1/*
2 * Driver for CSR SiRFprimaII onboard UARTs.
3 *
4 * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
5 *
6 * Licensed under GPLv2 or later.
7 */
8
9#include <linux/module.h>
10#include <linux/ioport.h>
11#include <linux/platform_device.h>
12#include <linux/init.h>
13#include <linux/sysrq.h>
14#include <linux/console.h>
15#include <linux/tty.h>
16#include <linux/tty_flip.h>
17#include <linux/serial_core.h>
18#include <linux/serial.h>
19#include <linux/clk.h>
20#include <linux/of.h>
21#include <linux/slab.h>
22#include <linux/io.h>
23#include <linux/of_gpio.h>
24#include <linux/dmaengine.h>
25#include <linux/dma-direction.h>
26#include <linux/dma-mapping.h>
27#include <asm/irq.h>
28#include <asm/mach/irq.h>
29
30#include "sirfsoc_uart.h"
31
32static unsigned int
33sirfsoc_uart_pio_tx_chars(struct sirfsoc_uart_port *sirfport, int count);
34static unsigned int
35sirfsoc_uart_pio_rx_chars(struct uart_port *port, unsigned int max_rx_count);
36static struct uart_driver sirfsoc_uart_drv;
37
38static void sirfsoc_uart_tx_dma_complete_callback(void *param);
39static const struct sirfsoc_baudrate_to_regv baudrate_to_regv[] = {
40	{4000000, 2359296},
41	{3500000, 1310721},
42	{3000000, 1572865},
43	{2500000, 1245186},
44	{2000000, 1572866},
45	{1500000, 1245188},
46	{1152000, 1638404},
47	{1000000, 1572869},
48	{921600, 1114120},
49	{576000, 1245196},
50	{500000, 1245198},
51	{460800, 1572876},
52	{230400, 1310750},
53	{115200, 1310781},
54	{57600, 1310843},
55	{38400, 1114328},
56	{19200, 1114545},
57	{9600, 1114979},
58};
59
60static struct sirfsoc_uart_port *sirf_ports[SIRFSOC_UART_NR];
61
62static inline struct sirfsoc_uart_port *to_sirfport(struct uart_port *port)
63{
64	return container_of(port, struct sirfsoc_uart_port, port);
65}
66
67static inline unsigned int sirfsoc_uart_tx_empty(struct uart_port *port)
68{
69	unsigned long reg;
70	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
71	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
72	struct sirfsoc_fifo_status *ufifo_st = &sirfport->uart_reg->fifo_status;
73	reg = rd_regl(port, ureg->sirfsoc_tx_fifo_status);
74	return (reg & ufifo_st->ff_empty(port)) ? TIOCSER_TEMT : 0;
75}
76
77static unsigned int sirfsoc_uart_get_mctrl(struct uart_port *port)
78{
79	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
80	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
81	if (!sirfport->hw_flow_ctrl || !sirfport->ms_enabled)
82		goto cts_asserted;
83	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
84		if (!(rd_regl(port, ureg->sirfsoc_afc_ctrl) &
85						SIRFUART_AFC_CTS_STATUS))
86			goto cts_asserted;
87		else
88			goto cts_deasserted;
89	} else {
90		if (!gpio_get_value(sirfport->cts_gpio))
91			goto cts_asserted;
92		else
93			goto cts_deasserted;
94	}
95cts_deasserted:
96	return TIOCM_CAR | TIOCM_DSR;
97cts_asserted:
98	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
99}
100
101static void sirfsoc_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
102{
103	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
104	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
105	unsigned int assert = mctrl & TIOCM_RTS;
106	unsigned int val = assert ? SIRFUART_AFC_CTRL_RX_THD : 0x0;
107	unsigned int current_val;
108
109	if (mctrl & TIOCM_LOOP) {
110		if (sirfport->uart_reg->uart_type == SIRF_REAL_UART)
111			wr_regl(port, ureg->sirfsoc_line_ctrl,
112				rd_regl(port, ureg->sirfsoc_line_ctrl) |
113				SIRFUART_LOOP_BACK);
114		else
115			wr_regl(port, ureg->sirfsoc_mode1,
116				rd_regl(port, ureg->sirfsoc_mode1) |
117				SIRFSOC_USP_LOOP_BACK_CTRL);
118	} else {
119		if (sirfport->uart_reg->uart_type == SIRF_REAL_UART)
120			wr_regl(port, ureg->sirfsoc_line_ctrl,
121				rd_regl(port, ureg->sirfsoc_line_ctrl) &
122				~SIRFUART_LOOP_BACK);
123		else
124			wr_regl(port, ureg->sirfsoc_mode1,
125				rd_regl(port, ureg->sirfsoc_mode1) &
126				~SIRFSOC_USP_LOOP_BACK_CTRL);
127	}
128
129	if (!sirfport->hw_flow_ctrl || !sirfport->ms_enabled)
130		return;
131	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
132		current_val = rd_regl(port, ureg->sirfsoc_afc_ctrl) & ~0xFF;
133		val |= current_val;
134		wr_regl(port, ureg->sirfsoc_afc_ctrl, val);
135	} else {
136		if (!val)
137			gpio_set_value(sirfport->rts_gpio, 1);
138		else
139			gpio_set_value(sirfport->rts_gpio, 0);
140	}
141}
142
143static void sirfsoc_uart_stop_tx(struct uart_port *port)
144{
145	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
146	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
147	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
148
149	if (sirfport->tx_dma_chan) {
150		if (sirfport->tx_dma_state == TX_DMA_RUNNING) {
151			dmaengine_pause(sirfport->tx_dma_chan);
152			sirfport->tx_dma_state = TX_DMA_PAUSE;
153		} else {
154			if (!sirfport->is_atlas7)
155				wr_regl(port, ureg->sirfsoc_int_en_reg,
156				rd_regl(port, ureg->sirfsoc_int_en_reg) &
157				~uint_en->sirfsoc_txfifo_empty_en);
158			else
159				wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
160				uint_en->sirfsoc_txfifo_empty_en);
161		}
162	} else {
163		if (sirfport->uart_reg->uart_type == SIRF_USP_UART)
164			wr_regl(port, ureg->sirfsoc_tx_rx_en, rd_regl(port,
165				ureg->sirfsoc_tx_rx_en) & ~SIRFUART_TX_EN);
166		if (!sirfport->is_atlas7)
167			wr_regl(port, ureg->sirfsoc_int_en_reg,
168				rd_regl(port, ureg->sirfsoc_int_en_reg) &
169				~uint_en->sirfsoc_txfifo_empty_en);
170		else
171			wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
172				uint_en->sirfsoc_txfifo_empty_en);
173	}
174}
175
176static void sirfsoc_uart_tx_with_dma(struct sirfsoc_uart_port *sirfport)
177{
178	struct uart_port *port = &sirfport->port;
179	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
180	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
181	struct circ_buf *xmit = &port->state->xmit;
182	unsigned long tran_size;
183	unsigned long tran_start;
184	unsigned long pio_tx_size;
185
186	tran_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
187	tran_start = (unsigned long)(xmit->buf + xmit->tail);
188	if (uart_circ_empty(xmit) || uart_tx_stopped(port) ||
189			!tran_size)
190		return;
191	if (sirfport->tx_dma_state == TX_DMA_PAUSE) {
192		dmaengine_resume(sirfport->tx_dma_chan);
193		return;
194	}
195	if (sirfport->tx_dma_state == TX_DMA_RUNNING)
196		return;
197	if (!sirfport->is_atlas7)
198		wr_regl(port, ureg->sirfsoc_int_en_reg,
199				rd_regl(port, ureg->sirfsoc_int_en_reg)&
200				~(uint_en->sirfsoc_txfifo_empty_en));
201	else
202		wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
203				uint_en->sirfsoc_txfifo_empty_en);
204	/*
205	 * DMA requires buffer address and buffer length are both aligned with
206	 * 4 bytes, so we use PIO for
207	 * 1. if address is not aligned with 4bytes, use PIO for the first 1~3
208	 * bytes, and move to DMA for the left part aligned with 4bytes
209	 * 2. if buffer length is not aligned with 4bytes, use DMA for aligned
210	 * part first, move to PIO for the left 1~3 bytes
211	 */
212	if (tran_size < 4 || BYTES_TO_ALIGN(tran_start)) {
213		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_STOP);
214		wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl,
215			rd_regl(port, ureg->sirfsoc_tx_dma_io_ctrl)|
216			SIRFUART_IO_MODE);
217		if (BYTES_TO_ALIGN(tran_start)) {
218			pio_tx_size = sirfsoc_uart_pio_tx_chars(sirfport,
219				BYTES_TO_ALIGN(tran_start));
220			tran_size -= pio_tx_size;
221		}
222		if (tran_size < 4)
223			sirfsoc_uart_pio_tx_chars(sirfport, tran_size);
224		if (!sirfport->is_atlas7)
225			wr_regl(port, ureg->sirfsoc_int_en_reg,
226				rd_regl(port, ureg->sirfsoc_int_en_reg)|
227				uint_en->sirfsoc_txfifo_empty_en);
228		else
229			wr_regl(port, ureg->sirfsoc_int_en_reg,
230				uint_en->sirfsoc_txfifo_empty_en);
231		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_START);
232	} else {
233		/* tx transfer mode switch into dma mode */
234		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_STOP);
235		wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl,
236			rd_regl(port, ureg->sirfsoc_tx_dma_io_ctrl)&
237			~SIRFUART_IO_MODE);
238		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_START);
239		tran_size &= ~(0x3);
240
241		sirfport->tx_dma_addr = dma_map_single(port->dev,
242			xmit->buf + xmit->tail,
243			tran_size, DMA_TO_DEVICE);
244		sirfport->tx_dma_desc = dmaengine_prep_slave_single(
245			sirfport->tx_dma_chan, sirfport->tx_dma_addr,
246			tran_size, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
247		if (!sirfport->tx_dma_desc) {
248			dev_err(port->dev, "DMA prep slave single fail\n");
249			return;
250		}
251		sirfport->tx_dma_desc->callback =
252			sirfsoc_uart_tx_dma_complete_callback;
253		sirfport->tx_dma_desc->callback_param = (void *)sirfport;
254		sirfport->transfer_size = tran_size;
255
256		dmaengine_submit(sirfport->tx_dma_desc);
257		dma_async_issue_pending(sirfport->tx_dma_chan);
258		sirfport->tx_dma_state = TX_DMA_RUNNING;
259	}
260}
261
262static void sirfsoc_uart_start_tx(struct uart_port *port)
263{
264	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
265	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
266	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
267	if (sirfport->tx_dma_chan)
268		sirfsoc_uart_tx_with_dma(sirfport);
269	else {
270		if (sirfport->uart_reg->uart_type == SIRF_USP_UART)
271			wr_regl(port, ureg->sirfsoc_tx_rx_en, rd_regl(port,
272				ureg->sirfsoc_tx_rx_en) | SIRFUART_TX_EN);
273		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_STOP);
274		sirfsoc_uart_pio_tx_chars(sirfport, port->fifosize);
275		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_START);
276		if (!sirfport->is_atlas7)
277			wr_regl(port, ureg->sirfsoc_int_en_reg,
278					rd_regl(port, ureg->sirfsoc_int_en_reg)|
279					uint_en->sirfsoc_txfifo_empty_en);
280		else
281			wr_regl(port, ureg->sirfsoc_int_en_reg,
282					uint_en->sirfsoc_txfifo_empty_en);
283	}
284}
285
286static void sirfsoc_uart_stop_rx(struct uart_port *port)
287{
288	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
289	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
290	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
291
292	wr_regl(port, ureg->sirfsoc_rx_fifo_op, 0);
293	if (sirfport->rx_dma_chan) {
294		if (!sirfport->is_atlas7)
295			wr_regl(port, ureg->sirfsoc_int_en_reg,
296				rd_regl(port, ureg->sirfsoc_int_en_reg) &
297				~(SIRFUART_RX_DMA_INT_EN(uint_en,
298				sirfport->uart_reg->uart_type) |
299				uint_en->sirfsoc_rx_done_en));
300		else
301			wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
302				SIRFUART_RX_DMA_INT_EN(uint_en,
303				sirfport->uart_reg->uart_type)|
304				uint_en->sirfsoc_rx_done_en);
305		dmaengine_terminate_all(sirfport->rx_dma_chan);
306	} else {
307		if (!sirfport->is_atlas7)
308			wr_regl(port, ureg->sirfsoc_int_en_reg,
309				rd_regl(port, ureg->sirfsoc_int_en_reg)&
310				~(SIRFUART_RX_IO_INT_EN(uint_en,
311				sirfport->uart_reg->uart_type)));
312		else
313			wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
314				SIRFUART_RX_IO_INT_EN(uint_en,
315				sirfport->uart_reg->uart_type));
316	}
317}
318
319static void sirfsoc_uart_disable_ms(struct uart_port *port)
320{
321	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
322	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
323	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
324
325	if (!sirfport->hw_flow_ctrl)
326		return;
327	sirfport->ms_enabled = false;
328	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
329		wr_regl(port, ureg->sirfsoc_afc_ctrl,
330				rd_regl(port, ureg->sirfsoc_afc_ctrl) & ~0x3FF);
331		if (!sirfport->is_atlas7)
332			wr_regl(port, ureg->sirfsoc_int_en_reg,
333					rd_regl(port, ureg->sirfsoc_int_en_reg)&
334					~uint_en->sirfsoc_cts_en);
335		else
336			wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
337					uint_en->sirfsoc_cts_en);
338	} else
339		disable_irq(gpio_to_irq(sirfport->cts_gpio));
340}
341
342static irqreturn_t sirfsoc_uart_usp_cts_handler(int irq, void *dev_id)
343{
344	struct sirfsoc_uart_port *sirfport = (struct sirfsoc_uart_port *)dev_id;
345	struct uart_port *port = &sirfport->port;
346	spin_lock(&port->lock);
347	if (gpio_is_valid(sirfport->cts_gpio) && sirfport->ms_enabled)
348		uart_handle_cts_change(port,
349				!gpio_get_value(sirfport->cts_gpio));
350	spin_unlock(&port->lock);
351	return IRQ_HANDLED;
352}
353
354static void sirfsoc_uart_enable_ms(struct uart_port *port)
355{
356	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
357	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
358	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
359
360	if (!sirfport->hw_flow_ctrl)
361		return;
362	sirfport->ms_enabled = true;
363	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
364		wr_regl(port, ureg->sirfsoc_afc_ctrl,
365				rd_regl(port, ureg->sirfsoc_afc_ctrl) |
366				SIRFUART_AFC_TX_EN | SIRFUART_AFC_RX_EN |
367				SIRFUART_AFC_CTRL_RX_THD);
368		if (!sirfport->is_atlas7)
369			wr_regl(port, ureg->sirfsoc_int_en_reg,
370					rd_regl(port, ureg->sirfsoc_int_en_reg)
371					| uint_en->sirfsoc_cts_en);
372		else
373			wr_regl(port, ureg->sirfsoc_int_en_reg,
374					uint_en->sirfsoc_cts_en);
375	} else
376		enable_irq(gpio_to_irq(sirfport->cts_gpio));
377}
378
379static void sirfsoc_uart_break_ctl(struct uart_port *port, int break_state)
380{
381	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
382	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
383	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
384		unsigned long ulcon = rd_regl(port, ureg->sirfsoc_line_ctrl);
385		if (break_state)
386			ulcon |= SIRFUART_SET_BREAK;
387		else
388			ulcon &= ~SIRFUART_SET_BREAK;
389		wr_regl(port, ureg->sirfsoc_line_ctrl, ulcon);
390	}
391}
392
393static unsigned int
394sirfsoc_uart_pio_rx_chars(struct uart_port *port, unsigned int max_rx_count)
395{
396	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
397	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
398	struct sirfsoc_fifo_status *ufifo_st = &sirfport->uart_reg->fifo_status;
399	unsigned int ch, rx_count = 0;
400	struct tty_struct *tty;
401	tty = tty_port_tty_get(&port->state->port);
402	if (!tty)
403		return -ENODEV;
404	while (!(rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
405					ufifo_st->ff_empty(port))) {
406		ch = rd_regl(port, ureg->sirfsoc_rx_fifo_data) |
407			SIRFUART_DUMMY_READ;
408		if (unlikely(uart_handle_sysrq_char(port, ch)))
409			continue;
410		uart_insert_char(port, 0, 0, ch, TTY_NORMAL);
411		rx_count++;
412		if (rx_count >= max_rx_count)
413			break;
414	}
415
416	port->icount.rx += rx_count;
417
418	return rx_count;
419}
420
421static unsigned int
422sirfsoc_uart_pio_tx_chars(struct sirfsoc_uart_port *sirfport, int count)
423{
424	struct uart_port *port = &sirfport->port;
425	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
426	struct sirfsoc_fifo_status *ufifo_st = &sirfport->uart_reg->fifo_status;
427	struct circ_buf *xmit = &port->state->xmit;
428	unsigned int num_tx = 0;
429	while (!uart_circ_empty(xmit) &&
430		!(rd_regl(port, ureg->sirfsoc_tx_fifo_status) &
431					ufifo_st->ff_full(port)) &&
432		count--) {
433		wr_regl(port, ureg->sirfsoc_tx_fifo_data,
434				xmit->buf[xmit->tail]);
435		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
436		port->icount.tx++;
437		num_tx++;
438	}
439	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
440		uart_write_wakeup(port);
441	return num_tx;
442}
443
444static void sirfsoc_uart_tx_dma_complete_callback(void *param)
445{
446	struct sirfsoc_uart_port *sirfport = (struct sirfsoc_uart_port *)param;
447	struct uart_port *port = &sirfport->port;
448	struct circ_buf *xmit = &port->state->xmit;
449	unsigned long flags;
450
451	spin_lock_irqsave(&port->lock, flags);
452	xmit->tail = (xmit->tail + sirfport->transfer_size) &
453				(UART_XMIT_SIZE - 1);
454	port->icount.tx += sirfport->transfer_size;
455	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
456		uart_write_wakeup(port);
457	if (sirfport->tx_dma_addr)
458		dma_unmap_single(port->dev, sirfport->tx_dma_addr,
459				sirfport->transfer_size, DMA_TO_DEVICE);
460	sirfport->tx_dma_state = TX_DMA_IDLE;
461	sirfsoc_uart_tx_with_dma(sirfport);
462	spin_unlock_irqrestore(&port->lock, flags);
463}
464
465static irqreturn_t sirfsoc_uart_isr(int irq, void *dev_id)
466{
467	unsigned long intr_status;
468	unsigned long cts_status;
469	unsigned long flag = TTY_NORMAL;
470	struct sirfsoc_uart_port *sirfport = (struct sirfsoc_uart_port *)dev_id;
471	struct uart_port *port = &sirfport->port;
472	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
473	struct sirfsoc_fifo_status *ufifo_st = &sirfport->uart_reg->fifo_status;
474	struct sirfsoc_int_status *uint_st = &sirfport->uart_reg->uart_int_st;
475	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
476	struct uart_state *state = port->state;
477	struct circ_buf *xmit = &port->state->xmit;
478	spin_lock(&port->lock);
479	intr_status = rd_regl(port, ureg->sirfsoc_int_st_reg);
480	wr_regl(port, ureg->sirfsoc_int_st_reg, intr_status);
481	intr_status &= rd_regl(port, ureg->sirfsoc_int_en_reg);
482	if (unlikely(intr_status & (SIRFUART_ERR_INT_STAT(uint_st,
483				sirfport->uart_reg->uart_type)))) {
484		if (intr_status & uint_st->sirfsoc_rxd_brk) {
485			port->icount.brk++;
486			if (uart_handle_break(port))
487				goto recv_char;
488		}
489		if (intr_status & uint_st->sirfsoc_rx_oflow) {
490			port->icount.overrun++;
491			flag = TTY_OVERRUN;
492		}
493		if (intr_status & uint_st->sirfsoc_frm_err) {
494			port->icount.frame++;
495			flag = TTY_FRAME;
496		}
497		if (intr_status & uint_st->sirfsoc_parity_err) {
498			port->icount.parity++;
499			flag = TTY_PARITY;
500		}
501		wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_RESET);
502		wr_regl(port, ureg->sirfsoc_rx_fifo_op, 0);
503		wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_START);
504		intr_status &= port->read_status_mask;
505		uart_insert_char(port, intr_status,
506					uint_en->sirfsoc_rx_oflow_en, 0, flag);
507	}
508recv_char:
509	if ((sirfport->uart_reg->uart_type == SIRF_REAL_UART) &&
510			(intr_status & SIRFUART_CTS_INT_ST(uint_st)) &&
511			!sirfport->tx_dma_state) {
512		cts_status = rd_regl(port, ureg->sirfsoc_afc_ctrl) &
513					SIRFUART_AFC_CTS_STATUS;
514		if (cts_status != 0)
515			cts_status = 0;
516		else
517			cts_status = 1;
518		uart_handle_cts_change(port, cts_status);
519		wake_up_interruptible(&state->port.delta_msr_wait);
520	}
521	if (!sirfport->rx_dma_chan &&
522		(intr_status & SIRFUART_RX_IO_INT_ST(uint_st))) {
523		/*
524		 * chip will trigger continuous RX_TIMEOUT interrupt
525		 * in RXFIFO empty and not trigger if RXFIFO recevice
526		 * data in limit time, original method use RX_TIMEOUT
527		 * will trigger lots of useless interrupt in RXFIFO
528		 * empty.RXFIFO received one byte will trigger RX_DONE
529		 * interrupt.use RX_DONE to wait for data received
530		 * into RXFIFO, use RX_THD/RX_FULL for lots data receive
531		 * and use RX_TIMEOUT for the last left data.
532		 */
533		if (intr_status & uint_st->sirfsoc_rx_done) {
534			if (!sirfport->is_atlas7) {
535				wr_regl(port, ureg->sirfsoc_int_en_reg,
536					rd_regl(port, ureg->sirfsoc_int_en_reg)
537					& ~(uint_en->sirfsoc_rx_done_en));
538				wr_regl(port, ureg->sirfsoc_int_en_reg,
539				rd_regl(port, ureg->sirfsoc_int_en_reg)
540				| (uint_en->sirfsoc_rx_timeout_en));
541			} else {
542				wr_regl(port, ureg->sirfsoc_int_en_clr_reg,
543					uint_en->sirfsoc_rx_done_en);
544				wr_regl(port, ureg->sirfsoc_int_en_reg,
545					uint_en->sirfsoc_rx_timeout_en);
546			}
547		} else {
548			if (intr_status & uint_st->sirfsoc_rx_timeout) {
549				if (!sirfport->is_atlas7) {
550					wr_regl(port, ureg->sirfsoc_int_en_reg,
551					rd_regl(port, ureg->sirfsoc_int_en_reg)
552					& ~(uint_en->sirfsoc_rx_timeout_en));
553					wr_regl(port, ureg->sirfsoc_int_en_reg,
554					rd_regl(port, ureg->sirfsoc_int_en_reg)
555					| (uint_en->sirfsoc_rx_done_en));
556				} else {
557					wr_regl(port,
558						ureg->sirfsoc_int_en_clr_reg,
559						uint_en->sirfsoc_rx_timeout_en);
560					wr_regl(port, ureg->sirfsoc_int_en_reg,
561						uint_en->sirfsoc_rx_done_en);
562				}
563			}
564			sirfsoc_uart_pio_rx_chars(port, port->fifosize);
565		}
566	}
567	spin_unlock(&port->lock);
568	tty_flip_buffer_push(&state->port);
569	spin_lock(&port->lock);
570	if (intr_status & uint_st->sirfsoc_txfifo_empty) {
571		if (sirfport->tx_dma_chan)
572			sirfsoc_uart_tx_with_dma(sirfport);
573		else {
574			if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
575				spin_unlock(&port->lock);
576				return IRQ_HANDLED;
577			} else {
578				sirfsoc_uart_pio_tx_chars(sirfport,
579						port->fifosize);
580				if ((uart_circ_empty(xmit)) &&
581				(rd_regl(port, ureg->sirfsoc_tx_fifo_status) &
582				ufifo_st->ff_empty(port)))
583					sirfsoc_uart_stop_tx(port);
584			}
585		}
586	}
587	spin_unlock(&port->lock);
588
589	return IRQ_HANDLED;
590}
591
592static void sirfsoc_uart_rx_dma_complete_callback(void *param)
593{
594}
595
596/* submit rx dma task into dmaengine */
597static void sirfsoc_uart_start_next_rx_dma(struct uart_port *port)
598{
599	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
600	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
601	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
602	wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
603		rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
604		~SIRFUART_IO_MODE);
605	sirfport->rx_dma_items.xmit.tail =
606		sirfport->rx_dma_items.xmit.head = 0;
607	sirfport->rx_dma_items.desc =
608		dmaengine_prep_dma_cyclic(sirfport->rx_dma_chan,
609		sirfport->rx_dma_items.dma_addr, SIRFSOC_RX_DMA_BUF_SIZE,
610		SIRFSOC_RX_DMA_BUF_SIZE / 2,
611		DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
612	if (IS_ERR_OR_NULL(sirfport->rx_dma_items.desc)) {
613		dev_err(port->dev, "DMA slave single fail\n");
614		return;
615	}
616	sirfport->rx_dma_items.desc->callback =
617		sirfsoc_uart_rx_dma_complete_callback;
618	sirfport->rx_dma_items.desc->callback_param = sirfport;
619	sirfport->rx_dma_items.cookie =
620		dmaengine_submit(sirfport->rx_dma_items.desc);
621	dma_async_issue_pending(sirfport->rx_dma_chan);
622	if (!sirfport->is_atlas7)
623		wr_regl(port, ureg->sirfsoc_int_en_reg,
624				rd_regl(port, ureg->sirfsoc_int_en_reg) |
625				SIRFUART_RX_DMA_INT_EN(uint_en,
626				sirfport->uart_reg->uart_type));
627	else
628		wr_regl(port, ureg->sirfsoc_int_en_reg,
629				SIRFUART_RX_DMA_INT_EN(uint_en,
630				sirfport->uart_reg->uart_type));
631}
632
633static unsigned int
634sirfsoc_usp_calc_sample_div(unsigned long set_rate,
635		unsigned long ioclk_rate, unsigned long *sample_reg)
636{
637	unsigned long min_delta = ~0UL;
638	unsigned short sample_div;
639	unsigned long ioclk_div = 0;
640	unsigned long temp_delta;
641
642	for (sample_div = SIRF_USP_MIN_SAMPLE_DIV;
643			sample_div <= SIRF_MAX_SAMPLE_DIV; sample_div++) {
644		temp_delta = ioclk_rate -
645		(ioclk_rate + (set_rate * sample_div) / 2)
646		/ (set_rate * sample_div) * set_rate * sample_div;
647
648		temp_delta = (temp_delta > 0) ? temp_delta : -temp_delta;
649		if (temp_delta < min_delta) {
650			ioclk_div = (2 * ioclk_rate /
651				(set_rate * sample_div) + 1) / 2 - 1;
652			if (ioclk_div > SIRF_IOCLK_DIV_MAX)
653				continue;
654			min_delta = temp_delta;
655			*sample_reg = sample_div;
656			if (!temp_delta)
657				break;
658		}
659	}
660	return ioclk_div;
661}
662
663static unsigned int
664sirfsoc_uart_calc_sample_div(unsigned long baud_rate,
665			unsigned long ioclk_rate, unsigned long *set_baud)
666{
667	unsigned long min_delta = ~0UL;
668	unsigned short sample_div;
669	unsigned int regv = 0;
670	unsigned long ioclk_div;
671	unsigned long baud_tmp;
672	int temp_delta;
673
674	for (sample_div = SIRF_MIN_SAMPLE_DIV;
675			sample_div <= SIRF_MAX_SAMPLE_DIV; sample_div++) {
676		ioclk_div = (ioclk_rate / (baud_rate * (sample_div + 1))) - 1;
677		if (ioclk_div > SIRF_IOCLK_DIV_MAX)
678			continue;
679		baud_tmp = ioclk_rate / ((ioclk_div + 1) * (sample_div + 1));
680		temp_delta = baud_tmp - baud_rate;
681		temp_delta = (temp_delta > 0) ? temp_delta : -temp_delta;
682		if (temp_delta < min_delta) {
683			regv = regv & (~SIRF_IOCLK_DIV_MASK);
684			regv = regv | ioclk_div;
685			regv = regv & (~SIRF_SAMPLE_DIV_MASK);
686			regv = regv | (sample_div << SIRF_SAMPLE_DIV_SHIFT);
687			min_delta = temp_delta;
688			*set_baud = baud_tmp;
689		}
690	}
691	return regv;
692}
693
694static void sirfsoc_uart_set_termios(struct uart_port *port,
695				       struct ktermios *termios,
696				       struct ktermios *old)
697{
698	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
699	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
700	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
701	unsigned long	config_reg = 0;
702	unsigned long	baud_rate;
703	unsigned long	set_baud;
704	unsigned long	flags;
705	unsigned long	ic;
706	unsigned int	clk_div_reg = 0;
707	unsigned long	txfifo_op_reg, ioclk_rate;
708	unsigned long	rx_time_out;
709	int		threshold_div;
710	u32		data_bit_len, stop_bit_len, len_val;
711	unsigned long	sample_div_reg = 0xf;
712	ioclk_rate	= port->uartclk;
713
714	switch (termios->c_cflag & CSIZE) {
715	default:
716	case CS8:
717		data_bit_len = 8;
718		config_reg |= SIRFUART_DATA_BIT_LEN_8;
719		break;
720	case CS7:
721		data_bit_len = 7;
722		config_reg |= SIRFUART_DATA_BIT_LEN_7;
723		break;
724	case CS6:
725		data_bit_len = 6;
726		config_reg |= SIRFUART_DATA_BIT_LEN_6;
727		break;
728	case CS5:
729		data_bit_len = 5;
730		config_reg |= SIRFUART_DATA_BIT_LEN_5;
731		break;
732	}
733	if (termios->c_cflag & CSTOPB) {
734		config_reg |= SIRFUART_STOP_BIT_LEN_2;
735		stop_bit_len = 2;
736	} else
737		stop_bit_len = 1;
738
739	spin_lock_irqsave(&port->lock, flags);
740	port->read_status_mask = uint_en->sirfsoc_rx_oflow_en;
741	port->ignore_status_mask = 0;
742	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
743		if (termios->c_iflag & INPCK)
744			port->read_status_mask |= uint_en->sirfsoc_frm_err_en |
745				uint_en->sirfsoc_parity_err_en;
746	} else {
747		if (termios->c_iflag & INPCK)
748			port->read_status_mask |= uint_en->sirfsoc_frm_err_en;
749	}
750	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
751			port->read_status_mask |= uint_en->sirfsoc_rxd_brk_en;
752	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
753		if (termios->c_iflag & IGNPAR)
754			port->ignore_status_mask |=
755				uint_en->sirfsoc_frm_err_en |
756				uint_en->sirfsoc_parity_err_en;
757		if (termios->c_cflag & PARENB) {
758			if (termios->c_cflag & CMSPAR) {
759				if (termios->c_cflag & PARODD)
760					config_reg |= SIRFUART_STICK_BIT_MARK;
761				else
762					config_reg |= SIRFUART_STICK_BIT_SPACE;
763			} else {
764				if (termios->c_cflag & PARODD)
765					config_reg |= SIRFUART_STICK_BIT_ODD;
766				else
767					config_reg |= SIRFUART_STICK_BIT_EVEN;
768			}
769		}
770	} else {
771		if (termios->c_iflag & IGNPAR)
772			port->ignore_status_mask |=
773				uint_en->sirfsoc_frm_err_en;
774		if (termios->c_cflag & PARENB)
775			dev_warn(port->dev,
776					"USP-UART not support parity err\n");
777	}
778	if (termios->c_iflag & IGNBRK) {
779		port->ignore_status_mask |=
780			uint_en->sirfsoc_rxd_brk_en;
781		if (termios->c_iflag & IGNPAR)
782			port->ignore_status_mask |=
783				uint_en->sirfsoc_rx_oflow_en;
784	}
785	if ((termios->c_cflag & CREAD) == 0)
786		port->ignore_status_mask |= SIRFUART_DUMMY_READ;
787	/* Hardware Flow Control Settings */
788	if (UART_ENABLE_MS(port, termios->c_cflag)) {
789		if (!sirfport->ms_enabled)
790			sirfsoc_uart_enable_ms(port);
791	} else {
792		if (sirfport->ms_enabled)
793			sirfsoc_uart_disable_ms(port);
794	}
795	baud_rate = uart_get_baud_rate(port, termios, old, 0, 4000000);
796	if (ioclk_rate == 150000000) {
797		for (ic = 0; ic < SIRF_BAUD_RATE_SUPPORT_NR; ic++)
798			if (baud_rate == baudrate_to_regv[ic].baud_rate)
799				clk_div_reg = baudrate_to_regv[ic].reg_val;
800	}
801	set_baud = baud_rate;
802	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
803		if (unlikely(clk_div_reg == 0))
804			clk_div_reg = sirfsoc_uart_calc_sample_div(baud_rate,
805					ioclk_rate, &set_baud);
806		wr_regl(port, ureg->sirfsoc_divisor, clk_div_reg);
807	} else {
808		clk_div_reg = sirfsoc_usp_calc_sample_div(baud_rate,
809				ioclk_rate, &sample_div_reg);
810		sample_div_reg--;
811		set_baud = ((ioclk_rate / (clk_div_reg+1) - 1) /
812				(sample_div_reg + 1));
813		/* setting usp mode 2 */
814		len_val = ((1 << SIRFSOC_USP_MODE2_RXD_DELAY_OFFSET) |
815				(1 << SIRFSOC_USP_MODE2_TXD_DELAY_OFFSET));
816		len_val |= ((clk_div_reg & SIRFSOC_USP_MODE2_CLK_DIVISOR_MASK)
817				<< SIRFSOC_USP_MODE2_CLK_DIVISOR_OFFSET);
818		wr_regl(port, ureg->sirfsoc_mode2, len_val);
819	}
820	if (tty_termios_baud_rate(termios))
821		tty_termios_encode_baud_rate(termios, set_baud, set_baud);
822	/* set receive timeout && data bits len */
823	rx_time_out = SIRFSOC_UART_RX_TIMEOUT(set_baud, 20000);
824	rx_time_out = SIRFUART_RECV_TIMEOUT_VALUE(rx_time_out);
825	txfifo_op_reg = rd_regl(port, ureg->sirfsoc_tx_fifo_op);
826	wr_regl(port, ureg->sirfsoc_tx_fifo_op,
827			(txfifo_op_reg & ~SIRFUART_FIFO_START));
828	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
829		config_reg |= SIRFUART_UART_RECV_TIMEOUT(rx_time_out);
830		wr_regl(port, ureg->sirfsoc_line_ctrl, config_reg);
831	} else {
832		/*tx frame ctrl*/
833		len_val = (data_bit_len - 1) << SIRFSOC_USP_TX_DATA_LEN_OFFSET;
834		len_val |= (data_bit_len + 1 + stop_bit_len - 1) <<
835				SIRFSOC_USP_TX_FRAME_LEN_OFFSET;
836		len_val |= ((data_bit_len - 1) <<
837				SIRFSOC_USP_TX_SHIFTER_LEN_OFFSET);
838		len_val |= (((clk_div_reg & 0xc00) >> 10) <<
839				SIRFSOC_USP_TX_CLK_DIVISOR_OFFSET);
840		wr_regl(port, ureg->sirfsoc_tx_frame_ctrl, len_val);
841		/*rx frame ctrl*/
842		len_val = (data_bit_len - 1) << SIRFSOC_USP_RX_DATA_LEN_OFFSET;
843		len_val |= (data_bit_len + 1 + stop_bit_len - 1) <<
844				SIRFSOC_USP_RX_FRAME_LEN_OFFSET;
845		len_val |= (data_bit_len - 1) <<
846				SIRFSOC_USP_RX_SHIFTER_LEN_OFFSET;
847		len_val |= (((clk_div_reg & 0xf000) >> 12) <<
848				SIRFSOC_USP_RX_CLK_DIVISOR_OFFSET);
849		wr_regl(port, ureg->sirfsoc_rx_frame_ctrl, len_val);
850		/*async param*/
851		wr_regl(port, ureg->sirfsoc_async_param_reg,
852			(SIRFUART_USP_RECV_TIMEOUT(rx_time_out)) |
853			(sample_div_reg & SIRFSOC_USP_ASYNC_DIV2_MASK) <<
854			SIRFSOC_USP_ASYNC_DIV2_OFFSET);
855	}
856	if (sirfport->tx_dma_chan)
857		wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl, SIRFUART_DMA_MODE);
858	else
859		wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl, SIRFUART_IO_MODE);
860	if (sirfport->rx_dma_chan)
861		wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
862			rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
863			~SIRFUART_IO_MODE);
864	else
865		wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
866			rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
867			SIRFUART_IO_MODE);
868	sirfport->rx_period_time = 20000000;
869	/* Reset Rx/Tx FIFO Threshold level for proper baudrate */
870	if (set_baud < 1000000)
871		threshold_div = 1;
872	else
873		threshold_div = 2;
874	wr_regl(port, ureg->sirfsoc_tx_fifo_ctrl,
875				SIRFUART_FIFO_THD(port) / threshold_div);
876	wr_regl(port, ureg->sirfsoc_rx_fifo_ctrl,
877				SIRFUART_FIFO_THD(port) / threshold_div);
878	txfifo_op_reg |= SIRFUART_FIFO_START;
879	wr_regl(port, ureg->sirfsoc_tx_fifo_op, txfifo_op_reg);
880	uart_update_timeout(port, termios->c_cflag, set_baud);
881	wr_regl(port, ureg->sirfsoc_tx_rx_en, SIRFUART_TX_EN | SIRFUART_RX_EN);
882	spin_unlock_irqrestore(&port->lock, flags);
883}
884
885static void sirfsoc_uart_pm(struct uart_port *port, unsigned int state,
886			      unsigned int oldstate)
887{
888	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
889	if (!state)
890		clk_prepare_enable(sirfport->clk);
891	else
892		clk_disable_unprepare(sirfport->clk);
893}
894
895static int sirfsoc_uart_startup(struct uart_port *port)
896{
897	struct sirfsoc_uart_port *sirfport	= to_sirfport(port);
898	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
899	struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
900	unsigned int index			= port->line;
901	int ret;
902	irq_modify_status(port->irq, IRQ_NOREQUEST, IRQ_NOAUTOEN);
903	ret = request_irq(port->irq,
904				sirfsoc_uart_isr,
905				0,
906				SIRFUART_PORT_NAME,
907				sirfport);
908	if (ret != 0) {
909		dev_err(port->dev, "UART%d request IRQ line (%d) failed.\n",
910							index, port->irq);
911		goto irq_err;
912	}
913	/* initial hardware settings */
914	wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl,
915		rd_regl(port, ureg->sirfsoc_tx_dma_io_ctrl) |
916		SIRFUART_IO_MODE);
917	wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
918		rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
919		SIRFUART_IO_MODE);
920	wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
921		rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
922		~SIRFUART_RX_DMA_FLUSH);
923	wr_regl(port, ureg->sirfsoc_tx_dma_io_len, 0);
924	wr_regl(port, ureg->sirfsoc_rx_dma_io_len, 0);
925	wr_regl(port, ureg->sirfsoc_tx_rx_en, SIRFUART_RX_EN | SIRFUART_TX_EN);
926	if (sirfport->uart_reg->uart_type == SIRF_USP_UART)
927		wr_regl(port, ureg->sirfsoc_mode1,
928			SIRFSOC_USP_ENDIAN_CTRL_LSBF |
929			SIRFSOC_USP_EN);
930	wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_RESET);
931	wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_RESET);
932	wr_regl(port, ureg->sirfsoc_rx_fifo_op, 0);
933	wr_regl(port, ureg->sirfsoc_tx_fifo_ctrl, SIRFUART_FIFO_THD(port));
934	wr_regl(port, ureg->sirfsoc_rx_fifo_ctrl, SIRFUART_FIFO_THD(port));
935	if (sirfport->rx_dma_chan)
936		wr_regl(port, ureg->sirfsoc_rx_fifo_level_chk,
937			SIRFUART_RX_FIFO_CHK_SC(port->line, 0x1) |
938			SIRFUART_RX_FIFO_CHK_LC(port->line, 0x2) |
939			SIRFUART_RX_FIFO_CHK_HC(port->line, 0x4));
940	if (sirfport->tx_dma_chan) {
941		sirfport->tx_dma_state = TX_DMA_IDLE;
942		wr_regl(port, ureg->sirfsoc_tx_fifo_level_chk,
943				SIRFUART_TX_FIFO_CHK_SC(port->line, 0x1b) |
944				SIRFUART_TX_FIFO_CHK_LC(port->line, 0xe) |
945				SIRFUART_TX_FIFO_CHK_HC(port->line, 0x4));
946	}
947	sirfport->ms_enabled = false;
948	if (sirfport->uart_reg->uart_type == SIRF_USP_UART &&
949		sirfport->hw_flow_ctrl) {
950		irq_modify_status(gpio_to_irq(sirfport->cts_gpio),
951			IRQ_NOREQUEST, IRQ_NOAUTOEN);
952		ret = request_irq(gpio_to_irq(sirfport->cts_gpio),
953			sirfsoc_uart_usp_cts_handler, IRQF_TRIGGER_FALLING |
954			IRQF_TRIGGER_RISING, "usp_cts_irq", sirfport);
955		if (ret != 0) {
956			dev_err(port->dev, "UART-USP:request gpio irq fail\n");
957			goto init_rx_err;
958		}
959	}
960	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART &&
961		sirfport->rx_dma_chan)
962		wr_regl(port, ureg->sirfsoc_swh_dma_io,
963			SIRFUART_CLEAR_RX_ADDR_EN);
964	if (sirfport->uart_reg->uart_type == SIRF_USP_UART &&
965			sirfport->rx_dma_chan)
966		wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
967			rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
968			SIRFSOC_USP_FRADDR_CLR_EN);
969	if (sirfport->rx_dma_chan && !sirfport->is_hrt_enabled) {
970		sirfport->is_hrt_enabled = true;
971		sirfport->rx_period_time = 20000000;
972		sirfport->rx_last_pos = -1;
973		sirfport->pio_fetch_cnt = 0;
974		sirfport->rx_dma_items.xmit.tail =
975			sirfport->rx_dma_items.xmit.head = 0;
976		hrtimer_start(&sirfport->hrt,
977			ns_to_ktime(sirfport->rx_period_time),
978			HRTIMER_MODE_REL);
979	}
980	wr_regl(port, ureg->sirfsoc_rx_fifo_op, SIRFUART_FIFO_START);
981	if (sirfport->rx_dma_chan)
982		sirfsoc_uart_start_next_rx_dma(port);
983	else {
984		if (!sirfport->is_atlas7)
985			wr_regl(port, ureg->sirfsoc_int_en_reg,
986				rd_regl(port, ureg->sirfsoc_int_en_reg) |
987				SIRFUART_RX_IO_INT_EN(uint_en,
988					sirfport->uart_reg->uart_type));
989		else
990			wr_regl(port, ureg->sirfsoc_int_en_reg,
991				SIRFUART_RX_IO_INT_EN(uint_en,
992					sirfport->uart_reg->uart_type));
993	}
994	enable_irq(port->irq);
995
996	return 0;
997init_rx_err:
998	free_irq(port->irq, sirfport);
999irq_err:
1000	return ret;
1001}
1002
1003static void sirfsoc_uart_shutdown(struct uart_port *port)
1004{
1005	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
1006	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
1007	struct circ_buf *xmit;
1008
1009	xmit = &sirfport->rx_dma_items.xmit;
1010	if (!sirfport->is_atlas7)
1011		wr_regl(port, ureg->sirfsoc_int_en_reg, 0);
1012	else
1013		wr_regl(port, ureg->sirfsoc_int_en_clr_reg, ~0UL);
1014
1015	free_irq(port->irq, sirfport);
1016	if (sirfport->ms_enabled)
1017		sirfsoc_uart_disable_ms(port);
1018	if (sirfport->uart_reg->uart_type == SIRF_USP_UART &&
1019			sirfport->hw_flow_ctrl) {
1020		gpio_set_value(sirfport->rts_gpio, 1);
1021		free_irq(gpio_to_irq(sirfport->cts_gpio), sirfport);
1022	}
1023	if (sirfport->tx_dma_chan)
1024		sirfport->tx_dma_state = TX_DMA_IDLE;
1025	if (sirfport->rx_dma_chan && sirfport->is_hrt_enabled) {
1026		while (((rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
1027			SIRFUART_RX_FIFO_MASK) > sirfport->pio_fetch_cnt) &&
1028			!CIRC_CNT(xmit->head, xmit->tail,
1029			SIRFSOC_RX_DMA_BUF_SIZE))
1030			;
1031		sirfport->is_hrt_enabled = false;
1032		hrtimer_cancel(&sirfport->hrt);
1033	}
1034}
1035
1036static const char *sirfsoc_uart_type(struct uart_port *port)
1037{
1038	return port->type == SIRFSOC_PORT_TYPE ? SIRFUART_PORT_NAME : NULL;
1039}
1040
1041static int sirfsoc_uart_request_port(struct uart_port *port)
1042{
1043	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
1044	struct sirfsoc_uart_param *uart_param = &sirfport->uart_reg->uart_param;
1045	void *ret;
1046	ret = request_mem_region(port->mapbase,
1047		SIRFUART_MAP_SIZE, uart_param->port_name);
1048	return ret ? 0 : -EBUSY;
1049}
1050
1051static void sirfsoc_uart_release_port(struct uart_port *port)
1052{
1053	release_mem_region(port->mapbase, SIRFUART_MAP_SIZE);
1054}
1055
1056static void sirfsoc_uart_config_port(struct uart_port *port, int flags)
1057{
1058	if (flags & UART_CONFIG_TYPE) {
1059		port->type = SIRFSOC_PORT_TYPE;
1060		sirfsoc_uart_request_port(port);
1061	}
1062}
1063
1064static struct uart_ops sirfsoc_uart_ops = {
1065	.tx_empty	= sirfsoc_uart_tx_empty,
1066	.get_mctrl	= sirfsoc_uart_get_mctrl,
1067	.set_mctrl	= sirfsoc_uart_set_mctrl,
1068	.stop_tx	= sirfsoc_uart_stop_tx,
1069	.start_tx	= sirfsoc_uart_start_tx,
1070	.stop_rx	= sirfsoc_uart_stop_rx,
1071	.enable_ms	= sirfsoc_uart_enable_ms,
1072	.break_ctl	= sirfsoc_uart_break_ctl,
1073	.startup	= sirfsoc_uart_startup,
1074	.shutdown	= sirfsoc_uart_shutdown,
1075	.set_termios	= sirfsoc_uart_set_termios,
1076	.pm		= sirfsoc_uart_pm,
1077	.type		= sirfsoc_uart_type,
1078	.release_port	= sirfsoc_uart_release_port,
1079	.request_port	= sirfsoc_uart_request_port,
1080	.config_port	= sirfsoc_uart_config_port,
1081};
1082
1083#ifdef CONFIG_SERIAL_SIRFSOC_CONSOLE
1084static int __init
1085sirfsoc_uart_console_setup(struct console *co, char *options)
1086{
1087	unsigned int baud = 115200;
1088	unsigned int bits = 8;
1089	unsigned int parity = 'n';
1090	unsigned int flow = 'n';
1091	struct sirfsoc_uart_port *sirfport;
1092	struct sirfsoc_register *ureg;
1093	if (co->index < 0 || co->index >= SIRFSOC_UART_NR)
1094		co->index = 1;
1095	sirfport = sirf_ports[co->index];
1096	if (!sirfport)
1097		return -ENODEV;
1098	ureg = &sirfport->uart_reg->uart_reg;
1099	if (!sirfport->port.mapbase)
1100		return -ENODEV;
1101
1102	/* enable usp in mode1 register */
1103	if (sirfport->uart_reg->uart_type == SIRF_USP_UART)
1104		wr_regl(&sirfport->port, ureg->sirfsoc_mode1, SIRFSOC_USP_EN |
1105				SIRFSOC_USP_ENDIAN_CTRL_LSBF);
1106	if (options)
1107		uart_parse_options(options, &baud, &parity, &bits, &flow);
1108	sirfport->port.cons = co;
1109
1110	/* default console tx/rx transfer using io mode */
1111	sirfport->rx_dma_chan = NULL;
1112	sirfport->tx_dma_chan = NULL;
1113	return uart_set_options(&sirfport->port, co, baud, parity, bits, flow);
1114}
1115
1116static void sirfsoc_uart_console_putchar(struct uart_port *port, int ch)
1117{
1118	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
1119	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
1120	struct sirfsoc_fifo_status *ufifo_st = &sirfport->uart_reg->fifo_status;
1121	while (rd_regl(port, ureg->sirfsoc_tx_fifo_status) &
1122		ufifo_st->ff_full(port))
1123		cpu_relax();
1124	wr_regl(port, ureg->sirfsoc_tx_fifo_data, ch);
1125}
1126
1127static void sirfsoc_uart_console_write(struct console *co, const char *s,
1128							unsigned int count)
1129{
1130	struct sirfsoc_uart_port *sirfport = sirf_ports[co->index];
1131
1132	uart_console_write(&sirfport->port, s, count,
1133			sirfsoc_uart_console_putchar);
1134}
1135
1136static struct console sirfsoc_uart_console = {
1137	.name		= SIRFSOC_UART_NAME,
1138	.device		= uart_console_device,
1139	.flags		= CON_PRINTBUFFER,
1140	.index		= -1,
1141	.write		= sirfsoc_uart_console_write,
1142	.setup		= sirfsoc_uart_console_setup,
1143	.data           = &sirfsoc_uart_drv,
1144};
1145
1146static int __init sirfsoc_uart_console_init(void)
1147{
1148	register_console(&sirfsoc_uart_console);
1149	return 0;
1150}
1151console_initcall(sirfsoc_uart_console_init);
1152#endif
1153
1154static struct uart_driver sirfsoc_uart_drv = {
1155	.owner		= THIS_MODULE,
1156	.driver_name	= SIRFUART_PORT_NAME,
1157	.nr		= SIRFSOC_UART_NR,
1158	.dev_name	= SIRFSOC_UART_NAME,
1159	.major		= SIRFSOC_UART_MAJOR,
1160	.minor		= SIRFSOC_UART_MINOR,
1161#ifdef CONFIG_SERIAL_SIRFSOC_CONSOLE
1162	.cons			= &sirfsoc_uart_console,
1163#else
1164	.cons			= NULL,
1165#endif
1166};
1167
1168static enum hrtimer_restart
1169	sirfsoc_uart_rx_dma_hrtimer_callback(struct hrtimer *hrt)
1170{
1171	struct sirfsoc_uart_port *sirfport;
1172	struct uart_port *port;
1173	int count, inserted;
1174	struct dma_tx_state tx_state;
1175	struct tty_struct *tty;
1176	struct sirfsoc_register *ureg;
1177	struct circ_buf *xmit;
1178	struct sirfsoc_fifo_status *ufifo_st;
1179	int max_pio_cnt;
1180
1181	sirfport = container_of(hrt, struct sirfsoc_uart_port, hrt);
1182	port = &sirfport->port;
1183	inserted = 0;
1184	tty = port->state->port.tty;
1185	ureg = &sirfport->uart_reg->uart_reg;
1186	xmit = &sirfport->rx_dma_items.xmit;
1187	ufifo_st = &sirfport->uart_reg->fifo_status;
1188
1189	dmaengine_tx_status(sirfport->rx_dma_chan,
1190			sirfport->rx_dma_items.cookie, &tx_state);
1191	if (SIRFSOC_RX_DMA_BUF_SIZE - tx_state.residue !=
1192		sirfport->rx_last_pos) {
1193		xmit->head = SIRFSOC_RX_DMA_BUF_SIZE - tx_state.residue;
1194		sirfport->rx_last_pos = xmit->head;
1195		sirfport->pio_fetch_cnt = 0;
1196	}
1197	count = CIRC_CNT_TO_END(xmit->head, xmit->tail,
1198			SIRFSOC_RX_DMA_BUF_SIZE);
1199	while (count > 0) {
1200		inserted = tty_insert_flip_string(tty->port,
1201			(const unsigned char *)&xmit->buf[xmit->tail], count);
1202		if (!inserted)
1203			goto next_hrt;
1204		port->icount.rx += inserted;
1205		xmit->tail = (xmit->tail + inserted) &
1206				(SIRFSOC_RX_DMA_BUF_SIZE - 1);
1207		count = CIRC_CNT_TO_END(xmit->head, xmit->tail,
1208				SIRFSOC_RX_DMA_BUF_SIZE);
1209		tty_flip_buffer_push(tty->port);
1210	}
1211	/*
1212	 * if RX DMA buffer data have all push into tty buffer, and there is
1213	 * only little data(less than a dma transfer unit) left in rxfifo,
1214	 * fetch it out in pio mode and switch back to dma immediately
1215	 */
1216	if (!inserted && !count &&
1217		((rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
1218		SIRFUART_RX_FIFO_MASK) > sirfport->pio_fetch_cnt)) {
1219		dmaengine_pause(sirfport->rx_dma_chan);
1220		/* switch to pio mode */
1221		wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
1222			rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
1223			SIRFUART_IO_MODE);
1224		/*
1225		 * UART controller SWH_DMA_IO register have CLEAR_RX_ADDR_EN
1226		 * When found changing I/O to DMA mode, it clears
1227		 * two low bits of read point;
1228		 * USP have similar FRADDR_CLR_EN bit in USP_RX_DMA_IO_CTRL.
1229		 * Fetch data out from rxfifo into DMA buffer in PIO mode,
1230		 * while switch back to DMA mode, the data fetched will override
1231		 * by DMA, as hardware have a strange behaviour:
1232		 * after switch back to DMA mode, check rxfifo status it will
1233		 * be the number PIO fetched, so record the fetched data count
1234		 * to avoid the repeated fetch
1235		 */
1236		max_pio_cnt = 3;
1237		while (!(rd_regl(port, ureg->sirfsoc_rx_fifo_status) &
1238			ufifo_st->ff_empty(port)) && max_pio_cnt--) {
1239			xmit->buf[xmit->head] =
1240				rd_regl(port, ureg->sirfsoc_rx_fifo_data);
1241			xmit->head = (xmit->head + 1) &
1242					(SIRFSOC_RX_DMA_BUF_SIZE - 1);
1243			sirfport->pio_fetch_cnt++;
1244		}
1245		/* switch back to dma mode */
1246		wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
1247			rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) &
1248			~SIRFUART_IO_MODE);
1249		dmaengine_resume(sirfport->rx_dma_chan);
1250	}
1251next_hrt:
1252	hrtimer_forward_now(hrt, ns_to_ktime(sirfport->rx_period_time));
1253	return HRTIMER_RESTART;
1254}
1255
1256static struct of_device_id sirfsoc_uart_ids[] = {
1257	{ .compatible = "sirf,prima2-uart", .data = &sirfsoc_uart,},
1258	{ .compatible = "sirf,atlas7-uart", .data = &sirfsoc_uart},
1259	{ .compatible = "sirf,prima2-usp-uart", .data = &sirfsoc_usp},
1260	{ .compatible = "sirf,atlas7-usp-uart", .data = &sirfsoc_usp},
1261	{}
1262};
1263MODULE_DEVICE_TABLE(of, sirfsoc_uart_ids);
1264
1265static int sirfsoc_uart_probe(struct platform_device *pdev)
1266{
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, pdev->dev.of_node);
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(pdev->dev.of_node, "serial");
1286	sirf_ports[sirfport->port.line] = sirfport;
1287	sirfport->port.iotype = UPIO_MEM;
1288	sirfport->port.flags = UPF_BOOT_AUTOCONF;
1289	port = &sirfport->port;
1290	port->dev = &pdev->dev;
1291	port->private_data = sirfport;
1292	sirfport->uart_reg = (struct sirfsoc_uart_register *)match->data;
1293
1294	sirfport->hw_flow_ctrl = of_property_read_bool(pdev->dev.of_node,
1295		"sirf,uart-has-rtscts");
1296	if (of_device_is_compatible(pdev->dev.of_node, "sirf,prima2-uart") ||
1297		of_device_is_compatible(pdev->dev.of_node, "sirf,atlas7-uart"))
1298		sirfport->uart_reg->uart_type = SIRF_REAL_UART;
1299	if (of_device_is_compatible(pdev->dev.of_node,
1300		"sirf,prima2-usp-uart") || of_device_is_compatible(
1301		pdev->dev.of_node, "sirf,atlas7-usp-uart")) {
1302		sirfport->uart_reg->uart_type =	SIRF_USP_UART;
1303		if (!sirfport->hw_flow_ctrl)
1304			goto usp_no_flow_control;
1305		if (of_find_property(pdev->dev.of_node, "cts-gpios", NULL))
1306			sirfport->cts_gpio = of_get_named_gpio(
1307					pdev->dev.of_node, "cts-gpios", 0);
1308		else
1309			sirfport->cts_gpio = -1;
1310		if (of_find_property(pdev->dev.of_node, "rts-gpios", NULL))
1311			sirfport->rts_gpio = of_get_named_gpio(
1312					pdev->dev.of_node, "rts-gpios", 0);
1313		else
1314			sirfport->rts_gpio = -1;
1315
1316		if ((!gpio_is_valid(sirfport->cts_gpio) ||
1317			 !gpio_is_valid(sirfport->rts_gpio))) {
1318			ret = -EINVAL;
1319			dev_err(&pdev->dev,
1320				"Usp flow control must have cts and rts gpio");
1321			goto err;
1322		}
1323		ret = devm_gpio_request(&pdev->dev, sirfport->cts_gpio,
1324				"usp-cts-gpio");
1325		if (ret) {
1326			dev_err(&pdev->dev, "Unable request cts gpio");
1327			goto err;
1328		}
1329		gpio_direction_input(sirfport->cts_gpio);
1330		ret = devm_gpio_request(&pdev->dev, sirfport->rts_gpio,
1331				"usp-rts-gpio");
1332		if (ret) {
1333			dev_err(&pdev->dev, "Unable request rts gpio");
1334			goto err;
1335		}
1336		gpio_direction_output(sirfport->rts_gpio, 1);
1337	}
1338usp_no_flow_control:
1339	if (of_device_is_compatible(pdev->dev.of_node, "sirf,atlas7-uart") ||
1340	    of_device_is_compatible(pdev->dev.of_node, "sirf,atlas7-usp-uart"))
1341		sirfport->is_atlas7 = true;
1342
1343	if (of_property_read_u32(pdev->dev.of_node,
1344			"fifosize",
1345			&port->fifosize)) {
1346		dev_err(&pdev->dev,
1347			"Unable to find fifosize in uart node.\n");
1348		ret = -EFAULT;
1349		goto err;
1350	}
1351
1352	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1353	if (res == NULL) {
1354		dev_err(&pdev->dev, "Insufficient resources.\n");
1355		ret = -EFAULT;
1356		goto err;
1357	}
1358	port->mapbase = res->start;
1359	port->membase = devm_ioremap(&pdev->dev,
1360			res->start, resource_size(res));
1361	if (!port->membase) {
1362		dev_err(&pdev->dev, "Cannot remap resource.\n");
1363		ret = -ENOMEM;
1364		goto err;
1365	}
1366	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
1367	if (res == NULL) {
1368		dev_err(&pdev->dev, "Insufficient resources.\n");
1369		ret = -EFAULT;
1370		goto err;
1371	}
1372	port->irq = res->start;
1373
1374	sirfport->clk = devm_clk_get(&pdev->dev, NULL);
1375	if (IS_ERR(sirfport->clk)) {
1376		ret = PTR_ERR(sirfport->clk);
1377		goto err;
1378	}
1379	port->uartclk = clk_get_rate(sirfport->clk);
1380
1381	port->ops = &sirfsoc_uart_ops;
1382	spin_lock_init(&port->lock);
1383
1384	platform_set_drvdata(pdev, sirfport);
1385	ret = uart_add_one_port(&sirfsoc_uart_drv, port);
1386	if (ret != 0) {
1387		dev_err(&pdev->dev, "Cannot add UART port(%d).\n", pdev->id);
1388		goto err;
1389	}
1390
1391	sirfport->rx_dma_chan = dma_request_slave_channel(port->dev, "rx");
1392	sirfport->rx_dma_items.xmit.buf =
1393		dma_alloc_coherent(port->dev, SIRFSOC_RX_DMA_BUF_SIZE,
1394		&sirfport->rx_dma_items.dma_addr, GFP_KERNEL);
1395	if (!sirfport->rx_dma_items.xmit.buf) {
1396		dev_err(port->dev, "Uart alloc bufa failed\n");
1397		ret = -ENOMEM;
1398		goto alloc_coherent_err;
1399	}
1400	sirfport->rx_dma_items.xmit.head =
1401		sirfport->rx_dma_items.xmit.tail = 0;
1402	if (sirfport->rx_dma_chan)
1403		dmaengine_slave_config(sirfport->rx_dma_chan, &slv_cfg);
1404	sirfport->tx_dma_chan = dma_request_slave_channel(port->dev, "tx");
1405	if (sirfport->tx_dma_chan)
1406		dmaengine_slave_config(sirfport->tx_dma_chan, &tx_slv_cfg);
1407	if (sirfport->rx_dma_chan) {
1408		hrtimer_init(&sirfport->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1409		sirfport->hrt.function = sirfsoc_uart_rx_dma_hrtimer_callback;
1410		sirfport->is_hrt_enabled = false;
1411	}
1412
1413	return 0;
1414alloc_coherent_err:
1415	dma_free_coherent(port->dev, SIRFSOC_RX_DMA_BUF_SIZE,
1416			sirfport->rx_dma_items.xmit.buf,
1417			sirfport->rx_dma_items.dma_addr);
1418	dma_release_channel(sirfport->rx_dma_chan);
1419err:
1420	return ret;
1421}
1422
1423static int sirfsoc_uart_remove(struct platform_device *pdev)
1424{
1425	struct sirfsoc_uart_port *sirfport = platform_get_drvdata(pdev);
1426	struct uart_port *port = &sirfport->port;
1427	uart_remove_one_port(&sirfsoc_uart_drv, port);
1428	if (sirfport->rx_dma_chan) {
1429		dmaengine_terminate_all(sirfport->rx_dma_chan);
1430		dma_release_channel(sirfport->rx_dma_chan);
1431		dma_free_coherent(port->dev, SIRFSOC_RX_DMA_BUF_SIZE,
1432				sirfport->rx_dma_items.xmit.buf,
1433				sirfport->rx_dma_items.dma_addr);
1434	}
1435	if (sirfport->tx_dma_chan) {
1436		dmaengine_terminate_all(sirfport->tx_dma_chan);
1437		dma_release_channel(sirfport->tx_dma_chan);
1438	}
1439	return 0;
1440}
1441
1442#ifdef CONFIG_PM_SLEEP
1443static int
1444sirfsoc_uart_suspend(struct device *pdev)
1445{
1446	struct sirfsoc_uart_port *sirfport = dev_get_drvdata(pdev);
1447	struct uart_port *port = &sirfport->port;
1448	uart_suspend_port(&sirfsoc_uart_drv, port);
1449	return 0;
1450}
1451
1452static int sirfsoc_uart_resume(struct device *pdev)
1453{
1454	struct sirfsoc_uart_port *sirfport = dev_get_drvdata(pdev);
1455	struct uart_port *port = &sirfport->port;
1456	uart_resume_port(&sirfsoc_uart_drv, port);
1457	return 0;
1458}
1459#endif
1460
1461static const struct dev_pm_ops sirfsoc_uart_pm_ops = {
1462	SET_SYSTEM_SLEEP_PM_OPS(sirfsoc_uart_suspend, sirfsoc_uart_resume)
1463};
1464
1465static struct platform_driver sirfsoc_uart_driver = {
1466	.probe		= sirfsoc_uart_probe,
1467	.remove		= sirfsoc_uart_remove,
1468	.driver		= {
1469		.name	= SIRFUART_PORT_NAME,
1470		.of_match_table = sirfsoc_uart_ids,
1471		.pm	= &sirfsoc_uart_pm_ops,
1472	},
1473};
1474
1475static int __init sirfsoc_uart_init(void)
1476{
1477	int ret = 0;
1478
1479	ret = uart_register_driver(&sirfsoc_uart_drv);
1480	if (ret)
1481		goto out;
1482
1483	ret = platform_driver_register(&sirfsoc_uart_driver);
1484	if (ret)
1485		uart_unregister_driver(&sirfsoc_uart_drv);
1486out:
1487	return ret;
1488}
1489module_init(sirfsoc_uart_init);
1490
1491static void __exit sirfsoc_uart_exit(void)
1492{
1493	platform_driver_unregister(&sirfsoc_uart_driver);
1494	uart_unregister_driver(&sirfsoc_uart_drv);
1495}
1496module_exit(sirfsoc_uart_exit);
1497
1498MODULE_LICENSE("GPL v2");
1499MODULE_AUTHOR("Bin Shi <Bin.Shi@csr.com>, Rong Wang<Rong.Wang@csr.com>");
1500MODULE_DESCRIPTION("CSR SiRFprimaII Uart Driver");
1501