forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
199 lines
4.3 KiB
199 lines
4.3 KiB
// SPDX-License-Identifier: GPL-2.0+ |
|
/* |
|
* Serial Port driver for Tegra devices |
|
* |
|
* Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved. |
|
*/ |
|
|
|
#include <linux/acpi.h> |
|
#include <linux/clk.h> |
|
#include <linux/console.h> |
|
#include <linux/delay.h> |
|
#include <linux/io.h> |
|
#include <linux/module.h> |
|
#include <linux/reset.h> |
|
#include <linux/slab.h> |
|
|
|
#include "8250.h" |
|
|
|
struct tegra_uart { |
|
struct clk *clk; |
|
struct reset_control *rst; |
|
int line; |
|
}; |
|
|
|
static void tegra_uart_handle_break(struct uart_port *p) |
|
{ |
|
unsigned int status, tmout = 10000; |
|
|
|
while (1) { |
|
status = p->serial_in(p, UART_LSR); |
|
if (!(status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))) |
|
break; |
|
|
|
p->serial_in(p, UART_RX); |
|
|
|
if (--tmout == 0) |
|
break; |
|
udelay(1); |
|
} |
|
} |
|
|
|
static int tegra_uart_probe(struct platform_device *pdev) |
|
{ |
|
struct uart_8250_port port8250; |
|
struct tegra_uart *uart; |
|
struct uart_port *port; |
|
struct resource *res; |
|
int ret; |
|
|
|
uart = devm_kzalloc(&pdev->dev, sizeof(*uart), GFP_KERNEL); |
|
if (!uart) |
|
return -ENOMEM; |
|
|
|
memset(&port8250, 0, sizeof(port8250)); |
|
|
|
port = &port8250.port; |
|
spin_lock_init(&port->lock); |
|
|
|
port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | |
|
UPF_FIXED_TYPE; |
|
port->iotype = UPIO_MEM32; |
|
port->regshift = 2; |
|
port->type = PORT_TEGRA; |
|
port->irqflags |= IRQF_SHARED; |
|
port->dev = &pdev->dev; |
|
port->handle_break = tegra_uart_handle_break; |
|
|
|
ret = of_alias_get_id(pdev->dev.of_node, "serial"); |
|
if (ret >= 0) |
|
port->line = ret; |
|
|
|
ret = platform_get_irq(pdev, 0); |
|
if (ret < 0) |
|
return ret; |
|
|
|
port->irq = ret; |
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
|
if (!res) |
|
return -ENODEV; |
|
|
|
port->membase = devm_ioremap(&pdev->dev, res->start, |
|
resource_size(res)); |
|
if (!port->membase) |
|
return -ENOMEM; |
|
|
|
port->mapbase = res->start; |
|
port->mapsize = resource_size(res); |
|
|
|
uart->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL); |
|
if (IS_ERR(uart->rst)) |
|
return PTR_ERR(uart->rst); |
|
|
|
if (device_property_read_u32(&pdev->dev, "clock-frequency", |
|
&port->uartclk)) { |
|
uart->clk = devm_clk_get(&pdev->dev, NULL); |
|
if (IS_ERR(uart->clk)) { |
|
dev_err(&pdev->dev, "failed to get clock!\n"); |
|
return -ENODEV; |
|
} |
|
|
|
ret = clk_prepare_enable(uart->clk); |
|
if (ret < 0) |
|
return ret; |
|
|
|
port->uartclk = clk_get_rate(uart->clk); |
|
} |
|
|
|
ret = reset_control_deassert(uart->rst); |
|
if (ret) |
|
goto err_clkdisable; |
|
|
|
ret = serial8250_register_8250_port(&port8250); |
|
if (ret < 0) |
|
goto err_clkdisable; |
|
|
|
platform_set_drvdata(pdev, uart); |
|
uart->line = ret; |
|
|
|
return 0; |
|
|
|
err_clkdisable: |
|
clk_disable_unprepare(uart->clk); |
|
|
|
return ret; |
|
} |
|
|
|
static int tegra_uart_remove(struct platform_device *pdev) |
|
{ |
|
struct tegra_uart *uart = platform_get_drvdata(pdev); |
|
|
|
serial8250_unregister_port(uart->line); |
|
reset_control_assert(uart->rst); |
|
clk_disable_unprepare(uart->clk); |
|
|
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_PM_SLEEP |
|
static int tegra_uart_suspend(struct device *dev) |
|
{ |
|
struct tegra_uart *uart = dev_get_drvdata(dev); |
|
struct uart_8250_port *port8250 = serial8250_get_port(uart->line); |
|
struct uart_port *port = &port8250->port; |
|
|
|
serial8250_suspend_port(uart->line); |
|
|
|
if (!uart_console(port) || console_suspend_enabled) |
|
clk_disable_unprepare(uart->clk); |
|
|
|
return 0; |
|
} |
|
|
|
static int tegra_uart_resume(struct device *dev) |
|
{ |
|
struct tegra_uart *uart = dev_get_drvdata(dev); |
|
struct uart_8250_port *port8250 = serial8250_get_port(uart->line); |
|
struct uart_port *port = &port8250->port; |
|
|
|
if (!uart_console(port) || console_suspend_enabled) |
|
clk_prepare_enable(uart->clk); |
|
|
|
serial8250_resume_port(uart->line); |
|
|
|
return 0; |
|
} |
|
#endif |
|
|
|
static SIMPLE_DEV_PM_OPS(tegra_uart_pm_ops, tegra_uart_suspend, |
|
tegra_uart_resume); |
|
|
|
static const struct of_device_id tegra_uart_of_match[] = { |
|
{ .compatible = "nvidia,tegra20-uart", }, |
|
{ }, |
|
}; |
|
MODULE_DEVICE_TABLE(of, tegra_uart_of_match); |
|
|
|
static const struct acpi_device_id tegra_uart_acpi_match[] = { |
|
{ "NVDA0100", 0 }, |
|
{ }, |
|
}; |
|
MODULE_DEVICE_TABLE(acpi, tegra_uart_acpi_match); |
|
|
|
static struct platform_driver tegra_uart_driver = { |
|
.driver = { |
|
.name = "tegra-uart", |
|
.pm = &tegra_uart_pm_ops, |
|
.of_match_table = tegra_uart_of_match, |
|
.acpi_match_table = ACPI_PTR(tegra_uart_acpi_match), |
|
}, |
|
.probe = tegra_uart_probe, |
|
.remove = tegra_uart_remove, |
|
}; |
|
|
|
module_platform_driver(tegra_uart_driver); |
|
|
|
MODULE_AUTHOR("Jeff Brasen <[email protected]>"); |
|
MODULE_DESCRIPTION("NVIDIA Tegra 8250 Driver"); |
|
MODULE_LICENSE("GPL v2");
|
|
|