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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * timbuart.c timberdale FPGA UART driver
4 * Copyright (c) 2009 Intel Corporation
5 */
6
7/* Supports:
8 * Timberdale FPGA UART
9 */
10
11#include <linux/pci.h>
12#include <linux/interrupt.h>
13#include <linux/serial_core.h>
14#include <linux/tty.h>
15#include <linux/tty_flip.h>
16#include <linux/kernel.h>
17#include <linux/platform_device.h>
18#include <linux/ioport.h>
19#include <linux/slab.h>
20#include <linux/module.h>
21
22#include "timbuart.h"
23
24struct timbuart_port {
25 struct uart_port port;
26 struct tasklet_struct tasklet;
27 int usedma;
28 u32 last_ier;
29 struct platform_device *dev;
30};
31
32static int baudrates[] = {9600, 19200, 38400, 57600, 115200, 230400, 460800,
33 921600, 1843200, 3250000};
34
35static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier);
36
37static irqreturn_t timbuart_handleinterrupt(int irq, void *devid);
38
39static void timbuart_stop_rx(struct uart_port *port)
40{
41 /* spin lock held by upper layer, disable all RX interrupts */
42 u32 ier = ioread32(port->membase + TIMBUART_IER) & ~RXFLAGS;
43 iowrite32(ier, port->membase + TIMBUART_IER);
44}
45
46static void timbuart_stop_tx(struct uart_port *port)
47{
48 /* spinlock held by upper layer, disable TX interrupt */
49 u32 ier = ioread32(port->membase + TIMBUART_IER) & ~TXBAE;
50 iowrite32(ier, port->membase + TIMBUART_IER);
51}
52
53static void timbuart_start_tx(struct uart_port *port)
54{
55 struct timbuart_port *uart =
56 container_of(port, struct timbuart_port, port);
57
58 /* do not transfer anything here -> fire off the tasklet */
59 tasklet_schedule(&uart->tasklet);
60}
61
62static unsigned int timbuart_tx_empty(struct uart_port *port)
63{
64 u32 isr = ioread32(port->membase + TIMBUART_ISR);
65
66 return (isr & TXBE) ? TIOCSER_TEMT : 0;
67}
68
69static void timbuart_flush_buffer(struct uart_port *port)
70{
71 if (!timbuart_tx_empty(port)) {
72 u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
73 TIMBUART_CTRL_FLSHTX;
74
75 iowrite8(ctl, port->membase + TIMBUART_CTRL);
76 iowrite32(TXBF, port->membase + TIMBUART_ISR);
77 }
78}
79
80static void timbuart_rx_chars(struct uart_port *port)
81{
82 struct tty_port *tport = &port->state->port;
83
84 while (ioread32(port->membase + TIMBUART_ISR) & RXDP) {
85 u8 ch = ioread8(port->membase + TIMBUART_RXFIFO);
86 port->icount.rx++;
87 tty_insert_flip_char(tport, ch, TTY_NORMAL);
88 }
89
90 tty_flip_buffer_push(tport);
91
92 dev_dbg(port->dev, "%s - total read %d bytes\n",
93 __func__, port->icount.rx);
94}
95
96static void timbuart_tx_chars(struct uart_port *port)
97{
98 struct circ_buf *xmit = &port->state->xmit;
99
100 while (!(ioread32(port->membase + TIMBUART_ISR) & TXBF) &&
101 !uart_circ_empty(xmit)) {
102 iowrite8(xmit->buf[xmit->tail],
103 port->membase + TIMBUART_TXFIFO);
104 uart_xmit_advance(port, 1);
105 }
106
107 dev_dbg(port->dev,
108 "%s - total written %d bytes, CTL: %x, RTS: %x, baud: %x\n",
109 __func__,
110 port->icount.tx,
111 ioread8(port->membase + TIMBUART_CTRL),
112 port->mctrl & TIOCM_RTS,
113 ioread8(port->membase + TIMBUART_BAUDRATE));
114}
115
116static void timbuart_handle_tx_port(struct uart_port *port, u32 isr, u32 *ier)
117{
118 struct timbuart_port *uart =
119 container_of(port, struct timbuart_port, port);
120 struct circ_buf *xmit = &port->state->xmit;
121
122 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
123 return;
124
125 if (port->x_char)
126 return;
127
128 if (isr & TXFLAGS) {
129 timbuart_tx_chars(port);
130 /* clear all TX interrupts */
131 iowrite32(TXFLAGS, port->membase + TIMBUART_ISR);
132
133 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
134 uart_write_wakeup(port);
135 } else
136 /* Re-enable any tx interrupt */
137 *ier |= uart->last_ier & TXFLAGS;
138
139 /* enable interrupts if there are chars in the transmit buffer,
140 * Or if we delivered some bytes and want the almost empty interrupt
141 * we wake up the upper layer later when we got the interrupt
142 * to give it some time to go out...
143 */
144 if (!uart_circ_empty(xmit))
145 *ier |= TXBAE;
146
147 dev_dbg(port->dev, "%s - leaving\n", __func__);
148}
149
150static void timbuart_handle_rx_port(struct uart_port *port, u32 isr, u32 *ier)
151{
152 if (isr & RXFLAGS) {
153 /* Some RX status is set */
154 if (isr & RXBF) {
155 u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
156 TIMBUART_CTRL_FLSHRX;
157 iowrite8(ctl, port->membase + TIMBUART_CTRL);
158 port->icount.overrun++;
159 } else if (isr & (RXDP))
160 timbuart_rx_chars(port);
161
162 /* ack all RX interrupts */
163 iowrite32(RXFLAGS, port->membase + TIMBUART_ISR);
164 }
165
166 /* always have the RX interrupts enabled */
167 *ier |= RXBAF | RXBF | RXTT;
168
169 dev_dbg(port->dev, "%s - leaving\n", __func__);
170}
171
172static void timbuart_tasklet(struct tasklet_struct *t)
173{
174 struct timbuart_port *uart = from_tasklet(uart, t, tasklet);
175 u32 isr, ier = 0;
176
177 uart_port_lock(&uart->port);
178
179 isr = ioread32(uart->port.membase + TIMBUART_ISR);
180 dev_dbg(uart->port.dev, "%s ISR: %x\n", __func__, isr);
181
182 if (!uart->usedma)
183 timbuart_handle_tx_port(&uart->port, isr, &ier);
184
185 timbuart_mctrl_check(&uart->port, isr, &ier);
186
187 if (!uart->usedma)
188 timbuart_handle_rx_port(&uart->port, isr, &ier);
189
190 iowrite32(ier, uart->port.membase + TIMBUART_IER);
191
192 uart_port_unlock(&uart->port);
193 dev_dbg(uart->port.dev, "%s leaving\n", __func__);
194}
195
196static unsigned int timbuart_get_mctrl(struct uart_port *port)
197{
198 u8 cts = ioread8(port->membase + TIMBUART_CTRL);
199 dev_dbg(port->dev, "%s - cts %x\n", __func__, cts);
200
201 if (cts & TIMBUART_CTRL_CTS)
202 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
203 else
204 return TIOCM_DSR | TIOCM_CAR;
205}
206
207static void timbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
208{
209 dev_dbg(port->dev, "%s - %x\n", __func__, mctrl);
210
211 if (mctrl & TIOCM_RTS)
212 iowrite8(TIMBUART_CTRL_RTS, port->membase + TIMBUART_CTRL);
213 else
214 iowrite8(0, port->membase + TIMBUART_CTRL);
215}
216
217static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier)
218{
219 unsigned int cts;
220
221 if (isr & CTS_DELTA) {
222 /* ack */
223 iowrite32(CTS_DELTA, port->membase + TIMBUART_ISR);
224 cts = timbuart_get_mctrl(port);
225 uart_handle_cts_change(port, cts & TIOCM_CTS);
226 wake_up_interruptible(&port->state->port.delta_msr_wait);
227 }
228
229 *ier |= CTS_DELTA;
230}
231
232static void timbuart_break_ctl(struct uart_port *port, int ctl)
233{
234 /* N/A */
235}
236
237static int timbuart_startup(struct uart_port *port)
238{
239 struct timbuart_port *uart =
240 container_of(port, struct timbuart_port, port);
241
242 dev_dbg(port->dev, "%s\n", __func__);
243
244 iowrite8(TIMBUART_CTRL_FLSHRX, port->membase + TIMBUART_CTRL);
245 iowrite32(0x1ff, port->membase + TIMBUART_ISR);
246 /* Enable all but TX interrupts */
247 iowrite32(RXBAF | RXBF | RXTT | CTS_DELTA,
248 port->membase + TIMBUART_IER);
249
250 return request_irq(port->irq, timbuart_handleinterrupt, IRQF_SHARED,
251 "timb-uart", uart);
252}
253
254static void timbuart_shutdown(struct uart_port *port)
255{
256 struct timbuart_port *uart =
257 container_of(port, struct timbuart_port, port);
258 dev_dbg(port->dev, "%s\n", __func__);
259 free_irq(port->irq, uart);
260 iowrite32(0, port->membase + TIMBUART_IER);
261
262 timbuart_flush_buffer(port);
263}
264
265static int get_bindex(int baud)
266{
267 int i;
268
269 for (i = 0; i < ARRAY_SIZE(baudrates); i++)
270 if (baud <= baudrates[i])
271 return i;
272
273 return -1;
274}
275
276static void timbuart_set_termios(struct uart_port *port,
277 struct ktermios *termios,
278 const struct ktermios *old)
279{
280 unsigned int baud;
281 short bindex;
282 unsigned long flags;
283
284 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
285 bindex = get_bindex(baud);
286 dev_dbg(port->dev, "%s - bindex %d\n", __func__, bindex);
287
288 if (bindex < 0)
289 bindex = 0;
290 baud = baudrates[bindex];
291
292 /* The serial layer calls into this once with old = NULL when setting
293 up initially */
294 if (old)
295 tty_termios_copy_hw(termios, old);
296 tty_termios_encode_baud_rate(termios, baud, baud);
297
298 uart_port_lock_irqsave(port, &flags);
299 iowrite8((u8)bindex, port->membase + TIMBUART_BAUDRATE);
300 uart_update_timeout(port, termios->c_cflag, baud);
301 uart_port_unlock_irqrestore(port, flags);
302}
303
304static const char *timbuart_type(struct uart_port *port)
305{
306 return port->type == PORT_UNKNOWN ? "timbuart" : NULL;
307}
308
309/* We do not request/release mappings of the registers here,
310 * currently it's done in the proble function.
311 */
312static void timbuart_release_port(struct uart_port *port)
313{
314 struct platform_device *pdev = to_platform_device(port->dev);
315 int size =
316 resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
317
318 if (port->flags & UPF_IOREMAP) {
319 iounmap(port->membase);
320 port->membase = NULL;
321 }
322
323 release_mem_region(port->mapbase, size);
324}
325
326static int timbuart_request_port(struct uart_port *port)
327{
328 struct platform_device *pdev = to_platform_device(port->dev);
329 int size =
330 resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
331
332 if (!request_mem_region(port->mapbase, size, "timb-uart"))
333 return -EBUSY;
334
335 if (port->flags & UPF_IOREMAP) {
336 port->membase = ioremap(port->mapbase, size);
337 if (port->membase == NULL) {
338 release_mem_region(port->mapbase, size);
339 return -ENOMEM;
340 }
341 }
342
343 return 0;
344}
345
346static irqreturn_t timbuart_handleinterrupt(int irq, void *devid)
347{
348 struct timbuart_port *uart = (struct timbuart_port *)devid;
349
350 if (ioread8(uart->port.membase + TIMBUART_IPR)) {
351 uart->last_ier = ioread32(uart->port.membase + TIMBUART_IER);
352
353 /* disable interrupts, the tasklet enables them again */
354 iowrite32(0, uart->port.membase + TIMBUART_IER);
355
356 /* fire off bottom half */
357 tasklet_schedule(&uart->tasklet);
358
359 return IRQ_HANDLED;
360 } else
361 return IRQ_NONE;
362}
363
364/*
365 * Configure/autoconfigure the port.
366 */
367static void timbuart_config_port(struct uart_port *port, int flags)
368{
369 if (flags & UART_CONFIG_TYPE) {
370 port->type = PORT_TIMBUART;
371 timbuart_request_port(port);
372 }
373}
374
375static int timbuart_verify_port(struct uart_port *port,
376 struct serial_struct *ser)
377{
378 /* we don't want the core code to modify any port params */
379 return -EINVAL;
380}
381
382static const struct uart_ops timbuart_ops = {
383 .tx_empty = timbuart_tx_empty,
384 .set_mctrl = timbuart_set_mctrl,
385 .get_mctrl = timbuart_get_mctrl,
386 .stop_tx = timbuart_stop_tx,
387 .start_tx = timbuart_start_tx,
388 .flush_buffer = timbuart_flush_buffer,
389 .stop_rx = timbuart_stop_rx,
390 .break_ctl = timbuart_break_ctl,
391 .startup = timbuart_startup,
392 .shutdown = timbuart_shutdown,
393 .set_termios = timbuart_set_termios,
394 .type = timbuart_type,
395 .release_port = timbuart_release_port,
396 .request_port = timbuart_request_port,
397 .config_port = timbuart_config_port,
398 .verify_port = timbuart_verify_port
399};
400
401static struct uart_driver timbuart_driver = {
402 .owner = THIS_MODULE,
403 .driver_name = "timberdale_uart",
404 .dev_name = "ttyTU",
405 .major = TIMBUART_MAJOR,
406 .minor = TIMBUART_MINOR,
407 .nr = 1
408};
409
410static int timbuart_probe(struct platform_device *dev)
411{
412 int err, irq;
413 struct timbuart_port *uart;
414 struct resource *iomem;
415
416 dev_dbg(&dev->dev, "%s\n", __func__);
417
418 uart = kzalloc(sizeof(*uart), GFP_KERNEL);
419 if (!uart) {
420 err = -EINVAL;
421 goto err_mem;
422 }
423
424 uart->usedma = 0;
425
426 uart->port.uartclk = 3250000 * 16;
427 uart->port.fifosize = TIMBUART_FIFO_SIZE;
428 uart->port.regshift = 2;
429 uart->port.iotype = UPIO_MEM;
430 uart->port.ops = &timbuart_ops;
431 uart->port.irq = 0;
432 uart->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
433 uart->port.line = 0;
434 uart->port.dev = &dev->dev;
435
436 iomem = platform_get_resource(dev, IORESOURCE_MEM, 0);
437 if (!iomem) {
438 err = -ENOMEM;
439 goto err_register;
440 }
441 uart->port.mapbase = iomem->start;
442 uart->port.membase = NULL;
443
444 irq = platform_get_irq(dev, 0);
445 if (irq < 0) {
446 err = -EINVAL;
447 goto err_register;
448 }
449 uart->port.irq = irq;
450
451 tasklet_setup(&uart->tasklet, timbuart_tasklet);
452
453 err = uart_register_driver(&timbuart_driver);
454 if (err)
455 goto err_register;
456
457 err = uart_add_one_port(&timbuart_driver, &uart->port);
458 if (err)
459 goto err_add_port;
460
461 platform_set_drvdata(dev, uart);
462
463 return 0;
464
465err_add_port:
466 uart_unregister_driver(&timbuart_driver);
467err_register:
468 kfree(uart);
469err_mem:
470 printk(KERN_ERR "timberdale: Failed to register Timberdale UART: %d\n",
471 err);
472
473 return err;
474}
475
476static void timbuart_remove(struct platform_device *dev)
477{
478 struct timbuart_port *uart = platform_get_drvdata(dev);
479
480 tasklet_kill(&uart->tasklet);
481 uart_remove_one_port(&timbuart_driver, &uart->port);
482 uart_unregister_driver(&timbuart_driver);
483 kfree(uart);
484}
485
486static struct platform_driver timbuart_platform_driver = {
487 .driver = {
488 .name = "timb-uart",
489 },
490 .probe = timbuart_probe,
491 .remove_new = timbuart_remove,
492};
493
494module_platform_driver(timbuart_platform_driver);
495
496MODULE_DESCRIPTION("Timberdale UART driver");
497MODULE_LICENSE("GPL v2");
498MODULE_ALIAS("platform:timb-uart");
499
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * timbuart.c timberdale FPGA UART driver
4 * Copyright (c) 2009 Intel Corporation
5 */
6
7/* Supports:
8 * Timberdale FPGA UART
9 */
10
11#include <linux/pci.h>
12#include <linux/interrupt.h>
13#include <linux/serial_core.h>
14#include <linux/tty.h>
15#include <linux/tty_flip.h>
16#include <linux/kernel.h>
17#include <linux/platform_device.h>
18#include <linux/ioport.h>
19#include <linux/slab.h>
20#include <linux/module.h>
21
22#include "timbuart.h"
23
24struct timbuart_port {
25 struct uart_port port;
26 struct tasklet_struct tasklet;
27 int usedma;
28 u32 last_ier;
29 struct platform_device *dev;
30};
31
32static int baudrates[] = {9600, 19200, 38400, 57600, 115200, 230400, 460800,
33 921600, 1843200, 3250000};
34
35static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier);
36
37static irqreturn_t timbuart_handleinterrupt(int irq, void *devid);
38
39static void timbuart_stop_rx(struct uart_port *port)
40{
41 /* spin lock held by upper layer, disable all RX interrupts */
42 u32 ier = ioread32(port->membase + TIMBUART_IER) & ~RXFLAGS;
43 iowrite32(ier, port->membase + TIMBUART_IER);
44}
45
46static void timbuart_stop_tx(struct uart_port *port)
47{
48 /* spinlock held by upper layer, disable TX interrupt */
49 u32 ier = ioread32(port->membase + TIMBUART_IER) & ~TXBAE;
50 iowrite32(ier, port->membase + TIMBUART_IER);
51}
52
53static void timbuart_start_tx(struct uart_port *port)
54{
55 struct timbuart_port *uart =
56 container_of(port, struct timbuart_port, port);
57
58 /* do not transfer anything here -> fire off the tasklet */
59 tasklet_schedule(&uart->tasklet);
60}
61
62static unsigned int timbuart_tx_empty(struct uart_port *port)
63{
64 u32 isr = ioread32(port->membase + TIMBUART_ISR);
65
66 return (isr & TXBE) ? TIOCSER_TEMT : 0;
67}
68
69static void timbuart_flush_buffer(struct uart_port *port)
70{
71 if (!timbuart_tx_empty(port)) {
72 u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
73 TIMBUART_CTRL_FLSHTX;
74
75 iowrite8(ctl, port->membase + TIMBUART_CTRL);
76 iowrite32(TXBF, port->membase + TIMBUART_ISR);
77 }
78}
79
80static void timbuart_rx_chars(struct uart_port *port)
81{
82 struct tty_port *tport = &port->state->port;
83
84 while (ioread32(port->membase + TIMBUART_ISR) & RXDP) {
85 u8 ch = ioread8(port->membase + TIMBUART_RXFIFO);
86 port->icount.rx++;
87 tty_insert_flip_char(tport, ch, TTY_NORMAL);
88 }
89
90 tty_flip_buffer_push(tport);
91
92 dev_dbg(port->dev, "%s - total read %d bytes\n",
93 __func__, port->icount.rx);
94}
95
96static void timbuart_tx_chars(struct uart_port *port)
97{
98 struct circ_buf *xmit = &port->state->xmit;
99
100 while (!(ioread32(port->membase + TIMBUART_ISR) & TXBF) &&
101 !uart_circ_empty(xmit)) {
102 iowrite8(xmit->buf[xmit->tail],
103 port->membase + TIMBUART_TXFIFO);
104 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
105 port->icount.tx++;
106 }
107
108 dev_dbg(port->dev,
109 "%s - total written %d bytes, CTL: %x, RTS: %x, baud: %x\n",
110 __func__,
111 port->icount.tx,
112 ioread8(port->membase + TIMBUART_CTRL),
113 port->mctrl & TIOCM_RTS,
114 ioread8(port->membase + TIMBUART_BAUDRATE));
115}
116
117static void timbuart_handle_tx_port(struct uart_port *port, u32 isr, u32 *ier)
118{
119 struct timbuart_port *uart =
120 container_of(port, struct timbuart_port, port);
121 struct circ_buf *xmit = &port->state->xmit;
122
123 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
124 return;
125
126 if (port->x_char)
127 return;
128
129 if (isr & TXFLAGS) {
130 timbuart_tx_chars(port);
131 /* clear all TX interrupts */
132 iowrite32(TXFLAGS, port->membase + TIMBUART_ISR);
133
134 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
135 uart_write_wakeup(port);
136 } else
137 /* Re-enable any tx interrupt */
138 *ier |= uart->last_ier & TXFLAGS;
139
140 /* enable interrupts if there are chars in the transmit buffer,
141 * Or if we delivered some bytes and want the almost empty interrupt
142 * we wake up the upper layer later when we got the interrupt
143 * to give it some time to go out...
144 */
145 if (!uart_circ_empty(xmit))
146 *ier |= TXBAE;
147
148 dev_dbg(port->dev, "%s - leaving\n", __func__);
149}
150
151static void timbuart_handle_rx_port(struct uart_port *port, u32 isr, u32 *ier)
152{
153 if (isr & RXFLAGS) {
154 /* Some RX status is set */
155 if (isr & RXBF) {
156 u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
157 TIMBUART_CTRL_FLSHRX;
158 iowrite8(ctl, port->membase + TIMBUART_CTRL);
159 port->icount.overrun++;
160 } else if (isr & (RXDP))
161 timbuart_rx_chars(port);
162
163 /* ack all RX interrupts */
164 iowrite32(RXFLAGS, port->membase + TIMBUART_ISR);
165 }
166
167 /* always have the RX interrupts enabled */
168 *ier |= RXBAF | RXBF | RXTT;
169
170 dev_dbg(port->dev, "%s - leaving\n", __func__);
171}
172
173static void timbuart_tasklet(struct tasklet_struct *t)
174{
175 struct timbuart_port *uart = from_tasklet(uart, t, tasklet);
176 u32 isr, ier = 0;
177
178 spin_lock(&uart->port.lock);
179
180 isr = ioread32(uart->port.membase + TIMBUART_ISR);
181 dev_dbg(uart->port.dev, "%s ISR: %x\n", __func__, isr);
182
183 if (!uart->usedma)
184 timbuart_handle_tx_port(&uart->port, isr, &ier);
185
186 timbuart_mctrl_check(&uart->port, isr, &ier);
187
188 if (!uart->usedma)
189 timbuart_handle_rx_port(&uart->port, isr, &ier);
190
191 iowrite32(ier, uart->port.membase + TIMBUART_IER);
192
193 spin_unlock(&uart->port.lock);
194 dev_dbg(uart->port.dev, "%s leaving\n", __func__);
195}
196
197static unsigned int timbuart_get_mctrl(struct uart_port *port)
198{
199 u8 cts = ioread8(port->membase + TIMBUART_CTRL);
200 dev_dbg(port->dev, "%s - cts %x\n", __func__, cts);
201
202 if (cts & TIMBUART_CTRL_CTS)
203 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
204 else
205 return TIOCM_DSR | TIOCM_CAR;
206}
207
208static void timbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
209{
210 dev_dbg(port->dev, "%s - %x\n", __func__, mctrl);
211
212 if (mctrl & TIOCM_RTS)
213 iowrite8(TIMBUART_CTRL_RTS, port->membase + TIMBUART_CTRL);
214 else
215 iowrite8(0, port->membase + TIMBUART_CTRL);
216}
217
218static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier)
219{
220 unsigned int cts;
221
222 if (isr & CTS_DELTA) {
223 /* ack */
224 iowrite32(CTS_DELTA, port->membase + TIMBUART_ISR);
225 cts = timbuart_get_mctrl(port);
226 uart_handle_cts_change(port, cts & TIOCM_CTS);
227 wake_up_interruptible(&port->state->port.delta_msr_wait);
228 }
229
230 *ier |= CTS_DELTA;
231}
232
233static void timbuart_break_ctl(struct uart_port *port, int ctl)
234{
235 /* N/A */
236}
237
238static int timbuart_startup(struct uart_port *port)
239{
240 struct timbuart_port *uart =
241 container_of(port, struct timbuart_port, port);
242
243 dev_dbg(port->dev, "%s\n", __func__);
244
245 iowrite8(TIMBUART_CTRL_FLSHRX, port->membase + TIMBUART_CTRL);
246 iowrite32(0x1ff, port->membase + TIMBUART_ISR);
247 /* Enable all but TX interrupts */
248 iowrite32(RXBAF | RXBF | RXTT | CTS_DELTA,
249 port->membase + TIMBUART_IER);
250
251 return request_irq(port->irq, timbuart_handleinterrupt, IRQF_SHARED,
252 "timb-uart", uart);
253}
254
255static void timbuart_shutdown(struct uart_port *port)
256{
257 struct timbuart_port *uart =
258 container_of(port, struct timbuart_port, port);
259 dev_dbg(port->dev, "%s\n", __func__);
260 free_irq(port->irq, uart);
261 iowrite32(0, port->membase + TIMBUART_IER);
262
263 timbuart_flush_buffer(port);
264}
265
266static int get_bindex(int baud)
267{
268 int i;
269
270 for (i = 0; i < ARRAY_SIZE(baudrates); i++)
271 if (baud <= baudrates[i])
272 return i;
273
274 return -1;
275}
276
277static void timbuart_set_termios(struct uart_port *port,
278 struct ktermios *termios,
279 struct ktermios *old)
280{
281 unsigned int baud;
282 short bindex;
283 unsigned long flags;
284
285 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
286 bindex = get_bindex(baud);
287 dev_dbg(port->dev, "%s - bindex %d\n", __func__, bindex);
288
289 if (bindex < 0)
290 bindex = 0;
291 baud = baudrates[bindex];
292
293 /* The serial layer calls into this once with old = NULL when setting
294 up initially */
295 if (old)
296 tty_termios_copy_hw(termios, old);
297 tty_termios_encode_baud_rate(termios, baud, baud);
298
299 spin_lock_irqsave(&port->lock, flags);
300 iowrite8((u8)bindex, port->membase + TIMBUART_BAUDRATE);
301 uart_update_timeout(port, termios->c_cflag, baud);
302 spin_unlock_irqrestore(&port->lock, flags);
303}
304
305static const char *timbuart_type(struct uart_port *port)
306{
307 return port->type == PORT_UNKNOWN ? "timbuart" : NULL;
308}
309
310/* We do not request/release mappings of the registers here,
311 * currently it's done in the proble function.
312 */
313static void timbuart_release_port(struct uart_port *port)
314{
315 struct platform_device *pdev = to_platform_device(port->dev);
316 int size =
317 resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
318
319 if (port->flags & UPF_IOREMAP) {
320 iounmap(port->membase);
321 port->membase = NULL;
322 }
323
324 release_mem_region(port->mapbase, size);
325}
326
327static int timbuart_request_port(struct uart_port *port)
328{
329 struct platform_device *pdev = to_platform_device(port->dev);
330 int size =
331 resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
332
333 if (!request_mem_region(port->mapbase, size, "timb-uart"))
334 return -EBUSY;
335
336 if (port->flags & UPF_IOREMAP) {
337 port->membase = ioremap(port->mapbase, size);
338 if (port->membase == NULL) {
339 release_mem_region(port->mapbase, size);
340 return -ENOMEM;
341 }
342 }
343
344 return 0;
345}
346
347static irqreturn_t timbuart_handleinterrupt(int irq, void *devid)
348{
349 struct timbuart_port *uart = (struct timbuart_port *)devid;
350
351 if (ioread8(uart->port.membase + TIMBUART_IPR)) {
352 uart->last_ier = ioread32(uart->port.membase + TIMBUART_IER);
353
354 /* disable interrupts, the tasklet enables them again */
355 iowrite32(0, uart->port.membase + TIMBUART_IER);
356
357 /* fire off bottom half */
358 tasklet_schedule(&uart->tasklet);
359
360 return IRQ_HANDLED;
361 } else
362 return IRQ_NONE;
363}
364
365/*
366 * Configure/autoconfigure the port.
367 */
368static void timbuart_config_port(struct uart_port *port, int flags)
369{
370 if (flags & UART_CONFIG_TYPE) {
371 port->type = PORT_TIMBUART;
372 timbuart_request_port(port);
373 }
374}
375
376static int timbuart_verify_port(struct uart_port *port,
377 struct serial_struct *ser)
378{
379 /* we don't want the core code to modify any port params */
380 return -EINVAL;
381}
382
383static const struct uart_ops timbuart_ops = {
384 .tx_empty = timbuart_tx_empty,
385 .set_mctrl = timbuart_set_mctrl,
386 .get_mctrl = timbuart_get_mctrl,
387 .stop_tx = timbuart_stop_tx,
388 .start_tx = timbuart_start_tx,
389 .flush_buffer = timbuart_flush_buffer,
390 .stop_rx = timbuart_stop_rx,
391 .break_ctl = timbuart_break_ctl,
392 .startup = timbuart_startup,
393 .shutdown = timbuart_shutdown,
394 .set_termios = timbuart_set_termios,
395 .type = timbuart_type,
396 .release_port = timbuart_release_port,
397 .request_port = timbuart_request_port,
398 .config_port = timbuart_config_port,
399 .verify_port = timbuart_verify_port
400};
401
402static struct uart_driver timbuart_driver = {
403 .owner = THIS_MODULE,
404 .driver_name = "timberdale_uart",
405 .dev_name = "ttyTU",
406 .major = TIMBUART_MAJOR,
407 .minor = TIMBUART_MINOR,
408 .nr = 1
409};
410
411static int timbuart_probe(struct platform_device *dev)
412{
413 int err, irq;
414 struct timbuart_port *uart;
415 struct resource *iomem;
416
417 dev_dbg(&dev->dev, "%s\n", __func__);
418
419 uart = kzalloc(sizeof(*uart), GFP_KERNEL);
420 if (!uart) {
421 err = -EINVAL;
422 goto err_mem;
423 }
424
425 uart->usedma = 0;
426
427 uart->port.uartclk = 3250000 * 16;
428 uart->port.fifosize = TIMBUART_FIFO_SIZE;
429 uart->port.regshift = 2;
430 uart->port.iotype = UPIO_MEM;
431 uart->port.ops = &timbuart_ops;
432 uart->port.irq = 0;
433 uart->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
434 uart->port.line = 0;
435 uart->port.dev = &dev->dev;
436
437 iomem = platform_get_resource(dev, IORESOURCE_MEM, 0);
438 if (!iomem) {
439 err = -ENOMEM;
440 goto err_register;
441 }
442 uart->port.mapbase = iomem->start;
443 uart->port.membase = NULL;
444
445 irq = platform_get_irq(dev, 0);
446 if (irq < 0) {
447 err = -EINVAL;
448 goto err_register;
449 }
450 uart->port.irq = irq;
451
452 tasklet_setup(&uart->tasklet, timbuart_tasklet);
453
454 err = uart_register_driver(&timbuart_driver);
455 if (err)
456 goto err_register;
457
458 err = uart_add_one_port(&timbuart_driver, &uart->port);
459 if (err)
460 goto err_add_port;
461
462 platform_set_drvdata(dev, uart);
463
464 return 0;
465
466err_add_port:
467 uart_unregister_driver(&timbuart_driver);
468err_register:
469 kfree(uart);
470err_mem:
471 printk(KERN_ERR "timberdale: Failed to register Timberdale UART: %d\n",
472 err);
473
474 return err;
475}
476
477static int timbuart_remove(struct platform_device *dev)
478{
479 struct timbuart_port *uart = platform_get_drvdata(dev);
480
481 tasklet_kill(&uart->tasklet);
482 uart_remove_one_port(&timbuart_driver, &uart->port);
483 uart_unregister_driver(&timbuart_driver);
484 kfree(uart);
485
486 return 0;
487}
488
489static struct platform_driver timbuart_platform_driver = {
490 .driver = {
491 .name = "timb-uart",
492 },
493 .probe = timbuart_probe,
494 .remove = timbuart_remove,
495};
496
497module_platform_driver(timbuart_platform_driver);
498
499MODULE_DESCRIPTION("Timberdale UART driver");
500MODULE_LICENSE("GPL v2");
501MODULE_ALIAS("platform:timb-uart");
502