1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
140 lines
3.8 KiB
C
140 lines
3.8 KiB
C
/*
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* arch/ppc/boot/simple/mpc52xx_tty.c
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*
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* Minimal serial functions needed to send messages out a MPC52xx
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* Programmable Serial Controller (PSC).
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*
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* Author: Dale Farnsworth <dfarnsworth@mvista.com>
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*
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* 2003-2004 (c) MontaVista, Software, Inc. This file is licensed under the
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* terms of the GNU General Public License version 2. This program is licensed
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* "as is" without any warranty of any kind, whether express or implied.
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*/
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#include <linux/config.h>
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#include <linux/types.h>
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#include <asm/uaccess.h>
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#include <asm/mpc52xx.h>
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#include <asm/mpc52xx_psc.h>
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#include <asm/serial.h>
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#include <asm/io.h>
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#include <asm/time.h>
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#ifdef MPC52xx_PF_CONSOLE_PORT
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#define MPC52xx_CONSOLE MPC52xx_PSCx_OFFSET(MPC52xx_PF_CONSOLE_PORT)
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#define MPC52xx_PSC_CONFIG_SHIFT ((MPC52xx_PF_CONSOLE_PORT-1)<<2)
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#else
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#error "MPC52xx_PF_CONSOLE_PORT not defined"
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#endif
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static struct mpc52xx_psc __iomem *psc =
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(struct mpc52xx_psc __iomem *) MPC52xx_PA(MPC52xx_CONSOLE);
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/* The decrementer counts at the system bus clock frequency
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* divided by four. The most accurate time base is connected to the
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* rtc. We read the decrementer change during one rtc tick
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* and multiply by 4 to get the system bus clock frequency. Since a
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* rtc tick is one seconds, and that's pretty long, we change the rtc
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* dividers temporarly to set them 64x faster ;)
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*/
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static int
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mpc52xx_ipbfreq(void)
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{
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struct mpc52xx_rtc __iomem *rtc =
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(struct mpc52xx_rtc __iomem *) MPC52xx_PA(MPC52xx_RTC_OFFSET);
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struct mpc52xx_cdm __iomem *cdm =
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(struct mpc52xx_cdm __iomem *) MPC52xx_PA(MPC52xx_CDM_OFFSET);
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int current_time, previous_time;
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int tbl_start, tbl_end;
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int xlbfreq, ipbfreq;
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out_be32(&rtc->dividers, 0x8f1f0000); /* Set RTC 64x faster */
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previous_time = in_be32(&rtc->time);
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while ((current_time = in_be32(&rtc->time)) == previous_time) ;
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tbl_start = get_tbl();
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previous_time = current_time;
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while ((current_time = in_be32(&rtc->time)) == previous_time) ;
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tbl_end = get_tbl();
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out_be32(&rtc->dividers, 0xffff0000); /* Restore RTC */
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xlbfreq = (tbl_end - tbl_start) << 8;
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ipbfreq = (in_8(&cdm->ipb_clk_sel) & 1) ? xlbfreq / 2 : xlbfreq;
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return ipbfreq;
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}
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unsigned long
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serial_init(int ignored, void *ignored2)
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{
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struct mpc52xx_gpio __iomem *gpio =
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(struct mpc52xx_gpio __iomem *) MPC52xx_PA(MPC52xx_GPIO_OFFSET);
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int divisor;
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int mode1;
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int mode2;
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u32 val32;
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static int been_here = 0;
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if (been_here)
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return 0;
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been_here = 1;
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val32 = in_be32(&gpio->port_config);
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val32 &= ~(0x7 << MPC52xx_PSC_CONFIG_SHIFT);
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val32 |= MPC52xx_GPIO_PSC_CONFIG_UART_WITHOUT_CD
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<< MPC52xx_PSC_CONFIG_SHIFT;
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out_be32(&gpio->port_config, val32);
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out_8(&psc->command, MPC52xx_PSC_RST_TX
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| MPC52xx_PSC_RX_DISABLE | MPC52xx_PSC_TX_ENABLE);
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out_8(&psc->command, MPC52xx_PSC_RST_RX);
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out_be32(&psc->sicr, 0x0);
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out_be16(&psc->mpc52xx_psc_clock_select, 0xdd00);
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out_be16(&psc->tfalarm, 0xf8);
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out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1
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| MPC52xx_PSC_RX_ENABLE
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| MPC52xx_PSC_TX_ENABLE);
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divisor = ((mpc52xx_ipbfreq()
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/ (CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD * 16)) + 1) >> 1;
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mode1 = MPC52xx_PSC_MODE_8_BITS | MPC52xx_PSC_MODE_PARNONE
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| MPC52xx_PSC_MODE_ERR;
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mode2 = MPC52xx_PSC_MODE_ONE_STOP;
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out_8(&psc->ctur, divisor>>8);
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out_8(&psc->ctlr, divisor);
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out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
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out_8(&psc->mode, mode1);
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out_8(&psc->mode, mode2);
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return 0; /* ignored */
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}
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void
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serial_putc(void *ignored, const char c)
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{
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serial_init(0, NULL);
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while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXEMP)) ;
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out_8(&psc->mpc52xx_psc_buffer_8, c);
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while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXEMP)) ;
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}
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char
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serial_getc(void *ignored)
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{
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while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_RXRDY)) ;
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return in_8(&psc->mpc52xx_psc_buffer_8);
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}
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int
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serial_tstc(void *ignored)
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{
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return (in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_RXRDY) != 0;
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}
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