1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Probe module for 8250/16550-type Exar chips PCI serial ports.
4  *
5  *  Based on drivers/tty/serial/8250/8250_pci.c,
6  *
7  *  Copyright (C) 2017 Sudip Mukherjee, All Rights Reserved.
8  */
9 #include <linux/acpi.h>
10 #include <linux/dmi.h>
11 #include <linux/io.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/pci.h>
15 #include <linux/property.h>
16 #include <linux/serial_core.h>
17 #include <linux/serial_reg.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 #include <linux/tty.h>
21 #include <linux/8250_pci.h>
22 #include <linux/delay.h>
23 
24 #include <asm/byteorder.h>
25 
26 #include "8250.h"
27 
28 #define PCI_DEVICE_ID_ACCESSIO_COM_2S		0x1052
29 #define PCI_DEVICE_ID_ACCESSIO_COM_4S		0x105d
30 #define PCI_DEVICE_ID_ACCESSIO_COM_8S		0x106c
31 #define PCI_DEVICE_ID_ACCESSIO_COM232_8		0x10a8
32 #define PCI_DEVICE_ID_ACCESSIO_COM_2SM		0x10d2
33 #define PCI_DEVICE_ID_ACCESSIO_COM_4SM		0x10db
34 #define PCI_DEVICE_ID_ACCESSIO_COM_8SM		0x10ea
35 
36 #define PCI_DEVICE_ID_COMMTECH_4224PCI335	0x0002
37 #define PCI_DEVICE_ID_COMMTECH_4222PCI335	0x0004
38 #define PCI_DEVICE_ID_COMMTECH_2324PCI335	0x000a
39 #define PCI_DEVICE_ID_COMMTECH_2328PCI335	0x000b
40 #define PCI_DEVICE_ID_COMMTECH_4224PCIE		0x0020
41 #define PCI_DEVICE_ID_COMMTECH_4228PCIE		0x0021
42 #define PCI_DEVICE_ID_COMMTECH_4222PCIE		0x0022
43 
44 #define PCI_VENDOR_ID_CONNECT_TECH				0x12c4
45 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_2_SP_OPTO        0x0340
46 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_4_SP_OPTO_A      0x0341
47 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_4_SP_OPTO_B      0x0342
48 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_2_XPRS           0x0350
49 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_4_XPRS_A         0x0351
50 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_4_XPRS_B         0x0352
51 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_8_XPRS           0x0353
52 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_16_XPRS_A        0x0354
53 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_16_XPRS_B        0x0355
54 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_2_XPRS_OPTO      0x0360
55 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_4_XPRS_OPTO_A    0x0361
56 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_4_XPRS_OPTO_B    0x0362
57 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_8_SP             0x0370
58 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_8_SP_232         0x0371
59 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_8_SP_485         0x0372
60 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_4_4_SP           0x0373
61 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_6_2_SP           0x0374
62 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_2_6_SP           0x0375
63 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_8_SP_232_NS      0x0376
64 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_2_XP_OPTO_LEFT   0x0380
65 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_2_XP_OPTO_RIGHT  0x0381
66 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_4_XP_OPTO        0x0382
67 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_4_4_XPRS_OPTO    0x0392
68 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_8_XPRS_LP        0x03A0
69 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_8_XPRS_LP_232    0x03A1
70 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_8_XPRS_LP_485    0x03A2
71 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_UART_8_XPRS_LP_232_NS 0x03A3
72 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCIE_XEG001               0x0602
73 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCIE_XR35X_BASE           0x1000
74 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCIE_XR35X_2              0x1002
75 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCIE_XR35X_4              0x1004
76 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCIE_XR35X_8              0x1008
77 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCIE_XR35X_12             0x100C
78 #define PCI_SUBDEVICE_ID_CONNECT_TECH_PCIE_XR35X_16             0x1010
79 #define PCI_DEVICE_ID_CONNECT_TECH_PCI_XR79X_12_XIG00X          0x110c
80 #define PCI_DEVICE_ID_CONNECT_TECH_PCI_XR79X_12_XIG01X          0x110d
81 #define PCI_DEVICE_ID_CONNECT_TECH_PCI_XR79X_16                 0x1110
82 
83 #define PCI_DEVICE_ID_EXAR_XR17V4358		0x4358
84 #define PCI_DEVICE_ID_EXAR_XR17V8358		0x8358
85 #define PCI_DEVICE_ID_EXAR_XR17V252		0x0252
86 #define PCI_DEVICE_ID_EXAR_XR17V254		0x0254
87 #define PCI_DEVICE_ID_EXAR_XR17V258		0x0258
88 
89 #define PCI_SUBDEVICE_ID_USR_2980		0x0128
90 #define PCI_SUBDEVICE_ID_USR_2981		0x0129
91 
92 #define PCI_DEVICE_ID_SEALEVEL_710xC		0x1001
93 #define PCI_DEVICE_ID_SEALEVEL_720xC		0x1002
94 #define PCI_DEVICE_ID_SEALEVEL_740xC		0x1004
95 #define PCI_DEVICE_ID_SEALEVEL_780xC		0x1008
96 #define PCI_DEVICE_ID_SEALEVEL_716xC		0x1010
97 
98 #define UART_EXAR_INT0		0x80
99 #define UART_EXAR_8XMODE	0x88	/* 8X sampling rate select */
100 #define UART_EXAR_SLEEP		0x8b	/* Sleep mode */
101 #define UART_EXAR_DVID		0x8d	/* Device identification */
102 
103 #define UART_EXAR_FCTR		0x08	/* Feature Control Register */
104 #define UART_FCTR_EXAR_IRDA	0x10	/* IrDa data encode select */
105 #define UART_FCTR_EXAR_485	0x20	/* Auto 485 half duplex dir ctl */
106 #define UART_FCTR_EXAR_TRGA	0x00	/* FIFO trigger table A */
107 #define UART_FCTR_EXAR_TRGB	0x60	/* FIFO trigger table B */
108 #define UART_FCTR_EXAR_TRGC	0x80	/* FIFO trigger table C */
109 #define UART_FCTR_EXAR_TRGD	0xc0	/* FIFO trigger table D programmable */
110 
111 #define UART_EXAR_TXTRG		0x0a	/* Tx FIFO trigger level write-only */
112 #define UART_EXAR_RXTRG		0x0b	/* Rx FIFO trigger level write-only */
113 
114 #define UART_EXAR_MPIOINT_7_0	0x8f	/* MPIOINT[7:0] */
115 #define UART_EXAR_MPIOLVL_7_0	0x90	/* MPIOLVL[7:0] */
116 #define UART_EXAR_MPIO3T_7_0	0x91	/* MPIO3T[7:0] */
117 #define UART_EXAR_MPIOINV_7_0	0x92	/* MPIOINV[7:0] */
118 #define UART_EXAR_MPIOSEL_7_0	0x93	/* MPIOSEL[7:0] */
119 #define UART_EXAR_MPIOOD_7_0	0x94	/* MPIOOD[7:0] */
120 #define UART_EXAR_MPIOINT_15_8	0x95	/* MPIOINT[15:8] */
121 #define UART_EXAR_MPIOLVL_15_8	0x96	/* MPIOLVL[15:8] */
122 #define UART_EXAR_MPIO3T_15_8	0x97	/* MPIO3T[15:8] */
123 #define UART_EXAR_MPIOINV_15_8	0x98	/* MPIOINV[15:8] */
124 #define UART_EXAR_MPIOSEL_15_8	0x99	/* MPIOSEL[15:8] */
125 #define UART_EXAR_MPIOOD_15_8	0x9a	/* MPIOOD[15:8] */
126 
127 #define UART_EXAR_RS485_DLY(x)	((x) << 4)
128 
129 /*
130  * IOT2040 MPIO wiring semantics:
131  *
132  * MPIO		Port	Function
133  * ----		----	--------
134  * 0		2 	Mode bit 0
135  * 1		2	Mode bit 1
136  * 2		2	Terminate bus
137  * 3		-	<reserved>
138  * 4		3	Mode bit 0
139  * 5		3	Mode bit 1
140  * 6		3	Terminate bus
141  * 7		-	<reserved>
142  * 8		2	Enable
143  * 9		3	Enable
144  * 10		-	Red LED
145  * 11..15	-	<unused>
146  */
147 
148 /* IOT2040 MPIOs 0..7 */
149 #define IOT2040_UART_MODE_RS232		0x01
150 #define IOT2040_UART_MODE_RS485		0x02
151 #define IOT2040_UART_MODE_RS422		0x03
152 #define IOT2040_UART_TERMINATE_BUS	0x04
153 
154 #define IOT2040_UART1_MASK		0x0f
155 #define IOT2040_UART2_SHIFT		4
156 
157 #define IOT2040_UARTS_DEFAULT_MODE	0x11	/* both RS232 */
158 #define IOT2040_UARTS_GPIO_LO_MODE	0x88	/* reserved pins as input */
159 
160 /* IOT2040 MPIOs 8..15 */
161 #define IOT2040_UARTS_ENABLE		0x03
162 #define IOT2040_UARTS_GPIO_HI_MODE	0xF8	/* enable & LED as outputs */
163 
164 struct exar8250;
165 
166 struct exar8250_platform {
167 	int (*rs485_config)(struct uart_port *port, struct ktermios *termios,
168 			    struct serial_rs485 *rs485);
169 	const struct serial_rs485 *rs485_supported;
170 	int (*register_gpio)(struct pci_dev *, struct uart_8250_port *);
171 	void (*unregister_gpio)(struct uart_8250_port *);
172 };
173 
174 /**
175  * struct exar8250_board - board information
176  * @num_ports: number of serial ports
177  * @reg_shift: describes UART register mapping in PCI memory
178  * @setup: quirk run at ->probe() stage
179  * @exit: quirk run at ->remove() stage
180  */
181 struct exar8250_board {
182 	unsigned int num_ports;
183 	unsigned int reg_shift;
184 	int	(*setup)(struct exar8250 *, struct pci_dev *,
185 			 struct uart_8250_port *, int);
186 	void	(*exit)(struct pci_dev *pcidev);
187 };
188 
189 struct exar8250 {
190 	unsigned int		nr;
191 	struct exar8250_board	*board;
192 	void __iomem		*virt;
193 	int			line[];
194 };
195 
196 static void exar_pm(struct uart_port *port, unsigned int state, unsigned int old)
197 {
198 	/*
199 	 * Exar UARTs have a SLEEP register that enables or disables each UART
200 	 * to enter sleep mode separately. On the XR17V35x the register
201 	 * is accessible to each UART at the UART_EXAR_SLEEP offset, but
202 	 * the UART channel may only write to the corresponding bit.
203 	 */
204 	serial_port_out(port, UART_EXAR_SLEEP, state ? 0xff : 0);
205 }
206 
207 /*
208  * XR17V35x UARTs have an extra fractional divisor register (DLD)
209  * Calculate divisor with extra 4-bit fractional portion
210  */
211 static unsigned int xr17v35x_get_divisor(struct uart_port *p, unsigned int baud,
212 					 unsigned int *frac)
213 {
214 	unsigned int quot_16;
215 
216 	quot_16 = DIV_ROUND_CLOSEST(p->uartclk, baud);
217 	*frac = quot_16 & 0x0f;
218 
219 	return quot_16 >> 4;
220 }
221 
222 static void xr17v35x_set_divisor(struct uart_port *p, unsigned int baud,
223 				 unsigned int quot, unsigned int quot_frac)
224 {
225 	serial8250_do_set_divisor(p, baud, quot, quot_frac);
226 
227 	/* Preserve bits not related to baudrate; DLD[7:4]. */
228 	quot_frac |= serial_port_in(p, 0x2) & 0xf0;
229 	serial_port_out(p, 0x2, quot_frac);
230 }
231 
232 static int xr17v35x_startup(struct uart_port *port)
233 {
234 	/*
235 	 * First enable access to IER [7:5], ISR [5:4], FCR [5:4],
236 	 * MCR [7:5] and MSR [7:0]
237 	 */
238 	serial_port_out(port, UART_XR_EFR, UART_EFR_ECB);
239 
240 	/*
241 	 * Make sure all interrups are masked until initialization is
242 	 * complete and the FIFOs are cleared
243 	 *
244 	 * Synchronize UART_IER access against the console.
245 	 */
246 	spin_lock_irq(&port->lock);
247 	serial_port_out(port, UART_IER, 0);
248 	spin_unlock_irq(&port->lock);
249 
250 	return serial8250_do_startup(port);
251 }
252 
253 static void exar_shutdown(struct uart_port *port)
254 {
255 	bool tx_complete = false;
256 	struct uart_8250_port *up = up_to_u8250p(port);
257 	struct circ_buf *xmit = &port->state->xmit;
258 	int i = 0;
259 	u16 lsr;
260 
261 	do {
262 		lsr = serial_in(up, UART_LSR);
263 		if (lsr & (UART_LSR_TEMT | UART_LSR_THRE))
264 			tx_complete = true;
265 		else
266 			tx_complete = false;
267 		usleep_range(1000, 1100);
268 	} while (!uart_circ_empty(xmit) && !tx_complete && i++ < 1000);
269 
270 	serial8250_do_shutdown(port);
271 }
272 
273 static int default_setup(struct exar8250 *priv, struct pci_dev *pcidev,
274 			 int idx, unsigned int offset,
275 			 struct uart_8250_port *port)
276 {
277 	const struct exar8250_board *board = priv->board;
278 	unsigned int bar = 0;
279 	unsigned char status;
280 
281 	port->port.iotype = UPIO_MEM;
282 	port->port.mapbase = pci_resource_start(pcidev, bar) + offset;
283 	port->port.membase = priv->virt + offset;
284 	port->port.regshift = board->reg_shift;
285 
286 	/*
287 	 * XR17V35x UARTs have an extra divisor register, DLD that gets enabled
288 	 * with when DLAB is set which will cause the device to incorrectly match
289 	 * and assign port type to PORT_16650. The EFR for this UART is found
290 	 * at offset 0x09. Instead check the Deice ID (DVID) register
291 	 * for a 2, 4 or 8 port UART.
292 	 */
293 	status = readb(port->port.membase + UART_EXAR_DVID);
294 	if (status == 0x82 || status == 0x84 || status == 0x88) {
295 		port->port.type = PORT_XR17V35X;
296 
297 		port->port.get_divisor = xr17v35x_get_divisor;
298 		port->port.set_divisor = xr17v35x_set_divisor;
299 
300 		port->port.startup = xr17v35x_startup;
301 	} else {
302 		port->port.type = PORT_XR17D15X;
303 	}
304 
305 	port->port.pm = exar_pm;
306 	port->port.shutdown = exar_shutdown;
307 
308 	return 0;
309 }
310 
311 static int
312 pci_fastcom335_setup(struct exar8250 *priv, struct pci_dev *pcidev,
313 		     struct uart_8250_port *port, int idx)
314 {
315 	unsigned int offset = idx * 0x200;
316 	unsigned int baud = 1843200;
317 	u8 __iomem *p;
318 	int err;
319 
320 	port->port.uartclk = baud * 16;
321 
322 	err = default_setup(priv, pcidev, idx, offset, port);
323 	if (err)
324 		return err;
325 
326 	p = port->port.membase;
327 
328 	writeb(0x00, p + UART_EXAR_8XMODE);
329 	writeb(UART_FCTR_EXAR_TRGD, p + UART_EXAR_FCTR);
330 	writeb(32, p + UART_EXAR_TXTRG);
331 	writeb(32, p + UART_EXAR_RXTRG);
332 
333 	/*
334 	 * Setup Multipurpose Input/Output pins.
335 	 */
336 	if (idx == 0) {
337 		switch (pcidev->device) {
338 		case PCI_DEVICE_ID_COMMTECH_4222PCI335:
339 		case PCI_DEVICE_ID_COMMTECH_4224PCI335:
340 			writeb(0x78, p + UART_EXAR_MPIOLVL_7_0);
341 			writeb(0x00, p + UART_EXAR_MPIOINV_7_0);
342 			writeb(0x00, p + UART_EXAR_MPIOSEL_7_0);
343 			break;
344 		case PCI_DEVICE_ID_COMMTECH_2324PCI335:
345 		case PCI_DEVICE_ID_COMMTECH_2328PCI335:
346 			writeb(0x00, p + UART_EXAR_MPIOLVL_7_0);
347 			writeb(0xc0, p + UART_EXAR_MPIOINV_7_0);
348 			writeb(0xc0, p + UART_EXAR_MPIOSEL_7_0);
349 			break;
350 		}
351 		writeb(0x00, p + UART_EXAR_MPIOINT_7_0);
352 		writeb(0x00, p + UART_EXAR_MPIO3T_7_0);
353 		writeb(0x00, p + UART_EXAR_MPIOOD_7_0);
354 	}
355 
356 	return 0;
357 }
358 
359 static int
360 pci_connect_tech_setup(struct exar8250 *priv, struct pci_dev *pcidev,
361 		       struct uart_8250_port *port, int idx)
362 {
363 	unsigned int offset = idx * 0x200;
364 	unsigned int baud = 1843200;
365 
366 	port->port.uartclk = baud * 16;
367 	return default_setup(priv, pcidev, idx, offset, port);
368 }
369 
370 static int
371 pci_xr17c154_setup(struct exar8250 *priv, struct pci_dev *pcidev,
372 		   struct uart_8250_port *port, int idx)
373 {
374 	unsigned int offset = idx * 0x200;
375 	unsigned int baud = 921600;
376 
377 	port->port.uartclk = baud * 16;
378 	return default_setup(priv, pcidev, idx, offset, port);
379 }
380 
381 static void setup_gpio(struct pci_dev *pcidev, u8 __iomem *p)
382 {
383 	/*
384 	 * The Commtech adapters required the MPIOs to be driven low. The Exar
385 	 * devices will export them as GPIOs, so we pre-configure them safely
386 	 * as inputs.
387 	 */
388 
389 	u8 dir = 0x00;
390 
391 	if  ((pcidev->vendor == PCI_VENDOR_ID_EXAR) &&
392 		(pcidev->subsystem_vendor != PCI_VENDOR_ID_SEALEVEL)) {
393 		// Configure GPIO as inputs for Commtech adapters
394 		dir = 0xff;
395 	} else {
396 		// Configure GPIO as outputs for SeaLevel adapters
397 		dir = 0x00;
398 	}
399 
400 	writeb(0x00, p + UART_EXAR_MPIOINT_7_0);
401 	writeb(0x00, p + UART_EXAR_MPIOLVL_7_0);
402 	writeb(0x00, p + UART_EXAR_MPIO3T_7_0);
403 	writeb(0x00, p + UART_EXAR_MPIOINV_7_0);
404 	writeb(dir,  p + UART_EXAR_MPIOSEL_7_0);
405 	writeb(0x00, p + UART_EXAR_MPIOOD_7_0);
406 	writeb(0x00, p + UART_EXAR_MPIOINT_15_8);
407 	writeb(0x00, p + UART_EXAR_MPIOLVL_15_8);
408 	writeb(0x00, p + UART_EXAR_MPIO3T_15_8);
409 	writeb(0x00, p + UART_EXAR_MPIOINV_15_8);
410 	writeb(dir,  p + UART_EXAR_MPIOSEL_15_8);
411 	writeb(0x00, p + UART_EXAR_MPIOOD_15_8);
412 }
413 
414 static struct platform_device *__xr17v35x_register_gpio(struct pci_dev *pcidev,
415 							const struct software_node *node)
416 {
417 	struct platform_device *pdev;
418 
419 	pdev = platform_device_alloc("gpio_exar", PLATFORM_DEVID_AUTO);
420 	if (!pdev)
421 		return NULL;
422 
423 	pdev->dev.parent = &pcidev->dev;
424 	ACPI_COMPANION_SET(&pdev->dev, ACPI_COMPANION(&pcidev->dev));
425 
426 	if (device_add_software_node(&pdev->dev, node) < 0 ||
427 	    platform_device_add(pdev) < 0) {
428 		platform_device_put(pdev);
429 		return NULL;
430 	}
431 
432 	return pdev;
433 }
434 
435 static void __xr17v35x_unregister_gpio(struct platform_device *pdev)
436 {
437 	device_remove_software_node(&pdev->dev);
438 	platform_device_unregister(pdev);
439 }
440 
441 static const struct property_entry exar_gpio_properties[] = {
442 	PROPERTY_ENTRY_U32("exar,first-pin", 0),
443 	PROPERTY_ENTRY_U32("ngpios", 16),
444 	{ }
445 };
446 
447 static const struct software_node exar_gpio_node = {
448 	.properties = exar_gpio_properties,
449 };
450 
451 static int xr17v35x_register_gpio(struct pci_dev *pcidev, struct uart_8250_port *port)
452 {
453 	if (pcidev->vendor == PCI_VENDOR_ID_EXAR)
454 		port->port.private_data =
455 			__xr17v35x_register_gpio(pcidev, &exar_gpio_node);
456 
457 	return 0;
458 }
459 
460 static void xr17v35x_unregister_gpio(struct uart_8250_port *port)
461 {
462 	if (!port->port.private_data)
463 		return;
464 
465 	__xr17v35x_unregister_gpio(port->port.private_data);
466 	port->port.private_data = NULL;
467 }
468 
469 static int generic_rs485_config(struct uart_port *port, struct ktermios *termios,
470 				struct serial_rs485 *rs485)
471 {
472 	bool is_rs485 = !!(rs485->flags & SER_RS485_ENABLED);
473 	u8 __iomem *p = port->membase;
474 	u8 value;
475 
476 	value = readb(p + UART_EXAR_FCTR);
477 	if (is_rs485)
478 		value |= UART_FCTR_EXAR_485;
479 	else
480 		value &= ~UART_FCTR_EXAR_485;
481 
482 	writeb(value, p + UART_EXAR_FCTR);
483 
484 	if (is_rs485)
485 		writeb(UART_EXAR_RS485_DLY(4), p + UART_MSR);
486 
487 	return 0;
488 }
489 
490 static const struct serial_rs485 generic_rs485_supported = {
491 	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
492 };
493 
494 static const struct exar8250_platform exar8250_default_platform = {
495 	.register_gpio = xr17v35x_register_gpio,
496 	.unregister_gpio = xr17v35x_unregister_gpio,
497 	.rs485_config = generic_rs485_config,
498 	.rs485_supported = &generic_rs485_supported,
499 };
500 
501 static int iot2040_rs485_config(struct uart_port *port, struct ktermios *termios,
502 				struct serial_rs485 *rs485)
503 {
504 	bool is_rs485 = !!(rs485->flags & SER_RS485_ENABLED);
505 	u8 __iomem *p = port->membase;
506 	u8 mask = IOT2040_UART1_MASK;
507 	u8 mode, value;
508 
509 	if (is_rs485) {
510 		if (rs485->flags & SER_RS485_RX_DURING_TX)
511 			mode = IOT2040_UART_MODE_RS422;
512 		else
513 			mode = IOT2040_UART_MODE_RS485;
514 
515 		if (rs485->flags & SER_RS485_TERMINATE_BUS)
516 			mode |= IOT2040_UART_TERMINATE_BUS;
517 	} else {
518 		mode = IOT2040_UART_MODE_RS232;
519 	}
520 
521 	if (port->line == 3) {
522 		mask <<= IOT2040_UART2_SHIFT;
523 		mode <<= IOT2040_UART2_SHIFT;
524 	}
525 
526 	value = readb(p + UART_EXAR_MPIOLVL_7_0);
527 	value &= ~mask;
528 	value |= mode;
529 	writeb(value, p + UART_EXAR_MPIOLVL_7_0);
530 
531 	return generic_rs485_config(port, termios, rs485);
532 }
533 
534 static const struct serial_rs485 iot2040_rs485_supported = {
535 	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
536 		 SER_RS485_RX_DURING_TX | SER_RS485_TERMINATE_BUS,
537 };
538 
539 static const struct property_entry iot2040_gpio_properties[] = {
540 	PROPERTY_ENTRY_U32("exar,first-pin", 10),
541 	PROPERTY_ENTRY_U32("ngpios", 1),
542 	{ }
543 };
544 
545 static const struct software_node iot2040_gpio_node = {
546 	.properties = iot2040_gpio_properties,
547 };
548 
549 static int iot2040_register_gpio(struct pci_dev *pcidev,
550 			      struct uart_8250_port *port)
551 {
552 	u8 __iomem *p = port->port.membase;
553 
554 	writeb(IOT2040_UARTS_DEFAULT_MODE, p + UART_EXAR_MPIOLVL_7_0);
555 	writeb(IOT2040_UARTS_GPIO_LO_MODE, p + UART_EXAR_MPIOSEL_7_0);
556 	writeb(IOT2040_UARTS_ENABLE, p + UART_EXAR_MPIOLVL_15_8);
557 	writeb(IOT2040_UARTS_GPIO_HI_MODE, p + UART_EXAR_MPIOSEL_15_8);
558 
559 	port->port.private_data =
560 		__xr17v35x_register_gpio(pcidev, &iot2040_gpio_node);
561 
562 	return 0;
563 }
564 
565 static const struct exar8250_platform iot2040_platform = {
566 	.rs485_config = iot2040_rs485_config,
567 	.rs485_supported = &iot2040_rs485_supported,
568 	.register_gpio = iot2040_register_gpio,
569 	.unregister_gpio = xr17v35x_unregister_gpio,
570 };
571 
572 /*
573  * For SIMATIC IOT2000, only IOT2040 and its variants have the Exar device,
574  * IOT2020 doesn't have. Therefore it is sufficient to match on the common
575  * board name after the device was found.
576  */
577 static const struct dmi_system_id exar_platforms[] = {
578 	{
579 		.matches = {
580 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "SIMATIC IOT2000"),
581 		},
582 		.driver_data = (void *)&iot2040_platform,
583 	},
584 	{}
585 };
586 
587 static const struct exar8250_platform *exar_get_platform(void)
588 {
589 	const struct dmi_system_id *dmi_match;
590 
591 	dmi_match = dmi_first_match(exar_platforms);
592 	if (dmi_match)
593 		return dmi_match->driver_data;
594 
595 	return &exar8250_default_platform;
596 }
597 
598 static int
599 pci_xr17v35x_setup(struct exar8250 *priv, struct pci_dev *pcidev,
600 		   struct uart_8250_port *port, int idx)
601 {
602 	const struct exar8250_platform *platform = exar_get_platform();
603 	unsigned int offset = idx * 0x400;
604 	unsigned int baud = 7812500;
605 	u8 __iomem *p;
606 	int ret;
607 
608 	port->port.uartclk = baud * 16;
609 	port->port.rs485_config = platform->rs485_config;
610 	port->port.rs485_supported = *(platform->rs485_supported);
611 
612 	/*
613 	 * Setup the UART clock for the devices on expansion slot to
614 	 * half the clock speed of the main chip (which is 125MHz)
615 	 */
616 	if (idx >= 8)
617 		port->port.uartclk /= 2;
618 
619 	ret = default_setup(priv, pcidev, idx, offset, port);
620 	if (ret)
621 		return ret;
622 
623 	p = port->port.membase;
624 
625 	writeb(0x00, p + UART_EXAR_8XMODE);
626 	writeb(UART_FCTR_EXAR_TRGD, p + UART_EXAR_FCTR);
627 	writeb(128, p + UART_EXAR_TXTRG);
628 	writeb(128, p + UART_EXAR_RXTRG);
629 
630 	if (idx == 0) {
631 		/* Setup Multipurpose Input/Output pins. */
632 		setup_gpio(pcidev, p);
633 
634 		ret = platform->register_gpio(pcidev, port);
635 	}
636 
637 	return ret;
638 }
639 
640 static void pci_xr17v35x_exit(struct pci_dev *pcidev)
641 {
642 	const struct exar8250_platform *platform = exar_get_platform();
643 	struct exar8250 *priv = pci_get_drvdata(pcidev);
644 	struct uart_8250_port *port = serial8250_get_port(priv->line[0]);
645 
646 	platform->unregister_gpio(port);
647 }
648 
649 static inline void exar_misc_clear(struct exar8250 *priv)
650 {
651 	/* Clear all PCI interrupts by reading INT0. No effect on IIR */
652 	readb(priv->virt + UART_EXAR_INT0);
653 
654 	/* Clear INT0 for Expansion Interface slave ports, too */
655 	if (priv->board->num_ports > 8)
656 		readb(priv->virt + 0x2000 + UART_EXAR_INT0);
657 }
658 
659 /*
660  * These Exar UARTs have an extra interrupt indicator that could fire for a
661  * few interrupts that are not presented/cleared through IIR.  One of which is
662  * a wakeup interrupt when coming out of sleep.  These interrupts are only
663  * cleared by reading global INT0 or INT1 registers as interrupts are
664  * associated with channel 0. The INT[3:0] registers _are_ accessible from each
665  * channel's address space, but for the sake of bus efficiency we register a
666  * dedicated handler at the PCI device level to handle them.
667  */
668 static irqreturn_t exar_misc_handler(int irq, void *data)
669 {
670 	exar_misc_clear(data);
671 
672 	return IRQ_HANDLED;
673 }
674 
675 static int
676 exar_pci_probe(struct pci_dev *pcidev, const struct pci_device_id *ent)
677 {
678 	unsigned int nr_ports, i, bar = 0, maxnr;
679 	struct exar8250_board *board;
680 	struct uart_8250_port uart;
681 	struct exar8250 *priv;
682 	int rc;
683 
684 	board = (struct exar8250_board *)ent->driver_data;
685 	if (!board)
686 		return -EINVAL;
687 
688 	rc = pcim_enable_device(pcidev);
689 	if (rc)
690 		return rc;
691 
692 	maxnr = pci_resource_len(pcidev, bar) >> (board->reg_shift + 3);
693 
694 	if (pcidev->vendor == PCI_VENDOR_ID_ACCESSIO)
695 		nr_ports = BIT(((pcidev->device & 0x38) >> 3) - 1);
696 	else if (board->num_ports)
697 		nr_ports = board->num_ports;
698 	else if (pcidev->vendor == PCI_VENDOR_ID_SEALEVEL)
699 		nr_ports = pcidev->device & 0xff;
700 	else
701 		nr_ports = pcidev->device & 0x0f;
702 
703 	priv = devm_kzalloc(&pcidev->dev, struct_size(priv, line, nr_ports), GFP_KERNEL);
704 	if (!priv)
705 		return -ENOMEM;
706 
707 	priv->board = board;
708 	priv->virt = pcim_iomap(pcidev, bar, 0);
709 	if (!priv->virt)
710 		return -ENOMEM;
711 
712 	pci_set_master(pcidev);
713 
714 	rc = pci_alloc_irq_vectors(pcidev, 1, 1, PCI_IRQ_ALL_TYPES);
715 	if (rc < 0)
716 		return rc;
717 
718 	memset(&uart, 0, sizeof(uart));
719 	uart.port.flags = UPF_SHARE_IRQ | UPF_EXAR_EFR | UPF_FIXED_TYPE | UPF_FIXED_PORT;
720 	uart.port.irq = pci_irq_vector(pcidev, 0);
721 	uart.port.dev = &pcidev->dev;
722 
723 	rc = devm_request_irq(&pcidev->dev, uart.port.irq, exar_misc_handler,
724 			 IRQF_SHARED, "exar_uart", priv);
725 	if (rc)
726 		return rc;
727 
728 	/* Clear interrupts */
729 	exar_misc_clear(priv);
730 
731 	for (i = 0; i < nr_ports && i < maxnr; i++) {
732 		rc = board->setup(priv, pcidev, &uart, i);
733 		if (rc) {
734 			dev_err(&pcidev->dev, "Failed to setup port %u\n", i);
735 			break;
736 		}
737 
738 		dev_dbg(&pcidev->dev, "Setup PCI port: port %lx, irq %d, type %d\n",
739 			uart.port.iobase, uart.port.irq, uart.port.iotype);
740 
741 		priv->line[i] = serial8250_register_8250_port(&uart);
742 		if (priv->line[i] < 0) {
743 			dev_err(&pcidev->dev,
744 				"Couldn't register serial port %lx, irq %d, type %d, error %d\n",
745 				uart.port.iobase, uart.port.irq,
746 				uart.port.iotype, priv->line[i]);
747 			break;
748 		}
749 	}
750 	priv->nr = i;
751 	pci_set_drvdata(pcidev, priv);
752 	return 0;
753 }
754 
755 static void exar_pci_remove(struct pci_dev *pcidev)
756 {
757 	struct exar8250 *priv = pci_get_drvdata(pcidev);
758 	unsigned int i;
759 
760 	for (i = 0; i < priv->nr; i++)
761 		serial8250_unregister_port(priv->line[i]);
762 
763 	/* Ensure that every init quirk is properly torn down */
764 	if (priv->board->exit)
765 		priv->board->exit(pcidev);
766 }
767 
768 static int __maybe_unused exar_suspend(struct device *dev)
769 {
770 	struct pci_dev *pcidev = to_pci_dev(dev);
771 	struct exar8250 *priv = pci_get_drvdata(pcidev);
772 	unsigned int i;
773 
774 	for (i = 0; i < priv->nr; i++)
775 		if (priv->line[i] >= 0)
776 			serial8250_suspend_port(priv->line[i]);
777 
778 	return 0;
779 }
780 
781 static int __maybe_unused exar_resume(struct device *dev)
782 {
783 	struct exar8250 *priv = dev_get_drvdata(dev);
784 	unsigned int i;
785 
786 	exar_misc_clear(priv);
787 
788 	for (i = 0; i < priv->nr; i++)
789 		if (priv->line[i] >= 0)
790 			serial8250_resume_port(priv->line[i]);
791 
792 	return 0;
793 }
794 
795 static SIMPLE_DEV_PM_OPS(exar_pci_pm, exar_suspend, exar_resume);
796 
797 static const struct exar8250_board pbn_fastcom335_2 = {
798 	.num_ports	= 2,
799 	.setup		= pci_fastcom335_setup,
800 };
801 
802 static const struct exar8250_board pbn_fastcom335_4 = {
803 	.num_ports	= 4,
804 	.setup		= pci_fastcom335_setup,
805 };
806 
807 static const struct exar8250_board pbn_fastcom335_8 = {
808 	.num_ports	= 8,
809 	.setup		= pci_fastcom335_setup,
810 };
811 
812 static const struct exar8250_board pbn_connect = {
813 	.setup		= pci_connect_tech_setup,
814 };
815 
816 static const struct exar8250_board pbn_exar_ibm_saturn = {
817 	.num_ports	= 1,
818 	.setup		= pci_xr17c154_setup,
819 };
820 
821 static const struct exar8250_board pbn_exar_XR17C15x = {
822 	.setup		= pci_xr17c154_setup,
823 };
824 
825 static const struct exar8250_board pbn_exar_XR17V35x = {
826 	.setup		= pci_xr17v35x_setup,
827 	.exit		= pci_xr17v35x_exit,
828 };
829 
830 static const struct exar8250_board pbn_fastcom35x_2 = {
831 	.num_ports	= 2,
832 	.setup		= pci_xr17v35x_setup,
833 	.exit		= pci_xr17v35x_exit,
834 };
835 
836 static const struct exar8250_board pbn_fastcom35x_4 = {
837 	.num_ports	= 4,
838 	.setup		= pci_xr17v35x_setup,
839 	.exit		= pci_xr17v35x_exit,
840 };
841 
842 static const struct exar8250_board pbn_fastcom35x_8 = {
843 	.num_ports	= 8,
844 	.setup		= pci_xr17v35x_setup,
845 	.exit		= pci_xr17v35x_exit,
846 };
847 
848 static const struct exar8250_board pbn_exar_XR17V4358 = {
849 	.num_ports	= 12,
850 	.setup		= pci_xr17v35x_setup,
851 	.exit		= pci_xr17v35x_exit,
852 };
853 
854 static const struct exar8250_board pbn_exar_XR17V8358 = {
855 	.num_ports	= 16,
856 	.setup		= pci_xr17v35x_setup,
857 	.exit		= pci_xr17v35x_exit,
858 };
859 
860 #define CONNECT_DEVICE(devid, sdevid, bd) {				\
861 	PCI_DEVICE_SUB(							\
862 		PCI_VENDOR_ID_EXAR,					\
863 		PCI_DEVICE_ID_EXAR_##devid,				\
864 		PCI_SUBVENDOR_ID_CONNECT_TECH,				\
865 		PCI_SUBDEVICE_ID_CONNECT_TECH_PCI_##sdevid), 0, 0,	\
866 		(kernel_ulong_t)&bd					\
867 	}
868 
869 #define EXAR_DEVICE(vend, devid, bd) { PCI_DEVICE_DATA(vend, devid, &bd) }
870 
871 #define IBM_DEVICE(devid, sdevid, bd) {			\
872 	PCI_DEVICE_SUB(					\
873 		PCI_VENDOR_ID_EXAR,			\
874 		PCI_DEVICE_ID_EXAR_##devid,		\
875 		PCI_VENDOR_ID_IBM,			\
876 		PCI_SUBDEVICE_ID_IBM_##sdevid), 0, 0,	\
877 		(kernel_ulong_t)&bd			\
878 	}
879 
880 #define USR_DEVICE(devid, sdevid, bd) {			\
881 	PCI_DEVICE_SUB(					\
882 		PCI_VENDOR_ID_USR,			\
883 		PCI_DEVICE_ID_EXAR_##devid,		\
884 		PCI_VENDOR_ID_EXAR,			\
885 		PCI_SUBDEVICE_ID_USR_##sdevid), 0, 0,	\
886 		(kernel_ulong_t)&bd			\
887 	}
888 
889 static const struct pci_device_id exar_pci_tbl[] = {
890 	EXAR_DEVICE(ACCESSIO, COM_2S, pbn_exar_XR17C15x),
891 	EXAR_DEVICE(ACCESSIO, COM_4S, pbn_exar_XR17C15x),
892 	EXAR_DEVICE(ACCESSIO, COM_8S, pbn_exar_XR17C15x),
893 	EXAR_DEVICE(ACCESSIO, COM232_8, pbn_exar_XR17C15x),
894 	EXAR_DEVICE(ACCESSIO, COM_2SM, pbn_exar_XR17C15x),
895 	EXAR_DEVICE(ACCESSIO, COM_4SM, pbn_exar_XR17C15x),
896 	EXAR_DEVICE(ACCESSIO, COM_8SM, pbn_exar_XR17C15x),
897 
898 	CONNECT_DEVICE(XR17C152, UART_2_232, pbn_connect),
899 	CONNECT_DEVICE(XR17C154, UART_4_232, pbn_connect),
900 	CONNECT_DEVICE(XR17C158, UART_8_232, pbn_connect),
901 	CONNECT_DEVICE(XR17C152, UART_1_1, pbn_connect),
902 	CONNECT_DEVICE(XR17C154, UART_2_2, pbn_connect),
903 	CONNECT_DEVICE(XR17C158, UART_4_4, pbn_connect),
904 	CONNECT_DEVICE(XR17C152, UART_2, pbn_connect),
905 	CONNECT_DEVICE(XR17C154, UART_4, pbn_connect),
906 	CONNECT_DEVICE(XR17C158, UART_8, pbn_connect),
907 	CONNECT_DEVICE(XR17C152, UART_2_485, pbn_connect),
908 	CONNECT_DEVICE(XR17C154, UART_4_485, pbn_connect),
909 	CONNECT_DEVICE(XR17C158, UART_8_485, pbn_connect),
910 
911 	IBM_DEVICE(XR17C152, SATURN_SERIAL_ONE_PORT, pbn_exar_ibm_saturn),
912 
913 	/* USRobotics USR298x-OEM PCI Modems */
914 	USR_DEVICE(XR17C152, 2980, pbn_exar_XR17C15x),
915 	USR_DEVICE(XR17C152, 2981, pbn_exar_XR17C15x),
916 
917 	/* Exar Corp. XR17C15[248] Dual/Quad/Octal UART */
918 	EXAR_DEVICE(EXAR, XR17C152, pbn_exar_XR17C15x),
919 	EXAR_DEVICE(EXAR, XR17C154, pbn_exar_XR17C15x),
920 	EXAR_DEVICE(EXAR, XR17C158, pbn_exar_XR17C15x),
921 
922 	/* Exar Corp. XR17V[48]35[248] Dual/Quad/Octal/Hexa PCIe UARTs */
923 	EXAR_DEVICE(EXAR, XR17V352, pbn_exar_XR17V35x),
924 	EXAR_DEVICE(EXAR, XR17V354, pbn_exar_XR17V35x),
925 	EXAR_DEVICE(EXAR, XR17V358, pbn_exar_XR17V35x),
926 	EXAR_DEVICE(EXAR, XR17V4358, pbn_exar_XR17V4358),
927 	EXAR_DEVICE(EXAR, XR17V8358, pbn_exar_XR17V8358),
928 	EXAR_DEVICE(COMMTECH, 4222PCIE, pbn_fastcom35x_2),
929 	EXAR_DEVICE(COMMTECH, 4224PCIE, pbn_fastcom35x_4),
930 	EXAR_DEVICE(COMMTECH, 4228PCIE, pbn_fastcom35x_8),
931 
932 	EXAR_DEVICE(COMMTECH, 4222PCI335, pbn_fastcom335_2),
933 	EXAR_DEVICE(COMMTECH, 4224PCI335, pbn_fastcom335_4),
934 	EXAR_DEVICE(COMMTECH, 2324PCI335, pbn_fastcom335_4),
935 	EXAR_DEVICE(COMMTECH, 2328PCI335, pbn_fastcom335_8),
936 
937 	EXAR_DEVICE(SEALEVEL, 710xC, pbn_exar_XR17V35x),
938 	EXAR_DEVICE(SEALEVEL, 720xC, pbn_exar_XR17V35x),
939 	EXAR_DEVICE(SEALEVEL, 740xC, pbn_exar_XR17V35x),
940 	EXAR_DEVICE(SEALEVEL, 780xC, pbn_exar_XR17V35x),
941 	EXAR_DEVICE(SEALEVEL, 716xC, pbn_exar_XR17V35x),
942 	{ 0, }
943 };
944 MODULE_DEVICE_TABLE(pci, exar_pci_tbl);
945 
946 static struct pci_driver exar_pci_driver = {
947 	.name		= "exar_serial",
948 	.probe		= exar_pci_probe,
949 	.remove		= exar_pci_remove,
950 	.driver         = {
951 		.pm     = &exar_pci_pm,
952 	},
953 	.id_table	= exar_pci_tbl,
954 };
955 module_pci_driver(exar_pci_driver);
956 
957 MODULE_LICENSE("GPL");
958 MODULE_DESCRIPTION("Exar Serial Driver");
959 MODULE_AUTHOR("Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>");
960