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20#include <linux/acpi.h>
21#include <linux/serial_reg.h>
22#include <linux/serial_8250.h>
23
24#include "8250.h"
25
26struct fsl8250_data {
27 int line;
28};
29
30int fsl8250_handle_irq(struct uart_port *port)
31{
32 unsigned char lsr, orig_lsr;
33 unsigned long flags;
34 unsigned int iir;
35 struct uart_8250_port *up = up_to_u8250p(port);
36
37 spin_lock_irqsave(&up->port.lock, flags);
38
39 iir = port->serial_in(port, UART_IIR);
40 if (iir & UART_IIR_NO_INT) {
41 spin_unlock_irqrestore(&up->port.lock, flags);
42 return 0;
43 }
44
45
46 if (unlikely(up->lsr_saved_flags & UART_LSR_BI)) {
47 up->lsr_saved_flags &= ~UART_LSR_BI;
48 port->serial_in(port, UART_RX);
49 spin_unlock_irqrestore(&up->port.lock, flags);
50 return 1;
51 }
52
53 lsr = orig_lsr = up->port.serial_in(&up->port, UART_LSR);
54
55
56 if ((lsr & (UART_LSR_DR | UART_LSR_BI)) &&
57 (up->ier & (UART_IER_RLSI | UART_IER_RDI))) {
58 lsr = serial8250_rx_chars(up, lsr);
59 }
60
61
62 if ((orig_lsr & UART_LSR_OE) && (up->overrun_backoff_time_ms > 0)) {
63 unsigned long delay;
64
65 up->ier = port->serial_in(port, UART_IER);
66 if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
67 port->ops->stop_rx(port);
68 } else {
69
70
71
72 cancel_delayed_work(&up->overrun_backoff);
73 }
74
75 delay = msecs_to_jiffies(up->overrun_backoff_time_ms);
76 schedule_delayed_work(&up->overrun_backoff, delay);
77 }
78
79 serial8250_modem_status(up);
80
81 if ((lsr & UART_LSR_THRE) && (up->ier & UART_IER_THRI))
82 serial8250_tx_chars(up);
83
84 up->lsr_saved_flags = orig_lsr;
85 uart_unlock_and_check_sysrq(&up->port, flags);
86 return 1;
87}
88EXPORT_SYMBOL_GPL(fsl8250_handle_irq);
89
90#ifdef CONFIG_ACPI
91static int fsl8250_acpi_probe(struct platform_device *pdev)
92{
93 struct fsl8250_data *data;
94 struct uart_8250_port port8250;
95 struct device *dev = &pdev->dev;
96 struct resource *regs;
97
98 int ret, irq;
99
100 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
101 if (!regs) {
102 dev_err(dev, "no registers defined\n");
103 return -EINVAL;
104 }
105
106 irq = platform_get_irq(pdev, 0);
107 if (irq < 0) {
108 if (irq != -EPROBE_DEFER)
109 dev_err(dev, "cannot get irq\n");
110 return irq;
111 }
112
113 memset(&port8250, 0, sizeof(port8250));
114
115 ret = device_property_read_u32(dev, "clock-frequency",
116 &port8250.port.uartclk);
117 if (ret)
118 return ret;
119
120 spin_lock_init(&port8250.port.lock);
121
122 port8250.port.mapbase = regs->start;
123 port8250.port.irq = irq;
124 port8250.port.handle_irq = fsl8250_handle_irq;
125 port8250.port.type = PORT_16550A;
126 port8250.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF
127 | UPF_FIXED_PORT | UPF_IOREMAP
128 | UPF_FIXED_TYPE;
129 port8250.port.dev = dev;
130 port8250.port.mapsize = resource_size(regs);
131 port8250.port.iotype = UPIO_MEM;
132 port8250.port.irqflags = IRQF_SHARED;
133
134 port8250.port.membase = devm_ioremap(dev, port8250.port.mapbase,
135 port8250.port.mapsize);
136 if (!port8250.port.membase)
137 return -ENOMEM;
138
139 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
140 if (!data)
141 return -ENOMEM;
142
143 data->line = serial8250_register_8250_port(&port8250);
144 if (data->line < 0)
145 return data->line;
146
147 platform_set_drvdata(pdev, data);
148 return 0;
149}
150
151static int fsl8250_acpi_remove(struct platform_device *pdev)
152{
153 struct fsl8250_data *data = platform_get_drvdata(pdev);
154
155 serial8250_unregister_port(data->line);
156 return 0;
157}
158
159static const struct acpi_device_id fsl_8250_acpi_id[] = {
160 { "NXP0018", 0 },
161 { },
162};
163MODULE_DEVICE_TABLE(acpi, fsl_8250_acpi_id);
164
165static struct platform_driver fsl8250_platform_driver = {
166 .driver = {
167 .name = "fsl-16550-uart",
168 .acpi_match_table = ACPI_PTR(fsl_8250_acpi_id),
169 },
170 .probe = fsl8250_acpi_probe,
171 .remove = fsl8250_acpi_remove,
172};
173
174module_platform_driver(fsl8250_platform_driver);
175#endif
176