xref: /openbmc/linux/drivers/tty/serial/msm_serial.c (revision 9a87ffc99ec8eb8d35eed7c4f816d75f5cc9662e)
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/delay.h>
28  #include <linux/of.h>
29  #include <linux/of_device.h>
30  #include <linux/wait.h>
31  
32  #define MSM_UART_MR1			0x0000
33  
34  #define MSM_UART_MR1_AUTO_RFR_LEVEL0	0x3F
35  #define MSM_UART_MR1_AUTO_RFR_LEVEL1	0x3FF00
36  #define MSM_UART_DM_MR1_AUTO_RFR_LEVEL1	0xFFFFFF00
37  #define MSM_UART_MR1_RX_RDY_CTL		BIT(7)
38  #define MSM_UART_MR1_CTS_CTL		BIT(6)
39  
40  #define MSM_UART_MR2			0x0004
41  #define MSM_UART_MR2_ERROR_MODE		BIT(6)
42  #define MSM_UART_MR2_BITS_PER_CHAR	0x30
43  #define MSM_UART_MR2_BITS_PER_CHAR_5	(0x0 << 4)
44  #define MSM_UART_MR2_BITS_PER_CHAR_6	(0x1 << 4)
45  #define MSM_UART_MR2_BITS_PER_CHAR_7	(0x2 << 4)
46  #define MSM_UART_MR2_BITS_PER_CHAR_8	(0x3 << 4)
47  #define MSM_UART_MR2_STOP_BIT_LEN_ONE	(0x1 << 2)
48  #define MSM_UART_MR2_STOP_BIT_LEN_TWO	(0x3 << 2)
49  #define MSM_UART_MR2_PARITY_MODE_NONE	0x0
50  #define MSM_UART_MR2_PARITY_MODE_ODD	0x1
51  #define MSM_UART_MR2_PARITY_MODE_EVEN	0x2
52  #define MSM_UART_MR2_PARITY_MODE_SPACE	0x3
53  #define MSM_UART_MR2_PARITY_MODE	0x3
54  
55  #define MSM_UART_CSR			0x0008
56  
57  #define MSM_UART_TF			0x000C
58  #define UARTDM_TF			0x0070
59  
60  #define MSM_UART_CR				0x0010
61  #define MSM_UART_CR_CMD_NULL			(0 << 4)
62  #define MSM_UART_CR_CMD_RESET_RX		(1 << 4)
63  #define MSM_UART_CR_CMD_RESET_TX		(2 << 4)
64  #define MSM_UART_CR_CMD_RESET_ERR		(3 << 4)
65  #define MSM_UART_CR_CMD_RESET_BREAK_INT		(4 << 4)
66  #define MSM_UART_CR_CMD_START_BREAK		(5 << 4)
67  #define MSM_UART_CR_CMD_STOP_BREAK		(6 << 4)
68  #define MSM_UART_CR_CMD_RESET_CTS		(7 << 4)
69  #define MSM_UART_CR_CMD_RESET_STALE_INT		(8 << 4)
70  #define MSM_UART_CR_CMD_PACKET_MODE		(9 << 4)
71  #define MSM_UART_CR_CMD_MODE_RESET		(12 << 4)
72  #define MSM_UART_CR_CMD_SET_RFR			(13 << 4)
73  #define MSM_UART_CR_CMD_RESET_RFR		(14 << 4)
74  #define MSM_UART_CR_CMD_PROTECTION_EN		(16 << 4)
75  #define MSM_UART_CR_CMD_STALE_EVENT_DISABLE	(6 << 8)
76  #define MSM_UART_CR_CMD_STALE_EVENT_ENABLE	(80 << 4)
77  #define MSM_UART_CR_CMD_FORCE_STALE		(4 << 8)
78  #define MSM_UART_CR_CMD_RESET_TX_READY		(3 << 8)
79  #define MSM_UART_CR_TX_DISABLE			BIT(3)
80  #define MSM_UART_CR_TX_ENABLE			BIT(2)
81  #define MSM_UART_CR_RX_DISABLE			BIT(1)
82  #define MSM_UART_CR_RX_ENABLE			BIT(0)
83  #define MSM_UART_CR_CMD_RESET_RXBREAK_START	((1 << 11) | (2 << 4))
84  
85  #define MSM_UART_IMR			0x0014
86  #define MSM_UART_IMR_TXLEV		BIT(0)
87  #define MSM_UART_IMR_RXSTALE		BIT(3)
88  #define MSM_UART_IMR_RXLEV		BIT(4)
89  #define MSM_UART_IMR_DELTA_CTS		BIT(5)
90  #define MSM_UART_IMR_CURRENT_CTS	BIT(6)
91  #define MSM_UART_IMR_RXBREAK_START	BIT(10)
92  
93  #define MSM_UART_IPR_RXSTALE_LAST		0x20
94  #define MSM_UART_IPR_STALE_LSB			0x1F
95  #define MSM_UART_IPR_STALE_TIMEOUT_MSB		0x3FF80
96  #define MSM_UART_DM_IPR_STALE_TIMEOUT_MSB	0xFFFFFF80
97  
98  #define MSM_UART_IPR			0x0018
99  #define MSM_UART_TFWR			0x001C
100  #define MSM_UART_RFWR			0x0020
101  #define MSM_UART_HCR			0x0024
102  
103  #define MSM_UART_MREG			0x0028
104  #define MSM_UART_NREG			0x002C
105  #define MSM_UART_DREG			0x0030
106  #define MSM_UART_MNDREG			0x0034
107  #define MSM_UART_IRDA			0x0038
108  #define MSM_UART_MISR_MODE		0x0040
109  #define MSM_UART_MISR_RESET		0x0044
110  #define MSM_UART_MISR_EXPORT		0x0048
111  #define MSM_UART_MISR_VAL		0x004C
112  #define MSM_UART_TEST_CTRL		0x0050
113  
114  #define MSM_UART_SR			0x0008
115  #define MSM_UART_SR_HUNT_CHAR		BIT(7)
116  #define MSM_UART_SR_RX_BREAK		BIT(6)
117  #define MSM_UART_SR_PAR_FRAME_ERR	BIT(5)
118  #define MSM_UART_SR_OVERRUN		BIT(4)
119  #define MSM_UART_SR_TX_EMPTY		BIT(3)
120  #define MSM_UART_SR_TX_READY		BIT(2)
121  #define MSM_UART_SR_RX_FULL		BIT(1)
122  #define MSM_UART_SR_RX_READY		BIT(0)
123  
124  #define MSM_UART_RF			0x000C
125  #define UARTDM_RF			0x0070
126  #define MSM_UART_MISR			0x0010
127  #define MSM_UART_ISR			0x0014
128  #define MSM_UART_ISR_TX_READY		BIT(7)
129  
130  #define UARTDM_RXFS			0x50
131  #define UARTDM_RXFS_BUF_SHIFT		0x7
132  #define UARTDM_RXFS_BUF_MASK		0x7
133  
134  #define UARTDM_DMEN			0x3C
135  #define UARTDM_DMEN_RX_SC_ENABLE	BIT(5)
136  #define UARTDM_DMEN_TX_SC_ENABLE	BIT(4)
137  
138  #define UARTDM_DMEN_TX_BAM_ENABLE	BIT(2)	/* UARTDM_1P4 */
139  #define UARTDM_DMEN_TX_DM_ENABLE	BIT(0)	/* < UARTDM_1P4 */
140  
141  #define UARTDM_DMEN_RX_BAM_ENABLE	BIT(3)	/* UARTDM_1P4 */
142  #define UARTDM_DMEN_RX_DM_ENABLE	BIT(1)	/* < UARTDM_1P4 */
143  
144  #define UARTDM_DMRX			0x34
145  #define UARTDM_NCF_TX			0x40
146  #define UARTDM_RX_TOTAL_SNAP		0x38
147  
148  #define UARTDM_BURST_SIZE		16   /* in bytes */
149  #define UARTDM_TX_AIGN(x)		((x) & ~0x3) /* valid for > 1p3 */
150  #define UARTDM_TX_MAX			256   /* in bytes, valid for <= 1p3 */
151  #define UARTDM_RX_SIZE			(UART_XMIT_SIZE / 4)
152  
153  enum {
154  	UARTDM_1P1 = 1,
155  	UARTDM_1P2,
156  	UARTDM_1P3,
157  	UARTDM_1P4,
158  };
159  
160  struct msm_dma {
161  	struct dma_chan		*chan;
162  	enum dma_data_direction dir;
163  	dma_addr_t		phys;
164  	unsigned char		*virt;
165  	dma_cookie_t		cookie;
166  	u32			enable_bit;
167  	unsigned int		count;
168  	struct dma_async_tx_descriptor	*desc;
169  };
170  
171  struct msm_port {
172  	struct uart_port	uart;
173  	char			name[16];
174  	struct clk		*clk;
175  	struct clk		*pclk;
176  	unsigned int		imr;
177  	int			is_uartdm;
178  	unsigned int		old_snap_state;
179  	bool			break_detected;
180  	struct msm_dma		tx_dma;
181  	struct msm_dma		rx_dma;
182  };
183  
to_msm_port(struct uart_port * up)184  static inline struct msm_port *to_msm_port(struct uart_port *up)
185  {
186  	return container_of(up, struct msm_port, uart);
187  }
188  
189  static
msm_write(struct uart_port * port,unsigned int val,unsigned int off)190  void msm_write(struct uart_port *port, unsigned int val, unsigned int off)
191  {
192  	writel_relaxed(val, port->membase + off);
193  }
194  
195  static
msm_read(struct uart_port * port,unsigned int off)196  unsigned int msm_read(struct uart_port *port, unsigned int off)
197  {
198  	return readl_relaxed(port->membase + off);
199  }
200  
201  /*
202   * Setup the MND registers to use the TCXO clock.
203   */
msm_serial_set_mnd_regs_tcxo(struct uart_port * port)204  static void msm_serial_set_mnd_regs_tcxo(struct uart_port *port)
205  {
206  	msm_write(port, 0x06, MSM_UART_MREG);
207  	msm_write(port, 0xF1, MSM_UART_NREG);
208  	msm_write(port, 0x0F, MSM_UART_DREG);
209  	msm_write(port, 0x1A, MSM_UART_MNDREG);
210  	port->uartclk = 1843200;
211  }
212  
213  /*
214   * Setup the MND registers to use the TCXO clock divided by 4.
215   */
msm_serial_set_mnd_regs_tcxoby4(struct uart_port * port)216  static void msm_serial_set_mnd_regs_tcxoby4(struct uart_port *port)
217  {
218  	msm_write(port, 0x18, MSM_UART_MREG);
219  	msm_write(port, 0xF6, MSM_UART_NREG);
220  	msm_write(port, 0x0F, MSM_UART_DREG);
221  	msm_write(port, 0x0A, MSM_UART_MNDREG);
222  	port->uartclk = 1843200;
223  }
224  
msm_serial_set_mnd_regs(struct uart_port * port)225  static void msm_serial_set_mnd_regs(struct uart_port *port)
226  {
227  	struct msm_port *msm_port = to_msm_port(port);
228  
229  	/*
230  	 * These registers don't exist so we change the clk input rate
231  	 * on uartdm hardware instead
232  	 */
233  	if (msm_port->is_uartdm)
234  		return;
235  
236  	if (port->uartclk == 19200000)
237  		msm_serial_set_mnd_regs_tcxo(port);
238  	else if (port->uartclk == 4800000)
239  		msm_serial_set_mnd_regs_tcxoby4(port);
240  }
241  
242  static void msm_handle_tx(struct uart_port *port);
243  static void msm_start_rx_dma(struct msm_port *msm_port);
244  
msm_stop_dma(struct uart_port * port,struct msm_dma * dma)245  static void msm_stop_dma(struct uart_port *port, struct msm_dma *dma)
246  {
247  	struct device *dev = port->dev;
248  	unsigned int mapped;
249  	u32 val;
250  
251  	mapped = dma->count;
252  	dma->count = 0;
253  
254  	dmaengine_terminate_all(dma->chan);
255  
256  	/*
257  	 * DMA Stall happens if enqueue and flush command happens concurrently.
258  	 * For example before changing the baud rate/protocol configuration and
259  	 * sending flush command to ADM, disable the channel of UARTDM.
260  	 * Note: should not reset the receiver here immediately as it is not
261  	 * suggested to do disable/reset or reset/disable at the same time.
262  	 */
263  	val = msm_read(port, UARTDM_DMEN);
264  	val &= ~dma->enable_bit;
265  	msm_write(port, val, UARTDM_DMEN);
266  
267  	if (mapped)
268  		dma_unmap_single(dev, dma->phys, mapped, dma->dir);
269  }
270  
msm_release_dma(struct msm_port * msm_port)271  static void msm_release_dma(struct msm_port *msm_port)
272  {
273  	struct msm_dma *dma;
274  
275  	dma = &msm_port->tx_dma;
276  	if (dma->chan) {
277  		msm_stop_dma(&msm_port->uart, dma);
278  		dma_release_channel(dma->chan);
279  	}
280  
281  	memset(dma, 0, sizeof(*dma));
282  
283  	dma = &msm_port->rx_dma;
284  	if (dma->chan) {
285  		msm_stop_dma(&msm_port->uart, dma);
286  		dma_release_channel(dma->chan);
287  		kfree(dma->virt);
288  	}
289  
290  	memset(dma, 0, sizeof(*dma));
291  }
292  
msm_request_tx_dma(struct msm_port * msm_port,resource_size_t base)293  static void msm_request_tx_dma(struct msm_port *msm_port, resource_size_t base)
294  {
295  	struct device *dev = msm_port->uart.dev;
296  	struct dma_slave_config conf;
297  	struct qcom_adm_peripheral_config periph_conf = {};
298  	struct msm_dma *dma;
299  	u32 crci = 0;
300  	int ret;
301  
302  	dma = &msm_port->tx_dma;
303  
304  	/* allocate DMA resources, if available */
305  	dma->chan = dma_request_chan(dev, "tx");
306  	if (IS_ERR(dma->chan))
307  		goto no_tx;
308  
309  	of_property_read_u32(dev->of_node, "qcom,tx-crci", &crci);
310  
311  	memset(&conf, 0, sizeof(conf));
312  	conf.direction = DMA_MEM_TO_DEV;
313  	conf.device_fc = true;
314  	conf.dst_addr = base + UARTDM_TF;
315  	conf.dst_maxburst = UARTDM_BURST_SIZE;
316  	if (crci) {
317  		conf.peripheral_config = &periph_conf;
318  		conf.peripheral_size = sizeof(periph_conf);
319  		periph_conf.crci = crci;
320  	}
321  
322  	ret = dmaengine_slave_config(dma->chan, &conf);
323  	if (ret)
324  		goto rel_tx;
325  
326  	dma->dir = DMA_TO_DEVICE;
327  
328  	if (msm_port->is_uartdm < UARTDM_1P4)
329  		dma->enable_bit = UARTDM_DMEN_TX_DM_ENABLE;
330  	else
331  		dma->enable_bit = UARTDM_DMEN_TX_BAM_ENABLE;
332  
333  	return;
334  
335  rel_tx:
336  	dma_release_channel(dma->chan);
337  no_tx:
338  	memset(dma, 0, sizeof(*dma));
339  }
340  
msm_request_rx_dma(struct msm_port * msm_port,resource_size_t base)341  static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base)
342  {
343  	struct device *dev = msm_port->uart.dev;
344  	struct dma_slave_config conf;
345  	struct qcom_adm_peripheral_config periph_conf = {};
346  	struct msm_dma *dma;
347  	u32 crci = 0;
348  	int ret;
349  
350  	dma = &msm_port->rx_dma;
351  
352  	/* allocate DMA resources, if available */
353  	dma->chan = dma_request_chan(dev, "rx");
354  	if (IS_ERR(dma->chan))
355  		goto no_rx;
356  
357  	of_property_read_u32(dev->of_node, "qcom,rx-crci", &crci);
358  
359  	dma->virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL);
360  	if (!dma->virt)
361  		goto rel_rx;
362  
363  	memset(&conf, 0, sizeof(conf));
364  	conf.direction = DMA_DEV_TO_MEM;
365  	conf.device_fc = true;
366  	conf.src_addr = base + UARTDM_RF;
367  	conf.src_maxburst = UARTDM_BURST_SIZE;
368  	if (crci) {
369  		conf.peripheral_config = &periph_conf;
370  		conf.peripheral_size = sizeof(periph_conf);
371  		periph_conf.crci = crci;
372  	}
373  
374  	ret = dmaengine_slave_config(dma->chan, &conf);
375  	if (ret)
376  		goto err;
377  
378  	dma->dir = DMA_FROM_DEVICE;
379  
380  	if (msm_port->is_uartdm < UARTDM_1P4)
381  		dma->enable_bit = UARTDM_DMEN_RX_DM_ENABLE;
382  	else
383  		dma->enable_bit = UARTDM_DMEN_RX_BAM_ENABLE;
384  
385  	return;
386  err:
387  	kfree(dma->virt);
388  rel_rx:
389  	dma_release_channel(dma->chan);
390  no_rx:
391  	memset(dma, 0, sizeof(*dma));
392  }
393  
msm_wait_for_xmitr(struct uart_port * port)394  static inline void msm_wait_for_xmitr(struct uart_port *port)
395  {
396  	unsigned int timeout = 500000;
397  
398  	while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_EMPTY)) {
399  		if (msm_read(port, MSM_UART_ISR) & MSM_UART_ISR_TX_READY)
400  			break;
401  		udelay(1);
402  		if (!timeout--)
403  			break;
404  	}
405  	msm_write(port, MSM_UART_CR_CMD_RESET_TX_READY, MSM_UART_CR);
406  }
407  
msm_stop_tx(struct uart_port * port)408  static void msm_stop_tx(struct uart_port *port)
409  {
410  	struct msm_port *msm_port = to_msm_port(port);
411  
412  	msm_port->imr &= ~MSM_UART_IMR_TXLEV;
413  	msm_write(port, msm_port->imr, MSM_UART_IMR);
414  }
415  
msm_start_tx(struct uart_port * port)416  static void msm_start_tx(struct uart_port *port)
417  {
418  	struct msm_port *msm_port = to_msm_port(port);
419  	struct msm_dma *dma = &msm_port->tx_dma;
420  
421  	/* Already started in DMA mode */
422  	if (dma->count)
423  		return;
424  
425  	msm_port->imr |= MSM_UART_IMR_TXLEV;
426  	msm_write(port, msm_port->imr, MSM_UART_IMR);
427  }
428  
msm_reset_dm_count(struct uart_port * port,int count)429  static void msm_reset_dm_count(struct uart_port *port, int count)
430  {
431  	msm_wait_for_xmitr(port);
432  	msm_write(port, count, UARTDM_NCF_TX);
433  	msm_read(port, UARTDM_NCF_TX);
434  }
435  
msm_complete_tx_dma(void * args)436  static void msm_complete_tx_dma(void *args)
437  {
438  	struct msm_port *msm_port = args;
439  	struct uart_port *port = &msm_port->uart;
440  	struct circ_buf *xmit = &port->state->xmit;
441  	struct msm_dma *dma = &msm_port->tx_dma;
442  	struct dma_tx_state state;
443  	unsigned long flags;
444  	unsigned int count;
445  	u32 val;
446  
447  	spin_lock_irqsave(&port->lock, flags);
448  
449  	/* Already stopped */
450  	if (!dma->count)
451  		goto done;
452  
453  	dmaengine_tx_status(dma->chan, dma->cookie, &state);
454  
455  	dma_unmap_single(port->dev, dma->phys, dma->count, dma->dir);
456  
457  	val = msm_read(port, UARTDM_DMEN);
458  	val &= ~dma->enable_bit;
459  	msm_write(port, val, UARTDM_DMEN);
460  
461  	if (msm_port->is_uartdm > UARTDM_1P3) {
462  		msm_write(port, MSM_UART_CR_CMD_RESET_TX, MSM_UART_CR);
463  		msm_write(port, MSM_UART_CR_TX_ENABLE, MSM_UART_CR);
464  	}
465  
466  	count = dma->count - state.residue;
467  	uart_xmit_advance(port, count);
468  	dma->count = 0;
469  
470  	/* Restore "Tx FIFO below watermark" interrupt */
471  	msm_port->imr |= MSM_UART_IMR_TXLEV;
472  	msm_write(port, msm_port->imr, MSM_UART_IMR);
473  
474  	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
475  		uart_write_wakeup(port);
476  
477  	msm_handle_tx(port);
478  done:
479  	spin_unlock_irqrestore(&port->lock, flags);
480  }
481  
msm_handle_tx_dma(struct msm_port * msm_port,unsigned int count)482  static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count)
483  {
484  	struct circ_buf *xmit = &msm_port->uart.state->xmit;
485  	struct uart_port *port = &msm_port->uart;
486  	struct msm_dma *dma = &msm_port->tx_dma;
487  	void *cpu_addr;
488  	int ret;
489  	u32 val;
490  
491  	cpu_addr = &xmit->buf[xmit->tail];
492  
493  	dma->phys = dma_map_single(port->dev, cpu_addr, count, dma->dir);
494  	ret = dma_mapping_error(port->dev, dma->phys);
495  	if (ret)
496  		return ret;
497  
498  	dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys,
499  						count, DMA_MEM_TO_DEV,
500  						DMA_PREP_INTERRUPT |
501  						DMA_PREP_FENCE);
502  	if (!dma->desc) {
503  		ret = -EIO;
504  		goto unmap;
505  	}
506  
507  	dma->desc->callback = msm_complete_tx_dma;
508  	dma->desc->callback_param = msm_port;
509  
510  	dma->cookie = dmaengine_submit(dma->desc);
511  	ret = dma_submit_error(dma->cookie);
512  	if (ret)
513  		goto unmap;
514  
515  	/*
516  	 * Using DMA complete for Tx FIFO reload, no need for
517  	 * "Tx FIFO below watermark" one, disable it
518  	 */
519  	msm_port->imr &= ~MSM_UART_IMR_TXLEV;
520  	msm_write(port, msm_port->imr, MSM_UART_IMR);
521  
522  	dma->count = count;
523  
524  	val = msm_read(port, UARTDM_DMEN);
525  	val |= dma->enable_bit;
526  
527  	if (msm_port->is_uartdm < UARTDM_1P4)
528  		msm_write(port, val, UARTDM_DMEN);
529  
530  	msm_reset_dm_count(port, count);
531  
532  	if (msm_port->is_uartdm > UARTDM_1P3)
533  		msm_write(port, val, UARTDM_DMEN);
534  
535  	dma_async_issue_pending(dma->chan);
536  	return 0;
537  unmap:
538  	dma_unmap_single(port->dev, dma->phys, count, dma->dir);
539  	return ret;
540  }
541  
msm_complete_rx_dma(void * args)542  static void msm_complete_rx_dma(void *args)
543  {
544  	struct msm_port *msm_port = args;
545  	struct uart_port *port = &msm_port->uart;
546  	struct tty_port *tport = &port->state->port;
547  	struct msm_dma *dma = &msm_port->rx_dma;
548  	int count = 0, i, sysrq;
549  	unsigned long flags;
550  	u32 val;
551  
552  	spin_lock_irqsave(&port->lock, flags);
553  
554  	/* Already stopped */
555  	if (!dma->count)
556  		goto done;
557  
558  	val = msm_read(port, UARTDM_DMEN);
559  	val &= ~dma->enable_bit;
560  	msm_write(port, val, UARTDM_DMEN);
561  
562  	if (msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN) {
563  		port->icount.overrun++;
564  		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
565  		msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
566  	}
567  
568  	count = msm_read(port, UARTDM_RX_TOTAL_SNAP);
569  
570  	port->icount.rx += count;
571  
572  	dma->count = 0;
573  
574  	dma_unmap_single(port->dev, dma->phys, UARTDM_RX_SIZE, dma->dir);
575  
576  	for (i = 0; i < count; i++) {
577  		char flag = TTY_NORMAL;
578  
579  		if (msm_port->break_detected && dma->virt[i] == 0) {
580  			port->icount.brk++;
581  			flag = TTY_BREAK;
582  			msm_port->break_detected = false;
583  			if (uart_handle_break(port))
584  				continue;
585  		}
586  
587  		if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK))
588  			flag = TTY_NORMAL;
589  
590  		spin_unlock_irqrestore(&port->lock, flags);
591  		sysrq = uart_handle_sysrq_char(port, dma->virt[i]);
592  		spin_lock_irqsave(&port->lock, flags);
593  		if (!sysrq)
594  			tty_insert_flip_char(tport, dma->virt[i], flag);
595  	}
596  
597  	msm_start_rx_dma(msm_port);
598  done:
599  	spin_unlock_irqrestore(&port->lock, flags);
600  
601  	if (count)
602  		tty_flip_buffer_push(tport);
603  }
604  
msm_start_rx_dma(struct msm_port * msm_port)605  static void msm_start_rx_dma(struct msm_port *msm_port)
606  {
607  	struct msm_dma *dma = &msm_port->rx_dma;
608  	struct uart_port *uart = &msm_port->uart;
609  	u32 val;
610  	int ret;
611  
612  	if (IS_ENABLED(CONFIG_CONSOLE_POLL))
613  		return;
614  
615  	if (!dma->chan)
616  		return;
617  
618  	dma->phys = dma_map_single(uart->dev, dma->virt,
619  				   UARTDM_RX_SIZE, dma->dir);
620  	ret = dma_mapping_error(uart->dev, dma->phys);
621  	if (ret)
622  		goto sw_mode;
623  
624  	dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys,
625  						UARTDM_RX_SIZE, DMA_DEV_TO_MEM,
626  						DMA_PREP_INTERRUPT);
627  	if (!dma->desc)
628  		goto unmap;
629  
630  	dma->desc->callback = msm_complete_rx_dma;
631  	dma->desc->callback_param = msm_port;
632  
633  	dma->cookie = dmaengine_submit(dma->desc);
634  	ret = dma_submit_error(dma->cookie);
635  	if (ret)
636  		goto unmap;
637  	/*
638  	 * Using DMA for FIFO off-load, no need for "Rx FIFO over
639  	 * watermark" or "stale" interrupts, disable them
640  	 */
641  	msm_port->imr &= ~(MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE);
642  
643  	/*
644  	 * Well, when DMA is ADM3 engine(implied by <= UARTDM v1.3),
645  	 * we need RXSTALE to flush input DMA fifo to memory
646  	 */
647  	if (msm_port->is_uartdm < UARTDM_1P4)
648  		msm_port->imr |= MSM_UART_IMR_RXSTALE;
649  
650  	msm_write(uart, msm_port->imr, MSM_UART_IMR);
651  
652  	dma->count = UARTDM_RX_SIZE;
653  
654  	dma_async_issue_pending(dma->chan);
655  
656  	msm_write(uart, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
657  	msm_write(uart, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
658  
659  	val = msm_read(uart, UARTDM_DMEN);
660  	val |= dma->enable_bit;
661  
662  	if (msm_port->is_uartdm < UARTDM_1P4)
663  		msm_write(uart, val, UARTDM_DMEN);
664  
665  	msm_write(uart, UARTDM_RX_SIZE, UARTDM_DMRX);
666  
667  	if (msm_port->is_uartdm > UARTDM_1P3)
668  		msm_write(uart, val, UARTDM_DMEN);
669  
670  	return;
671  unmap:
672  	dma_unmap_single(uart->dev, dma->phys, UARTDM_RX_SIZE, dma->dir);
673  
674  sw_mode:
675  	/*
676  	 * Switch from DMA to SW/FIFO mode. After clearing Rx BAM (UARTDM_DMEN),
677  	 * receiver must be reset.
678  	 */
679  	msm_write(uart, MSM_UART_CR_CMD_RESET_RX, MSM_UART_CR);
680  	msm_write(uart, MSM_UART_CR_RX_ENABLE, MSM_UART_CR);
681  
682  	msm_write(uart, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
683  	msm_write(uart, 0xFFFFFF, UARTDM_DMRX);
684  	msm_write(uart, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
685  
686  	/* Re-enable RX interrupts */
687  	msm_port->imr |= MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE;
688  	msm_write(uart, msm_port->imr, MSM_UART_IMR);
689  }
690  
msm_stop_rx(struct uart_port * port)691  static void msm_stop_rx(struct uart_port *port)
692  {
693  	struct msm_port *msm_port = to_msm_port(port);
694  	struct msm_dma *dma = &msm_port->rx_dma;
695  
696  	msm_port->imr &= ~(MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE);
697  	msm_write(port, msm_port->imr, MSM_UART_IMR);
698  
699  	if (dma->chan)
700  		msm_stop_dma(port, dma);
701  }
702  
msm_enable_ms(struct uart_port * port)703  static void msm_enable_ms(struct uart_port *port)
704  {
705  	struct msm_port *msm_port = to_msm_port(port);
706  
707  	msm_port->imr |= MSM_UART_IMR_DELTA_CTS;
708  	msm_write(port, msm_port->imr, MSM_UART_IMR);
709  }
710  
msm_handle_rx_dm(struct uart_port * port,unsigned int misr)711  static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr)
712  	__must_hold(&port->lock)
713  {
714  	struct tty_port *tport = &port->state->port;
715  	unsigned int sr;
716  	int count = 0;
717  	struct msm_port *msm_port = to_msm_port(port);
718  
719  	if ((msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN)) {
720  		port->icount.overrun++;
721  		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
722  		msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
723  	}
724  
725  	if (misr & MSM_UART_IMR_RXSTALE) {
726  		count = msm_read(port, UARTDM_RX_TOTAL_SNAP) -
727  			msm_port->old_snap_state;
728  		msm_port->old_snap_state = 0;
729  	} else {
730  		count = 4 * (msm_read(port, MSM_UART_RFWR));
731  		msm_port->old_snap_state += count;
732  	}
733  
734  	/* TODO: Precise error reporting */
735  
736  	port->icount.rx += count;
737  
738  	while (count > 0) {
739  		unsigned char buf[4];
740  		int sysrq, r_count, i;
741  
742  		sr = msm_read(port, MSM_UART_SR);
743  		if ((sr & MSM_UART_SR_RX_READY) == 0) {
744  			msm_port->old_snap_state -= count;
745  			break;
746  		}
747  
748  		ioread32_rep(port->membase + UARTDM_RF, buf, 1);
749  		r_count = min_t(int, count, sizeof(buf));
750  
751  		for (i = 0; i < r_count; i++) {
752  			char flag = TTY_NORMAL;
753  
754  			if (msm_port->break_detected && buf[i] == 0) {
755  				port->icount.brk++;
756  				flag = TTY_BREAK;
757  				msm_port->break_detected = false;
758  				if (uart_handle_break(port))
759  					continue;
760  			}
761  
762  			if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK))
763  				flag = TTY_NORMAL;
764  
765  			spin_unlock(&port->lock);
766  			sysrq = uart_handle_sysrq_char(port, buf[i]);
767  			spin_lock(&port->lock);
768  			if (!sysrq)
769  				tty_insert_flip_char(tport, buf[i], flag);
770  		}
771  		count -= r_count;
772  	}
773  
774  	tty_flip_buffer_push(tport);
775  
776  	if (misr & (MSM_UART_IMR_RXSTALE))
777  		msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
778  	msm_write(port, 0xFFFFFF, UARTDM_DMRX);
779  	msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
780  
781  	/* Try to use DMA */
782  	msm_start_rx_dma(msm_port);
783  }
784  
msm_handle_rx(struct uart_port * port)785  static void msm_handle_rx(struct uart_port *port)
786  	__must_hold(&port->lock)
787  {
788  	struct tty_port *tport = &port->state->port;
789  	unsigned int sr;
790  
791  	/*
792  	 * Handle overrun. My understanding of the hardware is that overrun
793  	 * is not tied to the RX buffer, so we handle the case out of band.
794  	 */
795  	if ((msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN)) {
796  		port->icount.overrun++;
797  		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
798  		msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
799  	}
800  
801  	/* and now the main RX loop */
802  	while ((sr = msm_read(port, MSM_UART_SR)) & MSM_UART_SR_RX_READY) {
803  		unsigned int c;
804  		char flag = TTY_NORMAL;
805  		int sysrq;
806  
807  		c = msm_read(port, MSM_UART_RF);
808  
809  		if (sr & MSM_UART_SR_RX_BREAK) {
810  			port->icount.brk++;
811  			if (uart_handle_break(port))
812  				continue;
813  		} else if (sr & MSM_UART_SR_PAR_FRAME_ERR) {
814  			port->icount.frame++;
815  		} else {
816  			port->icount.rx++;
817  		}
818  
819  		/* Mask conditions we're ignoring. */
820  		sr &= port->read_status_mask;
821  
822  		if (sr & MSM_UART_SR_RX_BREAK)
823  			flag = TTY_BREAK;
824  		else if (sr & MSM_UART_SR_PAR_FRAME_ERR)
825  			flag = TTY_FRAME;
826  
827  		spin_unlock(&port->lock);
828  		sysrq = uart_handle_sysrq_char(port, c);
829  		spin_lock(&port->lock);
830  		if (!sysrq)
831  			tty_insert_flip_char(tport, c, flag);
832  	}
833  
834  	tty_flip_buffer_push(tport);
835  }
836  
msm_handle_tx_pio(struct uart_port * port,unsigned int tx_count)837  static void msm_handle_tx_pio(struct uart_port *port, unsigned int tx_count)
838  {
839  	struct circ_buf *xmit = &port->state->xmit;
840  	struct msm_port *msm_port = to_msm_port(port);
841  	unsigned int num_chars;
842  	unsigned int tf_pointer = 0;
843  	void __iomem *tf;
844  
845  	if (msm_port->is_uartdm)
846  		tf = port->membase + UARTDM_TF;
847  	else
848  		tf = port->membase + MSM_UART_TF;
849  
850  	if (tx_count && msm_port->is_uartdm)
851  		msm_reset_dm_count(port, tx_count);
852  
853  	while (tf_pointer < tx_count) {
854  		int i;
855  		char buf[4] = { 0 };
856  
857  		if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
858  			break;
859  
860  		if (msm_port->is_uartdm)
861  			num_chars = min(tx_count - tf_pointer,
862  					(unsigned int)sizeof(buf));
863  		else
864  			num_chars = 1;
865  
866  		for (i = 0; i < num_chars; i++)
867  			buf[i] = xmit->buf[xmit->tail + i];
868  
869  		iowrite32_rep(tf, buf, 1);
870  		uart_xmit_advance(port, num_chars);
871  		tf_pointer += num_chars;
872  	}
873  
874  	/* disable tx interrupts if nothing more to send */
875  	if (uart_circ_empty(xmit))
876  		msm_stop_tx(port);
877  
878  	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
879  		uart_write_wakeup(port);
880  }
881  
msm_handle_tx(struct uart_port * port)882  static void msm_handle_tx(struct uart_port *port)
883  {
884  	struct msm_port *msm_port = to_msm_port(port);
885  	struct circ_buf *xmit = &msm_port->uart.state->xmit;
886  	struct msm_dma *dma = &msm_port->tx_dma;
887  	unsigned int pio_count, dma_count, dma_min;
888  	char buf[4] = { 0 };
889  	void __iomem *tf;
890  	int err = 0;
891  
892  	if (port->x_char) {
893  		if (msm_port->is_uartdm)
894  			tf = port->membase + UARTDM_TF;
895  		else
896  			tf = port->membase + MSM_UART_TF;
897  
898  		buf[0] = port->x_char;
899  
900  		if (msm_port->is_uartdm)
901  			msm_reset_dm_count(port, 1);
902  
903  		iowrite32_rep(tf, buf, 1);
904  		port->icount.tx++;
905  		port->x_char = 0;
906  		return;
907  	}
908  
909  	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
910  		msm_stop_tx(port);
911  		return;
912  	}
913  
914  	pio_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
915  	dma_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
916  
917  	dma_min = 1;	/* Always DMA */
918  	if (msm_port->is_uartdm > UARTDM_1P3) {
919  		dma_count = UARTDM_TX_AIGN(dma_count);
920  		dma_min = UARTDM_BURST_SIZE;
921  	} else {
922  		if (dma_count > UARTDM_TX_MAX)
923  			dma_count = UARTDM_TX_MAX;
924  	}
925  
926  	if (pio_count > port->fifosize)
927  		pio_count = port->fifosize;
928  
929  	if (!dma->chan || dma_count < dma_min)
930  		msm_handle_tx_pio(port, pio_count);
931  	else
932  		err = msm_handle_tx_dma(msm_port, dma_count);
933  
934  	if (err)	/* fall back to PIO mode */
935  		msm_handle_tx_pio(port, pio_count);
936  }
937  
msm_handle_delta_cts(struct uart_port * port)938  static void msm_handle_delta_cts(struct uart_port *port)
939  {
940  	msm_write(port, MSM_UART_CR_CMD_RESET_CTS, MSM_UART_CR);
941  	port->icount.cts++;
942  	wake_up_interruptible(&port->state->port.delta_msr_wait);
943  }
944  
msm_uart_irq(int irq,void * dev_id)945  static irqreturn_t msm_uart_irq(int irq, void *dev_id)
946  {
947  	struct uart_port *port = dev_id;
948  	struct msm_port *msm_port = to_msm_port(port);
949  	struct msm_dma *dma = &msm_port->rx_dma;
950  	unsigned long flags;
951  	unsigned int misr;
952  	u32 val;
953  
954  	spin_lock_irqsave(&port->lock, flags);
955  	misr = msm_read(port, MSM_UART_MISR);
956  	msm_write(port, 0, MSM_UART_IMR); /* disable interrupt */
957  
958  	if (misr & MSM_UART_IMR_RXBREAK_START) {
959  		msm_port->break_detected = true;
960  		msm_write(port, MSM_UART_CR_CMD_RESET_RXBREAK_START, MSM_UART_CR);
961  	}
962  
963  	if (misr & (MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE)) {
964  		if (dma->count) {
965  			val = MSM_UART_CR_CMD_STALE_EVENT_DISABLE;
966  			msm_write(port, val, MSM_UART_CR);
967  			val = MSM_UART_CR_CMD_RESET_STALE_INT;
968  			msm_write(port, val, MSM_UART_CR);
969  			/*
970  			 * Flush DMA input fifo to memory, this will also
971  			 * trigger DMA RX completion
972  			 */
973  			dmaengine_terminate_all(dma->chan);
974  		} else if (msm_port->is_uartdm) {
975  			msm_handle_rx_dm(port, misr);
976  		} else {
977  			msm_handle_rx(port);
978  		}
979  	}
980  	if (misr & MSM_UART_IMR_TXLEV)
981  		msm_handle_tx(port);
982  	if (misr & MSM_UART_IMR_DELTA_CTS)
983  		msm_handle_delta_cts(port);
984  
985  	msm_write(port, msm_port->imr, MSM_UART_IMR); /* restore interrupt */
986  	spin_unlock_irqrestore(&port->lock, flags);
987  
988  	return IRQ_HANDLED;
989  }
990  
msm_tx_empty(struct uart_port * port)991  static unsigned int msm_tx_empty(struct uart_port *port)
992  {
993  	return (msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
994  }
995  
msm_get_mctrl(struct uart_port * port)996  static unsigned int msm_get_mctrl(struct uart_port *port)
997  {
998  	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS;
999  }
1000  
msm_reset(struct uart_port * port)1001  static void msm_reset(struct uart_port *port)
1002  {
1003  	struct msm_port *msm_port = to_msm_port(port);
1004  	unsigned int mr;
1005  
1006  	/* reset everything */
1007  	msm_write(port, MSM_UART_CR_CMD_RESET_RX, MSM_UART_CR);
1008  	msm_write(port, MSM_UART_CR_CMD_RESET_TX, MSM_UART_CR);
1009  	msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR);
1010  	msm_write(port, MSM_UART_CR_CMD_RESET_BREAK_INT, MSM_UART_CR);
1011  	msm_write(port, MSM_UART_CR_CMD_RESET_CTS, MSM_UART_CR);
1012  	msm_write(port, MSM_UART_CR_CMD_RESET_RFR, MSM_UART_CR);
1013  	mr = msm_read(port, MSM_UART_MR1);
1014  	mr &= ~MSM_UART_MR1_RX_RDY_CTL;
1015  	msm_write(port, mr, MSM_UART_MR1);
1016  
1017  	/* Disable DM modes */
1018  	if (msm_port->is_uartdm)
1019  		msm_write(port, 0, UARTDM_DMEN);
1020  }
1021  
msm_set_mctrl(struct uart_port * port,unsigned int mctrl)1022  static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
1023  {
1024  	unsigned int mr;
1025  
1026  	mr = msm_read(port, MSM_UART_MR1);
1027  
1028  	if (!(mctrl & TIOCM_RTS)) {
1029  		mr &= ~MSM_UART_MR1_RX_RDY_CTL;
1030  		msm_write(port, mr, MSM_UART_MR1);
1031  		msm_write(port, MSM_UART_CR_CMD_RESET_RFR, MSM_UART_CR);
1032  	} else {
1033  		mr |= MSM_UART_MR1_RX_RDY_CTL;
1034  		msm_write(port, mr, MSM_UART_MR1);
1035  	}
1036  }
1037  
msm_break_ctl(struct uart_port * port,int break_ctl)1038  static void msm_break_ctl(struct uart_port *port, int break_ctl)
1039  {
1040  	if (break_ctl)
1041  		msm_write(port, MSM_UART_CR_CMD_START_BREAK, MSM_UART_CR);
1042  	else
1043  		msm_write(port, MSM_UART_CR_CMD_STOP_BREAK, MSM_UART_CR);
1044  }
1045  
1046  struct msm_baud_map {
1047  	u16	divisor;
1048  	u8	code;
1049  	u8	rxstale;
1050  };
1051  
1052  static const struct msm_baud_map *
msm_find_best_baud(struct uart_port * port,unsigned int baud,unsigned long * rate)1053  msm_find_best_baud(struct uart_port *port, unsigned int baud,
1054  		   unsigned long *rate)
1055  {
1056  	struct msm_port *msm_port = to_msm_port(port);
1057  	unsigned int divisor, result;
1058  	unsigned long target, old, best_rate = 0, diff, best_diff = ULONG_MAX;
1059  	const struct msm_baud_map *entry, *end, *best;
1060  	static const struct msm_baud_map table[] = {
1061  		{    1, 0xff, 31 },
1062  		{    2, 0xee, 16 },
1063  		{    3, 0xdd,  8 },
1064  		{    4, 0xcc,  6 },
1065  		{    6, 0xbb,  6 },
1066  		{    8, 0xaa,  6 },
1067  		{   12, 0x99,  6 },
1068  		{   16, 0x88,  1 },
1069  		{   24, 0x77,  1 },
1070  		{   32, 0x66,  1 },
1071  		{   48, 0x55,  1 },
1072  		{   96, 0x44,  1 },
1073  		{  192, 0x33,  1 },
1074  		{  384, 0x22,  1 },
1075  		{  768, 0x11,  1 },
1076  		{ 1536, 0x00,  1 },
1077  	};
1078  
1079  	best = table; /* Default to smallest divider */
1080  	target = clk_round_rate(msm_port->clk, 16 * baud);
1081  	divisor = DIV_ROUND_CLOSEST(target, 16 * baud);
1082  
1083  	end = table + ARRAY_SIZE(table);
1084  	entry = table;
1085  	while (entry < end) {
1086  		if (entry->divisor <= divisor) {
1087  			result = target / entry->divisor / 16;
1088  			diff = abs(result - baud);
1089  
1090  			/* Keep track of best entry */
1091  			if (diff < best_diff) {
1092  				best_diff = diff;
1093  				best = entry;
1094  				best_rate = target;
1095  			}
1096  
1097  			if (result == baud)
1098  				break;
1099  		} else if (entry->divisor > divisor) {
1100  			old = target;
1101  			target = clk_round_rate(msm_port->clk, old + 1);
1102  			/*
1103  			 * The rate didn't get any faster so we can't do
1104  			 * better at dividing it down
1105  			 */
1106  			if (target == old)
1107  				break;
1108  
1109  			/* Start the divisor search over at this new rate */
1110  			entry = table;
1111  			divisor = DIV_ROUND_CLOSEST(target, 16 * baud);
1112  			continue;
1113  		}
1114  		entry++;
1115  	}
1116  
1117  	*rate = best_rate;
1118  	return best;
1119  }
1120  
msm_set_baud_rate(struct uart_port * port,unsigned int baud,unsigned long * saved_flags)1121  static int msm_set_baud_rate(struct uart_port *port, unsigned int baud,
1122  			     unsigned long *saved_flags)
1123  	__must_hold(&port->lock)
1124  {
1125  	unsigned int rxstale, watermark, mask;
1126  	struct msm_port *msm_port = to_msm_port(port);
1127  	const struct msm_baud_map *entry;
1128  	unsigned long flags, rate;
1129  
1130  	flags = *saved_flags;
1131  	spin_unlock_irqrestore(&port->lock, flags);
1132  
1133  	entry = msm_find_best_baud(port, baud, &rate);
1134  	clk_set_rate(msm_port->clk, rate);
1135  	baud = rate / 16 / entry->divisor;
1136  
1137  	spin_lock_irqsave(&port->lock, flags);
1138  	*saved_flags = flags;
1139  	port->uartclk = rate;
1140  
1141  	msm_write(port, entry->code, MSM_UART_CSR);
1142  
1143  	/* RX stale watermark */
1144  	rxstale = entry->rxstale;
1145  	watermark = MSM_UART_IPR_STALE_LSB & rxstale;
1146  	if (msm_port->is_uartdm) {
1147  		mask = MSM_UART_DM_IPR_STALE_TIMEOUT_MSB;
1148  	} else {
1149  		watermark |= MSM_UART_IPR_RXSTALE_LAST;
1150  		mask = MSM_UART_IPR_STALE_TIMEOUT_MSB;
1151  	}
1152  
1153  	watermark |= mask & (rxstale << 2);
1154  
1155  	msm_write(port, watermark, MSM_UART_IPR);
1156  
1157  	/* set RX watermark */
1158  	watermark = (port->fifosize * 3) / 4;
1159  	msm_write(port, watermark, MSM_UART_RFWR);
1160  
1161  	/* set TX watermark */
1162  	msm_write(port, 10, MSM_UART_TFWR);
1163  
1164  	msm_write(port, MSM_UART_CR_CMD_PROTECTION_EN, MSM_UART_CR);
1165  	msm_reset(port);
1166  
1167  	/* Enable RX and TX */
1168  	msm_write(port, MSM_UART_CR_TX_ENABLE | MSM_UART_CR_RX_ENABLE, MSM_UART_CR);
1169  
1170  	/* turn on RX and CTS interrupts */
1171  	msm_port->imr = MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE |
1172  			MSM_UART_IMR_CURRENT_CTS | MSM_UART_IMR_RXBREAK_START;
1173  
1174  	msm_write(port, msm_port->imr, MSM_UART_IMR);
1175  
1176  	if (msm_port->is_uartdm) {
1177  		msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
1178  		msm_write(port, 0xFFFFFF, UARTDM_DMRX);
1179  		msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
1180  	}
1181  
1182  	return baud;
1183  }
1184  
msm_init_clock(struct uart_port * port)1185  static void msm_init_clock(struct uart_port *port)
1186  {
1187  	struct msm_port *msm_port = to_msm_port(port);
1188  
1189  	clk_prepare_enable(msm_port->clk);
1190  	clk_prepare_enable(msm_port->pclk);
1191  	msm_serial_set_mnd_regs(port);
1192  }
1193  
msm_startup(struct uart_port * port)1194  static int msm_startup(struct uart_port *port)
1195  {
1196  	struct msm_port *msm_port = to_msm_port(port);
1197  	unsigned int data, rfr_level, mask;
1198  	int ret;
1199  
1200  	snprintf(msm_port->name, sizeof(msm_port->name),
1201  		 "msm_serial%d", port->line);
1202  
1203  	msm_init_clock(port);
1204  
1205  	if (likely(port->fifosize > 12))
1206  		rfr_level = port->fifosize - 12;
1207  	else
1208  		rfr_level = port->fifosize;
1209  
1210  	/* set automatic RFR level */
1211  	data = msm_read(port, MSM_UART_MR1);
1212  
1213  	if (msm_port->is_uartdm)
1214  		mask = MSM_UART_DM_MR1_AUTO_RFR_LEVEL1;
1215  	else
1216  		mask = MSM_UART_MR1_AUTO_RFR_LEVEL1;
1217  
1218  	data &= ~mask;
1219  	data &= ~MSM_UART_MR1_AUTO_RFR_LEVEL0;
1220  	data |= mask & (rfr_level << 2);
1221  	data |= MSM_UART_MR1_AUTO_RFR_LEVEL0 & rfr_level;
1222  	msm_write(port, data, MSM_UART_MR1);
1223  
1224  	if (msm_port->is_uartdm) {
1225  		msm_request_tx_dma(msm_port, msm_port->uart.mapbase);
1226  		msm_request_rx_dma(msm_port, msm_port->uart.mapbase);
1227  	}
1228  
1229  	ret = request_irq(port->irq, msm_uart_irq, IRQF_TRIGGER_HIGH,
1230  			  msm_port->name, port);
1231  	if (unlikely(ret))
1232  		goto err_irq;
1233  
1234  	return 0;
1235  
1236  err_irq:
1237  	if (msm_port->is_uartdm)
1238  		msm_release_dma(msm_port);
1239  
1240  	clk_disable_unprepare(msm_port->pclk);
1241  	clk_disable_unprepare(msm_port->clk);
1242  
1243  	return ret;
1244  }
1245  
msm_shutdown(struct uart_port * port)1246  static void msm_shutdown(struct uart_port *port)
1247  {
1248  	struct msm_port *msm_port = to_msm_port(port);
1249  
1250  	msm_port->imr = 0;
1251  	msm_write(port, 0, MSM_UART_IMR); /* disable interrupts */
1252  
1253  	if (msm_port->is_uartdm)
1254  		msm_release_dma(msm_port);
1255  
1256  	clk_disable_unprepare(msm_port->clk);
1257  
1258  	free_irq(port->irq, port);
1259  }
1260  
msm_set_termios(struct uart_port * port,struct ktermios * termios,const struct ktermios * old)1261  static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
1262  			    const struct ktermios *old)
1263  {
1264  	struct msm_port *msm_port = to_msm_port(port);
1265  	struct msm_dma *dma = &msm_port->rx_dma;
1266  	unsigned long flags;
1267  	unsigned int baud, mr;
1268  
1269  	spin_lock_irqsave(&port->lock, flags);
1270  
1271  	if (dma->chan) /* Terminate if any */
1272  		msm_stop_dma(port, dma);
1273  
1274  	/* calculate and set baud rate */
1275  	baud = uart_get_baud_rate(port, termios, old, 300, 4000000);
1276  	baud = msm_set_baud_rate(port, baud, &flags);
1277  	if (tty_termios_baud_rate(termios))
1278  		tty_termios_encode_baud_rate(termios, baud, baud);
1279  
1280  	/* calculate parity */
1281  	mr = msm_read(port, MSM_UART_MR2);
1282  	mr &= ~MSM_UART_MR2_PARITY_MODE;
1283  	if (termios->c_cflag & PARENB) {
1284  		if (termios->c_cflag & PARODD)
1285  			mr |= MSM_UART_MR2_PARITY_MODE_ODD;
1286  		else if (termios->c_cflag & CMSPAR)
1287  			mr |= MSM_UART_MR2_PARITY_MODE_SPACE;
1288  		else
1289  			mr |= MSM_UART_MR2_PARITY_MODE_EVEN;
1290  	}
1291  
1292  	/* calculate bits per char */
1293  	mr &= ~MSM_UART_MR2_BITS_PER_CHAR;
1294  	switch (termios->c_cflag & CSIZE) {
1295  	case CS5:
1296  		mr |= MSM_UART_MR2_BITS_PER_CHAR_5;
1297  		break;
1298  	case CS6:
1299  		mr |= MSM_UART_MR2_BITS_PER_CHAR_6;
1300  		break;
1301  	case CS7:
1302  		mr |= MSM_UART_MR2_BITS_PER_CHAR_7;
1303  		break;
1304  	case CS8:
1305  	default:
1306  		mr |= MSM_UART_MR2_BITS_PER_CHAR_8;
1307  		break;
1308  	}
1309  
1310  	/* calculate stop bits */
1311  	mr &= ~(MSM_UART_MR2_STOP_BIT_LEN_ONE | MSM_UART_MR2_STOP_BIT_LEN_TWO);
1312  	if (termios->c_cflag & CSTOPB)
1313  		mr |= MSM_UART_MR2_STOP_BIT_LEN_TWO;
1314  	else
1315  		mr |= MSM_UART_MR2_STOP_BIT_LEN_ONE;
1316  
1317  	/* set parity, bits per char, and stop bit */
1318  	msm_write(port, mr, MSM_UART_MR2);
1319  
1320  	/* calculate and set hardware flow control */
1321  	mr = msm_read(port, MSM_UART_MR1);
1322  	mr &= ~(MSM_UART_MR1_CTS_CTL | MSM_UART_MR1_RX_RDY_CTL);
1323  	if (termios->c_cflag & CRTSCTS) {
1324  		mr |= MSM_UART_MR1_CTS_CTL;
1325  		mr |= MSM_UART_MR1_RX_RDY_CTL;
1326  	}
1327  	msm_write(port, mr, MSM_UART_MR1);
1328  
1329  	/* Configure status bits to ignore based on termio flags. */
1330  	port->read_status_mask = 0;
1331  	if (termios->c_iflag & INPCK)
1332  		port->read_status_mask |= MSM_UART_SR_PAR_FRAME_ERR;
1333  	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
1334  		port->read_status_mask |= MSM_UART_SR_RX_BREAK;
1335  
1336  	uart_update_timeout(port, termios->c_cflag, baud);
1337  
1338  	/* Try to use DMA */
1339  	msm_start_rx_dma(msm_port);
1340  
1341  	spin_unlock_irqrestore(&port->lock, flags);
1342  }
1343  
msm_type(struct uart_port * port)1344  static const char *msm_type(struct uart_port *port)
1345  {
1346  	return "MSM";
1347  }
1348  
msm_release_port(struct uart_port * port)1349  static void msm_release_port(struct uart_port *port)
1350  {
1351  	struct platform_device *pdev = to_platform_device(port->dev);
1352  	struct resource *uart_resource;
1353  	resource_size_t size;
1354  
1355  	uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1356  	if (unlikely(!uart_resource))
1357  		return;
1358  	size = resource_size(uart_resource);
1359  
1360  	release_mem_region(port->mapbase, size);
1361  	iounmap(port->membase);
1362  	port->membase = NULL;
1363  }
1364  
msm_request_port(struct uart_port * port)1365  static int msm_request_port(struct uart_port *port)
1366  {
1367  	struct platform_device *pdev = to_platform_device(port->dev);
1368  	struct resource *uart_resource;
1369  	resource_size_t size;
1370  	int ret;
1371  
1372  	uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1373  	if (unlikely(!uart_resource))
1374  		return -ENXIO;
1375  
1376  	size = resource_size(uart_resource);
1377  
1378  	if (!request_mem_region(port->mapbase, size, "msm_serial"))
1379  		return -EBUSY;
1380  
1381  	port->membase = ioremap(port->mapbase, size);
1382  	if (!port->membase) {
1383  		ret = -EBUSY;
1384  		goto fail_release_port;
1385  	}
1386  
1387  	return 0;
1388  
1389  fail_release_port:
1390  	release_mem_region(port->mapbase, size);
1391  	return ret;
1392  }
1393  
msm_config_port(struct uart_port * port,int flags)1394  static void msm_config_port(struct uart_port *port, int flags)
1395  {
1396  	int ret;
1397  
1398  	if (flags & UART_CONFIG_TYPE) {
1399  		port->type = PORT_MSM;
1400  		ret = msm_request_port(port);
1401  		if (ret)
1402  			return;
1403  	}
1404  }
1405  
msm_verify_port(struct uart_port * port,struct serial_struct * ser)1406  static int msm_verify_port(struct uart_port *port, struct serial_struct *ser)
1407  {
1408  	if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM))
1409  		return -EINVAL;
1410  	if (unlikely(port->irq != ser->irq))
1411  		return -EINVAL;
1412  	return 0;
1413  }
1414  
msm_power(struct uart_port * port,unsigned int state,unsigned int oldstate)1415  static void msm_power(struct uart_port *port, unsigned int state,
1416  		      unsigned int oldstate)
1417  {
1418  	struct msm_port *msm_port = to_msm_port(port);
1419  
1420  	switch (state) {
1421  	case 0:
1422  		clk_prepare_enable(msm_port->clk);
1423  		clk_prepare_enable(msm_port->pclk);
1424  		break;
1425  	case 3:
1426  		clk_disable_unprepare(msm_port->clk);
1427  		clk_disable_unprepare(msm_port->pclk);
1428  		break;
1429  	default:
1430  		pr_err("msm_serial: Unknown PM state %d\n", state);
1431  	}
1432  }
1433  
1434  #ifdef CONFIG_CONSOLE_POLL
msm_poll_get_char_single(struct uart_port * port)1435  static int msm_poll_get_char_single(struct uart_port *port)
1436  {
1437  	struct msm_port *msm_port = to_msm_port(port);
1438  	unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : MSM_UART_RF;
1439  
1440  	if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_RX_READY))
1441  		return NO_POLL_CHAR;
1442  
1443  	return msm_read(port, rf_reg) & 0xff;
1444  }
1445  
msm_poll_get_char_dm(struct uart_port * port)1446  static int msm_poll_get_char_dm(struct uart_port *port)
1447  {
1448  	int c;
1449  	static u32 slop;
1450  	static int count;
1451  	unsigned char *sp = (unsigned char *)&slop;
1452  
1453  	/* Check if a previous read had more than one char */
1454  	if (count) {
1455  		c = sp[sizeof(slop) - count];
1456  		count--;
1457  	/* Or if FIFO is empty */
1458  	} else if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_RX_READY)) {
1459  		/*
1460  		 * If RX packing buffer has less than a word, force stale to
1461  		 * push contents into RX FIFO
1462  		 */
1463  		count = msm_read(port, UARTDM_RXFS);
1464  		count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK;
1465  		if (count) {
1466  			msm_write(port, MSM_UART_CR_CMD_FORCE_STALE, MSM_UART_CR);
1467  			slop = msm_read(port, UARTDM_RF);
1468  			c = sp[0];
1469  			count--;
1470  			msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR);
1471  			msm_write(port, 0xFFFFFF, UARTDM_DMRX);
1472  			msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR);
1473  		} else {
1474  			c = NO_POLL_CHAR;
1475  		}
1476  	/* FIFO has a word */
1477  	} else {
1478  		slop = msm_read(port, UARTDM_RF);
1479  		c = sp[0];
1480  		count = sizeof(slop) - 1;
1481  	}
1482  
1483  	return c;
1484  }
1485  
msm_poll_get_char(struct uart_port * port)1486  static int msm_poll_get_char(struct uart_port *port)
1487  {
1488  	u32 imr;
1489  	int c;
1490  	struct msm_port *msm_port = to_msm_port(port);
1491  
1492  	/* Disable all interrupts */
1493  	imr = msm_read(port, MSM_UART_IMR);
1494  	msm_write(port, 0, MSM_UART_IMR);
1495  
1496  	if (msm_port->is_uartdm)
1497  		c = msm_poll_get_char_dm(port);
1498  	else
1499  		c = msm_poll_get_char_single(port);
1500  
1501  	/* Enable interrupts */
1502  	msm_write(port, imr, MSM_UART_IMR);
1503  
1504  	return c;
1505  }
1506  
msm_poll_put_char(struct uart_port * port,unsigned char c)1507  static void msm_poll_put_char(struct uart_port *port, unsigned char c)
1508  {
1509  	u32 imr;
1510  	struct msm_port *msm_port = to_msm_port(port);
1511  
1512  	/* Disable all interrupts */
1513  	imr = msm_read(port, MSM_UART_IMR);
1514  	msm_write(port, 0, MSM_UART_IMR);
1515  
1516  	if (msm_port->is_uartdm)
1517  		msm_reset_dm_count(port, 1);
1518  
1519  	/* Wait until FIFO is empty */
1520  	while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
1521  		cpu_relax();
1522  
1523  	/* Write a character */
1524  	msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : MSM_UART_TF);
1525  
1526  	/* Wait until FIFO is empty */
1527  	while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
1528  		cpu_relax();
1529  
1530  	/* Enable interrupts */
1531  	msm_write(port, imr, MSM_UART_IMR);
1532  }
1533  #endif
1534  
1535  static const struct uart_ops msm_uart_pops = {
1536  	.tx_empty = msm_tx_empty,
1537  	.set_mctrl = msm_set_mctrl,
1538  	.get_mctrl = msm_get_mctrl,
1539  	.stop_tx = msm_stop_tx,
1540  	.start_tx = msm_start_tx,
1541  	.stop_rx = msm_stop_rx,
1542  	.enable_ms = msm_enable_ms,
1543  	.break_ctl = msm_break_ctl,
1544  	.startup = msm_startup,
1545  	.shutdown = msm_shutdown,
1546  	.set_termios = msm_set_termios,
1547  	.type = msm_type,
1548  	.release_port = msm_release_port,
1549  	.request_port = msm_request_port,
1550  	.config_port = msm_config_port,
1551  	.verify_port = msm_verify_port,
1552  	.pm = msm_power,
1553  #ifdef CONFIG_CONSOLE_POLL
1554  	.poll_get_char	= msm_poll_get_char,
1555  	.poll_put_char	= msm_poll_put_char,
1556  #endif
1557  };
1558  
1559  static struct msm_port msm_uart_ports[] = {
1560  	{
1561  		.uart = {
1562  			.iotype = UPIO_MEM,
1563  			.ops = &msm_uart_pops,
1564  			.flags = UPF_BOOT_AUTOCONF,
1565  			.fifosize = 64,
1566  			.line = 0,
1567  		},
1568  	},
1569  	{
1570  		.uart = {
1571  			.iotype = UPIO_MEM,
1572  			.ops = &msm_uart_pops,
1573  			.flags = UPF_BOOT_AUTOCONF,
1574  			.fifosize = 64,
1575  			.line = 1,
1576  		},
1577  	},
1578  	{
1579  		.uart = {
1580  			.iotype = UPIO_MEM,
1581  			.ops = &msm_uart_pops,
1582  			.flags = UPF_BOOT_AUTOCONF,
1583  			.fifosize = 64,
1584  			.line = 2,
1585  		},
1586  	},
1587  };
1588  
1589  #define MSM_UART_NR	ARRAY_SIZE(msm_uart_ports)
1590  
msm_get_port_from_line(unsigned int line)1591  static inline struct uart_port *msm_get_port_from_line(unsigned int line)
1592  {
1593  	return &msm_uart_ports[line].uart;
1594  }
1595  
1596  #ifdef CONFIG_SERIAL_MSM_CONSOLE
__msm_console_write(struct uart_port * port,const char * s,unsigned int count,bool is_uartdm)1597  static void __msm_console_write(struct uart_port *port, const char *s,
1598  				unsigned int count, bool is_uartdm)
1599  {
1600  	unsigned long flags;
1601  	int i;
1602  	int num_newlines = 0;
1603  	bool replaced = false;
1604  	void __iomem *tf;
1605  	int locked = 1;
1606  
1607  	if (is_uartdm)
1608  		tf = port->membase + UARTDM_TF;
1609  	else
1610  		tf = port->membase + MSM_UART_TF;
1611  
1612  	/* Account for newlines that will get a carriage return added */
1613  	for (i = 0; i < count; i++)
1614  		if (s[i] == '\n')
1615  			num_newlines++;
1616  	count += num_newlines;
1617  
1618  	local_irq_save(flags);
1619  
1620  	if (port->sysrq)
1621  		locked = 0;
1622  	else if (oops_in_progress)
1623  		locked = spin_trylock(&port->lock);
1624  	else
1625  		spin_lock(&port->lock);
1626  
1627  	if (is_uartdm)
1628  		msm_reset_dm_count(port, count);
1629  
1630  	i = 0;
1631  	while (i < count) {
1632  		int j;
1633  		unsigned int num_chars;
1634  		char buf[4] = { 0 };
1635  
1636  		if (is_uartdm)
1637  			num_chars = min(count - i, (unsigned int)sizeof(buf));
1638  		else
1639  			num_chars = 1;
1640  
1641  		for (j = 0; j < num_chars; j++) {
1642  			char c = *s;
1643  
1644  			if (c == '\n' && !replaced) {
1645  				buf[j] = '\r';
1646  				j++;
1647  				replaced = true;
1648  			}
1649  			if (j < num_chars) {
1650  				buf[j] = c;
1651  				s++;
1652  				replaced = false;
1653  			}
1654  		}
1655  
1656  		while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY))
1657  			cpu_relax();
1658  
1659  		iowrite32_rep(tf, buf, 1);
1660  		i += num_chars;
1661  	}
1662  
1663  	if (locked)
1664  		spin_unlock(&port->lock);
1665  
1666  	local_irq_restore(flags);
1667  }
1668  
msm_console_write(struct console * co,const char * s,unsigned int count)1669  static void msm_console_write(struct console *co, const char *s,
1670  			      unsigned int count)
1671  {
1672  	struct uart_port *port;
1673  	struct msm_port *msm_port;
1674  
1675  	BUG_ON(co->index < 0 || co->index >= MSM_UART_NR);
1676  
1677  	port = msm_get_port_from_line(co->index);
1678  	msm_port = to_msm_port(port);
1679  
1680  	__msm_console_write(port, s, count, msm_port->is_uartdm);
1681  }
1682  
msm_console_setup(struct console * co,char * options)1683  static int msm_console_setup(struct console *co, char *options)
1684  {
1685  	struct uart_port *port;
1686  	int baud = 115200;
1687  	int bits = 8;
1688  	int parity = 'n';
1689  	int flow = 'n';
1690  
1691  	if (unlikely(co->index >= MSM_UART_NR || co->index < 0))
1692  		return -ENXIO;
1693  
1694  	port = msm_get_port_from_line(co->index);
1695  
1696  	if (unlikely(!port->membase))
1697  		return -ENXIO;
1698  
1699  	msm_init_clock(port);
1700  
1701  	if (options)
1702  		uart_parse_options(options, &baud, &parity, &bits, &flow);
1703  
1704  	pr_info("msm_serial: console setup on port #%d\n", port->line);
1705  
1706  	return uart_set_options(port, co, baud, parity, bits, flow);
1707  }
1708  
1709  static void
msm_serial_early_write(struct console * con,const char * s,unsigned n)1710  msm_serial_early_write(struct console *con, const char *s, unsigned n)
1711  {
1712  	struct earlycon_device *dev = con->data;
1713  
1714  	__msm_console_write(&dev->port, s, n, false);
1715  }
1716  
1717  static int __init
msm_serial_early_console_setup(struct earlycon_device * device,const char * opt)1718  msm_serial_early_console_setup(struct earlycon_device *device, const char *opt)
1719  {
1720  	if (!device->port.membase)
1721  		return -ENODEV;
1722  
1723  	device->con->write = msm_serial_early_write;
1724  	return 0;
1725  }
1726  OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart",
1727  		    msm_serial_early_console_setup);
1728  
1729  static void
msm_serial_early_write_dm(struct console * con,const char * s,unsigned n)1730  msm_serial_early_write_dm(struct console *con, const char *s, unsigned n)
1731  {
1732  	struct earlycon_device *dev = con->data;
1733  
1734  	__msm_console_write(&dev->port, s, n, true);
1735  }
1736  
1737  static int __init
msm_serial_early_console_setup_dm(struct earlycon_device * device,const char * opt)1738  msm_serial_early_console_setup_dm(struct earlycon_device *device,
1739  				  const char *opt)
1740  {
1741  	if (!device->port.membase)
1742  		return -ENODEV;
1743  
1744  	device->con->write = msm_serial_early_write_dm;
1745  	return 0;
1746  }
1747  OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm",
1748  		    msm_serial_early_console_setup_dm);
1749  
1750  static struct uart_driver msm_uart_driver;
1751  
1752  static struct console msm_console = {
1753  	.name = "ttyMSM",
1754  	.write = msm_console_write,
1755  	.device = uart_console_device,
1756  	.setup = msm_console_setup,
1757  	.flags = CON_PRINTBUFFER,
1758  	.index = -1,
1759  	.data = &msm_uart_driver,
1760  };
1761  
1762  #define MSM_CONSOLE	(&msm_console)
1763  
1764  #else
1765  #define MSM_CONSOLE	NULL
1766  #endif
1767  
1768  static struct uart_driver msm_uart_driver = {
1769  	.owner = THIS_MODULE,
1770  	.driver_name = "msm_serial",
1771  	.dev_name = "ttyMSM",
1772  	.nr = MSM_UART_NR,
1773  	.cons = MSM_CONSOLE,
1774  };
1775  
1776  static atomic_t msm_uart_next_id = ATOMIC_INIT(0);
1777  
1778  static const struct of_device_id msm_uartdm_table[] = {
1779  	{ .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 },
1780  	{ .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 },
1781  	{ .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 },
1782  	{ .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 },
1783  	{ }
1784  };
1785  
msm_serial_probe(struct platform_device * pdev)1786  static int msm_serial_probe(struct platform_device *pdev)
1787  {
1788  	struct msm_port *msm_port;
1789  	struct resource *resource;
1790  	struct uart_port *port;
1791  	const struct of_device_id *id;
1792  	int irq, line;
1793  
1794  	if (pdev->dev.of_node)
1795  		line = of_alias_get_id(pdev->dev.of_node, "serial");
1796  	else
1797  		line = pdev->id;
1798  
1799  	if (line < 0)
1800  		line = atomic_inc_return(&msm_uart_next_id) - 1;
1801  
1802  	if (unlikely(line < 0 || line >= MSM_UART_NR))
1803  		return -ENXIO;
1804  
1805  	dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line);
1806  
1807  	port = msm_get_port_from_line(line);
1808  	port->dev = &pdev->dev;
1809  	msm_port = to_msm_port(port);
1810  
1811  	id = of_match_device(msm_uartdm_table, &pdev->dev);
1812  	if (id)
1813  		msm_port->is_uartdm = (unsigned long)id->data;
1814  	else
1815  		msm_port->is_uartdm = 0;
1816  
1817  	msm_port->clk = devm_clk_get(&pdev->dev, "core");
1818  	if (IS_ERR(msm_port->clk))
1819  		return PTR_ERR(msm_port->clk);
1820  
1821  	if (msm_port->is_uartdm) {
1822  		msm_port->pclk = devm_clk_get(&pdev->dev, "iface");
1823  		if (IS_ERR(msm_port->pclk))
1824  			return PTR_ERR(msm_port->pclk);
1825  	}
1826  
1827  	port->uartclk = clk_get_rate(msm_port->clk);
1828  	dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk);
1829  
1830  	resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1831  	if (unlikely(!resource))
1832  		return -ENXIO;
1833  	port->mapbase = resource->start;
1834  
1835  	irq = platform_get_irq(pdev, 0);
1836  	if (unlikely(irq < 0))
1837  		return -ENXIO;
1838  	port->irq = irq;
1839  	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MSM_CONSOLE);
1840  
1841  	platform_set_drvdata(pdev, port);
1842  
1843  	return uart_add_one_port(&msm_uart_driver, port);
1844  }
1845  
msm_serial_remove(struct platform_device * pdev)1846  static int msm_serial_remove(struct platform_device *pdev)
1847  {
1848  	struct uart_port *port = platform_get_drvdata(pdev);
1849  
1850  	uart_remove_one_port(&msm_uart_driver, port);
1851  
1852  	return 0;
1853  }
1854  
1855  static const struct of_device_id msm_match_table[] = {
1856  	{ .compatible = "qcom,msm-uart" },
1857  	{ .compatible = "qcom,msm-uartdm" },
1858  	{}
1859  };
1860  MODULE_DEVICE_TABLE(of, msm_match_table);
1861  
msm_serial_suspend(struct device * dev)1862  static int __maybe_unused msm_serial_suspend(struct device *dev)
1863  {
1864  	struct msm_port *port = dev_get_drvdata(dev);
1865  
1866  	uart_suspend_port(&msm_uart_driver, &port->uart);
1867  
1868  	return 0;
1869  }
1870  
msm_serial_resume(struct device * dev)1871  static int __maybe_unused msm_serial_resume(struct device *dev)
1872  {
1873  	struct msm_port *port = dev_get_drvdata(dev);
1874  
1875  	uart_resume_port(&msm_uart_driver, &port->uart);
1876  
1877  	return 0;
1878  }
1879  
1880  static const struct dev_pm_ops msm_serial_dev_pm_ops = {
1881  	SET_SYSTEM_SLEEP_PM_OPS(msm_serial_suspend, msm_serial_resume)
1882  };
1883  
1884  static struct platform_driver msm_platform_driver = {
1885  	.remove = msm_serial_remove,
1886  	.probe = msm_serial_probe,
1887  	.driver = {
1888  		.name = "msm_serial",
1889  		.pm = &msm_serial_dev_pm_ops,
1890  		.of_match_table = msm_match_table,
1891  	},
1892  };
1893  
msm_serial_init(void)1894  static int __init msm_serial_init(void)
1895  {
1896  	int ret;
1897  
1898  	ret = uart_register_driver(&msm_uart_driver);
1899  	if (unlikely(ret))
1900  		return ret;
1901  
1902  	ret = platform_driver_register(&msm_platform_driver);
1903  	if (unlikely(ret))
1904  		uart_unregister_driver(&msm_uart_driver);
1905  
1906  	pr_info("msm_serial: driver initialized\n");
1907  
1908  	return ret;
1909  }
1910  
msm_serial_exit(void)1911  static void __exit msm_serial_exit(void)
1912  {
1913  	platform_driver_unregister(&msm_platform_driver);
1914  	uart_unregister_driver(&msm_uart_driver);
1915  }
1916  
1917  module_init(msm_serial_init);
1918  module_exit(msm_serial_exit);
1919  
1920  MODULE_AUTHOR("Robert Love <rlove@google.com>");
1921  MODULE_DESCRIPTION("Driver for msm7x serial device");
1922  MODULE_LICENSE("GPL");
1923