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341 lines
8.9 KiB
341 lines
8.9 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Serial Port driver for Open Firmware platform devices |
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* |
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* Copyright (C) 2006 Arnd Bergmann <[email protected]>, IBM Corp. |
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*/ |
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#include <linux/console.h> |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/serial_core.h> |
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#include <linux/serial_reg.h> |
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#include <linux/of_address.h> |
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#include <linux/of_irq.h> |
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#include <linux/of_platform.h> |
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#include <linux/pm_runtime.h> |
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#include <linux/clk.h> |
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#include <linux/reset.h> |
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#include "8250.h" |
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struct of_serial_info { |
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struct clk *clk; |
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struct reset_control *rst; |
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int type; |
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int line; |
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}; |
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/* |
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* Fill a struct uart_port for a given device node |
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*/ |
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static int of_platform_serial_setup(struct platform_device *ofdev, |
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int type, struct uart_8250_port *up, |
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struct of_serial_info *info) |
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{ |
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struct resource resource; |
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struct device_node *np = ofdev->dev.of_node; |
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struct uart_port *port = &up->port; |
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u32 clk, spd, prop; |
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int ret, irq; |
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memset(port, 0, sizeof *port); |
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pm_runtime_enable(&ofdev->dev); |
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pm_runtime_get_sync(&ofdev->dev); |
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if (of_property_read_u32(np, "clock-frequency", &clk)) { |
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/* Get clk rate through clk driver if present */ |
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info->clk = devm_clk_get(&ofdev->dev, NULL); |
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if (IS_ERR(info->clk)) { |
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ret = PTR_ERR(info->clk); |
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if (ret != -EPROBE_DEFER) |
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dev_warn(&ofdev->dev, |
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"failed to get clock: %d\n", ret); |
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goto err_pmruntime; |
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} |
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ret = clk_prepare_enable(info->clk); |
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if (ret < 0) |
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goto err_pmruntime; |
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clk = clk_get_rate(info->clk); |
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} |
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/* If current-speed was set, then try not to change it. */ |
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if (of_property_read_u32(np, "current-speed", &spd) == 0) |
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port->custom_divisor = clk / (16 * spd); |
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ret = of_address_to_resource(np, 0, &resource); |
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if (ret) { |
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dev_warn(&ofdev->dev, "invalid address\n"); |
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goto err_unprepare; |
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} |
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port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | |
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UPF_FIXED_TYPE; |
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spin_lock_init(&port->lock); |
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if (resource_type(&resource) == IORESOURCE_IO) { |
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port->iotype = UPIO_PORT; |
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port->iobase = resource.start; |
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} else { |
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port->mapbase = resource.start; |
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port->mapsize = resource_size(&resource); |
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/* Check for shifted address mapping */ |
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if (of_property_read_u32(np, "reg-offset", &prop) == 0) |
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port->mapbase += prop; |
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port->iotype = UPIO_MEM; |
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if (of_property_read_u32(np, "reg-io-width", &prop) == 0) { |
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switch (prop) { |
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case 1: |
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port->iotype = UPIO_MEM; |
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break; |
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case 2: |
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port->iotype = UPIO_MEM16; |
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break; |
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case 4: |
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port->iotype = of_device_is_big_endian(np) ? |
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UPIO_MEM32BE : UPIO_MEM32; |
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break; |
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default: |
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dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n", |
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prop); |
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ret = -EINVAL; |
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goto err_unprepare; |
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} |
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} |
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port->flags |= UPF_IOREMAP; |
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} |
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/* Compatibility with the deprecated pxa driver and 8250_pxa drivers. */ |
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if (of_device_is_compatible(np, "mrvl,mmp-uart")) |
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port->regshift = 2; |
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/* Check for registers offset within the devices address range */ |
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if (of_property_read_u32(np, "reg-shift", &prop) == 0) |
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port->regshift = prop; |
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/* Check for fifo size */ |
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if (of_property_read_u32(np, "fifo-size", &prop) == 0) |
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port->fifosize = prop; |
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/* Check for a fixed line number */ |
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ret = of_alias_get_id(np, "serial"); |
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if (ret >= 0) |
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port->line = ret; |
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irq = of_irq_get(np, 0); |
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if (irq < 0) { |
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if (irq == -EPROBE_DEFER) { |
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ret = -EPROBE_DEFER; |
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goto err_unprepare; |
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} |
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/* IRQ support not mandatory */ |
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irq = 0; |
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} |
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port->irq = irq; |
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info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL); |
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if (IS_ERR(info->rst)) { |
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ret = PTR_ERR(info->rst); |
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goto err_unprepare; |
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} |
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ret = reset_control_deassert(info->rst); |
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if (ret) |
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goto err_unprepare; |
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port->type = type; |
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port->uartclk = clk; |
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if (of_property_read_bool(np, "no-loopback-test")) |
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port->flags |= UPF_SKIP_TEST; |
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port->dev = &ofdev->dev; |
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port->rs485_config = serial8250_em485_config; |
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up->rs485_start_tx = serial8250_em485_start_tx; |
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up->rs485_stop_tx = serial8250_em485_stop_tx; |
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switch (type) { |
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case PORT_RT2880: |
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port->iotype = UPIO_AU; |
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break; |
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} |
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if (IS_ENABLED(CONFIG_SERIAL_8250_FSL) && |
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(of_device_is_compatible(np, "fsl,ns16550") || |
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of_device_is_compatible(np, "fsl,16550-FIFO64"))) { |
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port->handle_irq = fsl8250_handle_irq; |
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port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE); |
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} |
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return 0; |
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err_unprepare: |
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clk_disable_unprepare(info->clk); |
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err_pmruntime: |
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pm_runtime_put_sync(&ofdev->dev); |
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pm_runtime_disable(&ofdev->dev); |
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return ret; |
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} |
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/* |
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* Try to register a serial port |
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*/ |
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static int of_platform_serial_probe(struct platform_device *ofdev) |
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{ |
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struct of_serial_info *info; |
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struct uart_8250_port port8250; |
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unsigned int port_type; |
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u32 tx_threshold; |
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int ret; |
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port_type = (unsigned long)of_device_get_match_data(&ofdev->dev); |
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if (port_type == PORT_UNKNOWN) |
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return -EINVAL; |
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if (of_property_read_bool(ofdev->dev.of_node, "used-by-rtas")) |
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return -EBUSY; |
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info = kzalloc(sizeof(*info), GFP_KERNEL); |
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if (info == NULL) |
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return -ENOMEM; |
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memset(&port8250, 0, sizeof(port8250)); |
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ret = of_platform_serial_setup(ofdev, port_type, &port8250, info); |
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if (ret) |
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goto err_free; |
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if (port8250.port.fifosize) |
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port8250.capabilities = UART_CAP_FIFO; |
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/* Check for TX FIFO threshold & set tx_loadsz */ |
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if ((of_property_read_u32(ofdev->dev.of_node, "tx-threshold", |
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&tx_threshold) == 0) && |
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(tx_threshold < port8250.port.fifosize)) |
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port8250.tx_loadsz = port8250.port.fifosize - tx_threshold; |
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if (of_property_read_bool(ofdev->dev.of_node, "auto-flow-control")) |
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port8250.capabilities |= UART_CAP_AFE; |
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if (of_property_read_u32(ofdev->dev.of_node, |
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"overrun-throttle-ms", |
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&port8250.overrun_backoff_time_ms) != 0) |
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port8250.overrun_backoff_time_ms = 0; |
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ret = serial8250_register_8250_port(&port8250); |
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if (ret < 0) |
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goto err_dispose; |
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info->type = port_type; |
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info->line = ret; |
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platform_set_drvdata(ofdev, info); |
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return 0; |
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err_dispose: |
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irq_dispose_mapping(port8250.port.irq); |
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pm_runtime_put_sync(&ofdev->dev); |
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pm_runtime_disable(&ofdev->dev); |
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clk_disable_unprepare(info->clk); |
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err_free: |
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kfree(info); |
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return ret; |
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} |
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/* |
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* Release a line |
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*/ |
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static int of_platform_serial_remove(struct platform_device *ofdev) |
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{ |
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struct of_serial_info *info = platform_get_drvdata(ofdev); |
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serial8250_unregister_port(info->line); |
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reset_control_assert(info->rst); |
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pm_runtime_put_sync(&ofdev->dev); |
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pm_runtime_disable(&ofdev->dev); |
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clk_disable_unprepare(info->clk); |
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kfree(info); |
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return 0; |
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} |
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#ifdef CONFIG_PM_SLEEP |
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static int of_serial_suspend(struct device *dev) |
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{ |
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struct of_serial_info *info = dev_get_drvdata(dev); |
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struct uart_8250_port *port8250 = serial8250_get_port(info->line); |
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struct uart_port *port = &port8250->port; |
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serial8250_suspend_port(info->line); |
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if (!uart_console(port) || console_suspend_enabled) { |
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pm_runtime_put_sync(dev); |
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clk_disable_unprepare(info->clk); |
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} |
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return 0; |
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} |
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static int of_serial_resume(struct device *dev) |
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{ |
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struct of_serial_info *info = dev_get_drvdata(dev); |
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struct uart_8250_port *port8250 = serial8250_get_port(info->line); |
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struct uart_port *port = &port8250->port; |
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if (!uart_console(port) || console_suspend_enabled) { |
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pm_runtime_get_sync(dev); |
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clk_prepare_enable(info->clk); |
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} |
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serial8250_resume_port(info->line); |
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return 0; |
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} |
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#endif |
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static SIMPLE_DEV_PM_OPS(of_serial_pm_ops, of_serial_suspend, of_serial_resume); |
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/* |
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* A few common types, add more as needed. |
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*/ |
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static const struct of_device_id of_platform_serial_table[] = { |
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{ .compatible = "ns8250", .data = (void *)PORT_8250, }, |
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{ .compatible = "ns16450", .data = (void *)PORT_16450, }, |
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{ .compatible = "ns16550a", .data = (void *)PORT_16550A, }, |
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{ .compatible = "ns16550", .data = (void *)PORT_16550, }, |
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{ .compatible = "ns16750", .data = (void *)PORT_16750, }, |
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{ .compatible = "ns16850", .data = (void *)PORT_16850, }, |
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{ .compatible = "nxp,lpc3220-uart", .data = (void *)PORT_LPC3220, }, |
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{ .compatible = "ralink,rt2880-uart", .data = (void *)PORT_RT2880, }, |
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{ .compatible = "intel,xscale-uart", .data = (void *)PORT_XSCALE, }, |
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{ .compatible = "altr,16550-FIFO32", |
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.data = (void *)PORT_ALTR_16550_F32, }, |
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{ .compatible = "altr,16550-FIFO64", |
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.data = (void *)PORT_ALTR_16550_F64, }, |
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{ .compatible = "altr,16550-FIFO128", |
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.data = (void *)PORT_ALTR_16550_F128, }, |
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{ .compatible = "mediatek,mtk-btif", |
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.data = (void *)PORT_MTK_BTIF, }, |
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{ .compatible = "mrvl,mmp-uart", |
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.data = (void *)PORT_XSCALE, }, |
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{ .compatible = "ti,da830-uart", .data = (void *)PORT_DA830, }, |
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{ .compatible = "nuvoton,wpcm450-uart", .data = (void *)PORT_NPCM, }, |
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{ .compatible = "nuvoton,npcm750-uart", .data = (void *)PORT_NPCM, }, |
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{ /* end of list */ }, |
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}; |
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MODULE_DEVICE_TABLE(of, of_platform_serial_table); |
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static struct platform_driver of_platform_serial_driver = { |
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.driver = { |
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.name = "of_serial", |
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.of_match_table = of_platform_serial_table, |
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.pm = &of_serial_pm_ops, |
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}, |
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.probe = of_platform_serial_probe, |
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.remove = of_platform_serial_remove, |
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}; |
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module_platform_driver(of_platform_serial_driver); |
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MODULE_AUTHOR("Arnd Bergmann <[email protected]>"); |
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MODULE_LICENSE("GPL"); |
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MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");
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