/* * Serial Port driver for Open Firmware platform devices * * Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * */ #include <linux/init.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/delay.h> #include <linux/serial_core.h> #include <linux/serial_8250.h> #include <linux/serial_reg.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/of_serial.h> #include <linux/of_platform.h> #include <linux/nwpserial.h> #include <linux/clk.h> struct of_serial_info { struct clk *clk; int type; int line; }; #ifdef CONFIG_ARCH_TEGRA void tegra_serial_handle_break(struct uart_port *p) { unsigned int status, tmout = 10000; do { status = p->serial_in(p, UART_LSR); if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS)) status = p->serial_in(p, UART_RX); else break; if (--tmout == 0) break; udelay(1); } while (1); } /* FIXME remove this export when tegra finishes conversion to open firmware */ EXPORT_SYMBOL_GPL(tegra_serial_handle_break); #endif /* * Fill a struct uart_port for a given device node */ static int of_platform_serial_setup(struct platform_device *ofdev, int type, struct uart_port *port, struct of_serial_info *info) { struct resource resource; struct device_node *np = ofdev->dev.of_node; u32 clk, spd, prop; int ret; memset(port, 0, sizeof *port); if (of_property_read_u32(np, "clock-frequency", &clk)) { /* Get clk rate through clk driver if present */ info->clk = clk_get(&ofdev->dev, NULL); if (IS_ERR(info->clk)) { dev_warn(&ofdev->dev, "clk or clock-frequency not defined\n"); return PTR_ERR(info->clk); } clk_prepare_enable(info->clk); clk = clk_get_rate(info->clk); } /* If current-speed was set, then try not to change it. */ if (of_property_read_u32(np, "current-speed", &spd) == 0) port->custom_divisor = clk / (16 * spd); ret = of_address_to_resource(np, 0, &resource); if (ret) { dev_warn(&ofdev->dev, "invalid address\n"); goto out; } spin_lock_init(&port->lock); port->mapbase = resource.start; /* Check for shifted address mapping */ if (of_property_read_u32(np, "reg-offset", &prop) == 0) port->mapbase += prop; /* Check for registers offset within the devices address range */ if (of_property_read_u32(np, "reg-shift", &prop) == 0) port->regshift = prop; port->irq = irq_of_parse_and_map(np, 0); port->iotype = UPIO_MEM; if (of_property_read_u32(np, "reg-io-width", &prop) == 0) { switch (prop) { case 1: port->iotype = UPIO_MEM; break; case 4: port->iotype = UPIO_MEM32; break; default: dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n", prop); ret = -EINVAL; goto out; } } port->type = type; port->uartclk = clk; port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP | UPF_FIXED_PORT | UPF_FIXED_TYPE; if (of_find_property(np, "no-loopback-test", NULL)) port->flags |= UPF_SKIP_TEST; port->dev = &ofdev->dev; if (type == PORT_TEGRA) port->handle_break = tegra_serial_handle_break; return 0; out: if (info->clk) clk_disable_unprepare(info->clk); return ret; } /* * Try to register a serial port */ static struct of_device_id of_platform_serial_table[]; static int of_platform_serial_probe(struct platform_device *ofdev) { const struct of_device_id *match; struct of_serial_info *info; struct uart_port port; int port_type; int ret; match = of_match_device(of_platform_serial_table, &ofdev->dev); if (!match) return -EINVAL; if (of_find_property(ofdev->dev.of_node, "used-by-rtas", NULL)) return -EBUSY; info = kmalloc(sizeof(*info), GFP_KERNEL); if (info == NULL) return -ENOMEM; port_type = (unsigned long)match->data; ret = of_platform_serial_setup(ofdev, port_type, &port, info); if (ret) goto out; switch (port_type) { #ifdef CONFIG_SERIAL_8250 case PORT_8250 ... PORT_MAX_8250: { /* For now the of bindings don't support the extra 8250 specific bits */ struct uart_8250_port port8250; memset(&port8250, 0, sizeof(port8250)); port8250.port = port; ret = serial8250_register_8250_port(&port8250); break; } #endif #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL case PORT_NWPSERIAL: ret = nwpserial_register_port(&port); break; #endif default: /* need to add code for these */ case PORT_UNKNOWN: dev_info(&ofdev->dev, "Unknown serial port found, ignored\n"); ret = -ENODEV; break; } if (ret < 0) goto out; info->type = port_type; info->line = ret; dev_set_drvdata(&ofdev->dev, info); return 0; out: kfree(info); irq_dispose_mapping(port.irq); return ret; } /* * Release a line */ static int of_platform_serial_remove(struct platform_device *ofdev) { struct of_serial_info *info = dev_get_drvdata(&ofdev->dev); switch (info->type) { #ifdef CONFIG_SERIAL_8250 case PORT_8250 ... PORT_MAX_8250: serial8250_unregister_port(info->line); break; #endif #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL case PORT_NWPSERIAL: nwpserial_unregister_port(info->line); break; #endif default: /* need to add code for these */ break; } if (info->clk) clk_disable_unprepare(info->clk); kfree(info); return 0; } /* * A few common types, add more as needed. */ static struct of_device_id of_platform_serial_table[] = { { .compatible = "ns8250", .data = (void *)PORT_8250, }, { .compatible = "ns16450", .data = (void *)PORT_16450, }, { .compatible = "ns16550a", .data = (void *)PORT_16550A, }, { .compatible = "ns16550", .data = (void *)PORT_16550, }, { .compatible = "ns16750", .data = (void *)PORT_16750, }, { .compatible = "ns16850", .data = (void *)PORT_16850, }, { .compatible = "nvidia,tegra20-uart", .data = (void *)PORT_TEGRA, }, { .compatible = "nxp,lpc3220-uart", .data = (void *)PORT_LPC3220, }, #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL { .compatible = "ibm,qpace-nwp-serial", .data = (void *)PORT_NWPSERIAL, }, #endif { .type = "serial", .data = (void *)PORT_UNKNOWN, }, { /* end of list */ }, }; static struct platform_driver of_platform_serial_driver = { .driver = { .name = "of_serial", .owner = THIS_MODULE, .of_match_table = of_platform_serial_table, }, .probe = of_platform_serial_probe, .remove = of_platform_serial_remove, }; module_platform_driver(of_platform_serial_driver); MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>"); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");