1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
3 
4 /* Disable MMIO tracing to prevent excessive logging of unwanted MMIO traces */
5 #define __DISABLE_TRACE_MMIO__
6 
7 #include <linux/clk.h>
8 #include <linux/console.h>
9 #include <linux/io.h>
10 #include <linux/iopoll.h>
11 #include <linux/irq.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_device.h>
15 #include <linux/pm_opp.h>
16 #include <linux/platform_device.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/pm_wakeirq.h>
19 #include <linux/qcom-geni-se.h>
20 #include <linux/serial.h>
21 #include <linux/serial_core.h>
22 #include <linux/slab.h>
23 #include <linux/tty.h>
24 #include <linux/tty_flip.h>
25 
26 /* UART specific GENI registers */
27 #define SE_UART_LOOPBACK_CFG		0x22c
28 #define SE_UART_IO_MACRO_CTRL		0x240
29 #define SE_UART_TX_TRANS_CFG		0x25c
30 #define SE_UART_TX_WORD_LEN		0x268
31 #define SE_UART_TX_STOP_BIT_LEN		0x26c
32 #define SE_UART_TX_TRANS_LEN		0x270
33 #define SE_UART_RX_TRANS_CFG		0x280
34 #define SE_UART_RX_WORD_LEN		0x28c
35 #define SE_UART_RX_STALE_CNT		0x294
36 #define SE_UART_TX_PARITY_CFG		0x2a4
37 #define SE_UART_RX_PARITY_CFG		0x2a8
38 #define SE_UART_MANUAL_RFR		0x2ac
39 
40 /* SE_UART_TRANS_CFG */
41 #define UART_TX_PAR_EN		BIT(0)
42 #define UART_CTS_MASK		BIT(1)
43 
44 /* SE_UART_TX_WORD_LEN */
45 #define TX_WORD_LEN_MSK		GENMASK(9, 0)
46 
47 /* SE_UART_TX_STOP_BIT_LEN */
48 #define TX_STOP_BIT_LEN_MSK	GENMASK(23, 0)
49 #define TX_STOP_BIT_LEN_1	0
50 #define TX_STOP_BIT_LEN_1_5	1
51 #define TX_STOP_BIT_LEN_2	2
52 
53 /* SE_UART_TX_TRANS_LEN */
54 #define TX_TRANS_LEN_MSK	GENMASK(23, 0)
55 
56 /* SE_UART_RX_TRANS_CFG */
57 #define UART_RX_INS_STATUS_BIT	BIT(2)
58 #define UART_RX_PAR_EN		BIT(3)
59 
60 /* SE_UART_RX_WORD_LEN */
61 #define RX_WORD_LEN_MASK	GENMASK(9, 0)
62 
63 /* SE_UART_RX_STALE_CNT */
64 #define RX_STALE_CNT		GENMASK(23, 0)
65 
66 /* SE_UART_TX_PARITY_CFG/RX_PARITY_CFG */
67 #define PAR_CALC_EN		BIT(0)
68 #define PAR_MODE_MSK		GENMASK(2, 1)
69 #define PAR_MODE_SHFT		1
70 #define PAR_EVEN		0x00
71 #define PAR_ODD			0x01
72 #define PAR_SPACE		0x10
73 #define PAR_MARK		0x11
74 
75 /* SE_UART_MANUAL_RFR register fields */
76 #define UART_MANUAL_RFR_EN	BIT(31)
77 #define UART_RFR_NOT_READY	BIT(1)
78 #define UART_RFR_READY		BIT(0)
79 
80 /* UART M_CMD OP codes */
81 #define UART_START_TX		0x1
82 #define UART_START_BREAK	0x4
83 #define UART_STOP_BREAK		0x5
84 /* UART S_CMD OP codes */
85 #define UART_START_READ		0x1
86 #define UART_PARAM		0x1
87 
88 #define UART_OVERSAMPLING	32
89 #define STALE_TIMEOUT		16
90 #define DEFAULT_BITS_PER_CHAR	10
91 #define GENI_UART_CONS_PORTS	1
92 #define GENI_UART_PORTS		3
93 #define DEF_FIFO_DEPTH_WORDS	16
94 #define DEF_TX_WM		2
95 #define DEF_FIFO_WIDTH_BITS	32
96 #define UART_RX_WM		2
97 
98 /* SE_UART_LOOPBACK_CFG */
99 #define RX_TX_SORTED	BIT(0)
100 #define CTS_RTS_SORTED	BIT(1)
101 #define RX_TX_CTS_RTS_SORTED	(RX_TX_SORTED | CTS_RTS_SORTED)
102 
103 /* UART pin swap value */
104 #define DEFAULT_IO_MACRO_IO0_IO1_MASK		GENMASK(3, 0)
105 #define IO_MACRO_IO0_SEL		0x3
106 #define DEFAULT_IO_MACRO_IO2_IO3_MASK		GENMASK(15, 4)
107 #define IO_MACRO_IO2_IO3_SWAP		0x4640
108 
109 /* We always configure 4 bytes per FIFO word */
110 #define BYTES_PER_FIFO_WORD		4
111 
112 struct qcom_geni_private_data {
113 	/* NOTE: earlycon port will have NULL here */
114 	struct uart_driver *drv;
115 
116 	u32 poll_cached_bytes;
117 	unsigned int poll_cached_bytes_cnt;
118 
119 	u32 write_cached_bytes;
120 	unsigned int write_cached_bytes_cnt;
121 };
122 
123 struct qcom_geni_serial_port {
124 	struct uart_port uport;
125 	struct geni_se se;
126 	const char *name;
127 	u32 tx_fifo_depth;
128 	u32 tx_fifo_width;
129 	u32 rx_fifo_depth;
130 	bool setup;
131 	int (*handle_rx)(struct uart_port *uport, u32 bytes, bool drop);
132 	unsigned int baud;
133 	void *rx_fifo;
134 	u32 loopback;
135 	bool brk;
136 
137 	unsigned int tx_remaining;
138 	int wakeup_irq;
139 	bool rx_tx_swap;
140 	bool cts_rts_swap;
141 
142 	struct qcom_geni_private_data private_data;
143 };
144 
145 static const struct uart_ops qcom_geni_console_pops;
146 static const struct uart_ops qcom_geni_uart_pops;
147 static struct uart_driver qcom_geni_console_driver;
148 static struct uart_driver qcom_geni_uart_driver;
149 static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop);
150 static int handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop);
151 static unsigned int qcom_geni_serial_tx_empty(struct uart_port *port);
152 static void qcom_geni_serial_stop_rx(struct uart_port *uport);
153 static void qcom_geni_serial_handle_rx(struct uart_port *uport, bool drop);
154 
155 #define to_dev_port(ptr, member) \
156 		container_of(ptr, struct qcom_geni_serial_port, member)
157 
158 static struct qcom_geni_serial_port qcom_geni_uart_ports[GENI_UART_PORTS] = {
159 	[0] = {
160 		.uport = {
161 				.iotype = UPIO_MEM,
162 				.ops = &qcom_geni_uart_pops,
163 				.flags = UPF_BOOT_AUTOCONF,
164 				.line = 0,
165 		},
166 	},
167 	[1] = {
168 		.uport = {
169 				.iotype = UPIO_MEM,
170 				.ops = &qcom_geni_uart_pops,
171 				.flags = UPF_BOOT_AUTOCONF,
172 				.line = 1,
173 		},
174 	},
175 	[2] = {
176 		.uport = {
177 				.iotype = UPIO_MEM,
178 				.ops = &qcom_geni_uart_pops,
179 				.flags = UPF_BOOT_AUTOCONF,
180 				.line = 2,
181 		},
182 	},
183 };
184 
185 static struct qcom_geni_serial_port qcom_geni_console_port = {
186 	.uport = {
187 		.iotype = UPIO_MEM,
188 		.ops = &qcom_geni_console_pops,
189 		.flags = UPF_BOOT_AUTOCONF,
190 		.line = 0,
191 	},
192 };
193 
194 static int qcom_geni_serial_request_port(struct uart_port *uport)
195 {
196 	struct platform_device *pdev = to_platform_device(uport->dev);
197 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
198 
199 	uport->membase = devm_platform_ioremap_resource(pdev, 0);
200 	if (IS_ERR(uport->membase))
201 		return PTR_ERR(uport->membase);
202 	port->se.base = uport->membase;
203 	return 0;
204 }
205 
206 static void qcom_geni_serial_config_port(struct uart_port *uport, int cfg_flags)
207 {
208 	if (cfg_flags & UART_CONFIG_TYPE) {
209 		uport->type = PORT_MSM;
210 		qcom_geni_serial_request_port(uport);
211 	}
212 }
213 
214 static unsigned int qcom_geni_serial_get_mctrl(struct uart_port *uport)
215 {
216 	unsigned int mctrl = TIOCM_DSR | TIOCM_CAR;
217 	u32 geni_ios;
218 
219 	if (uart_console(uport)) {
220 		mctrl |= TIOCM_CTS;
221 	} else {
222 		geni_ios = readl(uport->membase + SE_GENI_IOS);
223 		if (!(geni_ios & IO2_DATA_IN))
224 			mctrl |= TIOCM_CTS;
225 	}
226 
227 	return mctrl;
228 }
229 
230 static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
231 							unsigned int mctrl)
232 {
233 	u32 uart_manual_rfr = 0;
234 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
235 
236 	if (uart_console(uport))
237 		return;
238 
239 	if (mctrl & TIOCM_LOOP)
240 		port->loopback = RX_TX_CTS_RTS_SORTED;
241 
242 	if (!(mctrl & TIOCM_RTS) && !uport->suspended)
243 		uart_manual_rfr = UART_MANUAL_RFR_EN | UART_RFR_NOT_READY;
244 	writel(uart_manual_rfr, uport->membase + SE_UART_MANUAL_RFR);
245 }
246 
247 static const char *qcom_geni_serial_get_type(struct uart_port *uport)
248 {
249 	return "MSM";
250 }
251 
252 static struct qcom_geni_serial_port *get_port_from_line(int line, bool console)
253 {
254 	struct qcom_geni_serial_port *port;
255 	int nr_ports = console ? GENI_UART_CONS_PORTS : GENI_UART_PORTS;
256 
257 	if (line < 0 || line >= nr_ports)
258 		return ERR_PTR(-ENXIO);
259 
260 	port = console ? &qcom_geni_console_port : &qcom_geni_uart_ports[line];
261 	return port;
262 }
263 
264 static bool qcom_geni_serial_poll_bit(struct uart_port *uport,
265 				int offset, int field, bool set)
266 {
267 	u32 reg;
268 	struct qcom_geni_serial_port *port;
269 	unsigned int baud;
270 	unsigned int fifo_bits;
271 	unsigned long timeout_us = 20000;
272 	struct qcom_geni_private_data *private_data = uport->private_data;
273 
274 	if (private_data->drv) {
275 		port = to_dev_port(uport, uport);
276 		baud = port->baud;
277 		if (!baud)
278 			baud = 115200;
279 		fifo_bits = port->tx_fifo_depth * port->tx_fifo_width;
280 		/*
281 		 * Total polling iterations based on FIFO worth of bytes to be
282 		 * sent at current baud. Add a little fluff to the wait.
283 		 */
284 		timeout_us = ((fifo_bits * USEC_PER_SEC) / baud) + 500;
285 	}
286 
287 	/*
288 	 * Use custom implementation instead of readl_poll_atomic since ktimer
289 	 * is not ready at the time of early console.
290 	 */
291 	timeout_us = DIV_ROUND_UP(timeout_us, 10) * 10;
292 	while (timeout_us) {
293 		reg = readl(uport->membase + offset);
294 		if ((bool)(reg & field) == set)
295 			return true;
296 		udelay(10);
297 		timeout_us -= 10;
298 	}
299 	return false;
300 }
301 
302 static void qcom_geni_serial_setup_tx(struct uart_port *uport, u32 xmit_size)
303 {
304 	u32 m_cmd;
305 
306 	writel(xmit_size, uport->membase + SE_UART_TX_TRANS_LEN);
307 	m_cmd = UART_START_TX << M_OPCODE_SHFT;
308 	writel(m_cmd, uport->membase + SE_GENI_M_CMD0);
309 }
310 
311 static void qcom_geni_serial_poll_tx_done(struct uart_port *uport)
312 {
313 	int done;
314 	u32 irq_clear = M_CMD_DONE_EN;
315 
316 	done = qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
317 						M_CMD_DONE_EN, true);
318 	if (!done) {
319 		writel(M_GENI_CMD_ABORT, uport->membase +
320 						SE_GENI_M_CMD_CTRL_REG);
321 		irq_clear |= M_CMD_ABORT_EN;
322 		qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
323 							M_CMD_ABORT_EN, true);
324 	}
325 	writel(irq_clear, uport->membase + SE_GENI_M_IRQ_CLEAR);
326 }
327 
328 static void qcom_geni_serial_abort_rx(struct uart_port *uport)
329 {
330 	u32 irq_clear = S_CMD_DONE_EN | S_CMD_ABORT_EN;
331 
332 	writel(S_GENI_CMD_ABORT, uport->membase + SE_GENI_S_CMD_CTRL_REG);
333 	qcom_geni_serial_poll_bit(uport, SE_GENI_S_CMD_CTRL_REG,
334 					S_GENI_CMD_ABORT, false);
335 	writel(irq_clear, uport->membase + SE_GENI_S_IRQ_CLEAR);
336 	writel(FORCE_DEFAULT, uport->membase + GENI_FORCE_DEFAULT_REG);
337 }
338 
339 #ifdef CONFIG_CONSOLE_POLL
340 
341 static int qcom_geni_serial_get_char(struct uart_port *uport)
342 {
343 	struct qcom_geni_private_data *private_data = uport->private_data;
344 	u32 status;
345 	u32 word_cnt;
346 	int ret;
347 
348 	if (!private_data->poll_cached_bytes_cnt) {
349 		status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
350 		writel(status, uport->membase + SE_GENI_M_IRQ_CLEAR);
351 
352 		status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
353 		writel(status, uport->membase + SE_GENI_S_IRQ_CLEAR);
354 
355 		status = readl(uport->membase + SE_GENI_RX_FIFO_STATUS);
356 		word_cnt = status & RX_FIFO_WC_MSK;
357 		if (!word_cnt)
358 			return NO_POLL_CHAR;
359 
360 		if (word_cnt == 1 && (status & RX_LAST))
361 			/*
362 			 * NOTE: If RX_LAST_BYTE_VALID is 0 it needs to be
363 			 * treated as if it was BYTES_PER_FIFO_WORD.
364 			 */
365 			private_data->poll_cached_bytes_cnt =
366 				(status & RX_LAST_BYTE_VALID_MSK) >>
367 				RX_LAST_BYTE_VALID_SHFT;
368 
369 		if (private_data->poll_cached_bytes_cnt == 0)
370 			private_data->poll_cached_bytes_cnt = BYTES_PER_FIFO_WORD;
371 
372 		private_data->poll_cached_bytes =
373 			readl(uport->membase + SE_GENI_RX_FIFOn);
374 	}
375 
376 	private_data->poll_cached_bytes_cnt--;
377 	ret = private_data->poll_cached_bytes & 0xff;
378 	private_data->poll_cached_bytes >>= 8;
379 
380 	return ret;
381 }
382 
383 static void qcom_geni_serial_poll_put_char(struct uart_port *uport,
384 							unsigned char c)
385 {
386 	writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
387 	qcom_geni_serial_setup_tx(uport, 1);
388 	WARN_ON(!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
389 						M_TX_FIFO_WATERMARK_EN, true));
390 	writel(c, uport->membase + SE_GENI_TX_FIFOn);
391 	writel(M_TX_FIFO_WATERMARK_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
392 	qcom_geni_serial_poll_tx_done(uport);
393 }
394 #endif
395 
396 #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
397 static void qcom_geni_serial_wr_char(struct uart_port *uport, unsigned char ch)
398 {
399 	struct qcom_geni_private_data *private_data = uport->private_data;
400 
401 	private_data->write_cached_bytes =
402 		(private_data->write_cached_bytes >> 8) | (ch << 24);
403 	private_data->write_cached_bytes_cnt++;
404 
405 	if (private_data->write_cached_bytes_cnt == BYTES_PER_FIFO_WORD) {
406 		writel(private_data->write_cached_bytes,
407 		       uport->membase + SE_GENI_TX_FIFOn);
408 		private_data->write_cached_bytes_cnt = 0;
409 	}
410 }
411 
412 static void
413 __qcom_geni_serial_console_write(struct uart_port *uport, const char *s,
414 				 unsigned int count)
415 {
416 	struct qcom_geni_private_data *private_data = uport->private_data;
417 
418 	int i;
419 	u32 bytes_to_send = count;
420 
421 	for (i = 0; i < count; i++) {
422 		/*
423 		 * uart_console_write() adds a carriage return for each newline.
424 		 * Account for additional bytes to be written.
425 		 */
426 		if (s[i] == '\n')
427 			bytes_to_send++;
428 	}
429 
430 	writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
431 	qcom_geni_serial_setup_tx(uport, bytes_to_send);
432 	for (i = 0; i < count; ) {
433 		size_t chars_to_write = 0;
434 		size_t avail = DEF_FIFO_DEPTH_WORDS - DEF_TX_WM;
435 
436 		/*
437 		 * If the WM bit never set, then the Tx state machine is not
438 		 * in a valid state, so break, cancel/abort any existing
439 		 * command. Unfortunately the current data being written is
440 		 * lost.
441 		 */
442 		if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
443 						M_TX_FIFO_WATERMARK_EN, true))
444 			break;
445 		chars_to_write = min_t(size_t, count - i, avail / 2);
446 		uart_console_write(uport, s + i, chars_to_write,
447 						qcom_geni_serial_wr_char);
448 		writel(M_TX_FIFO_WATERMARK_EN, uport->membase +
449 							SE_GENI_M_IRQ_CLEAR);
450 		i += chars_to_write;
451 	}
452 
453 	if (private_data->write_cached_bytes_cnt) {
454 		private_data->write_cached_bytes >>= BITS_PER_BYTE *
455 			(BYTES_PER_FIFO_WORD - private_data->write_cached_bytes_cnt);
456 		writel(private_data->write_cached_bytes,
457 		       uport->membase + SE_GENI_TX_FIFOn);
458 		private_data->write_cached_bytes_cnt = 0;
459 	}
460 
461 	qcom_geni_serial_poll_tx_done(uport);
462 }
463 
464 static void qcom_geni_serial_console_write(struct console *co, const char *s,
465 			      unsigned int count)
466 {
467 	struct uart_port *uport;
468 	struct qcom_geni_serial_port *port;
469 	bool locked = true;
470 	unsigned long flags;
471 	u32 geni_status;
472 	u32 irq_en;
473 
474 	WARN_ON(co->index < 0 || co->index >= GENI_UART_CONS_PORTS);
475 
476 	port = get_port_from_line(co->index, true);
477 	if (IS_ERR(port))
478 		return;
479 
480 	uport = &port->uport;
481 	if (oops_in_progress)
482 		locked = spin_trylock_irqsave(&uport->lock, flags);
483 	else
484 		spin_lock_irqsave(&uport->lock, flags);
485 
486 	geni_status = readl(uport->membase + SE_GENI_STATUS);
487 
488 	/* Cancel the current write to log the fault */
489 	if (!locked) {
490 		geni_se_cancel_m_cmd(&port->se);
491 		if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
492 						M_CMD_CANCEL_EN, true)) {
493 			geni_se_abort_m_cmd(&port->se);
494 			qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
495 							M_CMD_ABORT_EN, true);
496 			writel(M_CMD_ABORT_EN, uport->membase +
497 							SE_GENI_M_IRQ_CLEAR);
498 		}
499 		writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
500 	} else if ((geni_status & M_GENI_CMD_ACTIVE) && !port->tx_remaining) {
501 		/*
502 		 * It seems we can't interrupt existing transfers if all data
503 		 * has been sent, in which case we need to look for done first.
504 		 */
505 		qcom_geni_serial_poll_tx_done(uport);
506 
507 		if (!uart_circ_empty(&uport->state->xmit)) {
508 			irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
509 			writel(irq_en | M_TX_FIFO_WATERMARK_EN,
510 					uport->membase + SE_GENI_M_IRQ_EN);
511 		}
512 	}
513 
514 	__qcom_geni_serial_console_write(uport, s, count);
515 
516 	if (port->tx_remaining)
517 		qcom_geni_serial_setup_tx(uport, port->tx_remaining);
518 
519 	if (locked)
520 		spin_unlock_irqrestore(&uport->lock, flags);
521 }
522 
523 static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
524 {
525 	u32 i;
526 	unsigned char buf[sizeof(u32)];
527 	struct tty_port *tport;
528 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
529 
530 	tport = &uport->state->port;
531 	for (i = 0; i < bytes; ) {
532 		int c;
533 		int chunk = min_t(int, bytes - i, BYTES_PER_FIFO_WORD);
534 
535 		ioread32_rep(uport->membase + SE_GENI_RX_FIFOn, buf, 1);
536 		i += chunk;
537 		if (drop)
538 			continue;
539 
540 		for (c = 0; c < chunk; c++) {
541 			int sysrq;
542 
543 			uport->icount.rx++;
544 			if (port->brk && buf[c] == 0) {
545 				port->brk = false;
546 				if (uart_handle_break(uport))
547 					continue;
548 			}
549 
550 			sysrq = uart_prepare_sysrq_char(uport, buf[c]);
551 
552 			if (!sysrq)
553 				tty_insert_flip_char(tport, buf[c], TTY_NORMAL);
554 		}
555 	}
556 	if (!drop)
557 		tty_flip_buffer_push(tport);
558 	return 0;
559 }
560 #else
561 static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
562 {
563 	return -EPERM;
564 }
565 
566 #endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
567 
568 static int handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop)
569 {
570 	struct tty_port *tport;
571 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
572 	u32 num_bytes_pw = port->tx_fifo_width / BITS_PER_BYTE;
573 	u32 words = ALIGN(bytes, num_bytes_pw) / num_bytes_pw;
574 	int ret;
575 
576 	tport = &uport->state->port;
577 	ioread32_rep(uport->membase + SE_GENI_RX_FIFOn, port->rx_fifo, words);
578 	if (drop)
579 		return 0;
580 
581 	ret = tty_insert_flip_string(tport, port->rx_fifo, bytes);
582 	if (ret != bytes) {
583 		dev_err(uport->dev, "%s:Unable to push data ret %d_bytes %d\n",
584 				__func__, ret, bytes);
585 		WARN_ON_ONCE(1);
586 	}
587 	uport->icount.rx += ret;
588 	tty_flip_buffer_push(tport);
589 	return ret;
590 }
591 
592 static void qcom_geni_serial_start_tx(struct uart_port *uport)
593 {
594 	u32 irq_en;
595 	u32 status;
596 
597 	status = readl(uport->membase + SE_GENI_STATUS);
598 	if (status & M_GENI_CMD_ACTIVE)
599 		return;
600 
601 	if (!qcom_geni_serial_tx_empty(uport))
602 		return;
603 
604 	irq_en = readl(uport->membase +	SE_GENI_M_IRQ_EN);
605 	irq_en |= M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN;
606 
607 	writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
608 	writel(irq_en, uport->membase +	SE_GENI_M_IRQ_EN);
609 }
610 
611 static void qcom_geni_serial_stop_tx(struct uart_port *uport)
612 {
613 	u32 irq_en;
614 	u32 status;
615 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
616 
617 	irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
618 	irq_en &= ~(M_CMD_DONE_EN | M_TX_FIFO_WATERMARK_EN);
619 	writel(0, uport->membase + SE_GENI_TX_WATERMARK_REG);
620 	writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
621 	status = readl(uport->membase + SE_GENI_STATUS);
622 	/* Possible stop tx is called multiple times. */
623 	if (!(status & M_GENI_CMD_ACTIVE))
624 		return;
625 
626 	geni_se_cancel_m_cmd(&port->se);
627 	if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
628 						M_CMD_CANCEL_EN, true)) {
629 		geni_se_abort_m_cmd(&port->se);
630 		qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
631 						M_CMD_ABORT_EN, true);
632 		writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
633 	}
634 	writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
635 }
636 
637 static void qcom_geni_serial_start_rx(struct uart_port *uport)
638 {
639 	u32 irq_en;
640 	u32 status;
641 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
642 
643 	status = readl(uport->membase + SE_GENI_STATUS);
644 	if (status & S_GENI_CMD_ACTIVE)
645 		qcom_geni_serial_stop_rx(uport);
646 
647 	geni_se_setup_s_cmd(&port->se, UART_START_READ, 0);
648 
649 	irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN);
650 	irq_en |= S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN;
651 	writel(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
652 
653 	irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
654 	irq_en |= M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN;
655 	writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
656 }
657 
658 static void qcom_geni_serial_stop_rx(struct uart_port *uport)
659 {
660 	u32 irq_en;
661 	u32 status;
662 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
663 	u32 s_irq_status;
664 
665 	irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN);
666 	irq_en &= ~(S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
667 	writel(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
668 
669 	irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
670 	irq_en &= ~(M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
671 	writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
672 
673 	status = readl(uport->membase + SE_GENI_STATUS);
674 	/* Possible stop rx is called multiple times. */
675 	if (!(status & S_GENI_CMD_ACTIVE))
676 		return;
677 
678 	geni_se_cancel_s_cmd(&port->se);
679 	qcom_geni_serial_poll_bit(uport, SE_GENI_S_IRQ_STATUS,
680 					S_CMD_CANCEL_EN, true);
681 	/*
682 	 * If timeout occurs secondary engine remains active
683 	 * and Abort sequence is executed.
684 	 */
685 	s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
686 	/* Flush the Rx buffer */
687 	if (s_irq_status & S_RX_FIFO_LAST_EN)
688 		qcom_geni_serial_handle_rx(uport, true);
689 	writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
690 
691 	status = readl(uport->membase + SE_GENI_STATUS);
692 	if (status & S_GENI_CMD_ACTIVE)
693 		qcom_geni_serial_abort_rx(uport);
694 }
695 
696 static void qcom_geni_serial_handle_rx(struct uart_port *uport, bool drop)
697 {
698 	u32 status;
699 	u32 word_cnt;
700 	u32 last_word_byte_cnt;
701 	u32 last_word_partial;
702 	u32 total_bytes;
703 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
704 
705 	status = readl(uport->membase +	SE_GENI_RX_FIFO_STATUS);
706 	word_cnt = status & RX_FIFO_WC_MSK;
707 	last_word_partial = status & RX_LAST;
708 	last_word_byte_cnt = (status & RX_LAST_BYTE_VALID_MSK) >>
709 						RX_LAST_BYTE_VALID_SHFT;
710 
711 	if (!word_cnt)
712 		return;
713 	total_bytes = BYTES_PER_FIFO_WORD * (word_cnt - 1);
714 	if (last_word_partial && last_word_byte_cnt)
715 		total_bytes += last_word_byte_cnt;
716 	else
717 		total_bytes += BYTES_PER_FIFO_WORD;
718 	port->handle_rx(uport, total_bytes, drop);
719 }
720 
721 static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done,
722 		bool active)
723 {
724 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
725 	struct circ_buf *xmit = &uport->state->xmit;
726 	size_t avail;
727 	size_t remaining;
728 	size_t pending;
729 	int i;
730 	u32 status;
731 	u32 irq_en;
732 	unsigned int chunk;
733 	int tail;
734 
735 	status = readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
736 
737 	/* Complete the current tx command before taking newly added data */
738 	if (active)
739 		pending = port->tx_remaining;
740 	else
741 		pending = uart_circ_chars_pending(xmit);
742 
743 	/* All data has been transmitted and acknowledged as received */
744 	if (!pending && !status && done) {
745 		qcom_geni_serial_stop_tx(uport);
746 		goto out_write_wakeup;
747 	}
748 
749 	avail = port->tx_fifo_depth - (status & TX_FIFO_WC);
750 	avail *= BYTES_PER_FIFO_WORD;
751 
752 	tail = xmit->tail;
753 	chunk = min(avail, pending);
754 	if (!chunk)
755 		goto out_write_wakeup;
756 
757 	if (!port->tx_remaining) {
758 		qcom_geni_serial_setup_tx(uport, pending);
759 		port->tx_remaining = pending;
760 
761 		irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
762 		if (!(irq_en & M_TX_FIFO_WATERMARK_EN))
763 			writel(irq_en | M_TX_FIFO_WATERMARK_EN,
764 					uport->membase + SE_GENI_M_IRQ_EN);
765 	}
766 
767 	remaining = chunk;
768 	for (i = 0; i < chunk; ) {
769 		unsigned int tx_bytes;
770 		u8 buf[sizeof(u32)];
771 		int c;
772 
773 		memset(buf, 0, sizeof(buf));
774 		tx_bytes = min_t(size_t, remaining, BYTES_PER_FIFO_WORD);
775 
776 		for (c = 0; c < tx_bytes ; c++) {
777 			buf[c] = xmit->buf[tail++];
778 			tail &= UART_XMIT_SIZE - 1;
779 		}
780 
781 		iowrite32_rep(uport->membase + SE_GENI_TX_FIFOn, buf, 1);
782 
783 		i += tx_bytes;
784 		uport->icount.tx += tx_bytes;
785 		remaining -= tx_bytes;
786 		port->tx_remaining -= tx_bytes;
787 	}
788 
789 	xmit->tail = tail;
790 
791 	/*
792 	 * The tx fifo watermark is level triggered and latched. Though we had
793 	 * cleared it in qcom_geni_serial_isr it will have already reasserted
794 	 * so we must clear it again here after our writes.
795 	 */
796 	writel(M_TX_FIFO_WATERMARK_EN,
797 			uport->membase + SE_GENI_M_IRQ_CLEAR);
798 
799 out_write_wakeup:
800 	if (!port->tx_remaining) {
801 		irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
802 		if (irq_en & M_TX_FIFO_WATERMARK_EN)
803 			writel(irq_en & ~M_TX_FIFO_WATERMARK_EN,
804 					uport->membase + SE_GENI_M_IRQ_EN);
805 	}
806 
807 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
808 		uart_write_wakeup(uport);
809 }
810 
811 static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
812 {
813 	u32 m_irq_en;
814 	u32 m_irq_status;
815 	u32 s_irq_status;
816 	u32 geni_status;
817 	struct uart_port *uport = dev;
818 	bool drop_rx = false;
819 	struct tty_port *tport = &uport->state->port;
820 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
821 
822 	if (uport->suspended)
823 		return IRQ_NONE;
824 
825 	spin_lock(&uport->lock);
826 
827 	m_irq_status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
828 	s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
829 	geni_status = readl(uport->membase + SE_GENI_STATUS);
830 	m_irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
831 	writel(m_irq_status, uport->membase + SE_GENI_M_IRQ_CLEAR);
832 	writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
833 
834 	if (WARN_ON(m_irq_status & M_ILLEGAL_CMD_EN))
835 		goto out_unlock;
836 
837 	if (s_irq_status & S_RX_FIFO_WR_ERR_EN) {
838 		uport->icount.overrun++;
839 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
840 	}
841 
842 	if (m_irq_status & m_irq_en & (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN))
843 		qcom_geni_serial_handle_tx(uport, m_irq_status & M_CMD_DONE_EN,
844 					geni_status & M_GENI_CMD_ACTIVE);
845 
846 	if (s_irq_status & S_GP_IRQ_0_EN || s_irq_status & S_GP_IRQ_1_EN) {
847 		if (s_irq_status & S_GP_IRQ_0_EN)
848 			uport->icount.parity++;
849 		drop_rx = true;
850 	} else if (s_irq_status & S_GP_IRQ_2_EN ||
851 					s_irq_status & S_GP_IRQ_3_EN) {
852 		uport->icount.brk++;
853 		port->brk = true;
854 	}
855 
856 	if (s_irq_status & S_RX_FIFO_WATERMARK_EN ||
857 					s_irq_status & S_RX_FIFO_LAST_EN)
858 		qcom_geni_serial_handle_rx(uport, drop_rx);
859 
860 out_unlock:
861 	uart_unlock_and_check_sysrq(uport);
862 
863 	return IRQ_HANDLED;
864 }
865 
866 static void get_tx_fifo_size(struct qcom_geni_serial_port *port)
867 {
868 	struct uart_port *uport;
869 
870 	uport = &port->uport;
871 	port->tx_fifo_depth = geni_se_get_tx_fifo_depth(&port->se);
872 	port->tx_fifo_width = geni_se_get_tx_fifo_width(&port->se);
873 	port->rx_fifo_depth = geni_se_get_rx_fifo_depth(&port->se);
874 	uport->fifosize =
875 		(port->tx_fifo_depth * port->tx_fifo_width) / BITS_PER_BYTE;
876 }
877 
878 
879 static void qcom_geni_serial_shutdown(struct uart_port *uport)
880 {
881 	disable_irq(uport->irq);
882 }
883 
884 static int qcom_geni_serial_port_setup(struct uart_port *uport)
885 {
886 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
887 	u32 rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;
888 	u32 proto;
889 	u32 pin_swap;
890 
891 	proto = geni_se_read_proto(&port->se);
892 	if (proto != GENI_SE_UART) {
893 		dev_err(uport->dev, "Invalid FW loaded, proto: %d\n", proto);
894 		return -ENXIO;
895 	}
896 
897 	qcom_geni_serial_stop_rx(uport);
898 
899 	get_tx_fifo_size(port);
900 
901 	writel(rxstale, uport->membase + SE_UART_RX_STALE_CNT);
902 
903 	pin_swap = readl(uport->membase + SE_UART_IO_MACRO_CTRL);
904 	if (port->rx_tx_swap) {
905 		pin_swap &= ~DEFAULT_IO_MACRO_IO2_IO3_MASK;
906 		pin_swap |= IO_MACRO_IO2_IO3_SWAP;
907 	}
908 	if (port->cts_rts_swap) {
909 		pin_swap &= ~DEFAULT_IO_MACRO_IO0_IO1_MASK;
910 		pin_swap |= IO_MACRO_IO0_SEL;
911 	}
912 	/* Configure this register if RX-TX, CTS-RTS pins are swapped */
913 	if (port->rx_tx_swap || port->cts_rts_swap)
914 		writel(pin_swap, uport->membase + SE_UART_IO_MACRO_CTRL);
915 
916 	/*
917 	 * Make an unconditional cancel on the main sequencer to reset
918 	 * it else we could end up in data loss scenarios.
919 	 */
920 	if (uart_console(uport))
921 		qcom_geni_serial_poll_tx_done(uport);
922 	geni_se_config_packing(&port->se, BITS_PER_BYTE, BYTES_PER_FIFO_WORD,
923 			       false, true, true);
924 	geni_se_init(&port->se, UART_RX_WM, port->rx_fifo_depth - 2);
925 	geni_se_select_mode(&port->se, GENI_SE_FIFO);
926 	port->setup = true;
927 
928 	return 0;
929 }
930 
931 static int qcom_geni_serial_startup(struct uart_port *uport)
932 {
933 	int ret;
934 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
935 
936 	if (!port->setup) {
937 		ret = qcom_geni_serial_port_setup(uport);
938 		if (ret)
939 			return ret;
940 	}
941 	enable_irq(uport->irq);
942 
943 	return 0;
944 }
945 
946 static unsigned long find_clk_rate_in_tol(struct clk *clk, unsigned int desired_clk,
947 			unsigned int *clk_div, unsigned int percent_tol)
948 {
949 	unsigned long freq;
950 	unsigned long div, maxdiv;
951 	u64 mult;
952 	unsigned long offset, abs_tol, achieved;
953 
954 	abs_tol = div_u64((u64)desired_clk * percent_tol, 100);
955 	maxdiv = CLK_DIV_MSK >> CLK_DIV_SHFT;
956 	div = 1;
957 	while (div <= maxdiv) {
958 		mult = (u64)div * desired_clk;
959 		if (mult != (unsigned long)mult)
960 			break;
961 
962 		offset = div * abs_tol;
963 		freq = clk_round_rate(clk, mult - offset);
964 
965 		/* Can only get lower if we're done */
966 		if (freq < mult - offset)
967 			break;
968 
969 		/*
970 		 * Re-calculate div in case rounding skipped rates but we
971 		 * ended up at a good one, then check for a match.
972 		 */
973 		div = DIV_ROUND_CLOSEST(freq, desired_clk);
974 		achieved = DIV_ROUND_CLOSEST(freq, div);
975 		if (achieved <= desired_clk + abs_tol &&
976 		    achieved >= desired_clk - abs_tol) {
977 			*clk_div = div;
978 			return freq;
979 		}
980 
981 		div = DIV_ROUND_UP(freq, desired_clk);
982 	}
983 
984 	return 0;
985 }
986 
987 static unsigned long get_clk_div_rate(struct clk *clk, unsigned int baud,
988 			unsigned int sampling_rate, unsigned int *clk_div)
989 {
990 	unsigned long ser_clk;
991 	unsigned long desired_clk;
992 
993 	desired_clk = baud * sampling_rate;
994 	if (!desired_clk)
995 		return 0;
996 
997 	/*
998 	 * try to find a clock rate within 2% tolerance, then within 5%
999 	 */
1000 	ser_clk = find_clk_rate_in_tol(clk, desired_clk, clk_div, 2);
1001 	if (!ser_clk)
1002 		ser_clk = find_clk_rate_in_tol(clk, desired_clk, clk_div, 5);
1003 
1004 	return ser_clk;
1005 }
1006 
1007 static void qcom_geni_serial_set_termios(struct uart_port *uport,
1008 				struct ktermios *termios, struct ktermios *old)
1009 {
1010 	unsigned int baud;
1011 	u32 bits_per_char;
1012 	u32 tx_trans_cfg;
1013 	u32 tx_parity_cfg;
1014 	u32 rx_trans_cfg;
1015 	u32 rx_parity_cfg;
1016 	u32 stop_bit_len;
1017 	unsigned int clk_div;
1018 	u32 ser_clk_cfg;
1019 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
1020 	unsigned long clk_rate;
1021 	u32 ver, sampling_rate;
1022 	unsigned int avg_bw_core;
1023 
1024 	qcom_geni_serial_stop_rx(uport);
1025 	/* baud rate */
1026 	baud = uart_get_baud_rate(uport, termios, old, 300, 4000000);
1027 	port->baud = baud;
1028 
1029 	sampling_rate = UART_OVERSAMPLING;
1030 	/* Sampling rate is halved for IP versions >= 2.5 */
1031 	ver = geni_se_get_qup_hw_version(&port->se);
1032 	if (ver >= QUP_SE_VERSION_2_5)
1033 		sampling_rate /= 2;
1034 
1035 	clk_rate = get_clk_div_rate(port->se.clk, baud,
1036 		sampling_rate, &clk_div);
1037 	if (!clk_rate) {
1038 		dev_err(port->se.dev,
1039 			"Couldn't find suitable clock rate for %u\n",
1040 			baud * sampling_rate);
1041 		goto out_restart_rx;
1042 	}
1043 
1044 	dev_dbg(port->se.dev, "desired_rate-%u, clk_rate-%lu, clk_div-%u\n",
1045 			baud * sampling_rate, clk_rate, clk_div);
1046 
1047 	uport->uartclk = clk_rate;
1048 	dev_pm_opp_set_rate(uport->dev, clk_rate);
1049 	ser_clk_cfg = SER_CLK_EN;
1050 	ser_clk_cfg |= clk_div << CLK_DIV_SHFT;
1051 
1052 	/*
1053 	 * Bump up BW vote on CPU and CORE path as driver supports FIFO mode
1054 	 * only.
1055 	 */
1056 	avg_bw_core = (baud > 115200) ? Bps_to_icc(CORE_2X_50_MHZ)
1057 						: GENI_DEFAULT_BW;
1058 	port->se.icc_paths[GENI_TO_CORE].avg_bw = avg_bw_core;
1059 	port->se.icc_paths[CPU_TO_GENI].avg_bw = Bps_to_icc(baud);
1060 	geni_icc_set_bw(&port->se);
1061 
1062 	/* parity */
1063 	tx_trans_cfg = readl(uport->membase + SE_UART_TX_TRANS_CFG);
1064 	tx_parity_cfg = readl(uport->membase + SE_UART_TX_PARITY_CFG);
1065 	rx_trans_cfg = readl(uport->membase + SE_UART_RX_TRANS_CFG);
1066 	rx_parity_cfg = readl(uport->membase + SE_UART_RX_PARITY_CFG);
1067 	if (termios->c_cflag & PARENB) {
1068 		tx_trans_cfg |= UART_TX_PAR_EN;
1069 		rx_trans_cfg |= UART_RX_PAR_EN;
1070 		tx_parity_cfg |= PAR_CALC_EN;
1071 		rx_parity_cfg |= PAR_CALC_EN;
1072 		if (termios->c_cflag & PARODD) {
1073 			tx_parity_cfg |= PAR_ODD;
1074 			rx_parity_cfg |= PAR_ODD;
1075 		} else if (termios->c_cflag & CMSPAR) {
1076 			tx_parity_cfg |= PAR_SPACE;
1077 			rx_parity_cfg |= PAR_SPACE;
1078 		} else {
1079 			tx_parity_cfg |= PAR_EVEN;
1080 			rx_parity_cfg |= PAR_EVEN;
1081 		}
1082 	} else {
1083 		tx_trans_cfg &= ~UART_TX_PAR_EN;
1084 		rx_trans_cfg &= ~UART_RX_PAR_EN;
1085 		tx_parity_cfg &= ~PAR_CALC_EN;
1086 		rx_parity_cfg &= ~PAR_CALC_EN;
1087 	}
1088 
1089 	/* bits per char */
1090 	bits_per_char = tty_get_char_size(termios->c_cflag);
1091 
1092 	/* stop bits */
1093 	if (termios->c_cflag & CSTOPB)
1094 		stop_bit_len = TX_STOP_BIT_LEN_2;
1095 	else
1096 		stop_bit_len = TX_STOP_BIT_LEN_1;
1097 
1098 	/* flow control, clear the CTS_MASK bit if using flow control. */
1099 	if (termios->c_cflag & CRTSCTS)
1100 		tx_trans_cfg &= ~UART_CTS_MASK;
1101 	else
1102 		tx_trans_cfg |= UART_CTS_MASK;
1103 
1104 	if (baud)
1105 		uart_update_timeout(uport, termios->c_cflag, baud);
1106 
1107 	if (!uart_console(uport))
1108 		writel(port->loopback,
1109 				uport->membase + SE_UART_LOOPBACK_CFG);
1110 	writel(tx_trans_cfg, uport->membase + SE_UART_TX_TRANS_CFG);
1111 	writel(tx_parity_cfg, uport->membase + SE_UART_TX_PARITY_CFG);
1112 	writel(rx_trans_cfg, uport->membase + SE_UART_RX_TRANS_CFG);
1113 	writel(rx_parity_cfg, uport->membase + SE_UART_RX_PARITY_CFG);
1114 	writel(bits_per_char, uport->membase + SE_UART_TX_WORD_LEN);
1115 	writel(bits_per_char, uport->membase + SE_UART_RX_WORD_LEN);
1116 	writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
1117 	writel(ser_clk_cfg, uport->membase + GENI_SER_M_CLK_CFG);
1118 	writel(ser_clk_cfg, uport->membase + GENI_SER_S_CLK_CFG);
1119 out_restart_rx:
1120 	qcom_geni_serial_start_rx(uport);
1121 }
1122 
1123 static unsigned int qcom_geni_serial_tx_empty(struct uart_port *uport)
1124 {
1125 	return !readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
1126 }
1127 
1128 #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
1129 static int qcom_geni_console_setup(struct console *co, char *options)
1130 {
1131 	struct uart_port *uport;
1132 	struct qcom_geni_serial_port *port;
1133 	int baud = 115200;
1134 	int bits = 8;
1135 	int parity = 'n';
1136 	int flow = 'n';
1137 	int ret;
1138 
1139 	if (co->index >= GENI_UART_CONS_PORTS  || co->index < 0)
1140 		return -ENXIO;
1141 
1142 	port = get_port_from_line(co->index, true);
1143 	if (IS_ERR(port)) {
1144 		pr_err("Invalid line %d\n", co->index);
1145 		return PTR_ERR(port);
1146 	}
1147 
1148 	uport = &port->uport;
1149 
1150 	if (unlikely(!uport->membase))
1151 		return -ENXIO;
1152 
1153 	if (!port->setup) {
1154 		ret = qcom_geni_serial_port_setup(uport);
1155 		if (ret)
1156 			return ret;
1157 	}
1158 
1159 	if (options)
1160 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1161 
1162 	return uart_set_options(uport, co, baud, parity, bits, flow);
1163 }
1164 
1165 static void qcom_geni_serial_earlycon_write(struct console *con,
1166 					const char *s, unsigned int n)
1167 {
1168 	struct earlycon_device *dev = con->data;
1169 
1170 	__qcom_geni_serial_console_write(&dev->port, s, n);
1171 }
1172 
1173 #ifdef CONFIG_CONSOLE_POLL
1174 static int qcom_geni_serial_earlycon_read(struct console *con,
1175 					  char *s, unsigned int n)
1176 {
1177 	struct earlycon_device *dev = con->data;
1178 	struct uart_port *uport = &dev->port;
1179 	int num_read = 0;
1180 	int ch;
1181 
1182 	while (num_read < n) {
1183 		ch = qcom_geni_serial_get_char(uport);
1184 		if (ch == NO_POLL_CHAR)
1185 			break;
1186 		s[num_read++] = ch;
1187 	}
1188 
1189 	return num_read;
1190 }
1191 
1192 static void __init qcom_geni_serial_enable_early_read(struct geni_se *se,
1193 						      struct console *con)
1194 {
1195 	geni_se_setup_s_cmd(se, UART_START_READ, 0);
1196 	con->read = qcom_geni_serial_earlycon_read;
1197 }
1198 #else
1199 static inline void qcom_geni_serial_enable_early_read(struct geni_se *se,
1200 						      struct console *con) { }
1201 #endif
1202 
1203 static struct qcom_geni_private_data earlycon_private_data;
1204 
1205 static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev,
1206 								const char *opt)
1207 {
1208 	struct uart_port *uport = &dev->port;
1209 	u32 tx_trans_cfg;
1210 	u32 tx_parity_cfg = 0;	/* Disable Tx Parity */
1211 	u32 rx_trans_cfg = 0;
1212 	u32 rx_parity_cfg = 0;	/* Disable Rx Parity */
1213 	u32 stop_bit_len = 0;	/* Default stop bit length - 1 bit */
1214 	u32 bits_per_char;
1215 	struct geni_se se;
1216 
1217 	if (!uport->membase)
1218 		return -EINVAL;
1219 
1220 	uport->private_data = &earlycon_private_data;
1221 
1222 	memset(&se, 0, sizeof(se));
1223 	se.base = uport->membase;
1224 	if (geni_se_read_proto(&se) != GENI_SE_UART)
1225 		return -ENXIO;
1226 	/*
1227 	 * Ignore Flow control.
1228 	 * n = 8.
1229 	 */
1230 	tx_trans_cfg = UART_CTS_MASK;
1231 	bits_per_char = BITS_PER_BYTE;
1232 
1233 	/*
1234 	 * Make an unconditional cancel on the main sequencer to reset
1235 	 * it else we could end up in data loss scenarios.
1236 	 */
1237 	qcom_geni_serial_poll_tx_done(uport);
1238 	qcom_geni_serial_abort_rx(uport);
1239 	geni_se_config_packing(&se, BITS_PER_BYTE, BYTES_PER_FIFO_WORD,
1240 			       false, true, true);
1241 	geni_se_init(&se, DEF_FIFO_DEPTH_WORDS / 2, DEF_FIFO_DEPTH_WORDS - 2);
1242 	geni_se_select_mode(&se, GENI_SE_FIFO);
1243 
1244 	writel(tx_trans_cfg, uport->membase + SE_UART_TX_TRANS_CFG);
1245 	writel(tx_parity_cfg, uport->membase + SE_UART_TX_PARITY_CFG);
1246 	writel(rx_trans_cfg, uport->membase + SE_UART_RX_TRANS_CFG);
1247 	writel(rx_parity_cfg, uport->membase + SE_UART_RX_PARITY_CFG);
1248 	writel(bits_per_char, uport->membase + SE_UART_TX_WORD_LEN);
1249 	writel(bits_per_char, uport->membase + SE_UART_RX_WORD_LEN);
1250 	writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
1251 
1252 	dev->con->write = qcom_geni_serial_earlycon_write;
1253 	dev->con->setup = NULL;
1254 	qcom_geni_serial_enable_early_read(&se, dev->con);
1255 
1256 	return 0;
1257 }
1258 OF_EARLYCON_DECLARE(qcom_geni, "qcom,geni-debug-uart",
1259 				qcom_geni_serial_earlycon_setup);
1260 
1261 static int __init console_register(struct uart_driver *drv)
1262 {
1263 	return uart_register_driver(drv);
1264 }
1265 
1266 static void console_unregister(struct uart_driver *drv)
1267 {
1268 	uart_unregister_driver(drv);
1269 }
1270 
1271 static struct console cons_ops = {
1272 	.name = "ttyMSM",
1273 	.write = qcom_geni_serial_console_write,
1274 	.device = uart_console_device,
1275 	.setup = qcom_geni_console_setup,
1276 	.flags = CON_PRINTBUFFER,
1277 	.index = -1,
1278 	.data = &qcom_geni_console_driver,
1279 };
1280 
1281 static struct uart_driver qcom_geni_console_driver = {
1282 	.owner = THIS_MODULE,
1283 	.driver_name = "qcom_geni_console",
1284 	.dev_name = "ttyMSM",
1285 	.nr =  GENI_UART_CONS_PORTS,
1286 	.cons = &cons_ops,
1287 };
1288 #else
1289 static int console_register(struct uart_driver *drv)
1290 {
1291 	return 0;
1292 }
1293 
1294 static void console_unregister(struct uart_driver *drv)
1295 {
1296 }
1297 #endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
1298 
1299 static struct uart_driver qcom_geni_uart_driver = {
1300 	.owner = THIS_MODULE,
1301 	.driver_name = "qcom_geni_uart",
1302 	.dev_name = "ttyHS",
1303 	.nr =  GENI_UART_PORTS,
1304 };
1305 
1306 static void qcom_geni_serial_pm(struct uart_port *uport,
1307 		unsigned int new_state, unsigned int old_state)
1308 {
1309 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
1310 
1311 	/* If we've never been called, treat it as off */
1312 	if (old_state == UART_PM_STATE_UNDEFINED)
1313 		old_state = UART_PM_STATE_OFF;
1314 
1315 	if (new_state == UART_PM_STATE_ON && old_state == UART_PM_STATE_OFF) {
1316 		geni_icc_enable(&port->se);
1317 		geni_se_resources_on(&port->se);
1318 	} else if (new_state == UART_PM_STATE_OFF &&
1319 			old_state == UART_PM_STATE_ON) {
1320 		geni_se_resources_off(&port->se);
1321 		geni_icc_disable(&port->se);
1322 	}
1323 }
1324 
1325 static const struct uart_ops qcom_geni_console_pops = {
1326 	.tx_empty = qcom_geni_serial_tx_empty,
1327 	.stop_tx = qcom_geni_serial_stop_tx,
1328 	.start_tx = qcom_geni_serial_start_tx,
1329 	.stop_rx = qcom_geni_serial_stop_rx,
1330 	.start_rx = qcom_geni_serial_start_rx,
1331 	.set_termios = qcom_geni_serial_set_termios,
1332 	.startup = qcom_geni_serial_startup,
1333 	.request_port = qcom_geni_serial_request_port,
1334 	.config_port = qcom_geni_serial_config_port,
1335 	.shutdown = qcom_geni_serial_shutdown,
1336 	.type = qcom_geni_serial_get_type,
1337 	.set_mctrl = qcom_geni_serial_set_mctrl,
1338 	.get_mctrl = qcom_geni_serial_get_mctrl,
1339 #ifdef CONFIG_CONSOLE_POLL
1340 	.poll_get_char	= qcom_geni_serial_get_char,
1341 	.poll_put_char	= qcom_geni_serial_poll_put_char,
1342 #endif
1343 	.pm = qcom_geni_serial_pm,
1344 };
1345 
1346 static const struct uart_ops qcom_geni_uart_pops = {
1347 	.tx_empty = qcom_geni_serial_tx_empty,
1348 	.stop_tx = qcom_geni_serial_stop_tx,
1349 	.start_tx = qcom_geni_serial_start_tx,
1350 	.stop_rx = qcom_geni_serial_stop_rx,
1351 	.set_termios = qcom_geni_serial_set_termios,
1352 	.startup = qcom_geni_serial_startup,
1353 	.request_port = qcom_geni_serial_request_port,
1354 	.config_port = qcom_geni_serial_config_port,
1355 	.shutdown = qcom_geni_serial_shutdown,
1356 	.type = qcom_geni_serial_get_type,
1357 	.set_mctrl = qcom_geni_serial_set_mctrl,
1358 	.get_mctrl = qcom_geni_serial_get_mctrl,
1359 	.pm = qcom_geni_serial_pm,
1360 };
1361 
1362 static int qcom_geni_serial_probe(struct platform_device *pdev)
1363 {
1364 	int ret = 0;
1365 	int line;
1366 	struct qcom_geni_serial_port *port;
1367 	struct uart_port *uport;
1368 	struct resource *res;
1369 	int irq;
1370 	bool console = false;
1371 	struct uart_driver *drv;
1372 
1373 	if (of_device_is_compatible(pdev->dev.of_node, "qcom,geni-debug-uart"))
1374 		console = true;
1375 
1376 	if (console) {
1377 		drv = &qcom_geni_console_driver;
1378 		line = of_alias_get_id(pdev->dev.of_node, "serial");
1379 	} else {
1380 		drv = &qcom_geni_uart_driver;
1381 		line = of_alias_get_id(pdev->dev.of_node, "serial");
1382 		if (line == -ENODEV) /* compat with non-standard aliases */
1383 			line = of_alias_get_id(pdev->dev.of_node, "hsuart");
1384 	}
1385 
1386 	port = get_port_from_line(line, console);
1387 	if (IS_ERR(port)) {
1388 		dev_err(&pdev->dev, "Invalid line %d\n", line);
1389 		return PTR_ERR(port);
1390 	}
1391 
1392 	uport = &port->uport;
1393 	/* Don't allow 2 drivers to access the same port */
1394 	if (uport->private_data)
1395 		return -ENODEV;
1396 
1397 	uport->dev = &pdev->dev;
1398 	port->se.dev = &pdev->dev;
1399 	port->se.wrapper = dev_get_drvdata(pdev->dev.parent);
1400 	port->se.clk = devm_clk_get(&pdev->dev, "se");
1401 	if (IS_ERR(port->se.clk)) {
1402 		ret = PTR_ERR(port->se.clk);
1403 		dev_err(&pdev->dev, "Err getting SE Core clk %d\n", ret);
1404 		return ret;
1405 	}
1406 
1407 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1408 	if (!res)
1409 		return -EINVAL;
1410 	uport->mapbase = res->start;
1411 
1412 	port->tx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
1413 	port->rx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
1414 	port->tx_fifo_width = DEF_FIFO_WIDTH_BITS;
1415 
1416 	if (!console) {
1417 		port->rx_fifo = devm_kcalloc(uport->dev,
1418 			port->rx_fifo_depth, sizeof(u32), GFP_KERNEL);
1419 		if (!port->rx_fifo)
1420 			return -ENOMEM;
1421 	}
1422 
1423 	ret = geni_icc_get(&port->se, NULL);
1424 	if (ret)
1425 		return ret;
1426 	port->se.icc_paths[GENI_TO_CORE].avg_bw = GENI_DEFAULT_BW;
1427 	port->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
1428 
1429 	/* Set BW for register access */
1430 	ret = geni_icc_set_bw(&port->se);
1431 	if (ret)
1432 		return ret;
1433 
1434 	port->name = devm_kasprintf(uport->dev, GFP_KERNEL,
1435 			"qcom_geni_serial_%s%d",
1436 			uart_console(uport) ? "console" : "uart", uport->line);
1437 	if (!port->name)
1438 		return -ENOMEM;
1439 
1440 	irq = platform_get_irq(pdev, 0);
1441 	if (irq < 0)
1442 		return irq;
1443 	uport->irq = irq;
1444 	uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_QCOM_GENI_CONSOLE);
1445 
1446 	if (!console)
1447 		port->wakeup_irq = platform_get_irq_optional(pdev, 1);
1448 
1449 	if (of_property_read_bool(pdev->dev.of_node, "rx-tx-swap"))
1450 		port->rx_tx_swap = true;
1451 
1452 	if (of_property_read_bool(pdev->dev.of_node, "cts-rts-swap"))
1453 		port->cts_rts_swap = true;
1454 
1455 	ret = devm_pm_opp_set_clkname(&pdev->dev, "se");
1456 	if (ret)
1457 		return ret;
1458 	/* OPP table is optional */
1459 	ret = devm_pm_opp_of_add_table(&pdev->dev);
1460 	if (ret && ret != -ENODEV) {
1461 		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
1462 		return ret;
1463 	}
1464 
1465 	port->private_data.drv = drv;
1466 	uport->private_data = &port->private_data;
1467 	platform_set_drvdata(pdev, port);
1468 	port->handle_rx = console ? handle_rx_console : handle_rx_uart;
1469 
1470 	ret = uart_add_one_port(drv, uport);
1471 	if (ret)
1472 		return ret;
1473 
1474 	irq_set_status_flags(uport->irq, IRQ_NOAUTOEN);
1475 	ret = devm_request_irq(uport->dev, uport->irq, qcom_geni_serial_isr,
1476 			IRQF_TRIGGER_HIGH, port->name, uport);
1477 	if (ret) {
1478 		dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);
1479 		uart_remove_one_port(drv, uport);
1480 		return ret;
1481 	}
1482 
1483 	/*
1484 	 * Set pm_runtime status as ACTIVE so that wakeup_irq gets
1485 	 * enabled/disabled from dev_pm_arm_wake_irq during system
1486 	 * suspend/resume respectively.
1487 	 */
1488 	pm_runtime_set_active(&pdev->dev);
1489 
1490 	if (port->wakeup_irq > 0) {
1491 		device_init_wakeup(&pdev->dev, true);
1492 		ret = dev_pm_set_dedicated_wake_irq(&pdev->dev,
1493 						port->wakeup_irq);
1494 		if (ret) {
1495 			device_init_wakeup(&pdev->dev, false);
1496 			uart_remove_one_port(drv, uport);
1497 			return ret;
1498 		}
1499 	}
1500 
1501 	return 0;
1502 }
1503 
1504 static int qcom_geni_serial_remove(struct platform_device *pdev)
1505 {
1506 	struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
1507 	struct uart_driver *drv = port->private_data.drv;
1508 
1509 	dev_pm_clear_wake_irq(&pdev->dev);
1510 	device_init_wakeup(&pdev->dev, false);
1511 	uart_remove_one_port(drv, &port->uport);
1512 
1513 	return 0;
1514 }
1515 
1516 static int __maybe_unused qcom_geni_serial_sys_suspend(struct device *dev)
1517 {
1518 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
1519 	struct uart_port *uport = &port->uport;
1520 	struct qcom_geni_private_data *private_data = uport->private_data;
1521 
1522 	/*
1523 	 * This is done so we can hit the lowest possible state in suspend
1524 	 * even with no_console_suspend
1525 	 */
1526 	if (uart_console(uport)) {
1527 		geni_icc_set_tag(&port->se, 0x3);
1528 		geni_icc_set_bw(&port->se);
1529 	}
1530 	return uart_suspend_port(private_data->drv, uport);
1531 }
1532 
1533 static int __maybe_unused qcom_geni_serial_sys_resume(struct device *dev)
1534 {
1535 	int ret;
1536 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
1537 	struct uart_port *uport = &port->uport;
1538 	struct qcom_geni_private_data *private_data = uport->private_data;
1539 
1540 	ret = uart_resume_port(private_data->drv, uport);
1541 	if (uart_console(uport)) {
1542 		geni_icc_set_tag(&port->se, 0x7);
1543 		geni_icc_set_bw(&port->se);
1544 	}
1545 	return ret;
1546 }
1547 
1548 static const struct dev_pm_ops qcom_geni_serial_pm_ops = {
1549 	SET_SYSTEM_SLEEP_PM_OPS(qcom_geni_serial_sys_suspend,
1550 					qcom_geni_serial_sys_resume)
1551 };
1552 
1553 static const struct of_device_id qcom_geni_serial_match_table[] = {
1554 	{ .compatible = "qcom,geni-debug-uart", },
1555 	{ .compatible = "qcom,geni-uart", },
1556 	{}
1557 };
1558 MODULE_DEVICE_TABLE(of, qcom_geni_serial_match_table);
1559 
1560 static struct platform_driver qcom_geni_serial_platform_driver = {
1561 	.remove = qcom_geni_serial_remove,
1562 	.probe = qcom_geni_serial_probe,
1563 	.driver = {
1564 		.name = "qcom_geni_serial",
1565 		.of_match_table = qcom_geni_serial_match_table,
1566 		.pm = &qcom_geni_serial_pm_ops,
1567 	},
1568 };
1569 
1570 static int __init qcom_geni_serial_init(void)
1571 {
1572 	int ret;
1573 
1574 	ret = console_register(&qcom_geni_console_driver);
1575 	if (ret)
1576 		return ret;
1577 
1578 	ret = uart_register_driver(&qcom_geni_uart_driver);
1579 	if (ret) {
1580 		console_unregister(&qcom_geni_console_driver);
1581 		return ret;
1582 	}
1583 
1584 	ret = platform_driver_register(&qcom_geni_serial_platform_driver);
1585 	if (ret) {
1586 		console_unregister(&qcom_geni_console_driver);
1587 		uart_unregister_driver(&qcom_geni_uart_driver);
1588 	}
1589 	return ret;
1590 }
1591 module_init(qcom_geni_serial_init);
1592 
1593 static void __exit qcom_geni_serial_exit(void)
1594 {
1595 	platform_driver_unregister(&qcom_geni_serial_platform_driver);
1596 	console_unregister(&qcom_geni_console_driver);
1597 	uart_unregister_driver(&qcom_geni_uart_driver);
1598 }
1599 module_exit(qcom_geni_serial_exit);
1600 
1601 MODULE_DESCRIPTION("Serial driver for GENI based QUP cores");
1602 MODULE_LICENSE("GPL v2");
1603