ARM: BCM63xx: Add Broadcom BCM63xx PMB controller helpers

This patch adds both common register definitions and helper functions
used to issue read/write commands to the Broadcom BCM63xx PMB controller
which is used to power on and release from reset internal on-chip
peripherals such as the integrated Ethernet switch, AHCI, USB, as well
as the secondary CPU core.

This is going to be utilized by the BCM63138 SMP code, as well as by the
BCM63138 reset controller later.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

include/linux/reset/bcm63xx_pmb.h

+/*
+ * Broadcom BCM63xx Processor Monitor Bus shared routines (SMP and reset)
+ *
+ * Copyright (C) 2015, Broadcom Corporation
+ * Author: Florian Fainelli <f.fainelli@gmail.com>
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#ifndef __BCM63XX_PMB_H
+#define __BCM63XX_PMB_H
+
+#include <linux/io.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+
+/* PMB Master controller register */
+#define PMB_CTRL		0x00
+#define  PMC_PMBM_START		(1 << 31)
+#define  PMC_PMBM_TIMEOUT	(1 << 30)
+#define  PMC_PMBM_SLAVE_ERR	(1 << 29)
+#define  PMC_PMBM_BUSY		(1 << 28)
+#define  PMC_PMBM_READ		(0 << 20)
+#define  PMC_PMBM_WRITE		(1 << 20)
+#define PMB_WR_DATA		0x04
+#define PMB_TIMEOUT		0x08
+#define PMB_RD_DATA		0x0C
+
+#define PMB_BUS_ID_SHIFT	8
+
+/* Perform the low-level PMB master operation, shared between reads and
+ * writes.
+ */
+static inline int __bpcm_do_op(void __iomem *master, unsigned int addr,
+			       u32 off, u32 op)
+{
+	unsigned int timeout = 1000;
+	u32 cmd;
+
+	cmd = (PMC_PMBM_START | op | (addr & 0xff) << 12 | off);
+	writel(cmd, master + PMB_CTRL);
+	do {
+		cmd = readl(master + PMB_CTRL);
+		if (!(cmd & PMC_PMBM_START))
+			return 0;
+
+		if (cmd & PMC_PMBM_SLAVE_ERR)
+			return -EIO;
+
+		if (cmd & PMC_PMBM_TIMEOUT)
+			return -ETIMEDOUT;
+
+		udelay(1);
+	} while (timeout-- > 0);
+
+	return -ETIMEDOUT;
+}
+
+static inline int bpcm_rd(void __iomem *master, unsigned int addr,
+			  u32 off, u32 *val)
+{
+	int ret = 0;
+
+	ret = __bpcm_do_op(master, addr, off >> 2, PMC_PMBM_READ);
+	*val = readl(master + PMB_RD_DATA);
+
+	return ret;
+}
+
+static inline int bpcm_wr(void __iomem *master, unsigned int addr,
+			  u32 off, u32 val)
+{
+	int ret = 0;
+
+	writel(val, master + PMB_WR_DATA);
+	ret = __bpcm_do_op(master, addr, off >> 2, PMC_PMBM_WRITE);
+
+	return ret;
+}
+
+#endif /* __BCM63XX_PMB_H */