xref: /openbmc/linux/drivers/i2c/busses/i2c-brcmstb.c (revision 023e41632e065d49bcbe31b3c4b336217f96a271)
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 
29 /*
30  * PER_I2C/BSC count register mask depends on 1 byte/4 byte data register
31  * size. Cable modem and DSL SoCs with Peripheral i2c cores use 1 byte per
32  * data register whereas STB SoCs use 4 byte per data register transfer,
33  * account for this difference in total count per transaction and mask to
34  * use.
35  */
36 #define BSC_CNT_REG1_MASK(nb)	(nb == 1 ? GENMASK(3, 0) : GENMASK(5, 0))
37 #define BSC_CNT_REG1_SHIFT	0
38 
39 /* BSC CTL register field definitions */
40 #define BSC_CTL_REG_DTF_MASK				0x00000003
41 #define BSC_CTL_REG_SCL_SEL_MASK			0x00000030
42 #define BSC_CTL_REG_SCL_SEL_SHIFT			4
43 #define BSC_CTL_REG_INT_EN_MASK				0x00000040
44 #define BSC_CTL_REG_INT_EN_SHIFT			6
45 #define BSC_CTL_REG_DIV_CLK_MASK			0x00000080
46 
47 /* BSC_IIC_ENABLE r/w enable and interrupt field definitions */
48 #define BSC_IIC_EN_RESTART_MASK				0x00000040
49 #define BSC_IIC_EN_NOSTART_MASK				0x00000020
50 #define BSC_IIC_EN_NOSTOP_MASK				0x00000010
51 #define BSC_IIC_EN_NOACK_MASK				0x00000004
52 #define BSC_IIC_EN_INTRP_MASK				0x00000002
53 #define BSC_IIC_EN_ENABLE_MASK				0x00000001
54 
55 /* BSC_CTLHI control register field definitions */
56 #define BSC_CTLHI_REG_INPUT_SWITCHING_LEVEL_MASK	0x00000080
57 #define BSC_CTLHI_REG_DATAREG_SIZE_MASK			0x00000040
58 #define BSC_CTLHI_REG_IGNORE_ACK_MASK			0x00000002
59 #define BSC_CTLHI_REG_WAIT_DIS_MASK			0x00000001
60 
61 #define I2C_TIMEOUT					100 /* msecs */
62 
63 /* Condition mask used for non combined transfer */
64 #define COND_RESTART		BSC_IIC_EN_RESTART_MASK
65 #define COND_NOSTART		BSC_IIC_EN_NOSTART_MASK
66 #define COND_NOSTOP		BSC_IIC_EN_NOSTOP_MASK
67 #define COND_START_STOP		(COND_RESTART | COND_NOSTART | COND_NOSTOP)
68 
69 /* BSC data transfer direction */
70 #define DTF_WR_MASK		0x00000000
71 #define DTF_RD_MASK		0x00000001
72 /* BSC data transfer direction combined format */
73 #define DTF_RD_WR_MASK		0x00000002
74 #define DTF_WR_RD_MASK		0x00000003
75 
76 #define INT_ENABLE		true
77 #define INT_DISABLE		false
78 
79 /* BSC block register map structure to cache fields to be written */
80 struct bsc_regs {
81 	u32	chip_address;           /* slave address */
82 	u32	data_in[N_DATA_REGS];   /* tx data buffer*/
83 	u32	cnt_reg;		/* rx/tx data length */
84 	u32	ctl_reg;		/* control register */
85 	u32	iic_enable;		/* xfer enable and status */
86 	u32	data_out[N_DATA_REGS];  /* rx data buffer */
87 	u32	ctlhi_reg;		/* more control fields */
88 	u32	scl_param;		/* reserved */
89 };
90 
91 struct bsc_clk_param {
92 	u32 hz;
93 	u32 scl_mask;
94 	u32 div_mask;
95 };
96 
97 enum bsc_xfer_cmd {
98 	CMD_WR,
99 	CMD_RD,
100 	CMD_WR_NOACK,
101 	CMD_RD_NOACK,
102 };
103 
104 static char const *cmd_string[] = {
105 	[CMD_WR] = "WR",
106 	[CMD_RD] = "RD",
107 	[CMD_WR_NOACK] = "WR NOACK",
108 	[CMD_RD_NOACK] = "RD NOACK",
109 };
110 
111 enum bus_speeds {
112 	SPD_375K,
113 	SPD_390K,
114 	SPD_187K,
115 	SPD_200K,
116 	SPD_93K,
117 	SPD_97K,
118 	SPD_46K,
119 	SPD_50K
120 };
121 
122 static const struct bsc_clk_param bsc_clk[] = {
123 	[SPD_375K] = {
124 		.hz = 375000,
125 		.scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
126 		.div_mask = 0
127 	},
128 	[SPD_390K] = {
129 		.hz = 390000,
130 		.scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
131 		.div_mask = 0
132 	},
133 	[SPD_187K] = {
134 		.hz = 187500,
135 		.scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
136 		.div_mask = 0
137 	},
138 	[SPD_200K] = {
139 		.hz = 200000,
140 		.scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
141 		.div_mask = 0
142 	},
143 	[SPD_93K]  = {
144 		.hz = 93750,
145 		.scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
146 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
147 	},
148 	[SPD_97K]  = {
149 		.hz = 97500,
150 		.scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
151 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
152 	},
153 	[SPD_46K]  = {
154 		.hz = 46875,
155 		.scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
156 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
157 	},
158 	[SPD_50K]  = {
159 		.hz = 50000,
160 		.scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
161 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
162 	}
163 };
164 
165 struct brcmstb_i2c_dev {
166 	struct device *device;
167 	void __iomem *base;
168 	void __iomem *irq_base;
169 	int irq;
170 	struct bsc_regs *bsc_regmap;
171 	struct i2c_adapter adapter;
172 	struct completion done;
173 	u32 clk_freq_hz;
174 	int data_regsz;
175 };
176 
177 /* register accessors for both be and le cpu arch */
178 #ifdef CONFIG_CPU_BIG_ENDIAN
179 #define __bsc_readl(_reg) ioread32be(_reg)
180 #define __bsc_writel(_val, _reg) iowrite32be(_val, _reg)
181 #else
182 #define __bsc_readl(_reg) ioread32(_reg)
183 #define __bsc_writel(_val, _reg) iowrite32(_val, _reg)
184 #endif
185 
186 #define bsc_readl(_dev, _reg)						\
187 	__bsc_readl(_dev->base + offsetof(struct bsc_regs, _reg))
188 
189 #define bsc_writel(_dev, _val, _reg)					\
190 	__bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg))
191 
192 static inline int brcmstb_i2c_get_xfersz(struct brcmstb_i2c_dev *dev)
193 {
194 	return (N_DATA_REGS * dev->data_regsz);
195 }
196 
197 static inline int brcmstb_i2c_get_data_regsz(struct brcmstb_i2c_dev *dev)
198 {
199 	return dev->data_regsz;
200 }
201 
202 static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev,
203 					   bool int_en)
204 {
205 
206 	if (int_en)
207 		/* Enable BSC  CTL interrupt line */
208 		dev->bsc_regmap->ctl_reg |= BSC_CTL_REG_INT_EN_MASK;
209 	else
210 		/* Disable BSC CTL interrupt line */
211 		dev->bsc_regmap->ctl_reg &= ~BSC_CTL_REG_INT_EN_MASK;
212 
213 	barrier();
214 	bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
215 }
216 
217 static irqreturn_t brcmstb_i2c_isr(int irq, void *devid)
218 {
219 	struct brcmstb_i2c_dev *dev = devid;
220 	u32 status_bsc_ctl = bsc_readl(dev, ctl_reg);
221 	u32 status_iic_intrp = bsc_readl(dev, iic_enable);
222 
223 	dev_dbg(dev->device, "isr CTL_REG %x IIC_EN %x\n",
224 		status_bsc_ctl, status_iic_intrp);
225 
226 	if (!(status_bsc_ctl & BSC_CTL_REG_INT_EN_MASK))
227 		return IRQ_NONE;
228 
229 	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
230 	complete(&dev->done);
231 
232 	dev_dbg(dev->device, "isr handled");
233 	return IRQ_HANDLED;
234 }
235 
236 /* Wait for device to be ready */
237 static int brcmstb_i2c_wait_if_busy(struct brcmstb_i2c_dev *dev)
238 {
239 	unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
240 
241 	while ((bsc_readl(dev, iic_enable) & BSC_IIC_EN_INTRP_MASK)) {
242 		if (time_after(jiffies, timeout))
243 			return -ETIMEDOUT;
244 		cpu_relax();
245 	}
246 	return 0;
247 }
248 
249 /* i2c xfer completion function, handles both irq and polling mode */
250 static int brcmstb_i2c_wait_for_completion(struct brcmstb_i2c_dev *dev)
251 {
252 	int ret = 0;
253 	unsigned long timeout = msecs_to_jiffies(I2C_TIMEOUT);
254 
255 	if (dev->irq >= 0) {
256 		if (!wait_for_completion_timeout(&dev->done, timeout))
257 			ret = -ETIMEDOUT;
258 	} else {
259 		/* we are in polling mode */
260 		u32 bsc_intrp;
261 		unsigned long time_left = jiffies + timeout;
262 
263 		do {
264 			bsc_intrp = bsc_readl(dev, iic_enable) &
265 				BSC_IIC_EN_INTRP_MASK;
266 			if (time_after(jiffies, time_left)) {
267 				ret = -ETIMEDOUT;
268 				break;
269 			}
270 			cpu_relax();
271 		} while (!bsc_intrp);
272 	}
273 
274 	if (dev->irq < 0 || ret == -ETIMEDOUT)
275 		brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
276 
277 	return ret;
278 }
279 
280 /* Set xfer START/STOP conditions for subsequent transfer */
281 static void brcmstb_set_i2c_start_stop(struct brcmstb_i2c_dev *dev,
282 				       u32 cond_flag)
283 {
284 	u32 regval = dev->bsc_regmap->iic_enable;
285 
286 	dev->bsc_regmap->iic_enable = (regval & ~COND_START_STOP) | cond_flag;
287 }
288 
289 /* Send I2C request check completion */
290 static int brcmstb_send_i2c_cmd(struct brcmstb_i2c_dev *dev,
291 				enum bsc_xfer_cmd cmd)
292 {
293 	int rc = 0;
294 	struct bsc_regs *pi2creg = dev->bsc_regmap;
295 
296 	/* Make sure the hardware is ready */
297 	rc = brcmstb_i2c_wait_if_busy(dev);
298 	if (rc < 0)
299 		return rc;
300 
301 	/* only if we are in interrupt mode */
302 	if (dev->irq >= 0)
303 		reinit_completion(&dev->done);
304 
305 	/* enable BSC CTL interrupt line */
306 	brcmstb_i2c_enable_disable_irq(dev, INT_ENABLE);
307 
308 	/* initiate transfer by setting iic_enable */
309 	pi2creg->iic_enable |= BSC_IIC_EN_ENABLE_MASK;
310 	bsc_writel(dev, pi2creg->iic_enable, iic_enable);
311 
312 	/* Wait for transaction to finish or timeout */
313 	rc = brcmstb_i2c_wait_for_completion(dev);
314 	if (rc) {
315 		dev_dbg(dev->device, "intr timeout for cmd %s\n",
316 			cmd_string[cmd]);
317 		goto cmd_out;
318 	}
319 
320 	if ((CMD_RD || CMD_WR) &&
321 	    bsc_readl(dev, iic_enable) & BSC_IIC_EN_NOACK_MASK) {
322 		rc = -EREMOTEIO;
323 		dev_dbg(dev->device, "controller received NOACK intr for %s\n",
324 			cmd_string[cmd]);
325 	}
326 
327 cmd_out:
328 	bsc_writel(dev, 0, cnt_reg);
329 	bsc_writel(dev, 0, iic_enable);
330 
331 	return rc;
332 }
333 
334 /* Actual data transfer through the BSC master */
335 static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
336 				     u8 *buf, unsigned int len,
337 				     struct i2c_msg *pmsg)
338 {
339 	int cnt, byte, i, rc;
340 	enum bsc_xfer_cmd cmd;
341 	u32 ctl_reg;
342 	struct bsc_regs *pi2creg = dev->bsc_regmap;
343 	int no_ack = pmsg->flags & I2C_M_IGNORE_NAK;
344 	int data_regsz = brcmstb_i2c_get_data_regsz(dev);
345 
346 	/* see if the transaction needs to check NACK conditions */
347 	if (no_ack) {
348 		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK
349 			: CMD_WR_NOACK;
350 		pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK;
351 	} else {
352 		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD : CMD_WR;
353 		pi2creg->ctlhi_reg &= ~BSC_CTLHI_REG_IGNORE_ACK_MASK;
354 	}
355 	bsc_writel(dev, pi2creg->ctlhi_reg, ctlhi_reg);
356 
357 	/* set data transfer direction */
358 	ctl_reg = pi2creg->ctl_reg & ~BSC_CTL_REG_DTF_MASK;
359 	if (cmd == CMD_WR || cmd == CMD_WR_NOACK)
360 		pi2creg->ctl_reg = ctl_reg | DTF_WR_MASK;
361 	else
362 		pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK;
363 
364 	/* set the read/write length */
365 	bsc_writel(dev, BSC_CNT_REG1_MASK(data_regsz) &
366 		   (len << BSC_CNT_REG1_SHIFT), cnt_reg);
367 
368 	/* Write data into data_in register */
369 
370 	if (cmd == CMD_WR || cmd == CMD_WR_NOACK) {
371 		for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
372 			u32 word = 0;
373 
374 			for (byte = 0; byte < data_regsz; byte++) {
375 				word >>= BITS_PER_BYTE;
376 				if ((cnt + byte) < len)
377 					word |= buf[cnt + byte] <<
378 					(BITS_PER_BYTE * (data_regsz - 1));
379 			}
380 			bsc_writel(dev, word, data_in[i]);
381 		}
382 	}
383 
384 	/* Initiate xfer, the function will return on completion */
385 	rc = brcmstb_send_i2c_cmd(dev, cmd);
386 
387 	if (rc != 0) {
388 		dev_dbg(dev->device, "%s failure", cmd_string[cmd]);
389 		return rc;
390 	}
391 
392 	/* Read data from data_out register */
393 	if (cmd == CMD_RD || cmd == CMD_RD_NOACK) {
394 		for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
395 			u32 data = bsc_readl(dev, data_out[i]);
396 
397 			for (byte = 0; byte < data_regsz &&
398 				     (byte + cnt) < len; byte++) {
399 				buf[cnt + byte] = data & 0xff;
400 				data >>= BITS_PER_BYTE;
401 			}
402 		}
403 	}
404 
405 	return 0;
406 }
407 
408 /* Write a single byte of data to the i2c bus */
409 static int brcmstb_i2c_write_data_byte(struct brcmstb_i2c_dev *dev,
410 				       u8 *buf, unsigned int nak_expected)
411 {
412 	enum bsc_xfer_cmd cmd = nak_expected ? CMD_WR : CMD_WR_NOACK;
413 
414 	bsc_writel(dev, 1, cnt_reg);
415 	bsc_writel(dev, *buf, data_in);
416 
417 	return brcmstb_send_i2c_cmd(dev, cmd);
418 }
419 
420 /* Send i2c address */
421 static int brcmstb_i2c_do_addr(struct brcmstb_i2c_dev *dev,
422 			       struct i2c_msg *msg)
423 {
424 	unsigned char addr;
425 
426 	if (msg->flags & I2C_M_TEN) {
427 		/* First byte is 11110XX0 where XX is upper 2 bits */
428 		addr = 0xF0 | ((msg->addr & 0x300) >> 7);
429 		bsc_writel(dev, addr, chip_address);
430 
431 		/* Second byte is the remaining 8 bits */
432 		addr = msg->addr & 0xFF;
433 		if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
434 			return -EREMOTEIO;
435 
436 		if (msg->flags & I2C_M_RD) {
437 			/* For read, send restart without stop condition */
438 			brcmstb_set_i2c_start_stop(dev, COND_RESTART
439 						   | COND_NOSTOP);
440 			/* Then re-send the first byte with the read bit set */
441 			addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
442 			if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
443 				return -EREMOTEIO;
444 
445 		}
446 	} else {
447 		addr = i2c_8bit_addr_from_msg(msg);
448 
449 		bsc_writel(dev, addr, chip_address);
450 	}
451 
452 	return 0;
453 }
454 
455 /* Master transfer function */
456 static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
457 			    struct i2c_msg msgs[], int num)
458 {
459 	struct brcmstb_i2c_dev *dev = i2c_get_adapdata(adapter);
460 	struct i2c_msg *pmsg;
461 	int rc = 0;
462 	int i;
463 	int bytes_to_xfer;
464 	u8 *tmp_buf;
465 	int len = 0;
466 	int xfersz = brcmstb_i2c_get_xfersz(dev);
467 	u32 cond, cond_per_msg;
468 
469 	/* Loop through all messages */
470 	for (i = 0; i < num; i++) {
471 		pmsg = &msgs[i];
472 		len = pmsg->len;
473 		tmp_buf = pmsg->buf;
474 
475 		dev_dbg(dev->device,
476 			"msg# %d/%d flg %x buf %x len %d\n", i,
477 			num - 1, pmsg->flags,
478 			pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
479 
480 		if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
481 			cond = ~COND_START_STOP;
482 		else
483 			cond = COND_RESTART | COND_NOSTOP;
484 
485 		brcmstb_set_i2c_start_stop(dev, cond);
486 
487 		/* Send slave address */
488 		if (!(pmsg->flags & I2C_M_NOSTART)) {
489 			rc = brcmstb_i2c_do_addr(dev, pmsg);
490 			if (rc < 0) {
491 				dev_dbg(dev->device,
492 					"NACK for addr %2.2x msg#%d rc = %d\n",
493 					pmsg->addr, i, rc);
494 				goto out;
495 			}
496 		}
497 
498 		cond_per_msg = cond;
499 
500 		/* Perform data transfer */
501 		while (len) {
502 			bytes_to_xfer = min(len, xfersz);
503 
504 			if (len <= xfersz) {
505 				if (i == (num - 1))
506 					cond_per_msg = cond_per_msg &
507 						~(COND_RESTART | COND_NOSTOP);
508 				else
509 					cond_per_msg = cond;
510 			} else {
511 				cond_per_msg = (cond_per_msg & ~COND_RESTART) |
512 					COND_NOSTOP;
513 			}
514 
515 			brcmstb_set_i2c_start_stop(dev, cond_per_msg);
516 
517 			rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
518 						       bytes_to_xfer, pmsg);
519 			if (rc < 0)
520 				goto out;
521 
522 			len -=  bytes_to_xfer;
523 			tmp_buf += bytes_to_xfer;
524 
525 			cond_per_msg = COND_NOSTART | COND_NOSTOP;
526 		}
527 	}
528 
529 	rc = num;
530 out:
531 	return rc;
532 
533 }
534 
535 static u32 brcmstb_i2c_functionality(struct i2c_adapter *adap)
536 {
537 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR
538 		| I2C_FUNC_NOSTART | I2C_FUNC_PROTOCOL_MANGLING;
539 }
540 
541 static const struct i2c_algorithm brcmstb_i2c_algo = {
542 	.master_xfer = brcmstb_i2c_xfer,
543 	.functionality = brcmstb_i2c_functionality,
544 };
545 
546 static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev)
547 {
548 	int i = 0, num_speeds = ARRAY_SIZE(bsc_clk);
549 	u32 clk_freq_hz = dev->clk_freq_hz;
550 
551 	for (i = 0; i < num_speeds; i++) {
552 		if (bsc_clk[i].hz == clk_freq_hz) {
553 			dev->bsc_regmap->ctl_reg &= ~(BSC_CTL_REG_SCL_SEL_MASK
554 						| BSC_CTL_REG_DIV_CLK_MASK);
555 			dev->bsc_regmap->ctl_reg |= (bsc_clk[i].scl_mask |
556 						     bsc_clk[i].div_mask);
557 			bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
558 			break;
559 		}
560 	}
561 
562 	/* in case we did not get find a valid speed */
563 	if (i == num_speeds) {
564 		i = (bsc_readl(dev, ctl_reg) & BSC_CTL_REG_SCL_SEL_MASK) >>
565 			BSC_CTL_REG_SCL_SEL_SHIFT;
566 		dev_warn(dev->device, "leaving current clock-frequency @ %dHz\n",
567 			bsc_clk[i].hz);
568 	}
569 }
570 
571 static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev)
572 {
573 	if (brcmstb_i2c_get_data_regsz(dev) == sizeof(u32))
574 		/* set 4 byte data in/out xfers  */
575 		dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;
576 	else
577 		dev->bsc_regmap->ctlhi_reg &= ~BSC_CTLHI_REG_DATAREG_SIZE_MASK;
578 
579 	bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg);
580 	/* set bus speed */
581 	brcmstb_i2c_set_bus_speed(dev);
582 }
583 
584 static int brcmstb_i2c_probe(struct platform_device *pdev)
585 {
586 	int rc = 0;
587 	struct brcmstb_i2c_dev *dev;
588 	struct i2c_adapter *adap;
589 	struct resource *iomem;
590 	const char *int_name;
591 
592 	/* Allocate memory for private data structure */
593 	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
594 	if (!dev)
595 		return -ENOMEM;
596 
597 	dev->bsc_regmap = devm_kzalloc(&pdev->dev, sizeof(*dev->bsc_regmap), GFP_KERNEL);
598 	if (!dev->bsc_regmap)
599 		return -ENOMEM;
600 
601 	platform_set_drvdata(pdev, dev);
602 	dev->device = &pdev->dev;
603 	init_completion(&dev->done);
604 
605 	/* Map hardware registers */
606 	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
607 	dev->base = devm_ioremap_resource(dev->device, iomem);
608 	if (IS_ERR(dev->base)) {
609 		rc = -ENOMEM;
610 		goto probe_errorout;
611 	}
612 
613 	rc = of_property_read_string(dev->device->of_node, "interrupt-names",
614 				     &int_name);
615 	if (rc < 0)
616 		int_name = NULL;
617 
618 	/* Get the interrupt number */
619 	dev->irq = platform_get_irq(pdev, 0);
620 
621 	/* disable the bsc interrupt line */
622 	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
623 
624 	/* register the ISR handler */
625 	rc = devm_request_irq(&pdev->dev, dev->irq, brcmstb_i2c_isr,
626 			      IRQF_SHARED,
627 			      int_name ? int_name : pdev->name,
628 			      dev);
629 
630 	if (rc) {
631 		dev_dbg(dev->device, "falling back to polling mode");
632 		dev->irq = -1;
633 	}
634 
635 	if (of_property_read_u32(dev->device->of_node,
636 				 "clock-frequency", &dev->clk_freq_hz)) {
637 		dev_warn(dev->device, "setting clock-frequency@%dHz\n",
638 			 bsc_clk[0].hz);
639 		dev->clk_freq_hz = bsc_clk[0].hz;
640 	}
641 
642 	/* set the data in/out register size for compatible SoCs */
643 	if (of_device_is_compatible(dev->device->of_node,
644 				    "brcmstb,brcmper-i2c"))
645 		dev->data_regsz = sizeof(u8);
646 	else
647 		dev->data_regsz = sizeof(u32);
648 
649 	brcmstb_i2c_set_bsc_reg_defaults(dev);
650 
651 	/* Add the i2c adapter */
652 	adap = &dev->adapter;
653 	i2c_set_adapdata(adap, dev);
654 	adap->owner = THIS_MODULE;
655 	strlcpy(adap->name, "Broadcom STB : ", sizeof(adap->name));
656 	if (int_name)
657 		strlcat(adap->name, int_name, sizeof(adap->name));
658 	adap->algo = &brcmstb_i2c_algo;
659 	adap->dev.parent = &pdev->dev;
660 	adap->dev.of_node = pdev->dev.of_node;
661 	rc = i2c_add_adapter(adap);
662 	if (rc)
663 		goto probe_errorout;
664 
665 	dev_info(dev->device, "%s@%dhz registered in %s mode\n",
666 		 int_name ? int_name : " ", dev->clk_freq_hz,
667 		 (dev->irq >= 0) ? "interrupt" : "polling");
668 
669 	return 0;
670 
671 probe_errorout:
672 	return rc;
673 }
674 
675 static int brcmstb_i2c_remove(struct platform_device *pdev)
676 {
677 	struct brcmstb_i2c_dev *dev = platform_get_drvdata(pdev);
678 
679 	i2c_del_adapter(&dev->adapter);
680 	return 0;
681 }
682 
683 #ifdef CONFIG_PM_SLEEP
684 static int brcmstb_i2c_suspend(struct device *dev)
685 {
686 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
687 
688 	i2c_mark_adapter_suspended(&i2c_dev->adapter);
689 	return 0;
690 }
691 
692 static int brcmstb_i2c_resume(struct device *dev)
693 {
694 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
695 
696 	brcmstb_i2c_set_bsc_reg_defaults(i2c_dev);
697 	i2c_mark_adapter_resumed(&i2c_dev->adapter);
698 
699 	return 0;
700 }
701 #endif
702 
703 static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend,
704 			 brcmstb_i2c_resume);
705 
706 static const struct of_device_id brcmstb_i2c_of_match[] = {
707 	{.compatible = "brcm,brcmstb-i2c"},
708 	{.compatible = "brcm,brcmper-i2c"},
709 	{},
710 };
711 MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);
712 
713 static struct platform_driver brcmstb_i2c_driver = {
714 	.driver = {
715 		   .name = "brcmstb-i2c",
716 		   .of_match_table = brcmstb_i2c_of_match,
717 		   .pm = &brcmstb_i2c_pm,
718 		   },
719 	.probe = brcmstb_i2c_probe,
720 	.remove = brcmstb_i2c_remove,
721 };
722 module_platform_driver(brcmstb_i2c_driver);
723 
724 MODULE_AUTHOR("Kamal Dasu <kdasu@broadcom.com>");
725 MODULE_DESCRIPTION("Broadcom Settop I2C Driver");
726 MODULE_LICENSE("GPL v2");
727