linux/drivers/soc/bcm/brcmstb/biuctrl.c

118 lines
2.8 KiB
C

/*
* Broadcom STB SoCs Bus Unit Interface controls
*
* Copyright (C) 2015, Broadcom Corporation
*
* This program 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.
*
* 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.
*/
#define pr_fmt(fmt) "brcmstb: " KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/syscore_ops.h>
#include <linux/soc/brcmstb/brcmstb.h>
#define CPU_CREDIT_REG_OFFSET 0x184
#define CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK 0x70000000
static void __iomem *cpubiuctrl_base;
static bool mcp_wr_pairing_en;
static int __init mcp_write_pairing_set(void)
{
u32 creds = 0;
if (!cpubiuctrl_base)
return -1;
creds = readl_relaxed(cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
if (mcp_wr_pairing_en) {
pr_info("MCP: Enabling write pairing\n");
writel_relaxed(creds | CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK,
cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
} else if (creds & CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK) {
pr_info("MCP: Disabling write pairing\n");
writel_relaxed(creds & ~CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK,
cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
} else {
pr_info("MCP: Write pairing already disabled\n");
}
return 0;
}
static int __init setup_hifcpubiuctrl_regs(void)
{
struct device_node *np;
int ret = 0;
np = of_find_compatible_node(NULL, NULL, "brcm,brcmstb-cpu-biu-ctrl");
if (!np) {
pr_err("missing BIU control node\n");
return -ENODEV;
}
cpubiuctrl_base = of_iomap(np, 0);
if (!cpubiuctrl_base) {
pr_err("failed to remap BIU control base\n");
ret = -ENOMEM;
goto out;
}
mcp_wr_pairing_en = of_property_read_bool(np, "brcm,write-pairing");
out:
of_node_put(np);
return ret;
}
#ifdef CONFIG_PM_SLEEP
static u32 cpu_credit_reg_dump; /* for save/restore */
static int brcmstb_cpu_credit_reg_suspend(void)
{
if (cpubiuctrl_base)
cpu_credit_reg_dump =
readl_relaxed(cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
return 0;
}
static void brcmstb_cpu_credit_reg_resume(void)
{
if (cpubiuctrl_base)
writel_relaxed(cpu_credit_reg_dump,
cpubiuctrl_base + CPU_CREDIT_REG_OFFSET);
}
static struct syscore_ops brcmstb_cpu_credit_syscore_ops = {
.suspend = brcmstb_cpu_credit_reg_suspend,
.resume = brcmstb_cpu_credit_reg_resume,
};
#endif
void __init brcmstb_biuctrl_init(void)
{
int ret;
setup_hifcpubiuctrl_regs();
ret = mcp_write_pairing_set();
if (ret) {
pr_err("MCP: Unable to disable write pairing!\n");
return;
}
#ifdef CONFIG_PM_SLEEP
register_syscore_ops(&brcmstb_cpu_credit_syscore_ops);
#endif
}