xref: /freebsd/sys/arm/nvidia/tegra_i2c.c (revision ec65e4f8d0654361df5e97d4de3518edebf76b46)
1 /*-
2  * Copyright (c) 2016 Michal Meloun <mmel@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 /*
31  * I2C driver for Tegra SoCs.
32  */
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/bus.h>
36 #include <sys/kernel.h>
37 #include <sys/limits.h>
38 #include <sys/module.h>
39 #include <sys/resource.h>
40 
41 #include <machine/bus.h>
42 #include <machine/resource.h>
43 #include <sys/rman.h>
44 
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 
48 #include <dev/extres/clk/clk.h>
49 #include <dev/extres/hwreset/hwreset.h>
50 #include <dev/fdt/fdt_common.h>
51 #include <dev/iicbus/iiconf.h>
52 #include <dev/iicbus/iicbus.h>
53 #include <dev/ofw/ofw_bus.h>
54 #include <dev/ofw/ofw_bus_subr.h>
55 
56 #include "iicbus_if.h"
57 
58 #define	I2C_CNFG				0x000
59 #define	 I2C_CNFG_MSTR_CLR_BUS_ON_TIMEOUT		(1 << 15)
60 #define	 I2C_CNFG_DEBOUNCE_CNT(x)			(((x) & 0x07) << 12)
61 #define	 I2C_CNFG_NEW_MASTER_FSM			(1 << 11)
62 #define	 I2C_CNFG_PACKET_MODE_EN			(1 << 10)
63 #define	 I2C_CNFG_SEND					(1 <<  9)
64 #define	 I2C_CNFG_NOACK					(1 <<  8)
65 #define	 I2C_CNFG_CMD2					(1 <<  7)
66 #define	 I2C_CNFG_CMD1					(1 <<  6)
67 #define	 I2C_CNFG_START					(1 <<  5)
68 #define	 I2C_CNFG_SLV2					(1 <<  4)
69 #define	 I2C_CNFG_LENGTH_SHIFT				1
70 #define	 I2C_CNFG_LENGTH_MASK				0x7
71 #define	 I2C_CNFG_A_MOD					(1 <<  0)
72 
73 #define	I2C_CMD_ADDR0				0x004
74 #define	I2C_CMD_ADDR1				0x008
75 #define	I2C_CMD_DATA1				0x00c
76 #define	I2C_CMD_DATA2				0x010
77 #define	I2C_STATUS				0x01c
78 #define	I2C_SL_CNFG				0x020
79 #define	I2C_SL_RCVD				0x024
80 #define	I2C_SL_STATUS				0x028
81 #define	I2C_SL_ADDR1				0x02c
82 #define	I2C_SL_ADDR2				0x030
83 #define	I2C_TLOW_SEXT				0x034
84 #define	I2C_SL_DELAY_COUNT			0x03c
85 #define	I2C_SL_INT_MASK				0x040
86 #define	I2C_SL_INT_SOURCE			0x044
87 #define	I2C_SL_INT_SET				0x048
88 #define	I2C_TX_PACKET_FIFO			0x050
89 #define	I2C_RX_FIFO				0x054
90 #define	I2C_PACKET_TRANSFER_STATUS		0x058
91 #define	I2C_FIFO_CONTROL			0x05c
92 #define	 I2C_FIFO_CONTROL_SLV_TX_FIFO_TRIG(x)		(((x) & 0x07) << 13)
93 #define	 I2C_FIFO_CONTROL_SLV_RX_FIFO_TRIG(x)		(((x) & 0x07) << 10)
94 #define	 I2C_FIFO_CONTROL_SLV_TX_FIFO_FLUSH		(1 <<  9)
95 #define	 I2C_FIFO_CONTROL_SLV_RX_FIFO_FLUSH		(1 <<  8)
96 #define	 I2C_FIFO_CONTROL_TX_FIFO_TRIG(x)		(((x) & 0x07) << 5)
97 #define	 I2C_FIFO_CONTROL_RX_FIFO_TRIG(x)		(((x) & 0x07) << 2)
98 #define	 I2C_FIFO_CONTROL_TX_FIFO_FLUSH			(1 << 1)
99 #define	 I2C_FIFO_CONTROL_RX_FIFO_FLUSH			(1 << 0)
100 
101 #define	I2C_FIFO_STATUS				0x060
102 #define	 I2C_FIFO_STATUS_SLV_XFER_ERR_REASON		(1 << 25)
103 #define	 I2C_FIFO_STATUS_TX_FIFO_SLV_EMPTY_CNT(x)	(((x) >> 20) & 0xF)
104 #define	 I2C_FIFO_STATUS_RX_FIFO_SLV_FULL_CNT(x)	(((x) >> 16) & 0xF)
105 #define	 I2C_FIFO_STATUS_TX_FIFO_EMPTY_CNT(x)		(((x) >>  4) & 0xF)
106 #define	 I2C_FIFO_STATUS_RX_FIFO_FULL_CNT(x)		(((x) >>  0) & 0xF)
107 
108 #define	I2C_INTERRUPT_MASK_REGISTER		0x064
109 #define	I2C_INTERRUPT_STATUS_REGISTER		0x068
110 #define	 I2C_INT_SLV_ACK_WITHHELD			(1 << 28)
111 #define	 I2C_INT_SLV_RD2WR				(1 << 27)
112 #define	 I2C_INT_SLV_WR2RD				(1 << 26)
113 #define	 I2C_INT_SLV_PKT_XFER_ERR			(1 << 25)
114 #define	 I2C_INT_SLV_TX_BUFFER_REQ			(1 << 24)
115 #define	 I2C_INT_SLV_RX_BUFFER_FILLED			(1 << 23)
116 #define	 I2C_INT_SLV_PACKET_XFER_COMPLETE		(1 << 22)
117 #define	 I2C_INT_SLV_TFIFO_OVF				(1 << 21)
118 #define	 I2C_INT_SLV_RFIFO_UNF				(1 << 20)
119 #define	 I2C_INT_SLV_TFIFO_DATA_REQ			(1 << 17)
120 #define	 I2C_INT_SLV_RFIFO_DATA_REQ			(1 << 16)
121 #define	 I2C_INT_BUS_CLEAR_DONE				(1 << 11)
122 #define	 I2C_INT_TLOW_MEXT_TIMEOUT			(1 << 10)
123 #define	 I2C_INT_TLOW_SEXT_TIMEOUT			(1 <<  9)
124 #define	 I2C_INT_TIMEOUT				(1 <<  8)
125 #define	 I2C_INT_PACKET_XFER_COMPLETE			(1 <<  7)
126 #define	 I2C_INT_ALL_PACKETS_XFER_COMPLETE		(1 <<  6)
127 #define	 I2C_INT_TFIFO_OVR				(1 <<  5)
128 #define	 I2C_INT_RFIFO_UNF				(1 <<  4)
129 #define	 I2C_INT_NOACK					(1 <<  3)
130 #define	 I2C_INT_ARB_LOST				(1 <<  2)
131 #define	 I2C_INT_TFIFO_DATA_REQ				(1 <<  1)
132 #define	 I2C_INT_RFIFO_DATA_REQ				(1 <<  0)
133 #define	 I2C_ERROR_MASK		(I2C_INT_ARB_LOST | I2C_INT_NOACK |	 \
134 				I2C_INT_RFIFO_UNF | I2C_INT_TFIFO_OVR)
135 
136 #define	I2C_CLK_DIVISOR				0x06c
137 #define	 I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT		16
138 #define	 I2C_CLK_DIVISOR_STD_FAST_MODE_MASK		0xffff
139 #define	 I2C_CLK_DIVISOR_HSMODE_SHIFT			0
140 #define	 I2C_CLK_DIVISOR_HSMODE_MASK			0xffff
141 #define	I2C_INTERRUPT_SOURCE_REGISTER		0x070
142 #define	I2C_INTERRUPT_SET_REGISTER		0x074
143 #define	I2C_SLV_TX_PACKET_FIFO			0x07c
144 #define	I2C_SLV_PACKET_STATUS			0x080
145 #define	I2C_BUS_CLEAR_CONFIG			0x084
146 #define	 I2C_BUS_CLEAR_CONFIG_BC_SCLK_THRESHOLD(x)	(((x) & 0xFF) << 16)
147 #define	 I2C_BUS_CLEAR_CONFIG_BC_STOP_COND		(1 << 2)
148 #define	 I2C_BUS_CLEAR_CONFIG_BC_TERMINATE		(1 << 1)
149 #define	 I2C_BUS_CLEAR_CONFIG_BC_ENABLE			(1 << 0)
150 
151 #define	I2C_BUS_CLEAR_STATUS			0x088
152 #define	 I2C_BUS_CLEAR_STATUS_BC_STATUS			(1 << 0)
153 
154 #define	I2C_CONFIG_LOAD				0x08c
155 #define	 I2C_CONFIG_LOAD_TIMEOUT_CONFIG_LOAD		(1 << 2)
156 #define	 I2C_CONFIG_LOAD_SLV_CONFIG_LOAD		(1 << 1)
157 #define	 I2C_CONFIG_LOAD_MSTR_CONFIG_LOAD		(1 << 0)
158 
159 #define	I2C_INTERFACE_TIMING_0			0x094
160 #define	I2C_INTERFACE_TIMING_1			0x098
161 #define	I2C_HS_INTERFACE_TIMING_0		0x09c
162 #define	I2C_HS_INTERFACE_TIMING_1		0x0a0
163 
164 /* Protocol header 0 */
165 #define	PACKET_HEADER0_HEADER_SIZE_SHIFT	28
166 #define	PACKET_HEADER0_HEADER_SIZE_MASK		0x3
167 #define	PACKET_HEADER0_PACKET_ID_SHIFT		16
168 #define	PACKET_HEADER0_PACKET_ID_MASK		0xff
169 #define	PACKET_HEADER0_CONT_ID_SHIFT		12
170 #define	PACKET_HEADER0_CONT_ID_MASK		0xf
171 #define	PACKET_HEADER0_PROTOCOL_I2C		(1 << 4)
172 #define	PACKET_HEADER0_TYPE_SHIFT		0
173 #define	PACKET_HEADER0_TYPE_MASK		0x7
174 
175 /* I2C header */
176 #define	I2C_HEADER_HIGHSPEED_MODE		(1 << 22)
177 #define	I2C_HEADER_CONT_ON_NAK			(1 << 21)
178 #define	I2C_HEADER_SEND_START_BYTE		(1 << 20)
179 #define	I2C_HEADER_READ				(1 << 19)
180 #define	I2C_HEADER_10BIT_ADDR			(1 << 18)
181 #define	I2C_HEADER_IE_ENABLE			(1 << 17)
182 #define	I2C_HEADER_REPEAT_START			(1 << 16)
183 #define	I2C_HEADER_CONTINUE_XFER		(1 << 15)
184 #define	I2C_HEADER_MASTER_ADDR_SHIFT		12
185 #define	I2C_HEADER_MASTER_ADDR_MASK		0x7
186 #define	I2C_HEADER_SLAVE_ADDR_SHIFT		0
187 #define	I2C_HEADER_SLAVE_ADDR_MASK		0x3ff
188 
189 #define	I2C_CLK_DIVISOR_STD_FAST_MODE		0x19
190 #define	I2C_CLK_MULTIPLIER_STD_FAST_MODE	8
191 
192 #define	I2C_REQUEST_TIMEOUT			(5 * hz)
193 
194 #define	WR4(_sc, _r, _v)	bus_write_4((_sc)->mem_res, (_r), (_v))
195 #define	RD4(_sc, _r)		bus_read_4((_sc)->mem_res, (_r))
196 
197 #define	LOCK(_sc)		mtx_lock(&(_sc)->mtx)
198 #define	UNLOCK(_sc)		mtx_unlock(&(_sc)->mtx)
199 #define	SLEEP(_sc, timeout)						\
200 	mtx_sleep(sc, &sc->mtx, 0, "i2cbuswait", timeout);
201 #define	LOCK_INIT(_sc)							\
202 	mtx_init(&_sc->mtx, device_get_nameunit(_sc->dev), "tegra_i2c", MTX_DEF)
203 #define	LOCK_DESTROY(_sc)	mtx_destroy(&_sc->mtx)
204 #define	ASSERT_LOCKED(_sc)	mtx_assert(&_sc->mtx, MA_OWNED)
205 #define	ASSERT_UNLOCKED(_sc)	mtx_assert(&_sc->mtx, MA_NOTOWNED)
206 
207 static struct ofw_compat_data compat_data[] = {
208 	{"nvidia,tegra124-i2c",	1},
209 	{NULL,			0}
210 };
211 enum tegra_i2c_xfer_type {
212 	XFER_STOP, 		/* Send stop condition after xfer */
213 	XFER_REPEAT_START,	/* Send repeated start after xfer */
214 	XFER_CONTINUE		/* Don't send nothing */
215 } ;
216 
217 struct tegra_i2c_softc {
218 	device_t		dev;
219 	struct mtx		mtx;
220 
221 	struct resource		*mem_res;
222 	struct resource		*irq_res;
223 	void			*irq_h;
224 
225 	device_t		iicbus;
226 	clk_t			clk;
227 	hwreset_t		reset;
228 	uint32_t		core_freq;
229 	uint32_t		bus_freq;
230 	int			bus_inuse;
231 
232 	struct iic_msg		*msg;
233 	int			msg_idx;
234 	uint32_t		bus_err;
235 	int			done;
236 };
237 
238 static int
239 tegra_i2c_flush_fifo(struct tegra_i2c_softc *sc)
240 {
241 	int timeout;
242 	uint32_t reg;
243 
244 	reg = RD4(sc, I2C_FIFO_CONTROL);
245 	reg |= I2C_FIFO_CONTROL_TX_FIFO_FLUSH | I2C_FIFO_CONTROL_RX_FIFO_FLUSH;
246 	WR4(sc, I2C_FIFO_CONTROL, reg);
247 
248 	timeout = 10;
249 	while (timeout > 0) {
250 		reg = RD4(sc, I2C_FIFO_CONTROL);
251 		reg &= I2C_FIFO_CONTROL_TX_FIFO_FLUSH |
252 		    I2C_FIFO_CONTROL_RX_FIFO_FLUSH;
253 		if (reg == 0)
254 			break;
255 		DELAY(10);
256 	}
257 	if (timeout <= 0) {
258 		device_printf(sc->dev, "FIFO flush timedout\n");
259 		return (ETIMEDOUT);
260 	}
261 	return (0);
262 }
263 
264 static void
265 tegra_i2c_setup_clk(struct tegra_i2c_softc *sc, int clk_freq)
266 {
267 	int div;
268 
269 	div = ((sc->core_freq  / clk_freq)  / 10) - 1;
270 	if ((sc->core_freq / (10 * (div + 1)))  > clk_freq)
271 		div++;
272 	if (div > 65535)
273 		div = 65535;
274 	WR4(sc, I2C_CLK_DIVISOR,
275 	    (1 << I2C_CLK_DIVISOR_HSMODE_SHIFT) |
276 	    (div << I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT));
277 }
278 
279 static void
280 tegra_i2c_bus_clear(struct tegra_i2c_softc *sc)
281 {
282 	int timeout;
283 	uint32_t reg, status;
284 
285 	WR4(sc, I2C_BUS_CLEAR_CONFIG,
286 	    I2C_BUS_CLEAR_CONFIG_BC_SCLK_THRESHOLD(18) |
287 	    I2C_BUS_CLEAR_CONFIG_BC_STOP_COND |
288 	    I2C_BUS_CLEAR_CONFIG_BC_TERMINATE);
289 
290 	WR4(sc, I2C_CONFIG_LOAD, I2C_CONFIG_LOAD_MSTR_CONFIG_LOAD);
291 	for (timeout = 1000; timeout > 0; timeout--) {
292 		if (RD4(sc, I2C_CONFIG_LOAD) == 0)
293 			break;
294 		DELAY(10);
295 	}
296 	if (timeout <= 0)
297 		device_printf(sc->dev, "config load timeouted\n");
298 	reg = RD4(sc, I2C_BUS_CLEAR_CONFIG);
299 	reg |= I2C_BUS_CLEAR_CONFIG_BC_ENABLE;
300 	WR4(sc, I2C_BUS_CLEAR_CONFIG,reg);
301 
302 	for (timeout = 1000; timeout > 0; timeout--) {
303 		if ((RD4(sc, I2C_BUS_CLEAR_CONFIG) &
304 		    I2C_BUS_CLEAR_CONFIG_BC_ENABLE) == 0)
305 			break;
306 		DELAY(10);
307 	}
308 	if (timeout <= 0)
309 		device_printf(sc->dev, "bus clear timeouted\n");
310 
311 	status = RD4(sc, I2C_BUS_CLEAR_STATUS);
312 	if ((status & I2C_BUS_CLEAR_STATUS_BC_STATUS) == 0)
313 		device_printf(sc->dev, "bus clear failed\n");
314 }
315 
316 static int
317 tegra_i2c_hw_init(struct tegra_i2c_softc *sc)
318 {
319 	int rv, timeout;
320 
321 	/* Reset the core. */
322 	rv = hwreset_assert(sc->reset);
323 	if (rv != 0) {
324 		device_printf(sc->dev, "Cannot assert reset\n");
325 		return (rv);
326 	}
327 	DELAY(10);
328 	rv = hwreset_deassert(sc->reset);
329 	if (rv != 0) {
330 		device_printf(sc->dev, "Cannot clear reset\n");
331 		return (rv);
332 	}
333 
334 	WR4(sc, I2C_INTERRUPT_MASK_REGISTER, 0);
335 	WR4(sc, I2C_INTERRUPT_STATUS_REGISTER, 0xFFFFFFFF);
336 	WR4(sc, I2C_CNFG, I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
337 	    I2C_CNFG_DEBOUNCE_CNT(2));
338 
339 	tegra_i2c_setup_clk(sc, sc->bus_freq);
340 
341 	WR4(sc, I2C_FIFO_CONTROL, I2C_FIFO_CONTROL_TX_FIFO_TRIG(7) |
342 	    I2C_FIFO_CONTROL_RX_FIFO_TRIG(0));
343 
344 	WR4(sc, I2C_CONFIG_LOAD, I2C_CONFIG_LOAD_MSTR_CONFIG_LOAD);
345 	for (timeout = 1000; timeout > 0; timeout--) {
346 		if (RD4(sc, I2C_CONFIG_LOAD) == 0)
347 			break;
348 		DELAY(10);
349 	}
350 	if (timeout <= 0)
351 		device_printf(sc->dev, "config load timeouted\n");
352 
353 	tegra_i2c_bus_clear(sc);
354 	return (0);
355 }
356 
357 static int
358 tegra_i2c_tx(struct tegra_i2c_softc *sc)
359 {
360 	uint32_t reg;
361 	int cnt, i;
362 
363 	if (sc->msg_idx >= sc->msg->len)
364 		panic("Invalid call to tegra_i2c_tx\n");
365 
366 	while(sc->msg_idx < sc->msg->len) {
367 		reg = RD4(sc, I2C_FIFO_STATUS);
368 		if (I2C_FIFO_STATUS_TX_FIFO_EMPTY_CNT(reg) == 0)
369 			break;
370 		cnt = min(4, sc->msg->len - sc->msg_idx);
371 		reg = 0;
372 		for (i = 0;  i < cnt; i++) {
373 			reg |=  sc->msg->buf[sc->msg_idx] << (i * 8);
374 			sc->msg_idx++;
375 		}
376 		WR4(sc, I2C_TX_PACKET_FIFO, reg);
377 	}
378 	if (sc->msg_idx >= sc->msg->len)
379 		return (0);
380 	return (sc->msg->len - sc->msg_idx - 1);
381 }
382 
383 static int
384 tegra_i2c_rx(struct tegra_i2c_softc *sc)
385 {
386 	uint32_t reg;
387 	int cnt, i;
388 
389 	if (sc->msg_idx >= sc->msg->len)
390 		panic("Invalid call to tegra_i2c_rx\n");
391 
392 	while(sc->msg_idx < sc->msg->len) {
393 		reg = RD4(sc, I2C_FIFO_STATUS);
394 		if (I2C_FIFO_STATUS_RX_FIFO_FULL_CNT(reg) == 0)
395 			break;
396 		cnt = min(4, sc->msg->len - sc->msg_idx);
397 		reg = RD4(sc, I2C_RX_FIFO);
398 		for (i = 0;  i < cnt; i++) {
399 			sc->msg->buf[sc->msg_idx] = (reg >> (i * 8)) & 0xFF;
400 			sc->msg_idx++;
401 		}
402 	}
403 
404 	if (sc->msg_idx >= sc->msg->len)
405 		return (0);
406 	return (sc->msg->len - sc->msg_idx - 1);
407 }
408 
409 static void
410 tegra_i2c_intr(void *arg)
411 {
412 	struct tegra_i2c_softc *sc;
413 	uint32_t status, reg;
414 	int rv;
415 
416 	sc = (struct tegra_i2c_softc *)arg;
417 
418 	LOCK(sc);
419 	status = RD4(sc, I2C_INTERRUPT_SOURCE_REGISTER);
420 	if (sc->msg == NULL) {
421 		/* Unexpected interrupt - disable FIFOs, clear reset. */
422 		reg = RD4(sc, I2C_INTERRUPT_MASK_REGISTER);
423 		reg &= ~I2C_INT_TFIFO_DATA_REQ;
424 		reg &= ~I2C_INT_RFIFO_DATA_REQ;
425 		WR4(sc, I2C_INTERRUPT_MASK_REGISTER, 0);
426 		WR4(sc, I2C_INTERRUPT_STATUS_REGISTER, status);
427 		UNLOCK(sc);
428 		return;
429 	}
430 
431 	if ((status & I2C_ERROR_MASK) != 0) {
432 		if (status & I2C_INT_NOACK)
433 			sc->bus_err = IIC_ENOACK;
434 		if (status & I2C_INT_ARB_LOST)
435 			sc->bus_err = IIC_EBUSERR;
436 		if ((status & I2C_INT_TFIFO_OVR) ||
437 		    (status & I2C_INT_RFIFO_UNF))
438 			sc->bus_err = IIC_EBUSERR;
439 		sc->done = 1;
440 	} else if ((status & I2C_INT_RFIFO_DATA_REQ) &&
441 	    (sc->msg != NULL) && (sc->msg->flags & IIC_M_RD)) {
442 		rv = tegra_i2c_rx(sc);
443 		if (rv == 0) {
444 			reg = RD4(sc, I2C_INTERRUPT_MASK_REGISTER);
445 			reg &= ~I2C_INT_RFIFO_DATA_REQ;
446 			WR4(sc, I2C_INTERRUPT_MASK_REGISTER, reg);
447 		}
448 	} else if ((status & I2C_INT_TFIFO_DATA_REQ) &&
449 	    (sc->msg != NULL) && !(sc->msg->flags & IIC_M_RD)) {
450 		rv = tegra_i2c_tx(sc);
451 		if (rv == 0) {
452 			reg = RD4(sc, I2C_INTERRUPT_MASK_REGISTER);
453 			reg &= ~I2C_INT_TFIFO_DATA_REQ;
454 			WR4(sc, I2C_INTERRUPT_MASK_REGISTER, reg);
455 		}
456 	} else if ((status & I2C_INT_RFIFO_DATA_REQ) ||
457 		    (status & I2C_INT_TFIFO_DATA_REQ)) {
458 		device_printf(sc->dev, "Unexpected data interrupt: 0x%08X\n",
459 		    status);
460 		reg = RD4(sc, I2C_INTERRUPT_MASK_REGISTER);
461 		reg &= ~I2C_INT_TFIFO_DATA_REQ;
462 		reg &= ~I2C_INT_RFIFO_DATA_REQ;
463 		WR4(sc, I2C_INTERRUPT_MASK_REGISTER, reg);
464 	}
465 	if (status & I2C_INT_PACKET_XFER_COMPLETE)
466 		sc->done = 1;
467 	WR4(sc, I2C_INTERRUPT_STATUS_REGISTER, status);
468 	if (sc->done) {
469 		WR4(sc, I2C_INTERRUPT_MASK_REGISTER, 0);
470 		wakeup(&(sc->done));
471 	}
472 	UNLOCK(sc);
473 }
474 
475 static void
476 tegra_i2c_start_msg(struct tegra_i2c_softc *sc, struct iic_msg *msg,
477     enum tegra_i2c_xfer_type xtype)
478 {
479 	uint32_t tmp, mask;
480 
481 	/* Packet header. */
482 	tmp =  (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
483 	   PACKET_HEADER0_PROTOCOL_I2C |
484 	   (1 << PACKET_HEADER0_CONT_ID_SHIFT) |
485 	   (1 << PACKET_HEADER0_PACKET_ID_SHIFT);
486 	WR4(sc, I2C_TX_PACKET_FIFO, tmp);
487 
488 
489 	/* Packet size. */
490 	WR4(sc, I2C_TX_PACKET_FIFO, msg->len - 1);
491 
492 	/* I2C header. */
493 	tmp = I2C_HEADER_IE_ENABLE;
494 	if (xtype == XFER_CONTINUE)
495 		tmp |= I2C_HEADER_CONTINUE_XFER;
496 	else if (xtype == XFER_REPEAT_START)
497 		tmp |= I2C_HEADER_REPEAT_START;
498 	tmp |= msg->slave << I2C_HEADER_SLAVE_ADDR_SHIFT;
499 	if (msg->flags & IIC_M_RD) {
500 		tmp |= I2C_HEADER_READ;
501 		tmp |= 1 << I2C_HEADER_SLAVE_ADDR_SHIFT;
502 	} else
503 		tmp &= ~(1 << I2C_HEADER_SLAVE_ADDR_SHIFT);
504 
505 	WR4(sc, I2C_TX_PACKET_FIFO, tmp);
506 
507 	/* Interrupt mask. */
508 	mask = I2C_INT_NOACK | I2C_INT_ARB_LOST | I2C_INT_PACKET_XFER_COMPLETE;
509 	if (msg->flags & IIC_M_RD)
510 		mask |= I2C_INT_RFIFO_DATA_REQ;
511 	else
512 		mask |= I2C_INT_TFIFO_DATA_REQ;
513 	WR4(sc, I2C_INTERRUPT_MASK_REGISTER, mask);
514 }
515 
516 static int
517 tegra_i2c_poll(struct tegra_i2c_softc *sc)
518 {
519 	int timeout;
520 
521 	for(timeout = 10000; timeout > 0; timeout--)  {
522 		UNLOCK(sc);
523 		tegra_i2c_intr(sc);
524 		LOCK(sc);
525 		if (sc->done != 0)
526 			 break;
527 		DELAY(1);
528 	}
529 	if (timeout <= 0)
530 		return (ETIMEDOUT);
531 	return (0);
532 }
533 
534 static int
535 tegra_i2c_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
536 {
537 	int rv, i;
538 	struct tegra_i2c_softc *sc;
539 	enum tegra_i2c_xfer_type xtype;
540 
541 	sc = device_get_softc(dev);
542 	LOCK(sc);
543 
544 	/* Get the bus. */
545 	while (sc->bus_inuse == 1)
546 		SLEEP(sc,  0);
547 	sc->bus_inuse = 1;
548 
549 	rv = 0;
550 	for (i = 0; i < nmsgs; i++) {
551 		sc->msg = &msgs[i];
552 		sc->msg_idx = 0;
553 		sc->bus_err = 0;
554 		sc->done = 0;
555 		/* Check for valid parameters. */
556 		if (sc->msg == NULL || sc->msg->buf == NULL ||
557 		    sc->msg->len == 0) {
558 			rv = EINVAL;
559 			break;
560 		}
561 
562 		/* Get flags for next transfer. */
563 		if (i == (nmsgs - 1)) {
564 			if (msgs[i].flags & IIC_M_NOSTOP)
565 				xtype = XFER_CONTINUE;
566 			else
567 				xtype = XFER_STOP;
568 		} else {
569 			if (msgs[i + 1].flags & IIC_M_NOSTART)
570 				xtype = XFER_CONTINUE;
571 			else
572 				xtype = XFER_REPEAT_START;
573 		}
574 		tegra_i2c_start_msg(sc, sc->msg, xtype);
575 		if (cold)
576 			rv = tegra_i2c_poll(sc);
577 		else
578 			rv = msleep(&sc->done, &sc->mtx, PZERO, "iic",
579 			    I2C_REQUEST_TIMEOUT);
580 
581 		WR4(sc, I2C_INTERRUPT_MASK_REGISTER, 0);
582 		WR4(sc, I2C_INTERRUPT_STATUS_REGISTER, 0xFFFFFFFF);
583 		if (rv == 0)
584 			rv = sc->bus_err;
585 		if (rv != 0)
586 			break;
587 	}
588 
589 	if (rv != 0) {
590 		tegra_i2c_hw_init(sc);
591 		tegra_i2c_flush_fifo(sc);
592 	}
593 
594 	sc->msg = NULL;
595 	sc->msg_idx = 0;
596 	sc->bus_err = 0;
597 	sc->done = 0;
598 
599 	/* Wake up the processes that are waiting for the bus. */
600 	sc->bus_inuse = 0;
601 	wakeup(sc);
602 	UNLOCK(sc);
603 
604 	return (rv);
605 }
606 
607 static int
608 tegra_i2c_iicbus_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
609 {
610 	struct tegra_i2c_softc *sc;
611 	int busfreq;
612 
613 	sc = device_get_softc(dev);
614 	busfreq = IICBUS_GET_FREQUENCY(sc->iicbus, speed);
615 	sc = device_get_softc(dev);
616 	LOCK(sc);
617 	tegra_i2c_setup_clk(sc, busfreq);
618 	UNLOCK(sc);
619 	return (0);
620 }
621 
622 static int
623 tegra_i2c_probe(device_t dev)
624 {
625 	if (!ofw_bus_status_okay(dev))
626 		return (ENXIO);
627 
628 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
629 		return (ENXIO);
630 
631 	return (BUS_PROBE_DEFAULT);
632 }
633 
634 static int
635 tegra_i2c_attach(device_t dev)
636 {
637 	int rv, rid;
638 	phandle_t node;
639 	struct tegra_i2c_softc *sc;
640 	uint64_t freq;
641 
642 	sc = device_get_softc(dev);
643 	sc->dev = dev;
644 	node = ofw_bus_get_node(dev);
645 
646 	LOCK_INIT(sc);
647 
648 	/* Get the memory resource for the register mapping. */
649 	rid = 0;
650 	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
651 	    RF_ACTIVE);
652 	if (sc->mem_res == NULL) {
653 		device_printf(dev, "Cannot map registers.\n");
654 		rv = ENXIO;
655 		goto fail;
656 	}
657 
658 	/* Allocate our IRQ resource. */
659 	rid = 0;
660 	sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
661 	    RF_ACTIVE);
662 	if (sc->irq_res == NULL) {
663 		device_printf(dev, "Cannot allocate interrupt.\n");
664 		rv = ENXIO;
665 		goto fail;
666 	}
667 
668 	/* FDT resources. */
669 	rv = clk_get_by_ofw_name(dev, "div-clk", &sc->clk);
670 	if (rv != 0) {
671 		device_printf(dev, "Cannot get i2c clock: %d\n", rv);
672 		goto fail;
673 	}
674 	rv = hwreset_get_by_ofw_name(sc->dev, "i2c", &sc->reset);
675 	if (rv != 0) {
676 		device_printf(sc->dev, "Cannot get i2c reset\n");
677 		return (ENXIO);
678 	}
679 	rv = OF_getencprop(node, "clock-frequency", &sc->bus_freq,
680 	    sizeof(sc->bus_freq));
681 	if (rv != sizeof(sc->bus_freq)) {
682 		sc->bus_freq = 100000;
683 		goto fail;
684 	}
685 
686 	/* Request maximum frequency for I2C block 136MHz (408MHz / 3). */
687 	rv = clk_set_freq(sc->clk, 136000000, CLK_SET_ROUND_DOWN);
688 	if (rv != 0) {
689 		device_printf(dev, "Cannot set clock frequency\n");
690 		goto fail;
691 	}
692 	rv = clk_get_freq(sc->clk, &freq);
693 	if (rv != 0) {
694 		device_printf(dev, "Cannot get clock frequency\n");
695 		goto fail;
696 	}
697 	sc->core_freq = (uint32_t)freq;
698 
699 	rv = clk_enable(sc->clk);
700 	if (rv != 0) {
701 		device_printf(dev, "Cannot enable clock: %d\n", rv);
702 		goto fail;
703 	}
704 
705 	/* Init hardware. */
706 	rv = tegra_i2c_hw_init(sc);
707 	if (rv) {
708 		device_printf(dev, "tegra_i2c_activate failed\n");
709 		goto fail;
710 	}
711 
712 	/* Setup interrupt. */
713 	rv = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
714 	    NULL, tegra_i2c_intr, sc, &sc->irq_h);
715 	if (rv) {
716 		device_printf(dev, "Cannot setup interrupt.\n");
717 		goto fail;
718 	}
719 
720 	/* Attach the iicbus. */
721 	sc->iicbus = device_add_child(dev, "iicbus", -1);
722 	if (sc->iicbus == NULL) {
723 		device_printf(dev, "Could not allocate iicbus instance.\n");
724 		rv = ENXIO;
725 		goto fail;
726 	}
727 
728 	/* Probe and attach the iicbus. */
729 	return (bus_generic_attach(dev));
730 
731 fail:
732 	if (sc->irq_h != NULL)
733 		bus_teardown_intr(dev, sc->irq_res, sc->irq_h);
734 	if (sc->irq_res != NULL)
735 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq_res);
736 	if (sc->mem_res != NULL)
737 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res);
738 	LOCK_DESTROY(sc);
739 
740 	return (rv);
741 }
742 
743 static int
744 tegra_i2c_detach(device_t dev)
745 {
746 	struct tegra_i2c_softc *sc;
747 	int rv;
748 
749 	sc = device_get_softc(dev);
750 	tegra_i2c_hw_init(sc);
751 	if (sc->irq_h != NULL)
752 		bus_teardown_intr(dev, sc->irq_res, sc->irq_h);
753 	if (sc->irq_res != NULL)
754 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq_res);
755 	if (sc->mem_res != NULL)
756 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res);
757 
758 	LOCK_DESTROY(sc);
759 	if (sc->iicbus)
760 	    rv = device_delete_child(dev, sc->iicbus);
761 	return (bus_generic_detach(dev));
762 }
763 
764 static phandle_t
765 tegra_i2c_get_node(device_t bus, device_t dev)
766 {
767 
768 	/* Share controller node with iibus device. */
769 	return (ofw_bus_get_node(bus));
770 }
771 
772 static device_method_t tegra_i2c_methods[] = {
773 	/* Device interface */
774 	DEVMETHOD(device_probe,		tegra_i2c_probe),
775 	DEVMETHOD(device_attach,	tegra_i2c_attach),
776 	DEVMETHOD(device_detach,	tegra_i2c_detach),
777 
778 	/* Bus interface */
779 	DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
780 	DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
781 	DEVMETHOD(bus_alloc_resource,	bus_generic_alloc_resource),
782 	DEVMETHOD(bus_release_resource,	bus_generic_release_resource),
783 	DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
784 	DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
785 	DEVMETHOD(bus_adjust_resource,	bus_generic_adjust_resource),
786 	DEVMETHOD(bus_set_resource,	bus_generic_rl_set_resource),
787 	DEVMETHOD(bus_get_resource,	bus_generic_rl_get_resource),
788 
789 	/* OFW methods */
790 	DEVMETHOD(ofw_bus_get_node,	tegra_i2c_get_node),
791 
792 	/* iicbus interface */
793 	DEVMETHOD(iicbus_callback,	iicbus_null_callback),
794 	DEVMETHOD(iicbus_reset,		tegra_i2c_iicbus_reset),
795 	DEVMETHOD(iicbus_transfer,	tegra_i2c_transfer),
796 
797 	DEVMETHOD_END
798 };
799 
800 DEFINE_CLASS_0(iichb, tegra_i2c_driver, tegra_i2c_methods,
801     sizeof(struct tegra_i2c_softc));
802 static devclass_t tegra_i2c_devclass;
803 EARLY_DRIVER_MODULE(iichb, simplebus, tegra_i2c_driver, tegra_i2c_devclass, 0,
804     0, 73);
805