ARM: cns3xxx: Add basic support for Cavium Networks CNS3xxx processors

This patch adds very basic support for ECONA CNS3xxx ARM11 MPcore
(ARMv6) dual-core processors.

Note that SMP is not yet supported, as well as many peripheral
devices. Support for these features will be added later.

Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>

arch/arm/mach-cns3xxx/pm.c

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2008 Cavium Networks
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, Version 2, as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <mach/system.h>
+#include <mach/cns3xxx.h>
+
+void cns3xxx_pwr_clk_en(unsigned int block)
+{
+	PM_CLK_GATE_REG |= (block & PM_CLK_GATE_REG_MASK);
+}
+
+void cns3xxx_pwr_power_up(unsigned int block)
+{
+	PM_PLL_HM_PD_CTRL_REG &= ~(block & CNS3XXX_PWR_PLL_ALL);
+
+	/* Wait for 300us for the PLL output clock locked. */
+	udelay(300);
+};
+
+void cns3xxx_pwr_power_down(unsigned int block)
+{
+	/* write '1' to power down */
+	PM_PLL_HM_PD_CTRL_REG |= (block & CNS3XXX_PWR_PLL_ALL);
+};
+
+static void cns3xxx_pwr_soft_rst_force(unsigned int block)
+{
+	/*
+	 * bit 0, 28, 29 => program low to reset,
+	 * the other else program low and then high
+	 */
+	if (block & 0x30000001) {
+		PM_SOFT_RST_REG &= ~(block & PM_SOFT_RST_REG_MASK);
+	} else {
+		PM_SOFT_RST_REG &= ~(block & PM_SOFT_RST_REG_MASK);
+		PM_SOFT_RST_REG |= (block & PM_SOFT_RST_REG_MASK);
+	}
+}
+
+void cns3xxx_pwr_soft_rst(unsigned int block)
+{
+	static unsigned int soft_reset;
+
+	if (soft_reset & block) {
+		/* SPI/I2C/GPIO use the same block, reset once. */
+		return;
+	} else {
+		soft_reset |= block;
+	}
+	cns3xxx_pwr_soft_rst_force(block);
+}
+
+void arch_reset(char mode, const char *cmd)
+{
+	/*
+	 * To reset, we hit the on-board reset register
+	 * in the system FPGA.
+	 */
+	cns3xxx_pwr_soft_rst(CNS3XXX_PWR_SOFTWARE_RST(GLOBAL));
+}
+
+/*
+ * cns3xxx_cpu_clock - return CPU/L2 clock
+ *  aclk: cpu clock/2
+ *  hclk: cpu clock/4
+ *  pclk: cpu clock/8
+ */
+int cns3xxx_cpu_clock(void)
+{
+	int cpu;
+	int cpu_sel;
+	int div_sel;
+
+	cpu_sel = (PM_CLK_CTRL_REG >> PM_CLK_CTRL_REG_OFFSET_PLL_CPU_SEL) & 0xf;
+	div_sel = (PM_CLK_CTRL_REG >> PM_CLK_CTRL_REG_OFFSET_CPU_CLK_DIV) & 0x3;
+
+	cpu = (300 + ((cpu_sel / 3) * 100) + ((cpu_sel % 3) * 33)) >> div_sel;
+
+	return cpu;
+}