xref: /openbmc/linux/drivers/net/wan/ixp4xx_hss.c (revision 77d62fcc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Intel IXP4xx HSS (synchronous serial port) driver for Linux
4  *
5  * Copyright (C) 2007-2008 Krzysztof Hałasa <khc@pm.waw.pl>
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/module.h>
11 #include <linux/bitops.h>
12 #include <linux/cdev.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/dmapool.h>
15 #include <linux/fs.h>
16 #include <linux/hdlc.h>
17 #include <linux/io.h>
18 #include <linux/kernel.h>
19 #include <linux/platform_device.h>
20 #include <linux/poll.h>
21 #include <linux/slab.h>
22 #include <linux/gpio/consumer.h>
23 #include <linux/of.h>
24 #include <linux/soc/ixp4xx/npe.h>
25 #include <linux/soc/ixp4xx/qmgr.h>
26 #include <linux/soc/ixp4xx/cpu.h>
27 
28 /* This is what all IXP4xx platforms we know uses, if more frequencies
29  * are needed, we need to migrate to the clock framework.
30  */
31 #define IXP4XX_TIMER_FREQ	66666000
32 
33 #define DEBUG_DESC		0
34 #define DEBUG_RX		0
35 #define DEBUG_TX		0
36 #define DEBUG_PKT_BYTES		0
37 #define DEBUG_CLOSE		0
38 
39 #define DRV_NAME		"ixp4xx_hss"
40 
41 #define PKT_EXTRA_FLAGS		0 /* orig 1 */
42 #define PKT_NUM_PIPES		1 /* 1, 2 or 4 */
43 #define PKT_PIPE_FIFO_SIZEW	4 /* total 4 dwords per HSS */
44 
45 #define RX_DESCS		16 /* also length of all RX queues */
46 #define TX_DESCS		16 /* also length of all TX queues */
47 
48 #define POOL_ALLOC_SIZE		(sizeof(struct desc) * (RX_DESCS + TX_DESCS))
49 #define RX_SIZE			(HDLC_MAX_MRU + 4) /* NPE needs more space */
50 #define MAX_CLOSE_WAIT		1000 /* microseconds */
51 #define HSS_COUNT		2
52 #define FRAME_SIZE		256 /* doesn't matter at this point */
53 #define FRAME_OFFSET		0
54 #define MAX_CHANNELS		(FRAME_SIZE / 8)
55 
56 #define NAPI_WEIGHT		16
57 
58 /* Queue IDs */
59 #define HSS0_PKT_RX_QUEUE	13	/* orig size = 32 dwords */
60 #define HSS0_PKT_TX0_QUEUE	14	/* orig size = 16 dwords */
61 #define HSS0_PKT_TX1_QUEUE	15
62 #define HSS0_PKT_TX2_QUEUE	16
63 #define HSS0_PKT_TX3_QUEUE	17
64 #define HSS0_PKT_RXFREE0_QUEUE	18	/* orig size = 16 dwords */
65 #define HSS0_PKT_RXFREE1_QUEUE	19
66 #define HSS0_PKT_RXFREE2_QUEUE	20
67 #define HSS0_PKT_RXFREE3_QUEUE	21
68 #define HSS0_PKT_TXDONE_QUEUE	22	/* orig size = 64 dwords */
69 
70 #define HSS1_PKT_RX_QUEUE	0
71 #define HSS1_PKT_TX0_QUEUE	5
72 #define HSS1_PKT_TX1_QUEUE	6
73 #define HSS1_PKT_TX2_QUEUE	7
74 #define HSS1_PKT_TX3_QUEUE	8
75 #define HSS1_PKT_RXFREE0_QUEUE	1
76 #define HSS1_PKT_RXFREE1_QUEUE	2
77 #define HSS1_PKT_RXFREE2_QUEUE	3
78 #define HSS1_PKT_RXFREE3_QUEUE	4
79 #define HSS1_PKT_TXDONE_QUEUE	9
80 
81 #define NPE_PKT_MODE_HDLC		0
82 #define NPE_PKT_MODE_RAW		1
83 #define NPE_PKT_MODE_56KMODE		2
84 #define NPE_PKT_MODE_56KENDIAN_MSB	4
85 
86 /* PKT_PIPE_HDLC_CFG_WRITE flags */
87 #define PKT_HDLC_IDLE_ONES		0x1 /* default = flags */
88 #define PKT_HDLC_CRC_32			0x2 /* default = CRC-16 */
89 #define PKT_HDLC_MSB_ENDIAN		0x4 /* default = LE */
90 
91 /* hss_config, PCRs */
92 /* Frame sync sampling, default = active low */
93 #define PCR_FRM_SYNC_ACTIVE_HIGH	0x40000000
94 #define PCR_FRM_SYNC_FALLINGEDGE	0x80000000
95 #define PCR_FRM_SYNC_RISINGEDGE		0xC0000000
96 
97 /* Frame sync pin: input (default) or output generated off a given clk edge */
98 #define PCR_FRM_SYNC_OUTPUT_FALLING	0x20000000
99 #define PCR_FRM_SYNC_OUTPUT_RISING	0x30000000
100 
101 /* Frame and data clock sampling on edge, default = falling */
102 #define PCR_FCLK_EDGE_RISING		0x08000000
103 #define PCR_DCLK_EDGE_RISING		0x04000000
104 
105 /* Clock direction, default = input */
106 #define PCR_SYNC_CLK_DIR_OUTPUT		0x02000000
107 
108 /* Generate/Receive frame pulses, default = enabled */
109 #define PCR_FRM_PULSE_DISABLED		0x01000000
110 
111  /* Data rate is full (default) or half the configured clk speed */
112 #define PCR_HALF_CLK_RATE		0x00200000
113 
114 /* Invert data between NPE and HSS FIFOs? (default = no) */
115 #define PCR_DATA_POLARITY_INVERT	0x00100000
116 
117 /* TX/RX endianness, default = LSB */
118 #define PCR_MSB_ENDIAN			0x00080000
119 
120 /* Normal (default) / open drain mode (TX only) */
121 #define PCR_TX_PINS_OPEN_DRAIN		0x00040000
122 
123 /* No framing bit transmitted and expected on RX? (default = framing bit) */
124 #define PCR_SOF_NO_FBIT			0x00020000
125 
126 /* Drive data pins? */
127 #define PCR_TX_DATA_ENABLE		0x00010000
128 
129 /* Voice 56k type: drive the data pins low (default), high, high Z */
130 #define PCR_TX_V56K_HIGH		0x00002000
131 #define PCR_TX_V56K_HIGH_IMP		0x00004000
132 
133 /* Unassigned type: drive the data pins low (default), high, high Z */
134 #define PCR_TX_UNASS_HIGH		0x00000800
135 #define PCR_TX_UNASS_HIGH_IMP		0x00001000
136 
137 /* T1 @ 1.544MHz only: Fbit dictated in FIFO (default) or high Z */
138 #define PCR_TX_FB_HIGH_IMP		0x00000400
139 
140 /* 56k data endiannes - which bit unused: high (default) or low */
141 #define PCR_TX_56KE_BIT_0_UNUSED	0x00000200
142 
143 /* 56k data transmission type: 32/8 bit data (default) or 56K data */
144 #define PCR_TX_56KS_56K_DATA		0x00000100
145 
146 /* hss_config, cCR */
147 /* Number of packetized clients, default = 1 */
148 #define CCR_NPE_HFIFO_2_HDLC		0x04000000
149 #define CCR_NPE_HFIFO_3_OR_4HDLC	0x08000000
150 
151 /* default = no loopback */
152 #define CCR_LOOPBACK			0x02000000
153 
154 /* HSS number, default = 0 (first) */
155 #define CCR_SECOND_HSS			0x01000000
156 
157 /* hss_config, clkCR: main:10, num:10, denom:12 */
158 #define CLK42X_SPEED_EXP	((0x3FF << 22) | (2 << 12) |   15) /*65 KHz*/
159 
160 #define CLK42X_SPEED_512KHZ	((130 << 22) | (2 << 12) |   15)
161 #define CLK42X_SPEED_1536KHZ	((43 << 22) | (18 << 12) |   47)
162 #define CLK42X_SPEED_1544KHZ	((43 << 22) | (33 << 12) |  192)
163 #define CLK42X_SPEED_2048KHZ	((32 << 22) | (34 << 12) |   63)
164 #define CLK42X_SPEED_4096KHZ	((16 << 22) | (34 << 12) |  127)
165 #define CLK42X_SPEED_8192KHZ	((8 << 22) | (34 << 12) |  255)
166 
167 #define CLK46X_SPEED_512KHZ	((130 << 22) | (24 << 12) |  127)
168 #define CLK46X_SPEED_1536KHZ	((43 << 22) | (152 << 12) |  383)
169 #define CLK46X_SPEED_1544KHZ	((43 << 22) | (66 << 12) |  385)
170 #define CLK46X_SPEED_2048KHZ	((32 << 22) | (280 << 12) |  511)
171 #define CLK46X_SPEED_4096KHZ	((16 << 22) | (280 << 12) | 1023)
172 #define CLK46X_SPEED_8192KHZ	((8 << 22) | (280 << 12) | 2047)
173 
174 /* HSS_CONFIG_CLOCK_CR register consists of 3 parts:
175  *     A (10 bits), B (10 bits) and C (12 bits).
176  * IXP42x HSS clock generator operation (verified with an oscilloscope):
177  * Each clock bit takes 7.5 ns (1 / 133.xx MHz).
178  * The clock sequence consists of (C - B) states of 0s and 1s, each state is
179  * A bits wide. It's followed by (B + 1) states of 0s and 1s, each state is
180  * (A + 1) bits wide.
181  *
182  * The resulting average clock frequency (assuming 33.333 MHz oscillator) is:
183  * freq = 66.666 MHz / (A + (B + 1) / (C + 1))
184  * minimum freq = 66.666 MHz / (A + 1)
185  * maximum freq = 66.666 MHz / A
186  *
187  * Example: A = 2, B = 2, C = 7, CLOCK_CR register = 2 << 22 | 2 << 12 | 7
188  * freq = 66.666 MHz / (2 + (2 + 1) / (7 + 1)) = 28.07 MHz (Mb/s).
189  * The clock sequence is: 1100110011 (5 doubles) 000111000 (3 triples).
190  * The sequence takes (C - B) * A + (B + 1) * (A + 1) = 5 * 2 + 3 * 3 bits
191  * = 19 bits (each 7.5 ns long) = 142.5 ns (then the sequence repeats).
192  * The sequence consists of 4 complete clock periods, thus the average
193  * frequency (= clock rate) is 4 / 142.5 ns = 28.07 MHz (Mb/s).
194  * (max specified clock rate for IXP42x HSS is 8.192 Mb/s).
195  */
196 
197 /* hss_config, LUT entries */
198 #define TDMMAP_UNASSIGNED	0
199 #define TDMMAP_HDLC		1	/* HDLC - packetized */
200 #define TDMMAP_VOICE56K		2	/* Voice56K - 7-bit channelized */
201 #define TDMMAP_VOICE64K		3	/* Voice64K - 8-bit channelized */
202 
203 /* offsets into HSS config */
204 #define HSS_CONFIG_TX_PCR	0x00 /* port configuration registers */
205 #define HSS_CONFIG_RX_PCR	0x04
206 #define HSS_CONFIG_CORE_CR	0x08 /* loopback control, HSS# */
207 #define HSS_CONFIG_CLOCK_CR	0x0C /* clock generator control */
208 #define HSS_CONFIG_TX_FCR	0x10 /* frame configuration registers */
209 #define HSS_CONFIG_RX_FCR	0x14
210 #define HSS_CONFIG_TX_LUT	0x18 /* channel look-up tables */
211 #define HSS_CONFIG_RX_LUT	0x38
212 
213 /* NPE command codes */
214 /* writes the ConfigWord value to the location specified by offset */
215 #define PORT_CONFIG_WRITE		0x40
216 
217 /* triggers the NPE to load the contents of the configuration table */
218 #define PORT_CONFIG_LOAD		0x41
219 
220 /* triggers the NPE to return an HssErrorReadResponse message */
221 #define PORT_ERROR_READ			0x42
222 
223 /* triggers the NPE to reset internal status and enable the HssPacketized
224  * operation for the flow specified by pPipe
225  */
226 #define PKT_PIPE_FLOW_ENABLE		0x50
227 #define PKT_PIPE_FLOW_DISABLE		0x51
228 #define PKT_NUM_PIPES_WRITE		0x52
229 #define PKT_PIPE_FIFO_SIZEW_WRITE	0x53
230 #define PKT_PIPE_HDLC_CFG_WRITE		0x54
231 #define PKT_PIPE_IDLE_PATTERN_WRITE	0x55
232 #define PKT_PIPE_RX_SIZE_WRITE		0x56
233 #define PKT_PIPE_MODE_WRITE		0x57
234 
235 /* HDLC packet status values - desc->status */
236 #define ERR_SHUTDOWN		1 /* stop or shutdown occurrence */
237 #define ERR_HDLC_ALIGN		2 /* HDLC alignment error */
238 #define ERR_HDLC_FCS		3 /* HDLC Frame Check Sum error */
239 #define ERR_RXFREE_Q_EMPTY	4 /* RX-free queue became empty while receiving
240 				   * this packet (if buf_len < pkt_len)
241 				   */
242 #define ERR_HDLC_TOO_LONG	5 /* HDLC frame size too long */
243 #define ERR_HDLC_ABORT		6 /* abort sequence received */
244 #define ERR_DISCONNECTING	7 /* disconnect is in progress */
245 
246 #ifdef __ARMEB__
247 typedef struct sk_buff buffer_t;
248 #define free_buffer dev_kfree_skb
249 #define free_buffer_irq dev_consume_skb_irq
250 #else
251 typedef void buffer_t;
252 #define free_buffer kfree
253 #define free_buffer_irq kfree
254 #endif
255 
256 struct port {
257 	struct device *dev;
258 	struct npe *npe;
259 	unsigned int txreadyq;
260 	unsigned int rxtrigq;
261 	unsigned int rxfreeq;
262 	unsigned int rxq;
263 	unsigned int txq;
264 	unsigned int txdoneq;
265 	struct gpio_desc *cts;
266 	struct gpio_desc *rts;
267 	struct gpio_desc *dcd;
268 	struct gpio_desc *dtr;
269 	struct gpio_desc *clk_internal;
270 	struct net_device *netdev;
271 	struct napi_struct napi;
272 	buffer_t *rx_buff_tab[RX_DESCS], *tx_buff_tab[TX_DESCS];
273 	struct desc *desc_tab;	/* coherent */
274 	dma_addr_t desc_tab_phys;
275 	unsigned int id;
276 	unsigned int clock_type, clock_rate, loopback;
277 	unsigned int initialized, carrier;
278 	u8 hdlc_cfg;
279 	u32 clock_reg;
280 };
281 
282 /* NPE message structure */
283 struct msg {
284 #ifdef __ARMEB__
285 	u8 cmd, unused, hss_port, index;
286 	union {
287 		struct { u8 data8a, data8b, data8c, data8d; };
288 		struct { u16 data16a, data16b; };
289 		struct { u32 data32; };
290 	};
291 #else
292 	u8 index, hss_port, unused, cmd;
293 	union {
294 		struct { u8 data8d, data8c, data8b, data8a; };
295 		struct { u16 data16b, data16a; };
296 		struct { u32 data32; };
297 	};
298 #endif
299 };
300 
301 /* HDLC packet descriptor */
302 struct desc {
303 	u32 next;		/* pointer to next buffer, unused */
304 
305 #ifdef __ARMEB__
306 	u16 buf_len;		/* buffer length */
307 	u16 pkt_len;		/* packet length */
308 	u32 data;		/* pointer to data buffer in RAM */
309 	u8 status;
310 	u8 error_count;
311 	u16 __reserved;
312 #else
313 	u16 pkt_len;		/* packet length */
314 	u16 buf_len;		/* buffer length */
315 	u32 data;		/* pointer to data buffer in RAM */
316 	u16 __reserved;
317 	u8 error_count;
318 	u8 status;
319 #endif
320 	u32 __reserved1[4];
321 };
322 
323 #define rx_desc_phys(port, n)	((port)->desc_tab_phys +		\
324 				 (n) * sizeof(struct desc))
325 #define rx_desc_ptr(port, n)	(&(port)->desc_tab[n])
326 
327 #define tx_desc_phys(port, n)	((port)->desc_tab_phys +		\
328 				 ((n) + RX_DESCS) * sizeof(struct desc))
329 #define tx_desc_ptr(port, n)	(&(port)->desc_tab[(n) + RX_DESCS])
330 
331 /*****************************************************************************
332  * global variables
333  ****************************************************************************/
334 
335 static int ports_open;
336 static struct dma_pool *dma_pool;
337 static DEFINE_SPINLOCK(npe_lock);
338 
339 /*****************************************************************************
340  * utility functions
341  ****************************************************************************/
342 
343 static inline struct port *dev_to_port(struct net_device *dev)
344 {
345 	return dev_to_hdlc(dev)->priv;
346 }
347 
348 #ifndef __ARMEB__
349 static inline void memcpy_swab32(u32 *dest, u32 *src, int cnt)
350 {
351 	int i;
352 
353 	for (i = 0; i < cnt; i++)
354 		dest[i] = swab32(src[i]);
355 }
356 #endif
357 
358 /*****************************************************************************
359  * HSS access
360  ****************************************************************************/
361 
362 static void hss_npe_send(struct port *port, struct msg *msg, const char *what)
363 {
364 	u32 *val = (u32 *)msg;
365 
366 	if (npe_send_message(port->npe, msg, what)) {
367 		pr_crit("HSS-%i: unable to send command [%08X:%08X] to %s\n",
368 			port->id, val[0], val[1], npe_name(port->npe));
369 		BUG();
370 	}
371 }
372 
373 static void hss_config_set_lut(struct port *port)
374 {
375 	struct msg msg;
376 	int ch;
377 
378 	memset(&msg, 0, sizeof(msg));
379 	msg.cmd = PORT_CONFIG_WRITE;
380 	msg.hss_port = port->id;
381 
382 	for (ch = 0; ch < MAX_CHANNELS; ch++) {
383 		msg.data32 >>= 2;
384 		msg.data32 |= TDMMAP_HDLC << 30;
385 
386 		if (ch % 16 == 15) {
387 			msg.index = HSS_CONFIG_TX_LUT + ((ch / 4) & ~3);
388 			hss_npe_send(port, &msg, "HSS_SET_TX_LUT");
389 
390 			msg.index += HSS_CONFIG_RX_LUT - HSS_CONFIG_TX_LUT;
391 			hss_npe_send(port, &msg, "HSS_SET_RX_LUT");
392 		}
393 	}
394 }
395 
396 static void hss_config(struct port *port)
397 {
398 	struct msg msg;
399 
400 	memset(&msg, 0, sizeof(msg));
401 	msg.cmd = PORT_CONFIG_WRITE;
402 	msg.hss_port = port->id;
403 	msg.index = HSS_CONFIG_TX_PCR;
404 	msg.data32 = PCR_FRM_PULSE_DISABLED | PCR_MSB_ENDIAN |
405 		PCR_TX_DATA_ENABLE | PCR_SOF_NO_FBIT;
406 	if (port->clock_type == CLOCK_INT)
407 		msg.data32 |= PCR_SYNC_CLK_DIR_OUTPUT;
408 	hss_npe_send(port, &msg, "HSS_SET_TX_PCR");
409 
410 	msg.index = HSS_CONFIG_RX_PCR;
411 	msg.data32 ^= PCR_TX_DATA_ENABLE | PCR_DCLK_EDGE_RISING;
412 	hss_npe_send(port, &msg, "HSS_SET_RX_PCR");
413 
414 	memset(&msg, 0, sizeof(msg));
415 	msg.cmd = PORT_CONFIG_WRITE;
416 	msg.hss_port = port->id;
417 	msg.index = HSS_CONFIG_CORE_CR;
418 	msg.data32 = (port->loopback ? CCR_LOOPBACK : 0) |
419 		(port->id ? CCR_SECOND_HSS : 0);
420 	hss_npe_send(port, &msg, "HSS_SET_CORE_CR");
421 
422 	memset(&msg, 0, sizeof(msg));
423 	msg.cmd = PORT_CONFIG_WRITE;
424 	msg.hss_port = port->id;
425 	msg.index = HSS_CONFIG_CLOCK_CR;
426 	msg.data32 = port->clock_reg;
427 	hss_npe_send(port, &msg, "HSS_SET_CLOCK_CR");
428 
429 	memset(&msg, 0, sizeof(msg));
430 	msg.cmd = PORT_CONFIG_WRITE;
431 	msg.hss_port = port->id;
432 	msg.index = HSS_CONFIG_TX_FCR;
433 	msg.data16a = FRAME_OFFSET;
434 	msg.data16b = FRAME_SIZE - 1;
435 	hss_npe_send(port, &msg, "HSS_SET_TX_FCR");
436 
437 	memset(&msg, 0, sizeof(msg));
438 	msg.cmd = PORT_CONFIG_WRITE;
439 	msg.hss_port = port->id;
440 	msg.index = HSS_CONFIG_RX_FCR;
441 	msg.data16a = FRAME_OFFSET;
442 	msg.data16b = FRAME_SIZE - 1;
443 	hss_npe_send(port, &msg, "HSS_SET_RX_FCR");
444 
445 	hss_config_set_lut(port);
446 
447 	memset(&msg, 0, sizeof(msg));
448 	msg.cmd = PORT_CONFIG_LOAD;
449 	msg.hss_port = port->id;
450 	hss_npe_send(port, &msg, "HSS_LOAD_CONFIG");
451 
452 	if (npe_recv_message(port->npe, &msg, "HSS_LOAD_CONFIG") ||
453 	    /* HSS_LOAD_CONFIG for port #1 returns port_id = #4 */
454 	    msg.cmd != PORT_CONFIG_LOAD || msg.data32) {
455 		pr_crit("HSS-%i: HSS_LOAD_CONFIG failed\n", port->id);
456 		BUG();
457 	}
458 
459 	/* HDLC may stop working without this - check FIXME */
460 	npe_recv_message(port->npe, &msg, "FLUSH_IT");
461 }
462 
463 static void hss_set_hdlc_cfg(struct port *port)
464 {
465 	struct msg msg;
466 
467 	memset(&msg, 0, sizeof(msg));
468 	msg.cmd = PKT_PIPE_HDLC_CFG_WRITE;
469 	msg.hss_port = port->id;
470 	msg.data8a = port->hdlc_cfg; /* rx_cfg */
471 	msg.data8b = port->hdlc_cfg | (PKT_EXTRA_FLAGS << 3); /* tx_cfg */
472 	hss_npe_send(port, &msg, "HSS_SET_HDLC_CFG");
473 }
474 
475 static u32 hss_get_status(struct port *port)
476 {
477 	struct msg msg;
478 
479 	memset(&msg, 0, sizeof(msg));
480 	msg.cmd = PORT_ERROR_READ;
481 	msg.hss_port = port->id;
482 	hss_npe_send(port, &msg, "PORT_ERROR_READ");
483 	if (npe_recv_message(port->npe, &msg, "PORT_ERROR_READ")) {
484 		pr_crit("HSS-%i: unable to read HSS status\n", port->id);
485 		BUG();
486 	}
487 
488 	return msg.data32;
489 }
490 
491 static void hss_start_hdlc(struct port *port)
492 {
493 	struct msg msg;
494 
495 	memset(&msg, 0, sizeof(msg));
496 	msg.cmd = PKT_PIPE_FLOW_ENABLE;
497 	msg.hss_port = port->id;
498 	msg.data32 = 0;
499 	hss_npe_send(port, &msg, "HSS_ENABLE_PKT_PIPE");
500 }
501 
502 static void hss_stop_hdlc(struct port *port)
503 {
504 	struct msg msg;
505 
506 	memset(&msg, 0, sizeof(msg));
507 	msg.cmd = PKT_PIPE_FLOW_DISABLE;
508 	msg.hss_port = port->id;
509 	hss_npe_send(port, &msg, "HSS_DISABLE_PKT_PIPE");
510 	hss_get_status(port); /* make sure it's halted */
511 }
512 
513 static int hss_load_firmware(struct port *port)
514 {
515 	struct msg msg;
516 	int err;
517 
518 	if (port->initialized)
519 		return 0;
520 
521 	if (!npe_running(port->npe)) {
522 		err = npe_load_firmware(port->npe, npe_name(port->npe),
523 					port->dev);
524 		if (err)
525 			return err;
526 	}
527 
528 	/* HDLC mode configuration */
529 	memset(&msg, 0, sizeof(msg));
530 	msg.cmd = PKT_NUM_PIPES_WRITE;
531 	msg.hss_port = port->id;
532 	msg.data8a = PKT_NUM_PIPES;
533 	hss_npe_send(port, &msg, "HSS_SET_PKT_PIPES");
534 
535 	msg.cmd = PKT_PIPE_FIFO_SIZEW_WRITE;
536 	msg.data8a = PKT_PIPE_FIFO_SIZEW;
537 	hss_npe_send(port, &msg, "HSS_SET_PKT_FIFO");
538 
539 	msg.cmd = PKT_PIPE_MODE_WRITE;
540 	msg.data8a = NPE_PKT_MODE_HDLC;
541 	/* msg.data8b = inv_mask */
542 	/* msg.data8c = or_mask */
543 	hss_npe_send(port, &msg, "HSS_SET_PKT_MODE");
544 
545 	msg.cmd = PKT_PIPE_RX_SIZE_WRITE;
546 	msg.data16a = HDLC_MAX_MRU; /* including CRC */
547 	hss_npe_send(port, &msg, "HSS_SET_PKT_RX_SIZE");
548 
549 	msg.cmd = PKT_PIPE_IDLE_PATTERN_WRITE;
550 	msg.data32 = 0x7F7F7F7F; /* ??? FIXME */
551 	hss_npe_send(port, &msg, "HSS_SET_PKT_IDLE");
552 
553 	port->initialized = 1;
554 	return 0;
555 }
556 
557 /*****************************************************************************
558  * packetized (HDLC) operation
559  ****************************************************************************/
560 
561 static inline void debug_pkt(struct net_device *dev, const char *func,
562 			     u8 *data, int len)
563 {
564 #if DEBUG_PKT_BYTES
565 	int i;
566 
567 	printk(KERN_DEBUG "%s: %s(%i)", dev->name, func, len);
568 	for (i = 0; i < len; i++) {
569 		if (i >= DEBUG_PKT_BYTES)
570 			break;
571 		printk("%s%02X", !(i % 4) ? " " : "", data[i]);
572 	}
573 	printk("\n");
574 #endif
575 }
576 
577 static inline void debug_desc(u32 phys, struct desc *desc)
578 {
579 #if DEBUG_DESC
580 	printk(KERN_DEBUG "%X: %X %3X %3X %08X %X %X\n",
581 	       phys, desc->next, desc->buf_len, desc->pkt_len,
582 	       desc->data, desc->status, desc->error_count);
583 #endif
584 }
585 
586 static inline int queue_get_desc(unsigned int queue, struct port *port,
587 				 int is_tx)
588 {
589 	u32 phys, tab_phys, n_desc;
590 	struct desc *tab;
591 
592 	phys = qmgr_get_entry(queue);
593 	if (!phys)
594 		return -1;
595 
596 	BUG_ON(phys & 0x1F);
597 	tab_phys = is_tx ? tx_desc_phys(port, 0) : rx_desc_phys(port, 0);
598 	tab = is_tx ? tx_desc_ptr(port, 0) : rx_desc_ptr(port, 0);
599 	n_desc = (phys - tab_phys) / sizeof(struct desc);
600 	BUG_ON(n_desc >= (is_tx ? TX_DESCS : RX_DESCS));
601 	debug_desc(phys, &tab[n_desc]);
602 	BUG_ON(tab[n_desc].next);
603 	return n_desc;
604 }
605 
606 static inline void queue_put_desc(unsigned int queue, u32 phys,
607 				  struct desc *desc)
608 {
609 	debug_desc(phys, desc);
610 	BUG_ON(phys & 0x1F);
611 	qmgr_put_entry(queue, phys);
612 	/* Don't check for queue overflow here, we've allocated sufficient
613 	 * length and queues >= 32 don't support this check anyway.
614 	 */
615 }
616 
617 static inline void dma_unmap_tx(struct port *port, struct desc *desc)
618 {
619 #ifdef __ARMEB__
620 	dma_unmap_single(&port->netdev->dev, desc->data,
621 			 desc->buf_len, DMA_TO_DEVICE);
622 #else
623 	dma_unmap_single(&port->netdev->dev, desc->data & ~3,
624 			 ALIGN((desc->data & 3) + desc->buf_len, 4),
625 			 DMA_TO_DEVICE);
626 #endif
627 }
628 
629 static void hss_hdlc_set_carrier(void *pdev, int carrier)
630 {
631 	struct net_device *netdev = pdev;
632 	struct port *port = dev_to_port(netdev);
633 	unsigned long flags;
634 
635 	spin_lock_irqsave(&npe_lock, flags);
636 	port->carrier = carrier;
637 	if (!port->loopback) {
638 		if (carrier)
639 			netif_carrier_on(netdev);
640 		else
641 			netif_carrier_off(netdev);
642 	}
643 	spin_unlock_irqrestore(&npe_lock, flags);
644 }
645 
646 static void hss_hdlc_rx_irq(void *pdev)
647 {
648 	struct net_device *dev = pdev;
649 	struct port *port = dev_to_port(dev);
650 
651 #if DEBUG_RX
652 	printk(KERN_DEBUG "%s: hss_hdlc_rx_irq\n", dev->name);
653 #endif
654 	qmgr_disable_irq(port->rxq);
655 	napi_schedule(&port->napi);
656 }
657 
658 static int hss_hdlc_poll(struct napi_struct *napi, int budget)
659 {
660 	struct port *port = container_of(napi, struct port, napi);
661 	struct net_device *dev = port->netdev;
662 	unsigned int rxq = port->rxq;
663 	unsigned int rxfreeq = port->rxfreeq;
664 	int received = 0;
665 
666 #if DEBUG_RX
667 	printk(KERN_DEBUG "%s: hss_hdlc_poll\n", dev->name);
668 #endif
669 
670 	while (received < budget) {
671 		struct sk_buff *skb;
672 		struct desc *desc;
673 		int n;
674 #ifdef __ARMEB__
675 		struct sk_buff *temp;
676 		u32 phys;
677 #endif
678 
679 		n = queue_get_desc(rxq, port, 0);
680 		if (n < 0) {
681 #if DEBUG_RX
682 			printk(KERN_DEBUG "%s: hss_hdlc_poll"
683 			       " napi_complete\n", dev->name);
684 #endif
685 			napi_complete(napi);
686 			qmgr_enable_irq(rxq);
687 			if (!qmgr_stat_empty(rxq) &&
688 			    napi_reschedule(napi)) {
689 #if DEBUG_RX
690 				printk(KERN_DEBUG "%s: hss_hdlc_poll"
691 				       " napi_reschedule succeeded\n",
692 				       dev->name);
693 #endif
694 				qmgr_disable_irq(rxq);
695 				continue;
696 			}
697 #if DEBUG_RX
698 			printk(KERN_DEBUG "%s: hss_hdlc_poll all done\n",
699 			       dev->name);
700 #endif
701 			return received; /* all work done */
702 		}
703 
704 		desc = rx_desc_ptr(port, n);
705 #if 0 /* FIXME - error_count counts modulo 256, perhaps we should use it */
706 		if (desc->error_count)
707 			printk(KERN_DEBUG "%s: hss_hdlc_poll status 0x%02X"
708 			       " errors %u\n", dev->name, desc->status,
709 			       desc->error_count);
710 #endif
711 		skb = NULL;
712 		switch (desc->status) {
713 		case 0:
714 #ifdef __ARMEB__
715 			skb = netdev_alloc_skb(dev, RX_SIZE);
716 			if (skb) {
717 				phys = dma_map_single(&dev->dev, skb->data,
718 						      RX_SIZE,
719 						      DMA_FROM_DEVICE);
720 				if (dma_mapping_error(&dev->dev, phys)) {
721 					dev_kfree_skb(skb);
722 					skb = NULL;
723 				}
724 			}
725 #else
726 			skb = netdev_alloc_skb(dev, desc->pkt_len);
727 #endif
728 			if (!skb)
729 				dev->stats.rx_dropped++;
730 			break;
731 		case ERR_HDLC_ALIGN:
732 		case ERR_HDLC_ABORT:
733 			dev->stats.rx_frame_errors++;
734 			dev->stats.rx_errors++;
735 			break;
736 		case ERR_HDLC_FCS:
737 			dev->stats.rx_crc_errors++;
738 			dev->stats.rx_errors++;
739 			break;
740 		case ERR_HDLC_TOO_LONG:
741 			dev->stats.rx_length_errors++;
742 			dev->stats.rx_errors++;
743 			break;
744 		default:	/* FIXME - remove printk */
745 			netdev_err(dev, "hss_hdlc_poll: status 0x%02X errors %u\n",
746 				   desc->status, desc->error_count);
747 			dev->stats.rx_errors++;
748 		}
749 
750 		if (!skb) {
751 			/* put the desc back on RX-ready queue */
752 			desc->buf_len = RX_SIZE;
753 			desc->pkt_len = desc->status = 0;
754 			queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
755 			continue;
756 		}
757 
758 		/* process received frame */
759 #ifdef __ARMEB__
760 		temp = skb;
761 		skb = port->rx_buff_tab[n];
762 		dma_unmap_single(&dev->dev, desc->data,
763 				 RX_SIZE, DMA_FROM_DEVICE);
764 #else
765 		dma_sync_single_for_cpu(&dev->dev, desc->data,
766 					RX_SIZE, DMA_FROM_DEVICE);
767 		memcpy_swab32((u32 *)skb->data, (u32 *)port->rx_buff_tab[n],
768 			      ALIGN(desc->pkt_len, 4) / 4);
769 #endif
770 		skb_put(skb, desc->pkt_len);
771 
772 		debug_pkt(dev, "hss_hdlc_poll", skb->data, skb->len);
773 
774 		skb->protocol = hdlc_type_trans(skb, dev);
775 		dev->stats.rx_packets++;
776 		dev->stats.rx_bytes += skb->len;
777 		netif_receive_skb(skb);
778 
779 		/* put the new buffer on RX-free queue */
780 #ifdef __ARMEB__
781 		port->rx_buff_tab[n] = temp;
782 		desc->data = phys;
783 #endif
784 		desc->buf_len = RX_SIZE;
785 		desc->pkt_len = 0;
786 		queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
787 		received++;
788 	}
789 #if DEBUG_RX
790 	printk(KERN_DEBUG "hss_hdlc_poll: end, not all work done\n");
791 #endif
792 	return received;	/* not all work done */
793 }
794 
795 static void hss_hdlc_txdone_irq(void *pdev)
796 {
797 	struct net_device *dev = pdev;
798 	struct port *port = dev_to_port(dev);
799 	int n_desc;
800 
801 #if DEBUG_TX
802 	printk(KERN_DEBUG DRV_NAME ": hss_hdlc_txdone_irq\n");
803 #endif
804 	while ((n_desc = queue_get_desc(port->txdoneq,
805 					port, 1)) >= 0) {
806 		struct desc *desc;
807 		int start;
808 
809 		desc = tx_desc_ptr(port, n_desc);
810 
811 		dev->stats.tx_packets++;
812 		dev->stats.tx_bytes += desc->pkt_len;
813 
814 		dma_unmap_tx(port, desc);
815 #if DEBUG_TX
816 		printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq free %p\n",
817 		       dev->name, port->tx_buff_tab[n_desc]);
818 #endif
819 		free_buffer_irq(port->tx_buff_tab[n_desc]);
820 		port->tx_buff_tab[n_desc] = NULL;
821 
822 		start = qmgr_stat_below_low_watermark(port->txreadyq);
823 		queue_put_desc(port->txreadyq,
824 			       tx_desc_phys(port, n_desc), desc);
825 		if (start) { /* TX-ready queue was empty */
826 #if DEBUG_TX
827 			printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq xmit"
828 			       " ready\n", dev->name);
829 #endif
830 			netif_wake_queue(dev);
831 		}
832 	}
833 }
834 
835 static int hss_hdlc_xmit(struct sk_buff *skb, struct net_device *dev)
836 {
837 	struct port *port = dev_to_port(dev);
838 	unsigned int txreadyq = port->txreadyq;
839 	int len, offset, bytes, n;
840 	void *mem;
841 	u32 phys;
842 	struct desc *desc;
843 
844 #if DEBUG_TX
845 	printk(KERN_DEBUG "%s: hss_hdlc_xmit\n", dev->name);
846 #endif
847 
848 	if (unlikely(skb->len > HDLC_MAX_MRU)) {
849 		dev_kfree_skb(skb);
850 		dev->stats.tx_errors++;
851 		return NETDEV_TX_OK;
852 	}
853 
854 	debug_pkt(dev, "hss_hdlc_xmit", skb->data, skb->len);
855 
856 	len = skb->len;
857 #ifdef __ARMEB__
858 	offset = 0; /* no need to keep alignment */
859 	bytes = len;
860 	mem = skb->data;
861 #else
862 	offset = (int)skb->data & 3; /* keep 32-bit alignment */
863 	bytes = ALIGN(offset + len, 4);
864 	mem = kmalloc(bytes, GFP_ATOMIC);
865 	if (!mem) {
866 		dev_kfree_skb(skb);
867 		dev->stats.tx_dropped++;
868 		return NETDEV_TX_OK;
869 	}
870 	memcpy_swab32(mem, (u32 *)((uintptr_t)skb->data & ~3), bytes / 4);
871 	dev_kfree_skb(skb);
872 #endif
873 
874 	phys = dma_map_single(&dev->dev, mem, bytes, DMA_TO_DEVICE);
875 	if (dma_mapping_error(&dev->dev, phys)) {
876 #ifdef __ARMEB__
877 		dev_kfree_skb(skb);
878 #else
879 		kfree(mem);
880 #endif
881 		dev->stats.tx_dropped++;
882 		return NETDEV_TX_OK;
883 	}
884 
885 	n = queue_get_desc(txreadyq, port, 1);
886 	BUG_ON(n < 0);
887 	desc = tx_desc_ptr(port, n);
888 
889 #ifdef __ARMEB__
890 	port->tx_buff_tab[n] = skb;
891 #else
892 	port->tx_buff_tab[n] = mem;
893 #endif
894 	desc->data = phys + offset;
895 	desc->buf_len = desc->pkt_len = len;
896 
897 	wmb();
898 	queue_put_desc(port->txq, tx_desc_phys(port, n), desc);
899 
900 	if (qmgr_stat_below_low_watermark(txreadyq)) { /* empty */
901 #if DEBUG_TX
902 		printk(KERN_DEBUG "%s: hss_hdlc_xmit queue full\n", dev->name);
903 #endif
904 		netif_stop_queue(dev);
905 		/* we could miss TX ready interrupt */
906 		if (!qmgr_stat_below_low_watermark(txreadyq)) {
907 #if DEBUG_TX
908 			printk(KERN_DEBUG "%s: hss_hdlc_xmit ready again\n",
909 			       dev->name);
910 #endif
911 			netif_wake_queue(dev);
912 		}
913 	}
914 
915 #if DEBUG_TX
916 	printk(KERN_DEBUG "%s: hss_hdlc_xmit end\n", dev->name);
917 #endif
918 	return NETDEV_TX_OK;
919 }
920 
921 static int request_hdlc_queues(struct port *port)
922 {
923 	int err;
924 
925 	err = qmgr_request_queue(port->rxfreeq, RX_DESCS, 0, 0,
926 				 "%s:RX-free", port->netdev->name);
927 	if (err)
928 		return err;
929 
930 	err = qmgr_request_queue(port->rxq, RX_DESCS, 0, 0,
931 				 "%s:RX", port->netdev->name);
932 	if (err)
933 		goto rel_rxfree;
934 
935 	err = qmgr_request_queue(port->txq, TX_DESCS, 0, 0,
936 				 "%s:TX", port->netdev->name);
937 	if (err)
938 		goto rel_rx;
939 
940 	err = qmgr_request_queue(port->txreadyq, TX_DESCS, 0, 0,
941 				 "%s:TX-ready", port->netdev->name);
942 	if (err)
943 		goto rel_tx;
944 
945 	err = qmgr_request_queue(port->txdoneq, TX_DESCS, 0, 0,
946 				 "%s:TX-done", port->netdev->name);
947 	if (err)
948 		goto rel_txready;
949 	return 0;
950 
951 rel_txready:
952 	qmgr_release_queue(port->txreadyq);
953 rel_tx:
954 	qmgr_release_queue(port->txq);
955 rel_rx:
956 	qmgr_release_queue(port->rxq);
957 rel_rxfree:
958 	qmgr_release_queue(port->rxfreeq);
959 	printk(KERN_DEBUG "%s: unable to request hardware queues\n",
960 	       port->netdev->name);
961 	return err;
962 }
963 
964 static void release_hdlc_queues(struct port *port)
965 {
966 	qmgr_release_queue(port->rxfreeq);
967 	qmgr_release_queue(port->rxq);
968 	qmgr_release_queue(port->txdoneq);
969 	qmgr_release_queue(port->txq);
970 	qmgr_release_queue(port->txreadyq);
971 }
972 
973 static int init_hdlc_queues(struct port *port)
974 {
975 	int i;
976 
977 	if (!ports_open) {
978 		dma_pool = dma_pool_create(DRV_NAME, &port->netdev->dev,
979 					   POOL_ALLOC_SIZE, 32, 0);
980 		if (!dma_pool)
981 			return -ENOMEM;
982 	}
983 
984 	port->desc_tab = dma_pool_zalloc(dma_pool, GFP_KERNEL,
985 					&port->desc_tab_phys);
986 	if (!port->desc_tab)
987 		return -ENOMEM;
988 	memset(port->rx_buff_tab, 0, sizeof(port->rx_buff_tab)); /* tables */
989 	memset(port->tx_buff_tab, 0, sizeof(port->tx_buff_tab));
990 
991 	/* Setup RX buffers */
992 	for (i = 0; i < RX_DESCS; i++) {
993 		struct desc *desc = rx_desc_ptr(port, i);
994 		buffer_t *buff;
995 		void *data;
996 #ifdef __ARMEB__
997 		buff = netdev_alloc_skb(port->netdev, RX_SIZE);
998 		if (!buff)
999 			return -ENOMEM;
1000 		data = buff->data;
1001 #else
1002 		buff = kmalloc(RX_SIZE, GFP_KERNEL);
1003 		if (!buff)
1004 			return -ENOMEM;
1005 		data = buff;
1006 #endif
1007 		desc->buf_len = RX_SIZE;
1008 		desc->data = dma_map_single(&port->netdev->dev, data,
1009 					    RX_SIZE, DMA_FROM_DEVICE);
1010 		if (dma_mapping_error(&port->netdev->dev, desc->data)) {
1011 			free_buffer(buff);
1012 			return -EIO;
1013 		}
1014 		port->rx_buff_tab[i] = buff;
1015 	}
1016 
1017 	return 0;
1018 }
1019 
1020 static void destroy_hdlc_queues(struct port *port)
1021 {
1022 	int i;
1023 
1024 	if (port->desc_tab) {
1025 		for (i = 0; i < RX_DESCS; i++) {
1026 			struct desc *desc = rx_desc_ptr(port, i);
1027 			buffer_t *buff = port->rx_buff_tab[i];
1028 
1029 			if (buff) {
1030 				dma_unmap_single(&port->netdev->dev,
1031 						 desc->data, RX_SIZE,
1032 						 DMA_FROM_DEVICE);
1033 				free_buffer(buff);
1034 			}
1035 		}
1036 		for (i = 0; i < TX_DESCS; i++) {
1037 			struct desc *desc = tx_desc_ptr(port, i);
1038 			buffer_t *buff = port->tx_buff_tab[i];
1039 
1040 			if (buff) {
1041 				dma_unmap_tx(port, desc);
1042 				free_buffer(buff);
1043 			}
1044 		}
1045 		dma_pool_free(dma_pool, port->desc_tab, port->desc_tab_phys);
1046 		port->desc_tab = NULL;
1047 	}
1048 
1049 	if (!ports_open && dma_pool) {
1050 		dma_pool_destroy(dma_pool);
1051 		dma_pool = NULL;
1052 	}
1053 }
1054 
1055 static irqreturn_t hss_hdlc_dcd_irq(int irq, void *data)
1056 {
1057 	struct net_device *dev = data;
1058 	struct port *port = dev_to_port(dev);
1059 	int val;
1060 
1061 	val = gpiod_get_value(port->dcd);
1062 	hss_hdlc_set_carrier(dev, val);
1063 
1064 	return IRQ_HANDLED;
1065 }
1066 
1067 static int hss_hdlc_open(struct net_device *dev)
1068 {
1069 	struct port *port = dev_to_port(dev);
1070 	unsigned long flags;
1071 	int i, err = 0;
1072 	int val;
1073 
1074 	err = hdlc_open(dev);
1075 	if (err)
1076 		return err;
1077 
1078 	err = hss_load_firmware(port);
1079 	if (err)
1080 		goto err_hdlc_close;
1081 
1082 	err = request_hdlc_queues(port);
1083 	if (err)
1084 		goto err_hdlc_close;
1085 
1086 	err = init_hdlc_queues(port);
1087 	if (err)
1088 		goto err_destroy_queues;
1089 
1090 	spin_lock_irqsave(&npe_lock, flags);
1091 
1092 	/* Set the carrier, the GPIO is flagged active low so this will return
1093 	 * 1 if DCD is asserted.
1094 	 */
1095 	val = gpiod_get_value(port->dcd);
1096 	hss_hdlc_set_carrier(dev, val);
1097 
1098 	/* Set up an IRQ for DCD */
1099 	err = request_irq(gpiod_to_irq(port->dcd), hss_hdlc_dcd_irq, 0, "IXP4xx HSS", dev);
1100 	if (err) {
1101 		dev_err(&dev->dev, "ixp4xx_hss: failed to request DCD IRQ (%i)\n", err);
1102 		goto err_unlock;
1103 	}
1104 
1105 	/* GPIOs are flagged active low so this asserts DTR and RTS */
1106 	gpiod_set_value(port->dtr, 1);
1107 	gpiod_set_value(port->rts, 1);
1108 
1109 	spin_unlock_irqrestore(&npe_lock, flags);
1110 
1111 	/* Populate queues with buffers, no failure after this point */
1112 	for (i = 0; i < TX_DESCS; i++)
1113 		queue_put_desc(port->txreadyq,
1114 			       tx_desc_phys(port, i), tx_desc_ptr(port, i));
1115 
1116 	for (i = 0; i < RX_DESCS; i++)
1117 		queue_put_desc(port->rxfreeq,
1118 			       rx_desc_phys(port, i), rx_desc_ptr(port, i));
1119 
1120 	napi_enable(&port->napi);
1121 	netif_start_queue(dev);
1122 
1123 	qmgr_set_irq(port->rxq, QUEUE_IRQ_SRC_NOT_EMPTY,
1124 		     hss_hdlc_rx_irq, dev);
1125 
1126 	qmgr_set_irq(port->txdoneq, QUEUE_IRQ_SRC_NOT_EMPTY,
1127 		     hss_hdlc_txdone_irq, dev);
1128 	qmgr_enable_irq(port->txdoneq);
1129 
1130 	ports_open++;
1131 
1132 	hss_set_hdlc_cfg(port);
1133 	hss_config(port);
1134 
1135 	hss_start_hdlc(port);
1136 
1137 	/* we may already have RX data, enables IRQ */
1138 	napi_schedule(&port->napi);
1139 	return 0;
1140 
1141 err_unlock:
1142 	spin_unlock_irqrestore(&npe_lock, flags);
1143 err_destroy_queues:
1144 	destroy_hdlc_queues(port);
1145 	release_hdlc_queues(port);
1146 err_hdlc_close:
1147 	hdlc_close(dev);
1148 	return err;
1149 }
1150 
1151 static int hss_hdlc_close(struct net_device *dev)
1152 {
1153 	struct port *port = dev_to_port(dev);
1154 	unsigned long flags;
1155 	int i, buffs = RX_DESCS; /* allocated RX buffers */
1156 
1157 	spin_lock_irqsave(&npe_lock, flags);
1158 	ports_open--;
1159 	qmgr_disable_irq(port->rxq);
1160 	netif_stop_queue(dev);
1161 	napi_disable(&port->napi);
1162 
1163 	hss_stop_hdlc(port);
1164 
1165 	while (queue_get_desc(port->rxfreeq, port, 0) >= 0)
1166 		buffs--;
1167 	while (queue_get_desc(port->rxq, port, 0) >= 0)
1168 		buffs--;
1169 
1170 	if (buffs)
1171 		netdev_crit(dev, "unable to drain RX queue, %i buffer(s) left in NPE\n",
1172 			    buffs);
1173 
1174 	buffs = TX_DESCS;
1175 	while (queue_get_desc(port->txq, port, 1) >= 0)
1176 		buffs--; /* cancel TX */
1177 
1178 	i = 0;
1179 	do {
1180 		while (queue_get_desc(port->txreadyq, port, 1) >= 0)
1181 			buffs--;
1182 		if (!buffs)
1183 			break;
1184 	} while (++i < MAX_CLOSE_WAIT);
1185 
1186 	if (buffs)
1187 		netdev_crit(dev, "unable to drain TX queue, %i buffer(s) left in NPE\n",
1188 			    buffs);
1189 #if DEBUG_CLOSE
1190 	if (!buffs)
1191 		printk(KERN_DEBUG "Draining TX queues took %i cycles\n", i);
1192 #endif
1193 	qmgr_disable_irq(port->txdoneq);
1194 
1195 	free_irq(gpiod_to_irq(port->dcd), dev);
1196 	/* GPIOs are flagged active low so this de-asserts DTR and RTS */
1197 	gpiod_set_value(port->dtr, 0);
1198 	gpiod_set_value(port->rts, 0);
1199 	spin_unlock_irqrestore(&npe_lock, flags);
1200 
1201 	destroy_hdlc_queues(port);
1202 	release_hdlc_queues(port);
1203 	hdlc_close(dev);
1204 	return 0;
1205 }
1206 
1207 static int hss_hdlc_attach(struct net_device *dev, unsigned short encoding,
1208 			   unsigned short parity)
1209 {
1210 	struct port *port = dev_to_port(dev);
1211 
1212 	if (encoding != ENCODING_NRZ)
1213 		return -EINVAL;
1214 
1215 	switch (parity) {
1216 	case PARITY_CRC16_PR1_CCITT:
1217 		port->hdlc_cfg = 0;
1218 		return 0;
1219 
1220 	case PARITY_CRC32_PR1_CCITT:
1221 		port->hdlc_cfg = PKT_HDLC_CRC_32;
1222 		return 0;
1223 
1224 	default:
1225 		return -EINVAL;
1226 	}
1227 }
1228 
1229 static u32 check_clock(u32 timer_freq, u32 rate, u32 a, u32 b, u32 c,
1230 		       u32 *best, u32 *best_diff, u32 *reg)
1231 {
1232 	/* a is 10-bit, b is 10-bit, c is 12-bit */
1233 	u64 new_rate;
1234 	u32 new_diff;
1235 
1236 	new_rate = timer_freq * (u64)(c + 1);
1237 	do_div(new_rate, a * (c + 1) + b + 1);
1238 	new_diff = abs((u32)new_rate - rate);
1239 
1240 	if (new_diff < *best_diff) {
1241 		*best = new_rate;
1242 		*best_diff = new_diff;
1243 		*reg = (a << 22) | (b << 12) | c;
1244 	}
1245 	return new_diff;
1246 }
1247 
1248 static void find_best_clock(u32 timer_freq, u32 rate, u32 *best, u32 *reg)
1249 {
1250 	u32 a, b, diff = 0xFFFFFFFF;
1251 
1252 	a = timer_freq / rate;
1253 
1254 	if (a > 0x3FF) { /* 10-bit value - we can go as slow as ca. 65 kb/s */
1255 		check_clock(timer_freq, rate, 0x3FF, 1, 1, best, &diff, reg);
1256 		return;
1257 	}
1258 	if (a == 0) { /* > 66.666 MHz */
1259 		a = 1; /* minimum divider is 1 (a = 0, b = 1, c = 1) */
1260 		rate = timer_freq;
1261 	}
1262 
1263 	if (rate * a == timer_freq) { /* don't divide by 0 later */
1264 		check_clock(timer_freq, rate, a - 1, 1, 1, best, &diff, reg);
1265 		return;
1266 	}
1267 
1268 	for (b = 0; b < 0x400; b++) {
1269 		u64 c = (b + 1) * (u64)rate;
1270 
1271 		do_div(c, timer_freq - rate * a);
1272 		c--;
1273 		if (c >= 0xFFF) { /* 12-bit - no need to check more 'b's */
1274 			if (b == 0 && /* also try a bit higher rate */
1275 			    !check_clock(timer_freq, rate, a - 1, 1, 1, best,
1276 					 &diff, reg))
1277 				return;
1278 			check_clock(timer_freq, rate, a, b, 0xFFF, best,
1279 				    &diff, reg);
1280 			return;
1281 		}
1282 		if (!check_clock(timer_freq, rate, a, b, c, best, &diff, reg))
1283 			return;
1284 		if (!check_clock(timer_freq, rate, a, b, c + 1, best, &diff,
1285 				 reg))
1286 			return;
1287 	}
1288 }
1289 
1290 static int hss_hdlc_set_clock(struct port *port, unsigned int clock_type)
1291 {
1292 	switch (clock_type) {
1293 	case CLOCK_DEFAULT:
1294 	case CLOCK_EXT:
1295 		gpiod_set_value(port->clk_internal, 0);
1296 		return CLOCK_EXT;
1297 	case CLOCK_INT:
1298 		gpiod_set_value(port->clk_internal, 1);
1299 		return CLOCK_INT;
1300 	default:
1301 		return -EINVAL;
1302 	}
1303 }
1304 
1305 static int hss_hdlc_ioctl(struct net_device *dev, struct if_settings *ifs)
1306 {
1307 	const size_t size = sizeof(sync_serial_settings);
1308 	sync_serial_settings new_line;
1309 	sync_serial_settings __user *line = ifs->ifs_ifsu.sync;
1310 	struct port *port = dev_to_port(dev);
1311 	unsigned long flags;
1312 	int clk;
1313 
1314 	switch (ifs->type) {
1315 	case IF_GET_IFACE:
1316 		ifs->type = IF_IFACE_V35;
1317 		if (ifs->size < size) {
1318 			ifs->size = size; /* data size wanted */
1319 			return -ENOBUFS;
1320 		}
1321 		memset(&new_line, 0, sizeof(new_line));
1322 		new_line.clock_type = port->clock_type;
1323 		new_line.clock_rate = port->clock_rate;
1324 		new_line.loopback = port->loopback;
1325 		if (copy_to_user(line, &new_line, size))
1326 			return -EFAULT;
1327 		return 0;
1328 
1329 	case IF_IFACE_SYNC_SERIAL:
1330 	case IF_IFACE_V35:
1331 		if (!capable(CAP_NET_ADMIN))
1332 			return -EPERM;
1333 		if (copy_from_user(&new_line, line, size))
1334 			return -EFAULT;
1335 
1336 		clk = new_line.clock_type;
1337 		hss_hdlc_set_clock(port, clk);
1338 
1339 		if (clk != CLOCK_EXT && clk != CLOCK_INT)
1340 			return -EINVAL;	/* No such clock setting */
1341 
1342 		if (new_line.loopback != 0 && new_line.loopback != 1)
1343 			return -EINVAL;
1344 
1345 		port->clock_type = clk; /* Update settings */
1346 		if (clk == CLOCK_INT) {
1347 			find_best_clock(IXP4XX_TIMER_FREQ,
1348 					new_line.clock_rate,
1349 					&port->clock_rate, &port->clock_reg);
1350 		} else {
1351 			port->clock_rate = 0;
1352 			port->clock_reg = CLK42X_SPEED_2048KHZ;
1353 		}
1354 		port->loopback = new_line.loopback;
1355 
1356 		spin_lock_irqsave(&npe_lock, flags);
1357 
1358 		if (dev->flags & IFF_UP)
1359 			hss_config(port);
1360 
1361 		if (port->loopback || port->carrier)
1362 			netif_carrier_on(port->netdev);
1363 		else
1364 			netif_carrier_off(port->netdev);
1365 		spin_unlock_irqrestore(&npe_lock, flags);
1366 
1367 		return 0;
1368 
1369 	default:
1370 		return hdlc_ioctl(dev, ifs);
1371 	}
1372 }
1373 
1374 /*****************************************************************************
1375  * initialization
1376  ****************************************************************************/
1377 
1378 static const struct net_device_ops hss_hdlc_ops = {
1379 	.ndo_open       = hss_hdlc_open,
1380 	.ndo_stop       = hss_hdlc_close,
1381 	.ndo_start_xmit = hdlc_start_xmit,
1382 	.ndo_siocwandev = hss_hdlc_ioctl,
1383 };
1384 
1385 static int ixp4xx_hss_probe(struct platform_device *pdev)
1386 {
1387 	struct of_phandle_args queue_spec;
1388 	struct of_phandle_args npe_spec;
1389 	struct device *dev = &pdev->dev;
1390 	struct net_device *ndev;
1391 	struct device_node *np;
1392 	struct port *port;
1393 	hdlc_device *hdlc;
1394 	int err;
1395 
1396 	np = dev->of_node;
1397 
1398 	port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
1399 	if (!port)
1400 		return -ENOMEM;
1401 
1402 	err = of_parse_phandle_with_fixed_args(np, "intel,npe-handle", 1, 0,
1403 					       &npe_spec);
1404 	if (err)
1405 		return dev_err_probe(dev, err, "no NPE engine specified\n");
1406 	/* NPE ID 0x00, 0x10, 0x20... */
1407 	port->npe = npe_request(npe_spec.args[0] << 4);
1408 	if (!port->npe) {
1409 		dev_err(dev, "unable to obtain NPE instance\n");
1410 		return -ENODEV;
1411 	}
1412 
1413 	/* Get the TX ready queue as resource from queue manager */
1414 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-chl-txready", 1, 0,
1415 					       &queue_spec);
1416 	if (err)
1417 		return dev_err_probe(dev, err, "no txready queue phandle\n");
1418 	port->txreadyq = queue_spec.args[0];
1419 	/* Get the RX trig queue as resource from queue manager */
1420 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-chl-rxtrig", 1, 0,
1421 					       &queue_spec);
1422 	if (err)
1423 		return dev_err_probe(dev, err, "no rxtrig queue phandle\n");
1424 	port->rxtrigq = queue_spec.args[0];
1425 	/* Get the RX queue as resource from queue manager */
1426 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-rx", 1, 0,
1427 					       &queue_spec);
1428 	if (err)
1429 		return dev_err_probe(dev, err, "no RX queue phandle\n");
1430 	port->rxq = queue_spec.args[0];
1431 	/* Get the TX queue as resource from queue manager */
1432 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-tx", 1, 0,
1433 					       &queue_spec);
1434 	if (err)
1435 		return dev_err_probe(dev, err, "no RX queue phandle\n");
1436 	port->txq = queue_spec.args[0];
1437 	/* Get the RX free queue as resource from queue manager */
1438 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-rxfree", 1, 0,
1439 					       &queue_spec);
1440 	if (err)
1441 		return dev_err_probe(dev, err, "no RX free queue phandle\n");
1442 	port->rxfreeq = queue_spec.args[0];
1443 	/* Get the TX done queue as resource from queue manager */
1444 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-txdone", 1, 0,
1445 					       &queue_spec);
1446 	if (err)
1447 		return dev_err_probe(dev, err, "no TX done queue phandle\n");
1448 	port->txdoneq = queue_spec.args[0];
1449 
1450 	/* Obtain all the line control GPIOs */
1451 	port->cts = devm_gpiod_get(dev, "cts", GPIOD_OUT_LOW);
1452 	if (IS_ERR(port->cts))
1453 		return dev_err_probe(dev, PTR_ERR(port->cts), "unable to get CTS GPIO\n");
1454 	port->rts = devm_gpiod_get(dev, "rts", GPIOD_OUT_LOW);
1455 	if (IS_ERR(port->rts))
1456 		return dev_err_probe(dev, PTR_ERR(port->rts), "unable to get RTS GPIO\n");
1457 	port->dcd = devm_gpiod_get(dev, "dcd", GPIOD_IN);
1458 	if (IS_ERR(port->dcd))
1459 		return dev_err_probe(dev, PTR_ERR(port->dcd), "unable to get DCD GPIO\n");
1460 	port->dtr = devm_gpiod_get(dev, "dtr", GPIOD_OUT_LOW);
1461 	if (IS_ERR(port->dtr))
1462 		return dev_err_probe(dev, PTR_ERR(port->dtr), "unable to get DTR GPIO\n");
1463 	port->clk_internal = devm_gpiod_get(dev, "clk-internal", GPIOD_OUT_LOW);
1464 	if (IS_ERR(port->clk_internal))
1465 		return dev_err_probe(dev, PTR_ERR(port->clk_internal),
1466 				     "unable to get CLK internal GPIO\n");
1467 
1468 	ndev = alloc_hdlcdev(port);
1469 	port->netdev = alloc_hdlcdev(port);
1470 	if (!port->netdev) {
1471 		err = -ENOMEM;
1472 		goto err_plat;
1473 	}
1474 
1475 	SET_NETDEV_DEV(ndev, &pdev->dev);
1476 	hdlc = dev_to_hdlc(ndev);
1477 	hdlc->attach = hss_hdlc_attach;
1478 	hdlc->xmit = hss_hdlc_xmit;
1479 	ndev->netdev_ops = &hss_hdlc_ops;
1480 	ndev->tx_queue_len = 100;
1481 	port->clock_type = CLOCK_EXT;
1482 	port->clock_rate = 0;
1483 	port->clock_reg = CLK42X_SPEED_2048KHZ;
1484 	port->id = pdev->id;
1485 	port->dev = &pdev->dev;
1486 	netif_napi_add(ndev, &port->napi, hss_hdlc_poll, NAPI_WEIGHT);
1487 
1488 	err = register_hdlc_device(ndev);
1489 	if (err)
1490 		goto err_free_netdev;
1491 
1492 	platform_set_drvdata(pdev, port);
1493 
1494 	netdev_info(ndev, "initialized\n");
1495 	return 0;
1496 
1497 err_free_netdev:
1498 	free_netdev(ndev);
1499 err_plat:
1500 	npe_release(port->npe);
1501 	return err;
1502 }
1503 
1504 static int ixp4xx_hss_remove(struct platform_device *pdev)
1505 {
1506 	struct port *port = platform_get_drvdata(pdev);
1507 
1508 	unregister_hdlc_device(port->netdev);
1509 	free_netdev(port->netdev);
1510 	npe_release(port->npe);
1511 	return 0;
1512 }
1513 
1514 static struct platform_driver ixp4xx_hss_driver = {
1515 	.driver.name	= DRV_NAME,
1516 	.probe		= ixp4xx_hss_probe,
1517 	.remove		= ixp4xx_hss_remove,
1518 };
1519 
1520 static int __init hss_init_module(void)
1521 {
1522 	if ((ixp4xx_read_feature_bits() &
1523 	     (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) !=
1524 	    (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS))
1525 		return -ENODEV;
1526 
1527 	return platform_driver_register(&ixp4xx_hss_driver);
1528 }
1529 
1530 static void __exit hss_cleanup_module(void)
1531 {
1532 	platform_driver_unregister(&ixp4xx_hss_driver);
1533 }
1534 
1535 MODULE_AUTHOR("Krzysztof Halasa");
1536 MODULE_DESCRIPTION("Intel IXP4xx HSS driver");
1537 MODULE_LICENSE("GPL v2");
1538 MODULE_ALIAS("platform:ixp4xx_hss");
1539 module_init(hss_init_module);
1540 module_exit(hss_cleanup_module);
1541