2 * arch/ppc/boot/simple/mpc52xx_tty.c
4 * Minimal serial functions needed to send messages out a MPC52xx
5 * Programmable Serial Controller (PSC).
7 * Author: Dale Farnsworth <dfarnsworth@mvista.com>
9 * 2003-2004 (c) MontaVista, Software, Inc. This file is licensed under the
10 * terms of the GNU General Public License version 2. This program is licensed
11 * "as is" without any warranty of any kind, whether express or implied.
14 #include <linux/config.h>
15 #include <linux/types.h>
16 #include <asm/uaccess.h>
17 #include <asm/mpc52xx.h>
18 #include <asm/mpc52xx_psc.h>
19 #include <asm/serial.h>
23 #if MPC52xx_PF_CONSOLE_PORT == 0
24 #define MPC52xx_CONSOLE MPC52xx_PSC1
25 #define MPC52xx_PSC_CONFIG_SHIFT 0
26 #elif MPC52xx_PF_CONSOLE_PORT == 1
27 #define MPC52xx_CONSOLE MPC52xx_PSC2
28 #define MPC52xx_PSC_CONFIG_SHIFT 4
29 #elif MPC52xx_PF_CONSOLE_PORT == 2
30 #define MPC52xx_CONSOLE MPC52xx_PSC3
31 #define MPC52xx_PSC_CONFIG_SHIFT 8
33 #error "MPC52xx_PF_CONSOLE_PORT not defined"
36 static struct mpc52xx_psc *psc = (struct mpc52xx_psc *)MPC52xx_CONSOLE;
38 /* The decrementer counts at the system bus clock frequency
39 * divided by four. The most accurate time base is connected to the
40 * rtc. We read the decrementer change during one rtc tick (one second)
41 * and multiply by 4 to get the system bus clock frequency.
46 struct mpc52xx_rtc *rtc = (struct mpc52xx_rtc*)MPC52xx_RTC;
47 struct mpc52xx_cdm *cdm = (struct mpc52xx_cdm*)MPC52xx_CDM;
48 int current_time, previous_time;
49 int tbl_start, tbl_end;
52 out_be32(&rtc->dividers, 0x8f1f0000); /* Set RTC 64x faster */
53 previous_time = in_be32(&rtc->time);
54 while ((current_time = in_be32(&rtc->time)) == previous_time) ;
55 tbl_start = get_tbl();
56 previous_time = current_time;
57 while ((current_time = in_be32(&rtc->time)) == previous_time) ;
59 out_be32(&rtc->dividers, 0xffff0000); /* Restore RTC */
61 xlbfreq = (tbl_end - tbl_start) << 8;
62 ipbfreq = (in_8(&cdm->ipb_clk_sel) & 1) ? xlbfreq / 2 : xlbfreq;
68 serial_init(int ignored, void *ignored2)
70 struct mpc52xx_gpio *gpio = (struct mpc52xx_gpio *)MPC52xx_GPIO;
76 static int been_here = 0;
83 val32 = in_be32(&gpio->port_config);
84 val32 &= ~(0x7 << MPC52xx_PSC_CONFIG_SHIFT);
85 val32 |= MPC52xx_GPIO_PSC_CONFIG_UART_WITHOUT_CD
86 << MPC52xx_PSC_CONFIG_SHIFT;
87 out_be32(&gpio->port_config, val32);
89 out_8(&psc->command, MPC52xx_PSC_RST_TX
90 | MPC52xx_PSC_RX_DISABLE | MPC52xx_PSC_TX_ENABLE);
91 out_8(&psc->command, MPC52xx_PSC_RST_RX);
93 out_be32(&psc->sicr, 0x0);
94 out_be16(&psc->mpc52xx_psc_clock_select, 0xdd00);
95 out_be16(&psc->tfalarm, 0xf8);
97 out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1
98 | MPC52xx_PSC_RX_ENABLE
99 | MPC52xx_PSC_TX_ENABLE);
101 divisor = ((mpc52xx_ipbfreq()
102 / (CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD * 16)) + 1) >> 1;
104 mode1 = MPC52xx_PSC_MODE_8_BITS | MPC52xx_PSC_MODE_PARNONE
105 | MPC52xx_PSC_MODE_ERR;
106 mode2 = MPC52xx_PSC_MODE_ONE_STOP;
108 out_8(&psc->ctur, divisor>>8);
109 out_8(&psc->ctlr, divisor);
110 out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
111 out_8(&psc->mode, mode1);
112 out_8(&psc->mode, mode2);
114 return 0; /* ignored */
118 serial_putc(void *ignored, const char c)
122 while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXEMP)) ;
123 out_8(&psc->mpc52xx_psc_buffer_8, c);
124 while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXEMP)) ;
128 serial_getc(void *ignored)
130 while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_RXRDY)) ;
132 return in_8(&psc->mpc52xx_psc_buffer_8);
136 serial_tstc(void *ignored)
138 return (in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_RXRDY) != 0;