diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_pxa.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_pxa.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_pxa.c b/drivers/tty/serial/8250/8250_pxa.c new file mode 100644 index 000000000..33ca98bfa --- /dev/null +++ b/drivers/tty/serial/8250/8250_pxa.c @@ -0,0 +1,191 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * drivers/tty/serial/8250/8250_pxa.c -- driver for PXA on-board UARTS + * Copyright: (C) 2013 Sergei Ianovich <ynvich@gmail.com> + * + * replaces drivers/serial/pxa.c by Nicolas Pitre + * Created: Feb 20, 2003 + * Copyright: (C) 2003 Monta Vista Software, Inc. + * + * Based on drivers/serial/8250.c by Russell King. + */ + +#include <linux/device.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/serial_8250.h> +#include <linux/serial_core.h> +#include <linux/serial_reg.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/clk.h> +#include <linux/pm_runtime.h> + +#include "8250.h" + +struct pxa8250_data { + int line; + struct clk *clk; +}; + +static int __maybe_unused serial_pxa_suspend(struct device *dev) +{ + struct pxa8250_data *data = dev_get_drvdata(dev); + + serial8250_suspend_port(data->line); + + return 0; +} + +static int __maybe_unused serial_pxa_resume(struct device *dev) +{ + struct pxa8250_data *data = dev_get_drvdata(dev); + + serial8250_resume_port(data->line); + + return 0; +} + +static const struct dev_pm_ops serial_pxa_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume) +}; + +static const struct of_device_id serial_pxa_dt_ids[] = { + { .compatible = "mrvl,pxa-uart", }, + { .compatible = "mrvl,mmp-uart", }, + {} +}; +MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids); + +/* Uart divisor latch write */ +static void serial_pxa_dl_write(struct uart_8250_port *up, int value) +{ + unsigned int dll; + + serial_out(up, UART_DLL, value & 0xff); + /* + * work around Erratum #74 according to Marvel(R) PXA270M Processor + * Specification Update (April 19, 2010) + */ + dll = serial_in(up, UART_DLL); + WARN_ON(dll != (value & 0xff)); + + serial_out(up, UART_DLM, value >> 8 & 0xff); +} + + +static void serial_pxa_pm(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + struct pxa8250_data *data = port->private_data; + + if (!state) + clk_prepare_enable(data->clk); + else + clk_disable_unprepare(data->clk); +} + +static int serial_pxa_probe(struct platform_device *pdev) +{ + struct uart_8250_port uart = {}; + struct pxa8250_data *data; + struct resource *mmres; + int irq, ret; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mmres) + return -ENODEV; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(data->clk)) + return PTR_ERR(data->clk); + + ret = clk_prepare(data->clk); + if (ret) + return ret; + + ret = of_alias_get_id(pdev->dev.of_node, "serial"); + if (ret >= 0) + uart.port.line = ret; + + uart.port.type = PORT_XSCALE; + uart.port.iotype = UPIO_MEM32; + uart.port.mapbase = mmres->start; + uart.port.regshift = 2; + uart.port.irq = irq; + uart.port.fifosize = 64; + uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST | UPF_FIXED_TYPE; + uart.port.dev = &pdev->dev; + uart.port.uartclk = clk_get_rate(data->clk); + uart.port.pm = serial_pxa_pm; + uart.port.private_data = data; + uart.dl_write = serial_pxa_dl_write; + + ret = serial8250_register_8250_port(&uart); + if (ret < 0) + goto err_clk; + + data->line = ret; + + platform_set_drvdata(pdev, data); + + return 0; + + err_clk: + clk_unprepare(data->clk); + return ret; +} + +static int serial_pxa_remove(struct platform_device *pdev) +{ + struct pxa8250_data *data = platform_get_drvdata(pdev); + + serial8250_unregister_port(data->line); + + clk_unprepare(data->clk); + + return 0; +} + +static struct platform_driver serial_pxa_driver = { + .probe = serial_pxa_probe, + .remove = serial_pxa_remove, + + .driver = { + .name = "pxa2xx-uart", + .pm = &serial_pxa_pm_ops, + .of_match_table = serial_pxa_dt_ids, + }, +}; + +module_platform_driver(serial_pxa_driver); + +#ifdef CONFIG_SERIAL_8250_CONSOLE +static int __init early_serial_pxa_setup(struct earlycon_device *device, + const char *options) +{ + struct uart_port *port = &device->port; + + if (!(device->port.membase || device->port.iobase)) + return -ENODEV; + + port->regshift = 2; + return early_serial8250_setup(device, NULL); +} +OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup); +#endif + +MODULE_AUTHOR("Sergei Ianovich"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:pxa2xx-uart"); |