/* * Maxim (Dallas) MAX3107/8 serial driver * * Copyright (C) 2012 Alexander Shiyan * * Based on max3100.c, by Christian Pellegrin * Based on max3110.c, by Feng Tang * Based on max3107.c, by Aavamobile * * 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. */ /* TODO: MAX3109 support (Dual) */ /* TODO: MAX14830 support (Quad) */ #include #include #include #include #include #include #include #include #include #include #define MAX310X_MAJOR 204 #define MAX310X_MINOR 209 /* MAX310X register definitions */ #define MAX310X_RHR_REG (0x00) /* RX FIFO */ #define MAX310X_THR_REG (0x00) /* TX FIFO */ #define MAX310X_IRQEN_REG (0x01) /* IRQ enable */ #define MAX310X_IRQSTS_REG (0x02) /* IRQ status */ #define MAX310X_LSR_IRQEN_REG (0x03) /* LSR IRQ enable */ #define MAX310X_LSR_IRQSTS_REG (0x04) /* LSR IRQ status */ #define MAX310X_SPCHR_IRQEN_REG (0x05) /* Special char IRQ enable */ #define MAX310X_SPCHR_IRQSTS_REG (0x06) /* Special char IRQ status */ #define MAX310X_STS_IRQEN_REG (0x07) /* Status IRQ enable */ #define MAX310X_STS_IRQSTS_REG (0x08) /* Status IRQ status */ #define MAX310X_MODE1_REG (0x09) /* MODE1 */ #define MAX310X_MODE2_REG (0x0a) /* MODE2 */ #define MAX310X_LCR_REG (0x0b) /* LCR */ #define MAX310X_RXTO_REG (0x0c) /* RX timeout */ #define MAX310X_HDPIXDELAY_REG (0x0d) /* Auto transceiver delays */ #define MAX310X_IRDA_REG (0x0e) /* IRDA settings */ #define MAX310X_FLOWLVL_REG (0x0f) /* Flow control levels */ #define MAX310X_FIFOTRIGLVL_REG (0x10) /* FIFO IRQ trigger levels */ #define MAX310X_TXFIFOLVL_REG (0x11) /* TX FIFO level */ #define MAX310X_RXFIFOLVL_REG (0x12) /* RX FIFO level */ #define MAX310X_FLOWCTRL_REG (0x13) /* Flow control */ #define MAX310X_XON1_REG (0x14) /* XON1 character */ #define MAX310X_XON2_REG (0x15) /* XON2 character */ #define MAX310X_XOFF1_REG (0x16) /* XOFF1 character */ #define MAX310X_XOFF2_REG (0x17) /* XOFF2 character */ #define MAX310X_GPIOCFG_REG (0x18) /* GPIO config */ #define MAX310X_GPIODATA_REG (0x19) /* GPIO data */ #define MAX310X_PLLCFG_REG (0x1a) /* PLL config */ #define MAX310X_BRGCFG_REG (0x1b) /* Baud rate generator conf */ #define MAX310X_BRGDIVLSB_REG (0x1c) /* Baud rate divisor LSB */ #define MAX310X_BRGDIVMSB_REG (0x1d) /* Baud rate divisor MSB */ #define MAX310X_CLKSRC_REG (0x1e) /* Clock source */ /* Only present in MAX3107 */ #define MAX3107_REVID_REG (0x1f) /* Revision identification */ /* IRQ register bits */ #define MAX310X_IRQ_LSR_BIT (1 << 0) /* LSR interrupt */ #define MAX310X_IRQ_SPCHR_BIT (1 << 1) /* Special char interrupt */ #define MAX310X_IRQ_STS_BIT (1 << 2) /* Status interrupt */ #define MAX310X_IRQ_RXFIFO_BIT (1 << 3) /* RX FIFO interrupt */ #define MAX310X_IRQ_TXFIFO_BIT (1 << 4) /* TX FIFO interrupt */ #define MAX310X_IRQ_TXEMPTY_BIT (1 << 5) /* TX FIFO empty interrupt */ #define MAX310X_IRQ_RXEMPTY_BIT (1 << 6) /* RX FIFO empty interrupt */ #define MAX310X_IRQ_CTS_BIT (1 << 7) /* CTS interrupt */ /* LSR register bits */ #define MAX310X_LSR_RXTO_BIT (1 << 0) /* RX timeout */ #define MAX310X_LSR_RXOVR_BIT (1 << 1) /* RX overrun */ #define MAX310X_LSR_RXPAR_BIT (1 << 2) /* RX parity error */ #define MAX310X_LSR_FRERR_BIT (1 << 3) /* Frame error */ #define MAX310X_LSR_RXBRK_BIT (1 << 4) /* RX break */ #define MAX310X_LSR_RXNOISE_BIT (1 << 5) /* RX noise */ #define MAX310X_LSR_CTS_BIT (1 << 7) /* CTS pin state */ /* Special character register bits */ #define MAX310X_SPCHR_XON1_BIT (1 << 0) /* XON1 character */ #define MAX310X_SPCHR_XON2_BIT (1 << 1) /* XON2 character */ #define MAX310X_SPCHR_XOFF1_BIT (1 << 2) /* XOFF1 character */ #define MAX310X_SPCHR_XOFF2_BIT (1 << 3) /* XOFF2 character */ #define MAX310X_SPCHR_BREAK_BIT (1 << 4) /* RX break */ #define MAX310X_SPCHR_MULTIDROP_BIT (1 << 5) /* 9-bit multidrop addr char */ /* Status register bits */ #define MAX310X_STS_GPIO0_BIT (1 << 0) /* GPIO 0 interrupt */ #define MAX310X_STS_GPIO1_BIT (1 << 1) /* GPIO 1 interrupt */ #define MAX310X_STS_GPIO2_BIT (1 << 2) /* GPIO 2 interrupt */ #define MAX310X_STS_GPIO3_BIT (1 << 3) /* GPIO 3 interrupt */ #define MAX310X_STS_CLKREADY_BIT (1 << 5) /* Clock ready */ #define MAX310X_STS_SLEEP_BIT (1 << 6) /* Sleep interrupt */ /* MODE1 register bits */ #define MAX310X_MODE1_RXDIS_BIT (1 << 0) /* RX disable */ #define MAX310X_MODE1_TXDIS_BIT (1 << 1) /* TX disable */ #define MAX310X_MODE1_TXHIZ_BIT (1 << 2) /* TX pin three-state */ #define MAX310X_MODE1_RTSHIZ_BIT (1 << 3) /* RTS pin three-state */ #define MAX310X_MODE1_TRNSCVCTRL_BIT (1 << 4) /* Transceiver ctrl enable */ #define MAX310X_MODE1_FORCESLEEP_BIT (1 << 5) /* Force sleep mode */ #define MAX310X_MODE1_AUTOSLEEP_BIT (1 << 6) /* Auto sleep enable */ #define MAX310X_MODE1_IRQSEL_BIT (1 << 7) /* IRQ pin enable */ /* MODE2 register bits */ #define MAX310X_MODE2_RST_BIT (1 << 0) /* Chip reset */ #define MAX310X_MODE2_FIFORST_BIT (1 << 1) /* FIFO reset */ #define MAX310X_MODE2_RXTRIGINV_BIT (1 << 2) /* RX FIFO INT invert */ #define MAX310X_MODE2_RXEMPTINV_BIT (1 << 3) /* RX FIFO empty INT invert */ #define MAX310X_MODE2_SPCHR_BIT (1 << 4) /* Special chr detect enable */ #define MAX310X_MODE2_LOOPBACK_BIT (1 << 5) /* Internal loopback enable */ #define MAX310X_MODE2_MULTIDROP_BIT (1 << 6) /* 9-bit multidrop enable */ #define MAX310X_MODE2_ECHOSUPR_BIT (1 << 7) /* ECHO suppression enable */ /* LCR register bits */ #define MAX310X_LCR_LENGTH0_BIT (1 << 0) /* Word length bit 0 */ #define MAX310X_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 MAX310X_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 MAX310X_LCR_PARITY_BIT (1 << 3) /* Parity bit enable */ #define MAX310X_LCR_EVENPARITY_BIT (1 << 4) /* Even parity bit enable */ #define MAX310X_LCR_FORCEPARITY_BIT (1 << 5) /* 9-bit multidrop parity */ #define MAX310X_LCR_TXBREAK_BIT (1 << 6) /* TX break enable */ #define MAX310X_LCR_RTS_BIT (1 << 7) /* RTS pin control */ #define MAX310X_LCR_WORD_LEN_5 (0x00) #define MAX310X_LCR_WORD_LEN_6 (0x01) #define MAX310X_LCR_WORD_LEN_7 (0x02) #define MAX310X_LCR_WORD_LEN_8 (0x03) /* IRDA register bits */ #define MAX310X_IRDA_IRDAEN_BIT (1 << 0) /* IRDA mode enable */ #define MAX310X_IRDA_SIR_BIT (1 << 1) /* SIR mode enable */ #define MAX310X_IRDA_SHORTIR_BIT (1 << 2) /* Short SIR mode enable */ #define MAX310X_IRDA_MIR_BIT (1 << 3) /* MIR mode enable */ #define MAX310X_IRDA_RXINV_BIT (1 << 4) /* RX logic inversion enable */ #define MAX310X_IRDA_TXINV_BIT (1 << 5) /* TX logic inversion enable */ /* Flow control trigger level register masks */ #define MAX310X_FLOWLVL_HALT_MASK (0x000f) /* Flow control halt level */ #define MAX310X_FLOWLVL_RES_MASK (0x00f0) /* Flow control resume level */ #define MAX310X_FLOWLVL_HALT(words) ((words / 8) & 0x0f) #define MAX310X_FLOWLVL_RES(words) (((words / 8) & 0x0f) << 4) /* FIFO interrupt trigger level register masks */ #define MAX310X_FIFOTRIGLVL_TX_MASK (0x0f) /* TX FIFO trigger level */ #define MAX310X_FIFOTRIGLVL_RX_MASK (0xf0) /* RX FIFO trigger level */ #define MAX310X_FIFOTRIGLVL_TX(words) ((words / 8) & 0x0f) #define MAX310X_FIFOTRIGLVL_RX(words) (((words / 8) & 0x0f) << 4) /* Flow control register bits */ #define MAX310X_FLOWCTRL_AUTORTS_BIT (1 << 0) /* Auto RTS flow ctrl enable */ #define MAX310X_FLOWCTRL_AUTOCTS_BIT (1 << 1) /* Auto CTS flow ctrl enable */ #define MAX310X_FLOWCTRL_GPIADDR_BIT (1 << 2) /* Enables that GPIO inputs * are used in conjunction with * XOFF2 for definition of * special character */ #define MAX310X_FLOWCTRL_SWFLOWEN_BIT (1 << 3) /* Auto SW flow ctrl enable */ #define MAX310X_FLOWCTRL_SWFLOW0_BIT (1 << 4) /* SWFLOW bit 0 */ #define MAX310X_FLOWCTRL_SWFLOW1_BIT (1 << 5) /* SWFLOW bit 1 * * SWFLOW bits 1 & 0 table: * 00 -> no transmitter flow * control * 01 -> receiver compares * XON2 and XOFF2 * and controls * transmitter * 10 -> receiver compares * XON1 and XOFF1 * and controls * transmitter * 11 -> receiver compares * XON1, XON2, XOFF1 and * XOFF2 and controls * transmitter */ #define MAX310X_FLOWCTRL_SWFLOW2_BIT (1 << 6) /* SWFLOW bit 2 */ #define MAX310X_FLOWCTRL_SWFLOW3_BIT (1 << 7) /* SWFLOW bit 3 * * SWFLOW bits 3 & 2 table: * 00 -> no received flow * control * 01 -> transmitter generates * XON2 and XOFF2 * 10 -> transmitter generates * XON1 and XOFF1 * 11 -> transmitter generates * XON1, XON2, XOFF1 and * XOFF2 */ /* GPIO configuration register bits */ #define MAX310X_GPIOCFG_GP0OUT_BIT (1 << 0) /* GPIO 0 output enable */ #define MAX310X_GPIOCFG_GP1OUT_BIT (1 << 1) /* GPIO 1 output enable */ #define MAX310X_GPIOCFG_GP2OUT_BIT (1 << 2) /* GPIO 2 output enable */ #define MAX310X_GPIOCFG_GP3OUT_BIT (1 << 3) /* GPIO 3 output enable */ #define MAX310X_GPIOCFG_GP0OD_BIT (1 << 4) /* GPIO 0 open-drain enable */ #define MAX310X_GPIOCFG_GP1OD_BIT (1 << 5) /* GPIO 1 open-drain enable */ #define MAX310X_GPIOCFG_GP2OD_BIT (1 << 6) /* GPIO 2 open-drain enable */ #define MAX310X_GPIOCFG_GP3OD_BIT (1 << 7) /* GPIO 3 open-drain enable */ /* GPIO DATA register bits */ #define MAX310X_GPIODATA_GP0OUT_BIT (1 << 0) /* GPIO 0 output value */ #define MAX310X_GPIODATA_GP1OUT_BIT (1 << 1) /* GPIO 1 output value */ #define MAX310X_GPIODATA_GP2OUT_BIT (1 << 2) /* GPIO 2 output value */ #define MAX310X_GPIODATA_GP3OUT_BIT (1 << 3) /* GPIO 3 output value */ #define MAX310X_GPIODATA_GP0IN_BIT (1 << 4) /* GPIO 0 input value */ #define MAX310X_GPIODATA_GP1IN_BIT (1 << 5) /* GPIO 1 input value */ #define MAX310X_GPIODATA_GP2IN_BIT (1 << 6) /* GPIO 2 input value */ #define MAX310X_GPIODATA_GP3IN_BIT (1 << 7) /* GPIO 3 input value */ /* PLL configuration register masks */ #define MAX310X_PLLCFG_PREDIV_MASK (0x3f) /* PLL predivision value */ #define MAX310X_PLLCFG_PLLFACTOR_MASK (0xc0) /* PLL multiplication factor */ /* Baud rate generator configuration register bits */ #define MAX310X_BRGCFG_2XMODE_BIT (1 << 4) /* Double baud rate */ #define MAX310X_BRGCFG_4XMODE_BIT (1 << 5) /* Quadruple baud rate */ /* Clock source register bits */ #define MAX310X_CLKSRC_CRYST_BIT (1 << 1) /* Crystal osc enable */ #define MAX310X_CLKSRC_PLL_BIT (1 << 2) /* PLL enable */ #define MAX310X_CLKSRC_PLLBYP_BIT (1 << 3) /* PLL bypass */ #define MAX310X_CLKSRC_EXTCLK_BIT (1 << 4) /* External clock enable */ #define MAX310X_CLKSRC_CLK2RTS_BIT (1 << 7) /* Baud clk to RTS pin */ /* Misc definitions */ #define MAX310X_FIFO_SIZE (128) /* MAX3107 specific */ #define MAX3107_REV_ID (0xa0) #define MAX3107_REV_MASK (0xfe) /* IRQ status bits definitions */ #define MAX310X_IRQ_TX (MAX310X_IRQ_TXFIFO_BIT | \ MAX310X_IRQ_TXEMPTY_BIT) #define MAX310X_IRQ_RX (MAX310X_IRQ_RXFIFO_BIT | \ MAX310X_IRQ_RXEMPTY_BIT) /* Supported chip types */ enum { MAX310X_TYPE_MAX3107 = 3107, MAX310X_TYPE_MAX3108 = 3108, }; struct max310x_port { struct uart_driver uart; struct uart_port port; const char *name; int uartclk; unsigned int nr_gpio; #ifdef CONFIG_GPIOLIB struct gpio_chip gpio; #endif struct regmap *regmap; struct regmap_config regcfg; struct workqueue_struct *wq; struct work_struct tx_work; struct mutex max310x_mutex; struct max310x_pdata *pdata; }; static bool max3107_8_reg_writeable(struct device *dev, unsigned int reg) { switch (reg) { case MAX310X_IRQSTS_REG: case MAX310X_LSR_IRQSTS_REG: case MAX310X_SPCHR_IRQSTS_REG: case MAX310X_STS_IRQSTS_REG: case MAX310X_TXFIFOLVL_REG: case MAX310X_RXFIFOLVL_REG: case MAX3107_REVID_REG: /* Only available on MAX3107 */ return false; default: break; } return true; } static bool max310x_reg_volatile(struct device *dev, unsigned int reg) { switch (reg) { case MAX310X_RHR_REG: case MAX310X_IRQSTS_REG: case MAX310X_LSR_IRQSTS_REG: case MAX310X_SPCHR_IRQSTS_REG: case MAX310X_STS_IRQSTS_REG: case MAX310X_TXFIFOLVL_REG: case MAX310X_RXFIFOLVL_REG: case MAX310X_GPIODATA_REG: return true; default: break; } return false; } static bool max310x_reg_precious(struct device *dev, unsigned int reg) { switch (reg) { case MAX310X_RHR_REG: case MAX310X_IRQSTS_REG: case MAX310X_SPCHR_IRQSTS_REG: case MAX310X_STS_IRQSTS_REG: return true; default: break; } return false; } static void max310x_set_baud(struct max310x_port *s, int baud) { unsigned int mode = 0, div = s->uartclk / baud; if (!(div / 16)) { /* Mode x2 */ mode = MAX310X_BRGCFG_2XMODE_BIT; div = (s->uartclk * 2) / baud; } if (!(div / 16)) { /* Mode x4 */ mode = MAX310X_BRGCFG_4XMODE_BIT; div = (s->uartclk * 4) / baud; } regmap_write(s->regmap, MAX310X_BRGDIVMSB_REG, ((div / 16) >> 8) & 0xff); regmap_write(s->regmap, MAX310X_BRGDIVLSB_REG, (div / 16) & 0xff); regmap_write(s->regmap, MAX310X_BRGCFG_REG, (div % 16) | mode); } static void max310x_wait_pll(struct max310x_port *s) { int tryes = 1000; /* Wait for PLL only if crystal is used */ if (!(s->pdata->driver_flags & MAX310X_EXT_CLK)) { unsigned int sts = 0; while (tryes--) { regmap_read(s->regmap, MAX310X_STS_IRQSTS_REG, &sts); if (sts & MAX310X_STS_CLKREADY_BIT) break; } } } static int max310x_update_best_err(unsigned long f, long *besterr) { /* Use baudrate 115200 for calculate error */ long err = f % (115200 * 16); if ((*besterr < 0) || (*besterr > err)) { *besterr = err; return 0; } return 1; } static int max310x_set_ref_clk(struct max310x_port *s) { unsigned int div, clksrc, pllcfg = 0; long besterr = -1; unsigned long fdiv, fmul, bestfreq = s->pdata->frequency; /* First, update error without PLL */ max310x_update_best_err(s->pdata->frequency, &besterr); /* Try all possible PLL dividers */ for (div = 1; (div <= 63) && besterr; div++) { fdiv = DIV_ROUND_CLOSEST(s->pdata->frequency, div); /* Try multiplier 6 */ fmul = fdiv * 6; if ((fdiv >= 500000) && (fdiv <= 800000)) if (!max310x_update_best_err(fmul, &besterr)) { pllcfg = (0 << 6) | div; bestfreq = fmul; } /* Try multiplier 48 */ fmul = fdiv * 48; if ((fdiv >= 850000) && (fdiv <= 1200000)) if (!max310x_update_best_err(fmul, &besterr)) { pllcfg = (1 << 6) | div; bestfreq = fmul; } /* Try multiplier 96 */ fmul = fdiv * 96; if ((fdiv >= 425000) && (fdiv <= 1000000)) if (!max310x_update_best_err(fmul, &besterr)) { pllcfg = (2 << 6) | div; bestfreq = fmul; } /* Try multiplier 144 */ fmul = fdiv * 144; if ((fdiv >= 390000) && (fdiv <= 667000)) if (!max310x_update_best_err(fmul, &besterr)) { pllcfg = (3 << 6) | div; bestfreq = fmul; } } /* Configure clock source */ if (s->pdata->driver_flags & MAX310X_EXT_CLK) clksrc = MAX310X_CLKSRC_EXTCLK_BIT; else clksrc = MAX310X_CLKSRC_CRYST_BIT; /* Configure PLL */ if (pllcfg) { clksrc |= MAX310X_CLKSRC_PLL_BIT; regmap_write(s->regmap, MAX310X_PLLCFG_REG, pllcfg); } else clksrc |= MAX310X_CLKSRC_PLLBYP_BIT; regmap_write(s->regmap, MAX310X_CLKSRC_REG, clksrc); if (pllcfg) max310x_wait_pll(s); dev_dbg(s->port.dev, "Reference clock set to %lu Hz\n", bestfreq); return (int)bestfreq; } static void max310x_handle_rx(struct max310x_port *s, unsigned int rxlen) { unsigned int sts = 0, ch = 0, flag; if (unlikely(rxlen >= MAX310X_FIFO_SIZE)) { dev_warn(s->port.dev, "Possible RX FIFO overrun %d\n", rxlen); /* Ensure sanity of RX level */ rxlen = MAX310X_FIFO_SIZE; } dev_dbg(s->port.dev, "RX Len = %u\n", rxlen); while (rxlen--) { regmap_read(s->regmap, MAX310X_RHR_REG, &ch); regmap_read(s->regmap, MAX310X_LSR_IRQSTS_REG, &sts); sts &= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_FRERR_BIT | MAX310X_LSR_RXOVR_BIT | MAX310X_LSR_RXBRK_BIT; s->port.icount.rx++; flag = TTY_NORMAL; if (unlikely(sts)) { if (sts & MAX310X_LSR_RXBRK_BIT) { s->port.icount.brk++; if (uart_handle_break(&s->port)) continue; } else if (sts & MAX310X_LSR_RXPAR_BIT) s->port.icount.parity++; else if (sts & MAX310X_LSR_FRERR_BIT) s->port.icount.frame++; else if (sts & MAX310X_LSR_RXOVR_BIT) s->port.icount.overrun++; sts &= s->port.read_status_mask; if (sts & MAX310X_LSR_RXBRK_BIT) flag = TTY_BREAK; else if (sts & MAX310X_LSR_RXPAR_BIT) flag = TTY_PARITY; else if (sts & MAX310X_LSR_FRERR_BIT) flag = TTY_FRAME; else if (sts & MAX310X_LSR_RXOVR_BIT) flag = TTY_OVERRUN; } if (uart_handle_sysrq_char(s->port, ch)) continue; if (sts & s->port.ignore_status_mask) continue; uart_insert_char(&s->port, sts, MAX310X_LSR_RXOVR_BIT, ch, flag); } tty_flip_buffer_push(&s->port.state->port); } static void max310x_handle_tx(struct max310x_port *s) { struct circ_buf *xmit = &s->port.state->xmit; unsigned int txlen = 0, to_send; if (unlikely(s->port.x_char)) { regmap_write(s->regmap, MAX310X_THR_REG, s->port.x_char); s->port.icount.tx++; s->port.x_char = 0; return; } if (uart_circ_empty(xmit) || uart_tx_stopped(&s->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 */ regmap_read(s->regmap, MAX310X_TXFIFOLVL_REG, &txlen); txlen = MAX310X_FIFO_SIZE - txlen; to_send = (to_send > txlen) ? txlen : to_send; dev_dbg(s->port.dev, "TX Len = %u\n", to_send); /* Add data to send */ s->port.icount.tx += to_send; while (to_send--) { regmap_write(s->regmap, MAX310X_THR_REG, xmit->buf[xmit->tail]); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); }; } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&s->port); } static irqreturn_t max310x_ist(int irq, void *dev_id) { struct max310x_port *s = (struct max310x_port *)dev_id; unsigned int ists = 0, lsr = 0, rxlen = 0; mutex_lock(&s->max310x_mutex); for (;;) { /* Read IRQ status & RX FIFO level */ regmap_read(s->regmap, MAX310X_IRQSTS_REG, &ists); regmap_read(s->regmap, MAX310X_LSR_IRQSTS_REG, &lsr); regmap_read(s->regmap, MAX310X_RXFIFOLVL_REG, &rxlen); if (!ists && !(lsr & MAX310X_LSR_RXTO_BIT) && !rxlen) break; dev_dbg(s->port.dev, "IRQ status: 0x%02x\n", ists); if (rxlen) max310x_handle_rx(s, rxlen); if (ists & MAX310X_IRQ_TX) max310x_handle_tx(s); if (ists & MAX310X_IRQ_CTS_BIT) uart_handle_cts_change(&s->port, !!(lsr & MAX310X_LSR_CTS_BIT)); } mutex_unlock(&s->max310x_mutex); return IRQ_HANDLED; } static void max310x_wq_proc(struct work_struct *ws) { struct max310x_port *s = container_of(ws, struct max310x_port, tx_work); mutex_lock(&s->max310x_mutex); max310x_handle_tx(s); mutex_unlock(&s->max310x_mutex); } static void max310x_start_tx(struct uart_port *port) { struct max310x_port *s = container_of(port, struct max310x_port, port); queue_work(s->wq, &s->tx_work); } static void max310x_stop_tx(struct uart_port *port) { /* Do nothing */ } static void max310x_stop_rx(struct uart_port *port) { /* Do nothing */ } static unsigned int max310x_tx_empty(struct uart_port *port) { unsigned int val = 0; struct max310x_port *s = container_of(port, struct max310x_port, port); mutex_lock(&s->max310x_mutex); regmap_read(s->regmap, MAX310X_TXFIFOLVL_REG, &val); mutex_unlock(&s->max310x_mutex); return val ? 0 : TIOCSER_TEMT; } static void max310x_enable_ms(struct uart_port *port) { /* Modem status not supported */ } static unsigned int max310x_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 max310x_set_mctrl(struct uart_port *port, unsigned int mctrl) { /* DCD and DSR are not wired and CTS/RTS is hadnled automatically * so do nothing */ } static void max310x_break_ctl(struct uart_port *port, int break_state) { struct max310x_port *s = container_of(port, struct max310x_port, port); mutex_lock(&s->max310x_mutex); regmap_update_bits(s->regmap, MAX310X_LCR_REG, MAX310X_LCR_TXBREAK_BIT, break_state ? MAX310X_LCR_TXBREAK_BIT : 0); mutex_unlock(&s->max310x_mutex); } static void max310x_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct max310x_port *s = container_of(port, struct max310x_port, port); unsigned int lcr, flow = 0; int baud; mutex_lock(&s->max310x_mutex); /* Mask termios capabilities we don't support */ termios->c_cflag &= ~CMSPAR; termios->c_iflag &= ~IXANY; /* Word size */ switch (termios->c_cflag & CSIZE) { case CS5: lcr = MAX310X_LCR_WORD_LEN_5; break; case CS6: lcr = MAX310X_LCR_WORD_LEN_6; break; case CS7: lcr = MAX310X_LCR_WORD_LEN_7; break; case CS8: default: lcr = MAX310X_LCR_WORD_LEN_8; break; } /* Parity */ if (termios->c_cflag & PARENB) { lcr |= MAX310X_LCR_PARITY_BIT; if (!(termios->c_cflag & PARODD)) lcr |= MAX310X_LCR_EVENPARITY_BIT; } /* Stop bits */ if (termios->c_cflag & CSTOPB) lcr |= MAX310X_LCR_STOPLEN_BIT; /* 2 stops */ /* Update LCR register */ regmap_write(s->regmap, MAX310X_LCR_REG, lcr); /* Set read status mask */ port->read_status_mask = MAX310X_LSR_RXOVR_BIT; if (termios->c_iflag & INPCK) port->read_status_mask |= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_FRERR_BIT; if (termios->c_iflag & (BRKINT | PARMRK)) port->read_status_mask |= MAX310X_LSR_RXBRK_BIT; /* Set status ignore mask */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNBRK) port->ignore_status_mask |= MAX310X_LSR_RXBRK_BIT; if (!(termios->c_cflag & CREAD)) port->ignore_status_mask |= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_RXOVR_BIT | MAX310X_LSR_FRERR_BIT | MAX310X_LSR_RXBRK_BIT; /* Configure flow control */ regmap_write(s->regmap, MAX310X_XON1_REG, termios->c_cc[VSTART]); regmap_write(s->regmap, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]); if (termios->c_cflag & CRTSCTS) flow |= MAX310X_FLOWCTRL_AUTOCTS_BIT | MAX310X_FLOWCTRL_AUTORTS_BIT; if (termios->c_iflag & IXON) flow |= MAX310X_FLOWCTRL_SWFLOW3_BIT | MAX310X_FLOWCTRL_SWFLOWEN_BIT; if (termios->c_iflag & IXOFF) flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT | MAX310X_FLOWCTRL_SWFLOWEN_BIT; regmap_write(s->regmap, MAX310X_FLOWCTRL_REG, flow); /* Get baud rate generator configuration */ baud = uart_get_baud_rate(port, termios, old, port->uartclk / 16 / 0xffff, port->uartclk / 4); /* Setup baudrate generator */ max310x_set_baud(s, baud); /* Update timeout according to new baud rate */ uart_update_timeout(port, termios->c_cflag, baud); mutex_unlock(&s->max310x_mutex); } static int max310x_startup(struct uart_port *port) { unsigned int val, line = port->line; struct max310x_port *s = container_of(port, struct max310x_port, port); if (s->pdata->suspend) s->pdata->suspend(0); mutex_lock(&s->max310x_mutex); /* Configure baud rate, 9600 as default */ max310x_set_baud(s, 9600); /* Configure LCR register, 8N1 mode by default */ val = MAX310X_LCR_WORD_LEN_8; regmap_write(s->regmap, MAX310X_LCR_REG, val); /* Configure MODE1 register */ regmap_update_bits(s->regmap, MAX310X_MODE1_REG, MAX310X_MODE1_TRNSCVCTRL_BIT, (s->pdata->uart_flags[line] & MAX310X_AUTO_DIR_CTRL) ? MAX310X_MODE1_TRNSCVCTRL_BIT : 0); /* Configure MODE2 register */ val = MAX310X_MODE2_RXEMPTINV_BIT; if (s->pdata->uart_flags[line] & MAX310X_LOOPBACK) val |= MAX310X_MODE2_LOOPBACK_BIT; if (s->pdata->uart_flags[line] & MAX310X_ECHO_SUPRESS) val |= MAX310X_MODE2_ECHOSUPR_BIT; /* Reset FIFOs */ val |= MAX310X_MODE2_FIFORST_BIT; regmap_write(s->regmap, MAX310X_MODE2_REG, val); /* Configure FIFO trigger level register */ /* RX FIFO trigger for 16 words, TX FIFO trigger for 64 words */ val = MAX310X_FIFOTRIGLVL_RX(16) | MAX310X_FIFOTRIGLVL_TX(64); regmap_write(s->regmap, MAX310X_FIFOTRIGLVL_REG, val); /* Configure flow control levels */ /* Flow control halt level 96, resume level 48 */ val = MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96); regmap_write(s->regmap, MAX310X_FLOWLVL_REG, val); /* Clear timeout register */ regmap_write(s->regmap, MAX310X_RXTO_REG, 0); /* Configure LSR interrupt enable register */ /* Enable RX timeout interrupt */ val = MAX310X_LSR_RXTO_BIT; regmap_write(s->regmap, MAX310X_LSR_IRQEN_REG, val); /* Clear FIFO reset */ regmap_update_bits(s->regmap, MAX310X_MODE2_REG, MAX310X_MODE2_FIFORST_BIT, 0); /* Clear IRQ status register by reading it */ regmap_read(s->regmap, MAX310X_IRQSTS_REG, &val); /* Configure interrupt enable register */ /* Enable CTS change interrupt */ val = MAX310X_IRQ_CTS_BIT; /* Enable RX, TX interrupts */ val |= MAX310X_IRQ_RX | MAX310X_IRQ_TX; regmap_write(s->regmap, MAX310X_IRQEN_REG, val); mutex_unlock(&s->max310x_mutex); return 0; } static void max310x_shutdown(struct uart_port *port) { struct max310x_port *s = container_of(port, struct max310x_port, port); /* Disable all interrupts */ mutex_lock(&s->max310x_mutex); regmap_write(s->regmap, MAX310X_IRQEN_REG, 0); mutex_unlock(&s->max310x_mutex); if (s->pdata->suspend) s->pdata->suspend(1); } static const char *max310x_type(struct uart_port *port) { struct max310x_port *s = container_of(port, struct max310x_port, port); return (port->type == PORT_MAX310X) ? s->name : NULL; } static int max310x_request_port(struct uart_port *port) { /* Do nothing */ return 0; } static void max310x_release_port(struct uart_port *port) { /* Do nothing */ } static void max310x_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) port->type = PORT_MAX310X; } static int max310x_verify_port(struct uart_port *port, struct serial_struct *ser) { if ((ser->type == PORT_UNKNOWN) || (ser->type == PORT_MAX310X)) return 0; if (ser->irq == port->irq) return 0; return -EINVAL; } static struct uart_ops max310x_ops = { .tx_empty = max310x_tx_empty, .set_mctrl = max310x_set_mctrl, .get_mctrl = max310x_get_mctrl, .stop_tx = max310x_stop_tx, .start_tx = max310x_start_tx, .stop_rx = max310x_stop_rx, .enable_ms = max310x_enable_ms, .break_ctl = max310x_break_ctl, .startup = max310x_startup, .shutdown = max310x_shutdown, .set_termios = max310x_set_termios, .type = max310x_type, .request_port = max310x_request_port, .release_port = max310x_release_port, .config_port = max310x_config_port, .verify_port = max310x_verify_port, }; #ifdef CONFIG_PM_SLEEP static int max310x_suspend(struct device *dev) { int ret; struct max310x_port *s = dev_get_drvdata(dev); dev_dbg(dev, "Suspend\n"); ret = uart_suspend_port(&s->uart, &s->port); mutex_lock(&s->max310x_mutex); /* Enable sleep mode */ regmap_update_bits(s->regmap, MAX310X_MODE1_REG, MAX310X_MODE1_FORCESLEEP_BIT, MAX310X_MODE1_FORCESLEEP_BIT); mutex_unlock(&s->max310x_mutex); if (s->pdata->suspend) s->pdata->suspend(1); return ret; } static int max310x_resume(struct device *dev) { struct max310x_port *s = dev_get_drvdata(dev); dev_dbg(dev, "Resume\n"); if (s->pdata->suspend) s->pdata->suspend(0); mutex_lock(&s->max310x_mutex); /* Disable sleep mode */ regmap_update_bits(s->regmap, MAX310X_MODE1_REG, MAX310X_MODE1_FORCESLEEP_BIT, 0); max310x_wait_pll(s); mutex_unlock(&s->max310x_mutex); return uart_resume_port(&s->uart, &s->port); } static SIMPLE_DEV_PM_OPS(max310x_pm_ops, max310x_suspend, max310x_resume); #define MAX310X_PM_OPS (&max310x_pm_ops) #else #define MAX310X_PM_OPS NULL #endif #ifdef CONFIG_GPIOLIB static int max310x_gpio_get(struct gpio_chip *chip, unsigned offset) { unsigned int val = 0; struct max310x_port *s = container_of(chip, struct max310x_port, gpio); mutex_lock(&s->max310x_mutex); regmap_read(s->regmap, MAX310X_GPIODATA_REG, &val); mutex_unlock(&s->max310x_mutex); return !!((val >> 4) & (1 << offset)); } static void max310x_gpio_set(struct gpio_chip *chip, unsigned offset, int value) { struct max310x_port *s = container_of(chip, struct max310x_port, gpio); mutex_lock(&s->max310x_mutex); regmap_update_bits(s->regmap, MAX310X_GPIODATA_REG, 1 << offset, value ? 1 << offset : 0); mutex_unlock(&s->max310x_mutex); } static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned offset) { struct max310x_port *s = container_of(chip, struct max310x_port, gpio); mutex_lock(&s->max310x_mutex); regmap_update_bits(s->regmap, MAX310X_GPIOCFG_REG, 1 << offset, 0); mutex_unlock(&s->max310x_mutex); return 0; } static int max310x_gpio_direction_output(struct gpio_chip *chip, unsigned offset, int value) { struct max310x_port *s = container_of(chip, struct max310x_port, gpio); mutex_lock(&s->max310x_mutex); regmap_update_bits(s->regmap, MAX310X_GPIOCFG_REG, 1 << offset, 1 << offset); regmap_update_bits(s->regmap, MAX310X_GPIODATA_REG, 1 << offset, value ? 1 << offset : 0); mutex_unlock(&s->max310x_mutex); return 0; } #endif /* Generic platform data */ static struct max310x_pdata generic_plat_data = { .driver_flags = MAX310X_EXT_CLK, .uart_flags[0] = MAX310X_ECHO_SUPRESS, .frequency = 26000000, }; static int max310x_probe(struct spi_device *spi) { struct max310x_port *s; struct device *dev = &spi->dev; int chiptype = spi_get_device_id(spi)->driver_data; struct max310x_pdata *pdata = dev->platform_data; unsigned int val = 0; int ret; /* Check for IRQ */ if (spi->irq <= 0) { dev_err(dev, "No IRQ specified\n"); return -ENOTSUPP; } /* Alloc port structure */ s = devm_kzalloc(dev, sizeof(struct max310x_port), GFP_KERNEL); if (!s) { dev_err(dev, "Error allocating port structure\n"); return -ENOMEM; } dev_set_drvdata(dev, s); if (!pdata) { dev_warn(dev, "No platform data supplied, using defaults\n"); pdata = &generic_plat_data; } s->pdata = pdata; /* Individual chip settings */ switch (chiptype) { case MAX310X_TYPE_MAX3107: s->name = "MAX3107"; s->nr_gpio = 4; s->uart.nr = 1; s->regcfg.max_register = 0x1f; break; case MAX310X_TYPE_MAX3108: s->name = "MAX3108"; s->nr_gpio = 4; s->uart.nr = 1; s->regcfg.max_register = 0x1e; break; default: dev_err(dev, "Unsupported chip type %i\n", chiptype); return -ENOTSUPP; } /* Check input frequency */ if ((pdata->driver_flags & MAX310X_EXT_CLK) && ((pdata->frequency < 500000) || (pdata->frequency > 35000000))) goto err_freq; /* Check frequency for quartz */ if (!(pdata->driver_flags & MAX310X_EXT_CLK) && ((pdata->frequency < 1000000) || (pdata->frequency > 4000000))) goto err_freq; mutex_init(&s->max310x_mutex); /* Setup SPI bus */ spi->mode = SPI_MODE_0; spi->bits_per_word = 8; spi->max_speed_hz = 26000000; spi_setup(spi); /* Setup regmap */ s->regcfg.reg_bits = 8; s->regcfg.val_bits = 8; s->regcfg.read_flag_mask = 0x00; s->regcfg.write_flag_mask = 0x80; s->regcfg.cache_type = REGCACHE_RBTREE; s->regcfg.writeable_reg = max3107_8_reg_writeable; s->regcfg.volatile_reg = max310x_reg_volatile; s->regcfg.precious_reg = max310x_reg_precious; s->regmap = devm_regmap_init_spi(spi, &s->regcfg); if (IS_ERR(s->regmap)) { ret = PTR_ERR(s->regmap); dev_err(dev, "Failed to initialize register map\n"); goto err_out; } /* Reset chip & check SPI function */ ret = regmap_write(s->regmap, MAX310X_MODE2_REG, MAX310X_MODE2_RST_BIT); if (ret) { dev_err(dev, "SPI transfer failed\n"); goto err_out; } /* Clear chip reset */ regmap_write(s->regmap, MAX310X_MODE2_REG, 0); switch (chiptype) { case MAX310X_TYPE_MAX3107: /* Check REV ID to ensure we are talking to what we expect */ regmap_read(s->regmap, MAX3107_REVID_REG, &val); if (((val & MAX3107_REV_MASK) != MAX3107_REV_ID)) { dev_err(dev, "%s ID 0x%02x does not match\n", s->name, val); ret = -ENODEV; goto err_out; } break; case MAX310X_TYPE_MAX3108: /* MAX3108 have not REV ID register, we just check default value * from clocksource register to make sure everything works. */ regmap_read(s->regmap, MAX310X_CLKSRC_REG, &val); if (val != (MAX310X_CLKSRC_EXTCLK_BIT | MAX310X_CLKSRC_PLLBYP_BIT)) { dev_err(dev, "%s not present\n", s->name); ret = -ENODEV; goto err_out; } break; } /* Board specific configure */ if (pdata->init) pdata->init(); if (pdata->suspend) pdata->suspend(0); /* Calculate referecne clock */ s->uartclk = max310x_set_ref_clk(s); /* Disable all interrupts */ regmap_write(s->regmap, MAX310X_IRQEN_REG, 0); /* Setup MODE1 register */ val = MAX310X_MODE1_IRQSEL_BIT; /* Enable IRQ pin */ if (pdata->driver_flags & MAX310X_AUTOSLEEP) val = MAX310X_MODE1_AUTOSLEEP_BIT; regmap_write(s->regmap, MAX310X_MODE1_REG, val); /* Setup interrupt */ ret = devm_request_threaded_irq(dev, spi->irq, NULL, max310x_ist, IRQF_TRIGGER_FALLING | IRQF_ONESHOT, dev_name(dev), s); if (ret) { dev_err(dev, "Unable to reguest IRQ %i\n", spi->irq); goto err_out; } /* Register UART driver */ s->uart.owner = THIS_MODULE; s->uart.driver_name = dev_name(dev); s->uart.dev_name = "ttyMAX"; s->uart.major = MAX310X_MAJOR; s->uart.minor = MAX310X_MINOR; ret = uart_register_driver(&s->uart); if (ret) { dev_err(dev, "Registering UART driver failed\n"); goto err_out; } /* Initialize workqueue for start TX */ s->wq = create_freezable_workqueue(dev_name(dev)); INIT_WORK(&s->tx_work, max310x_wq_proc); /* Initialize UART port data */ s->port.line = 0; s->port.dev = dev; s->port.irq = spi->irq; s->port.type = PORT_MAX310X; s->port.fifosize = MAX310X_FIFO_SIZE; s->port.flags = UPF_SKIP_TEST | UPF_FIXED_TYPE; s->port.iotype = UPIO_PORT; s->port.membase = (void __iomem *)0xffffffff; /* Bogus value */ s->port.uartclk = s->uartclk; s->port.ops = &max310x_ops; uart_add_one_port(&s->uart, &s->port); #ifdef CONFIG_GPIOLIB /* Setup GPIO cotroller */ if (pdata->gpio_base) { s->gpio.owner = THIS_MODULE; s->gpio.dev = dev; s->gpio.label = dev_name(dev); s->gpio.direction_input = max310x_gpio_direction_input; s->gpio.get = max310x_gpio_get; s->gpio.direction_output= max310x_gpio_direction_output; s->gpio.set = max310x_gpio_set; s->gpio.base = pdata->gpio_base; s->gpio.ngpio = s->nr_gpio; s->gpio.can_sleep = 1; if (gpiochip_add(&s->gpio)) { /* Indicate that we should not call gpiochip_remove */ s->gpio.base = 0; } } else dev_info(dev, "GPIO support not enabled\n"); #endif /* Go to suspend mode */ if (pdata->suspend) pdata->suspend(1); return 0; err_freq: dev_err(dev, "Frequency parameter incorrect\n"); ret = -EINVAL; err_out: dev_set_drvdata(dev, NULL); return ret; } static int max310x_remove(struct spi_device *spi) { struct device *dev = &spi->dev; struct max310x_port *s = dev_get_drvdata(dev); int ret = 0; dev_dbg(dev, "Removing port\n"); devm_free_irq(dev, s->port.irq, s); destroy_workqueue(s->wq); uart_remove_one_port(&s->uart, &s->port); uart_unregister_driver(&s->uart); #ifdef CONFIG_GPIOLIB if (s->pdata->gpio_base) { ret = gpiochip_remove(&s->gpio); if (ret) dev_err(dev, "Failed to remove gpio chip: %d\n", ret); } #endif dev_set_drvdata(dev, NULL); if (s->pdata->suspend) s->pdata->suspend(1); if (s->pdata->exit) s->pdata->exit(); return ret; } static const struct spi_device_id max310x_id_table[] = { { "max3107", MAX310X_TYPE_MAX3107 }, { "max3108", MAX310X_TYPE_MAX3108 }, { } }; MODULE_DEVICE_TABLE(spi, max310x_id_table); static struct spi_driver max310x_driver = { .driver = { .name = "max310x", .owner = THIS_MODULE, .pm = MAX310X_PM_OPS, }, .probe = max310x_probe, .remove = max310x_remove, .id_table = max310x_id_table, }; module_spi_driver(max310x_driver); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Alexander Shiyan "); MODULE_DESCRIPTION("MAX310X serial driver");