1 #if defined(CONFIG_SERIAL_EFM32_UART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
2 #define SUPPORT_SYSRQ
3 #endif
4
5 #include <linux/kernel.h>
6 #include <linux/module.h>
7 #include <linux/io.h>
8 #include <linux/platform_device.h>
9 #include <linux/console.h>
10 #include <linux/sysrq.h>
11 #include <linux/serial_core.h>
12 #include <linux/tty_flip.h>
13 #include <linux/slab.h>
14 #include <linux/clk.h>
15 #include <linux/of.h>
16 #include <linux/of_device.h>
17
18 #include <linux/platform_data/efm32-uart.h>
19
20 #define DRIVER_NAME "efm32-uart"
21 #define DEV_NAME "ttyefm"
22
23 #define UARTn_CTRL 0x00
24 #define UARTn_CTRL_SYNC 0x0001
25 #define UARTn_CTRL_TXBIL 0x1000
26
27 #define UARTn_FRAME 0x04
28 #define UARTn_FRAME_DATABITS__MASK 0x000f
29 #define UARTn_FRAME_DATABITS(n) ((n) - 3)
30 #define UARTn_FRAME_PARITY_NONE 0x0000
31 #define UARTn_FRAME_PARITY_EVEN 0x0200
32 #define UARTn_FRAME_PARITY_ODD 0x0300
33 #define UARTn_FRAME_STOPBITS_HALF 0x0000
34 #define UARTn_FRAME_STOPBITS_ONE 0x1000
35 #define UARTn_FRAME_STOPBITS_TWO 0x3000
36
37 #define UARTn_CMD 0x0c
38 #define UARTn_CMD_RXEN 0x0001
39 #define UARTn_CMD_RXDIS 0x0002
40 #define UARTn_CMD_TXEN 0x0004
41 #define UARTn_CMD_TXDIS 0x0008
42
43 #define UARTn_STATUS 0x10
44 #define UARTn_STATUS_TXENS 0x0002
45 #define UARTn_STATUS_TXC 0x0020
46 #define UARTn_STATUS_TXBL 0x0040
47 #define UARTn_STATUS_RXDATAV 0x0080
48
49 #define UARTn_CLKDIV 0x14
50
51 #define UARTn_RXDATAX 0x18
52 #define UARTn_RXDATAX_RXDATA__MASK 0x01ff
53 #define UARTn_RXDATAX_PERR 0x4000
54 #define UARTn_RXDATAX_FERR 0x8000
55 /*
56 * This is a software only flag used for ignore_status_mask and
57 * read_status_mask! It's used for breaks that the hardware doesn't report
58 * explicitly.
59 */
60 #define SW_UARTn_RXDATAX_BERR 0x2000
61
62 #define UARTn_TXDATA 0x34
63
64 #define UARTn_IF 0x40
65 #define UARTn_IF_TXC 0x0001
66 #define UARTn_IF_TXBL 0x0002
67 #define UARTn_IF_RXDATAV 0x0004
68 #define UARTn_IF_RXOF 0x0010
69
70 #define UARTn_IFS 0x44
71 #define UARTn_IFC 0x48
72 #define UARTn_IEN 0x4c
73
74 #define UARTn_ROUTE 0x54
75 #define UARTn_ROUTE_LOCATION__MASK 0x0700
76 #define UARTn_ROUTE_LOCATION(n) (((n) << 8) & UARTn_ROUTE_LOCATION__MASK)
77 #define UARTn_ROUTE_RXPEN 0x0001
78 #define UARTn_ROUTE_TXPEN 0x0002
79
80 struct efm32_uart_port {
81 struct uart_port port;
82 unsigned int txirq;
83 struct clk *clk;
84 struct efm32_uart_pdata pdata;
85 };
86 #define to_efm_port(_port) container_of(_port, struct efm32_uart_port, port)
87 #define efm_debug(efm_port, format, arg...) \
88 dev_dbg(efm_port->port.dev, format, ##arg)
89
efm32_uart_write32(struct efm32_uart_port * efm_port,u32 value,unsigned offset)90 static void efm32_uart_write32(struct efm32_uart_port *efm_port,
91 u32 value, unsigned offset)
92 {
93 writel_relaxed(value, efm_port->port.membase + offset);
94 }
95
efm32_uart_read32(struct efm32_uart_port * efm_port,unsigned offset)96 static u32 efm32_uart_read32(struct efm32_uart_port *efm_port,
97 unsigned offset)
98 {
99 return readl_relaxed(efm_port->port.membase + offset);
100 }
101
efm32_uart_tx_empty(struct uart_port * port)102 static unsigned int efm32_uart_tx_empty(struct uart_port *port)
103 {
104 struct efm32_uart_port *efm_port = to_efm_port(port);
105 u32 status = efm32_uart_read32(efm_port, UARTn_STATUS);
106
107 if (status & UARTn_STATUS_TXC)
108 return TIOCSER_TEMT;
109 else
110 return 0;
111 }
112
efm32_uart_set_mctrl(struct uart_port * port,unsigned int mctrl)113 static void efm32_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
114 {
115 /* sorry, neither handshaking lines nor loop functionallity */
116 }
117
efm32_uart_get_mctrl(struct uart_port * port)118 static unsigned int efm32_uart_get_mctrl(struct uart_port *port)
119 {
120 /* sorry, no handshaking lines available */
121 return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR;
122 }
123
efm32_uart_stop_tx(struct uart_port * port)124 static void efm32_uart_stop_tx(struct uart_port *port)
125 {
126 struct efm32_uart_port *efm_port = to_efm_port(port);
127 u32 ien = efm32_uart_read32(efm_port, UARTn_IEN);
128
129 efm32_uart_write32(efm_port, UARTn_CMD_TXDIS, UARTn_CMD);
130 ien &= ~(UARTn_IF_TXC | UARTn_IF_TXBL);
131 efm32_uart_write32(efm_port, ien, UARTn_IEN);
132 }
133
efm32_uart_tx_chars(struct efm32_uart_port * efm_port)134 static void efm32_uart_tx_chars(struct efm32_uart_port *efm_port)
135 {
136 struct uart_port *port = &efm_port->port;
137 struct circ_buf *xmit = &port->state->xmit;
138
139 while (efm32_uart_read32(efm_port, UARTn_STATUS) &
140 UARTn_STATUS_TXBL) {
141 if (port->x_char) {
142 port->icount.tx++;
143 efm32_uart_write32(efm_port, port->x_char,
144 UARTn_TXDATA);
145 port->x_char = 0;
146 continue;
147 }
148 if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
149 port->icount.tx++;
150 efm32_uart_write32(efm_port, xmit->buf[xmit->tail],
151 UARTn_TXDATA);
152 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
153 } else
154 break;
155 }
156
157 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
158 uart_write_wakeup(port);
159
160 if (!port->x_char && uart_circ_empty(xmit) &&
161 efm32_uart_read32(efm_port, UARTn_STATUS) &
162 UARTn_STATUS_TXC)
163 efm32_uart_stop_tx(port);
164 }
165
efm32_uart_start_tx(struct uart_port * port)166 static void efm32_uart_start_tx(struct uart_port *port)
167 {
168 struct efm32_uart_port *efm_port = to_efm_port(port);
169 u32 ien;
170
171 efm32_uart_write32(efm_port,
172 UARTn_IF_TXBL | UARTn_IF_TXC, UARTn_IFC);
173 ien = efm32_uart_read32(efm_port, UARTn_IEN);
174 efm32_uart_write32(efm_port,
175 ien | UARTn_IF_TXBL | UARTn_IF_TXC, UARTn_IEN);
176 efm32_uart_write32(efm_port, UARTn_CMD_TXEN, UARTn_CMD);
177
178 efm32_uart_tx_chars(efm_port);
179 }
180
efm32_uart_stop_rx(struct uart_port * port)181 static void efm32_uart_stop_rx(struct uart_port *port)
182 {
183 struct efm32_uart_port *efm_port = to_efm_port(port);
184
185 efm32_uart_write32(efm_port, UARTn_CMD_RXDIS, UARTn_CMD);
186 }
187
efm32_uart_break_ctl(struct uart_port * port,int ctl)188 static void efm32_uart_break_ctl(struct uart_port *port, int ctl)
189 {
190 /* not possible without fiddling with gpios */
191 }
192
efm32_uart_rx_chars(struct efm32_uart_port * efm_port)193 static void efm32_uart_rx_chars(struct efm32_uart_port *efm_port)
194 {
195 struct uart_port *port = &efm_port->port;
196
197 while (efm32_uart_read32(efm_port, UARTn_STATUS) &
198 UARTn_STATUS_RXDATAV) {
199 u32 rxdata = efm32_uart_read32(efm_port, UARTn_RXDATAX);
200 int flag = 0;
201
202 /*
203 * This is a reserved bit and I only saw it read as 0. But to be
204 * sure not to be confused too much by new devices adhere to the
205 * warning in the reference manual that reserverd bits might
206 * read as 1 in the future.
207 */
208 rxdata &= ~SW_UARTn_RXDATAX_BERR;
209
210 port->icount.rx++;
211
212 if ((rxdata & UARTn_RXDATAX_FERR) &&
213 !(rxdata & UARTn_RXDATAX_RXDATA__MASK)) {
214 rxdata |= SW_UARTn_RXDATAX_BERR;
215 port->icount.brk++;
216 if (uart_handle_break(port))
217 continue;
218 } else if (rxdata & UARTn_RXDATAX_PERR)
219 port->icount.parity++;
220 else if (rxdata & UARTn_RXDATAX_FERR)
221 port->icount.frame++;
222
223 rxdata &= port->read_status_mask;
224
225 if (rxdata & SW_UARTn_RXDATAX_BERR)
226 flag = TTY_BREAK;
227 else if (rxdata & UARTn_RXDATAX_PERR)
228 flag = TTY_PARITY;
229 else if (rxdata & UARTn_RXDATAX_FERR)
230 flag = TTY_FRAME;
231 else if (uart_handle_sysrq_char(port,
232 rxdata & UARTn_RXDATAX_RXDATA__MASK))
233 continue;
234
235 if ((rxdata & port->ignore_status_mask) == 0)
236 tty_insert_flip_char(&port->state->port,
237 rxdata & UARTn_RXDATAX_RXDATA__MASK, flag);
238 }
239 }
240
efm32_uart_rxirq(int irq,void * data)241 static irqreturn_t efm32_uart_rxirq(int irq, void *data)
242 {
243 struct efm32_uart_port *efm_port = data;
244 u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF);
245 int handled = IRQ_NONE;
246 struct uart_port *port = &efm_port->port;
247 struct tty_port *tport = &port->state->port;
248
249 spin_lock(&port->lock);
250
251 if (irqflag & UARTn_IF_RXDATAV) {
252 efm32_uart_write32(efm_port, UARTn_IF_RXDATAV, UARTn_IFC);
253 efm32_uart_rx_chars(efm_port);
254
255 handled = IRQ_HANDLED;
256 }
257
258 if (irqflag & UARTn_IF_RXOF) {
259 efm32_uart_write32(efm_port, UARTn_IF_RXOF, UARTn_IFC);
260 port->icount.overrun++;
261 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
262
263 handled = IRQ_HANDLED;
264 }
265
266 spin_unlock(&port->lock);
267
268 tty_flip_buffer_push(tport);
269
270 return handled;
271 }
272
efm32_uart_txirq(int irq,void * data)273 static irqreturn_t efm32_uart_txirq(int irq, void *data)
274 {
275 struct efm32_uart_port *efm_port = data;
276 u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF);
277
278 /* TXBL doesn't need to be cleared */
279 if (irqflag & UARTn_IF_TXC)
280 efm32_uart_write32(efm_port, UARTn_IF_TXC, UARTn_IFC);
281
282 if (irqflag & (UARTn_IF_TXC | UARTn_IF_TXBL)) {
283 efm32_uart_tx_chars(efm_port);
284 return IRQ_HANDLED;
285 } else
286 return IRQ_NONE;
287 }
288
efm32_uart_startup(struct uart_port * port)289 static int efm32_uart_startup(struct uart_port *port)
290 {
291 struct efm32_uart_port *efm_port = to_efm_port(port);
292 int ret;
293
294 ret = clk_enable(efm_port->clk);
295 if (ret) {
296 efm_debug(efm_port, "failed to enable clk\n");
297 goto err_clk_enable;
298 }
299 port->uartclk = clk_get_rate(efm_port->clk);
300
301 /* Enable pins at configured location */
302 efm32_uart_write32(efm_port,
303 UARTn_ROUTE_LOCATION(efm_port->pdata.location) |
304 UARTn_ROUTE_RXPEN | UARTn_ROUTE_TXPEN,
305 UARTn_ROUTE);
306
307 ret = request_irq(port->irq, efm32_uart_rxirq, 0,
308 DRIVER_NAME, efm_port);
309 if (ret) {
310 efm_debug(efm_port, "failed to register rxirq\n");
311 goto err_request_irq_rx;
312 }
313
314 /* disable all irqs */
315 efm32_uart_write32(efm_port, 0, UARTn_IEN);
316
317 ret = request_irq(efm_port->txirq, efm32_uart_txirq, 0,
318 DRIVER_NAME, efm_port);
319 if (ret) {
320 efm_debug(efm_port, "failed to register txirq\n");
321 free_irq(port->irq, efm_port);
322 err_request_irq_rx:
323
324 clk_disable(efm_port->clk);
325 } else {
326 efm32_uart_write32(efm_port,
327 UARTn_IF_RXDATAV | UARTn_IF_RXOF, UARTn_IEN);
328 efm32_uart_write32(efm_port, UARTn_CMD_RXEN, UARTn_CMD);
329 }
330
331 err_clk_enable:
332 return ret;
333 }
334
efm32_uart_shutdown(struct uart_port * port)335 static void efm32_uart_shutdown(struct uart_port *port)
336 {
337 struct efm32_uart_port *efm_port = to_efm_port(port);
338
339 efm32_uart_write32(efm_port, 0, UARTn_IEN);
340 free_irq(port->irq, efm_port);
341
342 clk_disable(efm_port->clk);
343 }
344
efm32_uart_set_termios(struct uart_port * port,struct ktermios * new,struct ktermios * old)345 static void efm32_uart_set_termios(struct uart_port *port,
346 struct ktermios *new, struct ktermios *old)
347 {
348 struct efm32_uart_port *efm_port = to_efm_port(port);
349 unsigned long flags;
350 unsigned baud;
351 u32 clkdiv;
352 u32 frame = 0;
353
354 /* no modem control lines */
355 new->c_cflag &= ~(CRTSCTS | CMSPAR);
356
357 baud = uart_get_baud_rate(port, new, old,
358 DIV_ROUND_CLOSEST(port->uartclk, 16 * 8192),
359 DIV_ROUND_CLOSEST(port->uartclk, 16));
360
361 switch (new->c_cflag & CSIZE) {
362 case CS5:
363 frame |= UARTn_FRAME_DATABITS(5);
364 break;
365 case CS6:
366 frame |= UARTn_FRAME_DATABITS(6);
367 break;
368 case CS7:
369 frame |= UARTn_FRAME_DATABITS(7);
370 break;
371 case CS8:
372 frame |= UARTn_FRAME_DATABITS(8);
373 break;
374 }
375
376 if (new->c_cflag & CSTOPB)
377 /* the receiver only verifies the first stop bit */
378 frame |= UARTn_FRAME_STOPBITS_TWO;
379 else
380 frame |= UARTn_FRAME_STOPBITS_ONE;
381
382 if (new->c_cflag & PARENB) {
383 if (new->c_cflag & PARODD)
384 frame |= UARTn_FRAME_PARITY_ODD;
385 else
386 frame |= UARTn_FRAME_PARITY_EVEN;
387 } else
388 frame |= UARTn_FRAME_PARITY_NONE;
389
390 /*
391 * the 6 lowest bits of CLKDIV are dc, bit 6 has value 0.25.
392 * port->uartclk <= 14e6, so 4 * port->uartclk doesn't overflow.
393 */
394 clkdiv = (DIV_ROUND_CLOSEST(4 * port->uartclk, 16 * baud) - 4) << 6;
395
396 spin_lock_irqsave(&port->lock, flags);
397
398 efm32_uart_write32(efm_port,
399 UARTn_CMD_TXDIS | UARTn_CMD_RXDIS, UARTn_CMD);
400
401 port->read_status_mask = UARTn_RXDATAX_RXDATA__MASK;
402 if (new->c_iflag & INPCK)
403 port->read_status_mask |=
404 UARTn_RXDATAX_FERR | UARTn_RXDATAX_PERR;
405 if (new->c_iflag & (IGNBRK | BRKINT | PARMRK))
406 port->read_status_mask |= SW_UARTn_RXDATAX_BERR;
407
408 port->ignore_status_mask = 0;
409 if (new->c_iflag & IGNPAR)
410 port->ignore_status_mask |=
411 UARTn_RXDATAX_FERR | UARTn_RXDATAX_PERR;
412 if (new->c_iflag & IGNBRK)
413 port->ignore_status_mask |= SW_UARTn_RXDATAX_BERR;
414
415 uart_update_timeout(port, new->c_cflag, baud);
416
417 efm32_uart_write32(efm_port, UARTn_CTRL_TXBIL, UARTn_CTRL);
418 efm32_uart_write32(efm_port, frame, UARTn_FRAME);
419 efm32_uart_write32(efm_port, clkdiv, UARTn_CLKDIV);
420
421 efm32_uart_write32(efm_port, UARTn_CMD_TXEN | UARTn_CMD_RXEN,
422 UARTn_CMD);
423
424 spin_unlock_irqrestore(&port->lock, flags);
425 }
426
efm32_uart_type(struct uart_port * port)427 static const char *efm32_uart_type(struct uart_port *port)
428 {
429 return port->type == PORT_EFMUART ? "efm32-uart" : NULL;
430 }
431
efm32_uart_release_port(struct uart_port * port)432 static void efm32_uart_release_port(struct uart_port *port)
433 {
434 struct efm32_uart_port *efm_port = to_efm_port(port);
435
436 clk_unprepare(efm_port->clk);
437 clk_put(efm_port->clk);
438 iounmap(port->membase);
439 }
440
efm32_uart_request_port(struct uart_port * port)441 static int efm32_uart_request_port(struct uart_port *port)
442 {
443 struct efm32_uart_port *efm_port = to_efm_port(port);
444 int ret;
445
446 port->membase = ioremap(port->mapbase, 60);
447 if (!efm_port->port.membase) {
448 ret = -ENOMEM;
449 efm_debug(efm_port, "failed to remap\n");
450 goto err_ioremap;
451 }
452
453 efm_port->clk = clk_get(port->dev, NULL);
454 if (IS_ERR(efm_port->clk)) {
455 ret = PTR_ERR(efm_port->clk);
456 efm_debug(efm_port, "failed to get clock\n");
457 goto err_clk_get;
458 }
459
460 ret = clk_prepare(efm_port->clk);
461 if (ret) {
462 clk_put(efm_port->clk);
463 err_clk_get:
464
465 iounmap(port->membase);
466 err_ioremap:
467 return ret;
468 }
469 return 0;
470 }
471
efm32_uart_config_port(struct uart_port * port,int type)472 static void efm32_uart_config_port(struct uart_port *port, int type)
473 {
474 if (type & UART_CONFIG_TYPE &&
475 !efm32_uart_request_port(port))
476 port->type = PORT_EFMUART;
477 }
478
efm32_uart_verify_port(struct uart_port * port,struct serial_struct * serinfo)479 static int efm32_uart_verify_port(struct uart_port *port,
480 struct serial_struct *serinfo)
481 {
482 int ret = 0;
483
484 if (serinfo->type != PORT_UNKNOWN && serinfo->type != PORT_EFMUART)
485 ret = -EINVAL;
486
487 return ret;
488 }
489
490 static struct uart_ops efm32_uart_pops = {
491 .tx_empty = efm32_uart_tx_empty,
492 .set_mctrl = efm32_uart_set_mctrl,
493 .get_mctrl = efm32_uart_get_mctrl,
494 .stop_tx = efm32_uart_stop_tx,
495 .start_tx = efm32_uart_start_tx,
496 .stop_rx = efm32_uart_stop_rx,
497 .break_ctl = efm32_uart_break_ctl,
498 .startup = efm32_uart_startup,
499 .shutdown = efm32_uart_shutdown,
500 .set_termios = efm32_uart_set_termios,
501 .type = efm32_uart_type,
502 .release_port = efm32_uart_release_port,
503 .request_port = efm32_uart_request_port,
504 .config_port = efm32_uart_config_port,
505 .verify_port = efm32_uart_verify_port,
506 };
507
508 static struct efm32_uart_port *efm32_uart_ports[5];
509
510 #ifdef CONFIG_SERIAL_EFM32_UART_CONSOLE
efm32_uart_console_putchar(struct uart_port * port,int ch)511 static void efm32_uart_console_putchar(struct uart_port *port, int ch)
512 {
513 struct efm32_uart_port *efm_port = to_efm_port(port);
514 unsigned int timeout = 0x400;
515 u32 status;
516
517 while (1) {
518 status = efm32_uart_read32(efm_port, UARTn_STATUS);
519
520 if (status & UARTn_STATUS_TXBL)
521 break;
522 if (!timeout--)
523 return;
524 }
525 efm32_uart_write32(efm_port, ch, UARTn_TXDATA);
526 }
527
efm32_uart_console_write(struct console * co,const char * s,unsigned int count)528 static void efm32_uart_console_write(struct console *co, const char *s,
529 unsigned int count)
530 {
531 struct efm32_uart_port *efm_port = efm32_uart_ports[co->index];
532 u32 status = efm32_uart_read32(efm_port, UARTn_STATUS);
533 unsigned int timeout = 0x400;
534
535 if (!(status & UARTn_STATUS_TXENS))
536 efm32_uart_write32(efm_port, UARTn_CMD_TXEN, UARTn_CMD);
537
538 uart_console_write(&efm_port->port, s, count,
539 efm32_uart_console_putchar);
540
541 /* Wait for the transmitter to become empty */
542 while (1) {
543 u32 status = efm32_uart_read32(efm_port, UARTn_STATUS);
544 if (status & UARTn_STATUS_TXC)
545 break;
546 if (!timeout--)
547 break;
548 }
549
550 if (!(status & UARTn_STATUS_TXENS))
551 efm32_uart_write32(efm_port, UARTn_CMD_TXDIS, UARTn_CMD);
552 }
553
efm32_uart_console_get_options(struct efm32_uart_port * efm_port,int * baud,int * parity,int * bits)554 static void efm32_uart_console_get_options(struct efm32_uart_port *efm_port,
555 int *baud, int *parity, int *bits)
556 {
557 u32 ctrl = efm32_uart_read32(efm_port, UARTn_CTRL);
558 u32 route, clkdiv, frame;
559
560 if (ctrl & UARTn_CTRL_SYNC)
561 /* not operating in async mode */
562 return;
563
564 route = efm32_uart_read32(efm_port, UARTn_ROUTE);
565 if (!(route & UARTn_ROUTE_TXPEN))
566 /* tx pin not routed */
567 return;
568
569 clkdiv = efm32_uart_read32(efm_port, UARTn_CLKDIV);
570
571 *baud = DIV_ROUND_CLOSEST(4 * efm_port->port.uartclk,
572 16 * (4 + (clkdiv >> 6)));
573
574 frame = efm32_uart_read32(efm_port, UARTn_FRAME);
575 if (frame & UARTn_FRAME_PARITY_ODD)
576 *parity = 'o';
577 else if (frame & UARTn_FRAME_PARITY_EVEN)
578 *parity = 'e';
579 else
580 *parity = 'n';
581
582 *bits = (frame & UARTn_FRAME_DATABITS__MASK) -
583 UARTn_FRAME_DATABITS(4) + 4;
584
585 efm_debug(efm_port, "get_opts: options=%d%c%d\n",
586 *baud, *parity, *bits);
587 }
588
efm32_uart_console_setup(struct console * co,char * options)589 static int efm32_uart_console_setup(struct console *co, char *options)
590 {
591 struct efm32_uart_port *efm_port;
592 int baud = 115200;
593 int bits = 8;
594 int parity = 'n';
595 int flow = 'n';
596 int ret;
597
598 if (co->index < 0 || co->index >= ARRAY_SIZE(efm32_uart_ports)) {
599 unsigned i;
600 for (i = 0; i < ARRAY_SIZE(efm32_uart_ports); ++i) {
601 if (efm32_uart_ports[i]) {
602 pr_warn("efm32-console: fall back to console index %u (from %hhi)\n",
603 i, co->index);
604 co->index = i;
605 break;
606 }
607 }
608 }
609
610 efm_port = efm32_uart_ports[co->index];
611 if (!efm_port) {
612 pr_warn("efm32-console: No port at %d\n", co->index);
613 return -ENODEV;
614 }
615
616 ret = clk_prepare(efm_port->clk);
617 if (ret) {
618 dev_warn(efm_port->port.dev,
619 "console: clk_prepare failed: %d\n", ret);
620 return ret;
621 }
622
623 efm_port->port.uartclk = clk_get_rate(efm_port->clk);
624
625 if (options)
626 uart_parse_options(options, &baud, &parity, &bits, &flow);
627 else
628 efm32_uart_console_get_options(efm_port,
629 &baud, &parity, &bits);
630
631 return uart_set_options(&efm_port->port, co, baud, parity, bits, flow);
632 }
633
634 static struct uart_driver efm32_uart_reg;
635
636 static struct console efm32_uart_console = {
637 .name = DEV_NAME,
638 .write = efm32_uart_console_write,
639 .device = uart_console_device,
640 .setup = efm32_uart_console_setup,
641 .flags = CON_PRINTBUFFER,
642 .index = -1,
643 .data = &efm32_uart_reg,
644 };
645
646 #else
647 #define efm32_uart_console (*(struct console *)NULL)
648 #endif /* ifdef CONFIG_SERIAL_EFM32_UART_CONSOLE / else */
649
650 static struct uart_driver efm32_uart_reg = {
651 .owner = THIS_MODULE,
652 .driver_name = DRIVER_NAME,
653 .dev_name = DEV_NAME,
654 .nr = ARRAY_SIZE(efm32_uart_ports),
655 .cons = &efm32_uart_console,
656 };
657
efm32_uart_probe_dt(struct platform_device * pdev,struct efm32_uart_port * efm_port)658 static int efm32_uart_probe_dt(struct platform_device *pdev,
659 struct efm32_uart_port *efm_port)
660 {
661 struct device_node *np = pdev->dev.of_node;
662 u32 location;
663 int ret;
664
665 if (!np)
666 return 1;
667
668 ret = of_property_read_u32(np, "energymicro,location", &location);
669
670 if (ret)
671 /* fall back to wrongly namespaced property */
672 ret = of_property_read_u32(np, "efm32,location", &location);
673
674 if (ret)
675 /* fall back to old and (wrongly) generic property "location" */
676 ret = of_property_read_u32(np, "location", &location);
677
678 if (!ret) {
679 if (location > 5) {
680 dev_err(&pdev->dev, "invalid location\n");
681 return -EINVAL;
682 }
683 efm_debug(efm_port, "using location %u\n", location);
684 efm_port->pdata.location = location;
685 } else {
686 efm_debug(efm_port, "fall back to location 0\n");
687 }
688
689 ret = of_alias_get_id(np, "serial");
690 if (ret < 0) {
691 dev_err(&pdev->dev, "failed to get alias id: %d\n", ret);
692 return ret;
693 } else {
694 efm_port->port.line = ret;
695 return 0;
696 }
697
698 }
699
efm32_uart_probe(struct platform_device * pdev)700 static int efm32_uart_probe(struct platform_device *pdev)
701 {
702 struct efm32_uart_port *efm_port;
703 struct resource *res;
704 unsigned int line;
705 int ret;
706
707 efm_port = kzalloc(sizeof(*efm_port), GFP_KERNEL);
708 if (!efm_port) {
709 dev_dbg(&pdev->dev, "failed to allocate private data\n");
710 return -ENOMEM;
711 }
712
713 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
714 if (!res) {
715 ret = -ENODEV;
716 dev_dbg(&pdev->dev, "failed to determine base address\n");
717 goto err_get_base;
718 }
719
720 if (resource_size(res) < 60) {
721 ret = -EINVAL;
722 dev_dbg(&pdev->dev, "memory resource too small\n");
723 goto err_too_small;
724 }
725
726 ret = platform_get_irq(pdev, 0);
727 if (ret <= 0) {
728 dev_dbg(&pdev->dev, "failed to get rx irq\n");
729 goto err_get_rxirq;
730 }
731
732 efm_port->port.irq = ret;
733
734 ret = platform_get_irq(pdev, 1);
735 if (ret <= 0)
736 ret = efm_port->port.irq + 1;
737
738 efm_port->txirq = ret;
739
740 efm_port->port.dev = &pdev->dev;
741 efm_port->port.mapbase = res->start;
742 efm_port->port.type = PORT_EFMUART;
743 efm_port->port.iotype = UPIO_MEM32;
744 efm_port->port.fifosize = 2;
745 efm_port->port.ops = &efm32_uart_pops;
746 efm_port->port.flags = UPF_BOOT_AUTOCONF;
747
748 ret = efm32_uart_probe_dt(pdev, efm_port);
749 if (ret > 0) {
750 /* not created by device tree */
751 const struct efm32_uart_pdata *pdata = dev_get_platdata(&pdev->dev);
752
753 efm_port->port.line = pdev->id;
754
755 if (pdata)
756 efm_port->pdata = *pdata;
757 } else if (ret < 0)
758 goto err_probe_dt;
759
760 line = efm_port->port.line;
761
762 if (line >= 0 && line < ARRAY_SIZE(efm32_uart_ports))
763 efm32_uart_ports[line] = efm_port;
764
765 ret = uart_add_one_port(&efm32_uart_reg, &efm_port->port);
766 if (ret) {
767 dev_dbg(&pdev->dev, "failed to add port: %d\n", ret);
768
769 if (line >= 0 && line < ARRAY_SIZE(efm32_uart_ports))
770 efm32_uart_ports[line] = NULL;
771 err_probe_dt:
772 err_get_rxirq:
773 err_too_small:
774 err_get_base:
775 kfree(efm_port);
776 } else {
777 platform_set_drvdata(pdev, efm_port);
778 dev_dbg(&pdev->dev, "\\o/\n");
779 }
780
781 return ret;
782 }
783
efm32_uart_remove(struct platform_device * pdev)784 static int efm32_uart_remove(struct platform_device *pdev)
785 {
786 struct efm32_uart_port *efm_port = platform_get_drvdata(pdev);
787 unsigned int line = efm_port->port.line;
788
789 uart_remove_one_port(&efm32_uart_reg, &efm_port->port);
790
791 if (line >= 0 && line < ARRAY_SIZE(efm32_uart_ports))
792 efm32_uart_ports[line] = NULL;
793
794 kfree(efm_port);
795
796 return 0;
797 }
798
799 static const struct of_device_id efm32_uart_dt_ids[] = {
800 {
801 .compatible = "energymicro,efm32-uart",
802 }, {
803 /* doesn't follow the "vendor,device" scheme, don't use */
804 .compatible = "efm32,uart",
805 }, {
806 /* sentinel */
807 }
808 };
809 MODULE_DEVICE_TABLE(of, efm32_uart_dt_ids);
810
811 static struct platform_driver efm32_uart_driver = {
812 .probe = efm32_uart_probe,
813 .remove = efm32_uart_remove,
814
815 .driver = {
816 .name = DRIVER_NAME,
817 .of_match_table = efm32_uart_dt_ids,
818 },
819 };
820
efm32_uart_init(void)821 static int __init efm32_uart_init(void)
822 {
823 int ret;
824
825 ret = uart_register_driver(&efm32_uart_reg);
826 if (ret)
827 return ret;
828
829 ret = platform_driver_register(&efm32_uart_driver);
830 if (ret)
831 uart_unregister_driver(&efm32_uart_reg);
832
833 pr_info("EFM32 UART/USART driver\n");
834
835 return ret;
836 }
837 module_init(efm32_uart_init);
838
efm32_uart_exit(void)839 static void __exit efm32_uart_exit(void)
840 {
841 platform_driver_unregister(&efm32_uart_driver);
842 uart_unregister_driver(&efm32_uart_reg);
843 }
844 module_exit(efm32_uart_exit);
845
846 MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
847 MODULE_DESCRIPTION("EFM32 UART/USART driver");
848 MODULE_LICENSE("GPL v2");
849 MODULE_ALIAS("platform:" DRIVER_NAME);
850