xref: /openbmc/linux/drivers/i2c/busses/i2c-brcmstb.c (revision 4aea96f4)
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 	bool is_suspended;
174 	u32 clk_freq_hz;
175 	int data_regsz;
176 };
177 
178 /* register accessors for both be and le cpu arch */
179 #ifdef CONFIG_CPU_BIG_ENDIAN
180 #define __bsc_readl(_reg) ioread32be(_reg)
181 #define __bsc_writel(_val, _reg) iowrite32be(_val, _reg)
182 #else
183 #define __bsc_readl(_reg) ioread32(_reg)
184 #define __bsc_writel(_val, _reg) iowrite32(_val, _reg)
185 #endif
186 
187 #define bsc_readl(_dev, _reg)						\
188 	__bsc_readl(_dev->base + offsetof(struct bsc_regs, _reg))
189 
190 #define bsc_writel(_dev, _val, _reg)					\
191 	__bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg))
192 
193 static inline int brcmstb_i2c_get_xfersz(struct brcmstb_i2c_dev *dev)
194 {
195 	return (N_DATA_REGS * dev->data_regsz);
196 }
197 
198 static inline int brcmstb_i2c_get_data_regsz(struct brcmstb_i2c_dev *dev)
199 {
200 	return dev->data_regsz;
201 }
202 
203 static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev,
204 					   bool int_en)
205 {
206 
207 	if (int_en)
208 		/* Enable BSC  CTL interrupt line */
209 		dev->bsc_regmap->ctl_reg |= BSC_CTL_REG_INT_EN_MASK;
210 	else
211 		/* Disable BSC CTL interrupt line */
212 		dev->bsc_regmap->ctl_reg &= ~BSC_CTL_REG_INT_EN_MASK;
213 
214 	barrier();
215 	bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
216 }
217 
218 static irqreturn_t brcmstb_i2c_isr(int irq, void *devid)
219 {
220 	struct brcmstb_i2c_dev *dev = devid;
221 	u32 status_bsc_ctl = bsc_readl(dev, ctl_reg);
222 	u32 status_iic_intrp = bsc_readl(dev, iic_enable);
223 
224 	dev_dbg(dev->device, "isr CTL_REG %x IIC_EN %x\n",
225 		status_bsc_ctl, status_iic_intrp);
226 
227 	if (!(status_bsc_ctl & BSC_CTL_REG_INT_EN_MASK))
228 		return IRQ_NONE;
229 
230 	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
231 	complete(&dev->done);
232 
233 	dev_dbg(dev->device, "isr handled");
234 	return IRQ_HANDLED;
235 }
236 
237 /* Wait for device to be ready */
238 static int brcmstb_i2c_wait_if_busy(struct brcmstb_i2c_dev *dev)
239 {
240 	unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
241 
242 	while ((bsc_readl(dev, iic_enable) & BSC_IIC_EN_INTRP_MASK)) {
243 		if (time_after(jiffies, timeout))
244 			return -ETIMEDOUT;
245 		cpu_relax();
246 	}
247 	return 0;
248 }
249 
250 /* i2c xfer completion function, handles both irq and polling mode */
251 static int brcmstb_i2c_wait_for_completion(struct brcmstb_i2c_dev *dev)
252 {
253 	int ret = 0;
254 	unsigned long timeout = msecs_to_jiffies(I2C_TIMEOUT);
255 
256 	if (dev->irq >= 0) {
257 		if (!wait_for_completion_timeout(&dev->done, timeout))
258 			ret = -ETIMEDOUT;
259 	} else {
260 		/* we are in polling mode */
261 		u32 bsc_intrp;
262 		unsigned long time_left = jiffies + timeout;
263 
264 		do {
265 			bsc_intrp = bsc_readl(dev, iic_enable) &
266 				BSC_IIC_EN_INTRP_MASK;
267 			if (time_after(jiffies, time_left)) {
268 				ret = -ETIMEDOUT;
269 				break;
270 			}
271 			cpu_relax();
272 		} while (!bsc_intrp);
273 	}
274 
275 	if (dev->irq < 0 || ret == -ETIMEDOUT)
276 		brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
277 
278 	return ret;
279 }
280 
281 /* Set xfer START/STOP conditions for subsequent transfer */
282 static void brcmstb_set_i2c_start_stop(struct brcmstb_i2c_dev *dev,
283 				       u32 cond_flag)
284 {
285 	u32 regval = dev->bsc_regmap->iic_enable;
286 
287 	dev->bsc_regmap->iic_enable = (regval & ~COND_START_STOP) | cond_flag;
288 }
289 
290 /* Send I2C request check completion */
291 static int brcmstb_send_i2c_cmd(struct brcmstb_i2c_dev *dev,
292 				enum bsc_xfer_cmd cmd)
293 {
294 	int rc = 0;
295 	struct bsc_regs *pi2creg = dev->bsc_regmap;
296 
297 	/* Make sure the hardware is ready */
298 	rc = brcmstb_i2c_wait_if_busy(dev);
299 	if (rc < 0)
300 		return rc;
301 
302 	/* only if we are in interrupt mode */
303 	if (dev->irq >= 0)
304 		reinit_completion(&dev->done);
305 
306 	/* enable BSC CTL interrupt line */
307 	brcmstb_i2c_enable_disable_irq(dev, INT_ENABLE);
308 
309 	/* initiate transfer by setting iic_enable */
310 	pi2creg->iic_enable |= BSC_IIC_EN_ENABLE_MASK;
311 	bsc_writel(dev, pi2creg->iic_enable, iic_enable);
312 
313 	/* Wait for transaction to finish or timeout */
314 	rc = brcmstb_i2c_wait_for_completion(dev);
315 	if (rc) {
316 		dev_dbg(dev->device, "intr timeout for cmd %s\n",
317 			cmd_string[cmd]);
318 		goto cmd_out;
319 	}
320 
321 	if ((CMD_RD || CMD_WR) &&
322 	    bsc_readl(dev, iic_enable) & BSC_IIC_EN_NOACK_MASK) {
323 		rc = -EREMOTEIO;
324 		dev_dbg(dev->device, "controller received NOACK intr for %s\n",
325 			cmd_string[cmd]);
326 	}
327 
328 cmd_out:
329 	bsc_writel(dev, 0, cnt_reg);
330 	bsc_writel(dev, 0, iic_enable);
331 
332 	return rc;
333 }
334 
335 /* Actual data transfer through the BSC master */
336 static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
337 				     u8 *buf, unsigned int len,
338 				     struct i2c_msg *pmsg)
339 {
340 	int cnt, byte, i, rc;
341 	enum bsc_xfer_cmd cmd;
342 	u32 ctl_reg;
343 	struct bsc_regs *pi2creg = dev->bsc_regmap;
344 	int no_ack = pmsg->flags & I2C_M_IGNORE_NAK;
345 	int data_regsz = brcmstb_i2c_get_data_regsz(dev);
346 
347 	/* see if the transaction needs to check NACK conditions */
348 	if (no_ack) {
349 		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK
350 			: CMD_WR_NOACK;
351 		pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK;
352 	} else {
353 		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD : CMD_WR;
354 		pi2creg->ctlhi_reg &= ~BSC_CTLHI_REG_IGNORE_ACK_MASK;
355 	}
356 	bsc_writel(dev, pi2creg->ctlhi_reg, ctlhi_reg);
357 
358 	/* set data transfer direction */
359 	ctl_reg = pi2creg->ctl_reg & ~BSC_CTL_REG_DTF_MASK;
360 	if (cmd == CMD_WR || cmd == CMD_WR_NOACK)
361 		pi2creg->ctl_reg = ctl_reg | DTF_WR_MASK;
362 	else
363 		pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK;
364 
365 	/* set the read/write length */
366 	bsc_writel(dev, BSC_CNT_REG1_MASK(data_regsz) &
367 		   (len << BSC_CNT_REG1_SHIFT), cnt_reg);
368 
369 	/* Write data into data_in register */
370 
371 	if (cmd == CMD_WR || cmd == CMD_WR_NOACK) {
372 		for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
373 			u32 word = 0;
374 
375 			for (byte = 0; byte < data_regsz; byte++) {
376 				word >>= BITS_PER_BYTE;
377 				if ((cnt + byte) < len)
378 					word |= buf[cnt + byte] <<
379 					(BITS_PER_BYTE * (data_regsz - 1));
380 			}
381 			bsc_writel(dev, word, data_in[i]);
382 		}
383 	}
384 
385 	/* Initiate xfer, the function will return on completion */
386 	rc = brcmstb_send_i2c_cmd(dev, cmd);
387 
388 	if (rc != 0) {
389 		dev_dbg(dev->device, "%s failure", cmd_string[cmd]);
390 		return rc;
391 	}
392 
393 	/* Read data from data_out register */
394 	if (cmd == CMD_RD || cmd == CMD_RD_NOACK) {
395 		for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
396 			u32 data = bsc_readl(dev, data_out[i]);
397 
398 			for (byte = 0; byte < data_regsz &&
399 				     (byte + cnt) < len; byte++) {
400 				buf[cnt + byte] = data & 0xff;
401 				data >>= BITS_PER_BYTE;
402 			}
403 		}
404 	}
405 
406 	return 0;
407 }
408 
409 /* Write a single byte of data to the i2c bus */
410 static int brcmstb_i2c_write_data_byte(struct brcmstb_i2c_dev *dev,
411 				       u8 *buf, unsigned int nak_expected)
412 {
413 	enum bsc_xfer_cmd cmd = nak_expected ? CMD_WR : CMD_WR_NOACK;
414 
415 	bsc_writel(dev, 1, cnt_reg);
416 	bsc_writel(dev, *buf, data_in);
417 
418 	return brcmstb_send_i2c_cmd(dev, cmd);
419 }
420 
421 /* Send i2c address */
422 static int brcmstb_i2c_do_addr(struct brcmstb_i2c_dev *dev,
423 			       struct i2c_msg *msg)
424 {
425 	unsigned char addr;
426 
427 	if (msg->flags & I2C_M_TEN) {
428 		/* First byte is 11110XX0 where XX is upper 2 bits */
429 		addr = 0xF0 | ((msg->addr & 0x300) >> 7);
430 		bsc_writel(dev, addr, chip_address);
431 
432 		/* Second byte is the remaining 8 bits */
433 		addr = msg->addr & 0xFF;
434 		if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
435 			return -EREMOTEIO;
436 
437 		if (msg->flags & I2C_M_RD) {
438 			/* For read, send restart without stop condition */
439 			brcmstb_set_i2c_start_stop(dev, COND_RESTART
440 						   | COND_NOSTOP);
441 			/* Then re-send the first byte with the read bit set */
442 			addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
443 			if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
444 				return -EREMOTEIO;
445 
446 		}
447 	} else {
448 		addr = i2c_8bit_addr_from_msg(msg);
449 
450 		bsc_writel(dev, addr, chip_address);
451 	}
452 
453 	return 0;
454 }
455 
456 /* Master transfer function */
457 static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
458 			    struct i2c_msg msgs[], int num)
459 {
460 	struct brcmstb_i2c_dev *dev = i2c_get_adapdata(adapter);
461 	struct i2c_msg *pmsg;
462 	int rc = 0;
463 	int i;
464 	int bytes_to_xfer;
465 	u8 *tmp_buf;
466 	int len = 0;
467 	int xfersz = brcmstb_i2c_get_xfersz(dev);
468 	u32 cond, cond_per_msg;
469 
470 	if (dev->is_suspended)
471 		return -EBUSY;
472 
473 	/* Loop through all messages */
474 	for (i = 0; i < num; i++) {
475 		pmsg = &msgs[i];
476 		len = pmsg->len;
477 		tmp_buf = pmsg->buf;
478 
479 		dev_dbg(dev->device,
480 			"msg# %d/%d flg %x buf %x len %d\n", i,
481 			num - 1, pmsg->flags,
482 			pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
483 
484 		if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
485 			cond = ~COND_START_STOP;
486 		else
487 			cond = COND_RESTART | COND_NOSTOP;
488 
489 		brcmstb_set_i2c_start_stop(dev, cond);
490 
491 		/* Send slave address */
492 		if (!(pmsg->flags & I2C_M_NOSTART)) {
493 			rc = brcmstb_i2c_do_addr(dev, pmsg);
494 			if (rc < 0) {
495 				dev_dbg(dev->device,
496 					"NACK for addr %2.2x msg#%d rc = %d\n",
497 					pmsg->addr, i, rc);
498 				goto out;
499 			}
500 		}
501 
502 		cond_per_msg = cond;
503 
504 		/* Perform data transfer */
505 		while (len) {
506 			bytes_to_xfer = min(len, xfersz);
507 
508 			if (len <= xfersz) {
509 				if (i == (num - 1))
510 					cond_per_msg = cond_per_msg &
511 						~(COND_RESTART | COND_NOSTOP);
512 				else
513 					cond_per_msg = cond;
514 			} else {
515 				cond_per_msg = (cond_per_msg & ~COND_RESTART) |
516 					COND_NOSTOP;
517 			}
518 
519 			brcmstb_set_i2c_start_stop(dev, cond_per_msg);
520 
521 			rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
522 						       bytes_to_xfer, pmsg);
523 			if (rc < 0)
524 				goto out;
525 
526 			len -=  bytes_to_xfer;
527 			tmp_buf += bytes_to_xfer;
528 
529 			cond_per_msg = COND_NOSTART | COND_NOSTOP;
530 		}
531 	}
532 
533 	rc = num;
534 out:
535 	return rc;
536 
537 }
538 
539 static u32 brcmstb_i2c_functionality(struct i2c_adapter *adap)
540 {
541 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR
542 		| I2C_FUNC_NOSTART | I2C_FUNC_PROTOCOL_MANGLING;
543 }
544 
545 static const struct i2c_algorithm brcmstb_i2c_algo = {
546 	.master_xfer = brcmstb_i2c_xfer,
547 	.functionality = brcmstb_i2c_functionality,
548 };
549 
550 static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev)
551 {
552 	int i = 0, num_speeds = ARRAY_SIZE(bsc_clk);
553 	u32 clk_freq_hz = dev->clk_freq_hz;
554 
555 	for (i = 0; i < num_speeds; i++) {
556 		if (bsc_clk[i].hz == clk_freq_hz) {
557 			dev->bsc_regmap->ctl_reg &= ~(BSC_CTL_REG_SCL_SEL_MASK
558 						| BSC_CTL_REG_DIV_CLK_MASK);
559 			dev->bsc_regmap->ctl_reg |= (bsc_clk[i].scl_mask |
560 						     bsc_clk[i].div_mask);
561 			bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
562 			break;
563 		}
564 	}
565 
566 	/* in case we did not get find a valid speed */
567 	if (i == num_speeds) {
568 		i = (bsc_readl(dev, ctl_reg) & BSC_CTL_REG_SCL_SEL_MASK) >>
569 			BSC_CTL_REG_SCL_SEL_SHIFT;
570 		dev_warn(dev->device, "leaving current clock-frequency @ %dHz\n",
571 			bsc_clk[i].hz);
572 	}
573 }
574 
575 static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev)
576 {
577 	if (brcmstb_i2c_get_data_regsz(dev) == sizeof(u32))
578 		/* set 4 byte data in/out xfers  */
579 		dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;
580 	else
581 		dev->bsc_regmap->ctlhi_reg &= ~BSC_CTLHI_REG_DATAREG_SIZE_MASK;
582 
583 	bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg);
584 	/* set bus speed */
585 	brcmstb_i2c_set_bus_speed(dev);
586 }
587 
588 static int brcmstb_i2c_probe(struct platform_device *pdev)
589 {
590 	int rc = 0;
591 	struct brcmstb_i2c_dev *dev;
592 	struct i2c_adapter *adap;
593 	struct resource *iomem;
594 	const char *int_name;
595 
596 	/* Allocate memory for private data structure */
597 	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
598 	if (!dev)
599 		return -ENOMEM;
600 
601 	dev->bsc_regmap = devm_kzalloc(&pdev->dev, sizeof(*dev->bsc_regmap), GFP_KERNEL);
602 	if (!dev->bsc_regmap)
603 		return -ENOMEM;
604 
605 	platform_set_drvdata(pdev, dev);
606 	dev->device = &pdev->dev;
607 	init_completion(&dev->done);
608 
609 	/* Map hardware registers */
610 	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
611 	dev->base = devm_ioremap_resource(dev->device, iomem);
612 	if (IS_ERR(dev->base)) {
613 		rc = -ENOMEM;
614 		goto probe_errorout;
615 	}
616 
617 	rc = of_property_read_string(dev->device->of_node, "interrupt-names",
618 				     &int_name);
619 	if (rc < 0)
620 		int_name = NULL;
621 
622 	/* Get the interrupt number */
623 	dev->irq = platform_get_irq(pdev, 0);
624 
625 	/* disable the bsc interrupt line */
626 	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
627 
628 	/* register the ISR handler */
629 	rc = devm_request_irq(&pdev->dev, dev->irq, brcmstb_i2c_isr,
630 			      IRQF_SHARED,
631 			      int_name ? int_name : pdev->name,
632 			      dev);
633 
634 	if (rc) {
635 		dev_dbg(dev->device, "falling back to polling mode");
636 		dev->irq = -1;
637 	}
638 
639 	if (of_property_read_u32(dev->device->of_node,
640 				 "clock-frequency", &dev->clk_freq_hz)) {
641 		dev_warn(dev->device, "setting clock-frequency@%dHz\n",
642 			 bsc_clk[0].hz);
643 		dev->clk_freq_hz = bsc_clk[0].hz;
644 	}
645 
646 	/* set the data in/out register size for compatible SoCs */
647 	if (of_device_is_compatible(dev->device->of_node,
648 				    "brcmstb,brcmper-i2c"))
649 		dev->data_regsz = sizeof(u8);
650 	else
651 		dev->data_regsz = sizeof(u32);
652 
653 	brcmstb_i2c_set_bsc_reg_defaults(dev);
654 
655 	/* Add the i2c adapter */
656 	adap = &dev->adapter;
657 	i2c_set_adapdata(adap, dev);
658 	adap->owner = THIS_MODULE;
659 	strlcpy(adap->name, "Broadcom STB : ", sizeof(adap->name));
660 	if (int_name)
661 		strlcat(adap->name, int_name, sizeof(adap->name));
662 	adap->algo = &brcmstb_i2c_algo;
663 	adap->dev.parent = &pdev->dev;
664 	adap->dev.of_node = pdev->dev.of_node;
665 	rc = i2c_add_adapter(adap);
666 	if (rc)
667 		goto probe_errorout;
668 
669 	dev_info(dev->device, "%s@%dhz registered in %s mode\n",
670 		 int_name ? int_name : " ", dev->clk_freq_hz,
671 		 (dev->irq >= 0) ? "interrupt" : "polling");
672 
673 	return 0;
674 
675 probe_errorout:
676 	return rc;
677 }
678 
679 static int brcmstb_i2c_remove(struct platform_device *pdev)
680 {
681 	struct brcmstb_i2c_dev *dev = platform_get_drvdata(pdev);
682 
683 	i2c_del_adapter(&dev->adapter);
684 	return 0;
685 }
686 
687 #ifdef CONFIG_PM_SLEEP
688 static int brcmstb_i2c_suspend(struct device *dev)
689 {
690 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
691 
692 	i2c_lock_bus(&i2c_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
693 	i2c_dev->is_suspended = true;
694 	i2c_unlock_bus(&i2c_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
695 
696 	return 0;
697 }
698 
699 static int brcmstb_i2c_resume(struct device *dev)
700 {
701 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
702 
703 	i2c_lock_bus(&i2c_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
704 	brcmstb_i2c_set_bsc_reg_defaults(i2c_dev);
705 	i2c_dev->is_suspended = false;
706 	i2c_unlock_bus(&i2c_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
707 
708 	return 0;
709 }
710 #endif
711 
712 static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend,
713 			 brcmstb_i2c_resume);
714 
715 static const struct of_device_id brcmstb_i2c_of_match[] = {
716 	{.compatible = "brcm,brcmstb-i2c"},
717 	{.compatible = "brcm,brcmper-i2c"},
718 	{},
719 };
720 MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);
721 
722 static struct platform_driver brcmstb_i2c_driver = {
723 	.driver = {
724 		   .name = "brcmstb-i2c",
725 		   .of_match_table = brcmstb_i2c_of_match,
726 		   .pm = &brcmstb_i2c_pm,
727 		   },
728 	.probe = brcmstb_i2c_probe,
729 	.remove = brcmstb_i2c_remove,
730 };
731 module_platform_driver(brcmstb_i2c_driver);
732 
733 MODULE_AUTHOR("Kamal Dasu <kdasu@broadcom.com>");
734 MODULE_DESCRIPTION("Broadcom Settop I2C Driver");
735 MODULE_LICENSE("GPL v2");
736