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path: root/drivers/tty/serial/8250/8250_of.c
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Diffstat (limited to 'drivers/tty/serial/8250/8250_of.c')
-rw-r--r--drivers/tty/serial/8250/8250_of.c357
1 files changed, 357 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
new file mode 100644
index 000000000..1b461fba1
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Serial Port driver for Open Firmware platform devices
+ *
+ * Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
+ */
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/slab.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/pm_runtime.h>
+#include <linux/clk.h>
+#include <linux/reset.h>
+
+#include "8250.h"
+
+struct of_serial_info {
+ struct clk *clk;
+ struct reset_control *rst;
+ int type;
+ int line;
+};
+
+/*
+ * Fill a struct uart_port for a given device node
+ */
+static int of_platform_serial_setup(struct platform_device *ofdev,
+ int type, struct uart_8250_port *up,
+ struct of_serial_info *info)
+{
+ struct resource resource;
+ struct device_node *np = ofdev->dev.of_node;
+ struct uart_port *port = &up->port;
+ u32 clk, spd, prop;
+ int ret, irq;
+
+ memset(port, 0, sizeof *port);
+
+ pm_runtime_enable(&ofdev->dev);
+ pm_runtime_get_sync(&ofdev->dev);
+
+ if (of_property_read_u32(np, "clock-frequency", &clk)) {
+
+ /* Get clk rate through clk driver if present */
+ info->clk = devm_clk_get(&ofdev->dev, NULL);
+ if (IS_ERR(info->clk)) {
+ ret = PTR_ERR(info->clk);
+ if (ret != -EPROBE_DEFER)
+ dev_warn(&ofdev->dev,
+ "failed to get clock: %d\n", ret);
+ goto err_pmruntime;
+ }
+
+ ret = clk_prepare_enable(info->clk);
+ if (ret < 0)
+ goto err_pmruntime;
+
+ 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 err_unprepare;
+ }
+
+ port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT |
+ UPF_FIXED_TYPE;
+ spin_lock_init(&port->lock);
+
+ if (resource_type(&resource) == IORESOURCE_IO) {
+ port->iotype = UPIO_PORT;
+ port->iobase = resource.start;
+ } else {
+ port->mapbase = resource.start;
+ port->mapsize = resource_size(&resource);
+
+ /* Check for shifted address mapping */
+ if (of_property_read_u32(np, "reg-offset", &prop) == 0) {
+ if (prop >= port->mapsize) {
+ dev_warn(&ofdev->dev, "reg-offset %u exceeds region size %pa\n",
+ prop, &port->mapsize);
+ ret = -EINVAL;
+ goto err_unprepare;
+ }
+
+ port->mapbase += prop;
+ port->mapsize -= prop;
+ }
+
+ 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 2:
+ port->iotype = UPIO_MEM16;
+ 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 err_unprepare;
+ }
+ }
+ port->flags |= UPF_IOREMAP;
+ }
+
+ /* Compatibility with the deprecated pxa driver and 8250_pxa drivers. */
+ if (of_device_is_compatible(np, "mrvl,mmp-uart"))
+ port->regshift = 2;
+
+ /* 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;
+
+ irq = of_irq_get(np, 0);
+ if (irq < 0) {
+ if (irq == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto err_unprepare;
+ }
+ /* IRQ support not mandatory */
+ irq = 0;
+ }
+
+ port->irq = irq;
+
+ info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL);
+ if (IS_ERR(info->rst)) {
+ ret = PTR_ERR(info->rst);
+ goto err_unprepare;
+ }
+
+ ret = reset_control_deassert(info->rst);
+ if (ret)
+ goto err_unprepare;
+
+ port->type = type;
+ port->uartclk = clk;
+
+ if (of_property_read_bool(np, "no-loopback-test"))
+ port->flags |= UPF_SKIP_TEST;
+
+ port->dev = &ofdev->dev;
+ port->rs485_config = serial8250_em485_config;
+ port->rs485_supported = serial8250_em485_supported;
+ up->rs485_start_tx = serial8250_em485_start_tx;
+ up->rs485_stop_tx = serial8250_em485_stop_tx;
+
+ switch (type) {
+ case PORT_RT2880:
+ port->iotype = UPIO_AU;
+ break;
+ }
+
+ if (IS_ENABLED(CONFIG_SERIAL_8250_FSL) &&
+ (of_device_is_compatible(np, "fsl,ns16550") ||
+ of_device_is_compatible(np, "fsl,16550-FIFO64"))) {
+ port->handle_irq = fsl8250_handle_irq;
+ port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
+ }
+
+ return 0;
+err_unprepare:
+ clk_disable_unprepare(info->clk);
+err_pmruntime:
+ pm_runtime_put_sync(&ofdev->dev);
+ pm_runtime_disable(&ofdev->dev);
+ return ret;
+}
+
+/*
+ * Try to register a serial port
+ */
+static int of_platform_serial_probe(struct platform_device *ofdev)
+{
+ struct of_serial_info *info;
+ struct uart_8250_port port8250;
+ unsigned int port_type;
+ u32 tx_threshold;
+ int ret;
+
+ if (IS_ENABLED(CONFIG_SERIAL_8250_BCM7271) &&
+ of_device_is_compatible(ofdev->dev.of_node, "brcm,bcm7271-uart"))
+ return -ENODEV;
+
+ port_type = (unsigned long)of_device_get_match_data(&ofdev->dev);
+ if (port_type == PORT_UNKNOWN)
+ return -EINVAL;
+
+ if (of_property_read_bool(ofdev->dev.of_node, "used-by-rtas"))
+ return -EBUSY;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (info == NULL)
+ return -ENOMEM;
+
+ memset(&port8250, 0, sizeof(port8250));
+ ret = of_platform_serial_setup(ofdev, port_type, &port8250, info);
+ if (ret)
+ goto err_free;
+
+ if (port8250.port.fifosize)
+ port8250.capabilities = UART_CAP_FIFO;
+
+ /* Check for TX FIFO threshold & set tx_loadsz */
+ if ((of_property_read_u32(ofdev->dev.of_node, "tx-threshold",
+ &tx_threshold) == 0) &&
+ (tx_threshold < port8250.port.fifosize))
+ port8250.tx_loadsz = port8250.port.fifosize - tx_threshold;
+
+ if (of_property_read_bool(ofdev->dev.of_node, "auto-flow-control"))
+ port8250.capabilities |= UART_CAP_AFE;
+
+ if (of_property_read_u32(ofdev->dev.of_node,
+ "overrun-throttle-ms",
+ &port8250.overrun_backoff_time_ms) != 0)
+ port8250.overrun_backoff_time_ms = 0;
+
+ ret = serial8250_register_8250_port(&port8250);
+ if (ret < 0)
+ goto err_dispose;
+
+ info->type = port_type;
+ info->line = ret;
+ platform_set_drvdata(ofdev, info);
+ return 0;
+err_dispose:
+ irq_dispose_mapping(port8250.port.irq);
+ pm_runtime_put_sync(&ofdev->dev);
+ pm_runtime_disable(&ofdev->dev);
+ clk_disable_unprepare(info->clk);
+err_free:
+ kfree(info);
+ return ret;
+}
+
+/*
+ * Release a line
+ */
+static int of_platform_serial_remove(struct platform_device *ofdev)
+{
+ struct of_serial_info *info = platform_get_drvdata(ofdev);
+
+ serial8250_unregister_port(info->line);
+
+ reset_control_assert(info->rst);
+ pm_runtime_put_sync(&ofdev->dev);
+ pm_runtime_disable(&ofdev->dev);
+ clk_disable_unprepare(info->clk);
+ kfree(info);
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int of_serial_suspend(struct device *dev)
+{
+ struct of_serial_info *info = dev_get_drvdata(dev);
+ struct uart_8250_port *port8250 = serial8250_get_port(info->line);
+ struct uart_port *port = &port8250->port;
+
+ serial8250_suspend_port(info->line);
+
+ if (!uart_console(port) || console_suspend_enabled) {
+ pm_runtime_put_sync(dev);
+ clk_disable_unprepare(info->clk);
+ }
+ return 0;
+}
+
+static int of_serial_resume(struct device *dev)
+{
+ struct of_serial_info *info = dev_get_drvdata(dev);
+ struct uart_8250_port *port8250 = serial8250_get_port(info->line);
+ struct uart_port *port = &port8250->port;
+
+ if (!uart_console(port) || console_suspend_enabled) {
+ pm_runtime_get_sync(dev);
+ clk_prepare_enable(info->clk);
+ }
+
+ serial8250_resume_port(info->line);
+
+ 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 = "nxp,lpc3220-uart", .data = (void *)PORT_LPC3220, },
+ { .compatible = "ralink,rt2880-uart", .data = (void *)PORT_RT2880, },
+ { .compatible = "intel,xscale-uart", .data = (void *)PORT_XSCALE, },
+ { .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 = "fsl,16550-FIFO64",
+ .data = (void *)PORT_16550A_FSL64, },
+ { .compatible = "mediatek,mtk-btif",
+ .data = (void *)PORT_MTK_BTIF, },
+ { .compatible = "mrvl,mmp-uart",
+ .data = (void *)PORT_XSCALE, },
+ { .compatible = "ti,da830-uart", .data = (void *)PORT_DA830, },
+ { .compatible = "nuvoton,wpcm450-uart", .data = (void *)PORT_NPCM, },
+ { .compatible = "nuvoton,npcm750-uart", .data = (void *)PORT_NPCM, },
+ { /* end of list */ },
+};
+MODULE_DEVICE_TABLE(of, of_platform_serial_table);
+
+static struct platform_driver of_platform_serial_driver = {
+ .driver = {
+ .name = "of_serial",
+ .of_match_table = of_platform_serial_table,
+ .pm = &of_serial_pm_ops,
+ },
+ .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");