xref: /openbmc/linux/drivers/i2c/busses/i2c-brcmstb.c (revision c0e297dc)
1 /*
2  * Copyright (C) 2014 Broadcom Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation version 2.
7  *
8  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9  * kind, whether express or implied; without even the implied warranty
10  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/clk.h>
15 #include <linux/delay.h>
16 #include <linux/device.h>
17 #include <linux/i2c.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/sched.h>
24 #include <linux/slab.h>
25 #include <linux/version.h>
26 
27 #define N_DATA_REGS					8
28 #define N_DATA_BYTES					(N_DATA_REGS * 4)
29 
30 /* BSC count register field definitions */
31 #define BSC_CNT_REG1_MASK				0x0000003f
32 #define BSC_CNT_REG1_SHIFT				0
33 #define BSC_CNT_REG2_MASK				0x00000fc0
34 #define BSC_CNT_REG2_SHIFT				6
35 
36 /* BSC CTL register field definitions */
37 #define BSC_CTL_REG_DTF_MASK				0x00000003
38 #define BSC_CTL_REG_SCL_SEL_MASK			0x00000030
39 #define BSC_CTL_REG_SCL_SEL_SHIFT			4
40 #define BSC_CTL_REG_INT_EN_MASK				0x00000040
41 #define BSC_CTL_REG_INT_EN_SHIFT			6
42 #define BSC_CTL_REG_DIV_CLK_MASK			0x00000080
43 
44 /* BSC_IIC_ENABLE r/w enable and interrupt field defintions */
45 #define BSC_IIC_EN_RESTART_MASK				0x00000040
46 #define BSC_IIC_EN_NOSTART_MASK				0x00000020
47 #define BSC_IIC_EN_NOSTOP_MASK				0x00000010
48 #define BSC_IIC_EN_NOACK_MASK				0x00000004
49 #define BSC_IIC_EN_INTRP_MASK				0x00000002
50 #define BSC_IIC_EN_ENABLE_MASK				0x00000001
51 
52 /* BSC_CTLHI control register field definitions */
53 #define BSC_CTLHI_REG_INPUT_SWITCHING_LEVEL_MASK	0x00000080
54 #define BSC_CTLHI_REG_DATAREG_SIZE_MASK			0x00000040
55 #define BSC_CTLHI_REG_IGNORE_ACK_MASK			0x00000002
56 #define BSC_CTLHI_REG_WAIT_DIS_MASK			0x00000001
57 
58 #define I2C_TIMEOUT					100 /* msecs */
59 
60 /* Condition mask used for non combined transfer */
61 #define COND_RESTART		BSC_IIC_EN_RESTART_MASK
62 #define COND_NOSTART		BSC_IIC_EN_NOSTART_MASK
63 #define COND_NOSTOP		BSC_IIC_EN_NOSTOP_MASK
64 #define COND_START_STOP		(COND_RESTART | COND_NOSTART | COND_NOSTOP)
65 
66 /* BSC data transfer direction */
67 #define DTF_WR_MASK		0x00000000
68 #define DTF_RD_MASK		0x00000001
69 /* BSC data transfer direction combined format */
70 #define DTF_RD_WR_MASK		0x00000002
71 #define DTF_WR_RD_MASK		0x00000003
72 
73 #define INT_ENABLE		true
74 #define INT_DISABLE		false
75 
76 /* BSC block register map structure to cache fields to be written */
77 struct bsc_regs {
78 	u32	chip_address;           /* slave address */
79 	u32	data_in[N_DATA_REGS];   /* tx data buffer*/
80 	u32	cnt_reg;		/* rx/tx data length */
81 	u32	ctl_reg;		/* control register */
82 	u32	iic_enable;		/* xfer enable and status */
83 	u32	data_out[N_DATA_REGS];  /* rx data buffer */
84 	u32	ctlhi_reg;		/* more control fields */
85 	u32	scl_param;		/* reserved */
86 };
87 
88 struct bsc_clk_param {
89 	u32 hz;
90 	u32 scl_mask;
91 	u32 div_mask;
92 };
93 
94 enum bsc_xfer_cmd {
95 	CMD_WR,
96 	CMD_RD,
97 	CMD_WR_NOACK,
98 	CMD_RD_NOACK,
99 };
100 
101 static char const *cmd_string[] = {
102 	[CMD_WR] = "WR",
103 	[CMD_RD] = "RD",
104 	[CMD_WR_NOACK] = "WR NOACK",
105 	[CMD_RD_NOACK] = "RD NOACK",
106 };
107 
108 enum bus_speeds {
109 	SPD_375K,
110 	SPD_390K,
111 	SPD_187K,
112 	SPD_200K,
113 	SPD_93K,
114 	SPD_97K,
115 	SPD_46K,
116 	SPD_50K
117 };
118 
119 static const struct bsc_clk_param bsc_clk[] = {
120 	[SPD_375K] = {
121 		.hz = 375000,
122 		.scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
123 		.div_mask = 0
124 	},
125 	[SPD_390K] = {
126 		.hz = 390000,
127 		.scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
128 		.div_mask = 0
129 	},
130 	[SPD_187K] = {
131 		.hz = 187500,
132 		.scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
133 		.div_mask = 0
134 	},
135 	[SPD_200K] = {
136 		.hz = 200000,
137 		.scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
138 		.div_mask = 0
139 	},
140 	[SPD_93K]  = {
141 		.hz = 93750,
142 		.scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
143 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
144 	},
145 	[SPD_97K]  = {
146 		.hz = 97500,
147 		.scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
148 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
149 	},
150 	[SPD_46K]  = {
151 		.hz = 46875,
152 		.scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
153 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
154 	},
155 	[SPD_50K]  = {
156 		.hz = 50000,
157 		.scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
158 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
159 	}
160 };
161 
162 struct brcmstb_i2c_dev {
163 	struct device *device;
164 	void __iomem *base;
165 	void __iomem *irq_base;
166 	int irq;
167 	struct bsc_regs *bsc_regmap;
168 	struct i2c_adapter adapter;
169 	struct completion done;
170 	bool is_suspended;
171 	u32 clk_freq_hz;
172 };
173 
174 /* register accessors for both be and le cpu arch */
175 #ifdef CONFIG_CPU_BIG_ENDIAN
176 #define __bsc_readl(_reg) ioread32be(_reg)
177 #define __bsc_writel(_val, _reg) iowrite32be(_val, _reg)
178 #else
179 #define __bsc_readl(_reg) ioread32(_reg)
180 #define __bsc_writel(_val, _reg) iowrite32(_val, _reg)
181 #endif
182 
183 #define bsc_readl(_dev, _reg)						\
184 	__bsc_readl(_dev->base + offsetof(struct bsc_regs, _reg))
185 
186 #define bsc_writel(_dev, _val, _reg)					\
187 	__bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg))
188 
189 static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev,
190 					   bool int_en)
191 {
192 
193 	if (int_en)
194 		/* Enable BSC  CTL interrupt line */
195 		dev->bsc_regmap->ctl_reg |= BSC_CTL_REG_INT_EN_MASK;
196 	else
197 		/* Disable BSC CTL interrupt line */
198 		dev->bsc_regmap->ctl_reg &= ~BSC_CTL_REG_INT_EN_MASK;
199 
200 	barrier();
201 	bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
202 }
203 
204 static irqreturn_t brcmstb_i2c_isr(int irq, void *devid)
205 {
206 	struct brcmstb_i2c_dev *dev = devid;
207 	u32 status_bsc_ctl = bsc_readl(dev, ctl_reg);
208 	u32 status_iic_intrp = bsc_readl(dev, iic_enable);
209 
210 	dev_dbg(dev->device, "isr CTL_REG %x IIC_EN %x\n",
211 		status_bsc_ctl, status_iic_intrp);
212 
213 	if (!(status_bsc_ctl & BSC_CTL_REG_INT_EN_MASK))
214 		return IRQ_NONE;
215 
216 	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
217 	complete_all(&dev->done);
218 
219 	dev_dbg(dev->device, "isr handled");
220 	return IRQ_HANDLED;
221 }
222 
223 /* Wait for device to be ready */
224 static int brcmstb_i2c_wait_if_busy(struct brcmstb_i2c_dev *dev)
225 {
226 	unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
227 
228 	while ((bsc_readl(dev, iic_enable) & BSC_IIC_EN_INTRP_MASK)) {
229 		if (time_after(jiffies, timeout))
230 			return -ETIMEDOUT;
231 		cpu_relax();
232 	}
233 	return 0;
234 }
235 
236 /* i2c xfer completion function, handles both irq and polling mode */
237 static int brcmstb_i2c_wait_for_completion(struct brcmstb_i2c_dev *dev)
238 {
239 	int ret = 0;
240 	unsigned long timeout = msecs_to_jiffies(I2C_TIMEOUT);
241 
242 	if (dev->irq >= 0) {
243 		if (!wait_for_completion_timeout(&dev->done, timeout))
244 			ret = -ETIMEDOUT;
245 	} else {
246 		/* we are in polling mode */
247 		u32 bsc_intrp;
248 		unsigned long time_left = jiffies + timeout;
249 
250 		do {
251 			bsc_intrp = bsc_readl(dev, iic_enable) &
252 				BSC_IIC_EN_INTRP_MASK;
253 			if (time_after(jiffies, time_left)) {
254 				ret = -ETIMEDOUT;
255 				break;
256 			}
257 			cpu_relax();
258 		} while (!bsc_intrp);
259 	}
260 
261 	if (dev->irq < 0 || ret == -ETIMEDOUT)
262 		brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
263 
264 	return ret;
265 }
266 
267 /* Set xfer START/STOP conditions for subsequent transfer */
268 static void brcmstb_set_i2c_start_stop(struct brcmstb_i2c_dev *dev,
269 				       u32 cond_flag)
270 {
271 	u32 regval = dev->bsc_regmap->iic_enable;
272 
273 	dev->bsc_regmap->iic_enable = (regval & ~COND_START_STOP) | cond_flag;
274 }
275 
276 /* Send I2C request check completion */
277 static int brcmstb_send_i2c_cmd(struct brcmstb_i2c_dev *dev,
278 				enum bsc_xfer_cmd cmd)
279 {
280 	int rc = 0;
281 	struct bsc_regs *pi2creg = dev->bsc_regmap;
282 
283 	/* Make sure the hardware is ready */
284 	rc = brcmstb_i2c_wait_if_busy(dev);
285 	if (rc < 0)
286 		return rc;
287 
288 	/* only if we are in interrupt mode */
289 	if (dev->irq >= 0)
290 		reinit_completion(&dev->done);
291 
292 	/* enable BSC CTL interrupt line */
293 	brcmstb_i2c_enable_disable_irq(dev, INT_ENABLE);
294 
295 	/* initiate transfer by setting iic_enable */
296 	pi2creg->iic_enable |= BSC_IIC_EN_ENABLE_MASK;
297 	bsc_writel(dev, pi2creg->iic_enable, iic_enable);
298 
299 	/* Wait for transaction to finish or timeout */
300 	rc = brcmstb_i2c_wait_for_completion(dev);
301 	if (rc) {
302 		dev_dbg(dev->device, "intr timeout for cmd %s\n",
303 			cmd_string[cmd]);
304 		goto cmd_out;
305 	}
306 
307 	if ((CMD_RD || CMD_WR) &&
308 	    bsc_readl(dev, iic_enable) & BSC_IIC_EN_NOACK_MASK) {
309 		rc = -EREMOTEIO;
310 		dev_dbg(dev->device, "controller received NOACK intr for %s\n",
311 			cmd_string[cmd]);
312 	}
313 
314 cmd_out:
315 	bsc_writel(dev, 0, cnt_reg);
316 	bsc_writel(dev, 0, iic_enable);
317 
318 	return rc;
319 }
320 
321 /* Actual data transfer through the BSC master */
322 static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
323 				     u8 *buf, unsigned int len,
324 				     struct i2c_msg *pmsg)
325 {
326 	int cnt, byte, rc;
327 	enum bsc_xfer_cmd cmd;
328 	u32 ctl_reg;
329 	struct bsc_regs *pi2creg = dev->bsc_regmap;
330 	int no_ack = pmsg->flags & I2C_M_IGNORE_NAK;
331 
332 	/* see if the transaction needs to check NACK conditions */
333 	if (no_ack || len <= N_DATA_BYTES) {
334 		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK
335 			: CMD_WR_NOACK;
336 		pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK;
337 	} else {
338 		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD : CMD_WR;
339 		pi2creg->ctlhi_reg &= ~BSC_CTLHI_REG_IGNORE_ACK_MASK;
340 	}
341 	bsc_writel(dev, pi2creg->ctlhi_reg, ctlhi_reg);
342 
343 	/* set data transfer direction */
344 	ctl_reg = pi2creg->ctl_reg & ~BSC_CTL_REG_DTF_MASK;
345 	if (cmd == CMD_WR || cmd == CMD_WR_NOACK)
346 		pi2creg->ctl_reg = ctl_reg | DTF_WR_MASK;
347 	else
348 		pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK;
349 
350 	/* set the read/write length */
351 	bsc_writel(dev, BSC_CNT_REG1_MASK & (len << BSC_CNT_REG1_SHIFT),
352 		   cnt_reg);
353 
354 	/* Write data into data_in register */
355 	if (cmd == CMD_WR || cmd == CMD_WR_NOACK) {
356 		for (cnt = 0; cnt < len; cnt += 4) {
357 			u32 word = 0;
358 
359 			for (byte = 0; byte < 4; byte++) {
360 				word >>= 8;
361 				if ((cnt + byte) < len)
362 					word |= buf[cnt + byte] << 24;
363 			}
364 			bsc_writel(dev, word, data_in[cnt >> 2]);
365 		}
366 	}
367 
368 	/* Initiate xfer, the function will return on completion */
369 	rc = brcmstb_send_i2c_cmd(dev, cmd);
370 
371 	if (rc != 0) {
372 		dev_dbg(dev->device, "%s failure", cmd_string[cmd]);
373 		return rc;
374 	}
375 
376 	if (cmd == CMD_RD || cmd == CMD_RD_NOACK) {
377 		for (cnt = 0; cnt < len; cnt += 4) {
378 			u32 data = bsc_readl(dev, data_out[cnt >> 2]);
379 
380 			for (byte = 0; byte < 4 &&
381 				     (byte + cnt) < len; byte++) {
382 				buf[cnt + byte] = data & 0xff;
383 				data >>= 8;
384 			}
385 		}
386 	}
387 
388 	return 0;
389 }
390 
391 /* Write a single byte of data to the i2c bus */
392 static int brcmstb_i2c_write_data_byte(struct brcmstb_i2c_dev *dev,
393 				       u8 *buf, unsigned int nak_expected)
394 {
395 	enum bsc_xfer_cmd cmd = nak_expected ? CMD_WR : CMD_WR_NOACK;
396 
397 	bsc_writel(dev, 1, cnt_reg);
398 	bsc_writel(dev, *buf, data_in);
399 
400 	return brcmstb_send_i2c_cmd(dev, cmd);
401 }
402 
403 /* Send i2c address */
404 static int brcmstb_i2c_do_addr(struct brcmstb_i2c_dev *dev,
405 			       struct i2c_msg *msg)
406 {
407 	unsigned char addr;
408 
409 	if (msg->flags & I2C_M_TEN) {
410 		/* First byte is 11110XX0 where XX is upper 2 bits */
411 		addr = 0xF0 | ((msg->addr & 0x300) >> 7);
412 		bsc_writel(dev, addr, chip_address);
413 
414 		/* Second byte is the remaining 8 bits */
415 		addr = msg->addr & 0xFF;
416 		if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
417 			return -EREMOTEIO;
418 
419 		if (msg->flags & I2C_M_RD) {
420 			/* For read, send restart without stop condition */
421 			brcmstb_set_i2c_start_stop(dev, COND_RESTART
422 						   | COND_NOSTOP);
423 			/* Then re-send the first byte with the read bit set */
424 			addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
425 			if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
426 				return -EREMOTEIO;
427 
428 		}
429 	} else {
430 		addr = msg->addr << 1;
431 		if (msg->flags & I2C_M_RD)
432 			addr |= 1;
433 
434 		bsc_writel(dev, addr, chip_address);
435 	}
436 
437 	return 0;
438 }
439 
440 /* Master transfer function */
441 static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
442 			    struct i2c_msg msgs[], int num)
443 {
444 	struct brcmstb_i2c_dev *dev = i2c_get_adapdata(adapter);
445 	struct i2c_msg *pmsg;
446 	int rc = 0;
447 	int i;
448 	int bytes_to_xfer;
449 	u8 *tmp_buf;
450 	int len = 0;
451 
452 	if (dev->is_suspended)
453 		return -EBUSY;
454 
455 	/* Loop through all messages */
456 	for (i = 0; i < num; i++) {
457 		pmsg = &msgs[i];
458 		len = pmsg->len;
459 		tmp_buf = pmsg->buf;
460 
461 		dev_dbg(dev->device,
462 			"msg# %d/%d flg %x buf %x len %d\n", i,
463 			num - 1, pmsg->flags,
464 			pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
465 
466 		if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
467 			brcmstb_set_i2c_start_stop(dev, ~(COND_START_STOP));
468 		else
469 			brcmstb_set_i2c_start_stop(dev,
470 						   COND_RESTART | COND_NOSTOP);
471 
472 		/* Send slave address */
473 		if (!(pmsg->flags & I2C_M_NOSTART)) {
474 			rc = brcmstb_i2c_do_addr(dev, pmsg);
475 			if (rc < 0) {
476 				dev_dbg(dev->device,
477 					"NACK for addr %2.2x msg#%d rc = %d\n",
478 					pmsg->addr, i, rc);
479 				goto out;
480 			}
481 		}
482 
483 		/* Perform data transfer */
484 		while (len) {
485 			bytes_to_xfer = min(len, N_DATA_BYTES);
486 
487 			if (len <= N_DATA_BYTES && i == (num - 1))
488 				brcmstb_set_i2c_start_stop(dev,
489 							   ~(COND_START_STOP));
490 
491 			rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
492 						       bytes_to_xfer, pmsg);
493 			if (rc < 0)
494 				goto out;
495 
496 			len -=  bytes_to_xfer;
497 			tmp_buf += bytes_to_xfer;
498 		}
499 	}
500 
501 	rc = num;
502 out:
503 	return rc;
504 
505 }
506 
507 static u32 brcmstb_i2c_functionality(struct i2c_adapter *adap)
508 {
509 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR
510 		| I2C_FUNC_NOSTART | I2C_FUNC_PROTOCOL_MANGLING;
511 }
512 
513 static const struct i2c_algorithm brcmstb_i2c_algo = {
514 	.master_xfer = brcmstb_i2c_xfer,
515 	.functionality = brcmstb_i2c_functionality,
516 };
517 
518 static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev)
519 {
520 	int i = 0, num_speeds = ARRAY_SIZE(bsc_clk);
521 	u32 clk_freq_hz = dev->clk_freq_hz;
522 
523 	for (i = 0; i < num_speeds; i++) {
524 		if (bsc_clk[i].hz == clk_freq_hz) {
525 			dev->bsc_regmap->ctl_reg &= ~(BSC_CTL_REG_SCL_SEL_MASK
526 						| BSC_CTL_REG_DIV_CLK_MASK);
527 			dev->bsc_regmap->ctl_reg |= (bsc_clk[i].scl_mask |
528 						     bsc_clk[i].div_mask);
529 			bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
530 			break;
531 		}
532 	}
533 
534 	/* in case we did not get find a valid speed */
535 	if (i == num_speeds) {
536 		i = (bsc_readl(dev, ctl_reg) & BSC_CTL_REG_SCL_SEL_MASK) >>
537 			BSC_CTL_REG_SCL_SEL_SHIFT;
538 		dev_warn(dev->device, "leaving current clock-frequency @ %dHz\n",
539 			bsc_clk[i].hz);
540 	}
541 }
542 
543 static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev)
544 {
545 	/* 4 byte data register */
546 	dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;
547 	bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg);
548 	/* set bus speed */
549 	brcmstb_i2c_set_bus_speed(dev);
550 }
551 
552 static int brcmstb_i2c_probe(struct platform_device *pdev)
553 {
554 	int rc = 0;
555 	struct brcmstb_i2c_dev *dev;
556 	struct i2c_adapter *adap;
557 	struct resource *iomem;
558 	const char *int_name;
559 
560 	/* Allocate memory for private data structure */
561 	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
562 	if (!dev)
563 		return -ENOMEM;
564 
565 	dev->bsc_regmap = devm_kzalloc(&pdev->dev, sizeof(struct bsc_regs *),
566 				       GFP_KERNEL);
567 	if (!dev->bsc_regmap)
568 		return -ENOMEM;
569 
570 	platform_set_drvdata(pdev, dev);
571 	dev->device = &pdev->dev;
572 	init_completion(&dev->done);
573 
574 	/* Map hardware registers */
575 	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
576 	dev->base = devm_ioremap_resource(dev->device, iomem);
577 	if (IS_ERR(dev->base)) {
578 		rc = -ENOMEM;
579 		goto probe_errorout;
580 	}
581 
582 	rc = of_property_read_string(dev->device->of_node, "interrupt-names",
583 				     &int_name);
584 	if (rc < 0)
585 		int_name = NULL;
586 
587 	/* Get the interrupt number */
588 	dev->irq = platform_get_irq(pdev, 0);
589 
590 	/* disable the bsc interrupt line */
591 	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
592 
593 	/* register the ISR handler */
594 	rc = devm_request_irq(&pdev->dev, dev->irq, brcmstb_i2c_isr,
595 			      IRQF_SHARED,
596 			      int_name ? int_name : pdev->name,
597 			      dev);
598 
599 	if (rc) {
600 		dev_dbg(dev->device, "falling back to polling mode");
601 		dev->irq = -1;
602 	}
603 
604 	if (of_property_read_u32(dev->device->of_node,
605 				 "clock-frequency", &dev->clk_freq_hz)) {
606 		dev_warn(dev->device, "setting clock-frequency@%dHz\n",
607 			 bsc_clk[0].hz);
608 		dev->clk_freq_hz = bsc_clk[0].hz;
609 	}
610 
611 	brcmstb_i2c_set_bsc_reg_defaults(dev);
612 
613 	/* Add the i2c adapter */
614 	adap = &dev->adapter;
615 	i2c_set_adapdata(adap, dev);
616 	adap->owner = THIS_MODULE;
617 	strlcpy(adap->name, "Broadcom STB : ", sizeof(adap->name));
618 	if (int_name)
619 		strlcat(adap->name, int_name, sizeof(adap->name));
620 	adap->algo = &brcmstb_i2c_algo;
621 	adap->dev.parent = &pdev->dev;
622 	adap->dev.of_node = pdev->dev.of_node;
623 	rc = i2c_add_adapter(adap);
624 	if (rc) {
625 		dev_err(dev->device, "failed to add adapter\n");
626 		goto probe_errorout;
627 	}
628 
629 	dev_info(dev->device, "%s@%dhz registered in %s mode\n",
630 		 int_name ? int_name : " ", dev->clk_freq_hz,
631 		 (dev->irq >= 0) ? "interrupt" : "polling");
632 
633 	return 0;
634 
635 probe_errorout:
636 	return rc;
637 }
638 
639 static int brcmstb_i2c_remove(struct platform_device *pdev)
640 {
641 	struct brcmstb_i2c_dev *dev = platform_get_drvdata(pdev);
642 
643 	i2c_del_adapter(&dev->adapter);
644 	return 0;
645 }
646 
647 #ifdef CONFIG_PM_SLEEP
648 static int brcmstb_i2c_suspend(struct device *dev)
649 {
650 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
651 
652 	i2c_lock_adapter(&i2c_dev->adapter);
653 	i2c_dev->is_suspended = true;
654 	i2c_unlock_adapter(&i2c_dev->adapter);
655 
656 	return 0;
657 }
658 
659 static int brcmstb_i2c_resume(struct device *dev)
660 {
661 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
662 
663 	i2c_lock_adapter(&i2c_dev->adapter);
664 	brcmstb_i2c_set_bsc_reg_defaults(i2c_dev);
665 	i2c_dev->is_suspended = false;
666 	i2c_unlock_adapter(&i2c_dev->adapter);
667 
668 	return 0;
669 }
670 #endif
671 
672 static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend,
673 			 brcmstb_i2c_resume);
674 
675 static const struct of_device_id brcmstb_i2c_of_match[] = {
676 	{.compatible = "brcm,brcmstb-i2c"},
677 	{},
678 };
679 MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);
680 
681 static struct platform_driver brcmstb_i2c_driver = {
682 	.driver = {
683 		   .name = "brcmstb-i2c",
684 		   .of_match_table = brcmstb_i2c_of_match,
685 		   .pm = &brcmstb_i2c_pm,
686 		   },
687 	.probe = brcmstb_i2c_probe,
688 	.remove = brcmstb_i2c_remove,
689 };
690 module_platform_driver(brcmstb_i2c_driver);
691 
692 MODULE_AUTHOR("Kamal Dasu <kdasu@broadcom.com>");
693 MODULE_DESCRIPTION("Broadcom Settop I2C Driver");
694 MODULE_LICENSE("GPL v2");
695