1_UARTEN; + } + imx_uart_writel(sport, ucr1, UCR1); + + ucr4 = imx_uart_readl(sport, UCR4); + ucr4 &= ~UCR4_TCEN; + imx_uart_writel(sport, ucr4, UCR4); + + spin_unlock_irqrestore(&sport->port.lock, flags); + + clk_disable_unprepare(sport->clk_per); + clk_disable_unprepare(sport->clk_ipg); +} + +/* called with port.lock taken and irqs off */ +static void imx_uart_flush_buffer(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + struct scatterlist *sgl = &sport->tx_sgl[0]; + u32 ucr2; + 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) { + u32 ucr1; + + dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, + DMA_TO_DEVICE); + ucr1 = imx_uart_readl(sport, UCR1); + ucr1 &= ~UCR1_TXDMAEN; + imx_uart_writel(sport, ucr1, UCR1); + sport->dma_is_txing = 0; + } + + /* + * 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]". + * + * We don't need to restore the old values from USR1, USR2, URXD and + * UTXD. UBRC is read only, so only save/restore the other three + * registers. + */ + ubir = imx_uart_readl(sport, UBIR); + ubmr = imx_uart_readl(sport, UBMR); + uts = imx_uart_readl(sport, IMX21_UTS); + + ucr2 = imx_uart_readl(sport, UCR2); + ucr2 &= ~UCR2_SRST; + imx_uart_writel(sport, ucr2, UCR2); + + while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0)) + udelay(1); + + /* Restore the registers */ + imx_uart_writel(sport, ubir, UBIR); + imx_uart_writel(sport, ubmr, UBMR); + imx_uart_writel(sport, uts, IMX21_UTS); +} + +static void +imx_uart_set_termios(struct uart_port *port, struct ktermios *termios, + const struct ktermios *old) +{ + struct imx_port *sport = (struct imx_port *)port; + unsigned long flags; + u32 ucr2, old_ucr2, ufcr; + unsigned int baud, quot; + unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8; + unsigned long div; + unsigned long num, denom, old_ubir, old_ubmr; + 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; + } + + 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); + + /* + * Read current UCR2 and save it for future use, then clear all the bits + * except those we will or may need to preserve. + */ + old_ucr2 = imx_uart_readl(sport, UCR2); + ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS); + + ucr2 |= UCR2_SRST | UCR2_IRTS; + if ((termios->c_cflag & CSIZE) == CS8) + ucr2 |= UCR2_WS; + + if (!sport->have_rtscts) + termios->c_cflag &= ~CRTSCTS; + + 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) + imx_uart_rts_active(sport, &ucr2); + else + imx_uart_rts_inactive(sport, &ucr2); + + } else if (termios->c_cflag & CRTSCTS) { + /* + * Only let receiver control RTS output if we were not requested + * to have RTS inactive (which then should take precedence). + */ + if (ucr2 & UCR2_CTS) + ucr2 |= UCR2_CTSC; + } + + if (termios->c_cflag & CRTSCTS) + ucr2 &= ~UCR2_IRTS; + if (termios->c_cflag & CSTOPB) + ucr2 |= UCR2_STPB; + if (termios->c_cflag & PARENB) { + ucr2 |= UCR2_PREN; + if (termios->c_cflag & PARODD) + ucr2 |= UCR2_PROE; + } + + 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); + + /* 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 = imx_uart_readl(sport, UFCR); + ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div); + imx_uart_writel(sport, ufcr, UFCR); + + /* + * Two registers below should always be written both and in this + * particular order. One consequence is that we need to check if any of + * them changes and then update both. We do need the check for change + * as even writing the same values seem to "restart" + * transmission/receiving logic in the hardware, that leads to data + * breakage even when rate doesn't in fact change. E.g., user switches + * RTS/CTS handshake and suddenly gets broken bytes. + */ + old_ubir = imx_uart_readl(sport, UBIR); + old_ubmr = imx_uart_readl(sport, UBMR); + if (old_ubir != num || old_ubmr != denom) { + imx_uart_writel(sport, num, UBIR); + imx_uart_writel(sport, denom, UBMR); + } + + if (!imx_uart_is_imx1(sport)) + imx_uart_writel(sport, sport->port.uartclk / div / 1000, + IMX21_ONEMS); + + imx_uart_writel(sport, ucr2, UCR2); + + if (UART_ENABLE_MS(&sport->port, termios->c_cflag)) + imx_uart_enable_ms(&sport->port); + + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +static const char *imx_uart_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_uart_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_uart_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_uart_poll_init(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + unsigned long flags; + u32 ucr1, ucr2; + 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_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT); + + spin_lock_irqsave(&sport->port.lock, flags); + + /* + * Be careful about the order of enabling bits here. First enable the + * receiver (UARTEN + RXEN) and only then the corresponding irqs. + * This prevents that a character that already sits in the RX fifo is + * triggering an irq but the try to fetch it from there results in an + * exception because UARTEN or RXEN is still off. + */ + ucr1 = imx_uart_readl(sport, UCR1); + ucr2 = imx_uart_readl(sport, UCR2); + + if (imx_uart_is_imx1(sport)) + ucr1 |= IMX1_UCR1_UARTCLKEN; + + ucr1 |= UCR1_UARTEN; + ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN); + + ucr2 |= UCR2_RXEN | UCR2_TXEN; + ucr2 &= ~UCR2_ATEN; + + imx_uart_writel(sport, ucr1, UCR1); + imx_uart_writel(sport, ucr2, UCR2); + + /* now enable irqs */ + imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1); + imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2); + + spin_unlock_irqrestore(&sport->port.lock, flags); + + return 0; +} + +static int imx_uart_poll_get_char(struct uart_port *port) +{ + struct imx_port *sport = (struct imx_port *)port; + if (!(imx_uart_readl(sport, USR2) & USR2_RDR)) + return NO_POLL_CHAR; + + return imx_uart_readl(sport, URXD0) & URXD_RX_DATA; +} + +static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c) +{ + struct imx_port *sport = (struct imx_port *)port; + unsigned int status; + + /* drain */ + do { + status = imx_uart_readl(sport, USR1); + } while (~status & USR1_TRDY); + + /* write */ + imx_uart_writel(sport, c, URTX0); + + /* flush */ + do { + status = imx_uart_readl(sport, USR2); + } while (~status & USR2_TXDC); +} +#endif + +/* called with port.lock taken and irqs off or from .probe without locking */ +static int imx_uart_rs485_config(struct uart_port *port, struct ktermios *termios, + struct serial_rs485 *rs485conf) +{ + struct imx_port *sport = (struct imx_port *)port; + u32 ucr2; + + if (rs485conf->flags & SER_RS485_ENABLED) { + /* Enable receiver if low-active RTS signal is requested */ + if (sport->have_rtscts && !sport->have_rtsgpio && + !(rs485conf->flags & SER_RS485_RTS_ON_SEND)) + rs485conf->flags |= SER_RS485_RX_DURING_TX; + + /* disable transmitter */ + ucr2 = imx_uart_readl(sport, UCR2); + if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND) + imx_uart_rts_active(sport, &ucr2); + else + imx_uart_rts_inactive(sport, &ucr2); + imx_uart_writel(sport, ucr2, UCR2); + } + + /* Make sure Rx is enabled in case Tx is active with Rx disabled */ + if (!(rs485conf->flags & SER_RS485_ENABLED) || + rs485conf->flags & SER_RS485_RX_DURING_TX) + imx_uart_start_rx(port); + + return 0; +} + +static const struct uart_ops imx_uart_pops = { + .tx_empty = imx_uart_tx_empty, + .set_mctrl = imx_uart_set_mctrl, + .get_mctrl = imx_uart_get_mctrl, + .stop_tx = imx_uart_stop_tx, + .start_tx = imx_uart_start_tx, + .stop_rx = imx_uart_stop_rx, + .enable_ms = imx_uart_enable_ms, + .break_ctl = imx_uart_break_ctl, + .startup = imx_uart_startup, + .shutdown = imx_uart_shutdown, + .flush_buffer = imx_uart_flush_buffer, + .set_termios = imx_uart_set_termios, + .type = imx_uart_type, + .config_port = imx_uart_config_port, + .verify_port = imx_uart_verify_port, +#if defined(CONFIG_CONSOLE_POLL) + .poll_init = imx_uart_poll_init, + .poll_get_char = imx_uart_poll_get_char, + .poll_put_char = imx_uart_poll_put_char, +#endif +}; + +static struct imx_port *imx_uart_ports[UART_NR]; + +#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE) +static void imx_uart_console_putchar(struct uart_port *port, unsigned char ch) +{ + struct imx_port *sport = (struct imx_port *)port; + + while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL) + barrier(); + + imx_uart_writel(sport, ch, URTX0); +} + +/* + * Interrupts are disabled on entering + */ +static void +imx_uart_console_write(struct console *co, const char *s, unsigned int count) +{ + struct imx_port *sport = imx_uart_ports[co->index]; + struct imx_port_ucrs old_ucr; + unsigned long flags; + unsigned int ucr1; + int locked = 1; + + 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_uart_ucrs_save(sport, &old_ucr); + ucr1 = old_ucr.ucr1; + + if (imx_uart_is_imx1(sport)) + ucr1 |= IMX1_UCR1_UARTCLKEN; + ucr1 |= UCR1_UARTEN; + ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN); + + imx_uart_writel(sport, ucr1, UCR1); + + imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2); + + uart_console_write(&sport->port, s, count, imx_uart_console_putchar); + + /* + * Finally, wait for transmitter to become empty + * and restore UCR1/2/3 + */ + while (!(imx_uart_readl(sport, USR2) & USR2_TXDC)); + + imx_uart_ucrs_restore(sport, &old_ucr); + + if (locked) + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +/* + * If the port was already initialised (eg, by a boot loader), + * try to determine the current setup. + */ +static void +imx_uart_console_get_options(struct imx_port *sport, int *baud, + int *parity, int *bits) +{ + + if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) { + /* ok, the port was enabled */ + unsigned int ucr2, ubir, ubmr, uartclk; + unsigned int baud_raw; + unsigned int ucfr_rfdiv; + + ucr2 = imx_uart_readl(sport, 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 = imx_uart_readl(sport, UBIR) & 0xffff; + ubmr = imx_uart_readl(sport, UBMR) & 0xffff; + + ucfr_rfdiv = (imx_uart_readl(sport, 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) + dev_info(sport->port.dev, "Console IMX rounded baud rate from %d to %d\n", + baud_raw, *baud); + } +} + +static int +imx_uart_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_uart_ports)) + co->index = 0; + sport = imx_uart_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_uart_console_get_options(sport, &baud, &parity, &bits); + + imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT); + + retval = uart_set_options(&sport->port, co, baud, parity, bits, flow); + + if (retval) { + clk_disable_unprepare(sport->clk_ipg); + goto error_console; + } + + retval = clk_prepare_enable(sport->clk_per); + if (retval) + clk_disable_unprepare(sport->clk_ipg); + +error_console: + return retval; +} + +static int +imx_uart_console_exit(struct console *co) +{ + struct imx_port *sport = imx_uart_ports[co->index]; + + clk_disable_unprepare(sport->clk_per); + clk_disable_unprepare(sport->clk_ipg); + + return 0; +} + +static struct uart_driver imx_uart_uart_driver; +static struct console imx_uart_console = { + .name = DEV_NAME, + .write = imx_uart_console_write, + .device = uart_console_device, + .setup = imx_uart_console_setup, + .exit = imx_uart_console_exit, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &imx_uart_uart_driver, +}; + +#define IMX_CONSOLE &imx_uart_console + +#else +#define IMX_CONSOLE NULL +#endif + +static struct uart_driver imx_uart_uart_driver = { + .owner = THIS_MODULE, + .driver_name = DRIVER_NAME, + .dev_name = DEV_NAME, + .major = SERIAL_IMX_MAJOR, + .minor = MINOR_START, + .nr = ARRAY_SIZE(imx_uart_ports), + .cons = IMX_CONSOLE, +}; + +static enum hrtimer_restart imx_trigger_start_tx(struct hrtimer *t) +{ + struct imx_port *sport = container_of(t, struct imx_port, trigger_start_tx); + unsigned long flags; + + spin_lock_irqsave(&sport->port.lock, flags); + if (sport->tx_state == WAIT_AFTER_RTS) + imx_uart_start_tx(&sport->port); + spin_unlock_irqrestore(&sport->port.lock, flags); + + return HRTIMER_NORESTART; +} + +static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t) +{ + struct imx_port *sport = container_of(t, struct imx_port, trigger_stop_tx); + unsigned long flags; + + spin_lock_irqsave(&sport->port.lock, flags); + if (sport->tx_state == WAIT_AFTER_SEND) + imx_uart_stop_tx(&sport->port); + spin_unlock_irqrestore(&sport->port.lock, flags); + + return HRTIMER_NORESTART; +} + +static const struct serial_rs485 imx_rs485_supported = { + .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND | + SER_RS485_RX_DURING_TX, + .delay_rts_before_send = 1, + .delay_rts_after_send = 1, +}; + +/* Default RX DMA buffer configuration */ +#define RX_DMA_PERIODS 16 +#define RX_DMA_PERIOD_LEN (PAGE_SIZE / 4) + +static int imx_uart_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct imx_port *sport; + void __iomem *base; + u32 dma_buf_conf[2]; + int ret = 0; + u32 ucr1, ucr2, uts; + struct resource *res; + int txirq, rxirq, rtsirq; + + sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); + if (!sport) + return -ENOMEM; + + sport->devdata = of_device_get_match_data(&pdev->dev); + + 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, "uart-has-rtscts", NULL) || + of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */) + sport->have_rtscts = 1; + + if (of_get_property(np, "fsl,dte-mode", NULL)) + sport->dte_mode = 1; + + if (of_get_property(np, "rts-gpios", NULL)) + sport->have_rtsgpio = 1; + + if (of_get_property(np, "fsl,inverted-tx", NULL)) + sport->inverted_tx = 1; + + if (of_get_property(np, "fsl,inverted-rx", NULL)) + sport->inverted_rx = 1; + + if (!of_property_read_u32_array(np, "fsl,dma-info", dma_buf_conf, 2)) { + sport->rx_period_length = dma_buf_conf[0]; + sport->rx_periods = dma_buf_conf[1]; + } else { + sport->rx_period_length = RX_DMA_PERIOD_LEN; + sport->rx_periods = RX_DMA_PERIODS; + } + + if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) { + dev_err(&pdev->dev, "serial%d out of range\n", + sport->port.line); + return -EINVAL; + } + + 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); + if (rxirq < 0) + return rxirq; + txirq = platform_get_irq_optional(pdev, 1); + rtsirq = platform_get_irq_optional(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.has_sysrq = IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE); + sport->port.ops = &imx_uart_pops; + sport->port.rs485_config = imx_uart_rs485_config; + /* RTS is required to control the RS485 transmitter */ + if (sport->have_rtscts || sport->have_rtsgpio) + sport->port.rs485_supported = imx_rs485_supported; + sport->port.flags = UPF_BOOT_AUTOCONF; + timer_setup(&sport->timer, imx_uart_timeout, 0); + + sport->gpios = mctrl_gpio_init(&sport->port, 0); + if (IS_ERR(sport->gpios)) + return PTR_ERR(sport->gpios); + + 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); + + /* For register access, we only need to enable the ipg clock. */ + ret = clk_prepare_enable(sport->clk_ipg); + if (ret) { + dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret); + return ret; + } + + /* initialize shadow register values */ + sport->ucr1 = readl(sport->port.membase + UCR1); + sport->ucr2 = readl(sport->port.membase + UCR2); + sport->ucr3 = readl(sport->port.membase + UCR3); + sport->ucr4 = readl(sport->port.membase + UCR4); + sport->ufcr = readl(sport->port.membase + UFCR); + + ret = uart_get_rs485_mode(&sport->port); + if (ret) + goto err_clk; + + /* + * If using the i.MX UART RTS/CTS control then the RTS (CTS_B) + * signal cannot be set low during transmission in case the + * receiver is off (limitation of the i.MX UART IP). + */ + if (sport->port.rs485.flags & SER_RS485_ENABLED && + sport->have_rtscts && !sport->have_rtsgpio && + (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) && + !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX))) + dev_err(&pdev->dev, + "low-active RTS not possible when receiver is off, enabling receiver\n"); + + /* Disable interrupts before requesting them */ + ucr1 = imx_uart_readl(sport, UCR1); + ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN | UCR1_RTSDEN); + imx_uart_writel(sport, ucr1, UCR1); + + /* Disable Ageing Timer interrupt */ + ucr2 = imx_uart_readl(sport, UCR2); + ucr2 &= ~UCR2_ATEN; + imx_uart_writel(sport, ucr2, UCR2); + + /* + * In case RS485 is enabled without GPIO RTS control, the UART IP + * is used to control CTS signal. Keep both the UART and Receiver + * enabled, otherwise the UART IP pulls CTS signal always HIGH no + * matter how the UCR2 CTSC and CTS bits are set. To prevent any + * data from being fed into the RX FIFO, enable loopback mode in + * UTS register, which disconnects the RX path from external RXD + * pin and connects it to the Transceiver, which is disabled, so + * no data can be fed to the RX FIFO that way. + */ + if (sport->port.rs485.flags & SER_RS485_ENABLED && + sport->have_rtscts && !sport->have_rtsgpio) { + uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)); + uts |= UTS_LOOP; + imx_uart_writel(sport, uts, imx_uart_uts_reg(sport)); + + ucr1 = imx_uart_readl(sport, UCR1); + ucr1 |= UCR1_UARTEN; + imx_uart_writel(sport, ucr1, UCR1); + + ucr2 = imx_uart_readl(sport, UCR2); + ucr2 |= UCR2_RXEN; + imx_uart_writel(sport, ucr2, UCR2); + } + + if (!imx_uart_is_imx1(sport) && sport->dte_mode) { + /* + * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI + * and influences if UCR3_RI and UCR3_DCD changes the level of RI + * and DCD (when they are outputs) or enables the respective + * irqs. So set this bit early, i.e. before requesting irqs. + */ + u32 ufcr = imx_uart_readl(sport, UFCR); + if (!(ufcr & UFCR_DCEDTE)) + imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR); + + /* + * Disable UCR3_RI and UCR3_DCD irqs. They are also not + * enabled later because they cannot be cleared + * (confirmed on i.MX25) which makes them unusable. + */ + imx_uart_writel(sport, + IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR, + UCR3); + + } else { + u32 ucr3 = UCR3_DSR; + u32 ufcr = imx_uart_readl(sport, UFCR); + if (ufcr & UFCR_DCEDTE) + imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR); + + if (!imx_uart_is_imx1(sport)) + ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP; + imx_uart_writel(sport, ucr3, UCR3); + } + + hrtimer_init(&sport->trigger_start_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&sport->trigger_stop_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + sport->trigger_start_tx.function = imx_trigger_start_tx; + sport->trigger_stop_tx.function = imx_trigger_stop_tx; + + /* + * 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_uart_rxint, 0, + dev_name(&pdev->dev), sport); + if (ret) { + dev_err(&pdev->dev, "failed to request rx irq: %d\n", + ret); + goto err_clk; + } + + ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0, + dev_name(&pdev->dev), sport); + if (ret) { + dev_err(&pdev->dev, "failed to request tx irq: %d\n", + ret); + goto err_clk; + } + + ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0, + dev_name(&pdev->dev), sport); + if (ret) { + dev_err(&pdev->dev, "failed to request rts irq: %d\n", + ret); + goto err_clk; + } + } else { + ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0, + dev_name(&pdev->dev), sport); + if (ret) { + dev_err(&pdev->dev, "failed to request irq: %d\n", ret); + goto err_clk; + } + } + + imx_uart_ports[sport->port.line] = sport; + + platform_set_drvdata(pdev, sport); + + ret = uart_add_one_port(&imx_uart_uart_driver, &sport->port); + +err_clk: + clk_disable_unprepare(sport->clk_ipg); + + return ret; +} + +static int imx_uart_remove(struct platform_device *pdev) +{ + struct imx_port *sport = platform_get_drvdata(pdev); + + return uart_remove_one_port(&imx_uart_uart_driver, &sport->port); +} + +static void imx_uart_restore_context(struct imx_port *sport) +{ + unsigned long flags; + + spin_lock_irqsave(&sport->port.lock, flags); + if (!sport->context_saved) { + spin_unlock_irqrestore(&sport->port.lock, flags); + return; + } + + imx_uart_writel(sport, sport->saved_reg[4], UFCR); + imx_uart_writel(sport, sport->saved_reg[5], UESC); + imx_uart_writel(sport, sport->saved_reg[6], UTIM); + imx_uart_writel(sport, sport->saved_reg[7], UBIR); + imx_uart_writel(sport, sport->saved_reg[8], UBMR); + imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS); + imx_uart_writel(sport, sport->saved_reg[0], UCR1); + imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2); + imx_uart_writel(sport, sport->saved_reg[2], UCR3); + imx_uart_writel(sport, sport->saved_reg[3], UCR4); + sport->context_saved = false; + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +static void imx_uart_save_context(struct imx_port *sport) +{ + unsigned long flags; + + /* Save necessary regs */ + spin_lock_irqsave(&sport->port.lock, flags); + sport->saved_reg[0] = imx_uart_readl(sport, UCR1); + sport->saved_reg[1] = imx_uart_readl(sport, UCR2); + sport->saved_reg[2] = imx_uart_readl(sport, UCR3); + sport->saved_reg[3] = imx_uart_readl(sport, UCR4); + sport->saved_reg[4] = imx_uart_readl(sport, UFCR); + sport->saved_reg[5] = imx_uart_readl(sport, UESC); + sport->saved_reg[6] = imx_uart_readl(sport, UTIM); + sport->saved_reg[7] = imx_uart_readl(sport, UBIR); + sport->saved_reg[8] = imx_uart_readl(sport, UBMR); + sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS); + sport->context_saved = true; + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +static void imx_uart_enable_wakeup(struct imx_port *sport, bool on) +{ + u32 ucr3; + + ucr3 = imx_uart_readl(sport, UCR3); + if (on) { + imx_uart_writel(sport, USR1_AWAKE, USR1); + ucr3 |= UCR3_AWAKEN; + } else { + ucr3 &= ~UCR3_AWAKEN; + } + imx_uart_writel(sport, ucr3, UCR3); + + if (sport->have_rtscts) { + u32 ucr1 = imx_uart_readl(sport, UCR1); + if (on) { + imx_uart_writel(sport, USR1_RTSD, USR1); + ucr1 |= UCR1_RTSDEN; + } else { + ucr1 &= ~UCR1_RTSDEN; + } + imx_uart_writel(sport, ucr1, UCR1); + } +} + +static int imx_uart_suspend_noirq(struct device *dev) +{ + struct imx_port *sport = dev_get_drvdata(dev); + + imx_uart_save_context(sport); + + clk_disable(sport->clk_ipg); + + pinctrl_pm_select_sleep_state(dev); + + return 0; +} + +static int imx_uart_resume_noirq(struct device *dev) +{ + struct imx_port *sport = dev_get_drvdata(dev); + int ret; + + pinctrl_pm_select_default_state(dev); + + ret = clk_enable(sport->clk_ipg); + if (ret) + return ret; + + imx_uart_restore_context(sport); + + return 0; +} + +static int imx_uart_suspend(struct device *dev) +{ + struct imx_port *sport = dev_get_drvdata(dev); + int ret; + + uart_suspend_port(&imx_uart_uart_driver, &sport->port); + disable_irq(sport->port.irq); + + ret = clk_prepare_enable(sport->clk_ipg); + if (ret) + return ret; + + /* enable wakeup from i.MX UART */ + imx_uart_enable_wakeup(sport, true); + + return 0; +} + +static int imx_uart_resume(struct device *dev) +{ + struct imx_port *sport = dev_get_drvdata(dev); + + /* disable wakeup from i.MX UART */ + imx_uart_enable_wakeup(sport, false); + + uart_resume_port(&imx_uart_uart_driver, &sport->port); + enable_irq(sport->port.irq); + + clk_disable_unprepare(sport->clk_ipg); + + return 0; +} + +static int imx_uart_freeze(struct device *dev) +{ + struct imx_port *sport = dev_get_drvdata(dev); + + uart_suspend_port(&imx_uart_uart_driver, &sport->port); + + return clk_prepare_enable(sport->clk_ipg); +} + +static int imx_uart_thaw(struct device *dev) +{ + struct imx_port *sport = dev_get_drvdata(dev); + + uart_resume_port(&imx_uart_uart_driver, &sport->port); + + clk_disable_unprepare(sport->clk_ipg); + + return 0; +} + +static const struct dev_pm_ops imx_uart_pm_ops = { + .suspend_noirq = imx_uart_suspend_noirq, + .resume_noirq = imx_uart_resume_noirq, + .freeze_noirq = imx_uart_suspend_noirq, + .thaw_noirq = imx_uart_resume_noirq, + .restore_noirq = imx_uart_resume_noirq, + .suspend = imx_uart_suspend, + .resume = imx_uart_resume, + .freeze = imx_uart_freeze, + .thaw = imx_uart_thaw, + .restore = imx_uart_thaw, +}; + +static struct platform_driver imx_uart_platform_driver = { + .probe = imx_uart_probe, + .remove = imx_uart_remove, + + .driver = { + .name = "imx-uart", + .of_match_table = imx_uart_dt_ids, + .pm = &imx_uart_pm_ops, + }, +}; + +static int __init imx_uart_init(void) +{ + int ret = uart_register_driver(&imx_uart_uart_driver); + + if (ret) + return ret; + + ret = platform_driver_register(&imx_uart_platform_driver); + if (ret != 0) + uart_unregister_driver(&imx_uart_uart_driver); + + return ret; +} + +static void __exit imx_uart_exit(void) +{ + platform_driver_unregister(&imx_uart_platform_driver); + uart_unregister_driver(&imx_uart_uart_driver); +} + +module_init(imx_uart_init); +module_exit(imx_uart_exit); + +MODULE_AUTHOR("Sascha Hauer"); +MODULE_DESCRIPTION("IMX generic serial port driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:imx-uart"); |