Loading...
1/*
2 * Driver for the i2c controller on the Marvell line of host bridges
3 * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, and Orion SoC family).
4 *
5 * Author: Mark A. Greer <mgreer@mvista.com>
6 *
7 * 2005 (c) MontaVista, Software, Inc. This file is licensed under
8 * the terms of the GNU General Public License version 2. This program
9 * is licensed "as is" without any warranty of any kind, whether express
10 * or implied.
11 */
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/module.h>
15#include <linux/spinlock.h>
16#include <linux/i2c.h>
17#include <linux/interrupt.h>
18#include <linux/mv643xx_i2c.h>
19#include <linux/platform_device.h>
20#include <linux/pinctrl/consumer.h>
21#include <linux/pm_runtime.h>
22#include <linux/reset.h>
23#include <linux/io.h>
24#include <linux/of.h>
25#include <linux/of_device.h>
26#include <linux/of_irq.h>
27#include <linux/clk.h>
28#include <linux/err.h>
29#include <linux/delay.h>
30
31#define MV64XXX_I2C_ADDR_ADDR(val) ((val & 0x7f) << 1)
32#define MV64XXX_I2C_BAUD_DIV_N(val) (val & 0x7)
33#define MV64XXX_I2C_BAUD_DIV_M(val) ((val & 0xf) << 3)
34
35#define MV64XXX_I2C_REG_CONTROL_ACK BIT(2)
36#define MV64XXX_I2C_REG_CONTROL_IFLG BIT(3)
37#define MV64XXX_I2C_REG_CONTROL_STOP BIT(4)
38#define MV64XXX_I2C_REG_CONTROL_START BIT(5)
39#define MV64XXX_I2C_REG_CONTROL_TWSIEN BIT(6)
40#define MV64XXX_I2C_REG_CONTROL_INTEN BIT(7)
41
42/* Ctlr status values */
43#define MV64XXX_I2C_STATUS_BUS_ERR 0x00
44#define MV64XXX_I2C_STATUS_MAST_START 0x08
45#define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10
46#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18
47#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20
48#define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28
49#define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30
50#define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38
51#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40
52#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48
53#define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50
54#define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58
55#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0
56#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8
57#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0
58#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8
59#define MV64XXX_I2C_STATUS_NO_STATUS 0xf8
60
61/* Register defines (I2C bridge) */
62#define MV64XXX_I2C_REG_TX_DATA_LO 0xc0
63#define MV64XXX_I2C_REG_TX_DATA_HI 0xc4
64#define MV64XXX_I2C_REG_RX_DATA_LO 0xc8
65#define MV64XXX_I2C_REG_RX_DATA_HI 0xcc
66#define MV64XXX_I2C_REG_BRIDGE_CONTROL 0xd0
67#define MV64XXX_I2C_REG_BRIDGE_STATUS 0xd4
68#define MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE 0xd8
69#define MV64XXX_I2C_REG_BRIDGE_INTR_MASK 0xdC
70#define MV64XXX_I2C_REG_BRIDGE_TIMING 0xe0
71
72/* Bridge Control values */
73#define MV64XXX_I2C_BRIDGE_CONTROL_WR BIT(0)
74#define MV64XXX_I2C_BRIDGE_CONTROL_RD BIT(1)
75#define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT 2
76#define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT BIT(12)
77#define MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT 13
78#define MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT 16
79#define MV64XXX_I2C_BRIDGE_CONTROL_ENABLE BIT(19)
80#define MV64XXX_I2C_BRIDGE_CONTROL_REPEATED_START BIT(20)
81
82/* Bridge Status values */
83#define MV64XXX_I2C_BRIDGE_STATUS_ERROR BIT(0)
84
85/* Driver states */
86enum {
87 MV64XXX_I2C_STATE_INVALID,
88 MV64XXX_I2C_STATE_IDLE,
89 MV64XXX_I2C_STATE_WAITING_FOR_START_COND,
90 MV64XXX_I2C_STATE_WAITING_FOR_RESTART,
91 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
92 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
93 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK,
94 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA,
95};
96
97/* Driver actions */
98enum {
99 MV64XXX_I2C_ACTION_INVALID,
100 MV64XXX_I2C_ACTION_CONTINUE,
101 MV64XXX_I2C_ACTION_SEND_RESTART,
102 MV64XXX_I2C_ACTION_SEND_ADDR_1,
103 MV64XXX_I2C_ACTION_SEND_ADDR_2,
104 MV64XXX_I2C_ACTION_SEND_DATA,
105 MV64XXX_I2C_ACTION_RCV_DATA,
106 MV64XXX_I2C_ACTION_RCV_DATA_STOP,
107 MV64XXX_I2C_ACTION_SEND_STOP,
108};
109
110struct mv64xxx_i2c_regs {
111 u8 addr;
112 u8 ext_addr;
113 u8 data;
114 u8 control;
115 u8 status;
116 u8 clock;
117 u8 soft_reset;
118};
119
120struct mv64xxx_i2c_data {
121 struct i2c_msg *msgs;
122 int num_msgs;
123 int irq;
124 u32 state;
125 u32 action;
126 u32 aborting;
127 u32 cntl_bits;
128 void __iomem *reg_base;
129 struct mv64xxx_i2c_regs reg_offsets;
130 u32 addr1;
131 u32 addr2;
132 u32 bytes_left;
133 u32 byte_posn;
134 u32 send_stop;
135 u32 block;
136 int rc;
137 u32 freq_m;
138 u32 freq_n;
139 struct clk *clk;
140 struct clk *reg_clk;
141 wait_queue_head_t waitq;
142 spinlock_t lock;
143 struct i2c_msg *msg;
144 struct i2c_adapter adapter;
145 bool offload_enabled;
146/* 5us delay in order to avoid repeated start timing violation */
147 bool errata_delay;
148 struct reset_control *rstc;
149 bool irq_clear_inverted;
150 /* Clk div is 2 to the power n, not 2 to the power n + 1 */
151 bool clk_n_base_0;
152 struct i2c_bus_recovery_info rinfo;
153 bool atomic;
154};
155
156static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = {
157 .addr = 0x00,
158 .ext_addr = 0x10,
159 .data = 0x04,
160 .control = 0x08,
161 .status = 0x0c,
162 .clock = 0x0c,
163 .soft_reset = 0x1c,
164};
165
166static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_sun4i = {
167 .addr = 0x00,
168 .ext_addr = 0x04,
169 .data = 0x08,
170 .control = 0x0c,
171 .status = 0x10,
172 .clock = 0x14,
173 .soft_reset = 0x18,
174};
175
176static void
177mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data,
178 struct i2c_msg *msg)
179{
180 u32 dir = 0;
181
182 drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK |
183 MV64XXX_I2C_REG_CONTROL_TWSIEN;
184
185 if (!drv_data->atomic)
186 drv_data->cntl_bits |= MV64XXX_I2C_REG_CONTROL_INTEN;
187
188 if (msg->flags & I2C_M_RD)
189 dir = 1;
190
191 if (msg->flags & I2C_M_TEN) {
192 drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
193 drv_data->addr2 = (u32)msg->addr & 0xff;
194 } else {
195 drv_data->addr1 = MV64XXX_I2C_ADDR_ADDR((u32)msg->addr) | dir;
196 drv_data->addr2 = 0;
197 }
198}
199
200/*
201 *****************************************************************************
202 *
203 * Finite State Machine & Interrupt Routines
204 *
205 *****************************************************************************
206 */
207
208/* Reset hardware and initialize FSM */
209static void
210mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
211{
212 if (drv_data->offload_enabled) {
213 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
214 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_TIMING);
215 writel(0, drv_data->reg_base +
216 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
217 writel(0, drv_data->reg_base +
218 MV64XXX_I2C_REG_BRIDGE_INTR_MASK);
219 }
220
221 writel(0, drv_data->reg_base + drv_data->reg_offsets.soft_reset);
222 writel(MV64XXX_I2C_BAUD_DIV_M(drv_data->freq_m) | MV64XXX_I2C_BAUD_DIV_N(drv_data->freq_n),
223 drv_data->reg_base + drv_data->reg_offsets.clock);
224 writel(0, drv_data->reg_base + drv_data->reg_offsets.addr);
225 writel(0, drv_data->reg_base + drv_data->reg_offsets.ext_addr);
226 writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
227 drv_data->reg_base + drv_data->reg_offsets.control);
228
229 if (drv_data->errata_delay)
230 udelay(5);
231
232 drv_data->state = MV64XXX_I2C_STATE_IDLE;
233}
234
235static void
236mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
237{
238 /*
239 * If state is idle, then this is likely the remnants of an old
240 * operation that driver has given up on or the user has killed.
241 * If so, issue the stop condition and go to idle.
242 */
243 if (drv_data->state == MV64XXX_I2C_STATE_IDLE) {
244 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
245 return;
246 }
247
248 /* The status from the ctlr [mostly] tells us what to do next */
249 switch (status) {
250 /* Start condition interrupt */
251 case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */
252 case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
253 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
254 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
255 break;
256
257 /* Performing a write */
258 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
259 if (drv_data->msg->flags & I2C_M_TEN) {
260 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
261 drv_data->state =
262 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
263 break;
264 }
265 fallthrough;
266 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
267 case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
268 if ((drv_data->bytes_left == 0)
269 || (drv_data->aborting
270 && (drv_data->byte_posn != 0))) {
271 if (drv_data->send_stop || drv_data->aborting) {
272 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
273 drv_data->state = MV64XXX_I2C_STATE_IDLE;
274 } else {
275 drv_data->action =
276 MV64XXX_I2C_ACTION_SEND_RESTART;
277 drv_data->state =
278 MV64XXX_I2C_STATE_WAITING_FOR_RESTART;
279 }
280 } else {
281 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
282 drv_data->state =
283 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
284 drv_data->bytes_left--;
285 }
286 break;
287
288 /* Performing a read */
289 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
290 if (drv_data->msg->flags & I2C_M_TEN) {
291 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
292 drv_data->state =
293 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
294 break;
295 }
296 fallthrough;
297 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
298 if (drv_data->bytes_left == 0) {
299 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
300 drv_data->state = MV64XXX_I2C_STATE_IDLE;
301 break;
302 }
303 fallthrough;
304 case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
305 if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK)
306 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
307 else {
308 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA;
309 drv_data->bytes_left--;
310 }
311 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
312
313 if ((drv_data->bytes_left == 1) || drv_data->aborting)
314 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK;
315 break;
316
317 case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
318 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP;
319 drv_data->state = MV64XXX_I2C_STATE_IDLE;
320 break;
321
322 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
323 case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
324 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
325 /* Doesn't seem to be a device at other end */
326 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
327 drv_data->state = MV64XXX_I2C_STATE_IDLE;
328 drv_data->rc = -ENXIO;
329 break;
330
331 default:
332 dev_err(&drv_data->adapter.dev,
333 "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, "
334 "status: 0x%x, addr: 0x%x, flags: 0x%x\n",
335 drv_data->state, status, drv_data->msg->addr,
336 drv_data->msg->flags);
337 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
338 mv64xxx_i2c_hw_init(drv_data);
339 i2c_recover_bus(&drv_data->adapter);
340 drv_data->rc = -EAGAIN;
341 }
342}
343
344static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data)
345{
346 drv_data->msg = drv_data->msgs;
347 drv_data->byte_posn = 0;
348 drv_data->bytes_left = drv_data->msg->len;
349 drv_data->aborting = 0;
350 drv_data->rc = 0;
351
352 mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs);
353 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
354 drv_data->reg_base + drv_data->reg_offsets.control);
355}
356
357static void
358mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
359{
360 switch(drv_data->action) {
361 case MV64XXX_I2C_ACTION_SEND_RESTART:
362 /* We should only get here if we have further messages */
363 BUG_ON(drv_data->num_msgs == 0);
364
365 drv_data->msgs++;
366 drv_data->num_msgs--;
367 mv64xxx_i2c_send_start(drv_data);
368
369 if (drv_data->errata_delay)
370 udelay(5);
371
372 /*
373 * We're never at the start of the message here, and by this
374 * time it's already too late to do any protocol mangling.
375 * Thankfully, do not advertise support for that feature.
376 */
377 drv_data->send_stop = drv_data->num_msgs == 1;
378 break;
379
380 case MV64XXX_I2C_ACTION_CONTINUE:
381 writel(drv_data->cntl_bits,
382 drv_data->reg_base + drv_data->reg_offsets.control);
383 break;
384
385 case MV64XXX_I2C_ACTION_SEND_ADDR_1:
386 writel(drv_data->addr1,
387 drv_data->reg_base + drv_data->reg_offsets.data);
388 writel(drv_data->cntl_bits,
389 drv_data->reg_base + drv_data->reg_offsets.control);
390 break;
391
392 case MV64XXX_I2C_ACTION_SEND_ADDR_2:
393 writel(drv_data->addr2,
394 drv_data->reg_base + drv_data->reg_offsets.data);
395 writel(drv_data->cntl_bits,
396 drv_data->reg_base + drv_data->reg_offsets.control);
397 break;
398
399 case MV64XXX_I2C_ACTION_SEND_DATA:
400 writel(drv_data->msg->buf[drv_data->byte_posn++],
401 drv_data->reg_base + drv_data->reg_offsets.data);
402 writel(drv_data->cntl_bits,
403 drv_data->reg_base + drv_data->reg_offsets.control);
404 break;
405
406 case MV64XXX_I2C_ACTION_RCV_DATA:
407 drv_data->msg->buf[drv_data->byte_posn++] =
408 readl(drv_data->reg_base + drv_data->reg_offsets.data);
409 writel(drv_data->cntl_bits,
410 drv_data->reg_base + drv_data->reg_offsets.control);
411 break;
412
413 case MV64XXX_I2C_ACTION_RCV_DATA_STOP:
414 drv_data->msg->buf[drv_data->byte_posn++] =
415 readl(drv_data->reg_base + drv_data->reg_offsets.data);
416 if (!drv_data->atomic)
417 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
418 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
419 drv_data->reg_base + drv_data->reg_offsets.control);
420 drv_data->block = 0;
421 if (drv_data->errata_delay)
422 udelay(5);
423
424 wake_up(&drv_data->waitq);
425 break;
426
427 case MV64XXX_I2C_ACTION_INVALID:
428 default:
429 dev_err(&drv_data->adapter.dev,
430 "mv64xxx_i2c_do_action: Invalid action: %d\n",
431 drv_data->action);
432 drv_data->rc = -EIO;
433 fallthrough;
434 case MV64XXX_I2C_ACTION_SEND_STOP:
435 if (!drv_data->atomic)
436 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
437 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
438 drv_data->reg_base + drv_data->reg_offsets.control);
439 drv_data->block = 0;
440 wake_up(&drv_data->waitq);
441 break;
442 }
443}
444
445static void
446mv64xxx_i2c_read_offload_rx_data(struct mv64xxx_i2c_data *drv_data,
447 struct i2c_msg *msg)
448{
449 u32 buf[2];
450
451 buf[0] = readl(drv_data->reg_base + MV64XXX_I2C_REG_RX_DATA_LO);
452 buf[1] = readl(drv_data->reg_base + MV64XXX_I2C_REG_RX_DATA_HI);
453
454 memcpy(msg->buf, buf, msg->len);
455}
456
457static int
458mv64xxx_i2c_intr_offload(struct mv64xxx_i2c_data *drv_data)
459{
460 u32 cause, status;
461
462 cause = readl(drv_data->reg_base +
463 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
464 if (!cause)
465 return IRQ_NONE;
466
467 status = readl(drv_data->reg_base +
468 MV64XXX_I2C_REG_BRIDGE_STATUS);
469
470 if (status & MV64XXX_I2C_BRIDGE_STATUS_ERROR) {
471 drv_data->rc = -EIO;
472 goto out;
473 }
474
475 drv_data->rc = 0;
476
477 /*
478 * Transaction is a one message read transaction, read data
479 * for this message.
480 */
481 if (drv_data->num_msgs == 1 && drv_data->msgs[0].flags & I2C_M_RD) {
482 mv64xxx_i2c_read_offload_rx_data(drv_data, drv_data->msgs);
483 drv_data->msgs++;
484 drv_data->num_msgs--;
485 }
486 /*
487 * Transaction is a two messages write/read transaction, read
488 * data for the second (read) message.
489 */
490 else if (drv_data->num_msgs == 2 &&
491 !(drv_data->msgs[0].flags & I2C_M_RD) &&
492 drv_data->msgs[1].flags & I2C_M_RD) {
493 mv64xxx_i2c_read_offload_rx_data(drv_data, drv_data->msgs + 1);
494 drv_data->msgs += 2;
495 drv_data->num_msgs -= 2;
496 }
497
498out:
499 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
500 writel(0, drv_data->reg_base +
501 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
502 drv_data->block = 0;
503
504 wake_up(&drv_data->waitq);
505
506 return IRQ_HANDLED;
507}
508
509static irqreturn_t
510mv64xxx_i2c_intr(int irq, void *dev_id)
511{
512 struct mv64xxx_i2c_data *drv_data = dev_id;
513 u32 status;
514 irqreturn_t rc = IRQ_NONE;
515
516 spin_lock(&drv_data->lock);
517
518 if (drv_data->offload_enabled)
519 rc = mv64xxx_i2c_intr_offload(drv_data);
520
521 while (readl(drv_data->reg_base + drv_data->reg_offsets.control) &
522 MV64XXX_I2C_REG_CONTROL_IFLG) {
523 status = readl(drv_data->reg_base + drv_data->reg_offsets.status);
524 mv64xxx_i2c_fsm(drv_data, status);
525 mv64xxx_i2c_do_action(drv_data);
526
527 if (drv_data->irq_clear_inverted)
528 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_IFLG,
529 drv_data->reg_base + drv_data->reg_offsets.control);
530
531 rc = IRQ_HANDLED;
532 }
533 spin_unlock(&drv_data->lock);
534
535 return rc;
536}
537
538/*
539 *****************************************************************************
540 *
541 * I2C Msg Execution Routines
542 *
543 *****************************************************************************
544 */
545static void
546mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
547{
548 long time_left;
549 unsigned long flags;
550 char abort = 0;
551
552 time_left = wait_event_timeout(drv_data->waitq,
553 !drv_data->block, drv_data->adapter.timeout);
554
555 spin_lock_irqsave(&drv_data->lock, flags);
556 if (!time_left) { /* Timed out */
557 drv_data->rc = -ETIMEDOUT;
558 abort = 1;
559 } else if (time_left < 0) { /* Interrupted/Error */
560 drv_data->rc = time_left; /* errno value */
561 abort = 1;
562 }
563
564 if (abort && drv_data->block) {
565 drv_data->aborting = 1;
566 spin_unlock_irqrestore(&drv_data->lock, flags);
567
568 time_left = wait_event_timeout(drv_data->waitq,
569 !drv_data->block, drv_data->adapter.timeout);
570
571 if ((time_left <= 0) && drv_data->block) {
572 drv_data->state = MV64XXX_I2C_STATE_IDLE;
573 dev_err(&drv_data->adapter.dev,
574 "mv64xxx: I2C bus locked, block: %d, "
575 "time_left: %d\n", drv_data->block,
576 (int)time_left);
577 mv64xxx_i2c_hw_init(drv_data);
578 i2c_recover_bus(&drv_data->adapter);
579 }
580 } else
581 spin_unlock_irqrestore(&drv_data->lock, flags);
582}
583
584static void mv64xxx_i2c_wait_polling(struct mv64xxx_i2c_data *drv_data)
585{
586 ktime_t timeout = ktime_add_ms(ktime_get(), drv_data->adapter.timeout);
587
588 while (READ_ONCE(drv_data->block) &&
589 ktime_compare(ktime_get(), timeout) < 0) {
590 udelay(5);
591 mv64xxx_i2c_intr(0, drv_data);
592 }
593}
594
595static int
596mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg,
597 int is_last)
598{
599 unsigned long flags;
600
601 spin_lock_irqsave(&drv_data->lock, flags);
602
603 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
604
605 drv_data->send_stop = is_last;
606 drv_data->block = 1;
607 mv64xxx_i2c_send_start(drv_data);
608 spin_unlock_irqrestore(&drv_data->lock, flags);
609
610 if (!drv_data->atomic)
611 mv64xxx_i2c_wait_for_completion(drv_data);
612 else
613 mv64xxx_i2c_wait_polling(drv_data);
614
615 return drv_data->rc;
616}
617
618static void
619mv64xxx_i2c_prepare_tx(struct mv64xxx_i2c_data *drv_data)
620{
621 struct i2c_msg *msg = drv_data->msgs;
622 u32 buf[2];
623
624 memcpy(buf, msg->buf, msg->len);
625
626 writel(buf[0], drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_LO);
627 writel(buf[1], drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_HI);
628}
629
630static int
631mv64xxx_i2c_offload_xfer(struct mv64xxx_i2c_data *drv_data)
632{
633 struct i2c_msg *msgs = drv_data->msgs;
634 int num = drv_data->num_msgs;
635 unsigned long ctrl_reg;
636 unsigned long flags;
637
638 spin_lock_irqsave(&drv_data->lock, flags);
639
640 /* Build transaction */
641 ctrl_reg = MV64XXX_I2C_BRIDGE_CONTROL_ENABLE |
642 (msgs[0].addr << MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT);
643
644 if (msgs[0].flags & I2C_M_TEN)
645 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT;
646
647 /* Single write message transaction */
648 if (num == 1 && !(msgs[0].flags & I2C_M_RD)) {
649 size_t len = msgs[0].len - 1;
650
651 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_WR |
652 (len << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT);
653 mv64xxx_i2c_prepare_tx(drv_data);
654 }
655 /* Single read message transaction */
656 else if (num == 1 && msgs[0].flags & I2C_M_RD) {
657 size_t len = msgs[0].len - 1;
658
659 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_RD |
660 (len << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT);
661 }
662 /*
663 * Transaction with one write and one read message. This is
664 * guaranteed by the mv64xx_i2c_can_offload() checks.
665 */
666 else if (num == 2) {
667 size_t lentx = msgs[0].len - 1;
668 size_t lenrx = msgs[1].len - 1;
669
670 ctrl_reg |=
671 MV64XXX_I2C_BRIDGE_CONTROL_RD |
672 MV64XXX_I2C_BRIDGE_CONTROL_WR |
673 (lentx << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT) |
674 (lenrx << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT) |
675 MV64XXX_I2C_BRIDGE_CONTROL_REPEATED_START;
676 mv64xxx_i2c_prepare_tx(drv_data);
677 }
678
679 /* Execute transaction */
680 drv_data->block = 1;
681 writel(ctrl_reg, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
682 spin_unlock_irqrestore(&drv_data->lock, flags);
683
684 mv64xxx_i2c_wait_for_completion(drv_data);
685
686 return drv_data->rc;
687}
688
689static bool
690mv64xxx_i2c_valid_offload_sz(struct i2c_msg *msg)
691{
692 return msg->len <= 8 && msg->len >= 1;
693}
694
695static bool
696mv64xxx_i2c_can_offload(struct mv64xxx_i2c_data *drv_data)
697{
698 struct i2c_msg *msgs = drv_data->msgs;
699 int num = drv_data->num_msgs;
700
701 if (!drv_data->offload_enabled)
702 return false;
703
704 /*
705 * We can offload a transaction consisting of a single
706 * message, as long as the message has a length between 1 and
707 * 8 bytes.
708 */
709 if (num == 1 && mv64xxx_i2c_valid_offload_sz(msgs))
710 return true;
711
712 /*
713 * We can offload a transaction consisting of two messages, if
714 * the first is a write and a second is a read, and both have
715 * a length between 1 and 8 bytes.
716 */
717 if (num == 2 &&
718 mv64xxx_i2c_valid_offload_sz(msgs) &&
719 mv64xxx_i2c_valid_offload_sz(msgs + 1) &&
720 !(msgs[0].flags & I2C_M_RD) &&
721 msgs[1].flags & I2C_M_RD)
722 return true;
723
724 return false;
725}
726
727/*
728 *****************************************************************************
729 *
730 * I2C Core Support Routines (Interface to higher level I2C code)
731 *
732 *****************************************************************************
733 */
734static u32
735mv64xxx_i2c_functionality(struct i2c_adapter *adap)
736{
737 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
738}
739
740static int
741mv64xxx_i2c_xfer_core(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
742{
743 struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
744 int rc, ret = num;
745
746 rc = pm_runtime_resume_and_get(&adap->dev);
747 if (rc)
748 return rc;
749
750 BUG_ON(drv_data->msgs != NULL);
751 drv_data->msgs = msgs;
752 drv_data->num_msgs = num;
753
754 if (mv64xxx_i2c_can_offload(drv_data) && !drv_data->atomic)
755 rc = mv64xxx_i2c_offload_xfer(drv_data);
756 else
757 rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[0], num == 1);
758
759 if (rc < 0)
760 ret = rc;
761
762 drv_data->num_msgs = 0;
763 drv_data->msgs = NULL;
764
765 pm_runtime_mark_last_busy(&adap->dev);
766 pm_runtime_put_autosuspend(&adap->dev);
767
768 return ret;
769}
770
771static int
772mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
773{
774 struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
775
776 drv_data->atomic = 0;
777 return mv64xxx_i2c_xfer_core(adap, msgs, num);
778}
779
780static int mv64xxx_i2c_xfer_atomic(struct i2c_adapter *adap,
781 struct i2c_msg msgs[], int num)
782{
783 struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
784
785 drv_data->atomic = 1;
786 return mv64xxx_i2c_xfer_core(adap, msgs, num);
787}
788
789static const struct i2c_algorithm mv64xxx_i2c_algo = {
790 .master_xfer = mv64xxx_i2c_xfer,
791 .master_xfer_atomic = mv64xxx_i2c_xfer_atomic,
792 .functionality = mv64xxx_i2c_functionality,
793};
794
795/*
796 *****************************************************************************
797 *
798 * Driver Interface & Early Init Routines
799 *
800 *****************************************************************************
801 */
802static const struct of_device_id mv64xxx_i2c_of_match_table[] = {
803 { .compatible = "allwinner,sun4i-a10-i2c", .data = &mv64xxx_i2c_regs_sun4i},
804 { .compatible = "allwinner,sun6i-a31-i2c", .data = &mv64xxx_i2c_regs_sun4i},
805 { .compatible = "marvell,mv64xxx-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
806 { .compatible = "marvell,mv78230-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
807 { .compatible = "marvell,mv78230-a0-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
808 {}
809};
810MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
811
812#ifdef CONFIG_OF
813static int
814mv64xxx_calc_freq(struct mv64xxx_i2c_data *drv_data,
815 const int tclk, const int n, const int m)
816{
817 if (drv_data->clk_n_base_0)
818 return tclk / (10 * (m + 1) * (1 << n));
819 else
820 return tclk / (10 * (m + 1) * (2 << n));
821}
822
823static bool
824mv64xxx_find_baud_factors(struct mv64xxx_i2c_data *drv_data,
825 const u32 req_freq, const u32 tclk)
826{
827 int freq, delta, best_delta = INT_MAX;
828 int m, n;
829
830 for (n = 0; n <= 7; n++)
831 for (m = 0; m <= 15; m++) {
832 freq = mv64xxx_calc_freq(drv_data, tclk, n, m);
833 delta = req_freq - freq;
834 if (delta >= 0 && delta < best_delta) {
835 drv_data->freq_m = m;
836 drv_data->freq_n = n;
837 best_delta = delta;
838 }
839 if (best_delta == 0)
840 return true;
841 }
842 if (best_delta == INT_MAX)
843 return false;
844 return true;
845}
846
847static int
848mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
849 struct device *dev)
850{
851 const struct of_device_id *device;
852 struct device_node *np = dev->of_node;
853 u32 bus_freq, tclk;
854 int rc = 0;
855
856 /* CLK is mandatory when using DT to describe the i2c bus. We
857 * need to know tclk in order to calculate bus clock
858 * factors.
859 */
860 if (!drv_data->clk) {
861 rc = -ENODEV;
862 goto out;
863 }
864 tclk = clk_get_rate(drv_data->clk);
865
866 if (of_property_read_u32(np, "clock-frequency", &bus_freq))
867 bus_freq = I2C_MAX_STANDARD_MODE_FREQ; /* 100kHz by default */
868
869 if (of_device_is_compatible(np, "allwinner,sun4i-a10-i2c") ||
870 of_device_is_compatible(np, "allwinner,sun6i-a31-i2c"))
871 drv_data->clk_n_base_0 = true;
872
873 if (!mv64xxx_find_baud_factors(drv_data, bus_freq, tclk)) {
874 rc = -EINVAL;
875 goto out;
876 }
877
878 drv_data->rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
879 if (IS_ERR(drv_data->rstc)) {
880 rc = PTR_ERR(drv_data->rstc);
881 goto out;
882 }
883
884 /* Its not yet defined how timeouts will be specified in device tree.
885 * So hard code the value to 1 second.
886 */
887 drv_data->adapter.timeout = HZ;
888
889 device = of_match_device(mv64xxx_i2c_of_match_table, dev);
890 if (!device)
891 return -ENODEV;
892
893 memcpy(&drv_data->reg_offsets, device->data, sizeof(drv_data->reg_offsets));
894
895 /*
896 * For controllers embedded in new SoCs activate the
897 * Transaction Generator support and the errata fix.
898 */
899 if (of_device_is_compatible(np, "marvell,mv78230-i2c")) {
900 drv_data->offload_enabled = true;
901 /* The delay is only needed in standard mode (100kHz) */
902 if (bus_freq <= I2C_MAX_STANDARD_MODE_FREQ)
903 drv_data->errata_delay = true;
904 }
905
906 if (of_device_is_compatible(np, "marvell,mv78230-a0-i2c")) {
907 drv_data->offload_enabled = false;
908 /* The delay is only needed in standard mode (100kHz) */
909 if (bus_freq <= I2C_MAX_STANDARD_MODE_FREQ)
910 drv_data->errata_delay = true;
911 }
912
913 if (of_device_is_compatible(np, "allwinner,sun6i-a31-i2c"))
914 drv_data->irq_clear_inverted = true;
915
916out:
917 return rc;
918}
919#else /* CONFIG_OF */
920static int
921mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
922 struct device *dev)
923{
924 return -ENODEV;
925}
926#endif /* CONFIG_OF */
927
928static int mv64xxx_i2c_init_recovery_info(struct mv64xxx_i2c_data *drv_data,
929 struct device *dev)
930{
931 struct i2c_bus_recovery_info *rinfo = &drv_data->rinfo;
932
933 rinfo->pinctrl = devm_pinctrl_get(dev);
934 if (IS_ERR(rinfo->pinctrl)) {
935 if (PTR_ERR(rinfo->pinctrl) == -EPROBE_DEFER)
936 return -EPROBE_DEFER;
937 dev_info(dev, "can't get pinctrl, bus recovery not supported\n");
938 return PTR_ERR(rinfo->pinctrl);
939 } else if (!rinfo->pinctrl) {
940 return -ENODEV;
941 }
942
943 drv_data->adapter.bus_recovery_info = rinfo;
944 return 0;
945}
946
947static int
948mv64xxx_i2c_runtime_suspend(struct device *dev)
949{
950 struct mv64xxx_i2c_data *drv_data = dev_get_drvdata(dev);
951
952 reset_control_assert(drv_data->rstc);
953 clk_disable_unprepare(drv_data->reg_clk);
954 clk_disable_unprepare(drv_data->clk);
955
956 return 0;
957}
958
959static int
960mv64xxx_i2c_runtime_resume(struct device *dev)
961{
962 struct mv64xxx_i2c_data *drv_data = dev_get_drvdata(dev);
963
964 clk_prepare_enable(drv_data->clk);
965 clk_prepare_enable(drv_data->reg_clk);
966 reset_control_reset(drv_data->rstc);
967
968 mv64xxx_i2c_hw_init(drv_data);
969
970 return 0;
971}
972
973static int
974mv64xxx_i2c_probe(struct platform_device *pd)
975{
976 struct mv64xxx_i2c_data *drv_data;
977 struct mv64xxx_i2c_pdata *pdata = dev_get_platdata(&pd->dev);
978 int rc;
979
980 if ((!pdata && !pd->dev.of_node))
981 return -ENODEV;
982
983 drv_data = devm_kzalloc(&pd->dev, sizeof(struct mv64xxx_i2c_data),
984 GFP_KERNEL);
985 if (!drv_data)
986 return -ENOMEM;
987
988 drv_data->reg_base = devm_platform_ioremap_resource(pd, 0);
989 if (IS_ERR(drv_data->reg_base))
990 return PTR_ERR(drv_data->reg_base);
991
992 strscpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
993 sizeof(drv_data->adapter.name));
994
995 init_waitqueue_head(&drv_data->waitq);
996 spin_lock_init(&drv_data->lock);
997
998 /* Not all platforms have clocks */
999 drv_data->clk = devm_clk_get(&pd->dev, NULL);
1000 if (IS_ERR(drv_data->clk)) {
1001 if (PTR_ERR(drv_data->clk) == -EPROBE_DEFER)
1002 return -EPROBE_DEFER;
1003 drv_data->clk = NULL;
1004 }
1005
1006 drv_data->reg_clk = devm_clk_get(&pd->dev, "reg");
1007 if (IS_ERR(drv_data->reg_clk)) {
1008 if (PTR_ERR(drv_data->reg_clk) == -EPROBE_DEFER)
1009 return -EPROBE_DEFER;
1010 drv_data->reg_clk = NULL;
1011 }
1012
1013 drv_data->irq = platform_get_irq(pd, 0);
1014 if (drv_data->irq < 0)
1015 return drv_data->irq;
1016
1017 if (pdata) {
1018 drv_data->freq_m = pdata->freq_m;
1019 drv_data->freq_n = pdata->freq_n;
1020 drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
1021 drv_data->offload_enabled = false;
1022 memcpy(&drv_data->reg_offsets, &mv64xxx_i2c_regs_mv64xxx, sizeof(drv_data->reg_offsets));
1023 } else if (pd->dev.of_node) {
1024 rc = mv64xxx_of_config(drv_data, &pd->dev);
1025 if (rc)
1026 return rc;
1027 }
1028
1029 rc = mv64xxx_i2c_init_recovery_info(drv_data, &pd->dev);
1030 if (rc == -EPROBE_DEFER)
1031 return rc;
1032
1033 drv_data->adapter.dev.parent = &pd->dev;
1034 drv_data->adapter.algo = &mv64xxx_i2c_algo;
1035 drv_data->adapter.owner = THIS_MODULE;
1036 drv_data->adapter.class = I2C_CLASS_DEPRECATED;
1037 drv_data->adapter.nr = pd->id;
1038 drv_data->adapter.dev.of_node = pd->dev.of_node;
1039 platform_set_drvdata(pd, drv_data);
1040 i2c_set_adapdata(&drv_data->adapter, drv_data);
1041
1042 pm_runtime_set_autosuspend_delay(&pd->dev, MSEC_PER_SEC);
1043 pm_runtime_use_autosuspend(&pd->dev);
1044 pm_runtime_enable(&pd->dev);
1045 if (!pm_runtime_enabled(&pd->dev)) {
1046 rc = mv64xxx_i2c_runtime_resume(&pd->dev);
1047 if (rc)
1048 goto exit_disable_pm;
1049 }
1050
1051 rc = request_irq(drv_data->irq, mv64xxx_i2c_intr, 0,
1052 MV64XXX_I2C_CTLR_NAME, drv_data);
1053 if (rc) {
1054 dev_err(&drv_data->adapter.dev,
1055 "mv64xxx: Can't register intr handler irq%d: %d\n",
1056 drv_data->irq, rc);
1057 goto exit_disable_pm;
1058 } else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) {
1059 dev_err(&drv_data->adapter.dev,
1060 "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc);
1061 goto exit_free_irq;
1062 }
1063
1064 return 0;
1065
1066exit_free_irq:
1067 free_irq(drv_data->irq, drv_data);
1068exit_disable_pm:
1069 pm_runtime_disable(&pd->dev);
1070 if (!pm_runtime_status_suspended(&pd->dev))
1071 mv64xxx_i2c_runtime_suspend(&pd->dev);
1072
1073 return rc;
1074}
1075
1076static int
1077mv64xxx_i2c_remove(struct platform_device *pd)
1078{
1079 struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(pd);
1080
1081 i2c_del_adapter(&drv_data->adapter);
1082 free_irq(drv_data->irq, drv_data);
1083 pm_runtime_disable(&pd->dev);
1084 if (!pm_runtime_status_suspended(&pd->dev))
1085 mv64xxx_i2c_runtime_suspend(&pd->dev);
1086
1087 return 0;
1088}
1089
1090static const struct dev_pm_ops mv64xxx_i2c_pm_ops = {
1091 SET_RUNTIME_PM_OPS(mv64xxx_i2c_runtime_suspend,
1092 mv64xxx_i2c_runtime_resume, NULL)
1093 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1094 pm_runtime_force_resume)
1095};
1096
1097static struct platform_driver mv64xxx_i2c_driver = {
1098 .probe = mv64xxx_i2c_probe,
1099 .remove = mv64xxx_i2c_remove,
1100 .driver = {
1101 .name = MV64XXX_I2C_CTLR_NAME,
1102 .pm = &mv64xxx_i2c_pm_ops,
1103 .of_match_table = mv64xxx_i2c_of_match_table,
1104 },
1105};
1106
1107module_platform_driver(mv64xxx_i2c_driver);
1108
1109MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
1110MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver");
1111MODULE_LICENSE("GPL");
1/*
2 * Driver for the i2c controller on the Marvell line of host bridges
3 * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, and Orion SoC family).
4 *
5 * Author: Mark A. Greer <mgreer@mvista.com>
6 *
7 * 2005 (c) MontaVista, Software, Inc. This file is licensed under
8 * the terms of the GNU General Public License version 2. This program
9 * is licensed "as is" without any warranty of any kind, whether express
10 * or implied.
11 */
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/module.h>
15#include <linux/spinlock.h>
16#include <linux/i2c.h>
17#include <linux/interrupt.h>
18#include <linux/mv643xx_i2c.h>
19#include <linux/platform_device.h>
20#include <linux/reset.h>
21#include <linux/io.h>
22#include <linux/of.h>
23#include <linux/of_device.h>
24#include <linux/of_irq.h>
25#include <linux/clk.h>
26#include <linux/err.h>
27#include <linux/delay.h>
28
29#define MV64XXX_I2C_ADDR_ADDR(val) ((val & 0x7f) << 1)
30#define MV64XXX_I2C_BAUD_DIV_N(val) (val & 0x7)
31#define MV64XXX_I2C_BAUD_DIV_M(val) ((val & 0xf) << 3)
32
33#define MV64XXX_I2C_REG_CONTROL_ACK 0x00000004
34#define MV64XXX_I2C_REG_CONTROL_IFLG 0x00000008
35#define MV64XXX_I2C_REG_CONTROL_STOP 0x00000010
36#define MV64XXX_I2C_REG_CONTROL_START 0x00000020
37#define MV64XXX_I2C_REG_CONTROL_TWSIEN 0x00000040
38#define MV64XXX_I2C_REG_CONTROL_INTEN 0x00000080
39
40/* Ctlr status values */
41#define MV64XXX_I2C_STATUS_BUS_ERR 0x00
42#define MV64XXX_I2C_STATUS_MAST_START 0x08
43#define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10
44#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18
45#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20
46#define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28
47#define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30
48#define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38
49#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40
50#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48
51#define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50
52#define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58
53#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0
54#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8
55#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0
56#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8
57#define MV64XXX_I2C_STATUS_NO_STATUS 0xf8
58
59/* Register defines (I2C bridge) */
60#define MV64XXX_I2C_REG_TX_DATA_LO 0xc0
61#define MV64XXX_I2C_REG_TX_DATA_HI 0xc4
62#define MV64XXX_I2C_REG_RX_DATA_LO 0xc8
63#define MV64XXX_I2C_REG_RX_DATA_HI 0xcc
64#define MV64XXX_I2C_REG_BRIDGE_CONTROL 0xd0
65#define MV64XXX_I2C_REG_BRIDGE_STATUS 0xd4
66#define MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE 0xd8
67#define MV64XXX_I2C_REG_BRIDGE_INTR_MASK 0xdC
68#define MV64XXX_I2C_REG_BRIDGE_TIMING 0xe0
69
70/* Bridge Control values */
71#define MV64XXX_I2C_BRIDGE_CONTROL_WR 0x00000001
72#define MV64XXX_I2C_BRIDGE_CONTROL_RD 0x00000002
73#define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT 2
74#define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT 0x00001000
75#define MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT 13
76#define MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT 16
77#define MV64XXX_I2C_BRIDGE_CONTROL_ENABLE 0x00080000
78
79/* Bridge Status values */
80#define MV64XXX_I2C_BRIDGE_STATUS_ERROR 0x00000001
81#define MV64XXX_I2C_STATUS_OFFLOAD_ERROR 0xf0000001
82#define MV64XXX_I2C_STATUS_OFFLOAD_OK 0xf0000000
83
84
85/* Driver states */
86enum {
87 MV64XXX_I2C_STATE_INVALID,
88 MV64XXX_I2C_STATE_IDLE,
89 MV64XXX_I2C_STATE_WAITING_FOR_START_COND,
90 MV64XXX_I2C_STATE_WAITING_FOR_RESTART,
91 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
92 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
93 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK,
94 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA,
95};
96
97/* Driver actions */
98enum {
99 MV64XXX_I2C_ACTION_INVALID,
100 MV64XXX_I2C_ACTION_CONTINUE,
101 MV64XXX_I2C_ACTION_SEND_RESTART,
102 MV64XXX_I2C_ACTION_OFFLOAD_RESTART,
103 MV64XXX_I2C_ACTION_SEND_ADDR_1,
104 MV64XXX_I2C_ACTION_SEND_ADDR_2,
105 MV64XXX_I2C_ACTION_SEND_DATA,
106 MV64XXX_I2C_ACTION_RCV_DATA,
107 MV64XXX_I2C_ACTION_RCV_DATA_STOP,
108 MV64XXX_I2C_ACTION_SEND_STOP,
109 MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP,
110};
111
112struct mv64xxx_i2c_regs {
113 u8 addr;
114 u8 ext_addr;
115 u8 data;
116 u8 control;
117 u8 status;
118 u8 clock;
119 u8 soft_reset;
120};
121
122struct mv64xxx_i2c_data {
123 struct i2c_msg *msgs;
124 int num_msgs;
125 int irq;
126 u32 state;
127 u32 action;
128 u32 aborting;
129 u32 cntl_bits;
130 void __iomem *reg_base;
131 struct mv64xxx_i2c_regs reg_offsets;
132 u32 addr1;
133 u32 addr2;
134 u32 bytes_left;
135 u32 byte_posn;
136 u32 send_stop;
137 u32 block;
138 int rc;
139 u32 freq_m;
140 u32 freq_n;
141#if defined(CONFIG_HAVE_CLK)
142 struct clk *clk;
143#endif
144 wait_queue_head_t waitq;
145 spinlock_t lock;
146 struct i2c_msg *msg;
147 struct i2c_adapter adapter;
148 bool offload_enabled;
149/* 5us delay in order to avoid repeated start timing violation */
150 bool errata_delay;
151 struct reset_control *rstc;
152 bool irq_clear_inverted;
153};
154
155static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = {
156 .addr = 0x00,
157 .ext_addr = 0x10,
158 .data = 0x04,
159 .control = 0x08,
160 .status = 0x0c,
161 .clock = 0x0c,
162 .soft_reset = 0x1c,
163};
164
165static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_sun4i = {
166 .addr = 0x00,
167 .ext_addr = 0x04,
168 .data = 0x08,
169 .control = 0x0c,
170 .status = 0x10,
171 .clock = 0x14,
172 .soft_reset = 0x18,
173};
174
175static void
176mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data,
177 struct i2c_msg *msg)
178{
179 u32 dir = 0;
180
181 drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK |
182 MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN;
183
184 if (msg->flags & I2C_M_RD)
185 dir = 1;
186
187 if (msg->flags & I2C_M_TEN) {
188 drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
189 drv_data->addr2 = (u32)msg->addr & 0xff;
190 } else {
191 drv_data->addr1 = MV64XXX_I2C_ADDR_ADDR((u32)msg->addr) | dir;
192 drv_data->addr2 = 0;
193 }
194}
195
196static int mv64xxx_i2c_offload_msg(struct mv64xxx_i2c_data *drv_data)
197{
198 unsigned long data_reg_hi = 0;
199 unsigned long data_reg_lo = 0;
200 unsigned long ctrl_reg;
201 struct i2c_msg *msg = drv_data->msgs;
202
203 if (!drv_data->offload_enabled)
204 return -EOPNOTSUPP;
205
206 /* Only regular transactions can be offloaded */
207 if ((msg->flags & ~(I2C_M_TEN | I2C_M_RD)) != 0)
208 return -EINVAL;
209
210 /* Only 1-8 byte transfers can be offloaded */
211 if (msg->len < 1 || msg->len > 8)
212 return -EINVAL;
213
214 /* Build transaction */
215 ctrl_reg = MV64XXX_I2C_BRIDGE_CONTROL_ENABLE |
216 (msg->addr << MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT);
217
218 if ((msg->flags & I2C_M_TEN) != 0)
219 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT;
220
221 if ((msg->flags & I2C_M_RD) == 0) {
222 u8 local_buf[8] = { 0 };
223
224 memcpy(local_buf, msg->buf, msg->len);
225 data_reg_lo = cpu_to_le32(*((u32 *)local_buf));
226 data_reg_hi = cpu_to_le32(*((u32 *)(local_buf+4)));
227
228 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_WR |
229 (msg->len - 1) << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT;
230
231 writel(data_reg_lo,
232 drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_LO);
233 writel(data_reg_hi,
234 drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_HI);
235
236 } else {
237 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_RD |
238 (msg->len - 1) << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT;
239 }
240
241 /* Execute transaction */
242 writel(ctrl_reg, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
243
244 return 0;
245}
246
247static void
248mv64xxx_i2c_update_offload_data(struct mv64xxx_i2c_data *drv_data)
249{
250 struct i2c_msg *msg = drv_data->msg;
251
252 if (msg->flags & I2C_M_RD) {
253 u32 data_reg_lo = readl(drv_data->reg_base +
254 MV64XXX_I2C_REG_RX_DATA_LO);
255 u32 data_reg_hi = readl(drv_data->reg_base +
256 MV64XXX_I2C_REG_RX_DATA_HI);
257 u8 local_buf[8] = { 0 };
258
259 *((u32 *)local_buf) = le32_to_cpu(data_reg_lo);
260 *((u32 *)(local_buf+4)) = le32_to_cpu(data_reg_hi);
261 memcpy(msg->buf, local_buf, msg->len);
262 }
263
264}
265/*
266 *****************************************************************************
267 *
268 * Finite State Machine & Interrupt Routines
269 *
270 *****************************************************************************
271 */
272
273/* Reset hardware and initialize FSM */
274static void
275mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
276{
277 if (drv_data->offload_enabled) {
278 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
279 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_TIMING);
280 writel(0, drv_data->reg_base +
281 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
282 writel(0, drv_data->reg_base +
283 MV64XXX_I2C_REG_BRIDGE_INTR_MASK);
284 }
285
286 writel(0, drv_data->reg_base + drv_data->reg_offsets.soft_reset);
287 writel(MV64XXX_I2C_BAUD_DIV_M(drv_data->freq_m) | MV64XXX_I2C_BAUD_DIV_N(drv_data->freq_n),
288 drv_data->reg_base + drv_data->reg_offsets.clock);
289 writel(0, drv_data->reg_base + drv_data->reg_offsets.addr);
290 writel(0, drv_data->reg_base + drv_data->reg_offsets.ext_addr);
291 writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
292 drv_data->reg_base + drv_data->reg_offsets.control);
293 drv_data->state = MV64XXX_I2C_STATE_IDLE;
294}
295
296static void
297mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
298{
299 /*
300 * If state is idle, then this is likely the remnants of an old
301 * operation that driver has given up on or the user has killed.
302 * If so, issue the stop condition and go to idle.
303 */
304 if (drv_data->state == MV64XXX_I2C_STATE_IDLE) {
305 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
306 return;
307 }
308
309 /* The status from the ctlr [mostly] tells us what to do next */
310 switch (status) {
311 /* Start condition interrupt */
312 case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */
313 case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
314 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
315 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
316 break;
317
318 /* Performing a write */
319 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
320 if (drv_data->msg->flags & I2C_M_TEN) {
321 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
322 drv_data->state =
323 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
324 break;
325 }
326 /* FALLTHRU */
327 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
328 case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
329 if ((drv_data->bytes_left == 0)
330 || (drv_data->aborting
331 && (drv_data->byte_posn != 0))) {
332 if (drv_data->send_stop || drv_data->aborting) {
333 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
334 drv_data->state = MV64XXX_I2C_STATE_IDLE;
335 } else {
336 drv_data->action =
337 MV64XXX_I2C_ACTION_SEND_RESTART;
338 drv_data->state =
339 MV64XXX_I2C_STATE_WAITING_FOR_RESTART;
340 }
341 } else {
342 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
343 drv_data->state =
344 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
345 drv_data->bytes_left--;
346 }
347 break;
348
349 /* Performing a read */
350 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
351 if (drv_data->msg->flags & I2C_M_TEN) {
352 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
353 drv_data->state =
354 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
355 break;
356 }
357 /* FALLTHRU */
358 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
359 if (drv_data->bytes_left == 0) {
360 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
361 drv_data->state = MV64XXX_I2C_STATE_IDLE;
362 break;
363 }
364 /* FALLTHRU */
365 case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
366 if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK)
367 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
368 else {
369 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA;
370 drv_data->bytes_left--;
371 }
372 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
373
374 if ((drv_data->bytes_left == 1) || drv_data->aborting)
375 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK;
376 break;
377
378 case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
379 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP;
380 drv_data->state = MV64XXX_I2C_STATE_IDLE;
381 break;
382
383 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
384 case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
385 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
386 /* Doesn't seem to be a device at other end */
387 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
388 drv_data->state = MV64XXX_I2C_STATE_IDLE;
389 drv_data->rc = -ENXIO;
390 break;
391
392 case MV64XXX_I2C_STATUS_OFFLOAD_OK:
393 if (drv_data->send_stop || drv_data->aborting) {
394 drv_data->action = MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP;
395 drv_data->state = MV64XXX_I2C_STATE_IDLE;
396 } else {
397 drv_data->action = MV64XXX_I2C_ACTION_OFFLOAD_RESTART;
398 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_RESTART;
399 }
400 break;
401
402 default:
403 dev_err(&drv_data->adapter.dev,
404 "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, "
405 "status: 0x%x, addr: 0x%x, flags: 0x%x\n",
406 drv_data->state, status, drv_data->msg->addr,
407 drv_data->msg->flags);
408 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
409 mv64xxx_i2c_hw_init(drv_data);
410 drv_data->rc = -EIO;
411 }
412}
413
414static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data)
415{
416 drv_data->msg = drv_data->msgs;
417 drv_data->byte_posn = 0;
418 drv_data->bytes_left = drv_data->msg->len;
419 drv_data->aborting = 0;
420 drv_data->rc = 0;
421
422 /* Can we offload this msg ? */
423 if (mv64xxx_i2c_offload_msg(drv_data) < 0) {
424 /* No, switch to standard path */
425 mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs);
426 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
427 drv_data->reg_base + drv_data->reg_offsets.control);
428 }
429}
430
431static void
432mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
433{
434 switch(drv_data->action) {
435 case MV64XXX_I2C_ACTION_OFFLOAD_RESTART:
436 mv64xxx_i2c_update_offload_data(drv_data);
437 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
438 writel(0, drv_data->reg_base +
439 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
440 /* FALLTHRU */
441 case MV64XXX_I2C_ACTION_SEND_RESTART:
442 /* We should only get here if we have further messages */
443 BUG_ON(drv_data->num_msgs == 0);
444
445 drv_data->msgs++;
446 drv_data->num_msgs--;
447 mv64xxx_i2c_send_start(drv_data);
448
449 if (drv_data->errata_delay)
450 udelay(5);
451
452 /*
453 * We're never at the start of the message here, and by this
454 * time it's already too late to do any protocol mangling.
455 * Thankfully, do not advertise support for that feature.
456 */
457 drv_data->send_stop = drv_data->num_msgs == 1;
458 break;
459
460 case MV64XXX_I2C_ACTION_CONTINUE:
461 writel(drv_data->cntl_bits,
462 drv_data->reg_base + drv_data->reg_offsets.control);
463 break;
464
465 case MV64XXX_I2C_ACTION_SEND_ADDR_1:
466 writel(drv_data->addr1,
467 drv_data->reg_base + drv_data->reg_offsets.data);
468 writel(drv_data->cntl_bits,
469 drv_data->reg_base + drv_data->reg_offsets.control);
470 break;
471
472 case MV64XXX_I2C_ACTION_SEND_ADDR_2:
473 writel(drv_data->addr2,
474 drv_data->reg_base + drv_data->reg_offsets.data);
475 writel(drv_data->cntl_bits,
476 drv_data->reg_base + drv_data->reg_offsets.control);
477 break;
478
479 case MV64XXX_I2C_ACTION_SEND_DATA:
480 writel(drv_data->msg->buf[drv_data->byte_posn++],
481 drv_data->reg_base + drv_data->reg_offsets.data);
482 writel(drv_data->cntl_bits,
483 drv_data->reg_base + drv_data->reg_offsets.control);
484 break;
485
486 case MV64XXX_I2C_ACTION_RCV_DATA:
487 drv_data->msg->buf[drv_data->byte_posn++] =
488 readl(drv_data->reg_base + drv_data->reg_offsets.data);
489 writel(drv_data->cntl_bits,
490 drv_data->reg_base + drv_data->reg_offsets.control);
491 break;
492
493 case MV64XXX_I2C_ACTION_RCV_DATA_STOP:
494 drv_data->msg->buf[drv_data->byte_posn++] =
495 readl(drv_data->reg_base + drv_data->reg_offsets.data);
496 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
497 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
498 drv_data->reg_base + drv_data->reg_offsets.control);
499 drv_data->block = 0;
500 if (drv_data->errata_delay)
501 udelay(5);
502
503 wake_up(&drv_data->waitq);
504 break;
505
506 case MV64XXX_I2C_ACTION_INVALID:
507 default:
508 dev_err(&drv_data->adapter.dev,
509 "mv64xxx_i2c_do_action: Invalid action: %d\n",
510 drv_data->action);
511 drv_data->rc = -EIO;
512
513 /* FALLTHRU */
514 case MV64XXX_I2C_ACTION_SEND_STOP:
515 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
516 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
517 drv_data->reg_base + drv_data->reg_offsets.control);
518 drv_data->block = 0;
519 wake_up(&drv_data->waitq);
520 break;
521
522 case MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP:
523 mv64xxx_i2c_update_offload_data(drv_data);
524 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
525 writel(0, drv_data->reg_base +
526 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
527 drv_data->block = 0;
528 wake_up(&drv_data->waitq);
529 break;
530 }
531}
532
533static irqreturn_t
534mv64xxx_i2c_intr(int irq, void *dev_id)
535{
536 struct mv64xxx_i2c_data *drv_data = dev_id;
537 unsigned long flags;
538 u32 status;
539 irqreturn_t rc = IRQ_NONE;
540
541 spin_lock_irqsave(&drv_data->lock, flags);
542
543 if (drv_data->offload_enabled) {
544 while (readl(drv_data->reg_base +
545 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE)) {
546 int reg_status = readl(drv_data->reg_base +
547 MV64XXX_I2C_REG_BRIDGE_STATUS);
548 if (reg_status & MV64XXX_I2C_BRIDGE_STATUS_ERROR)
549 status = MV64XXX_I2C_STATUS_OFFLOAD_ERROR;
550 else
551 status = MV64XXX_I2C_STATUS_OFFLOAD_OK;
552 mv64xxx_i2c_fsm(drv_data, status);
553 mv64xxx_i2c_do_action(drv_data);
554 rc = IRQ_HANDLED;
555 }
556 }
557 while (readl(drv_data->reg_base + drv_data->reg_offsets.control) &
558 MV64XXX_I2C_REG_CONTROL_IFLG) {
559 status = readl(drv_data->reg_base + drv_data->reg_offsets.status);
560 mv64xxx_i2c_fsm(drv_data, status);
561 mv64xxx_i2c_do_action(drv_data);
562
563 if (drv_data->irq_clear_inverted)
564 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_IFLG,
565 drv_data->reg_base + drv_data->reg_offsets.control);
566
567 rc = IRQ_HANDLED;
568 }
569 spin_unlock_irqrestore(&drv_data->lock, flags);
570
571 return rc;
572}
573
574/*
575 *****************************************************************************
576 *
577 * I2C Msg Execution Routines
578 *
579 *****************************************************************************
580 */
581static void
582mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
583{
584 long time_left;
585 unsigned long flags;
586 char abort = 0;
587
588 time_left = wait_event_timeout(drv_data->waitq,
589 !drv_data->block, drv_data->adapter.timeout);
590
591 spin_lock_irqsave(&drv_data->lock, flags);
592 if (!time_left) { /* Timed out */
593 drv_data->rc = -ETIMEDOUT;
594 abort = 1;
595 } else if (time_left < 0) { /* Interrupted/Error */
596 drv_data->rc = time_left; /* errno value */
597 abort = 1;
598 }
599
600 if (abort && drv_data->block) {
601 drv_data->aborting = 1;
602 spin_unlock_irqrestore(&drv_data->lock, flags);
603
604 time_left = wait_event_timeout(drv_data->waitq,
605 !drv_data->block, drv_data->adapter.timeout);
606
607 if ((time_left <= 0) && drv_data->block) {
608 drv_data->state = MV64XXX_I2C_STATE_IDLE;
609 dev_err(&drv_data->adapter.dev,
610 "mv64xxx: I2C bus locked, block: %d, "
611 "time_left: %d\n", drv_data->block,
612 (int)time_left);
613 mv64xxx_i2c_hw_init(drv_data);
614 }
615 } else
616 spin_unlock_irqrestore(&drv_data->lock, flags);
617}
618
619static int
620mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg,
621 int is_last)
622{
623 unsigned long flags;
624
625 spin_lock_irqsave(&drv_data->lock, flags);
626
627 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
628
629 drv_data->send_stop = is_last;
630 drv_data->block = 1;
631 mv64xxx_i2c_send_start(drv_data);
632 spin_unlock_irqrestore(&drv_data->lock, flags);
633
634 mv64xxx_i2c_wait_for_completion(drv_data);
635 return drv_data->rc;
636}
637
638/*
639 *****************************************************************************
640 *
641 * I2C Core Support Routines (Interface to higher level I2C code)
642 *
643 *****************************************************************************
644 */
645static u32
646mv64xxx_i2c_functionality(struct i2c_adapter *adap)
647{
648 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
649}
650
651static int
652mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
653{
654 struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
655 int rc, ret = num;
656
657 BUG_ON(drv_data->msgs != NULL);
658 drv_data->msgs = msgs;
659 drv_data->num_msgs = num;
660
661 rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[0], num == 1);
662 if (rc < 0)
663 ret = rc;
664
665 drv_data->num_msgs = 0;
666 drv_data->msgs = NULL;
667
668 return ret;
669}
670
671static const struct i2c_algorithm mv64xxx_i2c_algo = {
672 .master_xfer = mv64xxx_i2c_xfer,
673 .functionality = mv64xxx_i2c_functionality,
674};
675
676/*
677 *****************************************************************************
678 *
679 * Driver Interface & Early Init Routines
680 *
681 *****************************************************************************
682 */
683static const struct of_device_id mv64xxx_i2c_of_match_table[] = {
684 { .compatible = "allwinner,sun4i-i2c", .data = &mv64xxx_i2c_regs_sun4i},
685 { .compatible = "allwinner,sun6i-a31-i2c", .data = &mv64xxx_i2c_regs_sun4i},
686 { .compatible = "marvell,mv64xxx-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
687 { .compatible = "marvell,mv78230-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
688 { .compatible = "marvell,mv78230-a0-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
689 {}
690};
691MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
692
693#ifdef CONFIG_OF
694#ifdef CONFIG_HAVE_CLK
695static int
696mv64xxx_calc_freq(const int tclk, const int n, const int m)
697{
698 return tclk / (10 * (m + 1) * (2 << n));
699}
700
701static bool
702mv64xxx_find_baud_factors(const u32 req_freq, const u32 tclk, u32 *best_n,
703 u32 *best_m)
704{
705 int freq, delta, best_delta = INT_MAX;
706 int m, n;
707
708 for (n = 0; n <= 7; n++)
709 for (m = 0; m <= 15; m++) {
710 freq = mv64xxx_calc_freq(tclk, n, m);
711 delta = req_freq - freq;
712 if (delta >= 0 && delta < best_delta) {
713 *best_m = m;
714 *best_n = n;
715 best_delta = delta;
716 }
717 if (best_delta == 0)
718 return true;
719 }
720 if (best_delta == INT_MAX)
721 return false;
722 return true;
723}
724#endif /* CONFIG_HAVE_CLK */
725
726static int
727mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
728 struct device *dev)
729{
730 /* CLK is mandatory when using DT to describe the i2c bus. We
731 * need to know tclk in order to calculate bus clock
732 * factors.
733 */
734#if !defined(CONFIG_HAVE_CLK)
735 /* Have OF but no CLK */
736 return -ENODEV;
737#else
738 const struct of_device_id *device;
739 struct device_node *np = dev->of_node;
740 u32 bus_freq, tclk;
741 int rc = 0;
742
743 if (IS_ERR(drv_data->clk)) {
744 rc = -ENODEV;
745 goto out;
746 }
747 tclk = clk_get_rate(drv_data->clk);
748
749 rc = of_property_read_u32(np, "clock-frequency", &bus_freq);
750 if (rc)
751 bus_freq = 100000; /* 100kHz by default */
752
753 if (!mv64xxx_find_baud_factors(bus_freq, tclk,
754 &drv_data->freq_n, &drv_data->freq_m)) {
755 rc = -EINVAL;
756 goto out;
757 }
758 drv_data->irq = irq_of_parse_and_map(np, 0);
759
760 drv_data->rstc = devm_reset_control_get_optional(dev, NULL);
761 if (IS_ERR(drv_data->rstc)) {
762 if (PTR_ERR(drv_data->rstc) == -EPROBE_DEFER) {
763 rc = -EPROBE_DEFER;
764 goto out;
765 }
766 } else {
767 reset_control_deassert(drv_data->rstc);
768 }
769
770 /* Its not yet defined how timeouts will be specified in device tree.
771 * So hard code the value to 1 second.
772 */
773 drv_data->adapter.timeout = HZ;
774
775 device = of_match_device(mv64xxx_i2c_of_match_table, dev);
776 if (!device)
777 return -ENODEV;
778
779 memcpy(&drv_data->reg_offsets, device->data, sizeof(drv_data->reg_offsets));
780
781 /*
782 * For controllers embedded in new SoCs activate the
783 * Transaction Generator support and the errata fix.
784 */
785 if (of_device_is_compatible(np, "marvell,mv78230-i2c")) {
786 drv_data->offload_enabled = true;
787 drv_data->errata_delay = true;
788 }
789
790 if (of_device_is_compatible(np, "marvell,mv78230-a0-i2c")) {
791 drv_data->offload_enabled = false;
792 drv_data->errata_delay = true;
793 }
794
795 if (of_device_is_compatible(np, "allwinner,sun6i-a31-i2c"))
796 drv_data->irq_clear_inverted = true;
797
798out:
799 return rc;
800#endif
801}
802#else /* CONFIG_OF */
803static int
804mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
805 struct device *dev)
806{
807 return -ENODEV;
808}
809#endif /* CONFIG_OF */
810
811static int
812mv64xxx_i2c_probe(struct platform_device *pd)
813{
814 struct mv64xxx_i2c_data *drv_data;
815 struct mv64xxx_i2c_pdata *pdata = dev_get_platdata(&pd->dev);
816 struct resource *r;
817 int rc;
818
819 if ((!pdata && !pd->dev.of_node))
820 return -ENODEV;
821
822 drv_data = devm_kzalloc(&pd->dev, sizeof(struct mv64xxx_i2c_data),
823 GFP_KERNEL);
824 if (!drv_data)
825 return -ENOMEM;
826
827 r = platform_get_resource(pd, IORESOURCE_MEM, 0);
828 drv_data->reg_base = devm_ioremap_resource(&pd->dev, r);
829 if (IS_ERR(drv_data->reg_base))
830 return PTR_ERR(drv_data->reg_base);
831
832 strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
833 sizeof(drv_data->adapter.name));
834
835 init_waitqueue_head(&drv_data->waitq);
836 spin_lock_init(&drv_data->lock);
837
838#if defined(CONFIG_HAVE_CLK)
839 /* Not all platforms have a clk */
840 drv_data->clk = devm_clk_get(&pd->dev, NULL);
841 if (!IS_ERR(drv_data->clk)) {
842 clk_prepare(drv_data->clk);
843 clk_enable(drv_data->clk);
844 }
845#endif
846 if (pdata) {
847 drv_data->freq_m = pdata->freq_m;
848 drv_data->freq_n = pdata->freq_n;
849 drv_data->irq = platform_get_irq(pd, 0);
850 drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
851 drv_data->offload_enabled = false;
852 memcpy(&drv_data->reg_offsets, &mv64xxx_i2c_regs_mv64xxx, sizeof(drv_data->reg_offsets));
853 } else if (pd->dev.of_node) {
854 rc = mv64xxx_of_config(drv_data, &pd->dev);
855 if (rc)
856 goto exit_clk;
857 }
858 if (drv_data->irq < 0) {
859 rc = -ENXIO;
860 goto exit_reset;
861 }
862
863 drv_data->adapter.dev.parent = &pd->dev;
864 drv_data->adapter.algo = &mv64xxx_i2c_algo;
865 drv_data->adapter.owner = THIS_MODULE;
866 drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD | I2C_CLASS_DEPRECATED;
867 drv_data->adapter.nr = pd->id;
868 drv_data->adapter.dev.of_node = pd->dev.of_node;
869 platform_set_drvdata(pd, drv_data);
870 i2c_set_adapdata(&drv_data->adapter, drv_data);
871
872 mv64xxx_i2c_hw_init(drv_data);
873
874 rc = request_irq(drv_data->irq, mv64xxx_i2c_intr, 0,
875 MV64XXX_I2C_CTLR_NAME, drv_data);
876 if (rc) {
877 dev_err(&drv_data->adapter.dev,
878 "mv64xxx: Can't register intr handler irq%d: %d\n",
879 drv_data->irq, rc);
880 goto exit_reset;
881 } else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) {
882 dev_err(&drv_data->adapter.dev,
883 "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc);
884 goto exit_free_irq;
885 }
886
887 return 0;
888
889exit_free_irq:
890 free_irq(drv_data->irq, drv_data);
891exit_reset:
892 if (!IS_ERR_OR_NULL(drv_data->rstc))
893 reset_control_assert(drv_data->rstc);
894exit_clk:
895#if defined(CONFIG_HAVE_CLK)
896 /* Not all platforms have a clk */
897 if (!IS_ERR(drv_data->clk)) {
898 clk_disable(drv_data->clk);
899 clk_unprepare(drv_data->clk);
900 }
901#endif
902 return rc;
903}
904
905static int
906mv64xxx_i2c_remove(struct platform_device *dev)
907{
908 struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(dev);
909
910 i2c_del_adapter(&drv_data->adapter);
911 free_irq(drv_data->irq, drv_data);
912 if (!IS_ERR_OR_NULL(drv_data->rstc))
913 reset_control_assert(drv_data->rstc);
914#if defined(CONFIG_HAVE_CLK)
915 /* Not all platforms have a clk */
916 if (!IS_ERR(drv_data->clk)) {
917 clk_disable(drv_data->clk);
918 clk_unprepare(drv_data->clk);
919 }
920#endif
921
922 return 0;
923}
924
925static struct platform_driver mv64xxx_i2c_driver = {
926 .probe = mv64xxx_i2c_probe,
927 .remove = mv64xxx_i2c_remove,
928 .driver = {
929 .owner = THIS_MODULE,
930 .name = MV64XXX_I2C_CTLR_NAME,
931 .of_match_table = mv64xxx_i2c_of_match_table,
932 },
933};
934
935module_platform_driver(mv64xxx_i2c_driver);
936
937MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
938MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver");
939MODULE_LICENSE("GPL");