// SPDX-License-Identifier: GPL-2.0+ /* * SC16IS7xx tty serial driver - common code * * Copyright (C) 2014 GridPoint * Author: Jon Ringle * Based on max310x.c, by Alexander Shiyan */ #undef DEFAULT_SYMBOL_NAMESPACE #define DEFAULT_SYMBOL_NAMESPACE SERIAL_NXP_SC16IS7XX #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "sc16is7xx.h" #define SC16IS7XX_MAX_DEVS 8 /* 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 BIT(0) /* Enable RX data interrupt */ #define SC16IS7XX_IER_THRI_BIT BIT(1) /* Enable TX holding register * interrupt */ #define SC16IS7XX_IER_RLSI_BIT BIT(2) /* Enable RX line status * interrupt */ #define SC16IS7XX_IER_MSI_BIT BIT(3) /* Enable Modem status * interrupt */ /* IER register bits - write only if (EFR[4] == 1) */ #define SC16IS7XX_IER_SLEEP_BIT BIT(4) /* Enable Sleep mode */ #define SC16IS7XX_IER_XOFFI_BIT BIT(5) /* Enable Xoff interrupt */ #define SC16IS7XX_IER_RTSI_BIT BIT(6) /* Enable nRTS interrupt */ #define SC16IS7XX_IER_CTSI_BIT BIT(7) /* Enable nCTS interrupt */ /* FCR register bits */ #define SC16IS7XX_FCR_FIFO_BIT BIT(0) /* Enable FIFO */ #define SC16IS7XX_FCR_RXRESET_BIT BIT(1) /* Reset RX FIFO */ #define SC16IS7XX_FCR_TXRESET_BIT BIT(2) /* Reset TX FIFO */ #define SC16IS7XX_FCR_RXLVLL_BIT BIT(6) /* RX Trigger level LSB */ #define SC16IS7XX_FCR_RXLVLH_BIT BIT(7) /* RX Trigger level MSB */ /* FCR register bits - write only if (EFR[4] == 1) */ #define SC16IS7XX_FCR_TXLVLL_BIT BIT(4) /* TX Trigger level LSB */ #define SC16IS7XX_FCR_TXLVLH_BIT BIT(5) /* TX Trigger level MSB */ /* IIR register bits */ #define SC16IS7XX_IIR_NO_INT_BIT 0x01 /* No interrupts pending */ #define SC16IS7XX_IIR_ID_MASK GENMASK(5, 1) /* 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 BIT(0) /* Word length bit 0 */ #define SC16IS7XX_LCR_LENGTH1_BIT BIT(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 BIT(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 BIT(3) /* Parity bit enable */ #define SC16IS7XX_LCR_EVENPARITY_BIT BIT(4) /* Even parity bit enable */ #define SC16IS7XX_LCR_FORCEPARITY_BIT BIT(5) /* 9-bit multidrop parity */ #define SC16IS7XX_LCR_TXBREAK_BIT BIT(6) /* TX break enable */ #define SC16IS7XX_LCR_DLAB_BIT BIT(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 BIT(0) /* DTR complement * - only on 75x/76x */ #define SC16IS7XX_MCR_RTS_BIT BIT(1) /* RTS complement */ #define SC16IS7XX_MCR_TCRTLR_BIT BIT(2) /* TCR/TLR register enable */ #define SC16IS7XX_MCR_LOOP_BIT BIT(4) /* Enable loopback test mode */ #define SC16IS7XX_MCR_XONANY_BIT BIT(5) /* Enable Xon Any * - write enabled * if (EFR[4] == 1) */ #define SC16IS7XX_MCR_IRDA_BIT BIT(6) /* Enable IrDA mode * - write enabled * if (EFR[4] == 1) */ #define SC16IS7XX_MCR_CLKSEL_BIT BIT(7) /* Divide clock by 4 * - write enabled * if (EFR[4] == 1) */ /* LSR register bits */ #define SC16IS7XX_LSR_DR_BIT BIT(0) /* Receiver data ready */ #define SC16IS7XX_LSR_OE_BIT BIT(1) /* Overrun Error */ #define SC16IS7XX_LSR_PE_BIT BIT(2) /* Parity Error */ #define SC16IS7XX_LSR_FE_BIT BIT(3) /* Frame Error */ #define SC16IS7XX_LSR_BI_BIT BIT(4) /* Break Interrupt */ #define SC16IS7XX_LSR_BRK_ERROR_MASK \ (SC16IS7XX_LSR_OE_BIT | \ SC16IS7XX_LSR_PE_BIT | \ SC16IS7XX_LSR_FE_BIT | \ SC16IS7XX_LSR_BI_BIT) #define SC16IS7XX_LSR_THRE_BIT BIT(5) /* TX holding register empty */ #define SC16IS7XX_LSR_TEMT_BIT BIT(6) /* Transmitter empty */ #define SC16IS7XX_LSR_FIFOE_BIT BIT(7) /* Fifo Error */ /* MSR register bits */ #define SC16IS7XX_MSR_DCTS_BIT BIT(0) /* Delta CTS Clear To Send */ #define SC16IS7XX_MSR_DDSR_BIT BIT(1) /* Delta DSR Data Set Ready * or (IO4) * - only on 75x/76x */ #define SC16IS7XX_MSR_DRI_BIT BIT(2) /* Delta RI Ring Indicator * or (IO7) * - only on 75x/76x */ #define SC16IS7XX_MSR_DCD_BIT BIT(3) /* Delta CD Carrier Detect * or (IO6) * - only on 75x/76x */ #define SC16IS7XX_MSR_CTS_BIT BIT(4) /* CTS */ #define SC16IS7XX_MSR_DSR_BIT BIT(5) /* DSR (IO4) * - only on 75x/76x */ #define SC16IS7XX_MSR_RI_BIT BIT(6) /* RI (IO7) * - only on 75x/76x */ #define SC16IS7XX_MSR_CD_BIT BIT(7) /* CD (IO6) * - only on 75x/76x */ /* * 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 SC16IS74x/75x/76x 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 75x/76x) */ #define SC16IS7XX_IOCONTROL_LATCH_BIT BIT(0) /* Enable input latching */ #define SC16IS7XX_IOCONTROL_MODEM_A_BIT BIT(1) /* Enable GPIO[7:4] as modem A pins */ #define SC16IS7XX_IOCONTROL_MODEM_B_BIT BIT(2) /* Enable GPIO[3:0] as modem B pins */ #define SC16IS7XX_IOCONTROL_SRESET_BIT BIT(3) /* Software Reset */ /* EFCR register bits */ #define SC16IS7XX_EFCR_9BIT_MODE_BIT BIT(0) /* Enable 9-bit or Multidrop * mode (RS485) */ #define SC16IS7XX_EFCR_RXDISABLE_BIT BIT(1) /* Disable receiver */ #define SC16IS7XX_EFCR_TXDISABLE_BIT BIT(2) /* Disable transmitter */ #define SC16IS7XX_EFCR_AUTO_RS485_BIT BIT(4) /* Auto RS485 RTS direction */ #define SC16IS7XX_EFCR_RTS_INVERT_BIT BIT(5) /* RTS output inversion */ #define SC16IS7XX_EFCR_IRDA_MODE_BIT BIT(7) /* IrDA mode * 0 = rate upto 115.2 kbit/s * - Only 75x/76x * 1 = rate upto 1.152 Mbit/s * - Only 76x */ /* EFR register bits */ #define SC16IS7XX_EFR_AUTORTS_BIT BIT(6) /* Auto RTS flow ctrl enable */ #define SC16IS7XX_EFR_AUTOCTS_BIT BIT(7) /* Auto CTS flow ctrl enable */ #define SC16IS7XX_EFR_XOFF2_DETECT_BIT BIT(5) /* Enable Xoff2 detection */ #define SC16IS7XX_EFR_ENABLE_BIT BIT(4) /* Enable enhanced functions * and writing to IER[7:4], * FCR[5:4], MCR[7:5] */ #define SC16IS7XX_EFR_SWFLOW3_BIT BIT(3) #define SC16IS7XX_EFR_SWFLOW2_BIT 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 BIT(1) #define SC16IS7XX_EFR_SWFLOW0_BIT BIT(0) /* * SWFLOW bits 1 & 0 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 */ #define SC16IS7XX_EFR_FLOWCTRL_BITS (SC16IS7XX_EFR_AUTORTS_BIT | \ SC16IS7XX_EFR_AUTOCTS_BIT | \ SC16IS7XX_EFR_XOFF2_DETECT_BIT | \ SC16IS7XX_EFR_SWFLOW3_BIT | \ SC16IS7XX_EFR_SWFLOW2_BIT | \ SC16IS7XX_EFR_SWFLOW1_BIT | \ SC16IS7XX_EFR_SWFLOW0_BIT) /* Misc definitions */ #define SC16IS7XX_FIFO_SIZE (64) #define SC16IS7XX_GPIOS_PER_BANK 4 #define SC16IS7XX_RECONF_MD BIT(0) #define SC16IS7XX_RECONF_IER BIT(1) #define SC16IS7XX_RECONF_RS485 BIT(2) struct sc16is7xx_one_config { unsigned int flags; u8 ier_mask; u8 ier_val; }; struct sc16is7xx_one { struct uart_port port; struct regmap *regmap; struct mutex efr_lock; /* EFR registers access */ struct kthread_work tx_work; struct kthread_work reg_work; struct kthread_delayed_work ms_work; struct sc16is7xx_one_config config; unsigned char buf[SC16IS7XX_FIFO_SIZE]; /* Rx buffer. */ unsigned int old_mctrl; u8 old_lcr; /* Value before EFR access. */ bool irda_mode; }; struct sc16is7xx_port { const struct sc16is7xx_devtype *devtype; struct clk *clk; #ifdef CONFIG_GPIOLIB struct gpio_chip gpio; unsigned long gpio_valid_mask; #endif u8 mctrl_mask; struct kthread_worker kworker; struct task_struct *kworker_task; struct sc16is7xx_one p[]; }; static DEFINE_IDA(sc16is7xx_lines); static struct uart_driver sc16is7xx_uart = { .owner = THIS_MODULE, .driver_name = SC16IS7XX_NAME, .dev_name = "ttySC", .nr = SC16IS7XX_MAX_DEVS, }; #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_one *one = to_sc16is7xx_one(port, port); unsigned int val = 0; regmap_read(one->regmap, reg, &val); return val; } static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); regmap_write(one->regmap, reg, val); } static void sc16is7xx_fifo_read(struct uart_port *port, u8 *rxbuf, unsigned int rxlen) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); regmap_noinc_read(one->regmap, SC16IS7XX_RHR_REG, rxbuf, rxlen); } static void sc16is7xx_fifo_write(struct uart_port *port, u8 *txbuf, u8 to_send) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); /* * Don't send zero-length data, at least on SPI it confuses the chip * delivering wrong TXLVL data. */ if (unlikely(!to_send)) return; regmap_noinc_write(one->regmap, SC16IS7XX_THR_REG, txbuf, to_send); } static void sc16is7xx_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); regmap_update_bits(one->regmap, reg, 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); } /* * In an amazing feat of design, the Enhanced Features Register (EFR) * shares the address of the Interrupt Identification Register (IIR). * Access to EFR is switched on by writing a magic value (0xbf) to the * Line Control Register (LCR). Any interrupt firing during this time will * see the EFR where it expects the IIR to be, leading to * "Unexpected interrupt" messages. * * Prevent this possibility by claiming a mutex while accessing the EFR, * and claiming the same mutex from within the interrupt handler. This is * similar to disabling the interrupt, but that doesn't work because the * bulk of the interrupt processing is run as a workqueue job in thread * context. */ static void sc16is7xx_efr_lock(struct uart_port *port) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); mutex_lock(&one->efr_lock); /* Backup content of LCR. */ one->old_lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG); /* Enable access to Enhanced register set */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_B); /* Disable cache updates when writing to EFR registers */ regcache_cache_bypass(one->regmap, true); } static void sc16is7xx_efr_unlock(struct uart_port *port) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); /* Re-enable cache updates when writing to normal registers */ regcache_cache_bypass(one->regmap, false); /* Restore original content of LCR */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, one->old_lcr); mutex_unlock(&one->efr_lock); } static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); lockdep_assert_held_once(&port->lock); one->config.flags |= SC16IS7XX_RECONF_IER; one->config.ier_mask |= bit; one->config.ier_val &= ~bit; kthread_queue_work(&s->kworker, &one->reg_work); } static void sc16is7xx_ier_set(struct uart_port *port, u8 bit) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); lockdep_assert_held_once(&port->lock); one->config.flags |= SC16IS7XX_RECONF_IER; one->config.ier_mask |= bit; one->config.ier_val |= bit; kthread_queue_work(&s->kworker, &one->reg_work); } static void sc16is7xx_stop_tx(struct uart_port *port) { sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT); } static void sc16is7xx_stop_rx(struct uart_port *port) { sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT); } const struct sc16is7xx_devtype sc16is74x_devtype = { .name = "SC16IS74X", .nr_gpio = 0, .nr_uart = 1, }; EXPORT_SYMBOL_GPL(sc16is74x_devtype); const struct sc16is7xx_devtype sc16is750_devtype = { .name = "SC16IS750", .nr_gpio = 8, .nr_uart = 1, }; EXPORT_SYMBOL_GPL(sc16is750_devtype); const struct sc16is7xx_devtype sc16is752_devtype = { .name = "SC16IS752", .nr_gpio = 8, .nr_uart = 2, }; EXPORT_SYMBOL_GPL(sc16is752_devtype); const struct sc16is7xx_devtype sc16is760_devtype = { .name = "SC16IS760", .nr_gpio = 8, .nr_uart = 1, }; EXPORT_SYMBOL_GPL(sc16is760_devtype); const struct sc16is7xx_devtype sc16is762_devtype = { .name = "SC16IS762", .nr_gpio = 8, .nr_uart = 2, }; EXPORT_SYMBOL_GPL(sc16is762_devtype); static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg) { switch (reg) { 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: case SC16IS7XX_IOCONTROL_REG: return true; default: return false; } } static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg) { switch (reg) { case SC16IS7XX_RHR_REG: return true; default: return false; } } static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg) { return reg == SC16IS7XX_RHR_REG; } /* * Configure programmable baud rate generator (divisor) according to the * desired baud rate. * * From the datasheet, the divisor is computed according to: * * XTAL1 input frequency * ----------------------- * prescaler * divisor = --------------------------- * baud-rate x sampling-rate */ static int sc16is7xx_set_baud(struct uart_port *port, int baud) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); u8 lcr; unsigned int prescaler = 1; unsigned long clk = port->uartclk, div = clk / 16 / baud; if (div >= BIT(16)) { prescaler = 4; div /= prescaler; } /* Enable enhanced features */ sc16is7xx_efr_lock(port); sc16is7xx_port_update(port, SC16IS7XX_EFR_REG, SC16IS7XX_EFR_ENABLE_BIT, SC16IS7XX_EFR_ENABLE_BIT); sc16is7xx_efr_unlock(port); /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_CLKSEL_BIT, prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT); mutex_lock(&one->efr_lock); /* Backup LCR and access special register set (DLL/DLH) */ lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG); sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_A); /* Write the new divisor */ regcache_cache_bypass(one->regmap, true); sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256); sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256); regcache_cache_bypass(one->regmap, false); /* Restore LCR and access to general register set */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); mutex_unlock(&one->efr_lock); return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div); } static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen, unsigned int iir) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); unsigned int lsr = 0, bytes_read, i; bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false; u8 ch, flag; if (unlikely(rxlen >= sizeof(one->buf))) { dev_warn_ratelimited(port->dev, "ttySC%i: Possible RX FIFO overrun: %d\n", port->line, rxlen); port->icount.buf_overrun++; /* Ensure sanity of RX level */ rxlen = sizeof(one->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) { one->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG); bytes_read = 1; } else { sc16is7xx_fifo_read(port, one->buf, rxlen); 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 = one->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 tty_port *tport = &port->state->port; unsigned long flags; unsigned int txlen; unsigned char *tail; if (unlikely(port->x_char)) { sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char); port->icount.tx++; port->x_char = 0; return; } if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) { uart_port_lock_irqsave(port, &flags); sc16is7xx_stop_tx(port); uart_port_unlock_irqrestore(port, flags); return; } /* Limit to space available in TX FIFO */ txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG); if (txlen > SC16IS7XX_FIFO_SIZE) { dev_err_ratelimited(port->dev, "chip reports %d free bytes in TX fifo, but it only has %d", txlen, SC16IS7XX_FIFO_SIZE); txlen = 0; } txlen = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail, txlen); sc16is7xx_fifo_write(port, tail, txlen); uart_xmit_advance(port, txlen); uart_port_lock_irqsave(port, &flags); if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS) uart_write_wakeup(port); if (kfifo_is_empty(&tport->xmit_fifo)) sc16is7xx_stop_tx(port); else sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT); uart_port_unlock_irqrestore(port, flags); } static unsigned int sc16is7xx_get_hwmctrl(struct uart_port *port) { u8 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG); unsigned int mctrl = 0; mctrl |= (msr & SC16IS7XX_MSR_CTS_BIT) ? TIOCM_CTS : 0; mctrl |= (msr & SC16IS7XX_MSR_DSR_BIT) ? TIOCM_DSR : 0; mctrl |= (msr & SC16IS7XX_MSR_CD_BIT) ? TIOCM_CAR : 0; mctrl |= (msr & SC16IS7XX_MSR_RI_BIT) ? TIOCM_RNG : 0; return mctrl; } static void sc16is7xx_update_mlines(struct sc16is7xx_one *one) { struct uart_port *port = &one->port; unsigned long flags; unsigned int status, changed; lockdep_assert_held_once(&one->efr_lock); status = sc16is7xx_get_hwmctrl(port); changed = status ^ one->old_mctrl; if (changed == 0) return; one->old_mctrl = status; uart_port_lock_irqsave(port, &flags); if ((changed & TIOCM_RNG) && (status & TIOCM_RNG)) port->icount.rng++; if (changed & TIOCM_DSR) port->icount.dsr++; if (changed & TIOCM_CAR) uart_handle_dcd_change(port, status & TIOCM_CAR); if (changed & TIOCM_CTS) uart_handle_cts_change(port, status & TIOCM_CTS); wake_up_interruptible(&port->state->port.delta_msr_wait); uart_port_unlock_irqrestore(port, flags); } static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno) { bool rc = true; unsigned int iir, rxlen; struct uart_port *port = &s->p[portno].port; struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); mutex_lock(&one->efr_lock); iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG); if (iir & SC16IS7XX_IIR_NO_INT_BIT) { rc = false; goto out_port_irq; } 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); /* * There is a silicon bug that makes the chip report a * time-out interrupt but no data in the FIFO. This is * described in errata section 18.1.4. * * When this happens, read one byte from the FIFO to * clear the interrupt. */ if (iir == SC16IS7XX_IIR_RTOI_SRC && !rxlen) rxlen = 1; if (rxlen) sc16is7xx_handle_rx(port, rxlen, iir); break; /* CTSRTS interrupt comes only when CTS goes inactive */ case SC16IS7XX_IIR_CTSRTS_SRC: case SC16IS7XX_IIR_MSI_SRC: sc16is7xx_update_mlines(one); break; case SC16IS7XX_IIR_THRI_SRC: sc16is7xx_handle_tx(port); break; default: dev_err_ratelimited(port->dev, "ttySC%i: Unexpected interrupt: %x", port->line, iir); break; } out_port_irq: mutex_unlock(&one->efr_lock); return rc; } static irqreturn_t sc16is7xx_irq(int irq, void *dev_id) { bool keep_polling; struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id; do { int i; keep_polling = false; for (i = 0; i < s->devtype->nr_uart; ++i) keep_polling |= sc16is7xx_port_irq(s, i); } while (keep_polling); return IRQ_HANDLED; } static void sc16is7xx_tx_proc(struct kthread_work *ws) { struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port); struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); if ((port->rs485.flags & SER_RS485_ENABLED) && (port->rs485.delay_rts_before_send > 0)) msleep(port->rs485.delay_rts_before_send); mutex_lock(&one->efr_lock); sc16is7xx_handle_tx(port); mutex_unlock(&one->efr_lock); } static void sc16is7xx_reconf_rs485(struct uart_port *port) { const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT | SC16IS7XX_EFCR_RTS_INVERT_BIT; u32 efcr = 0; struct serial_rs485 *rs485 = &port->rs485; unsigned long irqflags; uart_port_lock_irqsave(port, &irqflags); if (rs485->flags & SER_RS485_ENABLED) { efcr |= SC16IS7XX_EFCR_AUTO_RS485_BIT; if (rs485->flags & SER_RS485_RTS_AFTER_SEND) efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT; } uart_port_unlock_irqrestore(port, irqflags); sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr); } static void sc16is7xx_reg_proc(struct kthread_work *ws) { struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work); struct sc16is7xx_one_config config; unsigned long irqflags; uart_port_lock_irqsave(&one->port, &irqflags); config = one->config; memset(&one->config, 0, sizeof(one->config)); uart_port_unlock_irqrestore(&one->port, irqflags); if (config.flags & SC16IS7XX_RECONF_MD) { u8 mcr = 0; /* Device ignores RTS setting when hardware flow is enabled */ if (one->port.mctrl & TIOCM_RTS) mcr |= SC16IS7XX_MCR_RTS_BIT; if (one->port.mctrl & TIOCM_DTR) mcr |= SC16IS7XX_MCR_DTR_BIT; if (one->port.mctrl & TIOCM_LOOP) mcr |= SC16IS7XX_MCR_LOOP_BIT; sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_RTS_BIT | SC16IS7XX_MCR_DTR_BIT | SC16IS7XX_MCR_LOOP_BIT, mcr); } if (config.flags & SC16IS7XX_RECONF_IER) sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG, config.ier_mask, config.ier_val); if (config.flags & SC16IS7XX_RECONF_RS485) sc16is7xx_reconf_rs485(&one->port); } static void sc16is7xx_ms_proc(struct kthread_work *ws) { struct sc16is7xx_one *one = to_sc16is7xx_one(ws, ms_work.work); struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev); if (one->port.state) { mutex_lock(&one->efr_lock); sc16is7xx_update_mlines(one); mutex_unlock(&one->efr_lock); kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ); } } static void sc16is7xx_enable_ms(struct uart_port *port) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); struct sc16is7xx_port *s = dev_get_drvdata(port->dev); lockdep_assert_held_once(&port->lock); kthread_queue_delayed_work(&s->kworker, &one->ms_work, 0); } static void sc16is7xx_start_tx(struct uart_port *port) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); kthread_queue_work(&s->kworker, &one->tx_work); } static void sc16is7xx_throttle(struct uart_port *port) { unsigned long flags; /* * Hardware flow control is enabled and thus the device ignores RTS * value set in MCR register. Stop reading data from RX FIFO so the * AutoRTS feature will de-activate RTS output. */ uart_port_lock_irqsave(port, &flags); sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT); uart_port_unlock_irqrestore(port, flags); } static void sc16is7xx_unthrottle(struct uart_port *port) { unsigned long flags; uart_port_lock_irqsave(port, &flags); sc16is7xx_ier_set(port, SC16IS7XX_IER_RDI_BIT); uart_port_unlock_irqrestore(port, flags); } static unsigned int sc16is7xx_tx_empty(struct uart_port *port) { unsigned int lsr; lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG); return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0; } static unsigned int sc16is7xx_get_mctrl(struct uart_port *port) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); /* Called with port lock taken so we can only return cached value */ return one->old_mctrl; } static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); one->config.flags |= SC16IS7XX_RECONF_MD; kthread_queue_work(&s->kworker, &one->reg_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, const struct ktermios *old) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); unsigned int lcr, flow = 0; int baud; unsigned long flags; kthread_cancel_delayed_work_sync(&one->ms_work); /* 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; /* Configure flow control */ port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS); if (termios->c_cflag & CRTSCTS) { flow |= SC16IS7XX_EFR_AUTOCTS_BIT | SC16IS7XX_EFR_AUTORTS_BIT; port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS; } if (termios->c_iflag & IXON) flow |= SC16IS7XX_EFR_SWFLOW3_BIT; if (termios->c_iflag & IXOFF) flow |= SC16IS7XX_EFR_SWFLOW1_BIT; /* Update LCR register */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); /* Update EFR registers */ sc16is7xx_efr_lock(port); sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]); sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]); sc16is7xx_port_update(port, SC16IS7XX_EFR_REG, SC16IS7XX_EFR_FLOWCTRL_BITS, flow); sc16is7xx_efr_unlock(port); /* 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); uart_port_lock_irqsave(port, &flags); /* Update timeout according to new baud rate */ uart_update_timeout(port, termios->c_cflag, baud); if (UART_ENABLE_MS(port, termios->c_cflag)) sc16is7xx_enable_ms(port); uart_port_unlock_irqrestore(port, flags); } static int sc16is7xx_config_rs485(struct uart_port *port, struct ktermios *termios, struct serial_rs485 *rs485) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); if (rs485->flags & SER_RS485_ENABLED) { /* * RTS signal is handled by HW, it's timing can't be influenced. * However, it's sometimes useful to delay TX even without RTS * control therefore we try to handle .delay_rts_before_send. */ if (rs485->delay_rts_after_send) return -EINVAL; } one->config.flags |= SC16IS7XX_RECONF_RS485; kthread_queue_work(&s->kworker, &one->reg_work); return 0; } static int sc16is7xx_startup(struct uart_port *port) { struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); unsigned int val; unsigned long flags; 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(one->regmap, true); /* Enable write access to enhanced features and internal clock div */ sc16is7xx_port_update(port, SC16IS7XX_EFR_REG, SC16IS7XX_EFR_ENABLE_BIT, 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(one->regmap, false); /* Now, initialize the UART */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8); /* Enable IrDA mode if requested in DT */ /* This bit must be written with LCR[7] = 0 */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_IRDA_BIT, one->irda_mode ? SC16IS7XX_MCR_IRDA_BIT : 0); /* Enable the Rx and Tx FIFO */ sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, SC16IS7XX_EFCR_RXDISABLE_BIT | SC16IS7XX_EFCR_TXDISABLE_BIT, 0); /* Enable RX, CTS change and modem lines interrupts */ val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_CTSI_BIT | SC16IS7XX_IER_MSI_BIT; sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val); /* Enable modem status polling */ uart_port_lock_irqsave(port, &flags); sc16is7xx_enable_ms(port); uart_port_unlock_irqrestore(port, flags); return 0; } static void sc16is7xx_shutdown(struct uart_port *port) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); kthread_cancel_delayed_work_sync(&one->ms_work); /* Disable all interrupts */ sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0); /* Disable TX/RX */ sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, SC16IS7XX_EFCR_RXDISABLE_BIT | SC16IS7XX_EFCR_TXDISABLE_BIT, SC16IS7XX_EFCR_RXDISABLE_BIT | SC16IS7XX_EFCR_TXDISABLE_BIT); sc16is7xx_power(port, 0); kthread_flush_worker(&s->kworker); } 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, .throttle = sc16is7xx_throttle, .unthrottle = sc16is7xx_unthrottle, .stop_rx = sc16is7xx_stop_rx, .enable_ms = sc16is7xx_enable_ms, .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 = gpiochip_get_data(chip); 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 = gpiochip_get_data(chip); 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 = gpiochip_get_data(chip); 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 = gpiochip_get_data(chip); struct uart_port *port = &s->p[0].port; u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG); if (val) state |= BIT(offset); else state &= ~BIT(offset); /* * If we write IOSTATE first, and then IODIR, the output value is not * transferred to the corresponding I/O pin. * The datasheet states that each register bit will be transferred to * the corresponding I/O pin programmed as output when writing to * IOSTATE. Therefore, configure direction first with IODIR, and then * set value after with IOSTATE. */ sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), BIT(offset)); sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state); return 0; } static int sc16is7xx_gpio_init_valid_mask(struct gpio_chip *chip, unsigned long *valid_mask, unsigned int ngpios) { struct sc16is7xx_port *s = gpiochip_get_data(chip); *valid_mask = s->gpio_valid_mask; return 0; } static int sc16is7xx_setup_gpio_chip(struct sc16is7xx_port *s) { struct device *dev = s->p[0].port.dev; if (!s->devtype->nr_gpio) return 0; switch (s->mctrl_mask) { case 0: s->gpio_valid_mask = GENMASK(7, 0); break; case SC16IS7XX_IOCONTROL_MODEM_A_BIT: s->gpio_valid_mask = GENMASK(3, 0); break; case SC16IS7XX_IOCONTROL_MODEM_B_BIT: s->gpio_valid_mask = GENMASK(7, 4); break; default: break; } if (s->gpio_valid_mask == 0) return 0; s->gpio.owner = THIS_MODULE; s->gpio.parent = dev; s->gpio.label = dev_name(dev); s->gpio.init_valid_mask = sc16is7xx_gpio_init_valid_mask; 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 = s->devtype->nr_gpio; s->gpio.can_sleep = 1; return gpiochip_add_data(&s->gpio, s); } #endif static void sc16is7xx_setup_irda_ports(struct sc16is7xx_port *s) { int i; int ret; int count; u32 irda_port[SC16IS7XX_MAX_PORTS]; struct device *dev = s->p[0].port.dev; count = device_property_count_u32(dev, "irda-mode-ports"); if (count < 0 || count > ARRAY_SIZE(irda_port)) return; ret = device_property_read_u32_array(dev, "irda-mode-ports", irda_port, count); if (ret) return; for (i = 0; i < count; i++) { if (irda_port[i] < s->devtype->nr_uart) s->p[irda_port[i]].irda_mode = true; } } /* * Configure ports designated to operate as modem control lines. */ static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s, struct regmap *regmap) { int i; int ret; int count; u32 mctrl_port[SC16IS7XX_MAX_PORTS]; struct device *dev = s->p[0].port.dev; count = device_property_count_u32(dev, "nxp,modem-control-line-ports"); if (count < 0 || count > ARRAY_SIZE(mctrl_port)) return 0; ret = device_property_read_u32_array(dev, "nxp,modem-control-line-ports", mctrl_port, count); if (ret) return ret; s->mctrl_mask = 0; for (i = 0; i < count; i++) { /* Use GPIO lines as modem control lines */ if (mctrl_port[i] == 0) s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_A_BIT; else if (mctrl_port[i] == 1) s->mctrl_mask |= SC16IS7XX_IOCONTROL_MODEM_B_BIT; } if (s->mctrl_mask) regmap_update_bits( regmap, SC16IS7XX_IOCONTROL_REG, SC16IS7XX_IOCONTROL_MODEM_A_BIT | SC16IS7XX_IOCONTROL_MODEM_B_BIT, s->mctrl_mask); return 0; } static const struct serial_rs485 sc16is7xx_rs485_supported = { .flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND, .delay_rts_before_send = 1, .delay_rts_after_send = 1, /* Not supported but keep returning -EINVAL */ }; /* Reset device, purging any pending irq / data */ static int sc16is7xx_reset(struct device *dev, struct regmap *regmap) { struct gpio_desc *reset_gpio; /* Assert reset GPIO if defined and valid. */ reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); if (IS_ERR(reset_gpio)) return dev_err_probe(dev, PTR_ERR(reset_gpio), "Failed to get reset GPIO\n"); if (reset_gpio) { /* The minimum reset pulse width is 3 us. */ fsleep(5); gpiod_set_value_cansleep(reset_gpio, 0); /* Deassert GPIO */ } else { /* Software reset */ regmap_write(regmap, SC16IS7XX_IOCONTROL_REG, SC16IS7XX_IOCONTROL_SRESET_BIT); } return 0; } int sc16is7xx_probe(struct device *dev, const struct sc16is7xx_devtype *devtype, struct regmap *regmaps[], int irq) { unsigned long freq = 0, *pfreq = dev_get_platdata(dev); unsigned int val; u32 uartclk = 0; int i, ret; struct sc16is7xx_port *s; bool port_registered[SC16IS7XX_MAX_PORTS]; for (i = 0; i < devtype->nr_uart; i++) if (IS_ERR(regmaps[i])) return PTR_ERR(regmaps[i]); /* * This device does not have an identification register that would * tell us if we are really connected to the correct device. * The best we can do is to check if communication is at all possible. * * Note: regmap[0] is used in the probe function to access registers * common to all channels/ports, as it is guaranteed to be present on * all variants. */ ret = regmap_read(regmaps[0], SC16IS7XX_LSR_REG, &val); if (ret < 0) return -EPROBE_DEFER; /* Alloc port structure */ s = devm_kzalloc(dev, struct_size(s, p, devtype->nr_uart), GFP_KERNEL); if (!s) { dev_err(dev, "Error allocating port structure\n"); return -ENOMEM; } /* Always ask for fixed clock rate from a property. */ device_property_read_u32(dev, "clock-frequency", &uartclk); s->clk = devm_clk_get_optional(dev, NULL); if (IS_ERR(s->clk)) return PTR_ERR(s->clk); ret = clk_prepare_enable(s->clk); if (ret) return ret; freq = clk_get_rate(s->clk); if (freq == 0) { if (uartclk) freq = uartclk; if (pfreq) freq = *pfreq; if (freq) dev_dbg(dev, "Clock frequency: %luHz\n", freq); else return -EINVAL; } s->devtype = devtype; dev_set_drvdata(dev, s); kthread_init_worker(&s->kworker); s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker, "sc16is7xx"); if (IS_ERR(s->kworker_task)) { ret = PTR_ERR(s->kworker_task); goto out_clk; } sched_set_fifo(s->kworker_task); ret = sc16is7xx_reset(dev, regmaps[0]); if (ret) goto out_kthread; /* Mark each port line and status as uninitialised. */ for (i = 0; i < devtype->nr_uart; ++i) { s->p[i].port.line = SC16IS7XX_MAX_DEVS; port_registered[i] = false; } for (i = 0; i < devtype->nr_uart; ++i) { ret = ida_alloc_max(&sc16is7xx_lines, SC16IS7XX_MAX_DEVS - 1, GFP_KERNEL); if (ret < 0) goto out_ports; s->p[i].port.line = ret; /* Initialize port data */ 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.iobase = i; /* * Use all ones as membase to make sure uart_configure_port() in * serial_core.c does not abort for SPI/I2C devices where the * membase address is not applicable. */ s->p[i].port.membase = (void __iomem *)~0; 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.rs485_supported = sc16is7xx_rs485_supported; s->p[i].port.ops = &sc16is7xx_ops; s->p[i].old_mctrl = 0; s->p[i].regmap = regmaps[i]; mutex_init(&s->p[i].efr_lock); ret = uart_get_rs485_mode(&s->p[i].port); if (ret) goto out_ports; /* 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 kthread work structs */ kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc); kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc); kthread_init_delayed_work(&s->p[i].ms_work, sc16is7xx_ms_proc); /* Register port */ ret = uart_add_one_port(&sc16is7xx_uart, &s->p[i].port); if (ret) goto out_ports; port_registered[i] = true; /* Enable EFR */ sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_B); regcache_cache_bypass(regmaps[i], true); /* Enable write access to enhanced features */ sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFR_REG, SC16IS7XX_EFR_ENABLE_BIT); regcache_cache_bypass(regmaps[i], false); /* Restore access to general registers */ sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, 0x00); /* Go to suspend mode */ sc16is7xx_power(&s->p[i].port, 0); } sc16is7xx_setup_irda_ports(s); ret = sc16is7xx_setup_mctrl_ports(s, regmaps[0]); if (ret) goto out_ports; #ifdef CONFIG_GPIOLIB ret = sc16is7xx_setup_gpio_chip(s); if (ret) goto out_ports; #endif /* * Setup interrupt. We first try to acquire the IRQ line as level IRQ. * If that succeeds, we can allow sharing the interrupt as well. * In case the interrupt controller doesn't support that, we fall * back to a non-shared falling-edge trigger. */ ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq, IRQF_TRIGGER_LOW | IRQF_SHARED | IRQF_ONESHOT, dev_name(dev), s); if (!ret) return 0; ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq, IRQF_TRIGGER_FALLING | IRQF_ONESHOT, dev_name(dev), s); if (!ret) return 0; #ifdef CONFIG_GPIOLIB if (s->gpio_valid_mask) gpiochip_remove(&s->gpio); #endif out_ports: for (i = 0; i < devtype->nr_uart; i++) { if (s->p[i].port.line < SC16IS7XX_MAX_DEVS) ida_free(&sc16is7xx_lines, s->p[i].port.line); if (port_registered[i]) uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port); } out_kthread: kthread_stop(s->kworker_task); out_clk: clk_disable_unprepare(s->clk); return ret; } EXPORT_SYMBOL_GPL(sc16is7xx_probe); void sc16is7xx_remove(struct device *dev) { struct sc16is7xx_port *s = dev_get_drvdata(dev); int i; #ifdef CONFIG_GPIOLIB if (s->gpio_valid_mask) gpiochip_remove(&s->gpio); #endif for (i = 0; i < s->devtype->nr_uart; i++) { kthread_cancel_delayed_work_sync(&s->p[i].ms_work); ida_free(&sc16is7xx_lines, s->p[i].port.line); uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port); sc16is7xx_power(&s->p[i].port, 0); } kthread_flush_worker(&s->kworker); kthread_stop(s->kworker_task); clk_disable_unprepare(s->clk); } EXPORT_SYMBOL_GPL(sc16is7xx_remove); 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, }, { } }; EXPORT_SYMBOL_GPL(sc16is7xx_dt_ids); MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids); const struct regmap_config sc16is7xx_regcfg = { .reg_bits = 5, .pad_bits = 3, .val_bits = 8, .cache_type = REGCACHE_MAPLE, .volatile_reg = sc16is7xx_regmap_volatile, .precious_reg = sc16is7xx_regmap_precious, .writeable_noinc_reg = sc16is7xx_regmap_noinc, .readable_noinc_reg = sc16is7xx_regmap_noinc, .max_raw_read = SC16IS7XX_FIFO_SIZE, .max_raw_write = SC16IS7XX_FIFO_SIZE, .max_register = SC16IS7XX_EFCR_REG, }; EXPORT_SYMBOL_GPL(sc16is7xx_regcfg); const char *sc16is7xx_regmap_name(u8 port_id) { switch (port_id) { case 0: return "port0"; case 1: return "port1"; default: WARN_ON(true); return NULL; } } EXPORT_SYMBOL_GPL(sc16is7xx_regmap_name); unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id) { /* CH1,CH0 are at bits 2:1. */ return port_id << 1; } EXPORT_SYMBOL_GPL(sc16is7xx_regmap_port_mask); static int __init sc16is7xx_init(void) { return uart_register_driver(&sc16is7xx_uart); } module_init(sc16is7xx_init); static void __exit sc16is7xx_exit(void) { uart_unregister_driver(&sc16is7xx_uart); } module_exit(sc16is7xx_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Jon Ringle "); MODULE_DESCRIPTION("SC16IS7xx tty serial core driver");