cvmx-uart.c revision 302408 
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39
40
41#ifdef CVMX_BUILD_FOR_LINUX_KERNEL
42#include <linux/module.h>
43#include <asm/octeon/cvmx.h>
44#include <asm/octeon/cvmx-clock.h>
45#include <asm/octeon/cvmx-uart.h>
46#else
47#include "cvmx.h"
48#include "cvmx-uart.h"
49#include "cvmx-interrupt.h"
50#endif
51
52#ifndef CVMX_BUILD_FOR_TOOLCHAIN
53void cvmx_uart_enable_intr(int uart, cvmx_uart_intr_handler_t handler)
54{
55#ifndef CVMX_BUILD_FOR_LINUX_KERNEL
56    cvmx_uart_ier_t ier;
57
58    cvmx_interrupt_register(CVMX_IRQ_UART0 + uart, handler, NULL);
59    /* Enable uart interrupts for debugger Control-C processing */
60    ier.u64 = cvmx_read_csr(CVMX_MIO_UARTX_IER(uart));
61    ier.s.erbfi = 1;
62    cvmx_write_csr(CVMX_MIO_UARTX_IER(uart), ier.u64);
63
64    cvmx_interrupt_unmask_irq(CVMX_IRQ_UART0 + uart);
65#endif
66}
67#endif
68
69static int cvmx_uart_simulator_p(void)
70{
71#ifndef CVMX_BUILD_FOR_TOOLCHAIN
72  return cvmx_sysinfo_get()->board_type == CVMX_BOARD_TYPE_SIM;
73#else
74  extern int __octeon_simulator_p;
75  return __octeon_simulator_p;
76#endif
77}
78
79
80/**
81 * Function that does the real work of setting up the Octeon uart.
82 * Takes all parameters as arguments, so it does not require gd
83 * structure to be set up.
84 *
85 * @param uart_index Index of uart to configure
86 * @param cpu_clock_hertz
87 *                   CPU clock frequency in Hz
88 * @param baudrate   Baudrate to configure
89 *
90 * @return 0 on success
91 *         !0 on error
92 */
93int cvmx_uart_setup2(int uart_index, int cpu_clock_hertz, int baudrate)
94{
95    uint16_t divisor;
96    cvmx_uart_fcr_t fcrval;
97    cvmx_uart_mcr_t mcrval;
98    cvmx_uart_lcr_t lcrval;
99
100    fcrval.u64 = 0;
101    fcrval.s.en = 1;    /* enable the FIFO's */
102    fcrval.s.rxfr = 1;  /* reset the RX fifo */
103    fcrval.s.txfr = 1;  /* reset the TX fifo */
104
105    if (cvmx_uart_simulator_p())
106        divisor = 1;
107    else
108        divisor = ((unsigned long)(cpu_clock_hertz + 8 * baudrate) / (unsigned long)(16 * baudrate));
109
110    cvmx_write_csr(CVMX_MIO_UARTX_FCR(uart_index), fcrval.u64);
111
112    mcrval.u64 = 0;
113    if (uart_index == 1 && cvmx_uart_simulator_p())
114      mcrval.s.afce = 1;  /* enable auto flow control for simulator. Needed for  gdb regression callfuncs.exp. */
115    else
116      mcrval.s.afce = 0;  /* disable auto flow control so board can power on without serial port connected */
117
118    mcrval.s.rts = 1;   /* looks like this must be set for auto flow control to work */
119
120    cvmx_read_csr(CVMX_MIO_UARTX_LSR(uart_index));
121
122    lcrval.u64 = 0;
123    lcrval.s.cls = CVMX_UART_BITS8;
124    lcrval.s.stop = 0;  /* stop bit included? */
125    lcrval.s.pen = 0;   /* no parity? */
126    lcrval.s.eps = 1;   /* even parity? */
127    lcrval.s.dlab = 1;  /* temporary to program the divisor */
128    cvmx_write_csr(CVMX_MIO_UARTX_LCR(uart_index), lcrval.u64);
129
130    cvmx_write_csr(CVMX_MIO_UARTX_DLL(uart_index), divisor & 0xff);
131    cvmx_write_csr(CVMX_MIO_UARTX_DLH(uart_index), (divisor>>8) & 0xff);
132
133    lcrval.s.dlab = 0;  /* divisor is programmed now, set this back to normal */
134    cvmx_write_csr(CVMX_MIO_UARTX_LCR(uart_index), lcrval.u64);
135
136    /* spec says need to wait after you program the divisor */
137    if (!cvmx_uart_simulator_p())
138    {
139        uint64_t read_cycle;
140        CVMX_MF_CYCLE (read_cycle);
141        read_cycle += (2 * divisor * 16) + 10000;
142
143        /* Spin */
144        while (1)
145        {
146            uint64_t new_cycle;
147            CVMX_MF_CYCLE (new_cycle);
148            if (new_cycle >= read_cycle)
149                break;
150        }
151    }
152
153    /* Don't enable flow control until after baud rate is configured. - we don't want
154    ** to allow characters in until after the baud rate is fully configured */
155    cvmx_write_csr(CVMX_MIO_UARTX_MCR(uart_index), mcrval.u64);
156    return 0;
157
158}
159
160/**
161 * Setup a uart for use
162 *
163 * @param uart_index Uart to setup (0 or 1)
164 * @return Zero on success
165 */
166int cvmx_uart_setup (int uart_index)
167{
168    return cvmx_uart_setup2(uart_index, cvmx_clock_get_rate (CVMX_CLOCK_SCLK), 115200);
169}
170
171