xref: /linux/drivers/i2c/busses/i2c-tegra.c (revision 80d7da1cac62f28b3df4880e8143b39cabb4b59a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * drivers/i2c/busses/i2c-tegra.c
4  *
5  * Copyright (C) 2010 Google, Inc.
6  * Author: Colin Cross <ccross@android.com>
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/platform_device.h>
12 #include <linux/clk.h>
13 #include <linux/err.h>
14 #include <linux/i2c.h>
15 #include <linux/io.h>
16 #include <linux/interrupt.h>
17 #include <linux/delay.h>
18 #include <linux/slab.h>
19 #include <linux/of_device.h>
20 #include <linux/module.h>
21 #include <linux/reset.h>
22 #include <linux/pinctrl/consumer.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/iopoll.h>
25 
26 #include <asm/unaligned.h>
27 
28 #define TEGRA_I2C_TIMEOUT (msecs_to_jiffies(1000))
29 #define BYTES_PER_FIFO_WORD 4
30 
31 #define I2C_CNFG				0x000
32 #define I2C_CNFG_DEBOUNCE_CNT_SHIFT		12
33 #define I2C_CNFG_PACKET_MODE_EN			BIT(10)
34 #define I2C_CNFG_NEW_MASTER_FSM			BIT(11)
35 #define I2C_CNFG_MULTI_MASTER_MODE		BIT(17)
36 #define I2C_STATUS				0x01C
37 #define I2C_SL_CNFG				0x020
38 #define I2C_SL_CNFG_NACK			BIT(1)
39 #define I2C_SL_CNFG_NEWSL			BIT(2)
40 #define I2C_SL_ADDR1				0x02c
41 #define I2C_SL_ADDR2				0x030
42 #define I2C_TX_FIFO				0x050
43 #define I2C_RX_FIFO				0x054
44 #define I2C_PACKET_TRANSFER_STATUS		0x058
45 #define I2C_FIFO_CONTROL			0x05c
46 #define I2C_FIFO_CONTROL_TX_FLUSH		BIT(1)
47 #define I2C_FIFO_CONTROL_RX_FLUSH		BIT(0)
48 #define I2C_FIFO_CONTROL_TX_TRIG_SHIFT		5
49 #define I2C_FIFO_CONTROL_RX_TRIG_SHIFT		2
50 #define I2C_FIFO_STATUS				0x060
51 #define I2C_FIFO_STATUS_TX_MASK			0xF0
52 #define I2C_FIFO_STATUS_TX_SHIFT		4
53 #define I2C_FIFO_STATUS_RX_MASK			0x0F
54 #define I2C_FIFO_STATUS_RX_SHIFT		0
55 #define I2C_INT_MASK				0x064
56 #define I2C_INT_STATUS				0x068
57 #define I2C_INT_PACKET_XFER_COMPLETE		BIT(7)
58 #define I2C_INT_ALL_PACKETS_XFER_COMPLETE	BIT(6)
59 #define I2C_INT_TX_FIFO_OVERFLOW		BIT(5)
60 #define I2C_INT_RX_FIFO_UNDERFLOW		BIT(4)
61 #define I2C_INT_NO_ACK				BIT(3)
62 #define I2C_INT_ARBITRATION_LOST		BIT(2)
63 #define I2C_INT_TX_FIFO_DATA_REQ		BIT(1)
64 #define I2C_INT_RX_FIFO_DATA_REQ		BIT(0)
65 #define I2C_CLK_DIVISOR				0x06c
66 #define I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT	16
67 #define I2C_CLK_MULTIPLIER_STD_FAST_MODE	8
68 
69 #define DVC_CTRL_REG1				0x000
70 #define DVC_CTRL_REG1_INTR_EN			BIT(10)
71 #define DVC_CTRL_REG2				0x004
72 #define DVC_CTRL_REG3				0x008
73 #define DVC_CTRL_REG3_SW_PROG			BIT(26)
74 #define DVC_CTRL_REG3_I2C_DONE_INTR_EN		BIT(30)
75 #define DVC_STATUS				0x00c
76 #define DVC_STATUS_I2C_DONE_INTR		BIT(30)
77 
78 #define I2C_ERR_NONE				0x00
79 #define I2C_ERR_NO_ACK				0x01
80 #define I2C_ERR_ARBITRATION_LOST		0x02
81 #define I2C_ERR_UNKNOWN_INTERRUPT		0x04
82 
83 #define PACKET_HEADER0_HEADER_SIZE_SHIFT	28
84 #define PACKET_HEADER0_PACKET_ID_SHIFT		16
85 #define PACKET_HEADER0_CONT_ID_SHIFT		12
86 #define PACKET_HEADER0_PROTOCOL_I2C		BIT(4)
87 
88 #define I2C_HEADER_HIGHSPEED_MODE		BIT(22)
89 #define I2C_HEADER_CONT_ON_NAK			BIT(21)
90 #define I2C_HEADER_SEND_START_BYTE		BIT(20)
91 #define I2C_HEADER_READ				BIT(19)
92 #define I2C_HEADER_10BIT_ADDR			BIT(18)
93 #define I2C_HEADER_IE_ENABLE			BIT(17)
94 #define I2C_HEADER_REPEAT_START			BIT(16)
95 #define I2C_HEADER_CONTINUE_XFER		BIT(15)
96 #define I2C_HEADER_MASTER_ADDR_SHIFT		12
97 #define I2C_HEADER_SLAVE_ADDR_SHIFT		1
98 
99 #define I2C_CONFIG_LOAD				0x08C
100 #define I2C_MSTR_CONFIG_LOAD			BIT(0)
101 #define I2C_SLV_CONFIG_LOAD			BIT(1)
102 #define I2C_TIMEOUT_CONFIG_LOAD			BIT(2)
103 
104 #define I2C_CLKEN_OVERRIDE			0x090
105 #define I2C_MST_CORE_CLKEN_OVR			BIT(0)
106 
107 #define I2C_CONFIG_LOAD_TIMEOUT			1000000
108 
109 #define I2C_MST_FIFO_CONTROL			0x0b4
110 #define I2C_MST_FIFO_CONTROL_RX_FLUSH		BIT(0)
111 #define I2C_MST_FIFO_CONTROL_TX_FLUSH		BIT(1)
112 #define I2C_MST_FIFO_CONTROL_RX_TRIG(x)		(((x) - 1) <<  4)
113 #define I2C_MST_FIFO_CONTROL_TX_TRIG(x)		(((x) - 1) << 16)
114 
115 #define I2C_MST_FIFO_STATUS			0x0b8
116 #define I2C_MST_FIFO_STATUS_RX_MASK		0xff
117 #define I2C_MST_FIFO_STATUS_RX_SHIFT		0
118 #define I2C_MST_FIFO_STATUS_TX_MASK		0xff0000
119 #define I2C_MST_FIFO_STATUS_TX_SHIFT		16
120 
121 /*
122  * msg_end_type: The bus control which need to be send at end of transfer.
123  * @MSG_END_STOP: Send stop pulse at end of transfer.
124  * @MSG_END_REPEAT_START: Send repeat start at end of transfer.
125  * @MSG_END_CONTINUE: The following on message is coming and so do not send
126  *		stop or repeat start.
127  */
128 enum msg_end_type {
129 	MSG_END_STOP,
130 	MSG_END_REPEAT_START,
131 	MSG_END_CONTINUE,
132 };
133 
134 /**
135  * struct tegra_i2c_hw_feature : Different HW support on Tegra
136  * @has_continue_xfer_support: Continue transfer supports.
137  * @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer
138  *		complete interrupt per packet basis.
139  * @has_single_clk_source: The I2C controller has single clock source. Tegra30
140  *		and earlier SoCs have two clock sources i.e. div-clk and
141  *		fast-clk.
142  * @has_config_load_reg: Has the config load register to load the new
143  *		configuration.
144  * @clk_divisor_hs_mode: Clock divisor in HS mode.
145  * @clk_divisor_std_fast_mode: Clock divisor in standard/fast mode. It is
146  *		applicable if there is no fast clock source i.e. single clock
147  *		source.
148  * @clk_divisor_fast_plus_mode: Clock divisor in fast mode plus. It is
149  *		applicable if there is no fast clock source (i.e. single
150  *		clock source).
151  * @has_multi_master_mode: The I2C controller supports running in single-master
152  *		or multi-master mode.
153  * @has_slcg_override_reg: The I2C controller supports a register that
154  *		overrides the second level clock gating.
155  * @has_mst_fifo: The I2C controller contains the new MST FIFO interface that
156  *		provides additional features and allows for longer messages to
157  *		be transferred in one go.
158  * @quirks: i2c adapter quirks for limiting write/read transfer size and not
159  *		allowing 0 length transfers.
160  */
161 struct tegra_i2c_hw_feature {
162 	bool has_continue_xfer_support;
163 	bool has_per_pkt_xfer_complete_irq;
164 	bool has_single_clk_source;
165 	bool has_config_load_reg;
166 	int clk_divisor_hs_mode;
167 	int clk_divisor_std_fast_mode;
168 	u16 clk_divisor_fast_plus_mode;
169 	bool has_multi_master_mode;
170 	bool has_slcg_override_reg;
171 	bool has_mst_fifo;
172 	const struct i2c_adapter_quirks *quirks;
173 };
174 
175 /**
176  * struct tegra_i2c_dev - per device I2C context
177  * @dev: device reference for power management
178  * @hw: Tegra I2C HW feature
179  * @adapter: core I2C layer adapter information
180  * @div_clk: clock reference for div clock of I2C controller
181  * @fast_clk: clock reference for fast clock of I2C controller
182  * @rst: reset control for the I2C controller
183  * @base: ioremapped registers cookie
184  * @cont_id: I2C controller ID, used for packet header
185  * @irq: IRQ number of transfer complete interrupt
186  * @irq_disabled: used to track whether or not the interrupt is enabled
187  * @is_dvc: identifies the DVC I2C controller, has a different register layout
188  * @msg_complete: transfer completion notifier
189  * @msg_err: error code for completed message
190  * @msg_buf: pointer to current message data
191  * @msg_buf_remaining: size of unsent data in the message buffer
192  * @msg_read: identifies read transfers
193  * @bus_clk_rate: current I2C bus clock rate
194  * @clk_divisor_non_hs_mode: clock divider for non-high-speed modes
195  * @is_multimaster_mode: track if I2C controller is in multi-master mode
196  * @xfer_lock: lock to serialize transfer submission and processing
197  */
198 struct tegra_i2c_dev {
199 	struct device *dev;
200 	const struct tegra_i2c_hw_feature *hw;
201 	struct i2c_adapter adapter;
202 	struct clk *div_clk;
203 	struct clk *fast_clk;
204 	struct reset_control *rst;
205 	void __iomem *base;
206 	int cont_id;
207 	int irq;
208 	bool irq_disabled;
209 	int is_dvc;
210 	struct completion msg_complete;
211 	int msg_err;
212 	u8 *msg_buf;
213 	size_t msg_buf_remaining;
214 	int msg_read;
215 	u32 bus_clk_rate;
216 	u16 clk_divisor_non_hs_mode;
217 	bool is_multimaster_mode;
218 	spinlock_t xfer_lock;
219 };
220 
221 static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
222 		       unsigned long reg)
223 {
224 	writel(val, i2c_dev->base + reg);
225 }
226 
227 static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
228 {
229 	return readl(i2c_dev->base + reg);
230 }
231 
232 /*
233  * i2c_writel and i2c_readl will offset the register if necessary to talk
234  * to the I2C block inside the DVC block
235  */
236 static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
237 	unsigned long reg)
238 {
239 	if (i2c_dev->is_dvc)
240 		reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
241 	return reg;
242 }
243 
244 static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
245 	unsigned long reg)
246 {
247 	writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
248 
249 	/* Read back register to make sure that register writes completed */
250 	if (reg != I2C_TX_FIFO)
251 		readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
252 }
253 
254 static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
255 {
256 	return readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
257 }
258 
259 static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
260 	unsigned long reg, int len)
261 {
262 	writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
263 }
264 
265 static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
266 	unsigned long reg, int len)
267 {
268 	readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
269 }
270 
271 static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
272 {
273 	u32 int_mask;
274 
275 	int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) & ~mask;
276 	i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
277 }
278 
279 static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
280 {
281 	u32 int_mask;
282 
283 	int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) | mask;
284 	i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
285 }
286 
287 static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
288 {
289 	unsigned long timeout = jiffies + HZ;
290 	unsigned int offset;
291 	u32 mask, val;
292 
293 	if (i2c_dev->hw->has_mst_fifo) {
294 		mask = I2C_MST_FIFO_CONTROL_TX_FLUSH |
295 		       I2C_MST_FIFO_CONTROL_RX_FLUSH;
296 		offset = I2C_MST_FIFO_CONTROL;
297 	} else {
298 		mask = I2C_FIFO_CONTROL_TX_FLUSH |
299 		       I2C_FIFO_CONTROL_RX_FLUSH;
300 		offset = I2C_FIFO_CONTROL;
301 	}
302 
303 	val = i2c_readl(i2c_dev, offset);
304 	val |= mask;
305 	i2c_writel(i2c_dev, val, offset);
306 
307 	while (i2c_readl(i2c_dev, offset) & mask) {
308 		if (time_after(jiffies, timeout)) {
309 			dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
310 			return -ETIMEDOUT;
311 		}
312 		msleep(1);
313 	}
314 	return 0;
315 }
316 
317 static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
318 {
319 	u32 val;
320 	int rx_fifo_avail;
321 	u8 *buf = i2c_dev->msg_buf;
322 	size_t buf_remaining = i2c_dev->msg_buf_remaining;
323 	int words_to_transfer;
324 
325 	if (i2c_dev->hw->has_mst_fifo) {
326 		val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS);
327 		rx_fifo_avail = (val & I2C_MST_FIFO_STATUS_RX_MASK) >>
328 			I2C_MST_FIFO_STATUS_RX_SHIFT;
329 	} else {
330 		val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
331 		rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
332 			I2C_FIFO_STATUS_RX_SHIFT;
333 	}
334 
335 	/* Rounds down to not include partial word at the end of buf */
336 	words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
337 	if (words_to_transfer > rx_fifo_avail)
338 		words_to_transfer = rx_fifo_avail;
339 
340 	i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
341 
342 	buf += words_to_transfer * BYTES_PER_FIFO_WORD;
343 	buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
344 	rx_fifo_avail -= words_to_transfer;
345 
346 	/*
347 	 * If there is a partial word at the end of buf, handle it manually to
348 	 * prevent overwriting past the end of buf
349 	 */
350 	if (rx_fifo_avail > 0 && buf_remaining > 0) {
351 		BUG_ON(buf_remaining > 3);
352 		val = i2c_readl(i2c_dev, I2C_RX_FIFO);
353 		val = cpu_to_le32(val);
354 		memcpy(buf, &val, buf_remaining);
355 		buf_remaining = 0;
356 		rx_fifo_avail--;
357 	}
358 
359 	BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
360 	i2c_dev->msg_buf_remaining = buf_remaining;
361 	i2c_dev->msg_buf = buf;
362 
363 	return 0;
364 }
365 
366 static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
367 {
368 	u32 val;
369 	int tx_fifo_avail;
370 	u8 *buf = i2c_dev->msg_buf;
371 	size_t buf_remaining = i2c_dev->msg_buf_remaining;
372 	int words_to_transfer;
373 
374 	if (i2c_dev->hw->has_mst_fifo) {
375 		val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS);
376 		tx_fifo_avail = (val & I2C_MST_FIFO_STATUS_TX_MASK) >>
377 			I2C_MST_FIFO_STATUS_TX_SHIFT;
378 	} else {
379 		val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
380 		tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
381 			I2C_FIFO_STATUS_TX_SHIFT;
382 	}
383 
384 	/* Rounds down to not include partial word at the end of buf */
385 	words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
386 
387 	/* It's very common to have < 4 bytes, so optimize that case. */
388 	if (words_to_transfer) {
389 		if (words_to_transfer > tx_fifo_avail)
390 			words_to_transfer = tx_fifo_avail;
391 
392 		/*
393 		 * Update state before writing to FIFO.  If this casues us
394 		 * to finish writing all bytes (AKA buf_remaining goes to 0) we
395 		 * have a potential for an interrupt (PACKET_XFER_COMPLETE is
396 		 * not maskable).  We need to make sure that the isr sees
397 		 * buf_remaining as 0 and doesn't call us back re-entrantly.
398 		 */
399 		buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
400 		tx_fifo_avail -= words_to_transfer;
401 		i2c_dev->msg_buf_remaining = buf_remaining;
402 		i2c_dev->msg_buf = buf +
403 			words_to_transfer * BYTES_PER_FIFO_WORD;
404 		barrier();
405 
406 		i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
407 
408 		buf += words_to_transfer * BYTES_PER_FIFO_WORD;
409 	}
410 
411 	/*
412 	 * If there is a partial word at the end of buf, handle it manually to
413 	 * prevent reading past the end of buf, which could cross a page
414 	 * boundary and fault.
415 	 */
416 	if (tx_fifo_avail > 0 && buf_remaining > 0) {
417 		BUG_ON(buf_remaining > 3);
418 		memcpy(&val, buf, buf_remaining);
419 		val = le32_to_cpu(val);
420 
421 		/* Again update before writing to FIFO to make sure isr sees. */
422 		i2c_dev->msg_buf_remaining = 0;
423 		i2c_dev->msg_buf = NULL;
424 		barrier();
425 
426 		i2c_writel(i2c_dev, val, I2C_TX_FIFO);
427 	}
428 
429 	return 0;
430 }
431 
432 /*
433  * One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
434  * block.  This block is identical to the rest of the I2C blocks, except that
435  * it only supports master mode, it has registers moved around, and it needs
436  * some extra init to get it into I2C mode.  The register moves are handled
437  * by i2c_readl and i2c_writel
438  */
439 static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
440 {
441 	u32 val;
442 
443 	val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
444 	val |= DVC_CTRL_REG3_SW_PROG;
445 	val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
446 	dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
447 
448 	val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
449 	val |= DVC_CTRL_REG1_INTR_EN;
450 	dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
451 }
452 
453 static int tegra_i2c_runtime_resume(struct device *dev)
454 {
455 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
456 	int ret;
457 
458 	ret = pinctrl_pm_select_default_state(i2c_dev->dev);
459 	if (ret)
460 		return ret;
461 
462 	if (!i2c_dev->hw->has_single_clk_source) {
463 		ret = clk_enable(i2c_dev->fast_clk);
464 		if (ret < 0) {
465 			dev_err(i2c_dev->dev,
466 				"Enabling fast clk failed, err %d\n", ret);
467 			return ret;
468 		}
469 	}
470 
471 	ret = clk_enable(i2c_dev->div_clk);
472 	if (ret < 0) {
473 		dev_err(i2c_dev->dev,
474 			"Enabling div clk failed, err %d\n", ret);
475 		clk_disable(i2c_dev->fast_clk);
476 		return ret;
477 	}
478 
479 	return 0;
480 }
481 
482 static int tegra_i2c_runtime_suspend(struct device *dev)
483 {
484 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
485 
486 	clk_disable(i2c_dev->div_clk);
487 	if (!i2c_dev->hw->has_single_clk_source)
488 		clk_disable(i2c_dev->fast_clk);
489 
490 	return pinctrl_pm_select_idle_state(i2c_dev->dev);
491 }
492 
493 static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
494 {
495 	unsigned long reg_offset;
496 	void __iomem *addr;
497 	u32 val;
498 	int err;
499 
500 	if (i2c_dev->hw->has_config_load_reg) {
501 		reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_CONFIG_LOAD);
502 		addr = i2c_dev->base + reg_offset;
503 		i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
504 		if (in_interrupt())
505 			err = readl_poll_timeout_atomic(addr, val, val == 0,
506 					1000, I2C_CONFIG_LOAD_TIMEOUT);
507 		else
508 			err = readl_poll_timeout(addr, val, val == 0,
509 					1000, I2C_CONFIG_LOAD_TIMEOUT);
510 
511 		if (err) {
512 			dev_warn(i2c_dev->dev,
513 				 "timeout waiting for config load\n");
514 			return err;
515 		}
516 	}
517 
518 	return 0;
519 }
520 
521 static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
522 {
523 	u32 val;
524 	int err;
525 	u32 clk_divisor;
526 
527 	err = pm_runtime_get_sync(i2c_dev->dev);
528 	if (err < 0) {
529 		dev_err(i2c_dev->dev, "runtime resume failed %d\n", err);
530 		return err;
531 	}
532 
533 	reset_control_assert(i2c_dev->rst);
534 	udelay(2);
535 	reset_control_deassert(i2c_dev->rst);
536 
537 	if (i2c_dev->is_dvc)
538 		tegra_dvc_init(i2c_dev);
539 
540 	val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
541 		(0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);
542 
543 	if (i2c_dev->hw->has_multi_master_mode)
544 		val |= I2C_CNFG_MULTI_MASTER_MODE;
545 
546 	i2c_writel(i2c_dev, val, I2C_CNFG);
547 	i2c_writel(i2c_dev, 0, I2C_INT_MASK);
548 
549 	/* Make sure clock divisor programmed correctly */
550 	clk_divisor = i2c_dev->hw->clk_divisor_hs_mode;
551 	clk_divisor |= i2c_dev->clk_divisor_non_hs_mode <<
552 					I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT;
553 	i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
554 
555 	if (!i2c_dev->is_dvc) {
556 		u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
557 
558 		sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL;
559 		i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG);
560 		i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1);
561 		i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
562 	}
563 
564 	if (i2c_dev->hw->has_mst_fifo) {
565 		val = I2C_MST_FIFO_CONTROL_TX_TRIG(8) |
566 		      I2C_MST_FIFO_CONTROL_RX_TRIG(1);
567 		i2c_writel(i2c_dev, val, I2C_MST_FIFO_CONTROL);
568 	} else {
569 		val = 7 << I2C_FIFO_CONTROL_TX_TRIG_SHIFT |
570 			0 << I2C_FIFO_CONTROL_RX_TRIG_SHIFT;
571 		i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
572 	}
573 
574 	err = tegra_i2c_flush_fifos(i2c_dev);
575 	if (err)
576 		goto err;
577 
578 	if (i2c_dev->is_multimaster_mode && i2c_dev->hw->has_slcg_override_reg)
579 		i2c_writel(i2c_dev, I2C_MST_CORE_CLKEN_OVR, I2C_CLKEN_OVERRIDE);
580 
581 	err = tegra_i2c_wait_for_config_load(i2c_dev);
582 	if (err)
583 		goto err;
584 
585 	if (i2c_dev->irq_disabled) {
586 		i2c_dev->irq_disabled = false;
587 		enable_irq(i2c_dev->irq);
588 	}
589 
590 err:
591 	pm_runtime_put(i2c_dev->dev);
592 	return err;
593 }
594 
595 static int tegra_i2c_disable_packet_mode(struct tegra_i2c_dev *i2c_dev)
596 {
597 	u32 cnfg;
598 
599 	/*
600 	 * NACK interrupt is generated before the I2C controller generates
601 	 * the STOP condition on the bus. So wait for 2 clock periods
602 	 * before disabling the controller so that the STOP condition has
603 	 * been delivered properly.
604 	 */
605 	udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate));
606 
607 	cnfg = i2c_readl(i2c_dev, I2C_CNFG);
608 	if (cnfg & I2C_CNFG_PACKET_MODE_EN)
609 		i2c_writel(i2c_dev, cnfg & ~I2C_CNFG_PACKET_MODE_EN, I2C_CNFG);
610 
611 	return tegra_i2c_wait_for_config_load(i2c_dev);
612 }
613 
614 static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
615 {
616 	u32 status;
617 	const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
618 	struct tegra_i2c_dev *i2c_dev = dev_id;
619 
620 	status = i2c_readl(i2c_dev, I2C_INT_STATUS);
621 
622 	spin_lock(&i2c_dev->xfer_lock);
623 	if (status == 0) {
624 		dev_warn(i2c_dev->dev, "irq status 0 %08x %08x %08x\n",
625 			 i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS),
626 			 i2c_readl(i2c_dev, I2C_STATUS),
627 			 i2c_readl(i2c_dev, I2C_CNFG));
628 		i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
629 
630 		if (!i2c_dev->irq_disabled) {
631 			disable_irq_nosync(i2c_dev->irq);
632 			i2c_dev->irq_disabled = true;
633 		}
634 		goto err;
635 	}
636 
637 	if (unlikely(status & status_err)) {
638 		tegra_i2c_disable_packet_mode(i2c_dev);
639 		if (status & I2C_INT_NO_ACK)
640 			i2c_dev->msg_err |= I2C_ERR_NO_ACK;
641 		if (status & I2C_INT_ARBITRATION_LOST)
642 			i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
643 		goto err;
644 	}
645 
646 	if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
647 		if (i2c_dev->msg_buf_remaining)
648 			tegra_i2c_empty_rx_fifo(i2c_dev);
649 		else
650 			BUG();
651 	}
652 
653 	if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
654 		if (i2c_dev->msg_buf_remaining)
655 			tegra_i2c_fill_tx_fifo(i2c_dev);
656 		else
657 			tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ);
658 	}
659 
660 	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
661 	if (i2c_dev->is_dvc)
662 		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
663 
664 	if (status & I2C_INT_PACKET_XFER_COMPLETE) {
665 		BUG_ON(i2c_dev->msg_buf_remaining);
666 		complete(&i2c_dev->msg_complete);
667 	}
668 	goto done;
669 err:
670 	/* An error occurred, mask all interrupts */
671 	tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST |
672 		I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ |
673 		I2C_INT_RX_FIFO_DATA_REQ);
674 	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
675 	if (i2c_dev->is_dvc)
676 		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
677 
678 	complete(&i2c_dev->msg_complete);
679 done:
680 	spin_unlock(&i2c_dev->xfer_lock);
681 	return IRQ_HANDLED;
682 }
683 
684 static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
685 	struct i2c_msg *msg, enum msg_end_type end_state)
686 {
687 	u32 packet_header;
688 	u32 int_mask;
689 	unsigned long time_left;
690 	unsigned long flags;
691 
692 	tegra_i2c_flush_fifos(i2c_dev);
693 
694 	i2c_dev->msg_buf = msg->buf;
695 	i2c_dev->msg_buf_remaining = msg->len;
696 	i2c_dev->msg_err = I2C_ERR_NONE;
697 	i2c_dev->msg_read = (msg->flags & I2C_M_RD);
698 	reinit_completion(&i2c_dev->msg_complete);
699 
700 	spin_lock_irqsave(&i2c_dev->xfer_lock, flags);
701 
702 	int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
703 	tegra_i2c_unmask_irq(i2c_dev, int_mask);
704 
705 	packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
706 			PACKET_HEADER0_PROTOCOL_I2C |
707 			(i2c_dev->cont_id << PACKET_HEADER0_CONT_ID_SHIFT) |
708 			(1 << PACKET_HEADER0_PACKET_ID_SHIFT);
709 	i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
710 
711 	packet_header = msg->len - 1;
712 	i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
713 
714 	packet_header = I2C_HEADER_IE_ENABLE;
715 	if (end_state == MSG_END_CONTINUE)
716 		packet_header |= I2C_HEADER_CONTINUE_XFER;
717 	else if (end_state == MSG_END_REPEAT_START)
718 		packet_header |= I2C_HEADER_REPEAT_START;
719 	if (msg->flags & I2C_M_TEN) {
720 		packet_header |= msg->addr;
721 		packet_header |= I2C_HEADER_10BIT_ADDR;
722 	} else {
723 		packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
724 	}
725 	if (msg->flags & I2C_M_IGNORE_NAK)
726 		packet_header |= I2C_HEADER_CONT_ON_NAK;
727 	if (msg->flags & I2C_M_RD)
728 		packet_header |= I2C_HEADER_READ;
729 	i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
730 
731 	if (!(msg->flags & I2C_M_RD))
732 		tegra_i2c_fill_tx_fifo(i2c_dev);
733 
734 	if (i2c_dev->hw->has_per_pkt_xfer_complete_irq)
735 		int_mask |= I2C_INT_PACKET_XFER_COMPLETE;
736 	if (msg->flags & I2C_M_RD)
737 		int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
738 	else if (i2c_dev->msg_buf_remaining)
739 		int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
740 
741 	tegra_i2c_unmask_irq(i2c_dev, int_mask);
742 	spin_unlock_irqrestore(&i2c_dev->xfer_lock, flags);
743 	dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n",
744 		i2c_readl(i2c_dev, I2C_INT_MASK));
745 
746 	time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
747 						TEGRA_I2C_TIMEOUT);
748 	tegra_i2c_mask_irq(i2c_dev, int_mask);
749 
750 	if (time_left == 0) {
751 		dev_err(i2c_dev->dev, "i2c transfer timed out\n");
752 
753 		tegra_i2c_init(i2c_dev);
754 		return -ETIMEDOUT;
755 	}
756 
757 	dev_dbg(i2c_dev->dev, "transfer complete: %lu %d %d\n",
758 		time_left, completion_done(&i2c_dev->msg_complete),
759 		i2c_dev->msg_err);
760 
761 	if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
762 		return 0;
763 
764 	tegra_i2c_init(i2c_dev);
765 	if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
766 		if (msg->flags & I2C_M_IGNORE_NAK)
767 			return 0;
768 		return -EREMOTEIO;
769 	}
770 
771 	return -EIO;
772 }
773 
774 static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
775 	int num)
776 {
777 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
778 	int i;
779 	int ret = 0;
780 
781 	ret = pm_runtime_get_sync(i2c_dev->dev);
782 	if (ret < 0) {
783 		dev_err(i2c_dev->dev, "runtime resume failed %d\n", ret);
784 		return ret;
785 	}
786 
787 	for (i = 0; i < num; i++) {
788 		enum msg_end_type end_type = MSG_END_STOP;
789 
790 		if (i < (num - 1)) {
791 			if (msgs[i + 1].flags & I2C_M_NOSTART)
792 				end_type = MSG_END_CONTINUE;
793 			else
794 				end_type = MSG_END_REPEAT_START;
795 		}
796 		ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);
797 		if (ret)
798 			break;
799 	}
800 
801 	pm_runtime_put(i2c_dev->dev);
802 
803 	return ret ?: i;
804 }
805 
806 static u32 tegra_i2c_func(struct i2c_adapter *adap)
807 {
808 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
809 	u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
810 		  I2C_FUNC_10BIT_ADDR |	I2C_FUNC_PROTOCOL_MANGLING;
811 
812 	if (i2c_dev->hw->has_continue_xfer_support)
813 		ret |= I2C_FUNC_NOSTART;
814 	return ret;
815 }
816 
817 static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
818 {
819 	struct device_node *np = i2c_dev->dev->of_node;
820 	int ret;
821 
822 	ret = of_property_read_u32(np, "clock-frequency",
823 			&i2c_dev->bus_clk_rate);
824 	if (ret)
825 		i2c_dev->bus_clk_rate = 100000; /* default clock rate */
826 
827 	i2c_dev->is_multimaster_mode = of_property_read_bool(np,
828 			"multi-master");
829 }
830 
831 static const struct i2c_algorithm tegra_i2c_algo = {
832 	.master_xfer	= tegra_i2c_xfer,
833 	.functionality	= tegra_i2c_func,
834 };
835 
836 /* payload size is only 12 bit */
837 static const struct i2c_adapter_quirks tegra_i2c_quirks = {
838 	.flags = I2C_AQ_NO_ZERO_LEN,
839 	.max_read_len = 4096,
840 	.max_write_len = 4096,
841 };
842 
843 static const struct i2c_adapter_quirks tegra194_i2c_quirks = {
844 	.flags = I2C_AQ_NO_ZERO_LEN,
845 };
846 
847 static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
848 	.has_continue_xfer_support = false,
849 	.has_per_pkt_xfer_complete_irq = false,
850 	.has_single_clk_source = false,
851 	.clk_divisor_hs_mode = 3,
852 	.clk_divisor_std_fast_mode = 0,
853 	.clk_divisor_fast_plus_mode = 0,
854 	.has_config_load_reg = false,
855 	.has_multi_master_mode = false,
856 	.has_slcg_override_reg = false,
857 	.has_mst_fifo = false,
858 	.quirks = &tegra_i2c_quirks,
859 };
860 
861 static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
862 	.has_continue_xfer_support = true,
863 	.has_per_pkt_xfer_complete_irq = false,
864 	.has_single_clk_source = false,
865 	.clk_divisor_hs_mode = 3,
866 	.clk_divisor_std_fast_mode = 0,
867 	.clk_divisor_fast_plus_mode = 0,
868 	.has_config_load_reg = false,
869 	.has_multi_master_mode = false,
870 	.has_slcg_override_reg = false,
871 	.has_mst_fifo = false,
872 	.quirks = &tegra_i2c_quirks,
873 };
874 
875 static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
876 	.has_continue_xfer_support = true,
877 	.has_per_pkt_xfer_complete_irq = true,
878 	.has_single_clk_source = true,
879 	.clk_divisor_hs_mode = 1,
880 	.clk_divisor_std_fast_mode = 0x19,
881 	.clk_divisor_fast_plus_mode = 0x10,
882 	.has_config_load_reg = false,
883 	.has_multi_master_mode = false,
884 	.has_slcg_override_reg = false,
885 	.has_mst_fifo = false,
886 	.quirks = &tegra_i2c_quirks,
887 };
888 
889 static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
890 	.has_continue_xfer_support = true,
891 	.has_per_pkt_xfer_complete_irq = true,
892 	.has_single_clk_source = true,
893 	.clk_divisor_hs_mode = 1,
894 	.clk_divisor_std_fast_mode = 0x19,
895 	.clk_divisor_fast_plus_mode = 0x10,
896 	.has_config_load_reg = true,
897 	.has_multi_master_mode = false,
898 	.has_slcg_override_reg = true,
899 	.has_mst_fifo = false,
900 	.quirks = &tegra_i2c_quirks,
901 };
902 
903 static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
904 	.has_continue_xfer_support = true,
905 	.has_per_pkt_xfer_complete_irq = true,
906 	.has_single_clk_source = true,
907 	.clk_divisor_hs_mode = 1,
908 	.clk_divisor_std_fast_mode = 0x19,
909 	.clk_divisor_fast_plus_mode = 0x10,
910 	.has_config_load_reg = true,
911 	.has_multi_master_mode = true,
912 	.has_slcg_override_reg = true,
913 	.has_mst_fifo = false,
914 	.quirks = &tegra_i2c_quirks,
915 };
916 
917 static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
918 	.has_continue_xfer_support = true,
919 	.has_per_pkt_xfer_complete_irq = true,
920 	.has_single_clk_source = true,
921 	.clk_divisor_hs_mode = 1,
922 	.clk_divisor_std_fast_mode = 0x19,
923 	.clk_divisor_fast_plus_mode = 0x10,
924 	.has_config_load_reg = true,
925 	.has_multi_master_mode = true,
926 	.has_slcg_override_reg = true,
927 	.has_mst_fifo = true,
928 	.quirks = &tegra194_i2c_quirks,
929 };
930 
931 /* Match table for of_platform binding */
932 static const struct of_device_id tegra_i2c_of_match[] = {
933 	{ .compatible = "nvidia,tegra194-i2c", .data = &tegra194_i2c_hw, },
934 	{ .compatible = "nvidia,tegra210-i2c", .data = &tegra210_i2c_hw, },
935 	{ .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, },
936 	{ .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, },
937 	{ .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, },
938 	{ .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, },
939 	{ .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, },
940 	{},
941 };
942 MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
943 
944 static int tegra_i2c_probe(struct platform_device *pdev)
945 {
946 	struct tegra_i2c_dev *i2c_dev;
947 	struct resource *res;
948 	struct clk *div_clk;
949 	struct clk *fast_clk;
950 	void __iomem *base;
951 	int irq;
952 	int ret = 0;
953 	int clk_multiplier = I2C_CLK_MULTIPLIER_STD_FAST_MODE;
954 
955 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
956 	base = devm_ioremap_resource(&pdev->dev, res);
957 	if (IS_ERR(base))
958 		return PTR_ERR(base);
959 
960 	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
961 	if (!res) {
962 		dev_err(&pdev->dev, "no irq resource\n");
963 		return -EINVAL;
964 	}
965 	irq = res->start;
966 
967 	div_clk = devm_clk_get(&pdev->dev, "div-clk");
968 	if (IS_ERR(div_clk)) {
969 		dev_err(&pdev->dev, "missing controller clock\n");
970 		return PTR_ERR(div_clk);
971 	}
972 
973 	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
974 	if (!i2c_dev)
975 		return -ENOMEM;
976 
977 	i2c_dev->base = base;
978 	i2c_dev->div_clk = div_clk;
979 	i2c_dev->adapter.algo = &tegra_i2c_algo;
980 	i2c_dev->irq = irq;
981 	i2c_dev->cont_id = pdev->id;
982 	i2c_dev->dev = &pdev->dev;
983 
984 	i2c_dev->rst = devm_reset_control_get_exclusive(&pdev->dev, "i2c");
985 	if (IS_ERR(i2c_dev->rst)) {
986 		dev_err(&pdev->dev, "missing controller reset\n");
987 		return PTR_ERR(i2c_dev->rst);
988 	}
989 
990 	tegra_i2c_parse_dt(i2c_dev);
991 
992 	i2c_dev->hw = of_device_get_match_data(&pdev->dev);
993 	i2c_dev->is_dvc = of_device_is_compatible(pdev->dev.of_node,
994 						  "nvidia,tegra20-i2c-dvc");
995 	i2c_dev->adapter.quirks = i2c_dev->hw->quirks;
996 	init_completion(&i2c_dev->msg_complete);
997 	spin_lock_init(&i2c_dev->xfer_lock);
998 
999 	if (!i2c_dev->hw->has_single_clk_source) {
1000 		fast_clk = devm_clk_get(&pdev->dev, "fast-clk");
1001 		if (IS_ERR(fast_clk)) {
1002 			dev_err(&pdev->dev, "missing fast clock\n");
1003 			return PTR_ERR(fast_clk);
1004 		}
1005 		i2c_dev->fast_clk = fast_clk;
1006 	}
1007 
1008 	platform_set_drvdata(pdev, i2c_dev);
1009 
1010 	if (!i2c_dev->hw->has_single_clk_source) {
1011 		ret = clk_prepare(i2c_dev->fast_clk);
1012 		if (ret < 0) {
1013 			dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
1014 			return ret;
1015 		}
1016 	}
1017 
1018 	i2c_dev->clk_divisor_non_hs_mode =
1019 			i2c_dev->hw->clk_divisor_std_fast_mode;
1020 	if (i2c_dev->hw->clk_divisor_fast_plus_mode &&
1021 		(i2c_dev->bus_clk_rate == 1000000))
1022 		i2c_dev->clk_divisor_non_hs_mode =
1023 			i2c_dev->hw->clk_divisor_fast_plus_mode;
1024 
1025 	clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1);
1026 	ret = clk_set_rate(i2c_dev->div_clk,
1027 			   i2c_dev->bus_clk_rate * clk_multiplier);
1028 	if (ret) {
1029 		dev_err(i2c_dev->dev, "Clock rate change failed %d\n", ret);
1030 		goto unprepare_fast_clk;
1031 	}
1032 
1033 	ret = clk_prepare(i2c_dev->div_clk);
1034 	if (ret < 0) {
1035 		dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
1036 		goto unprepare_fast_clk;
1037 	}
1038 
1039 	pm_runtime_enable(&pdev->dev);
1040 	if (!pm_runtime_enabled(&pdev->dev)) {
1041 		ret = tegra_i2c_runtime_resume(&pdev->dev);
1042 		if (ret < 0) {
1043 			dev_err(&pdev->dev, "runtime resume failed\n");
1044 			goto unprepare_div_clk;
1045 		}
1046 	}
1047 
1048 	if (i2c_dev->is_multimaster_mode) {
1049 		ret = clk_enable(i2c_dev->div_clk);
1050 		if (ret < 0) {
1051 			dev_err(i2c_dev->dev, "div_clk enable failed %d\n",
1052 				ret);
1053 			goto disable_rpm;
1054 		}
1055 	}
1056 
1057 	ret = tegra_i2c_init(i2c_dev);
1058 	if (ret) {
1059 		dev_err(&pdev->dev, "Failed to initialize i2c controller\n");
1060 		goto disable_div_clk;
1061 	}
1062 
1063 	ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
1064 			tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
1065 	if (ret) {
1066 		dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
1067 		goto disable_div_clk;
1068 	}
1069 
1070 	i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
1071 	i2c_dev->adapter.owner = THIS_MODULE;
1072 	i2c_dev->adapter.class = I2C_CLASS_DEPRECATED;
1073 	strlcpy(i2c_dev->adapter.name, dev_name(&pdev->dev),
1074 		sizeof(i2c_dev->adapter.name));
1075 	i2c_dev->adapter.dev.parent = &pdev->dev;
1076 	i2c_dev->adapter.nr = pdev->id;
1077 	i2c_dev->adapter.dev.of_node = pdev->dev.of_node;
1078 
1079 	ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
1080 	if (ret)
1081 		goto disable_div_clk;
1082 
1083 	return 0;
1084 
1085 disable_div_clk:
1086 	if (i2c_dev->is_multimaster_mode)
1087 		clk_disable(i2c_dev->div_clk);
1088 
1089 disable_rpm:
1090 	pm_runtime_disable(&pdev->dev);
1091 	if (!pm_runtime_status_suspended(&pdev->dev))
1092 		tegra_i2c_runtime_suspend(&pdev->dev);
1093 
1094 unprepare_div_clk:
1095 	clk_unprepare(i2c_dev->div_clk);
1096 
1097 unprepare_fast_clk:
1098 	if (!i2c_dev->hw->has_single_clk_source)
1099 		clk_unprepare(i2c_dev->fast_clk);
1100 
1101 	return ret;
1102 }
1103 
1104 static int tegra_i2c_remove(struct platform_device *pdev)
1105 {
1106 	struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
1107 
1108 	i2c_del_adapter(&i2c_dev->adapter);
1109 
1110 	if (i2c_dev->is_multimaster_mode)
1111 		clk_disable(i2c_dev->div_clk);
1112 
1113 	pm_runtime_disable(&pdev->dev);
1114 	if (!pm_runtime_status_suspended(&pdev->dev))
1115 		tegra_i2c_runtime_suspend(&pdev->dev);
1116 
1117 	clk_unprepare(i2c_dev->div_clk);
1118 	if (!i2c_dev->hw->has_single_clk_source)
1119 		clk_unprepare(i2c_dev->fast_clk);
1120 
1121 	return 0;
1122 }
1123 
1124 #ifdef CONFIG_PM_SLEEP
1125 static const struct dev_pm_ops tegra_i2c_pm = {
1126 	SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
1127 			   NULL)
1128 };
1129 #define TEGRA_I2C_PM	(&tegra_i2c_pm)
1130 #else
1131 #define TEGRA_I2C_PM	NULL
1132 #endif
1133 
1134 static struct platform_driver tegra_i2c_driver = {
1135 	.probe   = tegra_i2c_probe,
1136 	.remove  = tegra_i2c_remove,
1137 	.driver  = {
1138 		.name  = "tegra-i2c",
1139 		.of_match_table = tegra_i2c_of_match,
1140 		.pm    = TEGRA_I2C_PM,
1141 	},
1142 };
1143 
1144 static int __init tegra_i2c_init_driver(void)
1145 {
1146 	return platform_driver_register(&tegra_i2c_driver);
1147 }
1148 
1149 static void __exit tegra_i2c_exit_driver(void)
1150 {
1151 	platform_driver_unregister(&tegra_i2c_driver);
1152 }
1153 
1154 subsys_initcall(tegra_i2c_init_driver);
1155 module_exit(tegra_i2c_exit_driver);
1156 
1157 MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver");
1158 MODULE_AUTHOR("Colin Cross");
1159 MODULE_LICENSE("GPL v2");
1160