powerpc: Partialy restore core of mpc8xx

CS Systemes d'Information (CSSI) manufactures 8xx boards for
critical communication systems. Those boards have been
running U-Boot since 2010 and will have to be maintained
until at least 2027.

commit 5b8e76c35ec312a3f73126bd1a2d2c0965b98a9f
("powerpc, 8xx: remove support for 8xx") orphaned those boards
by removing support for the mpc8xx CPU.

This commit partially restores support for the 8xx, with the
following limitations:
- Restores support for MPC866 and MPC885 only
- Does not restore IDE, PCMCIA, I2C, USB
- Does not restore examples
- Does not restore POST
- Does not restore Ethernet on SCC
- Does not restore console on SCC
- Does not restore bedbug and kgdb support

As the 866 and 885 do not support the following features,
they are not restored either:
- VIDEO / LCD
- RTC clock

The CPM uCODE patch is not restored either, because:
- 866 and 885 already have support for I2C and SPI relocation
without a uCODE patch
- relocation of SMC, I2C or SPI is only needed for using SCCs
for Ethernet or QMC

The dynamic setup/calculation of clocks is removed, we
expect the target being use with the clock and PLPRCR register
defined in the configuration.
All the clock settings for 8xx prior to 866 is removed as
well as we now only support 866 and 885.

This code is mature and addresses mature boards. Therefore
all code enclosed in '#if 0/#endif' and '#if XX_DEBUG/#endif'
is unneeded.

The following files are not restored by this patch:

- arch/powerpc/cpu/mpc8xx/bedbug_860.c
- arch/powerpc/cpu/mpc8xx/fec.h
- arch/powerpc/cpu/mpc8xx/kgdb.S
- arch/powerpc/cpu/mpc8xx/plprcr_write.S
- arch/powerpc/cpu/mpc8xx/scc.c
- arch/powerpc/cpu/mpc8xx/upatch.c
- arch/powerpc/cpu/mpc8xx/video.c
- arch/powerpc/include/asm/status_led.h
- arch/powerpc/lib/ide.c
- arch/powerpc/lib/ide.h
- doc/README.MPC866
- drivers/pcmcia/mpc8xx_pcmcia.c
- drivers/rtc/mpc8xx.c
- drivers/usb/gadget/mpc8xx_udc.c
- drivers/video/mpc8xx_lcd.c
- examples/standalone/test_burst.c
- examples/standalone/test_burst.h
- examples/standalone/test_burst_lib.S
- examples/standalone/timer.c
- include/mpc823_lcd.h
- include/usb/mpc8xx_udc.h
- post/cpu/mpc8xx/Makefile
- post/cpu/mpc8xx/cache.c
- post/cpu/mpc8xx/cache_8xx.S
- post/cpu/mpc8xx/ether.c
- post/cpu/mpc8xx/spr.c
- post/cpu/mpc8xx/uart.c
- post/cpu/mpc8xx/usb.c
- post/cpu/mpc8xx/watchdog.c

Some of the restored files are not located in a proper location.
In order to keep traceability of the changes, they will be
moved to their correct location and moved to Kconfig in a
followup patch.

This patch also declares CSSI as point of contact for the update
of the 8xx platform, as those boards are the only ones still
being maintained on the 8xx area. A later patch will add
those boards to the tree.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

1 files changed, 301 insertions, 0 deletions

diff --git a/arch/powerpc/cpu/mpc8xx/serial.c b/arch/powerpc/cpu/mpc8xx/serial.c
new file mode 100644
index 0000000..d4f1a41
--- /dev/null
+++ b/arch/powerpc/cpu/mpc8xx/serial.c
@@ -0,0 +1,301 @@
+/*
+ * (C) Copyright 2000
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <commproc.h>
+#include <command.h>
+#include <serial.h>
+#include <watchdog.h>
+#include <linux/compiler.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#if !defined(CONFIG_8xx_CONS_NONE)	/* No Console at all */
+
+#if defined(CONFIG_8xx_CONS_SMC1)	/* Console on SMC1 */
+#define	SMC_INDEX	0
+#define PROFF_SMC	PROFF_SMC1
+#define CPM_CR_CH_SMC	CPM_CR_CH_SMC1
+
+#elif defined(CONFIG_8xx_CONS_SMC2)	/* Console on SMC2 */
+#define SMC_INDEX	1
+#define PROFF_SMC	PROFF_SMC2
+#define CPM_CR_CH_SMC	CPM_CR_CH_SMC2
+
+#endif /* CONFIG_8xx_CONS_SMCx */
+
+#if !defined(CONFIG_SYS_SMC_RXBUFLEN)
+#define CONFIG_SYS_SMC_RXBUFLEN	1
+#define CONFIG_SYS_MAXIDLE	0
+#else
+#if !defined(CONFIG_SYS_MAXIDLE)
+#error "you must define CONFIG_SYS_MAXIDLE"
+#endif
+#endif
+
+typedef volatile struct serialbuffer {
+	cbd_t	rxbd;		/* Rx BD */
+	cbd_t	txbd;		/* Tx BD */
+	uint	rxindex;	/* index for next character to read */
+	volatile uchar	rxbuf[CONFIG_SYS_SMC_RXBUFLEN];/* rx buffers */
+	volatile uchar	txbuf;	/* tx buffers */
+} serialbuffer_t;
+
+static void serial_setdivisor(volatile cpm8xx_t *cp)
+{
+	int divisor=(gd->cpu_clk + 8*gd->baudrate)/16/gd->baudrate;
+
+	if(divisor/16>0x1000) {
+		/* bad divisor, assume 50MHz clock and 9600 baud */
+		divisor=(50*1000*1000 + 8*9600)/16/9600;
+	}
+
+#ifdef CONFIG_SYS_BRGCLK_PRESCALE
+	divisor /= CONFIG_SYS_BRGCLK_PRESCALE;
+#endif
+
+	if(divisor<=0x1000) {
+		cp->cp_brgc1=((divisor-1)<<1) | CPM_BRG_EN;
+	} else {
+		cp->cp_brgc1=((divisor/16-1)<<1) | CPM_BRG_EN | CPM_BRG_DIV16;
+	}
+}
+
+/*
+ * Minimal serial functions needed to use one of the SMC ports
+ * as serial console interface.
+ */
+
+static void smc_setbrg (void)
+{
+	volatile immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
+	volatile cpm8xx_t *cp = &(im->im_cpm);
+
+	/* Set up the baud rate generator.
+	 * See 8xx_io/commproc.c for details.
+	 *
+	 * Wire BRG1 to SMCx
+	 */
+
+	cp->cp_simode = 0x00000000;
+
+	serial_setdivisor(cp);
+}
+
+static int smc_init (void)
+{
+	volatile immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
+	volatile smc_t *sp;
+	volatile smc_uart_t *up;
+	volatile cpm8xx_t *cp = &(im->im_cpm);
+	uint	dpaddr;
+	volatile serialbuffer_t *rtx;
+
+	/* initialize pointers to SMC */
+
+	sp = (smc_t *) &(cp->cp_smc[SMC_INDEX]);
+	up = (smc_uart_t *) &cp->cp_dparam[PROFF_SMC];
+	/* Disable relocation */
+	up->smc_rpbase = 0;
+
+	/* Disable transmitter/receiver. */
+	sp->smc_smcmr &= ~(SMCMR_REN | SMCMR_TEN);
+
+	/* Enable SDMA. */
+	im->im_siu_conf.sc_sdcr = 1;
+
+	/* clear error conditions */
+#ifdef	CONFIG_SYS_SDSR
+	im->im_sdma.sdma_sdsr = CONFIG_SYS_SDSR;
+#else
+	im->im_sdma.sdma_sdsr = 0x83;
+#endif
+
+	/* clear SDMA interrupt mask */
+#ifdef	CONFIG_SYS_SDMR
+	im->im_sdma.sdma_sdmr = CONFIG_SYS_SDMR;
+#else
+	im->im_sdma.sdma_sdmr = 0x00;
+#endif
+
+#if defined(CONFIG_8xx_CONS_SMC1)
+	/* Use Port B for SMC1 instead of other functions. */
+	cp->cp_pbpar |=  0x000000c0;
+	cp->cp_pbdir &= ~0x000000c0;
+	cp->cp_pbodr &= ~0x000000c0;
+#else	/* CONFIG_8xx_CONS_SMC2 */
+	/* Use Port B for SMC2 instead of other functions.
+	 */
+	cp->cp_pbpar |=  0x00000c00;
+	cp->cp_pbdir &= ~0x00000c00;
+	cp->cp_pbodr &= ~0x00000c00;
+#endif
+
+	/* Set the physical address of the host memory buffers in
+	 * the buffer descriptors.
+	 */
+	dpaddr = CPM_SERIAL_BASE;
+
+	rtx = (serialbuffer_t *)&cp->cp_dpmem[dpaddr];
+	/* Allocate space for two buffer descriptors in the DP ram.
+	 * For now, this address seems OK, but it may have to
+	 * change with newer versions of the firmware.
+	 * damm: allocating space after the two buffers for rx/tx data
+	 */
+
+	rtx->rxbd.cbd_bufaddr = (uint) &rtx->rxbuf;
+	rtx->rxbd.cbd_sc      = 0;
+
+	rtx->txbd.cbd_bufaddr = (uint) &rtx->txbuf;
+	rtx->txbd.cbd_sc      = 0;
+
+	/* Set up the uart parameters in the parameter ram. */
+	up->smc_rbase = dpaddr;
+	up->smc_tbase = dpaddr+sizeof(cbd_t);
+	up->smc_rfcr = SMC_EB;
+	up->smc_tfcr = SMC_EB;
+
+	/* Set UART mode, 8 bit, no parity, one stop.
+	 * Enable receive and transmit.
+	 */
+	sp->smc_smcmr = smcr_mk_clen(9) |  SMCMR_SM_UART;
+
+	/* Mask all interrupts and remove anything pending.
+	*/
+	sp->smc_smcm = 0;
+	sp->smc_smce = 0xff;
+
+	/* Set up the baud rate generator */
+	smc_setbrg ();
+
+	/* Make the first buffer the only buffer. */
+	rtx->txbd.cbd_sc |= BD_SC_WRAP;
+	rtx->rxbd.cbd_sc |= BD_SC_EMPTY | BD_SC_WRAP;
+
+	/* single/multi character receive. */
+	up->smc_mrblr = CONFIG_SYS_SMC_RXBUFLEN;
+	up->smc_maxidl = CONFIG_SYS_MAXIDLE;
+	rtx->rxindex = 0;
+
+	/* Initialize Tx/Rx parameters.	*/
+	while (cp->cp_cpcr & CPM_CR_FLG)  /* wait if cp is busy */
+	  ;
+
+	cp->cp_cpcr = mk_cr_cmd(CPM_CR_CH_SMC, CPM_CR_INIT_TRX) | CPM_CR_FLG;
+
+	while (cp->cp_cpcr & CPM_CR_FLG)  /* wait if cp is busy */
+	  ;
+
+	/* Enable transmitter/receiver.	*/
+	sp->smc_smcmr |= SMCMR_REN | SMCMR_TEN;
+
+	return (0);
+}
+
+static void
+smc_putc(const char c)
+{
+	volatile smc_uart_t	*up;
+	volatile immap_t	*im = (immap_t *)CONFIG_SYS_IMMR;
+	volatile cpm8xx_t	*cpmp = &(im->im_cpm);
+	volatile serialbuffer_t	*rtx;
+
+	if (c == '\n')
+		smc_putc ('\r');
+
+	up = (smc_uart_t *)&cpmp->cp_dparam[PROFF_SMC];
+
+	rtx = (serialbuffer_t *)&cpmp->cp_dpmem[up->smc_rbase];
+
+	/* Wait for last character to go. */
+	rtx->txbuf = c;
+	rtx->txbd.cbd_datlen = 1;
+	rtx->txbd.cbd_sc |= BD_SC_READY;
+	__asm__("eieio");
+
+	while (rtx->txbd.cbd_sc & BD_SC_READY) {
+		WATCHDOG_RESET ();
+		__asm__("eieio");
+	}
+}
+
+static void
+smc_puts (const char *s)
+{
+	while (*s) {
+		smc_putc (*s++);
+	}
+}
+
+static int
+smc_getc(void)
+{
+	volatile smc_uart_t	*up;
+	volatile immap_t	*im = (immap_t *)CONFIG_SYS_IMMR;
+	volatile cpm8xx_t	*cpmp = &(im->im_cpm);
+	volatile serialbuffer_t	*rtx;
+	unsigned char  c;
+
+	up = (smc_uart_t *)&cpmp->cp_dparam[PROFF_SMC];
+	rtx = (serialbuffer_t *)&cpmp->cp_dpmem[up->smc_rbase];
+
+	/* Wait for character to show up. */
+	while (rtx->rxbd.cbd_sc & BD_SC_EMPTY)
+		WATCHDOG_RESET ();
+
+	/* the characters are read one by one,
+	 * use the rxindex to know the next char to deliver
+	 */
+	c = *(unsigned char *) (rtx->rxbd.cbd_bufaddr+rtx->rxindex);
+	rtx->rxindex++;
+
+	/* check if all char are readout, then make prepare for next receive */
+	if (rtx->rxindex >= rtx->rxbd.cbd_datlen) {
+		rtx->rxindex = 0;
+		rtx->rxbd.cbd_sc |= BD_SC_EMPTY;
+	}
+	return(c);
+}
+
+static int
+smc_tstc(void)
+{
+	volatile smc_uart_t	*up;
+	volatile immap_t	*im = (immap_t *)CONFIG_SYS_IMMR;
+	volatile cpm8xx_t	*cpmp = &(im->im_cpm);
+	volatile serialbuffer_t	*rtx;
+
+	up = (smc_uart_t *)&cpmp->cp_dparam[PROFF_SMC];
+
+	rtx = (serialbuffer_t *)&cpmp->cp_dpmem[up->smc_rbase];
+
+	return !(rtx->rxbd.cbd_sc & BD_SC_EMPTY);
+}
+
+struct serial_device serial_smc_device =
+{
+	.name	= "serial_smc",
+	.start	= smc_init,
+	.stop	= NULL,
+	.setbrg	= smc_setbrg,
+	.getc	= smc_getc,
+	.tstc	= smc_tstc,
+	.putc	= smc_putc,
+	.puts	= smc_puts,
+};
+
+__weak struct serial_device *default_serial_console(void)
+{
+	return &serial_smc_device;
+}
+
+void mpc8xx_serial_initialize(void)
+{
+	serial_register(&serial_smc_device);
+}
+
+#endif	/* CONFIG_8xx_CONS_NONE */