xref: /openbmc/linux/drivers/net/wan/ixp4xx_hss.c (revision ae213c44)
1 /*
2  * Intel IXP4xx HSS (synchronous serial port) driver for Linux
3  *
4  * Copyright (C) 2007-2008 Krzysztof Hałasa <khc@pm.waw.pl>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of version 2 of the GNU General Public License
8  * as published by the Free Software Foundation.
9  */
10 
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/module.h>
14 #include <linux/bitops.h>
15 #include <linux/cdev.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/dmapool.h>
18 #include <linux/fs.h>
19 #include <linux/hdlc.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/platform_device.h>
23 #include <linux/poll.h>
24 #include <linux/slab.h>
25 #include <linux/soc/ixp4xx/npe.h>
26 #include <linux/soc/ixp4xx/qmgr.h>
27 
28 #define DEBUG_DESC		0
29 #define DEBUG_RX		0
30 #define DEBUG_TX		0
31 #define DEBUG_PKT_BYTES		0
32 #define DEBUG_CLOSE		0
33 
34 #define DRV_NAME		"ixp4xx_hss"
35 
36 #define PKT_EXTRA_FLAGS		0 /* orig 1 */
37 #define PKT_NUM_PIPES		1 /* 1, 2 or 4 */
38 #define PKT_PIPE_FIFO_SIZEW	4 /* total 4 dwords per HSS */
39 
40 #define RX_DESCS		16 /* also length of all RX queues */
41 #define TX_DESCS		16 /* also length of all TX queues */
42 
43 #define POOL_ALLOC_SIZE		(sizeof(struct desc) * (RX_DESCS + TX_DESCS))
44 #define RX_SIZE			(HDLC_MAX_MRU + 4) /* NPE needs more space */
45 #define MAX_CLOSE_WAIT		1000 /* microseconds */
46 #define HSS_COUNT		2
47 #define FRAME_SIZE		256 /* doesn't matter at this point */
48 #define FRAME_OFFSET		0
49 #define MAX_CHANNELS		(FRAME_SIZE / 8)
50 
51 #define NAPI_WEIGHT		16
52 
53 /* Queue IDs */
54 #define HSS0_CHL_RXTRIG_QUEUE	12	/* orig size = 32 dwords */
55 #define HSS0_PKT_RX_QUEUE	13	/* orig size = 32 dwords */
56 #define HSS0_PKT_TX0_QUEUE	14	/* orig size = 16 dwords */
57 #define HSS0_PKT_TX1_QUEUE	15
58 #define HSS0_PKT_TX2_QUEUE	16
59 #define HSS0_PKT_TX3_QUEUE	17
60 #define HSS0_PKT_RXFREE0_QUEUE	18	/* orig size = 16 dwords */
61 #define HSS0_PKT_RXFREE1_QUEUE	19
62 #define HSS0_PKT_RXFREE2_QUEUE	20
63 #define HSS0_PKT_RXFREE3_QUEUE	21
64 #define HSS0_PKT_TXDONE_QUEUE	22	/* orig size = 64 dwords */
65 
66 #define HSS1_CHL_RXTRIG_QUEUE	10
67 #define HSS1_PKT_RX_QUEUE	0
68 #define HSS1_PKT_TX0_QUEUE	5
69 #define HSS1_PKT_TX1_QUEUE	6
70 #define HSS1_PKT_TX2_QUEUE	7
71 #define HSS1_PKT_TX3_QUEUE	8
72 #define HSS1_PKT_RXFREE0_QUEUE	1
73 #define HSS1_PKT_RXFREE1_QUEUE	2
74 #define HSS1_PKT_RXFREE2_QUEUE	3
75 #define HSS1_PKT_RXFREE3_QUEUE	4
76 #define HSS1_PKT_TXDONE_QUEUE	9
77 
78 #define NPE_PKT_MODE_HDLC		0
79 #define NPE_PKT_MODE_RAW		1
80 #define NPE_PKT_MODE_56KMODE		2
81 #define NPE_PKT_MODE_56KENDIAN_MSB	4
82 
83 /* PKT_PIPE_HDLC_CFG_WRITE flags */
84 #define PKT_HDLC_IDLE_ONES		0x1 /* default = flags */
85 #define PKT_HDLC_CRC_32			0x2 /* default = CRC-16 */
86 #define PKT_HDLC_MSB_ENDIAN		0x4 /* default = LE */
87 
88 
89 /* hss_config, PCRs */
90 /* Frame sync sampling, default = active low */
91 #define PCR_FRM_SYNC_ACTIVE_HIGH	0x40000000
92 #define PCR_FRM_SYNC_FALLINGEDGE	0x80000000
93 #define PCR_FRM_SYNC_RISINGEDGE		0xC0000000
94 
95 /* Frame sync pin: input (default) or output generated off a given clk edge */
96 #define PCR_FRM_SYNC_OUTPUT_FALLING	0x20000000
97 #define PCR_FRM_SYNC_OUTPUT_RISING	0x30000000
98 
99 /* Frame and data clock sampling on edge, default = falling */
100 #define PCR_FCLK_EDGE_RISING		0x08000000
101 #define PCR_DCLK_EDGE_RISING		0x04000000
102 
103 /* Clock direction, default = input */
104 #define PCR_SYNC_CLK_DIR_OUTPUT		0x02000000
105 
106 /* Generate/Receive frame pulses, default = enabled */
107 #define PCR_FRM_PULSE_DISABLED		0x01000000
108 
109  /* Data rate is full (default) or half the configured clk speed */
110 #define PCR_HALF_CLK_RATE		0x00200000
111 
112 /* Invert data between NPE and HSS FIFOs? (default = no) */
113 #define PCR_DATA_POLARITY_INVERT	0x00100000
114 
115 /* TX/RX endianness, default = LSB */
116 #define PCR_MSB_ENDIAN			0x00080000
117 
118 /* Normal (default) / open drain mode (TX only) */
119 #define PCR_TX_PINS_OPEN_DRAIN		0x00040000
120 
121 /* No framing bit transmitted and expected on RX? (default = framing bit) */
122 #define PCR_SOF_NO_FBIT			0x00020000
123 
124 /* Drive data pins? */
125 #define PCR_TX_DATA_ENABLE		0x00010000
126 
127 /* Voice 56k type: drive the data pins low (default), high, high Z */
128 #define PCR_TX_V56K_HIGH		0x00002000
129 #define PCR_TX_V56K_HIGH_IMP		0x00004000
130 
131 /* Unassigned type: drive the data pins low (default), high, high Z */
132 #define PCR_TX_UNASS_HIGH		0x00000800
133 #define PCR_TX_UNASS_HIGH_IMP		0x00001000
134 
135 /* T1 @ 1.544MHz only: Fbit dictated in FIFO (default) or high Z */
136 #define PCR_TX_FB_HIGH_IMP		0x00000400
137 
138 /* 56k data endiannes - which bit unused: high (default) or low */
139 #define PCR_TX_56KE_BIT_0_UNUSED	0x00000200
140 
141 /* 56k data transmission type: 32/8 bit data (default) or 56K data */
142 #define PCR_TX_56KS_56K_DATA		0x00000100
143 
144 /* hss_config, cCR */
145 /* Number of packetized clients, default = 1 */
146 #define CCR_NPE_HFIFO_2_HDLC		0x04000000
147 #define CCR_NPE_HFIFO_3_OR_4HDLC	0x08000000
148 
149 /* default = no loopback */
150 #define CCR_LOOPBACK			0x02000000
151 
152 /* HSS number, default = 0 (first) */
153 #define CCR_SECOND_HSS			0x01000000
154 
155 
156 /* hss_config, clkCR: main:10, num:10, denom:12 */
157 #define CLK42X_SPEED_EXP	((0x3FF << 22) | (  2 << 12) |   15) /*65 KHz*/
158 
159 #define CLK42X_SPEED_512KHZ	((  130 << 22) | (  2 << 12) |   15)
160 #define CLK42X_SPEED_1536KHZ	((   43 << 22) | ( 18 << 12) |   47)
161 #define CLK42X_SPEED_1544KHZ	((   43 << 22) | ( 33 << 12) |  192)
162 #define CLK42X_SPEED_2048KHZ	((   32 << 22) | ( 34 << 12) |   63)
163 #define CLK42X_SPEED_4096KHZ	((   16 << 22) | ( 34 << 12) |  127)
164 #define CLK42X_SPEED_8192KHZ	((    8 << 22) | ( 34 << 12) |  255)
165 
166 #define CLK46X_SPEED_512KHZ	((  130 << 22) | ( 24 << 12) |  127)
167 #define CLK46X_SPEED_1536KHZ	((   43 << 22) | (152 << 12) |  383)
168 #define CLK46X_SPEED_1544KHZ	((   43 << 22) | ( 66 << 12) |  385)
169 #define CLK46X_SPEED_2048KHZ	((   32 << 22) | (280 << 12) |  511)
170 #define CLK46X_SPEED_4096KHZ	((   16 << 22) | (280 << 12) | 1023)
171 #define CLK46X_SPEED_8192KHZ	((    8 << 22) | (280 << 12) | 2047)
172 
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 
214 /* NPE command codes */
215 /* writes the ConfigWord value to the location specified by offset */
216 #define PORT_CONFIG_WRITE		0x40
217 
218 /* triggers the NPE to load the contents of the configuration table */
219 #define PORT_CONFIG_LOAD		0x41
220 
221 /* triggers the NPE to return an HssErrorReadResponse message */
222 #define PORT_ERROR_READ			0x42
223 
224 /* triggers the NPE to reset internal status and enable the HssPacketized
225    operation for the flow specified by pPipe */
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 #define ERR_HDLC_TOO_LONG	5 /* HDLC frame size too long */
242 #define ERR_HDLC_ABORT		6 /* abort sequence received */
243 #define ERR_DISCONNECTING	7 /* disconnect is in progress */
244 
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 	struct net_device *netdev;
260 	struct napi_struct napi;
261 	struct hss_plat_info *plat;
262 	buffer_t *rx_buff_tab[RX_DESCS], *tx_buff_tab[TX_DESCS];
263 	struct desc *desc_tab;	/* coherent */
264 	u32 desc_tab_phys;
265 	unsigned int id;
266 	unsigned int clock_type, clock_rate, loopback;
267 	unsigned int initialized, carrier;
268 	u8 hdlc_cfg;
269 	u32 clock_reg;
270 };
271 
272 /* NPE message structure */
273 struct msg {
274 #ifdef __ARMEB__
275 	u8 cmd, unused, hss_port, index;
276 	union {
277 		struct { u8 data8a, data8b, data8c, data8d; };
278 		struct { u16 data16a, data16b; };
279 		struct { u32 data32; };
280 	};
281 #else
282 	u8 index, hss_port, unused, cmd;
283 	union {
284 		struct { u8 data8d, data8c, data8b, data8a; };
285 		struct { u16 data16b, data16a; };
286 		struct { u32 data32; };
287 	};
288 #endif
289 };
290 
291 /* HDLC packet descriptor */
292 struct desc {
293 	u32 next;		/* pointer to next buffer, unused */
294 
295 #ifdef __ARMEB__
296 	u16 buf_len;		/* buffer length */
297 	u16 pkt_len;		/* packet length */
298 	u32 data;		/* pointer to data buffer in RAM */
299 	u8 status;
300 	u8 error_count;
301 	u16 __reserved;
302 #else
303 	u16 pkt_len;		/* packet length */
304 	u16 buf_len;		/* buffer length */
305 	u32 data;		/* pointer to data buffer in RAM */
306 	u16 __reserved;
307 	u8 error_count;
308 	u8 status;
309 #endif
310 	u32 __reserved1[4];
311 };
312 
313 
314 #define rx_desc_phys(port, n)	((port)->desc_tab_phys +		\
315 				 (n) * sizeof(struct desc))
316 #define rx_desc_ptr(port, n)	(&(port)->desc_tab[n])
317 
318 #define tx_desc_phys(port, n)	((port)->desc_tab_phys +		\
319 				 ((n) + RX_DESCS) * sizeof(struct desc))
320 #define tx_desc_ptr(port, n)	(&(port)->desc_tab[(n) + RX_DESCS])
321 
322 /*****************************************************************************
323  * global variables
324  ****************************************************************************/
325 
326 static int ports_open;
327 static struct dma_pool *dma_pool;
328 static spinlock_t npe_lock;
329 
330 static const struct {
331 	int tx, txdone, rx, rxfree;
332 }queue_ids[2] = {{HSS0_PKT_TX0_QUEUE, HSS0_PKT_TXDONE_QUEUE, HSS0_PKT_RX_QUEUE,
333 		  HSS0_PKT_RXFREE0_QUEUE},
334 		 {HSS1_PKT_TX0_QUEUE, HSS1_PKT_TXDONE_QUEUE, HSS1_PKT_RX_QUEUE,
335 		  HSS1_PKT_RXFREE0_QUEUE},
336 };
337 
338 /*****************************************************************************
339  * utility functions
340  ****************************************************************************/
341 
342 static inline struct port* dev_to_port(struct net_device *dev)
343 {
344 	return dev_to_hdlc(dev)->priv;
345 }
346 
347 #ifndef __ARMEB__
348 static inline void memcpy_swab32(u32 *dest, u32 *src, int cnt)
349 {
350 	int i;
351 	for (i = 0; i < cnt; i++)
352 		dest[i] = swab32(src[i]);
353 }
354 #endif
355 
356 /*****************************************************************************
357  * HSS access
358  ****************************************************************************/
359 
360 static void hss_npe_send(struct port *port, struct msg *msg, const char* what)
361 {
362 	u32 *val = (u32*)msg;
363 	if (npe_send_message(port->npe, msg, what)) {
364 		pr_crit("HSS-%i: unable to send command [%08X:%08X] to %s\n",
365 			port->id, val[0], val[1], npe_name(port->npe));
366 		BUG();
367 	}
368 }
369 
370 static void hss_config_set_lut(struct port *port)
371 {
372 	struct msg msg;
373 	int ch;
374 
375 	memset(&msg, 0, sizeof(msg));
376 	msg.cmd = PORT_CONFIG_WRITE;
377 	msg.hss_port = port->id;
378 
379 	for (ch = 0; ch < MAX_CHANNELS; ch++) {
380 		msg.data32 >>= 2;
381 		msg.data32 |= TDMMAP_HDLC << 30;
382 
383 		if (ch % 16 == 15) {
384 			msg.index = HSS_CONFIG_TX_LUT + ((ch / 4) & ~3);
385 			hss_npe_send(port, &msg, "HSS_SET_TX_LUT");
386 
387 			msg.index += HSS_CONFIG_RX_LUT - HSS_CONFIG_TX_LUT;
388 			hss_npe_send(port, &msg, "HSS_SET_RX_LUT");
389 		}
390 	}
391 }
392 
393 static void hss_config(struct port *port)
394 {
395 	struct msg msg;
396 
397 	memset(&msg, 0, sizeof(msg));
398 	msg.cmd = PORT_CONFIG_WRITE;
399 	msg.hss_port = port->id;
400 	msg.index = HSS_CONFIG_TX_PCR;
401 	msg.data32 = PCR_FRM_PULSE_DISABLED | PCR_MSB_ENDIAN |
402 		PCR_TX_DATA_ENABLE | PCR_SOF_NO_FBIT;
403 	if (port->clock_type == CLOCK_INT)
404 		msg.data32 |= PCR_SYNC_CLK_DIR_OUTPUT;
405 	hss_npe_send(port, &msg, "HSS_SET_TX_PCR");
406 
407 	msg.index = HSS_CONFIG_RX_PCR;
408 	msg.data32 ^= PCR_TX_DATA_ENABLE | PCR_DCLK_EDGE_RISING;
409 	hss_npe_send(port, &msg, "HSS_SET_RX_PCR");
410 
411 	memset(&msg, 0, sizeof(msg));
412 	msg.cmd = PORT_CONFIG_WRITE;
413 	msg.hss_port = port->id;
414 	msg.index = HSS_CONFIG_CORE_CR;
415 	msg.data32 = (port->loopback ? CCR_LOOPBACK : 0) |
416 		(port->id ? CCR_SECOND_HSS : 0);
417 	hss_npe_send(port, &msg, "HSS_SET_CORE_CR");
418 
419 	memset(&msg, 0, sizeof(msg));
420 	msg.cmd = PORT_CONFIG_WRITE;
421 	msg.hss_port = port->id;
422 	msg.index = HSS_CONFIG_CLOCK_CR;
423 	msg.data32 = port->clock_reg;
424 	hss_npe_send(port, &msg, "HSS_SET_CLOCK_CR");
425 
426 	memset(&msg, 0, sizeof(msg));
427 	msg.cmd = PORT_CONFIG_WRITE;
428 	msg.hss_port = port->id;
429 	msg.index = HSS_CONFIG_TX_FCR;
430 	msg.data16a = FRAME_OFFSET;
431 	msg.data16b = FRAME_SIZE - 1;
432 	hss_npe_send(port, &msg, "HSS_SET_TX_FCR");
433 
434 	memset(&msg, 0, sizeof(msg));
435 	msg.cmd = PORT_CONFIG_WRITE;
436 	msg.hss_port = port->id;
437 	msg.index = HSS_CONFIG_RX_FCR;
438 	msg.data16a = FRAME_OFFSET;
439 	msg.data16b = FRAME_SIZE - 1;
440 	hss_npe_send(port, &msg, "HSS_SET_RX_FCR");
441 
442 	hss_config_set_lut(port);
443 
444 	memset(&msg, 0, sizeof(msg));
445 	msg.cmd = PORT_CONFIG_LOAD;
446 	msg.hss_port = port->id;
447 	hss_npe_send(port, &msg, "HSS_LOAD_CONFIG");
448 
449 	if (npe_recv_message(port->npe, &msg, "HSS_LOAD_CONFIG") ||
450 	    /* HSS_LOAD_CONFIG for port #1 returns port_id = #4 */
451 	    msg.cmd != PORT_CONFIG_LOAD || msg.data32) {
452 		pr_crit("HSS-%i: HSS_LOAD_CONFIG failed\n", port->id);
453 		BUG();
454 	}
455 
456 	/* HDLC may stop working without this - check FIXME */
457 	npe_recv_message(port->npe, &msg, "FLUSH_IT");
458 }
459 
460 static void hss_set_hdlc_cfg(struct port *port)
461 {
462 	struct msg msg;
463 
464 	memset(&msg, 0, sizeof(msg));
465 	msg.cmd = PKT_PIPE_HDLC_CFG_WRITE;
466 	msg.hss_port = port->id;
467 	msg.data8a = port->hdlc_cfg; /* rx_cfg */
468 	msg.data8b = port->hdlc_cfg | (PKT_EXTRA_FLAGS << 3); /* tx_cfg */
469 	hss_npe_send(port, &msg, "HSS_SET_HDLC_CFG");
470 }
471 
472 static u32 hss_get_status(struct port *port)
473 {
474 	struct msg msg;
475 
476 	memset(&msg, 0, sizeof(msg));
477 	msg.cmd = PORT_ERROR_READ;
478 	msg.hss_port = port->id;
479 	hss_npe_send(port, &msg, "PORT_ERROR_READ");
480 	if (npe_recv_message(port->npe, &msg, "PORT_ERROR_READ")) {
481 		pr_crit("HSS-%i: unable to read HSS status\n", port->id);
482 		BUG();
483 	}
484 
485 	return msg.data32;
486 }
487 
488 static void hss_start_hdlc(struct port *port)
489 {
490 	struct msg msg;
491 
492 	memset(&msg, 0, sizeof(msg));
493 	msg.cmd = PKT_PIPE_FLOW_ENABLE;
494 	msg.hss_port = port->id;
495 	msg.data32 = 0;
496 	hss_npe_send(port, &msg, "HSS_ENABLE_PKT_PIPE");
497 }
498 
499 static void hss_stop_hdlc(struct port *port)
500 {
501 	struct msg msg;
502 
503 	memset(&msg, 0, sizeof(msg));
504 	msg.cmd = PKT_PIPE_FLOW_DISABLE;
505 	msg.hss_port = port->id;
506 	hss_npe_send(port, &msg, "HSS_DISABLE_PKT_PIPE");
507 	hss_get_status(port); /* make sure it's halted */
508 }
509 
510 static int hss_load_firmware(struct port *port)
511 {
512 	struct msg msg;
513 	int err;
514 
515 	if (port->initialized)
516 		return 0;
517 
518 	if (!npe_running(port->npe) &&
519 	    (err = npe_load_firmware(port->npe, npe_name(port->npe),
520 				     port->dev)))
521 		return err;
522 
523 	/* HDLC mode configuration */
524 	memset(&msg, 0, sizeof(msg));
525 	msg.cmd = PKT_NUM_PIPES_WRITE;
526 	msg.hss_port = port->id;
527 	msg.data8a = PKT_NUM_PIPES;
528 	hss_npe_send(port, &msg, "HSS_SET_PKT_PIPES");
529 
530 	msg.cmd = PKT_PIPE_FIFO_SIZEW_WRITE;
531 	msg.data8a = PKT_PIPE_FIFO_SIZEW;
532 	hss_npe_send(port, &msg, "HSS_SET_PKT_FIFO");
533 
534 	msg.cmd = PKT_PIPE_MODE_WRITE;
535 	msg.data8a = NPE_PKT_MODE_HDLC;
536 	/* msg.data8b = inv_mask */
537 	/* msg.data8c = or_mask */
538 	hss_npe_send(port, &msg, "HSS_SET_PKT_MODE");
539 
540 	msg.cmd = PKT_PIPE_RX_SIZE_WRITE;
541 	msg.data16a = HDLC_MAX_MRU; /* including CRC */
542 	hss_npe_send(port, &msg, "HSS_SET_PKT_RX_SIZE");
543 
544 	msg.cmd = PKT_PIPE_IDLE_PATTERN_WRITE;
545 	msg.data32 = 0x7F7F7F7F; /* ??? FIXME */
546 	hss_npe_send(port, &msg, "HSS_SET_PKT_IDLE");
547 
548 	port->initialized = 1;
549 	return 0;
550 }
551 
552 /*****************************************************************************
553  * packetized (HDLC) operation
554  ****************************************************************************/
555 
556 static inline void debug_pkt(struct net_device *dev, const char *func,
557 			     u8 *data, int len)
558 {
559 #if DEBUG_PKT_BYTES
560 	int i;
561 
562 	printk(KERN_DEBUG "%s: %s(%i)", dev->name, func, len);
563 	for (i = 0; i < len; i++) {
564 		if (i >= DEBUG_PKT_BYTES)
565 			break;
566 		printk("%s%02X", !(i % 4) ? " " : "", data[i]);
567 	}
568 	printk("\n");
569 #endif
570 }
571 
572 
573 static inline void debug_desc(u32 phys, struct desc *desc)
574 {
575 #if DEBUG_DESC
576 	printk(KERN_DEBUG "%X: %X %3X %3X %08X %X %X\n",
577 	       phys, desc->next, desc->buf_len, desc->pkt_len,
578 	       desc->data, desc->status, desc->error_count);
579 #endif
580 }
581 
582 static inline int queue_get_desc(unsigned int queue, struct port *port,
583 				 int is_tx)
584 {
585 	u32 phys, tab_phys, n_desc;
586 	struct desc *tab;
587 
588 	if (!(phys = qmgr_get_entry(queue)))
589 		return -1;
590 
591 	BUG_ON(phys & 0x1F);
592 	tab_phys = is_tx ? tx_desc_phys(port, 0) : rx_desc_phys(port, 0);
593 	tab = is_tx ? tx_desc_ptr(port, 0) : rx_desc_ptr(port, 0);
594 	n_desc = (phys - tab_phys) / sizeof(struct desc);
595 	BUG_ON(n_desc >= (is_tx ? TX_DESCS : RX_DESCS));
596 	debug_desc(phys, &tab[n_desc]);
597 	BUG_ON(tab[n_desc].next);
598 	return n_desc;
599 }
600 
601 static inline void queue_put_desc(unsigned int queue, u32 phys,
602 				  struct desc *desc)
603 {
604 	debug_desc(phys, desc);
605 	BUG_ON(phys & 0x1F);
606 	qmgr_put_entry(queue, phys);
607 	/* Don't check for queue overflow here, we've allocated sufficient
608 	   length and queues >= 32 don't support this check anyway. */
609 }
610 
611 
612 static inline void dma_unmap_tx(struct port *port, struct desc *desc)
613 {
614 #ifdef __ARMEB__
615 	dma_unmap_single(&port->netdev->dev, desc->data,
616 			 desc->buf_len, DMA_TO_DEVICE);
617 #else
618 	dma_unmap_single(&port->netdev->dev, desc->data & ~3,
619 			 ALIGN((desc->data & 3) + desc->buf_len, 4),
620 			 DMA_TO_DEVICE);
621 #endif
622 }
623 
624 
625 static void hss_hdlc_set_carrier(void *pdev, int carrier)
626 {
627 	struct net_device *netdev = pdev;
628 	struct port *port = dev_to_port(netdev);
629 	unsigned long flags;
630 
631 	spin_lock_irqsave(&npe_lock, flags);
632 	port->carrier = carrier;
633 	if (!port->loopback) {
634 		if (carrier)
635 			netif_carrier_on(netdev);
636 		else
637 			netif_carrier_off(netdev);
638 	}
639 	spin_unlock_irqrestore(&npe_lock, flags);
640 }
641 
642 static void hss_hdlc_rx_irq(void *pdev)
643 {
644 	struct net_device *dev = pdev;
645 	struct port *port = dev_to_port(dev);
646 
647 #if DEBUG_RX
648 	printk(KERN_DEBUG "%s: hss_hdlc_rx_irq\n", dev->name);
649 #endif
650 	qmgr_disable_irq(queue_ids[port->id].rx);
651 	napi_schedule(&port->napi);
652 }
653 
654 static int hss_hdlc_poll(struct napi_struct *napi, int budget)
655 {
656 	struct port *port = container_of(napi, struct port, napi);
657 	struct net_device *dev = port->netdev;
658 	unsigned int rxq = queue_ids[port->id].rx;
659 	unsigned int rxfreeq = queue_ids[port->id].rxfree;
660 	int received = 0;
661 
662 #if DEBUG_RX
663 	printk(KERN_DEBUG "%s: hss_hdlc_poll\n", dev->name);
664 #endif
665 
666 	while (received < budget) {
667 		struct sk_buff *skb;
668 		struct desc *desc;
669 		int n;
670 #ifdef __ARMEB__
671 		struct sk_buff *temp;
672 		u32 phys;
673 #endif
674 
675 		if ((n = queue_get_desc(rxq, port, 0)) < 0) {
676 #if DEBUG_RX
677 			printk(KERN_DEBUG "%s: hss_hdlc_poll"
678 			       " napi_complete\n", dev->name);
679 #endif
680 			napi_complete(napi);
681 			qmgr_enable_irq(rxq);
682 			if (!qmgr_stat_empty(rxq) &&
683 			    napi_reschedule(napi)) {
684 #if DEBUG_RX
685 				printk(KERN_DEBUG "%s: hss_hdlc_poll"
686 				       " napi_reschedule succeeded\n",
687 				       dev->name);
688 #endif
689 				qmgr_disable_irq(rxq);
690 				continue;
691 			}
692 #if DEBUG_RX
693 			printk(KERN_DEBUG "%s: hss_hdlc_poll all done\n",
694 			       dev->name);
695 #endif
696 			return received; /* all work done */
697 		}
698 
699 		desc = rx_desc_ptr(port, n);
700 #if 0 /* FIXME - error_count counts modulo 256, perhaps we should use it */
701 		if (desc->error_count)
702 			printk(KERN_DEBUG "%s: hss_hdlc_poll status 0x%02X"
703 			       " errors %u\n", dev->name, desc->status,
704 			       desc->error_count);
705 #endif
706 		skb = NULL;
707 		switch (desc->status) {
708 		case 0:
709 #ifdef __ARMEB__
710 			if ((skb = netdev_alloc_skb(dev, RX_SIZE)) != NULL) {
711 				phys = dma_map_single(&dev->dev, skb->data,
712 						      RX_SIZE,
713 						      DMA_FROM_DEVICE);
714 				if (dma_mapping_error(&dev->dev, phys)) {
715 					dev_kfree_skb(skb);
716 					skb = NULL;
717 				}
718 			}
719 #else
720 			skb = netdev_alloc_skb(dev, desc->pkt_len);
721 #endif
722 			if (!skb)
723 				dev->stats.rx_dropped++;
724 			break;
725 		case ERR_HDLC_ALIGN:
726 		case ERR_HDLC_ABORT:
727 			dev->stats.rx_frame_errors++;
728 			dev->stats.rx_errors++;
729 			break;
730 		case ERR_HDLC_FCS:
731 			dev->stats.rx_crc_errors++;
732 			dev->stats.rx_errors++;
733 			break;
734 		case ERR_HDLC_TOO_LONG:
735 			dev->stats.rx_length_errors++;
736 			dev->stats.rx_errors++;
737 			break;
738 		default:	/* FIXME - remove printk */
739 			netdev_err(dev, "hss_hdlc_poll: status 0x%02X errors %u\n",
740 				   desc->status, desc->error_count);
741 			dev->stats.rx_errors++;
742 		}
743 
744 		if (!skb) {
745 			/* put the desc back on RX-ready queue */
746 			desc->buf_len = RX_SIZE;
747 			desc->pkt_len = desc->status = 0;
748 			queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
749 			continue;
750 		}
751 
752 		/* process received frame */
753 #ifdef __ARMEB__
754 		temp = skb;
755 		skb = port->rx_buff_tab[n];
756 		dma_unmap_single(&dev->dev, desc->data,
757 				 RX_SIZE, DMA_FROM_DEVICE);
758 #else
759 		dma_sync_single_for_cpu(&dev->dev, desc->data,
760 					RX_SIZE, DMA_FROM_DEVICE);
761 		memcpy_swab32((u32 *)skb->data, (u32 *)port->rx_buff_tab[n],
762 			      ALIGN(desc->pkt_len, 4) / 4);
763 #endif
764 		skb_put(skb, desc->pkt_len);
765 
766 		debug_pkt(dev, "hss_hdlc_poll", skb->data, skb->len);
767 
768 		skb->protocol = hdlc_type_trans(skb, dev);
769 		dev->stats.rx_packets++;
770 		dev->stats.rx_bytes += skb->len;
771 		netif_receive_skb(skb);
772 
773 		/* put the new buffer on RX-free queue */
774 #ifdef __ARMEB__
775 		port->rx_buff_tab[n] = temp;
776 		desc->data = phys;
777 #endif
778 		desc->buf_len = RX_SIZE;
779 		desc->pkt_len = 0;
780 		queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
781 		received++;
782 	}
783 #if DEBUG_RX
784 	printk(KERN_DEBUG "hss_hdlc_poll: end, not all work done\n");
785 #endif
786 	return received;	/* not all work done */
787 }
788 
789 
790 static void hss_hdlc_txdone_irq(void *pdev)
791 {
792 	struct net_device *dev = pdev;
793 	struct port *port = dev_to_port(dev);
794 	int n_desc;
795 
796 #if DEBUG_TX
797 	printk(KERN_DEBUG DRV_NAME ": hss_hdlc_txdone_irq\n");
798 #endif
799 	while ((n_desc = queue_get_desc(queue_ids[port->id].txdone,
800 					port, 1)) >= 0) {
801 		struct desc *desc;
802 		int start;
803 
804 		desc = tx_desc_ptr(port, n_desc);
805 
806 		dev->stats.tx_packets++;
807 		dev->stats.tx_bytes += desc->pkt_len;
808 
809 		dma_unmap_tx(port, desc);
810 #if DEBUG_TX
811 		printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq free %p\n",
812 		       dev->name, port->tx_buff_tab[n_desc]);
813 #endif
814 		free_buffer_irq(port->tx_buff_tab[n_desc]);
815 		port->tx_buff_tab[n_desc] = NULL;
816 
817 		start = qmgr_stat_below_low_watermark(port->plat->txreadyq);
818 		queue_put_desc(port->plat->txreadyq,
819 			       tx_desc_phys(port, n_desc), desc);
820 		if (start) { /* TX-ready queue was empty */
821 #if DEBUG_TX
822 			printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq xmit"
823 			       " ready\n", dev->name);
824 #endif
825 			netif_wake_queue(dev);
826 		}
827 	}
828 }
829 
830 static int hss_hdlc_xmit(struct sk_buff *skb, struct net_device *dev)
831 {
832 	struct port *port = dev_to_port(dev);
833 	unsigned int txreadyq = port->plat->txreadyq;
834 	int len, offset, bytes, n;
835 	void *mem;
836 	u32 phys;
837 	struct desc *desc;
838 
839 #if DEBUG_TX
840 	printk(KERN_DEBUG "%s: hss_hdlc_xmit\n", dev->name);
841 #endif
842 
843 	if (unlikely(skb->len > HDLC_MAX_MRU)) {
844 		dev_kfree_skb(skb);
845 		dev->stats.tx_errors++;
846 		return NETDEV_TX_OK;
847 	}
848 
849 	debug_pkt(dev, "hss_hdlc_xmit", skb->data, skb->len);
850 
851 	len = skb->len;
852 #ifdef __ARMEB__
853 	offset = 0; /* no need to keep alignment */
854 	bytes = len;
855 	mem = skb->data;
856 #else
857 	offset = (int)skb->data & 3; /* keep 32-bit alignment */
858 	bytes = ALIGN(offset + len, 4);
859 	if (!(mem = kmalloc(bytes, GFP_ATOMIC))) {
860 		dev_kfree_skb(skb);
861 		dev->stats.tx_dropped++;
862 		return NETDEV_TX_OK;
863 	}
864 	memcpy_swab32(mem, (u32 *)((int)skb->data & ~3), bytes / 4);
865 	dev_kfree_skb(skb);
866 #endif
867 
868 	phys = dma_map_single(&dev->dev, mem, bytes, DMA_TO_DEVICE);
869 	if (dma_mapping_error(&dev->dev, phys)) {
870 #ifdef __ARMEB__
871 		dev_kfree_skb(skb);
872 #else
873 		kfree(mem);
874 #endif
875 		dev->stats.tx_dropped++;
876 		return NETDEV_TX_OK;
877 	}
878 
879 	n = queue_get_desc(txreadyq, port, 1);
880 	BUG_ON(n < 0);
881 	desc = tx_desc_ptr(port, n);
882 
883 #ifdef __ARMEB__
884 	port->tx_buff_tab[n] = skb;
885 #else
886 	port->tx_buff_tab[n] = mem;
887 #endif
888 	desc->data = phys + offset;
889 	desc->buf_len = desc->pkt_len = len;
890 
891 	wmb();
892 	queue_put_desc(queue_ids[port->id].tx, tx_desc_phys(port, n), desc);
893 
894 	if (qmgr_stat_below_low_watermark(txreadyq)) { /* empty */
895 #if DEBUG_TX
896 		printk(KERN_DEBUG "%s: hss_hdlc_xmit queue full\n", dev->name);
897 #endif
898 		netif_stop_queue(dev);
899 		/* we could miss TX ready interrupt */
900 		if (!qmgr_stat_below_low_watermark(txreadyq)) {
901 #if DEBUG_TX
902 			printk(KERN_DEBUG "%s: hss_hdlc_xmit ready again\n",
903 			       dev->name);
904 #endif
905 			netif_wake_queue(dev);
906 		}
907 	}
908 
909 #if DEBUG_TX
910 	printk(KERN_DEBUG "%s: hss_hdlc_xmit end\n", dev->name);
911 #endif
912 	return NETDEV_TX_OK;
913 }
914 
915 
916 static int request_hdlc_queues(struct port *port)
917 {
918 	int err;
919 
920 	err = qmgr_request_queue(queue_ids[port->id].rxfree, RX_DESCS, 0, 0,
921 				 "%s:RX-free", port->netdev->name);
922 	if (err)
923 		return err;
924 
925 	err = qmgr_request_queue(queue_ids[port->id].rx, RX_DESCS, 0, 0,
926 				 "%s:RX", port->netdev->name);
927 	if (err)
928 		goto rel_rxfree;
929 
930 	err = qmgr_request_queue(queue_ids[port->id].tx, TX_DESCS, 0, 0,
931 				 "%s:TX", port->netdev->name);
932 	if (err)
933 		goto rel_rx;
934 
935 	err = qmgr_request_queue(port->plat->txreadyq, TX_DESCS, 0, 0,
936 				 "%s:TX-ready", port->netdev->name);
937 	if (err)
938 		goto rel_tx;
939 
940 	err = qmgr_request_queue(queue_ids[port->id].txdone, TX_DESCS, 0, 0,
941 				 "%s:TX-done", port->netdev->name);
942 	if (err)
943 		goto rel_txready;
944 	return 0;
945 
946 rel_txready:
947 	qmgr_release_queue(port->plat->txreadyq);
948 rel_tx:
949 	qmgr_release_queue(queue_ids[port->id].tx);
950 rel_rx:
951 	qmgr_release_queue(queue_ids[port->id].rx);
952 rel_rxfree:
953 	qmgr_release_queue(queue_ids[port->id].rxfree);
954 	printk(KERN_DEBUG "%s: unable to request hardware queues\n",
955 	       port->netdev->name);
956 	return err;
957 }
958 
959 static void release_hdlc_queues(struct port *port)
960 {
961 	qmgr_release_queue(queue_ids[port->id].rxfree);
962 	qmgr_release_queue(queue_ids[port->id].rx);
963 	qmgr_release_queue(queue_ids[port->id].txdone);
964 	qmgr_release_queue(queue_ids[port->id].tx);
965 	qmgr_release_queue(port->plat->txreadyq);
966 }
967 
968 static int init_hdlc_queues(struct port *port)
969 {
970 	int i;
971 
972 	if (!ports_open) {
973 		dma_pool = dma_pool_create(DRV_NAME, &port->netdev->dev,
974 					   POOL_ALLOC_SIZE, 32, 0);
975 		if (!dma_pool)
976 			return -ENOMEM;
977 	}
978 
979 	if (!(port->desc_tab = dma_pool_alloc(dma_pool, GFP_KERNEL,
980 					      &port->desc_tab_phys)))
981 		return -ENOMEM;
982 	memset(port->desc_tab, 0, POOL_ALLOC_SIZE);
983 	memset(port->rx_buff_tab, 0, sizeof(port->rx_buff_tab)); /* tables */
984 	memset(port->tx_buff_tab, 0, sizeof(port->tx_buff_tab));
985 
986 	/* Setup RX buffers */
987 	for (i = 0; i < RX_DESCS; i++) {
988 		struct desc *desc = rx_desc_ptr(port, i);
989 		buffer_t *buff;
990 		void *data;
991 #ifdef __ARMEB__
992 		if (!(buff = netdev_alloc_skb(port->netdev, RX_SIZE)))
993 			return -ENOMEM;
994 		data = buff->data;
995 #else
996 		if (!(buff = kmalloc(RX_SIZE, GFP_KERNEL)))
997 			return -ENOMEM;
998 		data = buff;
999 #endif
1000 		desc->buf_len = RX_SIZE;
1001 		desc->data = dma_map_single(&port->netdev->dev, data,
1002 					    RX_SIZE, DMA_FROM_DEVICE);
1003 		if (dma_mapping_error(&port->netdev->dev, desc->data)) {
1004 			free_buffer(buff);
1005 			return -EIO;
1006 		}
1007 		port->rx_buff_tab[i] = buff;
1008 	}
1009 
1010 	return 0;
1011 }
1012 
1013 static void destroy_hdlc_queues(struct port *port)
1014 {
1015 	int i;
1016 
1017 	if (port->desc_tab) {
1018 		for (i = 0; i < RX_DESCS; i++) {
1019 			struct desc *desc = rx_desc_ptr(port, i);
1020 			buffer_t *buff = port->rx_buff_tab[i];
1021 			if (buff) {
1022 				dma_unmap_single(&port->netdev->dev,
1023 						 desc->data, RX_SIZE,
1024 						 DMA_FROM_DEVICE);
1025 				free_buffer(buff);
1026 			}
1027 		}
1028 		for (i = 0; i < TX_DESCS; i++) {
1029 			struct desc *desc = tx_desc_ptr(port, i);
1030 			buffer_t *buff = port->tx_buff_tab[i];
1031 			if (buff) {
1032 				dma_unmap_tx(port, desc);
1033 				free_buffer(buff);
1034 			}
1035 		}
1036 		dma_pool_free(dma_pool, port->desc_tab, port->desc_tab_phys);
1037 		port->desc_tab = NULL;
1038 	}
1039 
1040 	if (!ports_open && dma_pool) {
1041 		dma_pool_destroy(dma_pool);
1042 		dma_pool = NULL;
1043 	}
1044 }
1045 
1046 static int hss_hdlc_open(struct net_device *dev)
1047 {
1048 	struct port *port = dev_to_port(dev);
1049 	unsigned long flags;
1050 	int i, err = 0;
1051 
1052 	if ((err = hdlc_open(dev)))
1053 		return err;
1054 
1055 	if ((err = hss_load_firmware(port)))
1056 		goto err_hdlc_close;
1057 
1058 	if ((err = request_hdlc_queues(port)))
1059 		goto err_hdlc_close;
1060 
1061 	if ((err = init_hdlc_queues(port)))
1062 		goto err_destroy_queues;
1063 
1064 	spin_lock_irqsave(&npe_lock, flags);
1065 	if (port->plat->open)
1066 		if ((err = port->plat->open(port->id, dev,
1067 					    hss_hdlc_set_carrier)))
1068 			goto err_unlock;
1069 	spin_unlock_irqrestore(&npe_lock, flags);
1070 
1071 	/* Populate queues with buffers, no failure after this point */
1072 	for (i = 0; i < TX_DESCS; i++)
1073 		queue_put_desc(port->plat->txreadyq,
1074 			       tx_desc_phys(port, i), tx_desc_ptr(port, i));
1075 
1076 	for (i = 0; i < RX_DESCS; i++)
1077 		queue_put_desc(queue_ids[port->id].rxfree,
1078 			       rx_desc_phys(port, i), rx_desc_ptr(port, i));
1079 
1080 	napi_enable(&port->napi);
1081 	netif_start_queue(dev);
1082 
1083 	qmgr_set_irq(queue_ids[port->id].rx, QUEUE_IRQ_SRC_NOT_EMPTY,
1084 		     hss_hdlc_rx_irq, dev);
1085 
1086 	qmgr_set_irq(queue_ids[port->id].txdone, QUEUE_IRQ_SRC_NOT_EMPTY,
1087 		     hss_hdlc_txdone_irq, dev);
1088 	qmgr_enable_irq(queue_ids[port->id].txdone);
1089 
1090 	ports_open++;
1091 
1092 	hss_set_hdlc_cfg(port);
1093 	hss_config(port);
1094 
1095 	hss_start_hdlc(port);
1096 
1097 	/* we may already have RX data, enables IRQ */
1098 	napi_schedule(&port->napi);
1099 	return 0;
1100 
1101 err_unlock:
1102 	spin_unlock_irqrestore(&npe_lock, flags);
1103 err_destroy_queues:
1104 	destroy_hdlc_queues(port);
1105 	release_hdlc_queues(port);
1106 err_hdlc_close:
1107 	hdlc_close(dev);
1108 	return err;
1109 }
1110 
1111 static int hss_hdlc_close(struct net_device *dev)
1112 {
1113 	struct port *port = dev_to_port(dev);
1114 	unsigned long flags;
1115 	int i, buffs = RX_DESCS; /* allocated RX buffers */
1116 
1117 	spin_lock_irqsave(&npe_lock, flags);
1118 	ports_open--;
1119 	qmgr_disable_irq(queue_ids[port->id].rx);
1120 	netif_stop_queue(dev);
1121 	napi_disable(&port->napi);
1122 
1123 	hss_stop_hdlc(port);
1124 
1125 	while (queue_get_desc(queue_ids[port->id].rxfree, port, 0) >= 0)
1126 		buffs--;
1127 	while (queue_get_desc(queue_ids[port->id].rx, port, 0) >= 0)
1128 		buffs--;
1129 
1130 	if (buffs)
1131 		netdev_crit(dev, "unable to drain RX queue, %i buffer(s) left in NPE\n",
1132 			    buffs);
1133 
1134 	buffs = TX_DESCS;
1135 	while (queue_get_desc(queue_ids[port->id].tx, port, 1) >= 0)
1136 		buffs--; /* cancel TX */
1137 
1138 	i = 0;
1139 	do {
1140 		while (queue_get_desc(port->plat->txreadyq, port, 1) >= 0)
1141 			buffs--;
1142 		if (!buffs)
1143 			break;
1144 	} while (++i < MAX_CLOSE_WAIT);
1145 
1146 	if (buffs)
1147 		netdev_crit(dev, "unable to drain TX queue, %i buffer(s) left in NPE\n",
1148 			    buffs);
1149 #if DEBUG_CLOSE
1150 	if (!buffs)
1151 		printk(KERN_DEBUG "Draining TX queues took %i cycles\n", i);
1152 #endif
1153 	qmgr_disable_irq(queue_ids[port->id].txdone);
1154 
1155 	if (port->plat->close)
1156 		port->plat->close(port->id, dev);
1157 	spin_unlock_irqrestore(&npe_lock, flags);
1158 
1159 	destroy_hdlc_queues(port);
1160 	release_hdlc_queues(port);
1161 	hdlc_close(dev);
1162 	return 0;
1163 }
1164 
1165 
1166 static int hss_hdlc_attach(struct net_device *dev, unsigned short encoding,
1167 			   unsigned short parity)
1168 {
1169 	struct port *port = dev_to_port(dev);
1170 
1171 	if (encoding != ENCODING_NRZ)
1172 		return -EINVAL;
1173 
1174 	switch(parity) {
1175 	case PARITY_CRC16_PR1_CCITT:
1176 		port->hdlc_cfg = 0;
1177 		return 0;
1178 
1179 	case PARITY_CRC32_PR1_CCITT:
1180 		port->hdlc_cfg = PKT_HDLC_CRC_32;
1181 		return 0;
1182 
1183 	default:
1184 		return -EINVAL;
1185 	}
1186 }
1187 
1188 static u32 check_clock(u32 rate, u32 a, u32 b, u32 c,
1189 		       u32 *best, u32 *best_diff, u32 *reg)
1190 {
1191 	/* a is 10-bit, b is 10-bit, c is 12-bit */
1192 	u64 new_rate;
1193 	u32 new_diff;
1194 
1195 	new_rate = ixp4xx_timer_freq * (u64)(c + 1);
1196 	do_div(new_rate, a * (c + 1) + b + 1);
1197 	new_diff = abs((u32)new_rate - rate);
1198 
1199 	if (new_diff < *best_diff) {
1200 		*best = new_rate;
1201 		*best_diff = new_diff;
1202 		*reg = (a << 22) | (b << 12) | c;
1203 	}
1204 	return new_diff;
1205 }
1206 
1207 static void find_best_clock(u32 rate, u32 *best, u32 *reg)
1208 {
1209 	u32 a, b, diff = 0xFFFFFFFF;
1210 
1211 	a = ixp4xx_timer_freq / rate;
1212 
1213 	if (a > 0x3FF) { /* 10-bit value - we can go as slow as ca. 65 kb/s */
1214 		check_clock(rate, 0x3FF, 1, 1, best, &diff, reg);
1215 		return;
1216 	}
1217 	if (a == 0) { /* > 66.666 MHz */
1218 		a = 1; /* minimum divider is 1 (a = 0, b = 1, c = 1) */
1219 		rate = ixp4xx_timer_freq;
1220 	}
1221 
1222 	if (rate * a == ixp4xx_timer_freq) { /* don't divide by 0 later */
1223 		check_clock(rate, a - 1, 1, 1, best, &diff, reg);
1224 		return;
1225 	}
1226 
1227 	for (b = 0; b < 0x400; b++) {
1228 		u64 c = (b + 1) * (u64)rate;
1229 		do_div(c, ixp4xx_timer_freq - rate * a);
1230 		c--;
1231 		if (c >= 0xFFF) { /* 12-bit - no need to check more 'b's */
1232 			if (b == 0 && /* also try a bit higher rate */
1233 			    !check_clock(rate, a - 1, 1, 1, best, &diff, reg))
1234 				return;
1235 			check_clock(rate, a, b, 0xFFF, best, &diff, reg);
1236 			return;
1237 		}
1238 		if (!check_clock(rate, a, b, c, best, &diff, reg))
1239 			return;
1240 		if (!check_clock(rate, a, b, c + 1, best, &diff, reg))
1241 			return;
1242 	}
1243 }
1244 
1245 static int hss_hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1246 {
1247 	const size_t size = sizeof(sync_serial_settings);
1248 	sync_serial_settings new_line;
1249 	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
1250 	struct port *port = dev_to_port(dev);
1251 	unsigned long flags;
1252 	int clk;
1253 
1254 	if (cmd != SIOCWANDEV)
1255 		return hdlc_ioctl(dev, ifr, cmd);
1256 
1257 	switch(ifr->ifr_settings.type) {
1258 	case IF_GET_IFACE:
1259 		ifr->ifr_settings.type = IF_IFACE_V35;
1260 		if (ifr->ifr_settings.size < size) {
1261 			ifr->ifr_settings.size = size; /* data size wanted */
1262 			return -ENOBUFS;
1263 		}
1264 		memset(&new_line, 0, sizeof(new_line));
1265 		new_line.clock_type = port->clock_type;
1266 		new_line.clock_rate = port->clock_rate;
1267 		new_line.loopback = port->loopback;
1268 		if (copy_to_user(line, &new_line, size))
1269 			return -EFAULT;
1270 		return 0;
1271 
1272 	case IF_IFACE_SYNC_SERIAL:
1273 	case IF_IFACE_V35:
1274 		if(!capable(CAP_NET_ADMIN))
1275 			return -EPERM;
1276 		if (copy_from_user(&new_line, line, size))
1277 			return -EFAULT;
1278 
1279 		clk = new_line.clock_type;
1280 		if (port->plat->set_clock)
1281 			clk = port->plat->set_clock(port->id, clk);
1282 
1283 		if (clk != CLOCK_EXT && clk != CLOCK_INT)
1284 			return -EINVAL;	/* No such clock setting */
1285 
1286 		if (new_line.loopback != 0 && new_line.loopback != 1)
1287 			return -EINVAL;
1288 
1289 		port->clock_type = clk; /* Update settings */
1290 		if (clk == CLOCK_INT)
1291 			find_best_clock(new_line.clock_rate, &port->clock_rate,
1292 					&port->clock_reg);
1293 		else {
1294 			port->clock_rate = 0;
1295 			port->clock_reg = CLK42X_SPEED_2048KHZ;
1296 		}
1297 		port->loopback = new_line.loopback;
1298 
1299 		spin_lock_irqsave(&npe_lock, flags);
1300 
1301 		if (dev->flags & IFF_UP)
1302 			hss_config(port);
1303 
1304 		if (port->loopback || port->carrier)
1305 			netif_carrier_on(port->netdev);
1306 		else
1307 			netif_carrier_off(port->netdev);
1308 		spin_unlock_irqrestore(&npe_lock, flags);
1309 
1310 		return 0;
1311 
1312 	default:
1313 		return hdlc_ioctl(dev, ifr, cmd);
1314 	}
1315 }
1316 
1317 /*****************************************************************************
1318  * initialization
1319  ****************************************************************************/
1320 
1321 static const struct net_device_ops hss_hdlc_ops = {
1322 	.ndo_open       = hss_hdlc_open,
1323 	.ndo_stop       = hss_hdlc_close,
1324 	.ndo_start_xmit = hdlc_start_xmit,
1325 	.ndo_do_ioctl   = hss_hdlc_ioctl,
1326 };
1327 
1328 static int hss_init_one(struct platform_device *pdev)
1329 {
1330 	struct port *port;
1331 	struct net_device *dev;
1332 	hdlc_device *hdlc;
1333 	int err;
1334 
1335 	if ((port = kzalloc(sizeof(*port), GFP_KERNEL)) == NULL)
1336 		return -ENOMEM;
1337 
1338 	if ((port->npe = npe_request(0)) == NULL) {
1339 		err = -ENODEV;
1340 		goto err_free;
1341 	}
1342 
1343 	if ((port->netdev = dev = alloc_hdlcdev(port)) == NULL) {
1344 		err = -ENOMEM;
1345 		goto err_plat;
1346 	}
1347 
1348 	SET_NETDEV_DEV(dev, &pdev->dev);
1349 	hdlc = dev_to_hdlc(dev);
1350 	hdlc->attach = hss_hdlc_attach;
1351 	hdlc->xmit = hss_hdlc_xmit;
1352 	dev->netdev_ops = &hss_hdlc_ops;
1353 	dev->tx_queue_len = 100;
1354 	port->clock_type = CLOCK_EXT;
1355 	port->clock_rate = 0;
1356 	port->clock_reg = CLK42X_SPEED_2048KHZ;
1357 	port->id = pdev->id;
1358 	port->dev = &pdev->dev;
1359 	port->plat = pdev->dev.platform_data;
1360 	netif_napi_add(dev, &port->napi, hss_hdlc_poll, NAPI_WEIGHT);
1361 
1362 	if ((err = register_hdlc_device(dev)))
1363 		goto err_free_netdev;
1364 
1365 	platform_set_drvdata(pdev, port);
1366 
1367 	netdev_info(dev, "initialized\n");
1368 	return 0;
1369 
1370 err_free_netdev:
1371 	free_netdev(dev);
1372 err_plat:
1373 	npe_release(port->npe);
1374 err_free:
1375 	kfree(port);
1376 	return err;
1377 }
1378 
1379 static int hss_remove_one(struct platform_device *pdev)
1380 {
1381 	struct port *port = platform_get_drvdata(pdev);
1382 
1383 	unregister_hdlc_device(port->netdev);
1384 	free_netdev(port->netdev);
1385 	npe_release(port->npe);
1386 	kfree(port);
1387 	return 0;
1388 }
1389 
1390 static struct platform_driver ixp4xx_hss_driver = {
1391 	.driver.name	= DRV_NAME,
1392 	.probe		= hss_init_one,
1393 	.remove		= hss_remove_one,
1394 };
1395 
1396 static int __init hss_init_module(void)
1397 {
1398 	if ((ixp4xx_read_feature_bits() &
1399 	     (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) !=
1400 	    (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS))
1401 		return -ENODEV;
1402 
1403 	spin_lock_init(&npe_lock);
1404 
1405 	return platform_driver_register(&ixp4xx_hss_driver);
1406 }
1407 
1408 static void __exit hss_cleanup_module(void)
1409 {
1410 	platform_driver_unregister(&ixp4xx_hss_driver);
1411 }
1412 
1413 MODULE_AUTHOR("Krzysztof Halasa");
1414 MODULE_DESCRIPTION("Intel IXP4xx HSS driver");
1415 MODULE_LICENSE("GPL v2");
1416 MODULE_ALIAS("platform:ixp4xx_hss");
1417 module_init(hss_init_module);
1418 module_exit(hss_cleanup_module);
1419