xref: /freebsd/sys/arm/freescale/imx/imx6_ccm.c (revision dda5b39711dab90ae1c5624bdd6ff7453177df31)
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("$FreeBSD$");
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 
56 struct ccm_softc {
57 	device_t	dev;
58 	struct resource	*mem_res;
59 };
60 
61 static struct ccm_softc *ccm_sc;
62 
63 static inline uint32_t
64 RD4(struct ccm_softc *sc, bus_size_t off)
65 {
66 
67 	return (bus_read_4(sc->mem_res, off));
68 }
69 
70 static inline void
71 WR4(struct ccm_softc *sc, bus_size_t off, uint32_t val)
72 {
73 
74 	bus_write_4(sc->mem_res, off, val);
75 }
76 
77 static int
78 ccm_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 
90 static int
91 ccm_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 
133 out:
134 
135 	if (err != 0)
136 		ccm_detach(dev);
137 
138 	return (err);
139 }
140 
141 static int
142 ccm_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 
156 void
157 imx_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 
167 void
168 imx_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.
217 u_int
218 imx51_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 
231 static 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 
240 static driver_t ccm_driver = {
241 	"ccm",
242 	ccm_methods,
243 	sizeof(struct ccm_softc)
244 };
245 
246 static devclass_t ccm_devclass;
247 
248 DRIVER_MODULE(ccm, simplebus, ccm_driver, ccm_devclass, 0, 0);
249 
250