xref: /openbmc/linux/drivers/i2c/busses/i2c-tegra.c (revision b830f94f)
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_slave_channel_reason(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_slave_channel_reason(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 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 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 	err = pm_runtime_get_sync(i2c_dev->dev);
717 	if (err < 0) {
718 		dev_err(i2c_dev->dev, "runtime resume failed %d\n", err);
719 		return err;
720 	}
721 
722 	reset_control_assert(i2c_dev->rst);
723 	udelay(2);
724 	reset_control_deassert(i2c_dev->rst);
725 
726 	if (i2c_dev->is_dvc)
727 		tegra_dvc_init(i2c_dev);
728 
729 	val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
730 		(0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);
731 
732 	if (i2c_dev->hw->has_multi_master_mode)
733 		val |= I2C_CNFG_MULTI_MASTER_MODE;
734 
735 	i2c_writel(i2c_dev, val, I2C_CNFG);
736 	i2c_writel(i2c_dev, 0, I2C_INT_MASK);
737 
738 	/* Make sure clock divisor programmed correctly */
739 	clk_divisor = i2c_dev->hw->clk_divisor_hs_mode;
740 	clk_divisor |= i2c_dev->clk_divisor_non_hs_mode <<
741 					I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT;
742 	i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
743 
744 	if (i2c_dev->bus_clk_rate > I2C_STANDARD_MODE &&
745 	    i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE) {
746 		tlow = i2c_dev->hw->tlow_fast_fastplus_mode;
747 		thigh = i2c_dev->hw->thigh_fast_fastplus_mode;
748 		tsu_thd = i2c_dev->hw->setup_hold_time_fast_fast_plus_mode;
749 	} else {
750 		tlow = i2c_dev->hw->tlow_std_mode;
751 		thigh = i2c_dev->hw->thigh_std_mode;
752 		tsu_thd = i2c_dev->hw->setup_hold_time_std_mode;
753 	}
754 
755 	if (i2c_dev->hw->has_interface_timing_reg) {
756 		val = (thigh << I2C_THIGH_SHIFT) | tlow;
757 		i2c_writel(i2c_dev, val, I2C_INTERFACE_TIMING_0);
758 	}
759 
760 	/*
761 	 * configure setup and hold times only when tsu_thd is non-zero.
762 	 * otherwise, preserve the chip default values
763 	 */
764 	if (i2c_dev->hw->has_interface_timing_reg && tsu_thd)
765 		i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
766 
767 	if (!clk_reinit) {
768 		clk_multiplier = (tlow + thigh + 2);
769 		clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1);
770 		err = clk_set_rate(i2c_dev->div_clk,
771 				   i2c_dev->bus_clk_rate * clk_multiplier);
772 		if (err) {
773 			dev_err(i2c_dev->dev,
774 				"failed changing clock rate: %d\n", err);
775 			goto err;
776 		}
777 	}
778 
779 	if (!i2c_dev->is_dvc) {
780 		u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
781 
782 		sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL;
783 		i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG);
784 		i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1);
785 		i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
786 	}
787 
788 	err = tegra_i2c_flush_fifos(i2c_dev);
789 	if (err)
790 		goto err;
791 
792 	if (i2c_dev->is_multimaster_mode && i2c_dev->hw->has_slcg_override_reg)
793 		i2c_writel(i2c_dev, I2C_MST_CORE_CLKEN_OVR, I2C_CLKEN_OVERRIDE);
794 
795 	err = tegra_i2c_wait_for_config_load(i2c_dev);
796 	if (err)
797 		goto err;
798 
799 	if (i2c_dev->irq_disabled) {
800 		i2c_dev->irq_disabled = false;
801 		enable_irq(i2c_dev->irq);
802 	}
803 
804 err:
805 	pm_runtime_put(i2c_dev->dev);
806 	return err;
807 }
808 
809 static int tegra_i2c_disable_packet_mode(struct tegra_i2c_dev *i2c_dev)
810 {
811 	u32 cnfg;
812 
813 	/*
814 	 * NACK interrupt is generated before the I2C controller generates
815 	 * the STOP condition on the bus. So wait for 2 clock periods
816 	 * before disabling the controller so that the STOP condition has
817 	 * been delivered properly.
818 	 */
819 	udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate));
820 
821 	cnfg = i2c_readl(i2c_dev, I2C_CNFG);
822 	if (cnfg & I2C_CNFG_PACKET_MODE_EN)
823 		i2c_writel(i2c_dev, cnfg & ~I2C_CNFG_PACKET_MODE_EN, I2C_CNFG);
824 
825 	return tegra_i2c_wait_for_config_load(i2c_dev);
826 }
827 
828 static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
829 {
830 	u32 status;
831 	const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
832 	struct tegra_i2c_dev *i2c_dev = dev_id;
833 
834 	status = i2c_readl(i2c_dev, I2C_INT_STATUS);
835 
836 	spin_lock(&i2c_dev->xfer_lock);
837 	if (status == 0) {
838 		dev_warn(i2c_dev->dev, "irq status 0 %08x %08x %08x\n",
839 			 i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS),
840 			 i2c_readl(i2c_dev, I2C_STATUS),
841 			 i2c_readl(i2c_dev, I2C_CNFG));
842 		i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
843 
844 		if (!i2c_dev->irq_disabled) {
845 			disable_irq_nosync(i2c_dev->irq);
846 			i2c_dev->irq_disabled = true;
847 		}
848 		goto err;
849 	}
850 
851 	if (unlikely(status & status_err)) {
852 		tegra_i2c_disable_packet_mode(i2c_dev);
853 		if (status & I2C_INT_NO_ACK)
854 			i2c_dev->msg_err |= I2C_ERR_NO_ACK;
855 		if (status & I2C_INT_ARBITRATION_LOST)
856 			i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
857 		goto err;
858 	}
859 
860 	/*
861 	 * I2C transfer is terminated during the bus clear so skip
862 	 * processing the other interrupts.
863 	 */
864 	if (i2c_dev->hw->supports_bus_clear && (status & I2C_INT_BUS_CLR_DONE))
865 		goto err;
866 
867 	if (!i2c_dev->is_curr_dma_xfer) {
868 		if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
869 			if (tegra_i2c_empty_rx_fifo(i2c_dev)) {
870 				/*
871 				 * Overflow error condition: message fully sent,
872 				 * with no XFER_COMPLETE interrupt but hardware
873 				 * asks to transfer more.
874 				 */
875 				i2c_dev->msg_err |= I2C_ERR_RX_BUFFER_OVERFLOW;
876 				goto err;
877 			}
878 		}
879 
880 		if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
881 			if (i2c_dev->msg_buf_remaining)
882 				tegra_i2c_fill_tx_fifo(i2c_dev);
883 			else
884 				tegra_i2c_mask_irq(i2c_dev,
885 						   I2C_INT_TX_FIFO_DATA_REQ);
886 		}
887 	}
888 
889 	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
890 	if (i2c_dev->is_dvc)
891 		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
892 
893 	/*
894 	 * During message read XFER_COMPLETE interrupt is triggered prior to
895 	 * DMA completion and during message write XFER_COMPLETE interrupt is
896 	 * triggered after DMA completion.
897 	 * PACKETS_XFER_COMPLETE indicates completion of all bytes of transfer.
898 	 * so forcing msg_buf_remaining to 0 in DMA mode.
899 	 */
900 	if (status & I2C_INT_PACKET_XFER_COMPLETE) {
901 		if (i2c_dev->is_curr_dma_xfer)
902 			i2c_dev->msg_buf_remaining = 0;
903 		/*
904 		 * Underflow error condition: XFER_COMPLETE before message
905 		 * fully sent.
906 		 */
907 		if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining)) {
908 			i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
909 			goto err;
910 		}
911 		complete(&i2c_dev->msg_complete);
912 	}
913 	goto done;
914 err:
915 	/* An error occurred, mask all interrupts */
916 	tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST |
917 		I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ |
918 		I2C_INT_RX_FIFO_DATA_REQ);
919 	if (i2c_dev->hw->supports_bus_clear)
920 		tegra_i2c_mask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE);
921 	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
922 	if (i2c_dev->is_dvc)
923 		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
924 
925 	if (i2c_dev->is_curr_dma_xfer) {
926 		if (i2c_dev->msg_read)
927 			dmaengine_terminate_async(i2c_dev->rx_dma_chan);
928 		else
929 			dmaengine_terminate_async(i2c_dev->tx_dma_chan);
930 
931 		complete(&i2c_dev->dma_complete);
932 	}
933 
934 	complete(&i2c_dev->msg_complete);
935 done:
936 	spin_unlock(&i2c_dev->xfer_lock);
937 	return IRQ_HANDLED;
938 }
939 
940 static void tegra_i2c_config_fifo_trig(struct tegra_i2c_dev *i2c_dev,
941 				       size_t len)
942 {
943 	u32 val, reg;
944 	u8 dma_burst;
945 	struct dma_slave_config slv_config = {0};
946 	struct dma_chan *chan;
947 	int ret;
948 	unsigned long reg_offset;
949 
950 	if (i2c_dev->hw->has_mst_fifo)
951 		reg = I2C_MST_FIFO_CONTROL;
952 	else
953 		reg = I2C_FIFO_CONTROL;
954 
955 	if (i2c_dev->is_curr_dma_xfer) {
956 		if (len & 0xF)
957 			dma_burst = 1;
958 		else if (len & 0x10)
959 			dma_burst = 4;
960 		else
961 			dma_burst = 8;
962 
963 		if (i2c_dev->msg_read) {
964 			chan = i2c_dev->rx_dma_chan;
965 			reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_RX_FIFO);
966 			slv_config.src_addr = i2c_dev->base_phys + reg_offset;
967 			slv_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
968 			slv_config.src_maxburst = dma_burst;
969 
970 			if (i2c_dev->hw->has_mst_fifo)
971 				val = I2C_MST_FIFO_CONTROL_RX_TRIG(dma_burst);
972 			else
973 				val = I2C_FIFO_CONTROL_RX_TRIG(dma_burst);
974 		} else {
975 			chan = i2c_dev->tx_dma_chan;
976 			reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_TX_FIFO);
977 			slv_config.dst_addr = i2c_dev->base_phys + reg_offset;
978 			slv_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
979 			slv_config.dst_maxburst = dma_burst;
980 
981 			if (i2c_dev->hw->has_mst_fifo)
982 				val = I2C_MST_FIFO_CONTROL_TX_TRIG(dma_burst);
983 			else
984 				val = I2C_FIFO_CONTROL_TX_TRIG(dma_burst);
985 		}
986 
987 		slv_config.device_fc = true;
988 		ret = dmaengine_slave_config(chan, &slv_config);
989 		if (ret < 0) {
990 			dev_err(i2c_dev->dev, "DMA slave config failed: %d\n",
991 				ret);
992 			dev_err(i2c_dev->dev, "falling back to PIO\n");
993 			tegra_i2c_release_dma(i2c_dev);
994 			i2c_dev->is_curr_dma_xfer = false;
995 		} else {
996 			goto out;
997 		}
998 	}
999 
1000 	if (i2c_dev->hw->has_mst_fifo)
1001 		val = I2C_MST_FIFO_CONTROL_TX_TRIG(8) |
1002 		      I2C_MST_FIFO_CONTROL_RX_TRIG(1);
1003 	else
1004 		val = I2C_FIFO_CONTROL_TX_TRIG(8) |
1005 		      I2C_FIFO_CONTROL_RX_TRIG(1);
1006 out:
1007 	i2c_writel(i2c_dev, val, reg);
1008 }
1009 
1010 static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap)
1011 {
1012 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
1013 	int err;
1014 	unsigned long time_left;
1015 	u32 reg;
1016 
1017 	reinit_completion(&i2c_dev->msg_complete);
1018 	reg = (I2C_BC_SCLK_THRESHOLD << I2C_BC_SCLK_THRESHOLD_SHIFT) |
1019 	      I2C_BC_STOP_COND | I2C_BC_TERMINATE;
1020 	i2c_writel(i2c_dev, reg, I2C_BUS_CLEAR_CNFG);
1021 	if (i2c_dev->hw->has_config_load_reg) {
1022 		err = tegra_i2c_wait_for_config_load(i2c_dev);
1023 		if (err)
1024 			return err;
1025 	}
1026 
1027 	reg |= I2C_BC_ENABLE;
1028 	i2c_writel(i2c_dev, reg, I2C_BUS_CLEAR_CNFG);
1029 	tegra_i2c_unmask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE);
1030 
1031 	time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
1032 						msecs_to_jiffies(50));
1033 	if (time_left == 0) {
1034 		dev_err(i2c_dev->dev, "timed out for bus clear\n");
1035 		return -ETIMEDOUT;
1036 	}
1037 
1038 	reg = i2c_readl(i2c_dev, I2C_BUS_CLEAR_STATUS);
1039 	if (!(reg & I2C_BC_STATUS)) {
1040 		dev_err(i2c_dev->dev,
1041 			"un-recovered arbitration lost\n");
1042 		return -EIO;
1043 	}
1044 
1045 	return -EAGAIN;
1046 }
1047 
1048 static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
1049 			      struct i2c_msg *msg,
1050 			      enum msg_end_type end_state)
1051 {
1052 	u32 packet_header;
1053 	u32 int_mask;
1054 	unsigned long time_left;
1055 	unsigned long flags;
1056 	size_t xfer_size;
1057 	u32 *buffer = NULL;
1058 	int err = 0;
1059 	bool dma;
1060 	u16 xfer_time = 100;
1061 
1062 	tegra_i2c_flush_fifos(i2c_dev);
1063 
1064 	i2c_dev->msg_buf = msg->buf;
1065 	i2c_dev->msg_buf_remaining = msg->len;
1066 	i2c_dev->msg_err = I2C_ERR_NONE;
1067 	i2c_dev->msg_read = (msg->flags & I2C_M_RD);
1068 	reinit_completion(&i2c_dev->msg_complete);
1069 
1070 	if (i2c_dev->msg_read)
1071 		xfer_size = msg->len;
1072 	else
1073 		xfer_size = msg->len + I2C_PACKET_HEADER_SIZE;
1074 
1075 	xfer_size = ALIGN(xfer_size, BYTES_PER_FIFO_WORD);
1076 	i2c_dev->is_curr_dma_xfer = (xfer_size > I2C_PIO_MODE_MAX_LEN) &&
1077 				    i2c_dev->dma_buf;
1078 	tegra_i2c_config_fifo_trig(i2c_dev, xfer_size);
1079 	dma = i2c_dev->is_curr_dma_xfer;
1080 	/*
1081 	 * Transfer time in mSec = Total bits / transfer rate
1082 	 * Total bits = 9 bits per byte (including ACK bit) + Start & stop bits
1083 	 */
1084 	xfer_time += DIV_ROUND_CLOSEST(((xfer_size * 9) + 2) * MSEC_PER_SEC,
1085 					i2c_dev->bus_clk_rate);
1086 	spin_lock_irqsave(&i2c_dev->xfer_lock, flags);
1087 
1088 	int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
1089 	tegra_i2c_unmask_irq(i2c_dev, int_mask);
1090 	if (dma) {
1091 		if (i2c_dev->msg_read) {
1092 			dma_sync_single_for_device(i2c_dev->dev,
1093 						   i2c_dev->dma_phys,
1094 						   xfer_size,
1095 						   DMA_FROM_DEVICE);
1096 			err = tegra_i2c_dma_submit(i2c_dev, xfer_size);
1097 			if (err < 0) {
1098 				dev_err(i2c_dev->dev,
1099 					"starting RX DMA failed, err %d\n",
1100 					err);
1101 				goto unlock;
1102 			}
1103 
1104 		} else {
1105 			dma_sync_single_for_cpu(i2c_dev->dev,
1106 						i2c_dev->dma_phys,
1107 						xfer_size,
1108 						DMA_TO_DEVICE);
1109 			buffer = i2c_dev->dma_buf;
1110 		}
1111 	}
1112 
1113 	packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
1114 			PACKET_HEADER0_PROTOCOL_I2C |
1115 			(i2c_dev->cont_id << PACKET_HEADER0_CONT_ID_SHIFT) |
1116 			(1 << PACKET_HEADER0_PACKET_ID_SHIFT);
1117 	if (dma && !i2c_dev->msg_read)
1118 		*buffer++ = packet_header;
1119 	else
1120 		i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
1121 
1122 	packet_header = msg->len - 1;
1123 	if (dma && !i2c_dev->msg_read)
1124 		*buffer++ = packet_header;
1125 	else
1126 		i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
1127 
1128 	packet_header = I2C_HEADER_IE_ENABLE;
1129 	if (end_state == MSG_END_CONTINUE)
1130 		packet_header |= I2C_HEADER_CONTINUE_XFER;
1131 	else if (end_state == MSG_END_REPEAT_START)
1132 		packet_header |= I2C_HEADER_REPEAT_START;
1133 	if (msg->flags & I2C_M_TEN) {
1134 		packet_header |= msg->addr;
1135 		packet_header |= I2C_HEADER_10BIT_ADDR;
1136 	} else {
1137 		packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
1138 	}
1139 	if (msg->flags & I2C_M_IGNORE_NAK)
1140 		packet_header |= I2C_HEADER_CONT_ON_NAK;
1141 	if (msg->flags & I2C_M_RD)
1142 		packet_header |= I2C_HEADER_READ;
1143 	if (dma && !i2c_dev->msg_read)
1144 		*buffer++ = packet_header;
1145 	else
1146 		i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
1147 
1148 	if (!i2c_dev->msg_read) {
1149 		if (dma) {
1150 			memcpy(buffer, msg->buf, msg->len);
1151 			dma_sync_single_for_device(i2c_dev->dev,
1152 						   i2c_dev->dma_phys,
1153 						   xfer_size,
1154 						   DMA_TO_DEVICE);
1155 			err = tegra_i2c_dma_submit(i2c_dev, xfer_size);
1156 			if (err < 0) {
1157 				dev_err(i2c_dev->dev,
1158 					"starting TX DMA failed, err %d\n",
1159 					err);
1160 				goto unlock;
1161 			}
1162 		} else {
1163 			tegra_i2c_fill_tx_fifo(i2c_dev);
1164 		}
1165 	}
1166 
1167 	if (i2c_dev->hw->has_per_pkt_xfer_complete_irq)
1168 		int_mask |= I2C_INT_PACKET_XFER_COMPLETE;
1169 	if (!dma) {
1170 		if (msg->flags & I2C_M_RD)
1171 			int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
1172 		else if (i2c_dev->msg_buf_remaining)
1173 			int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
1174 	}
1175 
1176 	tegra_i2c_unmask_irq(i2c_dev, int_mask);
1177 	dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n",
1178 		i2c_readl(i2c_dev, I2C_INT_MASK));
1179 
1180 unlock:
1181 	spin_unlock_irqrestore(&i2c_dev->xfer_lock, flags);
1182 
1183 	if (dma) {
1184 		if (err)
1185 			return err;
1186 
1187 		time_left = wait_for_completion_timeout(&i2c_dev->dma_complete,
1188 							msecs_to_jiffies(xfer_time));
1189 		if (time_left == 0) {
1190 			dev_err(i2c_dev->dev, "DMA transfer timeout\n");
1191 			dmaengine_terminate_sync(i2c_dev->msg_read ?
1192 						 i2c_dev->rx_dma_chan :
1193 						 i2c_dev->tx_dma_chan);
1194 			tegra_i2c_init(i2c_dev, true);
1195 			return -ETIMEDOUT;
1196 		}
1197 
1198 		if (i2c_dev->msg_read && i2c_dev->msg_err == I2C_ERR_NONE) {
1199 			dma_sync_single_for_cpu(i2c_dev->dev,
1200 						i2c_dev->dma_phys,
1201 						xfer_size,
1202 						DMA_FROM_DEVICE);
1203 			memcpy(i2c_dev->msg_buf, i2c_dev->dma_buf,
1204 			       msg->len);
1205 		}
1206 
1207 		if (i2c_dev->msg_err != I2C_ERR_NONE)
1208 			dmaengine_synchronize(i2c_dev->msg_read ?
1209 					      i2c_dev->rx_dma_chan :
1210 					      i2c_dev->tx_dma_chan);
1211 	}
1212 
1213 	time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
1214 						msecs_to_jiffies(xfer_time));
1215 	tegra_i2c_mask_irq(i2c_dev, int_mask);
1216 
1217 	if (time_left == 0) {
1218 		dev_err(i2c_dev->dev, "i2c transfer timed out\n");
1219 
1220 		tegra_i2c_init(i2c_dev, true);
1221 		return -ETIMEDOUT;
1222 	}
1223 
1224 	dev_dbg(i2c_dev->dev, "transfer complete: %lu %d %d\n",
1225 		time_left, completion_done(&i2c_dev->msg_complete),
1226 		i2c_dev->msg_err);
1227 
1228 	i2c_dev->is_curr_dma_xfer = false;
1229 	if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
1230 		return 0;
1231 
1232 	tegra_i2c_init(i2c_dev, true);
1233 	/* start recovery upon arbitration loss in single master mode */
1234 	if (i2c_dev->msg_err == I2C_ERR_ARBITRATION_LOST) {
1235 		if (!i2c_dev->is_multimaster_mode)
1236 			return i2c_recover_bus(&i2c_dev->adapter);
1237 		return -EAGAIN;
1238 	}
1239 
1240 	if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
1241 		if (msg->flags & I2C_M_IGNORE_NAK)
1242 			return 0;
1243 		return -EREMOTEIO;
1244 	}
1245 
1246 	return -EIO;
1247 }
1248 
1249 static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
1250 			  int num)
1251 {
1252 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
1253 	int i;
1254 	int ret;
1255 
1256 	ret = pm_runtime_get_sync(i2c_dev->dev);
1257 	if (ret < 0) {
1258 		dev_err(i2c_dev->dev, "runtime resume failed %d\n", ret);
1259 		return ret;
1260 	}
1261 
1262 	for (i = 0; i < num; i++) {
1263 		enum msg_end_type end_type = MSG_END_STOP;
1264 
1265 		if (i < (num - 1)) {
1266 			if (msgs[i + 1].flags & I2C_M_NOSTART)
1267 				end_type = MSG_END_CONTINUE;
1268 			else
1269 				end_type = MSG_END_REPEAT_START;
1270 		}
1271 		ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);
1272 		if (ret)
1273 			break;
1274 	}
1275 
1276 	pm_runtime_put(i2c_dev->dev);
1277 
1278 	return ret ?: i;
1279 }
1280 
1281 static u32 tegra_i2c_func(struct i2c_adapter *adap)
1282 {
1283 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
1284 	u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
1285 		  I2C_FUNC_10BIT_ADDR |	I2C_FUNC_PROTOCOL_MANGLING;
1286 
1287 	if (i2c_dev->hw->has_continue_xfer_support)
1288 		ret |= I2C_FUNC_NOSTART;
1289 	return ret;
1290 }
1291 
1292 static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
1293 {
1294 	struct device_node *np = i2c_dev->dev->of_node;
1295 	int ret;
1296 	bool multi_mode;
1297 
1298 	ret = of_property_read_u32(np, "clock-frequency",
1299 				   &i2c_dev->bus_clk_rate);
1300 	if (ret)
1301 		i2c_dev->bus_clk_rate = 100000; /* default clock rate */
1302 
1303 	multi_mode = of_property_read_bool(np, "multi-master");
1304 	i2c_dev->is_multimaster_mode = multi_mode;
1305 }
1306 
1307 static const struct i2c_algorithm tegra_i2c_algo = {
1308 	.master_xfer	= tegra_i2c_xfer,
1309 	.functionality	= tegra_i2c_func,
1310 };
1311 
1312 /* payload size is only 12 bit */
1313 static const struct i2c_adapter_quirks tegra_i2c_quirks = {
1314 	.flags = I2C_AQ_NO_ZERO_LEN,
1315 	.max_read_len = SZ_4K,
1316 	.max_write_len = SZ_4K - I2C_PACKET_HEADER_SIZE,
1317 };
1318 
1319 static const struct i2c_adapter_quirks tegra194_i2c_quirks = {
1320 	.flags = I2C_AQ_NO_ZERO_LEN,
1321 	.max_write_len = SZ_64K - I2C_PACKET_HEADER_SIZE,
1322 };
1323 
1324 static struct i2c_bus_recovery_info tegra_i2c_recovery_info = {
1325 	.recover_bus = tegra_i2c_issue_bus_clear,
1326 };
1327 
1328 static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
1329 	.has_continue_xfer_support = false,
1330 	.has_per_pkt_xfer_complete_irq = false,
1331 	.has_single_clk_source = false,
1332 	.clk_divisor_hs_mode = 3,
1333 	.clk_divisor_std_mode = 0,
1334 	.clk_divisor_fast_mode = 0,
1335 	.clk_divisor_fast_plus_mode = 0,
1336 	.has_config_load_reg = false,
1337 	.has_multi_master_mode = false,
1338 	.has_slcg_override_reg = false,
1339 	.has_mst_fifo = false,
1340 	.quirks = &tegra_i2c_quirks,
1341 	.supports_bus_clear = false,
1342 	.has_apb_dma = true,
1343 	.tlow_std_mode = 0x4,
1344 	.thigh_std_mode = 0x2,
1345 	.tlow_fast_fastplus_mode = 0x4,
1346 	.thigh_fast_fastplus_mode = 0x2,
1347 	.setup_hold_time_std_mode = 0x0,
1348 	.setup_hold_time_fast_fast_plus_mode = 0x0,
1349 	.setup_hold_time_hs_mode = 0x0,
1350 	.has_interface_timing_reg = false,
1351 };
1352 
1353 static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
1354 	.has_continue_xfer_support = true,
1355 	.has_per_pkt_xfer_complete_irq = false,
1356 	.has_single_clk_source = false,
1357 	.clk_divisor_hs_mode = 3,
1358 	.clk_divisor_std_mode = 0,
1359 	.clk_divisor_fast_mode = 0,
1360 	.clk_divisor_fast_plus_mode = 0,
1361 	.has_config_load_reg = false,
1362 	.has_multi_master_mode = false,
1363 	.has_slcg_override_reg = false,
1364 	.has_mst_fifo = false,
1365 	.quirks = &tegra_i2c_quirks,
1366 	.supports_bus_clear = false,
1367 	.has_apb_dma = true,
1368 	.tlow_std_mode = 0x4,
1369 	.thigh_std_mode = 0x2,
1370 	.tlow_fast_fastplus_mode = 0x4,
1371 	.thigh_fast_fastplus_mode = 0x2,
1372 	.setup_hold_time_std_mode = 0x0,
1373 	.setup_hold_time_fast_fast_plus_mode = 0x0,
1374 	.setup_hold_time_hs_mode = 0x0,
1375 	.has_interface_timing_reg = false,
1376 };
1377 
1378 static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
1379 	.has_continue_xfer_support = true,
1380 	.has_per_pkt_xfer_complete_irq = true,
1381 	.has_single_clk_source = true,
1382 	.clk_divisor_hs_mode = 1,
1383 	.clk_divisor_std_mode = 0x19,
1384 	.clk_divisor_fast_mode = 0x19,
1385 	.clk_divisor_fast_plus_mode = 0x10,
1386 	.has_config_load_reg = false,
1387 	.has_multi_master_mode = false,
1388 	.has_slcg_override_reg = false,
1389 	.has_mst_fifo = false,
1390 	.quirks = &tegra_i2c_quirks,
1391 	.supports_bus_clear = true,
1392 	.has_apb_dma = true,
1393 	.tlow_std_mode = 0x4,
1394 	.thigh_std_mode = 0x2,
1395 	.tlow_fast_fastplus_mode = 0x4,
1396 	.thigh_fast_fastplus_mode = 0x2,
1397 	.setup_hold_time_std_mode = 0x0,
1398 	.setup_hold_time_fast_fast_plus_mode = 0x0,
1399 	.setup_hold_time_hs_mode = 0x0,
1400 	.has_interface_timing_reg = false,
1401 };
1402 
1403 static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
1404 	.has_continue_xfer_support = true,
1405 	.has_per_pkt_xfer_complete_irq = true,
1406 	.has_single_clk_source = true,
1407 	.clk_divisor_hs_mode = 1,
1408 	.clk_divisor_std_mode = 0x19,
1409 	.clk_divisor_fast_mode = 0x19,
1410 	.clk_divisor_fast_plus_mode = 0x10,
1411 	.has_config_load_reg = true,
1412 	.has_multi_master_mode = false,
1413 	.has_slcg_override_reg = true,
1414 	.has_mst_fifo = false,
1415 	.quirks = &tegra_i2c_quirks,
1416 	.supports_bus_clear = true,
1417 	.has_apb_dma = true,
1418 	.tlow_std_mode = 0x4,
1419 	.thigh_std_mode = 0x2,
1420 	.tlow_fast_fastplus_mode = 0x4,
1421 	.thigh_fast_fastplus_mode = 0x2,
1422 	.setup_hold_time_std_mode = 0x0,
1423 	.setup_hold_time_fast_fast_plus_mode = 0x0,
1424 	.setup_hold_time_hs_mode = 0x0,
1425 	.has_interface_timing_reg = true,
1426 };
1427 
1428 static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
1429 	.has_continue_xfer_support = true,
1430 	.has_per_pkt_xfer_complete_irq = true,
1431 	.has_single_clk_source = true,
1432 	.clk_divisor_hs_mode = 1,
1433 	.clk_divisor_std_mode = 0x19,
1434 	.clk_divisor_fast_mode = 0x19,
1435 	.clk_divisor_fast_plus_mode = 0x10,
1436 	.has_config_load_reg = true,
1437 	.has_multi_master_mode = false,
1438 	.has_slcg_override_reg = true,
1439 	.has_mst_fifo = false,
1440 	.quirks = &tegra_i2c_quirks,
1441 	.supports_bus_clear = true,
1442 	.has_apb_dma = true,
1443 	.tlow_std_mode = 0x4,
1444 	.thigh_std_mode = 0x2,
1445 	.tlow_fast_fastplus_mode = 0x4,
1446 	.thigh_fast_fastplus_mode = 0x2,
1447 	.setup_hold_time_std_mode = 0,
1448 	.setup_hold_time_fast_fast_plus_mode = 0,
1449 	.setup_hold_time_hs_mode = 0,
1450 	.has_interface_timing_reg = true,
1451 };
1452 
1453 static const struct tegra_i2c_hw_feature tegra186_i2c_hw = {
1454 	.has_continue_xfer_support = true,
1455 	.has_per_pkt_xfer_complete_irq = true,
1456 	.has_single_clk_source = true,
1457 	.clk_divisor_hs_mode = 1,
1458 	.clk_divisor_std_mode = 0x16,
1459 	.clk_divisor_fast_mode = 0x19,
1460 	.clk_divisor_fast_plus_mode = 0x10,
1461 	.has_config_load_reg = true,
1462 	.has_multi_master_mode = false,
1463 	.has_slcg_override_reg = true,
1464 	.has_mst_fifo = false,
1465 	.quirks = &tegra_i2c_quirks,
1466 	.supports_bus_clear = true,
1467 	.has_apb_dma = false,
1468 	.tlow_std_mode = 0x4,
1469 	.thigh_std_mode = 0x3,
1470 	.tlow_fast_fastplus_mode = 0x4,
1471 	.thigh_fast_fastplus_mode = 0x2,
1472 	.setup_hold_time_std_mode = 0,
1473 	.setup_hold_time_fast_fast_plus_mode = 0,
1474 	.setup_hold_time_hs_mode = 0,
1475 	.has_interface_timing_reg = true,
1476 };
1477 
1478 static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
1479 	.has_continue_xfer_support = true,
1480 	.has_per_pkt_xfer_complete_irq = true,
1481 	.has_single_clk_source = true,
1482 	.clk_divisor_hs_mode = 1,
1483 	.clk_divisor_std_mode = 0x4f,
1484 	.clk_divisor_fast_mode = 0x3c,
1485 	.clk_divisor_fast_plus_mode = 0x16,
1486 	.has_config_load_reg = true,
1487 	.has_multi_master_mode = true,
1488 	.has_slcg_override_reg = true,
1489 	.has_mst_fifo = true,
1490 	.quirks = &tegra194_i2c_quirks,
1491 	.supports_bus_clear = true,
1492 	.has_apb_dma = false,
1493 	.tlow_std_mode = 0x8,
1494 	.thigh_std_mode = 0x7,
1495 	.tlow_fast_fastplus_mode = 0x2,
1496 	.thigh_fast_fastplus_mode = 0x2,
1497 	.setup_hold_time_std_mode = 0x08080808,
1498 	.setup_hold_time_fast_fast_plus_mode = 0x02020202,
1499 	.setup_hold_time_hs_mode = 0x090909,
1500 	.has_interface_timing_reg = true,
1501 };
1502 
1503 /* Match table for of_platform binding */
1504 static const struct of_device_id tegra_i2c_of_match[] = {
1505 	{ .compatible = "nvidia,tegra194-i2c", .data = &tegra194_i2c_hw, },
1506 	{ .compatible = "nvidia,tegra186-i2c", .data = &tegra186_i2c_hw, },
1507 	{ .compatible = "nvidia,tegra210-i2c", .data = &tegra210_i2c_hw, },
1508 	{ .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, },
1509 	{ .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, },
1510 	{ .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, },
1511 	{ .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, },
1512 	{ .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, },
1513 	{},
1514 };
1515 MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
1516 
1517 static int tegra_i2c_probe(struct platform_device *pdev)
1518 {
1519 	struct tegra_i2c_dev *i2c_dev;
1520 	struct resource *res;
1521 	struct clk *div_clk;
1522 	struct clk *fast_clk;
1523 	void __iomem *base;
1524 	phys_addr_t base_phys;
1525 	int irq;
1526 	int ret;
1527 
1528 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1529 	base_phys = res->start;
1530 	base = devm_ioremap_resource(&pdev->dev, res);
1531 	if (IS_ERR(base))
1532 		return PTR_ERR(base);
1533 
1534 	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
1535 	if (!res) {
1536 		dev_err(&pdev->dev, "no irq resource\n");
1537 		return -EINVAL;
1538 	}
1539 	irq = res->start;
1540 
1541 	div_clk = devm_clk_get(&pdev->dev, "div-clk");
1542 	if (IS_ERR(div_clk)) {
1543 		if (PTR_ERR(div_clk) != -EPROBE_DEFER)
1544 			dev_err(&pdev->dev, "missing controller clock\n");
1545 
1546 		return PTR_ERR(div_clk);
1547 	}
1548 
1549 	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
1550 	if (!i2c_dev)
1551 		return -ENOMEM;
1552 
1553 	i2c_dev->base = base;
1554 	i2c_dev->base_phys = base_phys;
1555 	i2c_dev->div_clk = div_clk;
1556 	i2c_dev->adapter.algo = &tegra_i2c_algo;
1557 	i2c_dev->adapter.retries = 1;
1558 	i2c_dev->adapter.timeout = 6 * HZ;
1559 	i2c_dev->irq = irq;
1560 	i2c_dev->cont_id = pdev->id;
1561 	i2c_dev->dev = &pdev->dev;
1562 
1563 	i2c_dev->rst = devm_reset_control_get_exclusive(&pdev->dev, "i2c");
1564 	if (IS_ERR(i2c_dev->rst)) {
1565 		dev_err(&pdev->dev, "missing controller reset\n");
1566 		return PTR_ERR(i2c_dev->rst);
1567 	}
1568 
1569 	tegra_i2c_parse_dt(i2c_dev);
1570 
1571 	i2c_dev->hw = of_device_get_match_data(&pdev->dev);
1572 	i2c_dev->is_dvc = of_device_is_compatible(pdev->dev.of_node,
1573 						  "nvidia,tegra20-i2c-dvc");
1574 	i2c_dev->adapter.quirks = i2c_dev->hw->quirks;
1575 	i2c_dev->dma_buf_size = i2c_dev->adapter.quirks->max_write_len +
1576 				I2C_PACKET_HEADER_SIZE;
1577 	init_completion(&i2c_dev->msg_complete);
1578 	init_completion(&i2c_dev->dma_complete);
1579 	spin_lock_init(&i2c_dev->xfer_lock);
1580 
1581 	if (!i2c_dev->hw->has_single_clk_source) {
1582 		fast_clk = devm_clk_get(&pdev->dev, "fast-clk");
1583 		if (IS_ERR(fast_clk)) {
1584 			dev_err(&pdev->dev, "missing fast clock\n");
1585 			return PTR_ERR(fast_clk);
1586 		}
1587 		i2c_dev->fast_clk = fast_clk;
1588 	}
1589 
1590 	platform_set_drvdata(pdev, i2c_dev);
1591 
1592 	if (!i2c_dev->hw->has_single_clk_source) {
1593 		ret = clk_prepare(i2c_dev->fast_clk);
1594 		if (ret < 0) {
1595 			dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
1596 			return ret;
1597 		}
1598 	}
1599 
1600 	if (i2c_dev->bus_clk_rate > I2C_FAST_MODE &&
1601 	    i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE)
1602 		i2c_dev->clk_divisor_non_hs_mode =
1603 				i2c_dev->hw->clk_divisor_fast_plus_mode;
1604 	else if (i2c_dev->bus_clk_rate > I2C_STANDARD_MODE &&
1605 		 i2c_dev->bus_clk_rate <= I2C_FAST_MODE)
1606 		i2c_dev->clk_divisor_non_hs_mode =
1607 				i2c_dev->hw->clk_divisor_fast_mode;
1608 	else
1609 		i2c_dev->clk_divisor_non_hs_mode =
1610 				i2c_dev->hw->clk_divisor_std_mode;
1611 
1612 	ret = clk_prepare(i2c_dev->div_clk);
1613 	if (ret < 0) {
1614 		dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
1615 		goto unprepare_fast_clk;
1616 	}
1617 
1618 	pm_runtime_enable(&pdev->dev);
1619 	if (!pm_runtime_enabled(&pdev->dev)) {
1620 		ret = tegra_i2c_runtime_resume(&pdev->dev);
1621 		if (ret < 0) {
1622 			dev_err(&pdev->dev, "runtime resume failed\n");
1623 			goto unprepare_div_clk;
1624 		}
1625 	}
1626 
1627 	if (i2c_dev->is_multimaster_mode) {
1628 		ret = clk_enable(i2c_dev->div_clk);
1629 		if (ret < 0) {
1630 			dev_err(i2c_dev->dev, "div_clk enable failed %d\n",
1631 				ret);
1632 			goto disable_rpm;
1633 		}
1634 	}
1635 
1636 	if (i2c_dev->hw->supports_bus_clear)
1637 		i2c_dev->adapter.bus_recovery_info = &tegra_i2c_recovery_info;
1638 
1639 	ret = tegra_i2c_init_dma(i2c_dev);
1640 	if (ret < 0)
1641 		goto disable_div_clk;
1642 
1643 	ret = tegra_i2c_init(i2c_dev, false);
1644 	if (ret) {
1645 		dev_err(&pdev->dev, "Failed to initialize i2c controller\n");
1646 		goto release_dma;
1647 	}
1648 
1649 	ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
1650 			       tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
1651 	if (ret) {
1652 		dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
1653 		goto release_dma;
1654 	}
1655 
1656 	i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
1657 	i2c_dev->adapter.owner = THIS_MODULE;
1658 	i2c_dev->adapter.class = I2C_CLASS_DEPRECATED;
1659 	strlcpy(i2c_dev->adapter.name, dev_name(&pdev->dev),
1660 		sizeof(i2c_dev->adapter.name));
1661 	i2c_dev->adapter.dev.parent = &pdev->dev;
1662 	i2c_dev->adapter.nr = pdev->id;
1663 	i2c_dev->adapter.dev.of_node = pdev->dev.of_node;
1664 
1665 	ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
1666 	if (ret)
1667 		goto release_dma;
1668 
1669 	return 0;
1670 
1671 release_dma:
1672 	tegra_i2c_release_dma(i2c_dev);
1673 
1674 disable_div_clk:
1675 	if (i2c_dev->is_multimaster_mode)
1676 		clk_disable(i2c_dev->div_clk);
1677 
1678 disable_rpm:
1679 	pm_runtime_disable(&pdev->dev);
1680 	if (!pm_runtime_status_suspended(&pdev->dev))
1681 		tegra_i2c_runtime_suspend(&pdev->dev);
1682 
1683 unprepare_div_clk:
1684 	clk_unprepare(i2c_dev->div_clk);
1685 
1686 unprepare_fast_clk:
1687 	if (!i2c_dev->hw->has_single_clk_source)
1688 		clk_unprepare(i2c_dev->fast_clk);
1689 
1690 	return ret;
1691 }
1692 
1693 static int tegra_i2c_remove(struct platform_device *pdev)
1694 {
1695 	struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
1696 
1697 	i2c_del_adapter(&i2c_dev->adapter);
1698 
1699 	if (i2c_dev->is_multimaster_mode)
1700 		clk_disable(i2c_dev->div_clk);
1701 
1702 	pm_runtime_disable(&pdev->dev);
1703 	if (!pm_runtime_status_suspended(&pdev->dev))
1704 		tegra_i2c_runtime_suspend(&pdev->dev);
1705 
1706 	clk_unprepare(i2c_dev->div_clk);
1707 	if (!i2c_dev->hw->has_single_clk_source)
1708 		clk_unprepare(i2c_dev->fast_clk);
1709 
1710 	tegra_i2c_release_dma(i2c_dev);
1711 	return 0;
1712 }
1713 
1714 #ifdef CONFIG_PM_SLEEP
1715 static int tegra_i2c_suspend(struct device *dev)
1716 {
1717 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1718 
1719 	i2c_mark_adapter_suspended(&i2c_dev->adapter);
1720 
1721 	return 0;
1722 }
1723 
1724 static int tegra_i2c_resume(struct device *dev)
1725 {
1726 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1727 	int err;
1728 
1729 	err = tegra_i2c_init(i2c_dev, false);
1730 	if (err)
1731 		return err;
1732 
1733 	i2c_mark_adapter_resumed(&i2c_dev->adapter);
1734 
1735 	return 0;
1736 }
1737 
1738 static const struct dev_pm_ops tegra_i2c_pm = {
1739 	SET_SYSTEM_SLEEP_PM_OPS(tegra_i2c_suspend, tegra_i2c_resume)
1740 	SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
1741 			   NULL)
1742 };
1743 
1744 #define TEGRA_I2C_PM	(&tegra_i2c_pm)
1745 #else
1746 #define TEGRA_I2C_PM	NULL
1747 #endif
1748 
1749 static struct platform_driver tegra_i2c_driver = {
1750 	.probe   = tegra_i2c_probe,
1751 	.remove  = tegra_i2c_remove,
1752 	.driver  = {
1753 		.name  = "tegra-i2c",
1754 		.of_match_table = tegra_i2c_of_match,
1755 		.pm    = TEGRA_I2C_PM,
1756 	},
1757 };
1758 
1759 module_platform_driver(tegra_i2c_driver);
1760 
1761 MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver");
1762 MODULE_AUTHOR("Colin Cross");
1763 MODULE_LICENSE("GPL v2");
1764