summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-bcm/bcm63xx_pmb.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-bcm/bcm63xx_pmb.c')
-rw-r--r--arch/arm/mach-bcm/bcm63xx_pmb.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/arch/arm/mach-bcm/bcm63xx_pmb.c b/arch/arm/mach-bcm/bcm63xx_pmb.c
new file mode 100644
index 000000000..003f1472a
--- /dev/null
+++ b/arch/arm/mach-bcm/bcm63xx_pmb.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Broadcom BCM63138 PMB initialization for secondary CPU(s)
+ *
+ * Copyright (C) 2015 Broadcom Corporation
+ * Author: Florian Fainelli <f.fainelli@gmail.com>
+ */
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <linux/reset/bcm63xx_pmb.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include "bcm63xx_smp.h"
+
+/* ARM Control register definitions */
+#define CORE_PWR_CTRL_SHIFT 0
+#define CORE_PWR_CTRL_MASK 0x3
+#define PLL_PWR_ON BIT(8)
+#define PLL_LDO_PWR_ON BIT(9)
+#define PLL_CLAMP_ON BIT(10)
+#define CPU_RESET_N(x) BIT(13 + (x))
+#define NEON_RESET_N BIT(15)
+#define PWR_CTRL_STATUS_SHIFT 28
+#define PWR_CTRL_STATUS_MASK 0x3
+#define PWR_DOWN_SHIFT 30
+#define PWR_DOWN_MASK 0x3
+
+/* CPU Power control register definitions */
+#define MEM_PWR_OK BIT(0)
+#define MEM_PWR_ON BIT(1)
+#define MEM_CLAMP_ON BIT(2)
+#define MEM_PWR_OK_STATUS BIT(4)
+#define MEM_PWR_ON_STATUS BIT(5)
+#define MEM_PDA_SHIFT 8
+#define MEM_PDA_MASK 0xf
+#define MEM_PDA_CPU_MASK 0x1
+#define MEM_PDA_NEON_MASK 0xf
+#define CLAMP_ON BIT(15)
+#define PWR_OK_SHIFT 16
+#define PWR_OK_MASK 0xf
+#define PWR_ON_SHIFT 20
+#define PWR_CPU_MASK 0x03
+#define PWR_NEON_MASK 0x01
+#define PWR_ON_MASK 0xf
+#define PWR_OK_STATUS_SHIFT 24
+#define PWR_OK_STATUS_MASK 0xf
+#define PWR_ON_STATUS_SHIFT 28
+#define PWR_ON_STATUS_MASK 0xf
+
+#define ARM_CONTROL 0x30
+#define ARM_PWR_CONTROL_BASE 0x34
+#define ARM_PWR_CONTROL(x) (ARM_PWR_CONTROL_BASE + (x) * 0x4)
+#define ARM_NEON_L2 0x3c
+
+/* Perform a value write, then spin until the value shifted by
+ * shift is seen, masked with mask and is different from cond.
+ */
+static int bpcm_wr_rd_mask(void __iomem *master,
+ unsigned int addr, u32 off, u32 *val,
+ u32 shift, u32 mask, u32 cond)
+{
+ int ret;
+
+ ret = bpcm_wr(master, addr, off, *val);
+ if (ret)
+ return ret;
+
+ do {
+ ret = bpcm_rd(master, addr, off, val);
+ if (ret)
+ return ret;
+
+ cpu_relax();
+ } while (((*val >> shift) & mask) != cond);
+
+ return ret;
+}
+
+/* Global lock to serialize accesses to the PMB registers while we
+ * are bringing up the secondary CPU
+ */
+static DEFINE_SPINLOCK(pmb_lock);
+
+static int bcm63xx_pmb_get_resources(struct device_node *dn,
+ void __iomem **base,
+ unsigned int *cpu,
+ unsigned int *addr)
+{
+ struct of_phandle_args args;
+ int ret;
+
+ *cpu = of_get_cpu_hwid(dn, 0);
+ if (*cpu == ~0U) {
+ pr_err("CPU is missing a reg node\n");
+ return -ENODEV;
+ }
+
+ ret = of_parse_phandle_with_args(dn, "resets", "#reset-cells",
+ 0, &args);
+ if (ret) {
+ pr_err("CPU is missing a resets phandle\n");
+ return ret;
+ }
+
+ if (args.args_count != 2) {
+ pr_err("reset-controller does not conform to reset-cells\n");
+ return -EINVAL;
+ }
+
+ *base = of_iomap(args.np, 0);
+ if (!*base) {
+ pr_err("failed remapping PMB register\n");
+ return -ENOMEM;
+ }
+
+ /* We do not need the number of zones */
+ *addr = args.args[0];
+
+ return 0;
+}
+
+int bcm63xx_pmb_power_on_cpu(struct device_node *dn)
+{
+ void __iomem *base;
+ unsigned int cpu, addr;
+ unsigned long flags;
+ u32 val, ctrl;
+ int ret;
+
+ ret = bcm63xx_pmb_get_resources(dn, &base, &cpu, &addr);
+ if (ret)
+ return ret;
+
+ /* We would not know how to enable a third and greater CPU */
+ WARN_ON(cpu > 1);
+
+ spin_lock_irqsave(&pmb_lock, flags);
+
+ /* Check if the CPU is already on and save the ARM_CONTROL register
+ * value since we will use it later for CPU de-assert once done with
+ * the CPU-specific power sequence
+ */
+ ret = bpcm_rd(base, addr, ARM_CONTROL, &ctrl);
+ if (ret)
+ goto out;
+
+ if (ctrl & CPU_RESET_N(cpu)) {
+ pr_info("PMB: CPU%d is already powered on\n", cpu);
+ ret = 0;
+ goto out;
+ }
+
+ /* Power on PLL */
+ ret = bpcm_rd(base, addr, ARM_PWR_CONTROL(cpu), &val);
+ if (ret)
+ goto out;
+
+ val |= (PWR_CPU_MASK << PWR_ON_SHIFT);
+
+ ret = bpcm_wr_rd_mask(base, addr, ARM_PWR_CONTROL(cpu), &val,
+ PWR_ON_STATUS_SHIFT, PWR_CPU_MASK, PWR_CPU_MASK);
+ if (ret)
+ goto out;
+
+ val |= (PWR_CPU_MASK << PWR_OK_SHIFT);
+
+ ret = bpcm_wr_rd_mask(base, addr, ARM_PWR_CONTROL(cpu), &val,
+ PWR_OK_STATUS_SHIFT, PWR_CPU_MASK, PWR_CPU_MASK);
+ if (ret)
+ goto out;
+
+ val &= ~CLAMP_ON;
+
+ ret = bpcm_wr(base, addr, ARM_PWR_CONTROL(cpu), val);
+ if (ret)
+ goto out;
+
+ /* Power on CPU<N> RAM */
+ val &= ~(MEM_PDA_MASK << MEM_PDA_SHIFT);
+
+ ret = bpcm_wr(base, addr, ARM_PWR_CONTROL(cpu), val);
+ if (ret)
+ goto out;
+
+ val |= MEM_PWR_ON;
+
+ ret = bpcm_wr_rd_mask(base, addr, ARM_PWR_CONTROL(cpu), &val,
+ 0, MEM_PWR_ON_STATUS, MEM_PWR_ON_STATUS);
+ if (ret)
+ goto out;
+
+ val |= MEM_PWR_OK;
+
+ ret = bpcm_wr_rd_mask(base, addr, ARM_PWR_CONTROL(cpu), &val,
+ 0, MEM_PWR_OK_STATUS, MEM_PWR_OK_STATUS);
+ if (ret)
+ goto out;
+
+ val &= ~MEM_CLAMP_ON;
+
+ ret = bpcm_wr(base, addr, ARM_PWR_CONTROL(cpu), val);
+ if (ret)
+ goto out;
+
+ /* De-assert CPU reset */
+ ctrl |= CPU_RESET_N(cpu);
+
+ ret = bpcm_wr(base, addr, ARM_CONTROL, ctrl);
+out:
+ spin_unlock_irqrestore(&pmb_lock, flags);
+ iounmap(base);
+ return ret;
+}