1 /*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2004-2007 Cavium Networks
7 */
8 #include <linux/console.h>
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/platform_device.h>
12 #include <linux/serial.h>
13 #include <linux/serial_8250.h>
14 #include <linux/serial_reg.h>
15 #include <linux/tty.h>
16 #include <linux/irq.h>
17
18 #include <asm/time.h>
19
20 #include <asm/octeon/octeon.h>
21
22 #define DEBUG_UART 1
23
octeon_serial_in(struct uart_port * up,int offset)24 unsigned int octeon_serial_in(struct uart_port *up, int offset)
25 {
26 int rv = cvmx_read_csr((uint64_t)(up->membase + (offset << 3)));
27 if (offset == UART_IIR && (rv & 0xf) == 7) {
28 /* Busy interrupt, read the USR (39) and try again. */
29 cvmx_read_csr((uint64_t)(up->membase + (39 << 3)));
30 rv = cvmx_read_csr((uint64_t)(up->membase + (offset << 3)));
31 }
32 return rv;
33 }
34
octeon_serial_out(struct uart_port * up,int offset,int value)35 void octeon_serial_out(struct uart_port *up, int offset, int value)
36 {
37 /*
38 * If bits 6 or 7 of the OCTEON UART's LCR are set, it quits
39 * working.
40 */
41 if (offset == UART_LCR)
42 value &= 0x9f;
43 cvmx_write_csr((uint64_t)(up->membase + (offset << 3)), (u8)value);
44 }
45
46 /*
47 * Allocated in .bss, so it is all zeroed.
48 */
49 #define OCTEON_MAX_UARTS 3
50 static struct plat_serial8250_port octeon_uart8250_data[OCTEON_MAX_UARTS + 1];
51 static struct platform_device octeon_uart8250_device = {
52 .name = "serial8250",
53 .id = PLAT8250_DEV_PLATFORM,
54 .dev = {
55 .platform_data = octeon_uart8250_data,
56 },
57 };
58
octeon_uart_set_common(struct plat_serial8250_port * p)59 static void __init octeon_uart_set_common(struct plat_serial8250_port *p)
60 {
61 p->flags = ASYNC_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
62 p->type = PORT_OCTEON;
63 p->iotype = UPIO_MEM;
64 p->regshift = 3; /* I/O addresses are every 8 bytes */
65 if (octeon_is_simulation())
66 /* Make simulator output fast*/
67 p->uartclk = 115200 * 16;
68 else
69 p->uartclk = octeon_get_io_clock_rate();
70 p->serial_in = octeon_serial_in;
71 p->serial_out = octeon_serial_out;
72 }
73
octeon_serial_init(void)74 static int __init octeon_serial_init(void)
75 {
76 int enable_uart0;
77 int enable_uart1;
78 int enable_uart2;
79 struct plat_serial8250_port *p;
80
81 #ifdef CONFIG_CAVIUM_OCTEON_2ND_KERNEL
82 /*
83 * If we are configured to run as the second of two kernels,
84 * disable uart0 and enable uart1. Uart0 is owned by the first
85 * kernel
86 */
87 enable_uart0 = 0;
88 enable_uart1 = 1;
89 #else
90 /*
91 * We are configured for the first kernel. We'll enable uart0
92 * if the bootloader told us to use 0, otherwise will enable
93 * uart 1.
94 */
95 enable_uart0 = (octeon_get_boot_uart() == 0);
96 enable_uart1 = (octeon_get_boot_uart() == 1);
97 #ifdef CONFIG_KGDB
98 enable_uart1 = 1;
99 #endif
100 #endif
101
102 /* Right now CN52XX is the only chip with a third uart */
103 enable_uart2 = OCTEON_IS_MODEL(OCTEON_CN52XX);
104
105 p = octeon_uart8250_data;
106 if (enable_uart0) {
107 /* Add a ttyS device for hardware uart 0 */
108 octeon_uart_set_common(p);
109 p->membase = (void *) CVMX_MIO_UARTX_RBR(0);
110 p->mapbase = CVMX_MIO_UARTX_RBR(0) & ((1ull << 49) - 1);
111 p->irq = OCTEON_IRQ_UART0;
112 p++;
113 }
114
115 if (enable_uart1) {
116 /* Add a ttyS device for hardware uart 1 */
117 octeon_uart_set_common(p);
118 p->membase = (void *) CVMX_MIO_UARTX_RBR(1);
119 p->mapbase = CVMX_MIO_UARTX_RBR(1) & ((1ull << 49) - 1);
120 p->irq = OCTEON_IRQ_UART1;
121 p++;
122 }
123 if (enable_uart2) {
124 /* Add a ttyS device for hardware uart 2 */
125 octeon_uart_set_common(p);
126 p->membase = (void *) CVMX_MIO_UART2_RBR;
127 p->mapbase = CVMX_MIO_UART2_RBR & ((1ull << 49) - 1);
128 p->irq = OCTEON_IRQ_UART2;
129 p++;
130 }
131
132 BUG_ON(p > &octeon_uart8250_data[OCTEON_MAX_UARTS]);
133
134 return platform_device_register(&octeon_uart8250_device);
135 }
136
137 device_initcall(octeon_serial_init);
138