1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (c) 2018 Alexander Graf <agraf (at) suse.de> 4 */ 5 6 #include <common.h> 7 #include <dm.h> 8 #include <asm/gpio.h> 9 #include <dm/pinctrl.h> 10 #include <dm/platform_data/serial_pl01x.h> 11 #include <serial.h> 12 #include "serial_pl01x_internal.h" 13 14 /* 15 * Check if this serial device is muxed 16 * 17 * The serial device will only work properly if it has been muxed to the serial 18 * pins by firmware. Check whether that happened here. 19 * 20 * @return true if serial device is muxed, false if not 21 */ 22 static bool bcm283x_is_serial_muxed(void) 23 { 24 int serial_gpio = 15; 25 struct udevice *dev; 26 27 if (uclass_first_device(UCLASS_PINCTRL, &dev) || !dev) 28 return false; 29 30 if (pinctrl_get_gpio_mux(dev, 0, serial_gpio) != BCM2835_GPIO_ALT0) 31 return false; 32 33 return true; 34 } 35 36 static int bcm283x_pl011_serial_ofdata_to_platdata(struct udevice *dev) 37 { 38 struct pl01x_serial_platdata *plat = dev_get_platdata(dev); 39 int ret; 40 41 /* Don't spawn the device if it's not muxed */ 42 if (!bcm283x_is_serial_muxed()) 43 return -ENODEV; 44 45 ret = pl01x_serial_ofdata_to_platdata(dev); 46 if (ret) 47 return ret; 48 49 /* 50 * TODO: Reinitialization doesn't always work for now, just skip 51 * init always - we know we're already initialized 52 */ 53 plat->skip_init = true; 54 55 return 0; 56 } 57 58 static int bcm283x_pl011_serial_setbrg(struct udevice *dev, int baudrate) 59 { 60 int r; 61 62 r = pl01x_serial_setbrg(dev, baudrate); 63 64 /* 65 * We may have been muxed to a bogus line before. Drain the RX 66 * queue so we start at a clean slate. 67 */ 68 while (pl01x_serial_getc(dev) != -EAGAIN) ; 69 70 return r; 71 } 72 73 static const struct dm_serial_ops bcm283x_pl011_serial_ops = { 74 .putc = pl01x_serial_putc, 75 .pending = pl01x_serial_pending, 76 .getc = pl01x_serial_getc, 77 .setbrg = bcm283x_pl011_serial_setbrg, 78 }; 79 80 static const struct udevice_id bcm283x_pl011_serial_id[] = { 81 {.compatible = "brcm,bcm2835-pl011", .data = TYPE_PL011}, 82 {} 83 }; 84 85 U_BOOT_DRIVER(bcm283x_pl011_uart) = { 86 .name = "bcm283x_pl011", 87 .id = UCLASS_SERIAL, 88 .of_match = of_match_ptr(bcm283x_pl011_serial_id), 89 .ofdata_to_platdata = of_match_ptr(bcm283x_pl011_serial_ofdata_to_platdata), 90 .platdata_auto_alloc_size = sizeof(struct pl01x_serial_platdata), 91 .probe = pl01x_serial_probe, 92 .ops = &bcm283x_pl011_serial_ops, 93 .flags = DM_FLAG_PRE_RELOC, 94 .priv_auto_alloc_size = sizeof(struct pl01x_priv), 95 }; 96
