diff options
Diffstat (limited to 'drivers/tty/serial/of_serial.c')
-rw-r--r-- | drivers/tty/serial/of_serial.c | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c new file mode 100644 index 000000000..137381e64 --- /dev/null +++ b/drivers/tty/serial/of_serial.c @@ -0,0 +1,365 @@ +/* + * 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/console.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/serial_core.h> +#include <linux/serial_reg.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> +#include <linux/nwpserial.h> +#include <linux/clk.h> + +#include "8250/8250.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); +} +#else +static inline void tegra_serial_handle_break(struct uart_port *port) +{ +} +#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; + port->mapsize = resource_size(&resource); + + /* 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; + + /* Check for fifo size */ + if (of_property_read_u32(np, "fifo-size", &prop) == 0) + port->fifosize = prop; + + /* Check for a fixed line number */ + ret = of_alias_get_id(np, "serial"); + if (ret >= 0) + port->line = ret; + + 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 = of_device_is_big_endian(np) ? + UPIO_MEM32BE : 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; + + switch (type) { + case PORT_TEGRA: + port->handle_break = tegra_serial_handle_break; + break; + + case PORT_RT2880: + port->iotype = UPIO_AU; + break; + } + + return 0; +out: + if (info->clk) + clk_disable_unprepare(info->clk); + return ret; +} + +/* + * Try to register a serial port + */ +static const 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 = kzalloc(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: + { + struct uart_8250_port port8250; + memset(&port8250, 0, sizeof(port8250)); + port.type = port_type; + port8250.port = port; + + if (port.fifosize) + port8250.capabilities = UART_CAP_FIFO; + + if (of_property_read_bool(ofdev->dev.of_node, + "auto-flow-control")) + port8250.capabilities |= UART_CAP_AFE; + + 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; + platform_set_drvdata(ofdev, 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 = platform_get_drvdata(ofdev); + 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; +} + +#ifdef CONFIG_PM_SLEEP +#ifdef CONFIG_SERIAL_8250 +static void of_serial_suspend_8250(struct of_serial_info *info) +{ + struct uart_8250_port *port8250 = serial8250_get_port(info->line); + struct uart_port *port = &port8250->port; + + serial8250_suspend_port(info->line); + if (info->clk && (!uart_console(port) || console_suspend_enabled)) + clk_disable_unprepare(info->clk); +} + +static void of_serial_resume_8250(struct of_serial_info *info) +{ + struct uart_8250_port *port8250 = serial8250_get_port(info->line); + struct uart_port *port = &port8250->port; + + if (info->clk && (!uart_console(port) || console_suspend_enabled)) + clk_prepare_enable(info->clk); + + serial8250_resume_port(info->line); +} +#else +static inline void of_serial_suspend_8250(struct of_serial_info *info) +{ +} + +static inline void of_serial_resume_8250(struct of_serial_info *info) +{ +} +#endif + +static int of_serial_suspend(struct device *dev) +{ + struct of_serial_info *info = dev_get_drvdata(dev); + + switch (info->type) { + case PORT_8250 ... PORT_MAX_8250: + of_serial_suspend_8250(info); + break; + default: + break; + } + + return 0; +} + +static int of_serial_resume(struct device *dev) +{ + struct of_serial_info *info = dev_get_drvdata(dev); + + switch (info->type) { + case PORT_8250 ... PORT_MAX_8250: + of_serial_resume_8250(info); + break; + default: + break; + } + + return 0; +} +#endif +static SIMPLE_DEV_PM_OPS(of_serial_pm_ops, of_serial_suspend, of_serial_resume); + +/* + * A few common types, add more as needed. + */ +static const 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, }, + { .compatible = "ralink,rt2880-uart", .data = (void *)PORT_RT2880, }, + { .compatible = "altr,16550-FIFO32", + .data = (void *)PORT_ALTR_16550_F32, }, + { .compatible = "altr,16550-FIFO64", + .data = (void *)PORT_ALTR_16550_F64, }, + { .compatible = "altr,16550-FIFO128", + .data = (void *)PORT_ALTR_16550_F128, }, + { .compatible = "mrvl,mmp-uart", + .data = (void *)PORT_XSCALE, }, + { .compatible = "mrvl,pxa-uart", + .data = (void *)PORT_XSCALE, }, +#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL + { .compatible = "ibm,qpace-nwp-serial", + .data = (void *)PORT_NWPSERIAL, }, +#endif + { /* end of list */ }, +}; + +static struct platform_driver of_platform_serial_driver = { + .driver = { + .name = "of_serial", + .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"); |