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      1 /* $NetBSD: bcm2835_aux.c,v 1.3 2021/01/27 03:10:19 thorpej Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2017 Jared D. McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: bcm2835_aux.c,v 1.3 2021/01/27 03:10:19 thorpej Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/systm.h>
     34 #include <sys/device.h>
     35 #include <sys/kmem.h>
     36 #include <sys/bus.h>
     37 
     38 #include <dev/clk/clk_backend.h>
     39 
     40 #include <dev/fdt/fdtvar.h>
     41 
     42 /* Registers */
     43 #define	BCMAUX_AUXIRQ_REG	0x00
     44 #define	BCMAUX_AUXENB_REG	0x04
     45 
     46 /* Clock IDs */
     47 #define	BCMAUX_CLOCK_UART	0
     48 #define	BCMAUX_CLOCK_SPI1	1
     49 #define	BCMAUX_CLOCK_SPI2	2
     50 #define	BCMAUX_NCLOCK		3
     51 
     52 static int	bcmaux_match(device_t, cfdata_t, void *);
     53 static void	bcmaux_attach(device_t, device_t, void *);
     54 
     55 static struct clk *bcmaux_decode(device_t, int, const void *, size_t);
     56 
     57 static const struct fdtbus_clock_controller_func bcmaux_fdt_funcs = {
     58 	.decode = bcmaux_decode
     59 };
     60 
     61 static struct clk *bcmaux_get(void *, const char *);
     62 static void	bcmaux_put(void *, struct clk *);
     63 static u_int	bcmaux_get_rate(void *, struct clk *);
     64 static int	bcmaux_enable(void *, struct clk *);
     65 static int	bcmaux_disable(void *, struct clk *);
     66 
     67 static const struct clk_funcs bcmaux_clk_funcs = {
     68 	.get = bcmaux_get,
     69 	.put = bcmaux_put,
     70 	.get_rate = bcmaux_get_rate,
     71 	.enable = bcmaux_enable,
     72 	.disable = bcmaux_disable,
     73 };
     74 
     75 struct bcmaux_clk {
     76 	struct clk	base;
     77 	uint32_t	mask;
     78 };
     79 
     80 struct bcmaux_softc {
     81 	device_t	sc_dev;
     82 	int		sc_phandle;
     83 	bus_space_tag_t	sc_bst;
     84 	bus_space_handle_t sc_bsh;
     85 
     86 	struct clk	*sc_pclk;
     87 
     88 	struct clk_domain sc_clkdom;
     89 	struct bcmaux_clk sc_clk[BCMAUX_NCLOCK];
     90 };
     91 
     92 #define	BCMAUX_READ(sc, reg)		\
     93 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
     94 #define	BCMAUX_WRITE(sc, reg, val)	\
     95 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
     96 
     97 CFATTACH_DECL_NEW(bcmaux_fdt, sizeof(struct bcmaux_softc),
     98     bcmaux_match, bcmaux_attach, NULL, NULL);
     99 
    100 static const struct device_compatible_entry compat_data[] = {
    101 	{ .compat = "brcm,bcm2835-aux" },
    102 	DEVICE_COMPAT_EOL
    103 };
    104 
    105 static int
    106 bcmaux_match(device_t parent, cfdata_t cf, void *aux)
    107 {
    108 	const struct fdt_attach_args *faa = aux;
    109 
    110 	return of_compatible_match(faa->faa_phandle, compat_data);
    111 }
    112 
    113 static void
    114 bcmaux_attach(device_t parent, device_t self, void *aux)
    115 {
    116 	struct bcmaux_softc * const sc = device_private(self);
    117 	const struct fdt_attach_args *faa = aux;
    118 	const int phandle = faa->faa_phandle;
    119 	bus_addr_t addr;
    120 	bus_size_t size;
    121 
    122 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
    123 		aprint_error(": couldn't get registers\n");
    124 		return;
    125 	}
    126 
    127 	sc->sc_dev = self;
    128 	sc->sc_phandle = phandle;
    129 	sc->sc_clkdom.funcs = &bcmaux_clk_funcs;
    130 	sc->sc_clkdom.priv = sc;
    131 	sc->sc_pclk = fdtbus_clock_get_index(phandle, 0);
    132 	if (sc->sc_pclk == NULL) {
    133 		aprint_error(": couldn't get parent clock\n");
    134 		return;
    135 	}
    136 	sc->sc_bst = faa->faa_bst;
    137 	if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
    138 		aprint_error(": couldn't map registers\n");
    139 		return;
    140 	}
    141 
    142 	sc->sc_clk[BCMAUX_CLOCK_UART].base.domain = &sc->sc_clkdom;
    143 	sc->sc_clk[BCMAUX_CLOCK_UART].base.name = "aux_uart";
    144 	sc->sc_clk[BCMAUX_CLOCK_UART].mask = __BIT(0);
    145 
    146 	sc->sc_clk[BCMAUX_CLOCK_SPI1].base.domain = &sc->sc_clkdom;
    147 	sc->sc_clk[BCMAUX_CLOCK_SPI1].base.name = "aux_spi1";
    148 	sc->sc_clk[BCMAUX_CLOCK_SPI1].mask = __BIT(1);
    149 
    150 	sc->sc_clk[BCMAUX_CLOCK_SPI2].base.domain = &sc->sc_clkdom;
    151 	sc->sc_clk[BCMAUX_CLOCK_SPI2].base.name = "aux_spi2";
    152 	sc->sc_clk[BCMAUX_CLOCK_SPI2].mask = __BIT(2);
    153 
    154 	aprint_naive("\n");
    155 	aprint_normal("\n");
    156 
    157 	fdtbus_register_clock_controller(self, phandle, &bcmaux_fdt_funcs);
    158 }
    159 
    160 static struct clk *
    161 bcmaux_decode(device_t dev, int cc_phandle, const void *data, size_t len)
    162 {
    163 	struct bcmaux_softc * const sc = device_private(dev);
    164 	u_int clkid;
    165 
    166 	if (len != 4)
    167 		return NULL;
    168 
    169 	clkid = be32dec(data);
    170 	if (clkid >= BCMAUX_NCLOCK)
    171 		return NULL;
    172 
    173 	return &sc->sc_clk[clkid].base;
    174 }
    175 
    176 static struct clk *
    177 bcmaux_get(void *priv, const char *name)
    178 {
    179 	struct bcmaux_softc * const sc = priv;
    180 
    181 	for (size_t i = 0; i < BCMAUX_NCLOCK; i++) {
    182 		if (strcmp(name, sc->sc_clk[i].base.name) == 0)
    183 			return &sc->sc_clk[i].base;
    184 	}
    185 
    186 	return NULL;
    187 }
    188 
    189 static void
    190 bcmaux_put(void *priv, struct clk *clk)
    191 {
    192 }
    193 
    194 static u_int
    195 bcmaux_get_rate(void *priv, struct clk *clk)
    196 {
    197 	struct bcmaux_softc * const sc = priv;
    198 
    199 	return clk_get_rate(sc->sc_pclk);
    200 }
    201 
    202 static int
    203 bcmaux_enable(void *priv, struct clk *clk)
    204 {
    205 	struct bcmaux_softc * const sc = priv;
    206 	struct bcmaux_clk *auxclk = (struct bcmaux_clk *)clk;
    207 	uint32_t val;
    208 
    209 	val = BCMAUX_READ(sc, BCMAUX_AUXENB_REG);
    210 	val |= auxclk->mask;
    211 	BCMAUX_WRITE(sc, BCMAUX_AUXENB_REG, val);
    212 
    213 	return 0;
    214 }
    215 
    216 static int
    217 bcmaux_disable(void *priv, struct clk *clk)
    218 {
    219 	struct bcmaux_softc * const sc = priv;
    220 	struct bcmaux_clk *auxclk = (struct bcmaux_clk *)clk;
    221 	uint32_t val;
    222 
    223 	val = BCMAUX_READ(sc, BCMAUX_AUXENB_REG);
    224 	val &= ~auxclk->mask;
    225 	BCMAUX_WRITE(sc, BCMAUX_AUXENB_REG, val);
    226 
    227 	return 0;
    228 }
    229