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   1/*
   2 *  Maxim (Dallas) MAX3107/8/9, MAX14830 serial driver
   3 *
   4 *  Copyright (C) 2012-2014 Alexander Shiyan <shc_work@mail.ru>
   5 *
   6 *  Based on max3100.c, by Christian Pellegrin <chripell@evolware.org>
   7 *  Based on max3110.c, by Feng Tang <feng.tang@intel.com>
   8 *  Based on max3107.c, by Aavamobile
   9 *
  10 *  This program is free software; you can redistribute it and/or modify
  11 *  it under the terms of the GNU General Public License as published by
  12 *  the Free Software Foundation; either version 2 of the License, or
  13 *  (at your option) any later version.
  14 */
  15
  16#include <linux/bitops.h>
  17#include <linux/clk.h>
  18#include <linux/delay.h>
  19#include <linux/device.h>
  20#include <linux/gpio.h>
  21#include <linux/module.h>
  22#include <linux/of.h>
  23#include <linux/of_device.h>
  24#include <linux/regmap.h>
  25#include <linux/serial_core.h>
  26#include <linux/serial.h>
  27#include <linux/tty.h>
  28#include <linux/tty_flip.h>
  29#include <linux/spi/spi.h>
  30#include <linux/uaccess.h>
  31
  32#define MAX310X_NAME			"max310x"
  33#define MAX310X_MAJOR			204
  34#define MAX310X_MINOR			209
  35
  36/* MAX310X register definitions */
  37#define MAX310X_RHR_REG			(0x00) /* RX FIFO */
  38#define MAX310X_THR_REG			(0x00) /* TX FIFO */
  39#define MAX310X_IRQEN_REG		(0x01) /* IRQ enable */
  40#define MAX310X_IRQSTS_REG		(0x02) /* IRQ status */
  41#define MAX310X_LSR_IRQEN_REG		(0x03) /* LSR IRQ enable */
  42#define MAX310X_LSR_IRQSTS_REG		(0x04) /* LSR IRQ status */
  43#define MAX310X_REG_05			(0x05)
  44#define MAX310X_SPCHR_IRQEN_REG		MAX310X_REG_05 /* Special char IRQ en */
  45#define MAX310X_SPCHR_IRQSTS_REG	(0x06) /* Special char IRQ status */
  46#define MAX310X_STS_IRQEN_REG		(0x07) /* Status IRQ enable */
  47#define MAX310X_STS_IRQSTS_REG		(0x08) /* Status IRQ status */
  48#define MAX310X_MODE1_REG		(0x09) /* MODE1 */
  49#define MAX310X_MODE2_REG		(0x0a) /* MODE2 */
  50#define MAX310X_LCR_REG			(0x0b) /* LCR */
  51#define MAX310X_RXTO_REG		(0x0c) /* RX timeout */
  52#define MAX310X_HDPIXDELAY_REG		(0x0d) /* Auto transceiver delays */
  53#define MAX310X_IRDA_REG		(0x0e) /* IRDA settings */
  54#define MAX310X_FLOWLVL_REG		(0x0f) /* Flow control levels */
  55#define MAX310X_FIFOTRIGLVL_REG		(0x10) /* FIFO IRQ trigger levels */
  56#define MAX310X_TXFIFOLVL_REG		(0x11) /* TX FIFO level */
  57#define MAX310X_RXFIFOLVL_REG		(0x12) /* RX FIFO level */
  58#define MAX310X_FLOWCTRL_REG		(0x13) /* Flow control */
  59#define MAX310X_XON1_REG		(0x14) /* XON1 character */
  60#define MAX310X_XON2_REG		(0x15) /* XON2 character */
  61#define MAX310X_XOFF1_REG		(0x16) /* XOFF1 character */
  62#define MAX310X_XOFF2_REG		(0x17) /* XOFF2 character */
  63#define MAX310X_GPIOCFG_REG		(0x18) /* GPIO config */
  64#define MAX310X_GPIODATA_REG		(0x19) /* GPIO data */
  65#define MAX310X_PLLCFG_REG		(0x1a) /* PLL config */
  66#define MAX310X_BRGCFG_REG		(0x1b) /* Baud rate generator conf */
  67#define MAX310X_BRGDIVLSB_REG		(0x1c) /* Baud rate divisor LSB */
  68#define MAX310X_BRGDIVMSB_REG		(0x1d) /* Baud rate divisor MSB */
  69#define MAX310X_CLKSRC_REG		(0x1e) /* Clock source */
  70#define MAX310X_REG_1F			(0x1f)
  71
  72#define MAX310X_REVID_REG		MAX310X_REG_1F /* Revision ID */
  73
  74#define MAX310X_GLOBALIRQ_REG		MAX310X_REG_1F /* Global IRQ (RO) */
  75#define MAX310X_GLOBALCMD_REG		MAX310X_REG_1F /* Global Command (WO) */
  76
  77/* Extended registers */
  78#define MAX310X_REVID_EXTREG		MAX310X_REG_05 /* Revision ID */
  79
  80/* IRQ register bits */
  81#define MAX310X_IRQ_LSR_BIT		(1 << 0) /* LSR interrupt */
  82#define MAX310X_IRQ_SPCHR_BIT		(1 << 1) /* Special char interrupt */
  83#define MAX310X_IRQ_STS_BIT		(1 << 2) /* Status interrupt */
  84#define MAX310X_IRQ_RXFIFO_BIT		(1 << 3) /* RX FIFO interrupt */
  85#define MAX310X_IRQ_TXFIFO_BIT		(1 << 4) /* TX FIFO interrupt */
  86#define MAX310X_IRQ_TXEMPTY_BIT		(1 << 5) /* TX FIFO empty interrupt */
  87#define MAX310X_IRQ_RXEMPTY_BIT		(1 << 6) /* RX FIFO empty interrupt */
  88#define MAX310X_IRQ_CTS_BIT		(1 << 7) /* CTS interrupt */
  89
  90/* LSR register bits */
  91#define MAX310X_LSR_RXTO_BIT		(1 << 0) /* RX timeout */
  92#define MAX310X_LSR_RXOVR_BIT		(1 << 1) /* RX overrun */
  93#define MAX310X_LSR_RXPAR_BIT		(1 << 2) /* RX parity error */
  94#define MAX310X_LSR_FRERR_BIT		(1 << 3) /* Frame error */
  95#define MAX310X_LSR_RXBRK_BIT		(1 << 4) /* RX break */
  96#define MAX310X_LSR_RXNOISE_BIT		(1 << 5) /* RX noise */
  97#define MAX310X_LSR_CTS_BIT		(1 << 7) /* CTS pin state */
  98
  99/* Special character register bits */
 100#define MAX310X_SPCHR_XON1_BIT		(1 << 0) /* XON1 character */
 101#define MAX310X_SPCHR_XON2_BIT		(1 << 1) /* XON2 character */
 102#define MAX310X_SPCHR_XOFF1_BIT		(1 << 2) /* XOFF1 character */
 103#define MAX310X_SPCHR_XOFF2_BIT		(1 << 3) /* XOFF2 character */
 104#define MAX310X_SPCHR_BREAK_BIT		(1 << 4) /* RX break */
 105#define MAX310X_SPCHR_MULTIDROP_BIT	(1 << 5) /* 9-bit multidrop addr char */
 106
 107/* Status register bits */
 108#define MAX310X_STS_GPIO0_BIT		(1 << 0) /* GPIO 0 interrupt */
 109#define MAX310X_STS_GPIO1_BIT		(1 << 1) /* GPIO 1 interrupt */
 110#define MAX310X_STS_GPIO2_BIT		(1 << 2) /* GPIO 2 interrupt */
 111#define MAX310X_STS_GPIO3_BIT		(1 << 3) /* GPIO 3 interrupt */
 112#define MAX310X_STS_CLKREADY_BIT	(1 << 5) /* Clock ready */
 113#define MAX310X_STS_SLEEP_BIT		(1 << 6) /* Sleep interrupt */
 114
 115/* MODE1 register bits */
 116#define MAX310X_MODE1_RXDIS_BIT		(1 << 0) /* RX disable */
 117#define MAX310X_MODE1_TXDIS_BIT		(1 << 1) /* TX disable */
 118#define MAX310X_MODE1_TXHIZ_BIT		(1 << 2) /* TX pin three-state */
 119#define MAX310X_MODE1_RTSHIZ_BIT	(1 << 3) /* RTS pin three-state */
 120#define MAX310X_MODE1_TRNSCVCTRL_BIT	(1 << 4) /* Transceiver ctrl enable */
 121#define MAX310X_MODE1_FORCESLEEP_BIT	(1 << 5) /* Force sleep mode */
 122#define MAX310X_MODE1_AUTOSLEEP_BIT	(1 << 6) /* Auto sleep enable */
 123#define MAX310X_MODE1_IRQSEL_BIT	(1 << 7) /* IRQ pin enable */
 124
 125/* MODE2 register bits */
 126#define MAX310X_MODE2_RST_BIT		(1 << 0) /* Chip reset */
 127#define MAX310X_MODE2_FIFORST_BIT	(1 << 1) /* FIFO reset */
 128#define MAX310X_MODE2_RXTRIGINV_BIT	(1 << 2) /* RX FIFO INT invert */
 129#define MAX310X_MODE2_RXEMPTINV_BIT	(1 << 3) /* RX FIFO empty INT invert */
 130#define MAX310X_MODE2_SPCHR_BIT		(1 << 4) /* Special chr detect enable */
 131#define MAX310X_MODE2_LOOPBACK_BIT	(1 << 5) /* Internal loopback enable */
 132#define MAX310X_MODE2_MULTIDROP_BIT	(1 << 6) /* 9-bit multidrop enable */
 133#define MAX310X_MODE2_ECHOSUPR_BIT	(1 << 7) /* ECHO suppression enable */
 134
 135/* LCR register bits */
 136#define MAX310X_LCR_LENGTH0_BIT		(1 << 0) /* Word length bit 0 */
 137#define MAX310X_LCR_LENGTH1_BIT		(1 << 1) /* Word length bit 1
 138						  *
 139						  * Word length bits table:
 140						  * 00 -> 5 bit words
 141						  * 01 -> 6 bit words
 142						  * 10 -> 7 bit words
 143						  * 11 -> 8 bit words
 144						  */
 145#define MAX310X_LCR_STOPLEN_BIT		(1 << 2) /* STOP length bit
 146						  *
 147						  * STOP length bit table:
 148						  * 0 -> 1 stop bit
 149						  * 1 -> 1-1.5 stop bits if
 150						  *      word length is 5,
 151						  *      2 stop bits otherwise
 152						  */
 153#define MAX310X_LCR_PARITY_BIT		(1 << 3) /* Parity bit enable */
 154#define MAX310X_LCR_EVENPARITY_BIT	(1 << 4) /* Even parity bit enable */
 155#define MAX310X_LCR_FORCEPARITY_BIT	(1 << 5) /* 9-bit multidrop parity */
 156#define MAX310X_LCR_TXBREAK_BIT		(1 << 6) /* TX break enable */
 157#define MAX310X_LCR_RTS_BIT		(1 << 7) /* RTS pin control */
 158#define MAX310X_LCR_WORD_LEN_5		(0x00)
 159#define MAX310X_LCR_WORD_LEN_6		(0x01)
 160#define MAX310X_LCR_WORD_LEN_7		(0x02)
 161#define MAX310X_LCR_WORD_LEN_8		(0x03)
 162
 163/* IRDA register bits */
 164#define MAX310X_IRDA_IRDAEN_BIT		(1 << 0) /* IRDA mode enable */
 165#define MAX310X_IRDA_SIR_BIT		(1 << 1) /* SIR mode enable */
 166
 167/* Flow control trigger level register masks */
 168#define MAX310X_FLOWLVL_HALT_MASK	(0x000f) /* Flow control halt level */
 169#define MAX310X_FLOWLVL_RES_MASK	(0x00f0) /* Flow control resume level */
 170#define MAX310X_FLOWLVL_HALT(words)	((words / 8) & 0x0f)
 171#define MAX310X_FLOWLVL_RES(words)	(((words / 8) & 0x0f) << 4)
 172
 173/* FIFO interrupt trigger level register masks */
 174#define MAX310X_FIFOTRIGLVL_TX_MASK	(0x0f) /* TX FIFO trigger level */
 175#define MAX310X_FIFOTRIGLVL_RX_MASK	(0xf0) /* RX FIFO trigger level */
 176#define MAX310X_FIFOTRIGLVL_TX(words)	((words / 8) & 0x0f)
 177#define MAX310X_FIFOTRIGLVL_RX(words)	(((words / 8) & 0x0f) << 4)
 178
 179/* Flow control register bits */
 180#define MAX310X_FLOWCTRL_AUTORTS_BIT	(1 << 0) /* Auto RTS flow ctrl enable */
 181#define MAX310X_FLOWCTRL_AUTOCTS_BIT	(1 << 1) /* Auto CTS flow ctrl enable */
 182#define MAX310X_FLOWCTRL_GPIADDR_BIT	(1 << 2) /* Enables that GPIO inputs
 183						  * are used in conjunction with
 184						  * XOFF2 for definition of
 185						  * special character */
 186#define MAX310X_FLOWCTRL_SWFLOWEN_BIT	(1 << 3) /* Auto SW flow ctrl enable */
 187#define MAX310X_FLOWCTRL_SWFLOW0_BIT	(1 << 4) /* SWFLOW bit 0 */
 188#define MAX310X_FLOWCTRL_SWFLOW1_BIT	(1 << 5) /* SWFLOW bit 1
 189						  *
 190						  * SWFLOW bits 1 & 0 table:
 191						  * 00 -> no transmitter flow
 192						  *       control
 193						  * 01 -> receiver compares
 194						  *       XON2 and XOFF2
 195						  *       and controls
 196						  *       transmitter
 197						  * 10 -> receiver compares
 198						  *       XON1 and XOFF1
 199						  *       and controls
 200						  *       transmitter
 201						  * 11 -> receiver compares
 202						  *       XON1, XON2, XOFF1 and
 203						  *       XOFF2 and controls
 204						  *       transmitter
 205						  */
 206#define MAX310X_FLOWCTRL_SWFLOW2_BIT	(1 << 6) /* SWFLOW bit 2 */
 207#define MAX310X_FLOWCTRL_SWFLOW3_BIT	(1 << 7) /* SWFLOW bit 3
 208						  *
 209						  * SWFLOW bits 3 & 2 table:
 210						  * 00 -> no received flow
 211						  *       control
 212						  * 01 -> transmitter generates
 213						  *       XON2 and XOFF2
 214						  * 10 -> transmitter generates
 215						  *       XON1 and XOFF1
 216						  * 11 -> transmitter generates
 217						  *       XON1, XON2, XOFF1 and
 218						  *       XOFF2
 219						  */
 220
 221/* PLL configuration register masks */
 222#define MAX310X_PLLCFG_PREDIV_MASK	(0x3f) /* PLL predivision value */
 223#define MAX310X_PLLCFG_PLLFACTOR_MASK	(0xc0) /* PLL multiplication factor */
 224
 225/* Baud rate generator configuration register bits */
 226#define MAX310X_BRGCFG_2XMODE_BIT	(1 << 4) /* Double baud rate */
 227#define MAX310X_BRGCFG_4XMODE_BIT	(1 << 5) /* Quadruple baud rate */
 228
 229/* Clock source register bits */
 230#define MAX310X_CLKSRC_CRYST_BIT	(1 << 1) /* Crystal osc enable */
 231#define MAX310X_CLKSRC_PLL_BIT		(1 << 2) /* PLL enable */
 232#define MAX310X_CLKSRC_PLLBYP_BIT	(1 << 3) /* PLL bypass */
 233#define MAX310X_CLKSRC_EXTCLK_BIT	(1 << 4) /* External clock enable */
 234#define MAX310X_CLKSRC_CLK2RTS_BIT	(1 << 7) /* Baud clk to RTS pin */
 235
 236/* Global commands */
 237#define MAX310X_EXTREG_ENBL		(0xce)
 238#define MAX310X_EXTREG_DSBL		(0xcd)
 239
 240/* Misc definitions */
 241#define MAX310X_FIFO_SIZE		(128)
 242#define MAX310x_REV_MASK		(0xfc)
 243
 244/* MAX3107 specific */
 245#define MAX3107_REV_ID			(0xa0)
 246
 247/* MAX3109 specific */
 248#define MAX3109_REV_ID			(0xc0)
 249
 250/* MAX14830 specific */
 251#define MAX14830_BRGCFG_CLKDIS_BIT	(1 << 6) /* Clock Disable */
 252#define MAX14830_REV_ID			(0xb0)
 253
 254struct max310x_devtype {
 255	char	name[9];
 256	int	nr;
 257	int	(*detect)(struct device *);
 258	void	(*power)(struct uart_port *, int);
 259};
 260
 261struct max310x_one {
 262	struct uart_port	port;
 263	struct work_struct	tx_work;
 264	struct work_struct	md_work;
 265};
 266
 267struct max310x_port {
 268	struct uart_driver	uart;
 269	struct max310x_devtype	*devtype;
 270	struct regmap		*regmap;
 271	struct mutex		mutex;
 272	struct clk		*clk;
 273#ifdef CONFIG_GPIOLIB
 274	struct gpio_chip	gpio;
 275#endif
 276	struct max310x_one	p[0];
 277};
 278
 279static u8 max310x_port_read(struct uart_port *port, u8 reg)
 280{
 281	struct max310x_port *s = dev_get_drvdata(port->dev);
 282	unsigned int val = 0;
 283
 284	regmap_read(s->regmap, port->iobase + reg, &val);
 285
 286	return val;
 287}
 288
 289static void max310x_port_write(struct uart_port *port, u8 reg, u8 val)
 290{
 291	struct max310x_port *s = dev_get_drvdata(port->dev);
 292
 293	regmap_write(s->regmap, port->iobase + reg, val);
 294}
 295
 296static void max310x_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val)
 297{
 298	struct max310x_port *s = dev_get_drvdata(port->dev);
 299
 300	regmap_update_bits(s->regmap, port->iobase + reg, mask, val);
 301}
 302
 303static int max3107_detect(struct device *dev)
 304{
 305	struct max310x_port *s = dev_get_drvdata(dev);
 306	unsigned int val = 0;
 307	int ret;
 308
 309	ret = regmap_read(s->regmap, MAX310X_REVID_REG, &val);
 310	if (ret)
 311		return ret;
 312
 313	if (((val & MAX310x_REV_MASK) != MAX3107_REV_ID)) {
 314		dev_err(dev,
 315			"%s ID 0x%02x does not match\n", s->devtype->name, val);
 316		return -ENODEV;
 317	}
 318
 319	return 0;
 320}
 321
 322static int max3108_detect(struct device *dev)
 323{
 324	struct max310x_port *s = dev_get_drvdata(dev);
 325	unsigned int val = 0;
 326	int ret;
 327
 328	/* MAX3108 have not REV ID register, we just check default value
 329	 * from clocksource register to make sure everything works.
 330	 */
 331	ret = regmap_read(s->regmap, MAX310X_CLKSRC_REG, &val);
 332	if (ret)
 333		return ret;
 334
 335	if (val != (MAX310X_CLKSRC_EXTCLK_BIT | MAX310X_CLKSRC_PLLBYP_BIT)) {
 336		dev_err(dev, "%s not present\n", s->devtype->name);
 337		return -ENODEV;
 338	}
 339
 340	return 0;
 341}
 342
 343static int max3109_detect(struct device *dev)
 344{
 345	struct max310x_port *s = dev_get_drvdata(dev);
 346	unsigned int val = 0;
 347	int ret;
 348
 349	ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
 350			   MAX310X_EXTREG_ENBL);
 351	if (ret)
 352		return ret;
 353
 354	regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
 355	regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
 356	if (((val & MAX310x_REV_MASK) != MAX3109_REV_ID)) {
 357		dev_err(dev,
 358			"%s ID 0x%02x does not match\n", s->devtype->name, val);
 359		return -ENODEV;
 360	}
 361
 362	return 0;
 363}
 364
 365static void max310x_power(struct uart_port *port, int on)
 366{
 367	max310x_port_update(port, MAX310X_MODE1_REG,
 368			    MAX310X_MODE1_FORCESLEEP_BIT,
 369			    on ? 0 : MAX310X_MODE1_FORCESLEEP_BIT);
 370	if (on)
 371		msleep(50);
 372}
 373
 374static int max14830_detect(struct device *dev)
 375{
 376	struct max310x_port *s = dev_get_drvdata(dev);
 377	unsigned int val = 0;
 378	int ret;
 379
 380	ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
 381			   MAX310X_EXTREG_ENBL);
 382	if (ret)
 383		return ret;
 384	
 385	regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
 386	regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
 387	if (((val & MAX310x_REV_MASK) != MAX14830_REV_ID)) {
 388		dev_err(dev,
 389			"%s ID 0x%02x does not match\n", s->devtype->name, val);
 390		return -ENODEV;
 391	}
 392
 393	return 0;
 394}
 395
 396static void max14830_power(struct uart_port *port, int on)
 397{
 398	max310x_port_update(port, MAX310X_BRGCFG_REG,
 399			    MAX14830_BRGCFG_CLKDIS_BIT,
 400			    on ? 0 : MAX14830_BRGCFG_CLKDIS_BIT);
 401	if (on)
 402		msleep(50);
 403}
 404
 405static const struct max310x_devtype max3107_devtype = {
 406	.name	= "MAX3107",
 407	.nr	= 1,
 408	.detect	= max3107_detect,
 409	.power	= max310x_power,
 410};
 411
 412static const struct max310x_devtype max3108_devtype = {
 413	.name	= "MAX3108",
 414	.nr	= 1,
 415	.detect	= max3108_detect,
 416	.power	= max310x_power,
 417};
 418
 419static const struct max310x_devtype max3109_devtype = {
 420	.name	= "MAX3109",
 421	.nr	= 2,
 422	.detect	= max3109_detect,
 423	.power	= max310x_power,
 424};
 425
 426static const struct max310x_devtype max14830_devtype = {
 427	.name	= "MAX14830",
 428	.nr	= 4,
 429	.detect	= max14830_detect,
 430	.power	= max14830_power,
 431};
 432
 433static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
 434{
 435	switch (reg & 0x1f) {
 436	case MAX310X_IRQSTS_REG:
 437	case MAX310X_LSR_IRQSTS_REG:
 438	case MAX310X_SPCHR_IRQSTS_REG:
 439	case MAX310X_STS_IRQSTS_REG:
 440	case MAX310X_TXFIFOLVL_REG:
 441	case MAX310X_RXFIFOLVL_REG:
 442		return false;
 443	default:
 444		break;
 445	}
 446
 447	return true;
 448}
 449
 450static bool max310x_reg_volatile(struct device *dev, unsigned int reg)
 451{
 452	switch (reg & 0x1f) {
 453	case MAX310X_RHR_REG:
 454	case MAX310X_IRQSTS_REG:
 455	case MAX310X_LSR_IRQSTS_REG:
 456	case MAX310X_SPCHR_IRQSTS_REG:
 457	case MAX310X_STS_IRQSTS_REG:
 458	case MAX310X_TXFIFOLVL_REG:
 459	case MAX310X_RXFIFOLVL_REG:
 460	case MAX310X_GPIODATA_REG:
 461	case MAX310X_BRGDIVLSB_REG:
 462	case MAX310X_REG_05:
 463	case MAX310X_REG_1F:
 464		return true;
 465	default:
 466		break;
 467	}
 468
 469	return false;
 470}
 471
 472static bool max310x_reg_precious(struct device *dev, unsigned int reg)
 473{
 474	switch (reg & 0x1f) {
 475	case MAX310X_RHR_REG:
 476	case MAX310X_IRQSTS_REG:
 477	case MAX310X_SPCHR_IRQSTS_REG:
 478	case MAX310X_STS_IRQSTS_REG:
 479		return true;
 480	default:
 481		break;
 482	}
 483
 484	return false;
 485}
 486
 487static int max310x_set_baud(struct uart_port *port, int baud)
 488{
 489	unsigned int mode = 0, clk = port->uartclk, div = clk / baud;
 490
 491	/* Check for minimal value for divider */
 492	if (div < 16)
 493		div = 16;
 494
 495	if (clk % baud && (div / 16) < 0x8000) {
 496		/* Mode x2 */
 497		mode = MAX310X_BRGCFG_2XMODE_BIT;
 498		clk = port->uartclk * 2;
 499		div = clk / baud;
 500
 501		if (clk % baud && (div / 16) < 0x8000) {
 502			/* Mode x4 */
 503			mode = MAX310X_BRGCFG_4XMODE_BIT;
 504			clk = port->uartclk * 4;
 505			div = clk / baud;
 506		}
 507	}
 508
 509	max310x_port_write(port, MAX310X_BRGDIVMSB_REG, (div / 16) >> 8);
 510	max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div / 16);
 511	max310x_port_write(port, MAX310X_BRGCFG_REG, (div % 16) | mode);
 512
 513	return DIV_ROUND_CLOSEST(clk, div);
 514}
 515
 516static int max310x_update_best_err(unsigned long f, long *besterr)
 517{
 518	/* Use baudrate 115200 for calculate error */
 519	long err = f % (115200 * 16);
 520
 521	if ((*besterr < 0) || (*besterr > err)) {
 522		*besterr = err;
 523		return 0;
 524	}
 525
 526	return 1;
 527}
 528
 529static int max310x_set_ref_clk(struct max310x_port *s, unsigned long freq,
 530			       bool xtal)
 531{
 532	unsigned int div, clksrc, pllcfg = 0;
 533	long besterr = -1;
 534	unsigned long fdiv, fmul, bestfreq = freq;
 535
 536	/* First, update error without PLL */
 537	max310x_update_best_err(freq, &besterr);
 538
 539	/* Try all possible PLL dividers */
 540	for (div = 1; (div <= 63) && besterr; div++) {
 541		fdiv = DIV_ROUND_CLOSEST(freq, div);
 542
 543		/* Try multiplier 6 */
 544		fmul = fdiv * 6;
 545		if ((fdiv >= 500000) && (fdiv <= 800000))
 546			if (!max310x_update_best_err(fmul, &besterr)) {
 547				pllcfg = (0 << 6) | div;
 548				bestfreq = fmul;
 549			}
 550		/* Try multiplier 48 */
 551		fmul = fdiv * 48;
 552		if ((fdiv >= 850000) && (fdiv <= 1200000))
 553			if (!max310x_update_best_err(fmul, &besterr)) {
 554				pllcfg = (1 << 6) | div;
 555				bestfreq = fmul;
 556			}
 557		/* Try multiplier 96 */
 558		fmul = fdiv * 96;
 559		if ((fdiv >= 425000) && (fdiv <= 1000000))
 560			if (!max310x_update_best_err(fmul, &besterr)) {
 561				pllcfg = (2 << 6) | div;
 562				bestfreq = fmul;
 563			}
 564		/* Try multiplier 144 */
 565		fmul = fdiv * 144;
 566		if ((fdiv >= 390000) && (fdiv <= 667000))
 567			if (!max310x_update_best_err(fmul, &besterr)) {
 568				pllcfg = (3 << 6) | div;
 569				bestfreq = fmul;
 570			}
 571	}
 572
 573	/* Configure clock source */
 574	clksrc = xtal ? MAX310X_CLKSRC_CRYST_BIT : MAX310X_CLKSRC_EXTCLK_BIT;
 575
 576	/* Configure PLL */
 577	if (pllcfg) {
 578		clksrc |= MAX310X_CLKSRC_PLL_BIT;
 579		regmap_write(s->regmap, MAX310X_PLLCFG_REG, pllcfg);
 580	} else
 581		clksrc |= MAX310X_CLKSRC_PLLBYP_BIT;
 582
 583	regmap_write(s->regmap, MAX310X_CLKSRC_REG, clksrc);
 584
 585	/* Wait for crystal */
 586	if (pllcfg && xtal)
 587		msleep(10);
 588
 589	return (int)bestfreq;
 590}
 591
 592static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
 593{
 594	unsigned int sts, ch, flag;
 595
 596	if (unlikely(rxlen >= port->fifosize)) {
 597		dev_warn_ratelimited(port->dev,
 598				     "Port %i: Possible RX FIFO overrun\n",
 599				     port->line);
 600		port->icount.buf_overrun++;
 601		/* Ensure sanity of RX level */
 602		rxlen = port->fifosize;
 603	}
 604
 605	while (rxlen--) {
 606		ch = max310x_port_read(port, MAX310X_RHR_REG);
 607		sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
 608
 609		sts &= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_FRERR_BIT |
 610		       MAX310X_LSR_RXOVR_BIT | MAX310X_LSR_RXBRK_BIT;
 611
 612		port->icount.rx++;
 613		flag = TTY_NORMAL;
 614
 615		if (unlikely(sts)) {
 616			if (sts & MAX310X_LSR_RXBRK_BIT) {
 617				port->icount.brk++;
 618				if (uart_handle_break(port))
 619					continue;
 620			} else if (sts & MAX310X_LSR_RXPAR_BIT)
 621				port->icount.parity++;
 622			else if (sts & MAX310X_LSR_FRERR_BIT)
 623				port->icount.frame++;
 624			else if (sts & MAX310X_LSR_RXOVR_BIT)
 625				port->icount.overrun++;
 626
 627			sts &= port->read_status_mask;
 628			if (sts & MAX310X_LSR_RXBRK_BIT)
 629				flag = TTY_BREAK;
 630			else if (sts & MAX310X_LSR_RXPAR_BIT)
 631				flag = TTY_PARITY;
 632			else if (sts & MAX310X_LSR_FRERR_BIT)
 633				flag = TTY_FRAME;
 634			else if (sts & MAX310X_LSR_RXOVR_BIT)
 635				flag = TTY_OVERRUN;
 636		}
 637
 638		if (uart_handle_sysrq_char(port, ch))
 639			continue;
 640
 641		if (sts & port->ignore_status_mask)
 642			continue;
 643
 644		uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT, ch, flag);
 645	}
 646
 647	tty_flip_buffer_push(&port->state->port);
 648}
 649
 650static void max310x_handle_tx(struct uart_port *port)
 651{
 652	struct circ_buf *xmit = &port->state->xmit;
 653	unsigned int txlen, to_send;
 654
 655	if (unlikely(port->x_char)) {
 656		max310x_port_write(port, MAX310X_THR_REG, port->x_char);
 657		port->icount.tx++;
 658		port->x_char = 0;
 659		return;
 660	}
 661
 662	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
 663		return;
 664
 665	/* Get length of data pending in circular buffer */
 666	to_send = uart_circ_chars_pending(xmit);
 667	if (likely(to_send)) {
 668		/* Limit to size of TX FIFO */
 669		txlen = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
 670		txlen = port->fifosize - txlen;
 671		to_send = (to_send > txlen) ? txlen : to_send;
 672
 673		/* Add data to send */
 674		port->icount.tx += to_send;
 675		while (to_send--) {
 676			max310x_port_write(port, MAX310X_THR_REG,
 677					   xmit->buf[xmit->tail]);
 678			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 679		}
 680	}
 681
 682	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 683		uart_write_wakeup(port);
 684}
 685
 686static void max310x_port_irq(struct max310x_port *s, int portno)
 687{
 688	struct uart_port *port = &s->p[portno].port;
 689
 690	do {
 691		unsigned int ists, lsr, rxlen;
 692
 693		/* Read IRQ status & RX FIFO level */
 694		ists = max310x_port_read(port, MAX310X_IRQSTS_REG);
 695		rxlen = max310x_port_read(port, MAX310X_RXFIFOLVL_REG);
 696		if (!ists && !rxlen)
 697			break;
 698
 699		if (ists & MAX310X_IRQ_CTS_BIT) {
 700			lsr = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
 701			uart_handle_cts_change(port,
 702					       !!(lsr & MAX310X_LSR_CTS_BIT));
 703		}
 704		if (rxlen)
 705			max310x_handle_rx(port, rxlen);
 706		if (ists & MAX310X_IRQ_TXEMPTY_BIT) {
 707			mutex_lock(&s->mutex);
 708			max310x_handle_tx(port);
 709			mutex_unlock(&s->mutex);
 710		}
 711	} while (1);
 712}
 713
 714static irqreturn_t max310x_ist(int irq, void *dev_id)
 715{
 716	struct max310x_port *s = (struct max310x_port *)dev_id;
 717
 718	if (s->uart.nr > 1) {
 719		do {
 720			unsigned int val = ~0;
 721
 722			WARN_ON_ONCE(regmap_read(s->regmap,
 723						 MAX310X_GLOBALIRQ_REG, &val));
 724			val = ((1 << s->uart.nr) - 1) & ~val;
 725			if (!val)
 726				break;
 727			max310x_port_irq(s, fls(val) - 1);
 728		} while (1);
 729	} else
 730		max310x_port_irq(s, 0);
 731
 732	return IRQ_HANDLED;
 733}
 734
 735static void max310x_wq_proc(struct work_struct *ws)
 736{
 737	struct max310x_one *one = container_of(ws, struct max310x_one, tx_work);
 738	struct max310x_port *s = dev_get_drvdata(one->port.dev);
 739
 740	mutex_lock(&s->mutex);
 741	max310x_handle_tx(&one->port);
 742	mutex_unlock(&s->mutex);
 743}
 744
 745static void max310x_start_tx(struct uart_port *port)
 746{
 747	struct max310x_one *one = container_of(port, struct max310x_one, port);
 748
 749	if (!work_pending(&one->tx_work))
 750		schedule_work(&one->tx_work);
 751}
 752
 753static unsigned int max310x_tx_empty(struct uart_port *port)
 754{
 755	unsigned int lvl, sts;
 756
 757	lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
 758	sts = max310x_port_read(port, MAX310X_IRQSTS_REG);
 759
 760	return ((sts & MAX310X_IRQ_TXEMPTY_BIT) && !lvl) ? TIOCSER_TEMT : 0;
 761}
 762
 763static unsigned int max310x_get_mctrl(struct uart_port *port)
 764{
 765	/* DCD and DSR are not wired and CTS/RTS is handled automatically
 766	 * so just indicate DSR and CAR asserted
 767	 */
 768	return TIOCM_DSR | TIOCM_CAR;
 769}
 770
 771static void max310x_md_proc(struct work_struct *ws)
 772{
 773	struct max310x_one *one = container_of(ws, struct max310x_one, md_work);
 774
 775	max310x_port_update(&one->port, MAX310X_MODE2_REG,
 776			    MAX310X_MODE2_LOOPBACK_BIT,
 777			    (one->port.mctrl & TIOCM_LOOP) ?
 778			    MAX310X_MODE2_LOOPBACK_BIT : 0);
 779}
 780
 781static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl)
 782{
 783	struct max310x_one *one = container_of(port, struct max310x_one, port);
 784
 785	schedule_work(&one->md_work);
 786}
 787
 788static void max310x_break_ctl(struct uart_port *port, int break_state)
 789{
 790	max310x_port_update(port, MAX310X_LCR_REG,
 791			    MAX310X_LCR_TXBREAK_BIT,
 792			    break_state ? MAX310X_LCR_TXBREAK_BIT : 0);
 793}
 794
 795static void max310x_set_termios(struct uart_port *port,
 796				struct ktermios *termios,
 797				struct ktermios *old)
 798{
 799	unsigned int lcr, flow = 0;
 800	int baud;
 801
 802	/* Mask termios capabilities we don't support */
 803	termios->c_cflag &= ~CMSPAR;
 804
 805	/* Word size */
 806	switch (termios->c_cflag & CSIZE) {
 807	case CS5:
 808		lcr = MAX310X_LCR_WORD_LEN_5;
 809		break;
 810	case CS6:
 811		lcr = MAX310X_LCR_WORD_LEN_6;
 812		break;
 813	case CS7:
 814		lcr = MAX310X_LCR_WORD_LEN_7;
 815		break;
 816	case CS8:
 817	default:
 818		lcr = MAX310X_LCR_WORD_LEN_8;
 819		break;
 820	}
 821
 822	/* Parity */
 823	if (termios->c_cflag & PARENB) {
 824		lcr |= MAX310X_LCR_PARITY_BIT;
 825		if (!(termios->c_cflag & PARODD))
 826			lcr |= MAX310X_LCR_EVENPARITY_BIT;
 827	}
 828
 829	/* Stop bits */
 830	if (termios->c_cflag & CSTOPB)
 831		lcr |= MAX310X_LCR_STOPLEN_BIT; /* 2 stops */
 832
 833	/* Update LCR register */
 834	max310x_port_write(port, MAX310X_LCR_REG, lcr);
 835
 836	/* Set read status mask */
 837	port->read_status_mask = MAX310X_LSR_RXOVR_BIT;
 838	if (termios->c_iflag & INPCK)
 839		port->read_status_mask |= MAX310X_LSR_RXPAR_BIT |
 840					  MAX310X_LSR_FRERR_BIT;
 841	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
 842		port->read_status_mask |= MAX310X_LSR_RXBRK_BIT;
 843
 844	/* Set status ignore mask */
 845	port->ignore_status_mask = 0;
 846	if (termios->c_iflag & IGNBRK)
 847		port->ignore_status_mask |= MAX310X_LSR_RXBRK_BIT;
 848	if (!(termios->c_cflag & CREAD))
 849		port->ignore_status_mask |= MAX310X_LSR_RXPAR_BIT |
 850					    MAX310X_LSR_RXOVR_BIT |
 851					    MAX310X_LSR_FRERR_BIT |
 852					    MAX310X_LSR_RXBRK_BIT;
 853
 854	/* Configure flow control */
 855	max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]);
 856	max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]);
 857	if (termios->c_cflag & CRTSCTS)
 858		flow |= MAX310X_FLOWCTRL_AUTOCTS_BIT |
 859			MAX310X_FLOWCTRL_AUTORTS_BIT;
 860	if (termios->c_iflag & IXON)
 861		flow |= MAX310X_FLOWCTRL_SWFLOW3_BIT |
 862			MAX310X_FLOWCTRL_SWFLOWEN_BIT;
 863	if (termios->c_iflag & IXOFF)
 864		flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT |
 865			MAX310X_FLOWCTRL_SWFLOWEN_BIT;
 866	max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow);
 867
 868	/* Get baud rate generator configuration */
 869	baud = uart_get_baud_rate(port, termios, old,
 870				  port->uartclk / 16 / 0xffff,
 871				  port->uartclk / 4);
 872
 873	/* Setup baudrate generator */
 874	baud = max310x_set_baud(port, baud);
 875
 876	/* Update timeout according to new baud rate */
 877	uart_update_timeout(port, termios->c_cflag, baud);
 878}
 879
 880static int max310x_rs485_config(struct uart_port *port,
 881				struct serial_rs485 *rs485)
 882{
 883	unsigned int val;
 884
 885	if (rs485->delay_rts_before_send > 0x0f ||
 886		    rs485->delay_rts_after_send > 0x0f)
 887		return -ERANGE;
 888
 889	val = (rs485->delay_rts_before_send << 4) |
 890		rs485->delay_rts_after_send;
 891	max310x_port_write(port, MAX310X_HDPIXDELAY_REG, val);
 892	if (rs485->flags & SER_RS485_ENABLED) {
 893		max310x_port_update(port, MAX310X_MODE1_REG,
 894				MAX310X_MODE1_TRNSCVCTRL_BIT,
 895				MAX310X_MODE1_TRNSCVCTRL_BIT);
 896		max310x_port_update(port, MAX310X_MODE2_REG,
 897				MAX310X_MODE2_ECHOSUPR_BIT,
 898				MAX310X_MODE2_ECHOSUPR_BIT);
 899	} else {
 900		max310x_port_update(port, MAX310X_MODE1_REG,
 901				MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
 902		max310x_port_update(port, MAX310X_MODE2_REG,
 903				MAX310X_MODE2_ECHOSUPR_BIT, 0);
 904	}
 905
 906	rs485->flags &= SER_RS485_RTS_ON_SEND | SER_RS485_ENABLED;
 907	memset(rs485->padding, 0, sizeof(rs485->padding));
 908	port->rs485 = *rs485;
 909
 910	return 0;
 911}
 912
 913static int max310x_startup(struct uart_port *port)
 914{
 915	struct max310x_port *s = dev_get_drvdata(port->dev);
 916	unsigned int val;
 917
 918	s->devtype->power(port, 1);
 919
 920	/* Configure MODE1 register */
 921	max310x_port_update(port, MAX310X_MODE1_REG,
 922			    MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
 923
 924	/* Configure MODE2 register & Reset FIFOs*/
 925	val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT;
 926	max310x_port_write(port, MAX310X_MODE2_REG, val);
 927	max310x_port_update(port, MAX310X_MODE2_REG,
 928			    MAX310X_MODE2_FIFORST_BIT, 0);
 929
 930	/* Configure flow control levels */
 931	/* Flow control halt level 96, resume level 48 */
 932	max310x_port_write(port, MAX310X_FLOWLVL_REG,
 933			   MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96));
 934
 935	/* Clear IRQ status register */
 936	max310x_port_read(port, MAX310X_IRQSTS_REG);
 937
 938	/* Enable RX, TX, CTS change interrupts */
 939	val = MAX310X_IRQ_RXEMPTY_BIT | MAX310X_IRQ_TXEMPTY_BIT;
 940	max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT);
 941
 942	return 0;
 943}
 944
 945static void max310x_shutdown(struct uart_port *port)
 946{
 947	struct max310x_port *s = dev_get_drvdata(port->dev);
 948
 949	/* Disable all interrupts */
 950	max310x_port_write(port, MAX310X_IRQEN_REG, 0);
 951
 952	s->devtype->power(port, 0);
 953}
 954
 955static const char *max310x_type(struct uart_port *port)
 956{
 957	struct max310x_port *s = dev_get_drvdata(port->dev);
 958
 959	return (port->type == PORT_MAX310X) ? s->devtype->name : NULL;
 960}
 961
 962static int max310x_request_port(struct uart_port *port)
 963{
 964	/* Do nothing */
 965	return 0;
 966}
 967
 968static void max310x_config_port(struct uart_port *port, int flags)
 969{
 970	if (flags & UART_CONFIG_TYPE)
 971		port->type = PORT_MAX310X;
 972}
 973
 974static int max310x_verify_port(struct uart_port *port, struct serial_struct *s)
 975{
 976	if ((s->type != PORT_UNKNOWN) && (s->type != PORT_MAX310X))
 977		return -EINVAL;
 978	if (s->irq != port->irq)
 979		return -EINVAL;
 980
 981	return 0;
 982}
 983
 984static void max310x_null_void(struct uart_port *port)
 985{
 986	/* Do nothing */
 987}
 988
 989static const struct uart_ops max310x_ops = {
 990	.tx_empty	= max310x_tx_empty,
 991	.set_mctrl	= max310x_set_mctrl,
 992	.get_mctrl	= max310x_get_mctrl,
 993	.stop_tx	= max310x_null_void,
 994	.start_tx	= max310x_start_tx,
 995	.stop_rx	= max310x_null_void,
 996	.break_ctl	= max310x_break_ctl,
 997	.startup	= max310x_startup,
 998	.shutdown	= max310x_shutdown,
 999	.set_termios	= max310x_set_termios,
1000	.type		= max310x_type,
1001	.request_port	= max310x_request_port,
1002	.release_port	= max310x_null_void,
1003	.config_port	= max310x_config_port,
1004	.verify_port	= max310x_verify_port,
1005};
1006
1007static int __maybe_unused max310x_suspend(struct device *dev)
1008{
1009	struct max310x_port *s = dev_get_drvdata(dev);
1010	int i;
1011
1012	for (i = 0; i < s->uart.nr; i++) {
1013		uart_suspend_port(&s->uart, &s->p[i].port);
1014		s->devtype->power(&s->p[i].port, 0);
1015	}
1016
1017	return 0;
1018}
1019
1020static int __maybe_unused max310x_resume(struct device *dev)
1021{
1022	struct max310x_port *s = dev_get_drvdata(dev);
1023	int i;
1024
1025	for (i = 0; i < s->uart.nr; i++) {
1026		s->devtype->power(&s->p[i].port, 1);
1027		uart_resume_port(&s->uart, &s->p[i].port);
1028	}
1029
1030	return 0;
1031}
1032
1033static SIMPLE_DEV_PM_OPS(max310x_pm_ops, max310x_suspend, max310x_resume);
1034
1035#ifdef CONFIG_GPIOLIB
1036static int max310x_gpio_get(struct gpio_chip *chip, unsigned offset)
1037{
1038	unsigned int val;
1039	struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1040	struct uart_port *port = &s->p[offset / 4].port;
1041
1042	val = max310x_port_read(port, MAX310X_GPIODATA_REG);
1043
1044	return !!((val >> 4) & (1 << (offset % 4)));
1045}
1046
1047static void max310x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
1048{
1049	struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1050	struct uart_port *port = &s->p[offset / 4].port;
1051
1052	max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1053			    value ? 1 << (offset % 4) : 0);
1054}
1055
1056static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
1057{
1058	struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1059	struct uart_port *port = &s->p[offset / 4].port;
1060
1061	max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4), 0);
1062
1063	return 0;
1064}
1065
1066static int max310x_gpio_direction_output(struct gpio_chip *chip,
1067					 unsigned offset, int value)
1068{
1069	struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1070	struct uart_port *port = &s->p[offset / 4].port;
1071
1072	max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1073			    value ? 1 << (offset % 4) : 0);
1074	max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4),
1075			    1 << (offset % 4));
1076
1077	return 0;
1078}
1079#endif
1080
1081static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
1082			 struct regmap *regmap, int irq, unsigned long flags)
1083{
1084	int i, ret, fmin, fmax, freq, uartclk;
1085	struct clk *clk_osc, *clk_xtal;
1086	struct max310x_port *s;
1087	bool xtal = false;
1088
1089	if (IS_ERR(regmap))
1090		return PTR_ERR(regmap);
1091
1092	/* Alloc port structure */
1093	s = devm_kzalloc(dev, sizeof(*s) +
1094			 sizeof(struct max310x_one) * devtype->nr, GFP_KERNEL);
1095	if (!s) {
1096		dev_err(dev, "Error allocating port structure\n");
1097		return -ENOMEM;
1098	}
1099
1100	clk_osc = devm_clk_get(dev, "osc");
1101	clk_xtal = devm_clk_get(dev, "xtal");
1102	if (!IS_ERR(clk_osc)) {
1103		s->clk = clk_osc;
1104		fmin = 500000;
1105		fmax = 35000000;
1106	} else if (!IS_ERR(clk_xtal)) {
1107		s->clk = clk_xtal;
1108		fmin = 1000000;
1109		fmax = 4000000;
1110		xtal = true;
1111	} else if (PTR_ERR(clk_osc) == -EPROBE_DEFER ||
1112		   PTR_ERR(clk_xtal) == -EPROBE_DEFER) {
1113		return -EPROBE_DEFER;
1114	} else {
1115		dev_err(dev, "Cannot get clock\n");
1116		return -EINVAL;
1117	}
1118
1119	ret = clk_prepare_enable(s->clk);
1120	if (ret)
1121		return ret;
1122
1123	freq = clk_get_rate(s->clk);
1124	/* Check frequency limits */
1125	if (freq < fmin || freq > fmax) {
1126		ret = -ERANGE;
1127		goto out_clk;
1128	}
1129
1130	s->regmap = regmap;
1131	s->devtype = devtype;
1132	dev_set_drvdata(dev, s);
1133
1134	/* Check device to ensure we are talking to what we expect */
1135	ret = devtype->detect(dev);
1136	if (ret)
1137		goto out_clk;
1138
1139	for (i = 0; i < devtype->nr; i++) {
1140		unsigned int offs = i << 5;
1141
1142		/* Reset port */
1143		regmap_write(s->regmap, MAX310X_MODE2_REG + offs,
1144			     MAX310X_MODE2_RST_BIT);
1145		/* Clear port reset */
1146		regmap_write(s->regmap, MAX310X_MODE2_REG + offs, 0);
1147
1148		/* Wait for port startup */
1149		do {
1150			regmap_read(s->regmap,
1151				    MAX310X_BRGDIVLSB_REG + offs, &ret);
1152		} while (ret != 0x01);
1153
1154		regmap_update_bits(s->regmap, MAX310X_MODE1_REG + offs,
1155				   MAX310X_MODE1_AUTOSLEEP_BIT,
1156				   MAX310X_MODE1_AUTOSLEEP_BIT);
1157	}
1158
1159	uartclk = max310x_set_ref_clk(s, freq, xtal);
1160	dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
1161
1162	/* Register UART driver */
1163	s->uart.owner		= THIS_MODULE;
1164	s->uart.dev_name	= "ttyMAX";
1165	s->uart.major		= MAX310X_MAJOR;
1166	s->uart.minor		= MAX310X_MINOR;
1167	s->uart.nr		= devtype->nr;
1168	ret = uart_register_driver(&s->uart);
1169	if (ret) {
1170		dev_err(dev, "Registering UART driver failed\n");
1171		goto out_clk;
1172	}
1173
1174#ifdef CONFIG_GPIOLIB
1175	/* Setup GPIO cotroller */
1176	s->gpio.owner		= THIS_MODULE;
1177	s->gpio.parent		= dev;
1178	s->gpio.label		= dev_name(dev);
1179	s->gpio.direction_input	= max310x_gpio_direction_input;
1180	s->gpio.get		= max310x_gpio_get;
1181	s->gpio.direction_output= max310x_gpio_direction_output;
1182	s->gpio.set		= max310x_gpio_set;
1183	s->gpio.base		= -1;
1184	s->gpio.ngpio		= devtype->nr * 4;
1185	s->gpio.can_sleep	= 1;
1186	ret = gpiochip_add(&s->gpio);
1187	if (ret)
1188		goto out_uart;
1189#endif
1190
1191	mutex_init(&s->mutex);
1192
1193	for (i = 0; i < devtype->nr; i++) {
1194		/* Initialize port data */
1195		s->p[i].port.line	= i;
1196		s->p[i].port.dev	= dev;
1197		s->p[i].port.irq	= irq;
1198		s->p[i].port.type	= PORT_MAX310X;
1199		s->p[i].port.fifosize	= MAX310X_FIFO_SIZE;
1200		s->p[i].port.flags	= UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1201		s->p[i].port.iotype	= UPIO_PORT;
1202		s->p[i].port.iobase	= i * 0x20;
1203		s->p[i].port.membase	= (void __iomem *)~0;
1204		s->p[i].port.uartclk	= uartclk;
1205		s->p[i].port.rs485_config = max310x_rs485_config;
1206		s->p[i].port.ops	= &max310x_ops;
1207		/* Disable all interrupts */
1208		max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0);
1209		/* Clear IRQ status register */
1210		max310x_port_read(&s->p[i].port, MAX310X_IRQSTS_REG);
1211		/* Enable IRQ pin */
1212		max310x_port_update(&s->p[i].port, MAX310X_MODE1_REG,
1213				    MAX310X_MODE1_IRQSEL_BIT,
1214				    MAX310X_MODE1_IRQSEL_BIT);
1215		/* Initialize queue for start TX */
1216		INIT_WORK(&s->p[i].tx_work, max310x_wq_proc);
1217		/* Initialize queue for changing mode */
1218		INIT_WORK(&s->p[i].md_work, max310x_md_proc);
1219		/* Register port */
1220		uart_add_one_port(&s->uart, &s->p[i].port);
1221		/* Go to suspend mode */
1222		devtype->power(&s->p[i].port, 0);
1223	}
1224
1225	/* Setup interrupt */
1226	ret = devm_request_threaded_irq(dev, irq, NULL, max310x_ist,
1227					IRQF_ONESHOT | flags, dev_name(dev), s);
1228	if (!ret)
1229		return 0;
1230
1231	dev_err(dev, "Unable to reguest IRQ %i\n", irq);
1232
1233	mutex_destroy(&s->mutex);
1234
1235#ifdef CONFIG_GPIOLIB
1236	gpiochip_remove(&s->gpio);
1237
1238out_uart:
1239#endif
1240	uart_unregister_driver(&s->uart);
1241
1242out_clk:
1243	clk_disable_unprepare(s->clk);
1244
1245	return ret;
1246}
1247
1248static int max310x_remove(struct device *dev)
1249{
1250	struct max310x_port *s = dev_get_drvdata(dev);
1251	int i;
1252
1253#ifdef CONFIG_GPIOLIB
1254	gpiochip_remove(&s->gpio);
1255#endif
1256
1257	for (i = 0; i < s->uart.nr; i++) {
1258		cancel_work_sync(&s->p[i].tx_work);
1259		cancel_work_sync(&s->p[i].md_work);
1260		uart_remove_one_port(&s->uart, &s->p[i].port);
1261		s->devtype->power(&s->p[i].port, 0);
1262	}
1263
1264	mutex_destroy(&s->mutex);
1265	uart_unregister_driver(&s->uart);
1266	clk_disable_unprepare(s->clk);
1267
1268	return 0;
1269}
1270
1271static const struct of_device_id __maybe_unused max310x_dt_ids[] = {
1272	{ .compatible = "maxim,max3107",	.data = &max3107_devtype, },
1273	{ .compatible = "maxim,max3108",	.data = &max3108_devtype, },
1274	{ .compatible = "maxim,max3109",	.data = &max3109_devtype, },
1275	{ .compatible = "maxim,max14830",	.data = &max14830_devtype },
1276	{ }
1277};
1278MODULE_DEVICE_TABLE(of, max310x_dt_ids);
1279
1280static struct regmap_config regcfg = {
1281	.reg_bits = 8,
1282	.val_bits = 8,
1283	.write_flag_mask = 0x80,
1284	.cache_type = REGCACHE_RBTREE,
1285	.writeable_reg = max310x_reg_writeable,
1286	.volatile_reg = max310x_reg_volatile,
1287	.precious_reg = max310x_reg_precious,
1288};
1289
1290#ifdef CONFIG_SPI_MASTER
1291static int max310x_spi_probe(struct spi_device *spi)
1292{
1293	struct max310x_devtype *devtype;
1294	unsigned long flags = 0;
1295	struct regmap *regmap;
1296	int ret;
1297
1298	/* Setup SPI bus */
1299	spi->bits_per_word	= 8;
1300	spi->mode		= spi->mode ? : SPI_MODE_0;
1301	spi->max_speed_hz	= spi->max_speed_hz ? : 26000000;
1302	ret = spi_setup(spi);
1303	if (ret)
1304		return ret;
1305
1306	if (spi->dev.of_node) {
1307		const struct of_device_id *of_id =
1308			of_match_device(max310x_dt_ids, &spi->dev);
1309
1310		devtype = (struct max310x_devtype *)of_id->data;
1311	} else {
1312		const struct spi_device_id *id_entry = spi_get_device_id(spi);
1313
1314		devtype = (struct max310x_devtype *)id_entry->driver_data;
1315		flags = IRQF_TRIGGER_FALLING;
1316	}
1317
1318	regcfg.max_register = devtype->nr * 0x20 - 1;
1319	regmap = devm_regmap_init_spi(spi, &regcfg);
1320
1321	return max310x_probe(&spi->dev, devtype, regmap, spi->irq, flags);
1322}
1323
1324static int max310x_spi_remove(struct spi_device *spi)
1325{
1326	return max310x_remove(&spi->dev);
1327}
1328
1329static const struct spi_device_id max310x_id_table[] = {
1330	{ "max3107",	(kernel_ulong_t)&max3107_devtype, },
1331	{ "max3108",	(kernel_ulong_t)&max3108_devtype, },
1332	{ "max3109",	(kernel_ulong_t)&max3109_devtype, },
1333	{ "max14830",	(kernel_ulong_t)&max14830_devtype, },
1334	{ }
1335};
1336MODULE_DEVICE_TABLE(spi, max310x_id_table);
1337
1338static struct spi_driver max310x_uart_driver = {
1339	.driver = {
1340		.name		= MAX310X_NAME,
1341		.of_match_table	= of_match_ptr(max310x_dt_ids),
1342		.pm		= &max310x_pm_ops,
1343	},
1344	.probe		= max310x_spi_probe,
1345	.remove		= max310x_spi_remove,
1346	.id_table	= max310x_id_table,
1347};
1348module_spi_driver(max310x_uart_driver);
1349#endif
1350
1351MODULE_LICENSE("GPL");
1352MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1353MODULE_DESCRIPTION("MAX310X serial driver");