xref: /freebsd/sys/arm/freescale/imx/imx6_ccm.c (revision 39ee7a7a6bdd1557b1c3532abf60d139798ac88b)
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/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 
58 struct ccm_softc {
59 	device_t	dev;
60 	struct resource	*mem_res;
61 };
62 
63 static struct ccm_softc *ccm_sc;
64 
65 static inline uint32_t
66 RD4(struct ccm_softc *sc, bus_size_t off)
67 {
68 
69 	return (bus_read_4(sc->mem_res, off));
70 }
71 
72 static inline void
73 WR4(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  */
88 static void
89 ccm_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, 0x0ffc00c0); /* uarts, ssi, sdma */
98 	WR4(sc, CCM_CCGR6, 0x000000ff); /* usdhc 1-4 */
99 }
100 
101 static int
102 ccm_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 
114 static int
115 ccm_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 
159 out:
160 
161 	if (err != 0)
162 		ccm_detach(dev);
163 
164 	return (err);
165 }
166 
167 static int
168 ccm_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 
182 void
183 imx_ccm_ssi_configure(device_t _ssidev)
184 {
185 	struct ccm_softc *sc;
186 	uint32_t reg;
187 
188 	sc = ccm_sc;
189 
190 	/*
191 	 * Select PLL4 (Audio PLL) clock multiplexer as source.
192 	 * PLL output frequency = Fref * (DIV_SELECT + NUM/DENOM).
193 	 */
194 
195 	reg = RD4(sc, CCM_CSCMR1);
196 	reg &= ~(SSI_CLK_SEL_M << SSI1_CLK_SEL_S);
197 	reg |= (SSI_CLK_SEL_PLL4 << SSI1_CLK_SEL_S);
198 	reg &= ~(SSI_CLK_SEL_M << SSI2_CLK_SEL_S);
199 	reg |= (SSI_CLK_SEL_PLL4 << SSI2_CLK_SEL_S);
200 	reg &= ~(SSI_CLK_SEL_M << SSI3_CLK_SEL_S);
201 	reg |= (SSI_CLK_SEL_PLL4 << SSI3_CLK_SEL_S);
202 	WR4(sc, CCM_CSCMR1, reg);
203 
204 	/*
205 	 * Ensure we have set hardware-default values
206 	 * for pre and post dividers.
207 	 */
208 
209 	/* SSI1 and SSI3 */
210 	reg = RD4(sc, CCM_CS1CDR);
211 	/* Divide by 2 */
212 	reg &= ~(SSI_CLK_PODF_MASK << SSI1_CLK_PODF_SHIFT);
213 	reg &= ~(SSI_CLK_PODF_MASK << SSI3_CLK_PODF_SHIFT);
214 	reg |= (0x1 << SSI1_CLK_PODF_SHIFT);
215 	reg |= (0x1 << SSI3_CLK_PODF_SHIFT);
216 	/* Divide by 4 */
217 	reg &= ~(SSI_CLK_PRED_MASK << SSI1_CLK_PRED_SHIFT);
218 	reg &= ~(SSI_CLK_PRED_MASK << SSI3_CLK_PRED_SHIFT);
219 	reg |= (0x3 << SSI1_CLK_PRED_SHIFT);
220 	reg |= (0x3 << SSI3_CLK_PRED_SHIFT);
221 	WR4(sc, CCM_CS1CDR, reg);
222 
223 	/* SSI2 */
224 	reg = RD4(sc, CCM_CS2CDR);
225 	/* Divide by 2 */
226 	reg &= ~(SSI_CLK_PODF_MASK << SSI2_CLK_PODF_SHIFT);
227 	reg |= (0x1 << SSI2_CLK_PODF_SHIFT);
228 	/* Divide by 4 */
229 	reg &= ~(SSI_CLK_PRED_MASK << SSI2_CLK_PRED_SHIFT);
230 	reg |= (0x3 << SSI2_CLK_PRED_SHIFT);
231 	WR4(sc, CCM_CS2CDR, reg);
232 }
233 
234 void
235 imx_ccm_usb_enable(device_t _usbdev)
236 {
237 
238 	/*
239 	 * For imx6, the USBOH3 clock gate is bits 0-1 of CCGR6, so no need for
240 	 * shifting and masking here, just set the low-order two bits to ALWAYS.
241 	 */
242 	WR4(ccm_sc, CCM_CCGR6, RD4(ccm_sc, CCM_CCGR6) | CCGR_CLK_MODE_ALWAYS);
243 }
244 
245 void
246 imx_ccm_usbphy_enable(device_t _phydev)
247 {
248         /*
249          * XXX Which unit?
250          * Right now it's not clear how to figure from fdt data which phy unit
251          * we're supposed to operate on.  Until this is worked out, just enable
252          * both PHYs.
253          */
254 #if 0
255 	int phy_num, regoff;
256 
257 	phy_num = 0; /* XXX */
258 
259 	switch (phy_num) {
260 	case 0:
261 		regoff = 0;
262 		break;
263 	case 1:
264 		regoff = 0x10;
265 		break;
266 	default:
267 		device_printf(ccm_sc->dev, "Bad PHY number %u,\n",
268 		    phy_num);
269 		return;
270 	}
271 
272 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_USB1 + regoff,
273 	    IMX6_ANALOG_CCM_PLL_USB_ENABLE |
274 	    IMX6_ANALOG_CCM_PLL_USB_POWER |
275 	    IMX6_ANALOG_CCM_PLL_USB_EN_USB_CLKS);
276 #else
277 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_USB1 + 0,
278 	    IMX6_ANALOG_CCM_PLL_USB_ENABLE |
279 	    IMX6_ANALOG_CCM_PLL_USB_POWER |
280 	    IMX6_ANALOG_CCM_PLL_USB_EN_USB_CLKS);
281 
282 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_USB1 + 0x10,
283 	    IMX6_ANALOG_CCM_PLL_USB_ENABLE |
284 	    IMX6_ANALOG_CCM_PLL_USB_POWER |
285 	    IMX6_ANALOG_CCM_PLL_USB_EN_USB_CLKS);
286 #endif
287 }
288 
289 uint32_t
290 imx_ccm_ipg_hz(void)
291 {
292 
293 	return (66000000);
294 }
295 
296 uint32_t
297 imx_ccm_perclk_hz(void)
298 {
299 
300 	return (66000000);
301 }
302 
303 uint32_t
304 imx_ccm_sdhci_hz(void)
305 {
306 
307 	return (200000000);
308 }
309 
310 uint32_t
311 imx_ccm_uart_hz(void)
312 {
313 
314 	return (80000000);
315 }
316 
317 uint32_t
318 imx_ccm_ahb_hz(void)
319 {
320 	return (132000000);
321 }
322 
323 uint32_t
324 imx_ccm_get_cacrr(void)
325 {
326 
327 	return (RD4(ccm_sc, CCM_CACCR));
328 }
329 
330 void
331 imx_ccm_set_cacrr(uint32_t divisor)
332 {
333 
334 	WR4(ccm_sc, CCM_CACCR, divisor);
335 }
336 
337 static device_method_t ccm_methods[] = {
338 	/* Device interface */
339 	DEVMETHOD(device_probe,  ccm_probe),
340 	DEVMETHOD(device_attach, ccm_attach),
341 	DEVMETHOD(device_detach, ccm_detach),
342 
343 	DEVMETHOD_END
344 };
345 
346 static driver_t ccm_driver = {
347 	"ccm",
348 	ccm_methods,
349 	sizeof(struct ccm_softc)
350 };
351 
352 static devclass_t ccm_devclass;
353 
354 EARLY_DRIVER_MODULE(ccm, simplebus, ccm_driver, ccm_devclass, 0, 0,
355     BUS_PASS_CPU + BUS_PASS_ORDER_EARLY);
356 
357