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e9ea096d LD |
1 | /* |
2 | * serial_tegra.c | |
3 | * | |
4 | * High-speed serial driver for NVIDIA Tegra SoCs | |
5 | * | |
6 | * Copyright (c) 2012-2013, NVIDIA CORPORATION. All rights reserved. | |
7 | * | |
8 | * Author: Laxman Dewangan <ldewangan@nvidia.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify it | |
11 | * under the terms and conditions of the GNU General Public License, | |
12 | * version 2, as published by the Free Software Foundation. | |
13 | * | |
14 | * This program is distributed in the hope it will be useful, but WITHOUT | |
15 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
16 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
17 | * more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
21 | */ | |
22 | ||
23 | #include <linux/clk.h> | |
24 | #include <linux/debugfs.h> | |
25 | #include <linux/delay.h> | |
26 | #include <linux/dmaengine.h> | |
27 | #include <linux/dma-mapping.h> | |
28 | #include <linux/dmapool.h> | |
84e81922 | 29 | #include <linux/err.h> |
e9ea096d LD |
30 | #include <linux/io.h> |
31 | #include <linux/irq.h> | |
32 | #include <linux/module.h> | |
33 | #include <linux/of.h> | |
34 | #include <linux/of_device.h> | |
35 | #include <linux/pagemap.h> | |
36 | #include <linux/platform_device.h> | |
d3d654ef | 37 | #include <linux/reset.h> |
e9ea096d LD |
38 | #include <linux/serial.h> |
39 | #include <linux/serial_8250.h> | |
40 | #include <linux/serial_core.h> | |
41 | #include <linux/serial_reg.h> | |
42 | #include <linux/slab.h> | |
43 | #include <linux/string.h> | |
44 | #include <linux/termios.h> | |
45 | #include <linux/tty.h> | |
46 | #include <linux/tty_flip.h> | |
47 | ||
e9ea096d LD |
48 | #define TEGRA_UART_TYPE "TEGRA_UART" |
49 | #define TX_EMPTY_STATUS (UART_LSR_TEMT | UART_LSR_THRE) | |
50 | #define BYTES_TO_ALIGN(x) ((unsigned long)(x) & 0x3) | |
51 | ||
52 | #define TEGRA_UART_RX_DMA_BUFFER_SIZE 4096 | |
53 | #define TEGRA_UART_LSR_TXFIFO_FULL 0x100 | |
54 | #define TEGRA_UART_IER_EORD 0x20 | |
55 | #define TEGRA_UART_MCR_RTS_EN 0x40 | |
56 | #define TEGRA_UART_MCR_CTS_EN 0x20 | |
57 | #define TEGRA_UART_LSR_ANY (UART_LSR_OE | UART_LSR_BI | \ | |
58 | UART_LSR_PE | UART_LSR_FE) | |
59 | #define TEGRA_UART_IRDA_CSR 0x08 | |
60 | #define TEGRA_UART_SIR_ENABLED 0x80 | |
61 | ||
62 | #define TEGRA_UART_TX_PIO 1 | |
63 | #define TEGRA_UART_TX_DMA 2 | |
64 | #define TEGRA_UART_MIN_DMA 16 | |
65 | #define TEGRA_UART_FIFO_SIZE 32 | |
66 | ||
67 | /* | |
68 | * Tx fifo trigger level setting in tegra uart is in | |
69 | * reverse way then conventional uart. | |
70 | */ | |
71 | #define TEGRA_UART_TX_TRIG_16B 0x00 | |
72 | #define TEGRA_UART_TX_TRIG_8B 0x10 | |
73 | #define TEGRA_UART_TX_TRIG_4B 0x20 | |
74 | #define TEGRA_UART_TX_TRIG_1B 0x30 | |
75 | ||
76 | #define TEGRA_UART_MAXIMUM 5 | |
77 | ||
78 | /* Default UART setting when started: 115200 no parity, stop, 8 data bits */ | |
79 | #define TEGRA_UART_DEFAULT_BAUD 115200 | |
80 | #define TEGRA_UART_DEFAULT_LSR UART_LCR_WLEN8 | |
81 | ||
82 | /* Tx transfer mode */ | |
83 | #define TEGRA_TX_PIO 1 | |
84 | #define TEGRA_TX_DMA 2 | |
85 | ||
86 | /** | |
87 | * tegra_uart_chip_data: SOC specific data. | |
88 | * | |
89 | * @tx_fifo_full_status: Status flag available for checking tx fifo full. | |
90 | * @allow_txfifo_reset_fifo_mode: allow_tx fifo reset with fifo mode or not. | |
91 | * Tegra30 does not allow this. | |
92 | * @support_clk_src_div: Clock source support the clock divider. | |
93 | */ | |
94 | struct tegra_uart_chip_data { | |
95 | bool tx_fifo_full_status; | |
96 | bool allow_txfifo_reset_fifo_mode; | |
97 | bool support_clk_src_div; | |
98 | }; | |
99 | ||
100 | struct tegra_uart_port { | |
101 | struct uart_port uport; | |
102 | const struct tegra_uart_chip_data *cdata; | |
103 | ||
104 | struct clk *uart_clk; | |
d3d654ef | 105 | struct reset_control *rst; |
e9ea096d LD |
106 | unsigned int current_baud; |
107 | ||
108 | /* Register shadow */ | |
109 | unsigned long fcr_shadow; | |
110 | unsigned long mcr_shadow; | |
111 | unsigned long lcr_shadow; | |
112 | unsigned long ier_shadow; | |
113 | bool rts_active; | |
114 | ||
115 | int tx_in_progress; | |
116 | unsigned int tx_bytes; | |
117 | ||
118 | bool enable_modem_interrupt; | |
119 | ||
120 | bool rx_timeout; | |
121 | int rx_in_progress; | |
122 | int symb_bit; | |
e9ea096d LD |
123 | |
124 | struct dma_chan *rx_dma_chan; | |
125 | struct dma_chan *tx_dma_chan; | |
126 | dma_addr_t rx_dma_buf_phys; | |
127 | dma_addr_t tx_dma_buf_phys; | |
128 | unsigned char *rx_dma_buf_virt; | |
129 | unsigned char *tx_dma_buf_virt; | |
130 | struct dma_async_tx_descriptor *tx_dma_desc; | |
131 | struct dma_async_tx_descriptor *rx_dma_desc; | |
132 | dma_cookie_t tx_cookie; | |
133 | dma_cookie_t rx_cookie; | |
0b0c1bdf JH |
134 | unsigned int tx_bytes_requested; |
135 | unsigned int rx_bytes_requested; | |
e9ea096d LD |
136 | }; |
137 | ||
138 | static void tegra_uart_start_next_tx(struct tegra_uart_port *tup); | |
139 | static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup); | |
140 | ||
141 | static inline unsigned long tegra_uart_read(struct tegra_uart_port *tup, | |
142 | unsigned long reg) | |
143 | { | |
144 | return readl(tup->uport.membase + (reg << tup->uport.regshift)); | |
145 | } | |
146 | ||
147 | static inline void tegra_uart_write(struct tegra_uart_port *tup, unsigned val, | |
148 | unsigned long reg) | |
149 | { | |
150 | writel(val, tup->uport.membase + (reg << tup->uport.regshift)); | |
151 | } | |
152 | ||
153 | static inline struct tegra_uart_port *to_tegra_uport(struct uart_port *u) | |
154 | { | |
155 | return container_of(u, struct tegra_uart_port, uport); | |
156 | } | |
157 | ||
158 | static unsigned int tegra_uart_get_mctrl(struct uart_port *u) | |
159 | { | |
160 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
161 | ||
162 | /* | |
163 | * RI - Ring detector is active | |
164 | * CD/DCD/CAR - Carrier detect is always active. For some reason | |
165 | * linux has different names for carrier detect. | |
166 | * DSR - Data Set ready is active as the hardware doesn't support it. | |
167 | * Don't know if the linux support this yet? | |
168 | * CTS - Clear to send. Always set to active, as the hardware handles | |
169 | * CTS automatically. | |
170 | */ | |
171 | if (tup->enable_modem_interrupt) | |
172 | return TIOCM_RI | TIOCM_CD | TIOCM_DSR | TIOCM_CTS; | |
173 | return TIOCM_CTS; | |
174 | } | |
175 | ||
176 | static void set_rts(struct tegra_uart_port *tup, bool active) | |
177 | { | |
178 | unsigned long mcr; | |
179 | ||
180 | mcr = tup->mcr_shadow; | |
181 | if (active) | |
182 | mcr |= TEGRA_UART_MCR_RTS_EN; | |
183 | else | |
184 | mcr &= ~TEGRA_UART_MCR_RTS_EN; | |
185 | if (mcr != tup->mcr_shadow) { | |
186 | tegra_uart_write(tup, mcr, UART_MCR); | |
187 | tup->mcr_shadow = mcr; | |
188 | } | |
e9ea096d LD |
189 | } |
190 | ||
191 | static void set_dtr(struct tegra_uart_port *tup, bool active) | |
192 | { | |
193 | unsigned long mcr; | |
194 | ||
195 | mcr = tup->mcr_shadow; | |
196 | if (active) | |
197 | mcr |= UART_MCR_DTR; | |
198 | else | |
199 | mcr &= ~UART_MCR_DTR; | |
200 | if (mcr != tup->mcr_shadow) { | |
201 | tegra_uart_write(tup, mcr, UART_MCR); | |
202 | tup->mcr_shadow = mcr; | |
203 | } | |
e9ea096d LD |
204 | } |
205 | ||
206 | static void tegra_uart_set_mctrl(struct uart_port *u, unsigned int mctrl) | |
207 | { | |
208 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
e9ea096d LD |
209 | int dtr_enable; |
210 | ||
e9ea096d LD |
211 | tup->rts_active = !!(mctrl & TIOCM_RTS); |
212 | set_rts(tup, tup->rts_active); | |
213 | ||
214 | dtr_enable = !!(mctrl & TIOCM_DTR); | |
215 | set_dtr(tup, dtr_enable); | |
e9ea096d LD |
216 | } |
217 | ||
218 | static void tegra_uart_break_ctl(struct uart_port *u, int break_ctl) | |
219 | { | |
220 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
221 | unsigned long lcr; | |
222 | ||
223 | lcr = tup->lcr_shadow; | |
224 | if (break_ctl) | |
225 | lcr |= UART_LCR_SBC; | |
226 | else | |
227 | lcr &= ~UART_LCR_SBC; | |
228 | tegra_uart_write(tup, lcr, UART_LCR); | |
229 | tup->lcr_shadow = lcr; | |
230 | } | |
231 | ||
245c0278 JH |
232 | /** |
233 | * tegra_uart_wait_cycle_time: Wait for N UART clock periods | |
234 | * | |
235 | * @tup: Tegra serial port data structure. | |
236 | * @cycles: Number of clock periods to wait. | |
237 | * | |
238 | * Tegra UARTs are clocked at 16X the baud/bit rate and hence the UART | |
239 | * clock speed is 16X the current baud rate. | |
240 | */ | |
241 | static void tegra_uart_wait_cycle_time(struct tegra_uart_port *tup, | |
242 | unsigned int cycles) | |
243 | { | |
244 | if (tup->current_baud) | |
245 | udelay(DIV_ROUND_UP(cycles * 1000000, tup->current_baud * 16)); | |
246 | } | |
247 | ||
e9ea096d LD |
248 | /* Wait for a symbol-time. */ |
249 | static void tegra_uart_wait_sym_time(struct tegra_uart_port *tup, | |
250 | unsigned int syms) | |
251 | { | |
252 | if (tup->current_baud) | |
253 | udelay(DIV_ROUND_UP(syms * tup->symb_bit * 1000000, | |
254 | tup->current_baud)); | |
255 | } | |
256 | ||
257 | static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits) | |
258 | { | |
259 | unsigned long fcr = tup->fcr_shadow; | |
260 | ||
261 | if (tup->cdata->allow_txfifo_reset_fifo_mode) { | |
262 | fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); | |
263 | tegra_uart_write(tup, fcr, UART_FCR); | |
264 | } else { | |
265 | fcr &= ~UART_FCR_ENABLE_FIFO; | |
266 | tegra_uart_write(tup, fcr, UART_FCR); | |
267 | udelay(60); | |
268 | fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); | |
269 | tegra_uart_write(tup, fcr, UART_FCR); | |
270 | fcr |= UART_FCR_ENABLE_FIFO; | |
271 | tegra_uart_write(tup, fcr, UART_FCR); | |
272 | } | |
273 | ||
274 | /* Dummy read to ensure the write is posted */ | |
275 | tegra_uart_read(tup, UART_SCR); | |
276 | ||
245c0278 JH |
277 | /* |
278 | * For all tegra devices (up to t210), there is a hardware issue that | |
279 | * requires software to wait for 32 UART clock periods for the flush | |
280 | * to propagate, otherwise data could be lost. | |
281 | */ | |
282 | tegra_uart_wait_cycle_time(tup, 32); | |
e9ea096d LD |
283 | } |
284 | ||
285 | static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud) | |
286 | { | |
287 | unsigned long rate; | |
288 | unsigned int divisor; | |
289 | unsigned long lcr; | |
290 | int ret; | |
291 | ||
292 | if (tup->current_baud == baud) | |
293 | return 0; | |
294 | ||
295 | if (tup->cdata->support_clk_src_div) { | |
296 | rate = baud * 16; | |
297 | ret = clk_set_rate(tup->uart_clk, rate); | |
298 | if (ret < 0) { | |
299 | dev_err(tup->uport.dev, | |
300 | "clk_set_rate() failed for rate %lu\n", rate); | |
301 | return ret; | |
302 | } | |
303 | divisor = 1; | |
304 | } else { | |
305 | rate = clk_get_rate(tup->uart_clk); | |
306 | divisor = DIV_ROUND_CLOSEST(rate, baud * 16); | |
307 | } | |
308 | ||
309 | lcr = tup->lcr_shadow; | |
310 | lcr |= UART_LCR_DLAB; | |
311 | tegra_uart_write(tup, lcr, UART_LCR); | |
312 | ||
313 | tegra_uart_write(tup, divisor & 0xFF, UART_TX); | |
314 | tegra_uart_write(tup, ((divisor >> 8) & 0xFF), UART_IER); | |
315 | ||
316 | lcr &= ~UART_LCR_DLAB; | |
317 | tegra_uart_write(tup, lcr, UART_LCR); | |
318 | ||
319 | /* Dummy read to ensure the write is posted */ | |
320 | tegra_uart_read(tup, UART_SCR); | |
321 | ||
322 | tup->current_baud = baud; | |
323 | ||
324 | /* wait two character intervals at new rate */ | |
325 | tegra_uart_wait_sym_time(tup, 2); | |
326 | return 0; | |
327 | } | |
328 | ||
329 | static char tegra_uart_decode_rx_error(struct tegra_uart_port *tup, | |
330 | unsigned long lsr) | |
331 | { | |
332 | char flag = TTY_NORMAL; | |
333 | ||
334 | if (unlikely(lsr & TEGRA_UART_LSR_ANY)) { | |
335 | if (lsr & UART_LSR_OE) { | |
336 | /* Overrrun error */ | |
f0c1e460 | 337 | flag = TTY_OVERRUN; |
e9ea096d LD |
338 | tup->uport.icount.overrun++; |
339 | dev_err(tup->uport.dev, "Got overrun errors\n"); | |
340 | } else if (lsr & UART_LSR_PE) { | |
341 | /* Parity error */ | |
f0c1e460 | 342 | flag = TTY_PARITY; |
e9ea096d LD |
343 | tup->uport.icount.parity++; |
344 | dev_err(tup->uport.dev, "Got Parity errors\n"); | |
345 | } else if (lsr & UART_LSR_FE) { | |
f0c1e460 | 346 | flag = TTY_FRAME; |
e9ea096d LD |
347 | tup->uport.icount.frame++; |
348 | dev_err(tup->uport.dev, "Got frame errors\n"); | |
349 | } else if (lsr & UART_LSR_BI) { | |
350 | dev_err(tup->uport.dev, "Got Break\n"); | |
351 | tup->uport.icount.brk++; | |
352 | /* If FIFO read error without any data, reset Rx FIFO */ | |
353 | if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE)) | |
354 | tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_RCVR); | |
355 | } | |
356 | } | |
357 | return flag; | |
358 | } | |
359 | ||
360 | static int tegra_uart_request_port(struct uart_port *u) | |
361 | { | |
362 | return 0; | |
363 | } | |
364 | ||
365 | static void tegra_uart_release_port(struct uart_port *u) | |
366 | { | |
367 | /* Nothing to do here */ | |
368 | } | |
369 | ||
370 | static void tegra_uart_fill_tx_fifo(struct tegra_uart_port *tup, int max_bytes) | |
371 | { | |
372 | struct circ_buf *xmit = &tup->uport.state->xmit; | |
373 | int i; | |
374 | ||
375 | for (i = 0; i < max_bytes; i++) { | |
376 | BUG_ON(uart_circ_empty(xmit)); | |
377 | if (tup->cdata->tx_fifo_full_status) { | |
378 | unsigned long lsr = tegra_uart_read(tup, UART_LSR); | |
379 | if ((lsr & TEGRA_UART_LSR_TXFIFO_FULL)) | |
380 | break; | |
381 | } | |
382 | tegra_uart_write(tup, xmit->buf[xmit->tail], UART_TX); | |
383 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); | |
384 | tup->uport.icount.tx++; | |
385 | } | |
386 | } | |
387 | ||
388 | static void tegra_uart_start_pio_tx(struct tegra_uart_port *tup, | |
389 | unsigned int bytes) | |
390 | { | |
391 | if (bytes > TEGRA_UART_MIN_DMA) | |
392 | bytes = TEGRA_UART_MIN_DMA; | |
393 | ||
394 | tup->tx_in_progress = TEGRA_UART_TX_PIO; | |
395 | tup->tx_bytes = bytes; | |
396 | tup->ier_shadow |= UART_IER_THRI; | |
397 | tegra_uart_write(tup, tup->ier_shadow, UART_IER); | |
398 | } | |
399 | ||
400 | static void tegra_uart_tx_dma_complete(void *args) | |
401 | { | |
402 | struct tegra_uart_port *tup = args; | |
403 | struct circ_buf *xmit = &tup->uport.state->xmit; | |
404 | struct dma_tx_state state; | |
405 | unsigned long flags; | |
0b0c1bdf | 406 | unsigned int count; |
e9ea096d | 407 | |
49433c80 | 408 | dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state); |
e9ea096d LD |
409 | count = tup->tx_bytes_requested - state.residue; |
410 | async_tx_ack(tup->tx_dma_desc); | |
411 | spin_lock_irqsave(&tup->uport.lock, flags); | |
412 | xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); | |
413 | tup->tx_in_progress = 0; | |
414 | if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) | |
415 | uart_write_wakeup(&tup->uport); | |
416 | tegra_uart_start_next_tx(tup); | |
417 | spin_unlock_irqrestore(&tup->uport.lock, flags); | |
418 | } | |
419 | ||
420 | static int tegra_uart_start_tx_dma(struct tegra_uart_port *tup, | |
421 | unsigned long count) | |
422 | { | |
423 | struct circ_buf *xmit = &tup->uport.state->xmit; | |
424 | dma_addr_t tx_phys_addr; | |
425 | ||
426 | dma_sync_single_for_device(tup->uport.dev, tup->tx_dma_buf_phys, | |
427 | UART_XMIT_SIZE, DMA_TO_DEVICE); | |
428 | ||
429 | tup->tx_bytes = count & ~(0xF); | |
430 | tx_phys_addr = tup->tx_dma_buf_phys + xmit->tail; | |
431 | tup->tx_dma_desc = dmaengine_prep_slave_single(tup->tx_dma_chan, | |
432 | tx_phys_addr, tup->tx_bytes, DMA_MEM_TO_DEV, | |
433 | DMA_PREP_INTERRUPT); | |
434 | if (!tup->tx_dma_desc) { | |
435 | dev_err(tup->uport.dev, "Not able to get desc for Tx\n"); | |
436 | return -EIO; | |
437 | } | |
438 | ||
439 | tup->tx_dma_desc->callback = tegra_uart_tx_dma_complete; | |
440 | tup->tx_dma_desc->callback_param = tup; | |
441 | tup->tx_in_progress = TEGRA_UART_TX_DMA; | |
442 | tup->tx_bytes_requested = tup->tx_bytes; | |
443 | tup->tx_cookie = dmaengine_submit(tup->tx_dma_desc); | |
444 | dma_async_issue_pending(tup->tx_dma_chan); | |
445 | return 0; | |
446 | } | |
447 | ||
448 | static void tegra_uart_start_next_tx(struct tegra_uart_port *tup) | |
449 | { | |
450 | unsigned long tail; | |
451 | unsigned long count; | |
452 | struct circ_buf *xmit = &tup->uport.state->xmit; | |
453 | ||
454 | tail = (unsigned long)&xmit->buf[xmit->tail]; | |
455 | count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); | |
456 | if (!count) | |
457 | return; | |
458 | ||
459 | if (count < TEGRA_UART_MIN_DMA) | |
460 | tegra_uart_start_pio_tx(tup, count); | |
461 | else if (BYTES_TO_ALIGN(tail) > 0) | |
462 | tegra_uart_start_pio_tx(tup, BYTES_TO_ALIGN(tail)); | |
463 | else | |
464 | tegra_uart_start_tx_dma(tup, count); | |
465 | } | |
466 | ||
467 | /* Called by serial core driver with u->lock taken. */ | |
468 | static void tegra_uart_start_tx(struct uart_port *u) | |
469 | { | |
470 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
471 | struct circ_buf *xmit = &u->state->xmit; | |
472 | ||
473 | if (!uart_circ_empty(xmit) && !tup->tx_in_progress) | |
474 | tegra_uart_start_next_tx(tup); | |
475 | } | |
476 | ||
477 | static unsigned int tegra_uart_tx_empty(struct uart_port *u) | |
478 | { | |
479 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
480 | unsigned int ret = 0; | |
481 | unsigned long flags; | |
482 | ||
483 | spin_lock_irqsave(&u->lock, flags); | |
484 | if (!tup->tx_in_progress) { | |
485 | unsigned long lsr = tegra_uart_read(tup, UART_LSR); | |
486 | if ((lsr & TX_EMPTY_STATUS) == TX_EMPTY_STATUS) | |
487 | ret = TIOCSER_TEMT; | |
488 | } | |
489 | spin_unlock_irqrestore(&u->lock, flags); | |
490 | return ret; | |
491 | } | |
492 | ||
493 | static void tegra_uart_stop_tx(struct uart_port *u) | |
494 | { | |
495 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
496 | struct circ_buf *xmit = &tup->uport.state->xmit; | |
497 | struct dma_tx_state state; | |
0b0c1bdf | 498 | unsigned int count; |
e9ea096d | 499 | |
5e3dbfca PG |
500 | if (tup->tx_in_progress != TEGRA_UART_TX_DMA) |
501 | return; | |
502 | ||
e9ea096d LD |
503 | dmaengine_terminate_all(tup->tx_dma_chan); |
504 | dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state); | |
505 | count = tup->tx_bytes_requested - state.residue; | |
506 | async_tx_ack(tup->tx_dma_desc); | |
507 | xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); | |
508 | tup->tx_in_progress = 0; | |
e9ea096d LD |
509 | } |
510 | ||
511 | static void tegra_uart_handle_tx_pio(struct tegra_uart_port *tup) | |
512 | { | |
513 | struct circ_buf *xmit = &tup->uport.state->xmit; | |
514 | ||
515 | tegra_uart_fill_tx_fifo(tup, tup->tx_bytes); | |
516 | tup->tx_in_progress = 0; | |
517 | if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) | |
518 | uart_write_wakeup(&tup->uport); | |
519 | tegra_uart_start_next_tx(tup); | |
e9ea096d LD |
520 | } |
521 | ||
522 | static void tegra_uart_handle_rx_pio(struct tegra_uart_port *tup, | |
962963e4 | 523 | struct tty_port *tty) |
e9ea096d LD |
524 | { |
525 | do { | |
526 | char flag = TTY_NORMAL; | |
527 | unsigned long lsr = 0; | |
528 | unsigned char ch; | |
529 | ||
530 | lsr = tegra_uart_read(tup, UART_LSR); | |
531 | if (!(lsr & UART_LSR_DR)) | |
532 | break; | |
533 | ||
534 | flag = tegra_uart_decode_rx_error(tup, lsr); | |
535 | ch = (unsigned char) tegra_uart_read(tup, UART_RX); | |
536 | tup->uport.icount.rx++; | |
537 | ||
538 | if (!uart_handle_sysrq_char(&tup->uport, ch) && tty) | |
539 | tty_insert_flip_char(tty, ch, flag); | |
540 | } while (1); | |
e9ea096d LD |
541 | } |
542 | ||
543 | static void tegra_uart_copy_rx_to_tty(struct tegra_uart_port *tup, | |
0b0c1bdf JH |
544 | struct tty_port *tty, |
545 | unsigned int count) | |
e9ea096d LD |
546 | { |
547 | int copied; | |
548 | ||
db8e7847 SSM |
549 | /* If count is zero, then there is no data to be copied */ |
550 | if (!count) | |
551 | return; | |
552 | ||
e9ea096d LD |
553 | tup->uport.icount.rx += count; |
554 | if (!tty) { | |
555 | dev_err(tup->uport.dev, "No tty port\n"); | |
556 | return; | |
557 | } | |
558 | dma_sync_single_for_cpu(tup->uport.dev, tup->rx_dma_buf_phys, | |
559 | TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE); | |
560 | copied = tty_insert_flip_string(tty, | |
561 | ((unsigned char *)(tup->rx_dma_buf_virt)), count); | |
562 | if (copied != count) { | |
563 | WARN_ON(1); | |
564 | dev_err(tup->uport.dev, "RxData copy to tty layer failed\n"); | |
565 | } | |
566 | dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys, | |
567 | TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_TO_DEVICE); | |
568 | } | |
569 | ||
32ede4a5 JH |
570 | static void tegra_uart_rx_buffer_push(struct tegra_uart_port *tup, |
571 | unsigned int residue) | |
572 | { | |
573 | struct tty_port *port = &tup->uport.state->port; | |
574 | struct tty_struct *tty = tty_port_tty_get(port); | |
575 | unsigned int count; | |
576 | ||
577 | async_tx_ack(tup->rx_dma_desc); | |
578 | count = tup->rx_bytes_requested - residue; | |
579 | ||
580 | /* If we are here, DMA is stopped */ | |
581 | tegra_uart_copy_rx_to_tty(tup, port, count); | |
582 | ||
583 | tegra_uart_handle_rx_pio(tup, port); | |
584 | if (tty) { | |
585 | tty_flip_buffer_push(port); | |
586 | tty_kref_put(tty); | |
587 | } | |
588 | } | |
589 | ||
e9ea096d LD |
590 | static void tegra_uart_rx_dma_complete(void *args) |
591 | { | |
592 | struct tegra_uart_port *tup = args; | |
593 | struct uart_port *u = &tup->uport; | |
e9ea096d | 594 | unsigned long flags; |
853a6997 SSM |
595 | struct dma_tx_state state; |
596 | enum dma_status status; | |
e9ea096d | 597 | |
e9ea096d LD |
598 | spin_lock_irqsave(&u->lock, flags); |
599 | ||
853a6997 SSM |
600 | status = dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state); |
601 | ||
602 | if (status == DMA_IN_PROGRESS) { | |
603 | dev_dbg(tup->uport.dev, "RX DMA is in progress\n"); | |
604 | goto done; | |
605 | } | |
606 | ||
e9ea096d LD |
607 | /* Deactivate flow control to stop sender */ |
608 | if (tup->rts_active) | |
609 | set_rts(tup, false); | |
610 | ||
32ede4a5 | 611 | tegra_uart_rx_buffer_push(tup, 0); |
e9ea096d LD |
612 | tegra_uart_start_rx_dma(tup); |
613 | ||
614 | /* Activate flow control to start transfer */ | |
615 | if (tup->rts_active) | |
616 | set_rts(tup, true); | |
617 | ||
853a6997 | 618 | done: |
e9ea096d LD |
619 | spin_unlock_irqrestore(&u->lock, flags); |
620 | } | |
621 | ||
2a24bb28 | 622 | static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup) |
e9ea096d LD |
623 | { |
624 | struct dma_tx_state state; | |
e9ea096d LD |
625 | |
626 | /* Deactivate flow control to stop sender */ | |
627 | if (tup->rts_active) | |
628 | set_rts(tup, false); | |
629 | ||
630 | dmaengine_terminate_all(tup->rx_dma_chan); | |
32ede4a5 JH |
631 | dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state); |
632 | tegra_uart_rx_buffer_push(tup, state.residue); | |
e9ea096d LD |
633 | tegra_uart_start_rx_dma(tup); |
634 | ||
635 | if (tup->rts_active) | |
636 | set_rts(tup, true); | |
637 | } | |
638 | ||
639 | static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup) | |
640 | { | |
641 | unsigned int count = TEGRA_UART_RX_DMA_BUFFER_SIZE; | |
642 | ||
643 | tup->rx_dma_desc = dmaengine_prep_slave_single(tup->rx_dma_chan, | |
644 | tup->rx_dma_buf_phys, count, DMA_DEV_TO_MEM, | |
645 | DMA_PREP_INTERRUPT); | |
646 | if (!tup->rx_dma_desc) { | |
647 | dev_err(tup->uport.dev, "Not able to get desc for Rx\n"); | |
648 | return -EIO; | |
649 | } | |
650 | ||
651 | tup->rx_dma_desc->callback = tegra_uart_rx_dma_complete; | |
652 | tup->rx_dma_desc->callback_param = tup; | |
653 | dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys, | |
654 | count, DMA_TO_DEVICE); | |
655 | tup->rx_bytes_requested = count; | |
656 | tup->rx_cookie = dmaengine_submit(tup->rx_dma_desc); | |
657 | dma_async_issue_pending(tup->rx_dma_chan); | |
658 | return 0; | |
659 | } | |
660 | ||
661 | static void tegra_uart_handle_modem_signal_change(struct uart_port *u) | |
662 | { | |
663 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
664 | unsigned long msr; | |
665 | ||
666 | msr = tegra_uart_read(tup, UART_MSR); | |
667 | if (!(msr & UART_MSR_ANY_DELTA)) | |
668 | return; | |
669 | ||
670 | if (msr & UART_MSR_TERI) | |
671 | tup->uport.icount.rng++; | |
672 | if (msr & UART_MSR_DDSR) | |
673 | tup->uport.icount.dsr++; | |
674 | /* We may only get DDCD when HW init and reset */ | |
675 | if (msr & UART_MSR_DDCD) | |
676 | uart_handle_dcd_change(&tup->uport, msr & UART_MSR_DCD); | |
677 | /* Will start/stop_tx accordingly */ | |
678 | if (msr & UART_MSR_DCTS) | |
679 | uart_handle_cts_change(&tup->uport, msr & UART_MSR_CTS); | |
e9ea096d LD |
680 | } |
681 | ||
682 | static irqreturn_t tegra_uart_isr(int irq, void *data) | |
683 | { | |
684 | struct tegra_uart_port *tup = data; | |
685 | struct uart_port *u = &tup->uport; | |
686 | unsigned long iir; | |
687 | unsigned long ier; | |
688 | bool is_rx_int = false; | |
689 | unsigned long flags; | |
690 | ||
691 | spin_lock_irqsave(&u->lock, flags); | |
692 | while (1) { | |
693 | iir = tegra_uart_read(tup, UART_IIR); | |
694 | if (iir & UART_IIR_NO_INT) { | |
695 | if (is_rx_int) { | |
2a24bb28 | 696 | tegra_uart_handle_rx_dma(tup); |
e9ea096d LD |
697 | if (tup->rx_in_progress) { |
698 | ier = tup->ier_shadow; | |
699 | ier |= (UART_IER_RLSI | UART_IER_RTOIE | | |
700 | TEGRA_UART_IER_EORD); | |
701 | tup->ier_shadow = ier; | |
702 | tegra_uart_write(tup, ier, UART_IER); | |
703 | } | |
704 | } | |
705 | spin_unlock_irqrestore(&u->lock, flags); | |
706 | return IRQ_HANDLED; | |
707 | } | |
708 | ||
709 | switch ((iir >> 1) & 0x7) { | |
710 | case 0: /* Modem signal change interrupt */ | |
711 | tegra_uart_handle_modem_signal_change(u); | |
712 | break; | |
713 | ||
714 | case 1: /* Transmit interrupt only triggered when using PIO */ | |
715 | tup->ier_shadow &= ~UART_IER_THRI; | |
716 | tegra_uart_write(tup, tup->ier_shadow, UART_IER); | |
717 | tegra_uart_handle_tx_pio(tup); | |
718 | break; | |
719 | ||
720 | case 4: /* End of data */ | |
721 | case 6: /* Rx timeout */ | |
722 | case 2: /* Receive */ | |
723 | if (!is_rx_int) { | |
724 | is_rx_int = true; | |
725 | /* Disable Rx interrupts */ | |
726 | ier = tup->ier_shadow; | |
727 | ier |= UART_IER_RDI; | |
728 | tegra_uart_write(tup, ier, UART_IER); | |
729 | ier &= ~(UART_IER_RDI | UART_IER_RLSI | | |
730 | UART_IER_RTOIE | TEGRA_UART_IER_EORD); | |
731 | tup->ier_shadow = ier; | |
732 | tegra_uart_write(tup, ier, UART_IER); | |
733 | } | |
734 | break; | |
735 | ||
736 | case 3: /* Receive error */ | |
737 | tegra_uart_decode_rx_error(tup, | |
738 | tegra_uart_read(tup, UART_LSR)); | |
739 | break; | |
740 | ||
741 | case 5: /* break nothing to handle */ | |
742 | case 7: /* break nothing to handle */ | |
743 | break; | |
744 | } | |
745 | } | |
746 | } | |
747 | ||
748 | static void tegra_uart_stop_rx(struct uart_port *u) | |
749 | { | |
750 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
e9ea096d LD |
751 | struct dma_tx_state state; |
752 | unsigned long ier; | |
e9ea096d LD |
753 | |
754 | if (tup->rts_active) | |
755 | set_rts(tup, false); | |
756 | ||
757 | if (!tup->rx_in_progress) | |
758 | return; | |
759 | ||
760 | tegra_uart_wait_sym_time(tup, 1); /* wait a character interval */ | |
761 | ||
762 | ier = tup->ier_shadow; | |
763 | ier &= ~(UART_IER_RDI | UART_IER_RLSI | UART_IER_RTOIE | | |
764 | TEGRA_UART_IER_EORD); | |
765 | tup->ier_shadow = ier; | |
766 | tegra_uart_write(tup, ier, UART_IER); | |
767 | tup->rx_in_progress = 0; | |
b0e066cc JH |
768 | dmaengine_terminate_all(tup->rx_dma_chan); |
769 | dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state); | |
32ede4a5 | 770 | tegra_uart_rx_buffer_push(tup, state.residue); |
e9ea096d LD |
771 | } |
772 | ||
773 | static void tegra_uart_hw_deinit(struct tegra_uart_port *tup) | |
774 | { | |
775 | unsigned long flags; | |
776 | unsigned long char_time = DIV_ROUND_UP(10000000, tup->current_baud); | |
777 | unsigned long fifo_empty_time = tup->uport.fifosize * char_time; | |
778 | unsigned long wait_time; | |
779 | unsigned long lsr; | |
780 | unsigned long msr; | |
781 | unsigned long mcr; | |
782 | ||
783 | /* Disable interrupts */ | |
784 | tegra_uart_write(tup, 0, UART_IER); | |
785 | ||
786 | lsr = tegra_uart_read(tup, UART_LSR); | |
787 | if ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) { | |
788 | msr = tegra_uart_read(tup, UART_MSR); | |
789 | mcr = tegra_uart_read(tup, UART_MCR); | |
790 | if ((mcr & TEGRA_UART_MCR_CTS_EN) && (msr & UART_MSR_CTS)) | |
791 | dev_err(tup->uport.dev, | |
792 | "Tx Fifo not empty, CTS disabled, waiting\n"); | |
793 | ||
794 | /* Wait for Tx fifo to be empty */ | |
795 | while ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) { | |
796 | wait_time = min(fifo_empty_time, 100lu); | |
797 | udelay(wait_time); | |
798 | fifo_empty_time -= wait_time; | |
799 | if (!fifo_empty_time) { | |
800 | msr = tegra_uart_read(tup, UART_MSR); | |
801 | mcr = tegra_uart_read(tup, UART_MCR); | |
802 | if ((mcr & TEGRA_UART_MCR_CTS_EN) && | |
803 | (msr & UART_MSR_CTS)) | |
804 | dev_err(tup->uport.dev, | |
805 | "Slave not ready\n"); | |
806 | break; | |
807 | } | |
808 | lsr = tegra_uart_read(tup, UART_LSR); | |
809 | } | |
810 | } | |
811 | ||
812 | spin_lock_irqsave(&tup->uport.lock, flags); | |
813 | /* Reset the Rx and Tx FIFOs */ | |
814 | tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR); | |
815 | tup->current_baud = 0; | |
816 | spin_unlock_irqrestore(&tup->uport.lock, flags); | |
817 | ||
818 | clk_disable_unprepare(tup->uart_clk); | |
819 | } | |
820 | ||
821 | static int tegra_uart_hw_init(struct tegra_uart_port *tup) | |
822 | { | |
823 | int ret; | |
824 | ||
825 | tup->fcr_shadow = 0; | |
826 | tup->mcr_shadow = 0; | |
827 | tup->lcr_shadow = 0; | |
828 | tup->ier_shadow = 0; | |
829 | tup->current_baud = 0; | |
830 | ||
831 | clk_prepare_enable(tup->uart_clk); | |
832 | ||
833 | /* Reset the UART controller to clear all previous status.*/ | |
d3d654ef | 834 | reset_control_assert(tup->rst); |
e9ea096d | 835 | udelay(10); |
d3d654ef | 836 | reset_control_deassert(tup->rst); |
e9ea096d LD |
837 | |
838 | tup->rx_in_progress = 0; | |
839 | tup->tx_in_progress = 0; | |
840 | ||
841 | /* | |
842 | * Set the trigger level | |
843 | * | |
844 | * For PIO mode: | |
845 | * | |
846 | * For receive, this will interrupt the CPU after that many number of | |
847 | * bytes are received, for the remaining bytes the receive timeout | |
848 | * interrupt is received. Rx high watermark is set to 4. | |
849 | * | |
850 | * For transmit, if the trasnmit interrupt is enabled, this will | |
851 | * interrupt the CPU when the number of entries in the FIFO reaches the | |
852 | * low watermark. Tx low watermark is set to 16 bytes. | |
853 | * | |
854 | * For DMA mode: | |
855 | * | |
856 | * Set the Tx trigger to 16. This should match the DMA burst size that | |
857 | * programmed in the DMA registers. | |
858 | */ | |
859 | tup->fcr_shadow = UART_FCR_ENABLE_FIFO; | |
860 | tup->fcr_shadow |= UART_FCR_R_TRIG_01; | |
861 | tup->fcr_shadow |= TEGRA_UART_TX_TRIG_16B; | |
862 | tegra_uart_write(tup, tup->fcr_shadow, UART_FCR); | |
863 | ||
11e71007 JH |
864 | /* Dummy read to ensure the write is posted */ |
865 | tegra_uart_read(tup, UART_SCR); | |
866 | ||
867 | /* | |
868 | * For all tegra devices (up to t210), there is a hardware issue that | |
869 | * requires software to wait for 3 UART clock periods after enabling | |
870 | * the TX fifo, otherwise data could be lost. | |
871 | */ | |
872 | tegra_uart_wait_cycle_time(tup, 3); | |
873 | ||
e9ea096d LD |
874 | /* |
875 | * Initialize the UART with default configuration | |
876 | * (115200, N, 8, 1) so that the receive DMA buffer may be | |
877 | * enqueued | |
878 | */ | |
879 | tup->lcr_shadow = TEGRA_UART_DEFAULT_LSR; | |
880 | tegra_set_baudrate(tup, TEGRA_UART_DEFAULT_BAUD); | |
881 | tup->fcr_shadow |= UART_FCR_DMA_SELECT; | |
882 | tegra_uart_write(tup, tup->fcr_shadow, UART_FCR); | |
883 | ||
884 | ret = tegra_uart_start_rx_dma(tup); | |
885 | if (ret < 0) { | |
886 | dev_err(tup->uport.dev, "Not able to start Rx DMA\n"); | |
887 | return ret; | |
888 | } | |
889 | tup->rx_in_progress = 1; | |
890 | ||
891 | /* | |
892 | * Enable IE_RXS for the receive status interrupts like line errros. | |
893 | * Enable IE_RX_TIMEOUT to get the bytes which cannot be DMA'd. | |
894 | * | |
895 | * If using DMA mode, enable EORD instead of receive interrupt which | |
896 | * will interrupt after the UART is done with the receive instead of | |
897 | * the interrupt when the FIFO "threshold" is reached. | |
898 | * | |
899 | * EORD is different interrupt than RX_TIMEOUT - RX_TIMEOUT occurs when | |
900 | * the DATA is sitting in the FIFO and couldn't be transferred to the | |
901 | * DMA as the DMA size alignment(4 bytes) is not met. EORD will be | |
902 | * triggered when there is a pause of the incomming data stream for 4 | |
903 | * characters long. | |
904 | * | |
905 | * For pauses in the data which is not aligned to 4 bytes, we get | |
906 | * both the EORD as well as RX_TIMEOUT - SW sees RX_TIMEOUT first | |
907 | * then the EORD. | |
908 | */ | |
909 | tup->ier_shadow = UART_IER_RLSI | UART_IER_RTOIE | TEGRA_UART_IER_EORD; | |
910 | tegra_uart_write(tup, tup->ier_shadow, UART_IER); | |
911 | return 0; | |
912 | } | |
913 | ||
ad909b3f JH |
914 | static void tegra_uart_dma_channel_free(struct tegra_uart_port *tup, |
915 | bool dma_to_memory) | |
916 | { | |
917 | if (dma_to_memory) { | |
918 | dmaengine_terminate_all(tup->rx_dma_chan); | |
919 | dma_release_channel(tup->rx_dma_chan); | |
920 | dma_free_coherent(tup->uport.dev, TEGRA_UART_RX_DMA_BUFFER_SIZE, | |
921 | tup->rx_dma_buf_virt, tup->rx_dma_buf_phys); | |
922 | tup->rx_dma_chan = NULL; | |
923 | tup->rx_dma_buf_phys = 0; | |
924 | tup->rx_dma_buf_virt = NULL; | |
925 | } else { | |
926 | dmaengine_terminate_all(tup->tx_dma_chan); | |
927 | dma_release_channel(tup->tx_dma_chan); | |
928 | dma_unmap_single(tup->uport.dev, tup->tx_dma_buf_phys, | |
929 | UART_XMIT_SIZE, DMA_TO_DEVICE); | |
930 | tup->tx_dma_chan = NULL; | |
931 | tup->tx_dma_buf_phys = 0; | |
932 | tup->tx_dma_buf_virt = NULL; | |
933 | } | |
934 | } | |
935 | ||
e9ea096d LD |
936 | static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup, |
937 | bool dma_to_memory) | |
938 | { | |
939 | struct dma_chan *dma_chan; | |
940 | unsigned char *dma_buf; | |
941 | dma_addr_t dma_phys; | |
942 | int ret; | |
943 | struct dma_slave_config dma_sconfig; | |
e9ea096d | 944 | |
c2b329f5 SW |
945 | dma_chan = dma_request_slave_channel_reason(tup->uport.dev, |
946 | dma_to_memory ? "rx" : "tx"); | |
947 | if (IS_ERR(dma_chan)) { | |
948 | ret = PTR_ERR(dma_chan); | |
e9ea096d | 949 | dev_err(tup->uport.dev, |
c2b329f5 SW |
950 | "DMA channel alloc failed: %d\n", ret); |
951 | return ret; | |
e9ea096d LD |
952 | } |
953 | ||
954 | if (dma_to_memory) { | |
955 | dma_buf = dma_alloc_coherent(tup->uport.dev, | |
956 | TEGRA_UART_RX_DMA_BUFFER_SIZE, | |
957 | &dma_phys, GFP_KERNEL); | |
958 | if (!dma_buf) { | |
959 | dev_err(tup->uport.dev, | |
960 | "Not able to allocate the dma buffer\n"); | |
961 | dma_release_channel(dma_chan); | |
962 | return -ENOMEM; | |
963 | } | |
8f8e48f4 JH |
964 | dma_sconfig.src_addr = tup->uport.mapbase; |
965 | dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; | |
966 | dma_sconfig.src_maxburst = 4; | |
967 | tup->rx_dma_chan = dma_chan; | |
968 | tup->rx_dma_buf_virt = dma_buf; | |
969 | tup->rx_dma_buf_phys = dma_phys; | |
e9ea096d LD |
970 | } else { |
971 | dma_phys = dma_map_single(tup->uport.dev, | |
972 | tup->uport.state->xmit.buf, UART_XMIT_SIZE, | |
973 | DMA_TO_DEVICE); | |
ad909b3f JH |
974 | if (dma_mapping_error(tup->uport.dev, dma_phys)) { |
975 | dev_err(tup->uport.dev, "dma_map_single tx failed\n"); | |
976 | dma_release_channel(dma_chan); | |
977 | return -ENOMEM; | |
978 | } | |
e9ea096d | 979 | dma_buf = tup->uport.state->xmit.buf; |
e9ea096d LD |
980 | dma_sconfig.dst_addr = tup->uport.mapbase; |
981 | dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; | |
982 | dma_sconfig.dst_maxburst = 16; | |
8f8e48f4 JH |
983 | tup->tx_dma_chan = dma_chan; |
984 | tup->tx_dma_buf_virt = dma_buf; | |
985 | tup->tx_dma_buf_phys = dma_phys; | |
e9ea096d LD |
986 | } |
987 | ||
988 | ret = dmaengine_slave_config(dma_chan, &dma_sconfig); | |
989 | if (ret < 0) { | |
990 | dev_err(tup->uport.dev, | |
991 | "Dma slave config failed, err = %d\n", ret); | |
8f8e48f4 JH |
992 | tegra_uart_dma_channel_free(tup, dma_to_memory); |
993 | return ret; | |
e9ea096d LD |
994 | } |
995 | ||
e9ea096d | 996 | return 0; |
e9ea096d LD |
997 | } |
998 | ||
e9ea096d LD |
999 | static int tegra_uart_startup(struct uart_port *u) |
1000 | { | |
1001 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
1002 | int ret; | |
1003 | ||
1004 | ret = tegra_uart_dma_channel_allocate(tup, false); | |
1005 | if (ret < 0) { | |
1006 | dev_err(u->dev, "Tx Dma allocation failed, err = %d\n", ret); | |
1007 | return ret; | |
1008 | } | |
1009 | ||
1010 | ret = tegra_uart_dma_channel_allocate(tup, true); | |
1011 | if (ret < 0) { | |
1012 | dev_err(u->dev, "Rx Dma allocation failed, err = %d\n", ret); | |
1013 | goto fail_rx_dma; | |
1014 | } | |
1015 | ||
1016 | ret = tegra_uart_hw_init(tup); | |
1017 | if (ret < 0) { | |
1018 | dev_err(u->dev, "Uart HW init failed, err = %d\n", ret); | |
1019 | goto fail_hw_init; | |
1020 | } | |
1021 | ||
cf81e054 | 1022 | ret = request_irq(u->irq, tegra_uart_isr, 0, |
e9ea096d LD |
1023 | dev_name(u->dev), tup); |
1024 | if (ret < 0) { | |
1025 | dev_err(u->dev, "Failed to register ISR for IRQ %d\n", u->irq); | |
1026 | goto fail_hw_init; | |
1027 | } | |
1028 | return 0; | |
1029 | ||
1030 | fail_hw_init: | |
1031 | tegra_uart_dma_channel_free(tup, true); | |
1032 | fail_rx_dma: | |
1033 | tegra_uart_dma_channel_free(tup, false); | |
1034 | return ret; | |
1035 | } | |
1036 | ||
479e9b94 PH |
1037 | /* |
1038 | * Flush any TX data submitted for DMA and PIO. Called when the | |
1039 | * TX circular buffer is reset. | |
1040 | */ | |
1041 | static void tegra_uart_flush_buffer(struct uart_port *u) | |
1042 | { | |
1043 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
1044 | ||
1045 | tup->tx_bytes = 0; | |
1046 | if (tup->tx_dma_chan) | |
1047 | dmaengine_terminate_all(tup->tx_dma_chan); | |
479e9b94 PH |
1048 | } |
1049 | ||
e9ea096d LD |
1050 | static void tegra_uart_shutdown(struct uart_port *u) |
1051 | { | |
1052 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
1053 | ||
1054 | tegra_uart_hw_deinit(tup); | |
1055 | ||
1056 | tup->rx_in_progress = 0; | |
1057 | tup->tx_in_progress = 0; | |
1058 | ||
1059 | tegra_uart_dma_channel_free(tup, true); | |
1060 | tegra_uart_dma_channel_free(tup, false); | |
1061 | free_irq(u->irq, tup); | |
1062 | } | |
1063 | ||
1064 | static void tegra_uart_enable_ms(struct uart_port *u) | |
1065 | { | |
1066 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
1067 | ||
1068 | if (tup->enable_modem_interrupt) { | |
1069 | tup->ier_shadow |= UART_IER_MSI; | |
1070 | tegra_uart_write(tup, tup->ier_shadow, UART_IER); | |
1071 | } | |
1072 | } | |
1073 | ||
1074 | static void tegra_uart_set_termios(struct uart_port *u, | |
1075 | struct ktermios *termios, struct ktermios *oldtermios) | |
1076 | { | |
1077 | struct tegra_uart_port *tup = to_tegra_uport(u); | |
1078 | unsigned int baud; | |
1079 | unsigned long flags; | |
1080 | unsigned int lcr; | |
1081 | int symb_bit = 1; | |
1082 | struct clk *parent_clk = clk_get_parent(tup->uart_clk); | |
1083 | unsigned long parent_clk_rate = clk_get_rate(parent_clk); | |
1084 | int max_divider = (tup->cdata->support_clk_src_div) ? 0x7FFF : 0xFFFF; | |
1085 | ||
1086 | max_divider *= 16; | |
1087 | spin_lock_irqsave(&u->lock, flags); | |
1088 | ||
1089 | /* Changing configuration, it is safe to stop any rx now */ | |
1090 | if (tup->rts_active) | |
1091 | set_rts(tup, false); | |
1092 | ||
1093 | /* Clear all interrupts as configuration is going to be change */ | |
1094 | tegra_uart_write(tup, tup->ier_shadow | UART_IER_RDI, UART_IER); | |
1095 | tegra_uart_read(tup, UART_IER); | |
1096 | tegra_uart_write(tup, 0, UART_IER); | |
1097 | tegra_uart_read(tup, UART_IER); | |
1098 | ||
1099 | /* Parity */ | |
1100 | lcr = tup->lcr_shadow; | |
1101 | lcr &= ~UART_LCR_PARITY; | |
1102 | ||
1103 | /* CMSPAR isn't supported by this driver */ | |
1104 | termios->c_cflag &= ~CMSPAR; | |
1105 | ||
1106 | if ((termios->c_cflag & PARENB) == PARENB) { | |
1107 | symb_bit++; | |
1108 | if (termios->c_cflag & PARODD) { | |
1109 | lcr |= UART_LCR_PARITY; | |
1110 | lcr &= ~UART_LCR_EPAR; | |
1111 | lcr &= ~UART_LCR_SPAR; | |
1112 | } else { | |
1113 | lcr |= UART_LCR_PARITY; | |
1114 | lcr |= UART_LCR_EPAR; | |
1115 | lcr &= ~UART_LCR_SPAR; | |
1116 | } | |
1117 | } | |
1118 | ||
1119 | lcr &= ~UART_LCR_WLEN8; | |
1120 | switch (termios->c_cflag & CSIZE) { | |
1121 | case CS5: | |
1122 | lcr |= UART_LCR_WLEN5; | |
1123 | symb_bit += 5; | |
1124 | break; | |
1125 | case CS6: | |
1126 | lcr |= UART_LCR_WLEN6; | |
1127 | symb_bit += 6; | |
1128 | break; | |
1129 | case CS7: | |
1130 | lcr |= UART_LCR_WLEN7; | |
1131 | symb_bit += 7; | |
1132 | break; | |
1133 | default: | |
1134 | lcr |= UART_LCR_WLEN8; | |
1135 | symb_bit += 8; | |
1136 | break; | |
1137 | } | |
1138 | ||
1139 | /* Stop bits */ | |
1140 | if (termios->c_cflag & CSTOPB) { | |
1141 | lcr |= UART_LCR_STOP; | |
1142 | symb_bit += 2; | |
1143 | } else { | |
1144 | lcr &= ~UART_LCR_STOP; | |
1145 | symb_bit++; | |
1146 | } | |
1147 | ||
1148 | tegra_uart_write(tup, lcr, UART_LCR); | |
1149 | tup->lcr_shadow = lcr; | |
1150 | tup->symb_bit = symb_bit; | |
1151 | ||
1152 | /* Baud rate. */ | |
1153 | baud = uart_get_baud_rate(u, termios, oldtermios, | |
1154 | parent_clk_rate/max_divider, | |
1155 | parent_clk_rate/16); | |
1156 | spin_unlock_irqrestore(&u->lock, flags); | |
1157 | tegra_set_baudrate(tup, baud); | |
1158 | if (tty_termios_baud_rate(termios)) | |
1159 | tty_termios_encode_baud_rate(termios, baud, baud); | |
1160 | spin_lock_irqsave(&u->lock, flags); | |
1161 | ||
1162 | /* Flow control */ | |
1163 | if (termios->c_cflag & CRTSCTS) { | |
1164 | tup->mcr_shadow |= TEGRA_UART_MCR_CTS_EN; | |
1165 | tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN; | |
1166 | tegra_uart_write(tup, tup->mcr_shadow, UART_MCR); | |
1167 | /* if top layer has asked to set rts active then do so here */ | |
1168 | if (tup->rts_active) | |
1169 | set_rts(tup, true); | |
1170 | } else { | |
1171 | tup->mcr_shadow &= ~TEGRA_UART_MCR_CTS_EN; | |
1172 | tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN; | |
1173 | tegra_uart_write(tup, tup->mcr_shadow, UART_MCR); | |
1174 | } | |
1175 | ||
1176 | /* update the port timeout based on new settings */ | |
1177 | uart_update_timeout(u, termios->c_cflag, baud); | |
1178 | ||
1179 | /* Make sure all write has completed */ | |
1180 | tegra_uart_read(tup, UART_IER); | |
1181 | ||
1182 | /* Reenable interrupt */ | |
1183 | tegra_uart_write(tup, tup->ier_shadow, UART_IER); | |
1184 | tegra_uart_read(tup, UART_IER); | |
1185 | ||
1186 | spin_unlock_irqrestore(&u->lock, flags); | |
e9ea096d LD |
1187 | } |
1188 | ||
e9ea096d LD |
1189 | static const char *tegra_uart_type(struct uart_port *u) |
1190 | { | |
1191 | return TEGRA_UART_TYPE; | |
1192 | } | |
1193 | ||
1194 | static struct uart_ops tegra_uart_ops = { | |
1195 | .tx_empty = tegra_uart_tx_empty, | |
1196 | .set_mctrl = tegra_uart_set_mctrl, | |
1197 | .get_mctrl = tegra_uart_get_mctrl, | |
1198 | .stop_tx = tegra_uart_stop_tx, | |
1199 | .start_tx = tegra_uart_start_tx, | |
1200 | .stop_rx = tegra_uart_stop_rx, | |
1201 | .flush_buffer = tegra_uart_flush_buffer, | |
1202 | .enable_ms = tegra_uart_enable_ms, | |
1203 | .break_ctl = tegra_uart_break_ctl, | |
1204 | .startup = tegra_uart_startup, | |
1205 | .shutdown = tegra_uart_shutdown, | |
1206 | .set_termios = tegra_uart_set_termios, | |
1207 | .type = tegra_uart_type, | |
1208 | .request_port = tegra_uart_request_port, | |
1209 | .release_port = tegra_uart_release_port, | |
1210 | }; | |
1211 | ||
1212 | static struct uart_driver tegra_uart_driver = { | |
1213 | .owner = THIS_MODULE, | |
1214 | .driver_name = "tegra_hsuart", | |
1215 | .dev_name = "ttyTHS", | |
fbf3ab27 | 1216 | .cons = NULL, |
e9ea096d LD |
1217 | .nr = TEGRA_UART_MAXIMUM, |
1218 | }; | |
1219 | ||
1220 | static int tegra_uart_parse_dt(struct platform_device *pdev, | |
1221 | struct tegra_uart_port *tup) | |
1222 | { | |
1223 | struct device_node *np = pdev->dev.of_node; | |
e9ea096d LD |
1224 | int port; |
1225 | ||
e9ea096d LD |
1226 | port = of_alias_get_id(np, "serial"); |
1227 | if (port < 0) { | |
1228 | dev_err(&pdev->dev, "failed to get alias id, errno %d\n", port); | |
1229 | return port; | |
1230 | } | |
1231 | tup->uport.line = port; | |
1232 | ||
1233 | tup->enable_modem_interrupt = of_property_read_bool(np, | |
1234 | "nvidia,enable-modem-interrupt"); | |
1235 | return 0; | |
1236 | } | |
1237 | ||
fbf3ab27 | 1238 | static struct tegra_uart_chip_data tegra20_uart_chip_data = { |
e9ea096d LD |
1239 | .tx_fifo_full_status = false, |
1240 | .allow_txfifo_reset_fifo_mode = true, | |
1241 | .support_clk_src_div = false, | |
1242 | }; | |
1243 | ||
fbf3ab27 | 1244 | static struct tegra_uart_chip_data tegra30_uart_chip_data = { |
e9ea096d LD |
1245 | .tx_fifo_full_status = true, |
1246 | .allow_txfifo_reset_fifo_mode = false, | |
1247 | .support_clk_src_div = true, | |
1248 | }; | |
1249 | ||
ed0bb232 | 1250 | static const struct of_device_id tegra_uart_of_match[] = { |
e9ea096d LD |
1251 | { |
1252 | .compatible = "nvidia,tegra30-hsuart", | |
1253 | .data = &tegra30_uart_chip_data, | |
1254 | }, { | |
1255 | .compatible = "nvidia,tegra20-hsuart", | |
1256 | .data = &tegra20_uart_chip_data, | |
1257 | }, { | |
1258 | }, | |
1259 | }; | |
1260 | MODULE_DEVICE_TABLE(of, tegra_uart_of_match); | |
1261 | ||
1262 | static int tegra_uart_probe(struct platform_device *pdev) | |
1263 | { | |
1264 | struct tegra_uart_port *tup; | |
1265 | struct uart_port *u; | |
1266 | struct resource *resource; | |
1267 | int ret; | |
1268 | const struct tegra_uart_chip_data *cdata; | |
1269 | const struct of_device_id *match; | |
1270 | ||
c3e1bece | 1271 | match = of_match_device(tegra_uart_of_match, &pdev->dev); |
e9ea096d LD |
1272 | if (!match) { |
1273 | dev_err(&pdev->dev, "Error: No device match found\n"); | |
1274 | return -ENODEV; | |
1275 | } | |
1276 | cdata = match->data; | |
1277 | ||
1278 | tup = devm_kzalloc(&pdev->dev, sizeof(*tup), GFP_KERNEL); | |
1279 | if (!tup) { | |
1280 | dev_err(&pdev->dev, "Failed to allocate memory for tup\n"); | |
1281 | return -ENOMEM; | |
1282 | } | |
1283 | ||
1284 | ret = tegra_uart_parse_dt(pdev, tup); | |
1285 | if (ret < 0) | |
1286 | return ret; | |
1287 | ||
1288 | u = &tup->uport; | |
1289 | u->dev = &pdev->dev; | |
1290 | u->ops = &tegra_uart_ops; | |
1291 | u->type = PORT_TEGRA; | |
1292 | u->fifosize = 32; | |
1293 | tup->cdata = cdata; | |
1294 | ||
1295 | platform_set_drvdata(pdev, tup); | |
1296 | resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
1297 | if (!resource) { | |
1298 | dev_err(&pdev->dev, "No IO memory resource\n"); | |
1299 | return -ENODEV; | |
1300 | } | |
1301 | ||
1302 | u->mapbase = resource->start; | |
84e81922 SK |
1303 | u->membase = devm_ioremap_resource(&pdev->dev, resource); |
1304 | if (IS_ERR(u->membase)) | |
1305 | return PTR_ERR(u->membase); | |
e9ea096d LD |
1306 | |
1307 | tup->uart_clk = devm_clk_get(&pdev->dev, NULL); | |
1308 | if (IS_ERR(tup->uart_clk)) { | |
1309 | dev_err(&pdev->dev, "Couldn't get the clock\n"); | |
1310 | return PTR_ERR(tup->uart_clk); | |
1311 | } | |
1312 | ||
d3d654ef SW |
1313 | tup->rst = devm_reset_control_get(&pdev->dev, "serial"); |
1314 | if (IS_ERR(tup->rst)) { | |
1315 | dev_err(&pdev->dev, "Couldn't get the reset\n"); | |
1316 | return PTR_ERR(tup->rst); | |
1317 | } | |
1318 | ||
e9ea096d | 1319 | u->iotype = UPIO_MEM32; |
394a9e2c JS |
1320 | ret = platform_get_irq(pdev, 0); |
1321 | if (ret < 0) { | |
1322 | dev_err(&pdev->dev, "Couldn't get IRQ\n"); | |
1323 | return ret; | |
1324 | } | |
1325 | u->irq = ret; | |
e9ea096d LD |
1326 | u->regshift = 2; |
1327 | ret = uart_add_one_port(&tegra_uart_driver, u); | |
1328 | if (ret < 0) { | |
1329 | dev_err(&pdev->dev, "Failed to add uart port, err %d\n", ret); | |
1330 | return ret; | |
1331 | } | |
1332 | return ret; | |
1333 | } | |
1334 | ||
1335 | static int tegra_uart_remove(struct platform_device *pdev) | |
1336 | { | |
1337 | struct tegra_uart_port *tup = platform_get_drvdata(pdev); | |
1338 | struct uart_port *u = &tup->uport; | |
1339 | ||
1340 | uart_remove_one_port(&tegra_uart_driver, u); | |
1341 | return 0; | |
1342 | } | |
1343 | ||
1344 | #ifdef CONFIG_PM_SLEEP | |
1345 | static int tegra_uart_suspend(struct device *dev) | |
1346 | { | |
1347 | struct tegra_uart_port *tup = dev_get_drvdata(dev); | |
1348 | struct uart_port *u = &tup->uport; | |
1349 | ||
1350 | return uart_suspend_port(&tegra_uart_driver, u); | |
1351 | } | |
1352 | ||
1353 | static int tegra_uart_resume(struct device *dev) | |
1354 | { | |
1355 | struct tegra_uart_port *tup = dev_get_drvdata(dev); | |
1356 | struct uart_port *u = &tup->uport; | |
1357 | ||
1358 | return uart_resume_port(&tegra_uart_driver, u); | |
1359 | } | |
1360 | #endif | |
1361 | ||
1362 | static const struct dev_pm_ops tegra_uart_pm_ops = { | |
1363 | SET_SYSTEM_SLEEP_PM_OPS(tegra_uart_suspend, tegra_uart_resume) | |
1364 | }; | |
1365 | ||
1366 | static struct platform_driver tegra_uart_platform_driver = { | |
1367 | .probe = tegra_uart_probe, | |
1368 | .remove = tegra_uart_remove, | |
1369 | .driver = { | |
1370 | .name = "serial-tegra", | |
c3e1bece | 1371 | .of_match_table = tegra_uart_of_match, |
e9ea096d LD |
1372 | .pm = &tegra_uart_pm_ops, |
1373 | }, | |
1374 | }; | |
1375 | ||
1376 | static int __init tegra_uart_init(void) | |
1377 | { | |
1378 | int ret; | |
1379 | ||
1380 | ret = uart_register_driver(&tegra_uart_driver); | |
1381 | if (ret < 0) { | |
1382 | pr_err("Could not register %s driver\n", | |
1383 | tegra_uart_driver.driver_name); | |
1384 | return ret; | |
1385 | } | |
1386 | ||
1387 | ret = platform_driver_register(&tegra_uart_platform_driver); | |
1388 | if (ret < 0) { | |
8b513d0c | 1389 | pr_err("Uart platform driver register failed, e = %d\n", ret); |
e9ea096d LD |
1390 | uart_unregister_driver(&tegra_uart_driver); |
1391 | return ret; | |
1392 | } | |
1393 | return 0; | |
1394 | } | |
1395 | ||
1396 | static void __exit tegra_uart_exit(void) | |
1397 | { | |
1398 | pr_info("Unloading tegra uart driver\n"); | |
1399 | platform_driver_unregister(&tegra_uart_platform_driver); | |
1400 | uart_unregister_driver(&tegra_uart_driver); | |
1401 | } | |
1402 | ||
1403 | module_init(tegra_uart_init); | |
1404 | module_exit(tegra_uart_exit); | |
1405 | ||
1406 | MODULE_ALIAS("platform:serial-tegra"); | |
1407 | MODULE_DESCRIPTION("High speed UART driver for tegra chipset"); | |
1408 | MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); | |
1409 | MODULE_LICENSE("GPL v2"); |