diff options
Diffstat (limited to 'arch/arm/mach-bcm/bcm63xx_pmb.c')
| -rw-r--r-- | arch/arm/mach-bcm/bcm63xx_pmb.c | 215 |
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; +} |