1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
4 * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
5 */
6
7 /* Disable MMIO tracing to prevent excessive logging of unwanted MMIO traces */
8 #define __DISABLE_TRACE_MMIO__
9
10 #define CREATE_TRACE_POINTS
11 #include <trace/events/qcom_geni_serial.h>
12
13 #include <linux/clk.h>
14 #include <linux/console.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/io.h>
17 #include <linux/iopoll.h>
18 #include <linux/irq.h>
19 #include <linux/irq_work.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/panic_notifier.h>
23 #include <linux/pm_domain.h>
24 #include <linux/pm_opp.h>
25 #include <linux/platform_device.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/pm_wakeirq.h>
28 #include <linux/soc/qcom/geni-se.h>
29 #include <linux/serial.h>
30 #include <linux/serial_core.h>
31 #include <linux/slab.h>
32 #include <linux/tty.h>
33 #include <linux/tty_flip.h>
34 #include <dt-bindings/interconnect/qcom,icc.h>
35
36 /* UART specific GENI registers */
37 #define SE_UART_LOOPBACK_CFG 0x22c
38 #define SE_UART_IO_MACRO_CTRL 0x240
39 #define SE_UART_TX_TRANS_CFG 0x25c
40 #define SE_UART_TX_WORD_LEN 0x268
41 #define SE_UART_TX_STOP_BIT_LEN 0x26c
42 #define SE_UART_TX_TRANS_LEN 0x270
43 #define SE_UART_RX_TRANS_CFG 0x280
44 #define SE_UART_RX_WORD_LEN 0x28c
45 #define SE_UART_RX_STALE_CNT 0x294
46 #define SE_UART_TX_PARITY_CFG 0x2a4
47 #define SE_UART_RX_PARITY_CFG 0x2a8
48 #define SE_UART_MANUAL_RFR 0x2ac
49
50 /* SE_UART_TRANS_CFG */
51 #define UART_TX_PAR_EN BIT(0)
52 #define UART_CTS_MASK BIT(1)
53
54 /* SE_UART_TX_STOP_BIT_LEN */
55 #define TX_STOP_BIT_LEN_1 0
56 #define TX_STOP_BIT_LEN_2 2
57
58 /* SE_UART_RX_TRANS_CFG */
59 #define UART_RX_PAR_EN BIT(4)
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_EVEN 0x00
70 #define PAR_ODD 0x01
71 #define PAR_SPACE 0x10
72
73 /* SE_UART_MANUAL_RFR register fields */
74 #define UART_MANUAL_RFR_EN BIT(31)
75 #define UART_RFR_NOT_READY BIT(1)
76 #define UART_RFR_READY BIT(0)
77
78 /* UART M_CMD OP codes */
79 #define UART_START_TX 0x1
80 /* UART S_CMD OP codes */
81 #define UART_START_READ 0x1
82 #define UART_PARAM 0x1
83 #define UART_PARAM_RFR_OPEN BIT(7)
84
85 #define UART_OVERSAMPLING 32
86 #define STALE_TIMEOUT 16
87 #define DEFAULT_BITS_PER_CHAR 10
88 #define GENI_UART_CONS_PORTS 1
89 #define DEF_FIFO_DEPTH_WORDS 16
90 #define DEF_TX_WM 2
91 #define DEF_FIFO_WIDTH_BITS 32
92 #define UART_RX_WM 2
93 #define CONSOLE_TX_CHUNK_SIZE 32
94
95 /* SE_UART_LOOPBACK_CFG */
96 #define RX_TX_SORTED BIT(0)
97 #define CTS_RTS_SORTED BIT(1)
98 #define RX_TX_CTS_RTS_SORTED (RX_TX_SORTED | CTS_RTS_SORTED)
99
100 /* UART pin swap value */
101 #define DEFAULT_IO_MACRO_IO0_IO1_MASK GENMASK(3, 0)
102 #define IO_MACRO_IO0_SEL 0x3
103 #define DEFAULT_IO_MACRO_IO2_IO3_MASK GENMASK(15, 4)
104 #define IO_MACRO_IO2_IO3_SWAP 0x4640
105
106 /* We always configure 4 bytes per FIFO word */
107 #define BYTES_PER_FIFO_WORD 4U
108
109 #define DMA_RX_BUF_SIZE 2048
110
111 static DEFINE_IDA(port_ida);
112
113 struct qcom_geni_device_data {
114 bool console;
115 enum geni_se_xfer_mode mode;
116 int (*resources_init)(struct geni_se *se);
117 int (*set_rate)(struct geni_se *se, unsigned long baud);
118 int (*power_on)(struct geni_se *se);
119 int (*power_off)(struct geni_se *se);
120 };
121
122 struct qcom_geni_private_data {
123 /* NOTE: earlycon port will have NULL here */
124 struct uart_driver *drv;
125
126 u32 poll_cached_bytes;
127 unsigned int poll_cached_bytes_cnt;
128
129 u32 write_cached_bytes;
130 unsigned int write_cached_bytes_cnt;
131 };
132
133 struct qcom_geni_serial_port {
134 struct uart_port uport;
135 struct geni_se se;
136 const char *name;
137 u32 tx_fifo_depth;
138 u32 tx_fifo_width;
139 u32 rx_fifo_depth;
140 dma_addr_t tx_dma_addr;
141 dma_addr_t rx_dma_addr;
142 bool setup;
143 unsigned long poll_timeout_us;
144 unsigned long clk_rate;
145 void *rx_buf;
146 u32 loopback;
147 bool brk;
148
149 unsigned int tx_remaining;
150 unsigned int tx_queued;
151 bool tx_dma_stale;
152 int wakeup_irq;
153 bool rx_tx_swap;
154 bool cts_rts_swap;
155 bool manual_flow;
156 bool tx_kick_enabled;
157 struct irq_work tx_kick;
158 struct qcom_geni_private_data private_data;
159 const struct qcom_geni_device_data *dev_data;
160 struct notifier_block panic_nb;
161 };
162
163 static const struct uart_ops qcom_geni_console_pops;
164 static const struct uart_ops qcom_geni_uart_pops;
165 static struct uart_driver qcom_geni_console_driver;
166 static struct uart_driver qcom_geni_uart_driver;
167
168 static void qcom_geni_serial_stop_tx_dma(struct uart_port *uport);
169 static void __qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport);
170 static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport);
171 static int qcom_geni_serial_port_setup(struct uart_port *uport);
172 static void qcom_geni_serial_start_tx_fifo(struct uart_port *uport);
173 static void qcom_geni_serial_resume_tx(struct uart_port *uport);
174
to_dev_port(struct uart_port * uport)175 static inline struct qcom_geni_serial_port *to_dev_port(struct uart_port *uport)
176 {
177 return container_of(uport, struct qcom_geni_serial_port, uport);
178 }
179
180 static struct qcom_geni_serial_port qcom_geni_console_port = {
181 .uport = {
182 .iotype = UPIO_MEM,
183 .ops = &qcom_geni_console_pops,
184 .flags = UPF_BOOT_AUTOCONF,
185 .line = 0,
186 },
187 };
188
189 static const struct serial_rs485 qcom_geni_rs485_supported = {
190 .flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND | SER_RS485_RTS_ON_SEND,
191 };
192
193 /**
194 * qcom_geni_set_rs485_mode - Set RTS pin state for RS485 mode
195 * @uport: UART port
196 * @flag: RS485 flag to determine RTS polarity
197 *
198 * Enables manual RTS control for RS485. Sets RTS to READY or NOT_READY
199 * based on the specified flag if RS485 mode is enabled.
200 */
qcom_geni_set_rs485_mode(struct uart_port * uport,u32 flag)201 static void qcom_geni_set_rs485_mode(struct uart_port *uport, u32 flag)
202 {
203 if (!(uport->rs485.flags & SER_RS485_ENABLED))
204 return;
205
206 u32 rfr = UART_MANUAL_RFR_EN;
207
208 if (uport->rs485.flags & flag)
209 rfr |= UART_RFR_NOT_READY;
210 else
211 rfr |= UART_RFR_READY;
212
213 writel(rfr, uport->membase + SE_UART_MANUAL_RFR);
214 }
215
qcom_geni_serial_request_port(struct uart_port * uport)216 static int qcom_geni_serial_request_port(struct uart_port *uport)
217 {
218 struct platform_device *pdev = to_platform_device(uport->dev);
219 struct qcom_geni_serial_port *port = to_dev_port(uport);
220
221 uport->membase = devm_platform_ioremap_resource(pdev, 0);
222 if (IS_ERR(uport->membase))
223 return PTR_ERR(uport->membase);
224 port->se.base = uport->membase;
225 return 0;
226 }
227
qcom_geni_serial_config_port(struct uart_port * uport,int cfg_flags)228 static void qcom_geni_serial_config_port(struct uart_port *uport, int cfg_flags)
229 {
230 if (cfg_flags & UART_CONFIG_TYPE) {
231 uport->type = PORT_MSM;
232 qcom_geni_serial_request_port(uport);
233 }
234 }
235
qcom_geni_serial_get_mctrl(struct uart_port * uport)236 static unsigned int qcom_geni_serial_get_mctrl(struct uart_port *uport)
237 {
238 unsigned int mctrl = TIOCM_DSR | TIOCM_CAR;
239 u32 geni_ios = 0;
240
241 if (uart_console(uport)) {
242 mctrl |= TIOCM_CTS;
243 } else {
244 geni_ios = readl(uport->membase + SE_GENI_IOS);
245 if (!(geni_ios & IO2_DATA_IN))
246 mctrl |= TIOCM_CTS;
247 }
248
249 trace_geni_serial_get_mctrl(uport->dev, mctrl, geni_ios);
250
251 return mctrl;
252 }
253
qcom_geni_serial_set_mctrl(struct uart_port * uport,unsigned int mctrl)254 static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
255 unsigned int mctrl)
256 {
257 u32 uart_manual_rfr = 0;
258 struct qcom_geni_serial_port *port = to_dev_port(uport);
259
260 if (uart_console(uport))
261 return;
262
263 if (mctrl & TIOCM_LOOP)
264 port->loopback = RX_TX_CTS_RTS_SORTED;
265
266 if (port->manual_flow && !(mctrl & TIOCM_RTS) && !uport->suspended)
267 uart_manual_rfr = UART_MANUAL_RFR_EN | UART_RFR_NOT_READY;
268 writel(uart_manual_rfr, uport->membase + SE_UART_MANUAL_RFR);
269
270 trace_geni_serial_set_mctrl(uport->dev, mctrl, uart_manual_rfr);
271 }
272
qcom_geni_serial_get_type(struct uart_port * uport)273 static const char *qcom_geni_serial_get_type(struct uart_port *uport)
274 {
275 return "MSM";
276 }
277
get_port_from_line(int line,bool console,struct device * dev)278 static struct qcom_geni_serial_port *get_port_from_line(int line, bool console, struct device *dev)
279 {
280 struct qcom_geni_serial_port *port;
281 int nr_ports = console ? GENI_UART_CONS_PORTS : CONFIG_SERIAL_QCOM_GENI_UART_PORTS;
282
283 if (console) {
284 if (line < 0 || line >= nr_ports)
285 return ERR_PTR(-ENXIO);
286
287 port = &qcom_geni_console_port;
288 } else {
289 int max_alias_num = of_alias_get_highest_id("serial");
290
291 if (line < 0 || line >= nr_ports)
292 line = ida_alloc_range(&port_ida, max_alias_num + 1,
293 nr_ports - 1, GFP_KERNEL);
294 else
295 line = ida_alloc_range(&port_ida, line,
296 nr_ports - 1, GFP_KERNEL);
297
298 if (line < 0)
299 return ERR_PTR(-ENXIO);
300
301 port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
302 if (!port)
303 return ERR_PTR(-ENOMEM);
304
305 port->uport.iotype = UPIO_MEM;
306 port->uport.ops = &qcom_geni_uart_pops;
307 port->uport.flags = UPF_BOOT_AUTOCONF;
308 port->uport.line = line;
309 }
310 return port;
311 }
312
qcom_geni_serial_main_active(struct uart_port * uport)313 static bool qcom_geni_serial_main_active(struct uart_port *uport)
314 {
315 return readl(uport->membase + SE_GENI_STATUS) & M_GENI_CMD_ACTIVE;
316 }
317
qcom_geni_serial_secondary_active(struct uart_port * uport)318 static bool qcom_geni_serial_secondary_active(struct uart_port *uport)
319 {
320 return readl(uport->membase + SE_GENI_STATUS) & S_GENI_CMD_ACTIVE;
321 }
322
qcom_geni_serial_poll_bitfield(struct uart_port * uport,unsigned int offset,u32 field,u32 val)323 static bool qcom_geni_serial_poll_bitfield(struct uart_port *uport,
324 unsigned int offset, u32 field, u32 val)
325 {
326 u32 reg;
327 struct qcom_geni_serial_port *port;
328 unsigned long timeout_us = 20000;
329 struct qcom_geni_private_data *private_data = uport->private_data;
330
331 if (private_data->drv) {
332 port = to_dev_port(uport);
333 if (port->poll_timeout_us)
334 timeout_us = port->poll_timeout_us;
335 }
336
337 /*
338 * Use custom implementation instead of readl_poll_atomic since ktimer
339 * is not ready at the time of early console.
340 */
341 timeout_us = DIV_ROUND_UP(timeout_us, 10) * 10;
342 while (timeout_us) {
343 reg = readl(uport->membase + offset);
344 if ((reg & field) == val)
345 return true;
346 udelay(10);
347 timeout_us -= 10;
348 }
349 return false;
350 }
351
qcom_geni_serial_poll_bit(struct uart_port * uport,unsigned int offset,u32 field,bool set)352 static bool qcom_geni_serial_poll_bit(struct uart_port *uport,
353 unsigned int offset, u32 field, bool set)
354 {
355 return qcom_geni_serial_poll_bitfield(uport, offset, field, set ? field : 0);
356 }
357
qcom_geni_serial_setup_tx(struct uart_port * uport,u32 xmit_size)358 static void qcom_geni_serial_setup_tx(struct uart_port *uport, u32 xmit_size)
359 {
360 u32 m_cmd;
361
362 writel(xmit_size, uport->membase + SE_UART_TX_TRANS_LEN);
363 m_cmd = UART_START_TX << M_OPCODE_SHFT;
364 writel(m_cmd, uport->membase + SE_GENI_M_CMD0);
365 }
366
qcom_geni_serial_poll_tx_done(struct uart_port * uport)367 static void qcom_geni_serial_poll_tx_done(struct uart_port *uport)
368 {
369 int done;
370
371 done = qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
372 M_CMD_DONE_EN, true);
373 if (!done) {
374 writel(M_GENI_CMD_ABORT, uport->membase +
375 SE_GENI_M_CMD_CTRL_REG);
376 qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
377 M_CMD_ABORT_EN, true);
378 writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
379 }
380 }
381
qcom_geni_serial_abort_rx(struct uart_port * uport)382 static void qcom_geni_serial_abort_rx(struct uart_port *uport)
383 {
384 u32 irq_clear = S_CMD_DONE_EN | S_CMD_ABORT_EN;
385
386 writel(S_GENI_CMD_ABORT, uport->membase + SE_GENI_S_CMD_CTRL_REG);
387 qcom_geni_serial_poll_bit(uport, SE_GENI_S_CMD_CTRL_REG,
388 S_GENI_CMD_ABORT, false);
389 writel(irq_clear, uport->membase + SE_GENI_S_IRQ_CLEAR);
390 writel(FORCE_DEFAULT, uport->membase + GENI_FORCE_DEFAULT_REG);
391 }
392
393 #ifdef CONFIG_CONSOLE_POLL
qcom_geni_serial_get_char(struct uart_port * uport)394 static int qcom_geni_serial_get_char(struct uart_port *uport)
395 {
396 struct qcom_geni_private_data *private_data = uport->private_data;
397 u32 status;
398 u32 word_cnt;
399 int ret;
400
401 if (!private_data->poll_cached_bytes_cnt) {
402 status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
403 writel(status, uport->membase + SE_GENI_M_IRQ_CLEAR);
404
405 status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
406 writel(status, uport->membase + SE_GENI_S_IRQ_CLEAR);
407
408 status = readl(uport->membase + SE_GENI_RX_FIFO_STATUS);
409 word_cnt = status & RX_FIFO_WC_MSK;
410 if (!word_cnt)
411 return NO_POLL_CHAR;
412
413 if (word_cnt == 1 && (status & RX_LAST))
414 /*
415 * NOTE: If RX_LAST_BYTE_VALID is 0 it needs to be
416 * treated as if it was BYTES_PER_FIFO_WORD.
417 */
418 private_data->poll_cached_bytes_cnt =
419 (status & RX_LAST_BYTE_VALID_MSK) >>
420 RX_LAST_BYTE_VALID_SHFT;
421
422 if (private_data->poll_cached_bytes_cnt == 0)
423 private_data->poll_cached_bytes_cnt = BYTES_PER_FIFO_WORD;
424
425 private_data->poll_cached_bytes =
426 readl(uport->membase + SE_GENI_RX_FIFOn);
427 }
428
429 private_data->poll_cached_bytes_cnt--;
430 ret = private_data->poll_cached_bytes & 0xff;
431 private_data->poll_cached_bytes >>= 8;
432
433 return ret;
434 }
435
qcom_geni_serial_poll_put_char(struct uart_port * uport,unsigned char c)436 static void qcom_geni_serial_poll_put_char(struct uart_port *uport,
437 unsigned char c)
438 {
439 if (qcom_geni_serial_main_active(uport)) {
440 qcom_geni_serial_poll_tx_done(uport);
441 __qcom_geni_serial_cancel_tx_cmd(uport);
442 }
443
444 writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
445 qcom_geni_serial_setup_tx(uport, 1);
446 writel(c, uport->membase + SE_GENI_TX_FIFOn);
447 qcom_geni_serial_poll_tx_done(uport);
448 }
449
qcom_geni_serial_poll_init(struct uart_port * uport)450 static int qcom_geni_serial_poll_init(struct uart_port *uport)
451 {
452 struct qcom_geni_serial_port *port = to_dev_port(uport);
453 int ret;
454
455 if (!port->setup) {
456 ret = qcom_geni_serial_port_setup(uport);
457 if (ret)
458 return ret;
459 }
460
461 if (!qcom_geni_serial_secondary_active(uport))
462 geni_se_setup_s_cmd(&port->se, UART_START_READ, 0);
463
464 return 0;
465 }
466 #endif
467
468 #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
handle_rx_console(struct uart_port * uport,u32 bytes,bool drop)469 static void handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
470 {
471 u32 i;
472 unsigned char buf[sizeof(u32)];
473 struct tty_port *tport;
474 struct qcom_geni_serial_port *port = to_dev_port(uport);
475
476 tport = &uport->state->port;
477 for (i = 0; i < bytes; ) {
478 int c;
479 int chunk = min_t(int, bytes - i, BYTES_PER_FIFO_WORD);
480
481 ioread32_rep(uport->membase + SE_GENI_RX_FIFOn, buf, 1);
482 i += chunk;
483 if (drop)
484 continue;
485
486 for (c = 0; c < chunk; c++) {
487 int sysrq;
488
489 uport->icount.rx++;
490 if (port->brk && buf[c] == 0) {
491 port->brk = false;
492 if (uart_handle_break(uport))
493 continue;
494 }
495
496 sysrq = uart_prepare_sysrq_char(uport, buf[c]);
497
498 if (!sysrq)
499 tty_insert_flip_char(tport, buf[c], TTY_NORMAL);
500 }
501 }
502 if (!drop)
503 tty_flip_buffer_push(tport);
504 }
505 #else
handle_rx_console(struct uart_port * uport,u32 bytes,bool drop)506 static void handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
507 {
508
509 }
510 #endif
511
qcom_geni_serial_handle_rx_fifo(struct uart_port * uport,bool drop)512 static void qcom_geni_serial_handle_rx_fifo(struct uart_port *uport, bool drop)
513 {
514 u32 status;
515 u32 word_cnt;
516 u32 last_word_byte_cnt;
517 u32 last_word_partial;
518 u32 total_bytes;
519
520 status = readl(uport->membase + SE_GENI_RX_FIFO_STATUS);
521 word_cnt = status & RX_FIFO_WC_MSK;
522 last_word_partial = status & RX_LAST;
523 last_word_byte_cnt = (status & RX_LAST_BYTE_VALID_MSK) >>
524 RX_LAST_BYTE_VALID_SHFT;
525
526 if (!word_cnt)
527 return;
528 total_bytes = BYTES_PER_FIFO_WORD * (word_cnt - 1);
529 if (last_word_partial && last_word_byte_cnt)
530 total_bytes += last_word_byte_cnt;
531 else
532 total_bytes += BYTES_PER_FIFO_WORD;
533 handle_rx_console(uport, total_bytes, drop);
534 }
535
536 #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
537 /* Caller holds the UART port lock. */
qcom_geni_serial_poll_rx_fifo_locked(struct uart_port * uport)538 static void qcom_geni_serial_poll_rx_fifo_locked(struct uart_port *uport)
539 {
540 struct qcom_geni_serial_port *port = to_dev_port(uport);
541 struct tty_port *tport = &uport->state->port;
542 u32 s_irq_status;
543 bool drop_rx = false;
544
545 s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
546 writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
547
548 if (s_irq_status & S_RX_FIFO_WR_ERR_EN) {
549 uport->icount.overrun++;
550 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
551 }
552
553 if (s_irq_status & (S_GP_IRQ_0_EN | S_GP_IRQ_1_EN)) {
554 if (s_irq_status & S_GP_IRQ_0_EN)
555 uport->icount.parity++;
556 drop_rx = true;
557 } else if (s_irq_status & (S_GP_IRQ_2_EN | S_GP_IRQ_3_EN)) {
558 uport->icount.brk++;
559 port->brk = true;
560 }
561
562 qcom_geni_serial_handle_rx_fifo(uport, drop_rx);
563 }
564
qcom_geni_serial_drain_fifo(struct uart_port * uport)565 static void qcom_geni_serial_drain_fifo(struct uart_port *uport)
566 {
567 struct qcom_geni_serial_port *port = to_dev_port(uport);
568
569 qcom_geni_serial_poll_bitfield(uport, SE_GENI_M_GP_LENGTH, GP_LENGTH,
570 port->tx_queued);
571 }
572
qcom_geni_serial_wr_char(struct uart_port * uport,unsigned char ch)573 static void qcom_geni_serial_wr_char(struct uart_port *uport, unsigned char ch)
574 {
575 struct qcom_geni_private_data *private_data = uport->private_data;
576
577 private_data->write_cached_bytes =
578 (private_data->write_cached_bytes >> 8) | (ch << 24);
579 private_data->write_cached_bytes_cnt++;
580
581 if (private_data->write_cached_bytes_cnt == BYTES_PER_FIFO_WORD) {
582 writel(private_data->write_cached_bytes,
583 uport->membase + SE_GENI_TX_FIFOn);
584 private_data->write_cached_bytes_cnt = 0;
585 }
586 }
587
588 static void
__qcom_geni_serial_console_write(struct uart_port * uport,const char * s,unsigned int count,bool poll_rx)589 __qcom_geni_serial_console_write(struct uart_port *uport, const char *s,
590 unsigned int count, bool poll_rx)
591 {
592 struct qcom_geni_private_data *private_data = uport->private_data;
593
594 int i;
595 u32 bytes_to_send = count;
596
597 for (i = 0; i < count; i++) {
598 /*
599 * uart_console_write() adds a carriage return for each newline.
600 * Account for additional bytes to be written.
601 */
602 if (s[i] == '\n')
603 bytes_to_send++;
604 }
605
606 writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
607 writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
608 qcom_geni_serial_setup_tx(uport, bytes_to_send);
609 for (i = 0; i < count; ) {
610 size_t chars_to_write = 0;
611 size_t avail = DEF_FIFO_DEPTH_WORDS - DEF_TX_WM;
612
613 /*
614 * If the WM bit never set, then the Tx state machine is not
615 * in a valid state, so break, cancel/abort any existing
616 * command. Unfortunately the current data being written is
617 * lost.
618 */
619 if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
620 M_TX_FIFO_WATERMARK_EN, true))
621 break;
622 if (poll_rx)
623 qcom_geni_serial_poll_rx_fifo_locked(uport);
624 chars_to_write = min_t(size_t, count - i, avail / 2);
625 uart_console_write(uport, s + i, chars_to_write,
626 qcom_geni_serial_wr_char);
627 writel(M_TX_FIFO_WATERMARK_EN, uport->membase +
628 SE_GENI_M_IRQ_CLEAR);
629 i += chars_to_write;
630 }
631
632 if (private_data->write_cached_bytes_cnt) {
633 private_data->write_cached_bytes >>= BITS_PER_BYTE *
634 (BYTES_PER_FIFO_WORD - private_data->write_cached_bytes_cnt);
635 writel(private_data->write_cached_bytes,
636 uport->membase + SE_GENI_TX_FIFOn);
637 private_data->write_cached_bytes_cnt = 0;
638 }
639
640 qcom_geni_serial_poll_tx_done(uport);
641 }
642
qcom_geni_serial_console_takeover(struct uart_port * uport,bool preserve_tx)643 static void qcom_geni_serial_console_takeover(struct uart_port *uport,
644 bool preserve_tx)
645 {
646 if (qcom_geni_serial_main_active(uport)) {
647 struct qcom_geni_serial_port *port = to_dev_port(uport);
648
649 if (preserve_tx) {
650 if (port->tx_remaining == 0)
651 qcom_geni_serial_poll_tx_done(uport);
652 else
653 qcom_geni_serial_drain_fifo(uport);
654 }
655
656 qcom_geni_serial_cancel_tx_cmd(uport);
657 }
658 }
659
qcom_geni_serial_console_write_thread(struct console * co,struct nbcon_write_context * wctxt)660 static void qcom_geni_serial_console_write_thread(struct console *co,
661 struct nbcon_write_context *wctxt)
662 {
663 struct qcom_geni_serial_port *port;
664 struct uart_port *uport;
665 unsigned int offset = 0;
666
667 port = get_port_from_line(co->index, true, NULL);
668 if (IS_ERR(port))
669 return;
670
671 uport = &port->uport;
672 if (!nbcon_enter_unsafe(wctxt))
673 return;
674
675 qcom_geni_serial_console_takeover(uport, true);
676 if (!nbcon_exit_unsafe(wctxt))
677 return;
678
679 while (offset < wctxt->len) {
680 /*
681 * Printk records can be much larger than the FIFO. Limit one
682 * M-side command to 32 source bytes so atomic console output can
683 * take over between commands instead of waiting for the record.
684 */
685 unsigned int count = min_t(unsigned int, wctxt->len - offset,
686 CONSOLE_TX_CHUNK_SIZE);
687
688 if (!nbcon_enter_unsafe(wctxt))
689 return;
690
691 __qcom_geni_serial_console_write(uport, wctxt->outbuf + offset,
692 count, true);
693 offset += count;
694
695 if (!nbcon_exit_unsafe(wctxt))
696 return;
697 }
698
699 if (!nbcon_enter_unsafe(wctxt))
700 return;
701
702 qcom_geni_serial_resume_tx(uport);
703 nbcon_exit_unsafe(wctxt);
704 }
705
qcom_geni_serial_console_write_atomic(struct console * co,struct nbcon_write_context * wctxt)706 static void qcom_geni_serial_console_write_atomic(struct console *co,
707 struct nbcon_write_context *wctxt)
708 {
709 struct qcom_geni_serial_port *port;
710 struct uart_port *uport;
711 u32 m_irq_en;
712
713 port = get_port_from_line(co->index, true, NULL);
714 if (IS_ERR(port))
715 return;
716
717 uport = &port->uport;
718 if (!nbcon_enter_unsafe(wctxt))
719 return;
720
721 m_irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
722 writel(m_irq_en & ~(M_CMD_DONE_EN | M_TX_FIFO_WATERMARK_EN),
723 uport->membase + SE_GENI_M_IRQ_EN);
724
725 /* Atomic console output takes priority over an active normal TX command. */
726 qcom_geni_serial_console_takeover(uport, false);
727 __qcom_geni_serial_console_write(uport, wctxt->outbuf, wctxt->len, false);
728
729 writel(m_irq_en, uport->membase + SE_GENI_M_IRQ_EN);
730 nbcon_exit_unsafe(wctxt);
731
732 /* Restart TTY data left queued when atomic output canceled M TX. */
733 if (READ_ONCE(port->tx_kick_enabled))
734 irq_work_queue(&port->tx_kick);
735 }
736
qcom_geni_serial_console_device_lock(struct console * co,unsigned long * flags)737 static void qcom_geni_serial_console_device_lock(struct console *co,
738 unsigned long *flags)
739 {
740 struct qcom_geni_serial_port *port;
741
742 port = get_port_from_line(co->index, true, NULL);
743 if (IS_ERR(port))
744 return;
745
746 __uart_port_lock_irqsave(&port->uport, flags);
747 }
748
qcom_geni_serial_console_device_unlock(struct console * co,unsigned long flags)749 static void qcom_geni_serial_console_device_unlock(struct console *co,
750 unsigned long flags)
751 {
752 struct qcom_geni_serial_port *port;
753 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL
754 u8 sysrq_ch;
755 #endif
756
757 port = get_port_from_line(co->index, true, NULL);
758 if (IS_ERR(port))
759 return;
760
761 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL
762 /* The threaded console writer can receive a SysRq character. */
763 sysrq_ch = port->uport.sysrq_ch;
764 port->uport.sysrq_ch = 0;
765 #endif
766 __uart_port_unlock_irqrestore(&port->uport, flags);
767
768 #ifdef CONFIG_MAGIC_SYSRQ_SERIAL
769 if (sysrq_ch)
770 handle_sysrq(sysrq_ch);
771 #endif
772 }
773
774 #endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
775
handle_rx_uart(struct uart_port * uport,u32 bytes)776 static void handle_rx_uart(struct uart_port *uport, u32 bytes)
777 {
778 struct qcom_geni_serial_port *port = to_dev_port(uport);
779 struct tty_port *tport = &uport->state->port;
780 int ret;
781
782 ret = tty_insert_flip_string(tport, port->rx_buf, bytes);
783 if (ret != bytes) {
784 dev_err_ratelimited(uport->dev, "failed to push data (%d < %u)\n",
785 ret, bytes);
786 }
787 uport->icount.rx += ret;
788 tty_flip_buffer_push(tport);
789 }
790
qcom_geni_serial_tx_empty(struct uart_port * uport)791 static unsigned int qcom_geni_serial_tx_empty(struct uart_port *uport)
792 {
793 return !readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
794 }
795
qcom_geni_serial_flush_buffer_dma(struct uart_port * uport)796 static void qcom_geni_serial_flush_buffer_dma(struct uart_port *uport)
797 {
798 struct qcom_geni_serial_port *port = to_dev_port(uport);
799
800 qcom_geni_serial_stop_tx_dma(uport);
801 port->tx_remaining = 0;
802 port->tx_queued = 0;
803 }
804
qcom_geni_serial_stop_tx_dma(struct uart_port * uport)805 static void qcom_geni_serial_stop_tx_dma(struct uart_port *uport)
806 {
807 struct qcom_geni_serial_port *port = to_dev_port(uport);
808
809 if (qcom_geni_serial_main_active(uport))
810 __qcom_geni_serial_cancel_tx_cmd(uport);
811
812 if (port->tx_dma_addr) {
813 writel(1, uport->membase + SE_DMA_TX_FSM_RST);
814 if (!qcom_geni_serial_poll_bit(uport, SE_DMA_TX_IRQ_STAT,
815 TX_RESET_DONE, true))
816 dev_err_ratelimited(uport->dev, "TX DMA reset failed");
817 writel(TX_RESET_DONE | TX_DMA_DONE,
818 uport->membase + SE_DMA_TX_IRQ_CLR);
819
820 geni_se_tx_dma_unprep(&port->se, port->tx_dma_addr,
821 port->tx_remaining);
822 port->tx_dma_addr = 0;
823 }
824 }
825
qcom_geni_serial_start_tx_dma(struct uart_port * uport)826 static void qcom_geni_serial_start_tx_dma(struct uart_port *uport)
827 {
828 struct qcom_geni_serial_port *port = to_dev_port(uport);
829 struct tty_port *tport = &uport->state->port;
830 unsigned int xmit_size;
831 u8 *tail;
832 int ret;
833
834 if (port->tx_dma_addr)
835 return;
836
837 if (kfifo_is_empty(&tport->xmit_fifo))
838 return;
839
840 xmit_size = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail,
841 UART_XMIT_SIZE);
842
843 trace_geni_serial_tx_data(uport->dev, tail, xmit_size);
844
845 qcom_geni_set_rs485_mode(uport, SER_RS485_RTS_ON_SEND);
846
847 qcom_geni_serial_setup_tx(uport, xmit_size);
848
849 ret = geni_se_tx_dma_prep(&port->se, tail, xmit_size,
850 &port->tx_dma_addr);
851 if (ret) {
852 dev_err(uport->dev, "unable to start TX SE DMA: %d\n", ret);
853 qcom_geni_serial_stop_tx_dma(uport);
854 return;
855 }
856
857 port->tx_remaining = xmit_size;
858 port->tx_dma_stale = false;
859 }
860
qcom_geni_serial_start_tx_fifo(struct uart_port * uport)861 static void qcom_geni_serial_start_tx_fifo(struct uart_port *uport)
862 {
863 unsigned char c;
864 u32 irq_en;
865
866 /*
867 * Start a new transfer in case the previous command was cancelled and
868 * left data in the FIFO which may prevent the watermark interrupt
869 * from triggering. Note that the stale data is discarded.
870 */
871 if (!qcom_geni_serial_main_active(uport) &&
872 !qcom_geni_serial_tx_empty(uport)) {
873 if (uart_fifo_out(uport, &c, 1) == 1) {
874 writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
875 qcom_geni_serial_setup_tx(uport, 1);
876 writel(c, uport->membase + SE_GENI_TX_FIFOn);
877 }
878 }
879
880 irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
881 irq_en |= M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN;
882 writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG);
883 writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
884 }
885
886 /* Caller holds the UART port lock. */
qcom_geni_serial_resume_tx(struct uart_port * uport)887 static void qcom_geni_serial_resume_tx(struct uart_port *uport)
888 {
889 if (!uart_tx_stopped(uport) &&
890 !kfifo_is_empty(&uport->state->port.xmit_fifo))
891 qcom_geni_serial_start_tx_fifo(uport);
892 }
893
qcom_geni_serial_restart_tx(struct irq_work * work)894 static void qcom_geni_serial_restart_tx(struct irq_work *work)
895 {
896 struct qcom_geni_serial_port *port = container_of(work,
897 struct qcom_geni_serial_port, tx_kick);
898 struct uart_port *uport = &port->uport;
899
900 if (!READ_ONCE(port->tx_kick_enabled) || !uport->state || uport->suspended)
901 return;
902
903 uart_port_lock(uport);
904 if (READ_ONCE(port->tx_kick_enabled) && uport->state && !uport->suspended)
905 qcom_geni_serial_resume_tx(uport);
906 uart_port_unlock(uport);
907 }
908
qcom_geni_serial_stop_tx_fifo(struct uart_port * uport)909 static void qcom_geni_serial_stop_tx_fifo(struct uart_port *uport)
910 {
911 u32 irq_en;
912
913 irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
914 irq_en &= ~(M_CMD_DONE_EN | M_TX_FIFO_WATERMARK_EN);
915 writel(0, uport->membase + SE_GENI_TX_WATERMARK_REG);
916 writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
917 }
918
__qcom_geni_serial_cancel_tx_cmd(struct uart_port * uport)919 static void __qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport)
920 {
921 struct qcom_geni_serial_port *port = to_dev_port(uport);
922
923 geni_se_cancel_m_cmd(&port->se);
924 if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
925 M_CMD_CANCEL_EN, true)) {
926 geni_se_abort_m_cmd(&port->se);
927 qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS,
928 M_CMD_ABORT_EN, true);
929 writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
930 }
931 writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
932 }
933
qcom_geni_serial_cancel_tx_cmd(struct uart_port * uport)934 static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport)
935 {
936 struct qcom_geni_serial_port *port = to_dev_port(uport);
937
938 if (!qcom_geni_serial_main_active(uport))
939 return;
940
941 __qcom_geni_serial_cancel_tx_cmd(uport);
942
943 port->tx_remaining = 0;
944 port->tx_queued = 0;
945 }
946
qcom_geni_serial_stop_rx_fifo(struct uart_port * uport)947 static void qcom_geni_serial_stop_rx_fifo(struct uart_port *uport)
948 {
949 u32 irq_en;
950 struct qcom_geni_serial_port *port = to_dev_port(uport);
951 u32 s_irq_status;
952
953 irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN);
954 irq_en &= ~(S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
955 writel(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
956
957 if (!qcom_geni_serial_secondary_active(uport))
958 return;
959
960 geni_se_cancel_s_cmd(&port->se);
961 qcom_geni_serial_poll_bit(uport, SE_GENI_S_IRQ_STATUS,
962 S_CMD_CANCEL_EN, true);
963 /*
964 * If timeout occurs secondary engine remains active
965 * and Abort sequence is executed.
966 */
967 s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
968 /* Flush the Rx buffer */
969 if (s_irq_status & S_RX_FIFO_LAST_EN)
970 qcom_geni_serial_handle_rx_fifo(uport, true);
971 writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
972
973 if (qcom_geni_serial_secondary_active(uport))
974 qcom_geni_serial_abort_rx(uport);
975 }
976
qcom_geni_serial_start_rx_fifo(struct uart_port * uport)977 static void qcom_geni_serial_start_rx_fifo(struct uart_port *uport)
978 {
979 u32 irq_en;
980 struct qcom_geni_serial_port *port = to_dev_port(uport);
981
982 if (qcom_geni_serial_secondary_active(uport))
983 qcom_geni_serial_stop_rx_fifo(uport);
984
985 geni_se_setup_s_cmd(&port->se, UART_START_READ, 0);
986
987 irq_en = readl(uport->membase + SE_GENI_S_IRQ_EN);
988 irq_en |= S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN;
989 writel(irq_en, uport->membase + SE_GENI_S_IRQ_EN);
990 }
991
qcom_geni_serial_stop_rx_dma(struct uart_port * uport)992 static void qcom_geni_serial_stop_rx_dma(struct uart_port *uport)
993 {
994 struct qcom_geni_serial_port *port = to_dev_port(uport);
995 bool done;
996
997 if (!qcom_geni_serial_secondary_active(uport))
998 return;
999
1000 geni_se_cancel_s_cmd(&port->se);
1001 done = qcom_geni_serial_poll_bit(uport, SE_DMA_RX_IRQ_STAT,
1002 RX_EOT, true);
1003 if (done) {
1004 writel(RX_EOT | RX_DMA_DONE,
1005 uport->membase + SE_DMA_RX_IRQ_CLR);
1006 } else {
1007 qcom_geni_serial_abort_rx(uport);
1008
1009 writel(1, uport->membase + SE_DMA_RX_FSM_RST);
1010 qcom_geni_serial_poll_bit(uport, SE_DMA_RX_IRQ_STAT,
1011 RX_RESET_DONE, true);
1012 writel(RX_RESET_DONE | RX_DMA_DONE,
1013 uport->membase + SE_DMA_RX_IRQ_CLR);
1014 }
1015
1016 }
1017
qcom_geni_serial_start_rx_dma(struct uart_port * uport)1018 static void qcom_geni_serial_start_rx_dma(struct uart_port *uport)
1019 {
1020 struct qcom_geni_serial_port *port = to_dev_port(uport);
1021
1022 if (qcom_geni_serial_secondary_active(uport))
1023 qcom_geni_serial_stop_rx_dma(uport);
1024
1025 geni_se_setup_s_cmd(&port->se, UART_START_READ, UART_PARAM_RFR_OPEN);
1026
1027 if (!port->rx_dma_addr) {
1028 dev_err(uport->dev, "RX DMA buffer not mapped\n");
1029 return;
1030 }
1031
1032 dma_sync_single_for_device(uport->dev->parent, port->rx_dma_addr,
1033 DMA_RX_BUF_SIZE, DMA_FROM_DEVICE);
1034 geni_se_rx_init_dma(&port->se, port->rx_dma_addr, DMA_RX_BUF_SIZE);
1035 }
1036
qcom_geni_serial_handle_rx_dma(struct uart_port * uport,bool drop)1037 static void qcom_geni_serial_handle_rx_dma(struct uart_port *uport, bool drop)
1038 {
1039 struct qcom_geni_serial_port *port = to_dev_port(uport);
1040 u32 rx_in;
1041
1042 if (!qcom_geni_serial_secondary_active(uport))
1043 return;
1044
1045 if (!port->rx_dma_addr)
1046 return;
1047
1048 dma_sync_single_for_cpu(uport->dev->parent, port->rx_dma_addr,
1049 DMA_RX_BUF_SIZE, DMA_FROM_DEVICE);
1050
1051 rx_in = readl(uport->membase + SE_DMA_RX_LEN_IN);
1052 if (!rx_in)
1053 dev_warn_ratelimited(uport->dev, "serial engine reports 0 RX bytes in!\n");
1054 else if (!drop) {
1055 trace_geni_serial_rx_data(uport->dev, port->rx_buf, rx_in);
1056 handle_rx_uart(uport, rx_in);
1057 }
1058
1059 dma_sync_single_for_device(uport->dev->parent, port->rx_dma_addr,
1060 DMA_RX_BUF_SIZE, DMA_FROM_DEVICE);
1061 geni_se_rx_init_dma(&port->se, port->rx_dma_addr, DMA_RX_BUF_SIZE);
1062 }
1063
qcom_geni_serial_start_rx(struct uart_port * uport)1064 static void qcom_geni_serial_start_rx(struct uart_port *uport)
1065 {
1066 uport->ops->start_rx(uport);
1067 }
1068
qcom_geni_serial_stop_rx(struct uart_port * uport)1069 static void qcom_geni_serial_stop_rx(struct uart_port *uport)
1070 {
1071 uport->ops->stop_rx(uport);
1072 }
1073
qcom_geni_serial_stop_tx(struct uart_port * uport)1074 static void qcom_geni_serial_stop_tx(struct uart_port *uport)
1075 {
1076 uport->ops->stop_tx(uport);
1077 }
1078
qcom_geni_serial_send_chunk_fifo(struct uart_port * uport,unsigned int chunk)1079 static void qcom_geni_serial_send_chunk_fifo(struct uart_port *uport,
1080 unsigned int chunk)
1081 {
1082 struct qcom_geni_serial_port *port = to_dev_port(uport);
1083 unsigned int tx_bytes, remaining = chunk;
1084 u8 buf[BYTES_PER_FIFO_WORD];
1085
1086 while (remaining) {
1087 memset(buf, 0, sizeof(buf));
1088 tx_bytes = min(remaining, BYTES_PER_FIFO_WORD);
1089
1090 uart_fifo_out(uport, buf, tx_bytes);
1091
1092 iowrite32_rep(uport->membase + SE_GENI_TX_FIFOn, buf, 1);
1093
1094 remaining -= tx_bytes;
1095 port->tx_remaining -= tx_bytes;
1096 }
1097 }
1098
qcom_geni_serial_handle_tx_fifo(struct uart_port * uport,bool done,bool active)1099 static void qcom_geni_serial_handle_tx_fifo(struct uart_port *uport,
1100 bool done, bool active)
1101 {
1102 struct qcom_geni_serial_port *port = to_dev_port(uport);
1103 struct tty_port *tport = &uport->state->port;
1104 size_t avail;
1105 size_t pending;
1106 u32 status;
1107 u32 irq_en;
1108 unsigned int chunk;
1109
1110 status = readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
1111
1112 /* Complete the current tx command before taking newly added data */
1113 if (active)
1114 pending = port->tx_remaining;
1115 else
1116 pending = kfifo_len(&tport->xmit_fifo);
1117
1118 /* All data has been transmitted or command has been cancelled */
1119 if (!pending && done) {
1120 qcom_geni_serial_stop_tx_fifo(uport);
1121 goto out_write_wakeup;
1122 }
1123
1124 if (active)
1125 avail = port->tx_fifo_depth - (status & TX_FIFO_WC);
1126 else
1127 avail = port->tx_fifo_depth;
1128
1129 avail *= BYTES_PER_FIFO_WORD;
1130
1131 chunk = min(avail, pending);
1132 if (!chunk)
1133 goto out_write_wakeup;
1134
1135 if (!active) {
1136 qcom_geni_serial_setup_tx(uport, pending);
1137 port->tx_remaining = pending;
1138 port->tx_queued = 0;
1139
1140 irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
1141 if (!(irq_en & M_TX_FIFO_WATERMARK_EN))
1142 writel(irq_en | M_TX_FIFO_WATERMARK_EN,
1143 uport->membase + SE_GENI_M_IRQ_EN);
1144 }
1145
1146 qcom_geni_serial_send_chunk_fifo(uport, chunk);
1147 port->tx_queued += chunk;
1148
1149 /*
1150 * The tx fifo watermark is level triggered and latched. Though we had
1151 * cleared it in qcom_geni_serial_isr it will have already reasserted
1152 * so we must clear it again here after our writes.
1153 */
1154 writel(M_TX_FIFO_WATERMARK_EN,
1155 uport->membase + SE_GENI_M_IRQ_CLEAR);
1156
1157 out_write_wakeup:
1158 if (!port->tx_remaining) {
1159 irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
1160 if (irq_en & M_TX_FIFO_WATERMARK_EN)
1161 writel(irq_en & ~M_TX_FIFO_WATERMARK_EN,
1162 uport->membase + SE_GENI_M_IRQ_EN);
1163 }
1164
1165 if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
1166 uart_write_wakeup(uport);
1167 }
1168
qcom_geni_serial_handle_tx_dma(struct uart_port * uport)1169 static void qcom_geni_serial_handle_tx_dma(struct uart_port *uport)
1170 {
1171 struct qcom_geni_serial_port *port = to_dev_port(uport);
1172 struct tty_port *tport = &uport->state->port;
1173 unsigned int fifo_len = kfifo_len(&tport->xmit_fifo);
1174 bool tx_dma_stale = port->tx_dma_stale;
1175
1176 /*
1177 * Only advance the kfifo if it still contains the bytes that were
1178 * transferred. uart_flush_buffer() may have run before this IRQ
1179 * fired: it calls kfifo_reset() under the port lock, making
1180 * fifo_len = 0 while tx_remaining remains non-zero. Calling
1181 * uart_xmit_advance() in that case would underflow kfifo->out past
1182 * kfifo->in, making kfifo_len() wrap to UART_XMIT_SIZE - tx_remaining
1183 * and triggering a spurious large DMA transfer of stale data.
1184 */
1185 if (!tx_dma_stale && fifo_len >= port->tx_remaining)
1186 uart_xmit_advance(uport, port->tx_remaining);
1187
1188 geni_se_tx_dma_unprep(&port->se, port->tx_dma_addr, port->tx_remaining);
1189 port->tx_dma_addr = 0;
1190 port->tx_remaining = 0;
1191 port->tx_dma_stale = false;
1192
1193 if (!kfifo_is_empty(&tport->xmit_fifo))
1194 qcom_geni_serial_start_tx_dma(uport);
1195
1196 if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
1197 uart_write_wakeup(uport);
1198 }
1199
qcom_geni_serial_isr(int isr,void * dev)1200 static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
1201 {
1202 u32 m_irq_en;
1203 u32 m_irq_status;
1204 u32 s_irq_status;
1205 u32 geni_status;
1206 u32 dma;
1207 u32 dma_tx_status;
1208 u32 dma_rx_status;
1209 struct uart_port *uport = dev;
1210 bool drop_rx = false;
1211 struct tty_port *tport = &uport->state->port;
1212 struct qcom_geni_serial_port *port = to_dev_port(uport);
1213
1214 if (uport->suspended)
1215 return IRQ_NONE;
1216
1217 uart_port_lock(uport);
1218
1219 s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
1220 dma_rx_status = readl(uport->membase + SE_DMA_RX_IRQ_STAT);
1221 writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
1222 writel(dma_rx_status, uport->membase + SE_DMA_RX_IRQ_CLR);
1223
1224 if (s_irq_status & S_RX_FIFO_WR_ERR_EN) {
1225 uport->icount.overrun++;
1226 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
1227 }
1228
1229 if (s_irq_status & (S_GP_IRQ_0_EN | S_GP_IRQ_1_EN)) {
1230 if (s_irq_status & S_GP_IRQ_0_EN)
1231 uport->icount.parity++;
1232 drop_rx = true;
1233 } else if (s_irq_status & (S_GP_IRQ_2_EN | S_GP_IRQ_3_EN)) {
1234 uport->icount.brk++;
1235 port->brk = true;
1236 }
1237
1238 m_irq_status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
1239 dma_tx_status = readl(uport->membase + SE_DMA_TX_IRQ_STAT);
1240 geni_status = readl(uport->membase + SE_GENI_STATUS);
1241 dma = readl(uport->membase + SE_GENI_DMA_MODE_EN);
1242 m_irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
1243
1244 trace_geni_serial_irq(uport->dev, m_irq_status, s_irq_status,
1245 dma_tx_status, dma_rx_status);
1246
1247 writel(m_irq_status, uport->membase + SE_GENI_M_IRQ_CLEAR);
1248 writel(dma_tx_status, uport->membase + SE_DMA_TX_IRQ_CLR);
1249
1250 if (WARN_ON(m_irq_status & M_ILLEGAL_CMD_EN))
1251 goto handle_rx;
1252
1253 if (dma) {
1254 if (dma_tx_status & TX_DMA_DONE) {
1255 qcom_geni_serial_handle_tx_dma(uport);
1256 qcom_geni_set_rs485_mode(uport, SER_RS485_RTS_AFTER_SEND);
1257 }
1258 } else if (m_irq_status & m_irq_en &
1259 (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN)) {
1260 qcom_geni_serial_handle_tx_fifo(uport,
1261 m_irq_status & M_CMD_DONE_EN,
1262 geni_status & M_GENI_CMD_ACTIVE);
1263 }
1264
1265 handle_rx:
1266 if (dma) {
1267 if (dma_rx_status) {
1268 if (dma_rx_status & RX_RESET_DONE)
1269 goto out_unlock;
1270
1271 if (dma_rx_status & RX_DMA_PARITY_ERR) {
1272 uport->icount.parity++;
1273 drop_rx = true;
1274 }
1275
1276 if (dma_rx_status & RX_DMA_BREAK)
1277 uport->icount.brk++;
1278
1279 if (dma_rx_status & (RX_DMA_DONE | RX_EOT))
1280 qcom_geni_serial_handle_rx_dma(uport, drop_rx);
1281 }
1282 } else {
1283 if (s_irq_status & (S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN))
1284 qcom_geni_serial_handle_rx_fifo(uport, drop_rx);
1285 }
1286
1287 out_unlock:
1288 uart_unlock_and_check_sysrq(uport);
1289
1290 return IRQ_HANDLED;
1291 }
1292
setup_fifos(struct qcom_geni_serial_port * port)1293 static int setup_fifos(struct qcom_geni_serial_port *port)
1294 {
1295 struct uart_port *uport;
1296 u32 old_rx_fifo_depth = port->rx_fifo_depth;
1297
1298 uport = &port->uport;
1299 port->tx_fifo_depth = geni_se_get_tx_fifo_depth(&port->se);
1300 port->tx_fifo_width = geni_se_get_tx_fifo_width(&port->se);
1301 port->rx_fifo_depth = geni_se_get_rx_fifo_depth(&port->se);
1302 uport->fifosize =
1303 (port->tx_fifo_depth * port->tx_fifo_width) / BITS_PER_BYTE;
1304
1305 if (port->rx_buf && (old_rx_fifo_depth != port->rx_fifo_depth) && port->rx_fifo_depth) {
1306 /*
1307 * Use krealloc rather than krealloc_array because rx_buf is
1308 * accessed as 1 byte entries as well as 4 byte entries so it's
1309 * not necessarily an array.
1310 */
1311 port->rx_buf = devm_krealloc(uport->dev, port->rx_buf,
1312 port->rx_fifo_depth * sizeof(u32),
1313 GFP_KERNEL);
1314 if (!port->rx_buf)
1315 return -ENOMEM;
1316 }
1317
1318 return 0;
1319 }
1320
1321
qcom_geni_serial_shutdown(struct uart_port * uport)1322 static void qcom_geni_serial_shutdown(struct uart_port *uport)
1323 {
1324 struct qcom_geni_serial_port *port = to_dev_port(uport);
1325
1326 /* Atomic console output queues tx_kick without taking the port lock. */
1327 WRITE_ONCE(port->tx_kick_enabled, false);
1328 irq_work_sync(&port->tx_kick);
1329 disable_irq(uport->irq);
1330
1331 uart_port_lock_irq(uport);
1332 qcom_geni_serial_stop_tx(uport);
1333 qcom_geni_serial_stop_rx(uport);
1334
1335 qcom_geni_serial_cancel_tx_cmd(uport);
1336 uart_port_unlock_irq(uport);
1337
1338 pm_runtime_put_sync(uport->dev);
1339 }
1340
qcom_geni_serial_flush_buffer_fifo(struct uart_port * uport)1341 static void qcom_geni_serial_flush_buffer_fifo(struct uart_port *uport)
1342 {
1343 struct qcom_geni_serial_port *port = to_dev_port(uport);
1344
1345 if (port->tx_dma_addr)
1346 port->tx_dma_stale = true;
1347 qcom_geni_serial_cancel_tx_cmd(uport);
1348 }
1349
qcom_geni_serial_port_setup(struct uart_port * uport)1350 static int qcom_geni_serial_port_setup(struct uart_port *uport)
1351 {
1352 struct qcom_geni_serial_port *port = to_dev_port(uport);
1353 u32 rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;
1354 u32 proto;
1355 u32 pin_swap;
1356 int ret;
1357
1358 proto = geni_se_read_proto(&port->se);
1359 if (proto == GENI_SE_INVALID_PROTO) {
1360 ret = geni_load_se_firmware(&port->se, GENI_SE_UART);
1361 if (ret) {
1362 dev_err(uport->dev, "UART firmware load failed ret: %d\n", ret);
1363 return ret;
1364 }
1365 } else if (proto != GENI_SE_UART) {
1366 dev_err(uport->dev, "Invalid FW loaded, proto: %d\n", proto);
1367 return -ENXIO;
1368 }
1369
1370 qcom_geni_serial_stop_rx(uport);
1371
1372 ret = setup_fifos(port);
1373 if (ret)
1374 return ret;
1375
1376 writel(rxstale, uport->membase + SE_UART_RX_STALE_CNT);
1377
1378 pin_swap = readl(uport->membase + SE_UART_IO_MACRO_CTRL);
1379 if (port->rx_tx_swap) {
1380 pin_swap &= ~DEFAULT_IO_MACRO_IO2_IO3_MASK;
1381 pin_swap |= IO_MACRO_IO2_IO3_SWAP;
1382 }
1383 if (port->cts_rts_swap) {
1384 pin_swap &= ~DEFAULT_IO_MACRO_IO0_IO1_MASK;
1385 pin_swap |= IO_MACRO_IO0_SEL;
1386 }
1387 /* Configure this register if RX-TX, CTS-RTS pins are swapped */
1388 if (port->rx_tx_swap || port->cts_rts_swap)
1389 writel(pin_swap, uport->membase + SE_UART_IO_MACRO_CTRL);
1390
1391 /*
1392 * Make an unconditional cancel on the main sequencer to reset
1393 * it else we could end up in data loss scenarios.
1394 */
1395 if (uart_console(uport))
1396 qcom_geni_serial_poll_tx_done(uport);
1397 geni_se_config_packing(&port->se, BITS_PER_BYTE, BYTES_PER_FIFO_WORD,
1398 false, true, true);
1399 geni_se_init(&port->se, UART_RX_WM, port->rx_fifo_depth - 2);
1400 geni_se_select_mode(&port->se, port->dev_data->mode);
1401 port->setup = true;
1402
1403 return 0;
1404 }
1405
qcom_geni_serial_startup(struct uart_port * uport)1406 static int qcom_geni_serial_startup(struct uart_port *uport)
1407 {
1408 int ret;
1409 struct qcom_geni_serial_port *port = to_dev_port(uport);
1410 struct tty_port *tport = &uport->state->port;
1411
1412 ret = pm_runtime_resume_and_get(uport->dev);
1413 if (ret < 0) {
1414 dev_err(uport->dev, "Failed to resume and get %d\n", ret);
1415 return ret;
1416 }
1417
1418 if (!port->setup) {
1419 ret = qcom_geni_serial_port_setup(uport);
1420 if (ret) {
1421 pm_runtime_put_sync(uport->dev);
1422 return ret;
1423 }
1424 }
1425
1426 /*
1427 * Skip the close-time transmit drain for console ports so that
1428 * shutdown can proceed without waiting for pending TX completion.
1429 */
1430 if (uart_console(uport))
1431 tport->closing_wait = ASYNC_CLOSING_WAIT_NONE;
1432
1433 uart_port_lock_irq(uport);
1434 qcom_geni_serial_start_rx(uport);
1435 uart_port_unlock_irq(uport);
1436
1437 enable_irq(uport->irq);
1438 WRITE_ONCE(port->tx_kick_enabled, true);
1439
1440 return 0;
1441 }
1442
geni_serial_set_rate(struct geni_se * se,unsigned long baud)1443 static int geni_serial_set_rate(struct geni_se *se, unsigned long baud)
1444 {
1445 struct qcom_geni_serial_port *port = dev_get_drvdata(se->dev);
1446 struct uart_port *uport = &port->uport;
1447 unsigned long clk_rate;
1448 unsigned int avg_bw_core, clk_idx;
1449 unsigned int clk_div;
1450 u32 ver, sampling_rate;
1451 u32 ser_clk_cfg;
1452 int ret;
1453
1454 sampling_rate = UART_OVERSAMPLING;
1455 /* Sampling rate is halved for IP versions >= 2.5 */
1456 ver = geni_se_get_qup_hw_version(&port->se);
1457 if (ver >= QUP_SE_VERSION_2_5)
1458 sampling_rate /= 2;
1459
1460 ret = geni_se_clk_freq_match(&port->se, baud * sampling_rate, &clk_idx, &clk_rate, false);
1461 if (ret) {
1462 dev_err(port->se.dev, "Failed to find src clk for baud rate: %lu ret: %d\n",
1463 baud, ret);
1464 return ret;
1465 }
1466
1467 clk_div = DIV_ROUND_UP(clk_rate, baud * sampling_rate);
1468 /* Check if calculated divider exceeds maximum allowed value */
1469 if (clk_div > (CLK_DIV_MSK >> CLK_DIV_SHFT)) {
1470 dev_err(port->se.dev, "Calculated clock divider %u exceeds maximum\n", clk_div);
1471 return -EINVAL;
1472 }
1473
1474 trace_geni_serial_clk_cfg(uport->dev, baud * sampling_rate, clk_rate,
1475 clk_div, clk_idx);
1476
1477 uport->uartclk = clk_rate;
1478 port->clk_rate = clk_rate;
1479 dev_pm_opp_set_rate(uport->dev, clk_rate);
1480 ser_clk_cfg = SER_CLK_EN;
1481 ser_clk_cfg |= clk_div << CLK_DIV_SHFT;
1482
1483 /*
1484 * Bump up BW vote on CPU and CORE path as driver supports FIFO mode
1485 * only.
1486 */
1487 avg_bw_core = baud > 115200 ? CORE_2X_50_MHZ : CORE_2X_19_2_MHZ;
1488 port->se.icc_paths[GENI_TO_CORE].avg_bw = Bps_to_icc(avg_bw_core);
1489 port->se.icc_paths[CPU_TO_GENI].avg_bw = Bps_to_icc(baud);
1490 geni_icc_set_bw(&port->se);
1491
1492 writel(ser_clk_cfg, uport->membase + GENI_SER_M_CLK_CFG);
1493 writel(ser_clk_cfg, uport->membase + GENI_SER_S_CLK_CFG);
1494 /* Configure clock selection register with the selected clock index */
1495 writel(clk_idx & CLK_SEL_MSK, uport->membase + SE_GENI_CLK_SEL);
1496 return 0;
1497 }
1498
qcom_geni_serial_set_termios(struct uart_port * uport,struct ktermios * termios,const struct ktermios * old)1499 static void qcom_geni_serial_set_termios(struct uart_port *uport,
1500 struct ktermios *termios,
1501 const struct ktermios *old)
1502 {
1503 struct qcom_geni_serial_port *port = to_dev_port(uport);
1504 unsigned int baud;
1505 unsigned long timeout;
1506 u32 bits_per_char;
1507 u32 tx_trans_cfg;
1508 u32 tx_parity_cfg;
1509 u32 rx_trans_cfg;
1510 u32 rx_parity_cfg;
1511 u32 stop_bit_len;
1512 int ret = 0;
1513
1514 /* baud rate */
1515 baud = uart_get_baud_rate(uport, termios, old, 300, 8000000);
1516
1517 ret = port->dev_data->set_rate(&port->se, baud);
1518 if (ret)
1519 return;
1520
1521 /* parity */
1522 tx_trans_cfg = readl(uport->membase + SE_UART_TX_TRANS_CFG);
1523 tx_parity_cfg = readl(uport->membase + SE_UART_TX_PARITY_CFG);
1524 rx_trans_cfg = readl(uport->membase + SE_UART_RX_TRANS_CFG);
1525 rx_parity_cfg = readl(uport->membase + SE_UART_RX_PARITY_CFG);
1526 if (termios->c_cflag & PARENB) {
1527 tx_trans_cfg |= UART_TX_PAR_EN;
1528 rx_trans_cfg |= UART_RX_PAR_EN;
1529 tx_parity_cfg |= PAR_CALC_EN;
1530 rx_parity_cfg |= PAR_CALC_EN;
1531 if (termios->c_cflag & PARODD) {
1532 tx_parity_cfg |= PAR_ODD;
1533 rx_parity_cfg |= PAR_ODD;
1534 } else if (termios->c_cflag & CMSPAR) {
1535 tx_parity_cfg |= PAR_SPACE;
1536 rx_parity_cfg |= PAR_SPACE;
1537 } else {
1538 tx_parity_cfg |= PAR_EVEN;
1539 rx_parity_cfg |= PAR_EVEN;
1540 }
1541 } else {
1542 tx_trans_cfg &= ~UART_TX_PAR_EN;
1543 rx_trans_cfg &= ~UART_RX_PAR_EN;
1544 tx_parity_cfg &= ~PAR_CALC_EN;
1545 rx_parity_cfg &= ~PAR_CALC_EN;
1546 }
1547
1548 /* bits per char */
1549 bits_per_char = tty_get_char_size(termios->c_cflag);
1550
1551 /* stop bits */
1552 if (termios->c_cflag & CSTOPB)
1553 stop_bit_len = TX_STOP_BIT_LEN_2;
1554 else
1555 stop_bit_len = TX_STOP_BIT_LEN_1;
1556
1557 /* Configure flow control based on CRTSCTS flag.
1558 * When CRTSCTS is set, use HW/auto flow control mode, where HW
1559 * controls the RTS/CTS pin based FIFO state.
1560 * When CRTSCTS is clear, the CTS pin value is ignored for TX
1561 * path and RTS pin can be set/cleared using registers, for RX
1562 * path.
1563 */
1564
1565 if (termios->c_cflag & CRTSCTS) {
1566 tx_trans_cfg &= ~UART_CTS_MASK;
1567 port->manual_flow = false;
1568 } else {
1569 tx_trans_cfg |= UART_CTS_MASK;
1570 port->manual_flow = true;
1571 }
1572
1573 if (baud) {
1574 uart_update_timeout(uport, termios->c_cflag, baud);
1575
1576 /*
1577 * Make sure that qcom_geni_serial_poll_bitfield() waits for
1578 * the FIFO, two-word intermediate transfer register and shift
1579 * register to clear.
1580 *
1581 * Note that uart_fifo_timeout() also adds a 20 ms margin.
1582 */
1583 timeout = jiffies_to_usecs(uart_fifo_timeout(uport));
1584 timeout += 3 * timeout / port->tx_fifo_depth;
1585 WRITE_ONCE(port->poll_timeout_us, timeout);
1586 }
1587
1588 if (!uart_console(uport))
1589 writel(port->loopback,
1590 uport->membase + SE_UART_LOOPBACK_CFG);
1591 writel(tx_trans_cfg, uport->membase + SE_UART_TX_TRANS_CFG);
1592 writel(tx_parity_cfg, uport->membase + SE_UART_TX_PARITY_CFG);
1593 writel(rx_trans_cfg, uport->membase + SE_UART_RX_TRANS_CFG);
1594 writel(rx_parity_cfg, uport->membase + SE_UART_RX_PARITY_CFG);
1595 writel(bits_per_char, uport->membase + SE_UART_TX_WORD_LEN);
1596 writel(bits_per_char, uport->membase + SE_UART_RX_WORD_LEN);
1597 writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
1598
1599 trace_geni_serial_set_termios(uport->dev, baud, bits_per_char,
1600 tx_trans_cfg, tx_parity_cfg, rx_trans_cfg,
1601 rx_parity_cfg, stop_bit_len);
1602 }
1603
1604 #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
qcom_geni_console_setup(struct console * co,char * options)1605 static int qcom_geni_console_setup(struct console *co, char *options)
1606 {
1607 struct uart_port *uport;
1608 struct qcom_geni_serial_port *port;
1609 int baud = 115200;
1610 int bits = 8;
1611 int parity = 'n';
1612 int flow = 'n';
1613 int ret;
1614
1615 if (co->index >= GENI_UART_CONS_PORTS || co->index < 0)
1616 return -ENXIO;
1617
1618 port = get_port_from_line(co->index, true, NULL);
1619 if (IS_ERR(port)) {
1620 pr_err("Invalid line %d\n", co->index);
1621 return PTR_ERR(port);
1622 }
1623
1624 uport = &port->uport;
1625
1626 if (unlikely(!uport->membase))
1627 return -ENXIO;
1628
1629 ret = pm_runtime_resume_and_get(uport->dev);
1630 if (ret < 0)
1631 return ret;
1632
1633 if (!port->setup) {
1634 ret = qcom_geni_serial_port_setup(uport);
1635 if (ret) {
1636 pm_runtime_put_sync(uport->dev);
1637 return ret;
1638 }
1639 }
1640
1641 if (options)
1642 uart_parse_options(options, &baud, &parity, &bits, &flow);
1643
1644 ret = uart_set_options(uport, co, baud, parity, bits, flow);
1645 if (ret)
1646 pm_runtime_put_sync(uport->dev);
1647
1648 return ret;
1649 }
1650
qcom_geni_console_exit(struct console * co)1651 static int qcom_geni_console_exit(struct console *co)
1652 {
1653 struct qcom_geni_serial_port *port;
1654
1655 port = get_port_from_line(co->index, true, NULL);
1656 if (IS_ERR(port))
1657 return PTR_ERR(port);
1658
1659 return pm_runtime_put_sync(port->uport.dev);
1660 }
1661
qcom_geni_serial_earlycon_write(struct console * con,const char * s,unsigned int n)1662 static void qcom_geni_serial_earlycon_write(struct console *con,
1663 const char *s, unsigned int n)
1664 {
1665 struct earlycon_device *dev = con->data;
1666
1667 __qcom_geni_serial_console_write(&dev->port, s, n, false);
1668 }
1669
1670 #ifdef CONFIG_CONSOLE_POLL
qcom_geni_serial_earlycon_read(struct console * con,char * s,unsigned int n)1671 static int qcom_geni_serial_earlycon_read(struct console *con,
1672 char *s, unsigned int n)
1673 {
1674 struct earlycon_device *dev = con->data;
1675 struct uart_port *uport = &dev->port;
1676 int num_read = 0;
1677 int ch;
1678
1679 while (num_read < n) {
1680 ch = qcom_geni_serial_get_char(uport);
1681 if (ch == NO_POLL_CHAR)
1682 break;
1683 s[num_read++] = ch;
1684 }
1685
1686 return num_read;
1687 }
1688
qcom_geni_serial_enable_early_read(struct geni_se * se,struct console * con)1689 static void __init qcom_geni_serial_enable_early_read(struct geni_se *se,
1690 struct console *con)
1691 {
1692 geni_se_setup_s_cmd(se, UART_START_READ, 0);
1693 con->read = qcom_geni_serial_earlycon_read;
1694 }
1695 #else
qcom_geni_serial_enable_early_read(struct geni_se * se,struct console * con)1696 static inline void qcom_geni_serial_enable_early_read(struct geni_se *se,
1697 struct console *con) { }
1698 #endif
1699
1700 static struct qcom_geni_private_data earlycon_private_data;
1701
qcom_geni_serial_earlycon_setup(struct earlycon_device * dev,const char * opt)1702 static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev,
1703 const char *opt)
1704 {
1705 struct uart_port *uport = &dev->port;
1706 u32 tx_trans_cfg;
1707 u32 tx_parity_cfg = 0; /* Disable Tx Parity */
1708 u32 rx_trans_cfg = 0;
1709 u32 rx_parity_cfg = 0; /* Disable Rx Parity */
1710 u32 stop_bit_len = 0; /* Default stop bit length - 1 bit */
1711 u32 bits_per_char;
1712 struct geni_se se;
1713
1714 if (!uport->membase)
1715 return -EINVAL;
1716
1717 uport->private_data = &earlycon_private_data;
1718
1719 memset(&se, 0, sizeof(se));
1720 se.base = uport->membase;
1721 if (geni_se_read_proto(&se) != GENI_SE_UART)
1722 return -ENXIO;
1723 /*
1724 * Ignore Flow control.
1725 * n = 8.
1726 */
1727 tx_trans_cfg = UART_CTS_MASK;
1728 bits_per_char = BITS_PER_BYTE;
1729
1730 /*
1731 * Make an unconditional cancel on the main sequencer to reset
1732 * it else we could end up in data loss scenarios.
1733 */
1734 qcom_geni_serial_poll_tx_done(uport);
1735 qcom_geni_serial_abort_rx(uport);
1736 geni_se_config_packing(&se, BITS_PER_BYTE, BYTES_PER_FIFO_WORD,
1737 false, true, true);
1738 geni_se_init(&se, DEF_FIFO_DEPTH_WORDS / 2, DEF_FIFO_DEPTH_WORDS - 2);
1739 geni_se_select_mode(&se, GENI_SE_FIFO);
1740
1741 writel(tx_trans_cfg, uport->membase + SE_UART_TX_TRANS_CFG);
1742 writel(tx_parity_cfg, uport->membase + SE_UART_TX_PARITY_CFG);
1743 writel(rx_trans_cfg, uport->membase + SE_UART_RX_TRANS_CFG);
1744 writel(rx_parity_cfg, uport->membase + SE_UART_RX_PARITY_CFG);
1745 writel(bits_per_char, uport->membase + SE_UART_TX_WORD_LEN);
1746 writel(bits_per_char, uport->membase + SE_UART_RX_WORD_LEN);
1747 writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
1748
1749 dev->con->write = qcom_geni_serial_earlycon_write;
1750 dev->con->setup = NULL;
1751 qcom_geni_serial_enable_early_read(&se, dev->con);
1752
1753 return 0;
1754 }
1755 OF_EARLYCON_DECLARE(qcom_geni, "qcom,geni-debug-uart",
1756 qcom_geni_serial_earlycon_setup);
1757
console_register(struct uart_driver * drv)1758 static int __init console_register(struct uart_driver *drv)
1759 {
1760 return uart_register_driver(drv);
1761 }
1762
console_unregister(struct uart_driver * drv)1763 static void console_unregister(struct uart_driver *drv)
1764 {
1765 uart_unregister_driver(drv);
1766 }
1767
1768 static struct console cons_ops = {
1769 .name = "ttyMSM",
1770 .write_atomic = qcom_geni_serial_console_write_atomic,
1771 .write_thread = qcom_geni_serial_console_write_thread,
1772 .device_lock = qcom_geni_serial_console_device_lock,
1773 .device_unlock = qcom_geni_serial_console_device_unlock,
1774 .device = uart_console_device,
1775 .setup = qcom_geni_console_setup,
1776 .exit = qcom_geni_console_exit,
1777 .flags = CON_PRINTBUFFER | CON_NBCON,
1778 .index = -1,
1779 .data = &qcom_geni_console_driver,
1780 };
1781
1782 static struct uart_driver qcom_geni_console_driver = {
1783 .owner = THIS_MODULE,
1784 .driver_name = "qcom_geni_console",
1785 .dev_name = "ttyMSM",
1786 .nr = GENI_UART_CONS_PORTS,
1787 .cons = &cons_ops,
1788 };
1789 #else
console_register(struct uart_driver * drv)1790 static int console_register(struct uart_driver *drv)
1791 {
1792 return 0;
1793 }
1794
console_unregister(struct uart_driver * drv)1795 static void console_unregister(struct uart_driver *drv)
1796 {
1797 }
1798 #endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
1799
1800 static struct uart_driver qcom_geni_uart_driver = {
1801 .owner = THIS_MODULE,
1802 .driver_name = "qcom_geni_uart",
1803 .dev_name = "ttyHS",
1804 .nr = CONFIG_SERIAL_QCOM_GENI_UART_PORTS,
1805 };
1806
1807 /**
1808 * qcom_geni_rs485_config - Configure RS485 settings for the UART port
1809 * @uport: Pointer to the UART port structure
1810 * @termios: Pointer to the termios structure
1811 * @rs485: Pointer to the RS485 configuration structure
1812 * This function configures the RTS (Request to Send) pin behavior for RS485 mode.
1813 * When RS485 mode is enabled, the RTS pin is kept in default ACTIVE HIGH state.
1814 * Return: Always returns 0.
1815 */
1816
qcom_geni_rs485_config(struct uart_port * uport,struct ktermios * termios,struct serial_rs485 * rs485)1817 static int qcom_geni_rs485_config(struct uart_port *uport,
1818 struct ktermios *termios, struct serial_rs485 *rs485)
1819 {
1820 qcom_geni_set_rs485_mode(uport, SER_RS485_ENABLED);
1821
1822 return 0;
1823 }
1824
1825 static const struct uart_ops qcom_geni_console_pops = {
1826 .tx_empty = qcom_geni_serial_tx_empty,
1827 .stop_tx = qcom_geni_serial_stop_tx_fifo,
1828 .start_tx = qcom_geni_serial_start_tx_fifo,
1829 .stop_rx = qcom_geni_serial_stop_rx_fifo,
1830 .start_rx = qcom_geni_serial_start_rx_fifo,
1831 .set_termios = qcom_geni_serial_set_termios,
1832 .startup = qcom_geni_serial_startup,
1833 .request_port = qcom_geni_serial_request_port,
1834 .config_port = qcom_geni_serial_config_port,
1835 .shutdown = qcom_geni_serial_shutdown,
1836 .flush_buffer = qcom_geni_serial_flush_buffer_fifo,
1837 .type = qcom_geni_serial_get_type,
1838 .set_mctrl = qcom_geni_serial_set_mctrl,
1839 .get_mctrl = qcom_geni_serial_get_mctrl,
1840 #ifdef CONFIG_CONSOLE_POLL
1841 .poll_get_char = qcom_geni_serial_get_char,
1842 .poll_put_char = qcom_geni_serial_poll_put_char,
1843 .poll_init = qcom_geni_serial_poll_init,
1844 #endif
1845 };
1846
1847 static const struct uart_ops qcom_geni_uart_pops = {
1848 .tx_empty = qcom_geni_serial_tx_empty,
1849 .stop_tx = qcom_geni_serial_stop_tx_dma,
1850 .start_tx = qcom_geni_serial_start_tx_dma,
1851 .start_rx = qcom_geni_serial_start_rx_dma,
1852 .stop_rx = qcom_geni_serial_stop_rx_dma,
1853 .set_termios = qcom_geni_serial_set_termios,
1854 .startup = qcom_geni_serial_startup,
1855 .request_port = qcom_geni_serial_request_port,
1856 .config_port = qcom_geni_serial_config_port,
1857 .shutdown = qcom_geni_serial_shutdown,
1858 .flush_buffer = qcom_geni_serial_flush_buffer_dma,
1859 .type = qcom_geni_serial_get_type,
1860 .set_mctrl = qcom_geni_serial_set_mctrl,
1861 .get_mctrl = qcom_geni_serial_get_mctrl,
1862 };
1863
qcom_geni_serial_panic_notifier(struct notifier_block * nb,unsigned long action,void * data)1864 static int qcom_geni_serial_panic_notifier(struct notifier_block *nb,
1865 unsigned long action, void *data)
1866 {
1867 struct qcom_geni_serial_port *port =
1868 container_of(nb, struct qcom_geni_serial_port, panic_nb);
1869 struct uart_port *uport = &port->uport;
1870
1871 if (pm_runtime_status_suspended(uport->dev))
1872 return NOTIFY_OK;
1873
1874 qcom_geni_serial_stop_tx(uport);
1875 qcom_geni_serial_stop_rx(uport);
1876
1877 return NOTIFY_OK;
1878 }
1879
qcom_geni_serial_probe(struct platform_device * pdev)1880 static int qcom_geni_serial_probe(struct platform_device *pdev)
1881 {
1882 int ret = 0;
1883 int line;
1884 struct qcom_geni_serial_port *port;
1885 struct uart_port *uport;
1886 struct resource *res;
1887 int irq;
1888 struct uart_driver *drv;
1889 const struct qcom_geni_device_data *data;
1890
1891 data = of_device_get_match_data(&pdev->dev);
1892 if (!data)
1893 return -EINVAL;
1894
1895 if (data->console) {
1896 drv = &qcom_geni_console_driver;
1897 line = of_alias_get_id(pdev->dev.of_node, "serial");
1898 } else {
1899 drv = &qcom_geni_uart_driver;
1900 line = of_alias_get_id(pdev->dev.of_node, "serial");
1901 if (line == -ENODEV) /* compat with non-standard aliases */
1902 line = of_alias_get_id(pdev->dev.of_node, "hsuart");
1903 }
1904
1905 port = get_port_from_line(line, data->console, &pdev->dev);
1906 if (IS_ERR(port)) {
1907 dev_err(&pdev->dev, "Invalid line %d\n", line);
1908 return PTR_ERR(port);
1909 }
1910
1911 uport = &port->uport;
1912 /* Don't allow 2 drivers to access the same port */
1913 if (uport->private_data)
1914 return -ENODEV;
1915
1916 uport->dev = &pdev->dev;
1917 port->dev_data = data;
1918 port->se.dev = &pdev->dev;
1919 port->se.wrapper = dev_get_drvdata(pdev->dev.parent);
1920
1921 ret = port->dev_data->resources_init(&port->se);
1922 if (ret)
1923 return ret;
1924
1925 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1926 if (!res) {
1927 ret = -EINVAL;
1928 goto error;
1929 }
1930
1931 uport->mapbase = res->start;
1932
1933 uport->rs485_config = qcom_geni_rs485_config;
1934 uport->rs485_supported = qcom_geni_rs485_supported;
1935 port->tx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
1936 port->rx_fifo_depth = DEF_FIFO_DEPTH_WORDS;
1937 port->tx_fifo_width = DEF_FIFO_WIDTH_BITS;
1938
1939 if (!data->console) {
1940 port->rx_buf = devm_kzalloc(uport->dev,
1941 DMA_RX_BUF_SIZE, GFP_KERNEL);
1942 if (!port->rx_buf) {
1943 ret = -ENOMEM;
1944 goto error;
1945 }
1946
1947 port->rx_dma_addr = dma_map_single(pdev->dev.parent, port->rx_buf,
1948 DMA_RX_BUF_SIZE, DMA_FROM_DEVICE);
1949 if (dma_mapping_error(pdev->dev.parent, port->rx_dma_addr)) {
1950 ret = -EIO;
1951 dev_err(&pdev->dev, "Failed to map RX DMA buffer: %d\n", ret);
1952 goto error;
1953 }
1954 }
1955
1956 port->name = devm_kasprintf(uport->dev, GFP_KERNEL,
1957 "qcom_geni_serial_%s%d",
1958 uart_console(uport) ? "console" : "uart", uport->line);
1959 if (!port->name) {
1960 ret = -ENOMEM;
1961 goto error;
1962 }
1963
1964 irq = platform_get_irq(pdev, 0);
1965 if (irq < 0) {
1966 ret = irq;
1967 goto error;
1968 }
1969
1970 uport->irq = irq;
1971 uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_QCOM_GENI_CONSOLE);
1972
1973 if (!data->console)
1974 port->wakeup_irq = platform_get_irq_optional(pdev, 1);
1975
1976 if (of_property_read_bool(pdev->dev.of_node, "rx-tx-swap"))
1977 port->rx_tx_swap = true;
1978
1979 if (of_property_read_bool(pdev->dev.of_node, "cts-rts-swap"))
1980 port->cts_rts_swap = true;
1981
1982 port->private_data.drv = drv;
1983 uport->private_data = &port->private_data;
1984 init_irq_work(&port->tx_kick, qcom_geni_serial_restart_tx);
1985 platform_set_drvdata(pdev, port);
1986
1987 irq_set_status_flags(uport->irq, IRQ_NOAUTOEN);
1988 ret = devm_request_irq(uport->dev, uport->irq, qcom_geni_serial_isr,
1989 IRQF_TRIGGER_HIGH, port->name, uport);
1990 if (ret) {
1991 dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);
1992 goto error;
1993 }
1994
1995 ret = uart_get_rs485_mode(uport);
1996 if (ret)
1997 goto error;
1998
1999 if (port->wakeup_irq > 0) {
2000 device_init_wakeup(&pdev->dev, true);
2001 ret = dev_pm_set_dedicated_wake_irq(&pdev->dev,
2002 port->wakeup_irq);
2003 if (ret) {
2004 device_init_wakeup(&pdev->dev, false);
2005 ida_free(&port_ida, uport->line);
2006 goto error;
2007 }
2008 }
2009
2010 devm_pm_runtime_enable(port->se.dev);
2011
2012 ret = pm_runtime_resume_and_get(uport->dev);
2013 if (ret < 0) {
2014 dev_err(uport->dev, "Failed to resume and get %d\n", ret);
2015 goto error;
2016 }
2017
2018 ret = uart_add_one_port(drv, uport);
2019 pm_runtime_put(uport->dev);
2020 if (ret)
2021 goto error;
2022
2023 port->panic_nb.notifier_call = qcom_geni_serial_panic_notifier;
2024 atomic_notifier_chain_register(&panic_notifier_list, &port->panic_nb);
2025
2026 return 0;
2027
2028 error:
2029 if (port->rx_dma_addr) {
2030 dma_unmap_single(pdev->dev.parent, port->rx_dma_addr,
2031 DMA_RX_BUF_SIZE, DMA_FROM_DEVICE);
2032 port->rx_dma_addr = 0;
2033 }
2034 dev_pm_domain_detach_list(port->se.pd_list);
2035 return ret;
2036 }
2037
qcom_geni_serial_remove(struct platform_device * pdev)2038 static void qcom_geni_serial_remove(struct platform_device *pdev)
2039 {
2040 struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
2041 struct uart_port *uport = &port->uport;
2042 struct uart_driver *drv = port->private_data.drv;
2043
2044 atomic_notifier_chain_unregister(&panic_notifier_list, &port->panic_nb);
2045
2046 WRITE_ONCE(port->tx_kick_enabled, false);
2047 irq_work_sync(&port->tx_kick);
2048 dev_pm_clear_wake_irq(&pdev->dev);
2049 device_init_wakeup(&pdev->dev, false);
2050 ida_free(&port_ida, uport->line);
2051 uart_remove_one_port(drv, &port->uport);
2052
2053 if (port->rx_dma_addr) {
2054 dma_unmap_single(pdev->dev.parent, port->rx_dma_addr,
2055 DMA_RX_BUF_SIZE, DMA_FROM_DEVICE);
2056 port->rx_dma_addr = 0;
2057 }
2058
2059 dev_pm_domain_detach_list(port->se.pd_list);
2060 }
2061
qcom_geni_serial_runtime_suspend(struct device * dev)2062 static int __maybe_unused qcom_geni_serial_runtime_suspend(struct device *dev)
2063 {
2064 struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
2065
2066 return port->dev_data->power_off ?
2067 port->dev_data->power_off(&port->se) : 0;
2068 }
2069
qcom_geni_serial_runtime_resume(struct device * dev)2070 static int __maybe_unused qcom_geni_serial_runtime_resume(struct device *dev)
2071 {
2072 struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
2073 struct uart_port *uport = &port->uport;
2074 int ret;
2075
2076 if (port->dev_data->power_on) {
2077 ret = port->dev_data->power_on(&port->se);
2078 if (ret)
2079 return ret;
2080 }
2081
2082 if (port->se.has_opp && port->clk_rate)
2083 return dev_pm_opp_set_rate(uport->dev, port->clk_rate);
2084
2085 return 0;
2086 }
2087
qcom_geni_serial_suspend(struct device * dev)2088 static int qcom_geni_serial_suspend(struct device *dev)
2089 {
2090 struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
2091 struct uart_port *uport = &port->uport;
2092 struct qcom_geni_private_data *private_data = uport->private_data;
2093 int ret;
2094
2095 /*
2096 * This is done so we can hit the lowest possible state in suspend
2097 * even with no_console_suspend
2098 */
2099 if (uart_console(uport)) {
2100 geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ACTIVE_ONLY);
2101 geni_icc_set_bw(&port->se);
2102 }
2103
2104 ret = uart_suspend_port(private_data->drv, uport);
2105 if (ret)
2106 return ret;
2107
2108 /*
2109 * When no_console_suspend is set the console must remain active
2110 * across system sleep, so skip the force suspend path.
2111 */
2112 if (!console_suspend_enabled && uart_console(uport))
2113 return 0;
2114
2115 return pm_runtime_force_suspend(dev);
2116 }
2117
qcom_geni_serial_resume(struct device * dev)2118 static int qcom_geni_serial_resume(struct device *dev)
2119 {
2120 int ret;
2121 struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
2122 struct uart_port *uport = &port->uport;
2123 struct qcom_geni_private_data *private_data = uport->private_data;
2124
2125 if (console_suspend_enabled || !uart_console(uport)) {
2126 ret = pm_runtime_force_resume(dev);
2127 if (ret)
2128 return ret;
2129 }
2130
2131 ret = uart_resume_port(private_data->drv, uport);
2132 if (uart_console(uport)) {
2133 geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ALWAYS);
2134 geni_icc_set_bw(&port->se);
2135 }
2136 return ret;
2137 }
2138
2139 #if IS_ENABLED(CONFIG_SERIAL_QCOM_GENI_CONSOLE)
2140 static const struct qcom_geni_device_data qcom_geni_console_data = {
2141 .console = true,
2142 .mode = GENI_SE_FIFO,
2143 .resources_init = geni_se_resources_init,
2144 .set_rate = geni_serial_set_rate,
2145 .power_on = geni_se_resources_activate,
2146 .power_off = geni_se_resources_deactivate,
2147 };
2148
2149 static const struct qcom_geni_device_data sa8255p_qcom_geni_console_data = {
2150 .console = true,
2151 .mode = GENI_SE_FIFO,
2152 .resources_init = geni_se_domain_attach,
2153 .set_rate = geni_se_set_perf_level,
2154 };
2155 #endif
2156
2157 static const struct qcom_geni_device_data qcom_geni_uart_data = {
2158 .console = false,
2159 .mode = GENI_SE_DMA,
2160 .resources_init = geni_se_resources_init,
2161 .set_rate = geni_serial_set_rate,
2162 .power_on = geni_se_resources_activate,
2163 .power_off = geni_se_resources_deactivate,
2164 };
2165
2166 static const struct qcom_geni_device_data sa8255p_qcom_geni_uart_data = {
2167 .console = false,
2168 .mode = GENI_SE_DMA,
2169 .resources_init = geni_se_domain_attach,
2170 .set_rate = geni_se_set_perf_level,
2171 };
2172
2173 static const struct dev_pm_ops qcom_geni_serial_pm_ops = {
2174 SET_RUNTIME_PM_OPS(qcom_geni_serial_runtime_suspend,
2175 qcom_geni_serial_runtime_resume, NULL)
2176 SYSTEM_SLEEP_PM_OPS(qcom_geni_serial_suspend, qcom_geni_serial_resume)
2177 };
2178
qcom_geni_serial_sys_shutdown(struct platform_device * pdev)2179 static void qcom_geni_serial_sys_shutdown(struct platform_device *pdev)
2180 {
2181 struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
2182 struct uart_port *uport = &port->uport;
2183
2184 if (pm_runtime_status_suspended(uport->dev))
2185 return;
2186
2187 qcom_geni_serial_stop_tx(uport);
2188 qcom_geni_serial_stop_rx(uport);
2189 }
2190
2191 static const struct of_device_id qcom_geni_serial_match_table[] = {
2192 #if IS_ENABLED(CONFIG_SERIAL_QCOM_GENI_CONSOLE)
2193 {
2194 .compatible = "qcom,geni-debug-uart",
2195 .data = &qcom_geni_console_data,
2196 },
2197 {
2198 .compatible = "qcom,sa8255p-geni-debug-uart",
2199 .data = &sa8255p_qcom_geni_console_data,
2200 },
2201 #endif
2202 {
2203 .compatible = "qcom,geni-uart",
2204 .data = &qcom_geni_uart_data,
2205 },
2206 {
2207 .compatible = "qcom,sa8255p-geni-uart",
2208 .data = &sa8255p_qcom_geni_uart_data,
2209 },
2210 {}
2211 };
2212 MODULE_DEVICE_TABLE(of, qcom_geni_serial_match_table);
2213
2214 static struct platform_driver qcom_geni_serial_platform_driver = {
2215 .remove = qcom_geni_serial_remove,
2216 .probe = qcom_geni_serial_probe,
2217 .shutdown = qcom_geni_serial_sys_shutdown,
2218 .driver = {
2219 .name = "qcom_geni_serial",
2220 .of_match_table = qcom_geni_serial_match_table,
2221 .pm = &qcom_geni_serial_pm_ops,
2222 },
2223 };
2224
qcom_geni_serial_init(void)2225 static int __init qcom_geni_serial_init(void)
2226 {
2227 int ret;
2228
2229 ret = console_register(&qcom_geni_console_driver);
2230 if (ret)
2231 return ret;
2232
2233 ret = uart_register_driver(&qcom_geni_uart_driver);
2234 if (ret) {
2235 console_unregister(&qcom_geni_console_driver);
2236 return ret;
2237 }
2238
2239 ret = platform_driver_register(&qcom_geni_serial_platform_driver);
2240 if (ret) {
2241 console_unregister(&qcom_geni_console_driver);
2242 uart_unregister_driver(&qcom_geni_uart_driver);
2243 }
2244 return ret;
2245 }
2246 module_init(qcom_geni_serial_init);
2247
qcom_geni_serial_exit(void)2248 static void __exit qcom_geni_serial_exit(void)
2249 {
2250 platform_driver_unregister(&qcom_geni_serial_platform_driver);
2251 console_unregister(&qcom_geni_console_driver);
2252 uart_unregister_driver(&qcom_geni_uart_driver);
2253 }
2254 module_exit(qcom_geni_serial_exit);
2255
2256 MODULE_DESCRIPTION("Serial driver for GENI based QUP cores");
2257 MODULE_LICENSE("GPL v2");
2258