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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_read(s->regmap, MAX310X_REVID_REG, &val);
 350	if (ret)
 351		return ret;
 352
 353	if (((val & MAX310x_REV_MASK) != MAX3109_REV_ID)) {
 354		dev_err(dev,
 355			"%s ID 0x%02x does not match\n", s->devtype->name, val);
 356		return -ENODEV;
 357	}
 358
 359	return 0;
 360}
 361
 362static void max310x_power(struct uart_port *port, int on)
 363{
 364	max310x_port_update(port, MAX310X_MODE1_REG,
 365			    MAX310X_MODE1_FORCESLEEP_BIT,
 366			    on ? 0 : MAX310X_MODE1_FORCESLEEP_BIT);
 367	if (on)
 368		msleep(50);
 369}
 370
 371static int max14830_detect(struct device *dev)
 372{
 373	struct max310x_port *s = dev_get_drvdata(dev);
 374	unsigned int val = 0;
 375	int ret;
 376
 377	ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
 378			   MAX310X_EXTREG_ENBL);
 379	if (ret)
 380		return ret;
 381	
 382	regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
 383	regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
 384	if (((val & MAX310x_REV_MASK) != MAX14830_REV_ID)) {
 385		dev_err(dev,
 386			"%s ID 0x%02x does not match\n", s->devtype->name, val);
 387		return -ENODEV;
 388	}
 389
 390	return 0;
 391}
 392
 393static void max14830_power(struct uart_port *port, int on)
 394{
 395	max310x_port_update(port, MAX310X_BRGCFG_REG,
 396			    MAX14830_BRGCFG_CLKDIS_BIT,
 397			    on ? 0 : MAX14830_BRGCFG_CLKDIS_BIT);
 398	if (on)
 399		msleep(50);
 400}
 401
 402static const struct max310x_devtype max3107_devtype = {
 403	.name	= "MAX3107",
 404	.nr	= 1,
 405	.detect	= max3107_detect,
 406	.power	= max310x_power,
 407};
 408
 409static const struct max310x_devtype max3108_devtype = {
 410	.name	= "MAX3108",
 411	.nr	= 1,
 412	.detect	= max3108_detect,
 413	.power	= max310x_power,
 414};
 415
 416static const struct max310x_devtype max3109_devtype = {
 417	.name	= "MAX3109",
 418	.nr	= 2,
 419	.detect	= max3109_detect,
 420	.power	= max310x_power,
 421};
 422
 423static const struct max310x_devtype max14830_devtype = {
 424	.name	= "MAX14830",
 425	.nr	= 4,
 426	.detect	= max14830_detect,
 427	.power	= max14830_power,
 428};
 429
 430static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
 431{
 432	switch (reg & 0x1f) {
 433	case MAX310X_IRQSTS_REG:
 434	case MAX310X_LSR_IRQSTS_REG:
 435	case MAX310X_SPCHR_IRQSTS_REG:
 436	case MAX310X_STS_IRQSTS_REG:
 437	case MAX310X_TXFIFOLVL_REG:
 438	case MAX310X_RXFIFOLVL_REG:
 439		return false;
 440	default:
 441		break;
 442	}
 443
 444	return true;
 445}
 446
 447static bool max310x_reg_volatile(struct device *dev, unsigned int reg)
 448{
 449	switch (reg & 0x1f) {
 450	case MAX310X_RHR_REG:
 451	case MAX310X_IRQSTS_REG:
 452	case MAX310X_LSR_IRQSTS_REG:
 453	case MAX310X_SPCHR_IRQSTS_REG:
 454	case MAX310X_STS_IRQSTS_REG:
 455	case MAX310X_TXFIFOLVL_REG:
 456	case MAX310X_RXFIFOLVL_REG:
 457	case MAX310X_GPIODATA_REG:
 458	case MAX310X_BRGDIVLSB_REG:
 459	case MAX310X_REG_05:
 460	case MAX310X_REG_1F:
 461		return true;
 462	default:
 463		break;
 464	}
 465
 466	return false;
 467}
 468
 469static bool max310x_reg_precious(struct device *dev, unsigned int reg)
 470{
 471	switch (reg & 0x1f) {
 472	case MAX310X_RHR_REG:
 473	case MAX310X_IRQSTS_REG:
 474	case MAX310X_SPCHR_IRQSTS_REG:
 475	case MAX310X_STS_IRQSTS_REG:
 476		return true;
 477	default:
 478		break;
 479	}
 480
 481	return false;
 482}
 483
 484static int max310x_set_baud(struct uart_port *port, int baud)
 485{
 486	unsigned int mode = 0, clk = port->uartclk, div = clk / baud;
 487
 488	/* Check for minimal value for divider */
 489	if (div < 16)
 490		div = 16;
 491
 492	if (clk % baud && (div / 16) < 0x8000) {
 493		/* Mode x2 */
 494		mode = MAX310X_BRGCFG_2XMODE_BIT;
 495		clk = port->uartclk * 2;
 496		div = clk / baud;
 497
 498		if (clk % baud && (div / 16) < 0x8000) {
 499			/* Mode x4 */
 500			mode = MAX310X_BRGCFG_4XMODE_BIT;
 501			clk = port->uartclk * 4;
 502			div = clk / baud;
 503		}
 504	}
 505
 506	max310x_port_write(port, MAX310X_BRGDIVMSB_REG, (div / 16) >> 8);
 507	max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div / 16);
 508	max310x_port_write(port, MAX310X_BRGCFG_REG, (div % 16) | mode);
 509
 510	return DIV_ROUND_CLOSEST(clk, div);
 511}
 512
 513static int max310x_update_best_err(unsigned long f, long *besterr)
 514{
 515	/* Use baudrate 115200 for calculate error */
 516	long err = f % (115200 * 16);
 517
 518	if ((*besterr < 0) || (*besterr > err)) {
 519		*besterr = err;
 520		return 0;
 521	}
 522
 523	return 1;
 524}
 525
 526static int max310x_set_ref_clk(struct max310x_port *s, unsigned long freq,
 527			       bool xtal)
 528{
 529	unsigned int div, clksrc, pllcfg = 0;
 530	long besterr = -1;
 531	unsigned long fdiv, fmul, bestfreq = freq;
 532
 533	/* First, update error without PLL */
 534	max310x_update_best_err(freq, &besterr);
 535
 536	/* Try all possible PLL dividers */
 537	for (div = 1; (div <= 63) && besterr; div++) {
 538		fdiv = DIV_ROUND_CLOSEST(freq, div);
 539
 540		/* Try multiplier 6 */
 541		fmul = fdiv * 6;
 542		if ((fdiv >= 500000) && (fdiv <= 800000))
 543			if (!max310x_update_best_err(fmul, &besterr)) {
 544				pllcfg = (0 << 6) | div;
 545				bestfreq = fmul;
 546			}
 547		/* Try multiplier 48 */
 548		fmul = fdiv * 48;
 549		if ((fdiv >= 850000) && (fdiv <= 1200000))
 550			if (!max310x_update_best_err(fmul, &besterr)) {
 551				pllcfg = (1 << 6) | div;
 552				bestfreq = fmul;
 553			}
 554		/* Try multiplier 96 */
 555		fmul = fdiv * 96;
 556		if ((fdiv >= 425000) && (fdiv <= 1000000))
 557			if (!max310x_update_best_err(fmul, &besterr)) {
 558				pllcfg = (2 << 6) | div;
 559				bestfreq = fmul;
 560			}
 561		/* Try multiplier 144 */
 562		fmul = fdiv * 144;
 563		if ((fdiv >= 390000) && (fdiv <= 667000))
 564			if (!max310x_update_best_err(fmul, &besterr)) {
 565				pllcfg = (3 << 6) | div;
 566				bestfreq = fmul;
 567			}
 568	}
 569
 570	/* Configure clock source */
 571	clksrc = xtal ? MAX310X_CLKSRC_CRYST_BIT : MAX310X_CLKSRC_EXTCLK_BIT;
 572
 573	/* Configure PLL */
 574	if (pllcfg) {
 575		clksrc |= MAX310X_CLKSRC_PLL_BIT;
 576		regmap_write(s->regmap, MAX310X_PLLCFG_REG, pllcfg);
 577	} else
 578		clksrc |= MAX310X_CLKSRC_PLLBYP_BIT;
 579
 580	regmap_write(s->regmap, MAX310X_CLKSRC_REG, clksrc);
 581
 582	/* Wait for crystal */
 583	if (pllcfg && xtal)
 584		msleep(10);
 585
 586	return (int)bestfreq;
 587}
 588
 589static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
 590{
 591	unsigned int sts, ch, flag;
 592
 593	if (unlikely(rxlen >= port->fifosize)) {
 594		dev_warn_ratelimited(port->dev,
 595				     "Port %i: Possible RX FIFO overrun\n",
 596				     port->line);
 597		port->icount.buf_overrun++;
 598		/* Ensure sanity of RX level */
 599		rxlen = port->fifosize;
 600	}
 601
 602	while (rxlen--) {
 603		ch = max310x_port_read(port, MAX310X_RHR_REG);
 604		sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
 605
 606		sts &= MAX310X_LSR_RXPAR_BIT | MAX310X_LSR_FRERR_BIT |
 607		       MAX310X_LSR_RXOVR_BIT | MAX310X_LSR_RXBRK_BIT;
 608
 609		port->icount.rx++;
 610		flag = TTY_NORMAL;
 611
 612		if (unlikely(sts)) {
 613			if (sts & MAX310X_LSR_RXBRK_BIT) {
 614				port->icount.brk++;
 615				if (uart_handle_break(port))
 616					continue;
 617			} else if (sts & MAX310X_LSR_RXPAR_BIT)
 618				port->icount.parity++;
 619			else if (sts & MAX310X_LSR_FRERR_BIT)
 620				port->icount.frame++;
 621			else if (sts & MAX310X_LSR_RXOVR_BIT)
 622				port->icount.overrun++;
 623
 624			sts &= port->read_status_mask;
 625			if (sts & MAX310X_LSR_RXBRK_BIT)
 626				flag = TTY_BREAK;
 627			else if (sts & MAX310X_LSR_RXPAR_BIT)
 628				flag = TTY_PARITY;
 629			else if (sts & MAX310X_LSR_FRERR_BIT)
 630				flag = TTY_FRAME;
 631			else if (sts & MAX310X_LSR_RXOVR_BIT)
 632				flag = TTY_OVERRUN;
 633		}
 634
 635		if (uart_handle_sysrq_char(port, ch))
 636			continue;
 637
 638		if (sts & port->ignore_status_mask)
 639			continue;
 640
 641		uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT, ch, flag);
 642	}
 643
 644	tty_flip_buffer_push(&port->state->port);
 645}
 646
 647static void max310x_handle_tx(struct uart_port *port)
 648{
 649	struct circ_buf *xmit = &port->state->xmit;
 650	unsigned int txlen, to_send;
 651
 652	if (unlikely(port->x_char)) {
 653		max310x_port_write(port, MAX310X_THR_REG, port->x_char);
 654		port->icount.tx++;
 655		port->x_char = 0;
 656		return;
 657	}
 658
 659	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
 660		return;
 661
 662	/* Get length of data pending in circular buffer */
 663	to_send = uart_circ_chars_pending(xmit);
 664	if (likely(to_send)) {
 665		/* Limit to size of TX FIFO */
 666		txlen = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
 667		txlen = port->fifosize - txlen;
 668		to_send = (to_send > txlen) ? txlen : to_send;
 669
 670		/* Add data to send */
 671		port->icount.tx += to_send;
 672		while (to_send--) {
 673			max310x_port_write(port, MAX310X_THR_REG,
 674					   xmit->buf[xmit->tail]);
 675			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 676		}
 677	}
 678
 679	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 680		uart_write_wakeup(port);
 681}
 682
 683static void max310x_port_irq(struct max310x_port *s, int portno)
 684{
 685	struct uart_port *port = &s->p[portno].port;
 686
 687	do {
 688		unsigned int ists, lsr, rxlen;
 689
 690		/* Read IRQ status & RX FIFO level */
 691		ists = max310x_port_read(port, MAX310X_IRQSTS_REG);
 692		rxlen = max310x_port_read(port, MAX310X_RXFIFOLVL_REG);
 693		if (!ists && !rxlen)
 694			break;
 695
 696		if (ists & MAX310X_IRQ_CTS_BIT) {
 697			lsr = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
 698			uart_handle_cts_change(port,
 699					       !!(lsr & MAX310X_LSR_CTS_BIT));
 700		}
 701		if (rxlen)
 702			max310x_handle_rx(port, rxlen);
 703		if (ists & MAX310X_IRQ_TXEMPTY_BIT) {
 704			mutex_lock(&s->mutex);
 705			max310x_handle_tx(port);
 706			mutex_unlock(&s->mutex);
 707		}
 708	} while (1);
 709}
 710
 711static irqreturn_t max310x_ist(int irq, void *dev_id)
 712{
 713	struct max310x_port *s = (struct max310x_port *)dev_id;
 714
 715	if (s->uart.nr > 1) {
 716		do {
 717			unsigned int val = ~0;
 718
 719			WARN_ON_ONCE(regmap_read(s->regmap,
 720						 MAX310X_GLOBALIRQ_REG, &val));
 721			val = ((1 << s->uart.nr) - 1) & ~val;
 722			if (!val)
 723				break;
 724			max310x_port_irq(s, fls(val) - 1);
 725		} while (1);
 726	} else
 727		max310x_port_irq(s, 0);
 728
 729	return IRQ_HANDLED;
 730}
 731
 732static void max310x_wq_proc(struct work_struct *ws)
 733{
 734	struct max310x_one *one = container_of(ws, struct max310x_one, tx_work);
 735	struct max310x_port *s = dev_get_drvdata(one->port.dev);
 736
 737	mutex_lock(&s->mutex);
 738	max310x_handle_tx(&one->port);
 739	mutex_unlock(&s->mutex);
 740}
 741
 742static void max310x_start_tx(struct uart_port *port)
 743{
 744	struct max310x_one *one = container_of(port, struct max310x_one, port);
 745
 746	if (!work_pending(&one->tx_work))
 747		schedule_work(&one->tx_work);
 748}
 749
 750static unsigned int max310x_tx_empty(struct uart_port *port)
 751{
 752	unsigned int lvl, sts;
 753
 754	lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
 755	sts = max310x_port_read(port, MAX310X_IRQSTS_REG);
 756
 757	return ((sts & MAX310X_IRQ_TXEMPTY_BIT) && !lvl) ? TIOCSER_TEMT : 0;
 758}
 759
 760static unsigned int max310x_get_mctrl(struct uart_port *port)
 761{
 762	/* DCD and DSR are not wired and CTS/RTS is handled automatically
 763	 * so just indicate DSR and CAR asserted
 764	 */
 765	return TIOCM_DSR | TIOCM_CAR;
 766}
 767
 768static void max310x_md_proc(struct work_struct *ws)
 769{
 770	struct max310x_one *one = container_of(ws, struct max310x_one, md_work);
 771
 772	max310x_port_update(&one->port, MAX310X_MODE2_REG,
 773			    MAX310X_MODE2_LOOPBACK_BIT,
 774			    (one->port.mctrl & TIOCM_LOOP) ?
 775			    MAX310X_MODE2_LOOPBACK_BIT : 0);
 776}
 777
 778static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl)
 779{
 780	struct max310x_one *one = container_of(port, struct max310x_one, port);
 781
 782	schedule_work(&one->md_work);
 783}
 784
 785static void max310x_break_ctl(struct uart_port *port, int break_state)
 786{
 787	max310x_port_update(port, MAX310X_LCR_REG,
 788			    MAX310X_LCR_TXBREAK_BIT,
 789			    break_state ? MAX310X_LCR_TXBREAK_BIT : 0);
 790}
 791
 792static void max310x_set_termios(struct uart_port *port,
 793				struct ktermios *termios,
 794				struct ktermios *old)
 795{
 796	unsigned int lcr, flow = 0;
 797	int baud;
 798
 799	/* Mask termios capabilities we don't support */
 800	termios->c_cflag &= ~CMSPAR;
 801
 802	/* Word size */
 803	switch (termios->c_cflag & CSIZE) {
 804	case CS5:
 805		lcr = MAX310X_LCR_WORD_LEN_5;
 806		break;
 807	case CS6:
 808		lcr = MAX310X_LCR_WORD_LEN_6;
 809		break;
 810	case CS7:
 811		lcr = MAX310X_LCR_WORD_LEN_7;
 812		break;
 813	case CS8:
 814	default:
 815		lcr = MAX310X_LCR_WORD_LEN_8;
 816		break;
 817	}
 818
 819	/* Parity */
 820	if (termios->c_cflag & PARENB) {
 821		lcr |= MAX310X_LCR_PARITY_BIT;
 822		if (!(termios->c_cflag & PARODD))
 823			lcr |= MAX310X_LCR_EVENPARITY_BIT;
 824	}
 825
 826	/* Stop bits */
 827	if (termios->c_cflag & CSTOPB)
 828		lcr |= MAX310X_LCR_STOPLEN_BIT; /* 2 stops */
 829
 830	/* Update LCR register */
 831	max310x_port_write(port, MAX310X_LCR_REG, lcr);
 832
 833	/* Set read status mask */
 834	port->read_status_mask = MAX310X_LSR_RXOVR_BIT;
 835	if (termios->c_iflag & INPCK)
 836		port->read_status_mask |= MAX310X_LSR_RXPAR_BIT |
 837					  MAX310X_LSR_FRERR_BIT;
 838	if (termios->c_iflag & (BRKINT | PARMRK))
 839		port->read_status_mask |= MAX310X_LSR_RXBRK_BIT;
 840
 841	/* Set status ignore mask */
 842	port->ignore_status_mask = 0;
 843	if (termios->c_iflag & IGNBRK)
 844		port->ignore_status_mask |= MAX310X_LSR_RXBRK_BIT;
 845	if (!(termios->c_cflag & CREAD))
 846		port->ignore_status_mask |= MAX310X_LSR_RXPAR_BIT |
 847					    MAX310X_LSR_RXOVR_BIT |
 848					    MAX310X_LSR_FRERR_BIT |
 849					    MAX310X_LSR_RXBRK_BIT;
 850
 851	/* Configure flow control */
 852	max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]);
 853	max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]);
 854	if (termios->c_cflag & CRTSCTS)
 855		flow |= MAX310X_FLOWCTRL_AUTOCTS_BIT |
 856			MAX310X_FLOWCTRL_AUTORTS_BIT;
 857	if (termios->c_iflag & IXON)
 858		flow |= MAX310X_FLOWCTRL_SWFLOW3_BIT |
 859			MAX310X_FLOWCTRL_SWFLOWEN_BIT;
 860	if (termios->c_iflag & IXOFF)
 861		flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT |
 862			MAX310X_FLOWCTRL_SWFLOWEN_BIT;
 863	max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow);
 864
 865	/* Get baud rate generator configuration */
 866	baud = uart_get_baud_rate(port, termios, old,
 867				  port->uartclk / 16 / 0xffff,
 868				  port->uartclk / 4);
 869
 870	/* Setup baudrate generator */
 871	baud = max310x_set_baud(port, baud);
 872
 873	/* Update timeout according to new baud rate */
 874	uart_update_timeout(port, termios->c_cflag, baud);
 875}
 876
 877static int max310x_ioctl(struct uart_port *port, unsigned int cmd,
 878			 unsigned long arg)
 879{
 880#if defined(TIOCSRS485) && defined(TIOCGRS485)
 881	struct serial_rs485 rs485;
 882	unsigned int val;
 883
 884	switch (cmd) {
 885	case TIOCSRS485:
 886		if (copy_from_user(&rs485, (void __user *)arg, sizeof(rs485)))
 887			return -EFAULT;
 888		if (rs485.delay_rts_before_send > 0x0f ||
 889		    rs485.delay_rts_after_send > 0x0f)
 890			return -ERANGE;
 891		val = (rs485.delay_rts_before_send << 4) |
 892		      rs485.delay_rts_after_send;
 893		max310x_port_write(port, MAX310X_HDPIXDELAY_REG, val);
 894		if (rs485.flags & SER_RS485_ENABLED) {
 895			max310x_port_update(port, MAX310X_MODE1_REG,
 896					    MAX310X_MODE1_TRNSCVCTRL_BIT,
 897					    MAX310X_MODE1_TRNSCVCTRL_BIT);
 898			max310x_port_update(port, MAX310X_MODE2_REG,
 899					    MAX310X_MODE2_ECHOSUPR_BIT,
 900					    MAX310X_MODE2_ECHOSUPR_BIT);
 901		} else {
 902			max310x_port_update(port, MAX310X_MODE1_REG,
 903					    MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
 904			max310x_port_update(port, MAX310X_MODE2_REG,
 905					    MAX310X_MODE2_ECHOSUPR_BIT, 0);
 906		}
 907		return 0;
 908	case TIOCGRS485:
 909		memset(&rs485, 0, sizeof(rs485));
 910		val = max310x_port_read(port, MAX310X_MODE1_REG);
 911		rs485.flags = (val & MAX310X_MODE1_TRNSCVCTRL_BIT) ?
 912			      SER_RS485_ENABLED : 0;
 913		rs485.flags |= SER_RS485_RTS_ON_SEND;
 914		val = max310x_port_read(port, MAX310X_HDPIXDELAY_REG);
 915		rs485.delay_rts_before_send = val >> 4;
 916		rs485.delay_rts_after_send = val & 0x0f;
 917		if (copy_to_user((void __user *)arg, &rs485, sizeof(rs485)))
 918			return -EFAULT;
 919		return 0;
 920	default:
 921		break;
 922	}
 923#endif
 924
 925	return -ENOIOCTLCMD;
 926}
 927
 928static int max310x_startup(struct uart_port *port)
 929{
 930	struct max310x_port *s = dev_get_drvdata(port->dev);
 931	unsigned int val;
 932
 933	s->devtype->power(port, 1);
 934
 935	/* Configure MODE1 register */
 936	max310x_port_update(port, MAX310X_MODE1_REG,
 937			    MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
 938
 939	/* Configure MODE2 register & Reset FIFOs*/
 940	val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT;
 941	max310x_port_write(port, MAX310X_MODE2_REG, val);
 942	max310x_port_update(port, MAX310X_MODE2_REG,
 943			    MAX310X_MODE2_FIFORST_BIT, 0);
 944
 945	/* Configure flow control levels */
 946	/* Flow control halt level 96, resume level 48 */
 947	max310x_port_write(port, MAX310X_FLOWLVL_REG,
 948			   MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96));
 949
 950	/* Clear IRQ status register */
 951	max310x_port_read(port, MAX310X_IRQSTS_REG);
 952
 953	/* Enable RX, TX, CTS change interrupts */
 954	val = MAX310X_IRQ_RXEMPTY_BIT | MAX310X_IRQ_TXEMPTY_BIT;
 955	max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT);
 956
 957	return 0;
 958}
 959
 960static void max310x_shutdown(struct uart_port *port)
 961{
 962	struct max310x_port *s = dev_get_drvdata(port->dev);
 963
 964	/* Disable all interrupts */
 965	max310x_port_write(port, MAX310X_IRQEN_REG, 0);
 966
 967	s->devtype->power(port, 0);
 968}
 969
 970static const char *max310x_type(struct uart_port *port)
 971{
 972	struct max310x_port *s = dev_get_drvdata(port->dev);
 973
 974	return (port->type == PORT_MAX310X) ? s->devtype->name : NULL;
 975}
 976
 977static int max310x_request_port(struct uart_port *port)
 978{
 979	/* Do nothing */
 980	return 0;
 981}
 982
 983static void max310x_config_port(struct uart_port *port, int flags)
 984{
 985	if (flags & UART_CONFIG_TYPE)
 986		port->type = PORT_MAX310X;
 987}
 988
 989static int max310x_verify_port(struct uart_port *port, struct serial_struct *s)
 990{
 991	if ((s->type != PORT_UNKNOWN) && (s->type != PORT_MAX310X))
 992		return -EINVAL;
 993	if (s->irq != port->irq)
 994		return -EINVAL;
 995
 996	return 0;
 997}
 998
 999static void max310x_null_void(struct uart_port *port)
1000{
1001	/* Do nothing */
1002}
1003
1004static const struct uart_ops max310x_ops = {
1005	.tx_empty	= max310x_tx_empty,
1006	.set_mctrl	= max310x_set_mctrl,
1007	.get_mctrl	= max310x_get_mctrl,
1008	.stop_tx	= max310x_null_void,
1009	.start_tx	= max310x_start_tx,
1010	.stop_rx	= max310x_null_void,
1011	.enable_ms	= max310x_null_void,
1012	.break_ctl	= max310x_break_ctl,
1013	.startup	= max310x_startup,
1014	.shutdown	= max310x_shutdown,
1015	.set_termios	= max310x_set_termios,
1016	.type		= max310x_type,
1017	.request_port	= max310x_request_port,
1018	.release_port	= max310x_null_void,
1019	.config_port	= max310x_config_port,
1020	.verify_port	= max310x_verify_port,
1021	.ioctl		= max310x_ioctl,
1022};
1023
1024static int __maybe_unused max310x_suspend(struct device *dev)
1025{
1026	struct max310x_port *s = dev_get_drvdata(dev);
1027	int i;
1028
1029	for (i = 0; i < s->uart.nr; i++) {
1030		uart_suspend_port(&s->uart, &s->p[i].port);
1031		s->devtype->power(&s->p[i].port, 0);
1032	}
1033
1034	return 0;
1035}
1036
1037static int __maybe_unused max310x_resume(struct device *dev)
1038{
1039	struct max310x_port *s = dev_get_drvdata(dev);
1040	int i;
1041
1042	for (i = 0; i < s->uart.nr; i++) {
1043		s->devtype->power(&s->p[i].port, 1);
1044		uart_resume_port(&s->uart, &s->p[i].port);
1045	}
1046
1047	return 0;
1048}
1049
1050static SIMPLE_DEV_PM_OPS(max310x_pm_ops, max310x_suspend, max310x_resume);
1051
1052#ifdef CONFIG_GPIOLIB
1053static int max310x_gpio_get(struct gpio_chip *chip, unsigned offset)
1054{
1055	unsigned int val;
1056	struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1057	struct uart_port *port = &s->p[offset / 4].port;
1058
1059	val = max310x_port_read(port, MAX310X_GPIODATA_REG);
1060
1061	return !!((val >> 4) & (1 << (offset % 4)));
1062}
1063
1064static void max310x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
1065{
1066	struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1067	struct uart_port *port = &s->p[offset / 4].port;
1068
1069	max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1070			    value ? 1 << (offset % 4) : 0);
1071}
1072
1073static int max310x_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
1074{
1075	struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1076	struct uart_port *port = &s->p[offset / 4].port;
1077
1078	max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4), 0);
1079
1080	return 0;
1081}
1082
1083static int max310x_gpio_direction_output(struct gpio_chip *chip,
1084					 unsigned offset, int value)
1085{
1086	struct max310x_port *s = container_of(chip, struct max310x_port, gpio);
1087	struct uart_port *port = &s->p[offset / 4].port;
1088
1089	max310x_port_update(port, MAX310X_GPIODATA_REG, 1 << (offset % 4),
1090			    value ? 1 << (offset % 4) : 0);
1091	max310x_port_update(port, MAX310X_GPIOCFG_REG, 1 << (offset % 4),
1092			    1 << (offset % 4));
1093
1094	return 0;
1095}
1096#endif
1097
1098static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
1099			 struct regmap *regmap, int irq, unsigned long flags)
1100{
1101	int i, ret, fmin, fmax, freq, uartclk;
1102	struct clk *clk_osc, *clk_xtal;
1103	struct max310x_port *s;
1104	bool xtal = false;
1105
1106	if (IS_ERR(regmap))
1107		return PTR_ERR(regmap);
1108
1109	/* Alloc port structure */
1110	s = devm_kzalloc(dev, sizeof(*s) +
1111			 sizeof(struct max310x_one) * devtype->nr, GFP_KERNEL);
1112	if (!s) {
1113		dev_err(dev, "Error allocating port structure\n");
1114		return -ENOMEM;
1115	}
1116
1117	clk_osc = devm_clk_get(dev, "osc");
1118	clk_xtal = devm_clk_get(dev, "xtal");
1119	if (!IS_ERR(clk_osc)) {
1120		s->clk = clk_osc;
1121		fmin = 500000;
1122		fmax = 35000000;
1123	} else if (!IS_ERR(clk_xtal)) {
1124		s->clk = clk_xtal;
1125		fmin = 1000000;
1126		fmax = 4000000;
1127		xtal = true;
1128	} else if (PTR_ERR(clk_osc) == -EPROBE_DEFER ||
1129		   PTR_ERR(clk_xtal) == -EPROBE_DEFER) {
1130		return -EPROBE_DEFER;
1131	} else {
1132		dev_err(dev, "Cannot get clock\n");
1133		return -EINVAL;
1134	}
1135
1136	ret = clk_prepare_enable(s->clk);
1137	if (ret)
1138		return ret;
1139
1140	freq = clk_get_rate(s->clk);
1141	/* Check frequency limits */
1142	if (freq < fmin || freq > fmax) {
1143		ret = -ERANGE;
1144		goto out_clk;
1145	}
1146
1147	s->regmap = regmap;
1148	s->devtype = devtype;
1149	dev_set_drvdata(dev, s);
1150
1151	/* Check device to ensure we are talking to what we expect */
1152	ret = devtype->detect(dev);
1153	if (ret)
1154		goto out_clk;
1155
1156	for (i = 0; i < devtype->nr; i++) {
1157		unsigned int offs = i << 5;
1158
1159		/* Reset port */
1160		regmap_write(s->regmap, MAX310X_MODE2_REG + offs,
1161			     MAX310X_MODE2_RST_BIT);
1162		/* Clear port reset */
1163		regmap_write(s->regmap, MAX310X_MODE2_REG + offs, 0);
1164
1165		/* Wait for port startup */
1166		do {
1167			regmap_read(s->regmap,
1168				    MAX310X_BRGDIVLSB_REG + offs, &ret);
1169		} while (ret != 0x01);
1170
1171		regmap_update_bits(s->regmap, MAX310X_MODE1_REG + offs,
1172				   MAX310X_MODE1_AUTOSLEEP_BIT,
1173				   MAX310X_MODE1_AUTOSLEEP_BIT);
1174	}
1175
1176	uartclk = max310x_set_ref_clk(s, freq, xtal);
1177	dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
1178
1179	/* Register UART driver */
1180	s->uart.owner		= THIS_MODULE;
1181	s->uart.dev_name	= "ttyMAX";
1182	s->uart.major		= MAX310X_MAJOR;
1183	s->uart.minor		= MAX310X_MINOR;
1184	s->uart.nr		= devtype->nr;
1185	ret = uart_register_driver(&s->uart);
1186	if (ret) {
1187		dev_err(dev, "Registering UART driver failed\n");
1188		goto out_clk;
1189	}
1190
1191#ifdef CONFIG_GPIOLIB
1192	/* Setup GPIO cotroller */
1193	s->gpio.owner		= THIS_MODULE;
1194	s->gpio.dev		= dev;
1195	s->gpio.label		= dev_name(dev);
1196	s->gpio.direction_input	= max310x_gpio_direction_input;
1197	s->gpio.get		= max310x_gpio_get;
1198	s->gpio.direction_output= max310x_gpio_direction_output;
1199	s->gpio.set		= max310x_gpio_set;
1200	s->gpio.base		= -1;
1201	s->gpio.ngpio		= devtype->nr * 4;
1202	s->gpio.can_sleep	= 1;
1203	ret = gpiochip_add(&s->gpio);
1204	if (ret)
1205		goto out_uart;
1206#endif
1207
1208	mutex_init(&s->mutex);
1209
1210	for (i = 0; i < devtype->nr; i++) {
1211		/* Initialize port data */
1212		s->p[i].port.line	= i;
1213		s->p[i].port.dev	= dev;
1214		s->p[i].port.irq	= irq;
1215		s->p[i].port.type	= PORT_MAX310X;
1216		s->p[i].port.fifosize	= MAX310X_FIFO_SIZE;
1217		s->p[i].port.flags	= UPF_FIXED_TYPE | UPF_LOW_LATENCY;
1218		s->p[i].port.iotype	= UPIO_PORT;
1219		s->p[i].port.iobase	= i * 0x20;
1220		s->p[i].port.membase	= (void __iomem *)~0;
1221		s->p[i].port.uartclk	= uartclk;
1222		s->p[i].port.ops	= &max310x_ops;
1223		/* Disable all interrupts */
1224		max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0);
1225		/* Clear IRQ status register */
1226		max310x_port_read(&s->p[i].port, MAX310X_IRQSTS_REG);
1227		/* Enable IRQ pin */
1228		max310x_port_update(&s->p[i].port, MAX310X_MODE1_REG,
1229				    MAX310X_MODE1_IRQSEL_BIT,
1230				    MAX310X_MODE1_IRQSEL_BIT);
1231		/* Initialize queue for start TX */
1232		INIT_WORK(&s->p[i].tx_work, max310x_wq_proc);
1233		/* Initialize queue for changing mode */
1234		INIT_WORK(&s->p[i].md_work, max310x_md_proc);
1235		/* Register port */
1236		uart_add_one_port(&s->uart, &s->p[i].port);
1237		/* Go to suspend mode */
1238		devtype->power(&s->p[i].port, 0);
1239	}
1240
1241	/* Setup interrupt */
1242	ret = devm_request_threaded_irq(dev, irq, NULL, max310x_ist,
1243					IRQF_ONESHOT | flags, dev_name(dev), s);
1244	if (!ret)
1245		return 0;
1246
1247	dev_err(dev, "Unable to reguest IRQ %i\n", irq);
1248
1249	mutex_destroy(&s->mutex);
1250
1251#ifdef CONFIG_GPIOLIB
1252	WARN_ON(gpiochip_remove(&s->gpio));
1253
1254out_uart:
1255#endif
1256	uart_unregister_driver(&s->uart);
1257
1258out_clk:
1259	clk_disable_unprepare(s->clk);
1260
1261	return ret;
1262}
1263
1264static int max310x_remove(struct device *dev)
1265{
1266	struct max310x_port *s = dev_get_drvdata(dev);
1267	int i, ret = 0;
1268
1269#ifdef CONFIG_GPIOLIB
1270	ret = gpiochip_remove(&s->gpio);
1271	if (ret)
1272		return ret;
1273#endif
1274
1275	for (i = 0; i < s->uart.nr; i++) {
1276		cancel_work_sync(&s->p[i].tx_work);
1277		cancel_work_sync(&s->p[i].md_work);
1278		uart_remove_one_port(&s->uart, &s->p[i].port);
1279		s->devtype->power(&s->p[i].port, 0);
1280	}
1281
1282	mutex_destroy(&s->mutex);
1283	uart_unregister_driver(&s->uart);
1284	clk_disable_unprepare(s->clk);
1285
1286	return ret;
1287}
1288
1289static const struct of_device_id __maybe_unused max310x_dt_ids[] = {
1290	{ .compatible = "maxim,max3107",	.data = &max3107_devtype, },
1291	{ .compatible = "maxim,max3108",	.data = &max3108_devtype, },
1292	{ .compatible = "maxim,max3109",	.data = &max3109_devtype, },
1293	{ .compatible = "maxim,max14830",	.data = &max14830_devtype },
1294	{ }
1295};
1296MODULE_DEVICE_TABLE(of, max310x_dt_ids);
1297
1298static struct regmap_config regcfg = {
1299	.reg_bits = 8,
1300	.val_bits = 8,
1301	.write_flag_mask = 0x80,
1302	.cache_type = REGCACHE_RBTREE,
1303	.writeable_reg = max310x_reg_writeable,
1304	.volatile_reg = max310x_reg_volatile,
1305	.precious_reg = max310x_reg_precious,
1306};
1307
1308#ifdef CONFIG_SPI_MASTER
1309static int max310x_spi_probe(struct spi_device *spi)
1310{
1311	struct max310x_devtype *devtype;
1312	unsigned long flags = 0;
1313	struct regmap *regmap;
1314	int ret;
1315
1316	/* Setup SPI bus */
1317	spi->bits_per_word	= 8;
1318	spi->mode		= spi->mode ? : SPI_MODE_0;
1319	spi->max_speed_hz	= spi->max_speed_hz ? : 26000000;
1320	ret = spi_setup(spi);
1321	if (ret)
1322		return ret;
1323
1324	if (spi->dev.of_node) {
1325		const struct of_device_id *of_id =
1326			of_match_device(max310x_dt_ids, &spi->dev);
1327
1328		devtype = (struct max310x_devtype *)of_id->data;
1329	} else {
1330		const struct spi_device_id *id_entry = spi_get_device_id(spi);
1331
1332		devtype = (struct max310x_devtype *)id_entry->driver_data;
1333		flags = IRQF_TRIGGER_FALLING;
1334	}
1335
1336	regcfg.max_register = devtype->nr * 0x20 - 1;
1337	regmap = devm_regmap_init_spi(spi, &regcfg);
1338
1339	return max310x_probe(&spi->dev, devtype, regmap, spi->irq, flags);
1340}
1341
1342static int max310x_spi_remove(struct spi_device *spi)
1343{
1344	return max310x_remove(&spi->dev);
1345}
1346
1347static const struct spi_device_id max310x_id_table[] = {
1348	{ "max3107",	(kernel_ulong_t)&max3107_devtype, },
1349	{ "max3108",	(kernel_ulong_t)&max3108_devtype, },
1350	{ "max3109",	(kernel_ulong_t)&max3109_devtype, },
1351	{ "max14830",	(kernel_ulong_t)&max14830_devtype, },
1352	{ }
1353};
1354MODULE_DEVICE_TABLE(spi, max310x_id_table);
1355
1356static struct spi_driver max310x_uart_driver = {
1357	.driver = {
1358		.name		= MAX310X_NAME,
1359		.owner		= THIS_MODULE,
1360		.of_match_table	= of_match_ptr(max310x_dt_ids),
1361		.pm		= &max310x_pm_ops,
1362	},
1363	.probe		= max310x_spi_probe,
1364	.remove		= max310x_spi_remove,
1365	.id_table	= max310x_id_table,
1366};
1367module_spi_driver(max310x_uart_driver);
1368#endif
1369
1370MODULE_LICENSE("GPL");
1371MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1372MODULE_DESCRIPTION("MAX310X serial driver");