1 /*
2  * Copyright (C) 2014 Broadcom Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation version 2.
7  *
8  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9  * kind, whether express or implied; without even the implied warranty
10  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/delay.h>
15 #include <linux/i2c.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/of_device.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
23 
24 #define IDM_CTRL_DIRECT_OFFSET       0x00
25 #define CFG_OFFSET                   0x00
26 #define CFG_RESET_SHIFT              31
27 #define CFG_EN_SHIFT                 30
28 #define CFG_SLAVE_ADDR_0_SHIFT       28
29 #define CFG_M_RETRY_CNT_SHIFT        16
30 #define CFG_M_RETRY_CNT_MASK         0x0f
31 
32 #define TIM_CFG_OFFSET               0x04
33 #define TIM_CFG_MODE_400_SHIFT       31
34 #define TIM_RAND_SLAVE_STRETCH_SHIFT      24
35 #define TIM_RAND_SLAVE_STRETCH_MASK       0x7f
36 #define TIM_PERIODIC_SLAVE_STRETCH_SHIFT  16
37 #define TIM_PERIODIC_SLAVE_STRETCH_MASK   0x7f
38 
39 #define S_CFG_SMBUS_ADDR_OFFSET           0x08
40 #define S_CFG_EN_NIC_SMB_ADDR3_SHIFT      31
41 #define S_CFG_NIC_SMB_ADDR3_SHIFT         24
42 #define S_CFG_NIC_SMB_ADDR3_MASK          0x7f
43 #define S_CFG_EN_NIC_SMB_ADDR2_SHIFT      23
44 #define S_CFG_NIC_SMB_ADDR2_SHIFT         16
45 #define S_CFG_NIC_SMB_ADDR2_MASK          0x7f
46 #define S_CFG_EN_NIC_SMB_ADDR1_SHIFT      15
47 #define S_CFG_NIC_SMB_ADDR1_SHIFT         8
48 #define S_CFG_NIC_SMB_ADDR1_MASK          0x7f
49 #define S_CFG_EN_NIC_SMB_ADDR0_SHIFT      7
50 #define S_CFG_NIC_SMB_ADDR0_SHIFT         0
51 #define S_CFG_NIC_SMB_ADDR0_MASK          0x7f
52 
53 #define M_FIFO_CTRL_OFFSET           0x0c
54 #define M_FIFO_RX_FLUSH_SHIFT        31
55 #define M_FIFO_TX_FLUSH_SHIFT        30
56 #define M_FIFO_RX_CNT_SHIFT          16
57 #define M_FIFO_RX_CNT_MASK           0x7f
58 #define M_FIFO_RX_THLD_SHIFT         8
59 #define M_FIFO_RX_THLD_MASK          0x3f
60 
61 #define S_FIFO_CTRL_OFFSET           0x10
62 #define S_FIFO_RX_FLUSH_SHIFT        31
63 #define S_FIFO_TX_FLUSH_SHIFT        30
64 #define S_FIFO_RX_CNT_SHIFT          16
65 #define S_FIFO_RX_CNT_MASK           0x7f
66 #define S_FIFO_RX_THLD_SHIFT         8
67 #define S_FIFO_RX_THLD_MASK          0x3f
68 
69 #define M_CMD_OFFSET                 0x30
70 #define M_CMD_START_BUSY_SHIFT       31
71 #define M_CMD_STATUS_SHIFT           25
72 #define M_CMD_STATUS_MASK            0x07
73 #define M_CMD_STATUS_SUCCESS         0x0
74 #define M_CMD_STATUS_LOST_ARB        0x1
75 #define M_CMD_STATUS_NACK_ADDR       0x2
76 #define M_CMD_STATUS_NACK_DATA       0x3
77 #define M_CMD_STATUS_TIMEOUT         0x4
78 #define M_CMD_STATUS_FIFO_UNDERRUN   0x5
79 #define M_CMD_STATUS_RX_FIFO_FULL    0x6
80 #define M_CMD_PROTOCOL_SHIFT         9
81 #define M_CMD_PROTOCOL_MASK          0xf
82 #define M_CMD_PROTOCOL_BLK_WR        0x7
83 #define M_CMD_PROTOCOL_BLK_RD        0x8
84 #define M_CMD_PROTOCOL_PROCESS       0xa
85 #define M_CMD_PEC_SHIFT              8
86 #define M_CMD_RD_CNT_SHIFT           0
87 #define M_CMD_RD_CNT_MASK            0xff
88 
89 #define S_CMD_OFFSET                 0x34
90 #define S_CMD_START_BUSY_SHIFT       31
91 #define S_CMD_STATUS_SHIFT           23
92 #define S_CMD_STATUS_MASK            0x07
93 #define S_CMD_STATUS_SUCCESS         0x0
94 #define S_CMD_STATUS_TIMEOUT         0x5
95 
96 #define IE_OFFSET                    0x38
97 #define IE_M_RX_FIFO_FULL_SHIFT      31
98 #define IE_M_RX_THLD_SHIFT           30
99 #define IE_M_START_BUSY_SHIFT        28
100 #define IE_M_TX_UNDERRUN_SHIFT       27
101 #define IE_S_RX_FIFO_FULL_SHIFT      26
102 #define IE_S_RX_THLD_SHIFT           25
103 #define IE_S_RX_EVENT_SHIFT          24
104 #define IE_S_START_BUSY_SHIFT        23
105 #define IE_S_TX_UNDERRUN_SHIFT       22
106 #define IE_S_RD_EVENT_SHIFT          21
107 
108 #define IS_OFFSET                    0x3c
109 #define IS_M_RX_FIFO_FULL_SHIFT      31
110 #define IS_M_RX_THLD_SHIFT           30
111 #define IS_M_START_BUSY_SHIFT        28
112 #define IS_M_TX_UNDERRUN_SHIFT       27
113 #define IS_S_RX_FIFO_FULL_SHIFT      26
114 #define IS_S_RX_THLD_SHIFT           25
115 #define IS_S_RX_EVENT_SHIFT          24
116 #define IS_S_START_BUSY_SHIFT        23
117 #define IS_S_TX_UNDERRUN_SHIFT       22
118 #define IS_S_RD_EVENT_SHIFT          21
119 
120 #define M_TX_OFFSET                  0x40
121 #define M_TX_WR_STATUS_SHIFT         31
122 #define M_TX_DATA_SHIFT              0
123 #define M_TX_DATA_MASK               0xff
124 
125 #define M_RX_OFFSET                  0x44
126 #define M_RX_STATUS_SHIFT            30
127 #define M_RX_STATUS_MASK             0x03
128 #define M_RX_PEC_ERR_SHIFT           29
129 #define M_RX_DATA_SHIFT              0
130 #define M_RX_DATA_MASK               0xff
131 
132 #define S_TX_OFFSET                  0x48
133 #define S_TX_WR_STATUS_SHIFT         31
134 #define S_TX_DATA_SHIFT              0
135 #define S_TX_DATA_MASK               0xff
136 
137 #define S_RX_OFFSET                  0x4c
138 #define S_RX_STATUS_SHIFT            30
139 #define S_RX_STATUS_MASK             0x03
140 #define S_RX_PEC_ERR_SHIFT           29
141 #define S_RX_DATA_SHIFT              0
142 #define S_RX_DATA_MASK               0xff
143 
144 #define I2C_TIMEOUT_MSEC             50000
145 #define M_TX_RX_FIFO_SIZE            64
146 #define M_RX_FIFO_MAX_THLD_VALUE     (M_TX_RX_FIFO_SIZE - 1)
147 
148 #define M_RX_MAX_READ_LEN            255
149 #define M_RX_FIFO_THLD_VALUE         50
150 
151 #define IE_M_ALL_INTERRUPT_SHIFT     27
152 #define IE_M_ALL_INTERRUPT_MASK      0x1e
153 
154 #define SLAVE_READ_WRITE_BIT_MASK    0x1
155 #define SLAVE_READ_WRITE_BIT_SHIFT   0x1
156 #define SLAVE_MAX_SIZE_TRANSACTION   64
157 #define SLAVE_CLOCK_STRETCH_TIME     25
158 
159 #define IE_S_ALL_INTERRUPT_SHIFT     21
160 #define IE_S_ALL_INTERRUPT_MASK      0x3f
161 
162 enum i2c_slave_read_status {
163 	I2C_SLAVE_RX_FIFO_EMPTY = 0,
164 	I2C_SLAVE_RX_START,
165 	I2C_SLAVE_RX_DATA,
166 	I2C_SLAVE_RX_END,
167 };
168 
169 enum bus_speed_index {
170 	I2C_SPD_100K = 0,
171 	I2C_SPD_400K,
172 };
173 
174 enum bcm_iproc_i2c_type {
175 	IPROC_I2C,
176 	IPROC_I2C_NIC
177 };
178 
179 struct bcm_iproc_i2c_dev {
180 	struct device *device;
181 	enum bcm_iproc_i2c_type type;
182 	int irq;
183 
184 	void __iomem *base;
185 	void __iomem *idm_base;
186 
187 	u32 ape_addr_mask;
188 
189 	/* lock for indirect access through IDM */
190 	spinlock_t idm_lock;
191 
192 	struct i2c_adapter adapter;
193 	unsigned int bus_speed;
194 
195 	struct completion done;
196 	int xfer_is_done;
197 
198 	struct i2c_msg *msg;
199 
200 	struct i2c_client *slave;
201 
202 	/* bytes that have been transferred */
203 	unsigned int tx_bytes;
204 	/* bytes that have been read */
205 	unsigned int rx_bytes;
206 	unsigned int thld_bytes;
207 };
208 
209 /*
210  * Can be expanded in the future if more interrupt status bits are utilized
211  */
212 #define ISR_MASK (BIT(IS_M_START_BUSY_SHIFT) | BIT(IS_M_TX_UNDERRUN_SHIFT)\
213 		| BIT(IS_M_RX_THLD_SHIFT))
214 
215 #define ISR_MASK_SLAVE (BIT(IS_S_START_BUSY_SHIFT)\
216 		| BIT(IS_S_RX_EVENT_SHIFT) | BIT(IS_S_RD_EVENT_SHIFT)\
217 		| BIT(IS_S_TX_UNDERRUN_SHIFT))
218 
219 static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave);
220 static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave);
221 static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
222 					 bool enable);
223 
224 static inline u32 iproc_i2c_rd_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
225 				   u32 offset)
226 {
227 	u32 val;
228 
229 	if (iproc_i2c->idm_base) {
230 		spin_lock(&iproc_i2c->idm_lock);
231 		writel(iproc_i2c->ape_addr_mask,
232 		       iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
233 		val = readl(iproc_i2c->base + offset);
234 		spin_unlock(&iproc_i2c->idm_lock);
235 	} else {
236 		val = readl(iproc_i2c->base + offset);
237 	}
238 
239 	return val;
240 }
241 
242 static inline void iproc_i2c_wr_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
243 				    u32 offset, u32 val)
244 {
245 	if (iproc_i2c->idm_base) {
246 		spin_lock(&iproc_i2c->idm_lock);
247 		writel(iproc_i2c->ape_addr_mask,
248 		       iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
249 		writel(val, iproc_i2c->base + offset);
250 		spin_unlock(&iproc_i2c->idm_lock);
251 	} else {
252 		writel(val, iproc_i2c->base + offset);
253 	}
254 }
255 
256 static void bcm_iproc_i2c_slave_init(
257 	struct bcm_iproc_i2c_dev *iproc_i2c, bool need_reset)
258 {
259 	u32 val;
260 
261 	if (need_reset) {
262 		/* put controller in reset */
263 		val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
264 		val |= BIT(CFG_RESET_SHIFT);
265 		iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
266 
267 		/* wait 100 usec per spec */
268 		udelay(100);
269 
270 		/* bring controller out of reset */
271 		val &= ~(BIT(CFG_RESET_SHIFT));
272 		iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
273 	}
274 
275 	/* flush TX/RX FIFOs */
276 	val = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT));
277 	iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val);
278 
279 	/* Maximum slave stretch time */
280 	val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
281 	val &= ~(TIM_RAND_SLAVE_STRETCH_MASK << TIM_RAND_SLAVE_STRETCH_SHIFT);
282 	val |= (SLAVE_CLOCK_STRETCH_TIME << TIM_RAND_SLAVE_STRETCH_SHIFT);
283 	iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
284 
285 	/* Configure the slave address */
286 	val = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET);
287 	val |= BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
288 	val &= ~(S_CFG_NIC_SMB_ADDR3_MASK << S_CFG_NIC_SMB_ADDR3_SHIFT);
289 	val |= (iproc_i2c->slave->addr << S_CFG_NIC_SMB_ADDR3_SHIFT);
290 	iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, val);
291 
292 	/* clear all pending slave interrupts */
293 	iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE);
294 
295 	/* Enable interrupt register to indicate a valid byte in receive fifo */
296 	val = BIT(IE_S_RX_EVENT_SHIFT);
297 	/* Enable interrupt register for the Slave BUSY command */
298 	val |= BIT(IE_S_START_BUSY_SHIFT);
299 	iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
300 }
301 
302 static void bcm_iproc_i2c_check_slave_status(
303 	struct bcm_iproc_i2c_dev *iproc_i2c)
304 {
305 	u32 val;
306 
307 	val = iproc_i2c_rd_reg(iproc_i2c, S_CMD_OFFSET);
308 	/* status is valid only when START_BUSY is cleared after it was set */
309 	if (val & BIT(S_CMD_START_BUSY_SHIFT))
310 		return;
311 
312 	val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK;
313 	if (val == S_CMD_STATUS_TIMEOUT) {
314 		dev_err(iproc_i2c->device, "slave random stretch time timeout\n");
315 
316 		/* re-initialize i2c for recovery */
317 		bcm_iproc_i2c_enable_disable(iproc_i2c, false);
318 		bcm_iproc_i2c_slave_init(iproc_i2c, true);
319 		bcm_iproc_i2c_enable_disable(iproc_i2c, true);
320 	}
321 }
322 
323 static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
324 				    u32 status)
325 {
326 	u32 val;
327 	u8 value, rx_status;
328 
329 	/* Slave RX byte receive */
330 	if (status & BIT(IS_S_RX_EVENT_SHIFT)) {
331 		val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET);
332 		rx_status = (val >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK;
333 		if (rx_status == I2C_SLAVE_RX_START) {
334 			/* Start of SMBUS for Master write */
335 			i2c_slave_event(iproc_i2c->slave,
336 					I2C_SLAVE_WRITE_REQUESTED, &value);
337 
338 			val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET);
339 			value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
340 			i2c_slave_event(iproc_i2c->slave,
341 					I2C_SLAVE_WRITE_RECEIVED, &value);
342 		} else if (status & BIT(IS_S_RD_EVENT_SHIFT)) {
343 			/* Start of SMBUS for Master Read */
344 			i2c_slave_event(iproc_i2c->slave,
345 					I2C_SLAVE_READ_REQUESTED, &value);
346 			iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
347 
348 			val = BIT(S_CMD_START_BUSY_SHIFT);
349 			iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
350 
351 			/*
352 			 * Enable interrupt for TX FIFO becomes empty and
353 			 * less than PKT_LENGTH bytes were output on the SMBUS
354 			 */
355 			val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
356 			val |= BIT(IE_S_TX_UNDERRUN_SHIFT);
357 			iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
358 		} else {
359 			/* Master write other than start */
360 			value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
361 			i2c_slave_event(iproc_i2c->slave,
362 					I2C_SLAVE_WRITE_RECEIVED, &value);
363 		}
364 	} else if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) {
365 		/* Master read other than start */
366 		i2c_slave_event(iproc_i2c->slave,
367 				I2C_SLAVE_READ_PROCESSED, &value);
368 
369 		iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
370 		val = BIT(S_CMD_START_BUSY_SHIFT);
371 		iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
372 	}
373 
374 	/* Stop */
375 	if (status & BIT(IS_S_START_BUSY_SHIFT)) {
376 		i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value);
377 		/*
378 		 * Enable interrupt for TX FIFO becomes empty and
379 		 * less than PKT_LENGTH bytes were output on the SMBUS
380 		 */
381 		val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
382 		val &= ~BIT(IE_S_TX_UNDERRUN_SHIFT);
383 		iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
384 	}
385 
386 	/* clear interrupt status */
387 	iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status);
388 
389 	bcm_iproc_i2c_check_slave_status(iproc_i2c);
390 	return true;
391 }
392 
393 static void bcm_iproc_i2c_read_valid_bytes(struct bcm_iproc_i2c_dev *iproc_i2c)
394 {
395 	struct i2c_msg *msg = iproc_i2c->msg;
396 	uint32_t val;
397 
398 	/* Read valid data from RX FIFO */
399 	while (iproc_i2c->rx_bytes < msg->len) {
400 		val = iproc_i2c_rd_reg(iproc_i2c, M_RX_OFFSET);
401 
402 		/* rx fifo empty */
403 		if (!((val >> M_RX_STATUS_SHIFT) & M_RX_STATUS_MASK))
404 			break;
405 
406 		msg->buf[iproc_i2c->rx_bytes] =
407 			(val >> M_RX_DATA_SHIFT) & M_RX_DATA_MASK;
408 		iproc_i2c->rx_bytes++;
409 	}
410 }
411 
412 static void bcm_iproc_i2c_send(struct bcm_iproc_i2c_dev *iproc_i2c)
413 {
414 	struct i2c_msg *msg = iproc_i2c->msg;
415 	unsigned int tx_bytes = msg->len - iproc_i2c->tx_bytes;
416 	unsigned int i;
417 	u32 val;
418 
419 	/* can only fill up to the FIFO size */
420 	tx_bytes = min_t(unsigned int, tx_bytes, M_TX_RX_FIFO_SIZE);
421 	for (i = 0; i < tx_bytes; i++) {
422 		/* start from where we left over */
423 		unsigned int idx = iproc_i2c->tx_bytes + i;
424 
425 		val = msg->buf[idx];
426 
427 		/* mark the last byte */
428 		if (idx == msg->len - 1) {
429 			val |= BIT(M_TX_WR_STATUS_SHIFT);
430 
431 			if (iproc_i2c->irq) {
432 				u32 tmp;
433 
434 				/*
435 				 * Since this is the last byte, we should now
436 				 * disable TX FIFO underrun interrupt
437 				 */
438 				tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
439 				tmp &= ~BIT(IE_M_TX_UNDERRUN_SHIFT);
440 				iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET,
441 						 tmp);
442 			}
443 		}
444 
445 		/* load data into TX FIFO */
446 		iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
447 	}
448 
449 	/* update number of transferred bytes */
450 	iproc_i2c->tx_bytes += tx_bytes;
451 }
452 
453 static void bcm_iproc_i2c_read(struct bcm_iproc_i2c_dev *iproc_i2c)
454 {
455 	struct i2c_msg *msg = iproc_i2c->msg;
456 	u32 bytes_left, val;
457 
458 	bcm_iproc_i2c_read_valid_bytes(iproc_i2c);
459 	bytes_left = msg->len - iproc_i2c->rx_bytes;
460 	if (bytes_left == 0) {
461 		if (iproc_i2c->irq) {
462 			/* finished reading all data, disable rx thld event */
463 			val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
464 			val &= ~BIT(IS_M_RX_THLD_SHIFT);
465 			iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
466 		}
467 	} else if (bytes_left < iproc_i2c->thld_bytes) {
468 		/* set bytes left as threshold */
469 		val = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET);
470 		val &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT);
471 		val |= (bytes_left << M_FIFO_RX_THLD_SHIFT);
472 		iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
473 		iproc_i2c->thld_bytes = bytes_left;
474 	}
475 	/*
476 	 * bytes_left >= iproc_i2c->thld_bytes,
477 	 * hence no need to change the THRESHOLD SET.
478 	 * It will remain as iproc_i2c->thld_bytes itself
479 	 */
480 }
481 
482 static void bcm_iproc_i2c_process_m_event(struct bcm_iproc_i2c_dev *iproc_i2c,
483 					  u32 status)
484 {
485 	/* TX FIFO is empty and we have more data to send */
486 	if (status & BIT(IS_M_TX_UNDERRUN_SHIFT))
487 		bcm_iproc_i2c_send(iproc_i2c);
488 
489 	/* RX FIFO threshold is reached and data needs to be read out */
490 	if (status & BIT(IS_M_RX_THLD_SHIFT))
491 		bcm_iproc_i2c_read(iproc_i2c);
492 
493 	/* transfer is done */
494 	if (status & BIT(IS_M_START_BUSY_SHIFT)) {
495 		iproc_i2c->xfer_is_done = 1;
496 		if (iproc_i2c->irq)
497 			complete(&iproc_i2c->done);
498 	}
499 }
500 
501 static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data)
502 {
503 	struct bcm_iproc_i2c_dev *iproc_i2c = data;
504 	u32 status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET);
505 	bool ret;
506 	u32 sl_status = status & ISR_MASK_SLAVE;
507 
508 	if (sl_status) {
509 		ret = bcm_iproc_i2c_slave_isr(iproc_i2c, sl_status);
510 		if (ret)
511 			return IRQ_HANDLED;
512 		else
513 			return IRQ_NONE;
514 	}
515 
516 	status &= ISR_MASK;
517 	if (!status)
518 		return IRQ_NONE;
519 
520 	/* process all master based events */
521 	bcm_iproc_i2c_process_m_event(iproc_i2c, status);
522 	iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status);
523 
524 	return IRQ_HANDLED;
525 }
526 
527 static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
528 {
529 	u32 val;
530 
531 	/* put controller in reset */
532 	val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
533 	val |= BIT(CFG_RESET_SHIFT);
534 	val &= ~(BIT(CFG_EN_SHIFT));
535 	iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
536 
537 	/* wait 100 usec per spec */
538 	udelay(100);
539 
540 	/* bring controller out of reset */
541 	val &= ~(BIT(CFG_RESET_SHIFT));
542 	iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
543 
544 	/* flush TX/RX FIFOs and set RX FIFO threshold to zero */
545 	val = (BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT));
546 	iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
547 	/* disable all interrupts */
548 	val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
549 	val &= ~(IE_M_ALL_INTERRUPT_MASK <<
550 			IE_M_ALL_INTERRUPT_SHIFT);
551 	iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
552 
553 	/* clear all pending interrupts */
554 	iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, 0xffffffff);
555 
556 	return 0;
557 }
558 
559 static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
560 					 bool enable)
561 {
562 	u32 val;
563 
564 	val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
565 	if (enable)
566 		val |= BIT(CFG_EN_SHIFT);
567 	else
568 		val &= ~BIT(CFG_EN_SHIFT);
569 	iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
570 }
571 
572 static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c,
573 				      struct i2c_msg *msg)
574 {
575 	u32 val;
576 
577 	val = iproc_i2c_rd_reg(iproc_i2c, M_CMD_OFFSET);
578 	val = (val >> M_CMD_STATUS_SHIFT) & M_CMD_STATUS_MASK;
579 
580 	switch (val) {
581 	case M_CMD_STATUS_SUCCESS:
582 		return 0;
583 
584 	case M_CMD_STATUS_LOST_ARB:
585 		dev_dbg(iproc_i2c->device, "lost bus arbitration\n");
586 		return -EAGAIN;
587 
588 	case M_CMD_STATUS_NACK_ADDR:
589 		dev_dbg(iproc_i2c->device, "NAK addr:0x%02x\n", msg->addr);
590 		return -ENXIO;
591 
592 	case M_CMD_STATUS_NACK_DATA:
593 		dev_dbg(iproc_i2c->device, "NAK data\n");
594 		return -ENXIO;
595 
596 	case M_CMD_STATUS_TIMEOUT:
597 		dev_dbg(iproc_i2c->device, "bus timeout\n");
598 		return -ETIMEDOUT;
599 
600 	case M_CMD_STATUS_FIFO_UNDERRUN:
601 		dev_dbg(iproc_i2c->device, "FIFO under-run\n");
602 		return -ENXIO;
603 
604 	case M_CMD_STATUS_RX_FIFO_FULL:
605 		dev_dbg(iproc_i2c->device, "RX FIFO full\n");
606 		return -ETIMEDOUT;
607 
608 	default:
609 		dev_dbg(iproc_i2c->device, "unknown error code=%d\n", val);
610 
611 		/* re-initialize i2c for recovery */
612 		bcm_iproc_i2c_enable_disable(iproc_i2c, false);
613 		bcm_iproc_i2c_init(iproc_i2c);
614 		bcm_iproc_i2c_enable_disable(iproc_i2c, true);
615 
616 		return -EIO;
617 	}
618 }
619 
620 static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c,
621 				   struct i2c_msg *msg,
622 				   u32 cmd)
623 {
624 	unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT_MSEC);
625 	u32 val, status;
626 	int ret;
627 
628 	iproc_i2c_wr_reg(iproc_i2c, M_CMD_OFFSET, cmd);
629 
630 	if (iproc_i2c->irq) {
631 		time_left = wait_for_completion_timeout(&iproc_i2c->done,
632 							time_left);
633 		/* disable all interrupts */
634 		iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
635 		/* read it back to flush the write */
636 		iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
637 		/* make sure the interrupt handler isn't running */
638 		synchronize_irq(iproc_i2c->irq);
639 
640 	} else { /* polling mode */
641 		unsigned long timeout = jiffies + time_left;
642 
643 		do {
644 			status = iproc_i2c_rd_reg(iproc_i2c,
645 						  IS_OFFSET) & ISR_MASK;
646 			bcm_iproc_i2c_process_m_event(iproc_i2c, status);
647 			iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status);
648 
649 			if (time_after(jiffies, timeout)) {
650 				time_left = 0;
651 				break;
652 			}
653 
654 			cpu_relax();
655 			cond_resched();
656 		} while (!iproc_i2c->xfer_is_done);
657 	}
658 
659 	if (!time_left && !iproc_i2c->xfer_is_done) {
660 		dev_err(iproc_i2c->device, "transaction timed out\n");
661 
662 		/* flush both TX/RX FIFOs */
663 		val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT);
664 		iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
665 		return -ETIMEDOUT;
666 	}
667 
668 	ret = bcm_iproc_i2c_check_status(iproc_i2c, msg);
669 	if (ret) {
670 		/* flush both TX/RX FIFOs */
671 		val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT);
672 		iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
673 		return ret;
674 	}
675 
676 	return 0;
677 }
678 
679 /*
680  * If 'process_call' is true, then this is a multi-msg transfer that requires
681  * a repeated start between the messages.
682  * More specifically, it must be a write (reg) followed by a read (data).
683  * The i2c quirks are set to enforce this rule.
684  */
685 static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c,
686 					struct i2c_msg *msgs, bool process_call)
687 {
688 	int i;
689 	u8 addr;
690 	u32 val, tmp, val_intr_en;
691 	unsigned int tx_bytes;
692 	struct i2c_msg *msg = &msgs[0];
693 
694 	/* check if bus is busy */
695 	if (!!(iproc_i2c_rd_reg(iproc_i2c,
696 				M_CMD_OFFSET) & BIT(M_CMD_START_BUSY_SHIFT))) {
697 		dev_warn(iproc_i2c->device, "bus is busy\n");
698 		return -EBUSY;
699 	}
700 
701 	iproc_i2c->msg = msg;
702 
703 	/* format and load slave address into the TX FIFO */
704 	addr = i2c_8bit_addr_from_msg(msg);
705 	iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, addr);
706 
707 	/*
708 	 * For a write transaction, load data into the TX FIFO. Only allow
709 	 * loading up to TX FIFO size - 1 bytes of data since the first byte
710 	 * has been used up by the slave address
711 	 */
712 	tx_bytes = min_t(unsigned int, msg->len, M_TX_RX_FIFO_SIZE - 1);
713 	if (!(msg->flags & I2C_M_RD)) {
714 		for (i = 0; i < tx_bytes; i++) {
715 			val = msg->buf[i];
716 
717 			/* mark the last byte */
718 			if (!process_call && (i == msg->len - 1))
719 				val |= 1 << M_TX_WR_STATUS_SHIFT;
720 
721 			iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
722 		}
723 		iproc_i2c->tx_bytes = tx_bytes;
724 	}
725 
726 	/* Process the read message if this is process call */
727 	if (process_call) {
728 		msg++;
729 		iproc_i2c->msg = msg;  /* point to second msg */
730 
731 		/*
732 		 * The last byte to be sent out should be a slave
733 		 * address with read operation
734 		 */
735 		addr = i2c_8bit_addr_from_msg(msg);
736 		/* mark it the last byte out */
737 		val = addr | (1 << M_TX_WR_STATUS_SHIFT);
738 		iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
739 	}
740 
741 	/* mark as incomplete before starting the transaction */
742 	if (iproc_i2c->irq)
743 		reinit_completion(&iproc_i2c->done);
744 
745 	iproc_i2c->xfer_is_done = 0;
746 
747 	/*
748 	 * Enable the "start busy" interrupt, which will be triggered after the
749 	 * transaction is done, i.e., the internal start_busy bit, transitions
750 	 * from 1 to 0.
751 	 */
752 	val_intr_en = BIT(IE_M_START_BUSY_SHIFT);
753 
754 	/*
755 	 * If TX data size is larger than the TX FIFO, need to enable TX
756 	 * underrun interrupt, which will be triggerred when the TX FIFO is
757 	 * empty. When that happens we can then pump more data into the FIFO
758 	 */
759 	if (!process_call && !(msg->flags & I2C_M_RD) &&
760 	    msg->len > iproc_i2c->tx_bytes)
761 		val_intr_en |= BIT(IE_M_TX_UNDERRUN_SHIFT);
762 
763 	/*
764 	 * Now we can activate the transfer. For a read operation, specify the
765 	 * number of bytes to read
766 	 */
767 	val = BIT(M_CMD_START_BUSY_SHIFT);
768 	if (msg->flags & I2C_M_RD) {
769 		u32 protocol;
770 
771 		iproc_i2c->rx_bytes = 0;
772 		if (msg->len > M_RX_FIFO_MAX_THLD_VALUE)
773 			iproc_i2c->thld_bytes = M_RX_FIFO_THLD_VALUE;
774 		else
775 			iproc_i2c->thld_bytes = msg->len;
776 
777 		/* set threshold value */
778 		tmp = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET);
779 		tmp &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT);
780 		tmp |= iproc_i2c->thld_bytes << M_FIFO_RX_THLD_SHIFT;
781 		iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, tmp);
782 
783 		/* enable the RX threshold interrupt */
784 		val_intr_en |= BIT(IE_M_RX_THLD_SHIFT);
785 
786 		protocol = process_call ?
787 				M_CMD_PROTOCOL_PROCESS : M_CMD_PROTOCOL_BLK_RD;
788 
789 		val |= (protocol << M_CMD_PROTOCOL_SHIFT) |
790 		       (msg->len << M_CMD_RD_CNT_SHIFT);
791 	} else {
792 		val |= (M_CMD_PROTOCOL_BLK_WR << M_CMD_PROTOCOL_SHIFT);
793 	}
794 
795 	if (iproc_i2c->irq)
796 		iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val_intr_en);
797 
798 	return bcm_iproc_i2c_xfer_wait(iproc_i2c, msg, val);
799 }
800 
801 static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter,
802 			      struct i2c_msg msgs[], int num)
803 {
804 	struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adapter);
805 	bool process_call = false;
806 	int ret;
807 
808 	if (num == 2) {
809 		/* Repeated start, use process call */
810 		process_call = true;
811 		if (msgs[1].flags & I2C_M_NOSTART) {
812 			dev_err(iproc_i2c->device, "Invalid repeated start\n");
813 			return -EOPNOTSUPP;
814 		}
815 	}
816 
817 	ret = bcm_iproc_i2c_xfer_internal(iproc_i2c, msgs, process_call);
818 	if (ret) {
819 		dev_dbg(iproc_i2c->device, "xfer failed\n");
820 		return ret;
821 	}
822 
823 	return num;
824 }
825 
826 static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap)
827 {
828 	u32 val;
829 
830 	/* We do not support the SMBUS Quick command */
831 	val = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
832 
833 	if (adap->algo->reg_slave)
834 		val |= I2C_FUNC_SLAVE;
835 
836 	return val;
837 }
838 
839 static struct i2c_algorithm bcm_iproc_algo = {
840 	.master_xfer = bcm_iproc_i2c_xfer,
841 	.functionality = bcm_iproc_i2c_functionality,
842 	.reg_slave = bcm_iproc_i2c_reg_slave,
843 	.unreg_slave = bcm_iproc_i2c_unreg_slave,
844 };
845 
846 static const struct i2c_adapter_quirks bcm_iproc_i2c_quirks = {
847 	.flags = I2C_AQ_COMB_WRITE_THEN_READ,
848 	.max_comb_1st_msg_len = M_TX_RX_FIFO_SIZE,
849 	.max_read_len = M_RX_MAX_READ_LEN,
850 };
851 
852 static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
853 {
854 	unsigned int bus_speed;
855 	u32 val;
856 	int ret = of_property_read_u32(iproc_i2c->device->of_node,
857 				       "clock-frequency", &bus_speed);
858 	if (ret < 0) {
859 		dev_info(iproc_i2c->device,
860 			"unable to interpret clock-frequency DT property\n");
861 		bus_speed = I2C_MAX_STANDARD_MODE_FREQ;
862 	}
863 
864 	if (bus_speed < I2C_MAX_STANDARD_MODE_FREQ) {
865 		dev_err(iproc_i2c->device, "%d Hz bus speed not supported\n",
866 			bus_speed);
867 		dev_err(iproc_i2c->device,
868 			"valid speeds are 100khz and 400khz\n");
869 		return -EINVAL;
870 	} else if (bus_speed < I2C_MAX_FAST_MODE_FREQ) {
871 		bus_speed = I2C_MAX_STANDARD_MODE_FREQ;
872 	} else {
873 		bus_speed = I2C_MAX_FAST_MODE_FREQ;
874 	}
875 
876 	iproc_i2c->bus_speed = bus_speed;
877 	val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
878 	val &= ~BIT(TIM_CFG_MODE_400_SHIFT);
879 	val |= (bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT;
880 	iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
881 
882 	dev_info(iproc_i2c->device, "bus set to %u Hz\n", bus_speed);
883 
884 	return 0;
885 }
886 
887 static int bcm_iproc_i2c_probe(struct platform_device *pdev)
888 {
889 	int irq, ret = 0;
890 	struct bcm_iproc_i2c_dev *iproc_i2c;
891 	struct i2c_adapter *adap;
892 	struct resource *res;
893 
894 	iproc_i2c = devm_kzalloc(&pdev->dev, sizeof(*iproc_i2c),
895 				 GFP_KERNEL);
896 	if (!iproc_i2c)
897 		return -ENOMEM;
898 
899 	platform_set_drvdata(pdev, iproc_i2c);
900 	iproc_i2c->device = &pdev->dev;
901 	iproc_i2c->type =
902 		(enum bcm_iproc_i2c_type)of_device_get_match_data(&pdev->dev);
903 	init_completion(&iproc_i2c->done);
904 
905 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
906 	iproc_i2c->base = devm_ioremap_resource(iproc_i2c->device, res);
907 	if (IS_ERR(iproc_i2c->base))
908 		return PTR_ERR(iproc_i2c->base);
909 
910 	if (iproc_i2c->type == IPROC_I2C_NIC) {
911 		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
912 		iproc_i2c->idm_base = devm_ioremap_resource(iproc_i2c->device,
913 							    res);
914 		if (IS_ERR(iproc_i2c->idm_base))
915 			return PTR_ERR(iproc_i2c->idm_base);
916 
917 		ret = of_property_read_u32(iproc_i2c->device->of_node,
918 					   "brcm,ape-hsls-addr-mask",
919 					   &iproc_i2c->ape_addr_mask);
920 		if (ret < 0) {
921 			dev_err(iproc_i2c->device,
922 				"'brcm,ape-hsls-addr-mask' missing\n");
923 			return -EINVAL;
924 		}
925 
926 		spin_lock_init(&iproc_i2c->idm_lock);
927 
928 		/* no slave support */
929 		bcm_iproc_algo.reg_slave = NULL;
930 		bcm_iproc_algo.unreg_slave = NULL;
931 	}
932 
933 	ret = bcm_iproc_i2c_init(iproc_i2c);
934 	if (ret)
935 		return ret;
936 
937 	ret = bcm_iproc_i2c_cfg_speed(iproc_i2c);
938 	if (ret)
939 		return ret;
940 
941 	irq = platform_get_irq(pdev, 0);
942 	if (irq > 0) {
943 		ret = devm_request_irq(iproc_i2c->device, irq,
944 				       bcm_iproc_i2c_isr, 0, pdev->name,
945 				       iproc_i2c);
946 		if (ret < 0) {
947 			dev_err(iproc_i2c->device,
948 				"unable to request irq %i\n", irq);
949 			return ret;
950 		}
951 
952 		iproc_i2c->irq = irq;
953 	} else {
954 		dev_warn(iproc_i2c->device,
955 			 "no irq resource, falling back to poll mode\n");
956 	}
957 
958 	bcm_iproc_i2c_enable_disable(iproc_i2c, true);
959 
960 	adap = &iproc_i2c->adapter;
961 	i2c_set_adapdata(adap, iproc_i2c);
962 	snprintf(adap->name, sizeof(adap->name),
963 		"Broadcom iProc (%s)",
964 		of_node_full_name(iproc_i2c->device->of_node));
965 	adap->algo = &bcm_iproc_algo;
966 	adap->quirks = &bcm_iproc_i2c_quirks;
967 	adap->dev.parent = &pdev->dev;
968 	adap->dev.of_node = pdev->dev.of_node;
969 
970 	return i2c_add_adapter(adap);
971 }
972 
973 static int bcm_iproc_i2c_remove(struct platform_device *pdev)
974 {
975 	struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
976 
977 	if (iproc_i2c->irq) {
978 		/*
979 		 * Make sure there's no pending interrupt when we remove the
980 		 * adapter
981 		 */
982 		iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
983 		iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
984 		synchronize_irq(iproc_i2c->irq);
985 	}
986 
987 	i2c_del_adapter(&iproc_i2c->adapter);
988 	bcm_iproc_i2c_enable_disable(iproc_i2c, false);
989 
990 	return 0;
991 }
992 
993 #ifdef CONFIG_PM_SLEEP
994 
995 static int bcm_iproc_i2c_suspend(struct device *dev)
996 {
997 	struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev);
998 
999 	if (iproc_i2c->irq) {
1000 		/*
1001 		 * Make sure there's no pending interrupt when we go into
1002 		 * suspend
1003 		 */
1004 		iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0);
1005 		iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
1006 		synchronize_irq(iproc_i2c->irq);
1007 	}
1008 
1009 	/* now disable the controller */
1010 	bcm_iproc_i2c_enable_disable(iproc_i2c, false);
1011 
1012 	return 0;
1013 }
1014 
1015 static int bcm_iproc_i2c_resume(struct device *dev)
1016 {
1017 	struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev);
1018 	int ret;
1019 	u32 val;
1020 
1021 	/*
1022 	 * Power domain could have been shut off completely in system deep
1023 	 * sleep, so re-initialize the block here
1024 	 */
1025 	ret = bcm_iproc_i2c_init(iproc_i2c);
1026 	if (ret)
1027 		return ret;
1028 
1029 	/* configure to the desired bus speed */
1030 	val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
1031 	val &= ~BIT(TIM_CFG_MODE_400_SHIFT);
1032 	val |= (iproc_i2c->bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT;
1033 	iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val);
1034 
1035 	bcm_iproc_i2c_enable_disable(iproc_i2c, true);
1036 
1037 	return 0;
1038 }
1039 
1040 static const struct dev_pm_ops bcm_iproc_i2c_pm_ops = {
1041 	.suspend_late = &bcm_iproc_i2c_suspend,
1042 	.resume_early = &bcm_iproc_i2c_resume
1043 };
1044 
1045 #define BCM_IPROC_I2C_PM_OPS (&bcm_iproc_i2c_pm_ops)
1046 #else
1047 #define BCM_IPROC_I2C_PM_OPS NULL
1048 #endif /* CONFIG_PM_SLEEP */
1049 
1050 
1051 static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave)
1052 {
1053 	struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
1054 
1055 	if (iproc_i2c->slave)
1056 		return -EBUSY;
1057 
1058 	if (slave->flags & I2C_CLIENT_TEN)
1059 		return -EAFNOSUPPORT;
1060 
1061 	iproc_i2c->slave = slave;
1062 	bcm_iproc_i2c_slave_init(iproc_i2c, false);
1063 	return 0;
1064 }
1065 
1066 static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave)
1067 {
1068 	u32 tmp;
1069 	struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
1070 
1071 	if (!iproc_i2c->slave)
1072 		return -EINVAL;
1073 
1074 	iproc_i2c->slave = NULL;
1075 
1076 	/* disable all slave interrupts */
1077 	tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
1078 	tmp &= ~(IE_S_ALL_INTERRUPT_MASK <<
1079 			IE_S_ALL_INTERRUPT_SHIFT);
1080 	iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, tmp);
1081 
1082 	/* Erase the slave address programmed */
1083 	tmp = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET);
1084 	tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
1085 	iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, tmp);
1086 
1087 	return 0;
1088 }
1089 
1090 static const struct of_device_id bcm_iproc_i2c_of_match[] = {
1091 	{
1092 		.compatible = "brcm,iproc-i2c",
1093 		.data = (int *)IPROC_I2C,
1094 	}, {
1095 		.compatible = "brcm,iproc-nic-i2c",
1096 		.data = (int *)IPROC_I2C_NIC,
1097 	},
1098 	{ /* sentinel */ }
1099 };
1100 MODULE_DEVICE_TABLE(of, bcm_iproc_i2c_of_match);
1101 
1102 static struct platform_driver bcm_iproc_i2c_driver = {
1103 	.driver = {
1104 		.name = "bcm-iproc-i2c",
1105 		.of_match_table = bcm_iproc_i2c_of_match,
1106 		.pm = BCM_IPROC_I2C_PM_OPS,
1107 	},
1108 	.probe = bcm_iproc_i2c_probe,
1109 	.remove = bcm_iproc_i2c_remove,
1110 };
1111 module_platform_driver(bcm_iproc_i2c_driver);
1112 
1113 MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
1114 MODULE_DESCRIPTION("Broadcom iProc I2C Driver");
1115 MODULE_LICENSE("GPL v2");
1116