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1 /*
2  * drivers/i2c/busses/i2c-tegra.c
3  *
4  * Copyright (C) 2010 Google, Inc.
5  * Author: Colin Cross <ccross@android.com>
6  *
7  * This software is licensed under the terms of the GNU General Public
8  * License version 2, as published by the Free Software Foundation, and
9  * may be copied, distributed, and modified under those terms.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  */
17 
18 #include <linux/kernel.h>
19 #include <linux/init.h>
20 #include <linux/platform_device.h>
21 #include <linux/clk.h>
22 #include <linux/err.h>
23 #include <linux/i2c.h>
24 #include <linux/io.h>
25 #include <linux/interrupt.h>
26 #include <linux/delay.h>
27 #include <linux/slab.h>
28 #include <linux/of_device.h>
29 #include <linux/module.h>
30 #include <linux/reset.h>
31 #include <linux/pinctrl/consumer.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/iopoll.h>
34 
35 #include <asm/unaligned.h>
36 
37 #define TEGRA_I2C_TIMEOUT (msecs_to_jiffies(1000))
38 #define BYTES_PER_FIFO_WORD 4
39 
40 #define I2C_CNFG				0x000
41 #define I2C_CNFG_DEBOUNCE_CNT_SHIFT		12
42 #define I2C_CNFG_PACKET_MODE_EN			BIT(10)
43 #define I2C_CNFG_NEW_MASTER_FSM			BIT(11)
44 #define I2C_CNFG_MULTI_MASTER_MODE		BIT(17)
45 #define I2C_STATUS				0x01C
46 #define I2C_SL_CNFG				0x020
47 #define I2C_SL_CNFG_NACK			BIT(1)
48 #define I2C_SL_CNFG_NEWSL			BIT(2)
49 #define I2C_SL_ADDR1				0x02c
50 #define I2C_SL_ADDR2				0x030
51 #define I2C_TX_FIFO				0x050
52 #define I2C_RX_FIFO				0x054
53 #define I2C_PACKET_TRANSFER_STATUS		0x058
54 #define I2C_FIFO_CONTROL			0x05c
55 #define I2C_FIFO_CONTROL_TX_FLUSH		BIT(1)
56 #define I2C_FIFO_CONTROL_RX_FLUSH		BIT(0)
57 #define I2C_FIFO_CONTROL_TX_TRIG_SHIFT		5
58 #define I2C_FIFO_CONTROL_RX_TRIG_SHIFT		2
59 #define I2C_FIFO_STATUS				0x060
60 #define I2C_FIFO_STATUS_TX_MASK			0xF0
61 #define I2C_FIFO_STATUS_TX_SHIFT		4
62 #define I2C_FIFO_STATUS_RX_MASK			0x0F
63 #define I2C_FIFO_STATUS_RX_SHIFT		0
64 #define I2C_INT_MASK				0x064
65 #define I2C_INT_STATUS				0x068
66 #define I2C_INT_PACKET_XFER_COMPLETE		BIT(7)
67 #define I2C_INT_ALL_PACKETS_XFER_COMPLETE	BIT(6)
68 #define I2C_INT_TX_FIFO_OVERFLOW		BIT(5)
69 #define I2C_INT_RX_FIFO_UNDERFLOW		BIT(4)
70 #define I2C_INT_NO_ACK				BIT(3)
71 #define I2C_INT_ARBITRATION_LOST		BIT(2)
72 #define I2C_INT_TX_FIFO_DATA_REQ		BIT(1)
73 #define I2C_INT_RX_FIFO_DATA_REQ		BIT(0)
74 #define I2C_CLK_DIVISOR				0x06c
75 #define I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT	16
76 #define I2C_CLK_MULTIPLIER_STD_FAST_MODE	8
77 
78 #define DVC_CTRL_REG1				0x000
79 #define DVC_CTRL_REG1_INTR_EN			BIT(10)
80 #define DVC_CTRL_REG2				0x004
81 #define DVC_CTRL_REG3				0x008
82 #define DVC_CTRL_REG3_SW_PROG			BIT(26)
83 #define DVC_CTRL_REG3_I2C_DONE_INTR_EN		BIT(30)
84 #define DVC_STATUS				0x00c
85 #define DVC_STATUS_I2C_DONE_INTR		BIT(30)
86 
87 #define I2C_ERR_NONE				0x00
88 #define I2C_ERR_NO_ACK				0x01
89 #define I2C_ERR_ARBITRATION_LOST		0x02
90 #define I2C_ERR_UNKNOWN_INTERRUPT		0x04
91 
92 #define PACKET_HEADER0_HEADER_SIZE_SHIFT	28
93 #define PACKET_HEADER0_PACKET_ID_SHIFT		16
94 #define PACKET_HEADER0_CONT_ID_SHIFT		12
95 #define PACKET_HEADER0_PROTOCOL_I2C		BIT(4)
96 
97 #define I2C_HEADER_HIGHSPEED_MODE		BIT(22)
98 #define I2C_HEADER_CONT_ON_NAK			BIT(21)
99 #define I2C_HEADER_SEND_START_BYTE		BIT(20)
100 #define I2C_HEADER_READ				BIT(19)
101 #define I2C_HEADER_10BIT_ADDR			BIT(18)
102 #define I2C_HEADER_IE_ENABLE			BIT(17)
103 #define I2C_HEADER_REPEAT_START			BIT(16)
104 #define I2C_HEADER_CONTINUE_XFER		BIT(15)
105 #define I2C_HEADER_MASTER_ADDR_SHIFT		12
106 #define I2C_HEADER_SLAVE_ADDR_SHIFT		1
107 
108 #define I2C_CONFIG_LOAD				0x08C
109 #define I2C_MSTR_CONFIG_LOAD			BIT(0)
110 #define I2C_SLV_CONFIG_LOAD			BIT(1)
111 #define I2C_TIMEOUT_CONFIG_LOAD			BIT(2)
112 
113 #define I2C_CLKEN_OVERRIDE			0x090
114 #define I2C_MST_CORE_CLKEN_OVR			BIT(0)
115 
116 #define I2C_CONFIG_LOAD_TIMEOUT			1000000
117 
118 /*
119  * msg_end_type: The bus control which need to be send at end of transfer.
120  * @MSG_END_STOP: Send stop pulse at end of transfer.
121  * @MSG_END_REPEAT_START: Send repeat start at end of transfer.
122  * @MSG_END_CONTINUE: The following on message is coming and so do not send
123  *		stop or repeat start.
124  */
125 enum msg_end_type {
126 	MSG_END_STOP,
127 	MSG_END_REPEAT_START,
128 	MSG_END_CONTINUE,
129 };
130 
131 /**
132  * struct tegra_i2c_hw_feature : Different HW support on Tegra
133  * @has_continue_xfer_support: Continue transfer supports.
134  * @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer
135  *		complete interrupt per packet basis.
136  * @has_single_clk_source: The i2c controller has single clock source. Tegra30
137  *		and earlier Socs has two clock sources i.e. div-clk and
138  *		fast-clk.
139  * @has_config_load_reg: Has the config load register to load the new
140  *		configuration.
141  * @clk_divisor_hs_mode: Clock divisor in HS mode.
142  * @clk_divisor_std_fast_mode: Clock divisor in standard/fast mode. It is
143  *		applicable if there is no fast clock source i.e. single clock
144  *		source.
145  */
146 
147 struct tegra_i2c_hw_feature {
148 	bool has_continue_xfer_support;
149 	bool has_per_pkt_xfer_complete_irq;
150 	bool has_single_clk_source;
151 	bool has_config_load_reg;
152 	int clk_divisor_hs_mode;
153 	int clk_divisor_std_fast_mode;
154 	u16 clk_divisor_fast_plus_mode;
155 	bool has_multi_master_mode;
156 	bool has_slcg_override_reg;
157 };
158 
159 /**
160  * struct tegra_i2c_dev	- per device i2c context
161  * @dev: device reference for power management
162  * @hw: Tegra i2c hw feature.
163  * @adapter: core i2c layer adapter information
164  * @div_clk: clock reference for div clock of i2c controller.
165  * @fast_clk: clock reference for fast clock of i2c controller.
166  * @base: ioremapped registers cookie
167  * @cont_id: i2c controller id, used for for packet header
168  * @irq: irq number of transfer complete interrupt
169  * @is_dvc: identifies the DVC i2c controller, has a different register layout
170  * @msg_complete: transfer completion notifier
171  * @msg_err: error code for completed message
172  * @msg_buf: pointer to current message data
173  * @msg_buf_remaining: size of unsent data in the message buffer
174  * @msg_read: identifies read transfers
175  * @bus_clk_rate: current i2c bus clock rate
176  * @is_suspended: prevents i2c controller accesses after suspend is called
177  */
178 struct tegra_i2c_dev {
179 	struct device *dev;
180 	const struct tegra_i2c_hw_feature *hw;
181 	struct i2c_adapter adapter;
182 	struct clk *div_clk;
183 	struct clk *fast_clk;
184 	struct reset_control *rst;
185 	void __iomem *base;
186 	int cont_id;
187 	int irq;
188 	bool irq_disabled;
189 	int is_dvc;
190 	struct completion msg_complete;
191 	int msg_err;
192 	u8 *msg_buf;
193 	size_t msg_buf_remaining;
194 	int msg_read;
195 	u32 bus_clk_rate;
196 	u16 clk_divisor_non_hs_mode;
197 	bool is_suspended;
198 	bool is_multimaster_mode;
199 	spinlock_t xfer_lock;
200 };
201 
dvc_writel(struct tegra_i2c_dev * i2c_dev,u32 val,unsigned long reg)202 static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
203 		       unsigned long reg)
204 {
205 	writel(val, i2c_dev->base + reg);
206 }
207 
dvc_readl(struct tegra_i2c_dev * i2c_dev,unsigned long reg)208 static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
209 {
210 	return readl(i2c_dev->base + reg);
211 }
212 
213 /*
214  * i2c_writel and i2c_readl will offset the register if necessary to talk
215  * to the I2C block inside the DVC block
216  */
tegra_i2c_reg_addr(struct tegra_i2c_dev * i2c_dev,unsigned long reg)217 static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
218 	unsigned long reg)
219 {
220 	if (i2c_dev->is_dvc)
221 		reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
222 	return reg;
223 }
224 
i2c_writel(struct tegra_i2c_dev * i2c_dev,u32 val,unsigned long reg)225 static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
226 	unsigned long reg)
227 {
228 	writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
229 
230 	/* Read back register to make sure that register writes completed */
231 	if (reg != I2C_TX_FIFO)
232 		readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
233 }
234 
i2c_readl(struct tegra_i2c_dev * i2c_dev,unsigned long reg)235 static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
236 {
237 	return readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
238 }
239 
i2c_writesl(struct tegra_i2c_dev * i2c_dev,void * data,unsigned long reg,int len)240 static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
241 	unsigned long reg, int len)
242 {
243 	writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
244 }
245 
i2c_readsl(struct tegra_i2c_dev * i2c_dev,void * data,unsigned long reg,int len)246 static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
247 	unsigned long reg, int len)
248 {
249 	readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
250 }
251 
tegra_i2c_mask_irq(struct tegra_i2c_dev * i2c_dev,u32 mask)252 static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
253 {
254 	u32 int_mask;
255 
256 	int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) & ~mask;
257 	i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
258 }
259 
tegra_i2c_unmask_irq(struct tegra_i2c_dev * i2c_dev,u32 mask)260 static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
261 {
262 	u32 int_mask;
263 
264 	int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) | mask;
265 	i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
266 }
267 
tegra_i2c_flush_fifos(struct tegra_i2c_dev * i2c_dev)268 static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
269 {
270 	unsigned long timeout = jiffies + HZ;
271 	u32 val = i2c_readl(i2c_dev, I2C_FIFO_CONTROL);
272 
273 	val |= I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH;
274 	i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
275 
276 	while (i2c_readl(i2c_dev, I2C_FIFO_CONTROL) &
277 		(I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH)) {
278 		if (time_after(jiffies, timeout)) {
279 			dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
280 			return -ETIMEDOUT;
281 		}
282 		msleep(1);
283 	}
284 	return 0;
285 }
286 
tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev * i2c_dev)287 static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
288 {
289 	u32 val;
290 	int rx_fifo_avail;
291 	u8 *buf = i2c_dev->msg_buf;
292 	size_t buf_remaining = i2c_dev->msg_buf_remaining;
293 	int words_to_transfer;
294 
295 	val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
296 	rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
297 		I2C_FIFO_STATUS_RX_SHIFT;
298 
299 	/* Rounds down to not include partial word at the end of buf */
300 	words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
301 	if (words_to_transfer > rx_fifo_avail)
302 		words_to_transfer = rx_fifo_avail;
303 
304 	i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
305 
306 	buf += words_to_transfer * BYTES_PER_FIFO_WORD;
307 	buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
308 	rx_fifo_avail -= words_to_transfer;
309 
310 	/*
311 	 * If there is a partial word at the end of buf, handle it manually to
312 	 * prevent overwriting past the end of buf
313 	 */
314 	if (rx_fifo_avail > 0 && buf_remaining > 0) {
315 		BUG_ON(buf_remaining > 3);
316 		val = i2c_readl(i2c_dev, I2C_RX_FIFO);
317 		val = cpu_to_le32(val);
318 		memcpy(buf, &val, buf_remaining);
319 		buf_remaining = 0;
320 		rx_fifo_avail--;
321 	}
322 
323 	BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
324 	i2c_dev->msg_buf_remaining = buf_remaining;
325 	i2c_dev->msg_buf = buf;
326 	return 0;
327 }
328 
tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev * i2c_dev)329 static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
330 {
331 	u32 val;
332 	int tx_fifo_avail;
333 	u8 *buf = i2c_dev->msg_buf;
334 	size_t buf_remaining = i2c_dev->msg_buf_remaining;
335 	int words_to_transfer;
336 
337 	val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
338 	tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
339 		I2C_FIFO_STATUS_TX_SHIFT;
340 
341 	/* Rounds down to not include partial word at the end of buf */
342 	words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
343 
344 	/* It's very common to have < 4 bytes, so optimize that case. */
345 	if (words_to_transfer) {
346 		if (words_to_transfer > tx_fifo_avail)
347 			words_to_transfer = tx_fifo_avail;
348 
349 		/*
350 		 * Update state before writing to FIFO.  If this casues us
351 		 * to finish writing all bytes (AKA buf_remaining goes to 0) we
352 		 * have a potential for an interrupt (PACKET_XFER_COMPLETE is
353 		 * not maskable).  We need to make sure that the isr sees
354 		 * buf_remaining as 0 and doesn't call us back re-entrantly.
355 		 */
356 		buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
357 		tx_fifo_avail -= words_to_transfer;
358 		i2c_dev->msg_buf_remaining = buf_remaining;
359 		i2c_dev->msg_buf = buf +
360 			words_to_transfer * BYTES_PER_FIFO_WORD;
361 		barrier();
362 
363 		i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
364 
365 		buf += words_to_transfer * BYTES_PER_FIFO_WORD;
366 	}
367 
368 	/*
369 	 * If there is a partial word at the end of buf, handle it manually to
370 	 * prevent reading past the end of buf, which could cross a page
371 	 * boundary and fault.
372 	 */
373 	if (tx_fifo_avail > 0 && buf_remaining > 0) {
374 		BUG_ON(buf_remaining > 3);
375 		memcpy(&val, buf, buf_remaining);
376 		val = le32_to_cpu(val);
377 
378 		/* Again update before writing to FIFO to make sure isr sees. */
379 		i2c_dev->msg_buf_remaining = 0;
380 		i2c_dev->msg_buf = NULL;
381 		barrier();
382 
383 		i2c_writel(i2c_dev, val, I2C_TX_FIFO);
384 	}
385 
386 	return 0;
387 }
388 
389 /*
390  * One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
391  * block.  This block is identical to the rest of the I2C blocks, except that
392  * it only supports master mode, it has registers moved around, and it needs
393  * some extra init to get it into I2C mode.  The register moves are handled
394  * by i2c_readl and i2c_writel
395  */
tegra_dvc_init(struct tegra_i2c_dev * i2c_dev)396 static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
397 {
398 	u32 val;
399 
400 	val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
401 	val |= DVC_CTRL_REG3_SW_PROG;
402 	val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
403 	dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
404 
405 	val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
406 	val |= DVC_CTRL_REG1_INTR_EN;
407 	dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
408 }
409 
tegra_i2c_runtime_resume(struct device * dev)410 static int tegra_i2c_runtime_resume(struct device *dev)
411 {
412 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
413 	int ret;
414 
415 	ret = pinctrl_pm_select_default_state(i2c_dev->dev);
416 	if (ret)
417 		return ret;
418 
419 	if (!i2c_dev->hw->has_single_clk_source) {
420 		ret = clk_enable(i2c_dev->fast_clk);
421 		if (ret < 0) {
422 			dev_err(i2c_dev->dev,
423 				"Enabling fast clk failed, err %d\n", ret);
424 			return ret;
425 		}
426 	}
427 
428 	ret = clk_enable(i2c_dev->div_clk);
429 	if (ret < 0) {
430 		dev_err(i2c_dev->dev,
431 			"Enabling div clk failed, err %d\n", ret);
432 		clk_disable(i2c_dev->fast_clk);
433 		return ret;
434 	}
435 
436 	return 0;
437 }
438 
tegra_i2c_runtime_suspend(struct device * dev)439 static int tegra_i2c_runtime_suspend(struct device *dev)
440 {
441 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
442 
443 	clk_disable(i2c_dev->div_clk);
444 	if (!i2c_dev->hw->has_single_clk_source)
445 		clk_disable(i2c_dev->fast_clk);
446 
447 	return pinctrl_pm_select_idle_state(i2c_dev->dev);
448 }
449 
tegra_i2c_wait_for_config_load(struct tegra_i2c_dev * i2c_dev)450 static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
451 {
452 	unsigned long reg_offset;
453 	void __iomem *addr;
454 	u32 val;
455 	int err;
456 
457 	if (i2c_dev->hw->has_config_load_reg) {
458 		reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_CONFIG_LOAD);
459 		addr = i2c_dev->base + reg_offset;
460 		i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
461 		if (in_interrupt())
462 			err = readl_poll_timeout_atomic(addr, val, val == 0,
463 					1000, I2C_CONFIG_LOAD_TIMEOUT);
464 		else
465 			err = readl_poll_timeout(addr, val, val == 0,
466 					1000, I2C_CONFIG_LOAD_TIMEOUT);
467 
468 		if (err) {
469 			dev_warn(i2c_dev->dev,
470 				 "timeout waiting for config load\n");
471 			return err;
472 		}
473 	}
474 
475 	return 0;
476 }
477 
tegra_i2c_init(struct tegra_i2c_dev * i2c_dev)478 static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
479 {
480 	u32 val;
481 	int err;
482 	u32 clk_divisor;
483 
484 	err = pm_runtime_get_sync(i2c_dev->dev);
485 	if (err < 0) {
486 		dev_err(i2c_dev->dev, "runtime resume failed %d\n", err);
487 		return err;
488 	}
489 
490 	reset_control_assert(i2c_dev->rst);
491 	udelay(2);
492 	reset_control_deassert(i2c_dev->rst);
493 
494 	if (i2c_dev->is_dvc)
495 		tegra_dvc_init(i2c_dev);
496 
497 	val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
498 		(0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT);
499 
500 	if (i2c_dev->hw->has_multi_master_mode)
501 		val |= I2C_CNFG_MULTI_MASTER_MODE;
502 
503 	i2c_writel(i2c_dev, val, I2C_CNFG);
504 	i2c_writel(i2c_dev, 0, I2C_INT_MASK);
505 
506 	/* Make sure clock divisor programmed correctly */
507 	clk_divisor = i2c_dev->hw->clk_divisor_hs_mode;
508 	clk_divisor |= i2c_dev->clk_divisor_non_hs_mode <<
509 					I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT;
510 	i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
511 
512 	if (!i2c_dev->is_dvc) {
513 		u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
514 
515 		sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL;
516 		i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG);
517 		i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1);
518 		i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
519 	}
520 
521 	val = 7 << I2C_FIFO_CONTROL_TX_TRIG_SHIFT |
522 		0 << I2C_FIFO_CONTROL_RX_TRIG_SHIFT;
523 	i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
524 
525 	err = tegra_i2c_flush_fifos(i2c_dev);
526 	if (err)
527 		goto err;
528 
529 	if (i2c_dev->is_multimaster_mode && i2c_dev->hw->has_slcg_override_reg)
530 		i2c_writel(i2c_dev, I2C_MST_CORE_CLKEN_OVR, I2C_CLKEN_OVERRIDE);
531 
532 	err = tegra_i2c_wait_for_config_load(i2c_dev);
533 	if (err)
534 		goto err;
535 
536 	if (i2c_dev->irq_disabled) {
537 		i2c_dev->irq_disabled = false;
538 		enable_irq(i2c_dev->irq);
539 	}
540 
541 err:
542 	pm_runtime_put(i2c_dev->dev);
543 	return err;
544 }
545 
tegra_i2c_disable_packet_mode(struct tegra_i2c_dev * i2c_dev)546 static int tegra_i2c_disable_packet_mode(struct tegra_i2c_dev *i2c_dev)
547 {
548 	u32 cnfg;
549 
550 	/*
551 	 * NACK interrupt is generated before the I2C controller generates
552 	 * the STOP condition on the bus. So wait for 2 clock periods
553 	 * before disabling the controller so that the STOP condition has
554 	 * been delivered properly.
555 	 */
556 	udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate));
557 
558 	cnfg = i2c_readl(i2c_dev, I2C_CNFG);
559 	if (cnfg & I2C_CNFG_PACKET_MODE_EN)
560 		i2c_writel(i2c_dev, cnfg & ~I2C_CNFG_PACKET_MODE_EN, I2C_CNFG);
561 
562 	return tegra_i2c_wait_for_config_load(i2c_dev);
563 }
564 
tegra_i2c_isr(int irq,void * dev_id)565 static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
566 {
567 	u32 status;
568 	const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
569 	struct tegra_i2c_dev *i2c_dev = dev_id;
570 	unsigned long flags;
571 
572 	status = i2c_readl(i2c_dev, I2C_INT_STATUS);
573 
574 	spin_lock_irqsave(&i2c_dev->xfer_lock, flags);
575 	if (status == 0) {
576 		dev_warn(i2c_dev->dev, "irq status 0 %08x %08x %08x\n",
577 			 i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS),
578 			 i2c_readl(i2c_dev, I2C_STATUS),
579 			 i2c_readl(i2c_dev, I2C_CNFG));
580 		i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
581 
582 		if (!i2c_dev->irq_disabled) {
583 			disable_irq_nosync(i2c_dev->irq);
584 			i2c_dev->irq_disabled = true;
585 		}
586 		goto err;
587 	}
588 
589 	if (unlikely(status & status_err)) {
590 		tegra_i2c_disable_packet_mode(i2c_dev);
591 		if (status & I2C_INT_NO_ACK)
592 			i2c_dev->msg_err |= I2C_ERR_NO_ACK;
593 		if (status & I2C_INT_ARBITRATION_LOST)
594 			i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
595 		goto err;
596 	}
597 
598 	if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
599 		if (i2c_dev->msg_buf_remaining)
600 			tegra_i2c_empty_rx_fifo(i2c_dev);
601 		else
602 			BUG();
603 	}
604 
605 	if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
606 		if (i2c_dev->msg_buf_remaining)
607 			tegra_i2c_fill_tx_fifo(i2c_dev);
608 		else
609 			tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ);
610 	}
611 
612 	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
613 	if (i2c_dev->is_dvc)
614 		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
615 
616 	if (status & I2C_INT_PACKET_XFER_COMPLETE) {
617 		BUG_ON(i2c_dev->msg_buf_remaining);
618 		complete(&i2c_dev->msg_complete);
619 	}
620 	goto done;
621 err:
622 	/* An error occurred, mask all interrupts */
623 	tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST |
624 		I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ |
625 		I2C_INT_RX_FIFO_DATA_REQ);
626 	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
627 	if (i2c_dev->is_dvc)
628 		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
629 
630 	complete(&i2c_dev->msg_complete);
631 done:
632 	spin_unlock_irqrestore(&i2c_dev->xfer_lock, flags);
633 	return IRQ_HANDLED;
634 }
635 
tegra_i2c_xfer_msg(struct tegra_i2c_dev * i2c_dev,struct i2c_msg * msg,enum msg_end_type end_state)636 static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
637 	struct i2c_msg *msg, enum msg_end_type end_state)
638 {
639 	u32 packet_header;
640 	u32 int_mask;
641 	unsigned long time_left;
642 	unsigned long flags;
643 
644 	tegra_i2c_flush_fifos(i2c_dev);
645 
646 	if (msg->len == 0)
647 		return -EINVAL;
648 
649 	i2c_dev->msg_buf = msg->buf;
650 	i2c_dev->msg_buf_remaining = msg->len;
651 	i2c_dev->msg_err = I2C_ERR_NONE;
652 	i2c_dev->msg_read = (msg->flags & I2C_M_RD);
653 	reinit_completion(&i2c_dev->msg_complete);
654 
655 	spin_lock_irqsave(&i2c_dev->xfer_lock, flags);
656 
657 	int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
658 	tegra_i2c_unmask_irq(i2c_dev, int_mask);
659 
660 	packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
661 			PACKET_HEADER0_PROTOCOL_I2C |
662 			(i2c_dev->cont_id << PACKET_HEADER0_CONT_ID_SHIFT) |
663 			(1 << PACKET_HEADER0_PACKET_ID_SHIFT);
664 	i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
665 
666 	packet_header = msg->len - 1;
667 	i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
668 
669 	packet_header = I2C_HEADER_IE_ENABLE;
670 	if (end_state == MSG_END_CONTINUE)
671 		packet_header |= I2C_HEADER_CONTINUE_XFER;
672 	else if (end_state == MSG_END_REPEAT_START)
673 		packet_header |= I2C_HEADER_REPEAT_START;
674 	if (msg->flags & I2C_M_TEN) {
675 		packet_header |= msg->addr;
676 		packet_header |= I2C_HEADER_10BIT_ADDR;
677 	} else {
678 		packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
679 	}
680 	if (msg->flags & I2C_M_IGNORE_NAK)
681 		packet_header |= I2C_HEADER_CONT_ON_NAK;
682 	if (msg->flags & I2C_M_RD)
683 		packet_header |= I2C_HEADER_READ;
684 	i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
685 
686 	if (!(msg->flags & I2C_M_RD))
687 		tegra_i2c_fill_tx_fifo(i2c_dev);
688 
689 	if (i2c_dev->hw->has_per_pkt_xfer_complete_irq)
690 		int_mask |= I2C_INT_PACKET_XFER_COMPLETE;
691 	if (msg->flags & I2C_M_RD)
692 		int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
693 	else if (i2c_dev->msg_buf_remaining)
694 		int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
695 
696 	tegra_i2c_unmask_irq(i2c_dev, int_mask);
697 	spin_unlock_irqrestore(&i2c_dev->xfer_lock, flags);
698 	dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n",
699 		i2c_readl(i2c_dev, I2C_INT_MASK));
700 
701 	time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
702 						TEGRA_I2C_TIMEOUT);
703 	tegra_i2c_mask_irq(i2c_dev, int_mask);
704 
705 	if (time_left == 0) {
706 		dev_err(i2c_dev->dev, "i2c transfer timed out\n");
707 
708 		tegra_i2c_init(i2c_dev);
709 		return -ETIMEDOUT;
710 	}
711 
712 	dev_dbg(i2c_dev->dev, "transfer complete: %lu %d %d\n",
713 		time_left, completion_done(&i2c_dev->msg_complete),
714 		i2c_dev->msg_err);
715 
716 	if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
717 		return 0;
718 
719 	tegra_i2c_init(i2c_dev);
720 	if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
721 		if (msg->flags & I2C_M_IGNORE_NAK)
722 			return 0;
723 		return -EREMOTEIO;
724 	}
725 
726 	return -EIO;
727 }
728 
tegra_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)729 static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
730 	int num)
731 {
732 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
733 	int i;
734 	int ret = 0;
735 
736 	if (i2c_dev->is_suspended)
737 		return -EBUSY;
738 
739 	ret = pm_runtime_get_sync(i2c_dev->dev);
740 	if (ret < 0) {
741 		dev_err(i2c_dev->dev, "runtime resume failed %d\n", ret);
742 		return ret;
743 	}
744 
745 	for (i = 0; i < num; i++) {
746 		enum msg_end_type end_type = MSG_END_STOP;
747 
748 		if (i < (num - 1)) {
749 			if (msgs[i + 1].flags & I2C_M_NOSTART)
750 				end_type = MSG_END_CONTINUE;
751 			else
752 				end_type = MSG_END_REPEAT_START;
753 		}
754 		ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);
755 		if (ret)
756 			break;
757 	}
758 
759 	pm_runtime_put(i2c_dev->dev);
760 
761 	return ret ?: i;
762 }
763 
tegra_i2c_func(struct i2c_adapter * adap)764 static u32 tegra_i2c_func(struct i2c_adapter *adap)
765 {
766 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
767 	u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
768 		  I2C_FUNC_10BIT_ADDR |	I2C_FUNC_PROTOCOL_MANGLING;
769 
770 	if (i2c_dev->hw->has_continue_xfer_support)
771 		ret |= I2C_FUNC_NOSTART;
772 	return ret;
773 }
774 
tegra_i2c_parse_dt(struct tegra_i2c_dev * i2c_dev)775 static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
776 {
777 	struct device_node *np = i2c_dev->dev->of_node;
778 	int ret;
779 
780 	ret = of_property_read_u32(np, "clock-frequency",
781 			&i2c_dev->bus_clk_rate);
782 	if (ret)
783 		i2c_dev->bus_clk_rate = 100000; /* default clock rate */
784 
785 	i2c_dev->is_multimaster_mode = of_property_read_bool(np,
786 			"multi-master");
787 }
788 
789 static const struct i2c_algorithm tegra_i2c_algo = {
790 	.master_xfer	= tegra_i2c_xfer,
791 	.functionality	= tegra_i2c_func,
792 };
793 
794 /* payload size is only 12 bit */
795 static const struct i2c_adapter_quirks tegra_i2c_quirks = {
796 	.max_read_len = 4096,
797 	.max_write_len = 4096 - 12,
798 };
799 
800 static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
801 	.has_continue_xfer_support = false,
802 	.has_per_pkt_xfer_complete_irq = false,
803 	.has_single_clk_source = false,
804 	.clk_divisor_hs_mode = 3,
805 	.clk_divisor_std_fast_mode = 0,
806 	.clk_divisor_fast_plus_mode = 0,
807 	.has_config_load_reg = false,
808 	.has_multi_master_mode = false,
809 	.has_slcg_override_reg = false,
810 };
811 
812 static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
813 	.has_continue_xfer_support = true,
814 	.has_per_pkt_xfer_complete_irq = false,
815 	.has_single_clk_source = false,
816 	.clk_divisor_hs_mode = 3,
817 	.clk_divisor_std_fast_mode = 0,
818 	.clk_divisor_fast_plus_mode = 0,
819 	.has_config_load_reg = false,
820 	.has_multi_master_mode = false,
821 	.has_slcg_override_reg = false,
822 };
823 
824 static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
825 	.has_continue_xfer_support = true,
826 	.has_per_pkt_xfer_complete_irq = true,
827 	.has_single_clk_source = true,
828 	.clk_divisor_hs_mode = 1,
829 	.clk_divisor_std_fast_mode = 0x19,
830 	.clk_divisor_fast_plus_mode = 0x10,
831 	.has_config_load_reg = false,
832 	.has_multi_master_mode = false,
833 	.has_slcg_override_reg = false,
834 };
835 
836 static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
837 	.has_continue_xfer_support = true,
838 	.has_per_pkt_xfer_complete_irq = true,
839 	.has_single_clk_source = true,
840 	.clk_divisor_hs_mode = 1,
841 	.clk_divisor_std_fast_mode = 0x19,
842 	.clk_divisor_fast_plus_mode = 0x10,
843 	.has_config_load_reg = true,
844 	.has_multi_master_mode = false,
845 	.has_slcg_override_reg = true,
846 };
847 
848 static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
849 	.has_continue_xfer_support = true,
850 	.has_per_pkt_xfer_complete_irq = true,
851 	.has_single_clk_source = true,
852 	.clk_divisor_hs_mode = 1,
853 	.clk_divisor_std_fast_mode = 0x19,
854 	.clk_divisor_fast_plus_mode = 0x10,
855 	.has_config_load_reg = true,
856 	.has_multi_master_mode = true,
857 	.has_slcg_override_reg = true,
858 };
859 
860 /* Match table for of_platform binding */
861 static const struct of_device_id tegra_i2c_of_match[] = {
862 	{ .compatible = "nvidia,tegra210-i2c", .data = &tegra210_i2c_hw, },
863 	{ .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, },
864 	{ .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, },
865 	{ .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, },
866 	{ .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, },
867 	{ .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, },
868 	{},
869 };
870 MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
871 
tegra_i2c_probe(struct platform_device * pdev)872 static int tegra_i2c_probe(struct platform_device *pdev)
873 {
874 	struct tegra_i2c_dev *i2c_dev;
875 	struct resource *res;
876 	struct clk *div_clk;
877 	struct clk *fast_clk;
878 	void __iomem *base;
879 	int irq;
880 	int ret = 0;
881 	int clk_multiplier = I2C_CLK_MULTIPLIER_STD_FAST_MODE;
882 
883 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
884 	base = devm_ioremap_resource(&pdev->dev, res);
885 	if (IS_ERR(base))
886 		return PTR_ERR(base);
887 
888 	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
889 	if (!res) {
890 		dev_err(&pdev->dev, "no irq resource\n");
891 		return -EINVAL;
892 	}
893 	irq = res->start;
894 
895 	div_clk = devm_clk_get(&pdev->dev, "div-clk");
896 	if (IS_ERR(div_clk)) {
897 		dev_err(&pdev->dev, "missing controller clock\n");
898 		return PTR_ERR(div_clk);
899 	}
900 
901 	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
902 	if (!i2c_dev)
903 		return -ENOMEM;
904 
905 	i2c_dev->base = base;
906 	i2c_dev->div_clk = div_clk;
907 	i2c_dev->adapter.algo = &tegra_i2c_algo;
908 	i2c_dev->adapter.quirks = &tegra_i2c_quirks;
909 	i2c_dev->irq = irq;
910 	i2c_dev->cont_id = pdev->id;
911 	i2c_dev->dev = &pdev->dev;
912 
913 	i2c_dev->rst = devm_reset_control_get_exclusive(&pdev->dev, "i2c");
914 	if (IS_ERR(i2c_dev->rst)) {
915 		dev_err(&pdev->dev, "missing controller reset\n");
916 		return PTR_ERR(i2c_dev->rst);
917 	}
918 
919 	tegra_i2c_parse_dt(i2c_dev);
920 
921 	i2c_dev->hw = of_device_get_match_data(&pdev->dev);
922 	i2c_dev->is_dvc = of_device_is_compatible(pdev->dev.of_node,
923 						  "nvidia,tegra20-i2c-dvc");
924 	init_completion(&i2c_dev->msg_complete);
925 	spin_lock_init(&i2c_dev->xfer_lock);
926 
927 	if (!i2c_dev->hw->has_single_clk_source) {
928 		fast_clk = devm_clk_get(&pdev->dev, "fast-clk");
929 		if (IS_ERR(fast_clk)) {
930 			dev_err(&pdev->dev, "missing fast clock\n");
931 			return PTR_ERR(fast_clk);
932 		}
933 		i2c_dev->fast_clk = fast_clk;
934 	}
935 
936 	platform_set_drvdata(pdev, i2c_dev);
937 
938 	if (!i2c_dev->hw->has_single_clk_source) {
939 		ret = clk_prepare(i2c_dev->fast_clk);
940 		if (ret < 0) {
941 			dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
942 			return ret;
943 		}
944 	}
945 
946 	i2c_dev->clk_divisor_non_hs_mode =
947 			i2c_dev->hw->clk_divisor_std_fast_mode;
948 	if (i2c_dev->hw->clk_divisor_fast_plus_mode &&
949 		(i2c_dev->bus_clk_rate == 1000000))
950 		i2c_dev->clk_divisor_non_hs_mode =
951 			i2c_dev->hw->clk_divisor_fast_plus_mode;
952 
953 	clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1);
954 	ret = clk_set_rate(i2c_dev->div_clk,
955 			   i2c_dev->bus_clk_rate * clk_multiplier);
956 	if (ret) {
957 		dev_err(i2c_dev->dev, "Clock rate change failed %d\n", ret);
958 		goto unprepare_fast_clk;
959 	}
960 
961 	ret = clk_prepare(i2c_dev->div_clk);
962 	if (ret < 0) {
963 		dev_err(i2c_dev->dev, "Clock prepare failed %d\n", ret);
964 		goto unprepare_fast_clk;
965 	}
966 
967 	pm_runtime_enable(&pdev->dev);
968 	if (!pm_runtime_enabled(&pdev->dev)) {
969 		ret = tegra_i2c_runtime_resume(&pdev->dev);
970 		if (ret < 0) {
971 			dev_err(&pdev->dev, "runtime resume failed\n");
972 			goto unprepare_div_clk;
973 		}
974 	}
975 
976 	if (i2c_dev->is_multimaster_mode) {
977 		ret = clk_enable(i2c_dev->div_clk);
978 		if (ret < 0) {
979 			dev_err(i2c_dev->dev, "div_clk enable failed %d\n",
980 				ret);
981 			goto disable_rpm;
982 		}
983 	}
984 
985 	ret = tegra_i2c_init(i2c_dev);
986 	if (ret) {
987 		dev_err(&pdev->dev, "Failed to initialize i2c controller\n");
988 		goto disable_div_clk;
989 	}
990 
991 	ret = devm_request_irq(&pdev->dev, i2c_dev->irq,
992 			tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev);
993 	if (ret) {
994 		dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
995 		goto disable_div_clk;
996 	}
997 
998 	i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
999 	i2c_dev->adapter.owner = THIS_MODULE;
1000 	i2c_dev->adapter.class = I2C_CLASS_DEPRECATED;
1001 	strlcpy(i2c_dev->adapter.name, dev_name(&pdev->dev),
1002 		sizeof(i2c_dev->adapter.name));
1003 	i2c_dev->adapter.dev.parent = &pdev->dev;
1004 	i2c_dev->adapter.nr = pdev->id;
1005 	i2c_dev->adapter.dev.of_node = pdev->dev.of_node;
1006 
1007 	ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
1008 	if (ret)
1009 		goto disable_div_clk;
1010 
1011 	return 0;
1012 
1013 disable_div_clk:
1014 	if (i2c_dev->is_multimaster_mode)
1015 		clk_disable(i2c_dev->div_clk);
1016 
1017 disable_rpm:
1018 	pm_runtime_disable(&pdev->dev);
1019 	if (!pm_runtime_status_suspended(&pdev->dev))
1020 		tegra_i2c_runtime_suspend(&pdev->dev);
1021 
1022 unprepare_div_clk:
1023 	clk_unprepare(i2c_dev->div_clk);
1024 
1025 unprepare_fast_clk:
1026 	if (!i2c_dev->hw->has_single_clk_source)
1027 		clk_unprepare(i2c_dev->fast_clk);
1028 
1029 	return ret;
1030 }
1031 
tegra_i2c_remove(struct platform_device * pdev)1032 static int tegra_i2c_remove(struct platform_device *pdev)
1033 {
1034 	struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
1035 
1036 	i2c_del_adapter(&i2c_dev->adapter);
1037 
1038 	if (i2c_dev->is_multimaster_mode)
1039 		clk_disable(i2c_dev->div_clk);
1040 
1041 	pm_runtime_disable(&pdev->dev);
1042 	if (!pm_runtime_status_suspended(&pdev->dev))
1043 		tegra_i2c_runtime_suspend(&pdev->dev);
1044 
1045 	clk_unprepare(i2c_dev->div_clk);
1046 	if (!i2c_dev->hw->has_single_clk_source)
1047 		clk_unprepare(i2c_dev->fast_clk);
1048 
1049 	return 0;
1050 }
1051 
1052 #ifdef CONFIG_PM_SLEEP
tegra_i2c_suspend(struct device * dev)1053 static int tegra_i2c_suspend(struct device *dev)
1054 {
1055 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1056 
1057 	i2c_lock_adapter(&i2c_dev->adapter);
1058 	i2c_dev->is_suspended = true;
1059 	i2c_unlock_adapter(&i2c_dev->adapter);
1060 
1061 	return 0;
1062 }
1063 
tegra_i2c_resume(struct device * dev)1064 static int tegra_i2c_resume(struct device *dev)
1065 {
1066 	struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1067 	int ret;
1068 
1069 	i2c_lock_adapter(&i2c_dev->adapter);
1070 
1071 	ret = tegra_i2c_init(i2c_dev);
1072 	if (!ret)
1073 		i2c_dev->is_suspended = false;
1074 
1075 	i2c_unlock_adapter(&i2c_dev->adapter);
1076 
1077 	return ret;
1078 }
1079 
1080 static const struct dev_pm_ops tegra_i2c_pm = {
1081 	SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
1082 			   NULL)
1083 	SET_SYSTEM_SLEEP_PM_OPS(tegra_i2c_suspend, tegra_i2c_resume)
1084 };
1085 #define TEGRA_I2C_PM	(&tegra_i2c_pm)
1086 #else
1087 #define TEGRA_I2C_PM	NULL
1088 #endif
1089 
1090 static struct platform_driver tegra_i2c_driver = {
1091 	.probe   = tegra_i2c_probe,
1092 	.remove  = tegra_i2c_remove,
1093 	.driver  = {
1094 		.name  = "tegra-i2c",
1095 		.of_match_table = tegra_i2c_of_match,
1096 		.pm    = TEGRA_I2C_PM,
1097 	},
1098 };
1099 
tegra_i2c_init_driver(void)1100 static int __init tegra_i2c_init_driver(void)
1101 {
1102 	return platform_driver_register(&tegra_i2c_driver);
1103 }
1104 
tegra_i2c_exit_driver(void)1105 static void __exit tegra_i2c_exit_driver(void)
1106 {
1107 	platform_driver_unregister(&tegra_i2c_driver);
1108 }
1109 
1110 subsys_initcall(tegra_i2c_init_driver);
1111 module_exit(tegra_i2c_exit_driver);
1112 
1113 MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver");
1114 MODULE_AUTHOR("Colin Cross");
1115 MODULE_LICENSE("GPL v2");
1116