diff options
Diffstat (limited to 'arch/mips/cavium-octeon/serial.c')
| -rw-r--r-- | arch/mips/cavium-octeon/serial.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/arch/mips/cavium-octeon/serial.c b/arch/mips/cavium-octeon/serial.c new file mode 100644 index 00000000000..8240728d485 --- /dev/null +++ b/arch/mips/cavium-octeon/serial.c @@ -0,0 +1,136 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2004-2007 Cavium Networks + */ +#include <linux/console.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/serial.h> +#include <linux/serial_8250.h> +#include <linux/serial_reg.h> +#include <linux/tty.h> + +#include <asm/time.h> + +#include <asm/octeon/octeon.h> + +#ifdef CONFIG_GDB_CONSOLE +#define DEBUG_UART 0 +#else +#define DEBUG_UART 1 +#endif + +unsigned int octeon_serial_in(struct uart_port *up, int offset) +{ + int rv = cvmx_read_csr((uint64_t)(up->membase + (offset << 3))); + if (offset == UART_IIR && (rv & 0xf) == 7) { + /* Busy interrupt, read the USR (39) and try again. */ + cvmx_read_csr((uint64_t)(up->membase + (39 << 3))); + rv = cvmx_read_csr((uint64_t)(up->membase + (offset << 3))); + } + return rv; +} + +void octeon_serial_out(struct uart_port *up, int offset, int value) +{ + /* + * If bits 6 or 7 of the OCTEON UART's LCR are set, it quits + * working. + */ + if (offset == UART_LCR) + value &= 0x9f; + cvmx_write_csr((uint64_t)(up->membase + (offset << 3)), (u8)value); +} + +/* + * Allocated in .bss, so it is all zeroed. + */ +#define OCTEON_MAX_UARTS 3 +static struct plat_serial8250_port octeon_uart8250_data[OCTEON_MAX_UARTS + 1]; +static struct platform_device octeon_uart8250_device = { + .name = "serial8250", + .id = PLAT8250_DEV_PLATFORM, + .dev = { + .platform_data = octeon_uart8250_data, + }, +}; + +static void __init octeon_uart_set_common(struct plat_serial8250_port *p) +{ + p->flags = ASYNC_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE; + p->type = PORT_OCTEON; + p->iotype = UPIO_MEM; + p->regshift = 3; /* I/O addresses are every 8 bytes */ + p->uartclk = mips_hpt_frequency; + p->serial_in = octeon_serial_in; + p->serial_out = octeon_serial_out; +} + +static int __init octeon_serial_init(void) +{ + int enable_uart0; + int enable_uart1; + int enable_uart2; + struct plat_serial8250_port *p; + +#ifdef CONFIG_CAVIUM_OCTEON_2ND_KERNEL + /* + * If we are configured to run as the second of two kernels, + * disable uart0 and enable uart1. Uart0 is owned by the first + * kernel + */ + enable_uart0 = 0; + enable_uart1 = 1; +#else + /* + * We are configured for the first kernel. We'll enable uart0 + * if the bootloader told us to use 0, otherwise will enable + * uart 1. + */ + enable_uart0 = (octeon_get_boot_uart() == 0); + enable_uart1 = (octeon_get_boot_uart() == 1); +#ifdef CONFIG_KGDB + enable_uart1 = 1; +#endif +#endif + + /* Right now CN52XX is the only chip with a third uart */ + enable_uart2 = OCTEON_IS_MODEL(OCTEON_CN52XX); + + p = octeon_uart8250_data; + if (enable_uart0) { + /* Add a ttyS device for hardware uart 0 */ + octeon_uart_set_common(p); + p->membase = (void *) CVMX_MIO_UARTX_RBR(0); + p->mapbase = CVMX_MIO_UARTX_RBR(0) & ((1ull << 49) - 1); + p->irq = OCTEON_IRQ_UART0; + p++; + } + + if (enable_uart1) { + /* Add a ttyS device for hardware uart 1 */ + octeon_uart_set_common(p); + p->membase = (void *) CVMX_MIO_UARTX_RBR(1); + p->mapbase = CVMX_MIO_UARTX_RBR(1) & ((1ull << 49) - 1); + p->irq = OCTEON_IRQ_UART1; + p++; + } + if (enable_uart2) { + /* Add a ttyS device for hardware uart 2 */ + octeon_uart_set_common(p); + p->membase = (void *) CVMX_MIO_UART2_RBR; + p->mapbase = CVMX_MIO_UART2_RBR & ((1ull << 49) - 1); + p->irq = OCTEON_IRQ_UART2; + p++; + } + + BUG_ON(p > &octeon_uart8250_data[OCTEON_MAX_UARTS]); + + return platform_device_register(&octeon_uart8250_device); +} + +device_initcall(octeon_serial_init); |