xref: /openbmc/linux/drivers/i2c/busses/i2c-brcmstb.c (revision 7a010c3c)
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 
26 #define N_DATA_REGS					8
27 
28 /*
29  * PER_I2C/BSC count register mask depends on 1 byte/4 byte data register
30  * size. Cable modem and DSL SoCs with Peripheral i2c cores use 1 byte per
31  * data register whereas STB SoCs use 4 byte per data register transfer,
32  * account for this difference in total count per transaction and mask to
33  * use.
34  */
35 #define BSC_CNT_REG1_MASK(nb)	(nb == 1 ? GENMASK(3, 0) : GENMASK(5, 0))
36 #define BSC_CNT_REG1_SHIFT	0
37 
38 /* BSC CTL register field definitions */
39 #define BSC_CTL_REG_DTF_MASK				0x00000003
40 #define BSC_CTL_REG_SCL_SEL_MASK			0x00000030
41 #define BSC_CTL_REG_SCL_SEL_SHIFT			4
42 #define BSC_CTL_REG_INT_EN_MASK				0x00000040
43 #define BSC_CTL_REG_INT_EN_SHIFT			6
44 #define BSC_CTL_REG_DIV_CLK_MASK			0x00000080
45 
46 /* BSC_IIC_ENABLE r/w enable and interrupt field definitions */
47 #define BSC_IIC_EN_RESTART_MASK				0x00000040
48 #define BSC_IIC_EN_NOSTART_MASK				0x00000020
49 #define BSC_IIC_EN_NOSTOP_MASK				0x00000010
50 #define BSC_IIC_EN_NOACK_MASK				0x00000004
51 #define BSC_IIC_EN_INTRP_MASK				0x00000002
52 #define BSC_IIC_EN_ENABLE_MASK				0x00000001
53 
54 /* BSC_CTLHI control register field definitions */
55 #define BSC_CTLHI_REG_INPUT_SWITCHING_LEVEL_MASK	0x00000080
56 #define BSC_CTLHI_REG_DATAREG_SIZE_MASK			0x00000040
57 #define BSC_CTLHI_REG_IGNORE_ACK_MASK			0x00000002
58 #define BSC_CTLHI_REG_WAIT_DIS_MASK			0x00000001
59 
60 #define I2C_TIMEOUT					100 /* msecs */
61 
62 /* Condition mask used for non combined transfer */
63 #define COND_RESTART		BSC_IIC_EN_RESTART_MASK
64 #define COND_NOSTART		BSC_IIC_EN_NOSTART_MASK
65 #define COND_NOSTOP		BSC_IIC_EN_NOSTOP_MASK
66 #define COND_START_STOP		(COND_RESTART | COND_NOSTART | COND_NOSTOP)
67 
68 /* BSC data transfer direction */
69 #define DTF_WR_MASK		0x00000000
70 #define DTF_RD_MASK		0x00000001
71 /* BSC data transfer direction combined format */
72 #define DTF_RD_WR_MASK		0x00000002
73 #define DTF_WR_RD_MASK		0x00000003
74 
75 #define INT_ENABLE		true
76 #define INT_DISABLE		false
77 
78 /* BSC block register map structure to cache fields to be written */
79 struct bsc_regs {
80 	u32	chip_address;           /* slave address */
81 	u32	data_in[N_DATA_REGS];   /* tx data buffer*/
82 	u32	cnt_reg;		/* rx/tx data length */
83 	u32	ctl_reg;		/* control register */
84 	u32	iic_enable;		/* xfer enable and status */
85 	u32	data_out[N_DATA_REGS];  /* rx data buffer */
86 	u32	ctlhi_reg;		/* more control fields */
87 	u32	scl_param;		/* reserved */
88 };
89 
90 struct bsc_clk_param {
91 	u32 hz;
92 	u32 scl_mask;
93 	u32 div_mask;
94 };
95 
96 enum bsc_xfer_cmd {
97 	CMD_WR,
98 	CMD_RD,
99 	CMD_WR_NOACK,
100 	CMD_RD_NOACK,
101 };
102 
103 static char const *cmd_string[] = {
104 	[CMD_WR] = "WR",
105 	[CMD_RD] = "RD",
106 	[CMD_WR_NOACK] = "WR NOACK",
107 	[CMD_RD_NOACK] = "RD NOACK",
108 };
109 
110 enum bus_speeds {
111 	SPD_375K,
112 	SPD_390K,
113 	SPD_187K,
114 	SPD_200K,
115 	SPD_93K,
116 	SPD_97K,
117 	SPD_46K,
118 	SPD_50K
119 };
120 
121 static const struct bsc_clk_param bsc_clk[] = {
122 	[SPD_375K] = {
123 		.hz = 375000,
124 		.scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
125 		.div_mask = 0
126 	},
127 	[SPD_390K] = {
128 		.hz = 390000,
129 		.scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
130 		.div_mask = 0
131 	},
132 	[SPD_187K] = {
133 		.hz = 187500,
134 		.scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
135 		.div_mask = 0
136 	},
137 	[SPD_200K] = {
138 		.hz = 200000,
139 		.scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
140 		.div_mask = 0
141 	},
142 	[SPD_93K]  = {
143 		.hz = 93750,
144 		.scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
145 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
146 	},
147 	[SPD_97K]  = {
148 		.hz = 97500,
149 		.scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
150 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
151 	},
152 	[SPD_46K]  = {
153 		.hz = 46875,
154 		.scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
155 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
156 	},
157 	[SPD_50K]  = {
158 		.hz = 50000,
159 		.scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
160 		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
161 	}
162 };
163 
164 struct brcmstb_i2c_dev {
165 	struct device *device;
166 	void __iomem *base;
167 	int irq;
168 	struct bsc_regs *bsc_regmap;
169 	struct i2c_adapter adapter;
170 	struct completion done;
171 	u32 clk_freq_hz;
172 	int data_regsz;
173 };
174 
175 /* register accessors for both be and le cpu arch */
176 #ifdef CONFIG_CPU_BIG_ENDIAN
177 #define __bsc_readl(_reg) ioread32be(_reg)
178 #define __bsc_writel(_val, _reg) iowrite32be(_val, _reg)
179 #else
180 #define __bsc_readl(_reg) ioread32(_reg)
181 #define __bsc_writel(_val, _reg) iowrite32(_val, _reg)
182 #endif
183 
184 #define bsc_readl(_dev, _reg)						\
185 	__bsc_readl(_dev->base + offsetof(struct bsc_regs, _reg))
186 
187 #define bsc_writel(_dev, _val, _reg)					\
188 	__bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg))
189 
190 static inline int brcmstb_i2c_get_xfersz(struct brcmstb_i2c_dev *dev)
191 {
192 	return (N_DATA_REGS * dev->data_regsz);
193 }
194 
195 static inline int brcmstb_i2c_get_data_regsz(struct brcmstb_i2c_dev *dev)
196 {
197 	return dev->data_regsz;
198 }
199 
200 static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev,
201 					   bool int_en)
202 {
203 
204 	if (int_en)
205 		/* Enable BSC  CTL interrupt line */
206 		dev->bsc_regmap->ctl_reg |= BSC_CTL_REG_INT_EN_MASK;
207 	else
208 		/* Disable BSC CTL interrupt line */
209 		dev->bsc_regmap->ctl_reg &= ~BSC_CTL_REG_INT_EN_MASK;
210 
211 	barrier();
212 	bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
213 }
214 
215 static irqreturn_t brcmstb_i2c_isr(int irq, void *devid)
216 {
217 	struct brcmstb_i2c_dev *dev = devid;
218 	u32 status_bsc_ctl = bsc_readl(dev, ctl_reg);
219 	u32 status_iic_intrp = bsc_readl(dev, iic_enable);
220 
221 	dev_dbg(dev->device, "isr CTL_REG %x IIC_EN %x\n",
222 		status_bsc_ctl, status_iic_intrp);
223 
224 	if (!(status_bsc_ctl & BSC_CTL_REG_INT_EN_MASK))
225 		return IRQ_NONE;
226 
227 	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
228 	complete(&dev->done);
229 
230 	dev_dbg(dev->device, "isr handled");
231 	return IRQ_HANDLED;
232 }
233 
234 /* Wait for device to be ready */
235 static int brcmstb_i2c_wait_if_busy(struct brcmstb_i2c_dev *dev)
236 {
237 	unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
238 
239 	while ((bsc_readl(dev, iic_enable) & BSC_IIC_EN_INTRP_MASK)) {
240 		if (time_after(jiffies, timeout))
241 			return -ETIMEDOUT;
242 		cpu_relax();
243 	}
244 	return 0;
245 }
246 
247 /* i2c xfer completion function, handles both irq and polling mode */
248 static int brcmstb_i2c_wait_for_completion(struct brcmstb_i2c_dev *dev)
249 {
250 	int ret = 0;
251 	unsigned long timeout = msecs_to_jiffies(I2C_TIMEOUT);
252 
253 	if (dev->irq >= 0) {
254 		if (!wait_for_completion_timeout(&dev->done, timeout))
255 			ret = -ETIMEDOUT;
256 	} else {
257 		/* we are in polling mode */
258 		u32 bsc_intrp;
259 		unsigned long time_left = jiffies + timeout;
260 
261 		do {
262 			bsc_intrp = bsc_readl(dev, iic_enable) &
263 				BSC_IIC_EN_INTRP_MASK;
264 			if (time_after(jiffies, time_left)) {
265 				ret = -ETIMEDOUT;
266 				break;
267 			}
268 			cpu_relax();
269 		} while (!bsc_intrp);
270 	}
271 
272 	if (dev->irq < 0 || ret == -ETIMEDOUT)
273 		brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
274 
275 	return ret;
276 }
277 
278 /* Set xfer START/STOP conditions for subsequent transfer */
279 static void brcmstb_set_i2c_start_stop(struct brcmstb_i2c_dev *dev,
280 				       u32 cond_flag)
281 {
282 	u32 regval = dev->bsc_regmap->iic_enable;
283 
284 	dev->bsc_regmap->iic_enable = (regval & ~COND_START_STOP) | cond_flag;
285 }
286 
287 /* Send I2C request check completion */
288 static int brcmstb_send_i2c_cmd(struct brcmstb_i2c_dev *dev,
289 				enum bsc_xfer_cmd cmd)
290 {
291 	int rc = 0;
292 	struct bsc_regs *pi2creg = dev->bsc_regmap;
293 
294 	/* Make sure the hardware is ready */
295 	rc = brcmstb_i2c_wait_if_busy(dev);
296 	if (rc < 0)
297 		return rc;
298 
299 	/* only if we are in interrupt mode */
300 	if (dev->irq >= 0)
301 		reinit_completion(&dev->done);
302 
303 	/* enable BSC CTL interrupt line */
304 	brcmstb_i2c_enable_disable_irq(dev, INT_ENABLE);
305 
306 	/* initiate transfer by setting iic_enable */
307 	pi2creg->iic_enable |= BSC_IIC_EN_ENABLE_MASK;
308 	bsc_writel(dev, pi2creg->iic_enable, iic_enable);
309 
310 	/* Wait for transaction to finish or timeout */
311 	rc = brcmstb_i2c_wait_for_completion(dev);
312 	if (rc) {
313 		dev_dbg(dev->device, "intr timeout for cmd %s\n",
314 			cmd_string[cmd]);
315 		goto cmd_out;
316 	}
317 
318 	if ((cmd == CMD_RD || cmd == CMD_WR) &&
319 	    bsc_readl(dev, iic_enable) & BSC_IIC_EN_NOACK_MASK) {
320 		rc = -EREMOTEIO;
321 		dev_dbg(dev->device, "controller received NOACK intr for %s\n",
322 			cmd_string[cmd]);
323 	}
324 
325 cmd_out:
326 	bsc_writel(dev, 0, cnt_reg);
327 	bsc_writel(dev, 0, iic_enable);
328 
329 	return rc;
330 }
331 
332 /* Actual data transfer through the BSC master */
333 static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
334 				     u8 *buf, unsigned int len,
335 				     struct i2c_msg *pmsg)
336 {
337 	int cnt, byte, i, rc;
338 	enum bsc_xfer_cmd cmd;
339 	u32 ctl_reg;
340 	struct bsc_regs *pi2creg = dev->bsc_regmap;
341 	int no_ack = pmsg->flags & I2C_M_IGNORE_NAK;
342 	int data_regsz = brcmstb_i2c_get_data_regsz(dev);
343 
344 	/* see if the transaction needs to check NACK conditions */
345 	if (no_ack) {
346 		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK
347 			: CMD_WR_NOACK;
348 		pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK;
349 	} else {
350 		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD : CMD_WR;
351 		pi2creg->ctlhi_reg &= ~BSC_CTLHI_REG_IGNORE_ACK_MASK;
352 	}
353 	bsc_writel(dev, pi2creg->ctlhi_reg, ctlhi_reg);
354 
355 	/* set data transfer direction */
356 	ctl_reg = pi2creg->ctl_reg & ~BSC_CTL_REG_DTF_MASK;
357 	if (cmd == CMD_WR || cmd == CMD_WR_NOACK)
358 		pi2creg->ctl_reg = ctl_reg | DTF_WR_MASK;
359 	else
360 		pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK;
361 
362 	/* set the read/write length */
363 	bsc_writel(dev, BSC_CNT_REG1_MASK(data_regsz) &
364 		   (len << BSC_CNT_REG1_SHIFT), cnt_reg);
365 
366 	/* Write data into data_in register */
367 
368 	if (cmd == CMD_WR || cmd == CMD_WR_NOACK) {
369 		for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
370 			u32 word = 0;
371 
372 			for (byte = 0; byte < data_regsz; byte++) {
373 				word >>= BITS_PER_BYTE;
374 				if ((cnt + byte) < len)
375 					word |= buf[cnt + byte] <<
376 					(BITS_PER_BYTE * (data_regsz - 1));
377 			}
378 			bsc_writel(dev, word, data_in[i]);
379 		}
380 	}
381 
382 	/* Initiate xfer, the function will return on completion */
383 	rc = brcmstb_send_i2c_cmd(dev, cmd);
384 
385 	if (rc != 0) {
386 		dev_dbg(dev->device, "%s failure", cmd_string[cmd]);
387 		return rc;
388 	}
389 
390 	/* Read data from data_out register */
391 	if (cmd == CMD_RD || cmd == CMD_RD_NOACK) {
392 		for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
393 			u32 data = bsc_readl(dev, data_out[i]);
394 
395 			for (byte = 0; byte < data_regsz &&
396 				     (byte + cnt) < len; byte++) {
397 				buf[cnt + byte] = data & 0xff;
398 				data >>= BITS_PER_BYTE;
399 			}
400 		}
401 	}
402 
403 	return 0;
404 }
405 
406 /* Write a single byte of data to the i2c bus */
407 static int brcmstb_i2c_write_data_byte(struct brcmstb_i2c_dev *dev,
408 				       u8 *buf, unsigned int nak_expected)
409 {
410 	enum bsc_xfer_cmd cmd = nak_expected ? CMD_WR : CMD_WR_NOACK;
411 
412 	bsc_writel(dev, 1, cnt_reg);
413 	bsc_writel(dev, *buf, data_in);
414 
415 	return brcmstb_send_i2c_cmd(dev, cmd);
416 }
417 
418 /* Send i2c address */
419 static int brcmstb_i2c_do_addr(struct brcmstb_i2c_dev *dev,
420 			       struct i2c_msg *msg)
421 {
422 	unsigned char addr;
423 
424 	if (msg->flags & I2C_M_TEN) {
425 		/* First byte is 11110XX0 where XX is upper 2 bits */
426 		addr = 0xF0 | ((msg->addr & 0x300) >> 7);
427 		bsc_writel(dev, addr, chip_address);
428 
429 		/* Second byte is the remaining 8 bits */
430 		addr = msg->addr & 0xFF;
431 		if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
432 			return -EREMOTEIO;
433 
434 		if (msg->flags & I2C_M_RD) {
435 			/* For read, send restart without stop condition */
436 			brcmstb_set_i2c_start_stop(dev, COND_RESTART
437 						   | COND_NOSTOP);
438 			/* Then re-send the first byte with the read bit set */
439 			addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
440 			if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
441 				return -EREMOTEIO;
442 
443 		}
444 	} else {
445 		addr = i2c_8bit_addr_from_msg(msg);
446 
447 		bsc_writel(dev, addr, chip_address);
448 	}
449 
450 	return 0;
451 }
452 
453 /* Master transfer function */
454 static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
455 			    struct i2c_msg msgs[], int num)
456 {
457 	struct brcmstb_i2c_dev *dev = i2c_get_adapdata(adapter);
458 	struct i2c_msg *pmsg;
459 	int rc = 0;
460 	int i;
461 	int bytes_to_xfer;
462 	u8 *tmp_buf;
463 	int len = 0;
464 	int xfersz = brcmstb_i2c_get_xfersz(dev);
465 	u32 cond, cond_per_msg;
466 
467 	/* Loop through all messages */
468 	for (i = 0; i < num; i++) {
469 		pmsg = &msgs[i];
470 		len = pmsg->len;
471 		tmp_buf = pmsg->buf;
472 
473 		dev_dbg(dev->device,
474 			"msg# %d/%d flg %x buf %x len %d\n", i,
475 			num - 1, pmsg->flags,
476 			pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
477 
478 		if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
479 			cond = ~COND_START_STOP;
480 		else
481 			cond = COND_RESTART | COND_NOSTOP;
482 
483 		brcmstb_set_i2c_start_stop(dev, cond);
484 
485 		/* Send slave address */
486 		if (!(pmsg->flags & I2C_M_NOSTART)) {
487 			rc = brcmstb_i2c_do_addr(dev, pmsg);
488 			if (rc < 0) {
489 				dev_dbg(dev->device,
490 					"NACK for addr %2.2x msg#%d rc = %d\n",
491 					pmsg->addr, i, rc);
492 				goto out;
493 			}
494 		}
495 
496 		cond_per_msg = cond;
497 
498 		/* Perform data transfer */
499 		while (len) {
500 			bytes_to_xfer = min(len, xfersz);
501 
502 			if (len <= xfersz) {
503 				if (i == (num - 1))
504 					cond_per_msg = cond_per_msg &
505 						~(COND_RESTART | COND_NOSTOP);
506 				else
507 					cond_per_msg = cond;
508 			} else {
509 				cond_per_msg = (cond_per_msg & ~COND_RESTART) |
510 					COND_NOSTOP;
511 			}
512 
513 			brcmstb_set_i2c_start_stop(dev, cond_per_msg);
514 
515 			rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
516 						       bytes_to_xfer, pmsg);
517 			if (rc < 0)
518 				goto out;
519 
520 			len -=  bytes_to_xfer;
521 			tmp_buf += bytes_to_xfer;
522 
523 			cond_per_msg = COND_NOSTART | COND_NOSTOP;
524 		}
525 	}
526 
527 	rc = num;
528 out:
529 	return rc;
530 
531 }
532 
533 static u32 brcmstb_i2c_functionality(struct i2c_adapter *adap)
534 {
535 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR
536 		| I2C_FUNC_NOSTART | I2C_FUNC_PROTOCOL_MANGLING;
537 }
538 
539 static const struct i2c_algorithm brcmstb_i2c_algo = {
540 	.master_xfer = brcmstb_i2c_xfer,
541 	.functionality = brcmstb_i2c_functionality,
542 };
543 
544 static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev)
545 {
546 	int i = 0, num_speeds = ARRAY_SIZE(bsc_clk);
547 	u32 clk_freq_hz = dev->clk_freq_hz;
548 
549 	for (i = 0; i < num_speeds; i++) {
550 		if (bsc_clk[i].hz == clk_freq_hz) {
551 			dev->bsc_regmap->ctl_reg &= ~(BSC_CTL_REG_SCL_SEL_MASK
552 						| BSC_CTL_REG_DIV_CLK_MASK);
553 			dev->bsc_regmap->ctl_reg |= (bsc_clk[i].scl_mask |
554 						     bsc_clk[i].div_mask);
555 			bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
556 			break;
557 		}
558 	}
559 
560 	/* in case we did not get find a valid speed */
561 	if (i == num_speeds) {
562 		i = (bsc_readl(dev, ctl_reg) & BSC_CTL_REG_SCL_SEL_MASK) >>
563 			BSC_CTL_REG_SCL_SEL_SHIFT;
564 		dev_warn(dev->device, "leaving current clock-frequency @ %dHz\n",
565 			bsc_clk[i].hz);
566 	}
567 }
568 
569 static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev)
570 {
571 	if (brcmstb_i2c_get_data_regsz(dev) == sizeof(u32))
572 		/* set 4 byte data in/out xfers  */
573 		dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;
574 	else
575 		dev->bsc_regmap->ctlhi_reg &= ~BSC_CTLHI_REG_DATAREG_SIZE_MASK;
576 
577 	bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg);
578 	/* set bus speed */
579 	brcmstb_i2c_set_bus_speed(dev);
580 }
581 
582 #define AUTOI2C_CTRL0		0x26c
583 #define AUTOI2C_CTRL0_RELEASE_BSC	BIT(1)
584 
585 static int bcm2711_release_bsc(struct brcmstb_i2c_dev *dev)
586 {
587 	struct platform_device *pdev = to_platform_device(dev->device);
588 	struct resource *iomem;
589 	void __iomem *autoi2c;
590 
591 	/* Map hardware registers */
592 	iomem = platform_get_resource_byname(pdev, IORESOURCE_MEM, "auto-i2c");
593 	autoi2c = devm_ioremap_resource(&pdev->dev, iomem);
594 	if (IS_ERR(autoi2c))
595 		return PTR_ERR(autoi2c);
596 
597 	writel(AUTOI2C_CTRL0_RELEASE_BSC, autoi2c + AUTOI2C_CTRL0);
598 	devm_iounmap(&pdev->dev, autoi2c);
599 
600 	/* We need to reset the controller after the release */
601 	dev->bsc_regmap->iic_enable = 0;
602 	bsc_writel(dev, dev->bsc_regmap->iic_enable, iic_enable);
603 
604 	return 0;
605 }
606 
607 static int brcmstb_i2c_probe(struct platform_device *pdev)
608 {
609 	int rc = 0;
610 	struct brcmstb_i2c_dev *dev;
611 	struct i2c_adapter *adap;
612 	struct resource *iomem;
613 	const char *int_name;
614 
615 	/* Allocate memory for private data structure */
616 	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
617 	if (!dev)
618 		return -ENOMEM;
619 
620 	dev->bsc_regmap = devm_kzalloc(&pdev->dev, sizeof(*dev->bsc_regmap), GFP_KERNEL);
621 	if (!dev->bsc_regmap)
622 		return -ENOMEM;
623 
624 	platform_set_drvdata(pdev, dev);
625 	dev->device = &pdev->dev;
626 	init_completion(&dev->done);
627 
628 	/* Map hardware registers */
629 	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
630 	dev->base = devm_ioremap_resource(dev->device, iomem);
631 	if (IS_ERR(dev->base)) {
632 		rc = -ENOMEM;
633 		goto probe_errorout;
634 	}
635 
636 	if (of_device_is_compatible(dev->device->of_node,
637 				    "brcm,bcm2711-hdmi-i2c")) {
638 		rc = bcm2711_release_bsc(dev);
639 		if (rc)
640 			goto probe_errorout;
641 	}
642 
643 	rc = of_property_read_string(dev->device->of_node, "interrupt-names",
644 				     &int_name);
645 	if (rc < 0)
646 		int_name = NULL;
647 
648 	/* Get the interrupt number */
649 	dev->irq = platform_get_irq_optional(pdev, 0);
650 
651 	/* disable the bsc interrupt line */
652 	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
653 
654 	/* register the ISR handler */
655 	if (dev->irq >= 0) {
656 		rc = devm_request_irq(&pdev->dev, dev->irq, brcmstb_i2c_isr,
657 				      IRQF_SHARED,
658 				      int_name ? int_name : pdev->name,
659 				      dev);
660 
661 		if (rc) {
662 			dev_dbg(dev->device, "falling back to polling mode");
663 			dev->irq = -1;
664 		}
665 	}
666 
667 	if (of_property_read_u32(dev->device->of_node,
668 				 "clock-frequency", &dev->clk_freq_hz)) {
669 		dev_warn(dev->device, "setting clock-frequency@%dHz\n",
670 			 bsc_clk[0].hz);
671 		dev->clk_freq_hz = bsc_clk[0].hz;
672 	}
673 
674 	/* set the data in/out register size for compatible SoCs */
675 	if (of_device_is_compatible(dev->device->of_node,
676 				    "brcmstb,brcmper-i2c"))
677 		dev->data_regsz = sizeof(u8);
678 	else
679 		dev->data_regsz = sizeof(u32);
680 
681 	brcmstb_i2c_set_bsc_reg_defaults(dev);
682 
683 	/* Add the i2c adapter */
684 	adap = &dev->adapter;
685 	i2c_set_adapdata(adap, dev);
686 	adap->owner = THIS_MODULE;
687 	strlcpy(adap->name, "Broadcom STB : ", sizeof(adap->name));
688 	if (int_name)
689 		strlcat(adap->name, int_name, sizeof(adap->name));
690 	adap->algo = &brcmstb_i2c_algo;
691 	adap->dev.parent = &pdev->dev;
692 	adap->dev.of_node = pdev->dev.of_node;
693 	rc = i2c_add_adapter(adap);
694 	if (rc)
695 		goto probe_errorout;
696 
697 	dev_info(dev->device, "%s@%dhz registered in %s mode\n",
698 		 int_name ? int_name : " ", dev->clk_freq_hz,
699 		 (dev->irq >= 0) ? "interrupt" : "polling");
700 
701 	return 0;
702 
703 probe_errorout:
704 	return rc;
705 }
706 
707 static int brcmstb_i2c_remove(struct platform_device *pdev)
708 {
709 	struct brcmstb_i2c_dev *dev = platform_get_drvdata(pdev);
710 
711 	i2c_del_adapter(&dev->adapter);
712 	return 0;
713 }
714 
715 #ifdef CONFIG_PM_SLEEP
716 static int brcmstb_i2c_suspend(struct device *dev)
717 {
718 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
719 
720 	i2c_mark_adapter_suspended(&i2c_dev->adapter);
721 	return 0;
722 }
723 
724 static int brcmstb_i2c_resume(struct device *dev)
725 {
726 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
727 
728 	brcmstb_i2c_set_bsc_reg_defaults(i2c_dev);
729 	i2c_mark_adapter_resumed(&i2c_dev->adapter);
730 
731 	return 0;
732 }
733 #endif
734 
735 static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend,
736 			 brcmstb_i2c_resume);
737 
738 static const struct of_device_id brcmstb_i2c_of_match[] = {
739 	{.compatible = "brcm,brcmstb-i2c"},
740 	{.compatible = "brcm,brcmper-i2c"},
741 	{.compatible = "brcm,bcm2711-hdmi-i2c"},
742 	{},
743 };
744 MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);
745 
746 static struct platform_driver brcmstb_i2c_driver = {
747 	.driver = {
748 		   .name = "brcmstb-i2c",
749 		   .of_match_table = brcmstb_i2c_of_match,
750 		   .pm = &brcmstb_i2c_pm,
751 		   },
752 	.probe = brcmstb_i2c_probe,
753 	.remove = brcmstb_i2c_remove,
754 };
755 module_platform_driver(brcmstb_i2c_driver);
756 
757 MODULE_AUTHOR("Kamal Dasu <kdasu@broadcom.com>");
758 MODULE_DESCRIPTION("Broadcom Settop I2C Driver");
759 MODULE_LICENSE("GPL v2");
760