xref: /openbmc/linux/drivers/i2c/busses/i2c-brcmstb.c (revision 82df5b73)
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 	int irq;
169 	struct bsc_regs *bsc_regmap;
170 	struct i2c_adapter adapter;
171 	struct completion done;
172 	u32 clk_freq_hz;
173 	int data_regsz;
174 };
175 
176 /* register accessors for both be and le cpu arch */
177 #ifdef CONFIG_CPU_BIG_ENDIAN
178 #define __bsc_readl(_reg) ioread32be(_reg)
179 #define __bsc_writel(_val, _reg) iowrite32be(_val, _reg)
180 #else
181 #define __bsc_readl(_reg) ioread32(_reg)
182 #define __bsc_writel(_val, _reg) iowrite32(_val, _reg)
183 #endif
184 
185 #define bsc_readl(_dev, _reg)						\
186 	__bsc_readl(_dev->base + offsetof(struct bsc_regs, _reg))
187 
188 #define bsc_writel(_dev, _val, _reg)					\
189 	__bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg))
190 
191 static inline int brcmstb_i2c_get_xfersz(struct brcmstb_i2c_dev *dev)
192 {
193 	return (N_DATA_REGS * dev->data_regsz);
194 }
195 
196 static inline int brcmstb_i2c_get_data_regsz(struct brcmstb_i2c_dev *dev)
197 {
198 	return dev->data_regsz;
199 }
200 
201 static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev,
202 					   bool int_en)
203 {
204 
205 	if (int_en)
206 		/* Enable BSC  CTL interrupt line */
207 		dev->bsc_regmap->ctl_reg |= BSC_CTL_REG_INT_EN_MASK;
208 	else
209 		/* Disable BSC CTL interrupt line */
210 		dev->bsc_regmap->ctl_reg &= ~BSC_CTL_REG_INT_EN_MASK;
211 
212 	barrier();
213 	bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
214 }
215 
216 static irqreturn_t brcmstb_i2c_isr(int irq, void *devid)
217 {
218 	struct brcmstb_i2c_dev *dev = devid;
219 	u32 status_bsc_ctl = bsc_readl(dev, ctl_reg);
220 	u32 status_iic_intrp = bsc_readl(dev, iic_enable);
221 
222 	dev_dbg(dev->device, "isr CTL_REG %x IIC_EN %x\n",
223 		status_bsc_ctl, status_iic_intrp);
224 
225 	if (!(status_bsc_ctl & BSC_CTL_REG_INT_EN_MASK))
226 		return IRQ_NONE;
227 
228 	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
229 	complete(&dev->done);
230 
231 	dev_dbg(dev->device, "isr handled");
232 	return IRQ_HANDLED;
233 }
234 
235 /* Wait for device to be ready */
236 static int brcmstb_i2c_wait_if_busy(struct brcmstb_i2c_dev *dev)
237 {
238 	unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
239 
240 	while ((bsc_readl(dev, iic_enable) & BSC_IIC_EN_INTRP_MASK)) {
241 		if (time_after(jiffies, timeout))
242 			return -ETIMEDOUT;
243 		cpu_relax();
244 	}
245 	return 0;
246 }
247 
248 /* i2c xfer completion function, handles both irq and polling mode */
249 static int brcmstb_i2c_wait_for_completion(struct brcmstb_i2c_dev *dev)
250 {
251 	int ret = 0;
252 	unsigned long timeout = msecs_to_jiffies(I2C_TIMEOUT);
253 
254 	if (dev->irq >= 0) {
255 		if (!wait_for_completion_timeout(&dev->done, timeout))
256 			ret = -ETIMEDOUT;
257 	} else {
258 		/* we are in polling mode */
259 		u32 bsc_intrp;
260 		unsigned long time_left = jiffies + timeout;
261 
262 		do {
263 			bsc_intrp = bsc_readl(dev, iic_enable) &
264 				BSC_IIC_EN_INTRP_MASK;
265 			if (time_after(jiffies, time_left)) {
266 				ret = -ETIMEDOUT;
267 				break;
268 			}
269 			cpu_relax();
270 		} while (!bsc_intrp);
271 	}
272 
273 	if (dev->irq < 0 || ret == -ETIMEDOUT)
274 		brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
275 
276 	return ret;
277 }
278 
279 /* Set xfer START/STOP conditions for subsequent transfer */
280 static void brcmstb_set_i2c_start_stop(struct brcmstb_i2c_dev *dev,
281 				       u32 cond_flag)
282 {
283 	u32 regval = dev->bsc_regmap->iic_enable;
284 
285 	dev->bsc_regmap->iic_enable = (regval & ~COND_START_STOP) | cond_flag;
286 }
287 
288 /* Send I2C request check completion */
289 static int brcmstb_send_i2c_cmd(struct brcmstb_i2c_dev *dev,
290 				enum bsc_xfer_cmd cmd)
291 {
292 	int rc = 0;
293 	struct bsc_regs *pi2creg = dev->bsc_regmap;
294 
295 	/* Make sure the hardware is ready */
296 	rc = brcmstb_i2c_wait_if_busy(dev);
297 	if (rc < 0)
298 		return rc;
299 
300 	/* only if we are in interrupt mode */
301 	if (dev->irq >= 0)
302 		reinit_completion(&dev->done);
303 
304 	/* enable BSC CTL interrupt line */
305 	brcmstb_i2c_enable_disable_irq(dev, INT_ENABLE);
306 
307 	/* initiate transfer by setting iic_enable */
308 	pi2creg->iic_enable |= BSC_IIC_EN_ENABLE_MASK;
309 	bsc_writel(dev, pi2creg->iic_enable, iic_enable);
310 
311 	/* Wait for transaction to finish or timeout */
312 	rc = brcmstb_i2c_wait_for_completion(dev);
313 	if (rc) {
314 		dev_dbg(dev->device, "intr timeout for cmd %s\n",
315 			cmd_string[cmd]);
316 		goto cmd_out;
317 	}
318 
319 	if ((CMD_RD || CMD_WR) &&
320 	    bsc_readl(dev, iic_enable) & BSC_IIC_EN_NOACK_MASK) {
321 		rc = -EREMOTEIO;
322 		dev_dbg(dev->device, "controller received NOACK intr for %s\n",
323 			cmd_string[cmd]);
324 	}
325 
326 cmd_out:
327 	bsc_writel(dev, 0, cnt_reg);
328 	bsc_writel(dev, 0, iic_enable);
329 
330 	return rc;
331 }
332 
333 /* Actual data transfer through the BSC master */
334 static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
335 				     u8 *buf, unsigned int len,
336 				     struct i2c_msg *pmsg)
337 {
338 	int cnt, byte, i, rc;
339 	enum bsc_xfer_cmd cmd;
340 	u32 ctl_reg;
341 	struct bsc_regs *pi2creg = dev->bsc_regmap;
342 	int no_ack = pmsg->flags & I2C_M_IGNORE_NAK;
343 	int data_regsz = brcmstb_i2c_get_data_regsz(dev);
344 
345 	/* see if the transaction needs to check NACK conditions */
346 	if (no_ack) {
347 		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK
348 			: CMD_WR_NOACK;
349 		pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK;
350 	} else {
351 		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD : CMD_WR;
352 		pi2creg->ctlhi_reg &= ~BSC_CTLHI_REG_IGNORE_ACK_MASK;
353 	}
354 	bsc_writel(dev, pi2creg->ctlhi_reg, ctlhi_reg);
355 
356 	/* set data transfer direction */
357 	ctl_reg = pi2creg->ctl_reg & ~BSC_CTL_REG_DTF_MASK;
358 	if (cmd == CMD_WR || cmd == CMD_WR_NOACK)
359 		pi2creg->ctl_reg = ctl_reg | DTF_WR_MASK;
360 	else
361 		pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK;
362 
363 	/* set the read/write length */
364 	bsc_writel(dev, BSC_CNT_REG1_MASK(data_regsz) &
365 		   (len << BSC_CNT_REG1_SHIFT), cnt_reg);
366 
367 	/* Write data into data_in register */
368 
369 	if (cmd == CMD_WR || cmd == CMD_WR_NOACK) {
370 		for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
371 			u32 word = 0;
372 
373 			for (byte = 0; byte < data_regsz; byte++) {
374 				word >>= BITS_PER_BYTE;
375 				if ((cnt + byte) < len)
376 					word |= buf[cnt + byte] <<
377 					(BITS_PER_BYTE * (data_regsz - 1));
378 			}
379 			bsc_writel(dev, word, data_in[i]);
380 		}
381 	}
382 
383 	/* Initiate xfer, the function will return on completion */
384 	rc = brcmstb_send_i2c_cmd(dev, cmd);
385 
386 	if (rc != 0) {
387 		dev_dbg(dev->device, "%s failure", cmd_string[cmd]);
388 		return rc;
389 	}
390 
391 	/* Read data from data_out register */
392 	if (cmd == CMD_RD || cmd == CMD_RD_NOACK) {
393 		for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
394 			u32 data = bsc_readl(dev, data_out[i]);
395 
396 			for (byte = 0; byte < data_regsz &&
397 				     (byte + cnt) < len; byte++) {
398 				buf[cnt + byte] = data & 0xff;
399 				data >>= BITS_PER_BYTE;
400 			}
401 		}
402 	}
403 
404 	return 0;
405 }
406 
407 /* Write a single byte of data to the i2c bus */
408 static int brcmstb_i2c_write_data_byte(struct brcmstb_i2c_dev *dev,
409 				       u8 *buf, unsigned int nak_expected)
410 {
411 	enum bsc_xfer_cmd cmd = nak_expected ? CMD_WR : CMD_WR_NOACK;
412 
413 	bsc_writel(dev, 1, cnt_reg);
414 	bsc_writel(dev, *buf, data_in);
415 
416 	return brcmstb_send_i2c_cmd(dev, cmd);
417 }
418 
419 /* Send i2c address */
420 static int brcmstb_i2c_do_addr(struct brcmstb_i2c_dev *dev,
421 			       struct i2c_msg *msg)
422 {
423 	unsigned char addr;
424 
425 	if (msg->flags & I2C_M_TEN) {
426 		/* First byte is 11110XX0 where XX is upper 2 bits */
427 		addr = 0xF0 | ((msg->addr & 0x300) >> 7);
428 		bsc_writel(dev, addr, chip_address);
429 
430 		/* Second byte is the remaining 8 bits */
431 		addr = msg->addr & 0xFF;
432 		if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
433 			return -EREMOTEIO;
434 
435 		if (msg->flags & I2C_M_RD) {
436 			/* For read, send restart without stop condition */
437 			brcmstb_set_i2c_start_stop(dev, COND_RESTART
438 						   | COND_NOSTOP);
439 			/* Then re-send the first byte with the read bit set */
440 			addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
441 			if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
442 				return -EREMOTEIO;
443 
444 		}
445 	} else {
446 		addr = i2c_8bit_addr_from_msg(msg);
447 
448 		bsc_writel(dev, addr, chip_address);
449 	}
450 
451 	return 0;
452 }
453 
454 /* Master transfer function */
455 static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
456 			    struct i2c_msg msgs[], int num)
457 {
458 	struct brcmstb_i2c_dev *dev = i2c_get_adapdata(adapter);
459 	struct i2c_msg *pmsg;
460 	int rc = 0;
461 	int i;
462 	int bytes_to_xfer;
463 	u8 *tmp_buf;
464 	int len = 0;
465 	int xfersz = brcmstb_i2c_get_xfersz(dev);
466 	u32 cond, cond_per_msg;
467 
468 	/* Loop through all messages */
469 	for (i = 0; i < num; i++) {
470 		pmsg = &msgs[i];
471 		len = pmsg->len;
472 		tmp_buf = pmsg->buf;
473 
474 		dev_dbg(dev->device,
475 			"msg# %d/%d flg %x buf %x len %d\n", i,
476 			num - 1, pmsg->flags,
477 			pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
478 
479 		if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
480 			cond = ~COND_START_STOP;
481 		else
482 			cond = COND_RESTART | COND_NOSTOP;
483 
484 		brcmstb_set_i2c_start_stop(dev, cond);
485 
486 		/* Send slave address */
487 		if (!(pmsg->flags & I2C_M_NOSTART)) {
488 			rc = brcmstb_i2c_do_addr(dev, pmsg);
489 			if (rc < 0) {
490 				dev_dbg(dev->device,
491 					"NACK for addr %2.2x msg#%d rc = %d\n",
492 					pmsg->addr, i, rc);
493 				goto out;
494 			}
495 		}
496 
497 		cond_per_msg = cond;
498 
499 		/* Perform data transfer */
500 		while (len) {
501 			bytes_to_xfer = min(len, xfersz);
502 
503 			if (len <= xfersz) {
504 				if (i == (num - 1))
505 					cond_per_msg = cond_per_msg &
506 						~(COND_RESTART | COND_NOSTOP);
507 				else
508 					cond_per_msg = cond;
509 			} else {
510 				cond_per_msg = (cond_per_msg & ~COND_RESTART) |
511 					COND_NOSTOP;
512 			}
513 
514 			brcmstb_set_i2c_start_stop(dev, cond_per_msg);
515 
516 			rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
517 						       bytes_to_xfer, pmsg);
518 			if (rc < 0)
519 				goto out;
520 
521 			len -=  bytes_to_xfer;
522 			tmp_buf += bytes_to_xfer;
523 
524 			cond_per_msg = COND_NOSTART | COND_NOSTOP;
525 		}
526 	}
527 
528 	rc = num;
529 out:
530 	return rc;
531 
532 }
533 
534 static u32 brcmstb_i2c_functionality(struct i2c_adapter *adap)
535 {
536 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR
537 		| I2C_FUNC_NOSTART | I2C_FUNC_PROTOCOL_MANGLING;
538 }
539 
540 static const struct i2c_algorithm brcmstb_i2c_algo = {
541 	.master_xfer = brcmstb_i2c_xfer,
542 	.functionality = brcmstb_i2c_functionality,
543 };
544 
545 static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev)
546 {
547 	int i = 0, num_speeds = ARRAY_SIZE(bsc_clk);
548 	u32 clk_freq_hz = dev->clk_freq_hz;
549 
550 	for (i = 0; i < num_speeds; i++) {
551 		if (bsc_clk[i].hz == clk_freq_hz) {
552 			dev->bsc_regmap->ctl_reg &= ~(BSC_CTL_REG_SCL_SEL_MASK
553 						| BSC_CTL_REG_DIV_CLK_MASK);
554 			dev->bsc_regmap->ctl_reg |= (bsc_clk[i].scl_mask |
555 						     bsc_clk[i].div_mask);
556 			bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
557 			break;
558 		}
559 	}
560 
561 	/* in case we did not get find a valid speed */
562 	if (i == num_speeds) {
563 		i = (bsc_readl(dev, ctl_reg) & BSC_CTL_REG_SCL_SEL_MASK) >>
564 			BSC_CTL_REG_SCL_SEL_SHIFT;
565 		dev_warn(dev->device, "leaving current clock-frequency @ %dHz\n",
566 			bsc_clk[i].hz);
567 	}
568 }
569 
570 static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev)
571 {
572 	if (brcmstb_i2c_get_data_regsz(dev) == sizeof(u32))
573 		/* set 4 byte data in/out xfers  */
574 		dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;
575 	else
576 		dev->bsc_regmap->ctlhi_reg &= ~BSC_CTLHI_REG_DATAREG_SIZE_MASK;
577 
578 	bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg);
579 	/* set bus speed */
580 	brcmstb_i2c_set_bus_speed(dev);
581 }
582 
583 #define AUTOI2C_CTRL0		0x26c
584 #define AUTOI2C_CTRL0_RELEASE_BSC	BIT(1)
585 
586 static int bcm2711_release_bsc(struct brcmstb_i2c_dev *dev)
587 {
588 	struct platform_device *pdev = to_platform_device(dev->device);
589 	struct resource *iomem;
590 	void __iomem *autoi2c;
591 
592 	/* Map hardware registers */
593 	iomem = platform_get_resource_byname(pdev, IORESOURCE_MEM, "auto-i2c");
594 	autoi2c = devm_ioremap_resource(&pdev->dev, iomem);
595 	if (IS_ERR(autoi2c))
596 		return PTR_ERR(autoi2c);
597 
598 	writel(AUTOI2C_CTRL0_RELEASE_BSC, autoi2c + AUTOI2C_CTRL0);
599 	devm_iounmap(&pdev->dev, autoi2c);
600 
601 	/* We need to reset the controller after the release */
602 	dev->bsc_regmap->iic_enable = 0;
603 	bsc_writel(dev, dev->bsc_regmap->iic_enable, iic_enable);
604 
605 	return 0;
606 }
607 
608 static int brcmstb_i2c_probe(struct platform_device *pdev)
609 {
610 	int rc = 0;
611 	struct brcmstb_i2c_dev *dev;
612 	struct i2c_adapter *adap;
613 	struct resource *iomem;
614 	const char *int_name;
615 
616 	/* Allocate memory for private data structure */
617 	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
618 	if (!dev)
619 		return -ENOMEM;
620 
621 	dev->bsc_regmap = devm_kzalloc(&pdev->dev, sizeof(*dev->bsc_regmap), GFP_KERNEL);
622 	if (!dev->bsc_regmap)
623 		return -ENOMEM;
624 
625 	platform_set_drvdata(pdev, dev);
626 	dev->device = &pdev->dev;
627 	init_completion(&dev->done);
628 
629 	/* Map hardware registers */
630 	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
631 	dev->base = devm_ioremap_resource(dev->device, iomem);
632 	if (IS_ERR(dev->base)) {
633 		rc = -ENOMEM;
634 		goto probe_errorout;
635 	}
636 
637 	if (of_device_is_compatible(dev->device->of_node,
638 				    "brcm,bcm2711-hdmi-i2c")) {
639 		rc = bcm2711_release_bsc(dev);
640 		if (rc)
641 			goto probe_errorout;
642 	}
643 
644 	rc = of_property_read_string(dev->device->of_node, "interrupt-names",
645 				     &int_name);
646 	if (rc < 0)
647 		int_name = NULL;
648 
649 	/* Get the interrupt number */
650 	dev->irq = platform_get_irq_optional(pdev, 0);
651 
652 	/* disable the bsc interrupt line */
653 	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
654 
655 	/* register the ISR handler */
656 	if (dev->irq >= 0) {
657 		rc = devm_request_irq(&pdev->dev, dev->irq, brcmstb_i2c_isr,
658 				      IRQF_SHARED,
659 				      int_name ? int_name : pdev->name,
660 				      dev);
661 
662 		if (rc) {
663 			dev_dbg(dev->device, "falling back to polling mode");
664 			dev->irq = -1;
665 		}
666 	}
667 
668 	if (of_property_read_u32(dev->device->of_node,
669 				 "clock-frequency", &dev->clk_freq_hz)) {
670 		dev_warn(dev->device, "setting clock-frequency@%dHz\n",
671 			 bsc_clk[0].hz);
672 		dev->clk_freq_hz = bsc_clk[0].hz;
673 	}
674 
675 	/* set the data in/out register size for compatible SoCs */
676 	if (of_device_is_compatible(dev->device->of_node,
677 				    "brcmstb,brcmper-i2c"))
678 		dev->data_regsz = sizeof(u8);
679 	else
680 		dev->data_regsz = sizeof(u32);
681 
682 	brcmstb_i2c_set_bsc_reg_defaults(dev);
683 
684 	/* Add the i2c adapter */
685 	adap = &dev->adapter;
686 	i2c_set_adapdata(adap, dev);
687 	adap->owner = THIS_MODULE;
688 	strlcpy(adap->name, "Broadcom STB : ", sizeof(adap->name));
689 	if (int_name)
690 		strlcat(adap->name, int_name, sizeof(adap->name));
691 	adap->algo = &brcmstb_i2c_algo;
692 	adap->dev.parent = &pdev->dev;
693 	adap->dev.of_node = pdev->dev.of_node;
694 	rc = i2c_add_adapter(adap);
695 	if (rc)
696 		goto probe_errorout;
697 
698 	dev_info(dev->device, "%s@%dhz registered in %s mode\n",
699 		 int_name ? int_name : " ", dev->clk_freq_hz,
700 		 (dev->irq >= 0) ? "interrupt" : "polling");
701 
702 	return 0;
703 
704 probe_errorout:
705 	return rc;
706 }
707 
708 static int brcmstb_i2c_remove(struct platform_device *pdev)
709 {
710 	struct brcmstb_i2c_dev *dev = platform_get_drvdata(pdev);
711 
712 	i2c_del_adapter(&dev->adapter);
713 	return 0;
714 }
715 
716 #ifdef CONFIG_PM_SLEEP
717 static int brcmstb_i2c_suspend(struct device *dev)
718 {
719 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
720 
721 	i2c_mark_adapter_suspended(&i2c_dev->adapter);
722 	return 0;
723 }
724 
725 static int brcmstb_i2c_resume(struct device *dev)
726 {
727 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
728 
729 	brcmstb_i2c_set_bsc_reg_defaults(i2c_dev);
730 	i2c_mark_adapter_resumed(&i2c_dev->adapter);
731 
732 	return 0;
733 }
734 #endif
735 
736 static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend,
737 			 brcmstb_i2c_resume);
738 
739 static const struct of_device_id brcmstb_i2c_of_match[] = {
740 	{.compatible = "brcm,brcmstb-i2c"},
741 	{.compatible = "brcm,brcmper-i2c"},
742 	{.compatible = "brcm,bcm2711-hdmi-i2c"},
743 	{},
744 };
745 MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);
746 
747 static struct platform_driver brcmstb_i2c_driver = {
748 	.driver = {
749 		   .name = "brcmstb-i2c",
750 		   .of_match_table = brcmstb_i2c_of_match,
751 		   .pm = &brcmstb_i2c_pm,
752 		   },
753 	.probe = brcmstb_i2c_probe,
754 	.remove = brcmstb_i2c_remove,
755 };
756 module_platform_driver(brcmstb_i2c_driver);
757 
758 MODULE_AUTHOR("Kamal Dasu <kdasu@broadcom.com>");
759 MODULE_DESCRIPTION("Broadcom Settop I2C Driver");
760 MODULE_LICENSE("GPL v2");
761