/* * Maxim (Dallas) MAX3107/8/9, MAX14830 serial driver * * Copyright (C) 2012-2014 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define MAX310X_NAME "max310x" #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_REG_05 (0x05) #define MAX310X_SPCHR_IRQEN_REG MAX310X_REG_05 /* Special char IRQ en */ #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 */ #define MAX310X_REG_1F (0x1f) #define MAX310X_REVID_REG MAX310X_REG_1F /* Revision ID */ #define MAX310X_GLOBALIRQ_REG MAX310X_REG_1F /* Global IRQ (RO) */ #define MAX310X_GLOBALCMD_REG MAX310X_REG_1F /* Global Command (WO) */ /* Extended registers */ #define MAX310X_REVID_EXTREG MAX310X_REG_05 /* Revision ID */ /* 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 */ /* 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 */ /* 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 */ /* Global commands */ #define MAX310X_EXTREG_ENBL (0xce) #define MAX310X_EXTREG_DSBL (0xcd) /* Misc definitions */ #define MAX310X_FIFO_SIZE (128) #define MAX310x_REV_MASK (0xfc) /* MAX3107 specific */ #define MAX3107_REV_ID (0xa0) /* MAX3109 specific */ #define MAX3109_REV_ID (0xc0) /* MAX14830 specific */ #define MAX14830_BRGCFG_CLKDIS_BIT (1 << 6) /* Clock Disable */ #define MAX14830_REV_ID (0xb0) struct max310x_devtype { char name[9]; int nr; int (*detect)(struct device *); void (*power)(struct uart_port *, int); }; struct max310x_one { struct uart_port port; struct work_struct tx_work; struct work_struct md_work; }; struct max310x_port { struct uart_driver uart; struct max310x_devtype *devtype; struct regmap *regmap; struct mutex mutex; struct clk *clk; #ifdef CONFIG_GPIOLIB struct gpio_chip gpio; #endif struct max310x_one p[0]; }; static u8 max310x_port_read(struct uart_port *port, u8 reg) { struct max310x_port *s = dev_get_drvdata(port->dev); unsigned int val = 0; regmap_read(s->regmap, port->iobase + reg, &val); return val; } static void max310x_port_write(struct uart_port *port, u8 reg, u8 val) { struct max310x_port *s = dev_get_drvdata(port->dev); regmap_write(s->regmap, port->iobase + reg, val); } static void max310x_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val) { struct max310x_port *s = dev_get_drvdata(port->dev); regmap_update_bits(s->regmap, port->iobase + reg, mask, val); } static int max3107_detect(struct device *dev) { struct max310x_port *s = dev_get_drvdata(dev); unsigned int val = 0; int ret; ret = regmap_read(s->regmap, MAX310X_REVID_REG, &val); if (ret) return ret; if (((val & MAX310x_REV_MASK) != MAX3107_REV_ID)) { dev_err(dev, "%s ID 0x%02x does not match\n", s->devtype->name, val); return -ENODEV; } return 0; } static int max3108_detect(struct device *dev) { struct max310x_port *s = dev_get_drvdata(dev); unsigned int val = 0; int ret; /* MAX3108 have not REV ID register, we just check default value * from clocksource register to make sure everything works. */ ret = regmap_read(s->regmap, MAX310X_CLKSRC_REG, &val); if (ret) return ret; if (val != (MAX310X_CLKSRC_EXTCLK_BIT | MAX310X_CLKSRC_PLLBYP_BIT)) { dev_err(dev, "%s not present\n", s->devtype->name); return -ENODEV; } return 0; } static int max3109_detect(struct device *dev) { struct max310x_port *s = dev_get_drvdata(dev); unsigned int val = 0; int ret; ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_ENBL); if (ret) return ret; regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val); regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL); if (((val & MAX310x_REV_MASK) != MAX3109_REV_ID)) { dev_err(dev, "%s ID 0x%02x does not match\n", s->devtype->name, val); return -ENODEV; } return 0; } static void max310x_power(struct uart_port *port, int on) { max310x_port_update(port, MAX310X_MODE1_REG, MAX310X_MODE1_FORCESLEEP_BIT, on ? 0 : MAX310X_MODE1_FORCESLEEP_BIT); if (on) msleep(50); } static int max14830_detect(struct device *dev) { struct max310x_port *s = dev_get_drvdata(dev); unsigned int val = 0; int ret; ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_ENBL); if (ret) return ret; regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val); regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL); if (((val & MAX310x_REV_MASK) != MAX14830_REV_ID)) { dev_err(dev, "%s ID 0x%02x does not match\n", s->devtype->name, val); return -ENODEV; } return 0; } static void max14830_power(struct uart_port *port, int on) { max310x_port_update(port, MAX310X_BRGCFG_REG, MAX14830_BRGCFG_CLKDIS_BIT, on ? 0 : MAX14830_BRGCFG_CLKDIS_BIT); if (on) msleep(50); } static const struct max310x_devtype max3107_devtype = { .name = "MAX3107", .nr = 1, .detect = max3107_detect, .power = max310x_power, }; static const struct max310x_devtype max3108_devtype = { .name = "MAX3108", .nr = 1, .detect = max3108_detect, .power = max310x_power, }; static const struct max310x_devtype max3109_devtype = { .name = "MAX3109", .nr = 2, .detect = max3109_detect, .power = max310x_power, }; static const struct max310x_devtype max14830_devtype = { .name = "MAX14830", .nr = 4, .detect = max14830_detect, .power = max14830_power, }; static bool max310x_reg_writeable(struct device *dev, unsigned int reg) { switch (reg & 0x1f) { 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: return false; default: break; } return true; } static bool max310x_reg_volatile(struct device *dev, unsigned int reg) { switch (reg & 0x1f) { 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: case MAX310X_BRGDIVLSB_REG: case MAX310X_REG_05: case MAX310X_REG_1F: return true; default: break; } return false; } static bool max310x_reg_precious(struct device *dev, unsigned int reg) { switch (reg & 0x1f) { 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 int max310x_set_baud(struct uart_port *port, int baud) { unsigned int mode = 0, clk = port->uartclk, div = clk / baud; /* Check for minimal value for divider */ if (div < 16) div = 16; if (clk % baud && (div / 16) < 0x8000) { /* Mode x2 */ mode = MAX310X_BRGCFG_2XMODE_BIT; clk = port->uartclk * 2; div = clk / baud; if (clk % baud && (div / 16) < 0x8000) { /* Mode x4 */ mode = MAX310X_BRGCFG_4XMODE_BIT; clk = port->uartclk * 4; div = clk / baud; } } max310x_port_write(port, MAX310X_BRGDIVMSB_REG, (div / 16) >> 8); max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div / 16); max310x_port_write(port, MAX310X_BRGCFG_REG, (div % 16) | mode); return DIV_ROUND_CLOSEST(clk, div); } 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 long freq, bool xtal) { unsigned int div, clksrc, pllcfg = 0; long besterr = -1; unsigned long fdiv, fmul, bestfreq = freq; /* First, update error without PLL */ max310x_update_best_err(freq, &besterr); /* Try all possible PLL dividers */ for (div = 1; (div <= 63) && besterr; div++) { fdiv = DIV_ROUND_CLOSEST(freq, 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 */ clksrc = xtal ? MAX310X_CLKSRC_CRYST_BIT : MAX310X_CLKSRC_EXTCLK_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); /* Wait for crystal */ if (pllcfg && xtal) msleep(10); return (int)bestfreq; } static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen) { unsigned int sts, ch, flag; if (unlikely(rxlen >= port->fifosize)) { dev_warn_ratelimited(port->dev, "Port %i: Possible RX FIFO overrun\n", port->line); port->icount.buf_overrun++; /* Ensure sanity of RX level */ rxlen = port->fifosize; } while (rxlen--) { ch = max310x_port_read(port, MAX310X_RHR_REG); sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG); sts &= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_FRERR_BIT | MAX310X_LSR_RXOVR_BIT | MAX310X_LSR_RXBRK_BIT; port->icount.rx++; flag = TTY_NORMAL; if (unlikely(sts)) { if (sts & MAX310X_LSR_RXBRK_BIT) { port->icount.brk++; if (uart_handle_break(port)) continue; } else if (sts & MAX310X_LSR_RXPAR_BIT) port->icount.parity++; else if (sts & MAX310X_LSR_FRERR_BIT) port->icount.frame++; else if (sts & MAX310X_LSR_RXOVR_BIT) port->icount.overrun++; sts &= 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(port, ch)) continue; if (sts & port->ignore_status_mask) continue; uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT, ch, flag); } tty_flip_buffer_push(&port->state->port); } static void max310x_handle_tx(struct uart_port *port) { struct circ_buf *xmit = &port->state->xmit; unsigned int txlen, to_send; if (unlikely(port->x_char)) { max310x_port_write(port, MAX310X_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 = max310x_port_read(port, MAX310X_TXFIFOLVL_REG); txlen = port->fifosize - txlen; to_send = (to_send > txlen) ? txlen : to_send; /* Add data to send */ port->icount.tx += to_send; while (to_send--) { max310x_port_write(port, 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(port); } static void max310x_port_irq(struct max310x_port *s, int portno) { struct uart_port *port = &s->p[portno].port; do { unsigned int ists, lsr, rxlen; /* Read IRQ status & RX FIFO level */ ists = max310x_port_read(port, MAX310X_IRQSTS_REG); rxlen = max310x_port_read(port, MAX310X_RXFIFOLVL_REG); if (!ists && !rxlen) break; if (ists & MAX310X_IRQ_CTS_BIT) { lsr = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG); uart_handle_cts_change(port, !!(lsr & MAX310X_LSR_CTS_BIT)); } if (rxlen) max310x_handle_rx(port, rxlen); if (ists & MAX310X_IRQ_TXEMPTY_BIT) { mutex_lock(&s->mutex); max310x_handle_tx(port); mutex_unlock(&s->mutex); } } while (1); } static irqreturn_t max310x_ist(int irq, void *dev_id) { struct max310x_port *s = (struct max310x_port *)dev_id; if (s->uart.nr > 1) { do { unsigned int val = ~0; WARN_ON_ONCE(regmap_read(s->regmap, MAX310X_GLOBALIRQ_REG, &val)); val = ((1 << s->uart.nr) - 1) & ~val; if (!val) break; max310x_port_irq(s, fls(val) - 1); } while (1); } else max310x_port_irq(s, 0); return IRQ_HANDLED; } static void max310x_wq_proc(struct work_struct *ws) { struct max310x_one *one = container_of(ws, struct max310x_one, tx_work); struct max310x_port *s = dev_get_drvdata(one->port.dev); mutex_lock(&s->mutex); max310x_handle_tx(&one->port); mutex_unlock(&s->mutex); } static void max310x_start_tx(struct uart_port *port) { struct max310x_one *one = container_of(port, struct max310x_one, port); if (!work_pending(&one->tx_work)) schedule_work(&one->tx_work); } static unsigned int max310x_tx_empty(struct uart_port *port) { unsigned int lvl, sts; lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG); sts = max310x_port_read(port, MAX310X_IRQSTS_REG); return ((sts & MAX310X_IRQ_TXEMPTY_BIT) && !lvl) ? TIOCSER_TEMT : 0; } 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_md_proc(struct work_struct *ws) { struct max310x_one *one = container_of(ws, struct max310x_one, md_work); max310x_port_update(&one->port, MAX310X_MODE2_REG, MAX310X_MODE2_LOOPBACK_BIT, (one->port.mctrl & TIOCM_LOOP) ? MAX310X_MODE2_LOOPBACK_BIT : 0); } static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct max310x_one *one = container_of(port, struct max310x_one, port); schedule_work(&one->md_work); } static void max310x_break_ctl(struct uart_port *port, int break_state) { max310x_port_update(port, MAX310X_LCR_REG, MAX310X_LCR_TXBREAK_BIT, break_state ? MAX310X_LCR_TXBREAK_BIT : 0); } static void max310x_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { 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 = 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 */ max310x_port_write(port, 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 & (IGNBRK | 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 */ max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]); max310x_port_write(port, 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; max310x_port_write(port, 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 */ baud = max310x_set_baud(port, baud); /* Update timeout according to new baud rate */ uart_update_timeout(port, termios->c_cflag, baud); } static int max310x_rs485_config(struct uart_port *port, struct serial_rs485 *rs485) { unsigned int val; if (rs485->delay_rts_before_send > 0x0f || rs485->delay_rts_after_send > 0x0f) return -ERANGE; val = (rs485->delay_rts_before_send << 4) | rs485->delay_rts_after_send; max310x_port_write(port, MAX310X_HDPIXDELAY_REG, val); if (rs485->flags & SER_RS485_ENABLED) { max310x_port_update(port, MAX310X_MODE1_REG, MAX310X_MODE1_TRNSCVCTRL_BIT, MAX310X_MODE1_TRNSCVCTRL_BIT); max310x_port_update(port, MAX310X_MODE2_REG, MAX310X_MODE2_ECHOSUPR_BIT, MAX310X_MODE2_ECHOSUPR_BIT); } else { max310x_port_update(port, MAX310X_MODE1_REG, MAX310X_MODE1_TRNSCVCTRL_BIT, 0); max310x_port_update(port, MAX310X_MODE2_REG, MAX310X_MODE2_ECHOSUPR_BIT, 0); } rs485->flags &= SER_RS485_RTS_ON_SEND | SER_RS485_ENABLED; memset(rs485->padding, 0, sizeof(rs485->padding)); port->rs485 = *rs485; return 0; } static int max310x_startup(struct uart_port *port) { struct max310x_port *s = dev_get_drvdata(port->dev); unsigned int val; s->devtype->power(port, 1); /* Configure MODE1 register */ max310x_port_update(port, MAX310X_MODE1_REG, MAX310X_MODE1_TRNSCVCTRL_BIT, 0); /* Configure MODE2 register & Reset FIFOs*/ val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT; max310x_port_write(port, MAX310X_MODE2_REG, val); max310x_port_update(port, MAX310X_MODE2_REG, MAX310X_MODE2_FIFORST_BIT, 0); /* Configure flow control levels */ /* Flow control halt level 96, resume level 48 */ max310x_port_write(port, MAX310X_FLOWLVL_REG, MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96)); /* Clear IRQ status register */ max310x_port_read(port, MAX310X_IRQSTS_REG); /* Enable RX, TX, CTS change interrupts */ val = MAX310X_IRQ_RXEMPTY_BIT | MAX310X_IRQ_TXEMPTY_BIT; max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT); return 0; } static void max310x_shutdown(struct uart_port *port) { struct max310x_port *s = dev_get_drvdata(port->dev); /* Disable all interrupts */ max310x_port_write(port, MAX310X_IRQEN_REG, 0); s->devtype->power(port, 0); } static const char *max310x_type(struct uart_port *port) { struct max310x_port *s = dev_get_drvdata(port->dev); return (port->type == PORT_MAX310X) ? s->devtype->name : NULL; } static int max310x_request_port(struct uart_port *port) { /* Do nothing */ return 0; } 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 *s) { if ((s->type != PORT_UNKNOWN) && (s->type != PORT_MAX310X)) return -EINVAL; if (s->irq != port->irq) return -EINVAL; return 0; } static void max310x_null_void(struct uart_port *port) { /* Do nothing */ } static const struct uart_ops max310x_ops = { .tx_empty = max310x_tx_empty, .set_mctrl = max310x_set_mctrl, .get_mctrl = max310x_get_mctrl, .stop_tx = max310x_null_void, .start_tx = max310x_start_tx, .stop_rx = max310x_null_void, .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_null_void, .config_port = max310x_config_port, .verify_port = max310x_verify_port, }; static int __maybe_unused max310x_suspend(struct device *dev) { struct max310x_port *s = dev_get_drvdata(dev); int i; for (i = 0; i < s->uart.nr; i++) { uart_suspend_port(&s->uart, &s->p[i].port); s->devtype->power(&s->p[i].port, 0); } return 0; } static int __maybe_unused max310x_resume(struct device *dev) { struct max310x_port *s = dev_get_drvdata(dev); int i; for (i = 0; i < s->uart.nr; i++) { s->devtype->power(&s->p[i].port, 1); uart_resume_port(&s->uart, &s->p[i].port); } return 0; } static SIMPLE_DEV_PM_OPS(max310x_pm_ops, max310x_suspend, max310x_resume); #ifdef CONFIG_GPIOLIB static int max310x_gpio_get(struct gpio_chip *chip, unsigned offset) { unsigned int val; struct max310x_port *s = container_of(chip, struct max310x_port, gpio); struct uart_port *port = &s->p[offset / 4].port; val = max310x_port_read(port, MAX310X_GPIODATA_REG); return !!((val >> 4) & (1 << (offset % 4))); } static void max310x_gpio_set(struct gpio_chip *chip, unsigned offset, int value) { struct max310x_port *s = container_of(chip, struct max310x_port, gpio); struct uart_port *port = &s->p[offset / 4].port; max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4), value ? 1 << (offset % 4) : 0); } static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned offset) { struct max310x_port *s = container_of(chip, struct max310x_port, gpio); struct uart_port *port = &s->p[offset / 4].port; max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4), 0); 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); struct uart_port *port = &s->p[offset / 4].port; max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4), value ? 1 << (offset % 4) : 0); max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4), 1 << (offset % 4)); return 0; } #endif static int max310x_probe(struct device *dev, struct max310x_devtype *devtype, struct regmap *regmap, int irq, unsigned long flags) { int i, ret, fmin, fmax, freq, uartclk; struct clk *clk_osc, *clk_xtal; struct max310x_port *s; bool xtal = false; if (IS_ERR(regmap)) return PTR_ERR(regmap); /* Alloc port structure */ s = devm_kzalloc(dev, sizeof(*s) + sizeof(struct max310x_one) * devtype->nr, GFP_KERNEL); if (!s) { dev_err(dev, "Error allocating port structure\n"); return -ENOMEM; } clk_osc = devm_clk_get(dev, "osc"); clk_xtal = devm_clk_get(dev, "xtal"); if (!IS_ERR(clk_osc)) { s->clk = clk_osc; fmin = 500000; fmax = 35000000; } else if (!IS_ERR(clk_xtal)) { s->clk = clk_xtal; fmin = 1000000; fmax = 4000000; xtal = true; } else if (PTR_ERR(clk_osc) == -EPROBE_DEFER || PTR_ERR(clk_xtal) == -EPROBE_DEFER) { return -EPROBE_DEFER; } else { dev_err(dev, "Cannot get clock\n"); return -EINVAL; } ret = clk_prepare_enable(s->clk); if (ret) return ret; freq = clk_get_rate(s->clk); /* Check frequency limits */ if (freq < fmin || freq > fmax) { ret = -ERANGE; goto out_clk; } s->regmap = regmap; s->devtype = devtype; dev_set_drvdata(dev, s); /* Check device to ensure we are talking to what we expect */ ret = devtype->detect(dev); if (ret) goto out_clk; for (i = 0; i < devtype->nr; i++) { unsigned int offs = i << 5; /* Reset port */ regmap_write(s->regmap, MAX310X_MODE2_REG + offs, MAX310X_MODE2_RST_BIT); /* Clear port reset */ regmap_write(s->regmap, MAX310X_MODE2_REG + offs, 0); /* Wait for port startup */ do { regmap_read(s->regmap, MAX310X_BRGDIVLSB_REG + offs, &ret); } while (ret != 0x01); regmap_update_bits(s->regmap, MAX310X_MODE1_REG + offs, MAX310X_MODE1_AUTOSLEEP_BIT, MAX310X_MODE1_AUTOSLEEP_BIT); } uartclk = max310x_set_ref_clk(s, freq, xtal); dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk); /* Register UART driver */ s->uart.owner = THIS_MODULE; s->uart.dev_name = "ttyMAX"; s->uart.major = MAX310X_MAJOR; s->uart.minor = MAX310X_MINOR; s->uart.nr = devtype->nr; ret = uart_register_driver(&s->uart); if (ret) { dev_err(dev, "Registering UART driver failed\n"); goto out_clk; } #ifdef CONFIG_GPIOLIB /* Setup GPIO cotroller */ 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 = -1; s->gpio.ngpio = devtype->nr * 4; 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; 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_MAX310X; s->p[i].port.fifosize = MAX310X_FIFO_SIZE; s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY; s->p[i].port.iotype = UPIO_PORT; s->p[i].port.iobase = i * 0x20; s->p[i].port.membase = (void __iomem *)~0; s->p[i].port.uartclk = uartclk; s->p[i].port.rs485_config = max310x_rs485_config; s->p[i].port.ops = &max310x_ops; /* Disable all interrupts */ max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0); /* Clear IRQ status register */ max310x_port_read(&s->p[i].port, MAX310X_IRQSTS_REG); /* Enable IRQ pin */ max310x_port_update(&s->p[i].port, MAX310X_MODE1_REG, MAX310X_MODE1_IRQSEL_BIT, MAX310X_MODE1_IRQSEL_BIT); /* Initialize queue for start TX */ INIT_WORK(&s->p[i].tx_work, max310x_wq_proc); /* Initialize queue for changing mode */ INIT_WORK(&s->p[i].md_work, max310x_md_proc); /* Register port */ uart_add_one_port(&s->uart, &s->p[i].port); /* Go to suspend mode */ devtype->power(&s->p[i].port, 0); } /* Setup interrupt */ ret = devm_request_threaded_irq(dev, irq, NULL, max310x_ist, IRQF_ONESHOT | flags, dev_name(dev), s); if (!ret) return 0; dev_err(dev, "Unable to reguest IRQ %i\n", irq); mutex_destroy(&s->mutex); #ifdef CONFIG_GPIOLIB gpiochip_remove(&s->gpio); out_uart: #endif uart_unregister_driver(&s->uart); out_clk: clk_disable_unprepare(s->clk); return ret; } static int max310x_remove(struct device *dev) { struct max310x_port *s = dev_get_drvdata(dev); int i; #ifdef CONFIG_GPIOLIB 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); s->devtype->power(&s->p[i].port, 0); } mutex_destroy(&s->mutex); uart_unregister_driver(&s->uart); clk_disable_unprepare(s->clk); return 0; } static const struct of_device_id __maybe_unused max310x_dt_ids[] = { { .compatible = "maxim,max3107", .data = &max3107_devtype, }, { .compatible = "maxim,max3108", .data = &max3108_devtype, }, { .compatible = "maxim,max3109", .data = &max3109_devtype, }, { .compatible = "maxim,max14830", .data = &max14830_devtype }, { } }; MODULE_DEVICE_TABLE(of, max310x_dt_ids); static struct regmap_config regcfg = { .reg_bits = 8, .val_bits = 8, .write_flag_mask = 0x80, .cache_type = REGCACHE_RBTREE, .writeable_reg = max310x_reg_writeable, .volatile_reg = max310x_reg_volatile, .precious_reg = max310x_reg_precious, }; #ifdef CONFIG_SPI_MASTER static int max310x_spi_probe(struct spi_device *spi) { struct max310x_devtype *devtype; unsigned long flags = 0; struct regmap *regmap; int ret; /* Setup SPI bus */ spi->bits_per_word = 8; spi->mode = spi->mode ? : SPI_MODE_0; spi->max_speed_hz = spi->max_speed_hz ? : 26000000; ret = spi_setup(spi); if (ret) return ret; if (spi->dev.of_node) { const struct of_device_id *of_id = of_match_device(max310x_dt_ids, &spi->dev); devtype = (struct max310x_devtype *)of_id->data; } else { const struct spi_device_id *id_entry = spi_get_device_id(spi); devtype = (struct max310x_devtype *)id_entry->driver_data; flags = IRQF_TRIGGER_FALLING; } regcfg.max_register = devtype->nr * 0x20 - 1; regmap = devm_regmap_init_spi(spi, ®cfg); return max310x_probe(&spi->dev, devtype, regmap, spi->irq, flags); } static int max310x_spi_remove(struct spi_device *spi) { return max310x_remove(&spi->dev); } static const struct spi_device_id max310x_id_table[] = { { "max3107", (kernel_ulong_t)&max3107_devtype, }, { "max3108", (kernel_ulong_t)&max3108_devtype, }, { "max3109", (kernel_ulong_t)&max3109_devtype, }, { "max14830", (kernel_ulong_t)&max14830_devtype, }, { } }; MODULE_DEVICE_TABLE(spi, max310x_id_table); static struct spi_driver max310x_uart_driver = { .driver = { .name = MAX310X_NAME, .owner = THIS_MODULE, .of_match_table = of_match_ptr(max310x_dt_ids), .pm = &max310x_pm_ops, }, .probe = max310x_spi_probe, .remove = max310x_spi_remove, .id_table = max310x_id_table, }; module_spi_driver(max310x_uart_driver); #endif MODULE_LICENSE("GPL"); MODULE_AUTHOR("Alexander Shiyan "); MODULE_DESCRIPTION("MAX310X serial driver");