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 #include <dt-bindings/interconnect/qcom,icc.h>
26 
27 /* UART specific GENI registers */
28 #define SE_UART_LOOPBACK_CFG		0x22c
29 #define SE_UART_IO_MACRO_CTRL		0x240
30 #define SE_UART_TX_TRANS_CFG		0x25c
31 #define SE_UART_TX_WORD_LEN		0x268
32 #define SE_UART_TX_STOP_BIT_LEN		0x26c
33 #define SE_UART_TX_TRANS_LEN		0x270
34 #define SE_UART_RX_TRANS_CFG		0x280
35 #define SE_UART_RX_WORD_LEN		0x28c
36 #define SE_UART_RX_STALE_CNT		0x294
37 #define SE_UART_TX_PARITY_CFG		0x2a4
38 #define SE_UART_RX_PARITY_CFG		0x2a8
39 #define SE_UART_MANUAL_RFR		0x2ac
40 
41 /* SE_UART_TRANS_CFG */
42 #define UART_TX_PAR_EN		BIT(0)
43 #define UART_CTS_MASK		BIT(1)
44 
45 /* SE_UART_TX_WORD_LEN */
46 #define TX_WORD_LEN_MSK		GENMASK(9, 0)
47 
48 /* SE_UART_TX_STOP_BIT_LEN */
49 #define TX_STOP_BIT_LEN_MSK	GENMASK(23, 0)
50 #define TX_STOP_BIT_LEN_1	0
51 #define TX_STOP_BIT_LEN_1_5	1
52 #define TX_STOP_BIT_LEN_2	2
53 
54 /* SE_UART_TX_TRANS_LEN */
55 #define TX_TRANS_LEN_MSK	GENMASK(23, 0)
56 
57 /* SE_UART_RX_TRANS_CFG */
58 #define UART_RX_INS_STATUS_BIT	BIT(2)
59 #define UART_RX_PAR_EN		BIT(3)
60 
61 /* SE_UART_RX_WORD_LEN */
62 #define RX_WORD_LEN_MASK	GENMASK(9, 0)
63 
64 /* SE_UART_RX_STALE_CNT */
65 #define RX_STALE_CNT		GENMASK(23, 0)
66 
67 /* SE_UART_TX_PARITY_CFG/RX_PARITY_CFG */
68 #define PAR_CALC_EN		BIT(0)
69 #define PAR_MODE_MSK		GENMASK(2, 1)
70 #define PAR_MODE_SHFT		1
71 #define PAR_EVEN		0x00
72 #define PAR_ODD			0x01
73 #define PAR_SPACE		0x10
74 #define PAR_MARK		0x11
75 
76 /* SE_UART_MANUAL_RFR register fields */
77 #define UART_MANUAL_RFR_EN	BIT(31)
78 #define UART_RFR_NOT_READY	BIT(1)
79 #define UART_RFR_READY		BIT(0)
80 
81 /* UART M_CMD OP codes */
82 #define UART_START_TX		0x1
83 #define UART_START_BREAK	0x4
84 #define UART_STOP_BREAK		0x5
85 /* UART S_CMD OP codes */
86 #define UART_START_READ		0x1
87 #define UART_PARAM		0x1
88 
89 #define UART_OVERSAMPLING	32
90 #define STALE_TIMEOUT		16
91 #define DEFAULT_BITS_PER_CHAR	10
92 #define GENI_UART_CONS_PORTS	1
93 #define GENI_UART_PORTS		3
94 #define DEF_FIFO_DEPTH_WORDS	16
95 #define DEF_TX_WM		2
96 #define DEF_FIFO_WIDTH_BITS	32
97 #define UART_RX_WM		2
98 
99 /* SE_UART_LOOPBACK_CFG */
100 #define RX_TX_SORTED	BIT(0)
101 #define CTS_RTS_SORTED	BIT(1)
102 #define RX_TX_CTS_RTS_SORTED	(RX_TX_SORTED | CTS_RTS_SORTED)
103 
104 /* UART pin swap value */
105 #define DEFAULT_IO_MACRO_IO0_IO1_MASK		GENMASK(3, 0)
106 #define IO_MACRO_IO0_SEL		0x3
107 #define DEFAULT_IO_MACRO_IO2_IO3_MASK		GENMASK(15, 4)
108 #define IO_MACRO_IO2_IO3_SWAP		0x4640
109 
110 /* We always configure 4 bytes per FIFO word */
111 #define BYTES_PER_FIFO_WORD		4
112 
113 struct qcom_geni_private_data {
114 	/* NOTE: earlycon port will have NULL here */
115 	struct uart_driver *drv;
116 
117 	u32 poll_cached_bytes;
118 	unsigned int poll_cached_bytes_cnt;
119 
120 	u32 write_cached_bytes;
121 	unsigned int write_cached_bytes_cnt;
122 };
123 
124 struct qcom_geni_serial_port {
125 	struct uart_port uport;
126 	struct geni_se se;
127 	const char *name;
128 	u32 tx_fifo_depth;
129 	u32 tx_fifo_width;
130 	u32 rx_fifo_depth;
131 	bool setup;
132 	int (*handle_rx)(struct uart_port *uport, u32 bytes, bool drop);
133 	unsigned int baud;
134 	void *rx_fifo;
135 	u32 loopback;
136 	bool brk;
137 
138 	unsigned int tx_remaining;
139 	int wakeup_irq;
140 	bool rx_tx_swap;
141 	bool cts_rts_swap;
142 
143 	struct qcom_geni_private_data private_data;
144 };
145 
146 static const struct uart_ops qcom_geni_console_pops;
147 static const struct uart_ops qcom_geni_uart_pops;
148 static struct uart_driver qcom_geni_console_driver;
149 static struct uart_driver qcom_geni_uart_driver;
150 static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop);
151 static int handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop);
152 static unsigned int qcom_geni_serial_tx_empty(struct uart_port *port);
153 static void qcom_geni_serial_stop_rx(struct uart_port *uport);
154 static void qcom_geni_serial_handle_rx(struct uart_port *uport, bool drop);
155 
156 #define to_dev_port(ptr, member) \
157 		container_of(ptr, struct qcom_geni_serial_port, member)
158 
159 static struct qcom_geni_serial_port qcom_geni_uart_ports[GENI_UART_PORTS] = {
160 	[0] = {
161 		.uport = {
162 				.iotype = UPIO_MEM,
163 				.ops = &qcom_geni_uart_pops,
164 				.flags = UPF_BOOT_AUTOCONF,
165 				.line = 0,
166 		},
167 	},
168 	[1] = {
169 		.uport = {
170 				.iotype = UPIO_MEM,
171 				.ops = &qcom_geni_uart_pops,
172 				.flags = UPF_BOOT_AUTOCONF,
173 				.line = 1,
174 		},
175 	},
176 	[2] = {
177 		.uport = {
178 				.iotype = UPIO_MEM,
179 				.ops = &qcom_geni_uart_pops,
180 				.flags = UPF_BOOT_AUTOCONF,
181 				.line = 2,
182 		},
183 	},
184 };
185 
186 static struct qcom_geni_serial_port qcom_geni_console_port = {
187 	.uport = {
188 		.iotype = UPIO_MEM,
189 		.ops = &qcom_geni_console_pops,
190 		.flags = UPF_BOOT_AUTOCONF,
191 		.line = 0,
192 	},
193 };
194 
195 static int qcom_geni_serial_request_port(struct uart_port *uport)
196 {
197 	struct platform_device *pdev = to_platform_device(uport->dev);
198 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
199 
200 	uport->membase = devm_platform_ioremap_resource(pdev, 0);
201 	if (IS_ERR(uport->membase))
202 		return PTR_ERR(uport->membase);
203 	port->se.base = uport->membase;
204 	return 0;
205 }
206 
207 static void qcom_geni_serial_config_port(struct uart_port *uport, int cfg_flags)
208 {
209 	if (cfg_flags & UART_CONFIG_TYPE) {
210 		uport->type = PORT_MSM;
211 		qcom_geni_serial_request_port(uport);
212 	}
213 }
214 
215 static unsigned int qcom_geni_serial_get_mctrl(struct uart_port *uport)
216 {
217 	unsigned int mctrl = TIOCM_DSR | TIOCM_CAR;
218 	u32 geni_ios;
219 
220 	if (uart_console(uport)) {
221 		mctrl |= TIOCM_CTS;
222 	} else {
223 		geni_ios = readl(uport->membase + SE_GENI_IOS);
224 		if (!(geni_ios & IO2_DATA_IN))
225 			mctrl |= TIOCM_CTS;
226 	}
227 
228 	return mctrl;
229 }
230 
231 static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
232 							unsigned int mctrl)
233 {
234 	u32 uart_manual_rfr = 0;
235 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
236 
237 	if (uart_console(uport))
238 		return;
239 
240 	if (mctrl & TIOCM_LOOP)
241 		port->loopback = RX_TX_CTS_RTS_SORTED;
242 
243 	if (!(mctrl & TIOCM_RTS) && !uport->suspended)
244 		uart_manual_rfr = UART_MANUAL_RFR_EN | UART_RFR_NOT_READY;
245 	writel(uart_manual_rfr, uport->membase + SE_UART_MANUAL_RFR);
246 }
247 
248 static const char *qcom_geni_serial_get_type(struct uart_port *uport)
249 {
250 	return "MSM";
251 }
252 
253 static struct qcom_geni_serial_port *get_port_from_line(int line, bool console)
254 {
255 	struct qcom_geni_serial_port *port;
256 	int nr_ports = console ? GENI_UART_CONS_PORTS : GENI_UART_PORTS;
257 
258 	if (line < 0 || line >= nr_ports)
259 		return ERR_PTR(-ENXIO);
260 
261 	port = console ? &qcom_geni_console_port : &qcom_geni_uart_ports[line];
262 	return port;
263 }
264 
265 static bool qcom_geni_serial_poll_bit(struct uart_port *uport,
266 				int offset, int field, bool set)
267 {
268 	u32 reg;
269 	struct qcom_geni_serial_port *port;
270 	unsigned int baud;
271 	unsigned int fifo_bits;
272 	unsigned long timeout_us = 20000;
273 	struct qcom_geni_private_data *private_data = uport->private_data;
274 
275 	if (private_data->drv) {
276 		port = to_dev_port(uport, uport);
277 		baud = port->baud;
278 		if (!baud)
279 			baud = 115200;
280 		fifo_bits = port->tx_fifo_depth * port->tx_fifo_width;
281 		/*
282 		 * Total polling iterations based on FIFO worth of bytes to be
283 		 * sent at current baud. Add a little fluff to the wait.
284 		 */
285 		timeout_us = ((fifo_bits * USEC_PER_SEC) / baud) + 500;
286 	}
287 
288 	/*
289 	 * Use custom implementation instead of readl_poll_atomic since ktimer
290 	 * is not ready at the time of early console.
291 	 */
292 	timeout_us = DIV_ROUND_UP(timeout_us, 10) * 10;
293 	while (timeout_us) {
294 		reg = readl(uport->membase + offset);
295 		if ((bool)(reg & field) == set)
296 			return true;
297 		udelay(10);
298 		timeout_us -= 10;
299 	}
300 	return false;
301 }
302 
303 static void qcom_geni_serial_setup_tx(struct uart_port *uport, u32 xmit_size)
304 {
305 	u32 m_cmd;
306 
307 	writel(xmit_size, uport->membase + SE_UART_TX_TRANS_LEN);
308 	m_cmd = UART_START_TX << M_OPCODE_SHFT;
309 	writel(m_cmd, uport->membase + SE_GENI_M_CMD0);
310 }
311 
312 static void qcom_geni_serial_poll_tx_done(struct uart_port *uport)
313 {
314 	int done;
315 	u32 irq_clear = M_CMD_DONE_EN;
316 
317 	done = qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
318 						M_CMD_DONE_EN, true);
319 	if (!done) {
320 		writel(M_GENI_CMD_ABORT, uport->membase +
321 						SE_GENI_M_CMD_CTRL_REG);
322 		irq_clear |= M_CMD_ABORT_EN;
323 		qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
324 							M_CMD_ABORT_EN, true);
325 	}
326 	writel(irq_clear, uport->membase + SE_GENI_M_IRQ_CLEAR);
327 }
328 
329 static void qcom_geni_serial_abort_rx(struct uart_port *uport)
330 {
331 	u32 irq_clear = S_CMD_DONE_EN | S_CMD_ABORT_EN;
332 
333 	writel(S_GENI_CMD_ABORT, uport->membase + SE_GENI_S_CMD_CTRL_REG);
334 	qcom_geni_serial_poll_bit(uport, SE_GENI_S_CMD_CTRL_REG,
335 					S_GENI_CMD_ABORT, false);
336 	writel(irq_clear, uport->membase + SE_GENI_S_IRQ_CLEAR);
337 	writel(FORCE_DEFAULT, uport->membase + GENI_FORCE_DEFAULT_REG);
338 }
339 
340 #ifdef CONFIG_CONSOLE_POLL
341 
342 static int qcom_geni_serial_get_char(struct uart_port *uport)
343 {
344 	struct qcom_geni_private_data *private_data = uport->private_data;
345 	u32 status;
346 	u32 word_cnt;
347 	int ret;
348 
349 	if (!private_data->poll_cached_bytes_cnt) {
350 		status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
351 		writel(status, uport->membase + SE_GENI_M_IRQ_CLEAR);
352 
353 		status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
354 		writel(status, uport->membase + SE_GENI_S_IRQ_CLEAR);
355 
356 		status = readl(uport->membase + SE_GENI_RX_FIFO_STATUS);
357 		word_cnt = status & RX_FIFO_WC_MSK;
358 		if (!word_cnt)
359 			return NO_POLL_CHAR;
360 
361 		if (word_cnt == 1 && (status & RX_LAST))
362 			/*
363 			 * NOTE: If RX_LAST_BYTE_VALID is 0 it needs to be
364 			 * treated as if it was BYTES_PER_FIFO_WORD.
365 			 */
366 			private_data->poll_cached_bytes_cnt =
367 				(status & RX_LAST_BYTE_VALID_MSK) >>
368 				RX_LAST_BYTE_VALID_SHFT;
369 
370 		if (private_data->poll_cached_bytes_cnt == 0)
371 			private_data->poll_cached_bytes_cnt = BYTES_PER_FIFO_WORD;
372 
373 		private_data->poll_cached_bytes =
374 			readl(uport->membase + SE_GENI_RX_FIFOn);
375 	}
376 
377 	private_data->poll_cached_bytes_cnt--;
378 	ret = private_data->poll_cached_bytes & 0xff;
379 	private_data->poll_cached_bytes >>= 8;
380 
381 	return ret;
382 }
383 
384 static void qcom_geni_serial_poll_put_char(struct uart_port *uport,
385 							unsigned char c)
386 {
387 	writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
388 	qcom_geni_serial_setup_tx(uport, 1);
389 	WARN_ON(!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
390 						M_TX_FIFO_WATERMARK_EN, true));
391 	writel(c, uport->membase + SE_GENI_TX_FIFOn);
392 	writel(M_TX_FIFO_WATERMARK_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
393 	qcom_geni_serial_poll_tx_done(uport);
394 }
395 #endif
396 
397 #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
398 static void qcom_geni_serial_wr_char(struct uart_port *uport, unsigned char ch)
399 {
400 	struct qcom_geni_private_data *private_data = uport->private_data;
401 
402 	private_data->write_cached_bytes =
403 		(private_data->write_cached_bytes >> 8) | (ch << 24);
404 	private_data->write_cached_bytes_cnt++;
405 
406 	if (private_data->write_cached_bytes_cnt == BYTES_PER_FIFO_WORD) {
407 		writel(private_data->write_cached_bytes,
408 		       uport->membase + SE_GENI_TX_FIFOn);
409 		private_data->write_cached_bytes_cnt = 0;
410 	}
411 }
412 
413 static void
414 __qcom_geni_serial_console_write(struct uart_port *uport, const char *s,
415 				 unsigned int count)
416 {
417 	struct qcom_geni_private_data *private_data = uport->private_data;
418 
419 	int i;
420 	u32 bytes_to_send = count;
421 
422 	for (i = 0; i < count; i++) {
423 		/*
424 		 * uart_console_write() adds a carriage return for each newline.
425 		 * Account for additional bytes to be written.
426 		 */
427 		if (s[i] == '\n')
428 			bytes_to_send++;
429 	}
430 
431 	writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
432 	qcom_geni_serial_setup_tx(uport, bytes_to_send);
433 	for (i = 0; i < count; ) {
434 		size_t chars_to_write = 0;
435 		size_t avail = DEF_FIFO_DEPTH_WORDS - DEF_TX_WM;
436 
437 		/*
438 		 * If the WM bit never set, then the Tx state machine is not
439 		 * in a valid state, so break, cancel/abort any existing
440 		 * command. Unfortunately the current data being written is
441 		 * lost.
442 		 */
443 		if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
444 						M_TX_FIFO_WATERMARK_EN, true))
445 			break;
446 		chars_to_write = min_t(size_t, count - i, avail / 2);
447 		uart_console_write(uport, s + i, chars_to_write,
448 						qcom_geni_serial_wr_char);
449 		writel(M_TX_FIFO_WATERMARK_EN, uport->membase +
450 							SE_GENI_M_IRQ_CLEAR);
451 		i += chars_to_write;
452 	}
453 
454 	if (private_data->write_cached_bytes_cnt) {
455 		private_data->write_cached_bytes >>= BITS_PER_BYTE *
456 			(BYTES_PER_FIFO_WORD - private_data->write_cached_bytes_cnt);
457 		writel(private_data->write_cached_bytes,
458 		       uport->membase + SE_GENI_TX_FIFOn);
459 		private_data->write_cached_bytes_cnt = 0;
460 	}
461 
462 	qcom_geni_serial_poll_tx_done(uport);
463 }
464 
465 static void qcom_geni_serial_console_write(struct console *co, const char *s,
466 			      unsigned int count)
467 {
468 	struct uart_port *uport;
469 	struct qcom_geni_serial_port *port;
470 	bool locked = true;
471 	unsigned long flags;
472 	u32 geni_status;
473 	u32 irq_en;
474 
475 	WARN_ON(co->index < 0 || co->index >= GENI_UART_CONS_PORTS);
476 
477 	port = get_port_from_line(co->index, true);
478 	if (IS_ERR(port))
479 		return;
480 
481 	uport = &port->uport;
482 	if (oops_in_progress)
483 		locked = spin_trylock_irqsave(&uport->lock, flags);
484 	else
485 		spin_lock_irqsave(&uport->lock, flags);
486 
487 	geni_status = readl(uport->membase + SE_GENI_STATUS);
488 
489 	/* Cancel the current write to log the fault */
490 	if (!locked) {
491 		geni_se_cancel_m_cmd(&port->se);
492 		if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
493 						M_CMD_CANCEL_EN, true)) {
494 			geni_se_abort_m_cmd(&port->se);
495 			qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
496 							M_CMD_ABORT_EN, true);
497 			writel(M_CMD_ABORT_EN, uport->membase +
498 							SE_GENI_M_IRQ_CLEAR);
499 		}
500 		writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
501 	} else if ((geni_status & M_GENI_CMD_ACTIVE) && !port->tx_remaining) {
502 		/*
503 		 * It seems we can't interrupt existing transfers if all data
504 		 * has been sent, in which case we need to look for done first.
505 		 */
506 		qcom_geni_serial_poll_tx_done(uport);
507 
508 		if (!uart_circ_empty(&uport->state->xmit)) {
509 			irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
510 			writel(irq_en | M_TX_FIFO_WATERMARK_EN,
511 					uport->membase + SE_GENI_M_IRQ_EN);
512 		}
513 	}
514 
515 	__qcom_geni_serial_console_write(uport, s, count);
516 
517 	if (port->tx_remaining)
518 		qcom_geni_serial_setup_tx(uport, port->tx_remaining);
519 
520 	if (locked)
521 		spin_unlock_irqrestore(&uport->lock, flags);
522 }
523 
524 static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
525 {
526 	u32 i;
527 	unsigned char buf[sizeof(u32)];
528 	struct tty_port *tport;
529 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
530 
531 	tport = &uport->state->port;
532 	for (i = 0; i < bytes; ) {
533 		int c;
534 		int chunk = min_t(int, bytes - i, BYTES_PER_FIFO_WORD);
535 
536 		ioread32_rep(uport->membase + SE_GENI_RX_FIFOn, buf, 1);
537 		i += chunk;
538 		if (drop)
539 			continue;
540 
541 		for (c = 0; c < chunk; c++) {
542 			int sysrq;
543 
544 			uport->icount.rx++;
545 			if (port->brk && buf[c] == 0) {
546 				port->brk = false;
547 				if (uart_handle_break(uport))
548 					continue;
549 			}
550 
551 			sysrq = uart_prepare_sysrq_char(uport, buf[c]);
552 
553 			if (!sysrq)
554 				tty_insert_flip_char(tport, buf[c], TTY_NORMAL);
555 		}
556 	}
557 	if (!drop)
558 		tty_flip_buffer_push(tport);
559 	return 0;
560 }
561 #else
562 static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
563 {
564 	return -EPERM;
565 }
566 
567 #endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
568 
569 static int handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop)
570 {
571 	struct tty_port *tport;
572 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
573 	u32 num_bytes_pw = port->tx_fifo_width / BITS_PER_BYTE;
574 	u32 words = ALIGN(bytes, num_bytes_pw) / num_bytes_pw;
575 	int ret;
576 
577 	tport = &uport->state->port;
578 	ioread32_rep(uport->membase + SE_GENI_RX_FIFOn, port->rx_fifo, words);
579 	if (drop)
580 		return 0;
581 
582 	ret = tty_insert_flip_string(tport, port->rx_fifo, bytes);
583 	if (ret != bytes) {
584 		dev_err(uport->dev, "%s:Unable to push data ret %d_bytes %d\n",
585 				__func__, ret, bytes);
586 		WARN_ON_ONCE(1);
587 	}
588 	uport->icount.rx += ret;
589 	tty_flip_buffer_push(tport);
590 	return ret;
591 }
592 
593 static void qcom_geni_serial_start_tx(struct uart_port *uport)
594 {
595 	u32 irq_en;
596 	u32 status;
597 
598 	status = readl(uport->membase + SE_GENI_STATUS);
599 	if (status & M_GENI_CMD_ACTIVE)
600 		return;
601 
602 	if (!qcom_geni_serial_tx_empty(uport))
603 		return;
604 
605 	irq_en = readl(uport->membase +	SE_GENI_M_IRQ_EN);
606 	irq_en |= M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN;
607 
608 	writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
609 	writel(irq_en, uport->membase +	SE_GENI_M_IRQ_EN);
610 }
611 
612 static void qcom_geni_serial_stop_tx(struct uart_port *uport)
613 {
614 	u32 irq_en;
615 	u32 status;
616 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
617 
618 	irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
619 	irq_en &= ~(M_CMD_DONE_EN | M_TX_FIFO_WATERMARK_EN);
620 	writel(0, uport->membase + SE_GENI_TX_WATERMARK_REG);
621 	writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
622 	status = readl(uport->membase + SE_GENI_STATUS);
623 	/* Possible stop tx is called multiple times. */
624 	if (!(status & M_GENI_CMD_ACTIVE))
625 		return;
626 
627 	geni_se_cancel_m_cmd(&port->se);
628 	if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
629 						M_CMD_CANCEL_EN, true)) {
630 		geni_se_abort_m_cmd(&port->se);
631 		qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
632 						M_CMD_ABORT_EN, true);
633 		writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
634 	}
635 	writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
636 }
637 
638 static void qcom_geni_serial_start_rx(struct uart_port *uport)
639 {
640 	u32 irq_en;
641 	u32 status;
642 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
643 
644 	status = readl(uport->membase + SE_GENI_STATUS);
645 	if (status & S_GENI_CMD_ACTIVE)
646 		qcom_geni_serial_stop_rx(uport);
647 
648 	geni_se_setup_s_cmd(&port->se, UART_START_READ, 0);
649 
650 	irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN);
651 	irq_en |= S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN;
652 	writel(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
653 
654 	irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
655 	irq_en |= M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN;
656 	writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
657 }
658 
659 static void qcom_geni_serial_stop_rx(struct uart_port *uport)
660 {
661 	u32 irq_en;
662 	u32 status;
663 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
664 	u32 s_irq_status;
665 
666 	irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN);
667 	irq_en &= ~(S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
668 	writel(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
669 
670 	irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
671 	irq_en &= ~(M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
672 	writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
673 
674 	status = readl(uport->membase + SE_GENI_STATUS);
675 	/* Possible stop rx is called multiple times. */
676 	if (!(status & S_GENI_CMD_ACTIVE))
677 		return;
678 
679 	geni_se_cancel_s_cmd(&port->se);
680 	qcom_geni_serial_poll_bit(uport, SE_GENI_S_IRQ_STATUS,
681 					S_CMD_CANCEL_EN, true);
682 	/*
683 	 * If timeout occurs secondary engine remains active
684 	 * and Abort sequence is executed.
685 	 */
686 	s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
687 	/* Flush the Rx buffer */
688 	if (s_irq_status & S_RX_FIFO_LAST_EN)
689 		qcom_geni_serial_handle_rx(uport, true);
690 	writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
691 
692 	status = readl(uport->membase + SE_GENI_STATUS);
693 	if (status & S_GENI_CMD_ACTIVE)
694 		qcom_geni_serial_abort_rx(uport);
695 }
696 
697 static void qcom_geni_serial_handle_rx(struct uart_port *uport, bool drop)
698 {
699 	u32 status;
700 	u32 word_cnt;
701 	u32 last_word_byte_cnt;
702 	u32 last_word_partial;
703 	u32 total_bytes;
704 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
705 
706 	status = readl(uport->membase +	SE_GENI_RX_FIFO_STATUS);
707 	word_cnt = status & RX_FIFO_WC_MSK;
708 	last_word_partial = status & RX_LAST;
709 	last_word_byte_cnt = (status & RX_LAST_BYTE_VALID_MSK) >>
710 						RX_LAST_BYTE_VALID_SHFT;
711 
712 	if (!word_cnt)
713 		return;
714 	total_bytes = BYTES_PER_FIFO_WORD * (word_cnt - 1);
715 	if (last_word_partial && last_word_byte_cnt)
716 		total_bytes += last_word_byte_cnt;
717 	else
718 		total_bytes += BYTES_PER_FIFO_WORD;
719 	port->handle_rx(uport, total_bytes, drop);
720 }
721 
722 static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done,
723 		bool active)
724 {
725 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
726 	struct circ_buf *xmit = &uport->state->xmit;
727 	size_t avail;
728 	size_t remaining;
729 	size_t pending;
730 	int i;
731 	u32 status;
732 	u32 irq_en;
733 	unsigned int chunk;
734 	int tail;
735 
736 	status = readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
737 
738 	/* Complete the current tx command before taking newly added data */
739 	if (active)
740 		pending = port->tx_remaining;
741 	else
742 		pending = uart_circ_chars_pending(xmit);
743 
744 	/* All data has been transmitted and acknowledged as received */
745 	if (!pending && !status && done) {
746 		qcom_geni_serial_stop_tx(uport);
747 		goto out_write_wakeup;
748 	}
749 
750 	avail = port->tx_fifo_depth - (status & TX_FIFO_WC);
751 	avail *= BYTES_PER_FIFO_WORD;
752 
753 	tail = xmit->tail;
754 	chunk = min(avail, pending);
755 	if (!chunk)
756 		goto out_write_wakeup;
757 
758 	if (!port->tx_remaining) {
759 		qcom_geni_serial_setup_tx(uport, pending);
760 		port->tx_remaining = pending;
761 
762 		irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
763 		if (!(irq_en & M_TX_FIFO_WATERMARK_EN))
764 			writel(irq_en | M_TX_FIFO_WATERMARK_EN,
765 					uport->membase + SE_GENI_M_IRQ_EN);
766 	}
767 
768 	remaining = chunk;
769 	for (i = 0; i < chunk; ) {
770 		unsigned int tx_bytes;
771 		u8 buf[sizeof(u32)];
772 		int c;
773 
774 		memset(buf, 0, sizeof(buf));
775 		tx_bytes = min_t(size_t, remaining, BYTES_PER_FIFO_WORD);
776 
777 		for (c = 0; c < tx_bytes ; c++) {
778 			buf[c] = xmit->buf[tail++];
779 			tail &= UART_XMIT_SIZE - 1;
780 		}
781 
782 		iowrite32_rep(uport->membase + SE_GENI_TX_FIFOn, buf, 1);
783 
784 		i += tx_bytes;
785 		uport->icount.tx += tx_bytes;
786 		remaining -= tx_bytes;
787 		port->tx_remaining -= tx_bytes;
788 	}
789 
790 	xmit->tail = tail;
791 
792 	/*
793 	 * The tx fifo watermark is level triggered and latched. Though we had
794 	 * cleared it in qcom_geni_serial_isr it will have already reasserted
795 	 * so we must clear it again here after our writes.
796 	 */
797 	writel(M_TX_FIFO_WATERMARK_EN,
798 			uport->membase + SE_GENI_M_IRQ_CLEAR);
799 
800 out_write_wakeup:
801 	if (!port->tx_remaining) {
802 		irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
803 		if (irq_en & M_TX_FIFO_WATERMARK_EN)
804 			writel(irq_en & ~M_TX_FIFO_WATERMARK_EN,
805 					uport->membase + SE_GENI_M_IRQ_EN);
806 	}
807 
808 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
809 		uart_write_wakeup(uport);
810 }
811 
812 static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
813 {
814 	u32 m_irq_en;
815 	u32 m_irq_status;
816 	u32 s_irq_status;
817 	u32 geni_status;
818 	struct uart_port *uport = dev;
819 	bool drop_rx = false;
820 	struct tty_port *tport = &uport->state->port;
821 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
822 
823 	if (uport->suspended)
824 		return IRQ_NONE;
825 
826 	spin_lock(&uport->lock);
827 
828 	m_irq_status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
829 	s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
830 	geni_status = readl(uport->membase + SE_GENI_STATUS);
831 	m_irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
832 	writel(m_irq_status, uport->membase + SE_GENI_M_IRQ_CLEAR);
833 	writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
834 
835 	if (WARN_ON(m_irq_status & M_ILLEGAL_CMD_EN))
836 		goto out_unlock;
837 
838 	if (s_irq_status & S_RX_FIFO_WR_ERR_EN) {
839 		uport->icount.overrun++;
840 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
841 	}
842 
843 	if (m_irq_status & m_irq_en & (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN))
844 		qcom_geni_serial_handle_tx(uport, m_irq_status & M_CMD_DONE_EN,
845 					geni_status & M_GENI_CMD_ACTIVE);
846 
847 	if (s_irq_status & S_GP_IRQ_0_EN || s_irq_status & S_GP_IRQ_1_EN) {
848 		if (s_irq_status & S_GP_IRQ_0_EN)
849 			uport->icount.parity++;
850 		drop_rx = true;
851 	} else if (s_irq_status & S_GP_IRQ_2_EN ||
852 					s_irq_status & S_GP_IRQ_3_EN) {
853 		uport->icount.brk++;
854 		port->brk = true;
855 	}
856 
857 	if (s_irq_status & S_RX_FIFO_WATERMARK_EN ||
858 					s_irq_status & S_RX_FIFO_LAST_EN)
859 		qcom_geni_serial_handle_rx(uport, drop_rx);
860 
861 out_unlock:
862 	uart_unlock_and_check_sysrq(uport);
863 
864 	return IRQ_HANDLED;
865 }
866 
867 static int setup_fifos(struct qcom_geni_serial_port *port)
868 {
869 	struct uart_port *uport;
870 	u32 old_rx_fifo_depth = port->rx_fifo_depth;
871 
872 	uport = &port->uport;
873 	port->tx_fifo_depth = geni_se_get_tx_fifo_depth(&port->se);
874 	port->tx_fifo_width = geni_se_get_tx_fifo_width(&port->se);
875 	port->rx_fifo_depth = geni_se_get_rx_fifo_depth(&port->se);
876 	uport->fifosize =
877 		(port->tx_fifo_depth * port->tx_fifo_width) / BITS_PER_BYTE;
878 
879 	if (port->rx_fifo && (old_rx_fifo_depth != port->rx_fifo_depth) && port->rx_fifo_depth) {
880 		port->rx_fifo = devm_krealloc(uport->dev, port->rx_fifo,
881 					      port->rx_fifo_depth * sizeof(u32),
882 					      GFP_KERNEL);
883 		if (!port->rx_fifo)
884 			return -ENOMEM;
885 	}
886 
887 	return 0;
888 }
889 
890 
891 static void qcom_geni_serial_shutdown(struct uart_port *uport)
892 {
893 	disable_irq(uport->irq);
894 }
895 
896 static int qcom_geni_serial_port_setup(struct uart_port *uport)
897 {
898 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
899 	u32 rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;
900 	u32 proto;
901 	u32 pin_swap;
902 	int ret;
903 
904 	proto = geni_se_read_proto(&port->se);
905 	if (proto != GENI_SE_UART) {
906 		dev_err(uport->dev, "Invalid FW loaded, proto: %d\n", proto);
907 		return -ENXIO;
908 	}
909 
910 	qcom_geni_serial_stop_rx(uport);
911 
912 	ret = setup_fifos(port);
913 	if (ret)
914 		return ret;
915 
916 	writel(rxstale, uport->membase + SE_UART_RX_STALE_CNT);
917 
918 	pin_swap = readl(uport->membase + SE_UART_IO_MACRO_CTRL);
919 	if (port->rx_tx_swap) {
920 		pin_swap &= ~DEFAULT_IO_MACRO_IO2_IO3_MASK;
921 		pin_swap |= IO_MACRO_IO2_IO3_SWAP;
922 	}
923 	if (port->cts_rts_swap) {
924 		pin_swap &= ~DEFAULT_IO_MACRO_IO0_IO1_MASK;
925 		pin_swap |= IO_MACRO_IO0_SEL;
926 	}
927 	/* Configure this register if RX-TX, CTS-RTS pins are swapped */
928 	if (port->rx_tx_swap || port->cts_rts_swap)
929 		writel(pin_swap, uport->membase + SE_UART_IO_MACRO_CTRL);
930 
931 	/*
932 	 * Make an unconditional cancel on the main sequencer to reset
933 	 * it else we could end up in data loss scenarios.
934 	 */
935 	if (uart_console(uport))
936 		qcom_geni_serial_poll_tx_done(uport);
937 	geni_se_config_packing(&port->se, BITS_PER_BYTE, BYTES_PER_FIFO_WORD,
938 			       false, true, true);
939 	geni_se_init(&port->se, UART_RX_WM, port->rx_fifo_depth - 2);
940 	geni_se_select_mode(&port->se, GENI_SE_FIFO);
941 	qcom_geni_serial_start_rx(uport);
942 	port->setup = true;
943 
944 	return 0;
945 }
946 
947 static int qcom_geni_serial_startup(struct uart_port *uport)
948 {
949 	int ret;
950 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
951 
952 	if (!port->setup) {
953 		ret = qcom_geni_serial_port_setup(uport);
954 		if (ret)
955 			return ret;
956 	}
957 	enable_irq(uport->irq);
958 
959 	return 0;
960 }
961 
962 static unsigned long find_clk_rate_in_tol(struct clk *clk, unsigned int desired_clk,
963 			unsigned int *clk_div, unsigned int percent_tol)
964 {
965 	unsigned long freq;
966 	unsigned long div, maxdiv;
967 	u64 mult;
968 	unsigned long offset, abs_tol, achieved;
969 
970 	abs_tol = div_u64((u64)desired_clk * percent_tol, 100);
971 	maxdiv = CLK_DIV_MSK >> CLK_DIV_SHFT;
972 	div = 1;
973 	while (div <= maxdiv) {
974 		mult = (u64)div * desired_clk;
975 		if (mult != (unsigned long)mult)
976 			break;
977 
978 		offset = div * abs_tol;
979 		freq = clk_round_rate(clk, mult - offset);
980 
981 		/* Can only get lower if we're done */
982 		if (freq < mult - offset)
983 			break;
984 
985 		/*
986 		 * Re-calculate div in case rounding skipped rates but we
987 		 * ended up at a good one, then check for a match.
988 		 */
989 		div = DIV_ROUND_CLOSEST(freq, desired_clk);
990 		achieved = DIV_ROUND_CLOSEST(freq, div);
991 		if (achieved <= desired_clk + abs_tol &&
992 		    achieved >= desired_clk - abs_tol) {
993 			*clk_div = div;
994 			return freq;
995 		}
996 
997 		div = DIV_ROUND_UP(freq, desired_clk);
998 	}
999 
1000 	return 0;
1001 }
1002 
1003 static unsigned long get_clk_div_rate(struct clk *clk, unsigned int baud,
1004 			unsigned int sampling_rate, unsigned int *clk_div)
1005 {
1006 	unsigned long ser_clk;
1007 	unsigned long desired_clk;
1008 
1009 	desired_clk = baud * sampling_rate;
1010 	if (!desired_clk)
1011 		return 0;
1012 
1013 	/*
1014 	 * try to find a clock rate within 2% tolerance, then within 5%
1015 	 */
1016 	ser_clk = find_clk_rate_in_tol(clk, desired_clk, clk_div, 2);
1017 	if (!ser_clk)
1018 		ser_clk = find_clk_rate_in_tol(clk, desired_clk, clk_div, 5);
1019 
1020 	return ser_clk;
1021 }
1022 
1023 static void qcom_geni_serial_set_termios(struct uart_port *uport,
1024 					 struct ktermios *termios,
1025 					 const struct ktermios *old)
1026 {
1027 	unsigned int baud;
1028 	u32 bits_per_char;
1029 	u32 tx_trans_cfg;
1030 	u32 tx_parity_cfg;
1031 	u32 rx_trans_cfg;
1032 	u32 rx_parity_cfg;
1033 	u32 stop_bit_len;
1034 	unsigned int clk_div;
1035 	u32 ser_clk_cfg;
1036 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
1037 	unsigned long clk_rate;
1038 	u32 ver, sampling_rate;
1039 	unsigned int avg_bw_core;
1040 
1041 	qcom_geni_serial_stop_rx(uport);
1042 	/* baud rate */
1043 	baud = uart_get_baud_rate(uport, termios, old, 300, 4000000);
1044 	port->baud = baud;
1045 
1046 	sampling_rate = UART_OVERSAMPLING;
1047 	/* Sampling rate is halved for IP versions >= 2.5 */
1048 	ver = geni_se_get_qup_hw_version(&port->se);
1049 	if (ver >= QUP_SE_VERSION_2_5)
1050 		sampling_rate /= 2;
1051 
1052 	clk_rate = get_clk_div_rate(port->se.clk, baud,
1053 		sampling_rate, &clk_div);
1054 	if (!clk_rate) {
1055 		dev_err(port->se.dev,
1056 			"Couldn't find suitable clock rate for %u\n",
1057 			baud * sampling_rate);
1058 		goto out_restart_rx;
1059 	}
1060 
1061 	dev_dbg(port->se.dev, "desired_rate-%u, clk_rate-%lu, clk_div-%u\n",
1062 			baud * sampling_rate, clk_rate, clk_div);
1063 
1064 	uport->uartclk = clk_rate;
1065 	dev_pm_opp_set_rate(uport->dev, clk_rate);
1066 	ser_clk_cfg = SER_CLK_EN;
1067 	ser_clk_cfg |= clk_div << CLK_DIV_SHFT;
1068 
1069 	/*
1070 	 * Bump up BW vote on CPU and CORE path as driver supports FIFO mode
1071 	 * only.
1072 	 */
1073 	avg_bw_core = (baud > 115200) ? Bps_to_icc(CORE_2X_50_MHZ)
1074 						: GENI_DEFAULT_BW;
1075 	port->se.icc_paths[GENI_TO_CORE].avg_bw = avg_bw_core;
1076 	port->se.icc_paths[CPU_TO_GENI].avg_bw = Bps_to_icc(baud);
1077 	geni_icc_set_bw(&port->se);
1078 
1079 	/* parity */
1080 	tx_trans_cfg = readl(uport->membase + SE_UART_TX_TRANS_CFG);
1081 	tx_parity_cfg = readl(uport->membase + SE_UART_TX_PARITY_CFG);
1082 	rx_trans_cfg = readl(uport->membase + SE_UART_RX_TRANS_CFG);
1083 	rx_parity_cfg = readl(uport->membase + SE_UART_RX_PARITY_CFG);
1084 	if (termios->c_cflag & PARENB) {
1085 		tx_trans_cfg |= UART_TX_PAR_EN;
1086 		rx_trans_cfg |= UART_RX_PAR_EN;
1087 		tx_parity_cfg |= PAR_CALC_EN;
1088 		rx_parity_cfg |= PAR_CALC_EN;
1089 		if (termios->c_cflag & PARODD) {
1090 			tx_parity_cfg |= PAR_ODD;
1091 			rx_parity_cfg |= PAR_ODD;
1092 		} else if (termios->c_cflag & CMSPAR) {
1093 			tx_parity_cfg |= PAR_SPACE;
1094 			rx_parity_cfg |= PAR_SPACE;
1095 		} else {
1096 			tx_parity_cfg |= PAR_EVEN;
1097 			rx_parity_cfg |= PAR_EVEN;
1098 		}
1099 	} else {
1100 		tx_trans_cfg &= ~UART_TX_PAR_EN;
1101 		rx_trans_cfg &= ~UART_RX_PAR_EN;
1102 		tx_parity_cfg &= ~PAR_CALC_EN;
1103 		rx_parity_cfg &= ~PAR_CALC_EN;
1104 	}
1105 
1106 	/* bits per char */
1107 	bits_per_char = tty_get_char_size(termios->c_cflag);
1108 
1109 	/* stop bits */
1110 	if (termios->c_cflag & CSTOPB)
1111 		stop_bit_len = TX_STOP_BIT_LEN_2;
1112 	else
1113 		stop_bit_len = TX_STOP_BIT_LEN_1;
1114 
1115 	/* flow control, clear the CTS_MASK bit if using flow control. */
1116 	if (termios->c_cflag & CRTSCTS)
1117 		tx_trans_cfg &= ~UART_CTS_MASK;
1118 	else
1119 		tx_trans_cfg |= UART_CTS_MASK;
1120 
1121 	if (baud)
1122 		uart_update_timeout(uport, termios->c_cflag, baud);
1123 
1124 	if (!uart_console(uport))
1125 		writel(port->loopback,
1126 				uport->membase + SE_UART_LOOPBACK_CFG);
1127 	writel(tx_trans_cfg, uport->membase + SE_UART_TX_TRANS_CFG);
1128 	writel(tx_parity_cfg, uport->membase + SE_UART_TX_PARITY_CFG);
1129 	writel(rx_trans_cfg, uport->membase + SE_UART_RX_TRANS_CFG);
1130 	writel(rx_parity_cfg, uport->membase + SE_UART_RX_PARITY_CFG);
1131 	writel(bits_per_char, uport->membase + SE_UART_TX_WORD_LEN);
1132 	writel(bits_per_char, uport->membase + SE_UART_RX_WORD_LEN);
1133 	writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
1134 	writel(ser_clk_cfg, uport->membase + GENI_SER_M_CLK_CFG);
1135 	writel(ser_clk_cfg, uport->membase + GENI_SER_S_CLK_CFG);
1136 out_restart_rx:
1137 	qcom_geni_serial_start_rx(uport);
1138 }
1139 
1140 static unsigned int qcom_geni_serial_tx_empty(struct uart_port *uport)
1141 {
1142 	return !readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
1143 }
1144 
1145 #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
1146 static int qcom_geni_console_setup(struct console *co, char *options)
1147 {
1148 	struct uart_port *uport;
1149 	struct qcom_geni_serial_port *port;
1150 	int baud = 115200;
1151 	int bits = 8;
1152 	int parity = 'n';
1153 	int flow = 'n';
1154 	int ret;
1155 
1156 	if (co->index >= GENI_UART_CONS_PORTS  || co->index < 0)
1157 		return -ENXIO;
1158 
1159 	port = get_port_from_line(co->index, true);
1160 	if (IS_ERR(port)) {
1161 		pr_err("Invalid line %d\n", co->index);
1162 		return PTR_ERR(port);
1163 	}
1164 
1165 	uport = &port->uport;
1166 
1167 	if (unlikely(!uport->membase))
1168 		return -ENXIO;
1169 
1170 	if (!port->setup) {
1171 		ret = qcom_geni_serial_port_setup(uport);
1172 		if (ret)
1173 			return ret;
1174 	}
1175 
1176 	if (options)
1177 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1178 
1179 	return uart_set_options(uport, co, baud, parity, bits, flow);
1180 }
1181 
1182 static void qcom_geni_serial_earlycon_write(struct console *con,
1183 					const char *s, unsigned int n)
1184 {
1185 	struct earlycon_device *dev = con->data;
1186 
1187 	__qcom_geni_serial_console_write(&dev->port, s, n);
1188 }
1189 
1190 #ifdef CONFIG_CONSOLE_POLL
1191 static int qcom_geni_serial_earlycon_read(struct console *con,
1192 					  char *s, unsigned int n)
1193 {
1194 	struct earlycon_device *dev = con->data;
1195 	struct uart_port *uport = &dev->port;
1196 	int num_read = 0;
1197 	int ch;
1198 
1199 	while (num_read < n) {
1200 		ch = qcom_geni_serial_get_char(uport);
1201 		if (ch == NO_POLL_CHAR)
1202 			break;
1203 		s[num_read++] = ch;
1204 	}
1205 
1206 	return num_read;
1207 }
1208 
1209 static void __init qcom_geni_serial_enable_early_read(struct geni_se *se,
1210 						      struct console *con)
1211 {
1212 	geni_se_setup_s_cmd(se, UART_START_READ, 0);
1213 	con->read = qcom_geni_serial_earlycon_read;
1214 }
1215 #else
1216 static inline void qcom_geni_serial_enable_early_read(struct geni_se *se,
1217 						      struct console *con) { }
1218 #endif
1219 
1220 static struct qcom_geni_private_data earlycon_private_data;
1221 
1222 static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev,
1223 								const char *opt)
1224 {
1225 	struct uart_port *uport = &dev->port;
1226 	u32 tx_trans_cfg;
1227 	u32 tx_parity_cfg = 0;	/* Disable Tx Parity */
1228 	u32 rx_trans_cfg = 0;
1229 	u32 rx_parity_cfg = 0;	/* Disable Rx Parity */
1230 	u32 stop_bit_len = 0;	/* Default stop bit length - 1 bit */
1231 	u32 bits_per_char;
1232 	struct geni_se se;
1233 
1234 	if (!uport->membase)
1235 		return -EINVAL;
1236 
1237 	uport->private_data = &earlycon_private_data;
1238 
1239 	memset(&se, 0, sizeof(se));
1240 	se.base = uport->membase;
1241 	if (geni_se_read_proto(&se) != GENI_SE_UART)
1242 		return -ENXIO;
1243 	/*
1244 	 * Ignore Flow control.
1245 	 * n = 8.
1246 	 */
1247 	tx_trans_cfg = UART_CTS_MASK;
1248 	bits_per_char = BITS_PER_BYTE;
1249 
1250 	/*
1251 	 * Make an unconditional cancel on the main sequencer to reset
1252 	 * it else we could end up in data loss scenarios.
1253 	 */
1254 	qcom_geni_serial_poll_tx_done(uport);
1255 	qcom_geni_serial_abort_rx(uport);
1256 	geni_se_config_packing(&se, BITS_PER_BYTE, BYTES_PER_FIFO_WORD,
1257 			       false, true, true);
1258 	geni_se_init(&se, DEF_FIFO_DEPTH_WORDS / 2, DEF_FIFO_DEPTH_WORDS - 2);
1259 	geni_se_select_mode(&se, GENI_SE_FIFO);
1260 
1261 	writel(tx_trans_cfg, uport->membase + SE_UART_TX_TRANS_CFG);
1262 	writel(tx_parity_cfg, uport->membase + SE_UART_TX_PARITY_CFG);
1263 	writel(rx_trans_cfg, uport->membase + SE_UART_RX_TRANS_CFG);
1264 	writel(rx_parity_cfg, uport->membase + SE_UART_RX_PARITY_CFG);
1265 	writel(bits_per_char, uport->membase + SE_UART_TX_WORD_LEN);
1266 	writel(bits_per_char, uport->membase + SE_UART_RX_WORD_LEN);
1267 	writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
1268 
1269 	dev->con->write = qcom_geni_serial_earlycon_write;
1270 	dev->con->setup = NULL;
1271 	qcom_geni_serial_enable_early_read(&se, dev->con);
1272 
1273 	return 0;
1274 }
1275 OF_EARLYCON_DECLARE(qcom_geni, "qcom,geni-debug-uart",
1276 				qcom_geni_serial_earlycon_setup);
1277 
1278 static int __init console_register(struct uart_driver *drv)
1279 {
1280 	return uart_register_driver(drv);
1281 }
1282 
1283 static void console_unregister(struct uart_driver *drv)
1284 {
1285 	uart_unregister_driver(drv);
1286 }
1287 
1288 static struct console cons_ops = {
1289 	.name = "ttyMSM",
1290 	.write = qcom_geni_serial_console_write,
1291 	.device = uart_console_device,
1292 	.setup = qcom_geni_console_setup,
1293 	.flags = CON_PRINTBUFFER,
1294 	.index = -1,
1295 	.data = &qcom_geni_console_driver,
1296 };
1297 
1298 static struct uart_driver qcom_geni_console_driver = {
1299 	.owner = THIS_MODULE,
1300 	.driver_name = "qcom_geni_console",
1301 	.dev_name = "ttyMSM",
1302 	.nr =  GENI_UART_CONS_PORTS,
1303 	.cons = &cons_ops,
1304 };
1305 #else
1306 static int console_register(struct uart_driver *drv)
1307 {
1308 	return 0;
1309 }
1310 
1311 static void console_unregister(struct uart_driver *drv)
1312 {
1313 }
1314 #endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
1315 
1316 static struct uart_driver qcom_geni_uart_driver = {
1317 	.owner = THIS_MODULE,
1318 	.driver_name = "qcom_geni_uart",
1319 	.dev_name = "ttyHS",
1320 	.nr =  GENI_UART_PORTS,
1321 };
1322 
1323 static void qcom_geni_serial_pm(struct uart_port *uport,
1324 		unsigned int new_state, unsigned int old_state)
1325 {
1326 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
1327 
1328 	/* If we've never been called, treat it as off */
1329 	if (old_state == UART_PM_STATE_UNDEFINED)
1330 		old_state = UART_PM_STATE_OFF;
1331 
1332 	if (new_state == UART_PM_STATE_ON && old_state == UART_PM_STATE_OFF) {
1333 		geni_icc_enable(&port->se);
1334 		geni_se_resources_on(&port->se);
1335 	} else if (new_state == UART_PM_STATE_OFF &&
1336 			old_state == UART_PM_STATE_ON) {
1337 		geni_se_resources_off(&port->se);
1338 		geni_icc_disable(&port->se);
1339 	}
1340 }
1341 
1342 static const struct uart_ops qcom_geni_console_pops = {
1343 	.tx_empty = qcom_geni_serial_tx_empty,
1344 	.stop_tx = qcom_geni_serial_stop_tx,
1345 	.start_tx = qcom_geni_serial_start_tx,
1346 	.stop_rx = qcom_geni_serial_stop_rx,
1347 	.start_rx = qcom_geni_serial_start_rx,
1348 	.set_termios = qcom_geni_serial_set_termios,
1349 	.startup = qcom_geni_serial_startup,
1350 	.request_port = qcom_geni_serial_request_port,
1351 	.config_port = qcom_geni_serial_config_port,
1352 	.shutdown = qcom_geni_serial_shutdown,
1353 	.type = qcom_geni_serial_get_type,
1354 	.set_mctrl = qcom_geni_serial_set_mctrl,
1355 	.get_mctrl = qcom_geni_serial_get_mctrl,
1356 #ifdef CONFIG_CONSOLE_POLL
1357 	.poll_get_char	= qcom_geni_serial_get_char,
1358 	.poll_put_char	= qcom_geni_serial_poll_put_char,
1359 #endif
1360 	.pm = qcom_geni_serial_pm,
1361 };
1362 
1363 static const struct uart_ops qcom_geni_uart_pops = {
1364 	.tx_empty = qcom_geni_serial_tx_empty,
1365 	.stop_tx = qcom_geni_serial_stop_tx,
1366 	.start_tx = qcom_geni_serial_start_tx,
1367 	.stop_rx = qcom_geni_serial_stop_rx,
1368 	.set_termios = qcom_geni_serial_set_termios,
1369 	.startup = qcom_geni_serial_startup,
1370 	.request_port = qcom_geni_serial_request_port,
1371 	.config_port = qcom_geni_serial_config_port,
1372 	.shutdown = qcom_geni_serial_shutdown,
1373 	.type = qcom_geni_serial_get_type,
1374 	.set_mctrl = qcom_geni_serial_set_mctrl,
1375 	.get_mctrl = qcom_geni_serial_get_mctrl,
1376 	.pm = qcom_geni_serial_pm,
1377 };
1378 
1379 static int qcom_geni_serial_probe(struct platform_device *pdev)
1380 {
1381 	int ret = 0;
1382 	int line;
1383 	struct qcom_geni_serial_port *port;
1384 	struct uart_port *uport;
1385 	struct resource *res;
1386 	int irq;
1387 	bool console = false;
1388 	struct uart_driver *drv;
1389 
1390 	if (of_device_is_compatible(pdev->dev.of_node, "qcom,geni-debug-uart"))
1391 		console = true;
1392 
1393 	if (console) {
1394 		drv = &qcom_geni_console_driver;
1395 		line = of_alias_get_id(pdev->dev.of_node, "serial");
1396 	} else {
1397 		drv = &qcom_geni_uart_driver;
1398 		line = of_alias_get_id(pdev->dev.of_node, "serial");
1399 		if (line == -ENODEV) /* compat with non-standard aliases */
1400 			line = of_alias_get_id(pdev->dev.of_node, "hsuart");
1401 	}
1402 
1403 	port = get_port_from_line(line, console);
1404 	if (IS_ERR(port)) {
1405 		dev_err(&pdev->dev, "Invalid line %d\n", line);
1406 		return PTR_ERR(port);
1407 	}
1408 
1409 	uport = &port->uport;
1410 	/* Don't allow 2 drivers to access the same port */
1411 	if (uport->private_data)
1412 		return -ENODEV;
1413 
1414 	uport->dev = &pdev->dev;
1415 	port->se.dev = &pdev->dev;
1416 	port->se.wrapper = dev_get_drvdata(pdev->dev.parent);
1417 	port->se.clk = devm_clk_get(&pdev->dev, "se");
1418 	if (IS_ERR(port->se.clk)) {
1419 		ret = PTR_ERR(port->se.clk);
1420 		dev_err(&pdev->dev, "Err getting SE Core clk %d\n", ret);
1421 		return ret;
1422 	}
1423 
1424 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1425 	if (!res)
1426 		return -EINVAL;
1427 	uport->mapbase = res->start;
1428 
1429 	port->tx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
1430 	port->rx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
1431 	port->tx_fifo_width = DEF_FIFO_WIDTH_BITS;
1432 
1433 	if (!console) {
1434 		port->rx_fifo = devm_kcalloc(uport->dev,
1435 			port->rx_fifo_depth, sizeof(u32), GFP_KERNEL);
1436 		if (!port->rx_fifo)
1437 			return -ENOMEM;
1438 	}
1439 
1440 	ret = geni_icc_get(&port->se, NULL);
1441 	if (ret)
1442 		return ret;
1443 	port->se.icc_paths[GENI_TO_CORE].avg_bw = GENI_DEFAULT_BW;
1444 	port->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
1445 
1446 	/* Set BW for register access */
1447 	ret = geni_icc_set_bw(&port->se);
1448 	if (ret)
1449 		return ret;
1450 
1451 	port->name = devm_kasprintf(uport->dev, GFP_KERNEL,
1452 			"qcom_geni_serial_%s%d",
1453 			uart_console(uport) ? "console" : "uart", uport->line);
1454 	if (!port->name)
1455 		return -ENOMEM;
1456 
1457 	irq = platform_get_irq(pdev, 0);
1458 	if (irq < 0)
1459 		return irq;
1460 	uport->irq = irq;
1461 	uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_QCOM_GENI_CONSOLE);
1462 
1463 	if (!console)
1464 		port->wakeup_irq = platform_get_irq_optional(pdev, 1);
1465 
1466 	if (of_property_read_bool(pdev->dev.of_node, "rx-tx-swap"))
1467 		port->rx_tx_swap = true;
1468 
1469 	if (of_property_read_bool(pdev->dev.of_node, "cts-rts-swap"))
1470 		port->cts_rts_swap = true;
1471 
1472 	ret = devm_pm_opp_set_clkname(&pdev->dev, "se");
1473 	if (ret)
1474 		return ret;
1475 	/* OPP table is optional */
1476 	ret = devm_pm_opp_of_add_table(&pdev->dev);
1477 	if (ret && ret != -ENODEV) {
1478 		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
1479 		return ret;
1480 	}
1481 
1482 	port->private_data.drv = drv;
1483 	uport->private_data = &port->private_data;
1484 	platform_set_drvdata(pdev, port);
1485 	port->handle_rx = console ? handle_rx_console : handle_rx_uart;
1486 
1487 	ret = uart_add_one_port(drv, uport);
1488 	if (ret)
1489 		return ret;
1490 
1491 	irq_set_status_flags(uport->irq, IRQ_NOAUTOEN);
1492 	ret = devm_request_irq(uport->dev, uport->irq, qcom_geni_serial_isr,
1493 			IRQF_TRIGGER_HIGH, port->name, uport);
1494 	if (ret) {
1495 		dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);
1496 		uart_remove_one_port(drv, uport);
1497 		return ret;
1498 	}
1499 
1500 	/*
1501 	 * Set pm_runtime status as ACTIVE so that wakeup_irq gets
1502 	 * enabled/disabled from dev_pm_arm_wake_irq during system
1503 	 * suspend/resume respectively.
1504 	 */
1505 	pm_runtime_set_active(&pdev->dev);
1506 
1507 	if (port->wakeup_irq > 0) {
1508 		device_init_wakeup(&pdev->dev, true);
1509 		ret = dev_pm_set_dedicated_wake_irq(&pdev->dev,
1510 						port->wakeup_irq);
1511 		if (ret) {
1512 			device_init_wakeup(&pdev->dev, false);
1513 			uart_remove_one_port(drv, uport);
1514 			return ret;
1515 		}
1516 	}
1517 
1518 	return 0;
1519 }
1520 
1521 static int qcom_geni_serial_remove(struct platform_device *pdev)
1522 {
1523 	struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
1524 	struct uart_driver *drv = port->private_data.drv;
1525 
1526 	dev_pm_clear_wake_irq(&pdev->dev);
1527 	device_init_wakeup(&pdev->dev, false);
1528 	uart_remove_one_port(drv, &port->uport);
1529 
1530 	return 0;
1531 }
1532 
1533 static int __maybe_unused qcom_geni_serial_sys_suspend(struct device *dev)
1534 {
1535 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
1536 	struct uart_port *uport = &port->uport;
1537 	struct qcom_geni_private_data *private_data = uport->private_data;
1538 
1539 	/*
1540 	 * This is done so we can hit the lowest possible state in suspend
1541 	 * even with no_console_suspend
1542 	 */
1543 	if (uart_console(uport)) {
1544 		geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ACTIVE_ONLY);
1545 		geni_icc_set_bw(&port->se);
1546 	}
1547 	return uart_suspend_port(private_data->drv, uport);
1548 }
1549 
1550 static int __maybe_unused qcom_geni_serial_sys_resume(struct device *dev)
1551 {
1552 	int ret;
1553 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
1554 	struct uart_port *uport = &port->uport;
1555 	struct qcom_geni_private_data *private_data = uport->private_data;
1556 
1557 	ret = uart_resume_port(private_data->drv, uport);
1558 	if (uart_console(uport)) {
1559 		geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ALWAYS);
1560 		geni_icc_set_bw(&port->se);
1561 	}
1562 	return ret;
1563 }
1564 
1565 static int qcom_geni_serial_sys_hib_resume(struct device *dev)
1566 {
1567 	int ret = 0;
1568 	struct uart_port *uport;
1569 	struct qcom_geni_private_data *private_data;
1570 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
1571 
1572 	uport = &port->uport;
1573 	private_data = uport->private_data;
1574 
1575 	if (uart_console(uport)) {
1576 		geni_icc_set_tag(&port->se, 0x7);
1577 		geni_icc_set_bw(&port->se);
1578 		ret = uart_resume_port(private_data->drv, uport);
1579 		/*
1580 		 * For hibernation usecase clients for
1581 		 * console UART won't call port setup during restore,
1582 		 * hence call port setup for console uart.
1583 		 */
1584 		qcom_geni_serial_port_setup(uport);
1585 	} else {
1586 		/*
1587 		 * Peripheral register settings are lost during hibernation.
1588 		 * Update setup flag such that port setup happens again
1589 		 * during next session. Clients of HS-UART will close and
1590 		 * open the port during hibernation.
1591 		 */
1592 		port->setup = false;
1593 	}
1594 	return ret;
1595 }
1596 
1597 static const struct dev_pm_ops qcom_geni_serial_pm_ops = {
1598 	SET_SYSTEM_SLEEP_PM_OPS(qcom_geni_serial_sys_suspend,
1599 					qcom_geni_serial_sys_resume)
1600 	.restore = qcom_geni_serial_sys_hib_resume,
1601 	.thaw = qcom_geni_serial_sys_hib_resume,
1602 };
1603 
1604 static const struct of_device_id qcom_geni_serial_match_table[] = {
1605 	{ .compatible = "qcom,geni-debug-uart", },
1606 	{ .compatible = "qcom,geni-uart", },
1607 	{}
1608 };
1609 MODULE_DEVICE_TABLE(of, qcom_geni_serial_match_table);
1610 
1611 static struct platform_driver qcom_geni_serial_platform_driver = {
1612 	.remove = qcom_geni_serial_remove,
1613 	.probe = qcom_geni_serial_probe,
1614 	.driver = {
1615 		.name = "qcom_geni_serial",
1616 		.of_match_table = qcom_geni_serial_match_table,
1617 		.pm = &qcom_geni_serial_pm_ops,
1618 	},
1619 };
1620 
1621 static int __init qcom_geni_serial_init(void)
1622 {
1623 	int ret;
1624 
1625 	ret = console_register(&qcom_geni_console_driver);
1626 	if (ret)
1627 		return ret;
1628 
1629 	ret = uart_register_driver(&qcom_geni_uart_driver);
1630 	if (ret) {
1631 		console_unregister(&qcom_geni_console_driver);
1632 		return ret;
1633 	}
1634 
1635 	ret = platform_driver_register(&qcom_geni_serial_platform_driver);
1636 	if (ret) {
1637 		console_unregister(&qcom_geni_console_driver);
1638 		uart_unregister_driver(&qcom_geni_uart_driver);
1639 	}
1640 	return ret;
1641 }
1642 module_init(qcom_geni_serial_init);
1643 
1644 static void __exit qcom_geni_serial_exit(void)
1645 {
1646 	platform_driver_unregister(&qcom_geni_serial_platform_driver);
1647 	console_unregister(&qcom_geni_console_driver);
1648 	uart_unregister_driver(&qcom_geni_uart_driver);
1649 }
1650 module_exit(qcom_geni_serial_exit);
1651 
1652 MODULE_DESCRIPTION("Serial driver for GENI based QUP cores");
1653 MODULE_LICENSE("GPL v2");
1654