imx6_ccm.c revision 266207 
1/*-
2 * Copyright (c) 2013 Ian Lepore <ian@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: stable/10/sys/arm/freescale/imx/imx6_ccm.c 266207 2014-05-16 02:21:51Z ian $");
29
30/*
31 * Clocks and power control driver for Freescale i.MX6 family of SoCs.
32 */
33
34#include <sys/param.h>
35#include <sys/systm.h>
36#include <sys/kernel.h>
37#include <sys/module.h>
38#include <sys/bus.h>
39#include <sys/rman.h>
40
41#include <dev/ofw/ofw_bus.h>
42#include <dev/ofw/ofw_bus_subr.h>
43
44#include <machine/bus.h>
45
46#include <arm/freescale/imx/imx6_anatopreg.h>
47#include <arm/freescale/imx/imx6_anatopvar.h>
48#include <arm/freescale/imx/imx_machdep.h>
49#include <arm/freescale/imx/imx6_ccmreg.h>
50
51
52/* XXX temp kludge for imx51_get_clock. */
53#include <arm/freescale/imx/imx51_ccmvar.h>
54#include <arm/freescale/imx/imx51_ccmreg.h>
55
56struct ccm_softc {
57	device_t	dev;
58	struct resource	*mem_res;
59};
60
61static struct ccm_softc *ccm_sc;
62
63static inline uint32_t
64RD4(struct ccm_softc *sc, bus_size_t off)
65{
66
67	return (bus_read_4(sc->mem_res, off));
68}
69
70static inline void
71WR4(struct ccm_softc *sc, bus_size_t off, uint32_t val)
72{
73
74	bus_write_4(sc->mem_res, off, val);
75}
76
77static int
78ccm_detach(device_t dev)
79{
80	struct ccm_softc *sc;
81
82	sc = device_get_softc(dev);
83
84	if (sc->mem_res != NULL)
85		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res);
86
87	return (0);
88}
89
90static int
91ccm_attach(device_t dev)
92{
93	struct ccm_softc *sc;
94	int err, rid;
95	uint32_t reg;
96
97	sc = device_get_softc(dev);
98	err = 0;
99
100	/* Allocate bus_space resources. */
101	rid = 0;
102	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
103	    RF_ACTIVE);
104	if (sc->mem_res == NULL) {
105		device_printf(dev, "Cannot allocate memory resources\n");
106		err = ENXIO;
107		goto out;
108	}
109
110	ccm_sc = sc;
111
112	/*
113	 * Configure the Low Power Mode setting to leave the ARM core power on
114	 * when a WFI instruction is executed.  This lets the MPCore timers and
115	 * GIC continue to run, which is helpful when the only thing that can
116	 * wake you up is an MPCore Private Timer interrupt delivered via GIC.
117	 *
118	 * XXX Based on the docs, setting CCM_CGPR_INT_MEM_CLK_LPM shouldn't be
119	 * required when the LPM bits are set to LPM_RUN.  But experimentally
120	 * I've experienced a fairly rare lockup when not setting it.  I was
121	 * unable to prove conclusively that the lockup was related to power
122	 * management or that this definitively fixes it.  Revisit this.
123	 */
124	reg = RD4(sc, CCM_CGPR);
125	reg |= CCM_CGPR_INT_MEM_CLK_LPM;
126	WR4(sc, CCM_CGPR, reg);
127	reg = RD4(sc, CCM_CLPCR);
128	reg = (reg & ~CCM_CLPCR_LPM_MASK) | CCM_CLPCR_LPM_RUN;
129	WR4(sc, CCM_CLPCR, reg);
130
131	err = 0;
132
133out:
134
135	if (err != 0)
136		ccm_detach(dev);
137
138	return (err);
139}
140
141static int
142ccm_probe(device_t dev)
143{
144
145	if (!ofw_bus_status_okay(dev))
146		return (ENXIO);
147
148        if (ofw_bus_is_compatible(dev, "fsl,imx6q-ccm") == 0)
149		return (ENXIO);
150
151	device_set_desc(dev, "Freescale i.MX6 Clock Control Module");
152
153	return (BUS_PROBE_DEFAULT);
154}
155
156void
157imx_ccm_usb_enable(device_t _usbdev)
158{
159
160	/*
161	 * For imx6, the USBOH3 clock gate is bits 0-1 of CCGR6, so no need for
162	 * shifting and masking here, just set the low-order two bits to ALWAYS.
163	 */
164	WR4(ccm_sc, CCM_CCGR6, RD4(ccm_sc, CCM_CCGR6) | CCGR_CLK_MODE_ALWAYS);
165}
166
167void
168imx_ccm_usbphy_enable(device_t _phydev)
169{
170        /*
171         * XXX Which unit?
172         * Right now it's not clear how to figure from fdt data which phy unit
173         * we're supposed to operate on.  Until this is worked out, just enable
174         * both PHYs.
175         */
176#if 0
177	int phy_num, regoff;
178
179	phy_num = 0; /* XXX */
180
181	switch (phy_num) {
182	case 0:
183		regoff = 0;
184		break;
185	case 1:
186		regoff = 0x10;
187		break;
188	default:
189		device_printf(ccm_sc->dev, "Bad PHY number %u,\n",
190		    phy_num);
191		return;
192	}
193
194	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_USB1 + regoff,
195	    IMX6_ANALOG_CCM_PLL_USB_ENABLE |
196	    IMX6_ANALOG_CCM_PLL_USB_POWER |
197	    IMX6_ANALOG_CCM_PLL_USB_EN_USB_CLKS);
198#else
199	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_USB1 + 0,
200	    IMX6_ANALOG_CCM_PLL_USB_ENABLE |
201	    IMX6_ANALOG_CCM_PLL_USB_POWER |
202	    IMX6_ANALOG_CCM_PLL_USB_EN_USB_CLKS);
203
204	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_USB1 + 0x10,
205	    IMX6_ANALOG_CCM_PLL_USB_ENABLE |
206	    IMX6_ANALOG_CCM_PLL_USB_POWER |
207	    IMX6_ANALOG_CCM_PLL_USB_EN_USB_CLKS);
208#endif
209}
210
211
212
213
214
215// XXX Fix this.  This has to be here for other code to link,
216// but it doesn't have to return anything useful for imx6 right now.
217u_int
218imx51_get_clock(enum imx51_clock clk)
219{
220	switch (clk)
221	{
222	case IMX51CLK_IPG_CLK_ROOT:
223		return 66000000;
224	default:
225		printf("imx51_get_clock() on imx6 doesn't know about clock %d\n", clk);
226		break;
227	}
228	return 0;
229}
230
231static device_method_t ccm_methods[] = {
232	/* Device interface */
233	DEVMETHOD(device_probe,  ccm_probe),
234	DEVMETHOD(device_attach, ccm_attach),
235	DEVMETHOD(device_detach, ccm_detach),
236
237	DEVMETHOD_END
238};
239
240static driver_t ccm_driver = {
241	"ccm",
242	ccm_methods,
243	sizeof(struct ccm_softc)
244};
245
246static devclass_t ccm_devclass;
247
248DRIVER_MODULE(ccm, simplebus, ccm_driver, ccm_devclass, 0, 0);
249
250