xref: /freebsd/sys/arm/freescale/imx/imx_iomux.c (revision ba8d15d3a8b10be9f3a0cb86a60246f225a36736)
1 /*-
2  * Copyright (c) 2014 Ian Lepore
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  * $FreeBSD$
27  */
28 
29 /*
30  * Pin mux and pad control driver for imx5 and imx6.
31  *
32  * This driver implements the fdt_pinctrl interface for configuring the gpio and
33  * peripheral pins based on fdt configuration data.
34  *
35  * When the driver attaches, it walks the entire fdt tree and automatically
36  * configures the pins for each device which has a pinctrl-0 property and whose
37  * status is "okay".  In addition it implements the fdt_pinctrl_configure()
38  * method which any other driver can call at any time to reconfigure its pins.
39  *
40  * The nature of the fsl,pins property in fdt data makes this driver's job very
41  * easy.  Instead of representing each pin and pad configuration using symbolic
42  * properties such as pullup-enable="true" and so on, the data simply contains
43  * the addresses of the registers that control the pins, and the raw values to
44  * store in those registers.
45  *
46  * The imx5 and imx6 SoCs also have a small number of "general purpose
47  * registers" in the iomuxc device which are used to control an assortment
48  * of completely unrelated aspects of SoC behavior.  This driver provides other
49  * drivers with direct access to those registers via simple accessor functions.
50  */
51 
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/bus.h>
55 #include <sys/kernel.h>
56 #include <sys/module.h>
57 #include <sys/malloc.h>
58 #include <sys/rman.h>
59 
60 #include <machine/bus.h>
61 #include <machine/fdt.h>
62 
63 #include <dev/fdt/fdt_common.h>
64 #include <dev/fdt/fdt_pinctrl.h>
65 #include <dev/ofw/openfirm.h>
66 #include <dev/ofw/ofw_bus.h>
67 #include <dev/ofw/ofw_bus_subr.h>
68 
69 #include <arm/freescale/imx/imx_iomuxvar.h>
70 #include <arm/freescale/imx/imx_machdep.h>
71 
72 struct iomux_softc {
73 	device_t	dev;
74 	struct resource	*mem_res;
75 	u_int		last_gpreg;
76 };
77 
78 static struct iomux_softc *iomux_sc;
79 
80 static struct ofw_compat_data compat_data[] = {
81 	{"fsl,imx6dl-iomuxc",	true},
82 	{"fsl,imx6q-iomuxc",	true},
83 	{"fsl,imx6sl-iomuxc",	true},
84 	{"fsl,imx6sx-iomuxc",	true},
85 	{"fsl,imx53-iomuxc",	true},
86 	{"fsl,imx51-iomuxc",	true},
87 	{NULL,			false},
88 };
89 
90 /*
91  * Each tuple in an fsl,pins property contains these fields.
92  */
93 struct pincfg {
94 	uint32_t mux_reg;
95 	uint32_t padconf_reg;
96 	uint32_t input_reg;
97 	uint32_t mux_val;
98 	uint32_t input_val;
99 	uint32_t padconf_val;
100 };
101 
102 #define	PADCONF_NONE	(1U << 31)	/* Do not configure pad. */
103 #define	PADCONF_SION	(1U << 30)	/* Force SION bit in mux register. */
104 #define	PADMUX_SION	(1U <<  4)	/* The SION bit in the mux register. */
105 
106 static inline uint32_t
107 RD4(struct iomux_softc *sc, bus_size_t off)
108 {
109 
110 	return (bus_read_4(sc->mem_res, off));
111 }
112 
113 static inline void
114 WR4(struct iomux_softc *sc, bus_size_t off, uint32_t val)
115 {
116 
117 	bus_write_4(sc->mem_res, off, val);
118 }
119 
120 static void
121 iomux_configure_input(struct iomux_softc *sc, uint32_t reg, uint32_t val)
122 {
123 	u_int select, mask, shift, width;
124 
125 	/* If register and value are zero, there is nothing to configure. */
126 	if (reg == 0 && val == 0)
127 		return;
128 
129 	/*
130 	 * If the config value has 0xff in the high byte it is encoded:
131 	 * 	31     23      15      7        0
132 	 *      | 0xff | shift | width | select |
133 	 * We need to mask out the old select value and OR in the new, using a
134 	 * mask of the given width and shifting the values up by shift.
135 	 */
136 	if ((val & 0xff000000) == 0xff000000) {
137 		select = val & 0x000000ff;
138 		width = (val & 0x0000ff00) >> 8;
139 		shift = (val & 0x00ff0000) >> 16;
140 		mask  = ((1u << width) - 1) << shift;
141 		val = (RD4(sc, reg) & ~mask) | (select << shift);
142 	}
143 	WR4(sc, reg, val);
144 }
145 
146 static int
147 iomux_configure_pins(device_t dev, phandle_t cfgxref)
148 {
149 	struct iomux_softc *sc;
150 	struct pincfg *cfgtuples, *cfg;
151 	phandle_t cfgnode;
152 	int i, ntuples;
153 	uint32_t sion;
154 
155 	sc = device_get_softc(dev);
156 	cfgnode = OF_node_from_xref(cfgxref);
157 	ntuples = OF_getencprop_alloc(cfgnode, "fsl,pins", sizeof(*cfgtuples),
158 	    (void **)&cfgtuples);
159 	if (ntuples < 0)
160 		return (ENOENT);
161 	if (ntuples == 0)
162 		return (0); /* Empty property is not an error. */
163 	for (i = 0, cfg = cfgtuples; i < ntuples; i++, cfg++) {
164 		sion = (cfg->padconf_val & PADCONF_SION) ? PADMUX_SION : 0;
165 		WR4(sc, cfg->mux_reg, cfg->mux_val | sion);
166 		iomux_configure_input(sc, cfg->input_reg, cfg->input_val);
167 		if ((cfg->padconf_val & PADCONF_NONE) == 0)
168 			WR4(sc, cfg->padconf_reg, cfg->padconf_val);
169 		if (bootverbose) {
170 			char name[32];
171 			OF_getprop(cfgnode, "name", &name, sizeof(name));
172 			printf("%16s: muxreg 0x%04x muxval 0x%02x "
173 			    "inpreg 0x%04x inpval 0x%02x "
174 			    "padreg 0x%04x padval 0x%08x\n",
175 			    name, cfg->mux_reg, cfg->mux_val | sion,
176 			    cfg->input_reg, cfg->input_val,
177 			    cfg->padconf_reg, cfg->padconf_val);
178 		}
179 	}
180 	free(cfgtuples, M_OFWPROP);
181 	return (0);
182 }
183 
184 static int
185 iomux_probe(device_t dev)
186 {
187 
188 	if (!ofw_bus_status_okay(dev))
189 		return (ENXIO);
190 
191 	if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
192 		return (ENXIO);
193 
194 	device_set_desc(dev, "Freescale i.MX pin configuration");
195 	return (BUS_PROBE_DEFAULT);
196 }
197 
198 static int
199 iomux_detach(device_t dev)
200 {
201 
202         /* This device is always present. */
203 	return (EBUSY);
204 }
205 
206 static int
207 iomux_attach(device_t dev)
208 {
209 	struct iomux_softc * sc;
210 	int rid;
211 
212 	sc = device_get_softc(dev);
213 	sc->dev = dev;
214 
215 	switch (imx_soc_type()) {
216 	case IMXSOC_51:
217 		sc->last_gpreg = 1;
218 		break;
219 	case IMXSOC_53:
220 		sc->last_gpreg = 2;
221 		break;
222 	case IMXSOC_6DL:
223 	case IMXSOC_6S:
224 	case IMXSOC_6SL:
225 	case IMXSOC_6Q:
226 		sc->last_gpreg = 13;
227 		break;
228 	default:
229 		device_printf(dev, "Unknown SoC type\n");
230 		return (ENXIO);
231 	}
232 
233 	rid = 0;
234 	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
235 	    RF_ACTIVE);
236 	if (sc->mem_res == NULL) {
237 		device_printf(dev, "Cannot allocate memory resources\n");
238 		return (ENXIO);
239 	}
240 
241 	iomux_sc = sc;
242 
243 	/*
244 	 * Register as a pinctrl device, and call the convenience function that
245 	 * walks the entire device tree invoking FDT_PINCTRL_CONFIGURE() on any
246 	 * pinctrl-0 property cells whose xref phandle refers to a configuration
247 	 * that is a child node of our node in the tree.
248 	 *
249 	 * The pinctrl bindings documentation specifically mentions that the
250 	 * pinctrl device itself may have a pinctrl-0 property which contains
251 	 * static configuration to be applied at device init time.  The tree
252 	 * walk will automatically handle this for us when it passes through our
253 	 * node in the tree.
254 	 */
255 	fdt_pinctrl_register(dev, "fsl,pins");
256 	fdt_pinctrl_configure_tree(dev);
257 
258 	return (0);
259 }
260 
261 uint32_t
262 imx_iomux_gpr_get(u_int regnum)
263 {
264 	struct iomux_softc * sc;
265 
266 	sc = iomux_sc;
267 	KASSERT(sc != NULL, ("%s called before attach", __FUNCTION__));
268 	KASSERT(regnum >= 0 && regnum <= sc->last_gpreg,
269 	    ("%s bad regnum %u, max %u", __FUNCTION__, regnum, sc->last_gpreg));
270 
271 	return (RD4(iomux_sc, regnum * 4));
272 }
273 
274 void
275 imx_iomux_gpr_set(u_int regnum, uint32_t val)
276 {
277 	struct iomux_softc * sc;
278 
279 	sc = iomux_sc;
280 	KASSERT(sc != NULL, ("%s called before attach", __FUNCTION__));
281 	KASSERT(regnum >= 0 && regnum <= sc->last_gpreg,
282 	    ("%s bad regnum %u, max %u", __FUNCTION__, regnum, sc->last_gpreg));
283 
284 	WR4(iomux_sc, regnum * 4, val);
285 }
286 
287 void
288 imx_iomux_gpr_set_masked(u_int regnum, uint32_t clrbits, uint32_t setbits)
289 {
290 	struct iomux_softc * sc;
291 	uint32_t val;
292 
293 	sc = iomux_sc;
294 	KASSERT(sc != NULL, ("%s called before attach", __FUNCTION__));
295 	KASSERT(regnum >= 0 && regnum <= sc->last_gpreg,
296 	    ("%s bad regnum %u, max %u", __FUNCTION__, regnum, sc->last_gpreg));
297 
298 	val = RD4(iomux_sc, regnum * 4);
299 	val = (val & ~clrbits) | setbits;
300 	WR4(iomux_sc, regnum * 4, val);
301 }
302 
303 static device_method_t imx_iomux_methods[] = {
304 	/* Device interface */
305 	DEVMETHOD(device_probe,         iomux_probe),
306 	DEVMETHOD(device_attach,        iomux_attach),
307 	DEVMETHOD(device_detach,        iomux_detach),
308 
309         /* fdt_pinctrl interface */
310 	DEVMETHOD(fdt_pinctrl_configure,iomux_configure_pins),
311 
312 	DEVMETHOD_END
313 };
314 
315 static driver_t imx_iomux_driver = {
316 	"imx_iomux",
317 	imx_iomux_methods,
318 	sizeof(struct iomux_softc),
319 };
320 
321 static devclass_t imx_iomux_devclass;
322 
323 EARLY_DRIVER_MODULE(imx_iomux, simplebus, imx_iomux_driver,
324     imx_iomux_devclass, 0, 0, BUS_PASS_CPU + BUS_PASS_ORDER_LATE);
325 
326