xref: /linux/drivers/tty/serial/msm_serial.c (revision d8b78066f4c9c8ec898bd4246fc4db31d476dd88)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for msm7k serial device and console
4  *
5  * Copyright (C) 2007 Google, Inc.
6  * Author: Robert Love <rlove@google.com>
7  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/atomic.h>
12 #include <linux/dma/qcom_adm.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/dmaengine.h>
15 #include <linux/module.h>
16 #include <linux/io.h>
17 #include <linux/ioport.h>
18 #include <linux/interrupt.h>
19 #include <linux/init.h>
20 #include <linux/console.h>
21 #include <linux/tty.h>
22 #include <linux/tty_flip.h>
23 #include <linux/serial_core.h>
24 #include <linux/slab.h>
25 #include <linux/clk.h>
26 #include <linux/platform_device.h>
27 #include <linux/pm_opp.h>
28 #include <linux/delay.h>
29 #include <linux/of.h>
30 #include <linux/of_device.h>
31 #include <linux/wait.h>
32 
33 #define MSM_UART_MR1			0x0000
34 
35 #define MSM_UART_MR1_AUTO_RFR_LEVEL0	0x3F
36 #define MSM_UART_MR1_AUTO_RFR_LEVEL1	0x3FF00
37 #define MSM_UART_DM_MR1_AUTO_RFR_LEVEL1	0xFFFFFF00
38 #define MSM_UART_MR1_RX_RDY_CTL		BIT(7)
39 #define MSM_UART_MR1_CTS_CTL		BIT(6)
40 
41 #define MSM_UART_MR2			0x0004
42 #define MSM_UART_MR2_ERROR_MODE		BIT(6)
43 #define MSM_UART_MR2_BITS_PER_CHAR	0x30
44 #define MSM_UART_MR2_BITS_PER_CHAR_5	(0x0 << 4)
45 #define MSM_UART_MR2_BITS_PER_CHAR_6	(0x1 << 4)
46 #define MSM_UART_MR2_BITS_PER_CHAR_7	(0x2 << 4)
47 #define MSM_UART_MR2_BITS_PER_CHAR_8	(0x3 << 4)
48 #define MSM_UART_MR2_STOP_BIT_LEN_ONE	(0x1 << 2)
49 #define MSM_UART_MR2_STOP_BIT_LEN_TWO	(0x3 << 2)
50 #define MSM_UART_MR2_PARITY_MODE_NONE	0x0
51 #define MSM_UART_MR2_PARITY_MODE_ODD	0x1
52 #define MSM_UART_MR2_PARITY_MODE_EVEN	0x2
53 #define MSM_UART_MR2_PARITY_MODE_SPACE	0x3
54 #define MSM_UART_MR2_PARITY_MODE	0x3
55 
56 #define MSM_UART_CSR			0x0008
57 
58 #define MSM_UART_TF			0x000C
59 #define UARTDM_TF			0x0070
60 
61 #define MSM_UART_CR				0x0010
62 #define MSM_UART_CR_CMD_NULL			(0 << 4)
63 #define MSM_UART_CR_CMD_RESET_RX		(1 << 4)
64 #define MSM_UART_CR_CMD_RESET_TX		(2 << 4)
65 #define MSM_UART_CR_CMD_RESET_ERR		(3 << 4)
66 #define MSM_UART_CR_CMD_RESET_BREAK_INT		(4 << 4)
67 #define MSM_UART_CR_CMD_START_BREAK		(5 << 4)
68 #define MSM_UART_CR_CMD_STOP_BREAK		(6 << 4)
69 #define MSM_UART_CR_CMD_RESET_CTS		(7 << 4)
70 #define MSM_UART_CR_CMD_RESET_STALE_INT		(8 << 4)
71 #define MSM_UART_CR_CMD_PACKET_MODE		(9 << 4)
72 #define MSM_UART_CR_CMD_MODE_RESET		(12 << 4)
73 #define MSM_UART_CR_CMD_SET_RFR			(13 << 4)
74 #define MSM_UART_CR_CMD_RESET_RFR		(14 << 4)
75 #define MSM_UART_CR_CMD_PROTECTION_EN		(16 << 4)
76 #define MSM_UART_CR_CMD_STALE_EVENT_DISABLE	(6 << 8)
77 #define MSM_UART_CR_CMD_STALE_EVENT_ENABLE	(80 << 4)
78 #define MSM_UART_CR_CMD_FORCE_STALE		(4 << 8)
79 #define MSM_UART_CR_CMD_RESET_TX_READY		(3 << 8)
80 #define MSM_UART_CR_TX_DISABLE			BIT(3)
81 #define MSM_UART_CR_TX_ENABLE			BIT(2)
82 #define MSM_UART_CR_RX_DISABLE			BIT(1)
83 #define MSM_UART_CR_RX_ENABLE			BIT(0)
84 #define MSM_UART_CR_CMD_RESET_RXBREAK_START	((1 << 11) | (2 << 4))
85 
86 #define MSM_UART_IMR			0x0014
87 #define MSM_UART_IMR_TXLEV		BIT(0)
88 #define MSM_UART_IMR_RXSTALE		BIT(3)
89 #define MSM_UART_IMR_RXLEV		BIT(4)
90 #define MSM_UART_IMR_DELTA_CTS		BIT(5)
91 #define MSM_UART_IMR_CURRENT_CTS	BIT(6)
92 #define MSM_UART_IMR_RXBREAK_START	BIT(10)
93 
94 #define MSM_UART_IPR_RXSTALE_LAST		0x20
95 #define MSM_UART_IPR_STALE_LSB			0x1F
96 #define MSM_UART_IPR_STALE_TIMEOUT_MSB		0x3FF80
97 #define MSM_UART_DM_IPR_STALE_TIMEOUT_MSB	0xFFFFFF80
98 
99 #define MSM_UART_IPR			0x0018
100 #define MSM_UART_TFWR			0x001C
101 #define MSM_UART_RFWR			0x0020
102 #define MSM_UART_HCR			0x0024
103 
104 #define MSM_UART_MREG			0x0028
105 #define MSM_UART_NREG			0x002C
106 #define MSM_UART_DREG			0x0030
107 #define MSM_UART_MNDREG			0x0034
108 #define MSM_UART_IRDA			0x0038
109 #define MSM_UART_MISR_MODE		0x0040
110 #define MSM_UART_MISR_RESET		0x0044
111 #define MSM_UART_MISR_EXPORT		0x0048
112 #define MSM_UART_MISR_VAL		0x004C
113 #define MSM_UART_TEST_CTRL		0x0050
114 
115 #define MSM_UART_SR			0x0008
116 #define MSM_UART_SR_HUNT_CHAR		BIT(7)
117 #define MSM_UART_SR_RX_BREAK		BIT(6)
118 #define MSM_UART_SR_PAR_FRAME_ERR	BIT(5)
119 #define MSM_UART_SR_OVERRUN		BIT(4)
120 #define MSM_UART_SR_TX_EMPTY		BIT(3)
121 #define MSM_UART_SR_TX_READY		BIT(2)
122 #define MSM_UART_SR_RX_FULL		BIT(1)
123 #define MSM_UART_SR_RX_READY		BIT(0)
124 
125 #define MSM_UART_RF			0x000C
126 #define UARTDM_RF			0x0070
127 #define MSM_UART_MISR			0x0010
128 #define MSM_UART_ISR			0x0014
129 #define MSM_UART_ISR_TX_READY		BIT(7)
130 
131 #define UARTDM_RXFS			0x50
132 #define UARTDM_RXFS_BUF_SHIFT		0x7
133 #define UARTDM_RXFS_BUF_MASK		0x7
134 
135 #define UARTDM_DMEN			0x3C
136 #define UARTDM_DMEN_RX_SC_ENABLE	BIT(5)
137 #define UARTDM_DMEN_TX_SC_ENABLE	BIT(4)
138 
139 #define UARTDM_DMEN_TX_BAM_ENABLE	BIT(2)	/* UARTDM_1P4 */
140 #define UARTDM_DMEN_TX_DM_ENABLE	BIT(0)	/* < UARTDM_1P4 */
141 
142 #define UARTDM_DMEN_RX_BAM_ENABLE	BIT(3)	/* UARTDM_1P4 */
143 #define UARTDM_DMEN_RX_DM_ENABLE	BIT(1)	/* < UARTDM_1P4 */
144 
145 #define UARTDM_DMRX			0x34
146 #define UARTDM_NCF_TX			0x40
147 #define UARTDM_RX_TOTAL_SNAP		0x38
148 
149 #define UARTDM_BURST_SIZE		16   /* in bytes */
150 #define UARTDM_TX_AIGN(x)		((x) & ~0x3) /* valid for > 1p3 */
151 #define UARTDM_TX_MAX			256   /* in bytes, valid for <= 1p3 */
152 #define UARTDM_RX_SIZE			(UART_XMIT_SIZE / 4)
153 
154 enum {
155 	UARTDM_1P1 = 1,
156 	UARTDM_1P2,
157 	UARTDM_1P3,
158 	UARTDM_1P4,
159 };
160 
161 struct msm_dma {
162 	struct dma_chan		*chan;
163 	enum dma_data_direction dir;
164 	union {
165 		struct {
166 			dma_addr_t		phys;
167 			unsigned char		*virt;
168 			unsigned int		count;
169 		} rx;
170 		struct scatterlist tx_sg;
171 	};
172 	dma_cookie_t		cookie;
173 	u32			enable_bit;
174 	struct dma_async_tx_descriptor	*desc;
175 };
176 
177 struct msm_port {
178 	struct uart_port	uart;
179 	char			name[16];
180 	struct clk		*clk;
181 	struct clk		*pclk;
182 	unsigned int		imr;
183 	int			is_uartdm;
184 	unsigned int		old_snap_state;
185 	bool			break_detected;
186 	struct msm_dma		tx_dma;
187 	struct msm_dma		rx_dma;
188 };
189 
to_msm_port(struct uart_port * up)190 static inline struct msm_port *to_msm_port(struct uart_port *up)
191 {
192 	return container_of(up, struct msm_port, uart);
193 }
194 
195 static
msm_write(struct uart_port * port,unsigned int val,unsigned int off)196 void msm_write(struct uart_port *port, unsigned int val, unsigned int off)
197 {
198 	writel_relaxed(val, port->membase + off);
199 }
200 
201 static
msm_read(struct uart_port * port,unsigned int off)202 unsigned int msm_read(struct uart_port *port, unsigned int off)
203 {
204 	return readl_relaxed(port->membase + off);
205 }
206 
207 /*
208  * Setup the MND registers to use the TCXO clock.
209  */
msm_serial_set_mnd_regs_tcxo(struct uart_port * port)210 static void msm_serial_set_mnd_regs_tcxo(struct uart_port *port)
211 {
212 	msm_write(port, 0x06, MSM_UART_MREG);
213 	msm_write(port, 0xF1, MSM_UART_NREG);
214 	msm_write(port, 0x0F, MSM_UART_DREG);
215 	msm_write(port, 0x1A, MSM_UART_MNDREG);
216 	port->uartclk = 1843200;
217 }
218 
219 /*
220  * Setup the MND registers to use the TCXO clock divided by 4.
221  */
msm_serial_set_mnd_regs_tcxoby4(struct uart_port * port)222 static void msm_serial_set_mnd_regs_tcxoby4(struct uart_port *port)
223 {
224 	msm_write(port, 0x18, MSM_UART_MREG);
225 	msm_write(port, 0xF6, MSM_UART_NREG);
226 	msm_write(port, 0x0F, MSM_UART_DREG);
227 	msm_write(port, 0x0A, MSM_UART_MNDREG);
228 	port->uartclk = 1843200;
229 }
230 
msm_serial_set_mnd_regs(struct uart_port * port)231 static void msm_serial_set_mnd_regs(struct uart_port *port)
232 {
233 	struct msm_port *msm_port = to_msm_port(port);
234 
235 	/*
236 	 * These registers don't exist so we change the clk input rate
237 	 * on uartdm hardware instead
238 	 */
239 	if (msm_port->is_uartdm)
240 		return;
241 
242 	if (port->uartclk == 19200000)
243 		msm_serial_set_mnd_regs_tcxo(port);
244 	else if (port->uartclk == 4800000)
245 		msm_serial_set_mnd_regs_tcxoby4(port);
246 }
247 
248 static void msm_handle_tx(struct uart_port *port);
249 static void msm_start_rx_dma(struct msm_port *msm_port);
250 
msm_stop_dma(struct uart_port * port,struct msm_dma * dma)251 static void msm_stop_dma(struct uart_port *port, struct msm_dma *dma)
252 {
253 	struct device *dev = port->dev;
254 	unsigned int mapped;
255 	u32 val;
256 
257 	if (dma->dir == DMA_TO_DEVICE) {
258 		mapped = sg_dma_len(&dma->tx_sg);
259 	} else {
260 		mapped = dma->rx.count;
261 		dma->rx.count = 0;
262 	}
263 
264 	dmaengine_terminate_all(dma->chan);
265 
266 	/*
267 	 * DMA Stall happens if enqueue and flush command happens concurrently.
268 	 * For example before changing the baud rate/protocol configuration and
269 	 * sending flush command to ADM, disable the channel of UARTDM.
270 	 * Note: should not reset the receiver here immediately as it is not
271 	 * suggested to do disable/reset or reset/disable at the same time.
272 	 */
273 	val = msm_read(port, UARTDM_DMEN);
274 	val &= ~dma->enable_bit;
275 	msm_write(port, val, UARTDM_DMEN);
276 
277 	if (mapped) {
278 		if (dma->dir == DMA_TO_DEVICE) {
279 			dma_unmap_sg(dev, &dma->tx_sg, 1, dma->dir);
280 			sg_init_table(&dma->tx_sg, 1);
281 		} else
282 			dma_unmap_single(dev, dma->rx.phys, mapped, dma->dir);
283 	}
284 }
285 
msm_release_dma(struct msm_port * msm_port)286 static void msm_release_dma(struct msm_port *msm_port)
287 {
288 	struct msm_dma *dma;
289 
290 	dma = &msm_port->tx_dma;
291 	if (dma->chan) {
292 		msm_stop_dma(&msm_port->uart, dma);
293 		dma_release_channel(dma->chan);
294 	}
295 
296 	memset(dma, 0, sizeof(*dma));
297 
298 	dma = &msm_port->rx_dma;
299 	if (dma->chan) {
300 		msm_stop_dma(&msm_port->uart, dma);
301 		dma_release_channel(dma->chan);
302 		kfree(dma->rx.virt);
303 	}
304 
305 	memset(dma, 0, sizeof(*dma));
306 }
307 
msm_request_tx_dma(struct msm_port * msm_port,resource_size_t base)308 static void msm_request_tx_dma(struct msm_port *msm_port, resource_size_t base)
309 {
310 	struct device *dev = msm_port->uart.dev;
311 	struct dma_slave_config conf;
312 	struct qcom_adm_peripheral_config periph_conf = {};
313 	struct msm_dma *dma;
314 	u32 crci = 0;
315 	int ret;
316 
317 	dma = &msm_port->tx_dma;
318 
319 	/* allocate DMA resources, if available */
320 	dma->chan = dma_request_chan(dev, "tx");
321 	if (IS_ERR(dma->chan))
322 		goto no_tx;
323 
324 	of_property_read_u32(dev->of_node, "qcom,tx-crci", &crci);
325 
326 	memset(&conf, 0, sizeof(conf));
327 	conf.direction = DMA_MEM_TO_DEV;
328 	conf.device_fc = true;
329 	conf.dst_addr = base + UARTDM_TF;
330 	conf.dst_maxburst = UARTDM_BURST_SIZE;
331 	if (crci) {
332 		conf.peripheral_config = &periph_conf;
333 		conf.peripheral_size = sizeof(periph_conf);
334 		periph_conf.crci = crci;
335 	}
336 
337 	ret = dmaengine_slave_config(dma->chan, &conf);
338 	if (ret)
339 		goto rel_tx;
340 
341 	dma->dir = DMA_TO_DEVICE;
342 
343 	if (msm_port->is_uartdm < UARTDM_1P4)
344 		dma->enable_bit = UARTDM_DMEN_TX_DM_ENABLE;
345 	else
346 		dma->enable_bit = UARTDM_DMEN_TX_BAM_ENABLE;
347 
348 	return;
349 
350 rel_tx:
351 	dma_release_channel(dma->chan);
352 no_tx:
353 	memset(dma, 0, sizeof(*dma));
354 }
355 
msm_request_rx_dma(struct msm_port * msm_port,resource_size_t base)356 static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base)
357 {
358 	struct device *dev = msm_port->uart.dev;
359 	struct dma_slave_config conf;
360 	struct qcom_adm_peripheral_config periph_conf = {};
361 	struct msm_dma *dma;
362 	u32 crci = 0;
363 	int ret;
364 
365 	dma = &msm_port->rx_dma;
366 
367 	/* allocate DMA resources, if available */
368 	dma->chan = dma_request_chan(dev, "rx");
369 	if (IS_ERR(dma->chan))
370 		goto no_rx;
371 
372 	of_property_read_u32(dev->of_node, "qcom,rx-crci", &crci);
373 
374 	dma->rx.virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL);
375 	if (!dma->rx.virt)
376 		goto rel_rx;
377 
378 	memset(&conf, 0, sizeof(conf));
379 	conf.direction = DMA_DEV_TO_MEM;
380 	conf.device_fc = true;
381 	conf.src_addr = base + UARTDM_RF;
382 	conf.src_maxburst = UARTDM_BURST_SIZE;
383 	if (crci) {
384 		conf.peripheral_config = &periph_conf;
385 		conf.peripheral_size = sizeof(periph_conf);
386 		periph_conf.crci = crci;
387 	}
388 
389 	ret = dmaengine_slave_config(dma->chan, &conf);
390 	if (ret)
391 		goto err;
392 
393 	dma->dir = DMA_FROM_DEVICE;
394 
395 	if (msm_port->is_uartdm < UARTDM_1P4)
396 		dma->enable_bit = UARTDM_DMEN_RX_DM_ENABLE;
397 	else
398 		dma->enable_bit = UARTDM_DMEN_RX_BAM_ENABLE;
399 
400 	return;
401 err:
402 	kfree(dma->rx.virt);
403 rel_rx:
404 	dma_release_channel(dma->chan);
405 no_rx:
406 	memset(dma, 0, sizeof(*dma));
407 }
408 
msm_wait_for_xmitr(struct uart_port * port)409 static inline void msm_wait_for_xmitr(struct uart_port *port)
410 {
411 	unsigned int timeout = 500000;
412 
413 	while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_EMPTY)) {
414 		if (msm_read(port, MSM_UART_ISR) & MSM_UART_ISR_TX_READY)
415 			break;
416 		udelay(1);
417 		if (!timeout--)
418 			break;
419 	}
420 	msm_write(port, MSM_UART_CR_CMD_RESET_TX_READY, MSM_UART_CR);
421 }
422 
msm_stop_tx(struct uart_port * port)423 static void msm_stop_tx(struct uart_port *port)
424 {
425 	struct msm_port *msm_port = to_msm_port(port);
426 
427 	msm_port->imr &= ~MSM_UART_IMR_TXLEV;
428 	msm_write(port, msm_port->imr, MSM_UART_IMR);
429 }
430 
msm_start_tx(struct uart_port * port)431 static void msm_start_tx(struct uart_port *port)
432 {
433 	struct msm_port *msm_port = to_msm_port(port);
434 	struct msm_dma *dma = &msm_port->tx_dma;
435 
436 	/* Already started in DMA mode */
437 	if (sg_dma_len(&dma->tx_sg))
438 		return;
439 
440 	msm_port->imr |= MSM_UART_IMR_TXLEV;
441 	msm_write(port, msm_port->imr, MSM_UART_IMR);
442 }
443 
msm_reset_dm_count(struct uart_port * port,int count)444 static void msm_reset_dm_count(struct uart_port *port, int count)
445 {
446 	msm_wait_for_xmitr(port);
447 	msm_write(port, count, UARTDM_NCF_TX);
448 	msm_read(port, UARTDM_NCF_TX);
449 }
450 
msm_complete_tx_dma(void * args)451 static void msm_complete_tx_dma(void *args)
452 {
453 	struct msm_port *msm_port = args;
454 	struct uart_port *port = &msm_port->uart;
455 	struct tty_port *tport = &port->state->port;
456 	struct msm_dma *dma = &msm_port->tx_dma;
457 	struct dma_tx_state state;
458 	unsigned long flags;
459 	unsigned int count;
460 	u32 val;
461 
462 	uart_port_lock_irqsave(port, &flags);
463 
464 	/* Already stopped */
465 	if (!sg_dma_len(&dma->tx_sg))
466 		goto done;
467 
468 	dmaengine_tx_status(dma->chan, dma->cookie, &state);
469 
470 	dma_unmap_sg(port->dev, &dma->tx_sg, 1, dma->dir);
471 
472 	val = msm_read(port, UARTDM_DMEN);
473 	val &= ~dma->enable_bit;
474 	msm_write(port, val, UARTDM_DMEN);
475 
476 	if (msm_port->is_uartdm > UARTDM_1P3) {
477 		msm_write(port, MSM_UART_CR_CMD_RESET_TX, MSM_UART_CR);
478 		msm_write(port, MSM_UART_CR_TX_ENABLE, MSM_UART_CR);
479 	}
480 
481 	count = sg_dma_len(&dma->tx_sg) - state.residue;
482 	uart_xmit_advance(port, count);
483 	sg_init_table(&dma->tx_sg, 1);
484 
485 	/* Restore "Tx FIFO below watermark" interrupt */
486 	msm_port->imr |= MSM_UART_IMR_TXLEV;
487 	msm_write(port, msm_port->imr, MSM_UART_IMR);
488 
489 	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
490 		uart_write_wakeup(port);
491 
492 	msm_handle_tx(port);
493 done:
494 	uart_port_unlock_irqrestore(port, flags);
495 }
496 
msm_handle_tx_dma(struct msm_port * msm_port,unsigned int count)497 static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count)
498 {
499 	struct uart_port *port = &msm_port->uart;
500 	struct tty_port *tport = &port->state->port;
501 	struct msm_dma *dma = &msm_port->tx_dma;
502 	unsigned int mapped;
503 	int ret;
504 	u32 val;
505 
506 	sg_init_table(&dma->tx_sg, 1);
507 	kfifo_dma_out_prepare(&tport->xmit_fifo, &dma->tx_sg, 1, count);
508 
509 	mapped = dma_map_sg(port->dev, &dma->tx_sg, 1, dma->dir);
510 	if (!mapped) {
511 		ret = -EIO;
512 		goto zero_sg;
513 	}
514 
515 	dma->desc = dmaengine_prep_slave_sg(dma->chan, &dma->tx_sg, 1,
516 						DMA_MEM_TO_DEV,
517 						DMA_PREP_INTERRUPT |
518 						DMA_PREP_FENCE);
519 	if (!dma->desc) {
520 		ret = -EIO;
521 		goto unmap;
522 	}
523 
524 	dma->desc->callback = msm_complete_tx_dma;
525 	dma->desc->callback_param = msm_port;
526 
527 	dma->cookie = dmaengine_submit(dma->desc);
528 	ret = dma_submit_error(dma->cookie);
529 	if (ret)
530 		goto unmap;
531 
532 	/*
533 	 * Using DMA complete for Tx FIFO reload, no need for
534 	 * "Tx FIFO below watermark" one, disable it
535 	 */
536 	msm_port->imr &= ~MSM_UART_IMR_TXLEV;
537 	msm_write(port, msm_port->imr, MSM_UART_IMR);
538 
539 	val = msm_read(port, UARTDM_DMEN);
540 	val |= dma->enable_bit;
541 
542 	if (msm_port->is_uartdm < UARTDM_1P4)
543 		msm_write(port, val, UARTDM_DMEN);
544 
545 	msm_reset_dm_count(port, count);
546 
547 	if (msm_port->is_uartdm > UARTDM_1P3)
548 		msm_write(port, val, UARTDM_DMEN);
549 
550 	dma_async_issue_pending(dma->chan);
551 	return 0;
552 unmap:
553 	dma_unmap_sg(port->dev, &dma->tx_sg, 1, dma->dir);
554 zero_sg:
555 	sg_init_table(&dma->tx_sg, 1);
556 	return ret;
557 }
558 
msm_complete_rx_dma(void * args)559 static void msm_complete_rx_dma(void *args)
560 {
561 	struct msm_port *msm_port = args;
562 	struct uart_port *port = &msm_port->uart;
563 	struct tty_port *tport = &port->state->port;
564 	struct msm_dma *dma = &msm_port->rx_dma;
565 	int count = 0, i, sysrq;
566 	unsigned long flags;
567 	u32 val;
568 
569 	uart_port_lock_irqsave(port, &flags);
570 
571 	/* Already stopped */
572 	if (!dma->rx.count)
573 		goto done;
574 
575 	val = msm_read(port, UARTDM_DMEN);
576 	val &= ~dma->enable_bit;
577 	msm_write(port, val, UARTDM_DMEN);
578 
579 	if (msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN) {
580 		port->icount.overrun++;
581 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
582 		msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
583 	}
584 
585 	count = msm_read(port, UARTDM_RX_TOTAL_SNAP);
586 
587 	port->icount.rx += count;
588 
589 	dma->rx.count = 0;
590 
591 	dma_unmap_single(port->dev, dma->rx.phys, UARTDM_RX_SIZE, dma->dir);
592 
593 	for (i = 0; i < count; i++) {
594 		char flag = TTY_NORMAL;
595 
596 		if (msm_port->break_detected && dma->rx.virt[i] == 0) {
597 			port->icount.brk++;
598 			flag = TTY_BREAK;
599 			msm_port->break_detected = false;
600 			if (uart_handle_break(port))
601 				continue;
602 		}
603 
604 		if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK))
605 			flag = TTY_NORMAL;
606 
607 		sysrq = uart_prepare_sysrq_char(port, dma->rx.virt[i]);
608 		if (!sysrq)
609 			tty_insert_flip_char(tport, dma->rx.virt[i], flag);
610 	}
611 
612 	msm_start_rx_dma(msm_port);
613 done:
614 	uart_unlock_and_check_sysrq_irqrestore(port, flags);
615 
616 	if (count)
617 		tty_flip_buffer_push(tport);
618 }
619 
msm_start_rx_dma(struct msm_port * msm_port)620 static void msm_start_rx_dma(struct msm_port *msm_port)
621 {
622 	struct msm_dma *dma = &msm_port->rx_dma;
623 	struct uart_port *uart = &msm_port->uart;
624 	u32 val;
625 	int ret;
626 
627 	if (IS_ENABLED(CONFIG_CONSOLE_POLL))
628 		return;
629 
630 	if (!dma->chan)
631 		return;
632 
633 	dma->rx.phys = dma_map_single(uart->dev, dma->rx.virt,
634 				   UARTDM_RX_SIZE, dma->dir);
635 	ret = dma_mapping_error(uart->dev, dma->rx.phys);
636 	if (ret)
637 		goto sw_mode;
638 
639 	dma->desc = dmaengine_prep_slave_single(dma->chan, dma->rx.phys,
640 						UARTDM_RX_SIZE, DMA_DEV_TO_MEM,
641 						DMA_PREP_INTERRUPT);
642 	if (!dma->desc)
643 		goto unmap;
644 
645 	dma->desc->callback = msm_complete_rx_dma;
646 	dma->desc->callback_param = msm_port;
647 
648 	dma->cookie = dmaengine_submit(dma->desc);
649 	ret = dma_submit_error(dma->cookie);
650 	if (ret)
651 		goto unmap;
652 	/*
653 	 * Using DMA for FIFO off-load, no need for "Rx FIFO over
654 	 * watermark" or "stale" interrupts, disable them
655 	 */
656 	msm_port->imr &= ~(MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE);
657 
658 	/*
659 	 * Well, when DMA is ADM3 engine(implied by <= UARTDM v1.3),
660 	 * we need RXSTALE to flush input DMA fifo to memory
661 	 */
662 	if (msm_port->is_uartdm < UARTDM_1P4)
663 		msm_port->imr |= MSM_UART_IMR_RXSTALE;
664 
665 	msm_write(uart, msm_port->imr, MSM_UART_IMR);
666 
667 	dma->rx.count = UARTDM_RX_SIZE;
668 
669 	dma_async_issue_pending(dma->chan);
670 
671 	msm_write(uart, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
672 	msm_write(uart, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
673 
674 	val = msm_read(uart, UARTDM_DMEN);
675 	val |= dma->enable_bit;
676 
677 	if (msm_port->is_uartdm < UARTDM_1P4)
678 		msm_write(uart, val, UARTDM_DMEN);
679 
680 	msm_write(uart, UARTDM_RX_SIZE, UARTDM_DMRX);
681 
682 	if (msm_port->is_uartdm > UARTDM_1P3)
683 		msm_write(uart, val, UARTDM_DMEN);
684 
685 	return;
686 unmap:
687 	dma_unmap_single(uart->dev, dma->rx.phys, UARTDM_RX_SIZE, dma->dir);
688 
689 sw_mode:
690 	/*
691 	 * Switch from DMA to SW/FIFO mode. After clearing Rx BAM (UARTDM_DMEN),
692 	 * receiver must be reset.
693 	 */
694 	msm_write(uart, MSM_UART_CR_CMD_RESET_RX, MSM_UART_CR);
695 	msm_write(uart, MSM_UART_CR_RX_ENABLE, MSM_UART_CR);
696 
697 	msm_write(uart, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
698 	msm_write(uart, 0xFFFFFF, UARTDM_DMRX);
699 	msm_write(uart, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
700 
701 	/* Re-enable RX interrupts */
702 	msm_port->imr |= MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE;
703 	msm_write(uart, msm_port->imr, MSM_UART_IMR);
704 }
705 
msm_stop_rx(struct uart_port * port)706 static void msm_stop_rx(struct uart_port *port)
707 {
708 	struct msm_port *msm_port = to_msm_port(port);
709 	struct msm_dma *dma = &msm_port->rx_dma;
710 
711 	msm_port->imr &= ~(MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE);
712 	msm_write(port, msm_port->imr, MSM_UART_IMR);
713 
714 	if (dma->chan)
715 		msm_stop_dma(port, dma);
716 }
717 
msm_enable_ms(struct uart_port * port)718 static void msm_enable_ms(struct uart_port *port)
719 {
720 	struct msm_port *msm_port = to_msm_port(port);
721 
722 	msm_port->imr |= MSM_UART_IMR_DELTA_CTS;
723 	msm_write(port, msm_port->imr, MSM_UART_IMR);
724 }
725 
msm_handle_rx_dm(struct uart_port * port,unsigned int misr)726 static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr)
727 	__must_hold(&port->lock)
728 {
729 	struct tty_port *tport = &port->state->port;
730 	unsigned int sr;
731 	int count = 0;
732 	struct msm_port *msm_port = to_msm_port(port);
733 
734 	if ((msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN)) {
735 		port->icount.overrun++;
736 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
737 		msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
738 	}
739 
740 	if (misr & MSM_UART_IMR_RXSTALE) {
741 		count = msm_read(port, UARTDM_RX_TOTAL_SNAP) -
742 			msm_port->old_snap_state;
743 		msm_port->old_snap_state = 0;
744 	} else {
745 		count = 4 * (msm_read(port, MSM_UART_RFWR));
746 		msm_port->old_snap_state += count;
747 	}
748 
749 	/* TODO: Precise error reporting */
750 
751 	port->icount.rx += count;
752 
753 	while (count > 0) {
754 		unsigned char buf[4];
755 		int sysrq, r_count, i;
756 
757 		sr = msm_read(port, MSM_UART_SR);
758 		if ((sr & MSM_UART_SR_RX_READY) == 0) {
759 			msm_port->old_snap_state -= count;
760 			break;
761 		}
762 
763 		ioread32_rep(port->membase + UARTDM_RF, buf, 1);
764 		r_count = min_t(int, count, sizeof(buf));
765 
766 		for (i = 0; i < r_count; i++) {
767 			char flag = TTY_NORMAL;
768 
769 			if (msm_port->break_detected && buf[i] == 0) {
770 				port->icount.brk++;
771 				flag = TTY_BREAK;
772 				msm_port->break_detected = false;
773 				if (uart_handle_break(port))
774 					continue;
775 			}
776 
777 			if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK))
778 				flag = TTY_NORMAL;
779 
780 			sysrq = uart_prepare_sysrq_char(port, buf[i]);
781 			if (!sysrq)
782 				tty_insert_flip_char(tport, buf[i], flag);
783 		}
784 		count -= r_count;
785 	}
786 
787 	tty_flip_buffer_push(tport);
788 
789 	if (misr & (MSM_UART_IMR_RXSTALE))
790 		msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
791 	msm_write(port, 0xFFFFFF, UARTDM_DMRX);
792 	msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
793 
794 	/* Try to use DMA */
795 	msm_start_rx_dma(msm_port);
796 }
797 
msm_handle_rx(struct uart_port * port)798 static void msm_handle_rx(struct uart_port *port)
799 	__must_hold(&port->lock)
800 {
801 	struct tty_port *tport = &port->state->port;
802 	unsigned int sr;
803 
804 	/*
805 	 * Handle overrun. My understanding of the hardware is that overrun
806 	 * is not tied to the RX buffer, so we handle the case out of band.
807 	 */
808 	if ((msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN)) {
809 		port->icount.overrun++;
810 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
811 		msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
812 	}
813 
814 	/* and now the main RX loop */
815 	while ((sr = msm_read(port, MSM_UART_SR)) & MSM_UART_SR_RX_READY) {
816 		unsigned int c;
817 		char flag = TTY_NORMAL;
818 		int sysrq;
819 
820 		c = msm_read(port, MSM_UART_RF);
821 
822 		if (sr & MSM_UART_SR_RX_BREAK) {
823 			port->icount.brk++;
824 			if (uart_handle_break(port))
825 				continue;
826 		} else if (sr & MSM_UART_SR_PAR_FRAME_ERR) {
827 			port->icount.frame++;
828 		} else {
829 			port->icount.rx++;
830 		}
831 
832 		/* Mask conditions we're ignoring. */
833 		sr &= port->read_status_mask;
834 
835 		if (sr & MSM_UART_SR_RX_BREAK)
836 			flag = TTY_BREAK;
837 		else if (sr & MSM_UART_SR_PAR_FRAME_ERR)
838 			flag = TTY_FRAME;
839 
840 		sysrq = uart_prepare_sysrq_char(port, c);
841 		if (!sysrq)
842 			tty_insert_flip_char(tport, c, flag);
843 	}
844 
845 	tty_flip_buffer_push(tport);
846 }
847 
msm_handle_tx_pio(struct uart_port * port,unsigned int tx_count)848 static void msm_handle_tx_pio(struct uart_port *port, unsigned int tx_count)
849 {
850 	struct msm_port *msm_port = to_msm_port(port);
851 	struct tty_port *tport = &port->state->port;
852 	unsigned int num_chars;
853 	unsigned int tf_pointer = 0;
854 	void __iomem *tf;
855 
856 	if (msm_port->is_uartdm)
857 		tf = port->membase + UARTDM_TF;
858 	else
859 		tf = port->membase + MSM_UART_TF;
860 
861 	if (tx_count && msm_port->is_uartdm)
862 		msm_reset_dm_count(port, tx_count);
863 
864 	while (tf_pointer < tx_count) {
865 		unsigned char buf[4] = { 0 };
866 
867 		if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
868 			break;
869 
870 		if (msm_port->is_uartdm)
871 			num_chars = min(tx_count - tf_pointer,
872 					(unsigned int)sizeof(buf));
873 		else
874 			num_chars = 1;
875 
876 		num_chars = uart_fifo_out(port, buf, num_chars);
877 		iowrite32_rep(tf, buf, 1);
878 		tf_pointer += num_chars;
879 	}
880 
881 	/* disable tx interrupts if nothing more to send */
882 	if (kfifo_is_empty(&tport->xmit_fifo))
883 		msm_stop_tx(port);
884 
885 	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
886 		uart_write_wakeup(port);
887 }
888 
msm_handle_tx(struct uart_port * port)889 static void msm_handle_tx(struct uart_port *port)
890 {
891 	struct msm_port *msm_port = to_msm_port(port);
892 	struct tty_port *tport = &port->state->port;
893 	struct msm_dma *dma = &msm_port->tx_dma;
894 	unsigned int pio_count, dma_count, dma_min;
895 	char buf[4] = { 0 };
896 	void __iomem *tf;
897 	int err = 0;
898 
899 	if (port->x_char) {
900 		if (msm_port->is_uartdm)
901 			tf = port->membase + UARTDM_TF;
902 		else
903 			tf = port->membase + MSM_UART_TF;
904 
905 		buf[0] = port->x_char;
906 
907 		if (msm_port->is_uartdm)
908 			msm_reset_dm_count(port, 1);
909 
910 		iowrite32_rep(tf, buf, 1);
911 		port->icount.tx++;
912 		port->x_char = 0;
913 		return;
914 	}
915 
916 	if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) {
917 		msm_stop_tx(port);
918 		return;
919 	}
920 
921 	dma_count = pio_count = kfifo_out_linear(&tport->xmit_fifo, NULL,
922 			UART_XMIT_SIZE);
923 
924 	dma_min = 1;	/* Always DMA */
925 	if (msm_port->is_uartdm > UARTDM_1P3) {
926 		dma_count = UARTDM_TX_AIGN(dma_count);
927 		dma_min = UARTDM_BURST_SIZE;
928 	} else {
929 		if (dma_count > UARTDM_TX_MAX)
930 			dma_count = UARTDM_TX_MAX;
931 	}
932 
933 	if (pio_count > port->fifosize)
934 		pio_count = port->fifosize;
935 
936 	if (!dma->chan || dma_count < dma_min)
937 		msm_handle_tx_pio(port, pio_count);
938 	else
939 		err = msm_handle_tx_dma(msm_port, dma_count);
940 
941 	if (err)	/* fall back to PIO mode */
942 		msm_handle_tx_pio(port, pio_count);
943 }
944 
msm_handle_delta_cts(struct uart_port * port)945 static void msm_handle_delta_cts(struct uart_port *port)
946 {
947 	msm_write(port, MSM_UART_CR_CMD_RESET_CTS, MSM_UART_CR);
948 	port->icount.cts++;
949 	wake_up_interruptible(&port->state->port.delta_msr_wait);
950 }
951 
msm_uart_irq(int irq,void * dev_id)952 static irqreturn_t msm_uart_irq(int irq, void *dev_id)
953 {
954 	struct uart_port *port = dev_id;
955 	struct msm_port *msm_port = to_msm_port(port);
956 	struct msm_dma *dma = &msm_port->rx_dma;
957 	unsigned int misr;
958 	u32 val;
959 
960 	uart_port_lock(port);
961 	misr = msm_read(port, MSM_UART_MISR);
962 	msm_write(port, 0, MSM_UART_IMR); /* disable interrupt */
963 
964 	if (misr & MSM_UART_IMR_RXBREAK_START) {
965 		msm_port->break_detected = true;
966 		msm_write(port, MSM_UART_CR_CMD_RESET_RXBREAK_START, MSM_UART_CR);
967 	}
968 
969 	if (misr & (MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE)) {
970 		if (dma->rx.count) {
971 			val = MSM_UART_CR_CMD_STALE_EVENT_DISABLE;
972 			msm_write(port, val, MSM_UART_CR);
973 			val = MSM_UART_CR_CMD_RESET_STALE_INT;
974 			msm_write(port, val, MSM_UART_CR);
975 			/*
976 			 * Flush DMA input fifo to memory, this will also
977 			 * trigger DMA RX completion
978 			 */
979 			dmaengine_terminate_all(dma->chan);
980 		} else if (msm_port->is_uartdm) {
981 			msm_handle_rx_dm(port, misr);
982 		} else {
983 			msm_handle_rx(port);
984 		}
985 	}
986 	if (misr & MSM_UART_IMR_TXLEV)
987 		msm_handle_tx(port);
988 	if (misr & MSM_UART_IMR_DELTA_CTS)
989 		msm_handle_delta_cts(port);
990 
991 	msm_write(port, msm_port->imr, MSM_UART_IMR); /* restore interrupt */
992 	uart_unlock_and_check_sysrq(port);
993 
994 	return IRQ_HANDLED;
995 }
996 
msm_tx_empty(struct uart_port * port)997 static unsigned int msm_tx_empty(struct uart_port *port)
998 {
999 	return (msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
1000 }
1001 
msm_get_mctrl(struct uart_port * port)1002 static unsigned int msm_get_mctrl(struct uart_port *port)
1003 {
1004 	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS;
1005 }
1006 
msm_reset(struct uart_port * port)1007 static void msm_reset(struct uart_port *port)
1008 {
1009 	struct msm_port *msm_port = to_msm_port(port);
1010 	unsigned int mr;
1011 
1012 	/* reset everything */
1013 	msm_write(port, MSM_UART_CR_CMD_RESET_RX, MSM_UART_CR);
1014 	msm_write(port, MSM_UART_CR_CMD_RESET_TX, MSM_UART_CR);
1015 	msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
1016 	msm_write(port, MSM_UART_CR_CMD_RESET_BREAK_INT, MSM_UART_CR);
1017 	msm_write(port, MSM_UART_CR_CMD_RESET_CTS, MSM_UART_CR);
1018 	msm_write(port, MSM_UART_CR_CMD_RESET_RFR, MSM_UART_CR);
1019 	mr = msm_read(port, MSM_UART_MR1);
1020 	mr &= ~MSM_UART_MR1_RX_RDY_CTL;
1021 	msm_write(port, mr, MSM_UART_MR1);
1022 
1023 	/* Disable DM modes */
1024 	if (msm_port->is_uartdm)
1025 		msm_write(port, 0, UARTDM_DMEN);
1026 }
1027 
msm_set_mctrl(struct uart_port * port,unsigned int mctrl)1028 static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
1029 {
1030 	unsigned int mr;
1031 
1032 	mr = msm_read(port, MSM_UART_MR1);
1033 
1034 	if (!(mctrl & TIOCM_RTS)) {
1035 		mr &= ~MSM_UART_MR1_RX_RDY_CTL;
1036 		msm_write(port, mr, MSM_UART_MR1);
1037 		msm_write(port, MSM_UART_CR_CMD_RESET_RFR, MSM_UART_CR);
1038 	} else {
1039 		mr |= MSM_UART_MR1_RX_RDY_CTL;
1040 		msm_write(port, mr, MSM_UART_MR1);
1041 	}
1042 }
1043 
msm_break_ctl(struct uart_port * port,int break_ctl)1044 static void msm_break_ctl(struct uart_port *port, int break_ctl)
1045 {
1046 	if (break_ctl)
1047 		msm_write(port, MSM_UART_CR_CMD_START_BREAK, MSM_UART_CR);
1048 	else
1049 		msm_write(port, MSM_UART_CR_CMD_STOP_BREAK, MSM_UART_CR);
1050 }
1051 
1052 struct msm_baud_map {
1053 	u16	divisor;
1054 	u8	code;
1055 	u8	rxstale;
1056 };
1057 
1058 static const struct msm_baud_map *
msm_find_best_baud(struct uart_port * port,unsigned int baud,unsigned long * rate)1059 msm_find_best_baud(struct uart_port *port, unsigned int baud,
1060 		   unsigned long *rate)
1061 {
1062 	struct msm_port *msm_port = to_msm_port(port);
1063 	unsigned int divisor, result;
1064 	unsigned long target, old, best_rate = 0, diff, best_diff = ULONG_MAX;
1065 	const struct msm_baud_map *entry, *end, *best;
1066 	static const struct msm_baud_map table[] = {
1067 		{    1, 0xff, 31 },
1068 		{    2, 0xee, 16 },
1069 		{    3, 0xdd,  8 },
1070 		{    4, 0xcc,  6 },
1071 		{    6, 0xbb,  6 },
1072 		{    8, 0xaa,  6 },
1073 		{   12, 0x99,  6 },
1074 		{   16, 0x88,  1 },
1075 		{   24, 0x77,  1 },
1076 		{   32, 0x66,  1 },
1077 		{   48, 0x55,  1 },
1078 		{   96, 0x44,  1 },
1079 		{  192, 0x33,  1 },
1080 		{  384, 0x22,  1 },
1081 		{  768, 0x11,  1 },
1082 		{ 1536, 0x00,  1 },
1083 	};
1084 
1085 	best = table; /* Default to smallest divider */
1086 	target = clk_round_rate(msm_port->clk, 16 * baud);
1087 	divisor = DIV_ROUND_CLOSEST(target, 16 * baud);
1088 
1089 	end = table + ARRAY_SIZE(table);
1090 	entry = table;
1091 	while (entry < end) {
1092 		if (entry->divisor <= divisor) {
1093 			result = target / entry->divisor / 16;
1094 			diff = abs(result - baud);
1095 
1096 			/* Keep track of best entry */
1097 			if (diff < best_diff) {
1098 				best_diff = diff;
1099 				best = entry;
1100 				best_rate = target;
1101 			}
1102 
1103 			if (result == baud)
1104 				break;
1105 		} else if (entry->divisor > divisor) {
1106 			old = target;
1107 			target = clk_round_rate(msm_port->clk, old + 1);
1108 			/*
1109 			 * The rate didn't get any faster so we can't do
1110 			 * better at dividing it down
1111 			 */
1112 			if (target == old)
1113 				break;
1114 
1115 			/* Start the divisor search over at this new rate */
1116 			entry = table;
1117 			divisor = DIV_ROUND_CLOSEST(target, 16 * baud);
1118 			continue;
1119 		}
1120 		entry++;
1121 	}
1122 
1123 	*rate = best_rate;
1124 	return best;
1125 }
1126 
msm_set_baud_rate(struct uart_port * port,unsigned int baud,unsigned long * saved_flags)1127 static int msm_set_baud_rate(struct uart_port *port, unsigned int baud,
1128 			     unsigned long *saved_flags)
1129 	__must_hold(&port->lock)
1130 {
1131 	unsigned int rxstale, watermark, mask;
1132 	struct msm_port *msm_port = to_msm_port(port);
1133 	const struct msm_baud_map *entry;
1134 	unsigned long flags, rate;
1135 
1136 	flags = *saved_flags;
1137 	uart_port_unlock_irqrestore(port, flags);
1138 
1139 	entry = msm_find_best_baud(port, baud, &rate);
1140 	dev_pm_opp_set_rate(port->dev, rate);
1141 	baud = rate / 16 / entry->divisor;
1142 
1143 	uart_port_lock_irqsave(port, &flags);
1144 	*saved_flags = flags;
1145 	port->uartclk = rate;
1146 
1147 	msm_write(port, entry->code, MSM_UART_CSR);
1148 
1149 	/* RX stale watermark */
1150 	rxstale = entry->rxstale;
1151 	watermark = MSM_UART_IPR_STALE_LSB & rxstale;
1152 	if (msm_port->is_uartdm) {
1153 		mask = MSM_UART_DM_IPR_STALE_TIMEOUT_MSB;
1154 	} else {
1155 		watermark |= MSM_UART_IPR_RXSTALE_LAST;
1156 		mask = MSM_UART_IPR_STALE_TIMEOUT_MSB;
1157 	}
1158 
1159 	watermark |= mask & (rxstale << 2);
1160 
1161 	msm_write(port, watermark, MSM_UART_IPR);
1162 
1163 	/* set RX watermark */
1164 	watermark = (port->fifosize * 3) / 4;
1165 	msm_write(port, watermark, MSM_UART_RFWR);
1166 
1167 	/* set TX watermark */
1168 	msm_write(port, 10, MSM_UART_TFWR);
1169 
1170 	msm_write(port, MSM_UART_CR_CMD_PROTECTION_EN, MSM_UART_CR);
1171 	msm_reset(port);
1172 
1173 	/* Enable RX and TX */
1174 	msm_write(port, MSM_UART_CR_TX_ENABLE | MSM_UART_CR_RX_ENABLE, MSM_UART_CR);
1175 
1176 	/* turn on RX and CTS interrupts */
1177 	msm_port->imr = MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE |
1178 			MSM_UART_IMR_CURRENT_CTS | MSM_UART_IMR_RXBREAK_START;
1179 
1180 	msm_write(port, msm_port->imr, MSM_UART_IMR);
1181 
1182 	if (msm_port->is_uartdm) {
1183 		msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
1184 		msm_write(port, 0xFFFFFF, UARTDM_DMRX);
1185 		msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
1186 	}
1187 
1188 	return baud;
1189 }
1190 
msm_init_clock(struct uart_port * port)1191 static void msm_init_clock(struct uart_port *port)
1192 {
1193 	struct msm_port *msm_port = to_msm_port(port);
1194 
1195 	dev_pm_opp_set_rate(port->dev, port->uartclk);
1196 	clk_prepare_enable(msm_port->clk);
1197 	clk_prepare_enable(msm_port->pclk);
1198 	msm_serial_set_mnd_regs(port);
1199 }
1200 
msm_startup(struct uart_port * port)1201 static int msm_startup(struct uart_port *port)
1202 {
1203 	struct msm_port *msm_port = to_msm_port(port);
1204 	unsigned int data, rfr_level, mask;
1205 	int ret;
1206 
1207 	snprintf(msm_port->name, sizeof(msm_port->name),
1208 		 "msm_serial%d", port->line);
1209 
1210 	msm_init_clock(port);
1211 
1212 	if (likely(port->fifosize > 12))
1213 		rfr_level = port->fifosize - 12;
1214 	else
1215 		rfr_level = port->fifosize;
1216 
1217 	/* set automatic RFR level */
1218 	data = msm_read(port, MSM_UART_MR1);
1219 
1220 	if (msm_port->is_uartdm)
1221 		mask = MSM_UART_DM_MR1_AUTO_RFR_LEVEL1;
1222 	else
1223 		mask = MSM_UART_MR1_AUTO_RFR_LEVEL1;
1224 
1225 	data &= ~mask;
1226 	data &= ~MSM_UART_MR1_AUTO_RFR_LEVEL0;
1227 	data |= mask & (rfr_level << 2);
1228 	data |= MSM_UART_MR1_AUTO_RFR_LEVEL0 & rfr_level;
1229 	msm_write(port, data, MSM_UART_MR1);
1230 
1231 	if (msm_port->is_uartdm) {
1232 		msm_request_tx_dma(msm_port, msm_port->uart.mapbase);
1233 		msm_request_rx_dma(msm_port, msm_port->uart.mapbase);
1234 	}
1235 
1236 	ret = request_irq(port->irq, msm_uart_irq, IRQF_TRIGGER_HIGH,
1237 			  msm_port->name, port);
1238 	if (unlikely(ret))
1239 		goto err_irq;
1240 
1241 	return 0;
1242 
1243 err_irq:
1244 	if (msm_port->is_uartdm)
1245 		msm_release_dma(msm_port);
1246 
1247 	clk_disable_unprepare(msm_port->pclk);
1248 	clk_disable_unprepare(msm_port->clk);
1249 	dev_pm_opp_set_rate(port->dev, 0);
1250 
1251 	return ret;
1252 }
1253 
msm_shutdown(struct uart_port * port)1254 static void msm_shutdown(struct uart_port *port)
1255 {
1256 	struct msm_port *msm_port = to_msm_port(port);
1257 
1258 	msm_port->imr = 0;
1259 	msm_write(port, 0, MSM_UART_IMR); /* disable interrupts */
1260 
1261 	if (msm_port->is_uartdm)
1262 		msm_release_dma(msm_port);
1263 
1264 	clk_disable_unprepare(msm_port->clk);
1265 	dev_pm_opp_set_rate(port->dev, 0);
1266 
1267 	free_irq(port->irq, port);
1268 }
1269 
msm_set_termios(struct uart_port * port,struct ktermios * termios,const struct ktermios * old)1270 static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
1271 			    const struct ktermios *old)
1272 {
1273 	struct msm_port *msm_port = to_msm_port(port);
1274 	struct msm_dma *dma = &msm_port->rx_dma;
1275 	unsigned long flags;
1276 	unsigned int baud, mr;
1277 
1278 	uart_port_lock_irqsave(port, &flags);
1279 
1280 	if (dma->chan) /* Terminate if any */
1281 		msm_stop_dma(port, dma);
1282 
1283 	/* calculate and set baud rate */
1284 	baud = uart_get_baud_rate(port, termios, old, 300, 4000000);
1285 	baud = msm_set_baud_rate(port, baud, &flags);
1286 	if (tty_termios_baud_rate(termios))
1287 		tty_termios_encode_baud_rate(termios, baud, baud);
1288 
1289 	/* calculate parity */
1290 	mr = msm_read(port, MSM_UART_MR2);
1291 	mr &= ~MSM_UART_MR2_PARITY_MODE;
1292 	if (termios->c_cflag & PARENB) {
1293 		if (termios->c_cflag & PARODD)
1294 			mr |= MSM_UART_MR2_PARITY_MODE_ODD;
1295 		else if (termios->c_cflag & CMSPAR)
1296 			mr |= MSM_UART_MR2_PARITY_MODE_SPACE;
1297 		else
1298 			mr |= MSM_UART_MR2_PARITY_MODE_EVEN;
1299 	}
1300 
1301 	/* calculate bits per char */
1302 	mr &= ~MSM_UART_MR2_BITS_PER_CHAR;
1303 	switch (termios->c_cflag & CSIZE) {
1304 	case CS5:
1305 		mr |= MSM_UART_MR2_BITS_PER_CHAR_5;
1306 		break;
1307 	case CS6:
1308 		mr |= MSM_UART_MR2_BITS_PER_CHAR_6;
1309 		break;
1310 	case CS7:
1311 		mr |= MSM_UART_MR2_BITS_PER_CHAR_7;
1312 		break;
1313 	case CS8:
1314 	default:
1315 		mr |= MSM_UART_MR2_BITS_PER_CHAR_8;
1316 		break;
1317 	}
1318 
1319 	/* calculate stop bits */
1320 	mr &= ~(MSM_UART_MR2_STOP_BIT_LEN_ONE | MSM_UART_MR2_STOP_BIT_LEN_TWO);
1321 	if (termios->c_cflag & CSTOPB)
1322 		mr |= MSM_UART_MR2_STOP_BIT_LEN_TWO;
1323 	else
1324 		mr |= MSM_UART_MR2_STOP_BIT_LEN_ONE;
1325 
1326 	/* set parity, bits per char, and stop bit */
1327 	msm_write(port, mr, MSM_UART_MR2);
1328 
1329 	/* calculate and set hardware flow control */
1330 	mr = msm_read(port, MSM_UART_MR1);
1331 	mr &= ~(MSM_UART_MR1_CTS_CTL | MSM_UART_MR1_RX_RDY_CTL);
1332 	if (termios->c_cflag & CRTSCTS) {
1333 		mr |= MSM_UART_MR1_CTS_CTL;
1334 		mr |= MSM_UART_MR1_RX_RDY_CTL;
1335 	}
1336 	msm_write(port, mr, MSM_UART_MR1);
1337 
1338 	/* Configure status bits to ignore based on termio flags. */
1339 	port->read_status_mask = 0;
1340 	if (termios->c_iflag & INPCK)
1341 		port->read_status_mask |= MSM_UART_SR_PAR_FRAME_ERR;
1342 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
1343 		port->read_status_mask |= MSM_UART_SR_RX_BREAK;
1344 
1345 	uart_update_timeout(port, termios->c_cflag, baud);
1346 
1347 	/* Try to use DMA */
1348 	msm_start_rx_dma(msm_port);
1349 
1350 	uart_port_unlock_irqrestore(port, flags);
1351 }
1352 
msm_type(struct uart_port * port)1353 static const char *msm_type(struct uart_port *port)
1354 {
1355 	return "MSM";
1356 }
1357 
msm_release_port(struct uart_port * port)1358 static void msm_release_port(struct uart_port *port)
1359 {
1360 	struct platform_device *pdev = to_platform_device(port->dev);
1361 	struct resource *uart_resource;
1362 	resource_size_t size;
1363 
1364 	uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1365 	if (unlikely(!uart_resource))
1366 		return;
1367 	size = resource_size(uart_resource);
1368 
1369 	release_mem_region(port->mapbase, size);
1370 	iounmap(port->membase);
1371 	port->membase = NULL;
1372 }
1373 
msm_request_port(struct uart_port * port)1374 static int msm_request_port(struct uart_port *port)
1375 {
1376 	struct platform_device *pdev = to_platform_device(port->dev);
1377 	struct resource *uart_resource;
1378 	resource_size_t size;
1379 	int ret;
1380 
1381 	uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1382 	if (unlikely(!uart_resource))
1383 		return -ENXIO;
1384 
1385 	size = resource_size(uart_resource);
1386 
1387 	if (!request_mem_region(port->mapbase, size, "msm_serial"))
1388 		return -EBUSY;
1389 
1390 	port->membase = ioremap(port->mapbase, size);
1391 	if (!port->membase) {
1392 		ret = -EBUSY;
1393 		goto fail_release_port;
1394 	}
1395 
1396 	return 0;
1397 
1398 fail_release_port:
1399 	release_mem_region(port->mapbase, size);
1400 	return ret;
1401 }
1402 
msm_config_port(struct uart_port * port,int flags)1403 static void msm_config_port(struct uart_port *port, int flags)
1404 {
1405 	int ret;
1406 
1407 	if (flags & UART_CONFIG_TYPE) {
1408 		port->type = PORT_MSM;
1409 		ret = msm_request_port(port);
1410 		if (ret)
1411 			return;
1412 	}
1413 }
1414 
msm_verify_port(struct uart_port * port,struct serial_struct * ser)1415 static int msm_verify_port(struct uart_port *port, struct serial_struct *ser)
1416 {
1417 	if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM))
1418 		return -EINVAL;
1419 	if (unlikely(port->irq != ser->irq))
1420 		return -EINVAL;
1421 	return 0;
1422 }
1423 
msm_power(struct uart_port * port,unsigned int state,unsigned int oldstate)1424 static void msm_power(struct uart_port *port, unsigned int state,
1425 		      unsigned int oldstate)
1426 {
1427 	struct msm_port *msm_port = to_msm_port(port);
1428 
1429 	switch (state) {
1430 	case 0:
1431 		dev_pm_opp_set_rate(port->dev, port->uartclk);
1432 		clk_prepare_enable(msm_port->clk);
1433 		clk_prepare_enable(msm_port->pclk);
1434 		break;
1435 	case 3:
1436 		clk_disable_unprepare(msm_port->clk);
1437 		dev_pm_opp_set_rate(port->dev, 0);
1438 		clk_disable_unprepare(msm_port->pclk);
1439 		break;
1440 	default:
1441 		pr_err("msm_serial: Unknown PM state %d\n", state);
1442 	}
1443 }
1444 
1445 #ifdef CONFIG_CONSOLE_POLL
msm_poll_get_char_single(struct uart_port * port)1446 static int msm_poll_get_char_single(struct uart_port *port)
1447 {
1448 	struct msm_port *msm_port = to_msm_port(port);
1449 	unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : MSM_UART_RF;
1450 
1451 	if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_RX_READY))
1452 		return NO_POLL_CHAR;
1453 
1454 	return msm_read(port, rf_reg) & 0xff;
1455 }
1456 
msm_poll_get_char_dm(struct uart_port * port)1457 static int msm_poll_get_char_dm(struct uart_port *port)
1458 {
1459 	int c;
1460 	static u32 slop;
1461 	static int count;
1462 	unsigned char *sp = (unsigned char *)&slop;
1463 
1464 	/* Check if a previous read had more than one char */
1465 	if (count) {
1466 		c = sp[sizeof(slop) - count];
1467 		count--;
1468 	/* Or if FIFO is empty */
1469 	} else if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_RX_READY)) {
1470 		/*
1471 		 * If RX packing buffer has less than a word, force stale to
1472 		 * push contents into RX FIFO
1473 		 */
1474 		count = msm_read(port, UARTDM_RXFS);
1475 		count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK;
1476 		if (count) {
1477 			msm_write(port, MSM_UART_CR_CMD_FORCE_STALE, MSM_UART_CR);
1478 			slop = msm_read(port, UARTDM_RF);
1479 			c = sp[0];
1480 			count--;
1481 			msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
1482 			msm_write(port, 0xFFFFFF, UARTDM_DMRX);
1483 			msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
1484 		} else {
1485 			c = NO_POLL_CHAR;
1486 		}
1487 	/* FIFO has a word */
1488 	} else {
1489 		slop = msm_read(port, UARTDM_RF);
1490 		c = sp[0];
1491 		count = sizeof(slop) - 1;
1492 	}
1493 
1494 	return c;
1495 }
1496 
msm_poll_get_char(struct uart_port * port)1497 static int msm_poll_get_char(struct uart_port *port)
1498 {
1499 	u32 imr;
1500 	int c;
1501 	struct msm_port *msm_port = to_msm_port(port);
1502 
1503 	/* Disable all interrupts */
1504 	imr = msm_read(port, MSM_UART_IMR);
1505 	msm_write(port, 0, MSM_UART_IMR);
1506 
1507 	if (msm_port->is_uartdm)
1508 		c = msm_poll_get_char_dm(port);
1509 	else
1510 		c = msm_poll_get_char_single(port);
1511 
1512 	/* Enable interrupts */
1513 	msm_write(port, imr, MSM_UART_IMR);
1514 
1515 	return c;
1516 }
1517 
msm_poll_put_char(struct uart_port * port,unsigned char c)1518 static void msm_poll_put_char(struct uart_port *port, unsigned char c)
1519 {
1520 	u32 imr;
1521 	struct msm_port *msm_port = to_msm_port(port);
1522 
1523 	/* Disable all interrupts */
1524 	imr = msm_read(port, MSM_UART_IMR);
1525 	msm_write(port, 0, MSM_UART_IMR);
1526 
1527 	if (msm_port->is_uartdm)
1528 		msm_reset_dm_count(port, 1);
1529 
1530 	/* Wait until FIFO is empty */
1531 	while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
1532 		cpu_relax();
1533 
1534 	/* Write a character */
1535 	msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : MSM_UART_TF);
1536 
1537 	/* Wait until FIFO is empty */
1538 	while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
1539 		cpu_relax();
1540 
1541 	/* Enable interrupts */
1542 	msm_write(port, imr, MSM_UART_IMR);
1543 }
1544 #endif
1545 
1546 static const struct uart_ops msm_uart_pops = {
1547 	.tx_empty = msm_tx_empty,
1548 	.set_mctrl = msm_set_mctrl,
1549 	.get_mctrl = msm_get_mctrl,
1550 	.stop_tx = msm_stop_tx,
1551 	.start_tx = msm_start_tx,
1552 	.stop_rx = msm_stop_rx,
1553 	.enable_ms = msm_enable_ms,
1554 	.break_ctl = msm_break_ctl,
1555 	.startup = msm_startup,
1556 	.shutdown = msm_shutdown,
1557 	.set_termios = msm_set_termios,
1558 	.type = msm_type,
1559 	.release_port = msm_release_port,
1560 	.request_port = msm_request_port,
1561 	.config_port = msm_config_port,
1562 	.verify_port = msm_verify_port,
1563 	.pm = msm_power,
1564 #ifdef CONFIG_CONSOLE_POLL
1565 	.poll_get_char	= msm_poll_get_char,
1566 	.poll_put_char	= msm_poll_put_char,
1567 #endif
1568 };
1569 
1570 static struct msm_port msm_uart_ports[] = {
1571 	{
1572 		.uart = {
1573 			.iotype = UPIO_MEM,
1574 			.ops = &msm_uart_pops,
1575 			.flags = UPF_BOOT_AUTOCONF,
1576 			.fifosize = 64,
1577 			.line = 0,
1578 		},
1579 	},
1580 	{
1581 		.uart = {
1582 			.iotype = UPIO_MEM,
1583 			.ops = &msm_uart_pops,
1584 			.flags = UPF_BOOT_AUTOCONF,
1585 			.fifosize = 64,
1586 			.line = 1,
1587 		},
1588 	},
1589 	{
1590 		.uart = {
1591 			.iotype = UPIO_MEM,
1592 			.ops = &msm_uart_pops,
1593 			.flags = UPF_BOOT_AUTOCONF,
1594 			.fifosize = 64,
1595 			.line = 2,
1596 		},
1597 	},
1598 };
1599 
1600 #define MSM_UART_NR	ARRAY_SIZE(msm_uart_ports)
1601 
msm_get_port_from_line(unsigned int line)1602 static inline struct uart_port *msm_get_port_from_line(unsigned int line)
1603 {
1604 	return &msm_uart_ports[line].uart;
1605 }
1606 
1607 #ifdef CONFIG_SERIAL_MSM_CONSOLE
__msm_console_write(struct uart_port * port,const char * s,unsigned int count,bool is_uartdm)1608 static void __msm_console_write(struct uart_port *port, const char *s,
1609 				unsigned int count, bool is_uartdm)
1610 {
1611 	unsigned long flags;
1612 	int i;
1613 	int num_newlines = 0;
1614 	bool replaced = false;
1615 	void __iomem *tf;
1616 	int locked = 1;
1617 
1618 	if (is_uartdm)
1619 		tf = port->membase + UARTDM_TF;
1620 	else
1621 		tf = port->membase + MSM_UART_TF;
1622 
1623 	/* Account for newlines that will get a carriage return added */
1624 	for (i = 0; i < count; i++)
1625 		if (s[i] == '\n')
1626 			num_newlines++;
1627 	count += num_newlines;
1628 
1629 	if (oops_in_progress)
1630 		locked = uart_port_trylock_irqsave(port, &flags);
1631 	else
1632 		uart_port_lock_irqsave(port, &flags);
1633 
1634 	if (is_uartdm)
1635 		msm_reset_dm_count(port, count);
1636 
1637 	i = 0;
1638 	while (i < count) {
1639 		int j;
1640 		unsigned int num_chars;
1641 		char buf[4] = { 0 };
1642 
1643 		if (is_uartdm)
1644 			num_chars = min(count - i, (unsigned int)sizeof(buf));
1645 		else
1646 			num_chars = 1;
1647 
1648 		for (j = 0; j < num_chars; j++) {
1649 			char c = *s;
1650 
1651 			if (c == '\n' && !replaced) {
1652 				buf[j] = '\r';
1653 				j++;
1654 				replaced = true;
1655 			}
1656 			if (j < num_chars) {
1657 				buf[j] = c;
1658 				s++;
1659 				replaced = false;
1660 			}
1661 		}
1662 
1663 		while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
1664 			cpu_relax();
1665 
1666 		iowrite32_rep(tf, buf, 1);
1667 		i += num_chars;
1668 	}
1669 
1670 	if (locked)
1671 		uart_port_unlock_irqrestore(port, flags);
1672 }
1673 
msm_console_write(struct console * co,const char * s,unsigned int count)1674 static void msm_console_write(struct console *co, const char *s,
1675 			      unsigned int count)
1676 {
1677 	struct uart_port *port;
1678 	struct msm_port *msm_port;
1679 
1680 	BUG_ON(co->index < 0 || co->index >= MSM_UART_NR);
1681 
1682 	port = msm_get_port_from_line(co->index);
1683 	msm_port = to_msm_port(port);
1684 
1685 	__msm_console_write(port, s, count, msm_port->is_uartdm);
1686 }
1687 
msm_console_setup(struct console * co,char * options)1688 static int msm_console_setup(struct console *co, char *options)
1689 {
1690 	struct uart_port *port;
1691 	int baud = 115200;
1692 	int bits = 8;
1693 	int parity = 'n';
1694 	int flow = 'n';
1695 
1696 	if (unlikely(co->index >= MSM_UART_NR || co->index < 0))
1697 		return -ENXIO;
1698 
1699 	port = msm_get_port_from_line(co->index);
1700 
1701 	if (unlikely(!port->membase))
1702 		return -ENXIO;
1703 
1704 	msm_init_clock(port);
1705 
1706 	if (options)
1707 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1708 
1709 	pr_info("msm_serial: console setup on port #%d\n", port->line);
1710 
1711 	return uart_set_options(port, co, baud, parity, bits, flow);
1712 }
1713 
1714 static void
msm_serial_early_write(struct console * con,const char * s,unsigned n)1715 msm_serial_early_write(struct console *con, const char *s, unsigned n)
1716 {
1717 	struct earlycon_device *dev = con->data;
1718 
1719 	__msm_console_write(&dev->port, s, n, false);
1720 }
1721 
1722 static int __init
msm_serial_early_console_setup(struct earlycon_device * device,const char * opt)1723 msm_serial_early_console_setup(struct earlycon_device *device, const char *opt)
1724 {
1725 	if (!device->port.membase)
1726 		return -ENODEV;
1727 
1728 	device->con->write = msm_serial_early_write;
1729 	return 0;
1730 }
1731 OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart",
1732 		    msm_serial_early_console_setup);
1733 
1734 static void
msm_serial_early_write_dm(struct console * con,const char * s,unsigned n)1735 msm_serial_early_write_dm(struct console *con, const char *s, unsigned n)
1736 {
1737 	struct earlycon_device *dev = con->data;
1738 
1739 	__msm_console_write(&dev->port, s, n, true);
1740 }
1741 
1742 static int __init
msm_serial_early_console_setup_dm(struct earlycon_device * device,const char * opt)1743 msm_serial_early_console_setup_dm(struct earlycon_device *device,
1744 				  const char *opt)
1745 {
1746 	if (!device->port.membase)
1747 		return -ENODEV;
1748 
1749 	device->con->write = msm_serial_early_write_dm;
1750 	return 0;
1751 }
1752 OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm",
1753 		    msm_serial_early_console_setup_dm);
1754 
1755 static struct uart_driver msm_uart_driver;
1756 
1757 static struct console msm_console = {
1758 	.name = "ttyMSM",
1759 	.write = msm_console_write,
1760 	.device = uart_console_device,
1761 	.setup = msm_console_setup,
1762 	.flags = CON_PRINTBUFFER,
1763 	.index = -1,
1764 	.data = &msm_uart_driver,
1765 };
1766 
1767 #define MSM_CONSOLE	(&msm_console)
1768 
1769 #else
1770 #define MSM_CONSOLE	NULL
1771 #endif
1772 
1773 static struct uart_driver msm_uart_driver = {
1774 	.owner = THIS_MODULE,
1775 	.driver_name = "msm_serial",
1776 	.dev_name = "ttyMSM",
1777 	.nr = MSM_UART_NR,
1778 	.cons = MSM_CONSOLE,
1779 };
1780 
1781 static atomic_t msm_uart_next_id = ATOMIC_INIT(0);
1782 
1783 static const struct of_device_id msm_uartdm_table[] = {
1784 	{ .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 },
1785 	{ .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 },
1786 	{ .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 },
1787 	{ .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 },
1788 	{ }
1789 };
1790 
msm_serial_probe(struct platform_device * pdev)1791 static int msm_serial_probe(struct platform_device *pdev)
1792 {
1793 	struct msm_port *msm_port;
1794 	struct resource *resource;
1795 	struct uart_port *port;
1796 	const struct of_device_id *id;
1797 	int irq, line, ret;
1798 
1799 	if (pdev->dev.of_node)
1800 		line = of_alias_get_id(pdev->dev.of_node, "serial");
1801 	else
1802 		line = pdev->id;
1803 
1804 	if (line < 0)
1805 		line = atomic_inc_return(&msm_uart_next_id) - 1;
1806 
1807 	if (unlikely(line < 0 || line >= MSM_UART_NR))
1808 		return -ENXIO;
1809 
1810 	dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line);
1811 
1812 	port = msm_get_port_from_line(line);
1813 	port->dev = &pdev->dev;
1814 	msm_port = to_msm_port(port);
1815 
1816 	id = of_match_device(msm_uartdm_table, &pdev->dev);
1817 	if (id)
1818 		msm_port->is_uartdm = (unsigned long)id->data;
1819 	else
1820 		msm_port->is_uartdm = 0;
1821 
1822 	msm_port->clk = devm_clk_get(&pdev->dev, "core");
1823 	if (IS_ERR(msm_port->clk))
1824 		return PTR_ERR(msm_port->clk);
1825 
1826 	if (msm_port->is_uartdm) {
1827 		msm_port->pclk = devm_clk_get(&pdev->dev, "iface");
1828 		if (IS_ERR(msm_port->pclk))
1829 			return PTR_ERR(msm_port->pclk);
1830 	}
1831 
1832 	ret = devm_pm_opp_set_clkname(&pdev->dev, "core");
1833 	if (ret)
1834 		return ret;
1835 
1836 	/* OPP table is optional */
1837 	ret = devm_pm_opp_of_add_table(&pdev->dev);
1838 	if (ret && ret != -ENODEV)
1839 		return dev_err_probe(&pdev->dev, ret, "invalid OPP table\n");
1840 
1841 	port->uartclk = clk_get_rate(msm_port->clk);
1842 	dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk);
1843 
1844 	resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1845 	if (unlikely(!resource))
1846 		return -ENXIO;
1847 	port->mapbase = resource->start;
1848 
1849 	irq = platform_get_irq(pdev, 0);
1850 	if (unlikely(irq < 0))
1851 		return -ENXIO;
1852 	port->irq = irq;
1853 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MSM_CONSOLE);
1854 
1855 	platform_set_drvdata(pdev, port);
1856 
1857 	return uart_add_one_port(&msm_uart_driver, port);
1858 }
1859 
msm_serial_remove(struct platform_device * pdev)1860 static void msm_serial_remove(struct platform_device *pdev)
1861 {
1862 	struct uart_port *port = platform_get_drvdata(pdev);
1863 
1864 	uart_remove_one_port(&msm_uart_driver, port);
1865 }
1866 
1867 static const struct of_device_id msm_match_table[] = {
1868 	{ .compatible = "qcom,msm-uart" },
1869 	{ .compatible = "qcom,msm-uartdm" },
1870 	{}
1871 };
1872 MODULE_DEVICE_TABLE(of, msm_match_table);
1873 
msm_serial_suspend(struct device * dev)1874 static int __maybe_unused msm_serial_suspend(struct device *dev)
1875 {
1876 	struct msm_port *port = dev_get_drvdata(dev);
1877 
1878 	uart_suspend_port(&msm_uart_driver, &port->uart);
1879 
1880 	return 0;
1881 }
1882 
msm_serial_resume(struct device * dev)1883 static int __maybe_unused msm_serial_resume(struct device *dev)
1884 {
1885 	struct msm_port *port = dev_get_drvdata(dev);
1886 
1887 	uart_resume_port(&msm_uart_driver, &port->uart);
1888 
1889 	return 0;
1890 }
1891 
1892 static const struct dev_pm_ops msm_serial_dev_pm_ops = {
1893 	SET_SYSTEM_SLEEP_PM_OPS(msm_serial_suspend, msm_serial_resume)
1894 };
1895 
1896 static struct platform_driver msm_platform_driver = {
1897 	.remove = msm_serial_remove,
1898 	.probe = msm_serial_probe,
1899 	.driver = {
1900 		.name = "msm_serial",
1901 		.pm = &msm_serial_dev_pm_ops,
1902 		.of_match_table = msm_match_table,
1903 	},
1904 };
1905 
msm_serial_init(void)1906 static int __init msm_serial_init(void)
1907 {
1908 	int ret;
1909 
1910 	ret = uart_register_driver(&msm_uart_driver);
1911 	if (unlikely(ret))
1912 		return ret;
1913 
1914 	ret = platform_driver_register(&msm_platform_driver);
1915 	if (unlikely(ret))
1916 		uart_unregister_driver(&msm_uart_driver);
1917 
1918 	pr_info("msm_serial: driver initialized\n");
1919 
1920 	return ret;
1921 }
1922 
msm_serial_exit(void)1923 static void __exit msm_serial_exit(void)
1924 {
1925 	platform_driver_unregister(&msm_platform_driver);
1926 	uart_unregister_driver(&msm_uart_driver);
1927 }
1928 
1929 module_init(msm_serial_init);
1930 module_exit(msm_serial_exit);
1931 
1932 MODULE_AUTHOR("Robert Love <rlove@google.com>");
1933 MODULE_DESCRIPTION("Driver for msm7x serial device");
1934 MODULE_LICENSE("GPL");
1935