/* * SC16IS7xx tty serial driver - Copyright (C) 2014 GridPoint * Author: Jon Ringle * * Based on max310x.c, by Alexander Shiyan * * 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. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define SC16IS7XX_NAME "sc16is7xx" /* SC16IS7XX register definitions */ #define SC16IS7XX_RHR_REG (0x00) /* RX FIFO */ #define SC16IS7XX_THR_REG (0x00) /* TX FIFO */ #define SC16IS7XX_IER_REG (0x01) /* Interrupt enable */ #define SC16IS7XX_IIR_REG (0x02) /* Interrupt Identification */ #define SC16IS7XX_FCR_REG (0x02) /* FIFO control */ #define SC16IS7XX_LCR_REG (0x03) /* Line Control */ #define SC16IS7XX_MCR_REG (0x04) /* Modem Control */ #define SC16IS7XX_LSR_REG (0x05) /* Line Status */ #define SC16IS7XX_MSR_REG (0x06) /* Modem Status */ #define SC16IS7XX_SPR_REG (0x07) /* Scratch Pad */ #define SC16IS7XX_TXLVL_REG (0x08) /* TX FIFO level */ #define SC16IS7XX_RXLVL_REG (0x09) /* RX FIFO level */ #define SC16IS7XX_IODIR_REG (0x0a) /* I/O Direction * - only on 75x/76x */ #define SC16IS7XX_IOSTATE_REG (0x0b) /* I/O State * - only on 75x/76x */ #define SC16IS7XX_IOINTENA_REG (0x0c) /* I/O Interrupt Enable * - only on 75x/76x */ #define SC16IS7XX_IOCONTROL_REG (0x0e) /* I/O Control * - only on 75x/76x */ #define SC16IS7XX_EFCR_REG (0x0f) /* Extra Features Control */ /* TCR/TLR Register set: Only if ((MCR[2] == 1) && (EFR[4] == 1)) */ #define SC16IS7XX_TCR_REG (0x06) /* Transmit control */ #define SC16IS7XX_TLR_REG (0x07) /* Trigger level */ /* Special Register set: Only if ((LCR[7] == 1) && (LCR != 0xBF)) */ #define SC16IS7XX_DLL_REG (0x00) /* Divisor Latch Low */ #define SC16IS7XX_DLH_REG (0x01) /* Divisor Latch High */ /* Enhanced Register set: Only if (LCR == 0xBF) */ #define SC16IS7XX_EFR_REG (0x02) /* Enhanced Features */ #define SC16IS7XX_XON1_REG (0x04) /* Xon1 word */ #define SC16IS7XX_XON2_REG (0x05) /* Xon2 word */ #define SC16IS7XX_XOFF1_REG (0x06) /* Xoff1 word */ #define SC16IS7XX_XOFF2_REG (0x07) /* Xoff2 word */ /* IER register bits */ #define SC16IS7XX_IER_RDI_BIT (1 << 0) /* Enable RX data interrupt */ #define SC16IS7XX_IER_THRI_BIT (1 << 1) /* Enable TX holding register * interrupt */ #define SC16IS7XX_IER_RLSI_BIT (1 << 2) /* Enable RX line status * interrupt */ #define SC16IS7XX_IER_MSI_BIT (1 << 3) /* Enable Modem status * interrupt */ /* IER register bits - write only if (EFR[4] == 1) */ #define SC16IS7XX_IER_SLEEP_BIT (1 << 4) /* Enable Sleep mode */ #define SC16IS7XX_IER_XOFFI_BIT (1 << 5) /* Enable Xoff interrupt */ #define SC16IS7XX_IER_RTSI_BIT (1 << 6) /* Enable nRTS interrupt */ #define SC16IS7XX_IER_CTSI_BIT (1 << 7) /* Enable nCTS interrupt */ /* FCR register bits */ #define SC16IS7XX_FCR_FIFO_BIT (1 << 0) /* Enable FIFO */ #define SC16IS7XX_FCR_RXRESET_BIT (1 << 1) /* Reset RX FIFO */ #define SC16IS7XX_FCR_TXRESET_BIT (1 << 2) /* Reset TX FIFO */ #define SC16IS7XX_FCR_RXLVLL_BIT (1 << 6) /* RX Trigger level LSB */ #define SC16IS7XX_FCR_RXLVLH_BIT (1 << 7) /* RX Trigger level MSB */ /* FCR register bits - write only if (EFR[4] == 1) */ #define SC16IS7XX_FCR_TXLVLL_BIT (1 << 4) /* TX Trigger level LSB */ #define SC16IS7XX_FCR_TXLVLH_BIT (1 << 5) /* TX Trigger level MSB */ /* IIR register bits */ #define SC16IS7XX_IIR_NO_INT_BIT (1 << 0) /* No interrupts pending */ #define SC16IS7XX_IIR_ID_MASK 0x3e /* Mask for the interrupt ID */ #define SC16IS7XX_IIR_THRI_SRC 0x02 /* TX holding register empty */ #define SC16IS7XX_IIR_RDI_SRC 0x04 /* RX data interrupt */ #define SC16IS7XX_IIR_RLSE_SRC 0x06 /* RX line status error */ #define SC16IS7XX_IIR_RTOI_SRC 0x0c /* RX time-out interrupt */ #define SC16IS7XX_IIR_MSI_SRC 0x00 /* Modem status interrupt * - only on 75x/76x */ #define SC16IS7XX_IIR_INPIN_SRC 0x30 /* Input pin change of state * - only on 75x/76x */ #define SC16IS7XX_IIR_XOFFI_SRC 0x10 /* Received Xoff */ #define SC16IS7XX_IIR_CTSRTS_SRC 0x20 /* nCTS,nRTS change of state * from active (LOW) * to inactive (HIGH) */ /* LCR register bits */ #define SC16IS7XX_LCR_LENGTH0_BIT (1 << 0) /* Word length bit 0 */ #define SC16IS7XX_LCR_LENGTH1_BIT (1 << 1) /* Word length bit 1 * * Word length bits table: * 00 -> 5 bit words * 01 -> 6 bit words * 10 -> 7 bit words * 11 -> 8 bit words */ #define SC16IS7XX_LCR_STOPLEN_BIT (1 << 2) /* STOP length bit * * STOP length bit table: * 0 -> 1 stop bit * 1 -> 1-1.5 stop bits if * word length is 5, * 2 stop bits otherwise */ #define SC16IS7XX_LCR_PARITY_BIT (1 << 3) /* Parity bit enable */ #define SC16IS7XX_LCR_EVENPARITY_BIT (1 << 4) /* Even parity bit enable */ #define SC16IS7XX_LCR_FORCEPARITY_BIT (1 << 5) /* 9-bit multidrop parity */ #define SC16IS7XX_LCR_TXBREAK_BIT (1 << 6) /* TX break enable */ #define SC16IS7XX_LCR_DLAB_BIT (1 << 7) /* Divisor Latch enable */ #define SC16IS7XX_LCR_WORD_LEN_5 (0x00) #define SC16IS7XX_LCR_WORD_LEN_6 (0x01) #define SC16IS7XX_LCR_WORD_LEN_7 (0x02) #define SC16IS7XX_LCR_WORD_LEN_8 (0x03) #define SC16IS7XX_LCR_CONF_MODE_A SC16IS7XX_LCR_DLAB_BIT /* Special * reg set */ #define SC16IS7XX_LCR_CONF_MODE_B 0xBF /* Enhanced * reg set */ /* MCR register bits */ #define SC16IS7XX_MCR_DTR_BIT (1 << 0) /* DTR complement * - only on 75x/76x */ #define SC16IS7XX_MCR_RTS_BIT (1 << 1) /* RTS complement */ #define SC16IS7XX_MCR_TCRTLR_BIT (1 << 2) /* TCR/TLR register enable */ #define SC16IS7XX_MCR_LOOP_BIT (1 << 4) /* Enable loopback test mode */ #define SC16IS7XX_MCR_XONANY_BIT (1 << 5) /* Enable Xon Any * - write enabled * if (EFR[4] == 1) */ #define SC16IS7XX_MCR_IRDA_BIT (1 << 6) /* Enable IrDA mode * - write enabled * if (EFR[4] == 1) */ #define SC16IS7XX_MCR_CLKSEL_BIT (1 << 7) /* Divide clock by 4 * - write enabled * if (EFR[4] == 1) */ /* LSR register bits */ #define SC16IS7XX_LSR_DR_BIT (1 << 0) /* Receiver data ready */ #define SC16IS7XX_LSR_OE_BIT (1 << 1) /* Overrun Error */ #define SC16IS7XX_LSR_PE_BIT (1 << 2) /* Parity Error */ #define SC16IS7XX_LSR_FE_BIT (1 << 3) /* Frame Error */ #define SC16IS7XX_LSR_BI_BIT (1 << 4) /* Break Interrupt */ #define SC16IS7XX_LSR_BRK_ERROR_MASK 0x1E /* BI, FE, PE, OE bits */ #define SC16IS7XX_LSR_THRE_BIT (1 << 5) /* TX holding register empty */ #define SC16IS7XX_LSR_TEMT_BIT (1 << 6) /* Transmitter empty */ #define SC16IS7XX_LSR_FIFOE_BIT (1 << 7) /* Fifo Error */ /* MSR register bits */ #define SC16IS7XX_MSR_DCTS_BIT (1 << 0) /* Delta CTS Clear To Send */ #define SC16IS7XX_MSR_DDSR_BIT (1 << 1) /* Delta DSR Data Set Ready * or (IO4) * - only on 75x/76x */ #define SC16IS7XX_MSR_DRI_BIT (1 << 2) /* Delta RI Ring Indicator * or (IO7) * - only on 75x/76x */ #define SC16IS7XX_MSR_DCD_BIT (1 << 3) /* Delta CD Carrier Detect * or (IO6) * - only on 75x/76x */ #define SC16IS7XX_MSR_CTS_BIT (1 << 0) /* CTS */ #define SC16IS7XX_MSR_DSR_BIT (1 << 1) /* DSR (IO4) * - only on 75x/76x */ #define SC16IS7XX_MSR_RI_BIT (1 << 2) /* RI (IO7) * - only on 75x/76x */ #define SC16IS7XX_MSR_CD_BIT (1 << 3) /* CD (IO6) * - only on 75x/76x */ #define SC16IS7XX_MSR_DELTA_MASK 0x0F /* Any of the delta bits! */ /* * TCR register bits * TCR trigger levels are available from 0 to 60 characters with a granularity * of four. * The programmer must program the TCR such that TCR[3:0] > TCR[7:4]. There is * no built-in hardware check to make sure this condition is met. Also, the TCR * must be programmed with this condition before auto RTS or software flow * control is enabled to avoid spurious operation of the device. */ #define SC16IS7XX_TCR_RX_HALT(words) ((((words) / 4) & 0x0f) << 0) #define SC16IS7XX_TCR_RX_RESUME(words) ((((words) / 4) & 0x0f) << 4) /* * TLR register bits * If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the * FIFO Control Register (FCR) are used for the transmit and receive FIFO * trigger levels. Trigger levels from 4 characters to 60 characters are * available with a granularity of four. * * When the trigger level setting in TLR is zero, the SC16IS740/750/760 uses the * trigger level setting defined in FCR. If TLR has non-zero trigger level value * the trigger level defined in FCR is discarded. This applies to both transmit * FIFO and receive FIFO trigger level setting. * * When TLR is used for RX trigger level control, FCR[7:6] should be left at the * default state, that is, '00'. */ #define SC16IS7XX_TLR_TX_TRIGGER(words) ((((words) / 4) & 0x0f) << 0) #define SC16IS7XX_TLR_RX_TRIGGER(words) ((((words) / 4) & 0x0f) << 4) /* IOControl register bits (Only 750/760) */ #define SC16IS7XX_IOCONTROL_LATCH_BIT (1 << 0) /* Enable input latching */ #define SC16IS7XX_IOCONTROL_GPIO_BIT (1 << 1) /* Enable GPIO[7:4] */ #define SC16IS7XX_IOCONTROL_SRESET_BIT (1 << 3) /* Software Reset */ /* EFCR register bits */ #define SC16IS7XX_EFCR_9BIT_MODE_BIT (1 << 0) /* Enable 9-bit or Multidrop * mode (RS485) */ #define SC16IS7XX_EFCR_RXDISABLE_BIT (1 << 1) /* Disable receiver */ #define SC16IS7XX_EFCR_TXDISABLE_BIT (1 << 2) /* Disable transmitter */ #define SC16IS7XX_EFCR_AUTO_RS485_BIT (1 << 4) /* Auto RS485 RTS direction */ #define SC16IS7XX_EFCR_RTS_INVERT_BIT (1 << 5) /* RTS output inversion */ #define SC16IS7XX_EFCR_IRDA_MODE_BIT (1 << 7) /* IrDA mode * 0 = rate upto 115.2 kbit/s * - Only 750/760 * 1 = rate upto 1.152 Mbit/s * - Only 760 */ /* EFR register bits */ #define SC16IS7XX_EFR_AUTORTS_BIT (1 << 6) /* Auto RTS flow ctrl enable */ #define SC16IS7XX_EFR_AUTOCTS_BIT (1 << 7) /* Auto CTS flow ctrl enable */ #define SC16IS7XX_EFR_XOFF2_DETECT_BIT (1 << 5) /* Enable Xoff2 detection */ #define SC16IS7XX_EFR_ENABLE_BIT (1 << 4) /* Enable enhanced functions * and writing to IER[7:4], * FCR[5:4], MCR[7:5] */ #define SC16IS7XX_EFR_SWFLOW3_BIT (1 << 3) /* SWFLOW bit 3 */ #define SC16IS7XX_EFR_SWFLOW2_BIT (1 << 2) /* SWFLOW bit 2 * * SWFLOW bits 3 & 2 table: * 00 -> no transmitter flow * control * 01 -> transmitter generates * XON2 and XOFF2 * 10 -> transmitter generates * XON1 and XOFF1 * 11 -> transmitter generates * XON1, XON2, XOFF1 and * XOFF2 */ #define SC16IS7XX_EFR_SWFLOW1_BIT (1 << 1) /* SWFLOW bit 2 */ #define SC16IS7XX_EFR_SWFLOW0_BIT (1 << 0) /* SWFLOW bit 3 * * SWFLOW bits 3 & 2 table: * 00 -> no received flow * control * 01 -> receiver compares * XON2 and XOFF2 * 10 -> receiver compares * XON1 and XOFF1 * 11 -> receiver compares * XON1, XON2, XOFF1 and * XOFF2 */ /* Misc definitions */ #define SC16IS7XX_FIFO_SIZE (64) #define SC16IS7XX_REG_SHIFT 2 struct sc16is7xx_devtype { char name[10]; int nr_gpio; int nr_uart; }; struct sc16is7xx_one { struct uart_port port; struct work_struct tx_work; struct work_struct md_work; }; struct sc16is7xx_port { struct uart_driver uart; struct sc16is7xx_devtype *devtype; struct regmap *regmap; struct mutex mutex; struct clk *clk; #ifdef CONFIG_GPIOLIB struct gpio_chip gpio; #endif unsigned char buf[SC16IS7XX_FIFO_SIZE]; struct sc16is7xx_one p[0]; }; #define to_sc16is7xx_one(p,e) ((container_of((p), struct sc16is7xx_one, e))) static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); unsigned int val = 0; regmap_read(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | port->line, &val); return val; } static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); regmap_write(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | port->line, val); } static void sc16is7xx_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); regmap_update_bits(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | port->line, mask, val); } static void sc16is7xx_power(struct uart_port *port, int on) { sc16is7xx_port_update(port, SC16IS7XX_IER_REG, SC16IS7XX_IER_SLEEP_BIT, on ? 0 : SC16IS7XX_IER_SLEEP_BIT); } static const struct sc16is7xx_devtype sc16is74x_devtype = { .name = "SC16IS74X", .nr_gpio = 0, .nr_uart = 1, }; static const struct sc16is7xx_devtype sc16is750_devtype = { .name = "SC16IS750", .nr_gpio = 8, .nr_uart = 1, }; static const struct sc16is7xx_devtype sc16is752_devtype = { .name = "SC16IS752", .nr_gpio = 8, .nr_uart = 2, }; static const struct sc16is7xx_devtype sc16is760_devtype = { .name = "SC16IS760", .nr_gpio = 8, .nr_uart = 1, }; static const struct sc16is7xx_devtype sc16is762_devtype = { .name = "SC16IS762", .nr_gpio = 8, .nr_uart = 2, }; static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg) { switch (reg >> SC16IS7XX_REG_SHIFT) { case SC16IS7XX_RHR_REG: case SC16IS7XX_IIR_REG: case SC16IS7XX_LSR_REG: case SC16IS7XX_MSR_REG: case SC16IS7XX_TXLVL_REG: case SC16IS7XX_RXLVL_REG: case SC16IS7XX_IOSTATE_REG: return true; default: break; } return false; } static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg) { switch (reg >> SC16IS7XX_REG_SHIFT) { case SC16IS7XX_RHR_REG: return true; default: break; } return false; } static int sc16is7xx_set_baud(struct uart_port *port, int baud) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); u8 lcr; u8 prescaler = 0; unsigned long clk = port->uartclk, div = clk / 16 / baud; if (div > 0xffff) { prescaler = SC16IS7XX_MCR_CLKSEL_BIT; div /= 4; } lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG); /* Open the LCR divisors for configuration */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_B); /* Enable enhanced features */ regcache_cache_bypass(s->regmap, true); sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, SC16IS7XX_EFR_ENABLE_BIT); regcache_cache_bypass(s->regmap, false); /* Put LCR back to the normal mode */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_CLKSEL_BIT, prescaler); /* Open the LCR divisors for configuration */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_A); /* Write the new divisor */ regcache_cache_bypass(s->regmap, true); sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256); sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256); regcache_cache_bypass(s->regmap, false); /* Put LCR back to the normal mode */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); return DIV_ROUND_CLOSEST(clk / 16, div); } static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen, unsigned int iir) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); unsigned int lsr = 0, ch, flag, bytes_read, i; bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false; if (unlikely(rxlen >= sizeof(s->buf))) { dev_warn_ratelimited(port->dev, "Port %i: Possible RX FIFO overrun: %d\n", port->line, rxlen); port->icount.buf_overrun++; /* Ensure sanity of RX level */ rxlen = sizeof(s->buf); } while (rxlen) { /* Only read lsr if there are possible errors in FIFO */ if (read_lsr) { lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG); if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT)) read_lsr = false; /* No errors left in FIFO */ } else lsr = 0; if (read_lsr) { s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG); bytes_read = 1; } else { regcache_cache_bypass(s->regmap, true); regmap_raw_read(s->regmap, SC16IS7XX_RHR_REG, s->buf, rxlen); regcache_cache_bypass(s->regmap, false); bytes_read = rxlen; } lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK; port->icount.rx++; flag = TTY_NORMAL; if (unlikely(lsr)) { if (lsr & SC16IS7XX_LSR_BI_BIT) { port->icount.brk++; if (uart_handle_break(port)) continue; } else if (lsr & SC16IS7XX_LSR_PE_BIT) port->icount.parity++; else if (lsr & SC16IS7XX_LSR_FE_BIT) port->icount.frame++; else if (lsr & SC16IS7XX_LSR_OE_BIT) port->icount.overrun++; lsr &= port->read_status_mask; if (lsr & SC16IS7XX_LSR_BI_BIT) flag = TTY_BREAK; else if (lsr & SC16IS7XX_LSR_PE_BIT) flag = TTY_PARITY; else if (lsr & SC16IS7XX_LSR_FE_BIT) flag = TTY_FRAME; else if (lsr & SC16IS7XX_LSR_OE_BIT) flag = TTY_OVERRUN; } for (i = 0; i < bytes_read; ++i) { ch = s->buf[i]; if (uart_handle_sysrq_char(port, ch)) continue; if (lsr & port->ignore_status_mask) continue; uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch, flag); } rxlen -= bytes_read; } tty_flip_buffer_push(&port->state->port); } static void sc16is7xx_handle_tx(struct uart_port *port) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); struct circ_buf *xmit = &port->state->xmit; unsigned int txlen, to_send, i; if (unlikely(port->x_char)) { sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char); port->icount.tx++; port->x_char = 0; return; } if (uart_circ_empty(xmit) || uart_tx_stopped(port)) return; /* Get length of data pending in circular buffer */ to_send = uart_circ_chars_pending(xmit); if (likely(to_send)) { /* Limit to size of TX FIFO */ txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG); to_send = (to_send > txlen) ? txlen : to_send; /* Add data to send */ port->icount.tx += to_send; /* Convert to linear buffer */ for (i = 0; i < to_send; ++i) { s->buf[i] = xmit->buf[xmit->tail]; xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); } regcache_cache_bypass(s->regmap, true); regmap_raw_write(s->regmap, SC16IS7XX_THR_REG, s->buf, to_send); regcache_cache_bypass(s->regmap, false); } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); } static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno) { struct uart_port *port = &s->p[portno].port; do { unsigned int iir, msr, rxlen; iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG); if (iir & SC16IS7XX_IIR_NO_INT_BIT) break; iir &= SC16IS7XX_IIR_ID_MASK; switch (iir) { case SC16IS7XX_IIR_RDI_SRC: case SC16IS7XX_IIR_RLSE_SRC: case SC16IS7XX_IIR_RTOI_SRC: case SC16IS7XX_IIR_XOFFI_SRC: rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG); if (rxlen) sc16is7xx_handle_rx(port, rxlen, iir); break; case SC16IS7XX_IIR_CTSRTS_SRC: msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG); uart_handle_cts_change(port, !!(msr & SC16IS7XX_MSR_CTS_BIT)); break; case SC16IS7XX_IIR_THRI_SRC: mutex_lock(&s->mutex); sc16is7xx_handle_tx(port); mutex_unlock(&s->mutex); break; default: dev_err_ratelimited(port->dev, "Port %i: Unexpected interrupt: %x", port->line, iir); break; } } while (1); } static irqreturn_t sc16is7xx_ist(int irq, void *dev_id) { struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id; int i; for (i = 0; i < s->uart.nr; ++i) sc16is7xx_port_irq(s, i); return IRQ_HANDLED; } static void sc16is7xx_wq_proc(struct work_struct *ws) { struct sc16is7xx_one *one = to_sc16is7xx_one(ws, tx_work); struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev); mutex_lock(&s->mutex); sc16is7xx_handle_tx(&one->port); mutex_unlock(&s->mutex); } static void sc16is7xx_stop_tx(struct uart_port* port) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); struct circ_buf *xmit = &one->port.state->xmit; /* handle rs485 */ if (port->rs485.flags & SER_RS485_ENABLED) { /* do nothing if current tx not yet completed */ int lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG); if (!(lsr & SC16IS7XX_LSR_TEMT_BIT)) return; if (uart_circ_empty(xmit) && (port->rs485.delay_rts_after_send > 0)) mdelay(port->rs485.delay_rts_after_send); } sc16is7xx_port_update(port, SC16IS7XX_IER_REG, SC16IS7XX_IER_THRI_BIT, 0); } static void sc16is7xx_stop_rx(struct uart_port* port) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); one->port.read_status_mask &= ~SC16IS7XX_LSR_DR_BIT; sc16is7xx_port_update(port, SC16IS7XX_IER_REG, SC16IS7XX_LSR_DR_BIT, 0); } static void sc16is7xx_start_tx(struct uart_port *port) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); /* handle rs485 */ if ((port->rs485.flags & SER_RS485_ENABLED) && (port->rs485.delay_rts_before_send > 0)) { mdelay(port->rs485.delay_rts_before_send); } if (!work_pending(&one->tx_work)) schedule_work(&one->tx_work); } static unsigned int sc16is7xx_tx_empty(struct uart_port *port) { unsigned int lvl, lsr; lvl = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG); lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG); return ((lsr & SC16IS7XX_LSR_THRE_BIT) && !lvl) ? TIOCSER_TEMT : 0; } static unsigned int sc16is7xx_get_mctrl(struct uart_port *port) { /* DCD and DSR are not wired and CTS/RTS is handled automatically * so just indicate DSR and CAR asserted */ return TIOCM_DSR | TIOCM_CAR; } static void sc16is7xx_md_proc(struct work_struct *ws) { struct sc16is7xx_one *one = to_sc16is7xx_one(ws, md_work); sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_LOOP_BIT, (one->port.mctrl & TIOCM_LOOP) ? SC16IS7XX_MCR_LOOP_BIT : 0); } static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); schedule_work(&one->md_work); } static void sc16is7xx_break_ctl(struct uart_port *port, int break_state) { sc16is7xx_port_update(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_TXBREAK_BIT, break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0); } static void sc16is7xx_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); unsigned int lcr, flow = 0; int baud; /* Mask termios capabilities we don't support */ termios->c_cflag &= ~CMSPAR; /* Word size */ switch (termios->c_cflag & CSIZE) { case CS5: lcr = SC16IS7XX_LCR_WORD_LEN_5; break; case CS6: lcr = SC16IS7XX_LCR_WORD_LEN_6; break; case CS7: lcr = SC16IS7XX_LCR_WORD_LEN_7; break; case CS8: lcr = SC16IS7XX_LCR_WORD_LEN_8; break; default: lcr = SC16IS7XX_LCR_WORD_LEN_8; termios->c_cflag &= ~CSIZE; termios->c_cflag |= CS8; break; } /* Parity */ if (termios->c_cflag & PARENB) { lcr |= SC16IS7XX_LCR_PARITY_BIT; if (!(termios->c_cflag & PARODD)) lcr |= SC16IS7XX_LCR_EVENPARITY_BIT; } /* Stop bits */ if (termios->c_cflag & CSTOPB) lcr |= SC16IS7XX_LCR_STOPLEN_BIT; /* 2 stops */ /* Set read status mask */ port->read_status_mask = SC16IS7XX_LSR_OE_BIT; if (termios->c_iflag & INPCK) port->read_status_mask |= SC16IS7XX_LSR_PE_BIT | SC16IS7XX_LSR_FE_BIT; if (termios->c_iflag & (BRKINT | PARMRK)) port->read_status_mask |= SC16IS7XX_LSR_BI_BIT; /* Set status ignore mask */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNBRK) port->ignore_status_mask |= SC16IS7XX_LSR_BI_BIT; if (!(termios->c_cflag & CREAD)) port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK; sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_B); /* Configure flow control */ regcache_cache_bypass(s->regmap, true); sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]); sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]); if (termios->c_cflag & CRTSCTS) flow |= SC16IS7XX_EFR_AUTOCTS_BIT | SC16IS7XX_EFR_AUTORTS_BIT; if (termios->c_iflag & IXON) flow |= SC16IS7XX_EFR_SWFLOW3_BIT; if (termios->c_iflag & IXOFF) flow |= SC16IS7XX_EFR_SWFLOW1_BIT; sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, flow); regcache_cache_bypass(s->regmap, false); /* Update LCR register */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); /* Get baud rate generator configuration */ baud = uart_get_baud_rate(port, termios, old, port->uartclk / 16 / 4 / 0xffff, port->uartclk / 16); /* Setup baudrate generator */ baud = sc16is7xx_set_baud(port, baud); /* Update timeout according to new baud rate */ uart_update_timeout(port, termios->c_cflag, baud); } static int sc16is7xx_config_rs485(struct uart_port *port, struct serial_rs485 *rs485) { if (port->rs485.flags & SER_RS485_ENABLED) sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, SC16IS7XX_EFCR_AUTO_RS485_BIT, SC16IS7XX_EFCR_AUTO_RS485_BIT); else sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, SC16IS7XX_EFCR_AUTO_RS485_BIT, 0); port->rs485 = *rs485; return 0; } static int sc16is7xx_startup(struct uart_port *port) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); unsigned int val; sc16is7xx_power(port, 1); /* Reset FIFOs*/ val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT; sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val); udelay(5); sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, SC16IS7XX_FCR_FIFO_BIT); /* Enable EFR */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_B); regcache_cache_bypass(s->regmap, true); /* Enable write access to enhanced features and internal clock div */ sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, SC16IS7XX_EFR_ENABLE_BIT); /* Enable TCR/TLR */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_TCRTLR_BIT, SC16IS7XX_MCR_TCRTLR_BIT); /* Configure flow control levels */ /* Flow control halt level 48, resume level 24 */ sc16is7xx_port_write(port, SC16IS7XX_TCR_REG, SC16IS7XX_TCR_RX_RESUME(24) | SC16IS7XX_TCR_RX_HALT(48)); regcache_cache_bypass(s->regmap, false); /* Now, initialize the UART */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8); /* Enable the Rx and Tx FIFO */ sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, SC16IS7XX_EFCR_RXDISABLE_BIT | SC16IS7XX_EFCR_TXDISABLE_BIT, 0); /* Enable RX, TX, CTS change interrupts */ val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_THRI_BIT | SC16IS7XX_IER_CTSI_BIT; sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val); return 0; } static void sc16is7xx_shutdown(struct uart_port *port) { /* Disable all interrupts */ sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0); /* Disable TX/RX */ sc16is7xx_port_write(port, SC16IS7XX_EFCR_REG, SC16IS7XX_EFCR_RXDISABLE_BIT | SC16IS7XX_EFCR_TXDISABLE_BIT); sc16is7xx_power(port, 0); } static const char *sc16is7xx_type(struct uart_port *port) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL; } static int sc16is7xx_request_port(struct uart_port *port) { /* Do nothing */ return 0; } static void sc16is7xx_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) port->type = PORT_SC16IS7XX; } static int sc16is7xx_verify_port(struct uart_port *port, struct serial_struct *s) { if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX)) return -EINVAL; if (s->irq != port->irq) return -EINVAL; return 0; } static void sc16is7xx_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0); } static void sc16is7xx_null_void(struct uart_port *port) { /* Do nothing */ } static const struct uart_ops sc16is7xx_ops = { .tx_empty = sc16is7xx_tx_empty, .set_mctrl = sc16is7xx_set_mctrl, .get_mctrl = sc16is7xx_get_mctrl, .stop_tx = sc16is7xx_stop_tx, .start_tx = sc16is7xx_start_tx, .stop_rx = sc16is7xx_stop_rx, .break_ctl = sc16is7xx_break_ctl, .startup = sc16is7xx_startup, .shutdown = sc16is7xx_shutdown, .set_termios = sc16is7xx_set_termios, .type = sc16is7xx_type, .request_port = sc16is7xx_request_port, .release_port = sc16is7xx_null_void, .config_port = sc16is7xx_config_port, .verify_port = sc16is7xx_verify_port, .pm = sc16is7xx_pm, }; #ifdef CONFIG_GPIOLIB static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset) { unsigned int val; struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port, gpio); struct uart_port *port = &s->p[0].port; val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG); return !!(val & BIT(offset)); } static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val) { struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port, gpio); struct uart_port *port = &s->p[0].port; sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset), val ? BIT(offset) : 0); } static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset) { struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port, gpio); struct uart_port *port = &s->p[0].port; sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0); return 0; } static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip, unsigned offset, int val) { struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port, gpio); struct uart_port *port = &s->p[0].port; sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset), val ? BIT(offset) : 0); sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), BIT(offset)); return 0; } #endif static int sc16is7xx_probe(struct device *dev, struct sc16is7xx_devtype *devtype, struct regmap *regmap, int irq, unsigned long flags) { unsigned long freq, *pfreq = dev_get_platdata(dev); int i, ret; struct sc16is7xx_port *s; if (IS_ERR(regmap)) return PTR_ERR(regmap); /* Alloc port structure */ s = devm_kzalloc(dev, sizeof(*s) + sizeof(struct sc16is7xx_one) * devtype->nr_uart, GFP_KERNEL); if (!s) { dev_err(dev, "Error allocating port structure\n"); return -ENOMEM; } s->clk = devm_clk_get(dev, NULL); if (IS_ERR(s->clk)) { if (pfreq) freq = *pfreq; else return PTR_ERR(s->clk); } else { freq = clk_get_rate(s->clk); } s->regmap = regmap; s->devtype = devtype; dev_set_drvdata(dev, s); /* Register UART driver */ s->uart.owner = THIS_MODULE; s->uart.dev_name = "ttySC"; s->uart.nr = devtype->nr_uart; ret = uart_register_driver(&s->uart); if (ret) { dev_err(dev, "Registering UART driver failed\n"); goto out_clk; } #ifdef CONFIG_GPIOLIB if (devtype->nr_gpio) { /* Setup GPIO cotroller */ s->gpio.owner = THIS_MODULE; s->gpio.dev = dev; s->gpio.label = dev_name(dev); s->gpio.direction_input = sc16is7xx_gpio_direction_input; s->gpio.get = sc16is7xx_gpio_get; s->gpio.direction_output = sc16is7xx_gpio_direction_output; s->gpio.set = sc16is7xx_gpio_set; s->gpio.base = -1; s->gpio.ngpio = devtype->nr_gpio; s->gpio.can_sleep = 1; ret = gpiochip_add(&s->gpio); if (ret) goto out_uart; } #endif mutex_init(&s->mutex); for (i = 0; i < devtype->nr_uart; ++i) { /* Initialize port data */ s->p[i].port.line = i; s->p[i].port.dev = dev; s->p[i].port.irq = irq; s->p[i].port.type = PORT_SC16IS7XX; s->p[i].port.fifosize = SC16IS7XX_FIFO_SIZE; s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY; s->p[i].port.iotype = UPIO_PORT; s->p[i].port.uartclk = freq; s->p[i].port.rs485_config = sc16is7xx_config_rs485; s->p[i].port.ops = &sc16is7xx_ops; /* Disable all interrupts */ sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0); /* Disable TX/RX */ sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG, SC16IS7XX_EFCR_RXDISABLE_BIT | SC16IS7XX_EFCR_TXDISABLE_BIT); /* Initialize queue for start TX */ INIT_WORK(&s->p[i].tx_work, sc16is7xx_wq_proc); /* Initialize queue for changing mode */ INIT_WORK(&s->p[i].md_work, sc16is7xx_md_proc); /* Register port */ uart_add_one_port(&s->uart, &s->p[i].port); /* Go to suspend mode */ sc16is7xx_power(&s->p[i].port, 0); } /* Setup interrupt */ ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_ist, IRQF_ONESHOT | flags, dev_name(dev), s); if (!ret) return 0; mutex_destroy(&s->mutex); #ifdef CONFIG_GPIOLIB if (devtype->nr_gpio) gpiochip_remove(&s->gpio); out_uart: #endif uart_unregister_driver(&s->uart); out_clk: if (!IS_ERR(s->clk)) clk_disable_unprepare(s->clk); return ret; } static int sc16is7xx_remove(struct device *dev) { struct sc16is7xx_port *s = dev_get_drvdata(dev); int i; #ifdef CONFIG_GPIOLIB if (s->devtype->nr_gpio) gpiochip_remove(&s->gpio); #endif for (i = 0; i < s->uart.nr; i++) { cancel_work_sync(&s->p[i].tx_work); cancel_work_sync(&s->p[i].md_work); uart_remove_one_port(&s->uart, &s->p[i].port); sc16is7xx_power(&s->p[i].port, 0); } mutex_destroy(&s->mutex); uart_unregister_driver(&s->uart); if (!IS_ERR(s->clk)) clk_disable_unprepare(s->clk); return 0; } static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = { { .compatible = "nxp,sc16is740", .data = &sc16is74x_devtype, }, { .compatible = "nxp,sc16is741", .data = &sc16is74x_devtype, }, { .compatible = "nxp,sc16is750", .data = &sc16is750_devtype, }, { .compatible = "nxp,sc16is752", .data = &sc16is752_devtype, }, { .compatible = "nxp,sc16is760", .data = &sc16is760_devtype, }, { .compatible = "nxp,sc16is762", .data = &sc16is762_devtype, }, { } }; MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids); static struct regmap_config regcfg = { .reg_bits = 7, .pad_bits = 1, .val_bits = 8, .cache_type = REGCACHE_RBTREE, .volatile_reg = sc16is7xx_regmap_volatile, .precious_reg = sc16is7xx_regmap_precious, }; static int sc16is7xx_i2c_probe(struct i2c_client *i2c, const struct i2c_device_id *id) { struct sc16is7xx_devtype *devtype; unsigned long flags = 0; struct regmap *regmap; if (i2c->dev.of_node) { const struct of_device_id *of_id = of_match_device(sc16is7xx_dt_ids, &i2c->dev); devtype = (struct sc16is7xx_devtype *)of_id->data; } else { devtype = (struct sc16is7xx_devtype *)id->driver_data; flags = IRQF_TRIGGER_FALLING; } regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) | (devtype->nr_uart - 1); regmap = devm_regmap_init_i2c(i2c, ®cfg); return sc16is7xx_probe(&i2c->dev, devtype, regmap, i2c->irq, flags); } static int sc16is7xx_i2c_remove(struct i2c_client *client) { return sc16is7xx_remove(&client->dev); } static const struct i2c_device_id sc16is7xx_i2c_id_table[] = { { "sc16is74x", (kernel_ulong_t)&sc16is74x_devtype, }, { "sc16is750", (kernel_ulong_t)&sc16is750_devtype, }, { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, }, { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, }, { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, }, { } }; MODULE_DEVICE_TABLE(i2c, sc16is7xx_i2c_id_table); static struct i2c_driver sc16is7xx_i2c_uart_driver = { .driver = { .name = SC16IS7XX_NAME, .owner = THIS_MODULE, .of_match_table = of_match_ptr(sc16is7xx_dt_ids), }, .probe = sc16is7xx_i2c_probe, .remove = sc16is7xx_i2c_remove, .id_table = sc16is7xx_i2c_id_table, }; module_i2c_driver(sc16is7xx_i2c_uart_driver); MODULE_ALIAS("i2c:sc16is7xx"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Jon Ringle "); MODULE_DESCRIPTION("SC16IS7XX serial driver");