1/*-
2 * Copyright (C) 2008 MARVELL INTERNATIONAL LTD.
3 * All rights reserved.
4 *
5 * Developed by Semihalf.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of MARVELL nor the names of contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32/*
33 * Driver for the TWSI (aka I2C, aka IIC) bus controller found on Marvell
34 * and Allwinner SoCs. Supports master operation only, and works in polling mode.
35 *
36 * Calls to DELAY() are needed per Application Note AN-179 "TWSI Software
37 * Guidelines for Discovery(TM), Horizon (TM) and Feroceon(TM) Devices".
38 */
39
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD$");
42
43#include <sys/param.h>
44#include <sys/systm.h>
45#include <sys/bus.h>
46#include <sys/kernel.h>
47#include <sys/module.h>
48#include <sys/resource.h>
49
50#include <machine/_inttypes.h>
51#include <machine/bus.h>
52#include <machine/resource.h>
53
54#include <sys/rman.h>
55
56#include <sys/lock.h>
57#include <sys/mutex.h>
58
59#include <dev/iicbus/iiconf.h>
60#include <dev/iicbus/iicbus.h>
61#include <dev/ofw/ofw_bus.h>
62#include <dev/ofw/ofw_bus_subr.h>
63
64#ifdef EXT_RESOURCES
65#include <dev/extres/clk/clk.h>
66#endif
67
68#include <arm/mv/mvreg.h>
69#include <arm/mv/mvvar.h>
70#include <dev/iicbus/twsi/twsi.h>
71
72#include "iicbus_if.h"
73
74#define MV_TWSI_NAME		"twsi"
75#define	IICBUS_DEVNAME		"iicbus"
76
77#define TWSI_ADDR	0x00
78#define TWSI_DATA	0x04
79#define TWSI_CNTR	0x08
80#define TWSI_XADDR	0x10
81#define TWSI_STAT	0x0c
82#define TWSI_BAUD_RATE	0x0c
83#define TWSI_SRST	0x1c
84
85#define	TWSI_BAUD_RATE_RAW(C,M,N)	((C)/((10*(M+1))<<(N+1)))
86#define	TWSI_BAUD_RATE_SLOW		50000	/* 50kHz */
87#define	TWSI_BAUD_RATE_FAST		100000	/* 100kHz */
88
89#define TWSI_DEBUG
90#undef TWSI_DEBUG
91
92#ifdef  TWSI_DEBUG
93#define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt,##args); } while (0)
94#else
95#define debugf(fmt, args...)
96#endif
97
98static phandle_t mv_twsi_get_node(device_t, device_t);
99static int mv_twsi_probe(device_t);
100static int mv_twsi_attach(device_t);
101
102static struct ofw_compat_data compat_data[] = {
103	{ "mrvl,twsi",			true },
104	{ "marvell,mv64xxx-i2c",	true },
105	{ "marvell,mv78230-i2c",	true },
106	{ NULL,				false }
107};
108
109static device_method_t mv_twsi_methods[] = {
110	/* device interface */
111	DEVMETHOD(device_probe,		mv_twsi_probe),
112	DEVMETHOD(device_attach,	mv_twsi_attach),
113
114	/* ofw_bus interface */
115	DEVMETHOD(ofw_bus_get_node,	mv_twsi_get_node),
116
117	DEVMETHOD_END
118};
119
120DEFINE_CLASS_1(twsi, mv_twsi_driver, mv_twsi_methods,
121    sizeof(struct twsi_softc), twsi_driver);
122
123static devclass_t mv_twsi_devclass;
124
125DRIVER_MODULE(twsi, simplebus, mv_twsi_driver, mv_twsi_devclass, 0, 0);
126DRIVER_MODULE(iicbus, twsi, iicbus_driver, iicbus_devclass, 0, 0);
127MODULE_DEPEND(twsi, iicbus, 1, 1, 1);
128SIMPLEBUS_PNP_INFO(compat_data);
129
130static phandle_t
131mv_twsi_get_node(device_t bus, device_t dev)
132{
133
134	/* Used by ofw_iicbus. */
135	return (ofw_bus_get_node(bus));
136}
137
138static int
139mv_twsi_probe(device_t dev)
140{
141	struct twsi_softc *sc;
142
143	sc = device_get_softc(dev);
144	if (!ofw_bus_status_okay(dev))
145		return (ENXIO);
146
147	if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
148		return (ENXIO);
149
150	device_set_desc(dev, "Marvell Integrated I2C Bus Controller");
151	return (BUS_PROBE_DEFAULT);
152}
153
154#define	ABSSUB(a,b)	(((a) > (b)) ? (a) - (b) : (b) - (a))
155static void
156mv_twsi_cal_baud_rate(struct twsi_softc *sc, const uint32_t target,
157    struct twsi_baud_rate *rate)
158{
159	uint64_t clk;
160	uint32_t cur, diff, diff0;
161	int m, n, m0, n0;
162
163	/* Calculate baud rate. */
164	m0 = n0 = 4;	/* Default values on reset */
165	diff0 = 0xffffffff;
166#ifdef __aarch64__
167	clk_get_freq(sc->clk_core, &clk);
168#else
169	clk = get_tclk();
170#endif
171
172	for (n = 0; n < 8; n++) {
173		for (m = 0; m < 16; m++) {
174			cur = TWSI_BAUD_RATE_RAW(clk,m,n);
175			diff = ABSSUB(target, cur);
176			if (diff < diff0) {
177				m0 = m;
178				n0 = n;
179				diff0 = diff;
180			}
181		}
182	}
183	rate->raw = TWSI_BAUD_RATE_RAW(clk, m0, n0);
184	rate->param = TWSI_BAUD_RATE_PARAM(m0, n0);
185	rate->m = m0;
186	rate->n = n0;
187}
188
189static int
190mv_twsi_attach(device_t dev)
191{
192	struct twsi_softc *sc;
193#ifdef __aarch64__
194	int error;
195#endif
196
197	sc = device_get_softc(dev);
198	sc->dev = dev;
199
200#ifdef __aarch64__
201	/* Activate clock */
202	error = clk_get_by_ofw_index(dev, 0, 0, &sc->clk_core);
203	if (error != 0) {
204		device_printf(dev, "could not find core clock\n");
205		return (error);
206	}
207	error = clk_enable(sc->clk_core);
208	if (error != 0) {
209		device_printf(dev, "could not enable core clock\n");
210		return (error);
211	}
212
213	if (clk_get_by_ofw_index(dev, 0, 1, &sc->clk_reg) == 0) {
214		error = clk_enable(sc->clk_reg);
215		if (error != 0) {
216			device_printf(dev, "could not enable core clock\n");
217			return (error);
218		}
219	}
220#endif
221
222	mv_twsi_cal_baud_rate(sc, TWSI_BAUD_RATE_SLOW, &sc->baud_rate[IIC_SLOW]);
223	mv_twsi_cal_baud_rate(sc, TWSI_BAUD_RATE_FAST, &sc->baud_rate[IIC_FAST]);
224	if (bootverbose)
225		device_printf(dev, "calculated baud rates are:\n"
226		    " %" PRIu32 " kHz (M=%d, N=%d) for slow,\n"
227		    " %" PRIu32 " kHz (M=%d, N=%d) for fast.\n",
228		    sc->baud_rate[IIC_SLOW].raw / 1000,
229		    sc->baud_rate[IIC_SLOW].m,
230		    sc->baud_rate[IIC_SLOW].n,
231		    sc->baud_rate[IIC_FAST].raw / 1000,
232		    sc->baud_rate[IIC_FAST].m,
233		    sc->baud_rate[IIC_FAST].n);
234
235	sc->reg_data = TWSI_DATA;
236	sc->reg_slave_addr = TWSI_ADDR;
237	sc->reg_slave_ext_addr = TWSI_XADDR;
238	sc->reg_control = TWSI_CNTR;
239	sc->reg_status = TWSI_STAT;
240	sc->reg_baud_rate = TWSI_BAUD_RATE;
241	sc->reg_soft_reset = TWSI_SRST;
242
243	return (twsi_attach(dev));
244}
245