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      1 /* $NetBSD: dw_apb_uart.c,v 1.13 2025/09/06 22:53:48 thorpej 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 1.13 2025/09/06 22:53:48 thorpej 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 #include <dev/fdt/fdt_console.h>
     45 
     46 static int dw_apb_uart_match(device_t, cfdata_t, void *);
     47 static void dw_apb_uart_attach(device_t, device_t, void *);
     48 
     49 static const struct device_compatible_entry compat_data[] = {
     50 	{ .compat = "snps,dw-apb-uart" },
     51 	DEVICE_COMPAT_EOL
     52 };
     53 
     54 struct dw_apb_uart_softc {
     55 	struct com_softc ssc_sc;
     56 	void *ssc_ih;
     57 
     58 	struct clk *ssc_clk;
     59 	struct clk *ssc_pclk;
     60 	struct fdtbus_reset *ssc_rst;
     61 };
     62 
     63 CFATTACH_DECL_NEW(dw_apb_uart, sizeof(struct dw_apb_uart_softc),
     64 	dw_apb_uart_match, dw_apb_uart_attach, NULL, NULL);
     65 
     66 static int
     67 dw_apb_uart_match(device_t parent, cfdata_t cf, void *aux)
     68 {
     69 	struct fdt_attach_args * const faa = aux;
     70 
     71 	return of_compatible_match(faa->faa_phandle, compat_data);
     72 }
     73 
     74 static void
     75 dw_apb_uart_attach(device_t parent, device_t self, void *aux)
     76 {
     77 	struct dw_apb_uart_softc * const ssc = device_private(self);
     78 	struct com_softc * const sc = &ssc->ssc_sc;
     79 	struct fdt_attach_args * const faa = aux;
     80 	const int phandle = faa->faa_phandle;
     81 	bus_space_tag_t bst = faa->faa_bst;
     82 	bus_space_handle_t bsh;
     83 	char intrstr[128];
     84 	bus_addr_t addr;
     85 	bus_size_t size;
     86 	u_int reg_shift, reg_iowidth;
     87 	int error;
     88 
     89 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
     90 		aprint_error(": couldn't get registers\n");
     91 		return;
     92 	}
     93 
     94 	if (of_getprop_uint32(phandle, "reg-shift", &reg_shift)) {
     95 		/* missing or bad reg-shift property, assume 2 */
     96 		reg_shift = 2;
     97 	}
     98 	if (of_getprop_uint32(phandle, "reg-io-width", &reg_iowidth)) {
     99 		/* missing or bad reg-io-width property, assume 1 */
    100 		reg_iowidth = 1;
    101 	}
    102 
    103 	sc->sc_dev = self;
    104 
    105 	ssc->ssc_clk = fdtbus_clock_get_index(phandle, 0);
    106 	if (ssc->ssc_clk == NULL) {
    107 		aprint_error(": couldn't get clock\n");
    108 		return;
    109 	}
    110 	if (clk_enable(ssc->ssc_clk) != 0) {
    111 		aprint_error(": couldn't enable clock\n");
    112 		return;
    113 	}
    114 
    115 	ssc->ssc_pclk = fdtbus_clock_get(phandle, "apb_pclk");
    116 	if (ssc->ssc_pclk != NULL && clk_enable(ssc->ssc_pclk) != 0) {
    117 		aprint_error(": couldn't enable peripheral clock\n");
    118 		return;
    119 	}
    120 
    121 	ssc->ssc_rst = fdtbus_reset_get_index(phandle, 0);
    122 	if (ssc->ssc_rst && fdtbus_reset_deassert(ssc->ssc_rst) != 0) {
    123 		aprint_error(": couldn't de-assert reset\n");
    124 		return;
    125 	}
    126 
    127 	sc->sc_frequency = clk_get_rate(ssc->ssc_clk);
    128 	sc->sc_type = COM_TYPE_DW_APB;
    129 
    130 	error = bus_space_map(bst, addr, size, 0, &bsh);
    131 	if (error) {
    132 		aprint_error(": couldn't map %#" PRIx64 ": %d", (uint64_t)addr, error);
    133 		return;
    134 	}
    135 
    136 	com_init_regs_stride_width(&sc->sc_regs, bst, bsh, addr, reg_shift, reg_iowidth);
    137 
    138 	com_attach_subr(sc);
    139 
    140 	if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
    141 		aprint_error_dev(self, "failed to decode interrupt\n");
    142 		return;
    143 	}
    144 
    145 	ssc->ssc_ih = fdtbus_intr_establish_xname(phandle, 0,
    146 	    IPL_SERIAL, FDT_INTR_MPSAFE, comintr, sc, device_xname(self));
    147 	if (ssc->ssc_ih == NULL) {
    148 		aprint_error_dev(self, "failed to establish interrupt on %s\n",
    149 		    intrstr);
    150 	}
    151 	aprint_normal_dev(self, "interrupting on %s\n", intrstr);
    152 }
    153 
    154 /*
    155  * Console support
    156  */
    157 
    158 static int
    159 dw_apb_uart_console_match(int phandle)
    160 {
    161 	return of_compatible_match(phandle, compat_data);
    162 }
    163 
    164 static void
    165 dw_apb_uart_console_consinit(struct fdt_attach_args *faa, u_int uart_freq)
    166 {
    167 	const int phandle = faa->faa_phandle;
    168 	bus_space_tag_t bst = faa->faa_bst;
    169 	bus_space_handle_t dummy_bsh;
    170 	struct com_regs regs;
    171 	bus_addr_t addr;
    172 	tcflag_t flags;
    173 	u_int reg_shift, reg_iowidth;
    174 	int speed;
    175 
    176 	fdtbus_get_reg(phandle, 0, &addr, NULL);
    177 	speed = fdtbus_get_stdout_speed();
    178 	if (speed < 0)
    179 		speed = 115200;	/* default */
    180 	flags = fdtbus_get_stdout_flags();
    181 
    182 	if (of_getprop_uint32(phandle, "reg-shift", &reg_shift)) {
    183 		/* missing or bad reg-shift property, assume 2 */
    184 		reg_shift = 2;
    185 	}
    186 	if (of_getprop_uint32(phandle, "reg-io-width", &reg_iowidth)) {
    187 		/* missing or bad reg-io-width property, assume 1 */
    188 		reg_iowidth = 1;
    189 	}
    190 
    191 	memset(&dummy_bsh, 0, sizeof(dummy_bsh));
    192 	com_init_regs_stride_width(&regs, bst, dummy_bsh, addr, reg_shift, reg_iowidth);
    193 
    194 	if (comcnattach1(&regs, speed, uart_freq, COM_TYPE_DW_APB, flags))
    195 		panic("Cannot initialize dw-apb-uart console");
    196 }
    197 
    198 static const struct fdt_console dw_apb_uart_console = {
    199 	.match = dw_apb_uart_console_match,
    200 	.consinit = dw_apb_uart_console_consinit,
    201 };
    202 
    203 FDT_CONSOLE(dw_apb_uart, &dw_apb_uart_console);
    204