xref: /freebsd/sys/powerpc/powermac/kiic.c (revision aa64588d28258aef88cc33b8043112e8856948d0)
1 /*-
2  * Copyright (c) 2001 Tsubai Masanari.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. The name of the author may not be used to endorse or promote products
13  *    derived from this software without specific prior written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  *	NetBSD: ki2c.c,v 1.11 2007/12/06 17:00:33 ad Exp
28  *	Id: ki2c.c,v 1.7 2002/10/05 09:56:05 tsubai Exp
29  */
30 
31 /*
32  * 	Support routines for the Keywest I2C controller.
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/bus.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <machine/resource.h>
43 #include <machine/bus.h>
44 #include <sys/rman.h>
45 
46 #include <dev/iicbus/iicbus.h>
47 #include <dev/iicbus/iiconf.h>
48 #include <dev/ofw/ofw_bus.h>
49 #include "iicbus_if.h"
50 
51 /* Keywest I2C Register offsets */
52 #define MODE	0
53 #define CONTROL	1
54 #define STATUS	2
55 #define ISR	3
56 #define IER	4
57 #define ADDR	5
58 #define SUBADDR	6
59 #define DATA	7
60 
61 /* MODE */
62 #define I2C_SPEED	0x03	/* Speed mask */
63 #define  I2C_100kHz	0x00
64 #define  I2C_50kHz	0x01
65 #define  I2C_25kHz	0x02
66 #define I2C_MODE	0x0c	/* Mode mask */
67 #define  I2C_DUMBMODE	0x00	/*  Dumb mode */
68 #define  I2C_STDMODE	0x04	/*  Standard mode */
69 #define  I2C_STDSUBMODE	0x08	/*  Standard mode + sub address */
70 #define  I2C_COMBMODE	0x0c	/*  Combined mode */
71 #define I2C_PORT	0xf0	/* Port mask */
72 
73 /* CONTROL */
74 #define I2C_CT_AAK	0x01	/* Send AAK */
75 #define I2C_CT_ADDR	0x02	/* Send address(es) */
76 #define I2C_CT_STOP	0x04	/* Send STOP */
77 #define I2C_CT_START	0x08	/* Send START */
78 
79 /* STATUS */
80 #define I2C_ST_BUSY	0x01	/* Busy */
81 #define I2C_ST_LASTAAK	0x02	/* Last AAK */
82 #define I2C_ST_LASTRW	0x04	/* Last R/W */
83 #define I2C_ST_SDA	0x08	/* SDA */
84 #define I2C_ST_SCL	0x10	/* SCL */
85 
86 /* ISR/IER */
87 #define I2C_INT_DATA	0x01	/* Data byte sent/received */
88 #define I2C_INT_ADDR	0x02	/* Address sent */
89 #define I2C_INT_STOP	0x04	/* STOP condition sent */
90 #define I2C_INT_START	0x08	/* START condition sent */
91 
92 /* I2C flags */
93 #define I2C_BUSY	0x01
94 #define I2C_READING	0x02
95 #define I2C_ERROR	0x04
96 #define I2C_SELECTED	0x08
97 
98 struct kiic_softc {
99 	device_t 		 sc_dev;
100 	phandle_t		 sc_node;
101 	struct mtx 		 sc_mutex;
102 	struct resource		*sc_reg;
103 	int			 sc_irqrid;
104 	struct resource		*sc_irq;
105 	void			*sc_ih;
106 	u_int 			 sc_regstep;
107 	u_int 			 sc_flags;
108 	u_char			*sc_data;
109 	int 			 sc_resid;
110 	uint16_t		 sc_i2c_base;
111 	device_t 		 sc_iicbus;
112 };
113 
114 static int 	kiic_probe(device_t dev);
115 static int 	kiic_attach(device_t dev);
116 static void 	kiic_writereg(struct kiic_softc *sc, u_int, u_int);
117 static u_int 	kiic_readreg(struct kiic_softc *, u_int);
118 static void 	kiic_setport(struct kiic_softc *, u_int);
119 static void 	kiic_setmode(struct kiic_softc *, u_int);
120 static void 	kiic_setspeed(struct kiic_softc *, u_int);
121 static void 	kiic_intr(void *xsc);
122 static int	kiic_transfer(device_t dev, struct iic_msg *msgs,
123 		    uint32_t nmsgs);
124 static phandle_t kiic_get_node(device_t bus, device_t dev);
125 
126 static device_method_t kiic_methods[] = {
127 	/* device interface */
128 	DEVMETHOD(device_probe, 	kiic_probe),
129 	DEVMETHOD(device_attach, 	kiic_attach),
130 
131 	/* iicbus interface */
132 	DEVMETHOD(iicbus_callback,	iicbus_null_callback),
133 	DEVMETHOD(iicbus_transfer,	kiic_transfer),
134 
135 	/* ofw_bus interface */
136 	DEVMETHOD(ofw_bus_get_node,	kiic_get_node),
137 
138 	{ 0, 0 }
139 };
140 
141 static driver_t kiic_driver = {
142 	"iichb",
143 	kiic_methods,
144 	sizeof(struct kiic_softc)
145 };
146 static devclass_t kiic_devclass;
147 
148 DRIVER_MODULE(kiic, macio, kiic_driver, kiic_devclass, 0, 0);
149 
150 static int
151 kiic_probe(device_t self)
152 {
153 	const char *name;
154 
155 	name = ofw_bus_get_name(self);
156 	if (name && strcmp(name, "i2c") == 0) {
157 		device_set_desc(self, "Keywest I2C controller");
158 		return (0);
159 	}
160 
161 	return (ENXIO);
162 }
163 
164 static int
165 kiic_attach(device_t self)
166 {
167 	struct kiic_softc *sc = device_get_softc(self);
168 	int rid, rate;
169 	phandle_t node;
170 	char name[64];
171 
172 	bzero(sc, sizeof(*sc));
173 	sc->sc_dev = self;
174 
175 	node = ofw_bus_get_node(self);
176 	if (node == 0 || node == -1) {
177 		return (EINVAL);
178 	}
179 
180 	rid = 0;
181 	sc->sc_reg = bus_alloc_resource_any(self, SYS_RES_MEMORY,
182 			&rid, RF_ACTIVE);
183 	if (sc->sc_reg == NULL) {
184 		return (ENOMEM);
185 	}
186 
187 	if (OF_getprop(node, "AAPL,i2c-rate", &rate, 4) != 4) {
188 		device_printf(self, "cannot get i2c-rate\n");
189 		return (ENXIO);
190 	}
191 	if (OF_getprop(node, "AAPL,address-step", &sc->sc_regstep, 4) != 4) {
192 		device_printf(self, "unable to find i2c address step\n");
193 		return (ENXIO);
194 	}
195 
196 	/*
197 	 * Some Keywest I2C devices have their children attached directly
198 	 * underneath them.  Some have a single 'iicbus' child with the
199 	 * devices underneath that.  Sort this out, and make sure that the
200 	 * OFW I2C layer has the correct node.
201 	 *
202 	 * Note: the I2C children of the Uninorth bridges have two ports.
203 	 *  In general, the port is designated in the 9th bit of the I2C
204 	 *  address. However, for kiic devices with children attached below
205 	 *  an i2c-bus node, the port is indicated in the 'reg' property
206 	 *  of the i2c-bus node.
207 	 */
208 
209 	sc->sc_node = node;
210 
211 	node = OF_child(node);
212 	if (OF_getprop(node, "name", name, sizeof(name)) > 0) {
213 		if (strcmp(name,"i2c-bus") == 0) {
214 			phandle_t reg;
215 			if (OF_getprop(node, "reg", &reg, sizeof(reg)) > 0)
216 				sc->sc_i2c_base = reg << 8;
217 
218 			sc->sc_node = node;
219 		}
220 	}
221 
222 	mtx_init(&sc->sc_mutex, "kiic", NULL, MTX_DEF);
223 
224 	sc->sc_irq = bus_alloc_resource_any(self, SYS_RES_IRQ, &sc->sc_irqrid,
225 	    RF_ACTIVE);
226 	bus_setup_intr(self, sc->sc_irq, INTR_TYPE_MISC | INTR_MPSAFE, NULL,
227 	    kiic_intr, sc, &sc->sc_ih);
228 
229 	kiic_writereg(sc, ISR, kiic_readreg(sc, ISR));
230 	kiic_writereg(sc, STATUS, 0);
231 	kiic_writereg(sc, IER, 0);
232 
233 	kiic_setmode(sc, I2C_STDMODE);
234 	kiic_setspeed(sc, I2C_100kHz);		/* XXX rate */
235 
236 	kiic_writereg(sc, IER, I2C_INT_DATA | I2C_INT_ADDR | I2C_INT_STOP);
237 
238 	/* Add the IIC bus layer */
239 	sc->sc_iicbus = device_add_child(self, "iicbus", -1);
240 
241 	return (bus_generic_attach(self));
242 }
243 
244 static void
245 kiic_writereg(struct kiic_softc *sc, u_int reg, u_int val)
246 {
247 	bus_write_1(sc->sc_reg, sc->sc_regstep * reg, val);
248 	DELAY(10); /* register access delay */
249 }
250 
251 static u_int
252 kiic_readreg(struct kiic_softc *sc, u_int reg)
253 {
254 	return bus_read_1(sc->sc_reg, sc->sc_regstep * reg);
255 }
256 
257 static void
258 kiic_setmode(struct kiic_softc *sc, u_int mode)
259 {
260 	u_int x;
261 
262 	KASSERT((mode & ~I2C_MODE) == 0, ("bad mode"));
263 	x = kiic_readreg(sc, MODE);
264 	x &= ~I2C_MODE;
265 	x |= mode;
266 	kiic_writereg(sc, MODE, x);
267 }
268 
269 static void
270 kiic_setport(struct kiic_softc *sc, u_int port)
271 {
272 	u_int x;
273 
274 	KASSERT(port == 1 || port == 0, ("bad port"));
275 	x = kiic_readreg(sc, MODE);
276 	x &= ~I2C_PORT;
277 	x |= (port << 4);
278 	kiic_writereg(sc, MODE, x);
279 }
280 
281 static void
282 kiic_setspeed(struct kiic_softc *sc, u_int speed)
283 {
284 	u_int x;
285 
286 	KASSERT((speed & ~I2C_SPEED) == 0, ("bad speed"));
287 	x = kiic_readreg(sc, MODE);
288 	x &= ~I2C_SPEED;
289 	x |= speed;
290 	kiic_writereg(sc, MODE, x);
291 }
292 
293 static void
294 kiic_intr(void *xsc)
295 {
296 	struct kiic_softc *sc = xsc;
297 	u_int isr;
298 	uint32_t x;
299 
300 	mtx_lock(&sc->sc_mutex);
301 	isr = kiic_readreg(sc, ISR);
302 
303 	if (isr & I2C_INT_ADDR) {
304 		sc->sc_flags |= I2C_SELECTED;
305 
306 		if (sc->sc_flags & I2C_READING) {
307 			if (sc->sc_resid > 1) {
308 				x = kiic_readreg(sc, CONTROL);
309 				x |= I2C_CT_AAK;
310 				kiic_writereg(sc, CONTROL, x);
311 			}
312 		} else {
313 			kiic_writereg(sc, DATA, *sc->sc_data++);
314 			sc->sc_resid--;
315 		}
316 	}
317 
318 	if (isr & I2C_INT_DATA) {
319 		if (sc->sc_flags & I2C_READING) {
320 			if (sc->sc_resid > 0) {
321 				*sc->sc_data++ = kiic_readreg(sc, DATA);
322 				sc->sc_resid--;
323 			}
324 			if (sc->sc_resid == 0)  /* done */
325 				kiic_writereg(sc, CONTROL, 0);
326 		} else {
327 			if (sc->sc_resid == 0) {
328 				x = kiic_readreg(sc, CONTROL);
329 				x |= I2C_CT_STOP;
330 				kiic_writereg(sc, CONTROL, x);
331 			} else {
332 				kiic_writereg(sc, DATA, *sc->sc_data++);
333 				sc->sc_resid--;
334 			}
335 		}
336 	}
337 
338 	if (isr & I2C_INT_STOP) {
339 		kiic_writereg(sc, CONTROL, 0);
340 		sc->sc_flags &= ~I2C_SELECTED;
341 		wakeup(sc->sc_dev);
342 	}
343 
344 	kiic_writereg(sc, ISR, isr);
345 	mtx_unlock(&sc->sc_mutex);
346 }
347 
348 static int
349 kiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
350 {
351 	struct kiic_softc *sc;
352 	int i, x, timo, err;
353 	uint16_t addr;
354 	uint8_t subaddr;
355 
356 	sc = device_get_softc(dev);
357 	timo = 100;
358 	subaddr = 0;
359 
360 	mtx_lock(&sc->sc_mutex);
361 
362 	if (sc->sc_flags & I2C_BUSY)
363 		mtx_sleep(dev, &sc->sc_mutex, 0, "kiic", timo);
364 
365 	if (sc->sc_flags & I2C_BUSY) {
366 		mtx_unlock(&sc->sc_mutex);
367 		return (ETIMEDOUT);
368 	}
369 
370 	sc->sc_flags = I2C_BUSY;
371 
372 	/* Clear pending interrupts, and reset controller */
373 	kiic_writereg(sc, ISR, kiic_readreg(sc, ISR));
374 	kiic_writereg(sc, STATUS, 0);
375 
376 	for (i = 0; i < nmsgs; i++) {
377 		if (msgs[i].flags & IIC_M_NOSTOP) {
378 			if (msgs[i+1].flags & IIC_M_RD)
379 				kiic_setmode(sc, I2C_COMBMODE);
380 			else
381 				kiic_setmode(sc, I2C_STDSUBMODE);
382 			KASSERT(msgs[i].len == 1, ("oversize I2C message"));
383 			subaddr = msgs[i].buf[0];
384 			i++;
385 		} else {
386 			kiic_setmode(sc, I2C_STDMODE);
387 		}
388 
389 		sc->sc_data = msgs[i].buf;
390 		sc->sc_resid = msgs[i].len;
391 		sc->sc_flags = I2C_BUSY;
392 		addr = msgs[i].slave;
393 		timo = 1000 + sc->sc_resid * 200;
394 		timo += 100000;
395 
396 		if (msgs[i].flags & IIC_M_RD) {
397 			sc->sc_flags |= I2C_READING;
398 			addr |= 1;
399 		}
400 
401 		addr |= sc->sc_i2c_base;
402 
403 		kiic_setport(sc, (addr & 0x100) >> 8);
404 		kiic_writereg(sc, ADDR, addr & 0xff);
405 		kiic_writereg(sc, SUBADDR, subaddr);
406 
407 		x = kiic_readreg(sc, CONTROL) | I2C_CT_ADDR;
408 		kiic_writereg(sc, CONTROL, x);
409 
410 		err = mtx_sleep(dev, &sc->sc_mutex, 0, "kiic", timo);
411 
412 		msgs[i].len -= sc->sc_resid;
413 
414 		if ((sc->sc_flags & I2C_ERROR) || err == EWOULDBLOCK) {
415 			device_printf(sc->sc_dev, "I2C error\n");
416 			sc->sc_flags = 0;
417 			mtx_unlock(&sc->sc_mutex);
418 			return (-1);
419 		}
420 	}
421 
422 	sc->sc_flags = 0;
423 
424 	mtx_unlock(&sc->sc_mutex);
425 
426 	return (0);
427 }
428 
429 static phandle_t
430 kiic_get_node(device_t bus, device_t dev)
431 {
432 	struct kiic_softc *sc;
433 
434 	sc = device_get_softc(bus);
435 	/* We only have one child, the I2C bus, which needs our own node. */
436 
437 	return sc->sc_node;
438 }
439 
440