2 * SC16IS7xx tty serial driver - Copyright (C) 2014 GridPoint
3 * Author: Jon Ringle <jringle@gridpoint.com>
5 * Based on max310x.c, by Alexander Shiyan <shc_work@mail.ru>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
14 #include <linux/bitops.h>
15 #include <linux/clk.h>
16 #include <linux/delay.h>
17 #include <linux/device.h>
18 #include <linux/gpio.h>
19 #include <linux/i2c.h>
20 #include <linux/module.h>
22 #include <linux/of_device.h>
23 #include <linux/regmap.h>
24 #include <linux/serial_core.h>
25 #include <linux/serial.h>
26 #include <linux/tty.h>
27 #include <linux/tty_flip.h>
28 #include <linux/uaccess.h>
30 #define SC16IS7XX_NAME "sc16is7xx"
32 /* SC16IS7XX register definitions */
33 #define SC16IS7XX_RHR_REG (0x00) /* RX FIFO */
34 #define SC16IS7XX_THR_REG (0x00) /* TX FIFO */
35 #define SC16IS7XX_IER_REG (0x01) /* Interrupt enable */
36 #define SC16IS7XX_IIR_REG (0x02) /* Interrupt Identification */
37 #define SC16IS7XX_FCR_REG (0x02) /* FIFO control */
38 #define SC16IS7XX_LCR_REG (0x03) /* Line Control */
39 #define SC16IS7XX_MCR_REG (0x04) /* Modem Control */
40 #define SC16IS7XX_LSR_REG (0x05) /* Line Status */
41 #define SC16IS7XX_MSR_REG (0x06) /* Modem Status */
42 #define SC16IS7XX_SPR_REG (0x07) /* Scratch Pad */
43 #define SC16IS7XX_TXLVL_REG (0x08) /* TX FIFO level */
44 #define SC16IS7XX_RXLVL_REG (0x09) /* RX FIFO level */
45 #define SC16IS7XX_IODIR_REG (0x0a) /* I/O Direction
48 #define SC16IS7XX_IOSTATE_REG (0x0b) /* I/O State
51 #define SC16IS7XX_IOINTENA_REG (0x0c) /* I/O Interrupt Enable
54 #define SC16IS7XX_IOCONTROL_REG (0x0e) /* I/O Control
57 #define SC16IS7XX_EFCR_REG (0x0f) /* Extra Features Control */
59 /* TCR/TLR Register set: Only if ((MCR[2] == 1) && (EFR[4] == 1)) */
60 #define SC16IS7XX_TCR_REG (0x06) /* Transmit control */
61 #define SC16IS7XX_TLR_REG (0x07) /* Trigger level */
63 /* Special Register set: Only if ((LCR[7] == 1) && (LCR != 0xBF)) */
64 #define SC16IS7XX_DLL_REG (0x00) /* Divisor Latch Low */
65 #define SC16IS7XX_DLH_REG (0x01) /* Divisor Latch High */
67 /* Enhanced Register set: Only if (LCR == 0xBF) */
68 #define SC16IS7XX_EFR_REG (0x02) /* Enhanced Features */
69 #define SC16IS7XX_XON1_REG (0x04) /* Xon1 word */
70 #define SC16IS7XX_XON2_REG (0x05) /* Xon2 word */
71 #define SC16IS7XX_XOFF1_REG (0x06) /* Xoff1 word */
72 #define SC16IS7XX_XOFF2_REG (0x07) /* Xoff2 word */
74 /* IER register bits */
75 #define SC16IS7XX_IER_RDI_BIT (1 << 0) /* Enable RX data interrupt */
76 #define SC16IS7XX_IER_THRI_BIT (1 << 1) /* Enable TX holding register
78 #define SC16IS7XX_IER_RLSI_BIT (1 << 2) /* Enable RX line status
80 #define SC16IS7XX_IER_MSI_BIT (1 << 3) /* Enable Modem status
83 /* IER register bits - write only if (EFR[4] == 1) */
84 #define SC16IS7XX_IER_SLEEP_BIT (1 << 4) /* Enable Sleep mode */
85 #define SC16IS7XX_IER_XOFFI_BIT (1 << 5) /* Enable Xoff interrupt */
86 #define SC16IS7XX_IER_RTSI_BIT (1 << 6) /* Enable nRTS interrupt */
87 #define SC16IS7XX_IER_CTSI_BIT (1 << 7) /* Enable nCTS interrupt */
89 /* FCR register bits */
90 #define SC16IS7XX_FCR_FIFO_BIT (1 << 0) /* Enable FIFO */
91 #define SC16IS7XX_FCR_RXRESET_BIT (1 << 1) /* Reset RX FIFO */
92 #define SC16IS7XX_FCR_TXRESET_BIT (1 << 2) /* Reset TX FIFO */
93 #define SC16IS7XX_FCR_RXLVLL_BIT (1 << 6) /* RX Trigger level LSB */
94 #define SC16IS7XX_FCR_RXLVLH_BIT (1 << 7) /* RX Trigger level MSB */
96 /* FCR register bits - write only if (EFR[4] == 1) */
97 #define SC16IS7XX_FCR_TXLVLL_BIT (1 << 4) /* TX Trigger level LSB */
98 #define SC16IS7XX_FCR_TXLVLH_BIT (1 << 5) /* TX Trigger level MSB */
100 /* IIR register bits */
101 #define SC16IS7XX_IIR_NO_INT_BIT (1 << 0) /* No interrupts pending */
102 #define SC16IS7XX_IIR_ID_MASK 0x3e /* Mask for the interrupt ID */
103 #define SC16IS7XX_IIR_THRI_SRC 0x02 /* TX holding register empty */
104 #define SC16IS7XX_IIR_RDI_SRC 0x04 /* RX data interrupt */
105 #define SC16IS7XX_IIR_RLSE_SRC 0x06 /* RX line status error */
106 #define SC16IS7XX_IIR_RTOI_SRC 0x0c /* RX time-out interrupt */
107 #define SC16IS7XX_IIR_MSI_SRC 0x00 /* Modem status interrupt
110 #define SC16IS7XX_IIR_INPIN_SRC 0x30 /* Input pin change of state
113 #define SC16IS7XX_IIR_XOFFI_SRC 0x10 /* Received Xoff */
114 #define SC16IS7XX_IIR_CTSRTS_SRC 0x20 /* nCTS,nRTS change of state
118 /* LCR register bits */
119 #define SC16IS7XX_LCR_LENGTH0_BIT (1 << 0) /* Word length bit 0 */
120 #define SC16IS7XX_LCR_LENGTH1_BIT (1 << 1) /* Word length bit 1
122 * Word length bits table:
128 #define SC16IS7XX_LCR_STOPLEN_BIT (1 << 2) /* STOP length bit
130 * STOP length bit table:
132 * 1 -> 1-1.5 stop bits if
134 * 2 stop bits otherwise
136 #define SC16IS7XX_LCR_PARITY_BIT (1 << 3) /* Parity bit enable */
137 #define SC16IS7XX_LCR_EVENPARITY_BIT (1 << 4) /* Even parity bit enable */
138 #define SC16IS7XX_LCR_FORCEPARITY_BIT (1 << 5) /* 9-bit multidrop parity */
139 #define SC16IS7XX_LCR_TXBREAK_BIT (1 << 6) /* TX break enable */
140 #define SC16IS7XX_LCR_DLAB_BIT (1 << 7) /* Divisor Latch enable */
141 #define SC16IS7XX_LCR_WORD_LEN_5 (0x00)
142 #define SC16IS7XX_LCR_WORD_LEN_6 (0x01)
143 #define SC16IS7XX_LCR_WORD_LEN_7 (0x02)
144 #define SC16IS7XX_LCR_WORD_LEN_8 (0x03)
145 #define SC16IS7XX_LCR_CONF_MODE_A SC16IS7XX_LCR_DLAB_BIT /* Special
147 #define SC16IS7XX_LCR_CONF_MODE_B 0xBF /* Enhanced
150 /* MCR register bits */
151 #define SC16IS7XX_MCR_DTR_BIT (1 << 0) /* DTR complement
154 #define SC16IS7XX_MCR_RTS_BIT (1 << 1) /* RTS complement */
155 #define SC16IS7XX_MCR_TCRTLR_BIT (1 << 2) /* TCR/TLR register enable */
156 #define SC16IS7XX_MCR_LOOP_BIT (1 << 4) /* Enable loopback test mode */
157 #define SC16IS7XX_MCR_XONANY_BIT (1 << 5) /* Enable Xon Any
161 #define SC16IS7XX_MCR_IRDA_BIT (1 << 6) /* Enable IrDA mode
165 #define SC16IS7XX_MCR_CLKSEL_BIT (1 << 7) /* Divide clock by 4
170 /* LSR register bits */
171 #define SC16IS7XX_LSR_DR_BIT (1 << 0) /* Receiver data ready */
172 #define SC16IS7XX_LSR_OE_BIT (1 << 1) /* Overrun Error */
173 #define SC16IS7XX_LSR_PE_BIT (1 << 2) /* Parity Error */
174 #define SC16IS7XX_LSR_FE_BIT (1 << 3) /* Frame Error */
175 #define SC16IS7XX_LSR_BI_BIT (1 << 4) /* Break Interrupt */
176 #define SC16IS7XX_LSR_BRK_ERROR_MASK 0x1E /* BI, FE, PE, OE bits */
177 #define SC16IS7XX_LSR_THRE_BIT (1 << 5) /* TX holding register empty */
178 #define SC16IS7XX_LSR_TEMT_BIT (1 << 6) /* Transmitter empty */
179 #define SC16IS7XX_LSR_FIFOE_BIT (1 << 7) /* Fifo Error */
181 /* MSR register bits */
182 #define SC16IS7XX_MSR_DCTS_BIT (1 << 0) /* Delta CTS Clear To Send */
183 #define SC16IS7XX_MSR_DDSR_BIT (1 << 1) /* Delta DSR Data Set Ready
187 #define SC16IS7XX_MSR_DRI_BIT (1 << 2) /* Delta RI Ring Indicator
191 #define SC16IS7XX_MSR_DCD_BIT (1 << 3) /* Delta CD Carrier Detect
195 #define SC16IS7XX_MSR_CTS_BIT (1 << 0) /* CTS */
196 #define SC16IS7XX_MSR_DSR_BIT (1 << 1) /* DSR (IO4)
199 #define SC16IS7XX_MSR_RI_BIT (1 << 2) /* RI (IO7)
202 #define SC16IS7XX_MSR_CD_BIT (1 << 3) /* CD (IO6)
205 #define SC16IS7XX_MSR_DELTA_MASK 0x0F /* Any of the delta bits! */
209 * TCR trigger levels are available from 0 to 60 characters with a granularity
211 * The programmer must program the TCR such that TCR[3:0] > TCR[7:4]. There is
212 * no built-in hardware check to make sure this condition is met. Also, the TCR
213 * must be programmed with this condition before auto RTS or software flow
214 * control is enabled to avoid spurious operation of the device.
216 #define SC16IS7XX_TCR_RX_HALT(words) ((((words) / 4) & 0x0f) << 0)
217 #define SC16IS7XX_TCR_RX_RESUME(words) ((((words) / 4) & 0x0f) << 4)
221 * If TLR[3:0] or TLR[7:4] are logical 0, the selectable trigger levels via the
222 * FIFO Control Register (FCR) are used for the transmit and receive FIFO
223 * trigger levels. Trigger levels from 4 characters to 60 characters are
224 * available with a granularity of four.
226 * When the trigger level setting in TLR is zero, the SC16IS740/750/760 uses the
227 * trigger level setting defined in FCR. If TLR has non-zero trigger level value
228 * the trigger level defined in FCR is discarded. This applies to both transmit
229 * FIFO and receive FIFO trigger level setting.
231 * When TLR is used for RX trigger level control, FCR[7:6] should be left at the
232 * default state, that is, '00'.
234 #define SC16IS7XX_TLR_TX_TRIGGER(words) ((((words) / 4) & 0x0f) << 0)
235 #define SC16IS7XX_TLR_RX_TRIGGER(words) ((((words) / 4) & 0x0f) << 4)
237 /* IOControl register bits (Only 750/760) */
238 #define SC16IS7XX_IOCONTROL_LATCH_BIT (1 << 0) /* Enable input latching */
239 #define SC16IS7XX_IOCONTROL_GPIO_BIT (1 << 1) /* Enable GPIO[7:4] */
240 #define SC16IS7XX_IOCONTROL_SRESET_BIT (1 << 3) /* Software Reset */
242 /* EFCR register bits */
243 #define SC16IS7XX_EFCR_9BIT_MODE_BIT (1 << 0) /* Enable 9-bit or Multidrop
245 #define SC16IS7XX_EFCR_RXDISABLE_BIT (1 << 1) /* Disable receiver */
246 #define SC16IS7XX_EFCR_TXDISABLE_BIT (1 << 2) /* Disable transmitter */
247 #define SC16IS7XX_EFCR_AUTO_RS485_BIT (1 << 4) /* Auto RS485 RTS direction */
248 #define SC16IS7XX_EFCR_RTS_INVERT_BIT (1 << 5) /* RTS output inversion */
249 #define SC16IS7XX_EFCR_IRDA_MODE_BIT (1 << 7) /* IrDA mode
250 * 0 = rate upto 115.2 kbit/s
252 * 1 = rate upto 1.152 Mbit/s
256 /* EFR register bits */
257 #define SC16IS7XX_EFR_AUTORTS_BIT (1 << 6) /* Auto RTS flow ctrl enable */
258 #define SC16IS7XX_EFR_AUTOCTS_BIT (1 << 7) /* Auto CTS flow ctrl enable */
259 #define SC16IS7XX_EFR_XOFF2_DETECT_BIT (1 << 5) /* Enable Xoff2 detection */
260 #define SC16IS7XX_EFR_ENABLE_BIT (1 << 4) /* Enable enhanced functions
261 * and writing to IER[7:4],
264 #define SC16IS7XX_EFR_SWFLOW3_BIT (1 << 3) /* SWFLOW bit 3 */
265 #define SC16IS7XX_EFR_SWFLOW2_BIT (1 << 2) /* SWFLOW bit 2
267 * SWFLOW bits 3 & 2 table:
268 * 00 -> no transmitter flow
270 * 01 -> transmitter generates
272 * 10 -> transmitter generates
274 * 11 -> transmitter generates
275 * XON1, XON2, XOFF1 and
278 #define SC16IS7XX_EFR_SWFLOW1_BIT (1 << 1) /* SWFLOW bit 2 */
279 #define SC16IS7XX_EFR_SWFLOW0_BIT (1 << 0) /* SWFLOW bit 3
281 * SWFLOW bits 3 & 2 table:
282 * 00 -> no received flow
284 * 01 -> receiver compares
286 * 10 -> receiver compares
288 * 11 -> receiver compares
289 * XON1, XON2, XOFF1 and
293 /* Misc definitions */
294 #define SC16IS7XX_FIFO_SIZE (64)
295 #define SC16IS7XX_REG_SHIFT 2
297 struct sc16is7xx_devtype {
303 struct sc16is7xx_one {
304 struct uart_port port;
305 struct work_struct tx_work;
306 struct work_struct md_work;
308 struct serial_rs485 rs485;
311 struct sc16is7xx_port {
312 struct uart_driver uart;
313 struct sc16is7xx_devtype *devtype;
314 struct regmap *regmap;
317 #ifdef CONFIG_GPIOLIB
318 struct gpio_chip gpio;
320 unsigned char buf[SC16IS7XX_FIFO_SIZE];
321 struct sc16is7xx_one p[0];
324 #define to_sc16is7xx_one(p,e) ((container_of((p), struct sc16is7xx_one, e)))
326 static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
328 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
329 unsigned int val = 0;
331 regmap_read(s->regmap,
332 (reg << SC16IS7XX_REG_SHIFT) | port->line, &val);
337 static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val)
339 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
341 regmap_write(s->regmap,
342 (reg << SC16IS7XX_REG_SHIFT) | port->line, val);
345 static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
348 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
350 regmap_update_bits(s->regmap,
351 (reg << SC16IS7XX_REG_SHIFT) | port->line,
356 static void sc16is7xx_power(struct uart_port *port, int on)
358 sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
359 SC16IS7XX_IER_SLEEP_BIT,
360 on ? 0 : SC16IS7XX_IER_SLEEP_BIT);
363 static const struct sc16is7xx_devtype sc16is74x_devtype = {
369 static const struct sc16is7xx_devtype sc16is750_devtype = {
375 static const struct sc16is7xx_devtype sc16is752_devtype = {
381 static const struct sc16is7xx_devtype sc16is760_devtype = {
387 static const struct sc16is7xx_devtype sc16is762_devtype = {
393 static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
395 switch (reg >> SC16IS7XX_REG_SHIFT) {
396 case SC16IS7XX_RHR_REG:
397 case SC16IS7XX_IIR_REG:
398 case SC16IS7XX_LSR_REG:
399 case SC16IS7XX_MSR_REG:
400 case SC16IS7XX_TXLVL_REG:
401 case SC16IS7XX_RXLVL_REG:
402 case SC16IS7XX_IOSTATE_REG:
411 static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
413 switch (reg >> SC16IS7XX_REG_SHIFT) {
414 case SC16IS7XX_RHR_REG:
423 static int sc16is7xx_set_baud(struct uart_port *port, int baud)
425 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
428 unsigned long clk = port->uartclk, div = clk / 16 / baud;
431 prescaler = SC16IS7XX_MCR_CLKSEL_BIT;
435 lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
437 /* Open the LCR divisors for configuration */
438 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
439 SC16IS7XX_LCR_CONF_MODE_B);
441 /* Enable enhanced features */
442 regcache_cache_bypass(s->regmap, true);
443 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG,
444 SC16IS7XX_EFR_ENABLE_BIT);
445 regcache_cache_bypass(s->regmap, false);
447 /* Put LCR back to the normal mode */
448 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
450 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
451 SC16IS7XX_MCR_CLKSEL_BIT,
454 /* Open the LCR divisors for configuration */
455 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
456 SC16IS7XX_LCR_CONF_MODE_A);
458 /* Write the new divisor */
459 regcache_cache_bypass(s->regmap, true);
460 sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
461 sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
462 regcache_cache_bypass(s->regmap, false);
464 /* Put LCR back to the normal mode */
465 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
467 return DIV_ROUND_CLOSEST(clk / 16, div);
470 static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
473 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
474 unsigned int lsr = 0, ch, flag, bytes_read, i;
475 bool read_lsr = (iir == SC16IS7XX_IIR_RLSE_SRC) ? true : false;
477 if (unlikely(rxlen >= sizeof(s->buf))) {
478 dev_warn_ratelimited(port->dev,
479 "Port %i: Possible RX FIFO overrun: %d\n",
481 port->icount.buf_overrun++;
482 /* Ensure sanity of RX level */
483 rxlen = sizeof(s->buf);
487 /* Only read lsr if there are possible errors in FIFO */
489 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
490 if (!(lsr & SC16IS7XX_LSR_FIFOE_BIT))
491 read_lsr = false; /* No errors left in FIFO */
496 s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
499 regcache_cache_bypass(s->regmap, true);
500 regmap_raw_read(s->regmap, SC16IS7XX_RHR_REG,
502 regcache_cache_bypass(s->regmap, false);
506 lsr &= SC16IS7XX_LSR_BRK_ERROR_MASK;
512 if (lsr & SC16IS7XX_LSR_BI_BIT) {
514 if (uart_handle_break(port))
516 } else if (lsr & SC16IS7XX_LSR_PE_BIT)
517 port->icount.parity++;
518 else if (lsr & SC16IS7XX_LSR_FE_BIT)
519 port->icount.frame++;
520 else if (lsr & SC16IS7XX_LSR_OE_BIT)
521 port->icount.overrun++;
523 lsr &= port->read_status_mask;
524 if (lsr & SC16IS7XX_LSR_BI_BIT)
526 else if (lsr & SC16IS7XX_LSR_PE_BIT)
528 else if (lsr & SC16IS7XX_LSR_FE_BIT)
530 else if (lsr & SC16IS7XX_LSR_OE_BIT)
534 for (i = 0; i < bytes_read; ++i) {
536 if (uart_handle_sysrq_char(port, ch))
539 if (lsr & port->ignore_status_mask)
542 uart_insert_char(port, lsr, SC16IS7XX_LSR_OE_BIT, ch,
548 tty_flip_buffer_push(&port->state->port);
551 static void sc16is7xx_handle_tx(struct uart_port *port)
553 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
554 struct circ_buf *xmit = &port->state->xmit;
555 unsigned int txlen, to_send, i;
557 if (unlikely(port->x_char)) {
558 sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char);
564 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
567 /* Get length of data pending in circular buffer */
568 to_send = uart_circ_chars_pending(xmit);
569 if (likely(to_send)) {
570 /* Limit to size of TX FIFO */
571 txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
572 to_send = (to_send > txlen) ? txlen : to_send;
574 /* Add data to send */
575 port->icount.tx += to_send;
577 /* Convert to linear buffer */
578 for (i = 0; i < to_send; ++i) {
579 s->buf[i] = xmit->buf[xmit->tail];
580 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
582 regcache_cache_bypass(s->regmap, true);
583 regmap_raw_write(s->regmap, SC16IS7XX_THR_REG, s->buf, to_send);
584 regcache_cache_bypass(s->regmap, false);
587 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
588 uart_write_wakeup(port);
591 static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
593 struct uart_port *port = &s->p[portno].port;
596 unsigned int iir, msr, rxlen;
598 iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
599 if (iir & SC16IS7XX_IIR_NO_INT_BIT)
602 iir &= SC16IS7XX_IIR_ID_MASK;
605 case SC16IS7XX_IIR_RDI_SRC:
606 case SC16IS7XX_IIR_RLSE_SRC:
607 case SC16IS7XX_IIR_RTOI_SRC:
608 case SC16IS7XX_IIR_XOFFI_SRC:
609 rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
611 sc16is7xx_handle_rx(port, rxlen, iir);
614 case SC16IS7XX_IIR_CTSRTS_SRC:
615 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
616 uart_handle_cts_change(port,
617 !!(msr & SC16IS7XX_MSR_CTS_BIT));
619 case SC16IS7XX_IIR_THRI_SRC:
620 mutex_lock(&s->mutex);
621 sc16is7xx_handle_tx(port);
622 mutex_unlock(&s->mutex);
625 dev_err_ratelimited(port->dev,
626 "Port %i: Unexpected interrupt: %x",
633 static irqreturn_t sc16is7xx_ist(int irq, void *dev_id)
635 struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
638 for (i = 0; i < s->uart.nr; ++i)
639 sc16is7xx_port_irq(s, i);
644 static void sc16is7xx_wq_proc(struct work_struct *ws)
646 struct sc16is7xx_one *one = to_sc16is7xx_one(ws, tx_work);
647 struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev);
649 mutex_lock(&s->mutex);
650 sc16is7xx_handle_tx(&one->port);
651 mutex_unlock(&s->mutex);
654 static void sc16is7xx_stop_tx(struct uart_port* port)
656 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
657 struct circ_buf *xmit = &one->port.state->xmit;
660 if (one->rs485.flags & SER_RS485_ENABLED) {
661 /* do nothing if current tx not yet completed */
662 int lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
663 if (!(lsr & SC16IS7XX_LSR_TEMT_BIT))
666 if (uart_circ_empty(xmit) &&
667 (one->rs485.delay_rts_after_send > 0))
668 mdelay(one->rs485.delay_rts_after_send);
671 sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
672 SC16IS7XX_IER_THRI_BIT,
676 static void sc16is7xx_stop_rx(struct uart_port* port)
678 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
680 one->port.read_status_mask &= ~SC16IS7XX_LSR_DR_BIT;
681 sc16is7xx_port_update(port, SC16IS7XX_IER_REG,
682 SC16IS7XX_LSR_DR_BIT,
686 static void sc16is7xx_start_tx(struct uart_port *port)
688 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
691 if ((one->rs485.flags & SER_RS485_ENABLED) &&
692 (one->rs485.delay_rts_before_send > 0)) {
693 mdelay(one->rs485.delay_rts_before_send);
696 if (!work_pending(&one->tx_work))
697 schedule_work(&one->tx_work);
700 static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
702 unsigned int lvl, lsr;
704 lvl = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
705 lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG);
707 return ((lsr & SC16IS7XX_LSR_THRE_BIT) && !lvl) ? TIOCSER_TEMT : 0;
710 static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
712 /* DCD and DSR are not wired and CTS/RTS is handled automatically
713 * so just indicate DSR and CAR asserted
715 return TIOCM_DSR | TIOCM_CAR;
718 static void sc16is7xx_md_proc(struct work_struct *ws)
720 struct sc16is7xx_one *one = to_sc16is7xx_one(ws, md_work);
722 sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG,
723 SC16IS7XX_MCR_LOOP_BIT,
724 (one->port.mctrl & TIOCM_LOOP) ?
725 SC16IS7XX_MCR_LOOP_BIT : 0);
728 static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
730 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
732 schedule_work(&one->md_work);
735 static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
737 sc16is7xx_port_update(port, SC16IS7XX_LCR_REG,
738 SC16IS7XX_LCR_TXBREAK_BIT,
739 break_state ? SC16IS7XX_LCR_TXBREAK_BIT : 0);
742 static void sc16is7xx_set_termios(struct uart_port *port,
743 struct ktermios *termios,
744 struct ktermios *old)
746 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
747 unsigned int lcr, flow = 0;
750 /* Mask termios capabilities we don't support */
751 termios->c_cflag &= ~CMSPAR;
754 switch (termios->c_cflag & CSIZE) {
756 lcr = SC16IS7XX_LCR_WORD_LEN_5;
759 lcr = SC16IS7XX_LCR_WORD_LEN_6;
762 lcr = SC16IS7XX_LCR_WORD_LEN_7;
765 lcr = SC16IS7XX_LCR_WORD_LEN_8;
768 lcr = SC16IS7XX_LCR_WORD_LEN_8;
769 termios->c_cflag &= ~CSIZE;
770 termios->c_cflag |= CS8;
775 if (termios->c_cflag & PARENB) {
776 lcr |= SC16IS7XX_LCR_PARITY_BIT;
777 if (!(termios->c_cflag & PARODD))
778 lcr |= SC16IS7XX_LCR_EVENPARITY_BIT;
782 if (termios->c_cflag & CSTOPB)
783 lcr |= SC16IS7XX_LCR_STOPLEN_BIT; /* 2 stops */
785 /* Set read status mask */
786 port->read_status_mask = SC16IS7XX_LSR_OE_BIT;
787 if (termios->c_iflag & INPCK)
788 port->read_status_mask |= SC16IS7XX_LSR_PE_BIT |
789 SC16IS7XX_LSR_FE_BIT;
790 if (termios->c_iflag & (BRKINT | PARMRK))
791 port->read_status_mask |= SC16IS7XX_LSR_BI_BIT;
793 /* Set status ignore mask */
794 port->ignore_status_mask = 0;
795 if (termios->c_iflag & IGNBRK)
796 port->ignore_status_mask |= SC16IS7XX_LSR_BI_BIT;
797 if (!(termios->c_cflag & CREAD))
798 port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
800 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
801 SC16IS7XX_LCR_CONF_MODE_B);
803 /* Configure flow control */
804 regcache_cache_bypass(s->regmap, true);
805 sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
806 sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
807 if (termios->c_cflag & CRTSCTS)
808 flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
809 SC16IS7XX_EFR_AUTORTS_BIT;
810 if (termios->c_iflag & IXON)
811 flow |= SC16IS7XX_EFR_SWFLOW3_BIT;
812 if (termios->c_iflag & IXOFF)
813 flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
815 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, flow);
816 regcache_cache_bypass(s->regmap, false);
818 /* Update LCR register */
819 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
821 /* Get baud rate generator configuration */
822 baud = uart_get_baud_rate(port, termios, old,
823 port->uartclk / 16 / 4 / 0xffff,
826 /* Setup baudrate generator */
827 baud = sc16is7xx_set_baud(port, baud);
829 /* Update timeout according to new baud rate */
830 uart_update_timeout(port, termios->c_cflag, baud);
833 #if defined(TIOCSRS485) && defined(TIOCGRS485)
834 static void sc16is7xx_config_rs485(struct uart_port *port,
835 struct serial_rs485 *rs485)
837 struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
841 if (one->rs485.flags & SER_RS485_ENABLED) {
842 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
843 SC16IS7XX_EFCR_AUTO_RS485_BIT,
844 SC16IS7XX_EFCR_AUTO_RS485_BIT);
846 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
847 SC16IS7XX_EFCR_AUTO_RS485_BIT,
853 static int sc16is7xx_ioctl(struct uart_port *port, unsigned int cmd,
856 #if defined(TIOCSRS485) && defined(TIOCGRS485)
857 struct serial_rs485 rs485;
861 if (copy_from_user(&rs485, (void __user *)arg, sizeof(rs485)))
864 sc16is7xx_config_rs485(port, &rs485);
867 if (copy_to_user((void __user *)arg,
868 &(to_sc16is7xx_one(port, port)->rs485),
880 static int sc16is7xx_startup(struct uart_port *port)
882 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
885 sc16is7xx_power(port, 1);
888 val = SC16IS7XX_FCR_RXRESET_BIT | SC16IS7XX_FCR_TXRESET_BIT;
889 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG, val);
891 sc16is7xx_port_write(port, SC16IS7XX_FCR_REG,
892 SC16IS7XX_FCR_FIFO_BIT);
895 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
896 SC16IS7XX_LCR_CONF_MODE_B);
898 regcache_cache_bypass(s->regmap, true);
900 /* Enable write access to enhanced features and internal clock div */
901 sc16is7xx_port_write(port, SC16IS7XX_EFR_REG,
902 SC16IS7XX_EFR_ENABLE_BIT);
905 sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
906 SC16IS7XX_MCR_TCRTLR_BIT,
907 SC16IS7XX_MCR_TCRTLR_BIT);
909 /* Configure flow control levels */
910 /* Flow control halt level 48, resume level 24 */
911 sc16is7xx_port_write(port, SC16IS7XX_TCR_REG,
912 SC16IS7XX_TCR_RX_RESUME(24) |
913 SC16IS7XX_TCR_RX_HALT(48));
915 regcache_cache_bypass(s->regmap, false);
917 /* Now, initialize the UART */
918 sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
920 /* Enable the Rx and Tx FIFO */
921 sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG,
922 SC16IS7XX_EFCR_RXDISABLE_BIT |
923 SC16IS7XX_EFCR_TXDISABLE_BIT,
926 /* Enable RX, TX, CTS change interrupts */
927 val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_THRI_BIT |
928 SC16IS7XX_IER_CTSI_BIT;
929 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
934 static void sc16is7xx_shutdown(struct uart_port *port)
936 /* Disable all interrupts */
937 sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0);
939 sc16is7xx_port_write(port, SC16IS7XX_EFCR_REG,
940 SC16IS7XX_EFCR_RXDISABLE_BIT |
941 SC16IS7XX_EFCR_TXDISABLE_BIT);
943 sc16is7xx_power(port, 0);
946 static const char *sc16is7xx_type(struct uart_port *port)
948 struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
950 return (port->type == PORT_SC16IS7XX) ? s->devtype->name : NULL;
953 static int sc16is7xx_request_port(struct uart_port *port)
959 static void sc16is7xx_config_port(struct uart_port *port, int flags)
961 if (flags & UART_CONFIG_TYPE)
962 port->type = PORT_SC16IS7XX;
965 static int sc16is7xx_verify_port(struct uart_port *port,
966 struct serial_struct *s)
968 if ((s->type != PORT_UNKNOWN) && (s->type != PORT_SC16IS7XX))
970 if (s->irq != port->irq)
976 static void sc16is7xx_pm(struct uart_port *port, unsigned int state,
977 unsigned int oldstate)
979 sc16is7xx_power(port, (state == UART_PM_STATE_ON) ? 1 : 0);
982 static void sc16is7xx_null_void(struct uart_port *port)
987 static const struct uart_ops sc16is7xx_ops = {
988 .tx_empty = sc16is7xx_tx_empty,
989 .set_mctrl = sc16is7xx_set_mctrl,
990 .get_mctrl = sc16is7xx_get_mctrl,
991 .stop_tx = sc16is7xx_stop_tx,
992 .start_tx = sc16is7xx_start_tx,
993 .stop_rx = sc16is7xx_stop_rx,
994 .break_ctl = sc16is7xx_break_ctl,
995 .startup = sc16is7xx_startup,
996 .shutdown = sc16is7xx_shutdown,
997 .set_termios = sc16is7xx_set_termios,
998 .type = sc16is7xx_type,
999 .request_port = sc16is7xx_request_port,
1000 .release_port = sc16is7xx_null_void,
1001 .config_port = sc16is7xx_config_port,
1002 .verify_port = sc16is7xx_verify_port,
1003 .ioctl = sc16is7xx_ioctl,
1007 #ifdef CONFIG_GPIOLIB
1008 static int sc16is7xx_gpio_get(struct gpio_chip *chip, unsigned offset)
1011 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1013 struct uart_port *port = &s->p[0].port;
1015 val = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
1017 return !!(val & BIT(offset));
1020 static void sc16is7xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
1022 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1024 struct uart_port *port = &s->p[0].port;
1026 sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1027 val ? BIT(offset) : 0);
1030 static int sc16is7xx_gpio_direction_input(struct gpio_chip *chip,
1033 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1035 struct uart_port *port = &s->p[0].port;
1037 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset), 0);
1042 static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
1043 unsigned offset, int val)
1045 struct sc16is7xx_port *s = container_of(chip, struct sc16is7xx_port,
1047 struct uart_port *port = &s->p[0].port;
1049 sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
1050 val ? BIT(offset) : 0);
1051 sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
1058 static int sc16is7xx_probe(struct device *dev,
1059 struct sc16is7xx_devtype *devtype,
1060 struct regmap *regmap, int irq, unsigned long flags)
1062 unsigned long freq, *pfreq = dev_get_platdata(dev);
1064 struct sc16is7xx_port *s;
1067 return PTR_ERR(regmap);
1069 /* Alloc port structure */
1070 s = devm_kzalloc(dev, sizeof(*s) +
1071 sizeof(struct sc16is7xx_one) * devtype->nr_uart,
1074 dev_err(dev, "Error allocating port structure\n");
1078 s->clk = devm_clk_get(dev, NULL);
1079 if (IS_ERR(s->clk)) {
1083 return PTR_ERR(s->clk);
1085 freq = clk_get_rate(s->clk);
1089 s->devtype = devtype;
1090 dev_set_drvdata(dev, s);
1092 /* Register UART driver */
1093 s->uart.owner = THIS_MODULE;
1094 s->uart.dev_name = "ttySC";
1095 s->uart.nr = devtype->nr_uart;
1096 ret = uart_register_driver(&s->uart);
1098 dev_err(dev, "Registering UART driver failed\n");
1102 #ifdef CONFIG_GPIOLIB
1103 if (devtype->nr_gpio) {
1104 /* Setup GPIO cotroller */
1105 s->gpio.owner = THIS_MODULE;
1107 s->gpio.label = dev_name(dev);
1108 s->gpio.direction_input = sc16is7xx_gpio_direction_input;
1109 s->gpio.get = sc16is7xx_gpio_get;
1110 s->gpio.direction_output = sc16is7xx_gpio_direction_output;
1111 s->gpio.set = sc16is7xx_gpio_set;
1113 s->gpio.ngpio = devtype->nr_gpio;
1114 s->gpio.can_sleep = 1;
1115 ret = gpiochip_add(&s->gpio);
1121 mutex_init(&s->mutex);
1123 for (i = 0; i < devtype->nr_uart; ++i) {
1124 /* Initialize port data */
1125 s->p[i].port.line = i;
1126 s->p[i].port.dev = dev;
1127 s->p[i].port.irq = irq;
1128 s->p[i].port.type = PORT_SC16IS7XX;
1129 s->p[i].port.fifosize = SC16IS7XX_FIFO_SIZE;
1130 s->p[i].port.flags = UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1131 s->p[i].port.iotype = UPIO_PORT;
1132 s->p[i].port.uartclk = freq;
1133 s->p[i].port.ops = &sc16is7xx_ops;
1134 /* Disable all interrupts */
1135 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
1137 sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG,
1138 SC16IS7XX_EFCR_RXDISABLE_BIT |
1139 SC16IS7XX_EFCR_TXDISABLE_BIT);
1140 /* Initialize queue for start TX */
1141 INIT_WORK(&s->p[i].tx_work, sc16is7xx_wq_proc);
1142 /* Initialize queue for changing mode */
1143 INIT_WORK(&s->p[i].md_work, sc16is7xx_md_proc);
1145 uart_add_one_port(&s->uart, &s->p[i].port);
1146 /* Go to suspend mode */
1147 sc16is7xx_power(&s->p[i].port, 0);
1150 /* Setup interrupt */
1151 ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_ist,
1152 IRQF_ONESHOT | flags, dev_name(dev), s);
1156 mutex_destroy(&s->mutex);
1158 #ifdef CONFIG_GPIOLIB
1159 if (devtype->nr_gpio)
1160 gpiochip_remove(&s->gpio);
1164 uart_unregister_driver(&s->uart);
1167 if (!IS_ERR(s->clk))
1168 clk_disable_unprepare(s->clk);
1173 static int sc16is7xx_remove(struct device *dev)
1175 struct sc16is7xx_port *s = dev_get_drvdata(dev);
1178 #ifdef CONFIG_GPIOLIB
1179 if (s->devtype->nr_gpio)
1180 gpiochip_remove(&s->gpio);
1183 for (i = 0; i < s->uart.nr; i++) {
1184 cancel_work_sync(&s->p[i].tx_work);
1185 cancel_work_sync(&s->p[i].md_work);
1186 uart_remove_one_port(&s->uart, &s->p[i].port);
1187 sc16is7xx_power(&s->p[i].port, 0);
1190 mutex_destroy(&s->mutex);
1191 uart_unregister_driver(&s->uart);
1192 if (!IS_ERR(s->clk))
1193 clk_disable_unprepare(s->clk);
1198 static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
1199 { .compatible = "nxp,sc16is740", .data = &sc16is74x_devtype, },
1200 { .compatible = "nxp,sc16is741", .data = &sc16is74x_devtype, },
1201 { .compatible = "nxp,sc16is750", .data = &sc16is750_devtype, },
1202 { .compatible = "nxp,sc16is752", .data = &sc16is752_devtype, },
1203 { .compatible = "nxp,sc16is760", .data = &sc16is760_devtype, },
1204 { .compatible = "nxp,sc16is762", .data = &sc16is762_devtype, },
1207 MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
1209 static struct regmap_config regcfg = {
1213 .cache_type = REGCACHE_RBTREE,
1214 .volatile_reg = sc16is7xx_regmap_volatile,
1215 .precious_reg = sc16is7xx_regmap_precious,
1218 static int sc16is7xx_i2c_probe(struct i2c_client *i2c,
1219 const struct i2c_device_id *id)
1221 struct sc16is7xx_devtype *devtype;
1222 unsigned long flags = 0;
1223 struct regmap *regmap;
1225 if (i2c->dev.of_node) {
1226 const struct of_device_id *of_id =
1227 of_match_device(sc16is7xx_dt_ids, &i2c->dev);
1229 devtype = (struct sc16is7xx_devtype *)of_id->data;
1231 devtype = (struct sc16is7xx_devtype *)id->driver_data;
1232 flags = IRQF_TRIGGER_FALLING;
1235 regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
1236 (devtype->nr_uart - 1);
1237 regmap = devm_regmap_init_i2c(i2c, ®cfg);
1239 return sc16is7xx_probe(&i2c->dev, devtype, regmap, i2c->irq, flags);
1242 static int sc16is7xx_i2c_remove(struct i2c_client *client)
1244 return sc16is7xx_remove(&client->dev);
1247 static const struct i2c_device_id sc16is7xx_i2c_id_table[] = {
1248 { "sc16is74x", (kernel_ulong_t)&sc16is74x_devtype, },
1249 { "sc16is750", (kernel_ulong_t)&sc16is750_devtype, },
1250 { "sc16is752", (kernel_ulong_t)&sc16is752_devtype, },
1251 { "sc16is760", (kernel_ulong_t)&sc16is760_devtype, },
1252 { "sc16is762", (kernel_ulong_t)&sc16is762_devtype, },
1255 MODULE_DEVICE_TABLE(i2c, sc16is7xx_i2c_id_table);
1257 static struct i2c_driver sc16is7xx_i2c_uart_driver = {
1259 .name = SC16IS7XX_NAME,
1260 .owner = THIS_MODULE,
1261 .of_match_table = of_match_ptr(sc16is7xx_dt_ids),
1263 .probe = sc16is7xx_i2c_probe,
1264 .remove = sc16is7xx_i2c_remove,
1265 .id_table = sc16is7xx_i2c_id_table,
1267 module_i2c_driver(sc16is7xx_i2c_uart_driver);
1268 MODULE_ALIAS("i2c:sc16is7xx");
1270 MODULE_LICENSE("GPL");
1271 MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
1272 MODULE_DESCRIPTION("SC16IS7XX serial driver");