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dw_apb_uart.c revision 1.9
      1 /* $NetBSD: dw_apb_uart.c,v 1.9 2021/01/15 20:50:49 ryo Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2017 Jared 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 
     31 __KERNEL_RCSID(1, "$NetBSD: dw_apb_uart.c,v 1.9 2021/01/15 20:50:49 ryo Exp $");
     32 
     33 #include <sys/param.h>
     34 #include <sys/bus.h>
     35 #include <sys/device.h>
     36 #include <sys/intr.h>
     37 #include <sys/systm.h>
     38 #include <sys/time.h>
     39 #include <sys/termios.h>
     40 
     41 #include <dev/ic/comvar.h>
     42 
     43 #include <dev/fdt/fdtvar.h>
     44 
     45 static int dw_apb_uart_match(device_t, cfdata_t, void *);
     46 static void dw_apb_uart_attach(device_t, device_t, void *);
     47 
     48 static const char * const compatible[] = {
     49 	"snps,dw-apb-uart",
     50 	NULL
     51 };
     52 
     53 struct dw_apb_uart_softc {
     54 	struct com_softc ssc_sc;
     55 	void *ssc_ih;
     56 
     57 	struct clk *ssc_clk;
     58 	struct clk *ssc_pclk;
     59 	struct fdtbus_reset *ssc_rst;
     60 };
     61 
     62 CFATTACH_DECL_NEW(dw_apb_uart, sizeof(struct dw_apb_uart_softc),
     63 	dw_apb_uart_match, dw_apb_uart_attach, NULL, NULL);
     64 
     65 static int
     66 dw_apb_uart_match(device_t parent, cfdata_t cf, void *aux)
     67 {
     68 	struct fdt_attach_args * const faa = aux;
     69 
     70 	return of_match_compatible(faa->faa_phandle, compatible);
     71 }
     72 
     73 static void
     74 dw_apb_uart_attach(device_t parent, device_t self, void *aux)
     75 {
     76 	struct dw_apb_uart_softc * const ssc = device_private(self);
     77 	struct com_softc * const sc = &ssc->ssc_sc;
     78 	struct fdt_attach_args * const faa = aux;
     79 	bus_space_tag_t bst = faa->faa_bst;
     80 	bus_space_handle_t bsh;
     81 	char intrstr[128];
     82 	bus_addr_t addr;
     83 	bus_size_t size;
     84 	u_int reg_shift;
     85 	int error;
     86 
     87 	if (fdtbus_get_reg(faa->faa_phandle, 0, &addr, &size) != 0) {
     88 		aprint_error(": couldn't get registers\n");
     89 		return;
     90 	}
     91 
     92 	if (of_getprop_uint32(faa->faa_phandle, "reg-shift", &reg_shift)) {
     93 		/* missing or bad reg-shift property, assume 2 */
     94 		reg_shift = 2;
     95 	}
     96 
     97 	sc->sc_dev = self;
     98 
     99 	ssc->ssc_clk = fdtbus_clock_get_index(faa->faa_phandle, 0);
    100 	if (ssc->ssc_clk == NULL) {
    101 		aprint_error(": couldn't get clock\n");
    102 		return;
    103 	}
    104 	if (clk_enable(ssc->ssc_clk) != 0) {
    105 		aprint_error(": couldn't enable clock\n");
    106 		return;
    107 	}
    108 
    109 	ssc->ssc_pclk = fdtbus_clock_get(faa->faa_phandle, "apb_pclk");
    110 	if (ssc->ssc_pclk != NULL && clk_enable(ssc->ssc_pclk) != 0) {
    111 		aprint_error(": couldn't enable peripheral clock\n");
    112 		return;
    113 	}
    114 
    115 	ssc->ssc_rst = fdtbus_reset_get_index(faa->faa_phandle, 0);
    116 	if (ssc->ssc_rst && fdtbus_reset_deassert(ssc->ssc_rst) != 0) {
    117 		aprint_error(": couldn't de-assert reset\n");
    118 		return;
    119 	}
    120 
    121 	sc->sc_frequency = clk_get_rate(ssc->ssc_clk);
    122 	sc->sc_type = COM_TYPE_DW_APB;
    123 
    124 	error = bus_space_map(bst, addr, size, 0, &bsh);
    125 	if (error) {
    126 		aprint_error(": couldn't map %#" PRIx64 ": %d", (uint64_t)addr, error);
    127 		return;
    128 	}
    129 
    130 	com_init_regs_stride(&sc->sc_regs, bst, bsh, addr, reg_shift);
    131 
    132 	com_attach_subr(sc);
    133 
    134 	if (!fdtbus_intr_str(faa->faa_phandle, 0, intrstr, sizeof(intrstr))) {
    135 		aprint_error_dev(self, "failed to decode interrupt\n");
    136 		return;
    137 	}
    138 
    139 	ssc->ssc_ih = fdtbus_intr_establish_xname(faa->faa_phandle, 0,
    140 	    IPL_SERIAL, FDT_INTR_MPSAFE, comintr, sc, device_xname(self));
    141 	if (ssc->ssc_ih == NULL) {
    142 		aprint_error_dev(self, "failed to establish interrupt on %s\n",
    143 		    intrstr);
    144 	}
    145 	aprint_normal_dev(self, "interrupting on %s\n", intrstr);
    146 }
    147 
    148 /*
    149  * Console support
    150  */
    151 
    152 static int
    153 dw_apb_uart_console_match(int phandle)
    154 {
    155 	return of_match_compatible(phandle, compatible);
    156 }
    157 
    158 static void
    159 dw_apb_uart_console_consinit(struct fdt_attach_args *faa, u_int uart_freq)
    160 {
    161 	const int phandle = faa->faa_phandle;
    162 	bus_space_tag_t bst = faa->faa_bst;
    163 	bus_space_handle_t dummy_bsh;
    164 	struct com_regs regs;
    165 	bus_addr_t addr;
    166 	tcflag_t flags;
    167 	u_int reg_shift;
    168 	int speed;
    169 
    170 	fdtbus_get_reg(phandle, 0, &addr, NULL);
    171 	speed = fdtbus_get_stdout_speed();
    172 	if (speed < 0)
    173 		speed = 115200;	/* default */
    174 	flags = fdtbus_get_stdout_flags();
    175 
    176 	if (of_getprop_uint32(phandle, "reg-shift", &reg_shift)) {
    177 		/* missing or bad reg-shift property, assume 2 */
    178 		reg_shift = 2;
    179 	}
    180 
    181 	memset(&dummy_bsh, 0, sizeof(dummy_bsh));
    182 	com_init_regs_stride(&regs, bst, dummy_bsh, addr, reg_shift);
    183 
    184 	if (comcnattach1(&regs, speed, uart_freq, COM_TYPE_DW_APB, flags))
    185 		panic("Cannot initialize dw-apb-uart console");
    186 }
    187 
    188 static const struct fdt_console dw_apb_uart_console = {
    189 	.match = dw_apb_uart_console_match,
    190 	.consinit = dw_apb_uart_console_consinit,
    191 };
    192 
    193 FDT_CONSOLE(dw_apb_uart, &dw_apb_uart_console);
    194