dw_apb_uart.c revision 1.4
1 /* $NetBSD: dw_apb_uart.c,v 1.4 2018/12/08 17:46:13 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 1.4 2018/12/08 17:46:13 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 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_handle_t bsh; 80 bus_space_tag_t bst; 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", ®_shift)) { 93 /* missing or bad reg-shift property, assume 2 */ 94 bst = faa->faa_a4x_bst; 95 } else { 96 if (reg_shift == 2) { 97 bst = faa->faa_a4x_bst; 98 } else if (reg_shift == 0) { 99 bst = faa->faa_bst; 100 } else { 101 aprint_error(": unsupported reg-shift value %d\n", 102 reg_shift); 103 return; 104 } 105 } 106 107 sc->sc_dev = self; 108 109 ssc->ssc_clk = fdtbus_clock_get_index(faa->faa_phandle, 0); 110 if (ssc->ssc_clk == NULL) { 111 aprint_error(": couldn't get clock\n"); 112 return; 113 } 114 if (clk_enable(ssc->ssc_clk) != 0) { 115 aprint_error(": couldn't enable clock\n"); 116 return; 117 } 118 119 ssc->ssc_pclk = fdtbus_clock_get(faa->faa_phandle, "apb_pclk"); 120 if (ssc->ssc_pclk != NULL && clk_enable(ssc->ssc_pclk) != 0) { 121 aprint_error(": couldn't enable peripheral clock\n"); 122 return; 123 } 124 125 ssc->ssc_rst = fdtbus_reset_get_index(faa->faa_phandle, 0); 126 if (ssc->ssc_rst && fdtbus_reset_deassert(ssc->ssc_rst) != 0) { 127 aprint_error(": couldn't de-assert reset\n"); 128 return; 129 } 130 131 sc->sc_frequency = clk_get_rate(ssc->ssc_clk); 132 sc->sc_type = COM_TYPE_DW_APB; 133 134 error = bus_space_map(bst, addr, size, 0, &bsh); 135 if (error) { 136 aprint_error(": couldn't map %#" PRIx64 ": %d", (uint64_t)addr, error); 137 return; 138 } 139 140 com_init_regs(&sc->sc_regs, bst, bsh, addr); 141 142 com_attach_subr(sc); 143 144 if (!fdtbus_intr_str(faa->faa_phandle, 0, intrstr, sizeof(intrstr))) { 145 aprint_error_dev(self, "failed to decode interrupt\n"); 146 return; 147 } 148 149 ssc->ssc_ih = fdtbus_intr_establish(faa->faa_phandle, 0, IPL_SERIAL, 150 FDT_INTR_MPSAFE, comintr, sc); 151 if (ssc->ssc_ih == NULL) { 152 aprint_error_dev(self, "failed to establish interrupt on %s\n", 153 intrstr); 154 } 155 aprint_normal_dev(self, "interrupting on %s\n", intrstr); 156 } 157 158 /* 159 * Console support 160 */ 161 162 static int 163 dw_apb_uart_console_match(int phandle) 164 { 165 return of_match_compatible(phandle, compatible); 166 } 167 168 static void 169 dw_apb_uart_console_consinit(struct fdt_attach_args *faa, u_int uart_freq) 170 { 171 const int phandle = faa->faa_phandle; 172 bus_space_tag_t bst = faa->faa_a4x_bst; 173 bus_addr_t addr; 174 tcflag_t flags; 175 int speed; 176 177 fdtbus_get_reg(phandle, 0, &addr, NULL); 178 speed = fdtbus_get_stdout_speed(); 179 if (speed < 0) 180 speed = 115200; /* default */ 181 flags = fdtbus_get_stdout_flags(); 182 183 if (comcnattach(bst, addr, speed, uart_freq, COM_TYPE_DW_APB, flags)) 184 panic("Cannot initialize dw-apb-uart console"); 185 } 186 187 static const struct fdt_console dw_apb_uart_console = { 188 .match = dw_apb_uart_console_match, 189 .consinit = dw_apb_uart_console_consinit, 190 }; 191 192 FDT_CONSOLE(dw_apb_uart, &dw_apb_uart_console); 193
Indexes created Fri Sep 26 20:09:58 GMT 2025