2 * Copyright (C) 2008 MARVELL INTERNATIONAL LTD.
5 * Developed by Semihalf.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
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.
36 * Calls to DELAY() are needed per Application Note AN-179 "TWSI Software
37 * Guidelines for Discovery(TM), Horizon (TM) and Feroceon(TM) Devices".
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
43 #include <sys/param.h>
44 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/module.h>
48 #include <sys/resource.h>
50 #include <machine/_inttypes.h>
51 #include <machine/bus.h>
52 #include <machine/resource.h>
57 #include <sys/mutex.h>
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>
65 #include <dev/extres/clk/clk.h>
68 #include <arm/mv/mvreg.h>
69 #include <arm/mv/mvvar.h>
70 #include <dev/iicbus/twsi/twsi.h>
72 #include "iicbus_if.h"
74 #define MV_TWSI_NAME "twsi"
75 #define IICBUS_DEVNAME "iicbus"
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
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 */
93 #define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt,##args); } while (0)
95 #define debugf(fmt, args...)
98 static phandle_t mv_twsi_get_node(device_t, device_t);
99 static int mv_twsi_probe(device_t);
100 static int mv_twsi_attach(device_t);
102 static struct ofw_compat_data compat_data[] = {
103 { "mrvl,twsi", true },
104 { "marvell,mv64xxx-i2c", true },
105 { "marvell,mv78230-i2c", true },
109 static device_method_t mv_twsi_methods[] = {
110 /* device interface */
111 DEVMETHOD(device_probe, mv_twsi_probe),
112 DEVMETHOD(device_attach, mv_twsi_attach),
114 /* ofw_bus interface */
115 DEVMETHOD(ofw_bus_get_node, mv_twsi_get_node),
120 DEFINE_CLASS_1(twsi, mv_twsi_driver, mv_twsi_methods,
121 sizeof(struct twsi_softc), twsi_driver);
123 static devclass_t mv_twsi_devclass;
125 DRIVER_MODULE(twsi, simplebus, mv_twsi_driver, mv_twsi_devclass, 0, 0);
126 DRIVER_MODULE(iicbus, twsi, iicbus_driver, iicbus_devclass, 0, 0);
127 MODULE_DEPEND(twsi, iicbus, 1, 1, 1);
128 SIMPLEBUS_PNP_INFO(compat_data);
131 mv_twsi_get_node(device_t bus, device_t dev)
134 /* Used by ofw_iicbus. */
135 return (ofw_bus_get_node(bus));
139 mv_twsi_probe(device_t dev)
141 struct twsi_softc *sc;
143 sc = device_get_softc(dev);
144 if (!ofw_bus_status_okay(dev))
147 if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
150 device_set_desc(dev, "Marvell Integrated I2C Bus Controller");
151 return (BUS_PROBE_DEFAULT);
154 #define ABSSUB(a,b) (((a) > (b)) ? (a) - (b) : (b) - (a))
156 mv_twsi_cal_baud_rate(struct twsi_softc *sc, const uint32_t target,
157 struct twsi_baud_rate *rate)
160 uint32_t cur, diff, diff0;
163 /* Calculate baud rate. */
164 m0 = n0 = 4; /* Default values on reset */
167 clk_get_freq(sc->clk_core, &clk);
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);
183 rate->raw = TWSI_BAUD_RATE_RAW(clk, m0, n0);
184 rate->param = TWSI_BAUD_RATE_PARAM(m0, n0);
190 mv_twsi_attach(device_t dev)
192 struct twsi_softc *sc;
197 sc = device_get_softc(dev);
202 error = clk_get_by_ofw_index(dev, 0, 0, &sc->clk_core);
204 device_printf(dev, "could not find core clock\n");
207 error = clk_enable(sc->clk_core);
209 device_printf(dev, "could not enable core clock\n");
213 if (clk_get_by_ofw_index(dev, 0, 1, &sc->clk_reg) == 0) {
214 error = clk_enable(sc->clk_reg);
216 device_printf(dev, "could not enable core clock\n");
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]);
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);
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;
243 return (twsi_attach(dev));