imx6_ccm.c revision 273682 
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 273682 2014-10-26 04:17:20Z 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/imx6_ccmreg.h>
49#include <arm/freescale/imx/imx_machdep.h>
50#include <arm/freescale/imx/imx_ccmvar.h>
51
52#ifndef CCGR_CLK_MODE_ALWAYS
53#define	CCGR_CLK_MODE_OFF		0
54#define	CCGR_CLK_MODE_RUNMODE		1
55#define	CCGR_CLK_MODE_ALWAYS		3
56#endif
57
58struct ccm_softc {
59	device_t	dev;
60	struct resource	*mem_res;
61};
62
63static struct ccm_softc *ccm_sc;
64
65static inline uint32_t
66RD4(struct ccm_softc *sc, bus_size_t off)
67{
68
69	return (bus_read_4(sc->mem_res, off));
70}
71
72static inline void
73WR4(struct ccm_softc *sc, bus_size_t off, uint32_t val)
74{
75
76	bus_write_4(sc->mem_res, off, val);
77}
78
79/*
80 * Until we have a fully functional ccm driver which implements the fdt_clock
81 * interface, use the age-old workaround of unconditionally enabling the clocks
82 * for devices we might need to use.  The SoC defaults to most clocks enabled,
83 * but the rom boot code and u-boot disable a few of them.  We turn on only
84 * what's needed to run the chip plus devices we have drivers for, and turn off
85 * devices we don't yet have drivers for.  (Note that USB is not turned on here
86 * because that is one we do when the driver asks for it.)
87 */
88static void
89ccm_init_gates(struct ccm_softc *sc)
90{
91                                        /* Turns on... */
92	WR4(sc, CCM_CCGR0, 0x0000003f); /* ahpbdma, aipstz 1 & 2 busses */
93	WR4(sc, CCM_CCGR1, 0x00300c00); /* gpt, enet */
94	WR4(sc, CCM_CCGR2, 0x0fffffc0); /* ipmux & ipsync (bridges), iomux, i2c */
95	WR4(sc, CCM_CCGR3, 0x3ff00000); /* DDR memory controller */
96	WR4(sc, CCM_CCGR4, 0x0000f300); /* pl301 bus crossbar */
97	WR4(sc, CCM_CCGR5, 0x0f000000); /* uarts */
98	WR4(sc, CCM_CCGR6, 0x000000cc); /* usdhc 1 & 3 */
99}
100
101static int
102ccm_detach(device_t dev)
103{
104	struct ccm_softc *sc;
105
106	sc = device_get_softc(dev);
107
108	if (sc->mem_res != NULL)
109		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res);
110
111	return (0);
112}
113
114static int
115ccm_attach(device_t dev)
116{
117	struct ccm_softc *sc;
118	int err, rid;
119	uint32_t reg;
120
121	sc = device_get_softc(dev);
122	err = 0;
123
124	/* Allocate bus_space resources. */
125	rid = 0;
126	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
127	    RF_ACTIVE);
128	if (sc->mem_res == NULL) {
129		device_printf(dev, "Cannot allocate memory resources\n");
130		err = ENXIO;
131		goto out;
132	}
133
134	ccm_sc = sc;
135
136	/*
137	 * Configure the Low Power Mode setting to leave the ARM core power on
138	 * when a WFI instruction is executed.  This lets the MPCore timers and
139	 * GIC continue to run, which is helpful when the only thing that can
140	 * wake you up is an MPCore Private Timer interrupt delivered via GIC.
141	 *
142	 * XXX Based on the docs, setting CCM_CGPR_INT_MEM_CLK_LPM shouldn't be
143	 * required when the LPM bits are set to LPM_RUN.  But experimentally
144	 * I've experienced a fairly rare lockup when not setting it.  I was
145	 * unable to prove conclusively that the lockup was related to power
146	 * management or that this definitively fixes it.  Revisit this.
147	 */
148	reg = RD4(sc, CCM_CGPR);
149	reg |= CCM_CGPR_INT_MEM_CLK_LPM;
150	WR4(sc, CCM_CGPR, reg);
151	reg = RD4(sc, CCM_CLPCR);
152	reg = (reg & ~CCM_CLPCR_LPM_MASK) | CCM_CLPCR_LPM_RUN;
153	WR4(sc, CCM_CLPCR, reg);
154
155	ccm_init_gates(sc);
156
157	err = 0;
158
159out:
160
161	if (err != 0)
162		ccm_detach(dev);
163
164	return (err);
165}
166
167static int
168ccm_probe(device_t dev)
169{
170
171	if (!ofw_bus_status_okay(dev))
172		return (ENXIO);
173
174        if (ofw_bus_is_compatible(dev, "fsl,imx6q-ccm") == 0)
175		return (ENXIO);
176
177	device_set_desc(dev, "Freescale i.MX6 Clock Control Module");
178
179	return (BUS_PROBE_DEFAULT);
180}
181
182void
183imx_ccm_usb_enable(device_t _usbdev)
184{
185
186	/*
187	 * For imx6, the USBOH3 clock gate is bits 0-1 of CCGR6, so no need for
188	 * shifting and masking here, just set the low-order two bits to ALWAYS.
189	 */
190	WR4(ccm_sc, CCM_CCGR6, RD4(ccm_sc, CCM_CCGR6) | CCGR_CLK_MODE_ALWAYS);
191}
192
193void
194imx_ccm_usbphy_enable(device_t _phydev)
195{
196        /*
197         * XXX Which unit?
198         * Right now it's not clear how to figure from fdt data which phy unit
199         * we're supposed to operate on.  Until this is worked out, just enable
200         * both PHYs.
201         */
202#if 0
203	int phy_num, regoff;
204
205	phy_num = 0; /* XXX */
206
207	switch (phy_num) {
208	case 0:
209		regoff = 0;
210		break;
211	case 1:
212		regoff = 0x10;
213		break;
214	default:
215		device_printf(ccm_sc->dev, "Bad PHY number %u,\n",
216		    phy_num);
217		return;
218	}
219
220	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_USB1 + regoff,
221	    IMX6_ANALOG_CCM_PLL_USB_ENABLE |
222	    IMX6_ANALOG_CCM_PLL_USB_POWER |
223	    IMX6_ANALOG_CCM_PLL_USB_EN_USB_CLKS);
224#else
225	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_USB1 + 0,
226	    IMX6_ANALOG_CCM_PLL_USB_ENABLE |
227	    IMX6_ANALOG_CCM_PLL_USB_POWER |
228	    IMX6_ANALOG_CCM_PLL_USB_EN_USB_CLKS);
229
230	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_USB1 + 0x10,
231	    IMX6_ANALOG_CCM_PLL_USB_ENABLE |
232	    IMX6_ANALOG_CCM_PLL_USB_POWER |
233	    IMX6_ANALOG_CCM_PLL_USB_EN_USB_CLKS);
234#endif
235}
236
237uint32_t
238imx_ccm_ipg_hz(void)
239{
240
241	return (66000000);
242}
243
244uint32_t
245imx_ccm_perclk_hz(void)
246{
247
248	return (66000000);
249}
250
251uint32_t
252imx_ccm_sdhci_hz(void)
253{
254
255	return (200000000);
256}
257
258uint32_t
259imx_ccm_uart_hz(void)
260{
261
262	return (80000000);
263}
264
265uint32_t
266imx_ccm_ahb_hz(void)
267{
268	return (132000000);
269}
270
271static device_method_t ccm_methods[] = {
272	/* Device interface */
273	DEVMETHOD(device_probe,  ccm_probe),
274	DEVMETHOD(device_attach, ccm_attach),
275	DEVMETHOD(device_detach, ccm_detach),
276
277	DEVMETHOD_END
278};
279
280static driver_t ccm_driver = {
281	"ccm",
282	ccm_methods,
283	sizeof(struct ccm_softc)
284};
285
286static devclass_t ccm_devclass;
287
288EARLY_DRIVER_MODULE(ccm, simplebus, ccm_driver, ccm_devclass, 0, 0,
289    BUS_PASS_CPU + BUS_PASS_ORDER_EARLY);
290
291