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8#include <linux/acpi.h>
9#include <linux/clk.h>
10#include <linux/console.h>
11#include <linux/delay.h>
12#include <linux/io.h>
13#include <linux/module.h>
14#include <linux/reset.h>
15#include <linux/slab.h>
16
17#include "8250.h"
18
19struct tegra_uart {
20 struct clk *clk;
21 struct reset_control *rst;
22 int line;
23};
24
25static void tegra_uart_handle_break(struct uart_port *p)
26{
27 unsigned int status, tmout = 10000;
28
29 do {
30 status = p->serial_in(p, UART_LSR);
31 if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
32 status = p->serial_in(p, UART_RX);
33 else
34 break;
35 if (--tmout == 0)
36 break;
37 udelay(1);
38 } while (1);
39}
40
41static int tegra_uart_probe(struct platform_device *pdev)
42{
43 struct uart_8250_port port8250;
44 struct tegra_uart *uart;
45 struct uart_port *port;
46 struct resource *res;
47 int ret;
48
49 uart = devm_kzalloc(&pdev->dev, sizeof(*uart), GFP_KERNEL);
50 if (!uart)
51 return -ENOMEM;
52
53 memset(&port8250, 0, sizeof(port8250));
54
55 port = &port8250.port;
56 spin_lock_init(&port->lock);
57
58 port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT |
59 UPF_FIXED_TYPE;
60 port->iotype = UPIO_MEM32;
61 port->regshift = 2;
62 port->type = PORT_TEGRA;
63 port->irqflags |= IRQF_SHARED;
64 port->dev = &pdev->dev;
65 port->handle_break = tegra_uart_handle_break;
66
67 ret = of_alias_get_id(pdev->dev.of_node, "serial");
68 if (ret >= 0)
69 port->line = ret;
70
71 ret = platform_get_irq(pdev, 0);
72 if (ret < 0)
73 return ret;
74
75 port->irq = ret;
76
77 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
78 if (!res)
79 return -ENODEV;
80
81 port->membase = devm_ioremap(&pdev->dev, res->start,
82 resource_size(res));
83 if (!port->membase)
84 return -ENOMEM;
85
86 port->mapbase = res->start;
87 port->mapsize = resource_size(res);
88
89 uart->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
90 if (IS_ERR(uart->rst))
91 return PTR_ERR(uart->rst);
92
93 if (device_property_read_u32(&pdev->dev, "clock-frequency",
94 &port->uartclk)) {
95 uart->clk = devm_clk_get(&pdev->dev, NULL);
96 if (IS_ERR(uart->clk)) {
97 dev_err(&pdev->dev, "failed to get clock!\n");
98 return -ENODEV;
99 }
100
101 ret = clk_prepare_enable(uart->clk);
102 if (ret < 0)
103 return ret;
104
105 port->uartclk = clk_get_rate(uart->clk);
106 }
107
108 ret = reset_control_deassert(uart->rst);
109 if (ret)
110 goto err_clkdisable;
111
112 ret = serial8250_register_8250_port(&port8250);
113 if (ret < 0)
114 goto err_clkdisable;
115
116 platform_set_drvdata(pdev, uart);
117 uart->line = ret;
118
119 return 0;
120
121err_clkdisable:
122 clk_disable_unprepare(uart->clk);
123
124 return ret;
125}
126
127static int tegra_uart_remove(struct platform_device *pdev)
128{
129 struct tegra_uart *uart = platform_get_drvdata(pdev);
130
131 serial8250_unregister_port(uart->line);
132 reset_control_assert(uart->rst);
133 clk_disable_unprepare(uart->clk);
134
135 return 0;
136}
137
138#ifdef CONFIG_PM_SLEEP
139static int tegra_uart_suspend(struct device *dev)
140{
141 struct tegra_uart *uart = dev_get_drvdata(dev);
142 struct uart_8250_port *port8250 = serial8250_get_port(uart->line);
143 struct uart_port *port = &port8250->port;
144
145 serial8250_suspend_port(uart->line);
146
147 if (!uart_console(port) || console_suspend_enabled)
148 clk_disable_unprepare(uart->clk);
149
150 return 0;
151}
152
153static int tegra_uart_resume(struct device *dev)
154{
155 struct tegra_uart *uart = dev_get_drvdata(dev);
156 struct uart_8250_port *port8250 = serial8250_get_port(uart->line);
157 struct uart_port *port = &port8250->port;
158
159 if (!uart_console(port) || console_suspend_enabled)
160 clk_prepare_enable(uart->clk);
161
162 serial8250_resume_port(uart->line);
163
164 return 0;
165}
166#endif
167
168static SIMPLE_DEV_PM_OPS(tegra_uart_pm_ops, tegra_uart_suspend,
169 tegra_uart_resume);
170
171static const struct of_device_id tegra_uart_of_match[] = {
172 { .compatible = "nvidia,tegra20-uart", },
173 { },
174};
175MODULE_DEVICE_TABLE(of, tegra_uart_of_match);
176
177static const struct acpi_device_id tegra_uart_acpi_match[] = {
178 { "NVDA0100", 0 },
179 { },
180};
181MODULE_DEVICE_TABLE(acpi, tegra_uart_acpi_match);
182
183static struct platform_driver tegra_uart_driver = {
184 .driver = {
185 .name = "tegra-uart",
186 .pm = &tegra_uart_pm_ops,
187 .of_match_table = tegra_uart_of_match,
188 .acpi_match_table = ACPI_PTR(tegra_uart_acpi_match),
189 },
190 .probe = tegra_uart_probe,
191 .remove = tegra_uart_remove,
192};
193
194module_platform_driver(tegra_uart_driver);
195
196MODULE_AUTHOR("Jeff Brasen <jbrasen@nvidia.com>");
197MODULE_DESCRIPTION("NVIDIA Tegra 8250 Driver");
198MODULE_LICENSE("GPL v2");
199
