1 // SPDX-License-Identifier: GPL-2.0
5 * High-speed serial driver for NVIDIA Tegra SoCs
7 * Copyright (c) 2012-2019, NVIDIA CORPORATION. All rights reserved.
9 * Author: Laxman Dewangan <ldewangan@nvidia.com>
12 #include <linux/clk.h>
13 #include <linux/debugfs.h>
14 #include <linux/delay.h>
15 #include <linux/dmaengine.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/dmapool.h>
18 #include <linux/err.h>
20 #include <linux/irq.h>
21 #include <linux/module.h>
23 #include <linux/of_device.h>
24 #include <linux/pagemap.h>
25 #include <linux/platform_device.h>
26 #include <linux/reset.h>
27 #include <linux/serial.h>
28 #include <linux/serial_8250.h>
29 #include <linux/serial_core.h>
30 #include <linux/serial_reg.h>
31 #include <linux/slab.h>
32 #include <linux/string.h>
33 #include <linux/termios.h>
34 #include <linux/tty.h>
35 #include <linux/tty_flip.h>
37 #define TEGRA_UART_TYPE "TEGRA_UART"
38 #define TX_EMPTY_STATUS (UART_LSR_TEMT | UART_LSR_THRE)
39 #define BYTES_TO_ALIGN(x) ((unsigned long)(x) & 0x3)
41 #define TEGRA_UART_RX_DMA_BUFFER_SIZE 4096
42 #define TEGRA_UART_LSR_TXFIFO_FULL 0x100
43 #define TEGRA_UART_IER_EORD 0x20
44 #define TEGRA_UART_MCR_RTS_EN 0x40
45 #define TEGRA_UART_MCR_CTS_EN 0x20
46 #define TEGRA_UART_LSR_ANY (UART_LSR_OE | UART_LSR_BI | \
47 UART_LSR_PE | UART_LSR_FE)
48 #define TEGRA_UART_IRDA_CSR 0x08
49 #define TEGRA_UART_SIR_ENABLED 0x80
51 #define TEGRA_UART_TX_PIO 1
52 #define TEGRA_UART_TX_DMA 2
53 #define TEGRA_UART_MIN_DMA 16
54 #define TEGRA_UART_FIFO_SIZE 32
57 * Tx fifo trigger level setting in tegra uart is in
58 * reverse way then conventional uart.
60 #define TEGRA_UART_TX_TRIG_16B 0x00
61 #define TEGRA_UART_TX_TRIG_8B 0x10
62 #define TEGRA_UART_TX_TRIG_4B 0x20
63 #define TEGRA_UART_TX_TRIG_1B 0x30
65 #define TEGRA_UART_MAXIMUM 8
67 /* Default UART setting when started: 115200 no parity, stop, 8 data bits */
68 #define TEGRA_UART_DEFAULT_BAUD 115200
69 #define TEGRA_UART_DEFAULT_LSR UART_LCR_WLEN8
71 /* Tx transfer mode */
72 #define TEGRA_TX_PIO 1
73 #define TEGRA_TX_DMA 2
75 #define TEGRA_UART_FCR_IIR_FIFO_EN 0x40
78 * tegra_uart_chip_data: SOC specific data.
80 * @tx_fifo_full_status: Status flag available for checking tx fifo full.
81 * @allow_txfifo_reset_fifo_mode: allow_tx fifo reset with fifo mode or not.
82 * Tegra30 does not allow this.
83 * @support_clk_src_div: Clock source support the clock divider.
85 struct tegra_uart_chip_data {
86 bool tx_fifo_full_status;
87 bool allow_txfifo_reset_fifo_mode;
88 bool support_clk_src_div;
89 bool fifo_mode_enable_status;
91 int max_dma_burst_bytes;
92 int error_tolerance_low_range;
93 int error_tolerance_high_range;
96 struct tegra_baud_tolerance {
102 struct tegra_uart_port {
103 struct uart_port uport;
104 const struct tegra_uart_chip_data *cdata;
106 struct clk *uart_clk;
107 struct reset_control *rst;
108 unsigned int current_baud;
110 /* Register shadow */
111 unsigned long fcr_shadow;
112 unsigned long mcr_shadow;
113 unsigned long lcr_shadow;
114 unsigned long ier_shadow;
118 unsigned int tx_bytes;
120 bool enable_modem_interrupt;
126 struct dma_chan *rx_dma_chan;
127 struct dma_chan *tx_dma_chan;
128 dma_addr_t rx_dma_buf_phys;
129 dma_addr_t tx_dma_buf_phys;
130 unsigned char *rx_dma_buf_virt;
131 unsigned char *tx_dma_buf_virt;
132 struct dma_async_tx_descriptor *tx_dma_desc;
133 struct dma_async_tx_descriptor *rx_dma_desc;
134 dma_cookie_t tx_cookie;
135 dma_cookie_t rx_cookie;
136 unsigned int tx_bytes_requested;
137 unsigned int rx_bytes_requested;
138 struct tegra_baud_tolerance *baud_tolerance;
139 int n_adjustable_baud_rates;
147 static void tegra_uart_start_next_tx(struct tegra_uart_port *tup);
148 static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup);
149 static void tegra_uart_dma_channel_free(struct tegra_uart_port *tup,
152 static inline unsigned long tegra_uart_read(struct tegra_uart_port *tup,
155 return readl(tup->uport.membase + (reg << tup->uport.regshift));
158 static inline void tegra_uart_write(struct tegra_uart_port *tup, unsigned val,
161 writel(val, tup->uport.membase + (reg << tup->uport.regshift));
164 static inline struct tegra_uart_port *to_tegra_uport(struct uart_port *u)
166 return container_of(u, struct tegra_uart_port, uport);
169 static unsigned int tegra_uart_get_mctrl(struct uart_port *u)
171 struct tegra_uart_port *tup = to_tegra_uport(u);
174 * RI - Ring detector is active
175 * CD/DCD/CAR - Carrier detect is always active. For some reason
176 * linux has different names for carrier detect.
177 * DSR - Data Set ready is active as the hardware doesn't support it.
178 * Don't know if the linux support this yet?
179 * CTS - Clear to send. Always set to active, as the hardware handles
182 if (tup->enable_modem_interrupt)
183 return TIOCM_RI | TIOCM_CD | TIOCM_DSR | TIOCM_CTS;
187 static void set_rts(struct tegra_uart_port *tup, bool active)
191 mcr = tup->mcr_shadow;
193 mcr |= TEGRA_UART_MCR_RTS_EN;
195 mcr &= ~TEGRA_UART_MCR_RTS_EN;
196 if (mcr != tup->mcr_shadow) {
197 tegra_uart_write(tup, mcr, UART_MCR);
198 tup->mcr_shadow = mcr;
202 static void set_dtr(struct tegra_uart_port *tup, bool active)
206 mcr = tup->mcr_shadow;
210 mcr &= ~UART_MCR_DTR;
211 if (mcr != tup->mcr_shadow) {
212 tegra_uart_write(tup, mcr, UART_MCR);
213 tup->mcr_shadow = mcr;
217 static void set_loopbk(struct tegra_uart_port *tup, bool active)
219 unsigned long mcr = tup->mcr_shadow;
222 mcr |= UART_MCR_LOOP;
224 mcr &= ~UART_MCR_LOOP;
226 if (mcr != tup->mcr_shadow) {
227 tegra_uart_write(tup, mcr, UART_MCR);
228 tup->mcr_shadow = mcr;
232 static void tegra_uart_set_mctrl(struct uart_port *u, unsigned int mctrl)
234 struct tegra_uart_port *tup = to_tegra_uport(u);
237 tup->rts_active = !!(mctrl & TIOCM_RTS);
238 set_rts(tup, tup->rts_active);
240 enable = !!(mctrl & TIOCM_DTR);
241 set_dtr(tup, enable);
243 enable = !!(mctrl & TIOCM_LOOP);
244 set_loopbk(tup, enable);
247 static void tegra_uart_break_ctl(struct uart_port *u, int break_ctl)
249 struct tegra_uart_port *tup = to_tegra_uport(u);
252 lcr = tup->lcr_shadow;
256 lcr &= ~UART_LCR_SBC;
257 tegra_uart_write(tup, lcr, UART_LCR);
258 tup->lcr_shadow = lcr;
262 * tegra_uart_wait_cycle_time: Wait for N UART clock periods
264 * @tup: Tegra serial port data structure.
265 * @cycles: Number of clock periods to wait.
267 * Tegra UARTs are clocked at 16X the baud/bit rate and hence the UART
268 * clock speed is 16X the current baud rate.
270 static void tegra_uart_wait_cycle_time(struct tegra_uart_port *tup,
273 if (tup->current_baud)
274 udelay(DIV_ROUND_UP(cycles * 1000000, tup->current_baud * 16));
277 /* Wait for a symbol-time. */
278 static void tegra_uart_wait_sym_time(struct tegra_uart_port *tup,
281 if (tup->current_baud)
282 udelay(DIV_ROUND_UP(syms * tup->symb_bit * 1000000,
286 static int tegra_uart_wait_fifo_mode_enabled(struct tegra_uart_port *tup)
289 unsigned int tmout = 100;
292 iir = tegra_uart_read(tup, UART_IIR);
293 if (iir & TEGRA_UART_FCR_IIR_FIFO_EN)
301 static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits)
303 unsigned long fcr = tup->fcr_shadow;
304 unsigned int lsr, tmout = 10000;
309 if (tup->cdata->allow_txfifo_reset_fifo_mode) {
310 fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
311 tegra_uart_write(tup, fcr, UART_FCR);
313 fcr &= ~UART_FCR_ENABLE_FIFO;
314 tegra_uart_write(tup, fcr, UART_FCR);
316 fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
317 tegra_uart_write(tup, fcr, UART_FCR);
318 fcr |= UART_FCR_ENABLE_FIFO;
319 tegra_uart_write(tup, fcr, UART_FCR);
320 if (tup->cdata->fifo_mode_enable_status)
321 tegra_uart_wait_fifo_mode_enabled(tup);
324 /* Dummy read to ensure the write is posted */
325 tegra_uart_read(tup, UART_SCR);
328 * For all tegra devices (up to t210), there is a hardware issue that
329 * requires software to wait for 32 UART clock periods for the flush
330 * to propagate, otherwise data could be lost.
332 tegra_uart_wait_cycle_time(tup, 32);
335 lsr = tegra_uart_read(tup, UART_LSR);
336 if ((lsr | UART_LSR_TEMT) && !(lsr & UART_LSR_DR))
345 static long tegra_get_tolerance_rate(struct tegra_uart_port *tup,
346 unsigned int baud, long rate)
350 for (i = 0; i < tup->n_adjustable_baud_rates; ++i) {
351 if (baud >= tup->baud_tolerance[i].lower_range_baud &&
352 baud <= tup->baud_tolerance[i].upper_range_baud)
353 return (rate + (rate *
354 tup->baud_tolerance[i].tolerance) / 10000);
360 static int tegra_check_rate_in_range(struct tegra_uart_port *tup)
364 diff = ((long)(tup->configured_rate - tup->required_rate) * 10000)
365 / tup->required_rate;
366 if (diff < (tup->cdata->error_tolerance_low_range * 100) ||
367 diff > (tup->cdata->error_tolerance_high_range * 100)) {
368 dev_err(tup->uport.dev,
369 "configured baud rate is out of range by %ld", diff);
376 static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
379 unsigned int divisor;
384 if (tup->current_baud == baud)
387 if (tup->cdata->support_clk_src_div) {
389 tup->required_rate = rate;
391 if (tup->n_adjustable_baud_rates)
392 rate = tegra_get_tolerance_rate(tup, baud, rate);
394 ret = clk_set_rate(tup->uart_clk, rate);
396 dev_err(tup->uport.dev,
397 "clk_set_rate() failed for rate %lu\n", rate);
400 tup->configured_rate = clk_get_rate(tup->uart_clk);
402 ret = tegra_check_rate_in_range(tup);
406 rate = clk_get_rate(tup->uart_clk);
407 divisor = DIV_ROUND_CLOSEST(rate, baud * 16);
410 spin_lock_irqsave(&tup->uport.lock, flags);
411 lcr = tup->lcr_shadow;
412 lcr |= UART_LCR_DLAB;
413 tegra_uart_write(tup, lcr, UART_LCR);
415 tegra_uart_write(tup, divisor & 0xFF, UART_TX);
416 tegra_uart_write(tup, ((divisor >> 8) & 0xFF), UART_IER);
418 lcr &= ~UART_LCR_DLAB;
419 tegra_uart_write(tup, lcr, UART_LCR);
421 /* Dummy read to ensure the write is posted */
422 tegra_uart_read(tup, UART_SCR);
423 spin_unlock_irqrestore(&tup->uport.lock, flags);
425 tup->current_baud = baud;
427 /* wait two character intervals at new rate */
428 tegra_uart_wait_sym_time(tup, 2);
432 static char tegra_uart_decode_rx_error(struct tegra_uart_port *tup,
435 char flag = TTY_NORMAL;
437 if (unlikely(lsr & TEGRA_UART_LSR_ANY)) {
438 if (lsr & UART_LSR_OE) {
441 tup->uport.icount.overrun++;
442 dev_err(tup->uport.dev, "Got overrun errors\n");
443 } else if (lsr & UART_LSR_PE) {
446 tup->uport.icount.parity++;
447 dev_err(tup->uport.dev, "Got Parity errors\n");
448 } else if (lsr & UART_LSR_FE) {
450 tup->uport.icount.frame++;
451 dev_err(tup->uport.dev, "Got frame errors\n");
452 } else if (lsr & UART_LSR_BI) {
455 * If FIFO read error without any data, reset Rx FIFO
457 if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE))
458 tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_RCVR);
459 if (tup->uport.ignore_status_mask & UART_LSR_BI)
462 tup->uport.icount.brk++;
463 dev_dbg(tup->uport.dev, "Got Break\n");
465 uart_insert_char(&tup->uport, lsr, UART_LSR_OE, 0, flag);
471 static int tegra_uart_request_port(struct uart_port *u)
476 static void tegra_uart_release_port(struct uart_port *u)
478 /* Nothing to do here */
481 static void tegra_uart_fill_tx_fifo(struct tegra_uart_port *tup, int max_bytes)
483 struct circ_buf *xmit = &tup->uport.state->xmit;
486 for (i = 0; i < max_bytes; i++) {
487 BUG_ON(uart_circ_empty(xmit));
488 if (tup->cdata->tx_fifo_full_status) {
489 unsigned long lsr = tegra_uart_read(tup, UART_LSR);
490 if ((lsr & TEGRA_UART_LSR_TXFIFO_FULL))
493 tegra_uart_write(tup, xmit->buf[xmit->tail], UART_TX);
494 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
495 tup->uport.icount.tx++;
499 static void tegra_uart_start_pio_tx(struct tegra_uart_port *tup,
502 if (bytes > TEGRA_UART_MIN_DMA)
503 bytes = TEGRA_UART_MIN_DMA;
505 tup->tx_in_progress = TEGRA_UART_TX_PIO;
506 tup->tx_bytes = bytes;
507 tup->ier_shadow |= UART_IER_THRI;
508 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
511 static void tegra_uart_tx_dma_complete(void *args)
513 struct tegra_uart_port *tup = args;
514 struct circ_buf *xmit = &tup->uport.state->xmit;
515 struct dma_tx_state state;
519 dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
520 count = tup->tx_bytes_requested - state.residue;
521 async_tx_ack(tup->tx_dma_desc);
522 spin_lock_irqsave(&tup->uport.lock, flags);
523 xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
524 tup->tx_in_progress = 0;
525 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
526 uart_write_wakeup(&tup->uport);
527 tegra_uart_start_next_tx(tup);
528 spin_unlock_irqrestore(&tup->uport.lock, flags);
531 static int tegra_uart_start_tx_dma(struct tegra_uart_port *tup,
534 struct circ_buf *xmit = &tup->uport.state->xmit;
535 dma_addr_t tx_phys_addr;
537 tup->tx_bytes = count & ~(0xF);
538 tx_phys_addr = tup->tx_dma_buf_phys + xmit->tail;
540 dma_sync_single_for_device(tup->uport.dev, tx_phys_addr,
541 tup->tx_bytes, DMA_TO_DEVICE);
543 tup->tx_dma_desc = dmaengine_prep_slave_single(tup->tx_dma_chan,
544 tx_phys_addr, tup->tx_bytes, DMA_MEM_TO_DEV,
546 if (!tup->tx_dma_desc) {
547 dev_err(tup->uport.dev, "Not able to get desc for Tx\n");
551 tup->tx_dma_desc->callback = tegra_uart_tx_dma_complete;
552 tup->tx_dma_desc->callback_param = tup;
553 tup->tx_in_progress = TEGRA_UART_TX_DMA;
554 tup->tx_bytes_requested = tup->tx_bytes;
555 tup->tx_cookie = dmaengine_submit(tup->tx_dma_desc);
556 dma_async_issue_pending(tup->tx_dma_chan);
560 static void tegra_uart_start_next_tx(struct tegra_uart_port *tup)
564 struct circ_buf *xmit = &tup->uport.state->xmit;
566 if (!tup->current_baud)
569 tail = (unsigned long)&xmit->buf[xmit->tail];
570 count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
574 if (tup->use_tx_pio || count < TEGRA_UART_MIN_DMA)
575 tegra_uart_start_pio_tx(tup, count);
576 else if (BYTES_TO_ALIGN(tail) > 0)
577 tegra_uart_start_pio_tx(tup, BYTES_TO_ALIGN(tail));
579 tegra_uart_start_tx_dma(tup, count);
582 /* Called by serial core driver with u->lock taken. */
583 static void tegra_uart_start_tx(struct uart_port *u)
585 struct tegra_uart_port *tup = to_tegra_uport(u);
586 struct circ_buf *xmit = &u->state->xmit;
588 if (!uart_circ_empty(xmit) && !tup->tx_in_progress)
589 tegra_uart_start_next_tx(tup);
592 static unsigned int tegra_uart_tx_empty(struct uart_port *u)
594 struct tegra_uart_port *tup = to_tegra_uport(u);
595 unsigned int ret = 0;
598 spin_lock_irqsave(&u->lock, flags);
599 if (!tup->tx_in_progress) {
600 unsigned long lsr = tegra_uart_read(tup, UART_LSR);
601 if ((lsr & TX_EMPTY_STATUS) == TX_EMPTY_STATUS)
604 spin_unlock_irqrestore(&u->lock, flags);
608 static void tegra_uart_stop_tx(struct uart_port *u)
610 struct tegra_uart_port *tup = to_tegra_uport(u);
611 struct circ_buf *xmit = &tup->uport.state->xmit;
612 struct dma_tx_state state;
615 if (tup->tx_in_progress != TEGRA_UART_TX_DMA)
618 dmaengine_terminate_all(tup->tx_dma_chan);
619 dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
620 count = tup->tx_bytes_requested - state.residue;
621 async_tx_ack(tup->tx_dma_desc);
622 xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
623 tup->tx_in_progress = 0;
626 static void tegra_uart_handle_tx_pio(struct tegra_uart_port *tup)
628 struct circ_buf *xmit = &tup->uport.state->xmit;
630 tegra_uart_fill_tx_fifo(tup, tup->tx_bytes);
631 tup->tx_in_progress = 0;
632 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
633 uart_write_wakeup(&tup->uport);
634 tegra_uart_start_next_tx(tup);
637 static void tegra_uart_handle_rx_pio(struct tegra_uart_port *tup,
638 struct tty_port *tty)
641 char flag = TTY_NORMAL;
642 unsigned long lsr = 0;
645 lsr = tegra_uart_read(tup, UART_LSR);
646 if (!(lsr & UART_LSR_DR))
649 flag = tegra_uart_decode_rx_error(tup, lsr);
650 if (flag != TTY_NORMAL)
653 ch = (unsigned char) tegra_uart_read(tup, UART_RX);
654 tup->uport.icount.rx++;
656 if (!uart_handle_sysrq_char(&tup->uport, ch) && tty)
657 tty_insert_flip_char(tty, ch, flag);
659 if (tup->uport.ignore_status_mask & UART_LSR_DR)
664 static void tegra_uart_copy_rx_to_tty(struct tegra_uart_port *tup,
665 struct tty_port *tty,
670 /* If count is zero, then there is no data to be copied */
674 tup->uport.icount.rx += count;
676 dev_err(tup->uport.dev, "No tty port\n");
680 if (tup->uport.ignore_status_mask & UART_LSR_DR)
683 dma_sync_single_for_cpu(tup->uport.dev, tup->rx_dma_buf_phys,
684 count, DMA_FROM_DEVICE);
685 copied = tty_insert_flip_string(tty,
686 ((unsigned char *)(tup->rx_dma_buf_virt)), count);
687 if (copied != count) {
689 dev_err(tup->uport.dev, "RxData copy to tty layer failed\n");
691 dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys,
692 count, DMA_TO_DEVICE);
695 static void do_handle_rx_pio(struct tegra_uart_port *tup)
697 struct tty_struct *tty = tty_port_tty_get(&tup->uport.state->port);
698 struct tty_port *port = &tup->uport.state->port;
700 tegra_uart_handle_rx_pio(tup, port);
702 tty_flip_buffer_push(port);
707 static void tegra_uart_rx_buffer_push(struct tegra_uart_port *tup,
708 unsigned int residue)
710 struct tty_port *port = &tup->uport.state->port;
713 async_tx_ack(tup->rx_dma_desc);
714 count = tup->rx_bytes_requested - residue;
716 /* If we are here, DMA is stopped */
717 tegra_uart_copy_rx_to_tty(tup, port, count);
719 do_handle_rx_pio(tup);
722 static void tegra_uart_rx_dma_complete(void *args)
724 struct tegra_uart_port *tup = args;
725 struct uart_port *u = &tup->uport;
727 struct dma_tx_state state;
728 enum dma_status status;
730 spin_lock_irqsave(&u->lock, flags);
732 status = dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
734 if (status == DMA_IN_PROGRESS) {
735 dev_dbg(tup->uport.dev, "RX DMA is in progress\n");
739 /* Deactivate flow control to stop sender */
743 tup->rx_dma_active = false;
744 tegra_uart_rx_buffer_push(tup, 0);
745 tegra_uart_start_rx_dma(tup);
747 /* Activate flow control to start transfer */
752 spin_unlock_irqrestore(&u->lock, flags);
755 static void tegra_uart_terminate_rx_dma(struct tegra_uart_port *tup)
757 struct dma_tx_state state;
759 if (!tup->rx_dma_active) {
760 do_handle_rx_pio(tup);
764 dmaengine_terminate_all(tup->rx_dma_chan);
765 dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
767 tegra_uart_rx_buffer_push(tup, state.residue);
768 tup->rx_dma_active = false;
771 static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup)
773 /* Deactivate flow control to stop sender */
777 tegra_uart_terminate_rx_dma(tup);
783 static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup)
785 unsigned int count = TEGRA_UART_RX_DMA_BUFFER_SIZE;
787 if (tup->rx_dma_active)
790 tup->rx_dma_desc = dmaengine_prep_slave_single(tup->rx_dma_chan,
791 tup->rx_dma_buf_phys, count, DMA_DEV_TO_MEM,
793 if (!tup->rx_dma_desc) {
794 dev_err(tup->uport.dev, "Not able to get desc for Rx\n");
798 tup->rx_dma_active = true;
799 tup->rx_dma_desc->callback = tegra_uart_rx_dma_complete;
800 tup->rx_dma_desc->callback_param = tup;
801 tup->rx_bytes_requested = count;
802 tup->rx_cookie = dmaengine_submit(tup->rx_dma_desc);
803 dma_async_issue_pending(tup->rx_dma_chan);
807 static void tegra_uart_handle_modem_signal_change(struct uart_port *u)
809 struct tegra_uart_port *tup = to_tegra_uport(u);
812 msr = tegra_uart_read(tup, UART_MSR);
813 if (!(msr & UART_MSR_ANY_DELTA))
816 if (msr & UART_MSR_TERI)
817 tup->uport.icount.rng++;
818 if (msr & UART_MSR_DDSR)
819 tup->uport.icount.dsr++;
820 /* We may only get DDCD when HW init and reset */
821 if (msr & UART_MSR_DDCD)
822 uart_handle_dcd_change(&tup->uport, msr & UART_MSR_DCD);
823 /* Will start/stop_tx accordingly */
824 if (msr & UART_MSR_DCTS)
825 uart_handle_cts_change(&tup->uport, msr & UART_MSR_CTS);
828 static irqreturn_t tegra_uart_isr(int irq, void *data)
830 struct tegra_uart_port *tup = data;
831 struct uart_port *u = &tup->uport;
834 bool is_rx_start = false;
835 bool is_rx_int = false;
838 spin_lock_irqsave(&u->lock, flags);
840 iir = tegra_uart_read(tup, UART_IIR);
841 if (iir & UART_IIR_NO_INT) {
842 if (!tup->use_rx_pio && is_rx_int) {
843 tegra_uart_handle_rx_dma(tup);
844 if (tup->rx_in_progress) {
845 ier = tup->ier_shadow;
846 ier |= (UART_IER_RLSI | UART_IER_RTOIE |
847 TEGRA_UART_IER_EORD | UART_IER_RDI);
848 tup->ier_shadow = ier;
849 tegra_uart_write(tup, ier, UART_IER);
851 } else if (is_rx_start) {
852 tegra_uart_start_rx_dma(tup);
854 spin_unlock_irqrestore(&u->lock, flags);
858 switch ((iir >> 1) & 0x7) {
859 case 0: /* Modem signal change interrupt */
860 tegra_uart_handle_modem_signal_change(u);
863 case 1: /* Transmit interrupt only triggered when using PIO */
864 tup->ier_shadow &= ~UART_IER_THRI;
865 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
866 tegra_uart_handle_tx_pio(tup);
869 case 4: /* End of data */
870 case 6: /* Rx timeout */
871 if (!tup->use_rx_pio) {
872 is_rx_int = tup->rx_in_progress;
873 /* Disable Rx interrupts */
874 ier = tup->ier_shadow;
875 ier &= ~(UART_IER_RDI | UART_IER_RLSI |
876 UART_IER_RTOIE | TEGRA_UART_IER_EORD);
877 tup->ier_shadow = ier;
878 tegra_uart_write(tup, ier, UART_IER);
882 case 2: /* Receive */
883 if (!tup->use_rx_pio) {
884 is_rx_start = tup->rx_in_progress;
885 tup->ier_shadow &= ~UART_IER_RDI;
886 tegra_uart_write(tup, tup->ier_shadow,
889 do_handle_rx_pio(tup);
893 case 3: /* Receive error */
894 tegra_uart_decode_rx_error(tup,
895 tegra_uart_read(tup, UART_LSR));
898 case 5: /* break nothing to handle */
899 case 7: /* break nothing to handle */
905 static void tegra_uart_stop_rx(struct uart_port *u)
907 struct tegra_uart_port *tup = to_tegra_uport(u);
908 struct tty_port *port = &tup->uport.state->port;
914 if (!tup->rx_in_progress)
917 tegra_uart_wait_sym_time(tup, 1); /* wait one character interval */
919 ier = tup->ier_shadow;
920 ier &= ~(UART_IER_RDI | UART_IER_RLSI | UART_IER_RTOIE |
921 TEGRA_UART_IER_EORD);
922 tup->ier_shadow = ier;
923 tegra_uart_write(tup, ier, UART_IER);
924 tup->rx_in_progress = 0;
926 if (!tup->use_rx_pio)
927 tegra_uart_terminate_rx_dma(tup);
929 tegra_uart_handle_rx_pio(tup, port);
932 static void tegra_uart_hw_deinit(struct tegra_uart_port *tup)
935 unsigned long char_time = DIV_ROUND_UP(10000000, tup->current_baud);
936 unsigned long fifo_empty_time = tup->uport.fifosize * char_time;
937 unsigned long wait_time;
942 /* Disable interrupts */
943 tegra_uart_write(tup, 0, UART_IER);
945 lsr = tegra_uart_read(tup, UART_LSR);
946 if ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
947 msr = tegra_uart_read(tup, UART_MSR);
948 mcr = tegra_uart_read(tup, UART_MCR);
949 if ((mcr & TEGRA_UART_MCR_CTS_EN) && (msr & UART_MSR_CTS))
950 dev_err(tup->uport.dev,
951 "Tx Fifo not empty, CTS disabled, waiting\n");
953 /* Wait for Tx fifo to be empty */
954 while ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
955 wait_time = min(fifo_empty_time, 100lu);
957 fifo_empty_time -= wait_time;
958 if (!fifo_empty_time) {
959 msr = tegra_uart_read(tup, UART_MSR);
960 mcr = tegra_uart_read(tup, UART_MCR);
961 if ((mcr & TEGRA_UART_MCR_CTS_EN) &&
962 (msr & UART_MSR_CTS))
963 dev_err(tup->uport.dev,
964 "Slave not ready\n");
967 lsr = tegra_uart_read(tup, UART_LSR);
971 spin_lock_irqsave(&tup->uport.lock, flags);
972 /* Reset the Rx and Tx FIFOs */
973 tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR);
974 tup->current_baud = 0;
975 spin_unlock_irqrestore(&tup->uport.lock, flags);
977 tup->rx_in_progress = 0;
978 tup->tx_in_progress = 0;
980 if (!tup->use_rx_pio)
981 tegra_uart_dma_channel_free(tup, true);
982 if (!tup->use_tx_pio)
983 tegra_uart_dma_channel_free(tup, false);
985 clk_disable_unprepare(tup->uart_clk);
988 static int tegra_uart_hw_init(struct tegra_uart_port *tup)
996 tup->current_baud = 0;
998 clk_prepare_enable(tup->uart_clk);
1000 /* Reset the UART controller to clear all previous status.*/
1001 reset_control_assert(tup->rst);
1003 reset_control_deassert(tup->rst);
1005 tup->rx_in_progress = 0;
1006 tup->tx_in_progress = 0;
1009 * Set the trigger level
1013 * For receive, this will interrupt the CPU after that many number of
1014 * bytes are received, for the remaining bytes the receive timeout
1015 * interrupt is received. Rx high watermark is set to 4.
1017 * For transmit, if the trasnmit interrupt is enabled, this will
1018 * interrupt the CPU when the number of entries in the FIFO reaches the
1019 * low watermark. Tx low watermark is set to 16 bytes.
1023 * Set the Tx trigger to 16. This should match the DMA burst size that
1024 * programmed in the DMA registers.
1026 tup->fcr_shadow = UART_FCR_ENABLE_FIFO;
1028 if (tup->use_rx_pio) {
1029 tup->fcr_shadow |= UART_FCR_R_TRIG_11;
1031 if (tup->cdata->max_dma_burst_bytes == 8)
1032 tup->fcr_shadow |= UART_FCR_R_TRIG_10;
1034 tup->fcr_shadow |= UART_FCR_R_TRIG_01;
1037 tup->fcr_shadow |= TEGRA_UART_TX_TRIG_16B;
1038 tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
1040 /* Dummy read to ensure the write is posted */
1041 tegra_uart_read(tup, UART_SCR);
1043 if (tup->cdata->fifo_mode_enable_status) {
1044 ret = tegra_uart_wait_fifo_mode_enabled(tup);
1045 dev_err(tup->uport.dev, "FIFO mode not enabled\n");
1050 * For all tegra devices (up to t210), there is a hardware
1051 * issue that requires software to wait for 3 UART clock
1052 * periods after enabling the TX fifo, otherwise data could
1055 tegra_uart_wait_cycle_time(tup, 3);
1059 * Initialize the UART with default configuration
1060 * (115200, N, 8, 1) so that the receive DMA buffer may be
1063 ret = tegra_set_baudrate(tup, TEGRA_UART_DEFAULT_BAUD);
1065 dev_err(tup->uport.dev, "Failed to set baud rate\n");
1068 if (!tup->use_rx_pio) {
1069 tup->lcr_shadow = TEGRA_UART_DEFAULT_LSR;
1070 tup->fcr_shadow |= UART_FCR_DMA_SELECT;
1071 tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
1073 tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
1075 tup->rx_in_progress = 1;
1078 * Enable IE_RXS for the receive status interrupts like line errros.
1079 * Enable IE_RX_TIMEOUT to get the bytes which cannot be DMA'd.
1081 * EORD is different interrupt than RX_TIMEOUT - RX_TIMEOUT occurs when
1082 * the DATA is sitting in the FIFO and couldn't be transferred to the
1083 * DMA as the DMA size alignment (4 bytes) is not met. EORD will be
1084 * triggered when there is a pause of the incomming data stream for 4
1087 * For pauses in the data which is not aligned to 4 bytes, we get
1088 * both the EORD as well as RX_TIMEOUT - SW sees RX_TIMEOUT first
1091 tup->ier_shadow = UART_IER_RLSI | UART_IER_RTOIE | UART_IER_RDI;
1094 * If using DMA mode, enable EORD interrupt to notify about RX
1097 if (!tup->use_rx_pio)
1098 tup->ier_shadow |= TEGRA_UART_IER_EORD;
1100 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
1104 static void tegra_uart_dma_channel_free(struct tegra_uart_port *tup,
1107 if (dma_to_memory) {
1108 dmaengine_terminate_all(tup->rx_dma_chan);
1109 dma_release_channel(tup->rx_dma_chan);
1110 dma_free_coherent(tup->uport.dev, TEGRA_UART_RX_DMA_BUFFER_SIZE,
1111 tup->rx_dma_buf_virt, tup->rx_dma_buf_phys);
1112 tup->rx_dma_chan = NULL;
1113 tup->rx_dma_buf_phys = 0;
1114 tup->rx_dma_buf_virt = NULL;
1116 dmaengine_terminate_all(tup->tx_dma_chan);
1117 dma_release_channel(tup->tx_dma_chan);
1118 dma_unmap_single(tup->uport.dev, tup->tx_dma_buf_phys,
1119 UART_XMIT_SIZE, DMA_TO_DEVICE);
1120 tup->tx_dma_chan = NULL;
1121 tup->tx_dma_buf_phys = 0;
1122 tup->tx_dma_buf_virt = NULL;
1126 static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup,
1129 struct dma_chan *dma_chan;
1130 unsigned char *dma_buf;
1131 dma_addr_t dma_phys;
1133 struct dma_slave_config dma_sconfig;
1135 dma_chan = dma_request_chan(tup->uport.dev, dma_to_memory ? "rx" : "tx");
1136 if (IS_ERR(dma_chan)) {
1137 ret = PTR_ERR(dma_chan);
1138 dev_err(tup->uport.dev,
1139 "DMA channel alloc failed: %d\n", ret);
1143 if (dma_to_memory) {
1144 dma_buf = dma_alloc_coherent(tup->uport.dev,
1145 TEGRA_UART_RX_DMA_BUFFER_SIZE,
1146 &dma_phys, GFP_KERNEL);
1148 dev_err(tup->uport.dev,
1149 "Not able to allocate the dma buffer\n");
1150 dma_release_channel(dma_chan);
1153 dma_sync_single_for_device(tup->uport.dev, dma_phys,
1154 TEGRA_UART_RX_DMA_BUFFER_SIZE,
1156 dma_sconfig.src_addr = tup->uport.mapbase;
1157 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1158 dma_sconfig.src_maxburst = tup->cdata->max_dma_burst_bytes;
1159 tup->rx_dma_chan = dma_chan;
1160 tup->rx_dma_buf_virt = dma_buf;
1161 tup->rx_dma_buf_phys = dma_phys;
1163 dma_phys = dma_map_single(tup->uport.dev,
1164 tup->uport.state->xmit.buf, UART_XMIT_SIZE,
1166 if (dma_mapping_error(tup->uport.dev, dma_phys)) {
1167 dev_err(tup->uport.dev, "dma_map_single tx failed\n");
1168 dma_release_channel(dma_chan);
1171 dma_buf = tup->uport.state->xmit.buf;
1172 dma_sconfig.dst_addr = tup->uport.mapbase;
1173 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1174 dma_sconfig.dst_maxburst = 16;
1175 tup->tx_dma_chan = dma_chan;
1176 tup->tx_dma_buf_virt = dma_buf;
1177 tup->tx_dma_buf_phys = dma_phys;
1180 ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
1182 dev_err(tup->uport.dev,
1183 "Dma slave config failed, err = %d\n", ret);
1184 tegra_uart_dma_channel_free(tup, dma_to_memory);
1191 static int tegra_uart_startup(struct uart_port *u)
1193 struct tegra_uart_port *tup = to_tegra_uport(u);
1196 if (!tup->use_tx_pio) {
1197 ret = tegra_uart_dma_channel_allocate(tup, false);
1199 dev_err(u->dev, "Tx Dma allocation failed, err = %d\n",
1205 if (!tup->use_rx_pio) {
1206 ret = tegra_uart_dma_channel_allocate(tup, true);
1208 dev_err(u->dev, "Rx Dma allocation failed, err = %d\n",
1214 ret = tegra_uart_hw_init(tup);
1216 dev_err(u->dev, "Uart HW init failed, err = %d\n", ret);
1220 ret = request_irq(u->irq, tegra_uart_isr, 0,
1221 dev_name(u->dev), tup);
1223 dev_err(u->dev, "Failed to register ISR for IRQ %d\n", u->irq);
1229 if (!tup->use_rx_pio)
1230 tegra_uart_dma_channel_free(tup, true);
1232 if (!tup->use_tx_pio)
1233 tegra_uart_dma_channel_free(tup, false);
1238 * Flush any TX data submitted for DMA and PIO. Called when the
1239 * TX circular buffer is reset.
1241 static void tegra_uart_flush_buffer(struct uart_port *u)
1243 struct tegra_uart_port *tup = to_tegra_uport(u);
1246 if (tup->tx_dma_chan)
1247 dmaengine_terminate_all(tup->tx_dma_chan);
1250 static void tegra_uart_shutdown(struct uart_port *u)
1252 struct tegra_uart_port *tup = to_tegra_uport(u);
1254 tegra_uart_hw_deinit(tup);
1255 free_irq(u->irq, tup);
1258 static void tegra_uart_enable_ms(struct uart_port *u)
1260 struct tegra_uart_port *tup = to_tegra_uport(u);
1262 if (tup->enable_modem_interrupt) {
1263 tup->ier_shadow |= UART_IER_MSI;
1264 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
1268 static void tegra_uart_set_termios(struct uart_port *u,
1269 struct ktermios *termios, struct ktermios *oldtermios)
1271 struct tegra_uart_port *tup = to_tegra_uport(u);
1273 unsigned long flags;
1276 struct clk *parent_clk = clk_get_parent(tup->uart_clk);
1277 unsigned long parent_clk_rate = clk_get_rate(parent_clk);
1278 int max_divider = (tup->cdata->support_clk_src_div) ? 0x7FFF : 0xFFFF;
1282 spin_lock_irqsave(&u->lock, flags);
1284 /* Changing configuration, it is safe to stop any rx now */
1285 if (tup->rts_active)
1286 set_rts(tup, false);
1288 /* Clear all interrupts as configuration is going to be changed */
1289 tegra_uart_write(tup, tup->ier_shadow | UART_IER_RDI, UART_IER);
1290 tegra_uart_read(tup, UART_IER);
1291 tegra_uart_write(tup, 0, UART_IER);
1292 tegra_uart_read(tup, UART_IER);
1295 lcr = tup->lcr_shadow;
1296 lcr &= ~UART_LCR_PARITY;
1298 /* CMSPAR isn't supported by this driver */
1299 termios->c_cflag &= ~CMSPAR;
1301 if ((termios->c_cflag & PARENB) == PARENB) {
1303 if (termios->c_cflag & PARODD) {
1304 lcr |= UART_LCR_PARITY;
1305 lcr &= ~UART_LCR_EPAR;
1306 lcr &= ~UART_LCR_SPAR;
1308 lcr |= UART_LCR_PARITY;
1309 lcr |= UART_LCR_EPAR;
1310 lcr &= ~UART_LCR_SPAR;
1314 lcr &= ~UART_LCR_WLEN8;
1315 switch (termios->c_cflag & CSIZE) {
1317 lcr |= UART_LCR_WLEN5;
1321 lcr |= UART_LCR_WLEN6;
1325 lcr |= UART_LCR_WLEN7;
1329 lcr |= UART_LCR_WLEN8;
1335 if (termios->c_cflag & CSTOPB) {
1336 lcr |= UART_LCR_STOP;
1339 lcr &= ~UART_LCR_STOP;
1343 tegra_uart_write(tup, lcr, UART_LCR);
1344 tup->lcr_shadow = lcr;
1345 tup->symb_bit = symb_bit;
1348 baud = uart_get_baud_rate(u, termios, oldtermios,
1349 parent_clk_rate/max_divider,
1350 parent_clk_rate/16);
1351 spin_unlock_irqrestore(&u->lock, flags);
1352 ret = tegra_set_baudrate(tup, baud);
1354 dev_err(tup->uport.dev, "Failed to set baud rate\n");
1357 if (tty_termios_baud_rate(termios))
1358 tty_termios_encode_baud_rate(termios, baud, baud);
1359 spin_lock_irqsave(&u->lock, flags);
1362 if (termios->c_cflag & CRTSCTS) {
1363 tup->mcr_shadow |= TEGRA_UART_MCR_CTS_EN;
1364 tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
1365 tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
1366 /* if top layer has asked to set rts active then do so here */
1367 if (tup->rts_active)
1370 tup->mcr_shadow &= ~TEGRA_UART_MCR_CTS_EN;
1371 tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
1372 tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
1375 /* update the port timeout based on new settings */
1376 uart_update_timeout(u, termios->c_cflag, baud);
1378 /* Make sure all writes have completed */
1379 tegra_uart_read(tup, UART_IER);
1381 /* Re-enable interrupt */
1382 tegra_uart_write(tup, tup->ier_shadow, UART_IER);
1383 tegra_uart_read(tup, UART_IER);
1385 tup->uport.ignore_status_mask = 0;
1386 /* Ignore all characters if CREAD is not set */
1387 if ((termios->c_cflag & CREAD) == 0)
1388 tup->uport.ignore_status_mask |= UART_LSR_DR;
1389 if (termios->c_iflag & IGNBRK)
1390 tup->uport.ignore_status_mask |= UART_LSR_BI;
1392 spin_unlock_irqrestore(&u->lock, flags);
1395 static const char *tegra_uart_type(struct uart_port *u)
1397 return TEGRA_UART_TYPE;
1400 static const struct uart_ops tegra_uart_ops = {
1401 .tx_empty = tegra_uart_tx_empty,
1402 .set_mctrl = tegra_uart_set_mctrl,
1403 .get_mctrl = tegra_uart_get_mctrl,
1404 .stop_tx = tegra_uart_stop_tx,
1405 .start_tx = tegra_uart_start_tx,
1406 .stop_rx = tegra_uart_stop_rx,
1407 .flush_buffer = tegra_uart_flush_buffer,
1408 .enable_ms = tegra_uart_enable_ms,
1409 .break_ctl = tegra_uart_break_ctl,
1410 .startup = tegra_uart_startup,
1411 .shutdown = tegra_uart_shutdown,
1412 .set_termios = tegra_uart_set_termios,
1413 .type = tegra_uart_type,
1414 .request_port = tegra_uart_request_port,
1415 .release_port = tegra_uart_release_port,
1418 static struct uart_driver tegra_uart_driver = {
1419 .owner = THIS_MODULE,
1420 .driver_name = "tegra_hsuart",
1421 .dev_name = "ttyTHS",
1423 .nr = TEGRA_UART_MAXIMUM,
1426 static int tegra_uart_parse_dt(struct platform_device *pdev,
1427 struct tegra_uart_port *tup)
1429 struct device_node *np = pdev->dev.of_node;
1437 port = of_alias_get_id(np, "serial");
1439 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", port);
1442 tup->uport.line = port;
1444 tup->enable_modem_interrupt = of_property_read_bool(np,
1445 "nvidia,enable-modem-interrupt");
1447 index = of_property_match_string(np, "dma-names", "rx");
1449 tup->use_rx_pio = true;
1450 dev_info(&pdev->dev, "RX in PIO mode\n");
1452 index = of_property_match_string(np, "dma-names", "tx");
1454 tup->use_tx_pio = true;
1455 dev_info(&pdev->dev, "TX in PIO mode\n");
1458 n_entries = of_property_count_u32_elems(np, "nvidia,adjust-baud-rates");
1459 if (n_entries > 0) {
1460 tup->n_adjustable_baud_rates = n_entries / 3;
1461 tup->baud_tolerance =
1462 devm_kzalloc(&pdev->dev, (tup->n_adjustable_baud_rates) *
1463 sizeof(*tup->baud_tolerance), GFP_KERNEL);
1464 if (!tup->baud_tolerance)
1466 for (count = 0, index = 0; count < n_entries; count += 3,
1469 of_property_read_u32_index(np,
1470 "nvidia,adjust-baud-rates",
1473 tup->baud_tolerance[index].lower_range_baud =
1476 of_property_read_u32_index(np,
1477 "nvidia,adjust-baud-rates",
1480 tup->baud_tolerance[index].upper_range_baud =
1483 of_property_read_u32_index(np,
1484 "nvidia,adjust-baud-rates",
1487 tup->baud_tolerance[index].tolerance =
1491 tup->n_adjustable_baud_rates = 0;
1497 static struct tegra_uart_chip_data tegra20_uart_chip_data = {
1498 .tx_fifo_full_status = false,
1499 .allow_txfifo_reset_fifo_mode = true,
1500 .support_clk_src_div = false,
1501 .fifo_mode_enable_status = false,
1503 .max_dma_burst_bytes = 4,
1504 .error_tolerance_low_range = 0,
1505 .error_tolerance_high_range = 4,
1508 static struct tegra_uart_chip_data tegra30_uart_chip_data = {
1509 .tx_fifo_full_status = true,
1510 .allow_txfifo_reset_fifo_mode = false,
1511 .support_clk_src_div = true,
1512 .fifo_mode_enable_status = false,
1514 .max_dma_burst_bytes = 4,
1515 .error_tolerance_low_range = 0,
1516 .error_tolerance_high_range = 4,
1519 static struct tegra_uart_chip_data tegra186_uart_chip_data = {
1520 .tx_fifo_full_status = true,
1521 .allow_txfifo_reset_fifo_mode = false,
1522 .support_clk_src_div = true,
1523 .fifo_mode_enable_status = true,
1525 .max_dma_burst_bytes = 8,
1526 .error_tolerance_low_range = 0,
1527 .error_tolerance_high_range = 4,
1530 static struct tegra_uart_chip_data tegra194_uart_chip_data = {
1531 .tx_fifo_full_status = true,
1532 .allow_txfifo_reset_fifo_mode = false,
1533 .support_clk_src_div = true,
1534 .fifo_mode_enable_status = true,
1536 .max_dma_burst_bytes = 8,
1537 .error_tolerance_low_range = -2,
1538 .error_tolerance_high_range = 2,
1541 static const struct of_device_id tegra_uart_of_match[] = {
1543 .compatible = "nvidia,tegra30-hsuart",
1544 .data = &tegra30_uart_chip_data,
1546 .compatible = "nvidia,tegra20-hsuart",
1547 .data = &tegra20_uart_chip_data,
1549 .compatible = "nvidia,tegra186-hsuart",
1550 .data = &tegra186_uart_chip_data,
1552 .compatible = "nvidia,tegra194-hsuart",
1553 .data = &tegra194_uart_chip_data,
1557 MODULE_DEVICE_TABLE(of, tegra_uart_of_match);
1559 static int tegra_uart_probe(struct platform_device *pdev)
1561 struct tegra_uart_port *tup;
1562 struct uart_port *u;
1563 struct resource *resource;
1565 const struct tegra_uart_chip_data *cdata;
1566 const struct of_device_id *match;
1568 match = of_match_device(tegra_uart_of_match, &pdev->dev);
1570 dev_err(&pdev->dev, "Error: No device match found\n");
1573 cdata = match->data;
1575 tup = devm_kzalloc(&pdev->dev, sizeof(*tup), GFP_KERNEL);
1577 dev_err(&pdev->dev, "Failed to allocate memory for tup\n");
1581 ret = tegra_uart_parse_dt(pdev, tup);
1586 u->dev = &pdev->dev;
1587 u->ops = &tegra_uart_ops;
1588 u->type = PORT_TEGRA;
1592 platform_set_drvdata(pdev, tup);
1593 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1595 dev_err(&pdev->dev, "No IO memory resource\n");
1599 u->mapbase = resource->start;
1600 u->membase = devm_ioremap_resource(&pdev->dev, resource);
1601 if (IS_ERR(u->membase))
1602 return PTR_ERR(u->membase);
1604 tup->uart_clk = devm_clk_get(&pdev->dev, NULL);
1605 if (IS_ERR(tup->uart_clk)) {
1606 dev_err(&pdev->dev, "Couldn't get the clock\n");
1607 return PTR_ERR(tup->uart_clk);
1610 tup->rst = devm_reset_control_get_exclusive(&pdev->dev, "serial");
1611 if (IS_ERR(tup->rst)) {
1612 dev_err(&pdev->dev, "Couldn't get the reset\n");
1613 return PTR_ERR(tup->rst);
1616 u->iotype = UPIO_MEM32;
1617 ret = platform_get_irq(pdev, 0);
1622 ret = uart_add_one_port(&tegra_uart_driver, u);
1624 dev_err(&pdev->dev, "Failed to add uart port, err %d\n", ret);
1630 static int tegra_uart_remove(struct platform_device *pdev)
1632 struct tegra_uart_port *tup = platform_get_drvdata(pdev);
1633 struct uart_port *u = &tup->uport;
1635 uart_remove_one_port(&tegra_uart_driver, u);
1639 #ifdef CONFIG_PM_SLEEP
1640 static int tegra_uart_suspend(struct device *dev)
1642 struct tegra_uart_port *tup = dev_get_drvdata(dev);
1643 struct uart_port *u = &tup->uport;
1645 return uart_suspend_port(&tegra_uart_driver, u);
1648 static int tegra_uart_resume(struct device *dev)
1650 struct tegra_uart_port *tup = dev_get_drvdata(dev);
1651 struct uart_port *u = &tup->uport;
1653 return uart_resume_port(&tegra_uart_driver, u);
1657 static const struct dev_pm_ops tegra_uart_pm_ops = {
1658 SET_SYSTEM_SLEEP_PM_OPS(tegra_uart_suspend, tegra_uart_resume)
1661 static struct platform_driver tegra_uart_platform_driver = {
1662 .probe = tegra_uart_probe,
1663 .remove = tegra_uart_remove,
1665 .name = "serial-tegra",
1666 .of_match_table = tegra_uart_of_match,
1667 .pm = &tegra_uart_pm_ops,
1671 static int __init tegra_uart_init(void)
1674 struct device_node *node;
1675 const struct of_device_id *match = NULL;
1676 const struct tegra_uart_chip_data *cdata = NULL;
1678 node = of_find_matching_node(NULL, tegra_uart_of_match);
1680 match = of_match_node(tegra_uart_of_match, node);
1682 cdata = match->data;
1684 tegra_uart_driver.nr = cdata->uart_max_port;
1686 ret = uart_register_driver(&tegra_uart_driver);
1688 pr_err("Could not register %s driver\n",
1689 tegra_uart_driver.driver_name);
1693 ret = platform_driver_register(&tegra_uart_platform_driver);
1695 pr_err("Uart platform driver register failed, e = %d\n", ret);
1696 uart_unregister_driver(&tegra_uart_driver);
1702 static void __exit tegra_uart_exit(void)
1704 pr_info("Unloading tegra uart driver\n");
1705 platform_driver_unregister(&tegra_uart_platform_driver);
1706 uart_unregister_driver(&tegra_uart_driver);
1709 module_init(tegra_uart_init);
1710 module_exit(tegra_uart_exit);
1712 MODULE_ALIAS("platform:serial-tegra");
1713 MODULE_DESCRIPTION("High speed UART driver for tegra chipset");
1714 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1715 MODULE_LICENSE("GPL v2");