xref: /openbmc/linux/drivers/i2c/busses/i2c-tegra.c (revision 5a158981)
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/clk.h>
10 #include <linux/delay.h>
11 #include <linux/dmaengine.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/err.h>
14 #include <linux/i2c.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/iopoll.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/of_device.h>
22 #include <linux/pinctrl/consumer.h>
23 #include <linux/platform_device.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/reset.h>
26 
27 #define BYTES_PER_FIFO_WORD 4
28 
29 #define I2C_CNFG				0x000
30 #define I2C_CNFG_DEBOUNCE_CNT_SHIFT		12
31 #define I2C_CNFG_PACKET_MODE_EN			BIT(10)
32 #define I2C_CNFG_NEW_MASTER_FSM			BIT(11)
33 #define I2C_CNFG_MULTI_MASTER_MODE		BIT(17)
34 #define I2C_STATUS				0x01C
35 #define I2C_SL_CNFG				0x020
36 #define I2C_SL_CNFG_NACK			BIT(1)
37 #define I2C_SL_CNFG_NEWSL			BIT(2)
38 #define I2C_SL_ADDR1				0x02c
39 #define I2C_SL_ADDR2				0x030
40 #define I2C_TX_FIFO				0x050
41 #define I2C_RX_FIFO				0x054
42 #define I2C_PACKET_TRANSFER_STATUS		0x058
43 #define I2C_FIFO_CONTROL			0x05c
44 #define I2C_FIFO_CONTROL_TX_FLUSH		BIT(1)
45 #define I2C_FIFO_CONTROL_RX_FLUSH		BIT(0)
46 #define I2C_FIFO_CONTROL_TX_TRIG(x)		(((x) - 1) << 5)
47 #define I2C_FIFO_CONTROL_RX_TRIG(x)		(((x) - 1) << 2)
48 #define I2C_FIFO_STATUS				0x060
49 #define I2C_FIFO_STATUS_TX_MASK			0xF0
50 #define I2C_FIFO_STATUS_TX_SHIFT		4
51 #define I2C_FIFO_STATUS_RX_MASK			0x0F
52 #define I2C_FIFO_STATUS_RX_SHIFT		0
53 #define I2C_INT_MASK				0x064
54 #define I2C_INT_STATUS				0x068
55 #define I2C_INT_BUS_CLR_DONE			BIT(11)
56 #define I2C_INT_PACKET_XFER_COMPLETE		BIT(7)
57 #define I2C_INT_NO_ACK				BIT(3)
58 #define I2C_INT_ARBITRATION_LOST		BIT(2)
59 #define I2C_INT_TX_FIFO_DATA_REQ		BIT(1)
60 #define I2C_INT_RX_FIFO_DATA_REQ		BIT(0)
61 #define I2C_CLK_DIVISOR				0x06c
62 #define I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT	16
63 
64 #define DVC_CTRL_REG1				0x000
65 #define DVC_CTRL_REG1_INTR_EN			BIT(10)
66 #define DVC_CTRL_REG3				0x008
67 #define DVC_CTRL_REG3_SW_PROG			BIT(26)
68 #define DVC_CTRL_REG3_I2C_DONE_INTR_EN		BIT(30)
69 #define DVC_STATUS				0x00c
70 #define DVC_STATUS_I2C_DONE_INTR		BIT(30)
71 
72 #define I2C_ERR_NONE				0x00
73 #define I2C_ERR_NO_ACK				BIT(0)
74 #define I2C_ERR_ARBITRATION_LOST		BIT(1)
75 #define I2C_ERR_UNKNOWN_INTERRUPT		BIT(2)
76 #define I2C_ERR_RX_BUFFER_OVERFLOW		BIT(3)
77 
78 #define PACKET_HEADER0_HEADER_SIZE_SHIFT	28
79 #define PACKET_HEADER0_PACKET_ID_SHIFT		16
80 #define PACKET_HEADER0_CONT_ID_SHIFT		12
81 #define PACKET_HEADER0_PROTOCOL_I2C		BIT(4)
82 
83 #define I2C_HEADER_CONT_ON_NAK			BIT(21)
84 #define I2C_HEADER_READ				BIT(19)
85 #define I2C_HEADER_10BIT_ADDR			BIT(18)
86 #define I2C_HEADER_IE_ENABLE			BIT(17)
87 #define I2C_HEADER_REPEAT_START			BIT(16)
88 #define I2C_HEADER_CONTINUE_XFER		BIT(15)
89 #define I2C_HEADER_SLAVE_ADDR_SHIFT		1
90 
91 #define I2C_BUS_CLEAR_CNFG			0x084
92 #define I2C_BC_SCLK_THRESHOLD			9
93 #define I2C_BC_SCLK_THRESHOLD_SHIFT		16
94 #define I2C_BC_STOP_COND			BIT(2)
95 #define I2C_BC_TERMINATE			BIT(1)
96 #define I2C_BC_ENABLE				BIT(0)
97 #define I2C_BUS_CLEAR_STATUS			0x088
98 #define I2C_BC_STATUS				BIT(0)
99 
100 #define I2C_CONFIG_LOAD				0x08C
101 #define I2C_MSTR_CONFIG_LOAD			BIT(0)
102 
103 #define I2C_CLKEN_OVERRIDE			0x090
104 #define I2C_MST_CORE_CLKEN_OVR			BIT(0)
105 
106 #define I2C_CONFIG_LOAD_TIMEOUT			1000000
107 
108 #define I2C_MST_FIFO_CONTROL			0x0b4
109 #define I2C_MST_FIFO_CONTROL_RX_FLUSH		BIT(0)
110 #define I2C_MST_FIFO_CONTROL_TX_FLUSH		BIT(1)
111 #define I2C_MST_FIFO_CONTROL_RX_TRIG(x)		(((x) - 1) <<  4)
112 #define I2C_MST_FIFO_CONTROL_TX_TRIG(x)		(((x) - 1) << 16)
113 
114 #define I2C_MST_FIFO_STATUS			0x0b8
115 #define I2C_MST_FIFO_STATUS_RX_MASK		0xff
116 #define I2C_MST_FIFO_STATUS_RX_SHIFT		0
117 #define I2C_MST_FIFO_STATUS_TX_MASK		0xff0000
118 #define I2C_MST_FIFO_STATUS_TX_SHIFT		16
119 
120 #define I2C_INTERFACE_TIMING_0			0x94
121 #define I2C_THIGH_SHIFT				8
122 #define I2C_INTERFACE_TIMING_1			0x98
123 
124 #define I2C_STANDARD_MODE			100000
125 #define I2C_FAST_MODE				400000
126 #define I2C_FAST_PLUS_MODE			1000000
127 
128 /* Packet header size in bytes */
129 #define I2C_PACKET_HEADER_SIZE			12
130 
131 /*
132  * Upto I2C_PIO_MODE_MAX_LEN bytes, controller will use PIO mode,
133  * above this, controller will use DMA to fill FIFO.
134  * MAX PIO len is 20 bytes excluding packet header.
135  */
136 #define I2C_PIO_MODE_MAX_LEN			32
137 
138 /*
139  * msg_end_type: The bus control which need to be send at end of transfer.
140  * @MSG_END_STOP: Send stop pulse at end of transfer.
141  * @MSG_END_REPEAT_START: Send repeat start at end of transfer.
142  * @MSG_END_CONTINUE: The following on message is coming and so do not send
143  *		stop or repeat start.
144  */
145 enum msg_end_type {
146 	MSG_END_STOP,
147 	MSG_END_REPEAT_START,
148 	MSG_END_CONTINUE,
149 };
150 
151 /**
152  * struct tegra_i2c_hw_feature : Different HW support on Tegra
153  * @has_continue_xfer_support: Continue transfer supports.
154  * @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer
155  *		complete interrupt per packet basis.
156  * @has_single_clk_source: The I2C controller has single clock source. Tegra30
157  *		and earlier SoCs have two clock sources i.e. div-clk and
158  *		fast-clk.
159  * @has_config_load_reg: Has the config load register to load the new
160  *		configuration.
161  * @clk_divisor_hs_mode: Clock divisor in HS mode.
162  * @clk_divisor_std_mode: Clock divisor in standard mode. It is
163  *		applicable if there is no fast clock source i.e. single clock
164  *		source.
165  * @clk_divisor_fast_mode: Clock divisor in fast mode. It is
166  *		applicable if there is no fast clock source i.e. single clock
167  *		source.
168  * @clk_divisor_fast_plus_mode: Clock divisor in fast mode plus. It is
169  *		applicable if there is no fast clock source (i.e. single
170  *		clock source).
171  * @has_multi_master_mode: The I2C controller supports running in single-master
172  *		or multi-master mode.
173  * @has_slcg_override_reg: The I2C controller supports a register that
174  *		overrides the second level clock gating.
175  * @has_mst_fifo: The I2C controller contains the new MST FIFO interface that
176  *		provides additional features and allows for longer messages to
177  *		be transferred in one go.
178  * @quirks: i2c adapter quirks for limiting write/read transfer size and not
179  *		allowing 0 length transfers.
180  * @supports_bus_clear: Bus Clear support to recover from bus hang during
181  *		SDA stuck low from device for some unknown reasons.
182  * @has_apb_dma: Support of APBDMA on corresponding Tegra chip.
183  * @tlow_std_mode: Low period of the clock in standard mode.
184  * @thigh_std_mode: High period of the clock in standard mode.
185  * @tlow_fast_fastplus_mode: Low period of the clock in fast/fast-plus modes.
186  * @thigh_fast_fastplus_mode: High period of the clock in fast/fast-plus modes.
187  * @setup_hold_time_std_mode: Setup and hold time for start and stop conditions
188  *		in standard mode.
189  * @setup_hold_time_fast_fast_plus_mode: Setup and hold time for start and stop
190  *		conditions in fast/fast-plus modes.
191  * @setup_hold_time_hs_mode: Setup and hold time for start and stop conditions
192  *		in HS mode.
193  * @has_interface_timing_reg: Has interface timing register to program the tuned
194  *		timing settings.
195  */
196 struct tegra_i2c_hw_feature {
197 	bool has_continue_xfer_support;
198 	bool has_per_pkt_xfer_complete_irq;
199 	bool has_single_clk_source;
200 	bool has_config_load_reg;
201 	int clk_divisor_hs_mode;
202 	int clk_divisor_std_mode;
203 	int clk_divisor_fast_mode;
204 	u16 clk_divisor_fast_plus_mode;
205 	bool has_multi_master_mode;
206 	bool has_slcg_override_reg;
207 	bool has_mst_fifo;
208 	const struct i2c_adapter_quirks *quirks;
209 	bool supports_bus_clear;
210 	bool has_apb_dma;
211 	u8 tlow_std_mode;
212 	u8 thigh_std_mode;
213 	u8 tlow_fast_fastplus_mode;
214 	u8 thigh_fast_fastplus_mode;
215 	u32 setup_hold_time_std_mode;
216 	u32 setup_hold_time_fast_fast_plus_mode;
217 	u32 setup_hold_time_hs_mode;
218 	bool has_interface_timing_reg;
219 };
220 
221 /**
222  * struct tegra_i2c_dev - per device I2C context
223  * @dev: device reference for power management
224  * @hw: Tegra I2C HW feature
225  * @adapter: core I2C layer adapter information
226  * @div_clk: clock reference for div clock of I2C controller
227  * @fast_clk: clock reference for fast clock of I2C controller
228  * @rst: reset control for the I2C controller
229  * @base: ioremapped registers cookie
230  * @base_phys: physical base address of the I2C controller
231  * @cont_id: I2C controller ID, used for packet header
232  * @irq: IRQ number of transfer complete interrupt
233  * @irq_disabled: used to track whether or not the interrupt is enabled
234  * @is_dvc: identifies the DVC I2C controller, has a different register layout
235  * @msg_complete: transfer completion notifier
236  * @msg_err: error code for completed message
237  * @msg_buf: pointer to current message data
238  * @msg_buf_remaining: size of unsent data in the message buffer
239  * @msg_read: identifies read transfers
240  * @bus_clk_rate: current I2C bus clock rate
241  * @clk_divisor_non_hs_mode: clock divider for non-high-speed modes
242  * @is_multimaster_mode: track if I2C controller is in multi-master mode
243  * @xfer_lock: lock to serialize transfer submission and processing
244  * @tx_dma_chan: DMA transmit channel
245  * @rx_dma_chan: DMA receive channel
246  * @dma_phys: handle to DMA resources
247  * @dma_buf: pointer to allocated DMA buffer
248  * @dma_buf_size: DMA buffer size
249  * @is_curr_dma_xfer: indicates active DMA transfer
250  * @dma_complete: DMA completion notifier
251  */
252 struct tegra_i2c_dev {
253 	struct device *dev;
254 	const struct tegra_i2c_hw_feature *hw;
255 	struct i2c_adapter adapter;
256 	struct clk *div_clk;
257 	struct clk *fast_clk;
258 	struct reset_control *rst;
259 	void __iomem *base;
260 	phys_addr_t base_phys;
261 	int cont_id;
262 	int irq;
263 	bool irq_disabled;
264 	int is_dvc;
265 	struct completion msg_complete;
266 	int msg_err;
267 	u8 *msg_buf;
268 	size_t msg_buf_remaining;
269 	int msg_read;
270 	u32 bus_clk_rate;
271 	u16 clk_divisor_non_hs_mode;
272 	bool is_multimaster_mode;
273 	/* xfer_lock: lock to serialize transfer submission and processing */
274 	spinlock_t xfer_lock;
275 	struct dma_chan *tx_dma_chan;
276 	struct dma_chan *rx_dma_chan;
277 	dma_addr_t dma_phys;
278 	u32 *dma_buf;
279 	unsigned int dma_buf_size;
280 	bool is_curr_dma_xfer;
281 	struct completion dma_complete;
282 };
283 
284 static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
285 		       unsigned long reg)
286 {
287 	writel(val, i2c_dev->base + reg);
288 }
289 
290 static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
291 {
292 	return readl(i2c_dev->base + reg);
293 }
294 
295 /*
296  * i2c_writel and i2c_readl will offset the register if necessary to talk
297  * to the I2C block inside the DVC block
298  */
299 static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
300 					unsigned long reg)
301 {
302 	if (i2c_dev->is_dvc)
303 		reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
304 	return reg;
305 }
306 
307 static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
308 		       unsigned long reg)
309 {
310 	writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
311 
312 	/* Read back register to make sure that register writes completed */
313 	if (reg != I2C_TX_FIFO)
314 		readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
315 }
316 
317 static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
318 {
319 	return readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
320 }
321 
322 static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
323 			unsigned long reg, int len)
324 {
325 	writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
326 }
327 
328 static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
329 		       unsigned long reg, int len)
330 {
331 	readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
332 }
333 
334 static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
335 {
336 	u32 int_mask;
337 
338 	int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) & ~mask;
339 	i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
340 }
341 
342 static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
343 {
344 	u32 int_mask;
345 
346 	int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) | mask;
347 	i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
348 }
349 
350 static void tegra_i2c_dma_complete(void *args)
351 {
352 	struct tegra_i2c_dev *i2c_dev = args;
353 
354 	complete(&i2c_dev->dma_complete);
355 }
356 
357 static int tegra_i2c_dma_submit(struct tegra_i2c_dev *i2c_dev, size_t len)
358 {
359 	struct dma_async_tx_descriptor *dma_desc;
360 	enum dma_transfer_direction dir;
361 	struct dma_chan *chan;
362 
363 	dev_dbg(i2c_dev->dev, "starting DMA for length: %zu\n", len);
364 	reinit_completion(&i2c_dev->dma_complete);
365 	dir = i2c_dev->msg_read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV;
366 	chan = i2c_dev->msg_read ? i2c_dev->rx_dma_chan : i2c_dev->tx_dma_chan;
367 	dma_desc = dmaengine_prep_slave_single(chan, i2c_dev->dma_phys,
368 					       len, dir, DMA_PREP_INTERRUPT |
369 					       DMA_CTRL_ACK);
370 	if (!dma_desc) {
371 		dev_err(i2c_dev->dev, "failed to get DMA descriptor\n");
372 		return -EINVAL;
373 	}
374 
375 	dma_desc->callback = tegra_i2c_dma_complete;
376 	dma_desc->callback_param = i2c_dev;
377 	dmaengine_submit(dma_desc);
378 	dma_async_issue_pending(chan);
379 	return 0;
380 }
381 
382 static void tegra_i2c_release_dma(struct tegra_i2c_dev *i2c_dev)
383 {
384 	if (i2c_dev->dma_buf) {
385 		dma_free_coherent(i2c_dev->dev, i2c_dev->dma_buf_size,
386 				  i2c_dev->dma_buf, i2c_dev->dma_phys);
387 		i2c_dev->dma_buf = NULL;
388 	}
389 
390 	if (i2c_dev->tx_dma_chan) {
391 		dma_release_channel(i2c_dev->tx_dma_chan);
392 		i2c_dev->tx_dma_chan = NULL;
393 	}
394 
395 	if (i2c_dev->rx_dma_chan) {
396 		dma_release_channel(i2c_dev->rx_dma_chan);
397 		i2c_dev->rx_dma_chan = NULL;
398 	}
399 }
400 
401 static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev)
402 {
403 	struct dma_chan *chan;
404 	u32 *dma_buf;
405 	dma_addr_t dma_phys;
406 	int err;
407 
408 	if (!i2c_dev->hw->has_apb_dma)
409 		return 0;
410 
411 	if (!IS_ENABLED(CONFIG_TEGRA20_APB_DMA)) {
412 		dev_dbg(i2c_dev->dev, "Support for APB DMA not enabled!\n");
413 		return 0;
414 	}
415 
416 	chan = dma_request_chan(i2c_dev->dev, "rx");
417 	if (IS_ERR(chan)) {
418 		err = PTR_ERR(chan);
419 		goto err_out;
420 	}
421 
422 	i2c_dev->rx_dma_chan = chan;
423 
424 	chan = dma_request_chan(i2c_dev->dev, "tx");
425 	if (IS_ERR(chan)) {
426 		err = PTR_ERR(chan);
427 		goto err_out;
428 	}
429 
430 	i2c_dev->tx_dma_chan = chan;
431 
432 	dma_buf = dma_alloc_coherent(i2c_dev->dev, i2c_dev->dma_buf_size,
433 				     &dma_phys, GFP_KERNEL | __GFP_NOWARN);
434 	if (!dma_buf) {
435 		dev_err(i2c_dev->dev, "failed to allocate the DMA buffer\n");
436 		err = -ENOMEM;
437 		goto err_out;
438 	}
439 
440 	i2c_dev->dma_buf = dma_buf;
441 	i2c_dev->dma_phys = dma_phys;
442 	return 0;
443 
444 err_out:
445 	tegra_i2c_release_dma(i2c_dev);
446 	if (err != -EPROBE_DEFER) {
447 		dev_err(i2c_dev->dev, "cannot use DMA: %d\n", err);
448 		dev_err(i2c_dev->dev, "falling back to PIO\n");
449 		return 0;
450 	}
451 
452 	return err;
453 }
454 
455 static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
456 {
457 	unsigned long timeout = jiffies + HZ;
458 	unsigned int offset;
459 	u32 mask, val;
460 
461 	if (i2c_dev->hw->has_mst_fifo) {
462 		mask = I2C_MST_FIFO_CONTROL_TX_FLUSH |
463 		       I2C_MST_FIFO_CONTROL_RX_FLUSH;
464 		offset = I2C_MST_FIFO_CONTROL;
465 	} else {
466 		mask = I2C_FIFO_CONTROL_TX_FLUSH |
467 		       I2C_FIFO_CONTROL_RX_FLUSH;
468 		offset = I2C_FIFO_CONTROL;
469 	}
470 
471 	val = i2c_readl(i2c_dev, offset);
472 	val |= mask;
473 	i2c_writel(i2c_dev, val, offset);
474 
475 	while (i2c_readl(i2c_dev, offset) & mask) {
476 		if (time_after(jiffies, timeout)) {
477 			dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
478 			return -ETIMEDOUT;
479 		}
480 		usleep_range(1000, 2000);
481 	}
482 	return 0;
483 }
484 
485 static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
486 {
487 	u32 val;
488 	int rx_fifo_avail;
489 	u8 *buf = i2c_dev->msg_buf;
490 	size_t buf_remaining = i2c_dev->msg_buf_remaining;
491 	int words_to_transfer;
492 
493 	/*
494 	 * Catch overflow due to message fully sent
495 	 * before the check for RX FIFO availability.
496 	 */
497 	if (WARN_ON_ONCE(!(i2c_dev->msg_buf_remaining)))
498 		return -EINVAL;
499 
500 	if (i2c_dev->hw->has_mst_fifo) {
501 		val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS);
502 		rx_fifo_avail = (val & I2C_MST_FIFO_STATUS_RX_MASK) >>
503 			I2C_MST_FIFO_STATUS_RX_SHIFT;
504 	} else {
505 		val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
506 		rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
507 			I2C_FIFO_STATUS_RX_SHIFT;
508 	}
509 
510 	/* Rounds down to not include partial word at the end of buf */
511 	words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
512 	if (words_to_transfer > rx_fifo_avail)
513 		words_to_transfer = rx_fifo_avail;
514 
515 	i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
516 
517 	buf += words_to_transfer * BYTES_PER_FIFO_WORD;
518 	buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
519 	rx_fifo_avail -= words_to_transfer;
520 
521 	/*
522 	 * If there is a partial word at the end of buf, handle it manually to
523 	 * prevent overwriting past the end of buf
524 	 */
525 	if (rx_fifo_avail > 0 && buf_remaining > 0) {
526 		/*
527 		 * buf_remaining > 3 check not needed as rx_fifo_avail == 0
528 		 * when (words_to_transfer was > rx_fifo_avail) earlier
529 		 * in this function.
530 		 */
531 		val = i2c_readl(i2c_dev, I2C_RX_FIFO);
532 		val = cpu_to_le32(val);
533 		memcpy(buf, &val, buf_remaining);
534 		buf_remaining = 0;
535 		rx_fifo_avail--;
536 	}
537 
538 	/* RX FIFO must be drained, otherwise it's an Overflow case. */
539 	if (WARN_ON_ONCE(rx_fifo_avail))
540 		return -EINVAL;
541 
542 	i2c_dev->msg_buf_remaining = buf_remaining;
543 	i2c_dev->msg_buf = buf;
544 
545 	return 0;
546 }
547 
548 static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
549 {
550 	u32 val;
551 	int tx_fifo_avail;
552 	u8 *buf = i2c_dev->msg_buf;
553 	size_t buf_remaining = i2c_dev->msg_buf_remaining;
554 	int words_to_transfer;
555 
556 	if (i2c_dev->hw->has_mst_fifo) {
557 		val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS);
558 		tx_fifo_avail = (val & I2C_MST_FIFO_STATUS_TX_MASK) >>
559 			I2C_MST_FIFO_STATUS_TX_SHIFT;
560 	} else {
561 		val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
562 		tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
563 			I2C_FIFO_STATUS_TX_SHIFT;
564 	}
565 
566 	/* Rounds down to not include partial word at the end of buf */
567 	words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
568 
569 	/* It's very common to have < 4 bytes, so optimize that case. */
570 	if (words_to_transfer) {
571 		if (words_to_transfer > tx_fifo_avail)
572 			words_to_transfer = tx_fifo_avail;
573 
574 		/*
575 		 * Update state before writing to FIFO.  If this casues us
576 		 * to finish writing all bytes (AKA buf_remaining goes to 0) we
577 		 * have a potential for an interrupt (PACKET_XFER_COMPLETE is
578 		 * not maskable).  We need to make sure that the isr sees
579 		 * buf_remaining as 0 and doesn't call us back re-entrantly.
580 		 */
581 		buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
582 		tx_fifo_avail -= words_to_transfer;
583 		i2c_dev->msg_buf_remaining = buf_remaining;
584 		i2c_dev->msg_buf = buf +
585 			words_to_transfer * BYTES_PER_FIFO_WORD;
586 		barrier();
587 
588 		i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
589 
590 		buf += words_to_transfer * BYTES_PER_FIFO_WORD;
591 	}
592 
593 	/*
594 	 * If there is a partial word at the end of buf, handle it manually to
595 	 * prevent reading past the end of buf, which could cross a page
596 	 * boundary and fault.
597 	 */
598 	if (tx_fifo_avail > 0 && buf_remaining > 0) {
599 		/*
600 		 * buf_remaining > 3 check not needed as tx_fifo_avail == 0
601 		 * when (words_to_transfer was > tx_fifo_avail) earlier
602 		 * in this function for non-zero words_to_transfer.
603 		 */
604 		memcpy(&val, buf, buf_remaining);
605 		val = le32_to_cpu(val);
606 
607 		/* Again update before writing to FIFO to make sure isr sees. */
608 		i2c_dev->msg_buf_remaining = 0;
609 		i2c_dev->msg_buf = NULL;
610 		barrier();
611 
612 		i2c_writel(i2c_dev, val, I2C_TX_FIFO);
613 	}
614 
615 	return 0;
616 }
617 
618 /*
619  * One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
620  * block.  This block is identical to the rest of the I2C blocks, except that
621  * it only supports master mode, it has registers moved around, and it needs
622  * some extra init to get it into I2C mode.  The register moves are handled
623  * by i2c_readl and i2c_writel
624  */
625 static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
626 {
627 	u32 val;
628 
629 	val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
630 	val |= DVC_CTRL_REG3_SW_PROG;
631 	val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
632 	dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
633 
634 	val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
635 	val |= DVC_CTRL_REG1_INTR_EN;
636 	dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
637 }
638 
639 static int __maybe_unused tegra_i2c_runtime_resume(struct device *dev)
640 {
641 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
642 	int ret;
643 
644 	ret = pinctrl_pm_select_default_state(i2c_dev->dev);
645 	if (ret)
646 		return ret;
647 
648 	if (!i2c_dev->hw->has_single_clk_source) {
649 		ret = clk_enable(i2c_dev->fast_clk);
650 		if (ret < 0) {
651 			dev_err(i2c_dev->dev,
652 				"Enabling fast clk failed, err %d\n", ret);
653 			return ret;
654 		}
655 	}
656 
657 	ret = clk_enable(i2c_dev->div_clk);
658 	if (ret < 0) {
659 		dev_err(i2c_dev->dev,
660 			"Enabling div clk failed, err %d\n", ret);
661 		clk_disable(i2c_dev->fast_clk);
662 		return ret;
663 	}
664 
665 	return 0;
666 }
667 
668 static int __maybe_unused tegra_i2c_runtime_suspend(struct device *dev)
669 {
670 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
671 
672 	clk_disable(i2c_dev->div_clk);
673 	if (!i2c_dev->hw->has_single_clk_source)
674 		clk_disable(i2c_dev->fast_clk);
675 
676 	return pinctrl_pm_select_idle_state(i2c_dev->dev);
677 }
678 
679 static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
680 {
681 	unsigned long reg_offset;
682 	void __iomem *addr;
683 	u32 val;
684 	int err;
685 
686 	if (i2c_dev->hw->has_config_load_reg) {
687 		reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_CONFIG_LOAD);
688 		addr = i2c_dev->base + reg_offset;
689 		i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
690 		if (in_interrupt())
691 			err = readl_poll_timeout_atomic(addr, val, val == 0,
692 							1000,
693 							I2C_CONFIG_LOAD_TIMEOUT);
694 		else
695 			err = readl_poll_timeout(addr, val, val == 0, 1000,
696 						 I2C_CONFIG_LOAD_TIMEOUT);
697 
698 		if (err) {
699 			dev_warn(i2c_dev->dev,
700 				 "timeout waiting for config load\n");
701 			return err;
702 		}
703 	}
704 
705 	return 0;
706 }
707 
708 static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit)
709 {
710 	u32 val;
711 	int err;
712 	u32 clk_divisor, clk_multiplier;
713 	u32 tsu_thd;
714 	u8 tlow, thigh;
715 
716 	reset_control_assert(i2c_dev->rst);
717 	udelay(2);
718 	reset_control_deassert(i2c_dev->rst);
719 
720 	if (i2c_dev->is_dvc)
721 		tegra_dvc_init(i2c_dev);
722 
723 	val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
724 		(0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);
725 
726 	if (i2c_dev->hw->has_multi_master_mode)
727 		val |= I2C_CNFG_MULTI_MASTER_MODE;
728 
729 	i2c_writel(i2c_dev, val, I2C_CNFG);
730 	i2c_writel(i2c_dev, 0, I2C_INT_MASK);
731 
732 	/* Make sure clock divisor programmed correctly */
733 	clk_divisor = i2c_dev->hw->clk_divisor_hs_mode;
734 	clk_divisor |= i2c_dev->clk_divisor_non_hs_mode <<
735 					I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT;
736 	i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
737 
738 	if (i2c_dev->bus_clk_rate > I2C_STANDARD_MODE &&
739 	    i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE) {
740 		tlow = i2c_dev->hw->tlow_fast_fastplus_mode;
741 		thigh = i2c_dev->hw->thigh_fast_fastplus_mode;
742 		tsu_thd = i2c_dev->hw->setup_hold_time_fast_fast_plus_mode;
743 	} else {
744 		tlow = i2c_dev->hw->tlow_std_mode;
745 		thigh = i2c_dev->hw->thigh_std_mode;
746 		tsu_thd = i2c_dev->hw->setup_hold_time_std_mode;
747 	}
748 
749 	if (i2c_dev->hw->has_interface_timing_reg) {
750 		val = (thigh << I2C_THIGH_SHIFT) | tlow;
751 		i2c_writel(i2c_dev, val, I2C_INTERFACE_TIMING_0);
752 	}
753 
754 	/*
755 	 * configure setup and hold times only when tsu_thd is non-zero.
756 	 * otherwise, preserve the chip default values
757 	 */
758 	if (i2c_dev->hw->has_interface_timing_reg && tsu_thd)
759 		i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
760 
761 	if (!clk_reinit) {
762 		clk_multiplier = (tlow + thigh + 2);
763 		clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1);
764 		err = clk_set_rate(i2c_dev->div_clk,
765 				   i2c_dev->bus_clk_rate * clk_multiplier);
766 		if (err) {
767 			dev_err(i2c_dev->dev,
768 				"failed changing clock rate: %d\n", err);
769 			return err;
770 		}
771 	}
772 
773 	if (!i2c_dev->is_dvc) {
774 		u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
775 
776 		sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL;
777 		i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG);
778 		i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1);
779 		i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
780 	}
781 
782 	err = tegra_i2c_flush_fifos(i2c_dev);
783 	if (err)
784 		return err;
785 
786 	if (i2c_dev->is_multimaster_mode && i2c_dev->hw->has_slcg_override_reg)
787 		i2c_writel(i2c_dev, I2C_MST_CORE_CLKEN_OVR, I2C_CLKEN_OVERRIDE);
788 
789 	err = tegra_i2c_wait_for_config_load(i2c_dev);
790 	if (err)
791 		return err;
792 
793 	if (i2c_dev->irq_disabled) {
794 		i2c_dev->irq_disabled = false;
795 		enable_irq(i2c_dev->irq);
796 	}
797 
798 	return 0;
799 }
800 
801 static int tegra_i2c_disable_packet_mode(struct tegra_i2c_dev *i2c_dev)
802 {
803 	u32 cnfg;
804 
805 	/*
806 	 * NACK interrupt is generated before the I2C controller generates
807 	 * the STOP condition on the bus. So wait for 2 clock periods
808 	 * before disabling the controller so that the STOP condition has
809 	 * been delivered properly.
810 	 */
811 	udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate));
812 
813 	cnfg = i2c_readl(i2c_dev, I2C_CNFG);
814 	if (cnfg & I2C_CNFG_PACKET_MODE_EN)
815 		i2c_writel(i2c_dev, cnfg & ~I2C_CNFG_PACKET_MODE_EN, I2C_CNFG);
816 
817 	return tegra_i2c_wait_for_config_load(i2c_dev);
818 }
819 
820 static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
821 {
822 	u32 status;
823 	const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
824 	struct tegra_i2c_dev *i2c_dev = dev_id;
825 
826 	status = i2c_readl(i2c_dev, I2C_INT_STATUS);
827 
828 	spin_lock(&i2c_dev->xfer_lock);
829 	if (status == 0) {
830 		dev_warn(i2c_dev->dev, "irq status 0 %08x %08x %08x\n",
831 			 i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS),
832 			 i2c_readl(i2c_dev, I2C_STATUS),
833 			 i2c_readl(i2c_dev, I2C_CNFG));
834 		i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
835 
836 		if (!i2c_dev->irq_disabled) {
837 			disable_irq_nosync(i2c_dev->irq);
838 			i2c_dev->irq_disabled = true;
839 		}
840 		goto err;
841 	}
842 
843 	if (unlikely(status & status_err)) {
844 		tegra_i2c_disable_packet_mode(i2c_dev);
845 		if (status & I2C_INT_NO_ACK)
846 			i2c_dev->msg_err |= I2C_ERR_NO_ACK;
847 		if (status & I2C_INT_ARBITRATION_LOST)
848 			i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
849 		goto err;
850 	}
851 
852 	/*
853 	 * I2C transfer is terminated during the bus clear so skip
854 	 * processing the other interrupts.
855 	 */
856 	if (i2c_dev->hw->supports_bus_clear && (status & I2C_INT_BUS_CLR_DONE))
857 		goto err;
858 
859 	if (!i2c_dev->is_curr_dma_xfer) {
860 		if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
861 			if (tegra_i2c_empty_rx_fifo(i2c_dev)) {
862 				/*
863 				 * Overflow error condition: message fully sent,
864 				 * with no XFER_COMPLETE interrupt but hardware
865 				 * asks to transfer more.
866 				 */
867 				i2c_dev->msg_err |= I2C_ERR_RX_BUFFER_OVERFLOW;
868 				goto err;
869 			}
870 		}
871 
872 		if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
873 			if (i2c_dev->msg_buf_remaining)
874 				tegra_i2c_fill_tx_fifo(i2c_dev);
875 			else
876 				tegra_i2c_mask_irq(i2c_dev,
877 						   I2C_INT_TX_FIFO_DATA_REQ);
878 		}
879 	}
880 
881 	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
882 	if (i2c_dev->is_dvc)
883 		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
884 
885 	/*
886 	 * During message read XFER_COMPLETE interrupt is triggered prior to
887 	 * DMA completion and during message write XFER_COMPLETE interrupt is
888 	 * triggered after DMA completion.
889 	 * PACKETS_XFER_COMPLETE indicates completion of all bytes of transfer.
890 	 * so forcing msg_buf_remaining to 0 in DMA mode.
891 	 */
892 	if (status & I2C_INT_PACKET_XFER_COMPLETE) {
893 		if (i2c_dev->is_curr_dma_xfer)
894 			i2c_dev->msg_buf_remaining = 0;
895 		/*
896 		 * Underflow error condition: XFER_COMPLETE before message
897 		 * fully sent.
898 		 */
899 		if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining)) {
900 			i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
901 			goto err;
902 		}
903 		complete(&i2c_dev->msg_complete);
904 	}
905 	goto done;
906 err:
907 	/* An error occurred, mask all interrupts */
908 	tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST |
909 		I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ |
910 		I2C_INT_RX_FIFO_DATA_REQ);
911 	if (i2c_dev->hw->supports_bus_clear)
912 		tegra_i2c_mask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE);
913 	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
914 	if (i2c_dev->is_dvc)
915 		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
916 
917 	if (i2c_dev->is_curr_dma_xfer) {
918 		if (i2c_dev->msg_read)
919 			dmaengine_terminate_async(i2c_dev->rx_dma_chan);
920 		else
921 			dmaengine_terminate_async(i2c_dev->tx_dma_chan);
922 
923 		complete(&i2c_dev->dma_complete);
924 	}
925 
926 	complete(&i2c_dev->msg_complete);
927 done:
928 	spin_unlock(&i2c_dev->xfer_lock);
929 	return IRQ_HANDLED;
930 }
931 
932 static void tegra_i2c_config_fifo_trig(struct tegra_i2c_dev *i2c_dev,
933 				       size_t len)
934 {
935 	u32 val, reg;
936 	u8 dma_burst;
937 	struct dma_slave_config slv_config = {0};
938 	struct dma_chan *chan;
939 	int ret;
940 	unsigned long reg_offset;
941 
942 	if (i2c_dev->hw->has_mst_fifo)
943 		reg = I2C_MST_FIFO_CONTROL;
944 	else
945 		reg = I2C_FIFO_CONTROL;
946 
947 	if (i2c_dev->is_curr_dma_xfer) {
948 		if (len & 0xF)
949 			dma_burst = 1;
950 		else if (len & 0x10)
951 			dma_burst = 4;
952 		else
953 			dma_burst = 8;
954 
955 		if (i2c_dev->msg_read) {
956 			chan = i2c_dev->rx_dma_chan;
957 			reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_RX_FIFO);
958 			slv_config.src_addr = i2c_dev->base_phys + reg_offset;
959 			slv_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
960 			slv_config.src_maxburst = dma_burst;
961 
962 			if (i2c_dev->hw->has_mst_fifo)
963 				val = I2C_MST_FIFO_CONTROL_RX_TRIG(dma_burst);
964 			else
965 				val = I2C_FIFO_CONTROL_RX_TRIG(dma_burst);
966 		} else {
967 			chan = i2c_dev->tx_dma_chan;
968 			reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_TX_FIFO);
969 			slv_config.dst_addr = i2c_dev->base_phys + reg_offset;
970 			slv_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
971 			slv_config.dst_maxburst = dma_burst;
972 
973 			if (i2c_dev->hw->has_mst_fifo)
974 				val = I2C_MST_FIFO_CONTROL_TX_TRIG(dma_burst);
975 			else
976 				val = I2C_FIFO_CONTROL_TX_TRIG(dma_burst);
977 		}
978 
979 		slv_config.device_fc = true;
980 		ret = dmaengine_slave_config(chan, &slv_config);
981 		if (ret < 0) {
982 			dev_err(i2c_dev->dev, "DMA slave config failed: %d\n",
983 				ret);
984 			dev_err(i2c_dev->dev, "falling back to PIO\n");
985 			tegra_i2c_release_dma(i2c_dev);
986 			i2c_dev->is_curr_dma_xfer = false;
987 		} else {
988 			goto out;
989 		}
990 	}
991 
992 	if (i2c_dev->hw->has_mst_fifo)
993 		val = I2C_MST_FIFO_CONTROL_TX_TRIG(8) |
994 		      I2C_MST_FIFO_CONTROL_RX_TRIG(1);
995 	else
996 		val = I2C_FIFO_CONTROL_TX_TRIG(8) |
997 		      I2C_FIFO_CONTROL_RX_TRIG(1);
998 out:
999 	i2c_writel(i2c_dev, val, reg);
1000 }
1001 
1002 static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap)
1003 {
1004 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
1005 	int err;
1006 	unsigned long time_left;
1007 	u32 reg;
1008 
1009 	reinit_completion(&i2c_dev->msg_complete);
1010 	reg = (I2C_BC_SCLK_THRESHOLD << I2C_BC_SCLK_THRESHOLD_SHIFT) |
1011 	      I2C_BC_STOP_COND | I2C_BC_TERMINATE;
1012 	i2c_writel(i2c_dev, reg, I2C_BUS_CLEAR_CNFG);
1013 	if (i2c_dev->hw->has_config_load_reg) {
1014 		err = tegra_i2c_wait_for_config_load(i2c_dev);
1015 		if (err)
1016 			return err;
1017 	}
1018 
1019 	reg |= I2C_BC_ENABLE;
1020 	i2c_writel(i2c_dev, reg, I2C_BUS_CLEAR_CNFG);
1021 	tegra_i2c_unmask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE);
1022 
1023 	time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
1024 						msecs_to_jiffies(50));
1025 	if (time_left == 0) {
1026 		dev_err(i2c_dev->dev, "timed out for bus clear\n");
1027 		return -ETIMEDOUT;
1028 	}
1029 
1030 	reg = i2c_readl(i2c_dev, I2C_BUS_CLEAR_STATUS);
1031 	if (!(reg & I2C_BC_STATUS)) {
1032 		dev_err(i2c_dev->dev,
1033 			"un-recovered arbitration lost\n");
1034 		return -EIO;
1035 	}
1036 
1037 	return -EAGAIN;
1038 }
1039 
1040 static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
1041 			      struct i2c_msg *msg,
1042 			      enum msg_end_type end_state)
1043 {
1044 	u32 packet_header;
1045 	u32 int_mask;
1046 	unsigned long time_left;
1047 	unsigned long flags;
1048 	size_t xfer_size;
1049 	u32 *buffer = NULL;
1050 	int err = 0;
1051 	bool dma;
1052 	u16 xfer_time = 100;
1053 
1054 	tegra_i2c_flush_fifos(i2c_dev);
1055 
1056 	i2c_dev->msg_buf = msg->buf;
1057 	i2c_dev->msg_buf_remaining = msg->len;
1058 	i2c_dev->msg_err = I2C_ERR_NONE;
1059 	i2c_dev->msg_read = (msg->flags & I2C_M_RD);
1060 	reinit_completion(&i2c_dev->msg_complete);
1061 
1062 	if (i2c_dev->msg_read)
1063 		xfer_size = msg->len;
1064 	else
1065 		xfer_size = msg->len + I2C_PACKET_HEADER_SIZE;
1066 
1067 	xfer_size = ALIGN(xfer_size, BYTES_PER_FIFO_WORD);
1068 	i2c_dev->is_curr_dma_xfer = (xfer_size > I2C_PIO_MODE_MAX_LEN) &&
1069 				    i2c_dev->dma_buf;
1070 	tegra_i2c_config_fifo_trig(i2c_dev, xfer_size);
1071 	dma = i2c_dev->is_curr_dma_xfer;
1072 	/*
1073 	 * Transfer time in mSec = Total bits / transfer rate
1074 	 * Total bits = 9 bits per byte (including ACK bit) + Start & stop bits
1075 	 */
1076 	xfer_time += DIV_ROUND_CLOSEST(((xfer_size * 9) + 2) * MSEC_PER_SEC,
1077 					i2c_dev->bus_clk_rate);
1078 	spin_lock_irqsave(&i2c_dev->xfer_lock, flags);
1079 
1080 	int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
1081 	tegra_i2c_unmask_irq(i2c_dev, int_mask);
1082 	if (dma) {
1083 		if (i2c_dev->msg_read) {
1084 			dma_sync_single_for_device(i2c_dev->dev,
1085 						   i2c_dev->dma_phys,
1086 						   xfer_size,
1087 						   DMA_FROM_DEVICE);
1088 			err = tegra_i2c_dma_submit(i2c_dev, xfer_size);
1089 			if (err < 0) {
1090 				dev_err(i2c_dev->dev,
1091 					"starting RX DMA failed, err %d\n",
1092 					err);
1093 				goto unlock;
1094 			}
1095 
1096 		} else {
1097 			dma_sync_single_for_cpu(i2c_dev->dev,
1098 						i2c_dev->dma_phys,
1099 						xfer_size,
1100 						DMA_TO_DEVICE);
1101 			buffer = i2c_dev->dma_buf;
1102 		}
1103 	}
1104 
1105 	packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
1106 			PACKET_HEADER0_PROTOCOL_I2C |
1107 			(i2c_dev->cont_id << PACKET_HEADER0_CONT_ID_SHIFT) |
1108 			(1 << PACKET_HEADER0_PACKET_ID_SHIFT);
1109 	if (dma && !i2c_dev->msg_read)
1110 		*buffer++ = packet_header;
1111 	else
1112 		i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
1113 
1114 	packet_header = msg->len - 1;
1115 	if (dma && !i2c_dev->msg_read)
1116 		*buffer++ = packet_header;
1117 	else
1118 		i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
1119 
1120 	packet_header = I2C_HEADER_IE_ENABLE;
1121 	if (end_state == MSG_END_CONTINUE)
1122 		packet_header |= I2C_HEADER_CONTINUE_XFER;
1123 	else if (end_state == MSG_END_REPEAT_START)
1124 		packet_header |= I2C_HEADER_REPEAT_START;
1125 	if (msg->flags & I2C_M_TEN) {
1126 		packet_header |= msg->addr;
1127 		packet_header |= I2C_HEADER_10BIT_ADDR;
1128 	} else {
1129 		packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
1130 	}
1131 	if (msg->flags & I2C_M_IGNORE_NAK)
1132 		packet_header |= I2C_HEADER_CONT_ON_NAK;
1133 	if (msg->flags & I2C_M_RD)
1134 		packet_header |= I2C_HEADER_READ;
1135 	if (dma && !i2c_dev->msg_read)
1136 		*buffer++ = packet_header;
1137 	else
1138 		i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
1139 
1140 	if (!i2c_dev->msg_read) {
1141 		if (dma) {
1142 			memcpy(buffer, msg->buf, msg->len);
1143 			dma_sync_single_for_device(i2c_dev->dev,
1144 						   i2c_dev->dma_phys,
1145 						   xfer_size,
1146 						   DMA_TO_DEVICE);
1147 			err = tegra_i2c_dma_submit(i2c_dev, xfer_size);
1148 			if (err < 0) {
1149 				dev_err(i2c_dev->dev,
1150 					"starting TX DMA failed, err %d\n",
1151 					err);
1152 				goto unlock;
1153 			}
1154 		} else {
1155 			tegra_i2c_fill_tx_fifo(i2c_dev);
1156 		}
1157 	}
1158 
1159 	if (i2c_dev->hw->has_per_pkt_xfer_complete_irq)
1160 		int_mask |= I2C_INT_PACKET_XFER_COMPLETE;
1161 	if (!dma) {
1162 		if (msg->flags & I2C_M_RD)
1163 			int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
1164 		else if (i2c_dev->msg_buf_remaining)
1165 			int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
1166 	}
1167 
1168 	tegra_i2c_unmask_irq(i2c_dev, int_mask);
1169 	dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n",
1170 		i2c_readl(i2c_dev, I2C_INT_MASK));
1171 
1172 unlock:
1173 	spin_unlock_irqrestore(&i2c_dev->xfer_lock, flags);
1174 
1175 	if (dma) {
1176 		if (err)
1177 			return err;
1178 
1179 		time_left = wait_for_completion_timeout(&i2c_dev->dma_complete,
1180 							msecs_to_jiffies(xfer_time));
1181 		if (time_left == 0) {
1182 			dev_err(i2c_dev->dev, "DMA transfer timeout\n");
1183 			dmaengine_terminate_sync(i2c_dev->msg_read ?
1184 						 i2c_dev->rx_dma_chan :
1185 						 i2c_dev->tx_dma_chan);
1186 			tegra_i2c_init(i2c_dev, true);
1187 			return -ETIMEDOUT;
1188 		}
1189 
1190 		if (i2c_dev->msg_read && i2c_dev->msg_err == I2C_ERR_NONE) {
1191 			dma_sync_single_for_cpu(i2c_dev->dev,
1192 						i2c_dev->dma_phys,
1193 						xfer_size,
1194 						DMA_FROM_DEVICE);
1195 			memcpy(i2c_dev->msg_buf, i2c_dev->dma_buf,
1196 			       msg->len);
1197 		}
1198 
1199 		if (i2c_dev->msg_err != I2C_ERR_NONE)
1200 			dmaengine_synchronize(i2c_dev->msg_read ?
1201 					      i2c_dev->rx_dma_chan :
1202 					      i2c_dev->tx_dma_chan);
1203 	}
1204 
1205 	time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
1206 						msecs_to_jiffies(xfer_time));
1207 	tegra_i2c_mask_irq(i2c_dev, int_mask);
1208 
1209 	if (time_left == 0) {
1210 		dev_err(i2c_dev->dev, "i2c transfer timed out\n");
1211 
1212 		tegra_i2c_init(i2c_dev, true);
1213 		return -ETIMEDOUT;
1214 	}
1215 
1216 	dev_dbg(i2c_dev->dev, "transfer complete: %lu %d %d\n",
1217 		time_left, completion_done(&i2c_dev->msg_complete),
1218 		i2c_dev->msg_err);
1219 
1220 	i2c_dev->is_curr_dma_xfer = false;
1221 	if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
1222 		return 0;
1223 
1224 	tegra_i2c_init(i2c_dev, true);
1225 	/* start recovery upon arbitration loss in single master mode */
1226 	if (i2c_dev->msg_err == I2C_ERR_ARBITRATION_LOST) {
1227 		if (!i2c_dev->is_multimaster_mode)
1228 			return i2c_recover_bus(&i2c_dev->adapter);
1229 		return -EAGAIN;
1230 	}
1231 
1232 	if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
1233 		if (msg->flags & I2C_M_IGNORE_NAK)
1234 			return 0;
1235 		return -EREMOTEIO;
1236 	}
1237 
1238 	return -EIO;
1239 }
1240 
1241 static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
1242 			  int num)
1243 {
1244 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
1245 	int i;
1246 	int ret;
1247 
1248 	ret = pm_runtime_get_sync(i2c_dev->dev);
1249 	if (ret < 0) {
1250 		dev_err(i2c_dev->dev, "runtime resume failed %d\n", ret);
1251 		return ret;
1252 	}
1253 
1254 	for (i = 0; i < num; i++) {
1255 		enum msg_end_type end_type = MSG_END_STOP;
1256 
1257 		if (i < (num - 1)) {
1258 			if (msgs[i + 1].flags & I2C_M_NOSTART)
1259 				end_type = MSG_END_CONTINUE;
1260 			else
1261 				end_type = MSG_END_REPEAT_START;
1262 		}
1263 		ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);
1264 		if (ret)
1265 			break;
1266 	}
1267 
1268 	pm_runtime_put(i2c_dev->dev);
1269 
1270 	return ret ?: i;
1271 }
1272 
1273 static u32 tegra_i2c_func(struct i2c_adapter *adap)
1274 {
1275 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
1276 	u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
1277 		  I2C_FUNC_10BIT_ADDR |	I2C_FUNC_PROTOCOL_MANGLING;
1278 
1279 	if (i2c_dev->hw->has_continue_xfer_support)
1280 		ret |= I2C_FUNC_NOSTART;
1281 	return ret;
1282 }
1283 
1284 static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
1285 {
1286 	struct device_node *np = i2c_dev->dev->of_node;
1287 	int ret;
1288 	bool multi_mode;
1289 
1290 	ret = of_property_read_u32(np, "clock-frequency",
1291 				   &i2c_dev->bus_clk_rate);
1292 	if (ret)
1293 		i2c_dev->bus_clk_rate = 100000; /* default clock rate */
1294 
1295 	multi_mode = of_property_read_bool(np, "multi-master");
1296 	i2c_dev->is_multimaster_mode = multi_mode;
1297 }
1298 
1299 static const struct i2c_algorithm tegra_i2c_algo = {
1300 	.master_xfer	= tegra_i2c_xfer,
1301 	.functionality	= tegra_i2c_func,
1302 };
1303 
1304 /* payload size is only 12 bit */
1305 static const struct i2c_adapter_quirks tegra_i2c_quirks = {
1306 	.flags = I2C_AQ_NO_ZERO_LEN,
1307 	.max_read_len = SZ_4K,
1308 	.max_write_len = SZ_4K - I2C_PACKET_HEADER_SIZE,
1309 };
1310 
1311 static const struct i2c_adapter_quirks tegra194_i2c_quirks = {
1312 	.flags = I2C_AQ_NO_ZERO_LEN,
1313 	.max_write_len = SZ_64K - I2C_PACKET_HEADER_SIZE,
1314 };
1315 
1316 static struct i2c_bus_recovery_info tegra_i2c_recovery_info = {
1317 	.recover_bus = tegra_i2c_issue_bus_clear,
1318 };
1319 
1320 static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
1321 	.has_continue_xfer_support = false,
1322 	.has_per_pkt_xfer_complete_irq = false,
1323 	.has_single_clk_source = false,
1324 	.clk_divisor_hs_mode = 3,
1325 	.clk_divisor_std_mode = 0,
1326 	.clk_divisor_fast_mode = 0,
1327 	.clk_divisor_fast_plus_mode = 0,
1328 	.has_config_load_reg = false,
1329 	.has_multi_master_mode = false,
1330 	.has_slcg_override_reg = false,
1331 	.has_mst_fifo = false,
1332 	.quirks = &tegra_i2c_quirks,
1333 	.supports_bus_clear = false,
1334 	.has_apb_dma = true,
1335 	.tlow_std_mode = 0x4,
1336 	.thigh_std_mode = 0x2,
1337 	.tlow_fast_fastplus_mode = 0x4,
1338 	.thigh_fast_fastplus_mode = 0x2,
1339 	.setup_hold_time_std_mode = 0x0,
1340 	.setup_hold_time_fast_fast_plus_mode = 0x0,
1341 	.setup_hold_time_hs_mode = 0x0,
1342 	.has_interface_timing_reg = false,
1343 };
1344 
1345 static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
1346 	.has_continue_xfer_support = true,
1347 	.has_per_pkt_xfer_complete_irq = false,
1348 	.has_single_clk_source = false,
1349 	.clk_divisor_hs_mode = 3,
1350 	.clk_divisor_std_mode = 0,
1351 	.clk_divisor_fast_mode = 0,
1352 	.clk_divisor_fast_plus_mode = 0,
1353 	.has_config_load_reg = false,
1354 	.has_multi_master_mode = false,
1355 	.has_slcg_override_reg = false,
1356 	.has_mst_fifo = false,
1357 	.quirks = &tegra_i2c_quirks,
1358 	.supports_bus_clear = false,
1359 	.has_apb_dma = true,
1360 	.tlow_std_mode = 0x4,
1361 	.thigh_std_mode = 0x2,
1362 	.tlow_fast_fastplus_mode = 0x4,
1363 	.thigh_fast_fastplus_mode = 0x2,
1364 	.setup_hold_time_std_mode = 0x0,
1365 	.setup_hold_time_fast_fast_plus_mode = 0x0,
1366 	.setup_hold_time_hs_mode = 0x0,
1367 	.has_interface_timing_reg = false,
1368 };
1369 
1370 static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
1371 	.has_continue_xfer_support = true,
1372 	.has_per_pkt_xfer_complete_irq = true,
1373 	.has_single_clk_source = true,
1374 	.clk_divisor_hs_mode = 1,
1375 	.clk_divisor_std_mode = 0x19,
1376 	.clk_divisor_fast_mode = 0x19,
1377 	.clk_divisor_fast_plus_mode = 0x10,
1378 	.has_config_load_reg = false,
1379 	.has_multi_master_mode = false,
1380 	.has_slcg_override_reg = false,
1381 	.has_mst_fifo = false,
1382 	.quirks = &tegra_i2c_quirks,
1383 	.supports_bus_clear = true,
1384 	.has_apb_dma = true,
1385 	.tlow_std_mode = 0x4,
1386 	.thigh_std_mode = 0x2,
1387 	.tlow_fast_fastplus_mode = 0x4,
1388 	.thigh_fast_fastplus_mode = 0x2,
1389 	.setup_hold_time_std_mode = 0x0,
1390 	.setup_hold_time_fast_fast_plus_mode = 0x0,
1391 	.setup_hold_time_hs_mode = 0x0,
1392 	.has_interface_timing_reg = false,
1393 };
1394 
1395 static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
1396 	.has_continue_xfer_support = true,
1397 	.has_per_pkt_xfer_complete_irq = true,
1398 	.has_single_clk_source = true,
1399 	.clk_divisor_hs_mode = 1,
1400 	.clk_divisor_std_mode = 0x19,
1401 	.clk_divisor_fast_mode = 0x19,
1402 	.clk_divisor_fast_plus_mode = 0x10,
1403 	.has_config_load_reg = true,
1404 	.has_multi_master_mode = false,
1405 	.has_slcg_override_reg = true,
1406 	.has_mst_fifo = false,
1407 	.quirks = &tegra_i2c_quirks,
1408 	.supports_bus_clear = true,
1409 	.has_apb_dma = true,
1410 	.tlow_std_mode = 0x4,
1411 	.thigh_std_mode = 0x2,
1412 	.tlow_fast_fastplus_mode = 0x4,
1413 	.thigh_fast_fastplus_mode = 0x2,
1414 	.setup_hold_time_std_mode = 0x0,
1415 	.setup_hold_time_fast_fast_plus_mode = 0x0,
1416 	.setup_hold_time_hs_mode = 0x0,
1417 	.has_interface_timing_reg = true,
1418 };
1419 
1420 static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
1421 	.has_continue_xfer_support = true,
1422 	.has_per_pkt_xfer_complete_irq = true,
1423 	.has_single_clk_source = true,
1424 	.clk_divisor_hs_mode = 1,
1425 	.clk_divisor_std_mode = 0x19,
1426 	.clk_divisor_fast_mode = 0x19,
1427 	.clk_divisor_fast_plus_mode = 0x10,
1428 	.has_config_load_reg = true,
1429 	.has_multi_master_mode = false,
1430 	.has_slcg_override_reg = true,
1431 	.has_mst_fifo = false,
1432 	.quirks = &tegra_i2c_quirks,
1433 	.supports_bus_clear = true,
1434 	.has_apb_dma = true,
1435 	.tlow_std_mode = 0x4,
1436 	.thigh_std_mode = 0x2,
1437 	.tlow_fast_fastplus_mode = 0x4,
1438 	.thigh_fast_fastplus_mode = 0x2,
1439 	.setup_hold_time_std_mode = 0,
1440 	.setup_hold_time_fast_fast_plus_mode = 0,
1441 	.setup_hold_time_hs_mode = 0,
1442 	.has_interface_timing_reg = true,
1443 };
1444 
1445 static const struct tegra_i2c_hw_feature tegra186_i2c_hw = {
1446 	.has_continue_xfer_support = true,
1447 	.has_per_pkt_xfer_complete_irq = true,
1448 	.has_single_clk_source = true,
1449 	.clk_divisor_hs_mode = 1,
1450 	.clk_divisor_std_mode = 0x16,
1451 	.clk_divisor_fast_mode = 0x19,
1452 	.clk_divisor_fast_plus_mode = 0x10,
1453 	.has_config_load_reg = true,
1454 	.has_multi_master_mode = false,
1455 	.has_slcg_override_reg = true,
1456 	.has_mst_fifo = false,
1457 	.quirks = &tegra_i2c_quirks,
1458 	.supports_bus_clear = true,
1459 	.has_apb_dma = false,
1460 	.tlow_std_mode = 0x4,
1461 	.thigh_std_mode = 0x3,
1462 	.tlow_fast_fastplus_mode = 0x4,
1463 	.thigh_fast_fastplus_mode = 0x2,
1464 	.setup_hold_time_std_mode = 0,
1465 	.setup_hold_time_fast_fast_plus_mode = 0,
1466 	.setup_hold_time_hs_mode = 0,
1467 	.has_interface_timing_reg = true,
1468 };
1469 
1470 static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
1471 	.has_continue_xfer_support = true,
1472 	.has_per_pkt_xfer_complete_irq = true,
1473 	.has_single_clk_source = true,
1474 	.clk_divisor_hs_mode = 1,
1475 	.clk_divisor_std_mode = 0x4f,
1476 	.clk_divisor_fast_mode = 0x3c,
1477 	.clk_divisor_fast_plus_mode = 0x16,
1478 	.has_config_load_reg = true,
1479 	.has_multi_master_mode = true,
1480 	.has_slcg_override_reg = true,
1481 	.has_mst_fifo = true,
1482 	.quirks = &tegra194_i2c_quirks,
1483 	.supports_bus_clear = true,
1484 	.has_apb_dma = false,
1485 	.tlow_std_mode = 0x8,
1486 	.thigh_std_mode = 0x7,
1487 	.tlow_fast_fastplus_mode = 0x2,
1488 	.thigh_fast_fastplus_mode = 0x2,
1489 	.setup_hold_time_std_mode = 0x08080808,
1490 	.setup_hold_time_fast_fast_plus_mode = 0x02020202,
1491 	.setup_hold_time_hs_mode = 0x090909,
1492 	.has_interface_timing_reg = true,
1493 };
1494 
1495 /* Match table for of_platform binding */
1496 static const struct of_device_id tegra_i2c_of_match[] = {
1497 	{ .compatible = "nvidia,tegra194-i2c", .data = &tegra194_i2c_hw, },
1498 	{ .compatible = "nvidia,tegra186-i2c", .data = &tegra186_i2c_hw, },
1499 	{ .compatible = "nvidia,tegra210-i2c", .data = &tegra210_i2c_hw, },
1500 	{ .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, },
1501 	{ .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, },
1502 	{ .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, },
1503 	{ .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, },
1504 	{ .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, },
1505 	{},
1506 };
1507 MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
1508 
1509 static int tegra_i2c_probe(struct platform_device *pdev)
1510 {
1511 	struct tegra_i2c_dev *i2c_dev;
1512 	struct resource *res;
1513 	struct clk *div_clk;
1514 	struct clk *fast_clk;
1515 	void __iomem *base;
1516 	phys_addr_t base_phys;
1517 	int irq;
1518 	int ret;
1519 
1520 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1521 	base_phys = res->start;
1522 	base = devm_ioremap_resource(&pdev->dev, res);
1523 	if (IS_ERR(base))
1524 		return PTR_ERR(base);
1525 
1526 	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
1527 	if (!res) {
1528 		dev_err(&pdev->dev, "no irq resource\n");
1529 		return -EINVAL;
1530 	}
1531 	irq = res->start;
1532 
1533 	div_clk = devm_clk_get(&pdev->dev, "div-clk");
1534 	if (IS_ERR(div_clk)) {
1535 		if (PTR_ERR(div_clk) != -EPROBE_DEFER)
1536 			dev_err(&pdev->dev, "missing controller clock\n");
1537 
1538 		return PTR_ERR(div_clk);
1539 	}
1540 
1541 	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
1542 	if (!i2c_dev)
1543 		return -ENOMEM;
1544 
1545 	i2c_dev->base = base;
1546 	i2c_dev->base_phys = base_phys;
1547 	i2c_dev->div_clk = div_clk;
1548 	i2c_dev->adapter.algo = &tegra_i2c_algo;
1549 	i2c_dev->adapter.retries = 1;
1550 	i2c_dev->adapter.timeout = 6 * HZ;
1551 	i2c_dev->irq = irq;
1552 	i2c_dev->cont_id = pdev->id;
1553 	i2c_dev->dev = &pdev->dev;
1554 
1555 	i2c_dev->rst = devm_reset_control_get_exclusive(&pdev->dev, "i2c");
1556 	if (IS_ERR(i2c_dev->rst)) {
1557 		dev_err(&pdev->dev, "missing controller reset\n");
1558 		return PTR_ERR(i2c_dev->rst);
1559 	}
1560 
1561 	tegra_i2c_parse_dt(i2c_dev);
1562 
1563 	i2c_dev->hw = of_device_get_match_data(&pdev->dev);
1564 	i2c_dev->is_dvc = of_device_is_compatible(pdev->dev.of_node,
1565 						  "nvidia,tegra20-i2c-dvc");
1566 	i2c_dev->adapter.quirks = i2c_dev->hw->quirks;
1567 	i2c_dev->dma_buf_size = i2c_dev->adapter.quirks->max_write_len +
1568 				I2C_PACKET_HEADER_SIZE;
1569 	init_completion(&i2c_dev->msg_complete);
1570 	init_completion(&i2c_dev->dma_complete);
1571 	spin_lock_init(&i2c_dev->xfer_lock);
1572 
1573 	if (!i2c_dev->hw->has_single_clk_source) {
1574 		fast_clk = devm_clk_get(&pdev->dev, "fast-clk");
1575 		if (IS_ERR(fast_clk)) {
1576 			dev_err(&pdev->dev, "missing fast clock\n");
1577 			return PTR_ERR(fast_clk);
1578 		}
1579 		i2c_dev->fast_clk = fast_clk;
1580 	}
1581 
1582 	platform_set_drvdata(pdev, i2c_dev);
1583 
1584 	if (!i2c_dev->hw->has_single_clk_source) {
1585 		ret = clk_prepare(i2c_dev->fast_clk);
1586 		if (ret < 0) {
1587 			dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
1588 			return ret;
1589 		}
1590 	}
1591 
1592 	if (i2c_dev->bus_clk_rate > I2C_FAST_MODE &&
1593 	    i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE)
1594 		i2c_dev->clk_divisor_non_hs_mode =
1595 				i2c_dev->hw->clk_divisor_fast_plus_mode;
1596 	else if (i2c_dev->bus_clk_rate > I2C_STANDARD_MODE &&
1597 		 i2c_dev->bus_clk_rate <= I2C_FAST_MODE)
1598 		i2c_dev->clk_divisor_non_hs_mode =
1599 				i2c_dev->hw->clk_divisor_fast_mode;
1600 	else
1601 		i2c_dev->clk_divisor_non_hs_mode =
1602 				i2c_dev->hw->clk_divisor_std_mode;
1603 
1604 	ret = clk_prepare(i2c_dev->div_clk);
1605 	if (ret < 0) {
1606 		dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
1607 		goto unprepare_fast_clk;
1608 	}
1609 
1610 	pm_runtime_enable(&pdev->dev);
1611 	if (!pm_runtime_enabled(&pdev->dev))
1612 		ret = tegra_i2c_runtime_resume(&pdev->dev);
1613 	else
1614 		ret = pm_runtime_get_sync(i2c_dev->dev);
1615 
1616 	if (ret < 0) {
1617 		dev_err(&pdev->dev, "runtime resume failed\n");
1618 		goto unprepare_div_clk;
1619 	}
1620 
1621 	if (i2c_dev->is_multimaster_mode) {
1622 		ret = clk_enable(i2c_dev->div_clk);
1623 		if (ret < 0) {
1624 			dev_err(i2c_dev->dev, "div_clk enable failed %d\n",
1625 				ret);
1626 			goto disable_rpm;
1627 		}
1628 	}
1629 
1630 	if (i2c_dev->hw->supports_bus_clear)
1631 		i2c_dev->adapter.bus_recovery_info = &tegra_i2c_recovery_info;
1632 
1633 	ret = tegra_i2c_init_dma(i2c_dev);
1634 	if (ret < 0)
1635 		goto disable_div_clk;
1636 
1637 	ret = tegra_i2c_init(i2c_dev, false);
1638 	if (ret) {
1639 		dev_err(&pdev->dev, "Failed to initialize i2c controller\n");
1640 		goto release_dma;
1641 	}
1642 
1643 	ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
1644 			       tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
1645 	if (ret) {
1646 		dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
1647 		goto release_dma;
1648 	}
1649 
1650 	i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
1651 	i2c_dev->adapter.owner = THIS_MODULE;
1652 	i2c_dev->adapter.class = I2C_CLASS_DEPRECATED;
1653 	strlcpy(i2c_dev->adapter.name, dev_name(&pdev->dev),
1654 		sizeof(i2c_dev->adapter.name));
1655 	i2c_dev->adapter.dev.parent = &pdev->dev;
1656 	i2c_dev->adapter.nr = pdev->id;
1657 	i2c_dev->adapter.dev.of_node = pdev->dev.of_node;
1658 
1659 	ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
1660 	if (ret)
1661 		goto release_dma;
1662 
1663 	pm_runtime_put(&pdev->dev);
1664 
1665 	return 0;
1666 
1667 release_dma:
1668 	tegra_i2c_release_dma(i2c_dev);
1669 
1670 disable_div_clk:
1671 	if (i2c_dev->is_multimaster_mode)
1672 		clk_disable(i2c_dev->div_clk);
1673 
1674 disable_rpm:
1675 	pm_runtime_disable(&pdev->dev);
1676 	if (!pm_runtime_status_suspended(&pdev->dev))
1677 		tegra_i2c_runtime_suspend(&pdev->dev);
1678 
1679 unprepare_div_clk:
1680 	clk_unprepare(i2c_dev->div_clk);
1681 
1682 unprepare_fast_clk:
1683 	if (!i2c_dev->hw->has_single_clk_source)
1684 		clk_unprepare(i2c_dev->fast_clk);
1685 
1686 	return ret;
1687 }
1688 
1689 static int tegra_i2c_remove(struct platform_device *pdev)
1690 {
1691 	struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
1692 
1693 	i2c_del_adapter(&i2c_dev->adapter);
1694 
1695 	if (i2c_dev->is_multimaster_mode)
1696 		clk_disable(i2c_dev->div_clk);
1697 
1698 	pm_runtime_disable(&pdev->dev);
1699 	if (!pm_runtime_status_suspended(&pdev->dev))
1700 		tegra_i2c_runtime_suspend(&pdev->dev);
1701 
1702 	clk_unprepare(i2c_dev->div_clk);
1703 	if (!i2c_dev->hw->has_single_clk_source)
1704 		clk_unprepare(i2c_dev->fast_clk);
1705 
1706 	tegra_i2c_release_dma(i2c_dev);
1707 	return 0;
1708 }
1709 
1710 static int __maybe_unused tegra_i2c_suspend(struct device *dev)
1711 {
1712 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1713 
1714 	i2c_mark_adapter_suspended(&i2c_dev->adapter);
1715 
1716 	return 0;
1717 }
1718 
1719 static int __maybe_unused tegra_i2c_resume(struct device *dev)
1720 {
1721 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1722 	int err;
1723 
1724 	err = tegra_i2c_runtime_resume(dev);
1725 	if (err)
1726 		return err;
1727 
1728 	err = tegra_i2c_init(i2c_dev, false);
1729 	if (err)
1730 		return err;
1731 
1732 	err = tegra_i2c_runtime_suspend(dev);
1733 	if (err)
1734 		return err;
1735 
1736 	i2c_mark_adapter_resumed(&i2c_dev->adapter);
1737 
1738 	return 0;
1739 }
1740 
1741 static const struct dev_pm_ops tegra_i2c_pm = {
1742 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_i2c_suspend, tegra_i2c_resume)
1743 	SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
1744 			   NULL)
1745 };
1746 
1747 static struct platform_driver tegra_i2c_driver = {
1748 	.probe   = tegra_i2c_probe,
1749 	.remove  = tegra_i2c_remove,
1750 	.driver  = {
1751 		.name  = "tegra-i2c",
1752 		.of_match_table = tegra_i2c_of_match,
1753 		.pm    = &tegra_i2c_pm,
1754 	},
1755 };
1756 
1757 module_platform_driver(tegra_i2c_driver);
1758 
1759 MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver");
1760 MODULE_AUTHOR("Colin Cross");
1761 MODULE_LICENSE("GPL v2");
1762