1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Probe for F81216A LPC to 4 UART
4  *
5  *  Copyright (C) 2014-2016 Ricardo Ribalda, Qtechnology A/S
6  */
7 #include <linux/module.h>
8 #include <linux/pci.h>
9 #include <linux/pnp.h>
10 #include <linux/kernel.h>
11 #include <linux/serial_core.h>
12 #include <linux/irq.h>
13 #include  "8250.h"
14 
15 #define ADDR_PORT 0
16 #define DATA_PORT 1
17 #define EXIT_KEY 0xAA
18 #define CHIP_ID1  0x20
19 #define CHIP_ID2  0x21
20 #define CHIP_ID_F81865 0x0407
21 #define CHIP_ID_F81866 0x1010
22 #define CHIP_ID_F81966 0x0215
23 #define CHIP_ID_F81216AD 0x1602
24 #define CHIP_ID_F81216H 0x0501
25 #define CHIP_ID_F81216 0x0802
26 #define VENDOR_ID1 0x23
27 #define VENDOR_ID1_VAL 0x19
28 #define VENDOR_ID2 0x24
29 #define VENDOR_ID2_VAL 0x34
30 #define IO_ADDR1 0x61
31 #define IO_ADDR2 0x60
32 #define LDN 0x7
33 
34 #define FINTEK_IRQ_MODE	0x70
35 #define IRQ_SHARE	BIT(4)
36 #define IRQ_MODE_MASK	(BIT(6) | BIT(5))
37 #define IRQ_LEVEL_LOW	0
38 #define IRQ_EDGE_HIGH	BIT(5)
39 
40 /*
41  * F81216H clock source register, the value and mask is the same with F81866,
42  * but it's on F0h.
43  *
44  * Clock speeds for UART (register F0h)
45  * 00: 1.8432MHz.
46  * 01: 18.432MHz.
47  * 10: 24MHz.
48  * 11: 14.769MHz.
49  */
50 #define RS485  0xF0
51 #define RTS_INVERT BIT(5)
52 #define RS485_URA BIT(4)
53 #define RXW4C_IRA BIT(3)
54 #define TXW4C_IRA BIT(2)
55 
56 #define FIFO_CTRL		0xF6
57 #define FIFO_MODE_MASK		(BIT(1) | BIT(0))
58 #define FIFO_MODE_128		(BIT(1) | BIT(0))
59 #define RXFTHR_MODE_MASK	(BIT(5) | BIT(4))
60 #define RXFTHR_MODE_4X		BIT(5)
61 
62 #define F81216_LDN_LOW	0x0
63 #define F81216_LDN_HIGH	0x4
64 
65 /*
66  * F81866/966 registers
67  *
68  * The IRQ setting mode of F81866/966 is not the same with F81216 series.
69  *	Level/Low: IRQ_MODE0:0, IRQ_MODE1:0
70  *	Edge/High: IRQ_MODE0:1, IRQ_MODE1:0
71  *
72  * Clock speeds for UART (register F2h)
73  * 00: 1.8432MHz.
74  * 01: 18.432MHz.
75  * 10: 24MHz.
76  * 11: 14.769MHz.
77  */
78 #define F81866_IRQ_MODE		0xf0
79 #define F81866_IRQ_SHARE	BIT(0)
80 #define F81866_IRQ_MODE0	BIT(1)
81 
82 #define F81866_FIFO_CTRL	FIFO_CTRL
83 #define F81866_IRQ_MODE1	BIT(3)
84 
85 #define F81866_LDN_LOW		0x10
86 #define F81866_LDN_HIGH		0x16
87 
88 #define F81866_UART_CLK 0xF2
89 #define F81866_UART_CLK_MASK (BIT(1) | BIT(0))
90 #define F81866_UART_CLK_1_8432MHZ 0
91 #define F81866_UART_CLK_14_769MHZ (BIT(1) | BIT(0))
92 #define F81866_UART_CLK_18_432MHZ BIT(0)
93 #define F81866_UART_CLK_24MHZ BIT(1)
94 
95 struct fintek_8250 {
96 	u16 pid;
97 	u16 base_port;
98 	u8 index;
99 	u8 key;
100 };
101 
102 static u8 sio_read_reg(struct fintek_8250 *pdata, u8 reg)
103 {
104 	outb(reg, pdata->base_port + ADDR_PORT);
105 	return inb(pdata->base_port + DATA_PORT);
106 }
107 
108 static void sio_write_reg(struct fintek_8250 *pdata, u8 reg, u8 data)
109 {
110 	outb(reg, pdata->base_port + ADDR_PORT);
111 	outb(data, pdata->base_port + DATA_PORT);
112 }
113 
114 static void sio_write_mask_reg(struct fintek_8250 *pdata, u8 reg, u8 mask,
115 			       u8 data)
116 {
117 	u8 tmp;
118 
119 	tmp = (sio_read_reg(pdata, reg) & ~mask) | (mask & data);
120 	sio_write_reg(pdata, reg, tmp);
121 }
122 
123 static int fintek_8250_enter_key(u16 base_port, u8 key)
124 {
125 	if (!request_muxed_region(base_port, 2, "8250_fintek"))
126 		return -EBUSY;
127 
128 	/* Force to deactive all SuperIO in this base_port */
129 	outb(EXIT_KEY, base_port + ADDR_PORT);
130 
131 	outb(key, base_port + ADDR_PORT);
132 	outb(key, base_port + ADDR_PORT);
133 	return 0;
134 }
135 
136 static void fintek_8250_exit_key(u16 base_port)
137 {
138 
139 	outb(EXIT_KEY, base_port + ADDR_PORT);
140 	release_region(base_port + ADDR_PORT, 2);
141 }
142 
143 static int fintek_8250_check_id(struct fintek_8250 *pdata)
144 {
145 	u16 chip;
146 
147 	if (sio_read_reg(pdata, VENDOR_ID1) != VENDOR_ID1_VAL)
148 		return -ENODEV;
149 
150 	if (sio_read_reg(pdata, VENDOR_ID2) != VENDOR_ID2_VAL)
151 		return -ENODEV;
152 
153 	chip = sio_read_reg(pdata, CHIP_ID1);
154 	chip |= sio_read_reg(pdata, CHIP_ID2) << 8;
155 
156 	switch (chip) {
157 	case CHIP_ID_F81865:
158 	case CHIP_ID_F81866:
159 	case CHIP_ID_F81966:
160 	case CHIP_ID_F81216AD:
161 	case CHIP_ID_F81216H:
162 	case CHIP_ID_F81216:
163 		break;
164 	default:
165 		return -ENODEV;
166 	}
167 
168 	pdata->pid = chip;
169 	return 0;
170 }
171 
172 static int fintek_8250_get_ldn_range(struct fintek_8250 *pdata, int *min,
173 				     int *max)
174 {
175 	switch (pdata->pid) {
176 	case CHIP_ID_F81966:
177 	case CHIP_ID_F81865:
178 	case CHIP_ID_F81866:
179 		*min = F81866_LDN_LOW;
180 		*max = F81866_LDN_HIGH;
181 		return 0;
182 
183 	case CHIP_ID_F81216AD:
184 	case CHIP_ID_F81216H:
185 	case CHIP_ID_F81216:
186 		*min = F81216_LDN_LOW;
187 		*max = F81216_LDN_HIGH;
188 		return 0;
189 	}
190 
191 	return -ENODEV;
192 }
193 
194 static int fintek_8250_rs485_config(struct uart_port *port, struct ktermios *termios,
195 			      struct serial_rs485 *rs485)
196 {
197 	uint8_t config = 0;
198 	struct fintek_8250 *pdata = port->private_data;
199 
200 	if (!pdata)
201 		return -EINVAL;
202 
203 
204 	if (rs485->flags & SER_RS485_ENABLED) {
205 		/* Hardware do not support same RTS level on send and receive */
206 		if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
207 		    !(rs485->flags & SER_RS485_RTS_AFTER_SEND))
208 			return -EINVAL;
209 		config |= RS485_URA;
210 	}
211 
212 	if (rs485->delay_rts_before_send) {
213 		rs485->delay_rts_before_send = 1;
214 		config |= TXW4C_IRA;
215 	}
216 
217 	if (rs485->delay_rts_after_send) {
218 		rs485->delay_rts_after_send = 1;
219 		config |= RXW4C_IRA;
220 	}
221 
222 	if (rs485->flags & SER_RS485_RTS_ON_SEND)
223 		config |= RTS_INVERT;
224 
225 	if (fintek_8250_enter_key(pdata->base_port, pdata->key))
226 		return -EBUSY;
227 
228 	sio_write_reg(pdata, LDN, pdata->index);
229 	sio_write_reg(pdata, RS485, config);
230 	fintek_8250_exit_key(pdata->base_port);
231 
232 	return 0;
233 }
234 
235 static void fintek_8250_set_irq_mode(struct fintek_8250 *pdata, bool is_level)
236 {
237 	sio_write_reg(pdata, LDN, pdata->index);
238 
239 	switch (pdata->pid) {
240 	case CHIP_ID_F81966:
241 	case CHIP_ID_F81866:
242 		sio_write_mask_reg(pdata, F81866_FIFO_CTRL, F81866_IRQ_MODE1,
243 				   0);
244 		fallthrough;
245 	case CHIP_ID_F81865:
246 		sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_SHARE,
247 				   F81866_IRQ_SHARE);
248 		sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_MODE0,
249 				   is_level ? 0 : F81866_IRQ_MODE0);
250 		break;
251 
252 	case CHIP_ID_F81216AD:
253 	case CHIP_ID_F81216H:
254 	case CHIP_ID_F81216:
255 		sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_SHARE,
256 				   IRQ_SHARE);
257 		sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_MODE_MASK,
258 				   is_level ? IRQ_LEVEL_LOW : IRQ_EDGE_HIGH);
259 		break;
260 	}
261 }
262 
263 static void fintek_8250_set_max_fifo(struct fintek_8250 *pdata)
264 {
265 	switch (pdata->pid) {
266 	case CHIP_ID_F81216H: /* 128Bytes FIFO */
267 	case CHIP_ID_F81966:
268 	case CHIP_ID_F81866:
269 		sio_write_mask_reg(pdata, FIFO_CTRL,
270 				   FIFO_MODE_MASK | RXFTHR_MODE_MASK,
271 				   FIFO_MODE_128 | RXFTHR_MODE_4X);
272 		break;
273 
274 	default: /* Default 16Bytes FIFO */
275 		break;
276 	}
277 }
278 
279 static void fintek_8250_set_termios(struct uart_port *port,
280 				    struct ktermios *termios,
281 				    const struct ktermios *old)
282 {
283 	struct fintek_8250 *pdata = port->private_data;
284 	unsigned int baud = tty_termios_baud_rate(termios);
285 	int i;
286 	u8 reg;
287 	static u32 baudrate_table[] = {115200, 921600, 1152000, 1500000};
288 	static u8 clock_table[] = { F81866_UART_CLK_1_8432MHZ,
289 			F81866_UART_CLK_14_769MHZ, F81866_UART_CLK_18_432MHZ,
290 			F81866_UART_CLK_24MHZ };
291 
292 	/*
293 	 * We'll use serial8250_do_set_termios() for baud = 0, otherwise It'll
294 	 * crash on baudrate_table[i] % baud with "division by zero".
295 	 */
296 	if (!baud)
297 		goto exit;
298 
299 	switch (pdata->pid) {
300 	case CHIP_ID_F81216H:
301 		reg = RS485;
302 		break;
303 	case CHIP_ID_F81966:
304 	case CHIP_ID_F81866:
305 		reg = F81866_UART_CLK;
306 		break;
307 	default:
308 		/* Don't change clocksource with unknown PID */
309 		dev_warn(port->dev,
310 			"%s: pid: %x Not support. use default set_termios.\n",
311 			__func__, pdata->pid);
312 		goto exit;
313 	}
314 
315 	for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
316 		if (baud > baudrate_table[i] || baudrate_table[i] % baud != 0)
317 			continue;
318 
319 		if (port->uartclk == baudrate_table[i] * 16)
320 			break;
321 
322 		if (fintek_8250_enter_key(pdata->base_port, pdata->key))
323 			continue;
324 
325 		port->uartclk = baudrate_table[i] * 16;
326 
327 		sio_write_reg(pdata, LDN, pdata->index);
328 		sio_write_mask_reg(pdata, reg, F81866_UART_CLK_MASK,
329 				clock_table[i]);
330 
331 		fintek_8250_exit_key(pdata->base_port);
332 		break;
333 	}
334 
335 	if (i == ARRAY_SIZE(baudrate_table)) {
336 		baud = tty_termios_baud_rate(old);
337 		tty_termios_encode_baud_rate(termios, baud, baud);
338 	}
339 
340 exit:
341 	serial8250_do_set_termios(port, termios, old);
342 }
343 
344 static void fintek_8250_set_termios_handler(struct uart_8250_port *uart)
345 {
346 	struct fintek_8250 *pdata = uart->port.private_data;
347 
348 	switch (pdata->pid) {
349 	case CHIP_ID_F81216H:
350 	case CHIP_ID_F81966:
351 	case CHIP_ID_F81866:
352 		uart->port.set_termios = fintek_8250_set_termios;
353 		break;
354 
355 	default:
356 		break;
357 	}
358 }
359 
360 static int probe_setup_port(struct fintek_8250 *pdata,
361 					struct uart_8250_port *uart)
362 {
363 	static const u16 addr[] = {0x4e, 0x2e};
364 	static const u8 keys[] = {0x77, 0xa0, 0x87, 0x67};
365 	struct irq_data *irq_data;
366 	bool level_mode = false;
367 	int i, j, k, min, max;
368 
369 	for (i = 0; i < ARRAY_SIZE(addr); i++) {
370 		for (j = 0; j < ARRAY_SIZE(keys); j++) {
371 			pdata->base_port = addr[i];
372 			pdata->key = keys[j];
373 
374 			if (fintek_8250_enter_key(addr[i], keys[j]))
375 				continue;
376 			if (fintek_8250_check_id(pdata) ||
377 			    fintek_8250_get_ldn_range(pdata, &min, &max)) {
378 				fintek_8250_exit_key(addr[i]);
379 				continue;
380 			}
381 
382 			for (k = min; k < max; k++) {
383 				u16 aux;
384 
385 				sio_write_reg(pdata, LDN, k);
386 				aux = sio_read_reg(pdata, IO_ADDR1);
387 				aux |= sio_read_reg(pdata, IO_ADDR2) << 8;
388 				if (aux != uart->port.iobase)
389 					continue;
390 
391 				pdata->index = k;
392 
393 				irq_data = irq_get_irq_data(uart->port.irq);
394 				if (irq_data)
395 					level_mode =
396 						irqd_is_level_type(irq_data);
397 
398 				fintek_8250_set_irq_mode(pdata, level_mode);
399 				fintek_8250_set_max_fifo(pdata);
400 
401 				fintek_8250_exit_key(addr[i]);
402 
403 				return 0;
404 			}
405 
406 			fintek_8250_exit_key(addr[i]);
407 		}
408 	}
409 
410 	return -ENODEV;
411 }
412 
413 /* Only the first port supports delays */
414 static const struct serial_rs485 fintek_8250_rs485_supported_port0 = {
415 	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
416 	.delay_rts_before_send = 1,
417 	.delay_rts_after_send = 1,
418 };
419 
420 static const struct serial_rs485 fintek_8250_rs485_supported = {
421 	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND,
422 };
423 
424 static void fintek_8250_set_rs485_handler(struct uart_8250_port *uart)
425 {
426 	struct fintek_8250 *pdata = uart->port.private_data;
427 
428 	switch (pdata->pid) {
429 	case CHIP_ID_F81216AD:
430 	case CHIP_ID_F81216H:
431 	case CHIP_ID_F81966:
432 	case CHIP_ID_F81866:
433 	case CHIP_ID_F81865:
434 		uart->port.rs485_config = fintek_8250_rs485_config;
435 		if (!pdata->index)
436 			uart->port.rs485_supported = fintek_8250_rs485_supported_port0;
437 		else
438 			uart->port.rs485_supported = fintek_8250_rs485_supported;
439 		break;
440 
441 	default: /* No RS485 Auto direction functional */
442 		break;
443 	}
444 }
445 
446 int fintek_8250_probe(struct uart_8250_port *uart)
447 {
448 	struct fintek_8250 *pdata;
449 	struct fintek_8250 probe_data;
450 
451 	if (probe_setup_port(&probe_data, uart))
452 		return -ENODEV;
453 
454 	pdata = devm_kzalloc(uart->port.dev, sizeof(*pdata), GFP_KERNEL);
455 	if (!pdata)
456 		return -ENOMEM;
457 
458 	memcpy(pdata, &probe_data, sizeof(probe_data));
459 	uart->port.private_data = pdata;
460 	fintek_8250_set_rs485_handler(uart);
461 	fintek_8250_set_termios_handler(uart);
462 
463 	return 0;
464 }
465