projects / linux-2.6-block.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
TTY: 8250, deprecated 8250_core.* options
[linux-2.6-block.git] / drivers / tty / serial / xilinx_uartps.c
CommitLineData
61ec9016
JL		 1/*
2 * Xilinx PS UART driver
3 *
4 * 2011 (c) Xilinx Inc.
5 *
6 * This program is free software; you can redistribute it
7 * and/or modify it under the terms of the GNU General Public
8 * License as published by the Free Software Foundation;
9 * either version 2 of the License, or (at your option) any
10 * later version.
11 *
12 */
13
14#include <linux/platform_device.h>
ee160a38 15#include <linux/serial.h>
61ec9016 16#include <linux/serial_core.h>
ee160a38
JS		 17#include <linux/tty.h>
18#include <linux/tty_flip.h>
61ec9016 19#include <linux/console.h>
2326669c 20#include <linux/clk.h>
61ec9016
JL		 21#include <linux/irq.h>
22#include <linux/io.h>
23#include <linux/of.h>
578b9ce0 24#include <linux/module.h>
61ec9016
JL		 25
26#define XUARTPS_TTY_NAME "ttyPS"
27#define XUARTPS_NAME "xuartps"
28#define XUARTPS_MAJOR 0 /* use dynamic node allocation */
29#define XUARTPS_MINOR 0 /* works best with devtmpfs */
30#define XUARTPS_NR_PORTS 2
31#define XUARTPS_FIFO_SIZE 16 /* FIFO size */
32#define XUARTPS_REGISTER_SPACE 0xFFF
33
34#define xuartps_readl(offset) ioread32(port->membase + offset)
35#define xuartps_writel(val, offset) iowrite32(val, port->membase + offset)
36
37/********************************Register Map********************************/
38/** UART
39 *
40 * Register offsets for the UART.
41 *
42 */
43#define XUARTPS_CR_OFFSET 0x00 /* Control Register [8:0] */
44#define XUARTPS_MR_OFFSET 0x04 /* Mode Register [10:0] */
45#define XUARTPS_IER_OFFSET 0x08 /* Interrupt Enable [10:0] */
46#define XUARTPS_IDR_OFFSET 0x0C /* Interrupt Disable [10:0] */
47#define XUARTPS_IMR_OFFSET 0x10 /* Interrupt Mask [10:0] */
48#define XUARTPS_ISR_OFFSET 0x14 /* Interrupt Status [10:0]*/
49#define XUARTPS_BAUDGEN_OFFSET 0x18 /* Baud Rate Generator [15:0] */
50#define XUARTPS_RXTOUT_OFFSET 0x1C /* RX Timeout [7:0] */
51#define XUARTPS_RXWM_OFFSET 0x20 /* RX FIFO Trigger Level [5:0] */
52#define XUARTPS_MODEMCR_OFFSET 0x24 /* Modem Control [5:0] */
53#define XUARTPS_MODEMSR_OFFSET 0x28 /* Modem Status [8:0] */
54#define XUARTPS_SR_OFFSET 0x2C /* Channel Status [11:0] */
55#define XUARTPS_FIFO_OFFSET 0x30 /* FIFO [15:0] or [7:0] */
56#define XUARTPS_BAUDDIV_OFFSET 0x34 /* Baud Rate Divider [7:0] */
57#define XUARTPS_FLOWDEL_OFFSET 0x38 /* Flow Delay [15:0] */
58#define XUARTPS_IRRX_PWIDTH_OFFSET 0x3C /* IR Minimum Received Pulse
59 Width [15:0] */
60#define XUARTPS_IRTX_PWIDTH_OFFSET 0x40 /* IR Transmitted pulse
61 Width [7:0] */
62#define XUARTPS_TXWM_OFFSET 0x44 /* TX FIFO Trigger Level [5:0] */
63
64/** Control Register
65 *
66 * The Control register (CR) controls the major functions of the device.
67 *
68 * Control Register Bit Definitions
69 */
70#define XUARTPS_CR_STOPBRK 0x00000100 /* Stop TX break */
71#define XUARTPS_CR_STARTBRK 0x00000080 /* Set TX break */
72#define XUARTPS_CR_TX_DIS 0x00000020 /* TX disabled. */
73#define XUARTPS_CR_TX_EN 0x00000010 /* TX enabled */
74#define XUARTPS_CR_RX_DIS 0x00000008 /* RX disabled. */
75#define XUARTPS_CR_RX_EN 0x00000004 /* RX enabled */
76#define XUARTPS_CR_TXRST 0x00000002 /* TX logic reset */
77#define XUARTPS_CR_RXRST 0x00000001 /* RX logic reset */
78#define XUARTPS_CR_RST_TO 0x00000040 /* Restart Timeout Counter */
79
80/** Mode Register
81 *
82 * The mode register (MR) defines the mode of transfer as well as the data
83 * format. If this register is modified during transmission or reception,
84 * data validity cannot be guaranteed.
85 *
86 * Mode Register Bit Definitions
87 *
88 */
89#define XUARTPS_MR_CLKSEL 0x00000001 /* Pre-scalar selection */
90#define XUARTPS_MR_CHMODE_L_LOOP 0x00000200 /* Local loop back mode */
91#define XUARTPS_MR_CHMODE_NORM 0x00000000 /* Normal mode */
92
93#define XUARTPS_MR_STOPMODE_2_BIT 0x00000080 /* 2 stop bits */
94#define XUARTPS_MR_STOPMODE_1_BIT 0x00000000 /* 1 stop bit */
95
96#define XUARTPS_MR_PARITY_NONE 0x00000020 /* No parity mode */
97#define XUARTPS_MR_PARITY_MARK 0x00000018 /* Mark parity mode */
98#define XUARTPS_MR_PARITY_SPACE 0x00000010 /* Space parity mode */
99#define XUARTPS_MR_PARITY_ODD 0x00000008 /* Odd parity mode */
100#define XUARTPS_MR_PARITY_EVEN 0x00000000 /* Even parity mode */
101
102#define XUARTPS_MR_CHARLEN_6_BIT 0x00000006 /* 6 bits data */
103#define XUARTPS_MR_CHARLEN_7_BIT 0x00000004 /* 7 bits data */
104#define XUARTPS_MR_CHARLEN_8_BIT 0x00000000 /* 8 bits data */
105
106/** Interrupt Registers
107 *
108 * Interrupt control logic uses the interrupt enable register (IER) and the
109 * interrupt disable register (IDR) to set the value of the bits in the
110 * interrupt mask register (IMR). The IMR determines whether to pass an
111 * interrupt to the interrupt status register (ISR).
112 * Writing a 1 to IER Enables an interrupt, writing a 1 to IDR disables an
113 * interrupt. IMR and ISR are read only, and IER and IDR are write only.
114 * Reading either IER or IDR returns 0x00.
115 *
116 * All four registers have the same bit definitions.
117 */
118#define XUARTPS_IXR_TOUT 0x00000100 /* RX Timeout error interrupt */
119#define XUARTPS_IXR_PARITY 0x00000080 /* Parity error interrupt */
120#define XUARTPS_IXR_FRAMING 0x00000040 /* Framing error interrupt */
121#define XUARTPS_IXR_OVERRUN 0x00000020 /* Overrun error interrupt */
122#define XUARTPS_IXR_TXFULL 0x00000010 /* TX FIFO Full interrupt */
123#define XUARTPS_IXR_TXEMPTY 0x00000008 /* TX FIFO empty interrupt */
124#define XUARTPS_ISR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt */
125#define XUARTPS_IXR_RXTRIG 0x00000001 /* RX FIFO trigger interrupt */
126#define XUARTPS_IXR_RXFULL 0x00000004 /* RX FIFO full interrupt. */
127#define XUARTPS_IXR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt. */
128#define XUARTPS_IXR_MASK 0x00001FFF /* Valid bit mask */
129
130/** Channel Status Register
131 *
132 * The channel status register (CSR) is provided to enable the control logic
133 * to monitor the status of bits in the channel interrupt status register,
134 * even if these are masked out by the interrupt mask register.
135 */
136#define XUARTPS_SR_RXEMPTY 0x00000002 /* RX FIFO empty */
137#define XUARTPS_SR_TXEMPTY 0x00000008 /* TX FIFO empty */
138#define XUARTPS_SR_TXFULL 0x00000010 /* TX FIFO full */
139#define XUARTPS_SR_RXTRIG 0x00000001 /* Rx Trigger */
140
141/**
142 * xuartps_isr - Interrupt handler
143 * @irq: Irq number
144 * @dev_id: Id of the port
145 *
146 * Returns IRQHANDLED
147 **/
148static irqreturn_t xuartps_isr(int irq, void *dev_id)
149{
150 struct uart_port *port = (struct uart_port *)dev_id;
61ec9016
JL		 151 unsigned long flags;
152 unsigned int isrstatus, numbytes;
153 unsigned int data;
154 char status = TTY_NORMAL;
155
61ec9016
JL		 156 spin_lock_irqsave(&port->lock, flags);
157
158 /* Read the interrupt status register to determine which
159 * interrupt(s) is/are active.
160 */
161 isrstatus = xuartps_readl(XUARTPS_ISR_OFFSET);
162
163 /* drop byte with parity error if IGNPAR specified */
164 if (isrstatus & port->ignore_status_mask & XUARTPS_IXR_PARITY)
165 isrstatus &= ~(XUARTPS_IXR_RXTRIG | XUARTPS_IXR_TOUT);
166
167 isrstatus &= port->read_status_mask;
168 isrstatus &= ~port->ignore_status_mask;
169
170 if ((isrstatus & XUARTPS_IXR_TOUT) ||
171 (isrstatus & XUARTPS_IXR_RXTRIG)) {
172 /* Receive Timeout Interrupt */
173 while ((xuartps_readl(XUARTPS_SR_OFFSET) &
174 XUARTPS_SR_RXEMPTY) != XUARTPS_SR_RXEMPTY) {
175 data = xuartps_readl(XUARTPS_FIFO_OFFSET);
176 port->icount.rx++;
177
178 if (isrstatus & XUARTPS_IXR_PARITY) {
179 port->icount.parity++;
180 status = TTY_PARITY;
181 } else if (isrstatus & XUARTPS_IXR_FRAMING) {
182 port->icount.frame++;
183 status = TTY_FRAME;
184 } else if (isrstatus & XUARTPS_IXR_OVERRUN)
185 port->icount.overrun++;
186
2e124b4a
JS		 187 uart_insert_char(port, isrstatus, XUARTPS_IXR_OVERRUN,
188 data, status);
61ec9016
JL		 189 }
190 spin_unlock(&port->lock);
2e124b4a 191 tty_flip_buffer_push(&port->state->port);
61ec9016
JL		 192 spin_lock(&port->lock);
193 }
194
195 /* Dispatch an appropriate handler */
196 if ((isrstatus & XUARTPS_IXR_TXEMPTY) == XUARTPS_IXR_TXEMPTY) {
197 if (uart_circ_empty(&port->state->xmit)) {
198 xuartps_writel(XUARTPS_IXR_TXEMPTY,
199 XUARTPS_IDR_OFFSET);
200 } else {
201 numbytes = port->fifosize;
202 /* Break if no more data available in the UART buffer */
203 while (numbytes--) {
204 if (uart_circ_empty(&port->state->xmit))
205 break;
206 /* Get the data from the UART circular buffer
207 * and write it to the xuartps's TX_FIFO
208 * register.
209 */
210 xuartps_writel(
211 port->state->xmit.buf[port->state->xmit.
212 tail], XUARTPS_FIFO_OFFSET);
213
214 port->icount.tx++;
215
216 /* Adjust the tail of the UART buffer and wrap
217 * the buffer if it reaches limit.
218 */
219 port->state->xmit.tail =
220 (port->state->xmit.tail + 1) & \
221 (UART_XMIT_SIZE - 1);
222 }
223
224 if (uart_circ_chars_pending(
225 &port->state->xmit) < WAKEUP_CHARS)
226 uart_write_wakeup(port);
227 }
228 }
229
230 xuartps_writel(isrstatus, XUARTPS_ISR_OFFSET);
231
232 /* be sure to release the lock and tty before leaving */
233 spin_unlock_irqrestore(&port->lock, flags);
61ec9016
JL		 234
235 return IRQ_HANDLED;
236}
237
238/**
239 * xuartps_set_baud_rate - Calculate and set the baud rate
240 * @port: Handle to the uart port structure
241 * @baud: Baud rate to set
242 *
243 * Returns baud rate, requested baud when possible, or actual baud when there
244 * was too much error
245 **/
246static unsigned int xuartps_set_baud_rate(struct uart_port *port,
247 unsigned int baud)
248{
249 unsigned int sel_clk;
250 unsigned int calc_baud = 0;
251 unsigned int brgr_val, brdiv_val;
252 unsigned int bauderror;
253
254 /* Formula to obtain baud rate is
255 * baud_tx/rx rate = sel_clk/CD * (BDIV + 1)
256 * input_clk = (Uart User Defined Clock or Apb Clock)
257 * depends on UCLKEN in MR Reg
258 * sel_clk = input_clk or input_clk/8;
259 * depends on CLKS in MR reg
260 * CD and BDIV depends on values in
261 * baud rate generate register
262 * baud rate clock divisor register
263 */
264 sel_clk = port->uartclk;
265 if (xuartps_readl(XUARTPS_MR_OFFSET) & XUARTPS_MR_CLKSEL)
266 sel_clk = sel_clk / 8;
267
268 /* Find the best values for baud generation */
269 for (brdiv_val = 4; brdiv_val < 255; brdiv_val++) {
270
271 brgr_val = sel_clk / (baud * (brdiv_val + 1));
272 if (brgr_val < 2 || brgr_val > 65535)
273 continue;
274
275 calc_baud = sel_clk / (brgr_val * (brdiv_val + 1));
276
277 if (baud > calc_baud)
278 bauderror = baud - calc_baud;
279 else
280 bauderror = calc_baud - baud;
281
282 /* use the values when percent error is acceptable */
283 if (((bauderror * 100) / baud) < 3) {
284 calc_baud = baud;
285 break;
286 }
287 }
288
289 /* Set the values for the new baud rate */
290 xuartps_writel(brgr_val, XUARTPS_BAUDGEN_OFFSET);
291 xuartps_writel(brdiv_val, XUARTPS_BAUDDIV_OFFSET);
292
293 return calc_baud;
294}
295
296/*----------------------Uart Operations---------------------------*/
297
298/**
299 * xuartps_start_tx - Start transmitting bytes
300 * @port: Handle to the uart port structure
301 *
302 **/
303static void xuartps_start_tx(struct uart_port *port)
304{
305 unsigned int status, numbytes = port->fifosize;
306
307 if (uart_circ_empty(&port->state->xmit) || uart_tx_stopped(port))
308 return;
309
310 status = xuartps_readl(XUARTPS_CR_OFFSET);
311 /* Set the TX enable bit and clear the TX disable bit to enable the
312 * transmitter.
313 */
314 xuartps_writel((status & ~XUARTPS_CR_TX_DIS) | XUARTPS_CR_TX_EN,
315 XUARTPS_CR_OFFSET);
316
317 while (numbytes-- && ((xuartps_readl(XUARTPS_SR_OFFSET)
318 & XUARTPS_SR_TXFULL)) != XUARTPS_SR_TXFULL) {
319
320 /* Break if no more data available in the UART buffer */
321 if (uart_circ_empty(&port->state->xmit))
322 break;
323
324 /* Get the data from the UART circular buffer and
325 * write it to the xuartps's TX_FIFO register.
326 */
327 xuartps_writel(
328 port->state->xmit.buf[port->state->xmit.tail],
329 XUARTPS_FIFO_OFFSET);
330 port->icount.tx++;
331
332 /* Adjust the tail of the UART buffer and wrap
333 * the buffer if it reaches limit.
334 */
335 port->state->xmit.tail = (port->state->xmit.tail + 1) &
336 (UART_XMIT_SIZE - 1);
337 }
338
339 /* Enable the TX Empty interrupt */
340 xuartps_writel(XUARTPS_IXR_TXEMPTY, XUARTPS_IER_OFFSET);
341
342 if (uart_circ_chars_pending(&port->state->xmit) < WAKEUP_CHARS)
343 uart_write_wakeup(port);
344}
345
346/**
347 * xuartps_stop_tx - Stop TX
348 * @port: Handle to the uart port structure
349 *
350 **/
351static void xuartps_stop_tx(struct uart_port *port)
352{
353 unsigned int regval;
354
355 regval = xuartps_readl(XUARTPS_CR_OFFSET);
356 regval |= XUARTPS_CR_TX_DIS;
357 /* Disable the transmitter */
358 xuartps_writel(regval, XUARTPS_CR_OFFSET);
359}
360
361/**
362 * xuartps_stop_rx - Stop RX
363 * @port: Handle to the uart port structure
364 *
365 **/
366static void xuartps_stop_rx(struct uart_port *port)
367{
368 unsigned int regval;
369
370 regval = xuartps_readl(XUARTPS_CR_OFFSET);
371 regval |= XUARTPS_CR_RX_DIS;
372 /* Disable the receiver */
373 xuartps_writel(regval, XUARTPS_CR_OFFSET);
374}
375
376/**
377 * xuartps_tx_empty - Check whether TX is empty
378 * @port: Handle to the uart port structure
379 *
380 * Returns TIOCSER_TEMT on success, 0 otherwise
381 **/
382static unsigned int xuartps_tx_empty(struct uart_port *port)
383{
384 unsigned int status;
385
386 status = xuartps_readl(XUARTPS_ISR_OFFSET) & XUARTPS_IXR_TXEMPTY;
387 return status ? TIOCSER_TEMT : 0;
388}
389
390/**
391 * xuartps_break_ctl - Based on the input ctl we have to start or stop
392 * transmitting char breaks
393 * @port: Handle to the uart port structure
394 * @ctl: Value based on which start or stop decision is taken
395 *
396 **/
397static void xuartps_break_ctl(struct uart_port *port, int ctl)
398{
399 unsigned int status;
400 unsigned long flags;
401
402 spin_lock_irqsave(&port->lock, flags);
403
404 status = xuartps_readl(XUARTPS_CR_OFFSET);
405
406 if (ctl == -1)
407 xuartps_writel(XUARTPS_CR_STARTBRK | status,
408 XUARTPS_CR_OFFSET);
409 else {
410 if ((status & XUARTPS_CR_STOPBRK) == 0)
411 xuartps_writel(XUARTPS_CR_STOPBRK | status,
412 XUARTPS_CR_OFFSET);
413 }
414 spin_unlock_irqrestore(&port->lock, flags);
415}
416
417/**
418 * xuartps_set_termios - termios operations, handling data length, parity,
419 * stop bits, flow control, baud rate
420 * @port: Handle to the uart port structure
421 * @termios: Handle to the input termios structure
422 * @old: Values of the previously saved termios structure
423 *
424 **/
425static void xuartps_set_termios(struct uart_port *port,
426 struct ktermios *termios, struct ktermios *old)
427{
428 unsigned int cval = 0;
429 unsigned int baud;
430 unsigned long flags;
431 unsigned int ctrl_reg, mode_reg;
432
433 spin_lock_irqsave(&port->lock, flags);
434
435 /* Empty the receive FIFO 1st before making changes */
436 while ((xuartps_readl(XUARTPS_SR_OFFSET) &
437 XUARTPS_SR_RXEMPTY) != XUARTPS_SR_RXEMPTY) {
438 xuartps_readl(XUARTPS_FIFO_OFFSET);
439 }
440
441 /* Disable the TX and RX to set baud rate */
442 xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
443 (XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS),
444 XUARTPS_CR_OFFSET);
445
446 /* Min baud rate = 6bps and Max Baud Rate is 10Mbps for 100Mhz clk */
447 baud = uart_get_baud_rate(port, termios, old, 0, 10000000);
448 baud = xuartps_set_baud_rate(port, baud);
449 if (tty_termios_baud_rate(termios))
450 tty_termios_encode_baud_rate(termios, baud, baud);
451
452 /*
453 * Update the per-port timeout.
454 */
455 uart_update_timeout(port, termios->c_cflag, baud);
456
457 /* Set TX/RX Reset */
458 xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
459 (XUARTPS_CR_TXRST | XUARTPS_CR_RXRST),
460 XUARTPS_CR_OFFSET);
461
462 ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET);
463
464 /* Clear the RX disable and TX disable bits and then set the TX enable
465 * bit and RX enable bit to enable the transmitter and receiver.
466 */
467 xuartps_writel(
468 (ctrl_reg & ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS))
469 | (XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN),
470 XUARTPS_CR_OFFSET);
471
472 xuartps_writel(10, XUARTPS_RXTOUT_OFFSET);
473
474 port->read_status_mask = XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_RXTRIG |
475 XUARTPS_IXR_OVERRUN | XUARTPS_IXR_TOUT;
476 port->ignore_status_mask = 0;
477
478 if (termios->c_iflag & INPCK)
479 port->read_status_mask |= XUARTPS_IXR_PARITY |
480 XUARTPS_IXR_FRAMING;
481
482 if (termios->c_iflag & IGNPAR)
483 port->ignore_status_mask |= XUARTPS_IXR_PARITY |
484 XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN;
485
486 /* ignore all characters if CREAD is not set */
487 if ((termios->c_cflag & CREAD) == 0)
488 port->ignore_status_mask |= XUARTPS_IXR_RXTRIG |
489 XUARTPS_IXR_TOUT | XUARTPS_IXR_PARITY |
490 XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN;
491
492 mode_reg = xuartps_readl(XUARTPS_MR_OFFSET);
493
494 /* Handling Data Size */
495 switch (termios->c_cflag & CSIZE) {
496 case CS6:
497 cval |= XUARTPS_MR_CHARLEN_6_BIT;
498 break;
499 case CS7:
500 cval |= XUARTPS_MR_CHARLEN_7_BIT;
501 break;
502 default:
503 case CS8:
504 cval |= XUARTPS_MR_CHARLEN_8_BIT;
505 termios->c_cflag &= ~CSIZE;
506 termios->c_cflag |= CS8;
507 break;
508 }
509
510 /* Handling Parity and Stop Bits length */
511 if (termios->c_cflag & CSTOPB)
512 cval |= XUARTPS_MR_STOPMODE_2_BIT; /* 2 STOP bits */
513 else
514 cval |= XUARTPS_MR_STOPMODE_1_BIT; /* 1 STOP bit */
515
516 if (termios->c_cflag & PARENB) {
517 /* Mark or Space parity */
518 if (termios->c_cflag & CMSPAR) {
519 if (termios->c_cflag & PARODD)
520 cval |= XUARTPS_MR_PARITY_MARK;
521 else
522 cval |= XUARTPS_MR_PARITY_SPACE;
523 } else if (termios->c_cflag & PARODD)
524 cval |= XUARTPS_MR_PARITY_ODD;
525 else
526 cval |= XUARTPS_MR_PARITY_EVEN;
527 } else
528 cval |= XUARTPS_MR_PARITY_NONE;
529 xuartps_writel(cval , XUARTPS_MR_OFFSET);
530
531 spin_unlock_irqrestore(&port->lock, flags);
532}
533
534/**
535 * xuartps_startup - Called when an application opens a xuartps port
536 * @port: Handle to the uart port structure
537 *
538 * Returns 0 on success, negative error otherwise
539 **/
540static int xuartps_startup(struct uart_port *port)
541{
542 unsigned int retval = 0, status = 0;
543
544 retval = request_irq(port->irq, xuartps_isr, 0, XUARTPS_NAME,
545 (void *)port);
546 if (retval)
547 return retval;
548
549 /* Disable the TX and RX */
550 xuartps_writel(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS,
551 XUARTPS_CR_OFFSET);
552
553 /* Set the Control Register with TX/RX Enable, TX/RX Reset,
554 * no break chars.
555 */
556 xuartps_writel(XUARTPS_CR_TXRST | XUARTPS_CR_RXRST,
557 XUARTPS_CR_OFFSET);
558
559 status = xuartps_readl(XUARTPS_CR_OFFSET);
560
561 /* Clear the RX disable and TX disable bits and then set the TX enable
562 * bit and RX enable bit to enable the transmitter and receiver.
563 */
564 xuartps_writel((status & ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS))
565 | (XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN |
566 XUARTPS_CR_STOPBRK), XUARTPS_CR_OFFSET);
567
568 /* Set the Mode Register with normal mode,8 data bits,1 stop bit,
569 * no parity.
570 */
571 xuartps_writel(XUARTPS_MR_CHMODE_NORM | XUARTPS_MR_STOPMODE_1_BIT
572 | XUARTPS_MR_PARITY_NONE | XUARTPS_MR_CHARLEN_8_BIT,
573 XUARTPS_MR_OFFSET);
574
575 /* Set the RX FIFO Trigger level to 14 assuming FIFO size as 16 */
576 xuartps_writel(14, XUARTPS_RXWM_OFFSET);
577
578 /* Receive Timeout register is enabled with value of 10 */
579 xuartps_writel(10, XUARTPS_RXTOUT_OFFSET);
580
581
582 /* Set the Interrupt Registers with desired interrupts */
583 xuartps_writel(XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_PARITY |
584 XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN |
585 XUARTPS_IXR_RXTRIG | XUARTPS_IXR_TOUT, XUARTPS_IER_OFFSET);
586 xuartps_writel(~(XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_PARITY |
587 XUARTPS_IXR_FRAMING | XUARTPS_IXR_OVERRUN |
588 XUARTPS_IXR_RXTRIG | XUARTPS_IXR_TOUT), XUARTPS_IDR_OFFSET);
589
590 return retval;
591}
592
593/**
594 * xuartps_shutdown - Called when an application closes a xuartps port
595 * @port: Handle to the uart port structure
596 *
597 **/
598static void xuartps_shutdown(struct uart_port *port)
599{
600 int status;
601
602 /* Disable interrupts */
603 status = xuartps_readl(XUARTPS_IMR_OFFSET);
604 xuartps_writel(status, XUARTPS_IDR_OFFSET);
605
606 /* Disable the TX and RX */
607 xuartps_writel(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS,
608 XUARTPS_CR_OFFSET);
609 free_irq(port->irq, port);
610}
611
612/**
613 * xuartps_type - Set UART type to xuartps port
614 * @port: Handle to the uart port structure
615 *
616 * Returns string on success, NULL otherwise
617 **/
618static const char *xuartps_type(struct uart_port *port)
619{
620 return port->type == PORT_XUARTPS ? XUARTPS_NAME : NULL;
621}
622
623/**
624 * xuartps_verify_port - Verify the port params
625 * @port: Handle to the uart port structure
626 * @ser: Handle to the structure whose members are compared
627 *
628 * Returns 0 if success otherwise -EINVAL
629 **/
630static int xuartps_verify_port(struct uart_port *port,
631 struct serial_struct *ser)
632{
633 if (ser->type != PORT_UNKNOWN && ser->type != PORT_XUARTPS)
634 return -EINVAL;
635 if (port->irq != ser->irq)
636 return -EINVAL;
637 if (ser->io_type != UPIO_MEM)
638 return -EINVAL;
639 if (port->iobase != ser->port)
640 return -EINVAL;
641 if (ser->hub6 != 0)
642 return -EINVAL;
643 return 0;
644}
645
646/**
647 * xuartps_request_port - Claim the memory region attached to xuartps port,
648 * called when the driver adds a xuartps port via
649 * uart_add_one_port()
650 * @port: Handle to the uart port structure
651 *
652 * Returns 0, -ENOMEM if request fails
653 **/
654static int xuartps_request_port(struct uart_port *port)
655{
656 if (!request_mem_region(port->mapbase, XUARTPS_REGISTER_SPACE,
657 XUARTPS_NAME)) {
658 return -ENOMEM;
659 }
660
661 port->membase = ioremap(port->mapbase, XUARTPS_REGISTER_SPACE);
662 if (!port->membase) {
663 dev_err(port->dev, "Unable to map registers\n");
664 release_mem_region(port->mapbase, XUARTPS_REGISTER_SPACE);
665 return -ENOMEM;
666 }
667 return 0;
668}
669
670/**
671 * xuartps_release_port - Release the memory region attached to a xuartps
672 * port, called when the driver removes a xuartps
673 * port via uart_remove_one_port().
674 * @port: Handle to the uart port structure
675 *
676 **/
677static void xuartps_release_port(struct uart_port *port)
678{
679 release_mem_region(port->mapbase, XUARTPS_REGISTER_SPACE);
680 iounmap(port->membase);
681 port->membase = NULL;
682}
683
684/**
685 * xuartps_config_port - Configure xuartps, called when the driver adds a
686 * xuartps port
687 * @port: Handle to the uart port structure
688 * @flags: If any
689 *
690 **/
691static void xuartps_config_port(struct uart_port *port, int flags)
692{
693 if (flags & UART_CONFIG_TYPE && xuartps_request_port(port) == 0)
694 port->type = PORT_XUARTPS;
695}
696
697/**
698 * xuartps_get_mctrl - Get the modem control state
699 *
700 * @port: Handle to the uart port structure
701 *
702 * Returns the modem control state
703 *
704 **/
705static unsigned int xuartps_get_mctrl(struct uart_port *port)
706{
707 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
708}
709
710static void xuartps_set_mctrl(struct uart_port *port, unsigned int mctrl)
711{
712 /* N/A */
713}
714
715static void xuartps_enable_ms(struct uart_port *port)
716{
717 /* N/A */
718}
719
720/** The UART operations structure
721 */
722static struct uart_ops xuartps_ops = {
723 .set_mctrl = xuartps_set_mctrl,
724 .get_mctrl = xuartps_get_mctrl,
725 .enable_ms = xuartps_enable_ms,
726
727 .start_tx = xuartps_start_tx, /* Start transmitting */
728 .stop_tx = xuartps_stop_tx, /* Stop transmission */
729 .stop_rx = xuartps_stop_rx, /* Stop reception */
730 .tx_empty = xuartps_tx_empty, /* Transmitter busy? */
731 .break_ctl = xuartps_break_ctl, /* Start/stop
732 * transmitting break
733 */
734 .set_termios = xuartps_set_termios, /* Set termios */
735 .startup = xuartps_startup, /* App opens xuartps */
736 .shutdown = xuartps_shutdown, /* App closes xuartps */
737 .type = xuartps_type, /* Set UART type */
738 .verify_port = xuartps_verify_port, /* Verification of port
739 * params
740 */
741 .request_port = xuartps_request_port, /* Claim resources
742 * associated with a
743 * xuartps port
744 */
745 .release_port = xuartps_release_port, /* Release resources
746 * associated with a
747 * xuartps port
748 */
749 .config_port = xuartps_config_port, /* Configure when driver
750 * adds a xuartps port
751 */
752};
753
754static struct uart_port xuartps_port[2];
755
756/**
757 * xuartps_get_port - Configure the port from the platform device resource
758 * info
759 *
760 * Returns a pointer to a uart_port or NULL for failure
761 **/
762static struct uart_port *xuartps_get_port(void)
763{
764 struct uart_port *port;
765 int id;
766
767 /* Find the next unused port */
768 for (id = 0; id < XUARTPS_NR_PORTS; id++)
769 if (xuartps_port[id].mapbase == 0)
770 break;
771
772 if (id >= XUARTPS_NR_PORTS)
773 return NULL;
774
775 port = &xuartps_port[id];
776
777 /* At this point, we've got an empty uart_port struct, initialize it */
778 spin_lock_init(&port->lock);
779 port->membase = NULL;
780 port->iobase = 1; /* mark port in use */
781 port->irq = 0;
782 port->type = PORT_UNKNOWN;
783 port->iotype = UPIO_MEM32;
784 port->flags = UPF_BOOT_AUTOCONF;
785 port->ops = &xuartps_ops;
786 port->fifosize = XUARTPS_FIFO_SIZE;
787 port->line = id;
788 port->dev = NULL;
789 return port;
790}
791
792/*-----------------------Console driver operations--------------------------*/
793
794#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
795/**
796 * xuartps_console_wait_tx - Wait for the TX to be full
797 * @port: Handle to the uart port structure
798 *
799 **/
800static void xuartps_console_wait_tx(struct uart_port *port)
801{
802 while ((xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_TXEMPTY)
803 != XUARTPS_SR_TXEMPTY)
804 barrier();
805}
806
807/**
808 * xuartps_console_putchar - write the character to the FIFO buffer
809 * @port: Handle to the uart port structure
810 * @ch: Character to be written
811 *
812 **/
813static void xuartps_console_putchar(struct uart_port *port, int ch)
814{
815 xuartps_console_wait_tx(port);
816 xuartps_writel(ch, XUARTPS_FIFO_OFFSET);
817}
818
819/**
820 * xuartps_console_write - perform write operation
821 * @port: Handle to the uart port structure
822 * @s: Pointer to character array
823 * @count: No of characters
824 **/
825static void xuartps_console_write(struct console *co, const char *s,
826 unsigned int count)
827{
828 struct uart_port *port = &xuartps_port[co->index];
829 unsigned long flags;
830 unsigned int imr;
831 int locked = 1;
832
833 if (oops_in_progress)
834 locked = spin_trylock_irqsave(&port->lock, flags);
835 else
836 spin_lock_irqsave(&port->lock, flags);
837
838 /* save and disable interrupt */
839 imr = xuartps_readl(XUARTPS_IMR_OFFSET);
840 xuartps_writel(imr, XUARTPS_IDR_OFFSET);
841
842 uart_console_write(port, s, count, xuartps_console_putchar);
843 xuartps_console_wait_tx(port);
844
845 /* restore interrupt state, it seems like there may be a h/w bug
846 * in that the interrupt enable register should not need to be
847 * written based on the data sheet
848 */
849 xuartps_writel(~imr, XUARTPS_IDR_OFFSET);
850 xuartps_writel(imr, XUARTPS_IER_OFFSET);
851
852 if (locked)
853 spin_unlock_irqrestore(&port->lock, flags);
854}
855
856/**
857 * xuartps_console_setup - Initialize the uart to default config
858 * @co: Console handle
859 * @options: Initial settings of uart
860 *
861 * Returns 0, -ENODEV if no device
862 **/
863static int __init xuartps_console_setup(struct console *co, char *options)
864{
865 struct uart_port *port = &xuartps_port[co->index];
866 int baud = 9600;
867 int bits = 8;
868 int parity = 'n';
869 int flow = 'n';
870
871 if (co->index < 0 || co->index >= XUARTPS_NR_PORTS)
872 return -EINVAL;
873
874 if (!port->mapbase) {
875 pr_debug("console on ttyPS%i not present\n", co->index);
876 return -ENODEV;
877 }
878
879 if (options)
880 uart_parse_options(options, &baud, &parity, &bits, &flow);
881
882 return uart_set_options(port, co, baud, parity, bits, flow);
883}
884
885static struct uart_driver xuartps_uart_driver;
886
887static struct console xuartps_console = {
888 .name = XUARTPS_TTY_NAME,
889 .write = xuartps_console_write,
890 .device = uart_console_device,
891 .setup = xuartps_console_setup,
892 .flags = CON_PRINTBUFFER,
893 .index = -1, /* Specified on the cmdline (e.g. console=ttyPS ) */
894 .data = &xuartps_uart_driver,
895};
896
897/**
898 * xuartps_console_init - Initialization call
899 *
900 * Returns 0 on success, negative error otherwise
901 **/
902static int __init xuartps_console_init(void)
903{
904 register_console(&xuartps_console);
905 return 0;
906}
907
908console_initcall(xuartps_console_init);
909
910#endif /* CONFIG_SERIAL_XILINX_PS_UART_CONSOLE */
911
912/** Structure Definitions
913 */
914static struct uart_driver xuartps_uart_driver = {
915 .owner = THIS_MODULE, /* Owner */
916 .driver_name = XUARTPS_NAME, /* Driver name */
917 .dev_name = XUARTPS_TTY_NAME, /* Node name */
918 .major = XUARTPS_MAJOR, /* Major number */
919 .minor = XUARTPS_MINOR, /* Minor number */
920 .nr = XUARTPS_NR_PORTS, /* Number of UART ports */
921#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
922 .cons = &xuartps_console, /* Console */
923#endif
924};
925
926/* ---------------------------------------------------------------------
927 * Platform bus binding
928 */
929/**
930 * xuartps_probe - Platform driver probe
931 * @pdev: Pointer to the platform device structure
932 *
933 * Returns 0 on success, negative error otherwise
934 **/
9671f099 935static int xuartps_probe(struct platform_device *pdev)
61ec9016
JL		 936{
937 int rc;
938 struct uart_port *port;
939 struct resource *res, *res2;
2326669c 940 struct clk *clk;
61ec9016 941
2326669c
JC		 942 clk = of_clk_get(pdev->dev.of_node, 0);
943 if (IS_ERR(clk)) {
61ec9016 944 dev_err(&pdev->dev, "no clock specified\n");
2326669c
JC		 945 return PTR_ERR(clk);
946 }
947
948 rc = clk_prepare_enable(clk);
949 if (rc) {
950 dev_err(&pdev->dev, "could not enable clock\n");
951 return -EBUSY;
61ec9016
JL		 952 }
953
954 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
955 if (!res)
956 return -ENODEV;
957
958 res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
959 if (!res2)
960 return -ENODEV;
961
962 /* Initialize the port structure */
963 port = xuartps_get_port();
964
965 if (!port) {
966 dev_err(&pdev->dev, "Cannot get uart_port structure\n");
967 return -ENODEV;
968 } else {
969 /* Register the port.
970 * This function also registers this device with the tty layer
971 * and triggers invocation of the config_port() entry point.
972 */
973 port->mapbase = res->start;
974 port->irq = res2->start;
975 port->dev = &pdev->dev;
2326669c
JC		 976 port->uartclk = clk_get_rate(clk);
977 port->private_data = clk;
61ec9016
JL		 978 dev_set_drvdata(&pdev->dev, port);
979 rc = uart_add_one_port(&xuartps_uart_driver, port);
980 if (rc) {
981 dev_err(&pdev->dev,
982 "uart_add_one_port() failed; err=%i\n", rc);
983 dev_set_drvdata(&pdev->dev, NULL);
984 return rc;
985 }
986 return 0;
987 }
988}
989
990/**
991 * xuartps_remove - called when the platform driver is unregistered
992 * @pdev: Pointer to the platform device structure
993 *
994 * Returns 0 on success, negative error otherwise
995 **/
ae8d8a14 996static int xuartps_remove(struct platform_device *pdev)
61ec9016
JL		 997{
998 struct uart_port *port = dev_get_drvdata(&pdev->dev);
2326669c
JC		 999 struct clk *clk = port->private_data;
1000 int rc;
61ec9016
JL		 1001
1002 /* Remove the xuartps port from the serial core */
2326669c
JC		 1003 rc = uart_remove_one_port(&xuartps_uart_driver, port);
1004 dev_set_drvdata(&pdev->dev, NULL);
1005 port->mapbase = 0;
1006 clk_disable_unprepare(clk);
61ec9016
JL		 1007 return rc;
1008}
1009
1010/**
1011 * xuartps_suspend - suspend event
1012 * @pdev: Pointer to the platform device structure
1013 * @state: State of the device
1014 *
1015 * Returns 0
1016 **/
1017static int xuartps_suspend(struct platform_device *pdev, pm_message_t state)
1018{
1019 /* Call the API provided in serial_core.c file which handles
1020 * the suspend.
1021 */
1022 uart_suspend_port(&xuartps_uart_driver, &xuartps_port[pdev->id]);
1023 return 0;
1024}
1025
1026/**
1027 * xuartps_resume - Resume after a previous suspend
1028 * @pdev: Pointer to the platform device structure
1029 *
1030 * Returns 0
1031 **/
1032static int xuartps_resume(struct platform_device *pdev)
1033{
1034 uart_resume_port(&xuartps_uart_driver, &xuartps_port[pdev->id]);
1035 return 0;
1036}
1037
1038/* Match table for of_platform binding */
de88b340 1039static struct of_device_id xuartps_of_match[] = {
61ec9016
JL		 1040 { .compatible = "xlnx,xuartps", },
1041 {}
1042};
1043MODULE_DEVICE_TABLE(of, xuartps_of_match);
61ec9016
JL		 1044
1045static struct platform_driver xuartps_platform_driver = {
1046 .probe = xuartps_probe, /* Probe method */
eb51d917 1047 .remove = xuartps_remove, /* Detach method */
61ec9016
JL		 1048 .suspend = xuartps_suspend, /* Suspend */
1049 .resume = xuartps_resume, /* Resume after a suspend */
1050 .driver = {
1051 .owner = THIS_MODULE,
1052 .name = XUARTPS_NAME, /* Driver name */
1053 .of_match_table = xuartps_of_match,
1054 },
1055};
1056
1057/* ---------------------------------------------------------------------
1058 * Module Init and Exit
1059 */
1060/**
1061 * xuartps_init - Initial driver registration call
1062 *
1063 * Returns whether the registration was successful or not
1064 **/
1065static int __init xuartps_init(void)
1066{
1067 int retval = 0;
1068
1069 /* Register the xuartps driver with the serial core */
1070 retval = uart_register_driver(&xuartps_uart_driver);
1071 if (retval)
1072 return retval;
1073
1074 /* Register the platform driver */
1075 retval = platform_driver_register(&xuartps_platform_driver);
1076 if (retval)
1077 uart_unregister_driver(&xuartps_uart_driver);
1078
1079 return retval;
1080}
1081
1082/**
1083 * xuartps_exit - Driver unregistration call
1084 **/
1085static void __exit xuartps_exit(void)
1086{
1087 /* The order of unregistration is important. Unregister the
1088 * UART driver before the platform driver crashes the system.
1089 */
1090
1091 /* Unregister the platform driver */
1092 platform_driver_unregister(&xuartps_platform_driver);
1093
1094 /* Unregister the xuartps driver */
1095 uart_unregister_driver(&xuartps_uart_driver);
1096}
1097
1098module_init(xuartps_init);
1099module_exit(xuartps_exit);
1100
1101MODULE_DESCRIPTION("Driver for PS UART");
1102MODULE_AUTHOR("Xilinx Inc.");
1103MODULE_LICENSE("GPL");
Linux 6.x block layer and io_uring tree(s)