1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver for CSR SiRFprimaII onboard UARTs.
4 *
5 * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
6 */
7
8#include <linux/module.h>
9#include <linux/ioport.h>
10#include <linux/platform_device.h>
11#include <linux/init.h>
12#include <linux/sysrq.h>
13#include <linux/console.h>
14#include <linux/tty.h>
15#include <linux/tty_flip.h>
16#include <linux/serial_core.h>
17#include <linux/serial.h>
18#include <linux/clk.h>
19#include <linux/of.h>
20#include <linux/slab.h>
21#include <linux/io.h>
22#include <linux/of_gpio.h>
23#include <linux/dmaengine.h>
24#include <linux/dma-direction.h>
25#include <linux/dma-mapping.h>
26#include <asm/irq.h>
27#include <asm/mach/irq.h>
28
29#include "sirfsoc_uart.h"
30
31static unsigned int
32sirfsoc_uart_pio_tx_chars(struct sirfsoc_uart_port *sirfport, int count);
33static unsigned int
34sirfsoc_uart_pio_rx_chars(struct uart_port *port, unsigned int max_rx_count);
35static struct uart_driver sirfsoc_uart_drv;
36
37static void sirfsoc_uart_tx_dma_complete_callback(void *param);
38static const struct sirfsoc_baudrate_to_regv baudrate_to_regv[] = {
39	{4000000, 2359296},
40	{3500000, 1310721},
41	{3000000, 1572865},
42	{2500000, 1245186},
43	{2000000, 1572866},
44	{1500000, 1245188},
45	{1152000, 1638404},
46	{1000000, 1572869},
47	{921600, 1114120},
48	{576000, 1245196},
49	{500000, 1245198},
50	{460800, 1572876},
51	{230400, 1310750},
52	{115200, 1310781},
53	{57600, 1310843},
54	{38400, 1114328},
55	{19200, 1114545},
56	{9600, 1114979},
57};
58
59static struct sirfsoc_uart_port *sirf_ports[SIRFSOC_UART_NR];
60
61static inline struct sirfsoc_uart_port *to_sirfport(struct uart_port *port)
62{
63	return container_of(port, struct sirfsoc_uart_port, port);
64}
65
66static inline unsigned int sirfsoc_uart_tx_empty(struct uart_port *port)
67{
68	unsigned long reg;
69	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
70	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
71	struct sirfsoc_fifo_status *ufifo_st = &sirfport->uart_reg->fifo_status;
72	reg = rd_regl(port, ureg->sirfsoc_tx_fifo_status);
73	return (reg & ufifo_st->ff_empty(port)) ? TIOCSER_TEMT : 0;
74}
75
76static unsigned int sirfsoc_uart_get_mctrl(struct uart_port *port)
77{
78	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
79	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
80	if (!sirfport->hw_flow_ctrl || !sirfport->ms_enabled)
81		goto cts_asserted;
82	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
83		if (!(rd_regl(port, ureg->sirfsoc_afc_ctrl) &
84						SIRFUART_AFC_CTS_STATUS))
85			goto cts_asserted;
86		else
87			goto cts_deasserted;
88	} else {
89		if (!gpio_get_value(sirfport->cts_gpio))
90			goto cts_asserted;
91		else
92			goto cts_deasserted;
93	}
94cts_deasserted:
95	return TIOCM_CAR | TIOCM_DSR;
96cts_asserted:
97	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
98}
99
100static void sirfsoc_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
101{
102	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
103	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
104	unsigned int assert = mctrl & TIOCM_RTS;
105	unsigned int val = assert ? SIRFUART_AFC_CTRL_RX_THD : 0x0;
106	unsigned int current_val;
107
108	if (mctrl & TIOCM_LOOP) {
109		if (sirfport->uart_reg->uart_type == SIRF_REAL_UART)
110			wr_regl(port, ureg->sirfsoc_line_ctrl,
111				rd_regl(port, ureg->sirfsoc_line_ctrl) |
112				SIRFUART_LOOP_BACK);
113		else
114			wr_regl(port, ureg->sirfsoc_mode1,
115				rd_regl(port, ureg->sirfsoc_mode1) |
116				SIRFSOC_USP_LOOP_BACK_CTRL);
117	} else {
118		if (sirfport->uart_reg->uart_type == SIRF_REAL_UART)
119			wr_regl(port, ureg->sirfsoc_line_ctrl,
120				rd_regl(port, ureg->sirfsoc_line_ctrl) &
121				~SIRFUART_LOOP_BACK);
122		else
123			wr_regl(port, ureg->sirfsoc_mode1,
124				rd_regl(port, ureg->sirfsoc_mode1) &
125				~SIRFSOC_USP_LOOP_BACK_CTRL);
126	}
127
128	if (!sirfport->hw_flow_ctrl || !sirfport->ms_enabled)
129		return;
130	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
131		current_val = rd_regl(port, ureg->sirfsoc_afc_ctrl) & ~0xFF;
132		val |= current_val;
133		wr_regl(port, ureg->sirfsoc_afc_ctrl, val);
134	} else {
135		if (!val)
136			gpio_set_value(sirfport->rts_gpio, 1);
137		else
138			gpio_set_value(sirfport->rts_gpio, 0);
139	}
140}
141
142static void sirfsoc_uart_stop_tx(struct uart_port *port)
143{
144	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
145	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
146	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
147
148	if (sirfport->tx_dma_chan) {
149		if (sirfport->tx_dma_state == TX_DMA_RUNNING) {
150			dmaengine_pause(sirfport->tx_dma_chan);
151			sirfport->tx_dma_state = TX_DMA_PAUSE;
152		} else {
153			if (!sirfport->is_atlas7)
154				wr_regl(port, ureg->sirfsoc_int_en_reg,
155				rd_regl(port, ureg->sirfsoc_int_en_reg) &
156				~uint_en->sirfsoc_txfifo_empty_en);
157			else
158				wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
159				uint_en->sirfsoc_txfifo_empty_en);
160		}
161	} else {
162		if (sirfport->uart_reg->uart_type == SIRF_USP_UART)
163			wr_regl(port, ureg->sirfsoc_tx_rx_en, rd_regl(port,
164				ureg->sirfsoc_tx_rx_en) & ~SIRFUART_TX_EN);
165		if (!sirfport->is_atlas7)
166			wr_regl(port, ureg->sirfsoc_int_en_reg,
167				rd_regl(port, ureg->sirfsoc_int_en_reg) &
168				~uint_en->sirfsoc_txfifo_empty_en);
169		else
170			wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
171				uint_en->sirfsoc_txfifo_empty_en);
172	}
173}
174
175static void sirfsoc_uart_tx_with_dma(struct sirfsoc_uart_port *sirfport)
176{
177	struct uart_port *port = &sirfport->port;
178	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
179	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
180	struct circ_buf *xmit = &port->state->xmit;
181	unsigned long tran_size;
182	unsigned long tran_start;
183	unsigned long pio_tx_size;
184
185	tran_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
186	tran_start = (unsigned long)(xmit->buf + xmit->tail);
187	if (uart_circ_empty(xmit) || uart_tx_stopped(port) ||
188			!tran_size)
189		return;
190	if (sirfport->tx_dma_state == TX_DMA_PAUSE) {
191		dmaengine_resume(sirfport->tx_dma_chan);
192		return;
193	}
194	if (sirfport->tx_dma_state == TX_DMA_RUNNING)
195		return;
196	if (!sirfport->is_atlas7)
197		wr_regl(port, ureg->sirfsoc_int_en_reg,
198				rd_regl(port, ureg->sirfsoc_int_en_reg)&
199				~(uint_en->sirfsoc_txfifo_empty_en));
200	else
201		wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
202				uint_en->sirfsoc_txfifo_empty_en);
203	/*
204	 * DMA requires buffer address and buffer length are both aligned with
205	 * 4 bytes, so we use PIO for
206	 * 1. if address is not aligned with 4bytes, use PIO for the first 1~3
207	 * bytes, and move to DMA for the left part aligned with 4bytes
208	 * 2. if buffer length is not aligned with 4bytes, use DMA for aligned
209	 * part first, move to PIO for the left 1~3 bytes
210	 */
211	if (tran_size < 4 || BYTES_TO_ALIGN(tran_start)) {
212		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_STOP);
213		wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl,
214			rd_regl(port, ureg->sirfsoc_tx_dma_io_ctrl)|
215			SIRFUART_IO_MODE);
216		if (BYTES_TO_ALIGN(tran_start)) {
217			pio_tx_size = sirfsoc_uart_pio_tx_chars(sirfport,
218				BYTES_TO_ALIGN(tran_start));
219			tran_size -= pio_tx_size;
220		}
221		if (tran_size < 4)
222			sirfsoc_uart_pio_tx_chars(sirfport, tran_size);
223		if (!sirfport->is_atlas7)
224			wr_regl(port, ureg->sirfsoc_int_en_reg,
225				rd_regl(port, ureg->sirfsoc_int_en_reg)|
226				uint_en->sirfsoc_txfifo_empty_en);
227		else
228			wr_regl(port, ureg->sirfsoc_int_en_reg,
229				uint_en->sirfsoc_txfifo_empty_en);
230		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_START);
231	} else {
232		/* tx transfer mode switch into dma mode */
233		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_STOP);
234		wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl,
235			rd_regl(port, ureg->sirfsoc_tx_dma_io_ctrl)&
236			~SIRFUART_IO_MODE);
237		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_START);
238		tran_size &= ~(0x3);
239
240		sirfport->tx_dma_addr = dma_map_single(port->dev,
241			xmit->buf + xmit->tail,
242			tran_size, DMA_TO_DEVICE);
243		sirfport->tx_dma_desc = dmaengine_prep_slave_single(
244			sirfport->tx_dma_chan, sirfport->tx_dma_addr,
245			tran_size, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
246		if (!sirfport->tx_dma_desc) {
247			dev_err(port->dev, "DMA prep slave single fail\n");
248			return;
249		}
250		sirfport->tx_dma_desc->callback =
251			sirfsoc_uart_tx_dma_complete_callback;
252		sirfport->tx_dma_desc->callback_param = (void *)sirfport;
253		sirfport->transfer_size = tran_size;
254
255		dmaengine_submit(sirfport->tx_dma_desc);
256		dma_async_issue_pending(sirfport->tx_dma_chan);
257		sirfport->tx_dma_state = TX_DMA_RUNNING;
258	}
259}
260
261static void sirfsoc_uart_start_tx(struct uart_port *port)
262{
263	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
264	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
265	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
266	if (sirfport->tx_dma_chan)
267		sirfsoc_uart_tx_with_dma(sirfport);
268	else {
269		if (sirfport->uart_reg->uart_type == SIRF_USP_UART)
270			wr_regl(port, ureg->sirfsoc_tx_rx_en, rd_regl(port,
271				ureg->sirfsoc_tx_rx_en) | SIRFUART_TX_EN);
272		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_STOP);
273		sirfsoc_uart_pio_tx_chars(sirfport, port->fifosize);
274		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_START);
275		if (!sirfport->is_atlas7)
276			wr_regl(port, ureg->sirfsoc_int_en_reg,
277					rd_regl(port, ureg->sirfsoc_int_en_reg)|
278					uint_en->sirfsoc_txfifo_empty_en);
279		else
280			wr_regl(port, ureg->sirfsoc_int_en_reg,
281					uint_en->sirfsoc_txfifo_empty_en);
282	}
283}
284
285static void sirfsoc_uart_stop_rx(struct uart_port *port)
286{
287	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
288	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
289	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
290
291	wr_regl(port, ureg->sirfsoc_rx_fifo_op, 0);
292	if (sirfport->rx_dma_chan) {
293		if (!sirfport->is_atlas7)
294			wr_regl(port, ureg->sirfsoc_int_en_reg,
295				rd_regl(port, ureg->sirfsoc_int_en_reg) &
296				~(SIRFUART_RX_DMA_INT_EN(uint_en,
297				sirfport->uart_reg->uart_type) |
298				uint_en->sirfsoc_rx_done_en));
299		else
300			wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
301				SIRFUART_RX_DMA_INT_EN(uint_en,
302				sirfport->uart_reg->uart_type)|
303				uint_en->sirfsoc_rx_done_en);
304		dmaengine_terminate_all(sirfport->rx_dma_chan);
305	} else {
306		if (!sirfport->is_atlas7)
307			wr_regl(port, ureg->sirfsoc_int_en_reg,
308				rd_regl(port, ureg->sirfsoc_int_en_reg)&
309				~(SIRFUART_RX_IO_INT_EN(uint_en,
310				sirfport->uart_reg->uart_type)));
311		else
312			wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
313				SIRFUART_RX_IO_INT_EN(uint_en,
314				sirfport->uart_reg->uart_type));
315	}
316}
317
318static void sirfsoc_uart_disable_ms(struct uart_port *port)
319{
320	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
321	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
322	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
323
324	if (!sirfport->hw_flow_ctrl)
325		return;
326	sirfport->ms_enabled = false;
327	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
328		wr_regl(port, ureg->sirfsoc_afc_ctrl,
329				rd_regl(port, ureg->sirfsoc_afc_ctrl) & ~0x3FF);
330		if (!sirfport->is_atlas7)
331			wr_regl(port, ureg->sirfsoc_int_en_reg,
332					rd_regl(port, ureg->sirfsoc_int_en_reg)&
333					~uint_en->sirfsoc_cts_en);
334		else
335			wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
336					uint_en->sirfsoc_cts_en);
337	} else
338		disable_irq(gpio_to_irq(sirfport->cts_gpio));
339}
340
341static irqreturn_t sirfsoc_uart_usp_cts_handler(int irq, void *dev_id)
342{
343	struct sirfsoc_uart_port *sirfport = (struct sirfsoc_uart_port *)dev_id;
344	struct uart_port *port = &sirfport->port;
345	spin_lock(&port->lock);
346	if (gpio_is_valid(sirfport->cts_gpio) && sirfport->ms_enabled)
347		uart_handle_cts_change(port,
348				!gpio_get_value(sirfport->cts_gpio));
349	spin_unlock(&port->lock);
350	return IRQ_HANDLED;
351}
352
353static void sirfsoc_uart_enable_ms(struct uart_port *port)
354{
355	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
356	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
357	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
358
359	if (!sirfport->hw_flow_ctrl)
360		return;
361	sirfport->ms_enabled = true;
362	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
363		wr_regl(port, ureg->sirfsoc_afc_ctrl,
364				rd_regl(port, ureg->sirfsoc_afc_ctrl) |
365				SIRFUART_AFC_TX_EN | SIRFUART_AFC_RX_EN |
366				SIRFUART_AFC_CTRL_RX_THD);
367		if (!sirfport->is_atlas7)
368			wr_regl(port, ureg->sirfsoc_int_en_reg,
369					rd_regl(port, ureg->sirfsoc_int_en_reg)
370					| uint_en->sirfsoc_cts_en);
371		else
372			wr_regl(port, ureg->sirfsoc_int_en_reg,
373					uint_en->sirfsoc_cts_en);
374	} else
375		enable_irq(gpio_to_irq(sirfport->cts_gpio));
376}
377
378static void sirfsoc_uart_break_ctl(struct uart_port *port, int break_state)
379{
380	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
381	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
382	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
383		unsigned long ulcon = rd_regl(port, ureg->sirfsoc_line_ctrl);
384		if (break_state)
385			ulcon |= SIRFUART_SET_BREAK;
386		else
387			ulcon &= ~SIRFUART_SET_BREAK;
388		wr_regl(port, ureg->sirfsoc_line_ctrl, ulcon);
389	}
390}
391
392static unsigned int
393sirfsoc_uart_pio_rx_chars(struct uart_port *port, unsigned int max_rx_count)
394{
395	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
396	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
397	struct sirfsoc_fifo_status *ufifo_st = &sirfport->uart_reg->fifo_status;
398	unsigned int ch, rx_count = 0;
399	struct tty_struct *tty;
400	tty = tty_port_tty_get(&port->state->port);
401	if (!tty)
402		return -ENODEV;
403	while (!(rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
404					ufifo_st->ff_empty(port))) {
405		ch = rd_regl(port, ureg->sirfsoc_rx_fifo_data) |
406			SIRFUART_DUMMY_READ;
407		if (unlikely(uart_handle_sysrq_char(port, ch)))
408			continue;
409		uart_insert_char(port, 0, 0, ch, TTY_NORMAL);
410		rx_count++;
411		if (rx_count >= max_rx_count)
412			break;
413	}
414
415	port->icount.rx += rx_count;
416
417	return rx_count;
418}
419
420static unsigned int
421sirfsoc_uart_pio_tx_chars(struct sirfsoc_uart_port *sirfport, int count)
422{
423	struct uart_port *port = &sirfport->port;
424	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
425	struct sirfsoc_fifo_status *ufifo_st = &sirfport->uart_reg->fifo_status;
426	struct circ_buf *xmit = &port->state->xmit;
427	unsigned int num_tx = 0;
428	while (!uart_circ_empty(xmit) &&
429		!(rd_regl(port, ureg->sirfsoc_tx_fifo_status) &
430					ufifo_st->ff_full(port)) &&
431		count--) {
432		wr_regl(port, ureg->sirfsoc_tx_fifo_data,
433				xmit->buf[xmit->tail]);
434		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
435		port->icount.tx++;
436		num_tx++;
437	}
438	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
439		uart_write_wakeup(port);
440	return num_tx;
441}
442
443static void sirfsoc_uart_tx_dma_complete_callback(void *param)
444{
445	struct sirfsoc_uart_port *sirfport = (struct sirfsoc_uart_port *)param;
446	struct uart_port *port = &sirfport->port;
447	struct circ_buf *xmit = &port->state->xmit;
448	unsigned long flags;
449
450	spin_lock_irqsave(&port->lock, flags);
451	xmit->tail = (xmit->tail + sirfport->transfer_size) &
452				(UART_XMIT_SIZE - 1);
453	port->icount.tx += sirfport->transfer_size;
454	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
455		uart_write_wakeup(port);
456	if (sirfport->tx_dma_addr)
457		dma_unmap_single(port->dev, sirfport->tx_dma_addr,
458				sirfport->transfer_size, DMA_TO_DEVICE);
459	sirfport->tx_dma_state = TX_DMA_IDLE;
460	sirfsoc_uart_tx_with_dma(sirfport);
461	spin_unlock_irqrestore(&port->lock, flags);
462}
463
464static irqreturn_t sirfsoc_uart_isr(int irq, void *dev_id)
465{
466	unsigned long intr_status;
467	unsigned long cts_status;
468	unsigned long flag = TTY_NORMAL;
469	struct sirfsoc_uart_port *sirfport = (struct sirfsoc_uart_port *)dev_id;
470	struct uart_port *port = &sirfport->port;
471	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
472	struct sirfsoc_fifo_status *ufifo_st = &sirfport->uart_reg->fifo_status;
473	struct sirfsoc_int_status *uint_st = &sirfport->uart_reg->uart_int_st;
474	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
475	struct uart_state *state = port->state;
476	struct circ_buf *xmit = &port->state->xmit;
477	spin_lock(&port->lock);
478	intr_status = rd_regl(port, ureg->sirfsoc_int_st_reg);
479	wr_regl(port, ureg->sirfsoc_int_st_reg, intr_status);
480	intr_status &= rd_regl(port, ureg->sirfsoc_int_en_reg);
481	if (unlikely(intr_status & (SIRFUART_ERR_INT_STAT(uint_st,
482				sirfport->uart_reg->uart_type)))) {
483		if (intr_status & uint_st->sirfsoc_rxd_brk) {
484			port->icount.brk++;
485			if (uart_handle_break(port))
486				goto recv_char;
487		}
488		if (intr_status & uint_st->sirfsoc_rx_oflow) {
489			port->icount.overrun++;
490			flag = TTY_OVERRUN;
491		}
492		if (intr_status & uint_st->sirfsoc_frm_err) {
493			port->icount.frame++;
494			flag = TTY_FRAME;
495		}
496		if (intr_status & uint_st->sirfsoc_parity_err) {
497			port->icount.parity++;
498			flag = TTY_PARITY;
499		}
500		wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_RESET);
501		wr_regl(port, ureg->sirfsoc_rx_fifo_op, 0);
502		wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_START);
503		intr_status &= port->read_status_mask;
504		uart_insert_char(port, intr_status,
505					uint_en->sirfsoc_rx_oflow_en, 0, flag);
506	}
507recv_char:
508	if ((sirfport->uart_reg->uart_type == SIRF_REAL_UART) &&
509			(intr_status & SIRFUART_CTS_INT_ST(uint_st)) &&
510			!sirfport->tx_dma_state) {
511		cts_status = rd_regl(port, ureg->sirfsoc_afc_ctrl) &
512					SIRFUART_AFC_CTS_STATUS;
513		if (cts_status != 0)
514			cts_status = 0;
515		else
516			cts_status = 1;
517		uart_handle_cts_change(port, cts_status);
518		wake_up_interruptible(&state->port.delta_msr_wait);
519	}
520	if (!sirfport->rx_dma_chan &&
521		(intr_status & SIRFUART_RX_IO_INT_ST(uint_st))) {
522		/*
523		 * chip will trigger continuous RX_TIMEOUT interrupt
524		 * in RXFIFO empty and not trigger if RXFIFO recevice
525		 * data in limit time, original method use RX_TIMEOUT
526		 * will trigger lots of useless interrupt in RXFIFO
527		 * empty.RXFIFO received one byte will trigger RX_DONE
528		 * interrupt.use RX_DONE to wait for data received
529		 * into RXFIFO, use RX_THD/RX_FULL for lots data receive
530		 * and use RX_TIMEOUT for the last left data.
531		 */
532		if (intr_status & uint_st->sirfsoc_rx_done) {
533			if (!sirfport->is_atlas7) {
534				wr_regl(port, ureg->sirfsoc_int_en_reg,
535					rd_regl(port, ureg->sirfsoc_int_en_reg)
536					& ~(uint_en->sirfsoc_rx_done_en));
537				wr_regl(port, ureg->sirfsoc_int_en_reg,
538				rd_regl(port, ureg->sirfsoc_int_en_reg)
539				| (uint_en->sirfsoc_rx_timeout_en));
540			} else {
541				wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
542					uint_en->sirfsoc_rx_done_en);
543				wr_regl(port, ureg->sirfsoc_int_en_reg,
544					uint_en->sirfsoc_rx_timeout_en);
545			}
546		} else {
547			if (intr_status & uint_st->sirfsoc_rx_timeout) {
548				if (!sirfport->is_atlas7) {
549					wr_regl(port, ureg->sirfsoc_int_en_reg,
550					rd_regl(port, ureg->sirfsoc_int_en_reg)
551					& ~(uint_en->sirfsoc_rx_timeout_en));
552					wr_regl(port, ureg->sirfsoc_int_en_reg,
553					rd_regl(port, ureg->sirfsoc_int_en_reg)
554					| (uint_en->sirfsoc_rx_done_en));
555				} else {
556					wr_regl(port,
557						ureg->sirfsoc_int_en_clr_reg,
558						uint_en->sirfsoc_rx_timeout_en);
559					wr_regl(port, ureg->sirfsoc_int_en_reg,
560						uint_en->sirfsoc_rx_done_en);
561				}
562			}
563			sirfsoc_uart_pio_rx_chars(port, port->fifosize);
564		}
565	}
566	spin_unlock(&port->lock);
567	tty_flip_buffer_push(&state->port);
568	spin_lock(&port->lock);
569	if (intr_status & uint_st->sirfsoc_txfifo_empty) {
570		if (sirfport->tx_dma_chan)
571			sirfsoc_uart_tx_with_dma(sirfport);
572		else {
573			if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
574				spin_unlock(&port->lock);
575				return IRQ_HANDLED;
576			} else {
577				sirfsoc_uart_pio_tx_chars(sirfport,
578						port->fifosize);
579				if ((uart_circ_empty(xmit)) &&
580				(rd_regl(port, ureg->sirfsoc_tx_fifo_status) &
581				ufifo_st->ff_empty(port)))
582					sirfsoc_uart_stop_tx(port);
583			}
584		}
585	}
586	spin_unlock(&port->lock);
587
588	return IRQ_HANDLED;
589}
590
591static void sirfsoc_uart_rx_dma_complete_callback(void *param)
592{
593}
594
595/* submit rx dma task into dmaengine */
596static void sirfsoc_uart_start_next_rx_dma(struct uart_port *port)
597{
598	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
599	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
600	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
601	wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
602		rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
603		~SIRFUART_IO_MODE);
604	sirfport->rx_dma_items.xmit.tail =
605		sirfport->rx_dma_items.xmit.head = 0;
606	sirfport->rx_dma_items.desc =
607		dmaengine_prep_dma_cyclic(sirfport->rx_dma_chan,
608		sirfport->rx_dma_items.dma_addr, SIRFSOC_RX_DMA_BUF_SIZE,
609		SIRFSOC_RX_DMA_BUF_SIZE / 2,
610		DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
611	if (IS_ERR_OR_NULL(sirfport->rx_dma_items.desc)) {
612		dev_err(port->dev, "DMA slave single fail\n");
613		return;
614	}
615	sirfport->rx_dma_items.desc->callback =
616		sirfsoc_uart_rx_dma_complete_callback;
617	sirfport->rx_dma_items.desc->callback_param = sirfport;
618	sirfport->rx_dma_items.cookie =
619		dmaengine_submit(sirfport->rx_dma_items.desc);
620	dma_async_issue_pending(sirfport->rx_dma_chan);
621	if (!sirfport->is_atlas7)
622		wr_regl(port, ureg->sirfsoc_int_en_reg,
623				rd_regl(port, ureg->sirfsoc_int_en_reg) |
624				SIRFUART_RX_DMA_INT_EN(uint_en,
625				sirfport->uart_reg->uart_type));
626	else
627		wr_regl(port, ureg->sirfsoc_int_en_reg,
628				SIRFUART_RX_DMA_INT_EN(uint_en,
629				sirfport->uart_reg->uart_type));
630}
631
632static unsigned int
633sirfsoc_usp_calc_sample_div(unsigned long set_rate,
634		unsigned long ioclk_rate, unsigned long *sample_reg)
635{
636	unsigned long min_delta = ~0UL;
637	unsigned short sample_div;
638	unsigned long ioclk_div = 0;
639	unsigned long temp_delta;
640
641	for (sample_div = SIRF_USP_MIN_SAMPLE_DIV;
642			sample_div <= SIRF_MAX_SAMPLE_DIV; sample_div++) {
643		temp_delta = ioclk_rate -
644		(ioclk_rate + (set_rate * sample_div) / 2)
645		/ (set_rate * sample_div) * set_rate * sample_div;
646
647		temp_delta = (temp_delta > 0) ? temp_delta : -temp_delta;
648		if (temp_delta < min_delta) {
649			ioclk_div = (2 * ioclk_rate /
650				(set_rate * sample_div) + 1) / 2 - 1;
651			if (ioclk_div > SIRF_IOCLK_DIV_MAX)
652				continue;
653			min_delta = temp_delta;
654			*sample_reg = sample_div;
655			if (!temp_delta)
656				break;
657		}
658	}
659	return ioclk_div;
660}
661
662static unsigned int
663sirfsoc_uart_calc_sample_div(unsigned long baud_rate,
664			unsigned long ioclk_rate, unsigned long *set_baud)
665{
666	unsigned long min_delta = ~0UL;
667	unsigned short sample_div;
668	unsigned int regv = 0;
669	unsigned long ioclk_div;
670	unsigned long baud_tmp;
671	int temp_delta;
672
673	for (sample_div = SIRF_MIN_SAMPLE_DIV;
674			sample_div <= SIRF_MAX_SAMPLE_DIV; sample_div++) {
675		ioclk_div = (ioclk_rate / (baud_rate * (sample_div + 1))) - 1;
676		if (ioclk_div > SIRF_IOCLK_DIV_MAX)
677			continue;
678		baud_tmp = ioclk_rate / ((ioclk_div + 1) * (sample_div + 1));
679		temp_delta = baud_tmp - baud_rate;
680		temp_delta = (temp_delta > 0) ? temp_delta : -temp_delta;
681		if (temp_delta < min_delta) {
682			regv = regv & (~SIRF_IOCLK_DIV_MASK);
683			regv = regv | ioclk_div;
684			regv = regv & (~SIRF_SAMPLE_DIV_MASK);
685			regv = regv | (sample_div << SIRF_SAMPLE_DIV_SHIFT);
686			min_delta = temp_delta;
687			*set_baud = baud_tmp;
688		}
689	}
690	return regv;
691}
692
693static void sirfsoc_uart_set_termios(struct uart_port *port,
694				       struct ktermios *termios,
695				       struct ktermios *old)
696{
697	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
698	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
699	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
700	unsigned long	config_reg = 0;
701	unsigned long	baud_rate;
702	unsigned long	set_baud;
703	unsigned long	flags;
704	unsigned long	ic;
705	unsigned int	clk_div_reg = 0;
706	unsigned long	txfifo_op_reg, ioclk_rate;
707	unsigned long	rx_time_out;
708	int		threshold_div;
709	u32		data_bit_len, stop_bit_len, len_val;
710	unsigned long	sample_div_reg = 0xf;
711	ioclk_rate	= port->uartclk;
712
713	switch (termios->c_cflag & CSIZE) {
714	default:
715	case CS8:
716		data_bit_len = 8;
717		config_reg |= SIRFUART_DATA_BIT_LEN_8;
718		break;
719	case CS7:
720		data_bit_len = 7;
721		config_reg |= SIRFUART_DATA_BIT_LEN_7;
722		break;
723	case CS6:
724		data_bit_len = 6;
725		config_reg |= SIRFUART_DATA_BIT_LEN_6;
726		break;
727	case CS5:
728		data_bit_len = 5;
729		config_reg |= SIRFUART_DATA_BIT_LEN_5;
730		break;
731	}
732	if (termios->c_cflag & CSTOPB) {
733		config_reg |= SIRFUART_STOP_BIT_LEN_2;
734		stop_bit_len = 2;
735	} else
736		stop_bit_len = 1;
737
738	spin_lock_irqsave(&port->lock, flags);
739	port->read_status_mask = uint_en->sirfsoc_rx_oflow_en;
740	port->ignore_status_mask = 0;
741	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
742		if (termios->c_iflag & INPCK)
743			port->read_status_mask |= uint_en->sirfsoc_frm_err_en |
744				uint_en->sirfsoc_parity_err_en;
745	} else {
746		if (termios->c_iflag & INPCK)
747			port->read_status_mask |= uint_en->sirfsoc_frm_err_en;
748	}
749	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
750			port->read_status_mask |= uint_en->sirfsoc_rxd_brk_en;
751	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
752		if (termios->c_iflag & IGNPAR)
753			port->ignore_status_mask |=
754				uint_en->sirfsoc_frm_err_en |
755				uint_en->sirfsoc_parity_err_en;
756		if (termios->c_cflag & PARENB) {
757			if (termios->c_cflag & CMSPAR) {
758				if (termios->c_cflag & PARODD)
759					config_reg |= SIRFUART_STICK_BIT_MARK;
760				else
761					config_reg |= SIRFUART_STICK_BIT_SPACE;
762			} else {
763				if (termios->c_cflag & PARODD)
764					config_reg |= SIRFUART_STICK_BIT_ODD;
765				else
766					config_reg |= SIRFUART_STICK_BIT_EVEN;
767			}
768		}
769	} else {
770		if (termios->c_iflag & IGNPAR)
771			port->ignore_status_mask |=
772				uint_en->sirfsoc_frm_err_en;
773		if (termios->c_cflag & PARENB)
774			dev_warn(port->dev,
775					"USP-UART not support parity err\n");
776	}
777	if (termios->c_iflag & IGNBRK) {
778		port->ignore_status_mask |=
779			uint_en->sirfsoc_rxd_brk_en;
780		if (termios->c_iflag & IGNPAR)
781			port->ignore_status_mask |=
782				uint_en->sirfsoc_rx_oflow_en;
783	}
784	if ((termios->c_cflag & CREAD) == 0)
785		port->ignore_status_mask |= SIRFUART_DUMMY_READ;
786	/* Hardware Flow Control Settings */
787	if (UART_ENABLE_MS(port, termios->c_cflag)) {
788		if (!sirfport->ms_enabled)
789			sirfsoc_uart_enable_ms(port);
790	} else {
791		if (sirfport->ms_enabled)
792			sirfsoc_uart_disable_ms(port);
793	}
794	baud_rate = uart_get_baud_rate(port, termios, old, 0, 4000000);
795	if (ioclk_rate == 150000000) {
796		for (ic = 0; ic < SIRF_BAUD_RATE_SUPPORT_NR; ic++)
797			if (baud_rate == baudrate_to_regv[ic].baud_rate)
798				clk_div_reg = baudrate_to_regv[ic].reg_val;
799	}
800	set_baud = baud_rate;
801	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
802		if (unlikely(clk_div_reg == 0))
803			clk_div_reg = sirfsoc_uart_calc_sample_div(baud_rate,
804					ioclk_rate, &set_baud);
805		wr_regl(port, ureg->sirfsoc_divisor, clk_div_reg);
806	} else {
807		clk_div_reg = sirfsoc_usp_calc_sample_div(baud_rate,
808				ioclk_rate, &sample_div_reg);
809		sample_div_reg--;
810		set_baud = ((ioclk_rate / (clk_div_reg+1) - 1) /
811				(sample_div_reg + 1));
812		/* setting usp mode 2 */
813		len_val = ((1 << SIRFSOC_USP_MODE2_RXD_DELAY_OFFSET) |
814				(1 << SIRFSOC_USP_MODE2_TXD_DELAY_OFFSET));
815		len_val |= ((clk_div_reg & SIRFSOC_USP_MODE2_CLK_DIVISOR_MASK)
816				<< SIRFSOC_USP_MODE2_CLK_DIVISOR_OFFSET);
817		wr_regl(port, ureg->sirfsoc_mode2, len_val);
818	}
819	if (tty_termios_baud_rate(termios))
820		tty_termios_encode_baud_rate(termios, set_baud, set_baud);
821	/* set receive timeout && data bits len */
822	rx_time_out = SIRFSOC_UART_RX_TIMEOUT(set_baud, 20000);
823	rx_time_out = SIRFUART_RECV_TIMEOUT_VALUE(rx_time_out);
824	txfifo_op_reg = rd_regl(port, ureg->sirfsoc_tx_fifo_op);
825	wr_regl(port, ureg->sirfsoc_tx_fifo_op,
826			(txfifo_op_reg & ~SIRFUART_FIFO_START));
827	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
828		config_reg |= SIRFUART_UART_RECV_TIMEOUT(rx_time_out);
829		wr_regl(port, ureg->sirfsoc_line_ctrl, config_reg);
830	} else {
831		/*tx frame ctrl*/
832		len_val = (data_bit_len - 1) << SIRFSOC_USP_TX_DATA_LEN_OFFSET;
833		len_val |= (data_bit_len + 1 + stop_bit_len - 1) <<
834				SIRFSOC_USP_TX_FRAME_LEN_OFFSET;
835		len_val |= ((data_bit_len - 1) <<
836				SIRFSOC_USP_TX_SHIFTER_LEN_OFFSET);
837		len_val |= (((clk_div_reg & 0xc00) >> 10) <<
838				SIRFSOC_USP_TX_CLK_DIVISOR_OFFSET);
839		wr_regl(port, ureg->sirfsoc_tx_frame_ctrl, len_val);
840		/*rx frame ctrl*/
841		len_val = (data_bit_len - 1) << SIRFSOC_USP_RX_DATA_LEN_OFFSET;
842		len_val |= (data_bit_len + 1 + stop_bit_len - 1) <<
843				SIRFSOC_USP_RX_FRAME_LEN_OFFSET;
844		len_val |= (data_bit_len - 1) <<
845				SIRFSOC_USP_RX_SHIFTER_LEN_OFFSET;
846		len_val |= (((clk_div_reg & 0xf000) >> 12) <<
847				SIRFSOC_USP_RX_CLK_DIVISOR_OFFSET);
848		wr_regl(port, ureg->sirfsoc_rx_frame_ctrl, len_val);
849		/*async param*/
850		wr_regl(port, ureg->sirfsoc_async_param_reg,
851			(SIRFUART_USP_RECV_TIMEOUT(rx_time_out)) |
852			(sample_div_reg & SIRFSOC_USP_ASYNC_DIV2_MASK) <<
853			SIRFSOC_USP_ASYNC_DIV2_OFFSET);
854	}
855	if (sirfport->tx_dma_chan)
856		wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl, SIRFUART_DMA_MODE);
857	else
858		wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl, SIRFUART_IO_MODE);
859	if (sirfport->rx_dma_chan)
860		wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
861			rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
862			~SIRFUART_IO_MODE);
863	else
864		wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
865			rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
866			SIRFUART_IO_MODE);
867	sirfport->rx_period_time = 20000000;
868	/* Reset Rx/Tx FIFO Threshold level for proper baudrate */
869	if (set_baud < 1000000)
870		threshold_div = 1;
871	else
872		threshold_div = 2;
873	wr_regl(port, ureg->sirfsoc_tx_fifo_ctrl,
874				SIRFUART_FIFO_THD(port) / threshold_div);
875	wr_regl(port, ureg->sirfsoc_rx_fifo_ctrl,
876				SIRFUART_FIFO_THD(port) / threshold_div);
877	txfifo_op_reg |= SIRFUART_FIFO_START;
878	wr_regl(port, ureg->sirfsoc_tx_fifo_op, txfifo_op_reg);
879	uart_update_timeout(port, termios->c_cflag, set_baud);
880	wr_regl(port, ureg->sirfsoc_tx_rx_en, SIRFUART_TX_EN | SIRFUART_RX_EN);
881	spin_unlock_irqrestore(&port->lock, flags);
882}
883
884static void sirfsoc_uart_pm(struct uart_port *port, unsigned int state,
885			      unsigned int oldstate)
886{
887	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
888	if (!state)
889		clk_prepare_enable(sirfport->clk);
890	else
891		clk_disable_unprepare(sirfport->clk);
892}
893
894static int sirfsoc_uart_startup(struct uart_port *port)
895{
896	struct sirfsoc_uart_port *sirfport	= to_sirfport(port);
897	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
898	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
899	unsigned int index			= port->line;
900	int ret;
901	irq_modify_status(port->irq, IRQ_NOREQUEST, IRQ_NOAUTOEN);
902	ret = request_irq(port->irq,
903				sirfsoc_uart_isr,
904				0,
905				SIRFUART_PORT_NAME,
906				sirfport);
907	if (ret != 0) {
908		dev_err(port->dev, "UART%d request IRQ line (%d) failed.\n",
909							index, port->irq);
910		goto irq_err;
911	}
912	/* initial hardware settings */
913	wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl,
914		rd_regl(port, ureg->sirfsoc_tx_dma_io_ctrl) |
915		SIRFUART_IO_MODE);
916	wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
917		rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
918		SIRFUART_IO_MODE);
919	wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
920		rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
921		~SIRFUART_RX_DMA_FLUSH);
922	wr_regl(port, ureg->sirfsoc_tx_dma_io_len, 0);
923	wr_regl(port, ureg->sirfsoc_rx_dma_io_len, 0);
924	wr_regl(port, ureg->sirfsoc_tx_rx_en, SIRFUART_RX_EN | SIRFUART_TX_EN);
925	if (sirfport->uart_reg->uart_type == SIRF_USP_UART)
926		wr_regl(port, ureg->sirfsoc_mode1,
927			SIRFSOC_USP_ENDIAN_CTRL_LSBF |
928			SIRFSOC_USP_EN);
929	wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_RESET);
930	wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_RESET);
931	wr_regl(port, ureg->sirfsoc_rx_fifo_op, 0);
932	wr_regl(port, ureg->sirfsoc_tx_fifo_ctrl, SIRFUART_FIFO_THD(port));
933	wr_regl(port, ureg->sirfsoc_rx_fifo_ctrl, SIRFUART_FIFO_THD(port));
934	if (sirfport->rx_dma_chan)
935		wr_regl(port, ureg->sirfsoc_rx_fifo_level_chk,
936			SIRFUART_RX_FIFO_CHK_SC(port->line, 0x1) |
937			SIRFUART_RX_FIFO_CHK_LC(port->line, 0x2) |
938			SIRFUART_RX_FIFO_CHK_HC(port->line, 0x4));
939	if (sirfport->tx_dma_chan) {
940		sirfport->tx_dma_state = TX_DMA_IDLE;
941		wr_regl(port, ureg->sirfsoc_tx_fifo_level_chk,
942				SIRFUART_TX_FIFO_CHK_SC(port->line, 0x1b) |
943				SIRFUART_TX_FIFO_CHK_LC(port->line, 0xe) |
944				SIRFUART_TX_FIFO_CHK_HC(port->line, 0x4));
945	}
946	sirfport->ms_enabled = false;
947	if (sirfport->uart_reg->uart_type == SIRF_USP_UART &&
948		sirfport->hw_flow_ctrl) {
949		irq_modify_status(gpio_to_irq(sirfport->cts_gpio),
950			IRQ_NOREQUEST, IRQ_NOAUTOEN);
951		ret = request_irq(gpio_to_irq(sirfport->cts_gpio),
952			sirfsoc_uart_usp_cts_handler, IRQF_TRIGGER_FALLING |
953			IRQF_TRIGGER_RISING, "usp_cts_irq", sirfport);
954		if (ret != 0) {
955			dev_err(port->dev, "UART-USP:request gpio irq fail\n");
956			goto init_rx_err;
957		}
958	}
959	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART &&
960		sirfport->rx_dma_chan)
961		wr_regl(port, ureg->sirfsoc_swh_dma_io,
962			SIRFUART_CLEAR_RX_ADDR_EN);
963	if (sirfport->uart_reg->uart_type == SIRF_USP_UART &&
964			sirfport->rx_dma_chan)
965		wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
966			rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
967			SIRFSOC_USP_FRADDR_CLR_EN);
968	if (sirfport->rx_dma_chan && !sirfport->is_hrt_enabled) {
969		sirfport->is_hrt_enabled = true;
970		sirfport->rx_period_time = 20000000;
971		sirfport->rx_last_pos = -1;
972		sirfport->pio_fetch_cnt = 0;
973		sirfport->rx_dma_items.xmit.tail =
974			sirfport->rx_dma_items.xmit.head = 0;
975		hrtimer_start(&sirfport->hrt,
976			ns_to_ktime(sirfport->rx_period_time),
977			HRTIMER_MODE_REL);
978	}
979	wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_START);
980	if (sirfport->rx_dma_chan)
981		sirfsoc_uart_start_next_rx_dma(port);
982	else {
983		if (!sirfport->is_atlas7)
984			wr_regl(port, ureg->sirfsoc_int_en_reg,
985				rd_regl(port, ureg->sirfsoc_int_en_reg) |
986				SIRFUART_RX_IO_INT_EN(uint_en,
987					sirfport->uart_reg->uart_type));
988		else
989			wr_regl(port, ureg->sirfsoc_int_en_reg,
990				SIRFUART_RX_IO_INT_EN(uint_en,
991					sirfport->uart_reg->uart_type));
992	}
993	enable_irq(port->irq);
994
995	return 0;
996init_rx_err:
997	free_irq(port->irq, sirfport);
998irq_err:
999	return ret;
1000}
1001
1002static void sirfsoc_uart_shutdown(struct uart_port *port)
1003{
1004	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
1005	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
1006	struct circ_buf *xmit;
1007
1008	xmit = &sirfport->rx_dma_items.xmit;
1009	if (!sirfport->is_atlas7)
1010		wr_regl(port, ureg->sirfsoc_int_en_reg, 0);
1011	else
1012		wr_regl(port, ureg->sirfsoc_int_en_clr_reg, ~0UL);
1013
1014	free_irq(port->irq, sirfport);
1015	if (sirfport->ms_enabled)
1016		sirfsoc_uart_disable_ms(port);
1017	if (sirfport->uart_reg->uart_type == SIRF_USP_UART &&
1018			sirfport->hw_flow_ctrl) {
1019		gpio_set_value(sirfport->rts_gpio, 1);
1020		free_irq(gpio_to_irq(sirfport->cts_gpio), sirfport);
1021	}
1022	if (sirfport->tx_dma_chan)
1023		sirfport->tx_dma_state = TX_DMA_IDLE;
1024	if (sirfport->rx_dma_chan && sirfport->is_hrt_enabled) {
1025		while (((rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
1026			SIRFUART_RX_FIFO_MASK) > sirfport->pio_fetch_cnt) &&
1027			!CIRC_CNT(xmit->head, xmit->tail,
1028			SIRFSOC_RX_DMA_BUF_SIZE))
1029			;
1030		sirfport->is_hrt_enabled = false;
1031		hrtimer_cancel(&sirfport->hrt);
1032	}
1033}
1034
1035static const char *sirfsoc_uart_type(struct uart_port *port)
1036{
1037	return port->type == SIRFSOC_PORT_TYPE ? SIRFUART_PORT_NAME : NULL;
1038}
1039
1040static int sirfsoc_uart_request_port(struct uart_port *port)
1041{
1042	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
1043	struct sirfsoc_uart_param *uart_param = &sirfport->uart_reg->uart_param;
1044	void *ret;
1045	ret = request_mem_region(port->mapbase,
1046		SIRFUART_MAP_SIZE, uart_param->port_name);
1047	return ret ? 0 : -EBUSY;
1048}
1049
1050static void sirfsoc_uart_release_port(struct uart_port *port)
1051{
1052	release_mem_region(port->mapbase, SIRFUART_MAP_SIZE);
1053}
1054
1055static void sirfsoc_uart_config_port(struct uart_port *port, int flags)
1056{
1057	if (flags & UART_CONFIG_TYPE) {
1058		port->type = SIRFSOC_PORT_TYPE;
1059		sirfsoc_uart_request_port(port);
1060	}
1061}
1062
1063static const struct uart_ops sirfsoc_uart_ops = {
1064	.tx_empty	= sirfsoc_uart_tx_empty,
1065	.get_mctrl	= sirfsoc_uart_get_mctrl,
1066	.set_mctrl	= sirfsoc_uart_set_mctrl,
1067	.stop_tx	= sirfsoc_uart_stop_tx,
1068	.start_tx	= sirfsoc_uart_start_tx,
1069	.stop_rx	= sirfsoc_uart_stop_rx,
1070	.enable_ms	= sirfsoc_uart_enable_ms,
1071	.break_ctl	= sirfsoc_uart_break_ctl,
1072	.startup	= sirfsoc_uart_startup,
1073	.shutdown	= sirfsoc_uart_shutdown,
1074	.set_termios	= sirfsoc_uart_set_termios,
1075	.pm		= sirfsoc_uart_pm,
1076	.type		= sirfsoc_uart_type,
1077	.release_port	= sirfsoc_uart_release_port,
1078	.request_port	= sirfsoc_uart_request_port,
1079	.config_port	= sirfsoc_uart_config_port,
1080};
1081
1082#ifdef CONFIG_SERIAL_SIRFSOC_CONSOLE
1083static int __init
1084sirfsoc_uart_console_setup(struct console *co, char *options)
1085{
1086	unsigned int baud = 115200;
1087	unsigned int bits = 8;
1088	unsigned int parity = 'n';
1089	unsigned int flow = 'n';
1090	struct sirfsoc_uart_port *sirfport;
1091	struct sirfsoc_register *ureg;
1092	if (co->index < 0 || co->index >= SIRFSOC_UART_NR)
1093		co->index = 1;
1094	sirfport = sirf_ports[co->index];
1095	if (!sirfport)
1096		return -ENODEV;
1097	ureg = &sirfport->uart_reg->uart_reg;
1098	if (!sirfport->port.mapbase)
1099		return -ENODEV;
1100
1101	/* enable usp in mode1 register */
1102	if (sirfport->uart_reg->uart_type == SIRF_USP_UART)
1103		wr_regl(&sirfport->port, ureg->sirfsoc_mode1, SIRFSOC_USP_EN |
1104				SIRFSOC_USP_ENDIAN_CTRL_LSBF);
1105	if (options)
1106		uart_parse_options(options, &baud, &parity, &bits, &flow);
1107	sirfport->port.cons = co;
1108
1109	/* default console tx/rx transfer using io mode */
1110	sirfport->rx_dma_chan = NULL;
1111	sirfport->tx_dma_chan = NULL;
1112	return uart_set_options(&sirfport->port, co, baud, parity, bits, flow);
1113}
1114
1115static void sirfsoc_uart_console_putchar(struct uart_port *port, int ch)
1116{
1117	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
1118	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
1119	struct sirfsoc_fifo_status *ufifo_st = &sirfport->uart_reg->fifo_status;
1120	while (rd_regl(port, ureg->sirfsoc_tx_fifo_status) &
1121		ufifo_st->ff_full(port))
1122		cpu_relax();
1123	wr_regl(port, ureg->sirfsoc_tx_fifo_data, ch);
1124}
1125
1126static void sirfsoc_uart_console_write(struct console *co, const char *s,
1127							unsigned int count)
1128{
1129	struct sirfsoc_uart_port *sirfport = sirf_ports[co->index];
1130
1131	uart_console_write(&sirfport->port, s, count,
1132			sirfsoc_uart_console_putchar);
1133}
1134
1135static struct console sirfsoc_uart_console = {
1136	.name		= SIRFSOC_UART_NAME,
1137	.device		= uart_console_device,
1138	.flags		= CON_PRINTBUFFER,
1139	.index		= -1,
1140	.write		= sirfsoc_uart_console_write,
1141	.setup		= sirfsoc_uart_console_setup,
1142	.data           = &sirfsoc_uart_drv,
1143};
1144
1145static int __init sirfsoc_uart_console_init(void)
1146{
1147	register_console(&sirfsoc_uart_console);
1148	return 0;
1149}
1150console_initcall(sirfsoc_uart_console_init);
1151#endif
1152
1153static struct uart_driver sirfsoc_uart_drv = {
1154	.owner		= THIS_MODULE,
1155	.driver_name	= SIRFUART_PORT_NAME,
1156	.nr		= SIRFSOC_UART_NR,
1157	.dev_name	= SIRFSOC_UART_NAME,
1158	.major		= SIRFSOC_UART_MAJOR,
1159	.minor		= SIRFSOC_UART_MINOR,
1160#ifdef CONFIG_SERIAL_SIRFSOC_CONSOLE
1161	.cons			= &sirfsoc_uart_console,
1162#else
1163	.cons			= NULL,
1164#endif
1165};
1166
1167static enum hrtimer_restart
1168	sirfsoc_uart_rx_dma_hrtimer_callback(struct hrtimer *hrt)
1169{
1170	struct sirfsoc_uart_port *sirfport;
1171	struct uart_port *port;
1172	int count, inserted;
1173	struct dma_tx_state tx_state;
1174	struct tty_struct *tty;
1175	struct sirfsoc_register *ureg;
1176	struct circ_buf *xmit;
1177	struct sirfsoc_fifo_status *ufifo_st;
1178	int max_pio_cnt;
1179
1180	sirfport = container_of(hrt, struct sirfsoc_uart_port, hrt);
1181	port = &sirfport->port;
1182	inserted = 0;
1183	tty = port->state->port.tty;
1184	ureg = &sirfport->uart_reg->uart_reg;
1185	xmit = &sirfport->rx_dma_items.xmit;
1186	ufifo_st = &sirfport->uart_reg->fifo_status;
1187
1188	dmaengine_tx_status(sirfport->rx_dma_chan,
1189			sirfport->rx_dma_items.cookie, &tx_state);
1190	if (SIRFSOC_RX_DMA_BUF_SIZE - tx_state.residue !=
1191		sirfport->rx_last_pos) {
1192		xmit->head = SIRFSOC_RX_DMA_BUF_SIZE - tx_state.residue;
1193		sirfport->rx_last_pos = xmit->head;
1194		sirfport->pio_fetch_cnt = 0;
1195	}
1196	count = CIRC_CNT_TO_END(xmit->head, xmit->tail,
1197			SIRFSOC_RX_DMA_BUF_SIZE);
1198	while (count > 0) {
1199		inserted = tty_insert_flip_string(tty->port,
1200			(const unsigned char *)&xmit->buf[xmit->tail], count);
1201		if (!inserted)
1202			goto next_hrt;
1203		port->icount.rx += inserted;
1204		xmit->tail = (xmit->tail + inserted) &
1205				(SIRFSOC_RX_DMA_BUF_SIZE - 1);
1206		count = CIRC_CNT_TO_END(xmit->head, xmit->tail,
1207				SIRFSOC_RX_DMA_BUF_SIZE);
1208		tty_flip_buffer_push(tty->port);
1209	}
1210	/*
1211	 * if RX DMA buffer data have all push into tty buffer, and there is
1212	 * only little data(less than a dma transfer unit) left in rxfifo,
1213	 * fetch it out in pio mode and switch back to dma immediately
1214	 */
1215	if (!inserted && !count &&
1216		((rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
1217		SIRFUART_RX_FIFO_MASK) > sirfport->pio_fetch_cnt)) {
1218		dmaengine_pause(sirfport->rx_dma_chan);
1219		/* switch to pio mode */
1220		wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
1221			rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
1222			SIRFUART_IO_MODE);
1223		/*
1224		 * UART controller SWH_DMA_IO register have CLEAR_RX_ADDR_EN
1225		 * When found changing I/O to DMA mode, it clears
1226		 * two low bits of read point;
1227		 * USP have similar FRADDR_CLR_EN bit in USP_RX_DMA_IO_CTRL.
1228		 * Fetch data out from rxfifo into DMA buffer in PIO mode,
1229		 * while switch back to DMA mode, the data fetched will override
1230		 * by DMA, as hardware have a strange behaviour:
1231		 * after switch back to DMA mode, check rxfifo status it will
1232		 * be the number PIO fetched, so record the fetched data count
1233		 * to avoid the repeated fetch
1234		 */
1235		max_pio_cnt = 3;
1236		while (!(rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
1237			ufifo_st->ff_empty(port)) && max_pio_cnt--) {
1238			xmit->buf[xmit->head] =
1239				rd_regl(port, ureg->sirfsoc_rx_fifo_data);
1240			xmit->head = (xmit->head + 1) &
1241					(SIRFSOC_RX_DMA_BUF_SIZE - 1);
1242			sirfport->pio_fetch_cnt++;
1243		}
1244		/* switch back to dma mode */
1245		wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
1246			rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
1247			~SIRFUART_IO_MODE);
1248		dmaengine_resume(sirfport->rx_dma_chan);
1249	}
1250next_hrt:
1251	hrtimer_forward_now(hrt, ns_to_ktime(sirfport->rx_period_time));
1252	return HRTIMER_RESTART;
1253}
1254
1255static const struct of_device_id sirfsoc_uart_ids[] = {
1256	{ .compatible = "sirf,prima2-uart", .data = &sirfsoc_uart,},
1257	{ .compatible = "sirf,atlas7-uart", .data = &sirfsoc_uart},
1258	{ .compatible = "sirf,prima2-usp-uart", .data = &sirfsoc_usp},
1259	{ .compatible = "sirf,atlas7-usp-uart", .data = &sirfsoc_usp},
1260	{}
1261};
1262MODULE_DEVICE_TABLE(of, sirfsoc_uart_ids);
1263
1264static int sirfsoc_uart_probe(struct platform_device *pdev)
1265{
1266	struct device_node *np = pdev->dev.of_node;
1267	struct sirfsoc_uart_port *sirfport;
1268	struct uart_port *port;
1269	struct resource *res;
1270	int ret;
1271	struct dma_slave_config slv_cfg = {
1272		.src_maxburst = 1,
1273	};
1274	struct dma_slave_config tx_slv_cfg = {
1275		.dst_maxburst = 2,
1276	};
1277	const struct of_device_id *match;
1278
1279	match = of_match_node(sirfsoc_uart_ids, np);
1280	sirfport = devm_kzalloc(&pdev->dev, sizeof(*sirfport), GFP_KERNEL);
1281	if (!sirfport) {
1282		ret = -ENOMEM;
1283		goto err;
1284	}
1285	sirfport->port.line = of_alias_get_id(np, "serial");
1286	if (sirfport->port.line >= ARRAY_SIZE(sirf_ports)) {
1287		dev_err(&pdev->dev, "serial%d out of range\n",
1288			sirfport->port.line);
1289		return -EINVAL;
1290	}
1291	sirf_ports[sirfport->port.line] = sirfport;
1292	sirfport->port.iotype = UPIO_MEM;
1293	sirfport->port.flags = UPF_BOOT_AUTOCONF;
1294	port = &sirfport->port;
1295	port->dev = &pdev->dev;
1296	port->private_data = sirfport;
1297	sirfport->uart_reg = (struct sirfsoc_uart_register *)match->data;
1298
1299	sirfport->hw_flow_ctrl =
1300		of_property_read_bool(np, "uart-has-rtscts") ||
1301		of_property_read_bool(np, "sirf,uart-has-rtscts") /* deprecated */;
1302	if (of_device_is_compatible(np, "sirf,prima2-uart") ||
1303		of_device_is_compatible(np, "sirf,atlas7-uart"))
1304		sirfport->uart_reg->uart_type = SIRF_REAL_UART;
1305	if (of_device_is_compatible(np, "sirf,prima2-usp-uart") ||
1306	    of_device_is_compatible(np, "sirf,atlas7-usp-uart")) {
1307		sirfport->uart_reg->uart_type =	SIRF_USP_UART;
1308		if (!sirfport->hw_flow_ctrl)
1309			goto usp_no_flow_control;
1310		if (of_find_property(np, "cts-gpios", NULL))
1311			sirfport->cts_gpio =
1312				of_get_named_gpio(np, "cts-gpios", 0);
1313		else
1314			sirfport->cts_gpio = -1;
1315		if (of_find_property(np, "rts-gpios", NULL))
1316			sirfport->rts_gpio =
1317				of_get_named_gpio(np, "rts-gpios", 0);
1318		else
1319			sirfport->rts_gpio = -1;
1320
1321		if ((!gpio_is_valid(sirfport->cts_gpio) ||
1322			 !gpio_is_valid(sirfport->rts_gpio))) {
1323			ret = -EINVAL;
1324			dev_err(&pdev->dev,
1325				"Usp flow control must have cts and rts gpio");
1326			goto err;
1327		}
1328		ret = devm_gpio_request(&pdev->dev, sirfport->cts_gpio,
1329				"usp-cts-gpio");
1330		if (ret) {
1331			dev_err(&pdev->dev, "Unable request cts gpio");
1332			goto err;
1333		}
1334		gpio_direction_input(sirfport->cts_gpio);
1335		ret = devm_gpio_request(&pdev->dev, sirfport->rts_gpio,
1336				"usp-rts-gpio");
1337		if (ret) {
1338			dev_err(&pdev->dev, "Unable request rts gpio");
1339			goto err;
1340		}
1341		gpio_direction_output(sirfport->rts_gpio, 1);
1342	}
1343usp_no_flow_control:
1344	if (of_device_is_compatible(np, "sirf,atlas7-uart") ||
1345	    of_device_is_compatible(np, "sirf,atlas7-usp-uart"))
1346		sirfport->is_atlas7 = true;
1347
1348	if (of_property_read_u32(np, "fifosize", &port->fifosize)) {
1349		dev_err(&pdev->dev,
1350			"Unable to find fifosize in uart node.\n");
1351		ret = -EFAULT;
1352		goto err;
1353	}
1354
1355	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1356	if (res == NULL) {
1357		dev_err(&pdev->dev, "Insufficient resources.\n");
1358		ret = -EFAULT;
1359		goto err;
1360	}
1361	port->mapbase = res->start;
1362	port->membase = devm_ioremap(&pdev->dev,
1363			res->start, resource_size(res));
1364	if (!port->membase) {
1365		dev_err(&pdev->dev, "Cannot remap resource.\n");
1366		ret = -ENOMEM;
1367		goto err;
1368	}
1369	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
1370	if (res == NULL) {
1371		dev_err(&pdev->dev, "Insufficient resources.\n");
1372		ret = -EFAULT;
1373		goto err;
1374	}
1375	port->irq = res->start;
1376
1377	sirfport->clk = devm_clk_get(&pdev->dev, NULL);
1378	if (IS_ERR(sirfport->clk)) {
1379		ret = PTR_ERR(sirfport->clk);
1380		goto err;
1381	}
1382	port->uartclk = clk_get_rate(sirfport->clk);
1383
1384	port->ops = &sirfsoc_uart_ops;
1385	spin_lock_init(&port->lock);
1386
1387	platform_set_drvdata(pdev, sirfport);
1388	ret = uart_add_one_port(&sirfsoc_uart_drv, port);
1389	if (ret != 0) {
1390		dev_err(&pdev->dev, "Cannot add UART port(%d).\n", pdev->id);
1391		goto err;
1392	}
1393
1394	sirfport->rx_dma_chan = dma_request_slave_channel(port->dev, "rx");
1395	sirfport->rx_dma_items.xmit.buf =
1396		dma_alloc_coherent(port->dev, SIRFSOC_RX_DMA_BUF_SIZE,
1397		&sirfport->rx_dma_items.dma_addr, GFP_KERNEL);
1398	if (!sirfport->rx_dma_items.xmit.buf) {
1399		dev_err(port->dev, "Uart alloc bufa failed\n");
1400		ret = -ENOMEM;
1401		goto alloc_coherent_err;
1402	}
1403	sirfport->rx_dma_items.xmit.head =
1404		sirfport->rx_dma_items.xmit.tail = 0;
1405	if (sirfport->rx_dma_chan)
1406		dmaengine_slave_config(sirfport->rx_dma_chan, &slv_cfg);
1407	sirfport->tx_dma_chan = dma_request_slave_channel(port->dev, "tx");
1408	if (sirfport->tx_dma_chan)
1409		dmaengine_slave_config(sirfport->tx_dma_chan, &tx_slv_cfg);
1410	if (sirfport->rx_dma_chan) {
1411		hrtimer_init(&sirfport->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1412		sirfport->hrt.function = sirfsoc_uart_rx_dma_hrtimer_callback;
1413		sirfport->is_hrt_enabled = false;
1414	}
1415
1416	return 0;
1417alloc_coherent_err:
1418	dma_free_coherent(port->dev, SIRFSOC_RX_DMA_BUF_SIZE,
1419			sirfport->rx_dma_items.xmit.buf,
1420			sirfport->rx_dma_items.dma_addr);
1421	dma_release_channel(sirfport->rx_dma_chan);
1422err:
1423	return ret;
1424}
1425
1426static int sirfsoc_uart_remove(struct platform_device *pdev)
1427{
1428	struct sirfsoc_uart_port *sirfport = platform_get_drvdata(pdev);
1429	struct uart_port *port = &sirfport->port;
1430	uart_remove_one_port(&sirfsoc_uart_drv, port);
1431	if (sirfport->rx_dma_chan) {
1432		dmaengine_terminate_all(sirfport->rx_dma_chan);
1433		dma_release_channel(sirfport->rx_dma_chan);
1434		dma_free_coherent(port->dev, SIRFSOC_RX_DMA_BUF_SIZE,
1435				sirfport->rx_dma_items.xmit.buf,
1436				sirfport->rx_dma_items.dma_addr);
1437	}
1438	if (sirfport->tx_dma_chan) {
1439		dmaengine_terminate_all(sirfport->tx_dma_chan);
1440		dma_release_channel(sirfport->tx_dma_chan);
1441	}
1442	return 0;
1443}
1444
1445#ifdef CONFIG_PM_SLEEP
1446static int
1447sirfsoc_uart_suspend(struct device *pdev)
1448{
1449	struct sirfsoc_uart_port *sirfport = dev_get_drvdata(pdev);
1450	struct uart_port *port = &sirfport->port;
1451	uart_suspend_port(&sirfsoc_uart_drv, port);
1452	return 0;
1453}
1454
1455static int sirfsoc_uart_resume(struct device *pdev)
1456{
1457	struct sirfsoc_uart_port *sirfport = dev_get_drvdata(pdev);
1458	struct uart_port *port = &sirfport->port;
1459	uart_resume_port(&sirfsoc_uart_drv, port);
1460	return 0;
1461}
1462#endif
1463
1464static const struct dev_pm_ops sirfsoc_uart_pm_ops = {
1465	SET_SYSTEM_SLEEP_PM_OPS(sirfsoc_uart_suspend, sirfsoc_uart_resume)
1466};
1467
1468static struct platform_driver sirfsoc_uart_driver = {
1469	.probe		= sirfsoc_uart_probe,
1470	.remove		= sirfsoc_uart_remove,
1471	.driver		= {
1472		.name	= SIRFUART_PORT_NAME,
1473		.of_match_table = sirfsoc_uart_ids,
1474		.pm	= &sirfsoc_uart_pm_ops,
1475	},
1476};
1477
1478static int __init sirfsoc_uart_init(void)
1479{
1480	int ret = 0;
1481
1482	ret = uart_register_driver(&sirfsoc_uart_drv);
1483	if (ret)
1484		goto out;
1485
1486	ret = platform_driver_register(&sirfsoc_uart_driver);
1487	if (ret)
1488		uart_unregister_driver(&sirfsoc_uart_drv);
1489out:
1490	return ret;
1491}
1492module_init(sirfsoc_uart_init);
1493
1494static void __exit sirfsoc_uart_exit(void)
1495{
1496	platform_driver_unregister(&sirfsoc_uart_driver);
1497	uart_unregister_driver(&sirfsoc_uart_drv);
1498}
1499module_exit(sirfsoc_uart_exit);
1500
1501MODULE_LICENSE("GPL v2");
1502MODULE_AUTHOR("Bin Shi <Bin.Shi@csr.com>, Rong Wang<Rong.Wang@csr.com>");
1503MODULE_DESCRIPTION("CSR SiRFprimaII Uart Driver");
1504