davinci: split out some dm644x-specific bits from psc

Split out DaVinci DM6446-specific bits from more generic bits:

 - Add a CONFIG_SOC_DM644X.  All current boards use DM6446 chips;
   DM6443 and DM6441 chips differ in available peripherals.

 - Move most DM644X-specific bits from psc.c to a new dm644x.c file,
   which is conditionally built.  It provides device-specific setup.

Plus minor coding style and comment updates with respect to the PSC.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
diff --git a/cpu/arm926ejs/davinci/dm644x.c b/cpu/arm926ejs/davinci/dm644x.c
new file mode 100644
index 0000000..df382bd
--- /dev/null
+++ b/cpu/arm926ejs/davinci/dm644x.c
@@ -0,0 +1,94 @@
+/*
+ * SoC-specific code for tms320dm644x chips
+ *
+ * Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
+ * Copyright (C) 2008 Lyrtech <www.lyrtech.com>
+ * Copyright (C) 2004 Texas Instruments.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <common.h>
+#include <asm/arch/hardware.h>
+
+
+#define PINMUX0_EMACEN (1 << 31)
+#define PINMUX0_AECS5  (1 << 11)
+#define PINMUX0_AECS4  (1 << 10)
+
+#define PINMUX1_I2C    (1 <<  7)
+#define PINMUX1_UART1  (1 <<  1)
+#define PINMUX1_UART0  (1 <<  0)
+
+
+void davinci_enable_uart0(void)
+{
+	lpsc_on(DAVINCI_LPSC_UART0);
+
+	/* Bringup UART0 out of reset */
+	REG(UART0_PWREMU_MGMT) = 0x0000e003;
+
+	/* Enable UART0 MUX lines */
+	REG(PINMUX1) |= PINMUX1_UART0;
+}
+
+#ifdef CONFIG_DRIVER_TI_EMAC
+void davinci_enable_emac(void)
+{
+	lpsc_on(DAVINCI_LPSC_EMAC);
+	lpsc_on(DAVINCI_LPSC_EMAC_WRAPPER);
+	lpsc_on(DAVINCI_LPSC_MDIO);
+
+	/* Enable GIO3.3V cells used for EMAC */
+	REG(VDD3P3V_PWDN) = 0;
+
+	/* Enable EMAC. */
+	REG(PINMUX0) |= PINMUX0_EMACEN;
+}
+#endif
+
+void davinci_enable_i2c(void)
+{
+	lpsc_on(DAVINCI_LPSC_I2C);
+
+	/* Enable I2C pin Mux */
+	REG(PINMUX1) |= PINMUX1_I2C;
+}
+
+void davinci_errata_workarounds(void)
+{
+	/*
+	 * Workaround for TMS320DM6446 errata 1.3.22:
+	 *   PSC: PTSTAT Register Does Not Clear After Warm/Maximum Reset
+	 *   Revision(s) Affected: 1.3 and earlier
+	 */
+	REG(PSC_SILVER_BULLET) = 0;
+
+	/*
+	 * Set the PR_OLD_COUNT bits in the Bus Burst Priority Register (PBBPR)
+	 * as suggested in TMS320DM6446 errata 2.1.2:
+	 *
+	 * On DM6446 Silicon Revision 2.1 and earlier, under certain conditions
+	 * low priority modules can occupy the bus and prevent high priority
+	 * modules like the VPSS from getting the required DDR2 throughput.
+	 * A hex value of 0x20 should provide a good ARM (cache enabled)
+	 * performance and still allow good utilization by the VPSS or other
+	 * modules.
+	 */
+	REG(VBPR) = 0x20;
+}